Publications by authors named "Fa-Ming Chen"

92 Publications

ECM-mimicking nanofibrous matrix coaxes macrophages toward an anti-inflammatory phenotype: Cellular behaviors and transcriptome analysis.

Appl Mater Today 2020 Mar 26;18. Epub 2019 Nov 26.

Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, TX 75246, USA.

An in-depth understanding of biomaterial cues to selectively polarize macrophages is beneficial in the design of "immuno-informed" biomaterials that positively interact with the immune system to dictate a favorable macrophage response following implantation. Given the promising future of ECM-mimicking nanofibrous biomaterials in biomedical application, it is essential to elucidate how their intrinsic cues, especially the nanofibrous architecture, affect macrophages. In the present study, we evaluated how the nanofibrous architecture of a gelatin matrix modulated macrophage responses from the perspectives of cellular behaviors and a transcriptome analysis. In our results, the nanofibrous surface attenuated M1 polarization and down-regulated the inflammatory responses of macrophages compared with a smooth surface. Besides, the cell-material interaction was up-regulated and the adhered macrophages tended to maintain an original, non-polarized state on the nanofibrous matrix. Accordingly, whole transcriptome analysis revealed that nanofibrous architecture up-regulated the pathways related to ECM-receptor interaction and down-regulated pathways related to pro-inflammation. This study provides a panoramic view of the interaction between macrophages and nanofibers, and offers valuable information for the design of immunomodulatory ECM-mimicking biomaterials for tissue regeneration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.apmt.2019.100508DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7450828PMC
March 2020

Exosomes derived from P2X7 receptor gene-modified cells rescue inflammation-compromised periodontal ligament stem cells from dysfunction.

Stem Cells Transl Med 2020 11 29;9(11):1414-1430. Epub 2020 Jun 29.

State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases and Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi'an, People's Republic of China.

Although cellular therapy has been proposed for inflammation-related disorders such as periodontitis for decades, clinical application has been unsuccessful. One explanation for these disappointing results is that the functions of stem cells are substantially compromised when they are transplanted into an inflammatory in vivo milieu. Considering the previous finding that P2X7 receptor (P2X7R) gene modification is able to reverse inflammation-mediated impairment of periodontal ligament stem cells (PDLSCs), we further hypothesized that cells subjected to P2X7R gene transduction also exert influences on other cells within an in vivo milieu via an exosome-mediated paracrine mechanism. To define the paracrine ability of P2X7R gene-modified cells, P2X7R gene-modified stem cell-derived conditional medium (CM-Ad-P2X7) and exosomes (Exs-Ad-P2X7) were used to incubate PDLSCs. In an inflammatory osteogenic microenvironment, inflammation-mediated changes in PDLSCs were substantially reduced, as shown by quantitative real-time PCR (qRT-PCR) analysis, Western blot analysis, alkaline phosphatase (ALP) staining/activity assays, and Alizarin red staining. In addition, the Agilent miRNA microarray system combined with qRT-PCR analysis revealed that miR-3679-5p, miR-6515-5p, and miR-6747-5p were highly expressed in Exs-Ad-P2X7. Further functional tests and luciferase reporter assays revealed that miR-3679-5p and miR-6747-5p bound directly to the GREM-1 protein, while miR-6515-5p bound to the GREM-1 protein indirectly; these effects combined to rescue inflammation-compromised PDLSCs from dysfunction. Thus, in addition to maintaining their robust functionality under inflammatory conditions, P2X7R gene-modified stem cells may exert positive influences on their neighbors via a paracrine mechanism, pointing to a novel strategy for modifying the harsh local microenvironment to accommodate stem cells and promote improved tissue regeneration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/sctm.19-0418DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7581448PMC
November 2020

Calcitriol inhibits osteoclastogenesis in an inflammatory environment by changing the proportion and function of T helper cell subsets (Th2/Th17).

Cell Prolif 2020 Jun 13;53(6):e12827. Epub 2020 May 13.

State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi'an, China.

Objectives: Previously, we found that by regulating T helper (Th) cell polarization, calcitriol intervention inhibited lipopolysaccharide (LPS)-induced alveolar bone loss in an animal periodontitis model, but the underlying cellular events remain unknown.

Materials And Methods: In this study, mouse Th cells were incubated in an inflammatory environment in the presence of dendritic cells (DCs) and LPS. Then, the potential of the Th cells to undergo Th2/Th17 polarization, the RANKL expression of the polarized Th cells and the subsequent influences of the polarized Th cells on RAW264.7 cell osteoclastogenesis in response to calcitriol administration were assessed. Finally, the effects of calcitriol on antigen presentation by DCs during these cellular events were evaluated.

Results: In response to calcitriol administration, Th cells in an inflammatory environment exhibited an enhanced potential for Th2 polarization along with a decreased potential for Th17 polarization. In addition, RANKL expression in Th17-polarized cells was largely inhibited. Furthermore, inflammation-induced osteoclastogenesis in RAW264.7 cells was suppressed following coculture with calcitriol-treated Th cells. During these cellular events, increased expression of Th2 promoters (such as OX-40L and CCL17) and decreased expression of Th17 promoters (such as IL-23 and IL-6) were found in DCs.

Conclusions: Calcitriol can inhibit osteoclastogenesis in an inflammatory environment by changing the proportion and function of Th cell subsets. Our findings suggest that calcitriol may be an effective therapeutic agent for treating periodontitis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/cpr.12827DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7309596PMC
June 2020

Exosomes derived from M0, M1 and M2 macrophages exert distinct influences on the proliferation and differentiation of mesenchymal stem cells.

PeerJ 2020 24;8:e8970. Epub 2020 Apr 24.

State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China.

Background: Different phenotypes of macrophages (M0, M1 and M2 Mφs) have been demonstrated to play distinct roles in regulating mesenchymal stem cells in various in vitro and in vivo systems. Our previous study also found that cell-conditioned medium (CM) derived from M1 Mφs supported the proliferation and adipogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs), whereas CM derived from either M0 or M2 Mφs showed an enhanced effect on cell osteogenic differentiation. However, the underlying mechanism remains incompletely elucidated. Exosomes, as key components of Mφ-derived CM, have received increasing attention. Therefore, it is possible that exosomes may modulate the effect of Mφ-derived CM on the property of BMMSCs. This hypothesis was tested in the present study.

Methods: In this study, RAW264.7 cells were induced toward M1 or M2 polarization with different cytokines, and exosomes were isolated from the unpolarized (M0) and polarized (M1 and M2) Mφs. Mouse BMMSCs were then cultured with normal complete medium or inductive medium supplemented with M0-Exos, M1-Exos or M2-Exos. Finally, the proliferation ability and the osteogenic, adipogenic and chondrogenic differentiation capacity of the BMMSCs were measured and analyzed.

Results: We found that only the medium containing M1-Exos, rather than M0-Exos or M2-Exos, supported cell proliferation and osteogenic and adipogenic differentiation. This was inconsistent with CM-based incubation. In addition, all three types of exosomes had a suppressive effect on chondrogenic differentiation.

Conclusion: Although our data demonstrated that exosomes and CM derived from the same phenotype of Mφs didn't exert exactly the same cellular influences on the cocultured stem cells, it still confirmed the hypothesis that exosomes are key regulators during the modulation effect of Mφ-derived CM on BMMSC property.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7717/peerj.8970DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7185029PMC
April 2020

Suppression of histone deacetylases by SAHA relieves bone cancer pain in rats via inhibiting activation of glial cells in spinal dorsal horn and dorsal root ganglia.

J Neuroinflammation 2020 Apr 22;17(1):125. Epub 2020 Apr 22.

Department of Human Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, The Fourth Military Medical University, Xi'an, 710032, People's Republic of China.

Background: Robust activation of glial cells has been reported to occur particularly during the pathogenesis of bone cancer pain (BCP). Researchers from our group and others have shown that histone deacetylases (HDACs) play a significant role in modulating glia-mediated immune responses; however, it still remains unclear whether HDACs are involved in the activation of glial cells during the development of BCP.

Methods: BCP model was established by intra-tibia tumor cell inoculation (TCI). The expression levels and distribution sites of histone deacetylases (HDACs) in the spinal dorsal horn and dorsal root ganglia were evaluated by Western blot and immunofluorescent staining, respectively. Suberoylanilide hydroxamic acid (SAHA), a clinically used HDAC inhibitor, was then intraperitoneally and intrathecally injected to rescue the increased expression levels of HDAC1 and HDAC2. The analgesic effects of SAHA administration on BCP were then evaluated by measuring the paw withdrawal thresholds (PWTs). The effects of SAHA on activation of glial cells and expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) in the spinal dorsal horn and dorsal root ganglia of TCI rats were further evaluated by immunofluorescent staining and Western blot analysis. Subsequently, the effects of SAHA administration on tumor growth and cancer cell-induced bone destruction were analyzed by hematoxylin and eosin (HE) staining and micro-CT scanning.

Results: TCI caused rapid and long-lasting increased expression of HDAC1/HDAC2 in glial cells of the spinal dorsal horn and dorsal root ganglia. Inhibiting HDACs by SAHA not only reversed TCI-induced upregulation of HDACs but also inhibited the activation of glial cells in the spinal dorsal horn and dorsal root ganglia, and relieved TCI-induced mechanical allodynia. Further, we found that SAHA administration could not prevent cancer infiltration or bone destruction in the tibia, which indicated that the analgesic effects of SAHA were not due to its anti-tumor effects. Moreover, we found that SAHA administration could inhibit GSK3β activity in the spinal dorsal horn and dorsal root ganglia, which might contributed to the relief of BCP.

Conclusion: Our findings suggest that HDAC1 and HDAC2 are involved in the glia-mediated neuroinflammation in the spinal dorsal horn and dorsal root ganglia underlying the pathogenesis of BCP, which indicated that inhibiting HDACs by SAHA might be a potential strategy for pain relief of BCP.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12974-020-01740-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7175547PMC
April 2020

The proangiogenic effects of extracellular vesicles secreted by dental pulp stem cells derived from periodontally compromised teeth.

Stem Cell Res Ther 2020 03 6;11(1):110. Epub 2020 Mar 6.

State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, School of Stomatology, Fourth Military Medical University, Xi'an, 710032, Shaanxi, People's Republic of China.

Background: Although dental pulp stem cells (DPSCs) isolated from periodontally compromised teeth (P-DPSCs) have been demonstrated to retain pluripotency and regenerative potential, their use as therapeutics remains largely unexplored. In this study, we investigated the proangiogenic effects of extracellular vesicles (EVs) secreted by P-DPSCs using in vitro and in vivo testing models.

Methods: Patient-matched DPSCs derived from periodontally healthy teeth (H-DPSCs) were used as the control for P-DPSCs. Conditioned media (CMs) derived from H-DPSCs and P-DPSCs (H-CM and P-CM), CMs derived from both cell types pretreated with the EV secretion blocker GW4869 (H-GW and P-GW), and EVs secreted by H-DPSCs and P-DPSCs (H-EVs and P-EVs) were prepared to test their proangiogenic effects on endothelial cells (ECs). Cell proliferation, migration, and tube formation were assessed using the Cell Counting Kit-8 (CCK-8), transwell/scratch wound healing, and Matrigel assays, respectively. Specifically, quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and western blot analysis were used to examine the expression levels of angiogenesis-related genes/proteins in ECs in response to EV-based incubation. Finally, a full-thickness skin defect model was applied to test the effects of EVs on wound healing and new vessel formation.

Results: Both H-CM and P-CM promoted EC angiogenesis, but the proangiogenic effects were compromised when ECs were incubated in H-GW and P-GW, wherein the EV secretion was blocked by pretreatment with GW4869. In EV-based incubations, although both H-EVs and P-EVs were found to enhance the angiogenesis-related activities of ECs, P-EVs exerted a more robust potential to stimulate EC proliferation, migration, and tube formation. In addition, P-EVs led to higher expression levels of angiogenesis-related genes/proteins in ECs than H-EVs. Similarly, both P-EVs and H-EVs were found to accelerate wound healing and promote vascularization across skin defects in mice, but wounds treated with P-EVs resulted in a quicker healing outcome and enhanced new vessel formation.

Conclusions: The findings of the present study provide additional evidence that P-DPSCs derived from periodontally diseased teeth represent a potential source of cells for research and therapeutic use. Particularly, the proangiogenic effects of P-EVs suggest that P-DPSCs may be used to promote new vessel formation in cellular therapy and regenerative medicine.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13287-020-01614-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7060605PMC
March 2020

Impacts of non-impacted third molar removal on the periodontal condition of adjacent second molars.

Oral Dis 2020 Jul 12;26(5):1010-1019. Epub 2020 Mar 12.

State Key Laboratory of Military Stomatology, Department of Periodontology, School of Stomatology, National Clinical Research Center for Oral Diseases, Fourth Military Medical University, Xi'an, China.

Objective: The aim of this study was to determine how the removal of non-impacted third molars (N-M3s) affects the periodontal status of neighboring second molars (M2s).

Subjects And Methods: The periodontal condition of M2s for which the neighboring N-M3s were removed (more than 6 months previously) and those with intact N-M3s was analyzed in a cross-sectional observation study. In an additional case series, periodontal changes in M2s in response to adjacent N-M3 removal were observed during a 6-month follow-up period.

Results: A total of 457 patients with 1,301 M2s were enrolled in this cross-sectional observational study. Compared to M2s with neighboring N-M3s, M2s without neighboring N-M3s (teeth removed more than 6 months previously) exhibited a 0.27-mm reduction in the average pocket depth (PD) (p < .001) and a 0.38-fold reduced risk of at least one probing site with PD ≥5 mm (PD5+) (p < .001). Subsequently, a 41-case follow-up study showed that 6 months after neighboring N-M3 extraction, the PD of the M2s decreased by 0.31 mm (p < .001), while the incidence of PD5+ decreased by 21.9% when compared to the parameters detected before tooth extraction (p = .004).

Conclusions: Removing N-M3s was associated with an improved periodontal condition in neighboring M2s.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/odi.13314DOI Listing
July 2020

The relationship between T-helper cell polarization and the RANKL/OPG ratio in gingival tissues from chronic periodontitis patients.

Clin Exp Dent Res 2019 08 29;5(4):377-388. Epub 2019 May 29.

State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi'an, China.

This study aimed to investigate the relationship between inflammation-related T-helper cell polarization and the receptor activator for nuclear factor-κB ligand (RANKL)/osteoprotegerin (OPG) ratio, which is associated with bone resorption or remodeling of chronic periodontitis patients. Gingival crevicular fluid (GCF) and gingival tissues were obtained from periodontally healthy individuals (PH group) and chronic periodontitis patients (CP group). The GCF levels of IFN-γ, IL-4, IL-17, and IL-10 linked to T-helper cell polarization toward the Th1, Th2, Th17, and Treg phenotypes, respectively, were determined by ELISA. The expression levels of these cytokines and the polarized T-helper cells in gingival tissues were assessed through immunohistochemical and immunofluorescence assays. In addition, the RANKL and OPG expression levels in gingival tissues were detected by immunohistochemical assays, and linear regression analysis was used to identify the potential relationship between T-helper cell polarization and the RANKL/OPG ratio. In total, 22 individuals and 35 patients were enrolled in the present study. In both GCF and gingival tissues, increased levels of IL-17 and the decreased levels of IL-4 and IL-10 were observed in the CP group. When polarized T-helper cells were identified in gingival tissues, more Th1 and Th17 cells were found in the CP group, whereas more Th2 and Treg cells were found in the PH group. Although there was no significant difference in OPG expression between the two groups, the RANKL/OPG ratio in the CP group was higher than that in the PH group. The linear regression analysis showed that the presence of more Th1 and Th17 cells correlated with a higher RANKL/OPG ratio, whereas the presence of more Th2 cells correlated with a lower RANKL/OPG ratio. Th1 and Th17 cells are positively correlated and Th2 cells are negatively correlated with the RANKL/OPG ratio. Our data suggest that T-helper cell polarization is closely linked to the RANKL/OPG ratio in gingival tissues from chronic periodontitis patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cre2.192DOI Listing
August 2019

Surface modification via plasmid-mediated pLAMA3-CM gene transfection promotes the attachment of gingival epithelial cells to titanium sheets in vitro and improves biological sealing at the transmucosal sites of titanium implants in vivo.

J Mater Chem B 2019 12 11;7(46):7415-7427. Epub 2019 Nov 11.

State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, P. R. China.

Although titanium implants have been applied in dental clinics to replace lost teeth and to restore masticatory function for decades, strategies to design the surface of the transmucosal sites of implants to achieve ideal and predictable biological sealing following implantation remain to be optimized. In this study, we hypothesized that gingival epithelial cell (GEC) adhesion and new tissue attachment to titanium sheets/implants could be promoted by the release of plasmid pLAMA3-CM (encoding a motif of the C-terminal globular domain of LAMA3) from a titanium surface. To test this hypothesis, a chitosan/collagen (Chi/Col) coating was immobilized on the surfaces of titanium substrates with nanotube topography (NT-Ti) through cathodic electrophoretic deposition; it was found that pLAMA3-CM could be released from the coating in a highly sustained manner. After culturing on titanium with nanotube topography coated by Chi/Col with the plasmid pLAMA3-CM (Chi/Col/pLAMA3-CM-Ti), human GECs (hGECs) were found to effectively uptake the incorporated plasmids, which resulted in improved attachment, as evidenced by morphological and immunofluorescence analyses. In addition, Chi/Col/pLAMA3-CM-Ti induced better biological sealing at transmucosal sites following immediate implantation into Sprague-Dawley rats. Our findings indicate that the modification of titanium implants by plasmid-mediated pLAMA3-CM gene transfection points to a practical strategy for optimizing biological sealing around the transmucosal sites of implants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c9tb01715aDOI Listing
December 2019

M2 Macrophages Enhance the Cementoblastic Differentiation of Periodontal Ligament Stem Cells via the Akt and JNK Pathways.

Stem Cells 2019 12 24;37(12):1567-1580. Epub 2019 Aug 24.

Department of Periodontology, State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases and Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, School of Stomatology, Fourth Military Medical University, Xi'an, People's Republic of China.

Although macrophage (Mφ) polarization has been demonstrated to play crucial roles in cellular osteogenesis across the cascade of events in periodontal regeneration, how polarized Mφ phenotypes influence the cementoblastic differentiation of periodontal ligament stem cells (PDLSCs) remains unknown. In the present study, human monocyte leukemic cells (THP-1) were induced into M0, M1, and M2 subsets, and the influences of these polarized Mφs on the cementoblastic differentiation of PDLSCs were assessed in both conditioned medium-based and Transwell-based coculture systems. Furthermore, the potential pathways and cyto-/chemokines involved in Mφ-mediated cementoblastic differentiation were screened and identified. In both systems, M2 subsets increased cementoblastic differentiation-related gene/protein expression levels in cocultured PDLSCs, induced more PDLSCs to differentiate into polygonal and square cells, and enhanced alkaline phosphatase activity in PDLSCs. Furthermore, Akt and c-Jun N-terminal Kinase (JNK) signaling was identified as a potential pathway involved in M2 Mφ-enhanced PDLSC cementoblastic differentiation, and cyto-/chemokines (interleukin (IL)-10 and vascular endothelial growth factor [VEGF]) secreted by M2 Mφs were found to be key players that promoted cell cementoblastic differentiation by activating Akt signaling. Our data indicate for the first time that Mφs are key modulators during PDLSC cementoblastic differentiation and are hence very important for the regeneration of multiple periodontal tissues, including the cementum. Although the Akt and JNK pathways are involved in M2 Mφ-enhanced cementoblastic differentiation, only the Akt pathway can be activated via a cyto-/chemokine-associated mechanism, suggesting that players other than cyto-/chemokines also participate in the M2-mediated cementoblastic differentiation of PDLSCs. Stem Cells 2019;37:1567-1580.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/stem.3076DOI Listing
December 2019

Calcitriol suppresses lipopolysaccharide-induced alveolar bone damage in rats by regulating T helper cell subset polarization.

J Periodontal Res 2019 Dec 16;54(6):612-623. Epub 2019 May 16.

State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi'an, China.

Background: Although the immunomodulatory properties of calcitriol in bone metabolism have been documented for decades, its therapeutic role in the management of periodontitis remains largely unexplored. In this study, we hypothesized that calcitriol suppresses lipopolysaccharide (LPS)-induced alveolar bone loss by regulating T helper (Th) cell subset polarization.

Methods: To test this hypothesis, we determined the effect of calcitriol intervention on the development of LPS-induced periodontitis in rats in terms of bone loss (micro-CT analysis), local inflammatory infiltration levels, the number of osteoclasts (hematoxylin and eosin staining) and the level of osteoclastogenesis (tartrate-resistant acid phosphatase method). Furthermore, immunohistochemistry was used to assess the expression levels of the receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) as well as the cytokine levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), IL-17, and IL-10 throughout the LPS-injected region. Finally, the polarization potential of Th cells in peripheral blood was analyzed using flow cytometry.

Results: Calcitriol intervention decreased alveolar bone loss in response to LPS injection and inflammatory cell infiltration. Analysis of osteoclast number and RANKL and OPG expression showed that bone resorption activity was largely suppressed in response to calcitriol administration, along with decreased IL-17 levels but increased IL-4 and IL-10 levels in periodontal tissues (the LPS-injected region). Similarly, the percentages of Th2 and Treg cells in peripheral blood increased, but the percentages of Th1 and Th17 cells decreased in rats receiving calcitriol.

Conclusion: Our findings suggest that calcitriol can be used to inhibit bone loss in experimental periodontitis, likely via the regulation of local and systemic Th cell polarization.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jre.12661DOI Listing
December 2019

Modulating macrophage responses to promote tissue regeneration by changing the formulation of bone extracellular matrix from filler particles to gel bioscaffolds.

Mater Sci Eng C Mater Biol Appl 2019 Aug 29;101:330-340. Epub 2019 Mar 29.

State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, Department of Periodontology, School of Stomatology, Fourth Military Medical University, 145 West Changle Road, Xi'an 710032, China. Electronic address:

Extracellular matrices (ECMs) derived from native tissues/organs have been used as biomaterials for tissue engineering and regenerative medicine in a wide range of preclinical and clinical settings. The success or failure of these applications is largely contingent on the host responses to the matrices in vivo. Despite retaining their native structural and functional proteins, bone ECM-based transplants have been reported to evoke adverse immune responses in many cases; thus, optimizing the immunomodulatory properties of bone ECMs is critical for ensuring downstream regenerative outcomes. Using a simple digestion-neutralization protocol, we transformed the commonly used bone-derived filler particles into gel bioscaffolds. Instead of inducing macrophages toward proinflammatory (M1) polarization, as reported in the literature and confirmed in the present study for ECM particles, the ECM gels were found to be more likely to polarize macrophages toward regulatory/anti-inflammatory (M2) phenotypes, leading to enhanced tissue regeneration in a rat periodontal defect model. The present work demonstrates a simple, practical and economical strategy to modify the immunomodulatory properties of bone ECMs before their in vivo transplantation and hence has important implications that may facilitate the use of ECM-based bioscaffolds derived from diverse sources of tissues for regenerative purposes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.msec.2019.03.107DOI Listing
August 2019

Building capacity for macrophage modulation and stem cell recruitment in high-stiffness hydrogels for complex periodontal regeneration: Experimental studies in vitro and in rats.

Acta Biomater 2019 04 5;88:162-180. Epub 2019 Feb 5.

State Key Laboratory of Military Stomatology Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi'an, P.R. China; National Clinical Research Center for Oral Diseases, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi'an, P.R. China; Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi'an, P.R. China. Electronic address:

Recently, we found that although high-stiffness matrices stimulated osteogenic differentiation of bone marrow-derived stromal cells (BMSCs), the macrophages (Mφs) in high-stiffness transglutaminase crosslinked gelatins (TG-gels) tended to undergo M1 polarization and hence compromised cell osteogenesis. In this study, we hypothesized that the copresentation of interleukin (IL)-4 and stromal cell-derived factor (SDF)-1α in high-stiffness TG-gels may enhance periodontal regeneration by modulating Mφ polarization and promoting endogenous stem cell recruitment. We found that Mφs were more likely to polarize toward an immunomodulatory M2 state in the presence of IL-4 and hence positively influence the osteogenic differentiation of BMSCs when these cells coexisted in either indirect or direct co-culture systems. In cell migration assays, BMSCs exhibited an enhanced capability to move toward gels containing SDF-1α, and more cells could be recruited into the three-dimensional matrix of TG-gels. When TG-gels containing IL-4 and/or SDF-1α were used to repair periodontal defects, more new bone (MicroCT) was formed in animals that received the dual cytokine-loaded transplants at 4 weeks postsurgery. Mφs were recruited to all the transplanted gels, and after one week, more M1-phenotype cells were found in the groups without IL-4, while the presence of IL-4 was more likely to result in M2 polarization (immunofluorescence staining). When the tissue biopsies were histologically examined, the TG-gels containing both IL-4 and SDF-1α led to a generally satisfactory regeneration with respect to attachment recovery (epithelial and connective tissue) and hybrid tissue regeneration (bone, periodontal ligament and cementum). Our data suggest that the incorporation of IL-4 into high-stiffness TG-gels may promote the M2 polarization of Mφs and that SDF-1α can be applied to guide endogenous cell homing. Overall, building capacity for Mφ modulation and cell recruitment in high-stiffness hydrogels represents a simple and effective strategy that can support high levels of periodontal tissue regeneration. STATEMENT OF SIGNIFICANCE: The development of hydrogel-based regenerative therapies centered on the mobilization and stimulation of native cells for therapeutics opens a window toward realizing periodontal endogenous regeneration. In the present study, the parallel use of immunomodulatory and homing factors in high-stiffness hydrogel materials is shown to induce stem cell homing, modulate cell differentiation and indeed induce regrowth of the periodontium. We found that incorporation of interleukin (IL)-4 in high-stiffness TG-gels coaxed macrophages to polarize into M2 phenotypes, and stromal cell-derived factor (SDF)-1α could be applied to direct endogenous cell homing. Hence, we present for the first time a clinically relevant strategy based on macrophage modulation and host cell recruitment that can support high levels of periodontal tissue regeneration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.actbio.2019.02.004DOI Listing
April 2019

Role of the P2X7 receptor in inflammation-mediated changes in the osteogenesis of periodontal ligament stem cells.

Cell Death Dis 2019 01 8;10(1):20. Epub 2019 Jan 8.

State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases and Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China.

Accumulating evidence indicates that the pluripotency of periodontal ligament stem cells (PDLSCs) is compromised under inflammatory conditions; however, the underlying mechanisms remain largely unexplored. In this study, we hypothesize that the P2X7 receptor (P2X7R) is a key molecule linked to inflammation-associated impairment of PDLSCs. We first investigated P2X7R expression in PDLSCs under normal and inflammatory conditions and then determined the effect of a P2X7R agonist (BzATP) or antagonist (BBG) on PDLSC osteogenesis under various conditions. Gene-modified PDLSCs were used to further examine the role of P2X7R and the signaling pathway underlying P2X7R-enhanced osteogenesis. We found that inflammatory conditions decreased P2X7R expression in PDLSCs and reduced osteogenesis in these cells. In addition, activation of P2X7R by BzATP or overexpression of P2X7R via gene transduction reversed the inflammation-mediated decrease in PDLSC osteogenic differentiation. When selected osteogenesis-related signaling molecules were screened, the PI3K-AKT-mTOR pathway was identified as potentially involved in P2X7R-enhanced PDLSC osteogenesis. Our data reveal a crucial role for P2X7R in PDLSC osteogenesis under inflammatory conditions, suggesting a new therapeutic target to reverse or rescue inflammation-mediated changes in PDLSCs for future mainstream therapeutic uses.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41419-018-1253-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6325129PMC
January 2019

Concise Review: Periodontal Tissue Regeneration Using Stem Cells: Strategies and Translational Considerations.

Stem Cells Transl Med 2019 04 26;8(4):392-403. Epub 2018 Dec 26.

State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases and Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi'an, People's Republic of China.

Periodontitis is a widespread disease characterized by inflammation-induced progressive damage to the tooth-supporting structures until tooth loss occurs. The regeneration of lost/damaged support tissue in the periodontium, including the alveolar bone, periodontal ligament, and cementum, is an ambitious purpose of periodontal regenerative therapy and might effectively reduce periodontitis-caused tooth loss. The use of stem cells for periodontal regeneration is a hot field in translational research and an emerging potential treatment for periodontitis. This concise review summarizes the regenerative approaches using either culture-expanded or host-mobilized stem cells that are currently being investigated in the laboratory and with preclinical models for periodontal tissue regeneration and highlights the most recent evidence supporting their translational potential toward a widespread use in the clinic for combating highly prevalent periodontal disease. We conclude that in addition to in vitro cell-biomaterial design and transplantation, the engineering of biomaterial devices to encourage the innate regenerative capabilities of the periodontium warrants further investigation. In comparison to cell-based therapies, the use of biomaterials is comparatively simple and sufficiently reliable to support high levels of endogenous tissue regeneration. Thus, endogenous regenerative technology is a more economical and effective as well as safer method for the treatment of clinical patients. Stem Cells Translational Medicine 2019;8:392-403.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/sctm.18-0181DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6431686PMC
April 2019

Correction to: Treatment of periodontal intrabony defects using autologous periodontal ligament stem cells: a randomized clinical trial.

Stem Cell Res Ther 2018 10 7;9(1):260. Epub 2018 Oct 7.

State Key Laboratory of Military Stomatology, Research and Development Center for Tissue Engineering, School of Stomatology, Fourth Military Medical University, Xi'an, Shannxi, People's Republic of China.

The original article [1] contains a major error carried across the captions of Tables 1, 2, and 3. In each table caption, the data were expressed as "mean ± standard deviation (SD)"; unfortunately, the authors had mistakenly expressed the data as "mean ± standard error (SE)" instead. As such, all mentions of "mean ± standard error" in those table captions should of course state "mean ± standard deviation". The authors are deeply sorry for these errors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13287-018-1000-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6174065PMC
October 2018

Macrophage polarization in human gingival tissue in response to periodontal disease.

Oral Dis 2019 Jan 12;25(1):265-273. Epub 2018 Oct 12.

State Key Laboratory of Military Stomatology, Department of Periodontology, School of Stomatology, National Clinical Research Center for Oral Diseases, Fourth Military Medical University, Xi'an, China.

Objective: Although accumulating evidence indicates that macrophages are central players in the destructive and reparative phases of periodontal disease, their polarization states at different stages of periodontal inflammation remain unclear.

Methods: We collected gingival biopsies from patients with chronic periodontitis (P group), gingivitis (G group), or periodontally healthy individuals (H group). Polarized macrophages were identified through immunofluorescence. M1- and M2-related cytokines were detected by immunohistochemistry.

Results: Compared with the H group, the P group had more M1 cells (higher M1/M2 ratio) and significantly higher TNF-α, IFN-γ, IL-6, and IL-12 levels. Although the G group also exhibited higher TNF-α and IL-12 levels than the H group, they had similar M1/M2 ratios. The M1/M2 ratio and IFN-γ and IL-6 levels were significantly higher in the P than the G group. Among M2-related cytokines, IL-4 levels were significantly higher in the G than the H group. The M1/M2 ratio was positively correlated with clinical probing depth (PD), and both were positively correlated with IFN-γ and IL-6. PD was negatively correlated with IL-4.

Conclusion: Macrophage polarization in gingival tissue may be responsible for the development and progression of inflammation-induced tissue destruction, and modulating macrophage function may be a potential strategy for periodontal disease management.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/odi.12983DOI Listing
January 2019

Inhibition of Histone Deacetylases Attenuates Morphine Tolerance and Restores MOR Expression in the DRG of BCP Rats.

Front Pharmacol 2018 15;9:509. Epub 2018 May 15.

Department of Human Anatomy, Histology and Embryology, K.K. Leung Brain Research Centre, Preclinical School of Medicine, The Fourth Military Medical University, Xi'an, China.

The easily developed morphine tolerance in bone cancer pain (BCP) significantly hindered its clinical use. Increasing evidence suggests that histone deacetylases (HDACs) regulate analgesic tolerance subsequent to continuous opioid exposure. However, whether HDACs contribute to morphine tolerance in the pathogenesis of BCP is still unknown. In the current study, we explored the possible engagement of HDACs in morphine tolerance during the pathogenesis of BCP. After intra-tibia tumor cell inoculation (TCI), we found that the increased expression of HDACs was negatively correlated with the decreased expression of MOR in the DRG following TCI. The paw withdrawal threshold (PWT) and percentage maximum possible effects (MPEs) decreased rapidly in TCI rats when morphine was used alone. In contrast, the concomitant use of SAHA and morphine significantly elevated the PWT and MPEs of TCI rats compared to morphine alone. Additionally, we found that SAHA administration significantly elevated MOR expression in the DRG of TCI rats with or without morphine treatment. Moreover, the TCI-induced increase in the co-expression of MOR and HDAC1 in neurons was significantly decreased after SAHA administration. These results suggest that HDACs are correlated with the downregulation of MOR in the DRG during the pathogenesis of BCP. Inhibition of HDACs using SAHA can be used to attenuate morphine tolerance in BCP.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphar.2018.00509DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5962808PMC
May 2018

Melatonin Inhibits Reactive Oxygen Species-Driven Proliferation, Epithelial-Mesenchymal Transition, and Vasculogenic Mimicry in Oral Cancer.

Oxid Med Cell Longev 2018 21;2018:3510970. Epub 2018 Mar 21.

School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China.

Globally, oral cancer is the most common type of head and neck cancers. Melatonin elicits inhibitory effects on oral cancer; however, the biological function of melatonin and underlying mechanisms remain largely unknown. In this study, we found that melatonin impaired the proliferation and apoptosis resistance of oral cancer cells by inactivating ROS-dependent Akt signaling, involving in downregulation of cyclin D1, PCNA, and Bcl-2 and upregulation of Bax. Melatonin inhibited the migration and invasion of oral cancer cells by repressing ROS-activated Akt signaling, implicating with the reduction of Snail and Vimentin and the enhancement of E-cadherin. Moreover, melatonin hampered vasculogenic mimicry of oral cancer cells through blockage of ROS-activated extracellular-regulated protein kinases (ERKs) and Akt pathways involving the hypoxia-inducible factor 1. Consistently, melatonin retarded tumorigenesis of oral cancer . Overall, these findings indicated that melatonin exerts antisurvival, antimotility, and antiangiogenesis effects on oral cancer partly by suppressing ROS-reliant Akt or ERK signaling.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2018/3510970DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5884151PMC
September 2018

Macrophage involvement affects matrix stiffness-related influences on cell osteogenesis under three-dimensional culture conditions.

Acta Biomater 2018 04 17;71:132-147. Epub 2018 Feb 17.

State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases and Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi'an, PR China. Electronic address:

Accumulating evidence indicates that the physicochemical properties of biomaterials exert profound influences on stem cell fate decisions. However, matrix-based regulation selected through in vitro analyses based on a given cell population do not genuinely reflect the in vivo conditions, in which multiple cell types are involved and interact dynamically. This study constitutes the first investigation of how macrophages (Mφs) in stiffness-tunable transglutaminase cross-linked gelatin (TG-gel) affect the osteogenesis of bone marrow-derived mesenchymal stem cells (BMMSCs). When a single cell type was cultured, low-stiffness TG-gels promoted BMMSC proliferation, whereas high-stiffness TG-gels supported cell osteogenic differentiation. However, Mφs in high-stiffness TG-gels were more likely to polarize toward the pro-inflammatory M1 phenotype. Using either conditioned medium (CM)-based incubation or Transwell-based co-culture, we found that Mφs encapsulated in the low-stiffness matrix exerted a positive effect on the osteogenesis of co-cultured BMMSCs. Conversely, Mφs in high-stiffness TG-gels negatively affected cell osteogenic differentiation. When both cell types were cultured in the same TG-gel type and placed into the Transwell system, the stiffness-related influences of Mφs on BMMSCs were significantly altered; both the low- and high-stiffness matrix induced similar levels of BMMSC osteogenesis. Although the best material parameter for synergistically affecting Mφs and BMMSCs remains unknown, our data suggest that Mφ involvement in the co-culture system alters previously identified material-related influences on BMMSCs, such as matrix stiffness-related effects, which were identified based on a culture system involving a single cell type. Such Mφ-stem cell interactions should be considered when establishing proper matrix parameter-associated cell regulation in the development of biomimetic biomaterials for regenerative applications.

Statement Of Significance: The substrate stiffness of a scaffold plays critical roles in modulating both reparative cells, such as mesenchymal stem cells (MSCs), and immune cells, such as macrophages (Mφs). Although the influences of material stiffness on either Mφs or MSCs, have been extensively described, how the two cell types respond to matrix cues to dynamically affect each other in a three-dimensional (3D) biosystem remains largely unknown. Here, we report our findings that, in a platform wherein Mφs and bone marrow-derived MSCs coexist, matrix stiffness can influence stem cell fate through both direct matrix-associated regulation and indirect Mφ-based modulation. Our data support future studies of the MSC-Mφ-matrix interplay in the 3D context to optimize matrix parameters for the development of the next biomaterial.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.actbio.2018.02.015DOI Listing
April 2018

In vitro cell behaviors of bone mesenchymal stem cells derived from normal and postmenopausal osteoporotic rats.

Int J Mol Med 2018 Feb 22;41(2):669-678. Epub 2017 Nov 22.

State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Clinical Research Center for Oral Diseases, Department of Orthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China.

Postmenopausal osteoporosis (PMO) increases bone fragility and the risk of fractures, and impairs the healing procedure of bone defects in aged women. The stromal cell‑derived factor-1α (SDF-1α)/CXC chemokine receptor type 4 (CXCR4) axis helps to maintain the biological and physiological functions of bone marrow mesenchymal stem cells (BMSCs) and increase the homing efficiency of BMSCs. The present study aimed to provide insights into the possible association between migration and osteogenic ability and the SDF-1α/CXCR4 axis in BMSCs derived from a rat model of PMO. In order to do this, the general and SDF-1α/CXCR4-associated biological characteristics as well as associated molecular mechanisms in BMSCs isolated from a PMO rat model (OVX-BMSCs) and normal rats (Sham‑BMSCs) were investigated and compared. In comparison with Sham-BMSCs, OVX-BMSCs exhibited an impaired osteo-genic ability, but a stronger adipogenic activity as well as a higher proliferative ability. In addition, OVX-BMSCs presented a lower chemotactic activity towards SDF-1α, lower expression levels of CXCR4 and reduced levels of phosphorylated AKT (p-AKT). Therefore, the lower expression levels of CXCR4 and p-AKT may be responsible for the impaired osteogenic ability and lower chemotactic activity towards SDF-1α of OVX-BMSCs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/ijmm.2017.3280DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5752170PMC
February 2018

The effects of conditioned media generated by polarized macrophages on the cellular behaviours of bone marrow mesenchymal stem cells.

J Cell Mol Med 2018 02 6;22(2):1302-1315. Epub 2017 Nov 6.

State Key Laboratory of Military Stomatology, Department of Periodontology, National Clinical Research Center for Oral Diseases and Shaanxi Engineering Research Center for Dental Materials and Advanced Manufacture, School of Stomatology, Fourth Military Medical University, Xi'an, China.

Macrophages (Mφs) are involved in a variety of physiological and pathological events including wound healing and tissue regeneration, in which they play both positive and negative roles depending on their polarization state. In this study, we investigated the cellular behaviours of bone marrow mesenchymal stem cells (BMMSCs) after incubation in different conditioned media (CMs) generated by unpolarized Mφs (M0) or polarized Mφs (M1 and M2). Mφ polarization was induced by stimulation with various cytokines, and CMs were obtained from in vitro Mφ cultures termed CM0, CM1 and CM2 based on each Mφ phenotype. We found that CM1 supported the proliferation and adipogenic differentiation of BMMSCs, whereas CM0 had a remarkable effect on cell osteogenic differentiation. To a certain degree, CM2 also facilitated BMMSC osteogenesis; in particular, cells incubated with CM2 exhibited an enhanced capacity to form robust stem cell sheets. Although incubation with CM1 also increased production of extracellular matrix components, such as fibronectin, COL-1 and integrin β1during sheet induction, the sheets generated by CM2-incubated cells were thicker than those generated by CM1-incubated cells (P < 0.001). Our data suggest that each Mφ phenotype has a unique effect on BMMSCs. Fine-tuning Mφ polarization following transplantation may serve as an effective method to modulate the therapeutic potential of BMMSCs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jcmm.13431DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5783837PMC
February 2018

Exosomes secreted by stem cells from human exfoliated deciduous teeth contribute to functional recovery after traumatic brain injury by shifting microglia M1/M2 polarization in rats.

Stem Cell Res Ther 2017 09 29;8(1):198. Epub 2017 Sep 29.

Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Xi'an, Shaanxi, China.

Background: Traumatic brain injury (TBI) is one of the major causes of mortality and disability for all ages worldwide. Mesenchymal stem cells (MSCs)-originated exosomes have provided therapeutic effects. However, as an indispensable component of MSCs, whether odontogenic stem cell-generated exosomes could benefit TBI is still unclear. Thus we aimed to explore the potential of stem cells from human exfoliated deciduous teeth-originated exosomes (SHED-Ex) for the management of TBI.

Methods: First, a transwell system was used to co-culture activated BV-2 microglia cells with SHED. The secretion levels of neuroinflammatory factors and nitrite were evaluated by enzyme-linked immunosorbent assay (ELISA) and Griess assay. Furthermore, purified SHED-Ex were co-cultured with activated BV-2. ELISA, Griess assay, flow cytometry, immunofluorescence, and qRT-PCR were performed to test the levels of inflammatory factors as well as the microglia phenotype. Finally, SHED and SHED-Ex were locally injected into TBI rat models. Basso, Beattie, and Bresnahan (BBB) scores were chosen to evaluate the motor functional recovery. Histopathology and immunofluorescence were performed to measure the lesion volume and neuroinflammation.

Results: As a result, SHED-Ex could reduce neuroinflammation by shifting microglia polarization. The administration of SHED-Ex improves rat motor functional recovery and reduces cortical lesion compared with the control group 2 weeks post-injury (P < 0.05).

Conclusions: The current study demonstrates for the first time that SHED-Ex contribute a therapeutic benefit to TBI in rats, at least in part by shifting microglia polarization to reduce neuroinflammation. The use of odontogenic stem cells, and indeed their exosomes, may be expanded for the treatment of TBI or other neurological disorders.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13287-017-0648-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5622448PMC
September 2017

Administration of signalling molecules dictates stem cell homing for in situ regeneration.

J Cell Mol Med 2017 Dec 2;21(12):3162-3177. Epub 2017 Aug 2.

State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi'an, China.

Ex vivo-expanded stem cells have long been a cornerstone of biotherapeutics and have attracted increasing attention for treating intractable diseases and improving tissue regeneration. However, using exogenous cellular materials to develop restorative treatments for large numbers of patients has become a major concern for both economic and safety reasons. Advances in cell biological research over the past two decades have expanded the potential for using endogenous stem cells during wound healing processes, and in particular, recent insight into stem cell movement and homing has prompted regenerative research and therapy based on recruiting endogenous cells. Inspired by the natural healing process, artificial administration of specific chemokines as signals systemically or at the injury site, typically using biomaterials as vehicles, is a state-of-the-art strategy that potentiates stem cell homing and recreates an anti-inflammatory and immunomodulatory microenvironment to enhance in situ tissue regeneration. However, pharmacologically coaxing endogenous stem cells to act as therapeutics in the field of biomedicine remains in the early stages; its efficacy is limited by the lack of innovative methodologies for chemokine presentation and release. This review describes how to direct the homing of endogenous stem cells via the administration of specific signals, with a particular emphasis on targeted signalling molecules that regulate this homing process, to enhance in situ tissue regeneration. We also provide an outlook on and critical considerations for future investigations to enhance stem cell recruitment and harness the reparative potential of these recruited cells as a clinically relevant cell therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jcmm.13286DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5706509PMC
December 2017

Human platelet lysate supports the formation of robust human periodontal ligament cell sheets.

J Tissue Eng Regen Med 2018 04 10;12(4):961-972. Epub 2017 Nov 10.

State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, Department of Periodontology, School of Stomatology, Fourth Military Medical University, China.

The use of stem cell-derived sheets has become increasingly common in a wide variety of biomedical applications. Although substantial evidence has demonstrated that human platelet lysate (PL) can be used for therapeutic cell expansion, either as a substitute for or as a supplement to xenogeneic fetal bovine serum (FBS), its impact on cell sheet production remains largely unexplored. In this study, we manufactured periodontal ligament stem cell (PDLSC) sheets in vitro by incubating PDLSCs in sheet-induction media supplemented with various ratios of PL and FBS, i.e. 10% PL without FBS, 7.5% PL + 2.5% FBS, 5% PL + 5% FBS, 2.5% PL + 7.5% FBS or 10% FBS without PL. Cultures with the addition of all the designed supplements led to successful cell sheet production. In addition, all the resultant cellular materials exhibited similar expression profiles of matrix-related genes and proteins, such as collagen I, fibronectin and integrin β1. Interestingly, the cell components within sheets generated by media containing both PL and FBS exhibited improved osteogenic potential. Following in vivo transplantation, all sheets supported significant new bone formation. Our data suggest that robust PDLSC sheets can be produced by applying PL as either an alternative or an adjuvant to FBS. Further examination of the relevant influences of human PL that benefit cell behaviour and matrix production will pave the way towards optimized and standardized conditions for cell sheet production.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/term.2511DOI Listing
April 2018

Influences of age-related changes in mesenchymal stem cells on macrophages during in-vitro culture.

Stem Cell Res Ther 2017 06 24;8(1):153. Epub 2017 Jun 24.

State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases, Department of Periodontology, School of Stomatology, Fourth Military Medical University, 145th West Changle Road, Xi'an, 710032, People's Republic of China.

Background: Mesenchymal stem cells (MSCs) have been widely used in cytotherapy and tissue engineering due to their immunosuppressive ability and regenerative potential. Recently, the immunomodulatory influence of MSCs has been gaining increasing attention because their functional roles in modulating immune responses likely have high clinical significance.

Methods: In this study, we investigated the influence of MSCs on macrophages (Mφs) in in-vitro cell culture systems. Given evidence that aged MSCs are functionally compromised, bone marrow-derived MSCs (BMSCs) isolated from both young and aged mice (YMSCs and AMSCs) were evaluated and contrasted.

Results: We found that YMSCs exhibited greater proliferative and osteo-differentiation potential compared to AMSCs. When cocultured with RAW264.7 cells (an Mφ cell line), both YMSCs and AMSCs coaxed polarization of Mφs toward an M2 phenotype and induced secretion of anti-inflammatory and immunomodulatory cytokines. Compared to AMSCs, YMSCs exhibited a more potent immunomodulatory effect. While Mφs cocultured with either YMSCs or AMSCs displayed similar phagocytic ability, AMSC coculture was found to enhance Mφ migration in Transwell systems. When BMSCs were prestimulated with interferon gamma before coculture with RAW264.7 cells, their regulatory effects on Mφs appeared to be modified. Here, compared to stimulated AMSCs, stimulated YMSCs also exhibited enhanced cellular influence on cocultured RAW264.7 cells.

Conclusions: Our data suggest that BMSCs exert an age-related regulatory effect on Mφs with respect to their phenotype and functions but an optimized stimulation to enhance MSC immunomodulation is in need of further investigation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13287-017-0608-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5483296PMC
June 2017

Effect of Asymptomatic Visible Third Molars on Periodontal Health of Adjacent Second Molars: A Cross-Sectional Study.

J Oral Maxillofac Surg 2017 Oct 14;75(10):2048-2057. Epub 2017 Apr 14.

Head and Professor, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi'an, People's Republic of China. Electronic address:

Purpose: Evidence that asymptomatic third molars (M3s) negatively affect their adjacent second molars (A-M2s) is limited. The present study evaluated the association between visible M3s (V-M3s) of various clinical status with the periodontal pathologic features of their A-M2s.

Patients And Methods: Subjects with at least 1 quadrant having intact first and second molars, either with V-M3s and symptom free or without adjacent V-M3s, were enrolled in the present cross-sectional investigation. Periodontal parameters, including plaque index (PLI), bleeding on probing (BOP), probing pocket depth (PPD), and at least 1 site with a PPD of 5 mm or more (PPD5+), obtained from M2s were analyzed according to the presence or absence of V-M3s or the status of the M3s. The χ test or t test was used to compare the mean PLI, PPD, BOP percentage, and PPD5+ percentage. The association of PPD5+ with V-M3 status was assessed using a multivariable logistic regression model (quadrant-based analysis), and variances were adjusted for clustered observations within subjects.

Results: In total, 572 subjects were enrolled in the study, and 423 had at least 1 V-M3. At the in-quadrant level, the presence of a V-M3 significantly increased M2 pathologic parameters, including PLI, PPD, BOP, and PPD5+. When analyzed using a multivariate logistic regression model, impacted M3s and normally erupted M3s significantly elevated the risk of PPD5+ on their A-M2s (odds ratio 3.20 and 1.67, respectively). Other factors associated with an increased odds of PPD5+ were mandibular region and older age. Finally, the patient-matched comparison showed that the percentage of BOP and PPD5+ on M2s increased when V-M3s were present.

Conclusions: Irrespective of their status, the presence of V-M3s is a risk factor for the development of periodontal pathologic features in their A-M2s. Although the prophylactic removal of asymptomatic V-M3s remains controversial, medical decisions should be made as early as possible, because, ideally, extraction should be performed before symptom onset.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.joms.2017.04.006DOI Listing
October 2017

Engineering a Cell Home for Stem Cell Homing and Accommodation.

Adv Biosyst 2017 Apr 22;1(4):e1700004. Epub 2017 Mar 22.

State Key Laboratory of Military Stomatology, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi'an, P. R. China.

Distilling complexity to advance regenerative medicine from laboratory animals to humans, in situ regeneration will continue to evolve using biomaterial strategies to drive endogenous cells within the human body for therapeutic purposes; this approach avoids the need for delivering ex vivo-expanded cellular materials. Ensuring the recruitment of a significant number of reparative cells from an endogenous source to the site of interest is the first step toward achieving success. Subsequently, making the "cell home" cell-friendly by recapitulating the natural extracellular matrix (ECM) in terms of its chemistry, structure, dynamics, and function, and targeting specific aspects of the native stem cell niche (e.g., cell-ECM and cell-cell interactions) to program and steer the fates of those recruited stem cells play equally crucial roles in yielding a therapeutically regenerative solution. This review addresses the key aspects of material-guided cell homing and the engineering of novel biomaterials with desirable ECM composition, surface topography, biochemistry, and mechanical properties that can present both biochemical and physical cues required for in situ tissue regeneration. This growing body of knowledge will likely become a design basis for the development of regenerative biomaterials for, but not limited to, future in situ tissue engineering and regeneration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/adbi.201700004DOI Listing
April 2017

Nonimpacted Third Molars Affect the Periodontal Status of Adjacent Teeth: A Cross-Sectional Study.

J Oral Maxillofac Surg 2017 Jul 15;75(7):1344-1350. Epub 2017 Feb 15.

Head and Professor, Department of Periodontology, National Clinical Research Center for Oral Diseases, School of Stomatology, Fourth Military Medical University, Xi'an, China. Electronic address:

Purpose: Most previous studies of the effect of third molars (M3s) on the health of adjacent second molars (A-M2s) have focused on impacted M3s (I-M3s). The purpose of this study was to investigate whether nonimpacted M3 (N-M3s) could affect the periodontal status of A-M2s.

Patients And Methods: In this cross-sectional study, patients (≥18 years) who had at least 1 quadrant with intact first and second molars and a nonimpacted or absent M3 were enrolled in this study. The periodontal measurements of M2 (6 sites) in the examined quadrants included the gingival index (GI), plaque index (PLI), probing pocket depth (PPD), clinical attachment level (CAL), gingival recession, and bleeding on probing (BOP). The mean GI, PLI, PPD, CAL, and BOP proportion and the proportion with at least 1 site with a PPD of at least 5 mm (PPD5) were compared using the t test or χ test. The association of PPD5 (percentage) or BOP (percentage) with the presence of N-M3s was assessed using a 2-level logistic regression model (quadrant-based analysis).

Results: One hundred thirty-five patients (43.7% men; 40.6 ± 11.5 yr old) were enrolled in this study. Patients who had at least 1 quadrant with 3 intact molars and an N-M3 were enrolled in group A (105 patients), and patients who had at least 1 quadrant with intact first and second molars without an M3 were enrolled in group B (30 patients). The periodontal parameters (ie, GI, PLI, PPD, CAL, BOP, and PPD5) were markedly greater in group A. When other factors associated with periodontal disease were controlled, N-M3s were associated with the PPD5 (odds ratio = 6.7) and BOP (odds ratio = 4.0) of the A-M2s. Other factors positively associated with A-M2 PPD5 were location on the mandible, age older than 35 years, and smoking.

Conclusions: The presence of N-M3s is a potential risk factor for the development of periodontitis in A-M2s.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.joms.2017.02.005DOI Listing
July 2017

Influence of Non-Impacted Third Molars on Pathologies of Adjacent Second Molars: A Retrospective Study.

J Periodontol 2017 05 15;88(5):450-456. Epub 2016 Dec 15.

Department of Periodontology, National Clinical Research Center for Oral Diseases, School of Stomatology, Fourth Military Medical University, Xi'an, People's Republic of China.

Background: Although removal of impacted third molars (I-M3s) is common in dental clinics, the decision to retain or remove asymptomatic non-impacted third molars (N-M3s) presents a significant challenge. This study investigates influence of N-M3s on pathologies of adjacent second molars (A-M2s).

Methods: Clinical status of M3s was evaluated, and presence of distal caries, external root resorption (ERR), and alveolar bone loss (ABL) of A-M2s was assessed by orthopantomograms (OPGs). Prevalence of A-M2 pathologies was evaluated and association between N-M3s and pathologies of A-M2s was analyzed by multivariate logistic regression. Significance level was set at 0.05.

Results: OPGs from 1,958 patients were included in the present study. Among these patients, 45.1% presented with at least one N-M3, and 44.2% of retained M3s were non-impacted. Where N-M3s were present, prevalence of distal caries, ERR, and ABL of A-M2s was 10.0%, 0.8%, and 40.4%, respectively. Although N-M3s did not increase the odds of caries or ERR of A-M2s, presence of N-M3s was associated with 1.77 times higher likelihood of ABL from A-M2s when data were adjusted for age and sex.

Conclusions: Presence of N-M3s, even if they are asymptomatic, represents an important risk factor for periodontal health of A-M2s. This finding should be considered during clinical decision making regarding retention or extraction of N-M3s, especially when these teeth are non-functional or when their removal will not affect overall occlusal function.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1902/jop.2016.160453DOI Listing
May 2017