Publications by authors named "Guangxin Li"

59 Publications

Quantitative not qualitative histology differentiates aneurysmal from nondilated ascending aortas and reveals a net gain of medial components.

Sci Rep 2021 Jun 23;11(1):13185. Epub 2021 Jun 23.

Section of Cardiac Surgery, Department of Surgery, Yale School of Medicine, 10 Amistad Street 337B, New Haven, CT, 06520, USA.

Medial degeneration is a common histopathological finding in aortopathy and is considered a mechanism for dilatation. We investigated if medial degeneration is specific for sporadic thoracic aortic aneurysms versus nondilated aortas. Specimens were graded by pathologists, blinded to the clinical diagnosis, according to consensus histopathological criteria. The extent of medial degeneration by qualitative (semi-quantitative) assessment was not specific for aneurysmal compared to nondilated aortas. In contrast, blinded quantitative assessment of elastin amount and medial cell number distinguished aortic aneurysms and referent specimens, albeit with marked overlap in results. Specifically, the medial fraction of elastin decreased from dilution rather than loss of protein as cross-sectional amount was maintained while the cross-sectional number, though not density, of smooth muscle cells increased in proportion to expansion of the media. Furthermore, elastic lamellae did not thin and interlamellar distance did not diminish as expected for lumen dilatation, implying a net gain of lamellar elastin and intralamellar cells or extracellular matrix during aneurysmal wall remodeling. These findings support the concepts that: (1) medial degeneration need not induce aortic aneurysms, (2) adaptive responses to altered mechanical stresses increase medial tissue, and (3) greater turnover, not loss, of mural cells and extracellular matrix associates with aortic dilatation.
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http://dx.doi.org/10.1038/s41598-021-92659-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8222259PMC
June 2021

16S rRNA Gene Amplicon Sequencing of Gut Microbiota from Naked Carp (Gymnocypris przewalskii) in Qinghai Lake, China.

Microbiol Resour Announc 2021 Jun 10;10(23):e0037421. Epub 2021 Jun 10.

State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, China.

Naked carp (Gymnocypris przewalskii) is a second-grade animal under state protection of China. We report 16S rRNA gene amplicon analysis of the gut microbiota of Gymnocypris przewalskii. The three most abundant phyla are , , and , and the six most abundant genera are , , , , , and .
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http://dx.doi.org/10.1128/MRA.00374-21DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8354547PMC
June 2021

An ex vivo physiologic and hyperplastic vessel culture model to study intra-arterial stent therapies.

Biomaterials 2021 08 29;275:120911. Epub 2021 May 29.

Department of Anesthesiology, School of Medicine, Yale University, New Haven, CT, 06519, USA; Department of Biomedical Engineering, School of Medicine, Yale University, New Haven, CT, 06519, USA. Electronic address:

Conventional in vitro methods for biological evaluation of intra-arterial devices such as stents fail to accurately predict cytotoxicity and remodeling events. An ex vivo flow-tunable vascular bioreactor system (VesselBRx), comprising intra- and extra-luminal monitoring capabilities, addresses these limitations. VesselBRx mimics the in vivo physiological, hyperplastic, and cytocompatibility events of absorbable magnesium (Mg)-based stents in ex vivo stent-treated porcine and human coronary arteries, with in-situ and real-time monitoring of local stent degradation effects. Unlike conventional, static cell culture, the VesselBRx perfusion system eliminates unphysiologically high intracellular Mg concentrations and localized O consumption resulting from stent degradation. Whereas static stented arteries exhibited only 20.1% cell viability and upregulated apoptosis, necrosis, metallic ion, and hypoxia-related gene signatures, stented arteries in VesselBRx showed almost identical cell viability to in vivo rabbit models (~94.0%). Hyperplastic intimal remodeling developed in unstented arteries subjected to low shear stress, but was inhibited by Mg-based stents in VesselBRx, similarly to in vivo. VesselBRx represents a critical advance from the current static culture standard of testing absorbable vascular implants.
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http://dx.doi.org/10.1016/j.biomaterials.2021.120911DOI Listing
August 2021

Uncarboxylated osteocalcin alleviates the inhibitory effect of high glucose on osteogenic differentiation of mouse bone marrow-derived mesenchymal stem cells by regulating TP63.

BMC Mol Cell Biol 2021 Apr 27;22(1):24. Epub 2021 Apr 27.

Medical School, University of Chinese Academy of Sciences, Beijing, China.

Background: Progressive population aging has contributed to the increased global prevalence of diabetes and osteoporosis. Inhibition of osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) by hyperglycemia is a potential pathogenetic mechanism of osteoporosis in diabetic patients. Uncarboxylated osteocalcin (GluOC), a protein secreted by mature osteoblasts, regulates bone development as well as glucose and lipid metabolism. In our previous studies, GluOC was shown to promote osteoblastic differentiation of BMSCs; however, the underlying mechanisms are not well characterized. Tumor protein 63 (TP63), as a  transcription factor, is closely related to bone development and glucose metabolism.

Results: In this study, we verified that high glucose suppressed osteogenesis and upregulated adipogenesis in BMSCs, while GluOC alleviated this phenomenon. In addition, high glucose enhanced TP63 expression while GluOC diminished it. Knock-down of TP63 by siRNA transfection restored the inhibitory effect of high glucose on osteogenic differentiation. Furthermore, we detected the downstream signaling pathway PTEN/Akt/GSK3β. We found that diminishing TP63 decreased PTEN expression and promoted the phosphorylation of Akt and GSK3β. We then applied the activator and inhibitor of Akt, and concluded that PTEN/Akt/GSK3β participated in regulating the differentiation of BMSCs.

Conclusions: Our results indicate that GluOC reduces the inhibitory effect of high glucose on osteoblast differentiation by regulating the TP63/PTEN/Akt/GSK3β pathway. TP63 is a potential novel target for the prevention and treatment of diabetic osteoporosis.
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http://dx.doi.org/10.1186/s12860-021-00365-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8080387PMC
April 2021

Ultrathin Li-Si-O Coating Layer to Stabilize the Surface Structure and Prolong the Cycling Life of Single-Crystal LiNiCoMnO Cathode Materials at 4.5 V.

ACS Appl Mater Interfaces 2021 Mar 23;13(9):10952-10963. Epub 2021 Feb 23.

Laboratory of Advanced Materials, Institute of New Energy, Fudan University, 2205, Songhu Road, Shanghai 200438, China.

Single-crystal LiNiCoMnO cathode materials can effectively suppress intergranular cracks that usually is seen in commercial polycrystal LiNiCoMnO cathode materials. However, the surface structure degradation for single-crystal LiNiCoMnO cathode materials is still aggravated at a higher cutoff voltage (over 4.5 V). In this work, we prepare single-crystal LiNiCoMnO cathode materials via a solid-state method and then coat an ultrathin Li-Si-O layer on their surface by a wet coating method. The results show that the single-crystal LiNiCoMnO cathode materials with a Li-Si-O coating layer deliver excellent cycling performance even at a higher cutoff voltage of 4.5 V. The optimized Li-Si-O-modified sample displays a capacity retention of 90.6% after 100 cycles, whereas only 68.0% for unmodified single-crystal LiNiCoMnO. Further analysis of the cycled electrodes reveals that the surface structure degradation is the main reason for the decrease of electrochemical performance of single-crystal LiNiCoMnO at a high voltage (4.5 V). In contrast, with Li-Si-O coating, this phenomenon can be suppressed effectively to maintain interfacial stability and prolong the cycling life.
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http://dx.doi.org/10.1021/acsami.0c22356DOI Listing
March 2021

Revealing the Role of W-Doping in Enhancing the Electrochemical Performance of the LiNiCoMnO Cathode at 4.5 V.

ACS Appl Mater Interfaces 2021 Feb 2;13(6):7308-7316. Epub 2021 Feb 2.

Department of Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Institute of New Energy, Fudan University, Shanghai 200438, China.

More and more attention has been focused on Ni-rich ternary materials due to their superior specific capacity, but they still suffer inherent structural irreversibility and rapid capacity degradation under a high voltage. Oxidation of unstable oxygen will lead to the irreversible transformation of the structure. Taking into account the strong W-O bond, an appropriate amount of W-doping is studied to reinforce the thermal stability and electrochemical performance of LiNiCoMnO (NCM622) at 4.5 V. Combining experiments and theoretical calculations, it can be found that W-doping is most preferred at Co sites, and the average charge around O in the NiO octahedron becomes more negative after W-doping, which can successfully restrain the release of oxygen, thereby improving the stability of the crystal structure during deep delithiation. In addition, W-doping decreases the energy barrier of the Li migration slightly and boosts the kinetic diffusion of lithium ions. As a result, NCM622 doped with 0.5% W boasts an outstanding capacity retention of 96.7% at 1 C after 100 cycles and a discharge specific capacity of up to 152.8 mA h g at 5 C between 3.0 and 4.5 V. Furthermore, analysis of the cycled electrodes indicates that the lattice expansion and the formation of microcracks during long cycling are suppressed after W-doping, thereby elevating the structure and interface stability. Therefore, doping an appropriate amount of W via simple methods is helpful to obtain Ni-rich cathode materials with admirable performance.
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http://dx.doi.org/10.1021/acsami.0c21501DOI Listing
February 2021

A two-dimensional MXene-supported metal-organic framework for highly selective ambient electrocatalytic nitrogen reduction.

Nanoscale 2021 Feb 1;13(5):2843-2848. Epub 2021 Feb 1.

State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, China.

The conversion of nitrogen into ammonia is crucial for human activities. The electrochemical synthesis of ammonia from nitrogen and water is a green process with great application prospects; to this end, much effort has been made to improve the catalytic activity and selectivity. Here, a Co-based metal-organic framework (MOF), that is, zeolitic imidazolate framework-67 (ZIF-67), supported on a TiC MXene (defined as [email protected]) was prepared via in situ growth. Due to the high porosity and large active surface area of the MOF and the superior conductivity of the TiC MXene, the composite could efficiently synthesize ammonia electrochemically. In particular, the prepared [email protected] catalyst exhibited an excellent NH yield (6.52 μmol h cm), significantly higher than those achieved by TiC and ZIF-67 (2.77 and 1.61 μmol h cm, respectively) alone, and good Faraday efficiency (20.2%) at -0.4 V (vs. the reversible hydrogen electrode). This study not only expands the application of the MXene family in the electrochemical nitrogen reduction reaction but also provides ideas for the development of high-performance electrocatalysts for NRR.
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http://dx.doi.org/10.1039/d0nr08744kDOI Listing
February 2021

Developmental origins of mechanical homeostasis in the aorta.

Dev Dyn 2021 May 4;250(5):629-639. Epub 2021 Jan 4.

Department of Biomedical Engineering, Yale University, New Haven, Connecticut, USA.

Background: Mechanical homeostasis promotes proper aortic structure and function. Pathological conditions may arise, in part, from compromised or lost homeostasis. There is thus a need to quantify the homeostatic state and when it emerges. Here we quantify changes in mechanical loading, geometry, structure, and function of the murine aorta from the late prenatal period into maturity.

Results: Our data suggest that a homeostatic set-point is established by postnatal day P2 for the flow-induced shear stress experienced by endothelial cells; this value deviates from its set-point from P10 to P21 due to asynchronous changes in mechanical loading (flow, pressure) and geometry (radius, wall thickness), but is restored thereafter consistent with homeostasis. Smooth muscle contractility also decreases during this period of heightened matrix deposition but is also restored in maturity. The pressure-induced mechanical stress experienced by intramural cells initially remains low despite increasing blood pressure, and then increases while extracellular matrix accumulates.

Conclusions: These findings suggest that cell-level mechanical homeostasis emerges soon after birth to allow mechanosensitive cells to guide aortic development, with deposition of matrix after P2 increasingly stress shielding intramural cells. The associated tissue-level set-points that emerge for intramural stress can be used to assess and model the aorta that matures biomechanically by P56.
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http://dx.doi.org/10.1002/dvdy.283DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8089041PMC
May 2021

Raltitrexed Enhances the Antitumor Effect of Apatinib in Human Esophageal Squamous Carcinoma Cells via Akt and Erk Pathways.

Onco Targets Ther 2020 1;13:12325-12339. Epub 2020 Dec 1.

Cancer Center, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, People's Republic of China.

Objective: Apatinib has been proved effective in the treatment of advanced gastric cancer and a variety of solid tumors. Raltitrexed is emerging as a promising alternative for treating advanced colorectal cancer in China. This work aims to study the combinatory antitumor effect of apatinib and raltitrexed on human esophageal squamous carcinoma cells (ESCC).

Materials And Methods: Two VEGFR-2-positive human ESCC lines, KYSE-30 and TE-1, were treated with apatinib or raltitrexed, or both, then the cell proliferation rate was measured by MTS assay; cell migration and invasion were studied by transwell assays; cell apoptosis rate was determined by flow cytometry; cellular autophagy level affected was analyzed by Western blot analysis; finally, quantitative polymerase chain reaction (qPCR) was used to monitor transcription and Western blot was performed to check phosphorylation of apoptotic proteins after treatment.

Results: Both apatinib and raltitrexed significantly inhibited KYSE-30 and TE-1 cell proliferation in a dose-dependent manner. Treatment with both drugs showed enhanced inhibitory effects on cell proliferation, migration, and invasiveness compared with apatinib monotherapy. Apoptosis percentages in both cell lines were also remarkably increased by the combined treatment. Moreover, the combination of apatinib and raltitrexed down-regulated mRNA level of the anti-apoptotic protein Bcl-2, while up-regulated pro-apoptotic protein PARP, Bax, and caspase-3 transcription. Western blot analysis showed that phosphorylation levels of Erk, Akt, and invasiveness-associated protein matrix metalloproteinases-9 (MMP-9) were decreased in the combination group.

Conclusion: Taken together, these results indicate that raltitrexed enhances the antitumor effects of apatinib on human ESCC cells by down-regulating phosphorylation of Akt and Erk, implying a combination of raltitrexed and apatinib might be an effective option for treating esophageal squamous cell carcinoma patients.
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http://dx.doi.org/10.2147/OTT.S276125DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7719348PMC
December 2020

Xenogeneic-free generation of vascular smooth muscle cells from human induced pluripotent stem cells for vascular tissue engineering.

Acta Biomater 2021 01 29;119:155-168. Epub 2020 Oct 29.

Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine Yale School of Medicine, New Haven, CT 06511, USA; Yale Stem Cell Center, New Haven, CT 06520, USA; Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Pathology, Yale School of Medicine, New Haven, CT, 06520 USA. Electronic address:

Development of mechanically advanced tissue-engineered vascular grafts (TEVGs) from human induced pluripotent stem cell (hiPSC)-derived vascular smooth muscle cells (hiPSC-VSMCs) offers an innovative approach to replace or bypass diseased blood vessels. To move current hiPSC-TEVGs toward clinical application, it is essential to obtain hiPSC-VSMC-derived tissues under xenogeneic-free conditions, meaning without the use of any animal-derived reagents. Many approaches in VSMC differentiation of hiPSCs have been reported, although a xenogeneic-free method for generating hiPSC-VSMCs suitable for vascular tissue engineering has yet to be established. Based on our previously established standard method of xenogeneic VSMC differentiation, we have replaced all animal-derived reagents with functional counterparts of human origin and successfully derived functional xenogeneic-free hiPSC-VSMCs (XF-hiPSC-VSMCs). Next, our group developed tissue rings via cellular self-assembly from XF-hiPSC-VSMCs, which exhibited comparable mechanical strength to those developed from xenogeneic hiPSC-VSMCs. Moreover, by seeding XF-hiPSC-VSMCs onto biodegradable polyglycolic acid (PGA) scaffolds, we generated engineered vascular tissues presenting effective collagen deposition which were suitable for implantation into an immunodeficient mice model. In conclusion, our xenogeneic-free conditions for generating hiPSC-VSMCs produce cells with the comparable capacity for vascular tissue engineering as standard xenogeneic protocols, thereby moving the hiPSC-TEVG technology one step closer to safe and efficacious clinical translation.
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http://dx.doi.org/10.1016/j.actbio.2020.10.042DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8168373PMC
January 2021

Melatonin Plays a Critical Protective Role in Nicotine-Related Abdominal Aortic Aneurysm.

Front Physiol 2020 17;11:866. Epub 2020 Jul 17.

Department of Vascular Surgery, The First Hospital of China Medical University, Key Laboratory of Pathogenesis, Prevention and Therapeutics of Aortic Aneurysm, Shenyang, China.

: Smoking is a major risk factor for abdominal aortic aneurysm (AAA). Among the components of smoke, nicotine is known to exert pro-atherosclerotic, prothrombotic, and proangiogenic effects on vascular smooth muscle cells (VSMCs). The current study was designed to investigate the mechanisms through which nicotine induces vascular wall dysfunction and to examine whether melatonin protects against nicotine-related AAA. : In this study, an enzyme-linked immunosorbent assay (ELISA) was used to measure melatonin and TNF-α levels, as well as total antioxidant status (TAS), in patients with AAA. We established a nicotine-related AAA model and explored the mechanisms underlying the therapeutic effects of melatonin. Tissue histopathology was used to assess vascular function, while western blotting (WB) and immunofluorescence staining were performed to detect protein expression. : We observed melatonin insufficiency in the serum from patients with AAA, particularly smokers. Moreover, melatonin level was positively correlated with antioxidant capacity. In the model, nicotine accelerated AAA expansion and destroyed vascular structure. Furthermore, OPN, LC3II, p62, matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), NF-κB p65, TNF-α, phosphorylated AKT, and phosphorylated mTOR levels were increased, , following nicotine treatment, while SM22α and α-SMA levels were reduced. Additionally, melatonin attenuated the effects of nicotine on AAA and reversed changes in protein expression. Moreover, melatonin lost its protective effects following bafilomycin A1-mediated inhibition of autophagy. : Based on our data, melatonin exerts a beneficial effect on rats with nicotine-related AAA by downregulating the AKT-mTOR signaling pathway, improving autophagy dysfunction, and restoring the VSMC phenotype.
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http://dx.doi.org/10.3389/fphys.2020.00866DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7379742PMC
July 2020

Smooth Muscle Cell Reprogramming in Aortic Aneurysms.

Cell Stem Cell 2020 04;26(4):542-557.e11

Yale Cardiovascular Research Center, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA; Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA. Electronic address:

The etiology of aortic aneurysms is poorly understood, but it is associated with atherosclerosis, hypercholesterolemia, and abnormal transforming growth factor β (TGF-β) signaling in smooth muscle. Here, we investigated the interactions between these different factors in aortic aneurysm development and identified a key role for smooth muscle cell (SMC) reprogramming into a mesenchymal stem cell (MSC)-like state. SMC-specific ablation of TGF-β signaling in Apoe mice on a hypercholesterolemic diet led to development of aortic aneurysms exhibiting all the features of human disease, which was associated with transdifferentiation of a subset of contractile SMCs into an MSC-like intermediate state that generated osteoblasts, chondrocytes, adipocytes, and macrophages. This combination of medial SMC loss with marked increases in non-SMC aortic cell mass induced exuberant growth and dilation of the aorta, calcification and ossification of the aortic wall, and inflammation, resulting in aneurysm development.
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http://dx.doi.org/10.1016/j.stem.2020.02.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7182079PMC
April 2020

Chronic mTOR activation induces a degradative smooth muscle cell phenotype.

J Clin Invest 2020 03;130(3):1233-1251

Department of Surgery, Yale School of Medicine, New Haven, Connecticut, USA.

Smooth muscle cell (SMC) proliferation has been thought to limit the progression of thoracic aortic aneurysm and dissection (TAAD) because loss of medial cells associates with advanced disease. We investigated effects of SMC proliferation in the aortic media by conditional disruption of Tsc1, which hyperactivates mTOR complex 1. Consequent SMC hyperplasia led to progressive medial degeneration and TAAD. In addition to diminished contractile and synthetic functions, fate-mapped SMCs displayed increased proteolysis, endocytosis, phagocytosis, and lysosomal clearance of extracellular matrix and apoptotic cells. SMCs acquired a limited repertoire of macrophage markers and functions via biogenesis of degradative organelles through an mTOR/β-catenin/MITF-dependent pathway, but were distinguishable from conventional macrophages by an absence of hematopoietic lineage markers and certain immune effectors even in the context of hyperlipidemia. Similar mTOR activation and induction of a degradative SMC phenotype in a model of mild TAAD due to Fbn1 mutation greatly worsened disease with near-uniform lethality. The finding of increased lysosomal markers in medial SMCs from clinical TAAD specimens with hyperplasia and matrix degradation further supports the concept that proliferation of degradative SMCs within the media causes aortic disease, thus identifying mTOR-dependent phenotypic modulation as a therapeutic target for combating TAAD.
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http://dx.doi.org/10.1172/JCI131048DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7269581PMC
March 2020

Radiosensitization of HER2-positive esophageal cancer cells by pyrotinib.

Biosci Rep 2020 02;40(2)

Department of Surgery, Children's National Medical Center, WA 20010, U.S.A.

Radiation therapy is a widely used treatment for esophageal cancer. However, radiation resistance might result in a poor prognosis. Overexpression of HER2 has been related to adaptive radiation resistance. Pyrotinib is a HER2 inhibitor that shows an anti-tumor effect in breast cancer. The present study aims to explore the influence of pyrotinib combined with radiotherapy on HER2-positive esophageal cancer cells and explore the underlying mechanism. We screened two cell lines (TE-1 and KYSE30) that highly express HER2 from several human esophageal cancer cell lines. Cells were treated with pyrotinib or/and radiation. Cell proliferation, cell cycle distribution, and cell migration were measured. The protein levels involved in cell cycle and DNA repair were measured by Western blot. Results showed that pyrotinib inhibited HER2 activation and exerted an anti-proliferative effect in TE-1 and KYSE30 cells. Furthermore, it enhanced the anti-proliferative effect of radiation in these two cell lines. These effects might be via inhibiting HER2 phosphorylation, inducing G0/G1 arrest, and reducing EMT and DNA repair. Our results indicated that pyrotinib sensitivitied HER2 positive esophageal cancer cells to radiation treatment through various mechanisms. These findings may provide a new therapeutic strategy for treating HER2 positive esophageal cancer.
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http://dx.doi.org/10.1042/BSR20194167DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7029153PMC
February 2020

Tissue-Engineered Vascular Grafts with Advanced Mechanical Strength from Human iPSCs.

Cell Stem Cell 2020 02 16;26(2):251-261.e8. Epub 2020 Jan 16.

Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, New Haven, CT 06511, USA; Yale Stem Cell Center, New Haven, CT 06520, USA; Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Pathology, Yale School of Medicine, New Haven, CT 06520, USA. Electronic address:

Vascular smooth muscle cells (VSMCs) can be derived in large numbers from human induced pluripotent stem cells (hiPSCs) for producing tissue-engineered vascular grafts (TEVGs). However, hiPSC-derived TEVGs are hampered by low mechanical strength and significant radial dilation after implantation. Here, we report generation of hiPSC-derived TEVGs with mechanical strength comparable to native vessels used in arterial bypass grafts by utilizing biodegradable scaffolds, incremental pulsatile stretching, and optimal culture conditions. Following implantation into a rat aortic model, hiPSC-derived TEVGs show excellent patency without luminal dilation and effectively maintain mechanical and contractile function. This study provides a foundation for future production of non-immunogenic, cellularized hiPSC-derived TEVGs composed of allogenic vascular cells, potentially serving needs to a considerable number of patients whose dysfunctional vascular cells preclude TEVG generation via other methods.
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http://dx.doi.org/10.1016/j.stem.2019.12.012DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7021512PMC
February 2020

Endothelial Cell-Derived Interleukin-18 Released During Ischemia Reperfusion Injury Selectively Expands T Peripheral Helper Cells to Promote Alloantibody Production.

Circulation 2020 02 20;141(6):464-478. Epub 2019 Nov 20.

Division of Cardiovascular Medicine (L.L., C.F., W.F., D.J.-w.), Yale University School of Medicine, New Haven, CT.

Background: Ischemia reperfusion injury (IRI) predisposes to the formation of donor-specific antibodies, a factor contributing to chronic rejection and late allograft loss.

Methods: We describe a mechanism underlying the correlative association between IRI and donor-specific antibodies by using humanized models and patient specimens.

Results: IRI induces immunoglobulin M-dependent complement activation on endothelial cells that assembles an NLRP3 (NOD-like receptor pyrin domain-containing protein 3) inflammasome via a Rab5-ZFYVE21-NIK axis and upregulates ICOS-L (inducible costimulator ligand) and PD-L2 (programmed death ligand 2). Endothelial cell-derived interleukin-18 (IL-18) selectively expands a T-cell population (CD4+CD45RO+PD-1ICOS+CCR2+CXCR5-) displaying features of recently described T peripheral helper cells. This population highly expressed IL-18R1 and promoted donor-specific antibodies in response to IL-18 in vivo. In patients with delayed graft function, a clinical manifestation of IRI, these cells were Ki-67+IL-18R1+ and could be expanded ex vivo in response to IL-18.

Conclusions: IRI promotes elaboration of IL-18 from endothelial cells to selectively expand alloreactive IL-18R1+ T peripheral helper cells in allograft tissues to promote donor-specific antibody formation.
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http://dx.doi.org/10.1161/CIRCULATIONAHA.119.042501DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7035199PMC
February 2020

miR-29a Regulates the Proliferation and Migration of Human Arterial Smooth Muscle Cells in Arteriosclerosis Obliterans of the Lower Extremities.

Kidney Blood Press Res 2019 15;44(5):1219-1232. Epub 2019 Oct 15.

Department of Vascular Surgery, Qianfoshan Hospital of Shandong Province, Jinan, China,

Background: The molecular mechanisms underlying the contribution of human arterial smooth muscle cells (HASMCs), one of the most important components of the arterial wall, to the pathogenesis of arteriosclerosis obliterans (ASO) remain elusive.

Methods: The expression levels of miR-29a in arterial walls were analyzed via real-time-polymerase chain reaction. An ASO cell model was established to investigate the expression of miR-29a on HASMCs. The interaction between miR-29a and platelet-derived growth factor receptor B (PDGFRB) was detected by luciferase reporter assay, and the alteration of the expression of PDGFRB was determined in platelet-derived growth factor‑BB (PDGF-BB)-stimulated HASMCs transfected with miR-NC, miR-29a mimics, and miR-29a inhibitors. Further, HASMCs cell proliferation was investigated by cell counting kit-8 and EdU assays, and cell migrations were evaluated by Transwell and wound closure assays.

Results: The expression of miR-29a was remarkably downregulated in the arterial walls of ASO patients compared with normal arterial walls. Furthermore, expression of miR-29a in HASMCs under PDGF-BB stimulation was lower than vehicle control. PDGFRB was identified as a target of miR-29a in HASMCs, and miR-29a inhibited the proliferation and migration in PDGF-BB-induced HASMCs, via regulating the expression of PDGFRB.

Conclusion: This study showed that miR-29a is downregulated in the arterial wall of ASO patients, as well as in the PDGF-BB-stimulated HASMCs. This alteration of miR-29a could upregulate target genes PDGFRB and inhibits the proliferation and migration of HASMCs. These findings discovered new mechanisms of ASO pathogenesis, and the miR-29a/PDGFRB axis could serve as potential therapy target of ASO.
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http://dx.doi.org/10.1159/000502649DOI Listing
March 2020

Endothelial TGF-β signalling drives vascular inflammation and atherosclerosis.

Nat Metab 2019 09 26;1(9):912-926. Epub 2019 Aug 26.

Yale Cardiovascular Research Center, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA.

Atherosclerosis is a progressive vascular disease triggered by interplay between abnormal shear stress and endothelial lipid retention. A combination of these and, potentially, other factors leads to a chronic inflammatory response in the vessel wall, which is thought to be responsible for disease progression characterized by a buildup of atherosclerotic plaques. Yet molecular events responsible for maintenance of plaque inflammation and plaque growth have not been fully defined. Here we show that endothelial TGFβ signaling is one of the primary drivers of atherosclerosis-associated vascular inflammation. Inhibition of endothelial TGFβ signaling in hyperlipidemic mice reduces vessel wall inflammation and vascular permeability and leads to arrest of disease progression and regression of established lesions. These pro-inflammatory effects of endothelial TGFβ signaling are in stark contrast with its effects in other cell types and identify it as an important driver of atherosclerotic plaque growth and show the potential of cell-type specific therapeutic intervention aimed at control of this disease.
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http://dx.doi.org/10.1038/s42255-019-0102-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6767930PMC
September 2019

Progenitor-derived human endothelial cells evade alloimmunity by CRISPR/Cas9-mediated complete ablation of MHC expression.

JCI Insight 2019 10 17;4(20). Epub 2019 Oct 17.

Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut, USA.

Tissue engineering may address organ shortages currently limiting clinical transplantation. Off-the-shelf engineered vascularized organs will likely use allogeneic endothelial cells (ECs) to construct microvessels required for graft perfusion. Vasculogenic ECs can be differentiated from committed progenitors (human endothelial colony-forming cells or HECFCs) without risk of mutation or teratoma formation associated with reprogrammed stem cells. Like other ECs, these cells can express both class I and class II major histocompatibility complex (MHC) molecules, bind donor-specific antibody (DSA), activate alloreactive T effector memory cells, and initiate rejection in the absence of donor leukocytes. CRISPR/Cas9-mediated dual ablation of β2-microglobulin and class II transactivator (CIITA) in HECFC-derived ECs eliminates both class I and II MHC expression while retaining EC functions and vasculogenic potential. Importantly, dually ablated ECs no longer bind human DSA or activate allogeneic CD4+ effector memory T cells and are resistant to killing by CD8+ alloreactive cytotoxic T lymphocytes in vitro and in vivo. Despite absent class I MHC molecules, these ECs do not activate or elicit cytotoxic activity from allogeneic natural killer cells. These data suggest that HECFC-derived ECs lacking MHC molecule expression can be utilized for engineering vascularized grafts that evade allorejection.
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http://dx.doi.org/10.1172/jci.insight.129739DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6824302PMC
October 2019

Complement Membrane Attack Complexes Assemble NLRP3 Inflammasomes Triggering IL-1 Activation of IFN-γ-Primed Human Endothelium.

Circ Res 2019 06 22;124(12):1747-1759. Epub 2019 Apr 22.

Division of Cardiovascular Medicine (C.F., D.J.-w), Yale University School of Medicine, New Haven, CT.

Rationale: Complement activation contributes to multiple immune-mediated pathologies. In late allograft failure, donor-specific antibody deposits complement membrane attack complexes (MAC) on graft endothelial cells (ECs), substantially increasing their immunogenicity without causing lysis. Internalized MAC stabilize NIK (NF-κB [nuclear factor kappa-light-chain-enhancer of activated B cells]-inducing kinase) protein on Rab5+MAC+ endosomes, activating noncanonical NF-κB signaling. However, the link to increased immunogenicity is unclear.

Objective: To identify mechanisms by which alloantibody and internalized MAC activate ECs to enhance their ability to increase T-cell responses.

Methods And Results: In human EC cultures, internalized MAC also causes NLRP3 (NOD-like receptor family pyrin domain containing 3) translocation from endoplasmic reticulum to Rab5+MAC+NIK+ endosomes followed by endosomal NIK-dependent inflammasome assembly. Cytosolic NIK, stabilized by LIGHT (lymphotoxin-like inducible protein that competes with glycoprotein D for herpesvirus entry on T cells), does not trigger inflammasome assembly, and ATP-triggered inflammasome assembly does not require NIK. IFN-γ (interferon-γ) primes EC responsiveness to MAC by increasing NLRP3, pro-caspase 1, and gasdermin D expression. NIK-activated noncanonical NF-κB signaling induces pro-IL (interleukin)-1β expression. Inflammasome processed pro-IL-1β, and gasdermin D results in IL-1β secretion that increases EC immunogenicity through IL-1 receptor signaling. Activation of human ECs lining human coronary artery grafts in immunodeficient mouse hosts by alloantibody and complement similarly depends on assembly of an NLRP3 inflammasome. Finally, in renal allograft biopsies showing chronic rejection, caspase-1 is activated in C4d ECs of interstitial microvessels, supporting the relevance of the cell culture findings.

Conclusions: In response to antibody-mediated complement activation, IFN-γ-primed human ECs internalize MAC, triggering both endosomal-associated NIK-dependent NLRP3 inflammasome assembly and IL-1 synthesis, resulting in autocrine/paracrine IL-1β-mediated increases in EC immunogenicity. Similar responses may underlie other complement-mediated pathologies.
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http://dx.doi.org/10.1161/CIRCRESAHA.119.314845DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6557295PMC
June 2019

Caveolin-1 Regulates Atherogenesis by Attenuating Low-Density Lipoprotein Transcytosis and Vascular Inflammation Independently of Endothelial Nitric Oxide Synthase Activation.

Circulation 2019 07 3;140(3):225-239. Epub 2019 Jun 3.

Vascular Biology and Therapeutics Program (C.M.R., X.Z., N.R., B.A., J.R.K., V.U., Y.S., W.C.S., C.F.-H.), Yale University School of Medicine, New Haven, CT.

Background: Atherosclerosis is driven by synergistic interactions between pathological, biomechanical, inflammatory, and lipid metabolic factors. Our previous studies demonstrated that absence of caveolin-1 (Cav1)/caveolae in hyperlipidemic mice strongly inhibits atherosclerosis, which was attributed to activation of endothelial nitric oxide (NO) synthase (eNOS) and increased production of NO and reduced inflammation and low-density lipoprotein trafficking. However, the contribution of eNOS activation and NO production in the athero-protection of Cav1 and the exact mechanisms by which Cav1/caveolae control the pathogenesis of diet-induced atherosclerosis are still not clear.

Methods: Triple-knockout mouse lacking expression of eNOS, Cav1, and Ldlr were generated to explore the role of NO production in Cav1-dependent athero-protective function. The effects of Cav1 on lipid trafficking, extracellular matrix remodeling, and vascular inflammation were studied both in vitro and in vivo with a mouse model of diet-induced atherosclerosis. The expression of Cav1 and distribution of caveolae regulated by flow were analyzed by immunofluorescence staining and transmission electron microscopy.

Results: We found that absence of Cav1 significantly suppressed atherogenesis in LdlreNOS mice, demonstrating that athero-suppression is independent of increased NO production. Instead, we find that the absence of Cav1/caveolae inhibited low-density lipoprotein transport across the endothelium and proatherogenic fibronectin deposition and disturbed flow-mediated endothelial cell inflammation. Consistent with the idea that Cav1/caveolae may play a role in early flow-dependent inflammatory priming, distinct patterns of Cav1 expression and caveolae distribution were observed in athero-prone and athero-resistant areas of the aortic arch even in wild-type mice.

Conclusions: These findings support a role for Cav1/caveolae as a central regulator of atherosclerosis that links biomechanical, metabolic, and inflammatory pathways independently of endothelial eNOS activation and NO production.
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http://dx.doi.org/10.1161/CIRCULATIONAHA.118.038571DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6778687PMC
July 2019

Pyrotinib treatment on HER2-positive gastric cancer cells promotes the released exosomes to enhance endothelial cell progression, which can be counteracted by apatinib.

Onco Targets Ther 2019 11;12:2777-2787. Epub 2019 Apr 11.

Cancer Center, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, People's Republic of China.

Pyrotinib is a newly developed irreversible pan-ErbB receptor tyrosine kinase inhibitor for treatment of human epidermal growth factor receptor 2 (HER2)-positive cancers, and clinic trials of pyrotinib in treatment of HER2-positive gastric cancer (GC) are underway. Exosomes are tiny vesicles secreted by cancer cells and take essential roles in the progression of carcinoma. Whether pyrotinib application has any effect on the cancer cell-released exosomes has not been studied. The aim of our work was to address if pyrotinib treatment impacts the effect of HER2-positive GC cell-derived exosomes on endothelial cell (EC) progression. Isolation of exosomes released by HER2-positive NCI-N87 and MKN45 lines after pyrotinib treatment was performed. Then, human umbilical vein endothelial cells (HUVECs) were incubated with different concentrations of exosomes to address their proliferation by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS). Effect of pyrotinib-treated exosomes at concentration of 10 µg/mL was compared to that without pyrotinib treatment over 96-hr time course. Transwell assay and wound-healing assay were carried out by incubating with exosomes released by NCI-N87 and MKN45 cells with/without pyrotinib treatment over 24-hr time course. The aforementioned experiments were done under same conditions in order to evaluate the combined effect of apatinib and pyrotinib on HUVEC motility and invasive capacity. We showed that HUVEC proliferation, motility and invasive capacity were further enhanced upon incubation with exosomes released by pyrotinib-treated GC cell lines, compared to those without pyrotinib treatment. Significantly, this effect was counteracted by the vascular endothelial growth factor receptor (VEGFR)-2 inhibitor apatinib which inhibits EC progression. Our study suggests that pyrotinib application on HER2-positive GC produces stronger exosomes that promote the proliferation and motility of vascular ECs, and combination of pyrotinib with apatinib provides potentially better therapy.
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http://dx.doi.org/10.2147/OTT.S194768DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6489591PMC
April 2019

ZFYVE21 is a complement-induced Rab5 effector that activates non-canonical NF-κB via phosphoinosotide remodeling of endosomes.

Nat Commun 2019 05 21;10(1):2247. Epub 2019 May 21.

Division of Cardiovascular Medicine, Yale University School of Medicine, New Haven, CT, 06520, USA.

Complement promotes vascular inflammation in transplant organ rejection and connective tissue diseases. Here we identify ZFYVE21 as a complement-induced Rab5 effector that induces non-canonical NF-κB in endothelial cells (EC). In response to membrane attack complexes (MAC), ZFYVE21 is post-translationally stabilized on MAC+Rab5+ endosomes in a Rab5- and PI(3)P-dependent manner. ZFYVE21 promotes SMURF2-mediated polyubiquitinylation and proteasome-dependent degradation of endosome-associated PTEN to induce vesicular enrichment of PI(3,4,5)P3 and sequential recruitment of activated Akt and NF-κB-inducing kinase (NIK). Pharmacologic alteration of cellular phosphoinositide content with miltefosine reduces ZFYVE21 induction, EC activation, and allograft vasculopathy in a humanized mouse model. ZFYVE21 induction distinctly occurs in response to MAC and is detected in human renal and synovial tissues. Our data identifies ZFYVE21 as a Rab5 effector, defines a Rab5-ZFYVE21-SMURF2-pAkt axis by which it mediates EC activation, and demonstrates a role for this pathway in complement-mediated conditions.
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http://dx.doi.org/10.1038/s41467-019-10041-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6529429PMC
May 2019

Fas ligand and nitric oxide combination to control smooth muscle growth while sparing endothelium.

Biomaterials 2019 08 7;212:28-38. Epub 2019 May 7.

Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Anesthesiology, Yale University, New Haven, CT 06519, USA; Department of Biomedical Engineering, Yale University, New Haven, CT 06519, USA; Yale Stem Cell Center, New Haven, CT 06520, USA.

Metallic stents cause vascular wall damage with subsequent smooth muscle cell (SMC) proliferation, neointimal hyperplasia, and treatment failure. To combat in-stent restenosis, drug-eluting stents (DES) delivering mTOR inhibitors such as sirolimus or everolimus have become standard for coronary stenting. However, the relatively non-specific action of mTOR inhibitors prevents efficient endothelium recovery and mandates dual antiplatelet therapy to prevent thrombosis. Unfortunately, long-term dual antiplatelet therapy leads to increased risk of bleeding/stroke and, paradoxically, myocardial infarction. Here, we took advantage of the fact that nitric oxide (NO) increases Fas receptors on the SMC surface. Fas forms a death-inducing complex upon binding to Fas ligand (FasL), while endothelial cells (ECs) are relatively resistant to this pathway. Selected doses of FasL and NO donor synergistically increased SMC apoptosis and inhibited SMC growth more potently than did everolimus or sirolimus, while having no significant effect on EC viability and proliferation. This differential effect was corroborated in ex vivo pig coronaries, where the neointimal formation was inhibited by the drug combination, but endothelial viability was retained. We also deployed FasL-NO donor-releasing ethylene-vinyl acetate copolymer (EVAc)-coated stents into pig coronary arteries, and cultured them in perfusion bioreactors for one week. FasL and NO donor, released from the stent coating, killed SMCs close to the stent struts, even in the presence of flow rates mimicking those of native arteries. Thus, the FasL-NO donor-combination has a potential to prevent intimal hyperplasia and in-stent restenosis, without harming endothelial restoration, and hence may be a superior drug delivery strategy for DES.
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http://dx.doi.org/10.1016/j.biomaterials.2019.05.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6567994PMC
August 2019

Ginsenoside Rb1 attenuates diabetic retinopathy in streptozotocin-induced diabetic rats1.

Acta Cir Bras 2019 Feb 28;34(2):e201900201. Epub 2019 Feb 28.

MD, Department of Ophthalmology, Yantai Yuhuangding Hospital, P.R. China. Conception and design of the study, critical revision, final approval.

Purpose: To investigated the effects of ginsenoside Rb1 on diabetic retinopathy in streptozotocin-induced diabetic rats.

Methods: Diabetes was induced by a single intraperitoneal injection of streptozotocin (80 mg/kg) in male Wistar rats. Ginsenoside Rb1 (20, 40 mg/kg) was injected (i.p.) once a day for 4 weeks. Then, using fundus photography, the diameter and vascular permeability of retinal vessels were investigated. Retinal histopathology was undertaken. Contents of malondialdehyde (MDA) and glutathione (GSH) in retinas were assayed. Levels of nuclear factor erythroid 2-related factor 2 (Nrf2), glutathione cysteine ligase catalytic subunit (GCLC), and glutathione cysteine ligase modulatory subunit (GCLM) were measured.

Results: Treatment with ginsenoside Rb1 attenuated the diabetes-induced increase in the diameter of retinal blood vessels. Ginsenoside Rb1 reduced extravasation of Evans Blue dye from retinal blood vessels. Ginsenoside Rb1 partially inhibited the increase in MDA content and decrease in GSH level in rat retinas. Nrf2 levels in the nuclei of retinal cells and expression of GCLC and GCLM were increased significantly in rats treated with ginsenoside Rb1.

Conclusion: These findings suggest that ginsenoside Rb1 can attenuate diabetic retinopathy by regulating the antioxidative function in rat retinas.
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http://dx.doi.org/10.1590/s0102-8650201900201DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6585913PMC
February 2019

Expression variations and clinical significance of MMP-1, MMP-2 and inflammatory factors in serum of patients with deep venous thrombosis of lower extremity.

Exp Ther Med 2019 Jan 2;17(1):181-186. Epub 2018 Nov 2.

Department of Vascular Surgery, Qianfoshan Hospital, Jinan, Shandong 251400, P.R. China.

Expression levels and clinical significance of matrix metalloproteinase-1 (MMP1), MMP-2 and inflammatory factors in the serum of patients with deep venous thrombosis (DVT) of lower extremity were investigated. Fifty untreated DVT patients were selected as the DVT group, and 50 patients undergoing health examination were enrolled as the normal control group. Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of MMP-1, MMP-2, interleukin-6 (IL-6), IL-8 and tumor necrosis factor-α (TNF-α) in the serum. Western blotting was adopted to detect the expression levels of MMP-1 and MMP-2 proteins. Fluorescent reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was applied to examine the messenger ribonucleic acid (mRNA) expression levels. Moreover, the circumferences of the patients were measured. The difference between the circumference of affected extremity and unaffected extremity was calculated. Correlation analysis was conducted separately for the levels of serum MMP-1, MMP-2, IL-6, IL-8 and TNF-α of patients in the DVT group. In the DVT group, the levels of MMP-1, MMP-2, IL-6, IL-8, and TNF-α at 7 days after treatment were significantly lower than those before treatment (P<0.01). Compared with that before treatment, the circumference difference of the affected and unaffected extremities of the patients was reduced at 7 days after treatment (P<0.01). The levels of IL-6, IL-8 and TNF-α were positively correlated with the levels of MMP-1 and MMP-2, respectively in the DVT group (P<0.05 or P<0.01). MMP-1, MMP-2 and inflammatory factors play an important role in the occurrence and development of DVT, of which the levels of IL-6, IL-8 and TNF-α are positively correlated with the levels of MMP-1 and MMP-2, respectively. Therefore, monitoring the concentration of MMP-1, MMP-2 and inflammatory factors is of significant value for the diagnosis, progression and judgement of treatment effect of DVT in clinical practice.
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http://dx.doi.org/10.3892/etm.2018.6922DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6307431PMC
January 2019

VEGFR-2 Inhibitor Apatinib Hinders Endothelial Cells Progression Triggered by Irradiated Gastric Cancer Cells-derived Exosomes.

J Cancer 2018 18;9(21):4049-4057. Epub 2018 Oct 18.

Cancer Center, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.

Radiotherapy is a standard treatment for a significant fraction of cancer patients. Nonetheless, to this day radiation resistance is a key impediment in gastric cancer (GC) treatment. Moreover, GC is characterized by its substantial neo-angiogenesis, driven by high levels of vascular endothelial growth factor (VEGF) correlated with the presence of stomach cancer. The aim of our study was to address if VEGFR inhibitors treatments impact the negative effect of radiotherapy regiments of gastric cancer. Isolation of exosomes released by SGC-7901 and BGC-823 lines after irradiation at 0 Gy or 6 Gy was performed by differential ultra-centrifugation. Incubation of Human Umbilical Vein Endothelial Cells (HUVEC) was carried out with different concentrations of exosomes from non- or irradiated GC cells to address their proliferation and survival fraction (SF) by MTS. 6 Gy irradiated cells exosomes at concentration of 20 µg/ml were compared to EC incubated with the same exosome concentration from non-irradiated human GC cells over 72-hour time course. Wound-healing and Transwell assays were performed in a migration buffer consisting of exosomes released by non- or irradiated SGC-7901 and BGC-823 cells over 24-hour time course. HUVEC cells stained with DAPI that have passed through a gluten gel were counted in order to monitor their invasion capacity. Employing IC50, 60 µg/ml was determined as the optimal Apatinib (YN968D1) concentration for the half-life of HUVEC, and incubated with exosomes from irradiated GC cells. The aforementioned assays were performed in the background of the same conditions in order to analyse the effect of Apatinib on HUVEC progression. We show that proliferation, motility and invasive capacity of HUVEC are enhanced upon incubation with exosomes released by irradiated GC cell lines. Importantly, the latter is counteracted by the VEGFR-2 inhibitor Apatinib which hinders ECs progression. Combining radiotherapy and VEGFR inhibitors treatment can provide potentially a substantial impact in decreasing cancer death rates by averting the negative effect of radiotherapy regiments and provide better standard for cancer patients.
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http://dx.doi.org/10.7150/jca.25370DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6218785PMC
October 2018

Sodium orthovanadate overcomes sorafenib resistance of hepatocellular carcinoma cells by inhibiting Na/K-ATPase activity and hypoxia-inducible pathways.

Sci Rep 2018 06 26;8(1):9706. Epub 2018 Jun 26.

Department of General Surgery, the First Affiliated Hospital of Harbin Medical University, Harbin, 150001, China.

The resistance to sorafenib highly affects its clinical benefits for treating hepatocellular carcinoma (HCC). Sodium orthovanadate (SOV) is a phosphate analog that displays anti-cancer activities against various types of malignancies including HCC. The present study has demonstrated that SOV is able to overcome sorafenib resistance and strengthens sorafenib in suppressing sorafenib-resistant HCC cells in vitro and in animal models. Similar to its action on parental HCC cells, SOV induced cell cycle arrest at G2/M phases by regulating cyclin B1 and cyclin-dependent kinase 1, and apoptosis by reducing mitochondrial membrane potential, in sorafenib-resistant HCC cells. More importantly, SOV inhibited ATPase activity, which was significantly elevated in sorafenib-resistant HCC cells. SOV also reduced the expression of HIF-1α and HIF-2α and their nuclear translocation, resulting in downregulation of their downstream factors including vascular endothelial growth factor, lactate dehydrogenase-A and glucose transporter 1. Its ability to inhibit ATPase activity and hypoxia-inducible pathways enabled SOV to efficiently suppress both normoxic and hypoxic cells, which compose cancer cell populations inside sorafenib-resistant HCC tumors. The present results indicate that SOV may be a potent candidate drug for overcoming the resistance to sorafenib in treating HCC.
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http://dx.doi.org/10.1038/s41598-018-28010-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6018801PMC
June 2018

Mitochondrial unfolded protein response gene Clpp is required to maintain ovarian follicular reserve during aging, for oocyte competence, and development of pre-implantation embryos.

Aging Cell 2018 08 30;17(4):e12784. Epub 2018 May 30.

Department of Obstetrics, Gynecology and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut.

Caseinolytic peptidase P mediates degradation of unfolded mitochondrial proteins and activates mitochondrial unfolded protein response (mtUPR) to maintain protein homeostasis. Clpp female mice generate a lower number of mature oocytes and two-cell embryos, and no blastocysts. Clpp oocytes have smaller mitochondria, with lower aspect ratio (length/width), and decreased expression of genes that promote fusion. A 4-fold increase in atretic follicles at 3 months, and reduced number of primordial follicles at 6-12 months are observed in Clpp ovaries. This is associated with upregulation of p-S6, p-S6K, p-4EBP1 and p-AKT473, p-mTOR2481 consistent with mTORC1 and mTORC2 activation, respectively, and Clpp oocyte competence is partially rescued by mTOR inhibitor rapamycin. Our findings demonstrate that CLPP is required for oocyte and embryo development and oocyte mitochondrial function and dynamics. Absence of CLPP results in mTOR pathway activation, and accelerated depletion of ovarian follicular reserve.
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http://dx.doi.org/10.1111/acel.12784DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6052477PMC
August 2018

Plasma exosomes as novel biomarker for the early diagnosis of gastric cancer.

Cancer Biomark 2018 ;21(4):805-812

Cancer Institute of Chongqing, Chongqing 400030, China.

Exosomes are lipid bilayer vesicles of endocytic origin ranging from 30 to 100 nm in size, and contain various nucleic acid molecules such as DNA, mRNA, miRNA, lncRNA and multiple proteins, which could be transferred into target cells. Recent study indicated that exosomes as information carriers between cells has introduced us to a new previously unknown biological communication system. Increasing evidences show that exosomes play a crucial role in gastric cancer because they are potential to influence normal cellular physiology and promote various states of the cancer. In this review, we focus on the latest findings on exosomes in the plasma of gastric cancer patients, mainly summarizing the functions of miRNAs, lncRNAs and multiple proteins in diagnosis, prognosis, and in establishing treatment regimens against gastric cancer. Furtherly, potential functions of exosomes as novel diagnostic biomarkers for gastric cancer are discussed extensively. Exosomes are believed to be a non-invasive disease biomarker with a dual capability to provide insights into the early diagnosis for gastric cancer.
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http://dx.doi.org/10.3233/CBM-170738DOI Listing
August 2018
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