Publications by authors named "Kun Liu"

1,289 Publications

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Soluble fibrinogen‑like protein 2 levels are decreased in patients with ischemic heart failure and associated with cardiac function.

Mol Med Rep 2021 Aug 10;24(2). Epub 2021 Jun 10.

Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China.

Soluble fibrinogen‑like protein 2 (sFGL2), as a novel effector of regulatory T cells (Tregs), exhibits immune regulatory activity in several inflammatory diseases. Immune activation and persistent inflammation participate in the progression of ischemic heart failure (IHF). The present study aimed to determine serum sFGL2 levels in patients with IHF and explore the relationship between sFGL2 levels and cardiac function. A total of 104 patients with IHF and 32 healthy controls were enrolled. patients with IHF were further split into subgroups according to the New York Heart Association functional classification or left ventricular ejection fraction (LVEF). Serum sFGL2 levels and peripheral Tregs frequencies were analyzed by ELISA and flow cytometry, respectively. The suppressive function of Tregs was measured by proliferation and functional suppression assays. Serum levels of sFGL2 and circulating Tregs frequencies were significantly decreased in patients with IHF compared with healthy controls. In patients with IHF, sFGL2 levels and Tregs frequencies were decreased with the deterioration of cardiac function. Tregs from patients with IHF exhibited compromised ability to suppress CD4CD25 T cells proliferation and inflammatory cytokines secretion. Specifically, sFGL2 levels and Tregs frequencies positively correlated with LVEF, whereas negatively correlated with left ventricular end‑diastolic dimension and N‑terminal pro‑brain natriuretic peptide. sFGL2 levels were positively correlated with Tregs frequencies. In conclusion, the reduction of serum sFGL2 levels are associated with the progression of IHF and sFGL2 could be used as a potential indicator for predicting disease severity.
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http://dx.doi.org/10.3892/mmr.2021.12198DOI Listing
August 2021

Prostaglandin E2 promotes Staphylococcus aureus infection via EP4 receptor in bovine endometrium.

Microb Pathog 2021 Jun 6:105019. Epub 2021 Jun 6.

Laboratory of Veterinary Pathology, College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, China. Electronic address:

Prostaglandin E2 (PGE) enhances Staphylococcus aureus infection but its mechanism is not well understood. Here, we examined the effect of PGE on Staphylococcal Protein A (SPA) expression in bovine endometrium and determined the role of select PGE receptors (i.e., EP2 and EP4) in adhesion and internalization of S. aureus. S. aureus isolate SA113 was used for in vitro infection of bovine endometrial tissues and epithelial cells, with treatment conditions consisting of untreated control, SA113 treatment, SA113 + PGE, SA113 + PGE + EP2 receptor antagonist (AH-6809), and SA113 + PGE + EP4 receptor antagonist (AH-23848). Immunofluorescence assay revealed that PGE could promote SPA expression in S. aureus-infected bovine endometrial tissues. PGE also enhanced the adhesion and internalization of S. aureus in bovine endometrial cells. The addition of EP4 antagonist, but not the EP2 antagonist, abrogated the ability of PGE to promote S. aureus SPA expression, adhesion, and internalization in endometrial cells. Our findings suggest that S. aureus infection in the endometrium is enhanced by PGE through the EP4 receptor. This result is essential for the development of new approach to treating S. aureus infection, such as the application of EP4 antagonist as an adjunct drug treatment.
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http://dx.doi.org/10.1016/j.micpath.2021.105019DOI Listing
June 2021

Dicer Deletion in Astrocytes Inhibits Oligodendroglial Differentiation and Myelination.

Neurosci Bull 2021 Jun 9. Epub 2021 Jun 9.

Department of Histology and Embryology, Chongqing Key Laboratory of Neurobiology, Brain and Intelligence Research Key Laboratory of Chongqing Education Commission, Third Military Medical University (Army Medical University), Chongqing, 400038, China.

Increasing evidence has shown that astrocytes are implicated in regulating oligodendrocyte myelination, but the underlying mechanisms remain largely unknown. To understand whether microRNAs in astrocytes function in regulating oligodendroglial differentiation and myelination in the developing and adult CNS, we generated inducible astrocyte-specific Dicer conditional knockout mice (hGFAP-CreERT; Dicer fl/fl). By using a reporter mouse line (mT/mG), we confirmed that hGFAP-CreERT drives an efficient and astrocyte-specific recombination in the developing CNS, upon tamoxifen treatment from postnatal day 3 (P3) to P7. The Dicer deletion in astrocytes resulted in inhibited oligodendroglial differentiation and myelination in the developing CNS of Dicer cKO mice at P10 and P14, and did not alter the densities of neurons or axons, indicating that Dicer in astrocytes is required for oligodendrocyte myelination. Consequently, the Dicer deletion in astrocytes at P3 resulted in impaired spatial memory and motor coordination at the age of 9 weeks. To understand whether Dicer in astrocytes is also required for remyelination, we induced Dicer deletion in 3-month-old mice and then injected lysolecithin into the corpus callosum to induce demyelination. The Dicer deletion in astrocytes blocked remyelination in the corpus callosum 14 days after induced demyelination. Together, our results indicate that Dicer in astrocytes is required for oligodendroglia myelination in both the developing and adult CNS.
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http://dx.doi.org/10.1007/s12264-021-00705-9DOI Listing
June 2021

Enhancing myelin renewal reverses cognitive dysfunction in a murine model of Alzheimer's disease.

Neuron 2021 Jun 3. Epub 2021 Jun 3.

Brain and Intelligence Research Key Laboratory of Chongqing Education Commission, Department of Histology and Embryology, Third Military Medical University, Chongqing 400038, China. Electronic address:

Severe cognitive decline is a hallmark of Alzheimer's disease (AD). In addition to gray matter loss, significant white matter pathology has been identified in AD patients. Here, we characterized the dynamics of myelin generation and loss in the APP/PS1 mouse model of AD. Unexpectedly, we observed a dramatic increase in the rate of new myelin formation in APP/PS1 mice, reminiscent of the robust oligodendroglial response to demyelination. Despite this increase, overall levels of myelination are decreased in the cortex and hippocampus of APP/PS1 mice and postmortem AD tissue. Genetically or pharmacologically enhancing myelin renewal, by oligodendroglial deletion of the muscarinic M1 receptor or systemic administration of the pro-myelinating drug clemastine, improved the performance of APP/PS1 mice in memory-related tasks and increased hippocampal sharp wave ripples. Taken together, these results demonstrate the potential of enhancing myelination as a therapeutic strategy to alleviate AD-related cognitive impairment.
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http://dx.doi.org/10.1016/j.neuron.2021.05.012DOI Listing
June 2021

AZ32 Reverses ABCG2-Mediated Multidrug Resistance in Colorectal Cancer.

Front Oncol 2021 20;11:680663. Epub 2021 May 20.

Department of Cell Biology & Institute of Biomedicine, National Engineering Research Center of Genetic Medicine, MOE Key Laboratory of Tumor Molecular Biology, Guangdong Provincial Key Laboratory of Bioengineering Medicine, College of Life Science and Technology, Jinan University, Guangzhou, China.

Colorectal cancer is a common malignancy with the third highest incidence and second highest mortality rate among all cancers in the world. Chemotherapy resistance in colorectal cancer is an essential factor leading to the high mortality rate. The ATP-binding cassette (ABC) superfamily G member 2 (ABCG2) confers multidrug resistance (MDR) to a range of chemotherapeutic agents by decreasing their intracellular content. The development of novel ABCG2 inhibitors has emerged as a tractable strategy to circumvent drug resistance. In this study, an ABCG2-knockout colorectal cancer cell line was established to assist inhibitor screening. Additionally, we found that ataxia-telangiectasia mutated (ATM) kinase inhibitor AZ32 could sensitize ABCG2-overexpressing colorectal cancer cells to ABCG2 substrate chemotherapeutic drugs mitoxantrone and doxorubicin by retaining them inside cells. Western blot assay showed that AZ32 did not alter the expression of ABCG2. Moreover, molecule docking analysis predicted that AZ32 stably located in the transmembrane domain of ABCG2. In conclusion, our result demonstrated that AZ32 could potently reverse ABCG2-mediated MDR in colorectal cancer.
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http://dx.doi.org/10.3389/fonc.2021.680663DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8173085PMC
May 2021

Diel variation of CH emission fluxes in a small artificial lake: Toward more accurate methods of observation.

Sci Total Environ 2021 Aug 16;784:147146. Epub 2021 Apr 16.

China Institute of Water Resources and Hydropower Research, Beijing 100038, China.

Lakes are significant sources in global methane (CH) budgets. However, estimations of the magnitude of global CH emissions from lakes may be highly biased owing to the uncertainties in data originating from observation times, methods, and parameterizations of the gas transfer velocity (k). Here, we conducted continuous 48-hour measurements of CH fluxes using the floating chamber method seasonally at Lake Baihua, a small reservoir in southwestern China, and compared the results with estimates derived from boundary layer models. Results showed that there was a weak dependency of k on wind speed, indicating that wind speed was not the major factor regulating gas exchange in such small lakes. It is thus concluded that the wind speed-dependent boundary layer model method is not suitable for CH flux observations in small and medium-sized lake, and that the floating chamber method is recommended for use instead. The measured CH fluxes displayed remarkably diurnal patterns, therefore the use of single observations to represent daily average values comes with unacceptably large uncertainties. A reasonable alternative is averaging observations made at sunrise and at sunset to represent daily values, which has a much smaller uncertainty (ranging from 0.8% to 13.6%). The coincident peaks of CH and chlorophyll concentrations in the subsurface indicate that CH originated mainly from aerobic methanogenesis. Solar radiation is likely one of the major factors regulating CH production and emissions in the lake through enhancing CH production, inhibiting CH oxidation, and probably changing hydrodynamics conditions. Therefore, irradiation should be taken into consideration as a key factor in observing CH fluxes in lakes. As sampling times are limited, observations during both sunny and cloudy weather should be proportionally included. This is the first time, to the best of our knowledge, that solar radiation has been proposed as a key driver of CH emissions from lakes.
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http://dx.doi.org/10.1016/j.scitotenv.2021.147146DOI Listing
August 2021

θ-Solvent-Mediated Double-Shell Polyethylene Glycol Brushes on Nanoparticles for Improved Stealth Properties and Delivery Efficiency.

J Phys Chem Lett 2021 Jun 2;12(22):5363-5370. Epub 2021 Jun 2.

State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China.

Antifouling polymer brushes are widely used to inhibit the formation of protein corona on nanoparticles (NPs) and subsequent accumulation in the liver and spleen. Herein, we demonstrate a θ-solvent-mediated method for the preparation of gold nanoparticles with a high polyethylene glycol (PEG) grafting density. Reaching the θ-solvent by adding salt (e.g., NaSO) can significantly increase the grafting density of the PEG brush to 2.08 chains/nm. The PEG polymer brush prepared in the θ-solvent possesses a double-shell structure consisting of a concentrated polymer brush (CPB) and a semidilute polymer brush (SDPB), denoted as [email protected]@SDPB, while those prepared in a good solvent have only a SDPB shell, i.e., [email protected] Compared to the [email protected] structure, the [email protected]@SDPB structure decreases the liver accumulation from 34.0%ID/g to 23.1%ID/g, leading to an increase in tumor accumulation from 8.5%ID/g to 12.8%ID/g. This work provides new insights from the perspective of polymer physical chemistry into the improved stealth properties and delivery efficiency of NPs, which will accelerate the clinical translation of nanomedicine.
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http://dx.doi.org/10.1021/acs.jpclett.1c01291DOI Listing
June 2021

Homocysteine induces podocyte apoptosis by regulating miR-1929-5p expression through c-Myc, DNMT1 and EZH2.

Mol Oncol 2021 May 31. Epub 2021 May 31.

School of Basic Medical Sciences, Ningxia Medical University, Yinchuan, 750004, China.

Chronic kidney disease (CKD) is a common and complex disease in kidneys which has been associated with an increased risk of renal cell carcinoma (RCC). Elevated homocysteine (Hcy) levels are known to influence the development and progression of CKD by regulating podocyte injury and apoptosis. To investigate the molecular mechanisms triggered in podocytes by Hcy, we used cbs mice and observed that higher Hcy levels increased the apoptosis rate of podocytes with accompanied glomerular damage. Hcy-induced podocyte injury and apoptosis in cbs mice was regulated by inhibition of miR-1929-5p expression. Overexpression of miR-1929-5p in podocytes inhibited apoptosis by upregulating Bcl-2. Furthermore, the expression of miR-1929-5p was regulated by epigenetic modifications of its promoter. Hcy upregulated DNA methytransferase 1 (DNMT1) and enhancer of zeste homolog 2 (EZH2) levels resulting in increased DNA methylation and H3K27me3 levels on the miR-1929-5p promoter. Additionally, we observed that c-Myc recruited DNMT1 and EZH2 to the miR-1929-5p promoter and suppressed the expression of miR-1929-5p. In summary, we demonstrated that Hcy promotes podocyte apoptosis through the regulation of the epigenetic modifiers DNMT1 and EZH2, which are recruited by c-Myc to the promoter of miR-1929-5p to silence miR-1929-5p expression.
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http://dx.doi.org/10.1002/1878-0261.13032DOI Listing
May 2021

Effect of Nitrogen Addition on Selection of Germination Trait in an Alpine Meadow on the Tibet Plateau.

Front Plant Sci 2021 14;12:634850. Epub 2021 May 14.

State Key Laboratory of Grassland and Agro-Ecosystems, School of Life Sciences, Lanzhou University, Lanzhou, China.

Seed germination requirements may determine the kinds of habitat in which plants can survive. We tested the hypothesis that nitrogen (N) addition can change seed germination trait-environmental filter interactions and ultimately redistribute seed germination traits in alpine meadows. We determined the role of N addition on germination trait selection in an alpine meadow after N addition by combining a 3-year N addition experiment in an alpine meadow and laboratory germination experiments. At the species level, germination percentage, germination rate (speed) and breadth of temperature niche for germination (BTN) were positively related to survival of a species in the fertilized community. In addition, community-weighted means of germination percentage, germination rate, germination response to alternating temperature and BTN increased. However, germination response to wet-cold storage (cold stratification) and functional richness of germination traits was lower in alpine meadows with high-nitrogen addition than in those with no, low and medium N addition. Thus, N addition had a significant influence on environmental filter-germination trait interactions and generated a different set of germination traits in the alpine meadow. Further, the effect of N addition on germination trait selection by environmental filters was amount-dependent. Low and medium levels of N addition had less effect on redistribution of germination traits than the high level.
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http://dx.doi.org/10.3389/fpls.2021.634850DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8160428PMC
May 2021

Ivacaftor Inhibits Glioblastoma Stem Cell Maintenance and Tumor Progression.

Front Cell Dev Biol 2021 11;9:678209. Epub 2021 May 11.

Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Kunming, China.

Glioblastoma (GBM) is the most common and malignant primary brain tumor. Glioblastoma stem cells (GSCs) not only initiate and sustain uncontrolled cell proliferation but also resistant to conventional clinical therapies including temozolomide (TMZ) dependent chemotherapy and radiotherapy, implying that there is an urgent need to identify new therapeutic strategies especially specific targeting GSCs. Here, we provide evidence showing that ivacaftor commonly applied in cystic fibrosis therapy acts as a potent inhibitor for GSCs maintenance. We found that ivacaftor promotes cellular apoptosis and represses patient-derived xenograft (PDX) tumor growth . In addition, we demonstrate that ivacaftor decreases stemness marker gene expressions of GSCs, including CD133, CD44, and Sox2. In summary, our findings reveal that ivacaftor inhibits glioblastoma progression via specifically eliminating GSCs, which opens a new avenue for GBM clinical therapy in the future.
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http://dx.doi.org/10.3389/fcell.2021.678209DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8147559PMC
May 2021

Sustainable preparation of bifunctional cellulose nanocrystals via mixed HSO/formic acid hydrolysis.

Carbohydr Polym 2021 Aug 24;266:118107. Epub 2021 Apr 24.

Tianjin Key Laboratory of Pulp and Paper, Tianjin University of Science and Technology, Tianjin 300457, China. Electronic address:

In this work, a sustainable and highly efficient approach for preparing bifunctional cellulose nanocrystals (CNCs) was proposed through a mixed acid system of sulfuric acid and formic acid (FA). It was found that low-concentration (5-10 wt%) sulfuric acid can significantly improve the hydrolysis efficiency of FA (65-80 wt%), which enabled the highly efficient preparation of CNCs, i.e., the maximum yield of CNCs reached up to 70.65%. The obtained CNCs exhibited a rod-like shape with high crystallinity, and good dispersibility in both water and some organic phases. Moreover, the as-prepared CNCs exhibited high thermal stability, which is much higher than that of the traditionally sulfuric acid hydrolyzed ones. In addition, it was demonstrated that the bifunctional CNCs were able to stabilize various oils to form stable Pickering emulsion gels. Thus, this work provides a promising approach for sustainable preparation of bifunctional CNCs, which may find high-end applications in diverse fields.
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http://dx.doi.org/10.1016/j.carbpol.2021.118107DOI Listing
August 2021

Clinical assessment of pterygoid and anterior implants in the atrophic edentulous maxilla: a retrospective study.

Hua Xi Kou Qiang Yi Xue Za Zhi 2021 Jun;39(3):286-292

Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University & Dept. of Dental Implantology, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, China.

Objectives: This study aims to evaluate the short-term clinical outcomes and patient satisfaction of anterior and pterygoid implants in the rehabilitation of edentulous maxilla with posterior atrophy.

Methods: Given a minimum follow-up of 1 year, 25 patients with fixed maxillary rehabilitation over anterior and pterygoid implants were enrolled in this retrospective study. The implant survival rates, peri-implant soft tissue status (including probing depth, modified sulcus bleeding index, and plaque index), marginal bone loss, and patient satisfaction were measured.

Results: The survival rates for anterior and pterygoid implants at 1-year follow-up were 96.5% and 97.8%, respectively (>0.05). No statistically significant difference in probing depth, modified sulcus bleeding index, and plaque index was observed between the two types of implants (>0.05). The marginal bone losses of anterior implants were 0.62 mm± 0.44 mm (mesial) and 0.61 mm± 0.40 mm (distal), and those of pterygoid implants were 0.64 mm± 0.46 mm (mesial) and 0.68 mm± 0.41 mm (distal) mm. These results showed no statistical difference in mesial and distal sites (>0.05). Patients indicated a high degree of satisfaction with the full-arch prostheses supported by anterior and pterygoid implants.

Conclusions: For the edentulous maxilla with posterior atrophy, full-arch fixed prostheses supported by anterior and pterygoid implants has an acceptable short-term clinical outcome and excellent patient satisfaction. It may be considered as a predictable and feasible method for maxillary rehabilitation.
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http://dx.doi.org/10.7518/hxkq.2021.03.007DOI Listing
June 2021

Value of neutrophil-to-lymphocyte ratio as a marker of renal damage in patients with H-type hypertension.

Biomark Med 2021 Jun 27;15(9):637-646. Epub 2021 May 27.

Hunan University of Traditional Chinese Medicine, Changsha, Hunan, China.

To explore the relationship between the neutrophil-to-lymphocyte ratio (NLR) and renal damage in patients with H-type hypertension. A total of 618 patients between 2017 and 2019 were analyzed retrospectively. NLR was significantly correlated with renal damage in hypertension patients. Appropriate cut-off value for NLR (2.247) was determined by receiver operating characteristic curve; linear regression analysis showed that NLR and estimated glomerular filtration rate, blood urea nitrogen/creatinine has a significant negative correlation in H-type hypertension group (p < 0.05); logistic regression analysis showed that the risk of renal damage increased by 10% for each 1 umol/l increase of homocysteine, and 51% for each 1.0 increase of NLR in H-type hypertension patients. NLR worth popularizing in prediction of renal damage in patients with H-type hypertension.
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http://dx.doi.org/10.2217/bmm-2020-0638DOI Listing
June 2021

Boosting oxygen reduction activity and enhancing stability through structural transformation of layered lithium manganese oxide.

Nat Commun 2021 May 25;12(1):3136. Epub 2021 May 25.

Shanghai Key Laboratory for R&D and Application of Metallic Functional Materials, Institute of New Energy for Vehicles, School of Materials Science and Engineering, Tongji University, Shanghai, China.

Structural degradation in manganese oxides leads to unstable electrocatalytic activity during long-term cycles. Herein, we overcome this obstacle by using proton exchange on well-defined layered LiMnO with an O3-type structure to construct protonated LiHMnO with a P3-type structure. The protonated catalyst exhibits high oxygen reduction reaction activity and excellent stability compared to previously reported cost-effective Mn-based oxides. Configuration interaction and density functional theory calculations indicate that LiHMnO has fewer unstable O 2p holes with a Mn valence state and a reduced interlayer distance, originating from the replacement of Li by H. The former is responsible for the structural stability, while the latter is responsible for the high transport property favorable for boosting activity. The optimization of both charge states to reduce unstable O 2p holes and crystalline structure to reduce the reaction pathway is an effective strategy for the rational design of electrocatalysts, with a likely extension to a broad variety of layered alkali-containing metal oxides.
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http://dx.doi.org/10.1038/s41467-021-23430-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8149866PMC
May 2021

Architecturing 1D-2D-3D Multidimensional Coupled CsPbI Br Perovskites toward Highly Effective and Stable Solar Cells.

Small 2021 May 25:e2100888. Epub 2021 May 25.

Institute of New Energy Technology, Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou, 510632, China.

Despite the rapid development of CsPbI Br (0 ≤ x ≤ 3) inorganic perovskite solar cells, associated with their superior thermal stability, their low moisture stability limits their commercial deployment. In this study, 1D-2D-3D multidimensional coupled perovskites are prepared by means of an in situ self-integration approach. This pioneering method allows incorporating thus far unreported 1D-Tpy Pb I and 2D-TpyPb I (Tpy; terpyridine) perovskites. Heterojunction perovskites demonstrate superior stability against water in comparison with control 3D CsPbI Br, which is related to the hydrophobicity of low-dimension (LD) perovskites. Remarkably, the spontaneous involvement of LD perovskites can adjust/reconstruct the interfacial structure. This modification allows releasing the residual strain, establishing effective charge transfer channels that increase the carrier transport ability. Accordingly, 1D-2D-3D hybrid CsPbI Br perovskite solar cells demonstrate a stabilized power conversion efficiency as high as 16.1%, which represents a very significant improvement, by a factor of 43%, with respect to control 3D CsPbI Br perovskite solar cell. Equally importantly, the multidimensional coupled perovskite solar cells exhibit extraordinary stability, well above 1000 h in ambient atmosphere.
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http://dx.doi.org/10.1002/smll.202100888DOI Listing
May 2021

Upper Critical Solution Temperature-Type Responsive Cyclodextrins with Characteristic Inclusion Abilities.

Chemistry 2021 May 18. Epub 2021 May 18.

International Joint Laboratory of Biomimetic and Smart Polymers, School of Materials Science and Engineering, Shanghai University, Materials Building Room 801, Nanchen Street 380, Shanghai, 200444, P. R. China.

Water-soluble and thermoresponsive macrocycles with stable inclusion toward guests are highly valuable to construct stimuli-responsive supramolecular materials for versatile applications. Here, we develop such macrocycles - ureido-substituted cyclodextrins (CDs) which exhibit unprecedented upper critical solution temperature (UCST) behavior in aqueous media. These novel CD derivatives showed good solubility in water at elevated temperature, but collapsed from water to form large coacervates upon cooling to low temperature. Their cloud points are greatly dependent on concentration and can be mediated through oxidation and chelation with silver ions. Significantly, the amphiphilicity of these CD derivatives is supportive to host-guest binding, which affords them inclusion abilities to guest dyes. The inclusion complexation remained nearly intact during thermally induced phase transitions, which is in contrast to the switchable inclusion behavior of lower critical solution temperature (LCST)-type CDs. Moreover, ureido-substituted CDs were exploited to co-encapsulate a pair of guest dyes whose fluorescence resonance energy transfer process can be switched by the UCST phase transition. We therefore believe these novel thermoresponsive CDs may form a new strategy for developing smart macrocycles and allow for exploring smart supramolecular materials.
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http://dx.doi.org/10.1002/chem.202101283DOI Listing
May 2021

Intravitreal conbercept for diabetic macular oedema: 2-year results from a randomised controlled trial and open-label extension study.

Br J Ophthalmol 2021 May 17. Epub 2021 May 17.

Department of Ophthalmology (aka National Clinical Research Center for Eye Diseases), Shanghai General Hospital, Shanghai, China

Background: To demonstrate the efficacy and safety of intravitreal injections of conbercept versus laser photocoagulation in the treatment of diabetic macular oedema (DME).

Methods: A 12-month multicentre, randomised, double-masked, double-sham, parallel controlled, phase III trial (Sailing Study), followed by a 12-month open-label extension study. Patients with centre-involved DME were randomly assigned to receive either laser photocoagulation followed by pro re nata (PRN) sham intravitreal injections (laser/sham) or sham laser photocoagulation followed by PRN 0.5 mg conbercept intravitreal injections (sham/conbercept). Patients who entered the extension study received PRN conbercept treatment. The primary endpoint was the changes in best-corrected visual acuity (BCVA) from baseline.

Results: A total of 248 eyes were included in the full analysis set and 157 eyes continued in the extension study. Significant improvement in mean change in BCVA from baseline to month 12 was observed in the sham/conbercept group (8.2±9.5 letters), whereas no improvement was observed in the laser/sham group (0.3±12.0 letters). Patients in the laser/sham group showed a marked improvement in BCVA after the switch to conbercept in the extension study, and there was no difference in BCVA between the two groups at the end of the extension study.

Conclusion: The use of a conbercept PRN intravitreal injection regimen improved the BCVA of patients with DME, and its efficacy was better than that of laser photocoagulations, and the same efficacy was observed when the eyes treated with laser alone were switched to conbercept.

Trial Registration Number: NCT02194634.
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http://dx.doi.org/10.1136/bjophthalmol-2020-318690DOI Listing
May 2021

Fibrinogen-like protein 2 contributes to normal murine cardiomyocyte maturation and heart development.

Exp Physiol 2021 May 16. Epub 2021 May 16.

Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.

New Findings: What is the central question of this study? What is the role of fibrinogen-like protein 2 (FGL2) in murine cardiomyocyte maturation? What is the main finding and its importance? This is the first study showing both global Fgl2 knockout and cardiac-specific FGL2 deletion trigger early death and dilated cardiomyopathy. By using an adeno-associated virus (AAV)-mediated CRISPR/Cas9-based somatic mutagenesis system, it was demonstrated that cardiac-specific FGL2 depletion induces ventricular dilatation and remodelling, and disrupts the normal hypertrophic growth and polyploidization of cardiomyocytes. In addition, it was shown that modulation of signal transducer and activator of transcription 3, extracellular signal-regulated kinases 1 and 2 and fibroblast growth factor 2 signalling is associated with loss-of-FGL2-mediated cardiac dysfunction. These results suggest FGL2 is an important determinant of cardiomyocyte maturation.

Abstract: In the first few weeks after birth in altricial mammals, postnatal cardiomyocytes (CMs) undergo dramatic changes, including cell volume enlargement, cell cycle withdrawal and polyploidization to become mature CMs. Aberrations in this process could disrupt the essential contractility and synchronization of adult CMs, leading to various heart diseases. However, the mechanism of CM maturation is poorly understood. Fibrinogen-like protein 2 (FGL2) is an immune coagulant which participates in maturation of multiple cell types. However, little evidence exists regarding a role of FGL2 in CM maturation. In this study, we observed that global Fgl2 pups had high lethality and suffered from cardiac dysfunction before P28. To further confirm the phenotype and study the mechanisms upon FGL2 deficiency, we used an adeno-associated virus (AAV)-mediated CRISPR/Cas9-based somatic mutagenesis system to generate loss-of-function mutations of Fgl2 specifically in CMs. We designed two guide RNAs (gRNAs) exclusively targeting Fgl2 exon1 and produced Fgl2-gRNA AAV9 to deliver to neonatal Cas9 mice. Here, we demonstrated the efficient FGL2 depletion in the heart after Fgl2-gRNA AAV9 delivery. Consistent with the findings in global Fgl2 mice, we observed AAV9-mediated FGL2 depletion triggered early death and dilated cardiomyopathy. In addition, FGL2 depletion perturbed the normal hypertrophic growth and polyploidization of maturing CMs. Furthermore, we found modulation of signal transducer and activator of transcription 3, extracellular signal-regulated kinases 1 and 2 and fibroblast growth factor 2 signalling was associated with FGL2 deficiency-mediated cardiac dysfunction. Here, we demonstrate the successful depletion of FGL2 in maturing CMs in vivo and show FGL2 is an important determinant for normal CM maturation.
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http://dx.doi.org/10.1113/EP089450DOI Listing
May 2021

Polymers via Reversible Addition-Fragmentation Chain Transfer Polymerization with High Thiol End-Group Fidelity for Effective Grafting-To Gold Nanoparticles.

J Phys Chem Lett 2021 May 13;12(19):4713-4721. Epub 2021 May 13.

State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P.R. China.

End-group fidelity is the most important property for end-functional polymers. Compared to other controlled living polymerization methods, reversible addition-fragmentation chain transfer (RAFT) polymerization often yields polymers with a lower end-group fidelity, which greatly affects their applications. Herein, we report a staged-thermal-initiation RAFT polymerization for the synthesis of polymers with high thiol end-group fidelity and their high efficiencies for grafting to various gold nanoparticles (GNPs). We experimentally prove that the decrease of end-group fidelity with their molecular weight is caused by the gradual decomposition of the initiator rather than the degradation of chain-transfer agents. We show that the staged-thermal-initiation RAFT polymerization is more effective for synthesis of polymers with high thiol end-group fidelity. The grafting-to assays for various GNPs illustrate the positive correlation between the end-group fidelity of polymers and grafting-to efficiency. This work highlights the prospects for synthesis of high end-group fidelity polymers and their application in the preparation of nanoparticles-polymer hybrid materials.
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http://dx.doi.org/10.1021/acs.jpclett.1c01039DOI Listing
May 2021

Exosomes from Adipose Mesenchymal Stem Cells Overexpressing Stanniocalcin-1 Promote Reendothelialization After Carotid Endarterium Mechanical Injury.

Stem Cell Rev Rep 2021 May 12. Epub 2021 May 12.

Department of Vascular Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China.

Objective: Stanniocalcin-1 (STC-1) is a secreted glycoprotein that participates in the regulation of inflammation, apoptosis, and necrosis. We investigated the reendothelialization effect of exosomes from adipose stem cells (ADSC) overexpressing STC-1 on injured carotid endarterium.

Methods: ADSCs were transfected with lentivirus vectors containing pre-STC-1. PHK-26 as molecular probe was used to track the exosomes engulfed by mice arterial endothelial cells (MAEC). The role of STC-1-ADSC-Exosome (S-ADSC-Exo) in MAECs was verified through scratch test and tube forming. Expressions of STC-1 and NLRP3 inflammasome were detected by western blot and quantitative reverse transcription polymerase chain reaction. Reendothelialization effect was inhibited by the antagonist of siRNA targeting STC-1. Carotid endarterium mechanical injury was induced by insertion with a guidewire into the common carotid artery lumen. Carotid arteries were harvested for histological examination, immunofluorescence staining, and Evan's blue staining.

Results: Transfection of STC-1 significantly enhanced STC-1 levels in ADSCs, their exosomes, and MAECs. Compared with the control group and the ADSC-Exo group, STC-1 enriched exosomes markedly inhibited the expressions of NLRP3, Caspase-1, and IL-1β in MAECs, exhibited good lateral migration capacity, and promoted angiogenesis. Administration of siRNA targeting STC-1 completely abolished down-regulation of NLRP3, Caspase-1, and IL-1β by STC-1 and inhibited effects of S-ADSC-Exo on lateral migration and angiogenesis. In vivo administration of S-ADSC-Exo had reendothelialization effect on post-injury carotid endarterium as evidenced by thinner arterial wall, low-expressed NLRP3 inflammasome, and more living endothelial cells.

Conclusions: The reendothelialization effect of exosomes from ADSCs on post-injury carotid endarterium could be enhanced by genetic modification of the exosomes to contain elevated STC-1, possibly through suppression of NLRP3 inflammasome-mediated inflammation.
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http://dx.doi.org/10.1007/s12015-021-10180-4DOI Listing
May 2021

Combined detection of circulating tumor cells, α-fetoprotein heterogene-3 and α-fetoprotein in the early diagnosis of HCC for the prediction of efficacy, prognosis, recurrence after microwave ablation.

Infect Agent Cancer 2021 May 10;16(1):28. Epub 2021 May 10.

Biological Cell Therapy Research Center, Puren Hospital Affiliated to Wuhan University of Science and Technology, 430081, Wuhan, China.

Background: Early diagnosis can significantly improve treatment outcomes for hepatocellular carcinoma (HCC) patients. Currently, the dosage of serum alpha fetoprotein (AFP) is widely used in the diagnosis of HCC, but this biomarker has low specificity and may cause false positive or false negative results. Thus, it's necessary to find and validate other serum tumor markers that in association for AFP would increase the sensitivity and the specificity in the HCC diagnosis. This study investigated the predictive value of combined of AFP, AFP-L3, and Circulating tumor cells (CTCs).

Methods: A total of 105 patients with HCC after microwave ablation (MWA) were divided into non recurrence group, recurrence group, good prognosis (CR + PR group, CR: Complete remission, PR: Partial remission) and poor prognosis (SD + PD group, SD: Stable, PD: Progression). ROC curve was used to analyze the short-term efficacy, prognosis and clinical value of combined detection of the three indicators in predicting postoperative recurrence of HCC patients with MWA.

Results: The positive rate of serum CTCs, AFP-L3 and AFP combined detection in the diagnosis of HCC is higher than that of single index and two index detection. The AUC, sensitivity and specificity of serum CTCs, AFP-L3 and AFP combined detection was better than that of single index and two indexes in patients with HCC after MWA.

Conclusions: Combined detection of AFP, AFP-L3, and CTCs can effectively make up for the shortcomings of the detection with single and pairwise indicators. It can't only diagnose HCC in early, but also has a high clinical value of predicting the short-term efficacy, prognosis and recurrence of HCC patients after MWA treatment.
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http://dx.doi.org/10.1186/s13027-021-00367-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8111940PMC
May 2021

Epidemiology and evolution of Middle East respiratory syndrome coronavirus, 2012-2020.

Infect Dis Poverty 2021 May 8;10(1):66. Epub 2021 May 8.

State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, 20 Dong-Da Street, Fengtai District, Beijing, 100071, People's Republic of China.

Background: The ongoing transmission of the Middle East respiratory syndrome coronavirus (MERS-CoV) in the Middle East and its expansion to other regions are raising concerns of a potential pandemic. An in-depth analysis about both population and molecular epidemiology of this pathogen is needed.

Methods: MERS cases reported globally as of June 2020 were collected mainly from World Health Organization official reports, supplemented by other reliable sources. Determinants for case fatality and spatial diffusion of MERS were assessed with Logistic regressions and Cox proportional hazard models, respectively. Phylogenetic and phylogeographic analyses were performed to examine the evolution and migration history of MERS-CoV.

Results: A total of 2562 confirmed MERS cases with 150 case clusters were reported with a case fatality rate of 32.7% (95% CI: 30.9‒34.6%). Saudi Arabia accounted for 83.6% of the cases. Age of ≥ 65 years old, underlying conditions and ≥ 5 days delay in diagnosis were independent risk factors for death. However, a history of animal contact was associated with a higher risk (adjusted OR = 2.97, 95% CI: 1.10-7.98) among female cases < 65 years but with a lower risk (adjusted OR = 0.31, 95% CI: 0.18-0.51) among male cases ≥ 65 years old. Diffusion of the disease was fastest from its origin in Saudi Arabia to the east, and was primarily driven by the transportation network. The most recent sub-clade C5.1 (since 2013) was associated with non-synonymous mutations and a higher mortality rate. Phylogeographic analyses pointed to Riyadh of Saudi Arabia and Abu Dhabi of the United Arab Emirates as the hubs for both local and international spread of MERS-CoV.

Conclusions: MERS-CoV remains primarily locally transmitted in the Middle East, with opportunistic exportation to other continents and a potential of causing transmission clusters of human cases. Animal contact is associated with a higher risk of death, but the association differs by age and sex. Transportation network is the leading driver for the spatial diffusion of the disease. These findings how this pathogen spread are helpful for targeting public health surveillance and interventions to control endemics and to prevent a potential pandemic.
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http://dx.doi.org/10.1186/s40249-021-00853-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8105704PMC
May 2021

Biodegradability of Micro/Nanomotors: Challenges and Opportunities.

Adv Healthc Mater 2021 May 6:e2100335. Epub 2021 May 6.

School of Pharmaceutical Sciences, Guangdong Provincial Key Laboratory of New Drug Screening, Southern Medical University, Guangzhou, 510515, China.

Micro/nanomotors (MNMs) are miniature machines that can convert chemical or external energy into their own mechanical motions. In previous decades, significant efforts have been made to improve the performance of MNMs. For practical applications, the biodegradability of MNMs is an important aspect that must be considered, particularly in the biomedical field. In this review, recent progress in the biodegradability of MNMs and their potential applications are summarized. Different biodegradable materials, including metals and polymers, or other strategies for the fabrication of MNMs, are presented. Current challenges and future perspectives are also discussed.
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http://dx.doi.org/10.1002/adhm.202100335DOI Listing
May 2021

Spectroscopically clean Au nanoparticles for catalytic decomposition of hydrogen peroxide.

Sci Rep 2021 May 6;11(1):9709. Epub 2021 May 6.

Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, NJ, 07030, USA.

Au nanoparticles synthesized from colloidal techniques have the capability in many applications such as catalysis and sensing. Au nanoparticles function as both catalyst and highly sensitive SERS probe can be employed for sustainable and green catalytic process. However, capping ligands that are necessary to stabilize nanoparticles during synthesis are negative for catalytic activity. In this work, a simple effective mild thermal treatment to remove capping ligands meanwhile preserving the high SERS sensitivity of Au nanoparticles is reported. We show that under the optimal treatment conditions (250 °C for 2 h), 50 nm Au nanoparticles surfaces are free from any capping molecules. The catalytic activity of treated Au nanoparticles is studied through HO decomposition, which proves that the treatment is favorable for catalytic performance improvement. A reaction intermediate during HO decomposition is observed and identified.
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http://dx.doi.org/10.1038/s41598-021-89235-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8102470PMC
May 2021

The RhHB1/RhLOX4 module affects the dehydration tolerance of rose flowers (Rosa hybrida) by fine-tuning jasmonic acid levels.

Hortic Res 2020 May 2;7(1):74. Epub 2020 May 2.

Department of Ornamental Horticulture, College of Horticulture, China Agricultural University, Beijing, 100193, China.

Phytohormones are key factors in plant responsiveness to abiotic and biotic stresses, and maintaining hormone homeostasis is critically important during stress responses. Cut rose (Rosa hybrida) flowers experience dehydration stress during postharvest handling, and jasmonic acid (JA) levels change as a result of this stress. However, how JA is involved in dehydration tolerance remains unclear. We investigated the functions of the JA- and dehydration-induced RhHB1 gene, which encodes a homeodomain-leucine zipper I γ-clade transcription factor, in rose flowers. Silencing RhHB1 decreased petal dehydration tolerance and resulted in a persistent increase in JA-Ile content and reduced dehydration tolerance. An elevated JA-Ile level had a detrimental effect on rose petal dehydration tolerance. RhHB1 was shown to lower the transient induction of JA-Ile accumulation in response to dehydration. In addition to transcriptomic data, we obtained evidence that RhHB1 suppresses the expression of the lipoxygenase 4 (RhLOX4) gene by directly binding to its promoter both in vivo and in vitro. We propose that increased JA-Ile levels weaken the capacity for osmotic adjustment in petal cells, resulting in reduced dehydration tolerance. In conclusion, a JA feedback loop mediated by an RhHB1/RhLOX4 regulatory module provides dehydration tolerance by fine-tuning bioactive JA levels in dehydrated flowers.
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http://dx.doi.org/10.1038/s41438-020-0299-zDOI Listing
May 2020

Mycoplasma pneumoniae infection and risk of childhood asthma: A systematic review and meta-analysis.

Microb Pathog 2021 Jun 29;155:104893. Epub 2021 Apr 29.

Pediatrics, Nanjing Integrated Traditional |Chinese and Western Medicine Hospital, Nanjing City, Jiangsu province, 211800, China. Electronic address:

The etiology of childhood asthma is multifactorial, atypical bacterial pathogens, including Mycoplasma pneumoniae, have been proposed as possible risk factors or contributors. This review aims to assess the possible association between M. pneumoniae infection and childhood asthma. We searched major international literature databases (up to January 10, 2021) to identify relevant studies. We used a random-effects meta-analysis (REM) model to generate the pooled odds ratio (OR) and 95% confidence intervals (CIs). Several subgroups analyses were performed concerning the IgG, IgM, and DNA detection of M. pneumoniae infection. We included 22 eligible studies; these studies involved a total of 5064 children. We found that there was a statistically significant association between M. pneumoniae infection, as determined by IgM serology (OR, 3.13; 95% CI, 1.78-5.48), and DNA detection (OR, 1.57; 95% CI, 1.25-1.97) with increased risk of any type of childhood asthma. Moreover, children with acute asthma had significantly higher seropositivity for anti- M. pneumoniae IgM antibodies (OR, 4.43; 95% CI, 2.80-7.02) than children with stable asthma. Although our findings indicate a positive association between M. pneumoniae infection and childhood asthma, well-designed and -controlled studies are need in the future to rigorously test this association and identify the underlying mechanisms.
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http://dx.doi.org/10.1016/j.micpath.2021.104893DOI Listing
June 2021

PINK1-mediated mitophagy maintains pluripotency through optineurin.

Cell Prolif 2021 May;54(5):e13034

State Key Laboratory of Stem Cell and Reproductive Biology, Institute for Stem Cell and Regeneration, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.

Objectives: Dysfunction of autophagy results in accumulation of depolarized mitochondria and breakdown of self-renewal and pluripotency in ESCs. However, the regulators that control how mitochondria are degraded by autophagy for pluripotency regulation remains largely unknown. This study aims to dissect the molecular mechanisms that regulate mitochondrial homeostasis for pluripotency regulation in mouse ESCs.

Materials And Methods: Parkin and parkin ESCs were established from E3.5 blastocysts of parkin x parkin mating mice. The pink1 , optn and ndp52 ESCs were generated by CRISPR-Cas9. shRNAs were used for function loss assay of target genes. Mito-Keima, ROS and ATP detection were used to investigate the mitophagy and mitochondrial function. Western blot, Q-PCR, AP staining and teratoma formation assay were performed to evaluate the PSC stemness.

Results: PINK1 or OPTN depletion impairs the degradation of dysfunctional mitochondria during reprogramming, and reduces the reprogramming efficiency and quality. In ESCs, PINK1 or OPTN deficiency leads to accumulation of dysfunctional mitochondria and compromised pluripotency. The defective mitochondrial homeostasis and pluripotency in pink1 ESCs can be compensated by gain expression of phosphomimetic Ubiquitin (Ub-S65D) together with WT or a constitutively active phosphomimetic OPTN mutant (S187D, S476D, S517D), rather than constitutively inactive OPTN (S187A, S476A, S517A) or a Ub-binding dead OPTN mutant (D477N).

Conclusions: The mitophagy receptor OPTN guards ESC mitochondrial homeostasis and pluripotency by scavenging damaged mitochondria through TBK1-activated OPTN binding of PINK1-phosphorylated Ubiquitin.
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http://dx.doi.org/10.1111/cpr.13034DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8088463PMC
May 2021

The role of E26 transformation-specific variant transcription factor 5 in colorectal cancer cell proliferation and cell cycle progression.

Cell Death Dis 2021 Apr 30;12(5):427. Epub 2021 Apr 30.

Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 200025, Shanghai, China.

E26 transformation-specific variant transcription factor 5 (ETV5) contributes to tumor growth and progression and promotes colorectal cancer (CRC) angiogenesis. Previous studies indicate that ETV5 may regulate the cell cycle, but its detailed mechanism remain unclear. Gene Ontology (GO) analysis of RNA-seq data revealed that ETV5 possibly regulates the cell cycle in CRC. Here, in vitro and in vivo experiments were performed to verify that ETV5 promoted tumor progression and influenced cell cycle G1/S transition. Cell cycle PCR array and co-immunoprecipitation (Co-IP) helped identify the p21-CDKs pathway. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays were performed to determine whether ETV5 binds to the p21 promoter. ETV5 and p21 were detected by immunohistochemistry, and the effects of their expression on CRC patients were evaluated. ETV5 upregulation enhanced tumor proliferative capacity and promoted G1 phase transfer to the S phase. ETV5 knockdown slowed the growth of CRC cells and repressed the G1/S transition. We also found p21 as a downstream target of ETV5. p21 knockdown resulted in faster CRC cell growth and in more cells being driven from the G0/1 phase into the S phase. Co-IP experiments showed that p21 banding to CDK2, CDK4, and CDK6 inhibited p130 phosphorylation. Using the ChIP and luciferase reporter assay, we confirmed that ETV5 bound to the p21 promoter and repressed p21 expression. CRC patients with high ETV5 expression and low p21 expression showed the worst prognosis. Finally, by targeting p21 to regulate CDK function, ETV5 also changed drug-sensitivity to palbociclib and dinaciclib. In conclusion, ETV5 promoted cell cycle G1/S transition through transcriptional inhibition of p21, thereby accelerating tumor growth. Moreover, ETV5 changed drug-sensitivity to palbociclib and dinaciclib. Therefore, therapeutic regimens targeting ETV5 may be promising in improving the efficacy of target-CDK treatment in CRC.
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http://dx.doi.org/10.1038/s41419-021-03717-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8087822PMC
April 2021

Harnessing Colloidal Self-Assembled Patterns (cSAPs) to Regulate Bacterial and Human Stem Cell Response at Biointerfaces and .

ACS Appl Mater Interfaces 2021 May 29;13(18):20982-20994. Epub 2021 Apr 29.

Shenzhen Key Laboratory of Biomimetic Materials and Cellular Immunomodulation, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China.

The generation of complex physicochemical signals on the surface of biomedical materials is still challenging despite the fact that a broad range of surface modification methods have been developed over the last few decades. Colloidal self-assembled patterns (cSAPs) are combinations of unique colloids differing in size and surface chemistry acting as building blocks that can be programmed to generate surface patterns with exquisite control of complexity. This study reports on producing a variety of pre-modified colloids for the fabrication of cSAPs as well as post-assembly modifications to yield complex surfaces. The surface of cSAPs presents hierarchical micro- and nanostructures, localized hydrophilic/hydrophobic characteristics, and tunable surface functionality imparted by the individual colloids. The selected cSAPs can control bacterial adhesion (, , and ) and affect the cell cycle of human bone marrow stem cells (hBMSCs). Moreover, in a mouse subcutaneous model, cSAPs with selective [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium (SBMA) modification can reduce the inflammatory response after being challenged with bacteria. This study reveals that functionalized cSAPs are versatile tools for controlling cellular responses at biointerfaces, which is instructive for biomaterials or biodevices.
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http://dx.doi.org/10.1021/acsami.1c02591DOI Listing
May 2021

Bioinspired Geometry-Gradient Metal Slippery Surface by One-Step Laser Ablation for Continuous Liquid Directional Self-Transport.

Langmuir 2021 05 25;37(17):5436-5444. Epub 2021 Apr 25.

Institute of Tribology, School of Mechanical Engineering, Hefei University of Technology, Hefei 230009, China.

Liquid directional self-transport on the functional surface plays an important role in both industrial and academic fields. Inspired by the natural cactus spine and pitcher plant, we have successfully designed a kind of geometry-gradient slippery surface (GGSS) based on aluminum alloy materials which could actively achieve directional self-movement and also antigravity self-movement of various liquid droplets by topography gradient. The mechanism of liquid directional self-transport was theoretically explored through the mechanical analysis of the triple contact line, which was mainly related to the competition between the driven force induced by Laplace pressure and the adhesive force induced by viscous resistance. The adhesive force between the droplet and the surface was quantitatively measured using a homemade experimental apparatus and the results showed that the lateral adhesive force on the GGSS is much smaller than that on the original surface. Additionally, a series of quantitative experiments were conducted to explore the influence of droplet volume and vertex angle on the transport distance and velocity. Finally, we achieved the antigravity self-transport of the droplet on the inclined GGSS to further verify the self-transport ability of the GGSS. We believe that the proposed GGSS with liquid directional self-transport ability in the present work would provide some potential opportunities in modern tribo-systems to optimize the lubricating qualities, especially the lubrication and friction at the extreme contact interface.
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http://dx.doi.org/10.1021/acs.langmuir.1c00911DOI Listing
May 2021