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Zhang W.K.,Hong Kong University of Science and Technology | Wang D.,Hong Kong University of Science and Technology | Wang D.,Stanford University | Duan Y.,Hong Kong University of Science and Technology | And 3 more authors.
Nature Cell Biology | Year: 2010

Cystic fibrosis transmembrane conductance regulator (CFTR) is an anion and intracellular ligand-gated channel associated with cystic fibrosis, a lethal genetic disorder common among Caucasians. Here we show that CFTR is robustly activated by membrane stretch induced by negative pressures as small as 5 mmHg at the single-channel, cellular and tissue levels. Stretch increased the product of the number of channels present and probability of being open (NPo), and also increased the unitary conductance of CFTR in cell-attached membrane patches. CFTR stretch-mediated activation appears to be an intrinsic property independent of cytosolic factors and kinase signalling. CFTR stretch-mediated activation resulted in chloride transport in Calu-3 human airway epithelial cells and mouse intestinal tissues. Our study has revealed an unexpected function of CFTR in mechanosensing, in addition to its roles as a ligand-gated anion channel and a regulator of other membrane transporters, demonstrating for the first time a mechanosensitive anion channel with a clearly defined molecular identity. Given that CFTR is often found in mechanically dynamic environments, its mechanosensitivity has important physiological implications in epithelial ion transport and cell volume regulation in vivo. © 2010 Macmillan Publishers Limited. All rights reserved. Source


Yang F.,Tongji University | Ruan Y.-C.,Epithelial Cell Biology Research Center | Ruan Y.-C.,Chinese University of Hong Kong | Yang Y.-J.,Tongji University | And 5 more authors.
Reproduction | Year: 2015

Women with polycystic ovary syndrome (PCOS) undergoing IVF-embryo transfer based-assisted reproductive technology (ART) treatment show variable ovarian responses to exogenous FSH administration. For better understanding and control of PCOS ovarian responses in ART, the present study was carried out to compare the follicular hormones and the expression of granulosa cell genes between PCOS and non-PCOS women during ART treatment as well as their IVF outcomes. Overall, 138 PCOS and 78 non-PCOS women were recruited for the present study. Follicular fluid collected from PCOS women showed high levels of testosterone. The expression of aromatase was found significantly reduced in luteinized granulosa cells from PCOS women. In cultured luteinized granulosa cells isolated from non-PCOS women, their exposure to testosterone at a level that was observed in PCOS follicles could decrease both mRNA and protein levels of aromatase in vitro. The inhibitory effect of testosterone was abolished by androgen receptor antagonist, flutamide. These results suggest that the hyperandrogenic follicular environment may be a key hazardous factor leading to the down-regulation of aromatase in PCOS. © 2015 Society for Reproduction and Fertility. Source


Ke C.,Shanghai JiaoTong University | Biao H.,Epithelial Cell Biology Research Center | Qianqian L.,Shanghai JiaoTong University | Yunwei S.,Shanghai JiaoTong University | And 2 more authors.
Current Stem Cell Research and Therapy | Year: 2015

Inflammatory Bowel Disease (IBD) is a complicated disease that arises as a consequence of the interaction among environment, genetic factors and autoimmunity. Available therapeutic interventions with pharmacological or biological drugs have a very selective action. Mesenchymal stem cells (MSCs) have been emerging as a promising cellular therapy for the treatment of IBD due to their multifaceted functions. This article summarizes recent progress in both preclinical studies and clinical trials employing MSCs in IBD treatment. We justify the use of MSC-based cell therapy as a novel strategy for IBD, discuss the biological roles that MSCs play underlying their therapeutic effects focusing on their immune-suppressive effects, illustrate methods to improve MSCs for better repair, and pinpoint the obstacles hindering their success and the challenges to overcome before their ultimate application. © 2015 Bentham Science Publishers. Source


Xie C.,Epithelial Cell Biology Research Center | Sun X.,Epithelial Cell Biology Research Center | Chen J.,Epithelial Cell Biology Research Center | Lau K.M.,Chinese University of Hong Kong | And 6 more authors.
Journal of Cellular Physiology | Year: 2015

Benign prostatic hyperplasia (BPH) is a hyper-proliferative disease of the aging prostate; however, the exact mechanism underlying the development of BPH remains incompletely understood. The present study investigated the possible involvement of the cystic fibrosis transmembrane conductance regulator (CFTR), which has been previously shown to negatively regulate nuclear factor-κB (NF-κB)/cyclooxygenase 2 (COX2)/prostaglandin E2 (PGE2) pathway, in the pathogenesis of BPH. Our results showed decreasing CFTR and increasing COX2 expression in rat prostate tissues with aging. Furthermore, suppression of CFTR led to increased expression of COX2 and over-production of PGE2 in a normal human prostate epithelial cell line (PNT1A) with elevated NF-κB activity. PGE2 stimulated the proliferation of primary rat prostate stromal cells but not epithelial cells, with increased PCNA expression. In addition, the condition medium from PNT1A cells after inhibition or knockdown of CFTR promoted cell proliferation of prostate stromal cells which could be reversed by COX2 or NF-κB inhibitor. More importantly, the involvement of CFTR in BPH was further demonstrated by the down-regulation of CFTR and up-regulation of COX2/NF-κB in human BPH samples. The present results suggest that CFTR may be involved in regulating PGE2 production through its negative regulation on NF-κB/COX2 pathway in prostate epithelial cells, which consequently stimulates cell growth of prostate stromal cells. The overstimulation of prostate stromal cell proliferation by down-regulation of CFTR-enhanced PGE2 production and release during aging may contribute to the development of BPH. J. Cell. Physiol. 230: 1906-1915, 2015. © 2014 Wiley Periodicals, Inc. Source


He Q.,Epithelial Cell Biology Research Center | Tsang L.L.,Epithelial Cell Biology Research Center | Ajonuma L.C.,Epithelial Cell Biology Research Center | Chan H.C.,Epithelial Cell Biology Research Center
Fertility and Sterility | Year: 2010

Objective: To investigate whether abnormal expression of cystic fibrosis transmembrane conductance regulator (CFTR), a cyclic adenosine 3′:5′ monophosphate (cAMP)-activated chloride channel, and uterine fluid accumulation upon Chlamydia trachomatis infection may result in implantation failure, thus contributing to C. trachomatis-induced female infertility. Design: Experimental animal study. Setting: University laboratory animal service center. Animal(s): Adult female mice with regular estrous cycles. Intervention(s): Intrauterine injection of C. trachomatis lipopolysaccharide (LPS), tumor necrosis factor-α (TNF-α), and estrogen (E) at diestrus and preimplantation. Main Outcome Measure(s): The CFTR messenger RNA (mRNA) and protein levels were evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot, respectively, in mouse uterus treated with C. trachomatis LPS, TNF-α or E. Endometrial electrolyte transport and uterine fluid accumulation were determined by the short circuit current and uterine wet weight, respectively. Number of implanted embryos was also counted to demonstrate the effect of treatments. Result(s): Uterine C. trachomatis LPS infection induced up-regulation of CFTR expression with enhanced anion secretion, abnormal fluid accumulation in mouse uterus at diestrus, and reduced implantation rate. Administration of exogenous TNF-α to mouse uterus mimicked the C. trachomatis LPS infection-induced CFTR up-regulation, enhanced CFTR channel activity, and fluid accumulation. Abnormal uterine fluid accumulation and implantation failure were also observed when CFTR was up-regulated by E. Conclusion(s): The present results suggest that C. trachomatis infection-induced release of cytokines could abnormally up-regulate CFTR expression leading to abnormal uterine fluid accumulation, which may result in infertility often associated with C. trachomatis infection. © 2010 American Society for Reproductive Medicine. Source

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