Mechanical stress modulates almost all functions of cells. The key to exploring its biological effects lies in studying the perception of mechanical stress and its mechanism of mechanotransduction. This article details the perception and mechanotransduction mechanism of mechanical stress by extracellular matrix, cell membrane, cytoskeleton and nucleus. There are two main pathways for the perception and mechanotransduction of mechanical stress by cells, one is the direct transmission of force, and the other is the conversion of mechanical signal into chemical signal. The purpose of this study is to provide some reference for the exploration of precise treatment of mechanical stress-related diseases and the optimization of construction of tissue engineered organs by mechanical stress.
Objective To study the leptin-mediated intracellular signal pathways and their effects on wound healing.Methods The literature was reviewed extensively, concerning the physical and chemical characters of leptin, the mechanism of its receptor action, the receptor-related intracellular signal pathways and their roles on wound healing. Results Leptin was a protein hormone expressed by ob gene with relative molecular mass 16×103, it could activate the main singal pathways such as Janus kinase/signal transducer and activator of transcription, mitogenactivated protein kinases and phosphoinositide-3-kinase pathways through binding with its specific receptor, to participate in the modulation of multiple functions including energy metabolism, weight balance and wound healing. Leptin receptors were widely distributed in various tissues, which suggest the multiple functions of leptin. Local leptin expression was increased after skin injured, and it could stimulate keratinocytes proliferation, epithelialization, fibroblast proliferation and collagen synthesis, resulting in accelarated wound repair. Leptin expression was significantly increased after mucosal injury or bacteria infections, leading to accelarated mucosal repair through modulation of mucosal glandular secretion, improvment of mucosal blood flow, and synergistic action with endothelin-1.Conclusion Leptin can promote wound healing through activating its receptor-related intracellular signal pathways.
Objective To review the latest development of the research on the selfrenwal signaling pathway and culture system in vitro of the embryonic stem cells(ESCs). Methods The recent articlesabout the selfrenewal signaling pathway and culture system in vitro of the ESCs were extensively reviewed. Results Understanding of the molecular mechanism of the selfrenewalin vitro and pluripotency of the ESCs was considered important for developing improved methods of deriving, culturing and differentiating these cells into the cells that could be successfully used in the clinical practice. Conclusion A further research is needed to elucidate the selfrenewal signaling pathway and the pluripotency of the ESCs and the culture systemin vitro forthe human ESCs remains to be further improved and developed.
Objective To introduce the basic research and cl inical potential of the hair foll icle stem cells related signal transduction in prol iferation and differentiation. Methods The recent original articles about the hair foll icle stem cells were extensively reviewed. Results Many different signal pathways had been involved in the skin development and self-newals.The hair foll icle stem cells could play an important role in the skin self-renewal and regeneration which were modulated by several different signal pathways, which included bone morphogenetic protein/transforming growth factor β, Wnt, Notch and ectodysplasin A genes. Conclusion The hair foll icle stem cells may be a future approach to repair cutaneous wounds as a cell therapy．
Objective To observe the expression and investigate the significance of suppressor of cytokine signaling (SOCS) in peripheral blood mononuclear cells (PBMC) of experimental autoimmune uveitis (EAU). Methods 100 Lewis rats were immunized with interphotoreceptor retinoid-binding protein (IRBP) to induce EAU animal model, and they were divided into control group and treatment group randomly. The treatment group was administered cyclosporine A 20mg/（kgmiddot;d）after 1 to 28 days of immunization; the control group received saline buffer at equal quantity. All eyes were evaluated by slit-lamp microscopy before and after 7, 14, 21, 28 days of immunization; IL-4，IL-12，IFN-gamma; in the serum were measured by enzyme linked immunosorbent assay(ELISA); the SOCS mRNA and protein level in PBMC were measured by quantitative polymerase chain reaction (q-PCR) and western blot. Results The inflammation was most obvious at 14 days after immunization. The control group showed obvious iridocyclitis; the treatment group showed mild anterior chamber inflammation but no posterior synechia and hypopyon. The highest level of IL-12 and IFN-gamma; were observed at 14 days after immunization, followed by decline to the baseline at 28 days after immunization in control group; the highest level of IL-12 and IFN-gamma; were found at 14 days after immunization in treatment group, but the level was lower than control group obviously. Compared with the level before immunization, there are no differences at other time-point. The concentration of IL-4 decreased indistinctly in control group but increased in treatment group. SOCS1、Both of SOCS1 and SOCS5 increased to the highest level at 14 days after immunization, as 4.05 and 383 times of preimmunization in control group respectively, as 1.15 and 1.16 times in treatment group respectively. The CIS and SOCS3 mRNA increased lightly in two groups and treatment group milder than control group. Marked increased expression of SOCS1 and SOCS5 protein was detected at 7, 14, 21days than preimmunization, both of CIS and SOCS3 protein were significantly increased on 14, 21 days in control group; only SOCS1 protein was significantly increased on 14 days in treatment group and there are no differences at other time-point compared to pre-immunization. Conclusion Up-regulation of SOCS1 and SOCS5 expression maybe related to intensive response of Th1 in the development of EAU. Mild up-regulation of CIS and SOCS3 maybe associated with intensive response of Th2 which against the reaction of Th1 to carry out the dynamic immune balance.
目的 研究活动期多发性肌炎患者外周血白细胞细胞因子信号转导蛋白抑制因子（SOCS）1、SOCS2、SOCS3和细胞因子诱导的含SH2区域蛋白1（CIS）与正常人表达的差异，探讨SOCS在多发性肌炎发病中可能的作用。 方法 2011年6月－12月，采用实时荧光定量聚合酶链反应法检测了14例活动期多发性肌炎患者和14例正常人外周血白细胞中SOCS1、SOCS2、SOCS3和CIS1基因的相对表达量。 结果 与对照组相比，多发性肌炎症患者外周血白细胞基因SOCS 1～3表达明显降低（P值均＜0.05），CIS1基因的表达较对照组明显升高（P＜0.05），差异有统计学意义。 结论 SOCS基因家族可能参与了多发性肌炎的发病，该蛋白分子家族的成员可能会成为多发性肌炎治疗的一种新的候选基因。
OBJECTIVE: To study the effect of overexpression of truncated type II TGF-beta receptor on transforming growth factor-beta 1(TGF-beta 1) autoproduction in normal dermal fibroblasts. METHODS: In vitro cultured dermal fibroblasts were treated with recombinant human TGF-beta 1(rhTGF-beta 1) (5 ng/ml) or recombinant adenovirus containing truncated type II TGF-beta receptor gene (50 pfu/cell). Their effects on regulating gene expression of TGF-beta 1 were observed with Northern blotting. RESULTS: rhTGF-beta 1 up-regulated the gene expression of TGF-beta 1 and type I procollagen. Overexpression of truncated receptor II down-regulated the gene expression of TGF-beta 1. CONCLUSION: Overexpression of the truncated TGF-beta receptor II decreases TGF-beta 1 autoproduction via blocking TGF-beta receptor signal. The results may provided a new strategy for scar gene therapy.
Rheumatoid arthritis (RA) is a chronic autoimmune disease remarkably characterized by synovitis of joints, whose pathogenesis is complicated and not yet fully elucidated. A variety of cells, cytokines and intercellular signaling pathways are involved in the occurrence and development of RA. The mitogen activation protein kinase (MAPK) signaling pathway is closely related to the pathogenesis of RA, and plays an important role in the formation of pannus, synovitis, and bone destruction. This paper reviews the research progress of MAPK signaling pathway in RA from the aspects of the interaction of MAPK signaling pathway with a variety of key cells and cytokines in the pathogenesis of RA, in order to provide a direction and theoretical basis for anti-RA drug therapy research.
ObjectiveTo investigate the expressions of Patched-1 (Ptch1) and glioma-associated oncogene homologl (Gli1) protein of sonic hedgehog signaling pathway in cholangiocarcinoma tissues, and explore their correlations to the occurrence and development of cholangiocarcinoma. MethodsThe expressions of Ptch1 and Gli1 protein in 62 specimens of cholangiocarcinoma and its bile duct tissues adjacent to cancer were detected by immunohistochemistry, and their positive rate correlated with patients, age, tumor size, differentiation grade, tumor location, lymph node metastasis, TNM stage, operation mode, and postoperative survival time were investigated by statistical analysis. ResultsThe positive rates of Ptch1 and Gli1 protein were significantly higher in cholangiocarcinoma than in tissues adjacent to cancer (74.2% vs. 14.5%, 88.7% vs. 9.7%, P < 0.05). The expressions of Ptch1 and Gli1 protein in cholangiocarcinoma had no correlation to patients age, tumor size, and tumor location (P > 0.05), but were correlated to the operation mode, differentiation grade, lymph node metastasis, TNM stage, and postoperative survival time of patients (P < 0.05). ConclusionsThe elevated expressions of Ptch1 and Gli1 protein of Hh signaling pathway participated in the occurrence and development of cholangiocarcinoma. They may be ideal targets for therapy against cholangiocarcinoma.
ObjectiveTo investigate the effect of icaritin on the small cell lung cancer cell lines NCI-H446 and its mechanism. MethodsThe NCI-H446 cells at logarithmic growth phase were divided into control and icaritin groups. The cells in the control group were normally treated and cells in the icaritin group were incubated with icaritin (8 μmol/L). Thiazole blue and flow cytometry were used to examine the proliferation and apoptotic changes in the two groups 48 hours after incubation respectively. Gene expression of Janus kinase 2 (JAK2) and signal transducers and activators of transcription 3 (STAT3) were detected by real-time quantitative polymerase chain reaction. The changes of JAK2, STAT3, phospho-JAK2 (p-JAK2), phospho-STAT3 (p-STAT3), Bax and BCL-2 protein were detected by Western blotting. ResultsCompared with the control group, the proliferation rate of NCI-H446 cells in the icaritin group was significantly lower (P<0.05), but the apoptotic rate of NCI-H446 cells in the icaritin group was significantly higher (P<0.05). After the treatment with icaritin, the expression of JAK2 and STAT3 mRNA had no obvious differences. The Western blotting results showed that there was no significant changes in total JAK2, STAT3 protein (P>0.05), but an increasing trend in p-JAK2, p-STAT3 and Bax was observed with the decreasing of BCL-2 (P<0.05). ConclusionIcaritin can inhibit the proliferation and promote the apoptosis of NCI-H446 cells and the effect may be achieved through JAK2/STAT3 signal transduction pathway.