RESUMO
BACKGROUND: Loss and/or dysfunction of interstitial Cajal-like cells (ICLCs) in the gallbladder may promote cholesterol gallstone formation by decreasing gallbladder motility. AIM: To study the effect of cholesterol on the proliferation and apoptosis of ICLCs from guinea pig gallbladders. METHODS: Guinea pig gallbladder ICLCs were isolated and cultured in vitro. The cells were exposed to cholesterol solutions at different concentrations (0, 25, 50, and 100 mg/L) for 24 h. Then, cell proliferation was detected by the CCK-8 method and the apoptosis rate was detected by flow cytometry. Further, the expression of the c-Kit protein was detected by Western blot and the expression level of c-Kit mRNA in the cells was detected by real-time quantitative PCR. RESULTS: After ICLCs were cultured with cholesterol at concentrations of 25, 50, and 100 mg/L, the proliferation rates decreased significantly (P < 0.05), whereas the apoptosis rates increased significantly (P < 0.05). Moreover, the expression of c-Kit protein and mRNA decreased significantly (P < 0.05). CONCLUSION: High cholesterol concentrations can inhibit the proliferation of ICLCs and promote apoptosis. This decrease in the ICLC proliferation rate might be caused by the inhibition of the stem cell factor/c-Kit signaling pathway.
RESUMO
OBJECTIVES: It is not clear whether TREM-2 (the "triggering receptor expressed on myeloid cells 2") is expressed in fibroblast-like synovial cells (FLSs). In this study, we aimed to determine the expression of TREM-2 in rheumatoid arthritis (RA)-FLSs and explore whether and how TREM-2 modulates the function of RA-FLSs. METHODS: Western blot and RT-PCR were used to detect the expression of TREM-2 in RA-FLSs, siRNA and lentivirus were used to down-regulate and up-regulate the expression of TREM-2 in RA-FLSs. Then mRNA expression of IL-1ß, IL-6, and MMP-13 was determined by RT-qPCR. Protein secretion of IL-1ß, IL-6, and MMP-13 in the supernatant was determined by ELISA assay; expression of cell signal transduction molecules was determined by western blot. RESULTS: A: Relative to OA-FLSs, mRNA and protein expression levels of TREM-2 in RA-FLSs are significantly elevated. TREM-2 protein is mainly expressed in the cytoplasm of RA-FLSs; B: In RA, the expression of TREM-2 was reduced at first and then up-regulated after stimulation by TNF-α. TREM-2 also inhibited the activation of TNF-α induced of inflammation in RA-FLSs by the p38 pathway, which regulates the production of cytokines and matrix metalloproteinases. CONCLUSIONS: TREM-2 expressed in RA-FLSs and TNF-α mediated reduction of inflammatory reactions. These phenomena indicated that TREM-2 may be a potential target in the treatment of RA.
