ABSTRACT
Objective To investigate the cytoprotection and mechanism of carbachol(CCH)to stimulate M3mus-carinic acetylcholine receptor(M3-mAChR) against hypoxia injury induced by cobaltous chloride hexahydrate (CoCl2) in rat cardiomyocyte line H9c2. Methods Select the normal rat cardiomyocyte line H9c2 as the control group, rat cardiomyocyte line H9c2 was managed with CoCl2to develop hypoxia injury model, M3-mAChR spe-cific agonist CCH and antagonist 4-diphenyl-acetoxy-N-methyl-piperidine methiodide(4-DAMP) were used for in-tervention. The cell viability was tested by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT); The apoptosis in cardiomyocyte was detected by flow cytomery(FCM); The expression of M3-mAChR,caspase-3, HIF-1α and HO-1 proteins was measured by Western blot assay. Results In hypoxia group,the ap-optosis rate was significantly increased while cell proliferation decreased, the expression of HIF-1α, caspase-3 and HO-1 proteins were up-regulated obviously;After treatment with CCH,the apoptosis and cell proliferation of cardiomyocytes were significantly decreased, while the proliferation of cells increased, and the expression of M3-mAChR, HIF-1α and HO-1 proteins increased, the expression of caspase-3 protein was significantly decreased. Moreover, when applying 4-DAMP as intervention, these effects mediated by CCH was abolished.Conclusions CCH stimulates M3-mAChR against hypoxia injury induced by CoCl2in rat cardiomyocyte strain H9c2, and the mechanism may be related to down-regulation of caspase-3 expression and up-regulation of HIF-1α and HO-1 protein expression.
ABSTRACT
S-phase kinase-associated protein 2 (Skp2), which plays a role in cell cycle regulation, is commonly overexpressed in a variety of human cancers and associated with poor prognosis. However, its role in nasopharyngeal carcinoma (NPC) is not well understood. In this study, we examined the clinical significance of Skp2, with a particular emphasis on overall survival (OS) and disease-free survival (DFS), in NPC cases in South China, where NPC is an epidemic. Additionally, we explored the function of Skp2 in maintaining a cancer stem cell-like phenotype in NPC cell lines. Skp2 expression was assessed for 127 NPC patients using tissue microarrays and immunohistochemistry and analyzed together with clinicopathologic features, OS, and DFS. Skp2 expression was detectable, or positive, in 75.6% of patients. Although there was no correlation between Skp2 and any clinicopathologic factor, Skp2 expression significantly portended inferior OS (P = 0.013) and DFS (P = 0.012). In the multivariate model, Skp2 expression remained significantly predictive of poor OS [P = 0.009, risk ratio (RR) = 4.06] and DFS (P = 0.008, RR = 3.56), and this was also true for clinical stage (P = 0.012 and RR=3.201 for OS; P = 0.002 and RR=1.94 for DFS) and sex (P = 0.016 and RR=0.31 for OS; P = 0.006 and RR = 0.27 for DFS). After Skp2 knockdown, a colony formation assay was used to evaluate the self-renewal property of stem-like cells in the NPC cell lines CNE-1 and CNE-2. The colony formation efficiency in CNE-1 and CNE-2 cells was decreased. In Skp2-transfected CNE-1 and CNE-2 cells, side population (SP) proportion was increased as detected by flow cytometry. Skp2 is an independent prognostic marker for OS and DFS in NPC. Skp2 may play a role in maintaining the cancer stem cell-like phenotype of NPC cell lines.
Subject(s)
Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Carcinoma , Cell Line, Tumor , China , Disease-Free Survival , Follow-Up Studies , Gene Knockdown Techniques , Nasopharyngeal Neoplasms , Genetics , Metabolism , Pathology , Neoplasm Staging , Neoplastic Stem Cells , Pathology , RNA, Small Interfering , Genetics , S-Phase Kinase-Associated Proteins , Genetics , Metabolism , Sex Factors , Survival Rate , Tissue Array Analysis , TransfectionABSTRACT
Objective To compare the biomechanical effect of three fixation instruments for SchatzkerⅥtibial plateau fractures.Methods Twenty four fresh knee specimens were made into models of SchatzkerⅥtibial plateau fractures.The specimens were divided randomly into three groups.Group A were fixed with a lateral periar- ticular plate and a posteromedial antiskid plate,and group B with a lateral periarticutar plate and an anteromedial lim- ited contact dynamic compression plate(LC-DCP),and group C with a lateral periarticular plate and a medical exter- nal fixator.Each model was tested for its biomechanical performance in resisting compression,bending and rotation. Results The performance of group B was higher than group A in anti-compression,anti-bending and anti-rotation, and group C was the poorest,there was no significant difference between group A and group B,and there was signifi- cant difference between group B and group C.Conclusion The biomechanical performance of group B was good. The method might have clinical applications in the treatment of SchatzkerⅥtibial plateau fractures.