ABSTRACT
Objective:To study the molecular mechanism for momordin in inducing apoptosis of multidrug-resistant human chronic leukemia K562/A02 cells. Methods:The growth inhibition value of K562/A02 cells was detected by CCK-8 method. Cell apoptosis was analyzed by Annexin Ⅴ flow cytometry (FCM) and cell morphological examination. FCM was also used in determining expression of P-glycoprotein, p53 protein, bcl-2 protein and caspase activity. Results:Momordin inhibited the proliferation of K562/A02 cells in a dose-dependent manner. It also induced cell apoptosis, reduced the expression of P-glycoprotein, p53 protein and bcl-2 protein, and increased caspase-3 and caspase-8 activity.Conclusion:Momordin reversed the inhibition of apoptosis in multidrug-resistant K562/A02 cells. The molecular mechanism may be related with down-regulation of expression of p53 protein, P-glycoprotein, and bcl-2 protein and up-regulation of caspase-3 and caspase-8 activities.
ABSTRACT
Objective To evaluate the alteration of CD4+ regulatory T cells in peripheral blood from patients with ankylosing spondylitis(AS). Methods Seventy-eight AS patients and 50 healthy individuals were included in this study. The proportion of CD4+CD25+CD127lo/- T cell population in CD4+ T cells as well as that cytotoxic T lymphocytes(CTL) and NK cells in lymphocytes was evaluated by flow cytometry. Serum TGF-β and TNF-α were measured by ELISA. The inhibitory function of CD4+CD25+ regulatory T cells was measured by mixed lymphocyte culture. Results The population of CD4+CD25+CD127lo/- T cells in peripheral blood of AS patients accounted for (4.36±1.21)% of CD4+ T lymphocytes, which was significantly lower than that in healthy individuals (P<0.05). The CD4+CD25+CD127lo/- T cells population in AS patients was positively correlated with TGF-β level, but negatively with TNF-α. Compared with healthy individuals, the function of CD4+CD25+ regulatory T cells in the inhibition of alloreactive T cells was lower in AS patients, which was related to the decreased secretion of TGF-β. Conclusion The CD4+ regulatory T cells in peripheral blood of AS patients are significantly decreased and its function is defective, which leads to immune regulatory dysfunction in vivo. It may be one of immune pathogenesis mechanisms of AS.
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AIM: To explore the change of the expression of cell adhesion molecule CD_ 54 and CD_ 44 in erythroleukemic K562 apoptosis cells induced by momordin from momordica charantia seeds and study the effects of cell adhesion molecule CD_ 54 and CD_ 44 on cell apoptosis induced by momordin. METHODS: After the treatment of K562 cells with appropriated concentration momordin, CCK-8 test was employed to determine K562 cells growth; flow cytometry FACScan (FITC-Annexin V staining) and electron microscopy were used to detect apoptosis; The expression of CD_ 54 and CD_ 44 were examined by flow cytometry FACScan (FITC-CD_ 54 and PE-CD_ 44 staining). RESULTS: CCK-8 test showed K562 cells growth was significant inhibited by momordin; the apoptosis was detected by cell morphology and flow cytometry FACScan (FITC-Annexin V) in K562 cells after treatment by appropriated concentration momordin. The expressions of CD_ 54 and CD_ 44 in momordin treated K562 cells were 18.62 % and 1.32 % respectively, and in negative momordin treated K562 cells were 0.25 % and 0.17 % respectively, and momordin could up-expresses the protein of CD_ 54 18.37 % and CD_ 44 1.15 %. CONCLUSION: Momordin can markedly induce the K562 cell to apoptosis. The up-expressions of CD_ 54 exist in the process of apoptosis induced by momordin. The change of cell adhesion molecule maybe one of the key factors in the mechanisms of apoptosis induced by momordin, and its mechanism maybe involve in adhesion-dependent apoptosis.
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To investigate the role of mitochondria in neuronal apoptosis, ischemia-reperfusion mediated neuronal cell injury model was established by depriving of glucose, serum and oxygen in media. DNA fragmentation, cell viability, cytochrome C releasing, caspase3 activity and mitochondrial transmembrane potential were observed after N2a cells suffered the insults. The results showed that N2a cells in ischemic territory exhibited survival damage, classical cell apoptosis change, DNA ladder and activation of caspase3. Apoptosis-related alterations in mitochondrial functions, including release of cytochrome C and depression of mitochondrial transmembrane potential (deltapsim) were testified in N2a cells after mimic ischemia-reperfusion. Moreover, activation of caspase3 occurred following the release of cytochrome C. However, the inhibitor of caspase3, Ac-DEVD-CHO, couldn't completely rescue N2a cells from apoptosis. Administration of cyclosporine A, an inhibitor of mitochondria permeability transition pore only partly inhibited caspase3 activity and reduced DNA damage. Interestingly, treatment of Z-IETD-FMK, an inhibitor of caspase8 could completely reverse DNA fragmentation, but can't completely inhibit caspase3 activity. It was concluded that there were caspase3 dependent and independent cellular apoptosis pathways in N2a cells suffering ischemia-reperfusion insults. Mitochondria dysfunction may early trigger apoptosis and amplify apoptosis signal.
Subject(s)
Animals , Mice , Apoptosis , Physiology , Caspase 3 , Caspases , Cytochromes c , Mitochondria , Physiology , Neuroblastoma , Pathology , Neurons , Pathology , Reperfusion Injury , Metabolism , Pathology , Tumor Cells, CulturedABSTRACT
Background and purpose:In order to look for the new biomarker with higher specificity and sensitivity, we investigated the relationship between expression of MGB-2 and chemotherapy response, and tried to find out whether MGB-2 may sever as a prognostic factor for the patients with ovarian carcinoma. Methods:The expression of MGB-2 was detected by flow-cytometry technology in ovarian carcinoma tissue. We analyzed the correlations among MGB-2 expression and clinical pathological factors, therapeutic effect and prognosis of the patients with ovarian carcinoma.Results:Positive detection of MGB-2 was 78%.(66/885). For the patients whose serum CA125 level did not drop to normal level after two courses of chemotherapy, the MGB-2 positive rate was significantly higher than in those whose serum CA125 level decreased markedly ( 85% vs. 62%, P=0.018). The positive rate was also higher in patients with recurrent disease than in those without recurrence (83% vs. 67%, P=0.097). In univariate survival analysis, the expression of MGB-2 was significantly associated with median survival time (P=0.021).Conclusions:MGB-2 expression is correlated with chemotherapy response and poor prognostic for the patients with ovarian carcinoma.