[The correlation research on miRNA378* and calumenin,endoplasmic reticulum stress,apoptosis in suckling mouse myocardial cells infected with coxsackie virus B3].

OBJECTIVE: To investigate the effects of silencing miRNA378* on apoptosis, endoplasmic reticulum stress and calumenin of cardiomyocyte with coxsackie virus B3 (CVB3) infection. METHODS: Primary cultured suckling mouse myocardium were divided into control group (normal cell), coxsackie virus infection group (normal cell and coxsackie virus B3), miRNA378* control group (normal cell +coxsackie virus B3+miRNA378* empty plasmid), miRNA378* silencing plasmid group(normal cells + coxsackie virus B3 + miRNA378* silencing plasmid). Four groups of cells were transfected, infected and treated in CO2 incubator at 37℃. The α-SMA protein, cell apoptosis rate, calumenin, glucose regulated protein 78 (GRP78), activation transcription factor 6(ATF6) and transcription factors c/ebp homologue protein (CHOP) in endoplasmic reticulum were analyzed. RESULTS: By detecting α-SMA protein, the isolated suckling mouse ventricular myocardium were confirmed. TUNEL detection of different groups of ventricular cell apoptosis found that coxsackie virus group of ventricular myocytes apoptosis was significant. Compared with the coxsackie virus infection group of myocardial cells, miRNA378* silencing plasmid expression of cardiomyocyte apoptosis cells significantly reduced(P<0.01). The expressions of GRP78, ATF6 and CHOP were increased compared with those infected by Coxsackie virus infection (P<0.01), while the expressions of calumenin were decreased (P<0.01). CONCLUSIONS: CVB3 infected myocardial cells effected miRNA378* expression. It can trigger endoplasmic reticulum stress and activates signaling pathway factor and increase myocardial cell apoptosis.>.

[Effects of caspase inhibitor z-VAD-fmk on the expressions of calumenin, caspase-3, GRP78 and GRP94 in adriamycin-injured cardiomyocytes].

OBJECTIVE: To study the effects of Caspase broad spectrum inhibitor Z-VAD-FMK on the expressions of calumenin,caspase-3, GRP78 and GRP94 in adriamycin-injured cardiomyocytes and to discuss whether there is a regulation relationship between calumenin and endo-plasmic reticulum stress and myocardial apoptosis. METHODS: The primary cultured suckling mouse myocardium were randomly divided into control group (cardiomyocyte), adriamycin group (3 mg/L adriamycin + cardiomyocyte) and z-VAD-fm group (3 mg/L adriamycin + 0.1 µmol/L Z-VAD-fmk + cardiomyocyte), each group of cardiomyocytes were cultured in CO2 incubator at 37℃ for 24 h (n=3). The expres-sion ofα -SMA protein in ventricular myocytes was detected by immunohistochemical method. The expressions of calumenin, GRP78, GRP94 and Caspase-3 in the myocardial cells were detected by Western blot. RESULTS: Compared with the control group, the expression of calumenin in adriamycin induced myocardial cells was significantly decreased (P < 0.01), while the expressions of GRP78, GRP94 and Caspase-3 ex-pression were increased (P < 0.01). Compared with adriamycin group, the expression of calumenin in z-VAD-fm group was increased (P < 0.01), while the expressions of GRP78, GRP94 and caspase-3 were decreased (P < 0.01). CONCLUSIONS: The caspase inhibitor z-VAD-fmk inhibited the expression of caspase and increased the expression of calumenin in adriamycin induced myocardial cells, and thus alleviated the endoplasmic reticulum stress.

[The relationship between miRNA378, calumenin and endoplasmic reticulum stress in suckling mouse myocardium with myocarditis caused by adriamycin].

OBJECTIVE: To investigate the relationship between miRNA378, calumenin and endoplasmic reticulum stress in suckling mouse myocardium with myocarditis caused by adriamycin. METHODS: The suckling mouse myocardium of primary culture were randomly divided into control group, adriamycin group, lentivirus infection miRNA378 over expression control group, lentivirus infection miRNA378 over expression group, lentivirus infection miRNA378 silence control group and lentivirus infection miRNA378 silence group. Firstly to identify the suckling mouse myocardium, α-SMA was monitored by immunohistochemical method, and secondly the ventricular myocytes were transfered by lentivirus plasmids. Then the expression change of miRNA378, calumenin and glucose regulated protein 78(GRP78) mRNA were detected by Quantitative Real-time PCR. RESULTS: Compared with the adriamycin infection group, the expression of calumenin mRNA in lentivirus infection miRNA378 over expression group was increased(P<0.01), while the expression of GRP78 mRNA was reduced(P<0.01); Compared with the adriamycin infection group, the expressions of calumenin and GRP78 mRNA in lentivirus infection miRNA378 silence group did not change insignificantly. CONCLUSIONS: Adriamycin injection may cause expression of calumenin in suckling mouse myocardium with myocarditis reduced, which may lead to the endoplasmic reticulum stress. This effect is related with miRNA378.