Résumé
Ischemia-reperfusion (IR) is one of the significant medical problems in China. Triphenyltetrazolium chloride (TTC) stainingis used to detect the status of the infarct size, and real-time PCR and western blotting are used to detect expressions ofgenes. TUNEL assay has been used to detect apoptosis. Using a tree shrew myocardial IR model, we found that in thereperfusion period, resina draconis (RD) treatment reduced the infarct size by TTC staining, and significantly enhanced thesuperoxide dismutase expression and down-regulated the malondialdehyde concentration in a dose-dependent manner. Inhearts showing IR, Bax was increased and Bcl-2 was reduced, and RD treatment inhibited the IR-induced Bax expressionand up-regulated the IR suppressed level of Bcl-2. TUNEL assay showed that IR induced the apoptosis of myocardial cells,and RD treatment suppressed the IR-induced apoptosis. CHOP and GRP78 were also upregulated in IR hearts, and RDtreatment could significantly attenuate the CHOP and GRP78 levels compared with IR group. We further found that IRdecreased the miR-423-3p expression and upregulated its target gene ERK both in mRNA and protein levels, and RDtreatment upregulated miR-423-3p expression and downregulated ERK expression compared with the IR group. Importantly, miR-423-3p mimics inhibited IR increased ERK, CHOP and GRP78 expressions, and enhanced IR decreased Bcl-2expression, and inhibited the IR-induced apoptosis of myocardial cells. The findings of this study suggest that RD treatmentinhibited the endoplasmic reticulum induced apoptosis of myocardial cells via regulating miR-423-3p/ERK signalingpathway in a tree shrew myocardial IR model.
Résumé
Beijing has been one of the epicenters attacked most severely by the SARS-CoV (severe acute respiratory syndrome-associated coronavirus) since the first patient was diagnosed in one of the city's hospitals. We now report complete genome sequences of the BJ Group, including four isolates (Isolates BJ01, BJ02, BJ03, and BJ04) of the SARS-CoV. It is remarkable that all members of the BJ Group share a common haplotype, consisting of seven loci that differentiate the group from other isolates published to date. Among 42 substitutions uniquely identified from the BJ group, 32 are non-synonymous changes at the amino acid level. Rooted phylogenetic trees, proposed on the basis of haplotypes and other sequence variations of SARS-CoV isolates from Canada, USA, Singapore, and China, gave rise to different paradigms but positioned the BJ Group, together with the newly discovered GD01 (GD-Ins29) in the same clade, followed by the H-U Group (from Hong Kong to USA) and the H-T Group (from Hong Kong to Toronto), leaving the SP Group (Singapore) more distant. This result appears to suggest a possible transmission path from Guangdong to Beijing/Hong Kong, then to other countries and regions.