目的 探讨慢性缺氧大鼠心肌HSP47 mRNA表达与血清Ⅰ型前胶原C端原肽(PⅠCP)、Ⅲ型前胶原N端原肽(PⅢNP)含量及心肌纤维化的相关性.方法 模拟缺氧环境,建立慢性缺氧大鼠模型.将40只SD大鼠随机分为5组,每组8只.对照组不给于缺氧处理(A组),各慢性缺氧组大鼠分别缺氧7 d(B组)、14 d(C组)、21 d(D组)、28 d(E组).采用实时荧光定量PCR(q-PCR)检测心肌中热休克蛋白(HSP47) mRNA的表达量;运用酶联免疫吸附测定(ELISA)方法检测血清及心肌中PⅠCP、PⅢNP的浓度;采用HE和MASSON染色法对对照组和慢性缺氧组大鼠进行组织切片染色.结果 与对照组比较,模型组的HSP47 mRNA表达量增多(P〈0.01),血清和心肌的PⅠCP、PⅢNP浓度升高(P〈0.01);心肌HSP47 mRNA的表达与血清和心肌的PⅠCP、PⅢNP含量呈正相关(P〈0.05);HE和MASSON染色显示慢性缺氧组心肌组织广泛纤维化.结论 在慢性缺氧条件下HSP47 mRNA的表达量与PⅠCP、PⅢNP浓度正相关,提示HSP47作为心肌胶原分子伴侣在慢性缺氧所致心肌纤维化中起一定作用.
Objective To investigate the mRNA level of heat shock protein 47 (HSP47) in the myocardium from the rats under chronic hypoxic condition, and explore its correlation with serum contents of procollagen Ⅰ C-propeptide (PⅠCP) and procollagen Ⅲ N-propeptide (PⅢNP) and myocardial fibrosis.Methods Hypoxic environment was simulated to establish rat model of chronic hypoxia.A total of 40 SD rats were randomly divided into 5 groups (8 animals in each group), that is, normal control group, and the 4 groups under chronic hypoxic condition for 7, 14, 21 and 28 d respectively.Real-time quantitative PCR (q-PCR) was used to detect the myocardial expression of HSP47 mRNA, and ELISA was adopted to measure the serum and myocardial contents of PⅠCP and PⅢNP.HE and MASSON staining were used to observe the histopathological changes in the control group and chronic hypoxia groups.Results Compared with the control group, the mRNA level of HSP47 was increased in the model groups (P〈0.01), so were the serum and myocardial contents of PⅠCP and PⅢNP (P〈0.01).The expression level was positively correlated with the serum contents of the 2 peptides (P〈0.01).HE and MASSON staining indicated that extensive myocardial fibrosis was observed in the chronic hypoxic groups.Conclusion The expression of HSP47 mRNA is positively correlated with serum contents of PⅠCP and PⅢNP under chronic hypoxic condition.Our findings suggest that HSP47, as a chaperone myocardial collagen, is involved in the myocardial fibrosis induced by chronic hypoxia.