钙敏感受体在糖尿病大鼠大血管病变中的表达

The expression of calcium-sensing receptor in hyperglacemia induced macroangiopathy

目的 探讨钙敏感受体（CaSR）在糖尿病大血管病变中的表达及其在发病机制中的意义.方法 SD大鼠随机分为正常对照组（Con,n=9）和糖尿病组（DM,n=9）.采用高脂饮食＋腹腔注射链脲佐菌素（STZ）的方法,建立大鼠糖尿病模型.采用ChoramnieT氧化比色法测定血管组织羟脯氨酸含量,实时定量聚合酶链反应（Real-time PCR）检测CaSR mRNA含量,Western blot法观察大鼠胸主动脉血管组织CaSR和B细胞淋巴瘤/白血病-2相关X蛋白（bax）的蛋白表达,原位缺口末端标记法（TUNEL）观察血管内皮细胞凋亡.结果 糖尿病组羟脯氨酸含量[（1.380 ±0.030） mg/L]、CaSRmRNA水平（3.960 ±0.110）、CaSR蛋白表达水平（2.600 ±0.170）、bax蛋白表达水平（3.201±0.177）均显著高于对照组[（1.053 ±0.041） mg/L、1.003 ±0.015、1.000±0.032、1.000±0.084,P＜0.05];内皮细胞凋亡率增高30％ （P ＜0.05）.结论 CaSR在糖尿病大鼠模型大血管病变从mRNA到蛋白水平的表达均显著增加,提示CaSR可能通过激活bax相关凋亡通路促进血管内皮细胞凋亡,参与糖尿病大血管病变的发生和发展过程.

Objective To explore the changes of calcium-sensing receptor （CaSR） in hyperglacemia induced macroangiopathy and the mechanisms.Methods SD rats were randomly divided into control group （Con,n =9） and diabetic group （DM,n =9）,diabetic rats were made with streptozotocin （STZ） and high-fat diet.Hydroxyproline level in thoracic aorta was measured via ChoramnieT oxidation method.Message RNA level of CaSR was detected via real-time quantitative polymerase chain reaction （Real-time PCR）,and protein level of CaSR and B cell lymphoma/leukemia-2 associated X protein （bax） was detected by Western blotting.Cell apoptosis was analyzed through TdT-mediated dUTP nick end labeling （TUNEL） assay.Results The hydroxyproline [（1.380 ± 0.030） mg/L],the CaSR mRNA （3.960 ± 0.110）,CaSR protein 1 （2.600 ± 0.170） and bax protein level （3.201 ±0.177） in diabetic group were higher than control group [（1.053 ± 0.041） mg/L,（1.003 ± 0.015）,（1.000 ± 0.032）,（1.000 ± 0.084）] （P ＜ 0.05）,the apoptotic ratic increased by about 30％ in diabetic group （P ＜ 0.05）.Conclusion The CaSR mRNA and CaSR protern in diabetic group were higher than control group,CaSR might participate in the pathogenesis and development of hyperglycemia induced macroangiopathy through promoting bax related apoptosis pathway and initiating programmed cell death.