目的骨髓间充质干细胞(BMSCs)具有力学敏感性,对周围力学微环境高度敏感。连接蛋白43(connexin 43,Cx43)作为骨组织细胞中组成半通道和间隙连接的主要蛋白,在力学信号传导中发挥重要作用。然而关于Cx43是否参与基质刚度对BMSCs分化的调...目的骨髓间充质干细胞(BMSCs)具有力学敏感性,对周围力学微环境高度敏感。连接蛋白43(connexin 43,Cx43)作为骨组织细胞中组成半通道和间隙连接的主要蛋白,在力学信号传导中发挥重要作用。然而关于Cx43是否参与基质刚度对BMSCs分化的调节仍有待研究。方法本实验制备了模拟骨髓力学微环境不同位置处基质刚度(1、10、34 k Pa)的聚丙烯酰胺水凝胶培养基底;培养间充质干细胞细胞系C3H10T1/2,利用18α-GA抑制C3H10T1/2中Cx43功能;提取BMSCs条件性敲除(c KO)Cx43小鼠(Prx1-Cre;Cx43 flox/flox)和同窝对照flox小鼠(Cx43 flox/flox)原代BMSCs进一步验证。结果抑制Cx43均会导致BMSCs在10、34 k Pa基质刚度上的成脂能力显著下降,而对1 k Pa上BMSCs成脂能力无影响。相比于1 k Pa和34 k Pa,在10 k Pa基质刚度上抑制Cx43导致了BMSCs成骨能力显著下降。在不同基质刚度上抑制BMSCs上Cx43均会导致糖酵解和线粒体融合裂变相关基因表达显著变化,以及成脂和成骨分化过程中ATP的生成。结论BMSCs响应骨髓力学微环境,较软的基质刚度可能对成脂能力有一定程度的恢复作用,而Cx43可能通过代谢途径参与了基质刚度对BMSCs分化的调节。展开更多
Objective: To explore the effect and mechanism of angiotensin II receptor blockers-Irbesartan on occurrence of ventricular arrhythmias in rats with myocardial ischemia. Methods: Rats with embryonic cardiomyocytes-H9c2...Objective: To explore the effect and mechanism of angiotensin II receptor blockers-Irbesartan on occurrence of ventricular arrhythmias in rats with myocardial ischemia. Methods: Rats with embryonic cardiomyocytes-H9c2 were randomly divided into control group. ischemia group. Irbesartan group and Irbesartan+ischemia group. The cell viability of rats in each group was tested using MTT. Real-time PCR was employed to detect the expression of connexin43 (Cx43) mRNA and western blot to detect the expression of Cx43 and phosphorylated Cx43. SD rats were randomly divided into the sham-operation group (SO). myocardial infarction group (MI). Irbesartan group and MI+ Irbesartan group, with 10 rats in each group. HE staining was employed to observe the change in the pathomorpholouy of left ventricular tissue and TUNEL method to analyze the cell apoptosis in the tissue. The immunofluorescence was adopted to observe the expression and distribution of Cx43 in the left ventricular myocardium and study the change in the expression of Cx43 in the cardiac muscular tissue at mRNA and protein level. Results: The intervention of lrbesartan in the condition of ischemia indicated the significant decrease in the number of necrotic cells. The expression of Cx43 was significantly decreased under the culture of ischemia (P<0.05), but in the presence of Irbesartan, the expression of Cx43 was increased compared with the ischemia group (p<0.01). The results of WB assay showed the similar trend of change at mRNA level. There was the significant difference in the score of ventricular arerythmia between MI group and SO group (P<0.01). The incidence of ventricular tachycardia or ventricular fibrillation was significantly increased compared with the one in SO group (P<0.05). There was the significant difference in the overall score between MI+Irbesartan group and MI group (P<0.05). The expression of Cx43 in the cardiac muscular tissue in MI group was significantly decreased (P<0.01(US) SO group). But the expression of Cx43 was increased after the treatment with Irbesartan. Conclusions: Irbesartan can inhibit the injury of H9c2 cardiomyocytes and the decreased expression of Cx43 that are induced by the ischemic myocardial infarction. Irbesartan can also improve the reconstruction of Cx43 in rats with ischemic myocardium to inhibit the myocardial infarction-induced arrhythmias.展开更多
文摘目的骨髓间充质干细胞(BMSCs)具有力学敏感性,对周围力学微环境高度敏感。连接蛋白43(connexin 43,Cx43)作为骨组织细胞中组成半通道和间隙连接的主要蛋白,在力学信号传导中发挥重要作用。然而关于Cx43是否参与基质刚度对BMSCs分化的调节仍有待研究。方法本实验制备了模拟骨髓力学微环境不同位置处基质刚度(1、10、34 k Pa)的聚丙烯酰胺水凝胶培养基底;培养间充质干细胞细胞系C3H10T1/2,利用18α-GA抑制C3H10T1/2中Cx43功能;提取BMSCs条件性敲除(c KO)Cx43小鼠(Prx1-Cre;Cx43 flox/flox)和同窝对照flox小鼠(Cx43 flox/flox)原代BMSCs进一步验证。结果抑制Cx43均会导致BMSCs在10、34 k Pa基质刚度上的成脂能力显著下降,而对1 k Pa上BMSCs成脂能力无影响。相比于1 k Pa和34 k Pa,在10 k Pa基质刚度上抑制Cx43导致了BMSCs成骨能力显著下降。在不同基质刚度上抑制BMSCs上Cx43均会导致糖酵解和线粒体融合裂变相关基因表达显著变化,以及成脂和成骨分化过程中ATP的生成。结论BMSCs响应骨髓力学微环境,较软的基质刚度可能对成脂能力有一定程度的恢复作用,而Cx43可能通过代谢途径参与了基质刚度对BMSCs分化的调节。
基金supported by Research Topic of Department of Health of Jiangxi Province(No.20131074)Natural Science Fund of Jiangxi Province(No:20122BAB205028)
文摘Objective: To explore the effect and mechanism of angiotensin II receptor blockers-Irbesartan on occurrence of ventricular arrhythmias in rats with myocardial ischemia. Methods: Rats with embryonic cardiomyocytes-H9c2 were randomly divided into control group. ischemia group. Irbesartan group and Irbesartan+ischemia group. The cell viability of rats in each group was tested using MTT. Real-time PCR was employed to detect the expression of connexin43 (Cx43) mRNA and western blot to detect the expression of Cx43 and phosphorylated Cx43. SD rats were randomly divided into the sham-operation group (SO). myocardial infarction group (MI). Irbesartan group and MI+ Irbesartan group, with 10 rats in each group. HE staining was employed to observe the change in the pathomorpholouy of left ventricular tissue and TUNEL method to analyze the cell apoptosis in the tissue. The immunofluorescence was adopted to observe the expression and distribution of Cx43 in the left ventricular myocardium and study the change in the expression of Cx43 in the cardiac muscular tissue at mRNA and protein level. Results: The intervention of lrbesartan in the condition of ischemia indicated the significant decrease in the number of necrotic cells. The expression of Cx43 was significantly decreased under the culture of ischemia (P<0.05), but in the presence of Irbesartan, the expression of Cx43 was increased compared with the ischemia group (p<0.01). The results of WB assay showed the similar trend of change at mRNA level. There was the significant difference in the score of ventricular arerythmia between MI group and SO group (P<0.01). The incidence of ventricular tachycardia or ventricular fibrillation was significantly increased compared with the one in SO group (P<0.05). There was the significant difference in the overall score between MI+Irbesartan group and MI group (P<0.05). The expression of Cx43 in the cardiac muscular tissue in MI group was significantly decreased (P<0.01(US) SO group). But the expression of Cx43 was increased after the treatment with Irbesartan. Conclusions: Irbesartan can inhibit the injury of H9c2 cardiomyocytes and the decreased expression of Cx43 that are induced by the ischemic myocardial infarction. Irbesartan can also improve the reconstruction of Cx43 in rats with ischemic myocardium to inhibit the myocardial infarction-induced arrhythmias.