Abstract：
Sepsis often leads to systemic multiple organ dysfunction, with the majority of deaths attributable to acute myocardial injury (AMI). In this study, we aimed to explore the functional role of miR-365a-3p in sepsis-induced AMI. The sepsis myocardial injury model was constructed using lipopolysaccharide (LPS) both in vitro and in vivo with selective regulation of miR-365a-3p expression. Real-time PCR or Western blot was employed to detect the expressions of miR-365a-3p, inflammatory cytokines (tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and IL-6), and inflammation-related proteins (nuclear factor-κB (NF-κB), I-κB, myeloid differentiation factor 88 (MyD88)) in myocardial tissues and cells. Also, cell counting kit-8 (CCK8) and flow cytometry assays were used to measure cardiomyocyte proliferation and apoptosis, respectively. Furthermore, the targeting relationship between miR-365a-3p and MyD88 was verified with the dual luciferase activity assay. miR-365a-3p was downregulated in LPS-induced myocardial injury model. miR-365a-3p overexpression attenuated cardiomyocyte apoptosis and suppressed the expressions of inflammatory cytokines and proteins. Inhibiting miR-365a-3p, however, produced the opposite effects. Mechanistically, miR-365a-3p targeted the 3\'-untranslated region of MyD88, thereby inactivating MyD88-mediated NF-κB pathway. miR-365a-3p overexpression mitigated sepsis-mediated myocardial injury by inhibiting MyD88-mediated NF-κB activation.
摘要：
脓毒症常导致全身多器官功能障碍,大多数死亡可归因于急性心肌损伤（AMI）。在这项研究中,我们旨在探讨miR-365a-3p在脓毒症诱导的AMI中的功能作用.在体外和体内使用脂多糖（LPS）构建脓毒症心肌损伤模型，并选择性调节miR-365a-3p的表达。采用Real-timePCR或Westernblot检测miR-365a-3p的表达,炎性细胞因子(肿瘤坏死因子α(TNF-α),白细胞介素-1β（IL-1β），和IL-6），和炎症相关蛋白（核因子-κB（NF-κB），I-κB,骨髓分化因子88（MyD88））在心肌组织和细胞中。此外，细胞计数试剂盒-8(CCK8)和流式细胞术检测心肌细胞增殖和凋亡,分别。此外，miR-365a-3p和MyD88之间的靶向关系通过双荧光素酶活性测定得到验证.miR-365a-3p在LPS诱导的心肌损伤模型中表达下调。miR-365a-3p过表达可降低心肌细胞凋亡,抑制炎性细胞因子和蛋白的表达。抑制miR-365a-3p,然而,产生了相反的效果。机械上,miR-365a-3p靶向MyD88的3'非翻译区，从而使MyD88介导的NF-κB途径失活。miR-365a-3p过表达通过抑制MyD88介导的NF-κB活化减轻脓毒症介导的心肌损伤。
