He Xiaoqing, Liu Shan, Zhang Zhanyu, Liu Qirui, Dong Juan, Lin Zhifeng, Chen Junhao, Li Lihuan, Liu Weihua, Liu Shaojun, Liu Shiming
Department of Cardiology, Guangdong Key Laboratory of Vascular Diseases, The Second Affiliated Hospital, Guangzhou Institute of Cardiovascular Disease, Guangzhou Medical University, Guangzhou, 510260, People's Republic of China.
BMC Cardiovasc Disord. 2024 Jul 16;24(1):365. doi: 10.1186/s12872-024-03893-0.
M1 macrophages are closely associated with cardiac injury after myocardial infarction (MI). Increasing evidence shows that exosomes play a key role in pathophysiological regulation after MI, but the role of M1 macrophage-derived exosomes (M1-Exos) in myocardial regeneration remains unclear. In this study, we explored the impact of M1 macrophage-derived exosomes on cardiomyocytes regeneration in vitro and in vivo.
M0 macrophages were induced to differentiate into M1 macrophages with GM-CSF (50 ng/mL) and IFN-γ (20 ng/mL). Then M1-Exos were isolated and co-incubated with cardiomyocytes. Cardiomyocyte proliferation was detected by pH3 or ki67 staining. Quantitative real-time PCR (qPCR) was used to test the level of miR-155 in macrophages, macrophage-derived exosomes and exosome-treated cardiomyocytes. MI model was constructed and LV-miR-155 was injected around the infarct area, the proliferation of cardiomyocytes was counted by pH3 or ki67 staining. The downstream gene and pathway of miR-155 were predicted and verified by dual-luciferase reporter gene assay, qPCR and immunoblotting analysis. IL-6 (50 ng/mL) was added to cardiomyocytes transfected with miR-155 mimics, and the proliferation of cardiomyocytes was calculated by immunofluorescence. The protein expressions of IL-6R, p-JAK2 and p-STAT3 were detected by Western blot.
The results showed that M1-Exos suppressed cardiomyocytes proliferation. Meanwhile, miR-155 was highly expressed in M1-Exos and transferred to cardiomyocytes. miR-155 inhibited the proliferation of cardiomyocytes and antagonized the pro-proliferation effect of interleukin 6 (IL-6). Furthermore, miR-155 targeted gene IL-6 receptor (IL-6R) and inhibited the Janus kinase 2(JAK)/Signal transducer and activator of transcription (STAT3) signaling pathway.
M1-Exos inhibited cardiomyocyte proliferation by delivering miR-155 and inhibiting the IL-6R/JAK/STAT3 signaling pathway. This study provided new insight and potential treatment strategy for the regulation of myocardial regeneration and cardiac repair by macrophages.
M1巨噬细胞与心肌梗死后的心脏损伤密切相关。越来越多的证据表明，外泌体在心肌梗死后的病理生理调节中起关键作用，但M1巨噬细胞衍生的外泌体（M1-Exos）在心肌再生中的作用仍不清楚。在本研究中，我们探讨了M1巨噬细胞衍生的外泌体在体外和体内对心肌细胞再生的影响。
用GM-CSF（50 ng/mL）和IFN-γ（20 ng/mL）诱导M0巨噬细胞分化为M1巨噬细胞。然后分离M1-Exos并与心肌细胞共孵育。通过pH3或ki67染色检测心肌细胞增殖。采用定量实时PCR（qPCR）检测巨噬细胞、巨噬细胞衍生的外泌体和外泌体处理的心肌细胞中miR-155的水平。构建心肌梗死模型并在梗死区域周围注射LV-miR-155，通过pH3或ki67染色计数心肌细胞的增殖情况。通过双荧光素酶报告基因检测、qPCR和免疫印迹分析预测并验证miR-155的下游基因和信号通路。将IL-6（50 ng/mL）添加到转染了miR-155模拟物的心肌细胞中，通过免疫荧光计算心肌细胞的增殖情况。通过蛋白质印迹法检测IL-6R、p-JAK2和p-STAT3的蛋白表达。
结果表明，M1-Exos抑制心肌细胞增殖。同时，miR-155在M1-Exos中高表达并转移至心肌细胞。miR-155抑制心肌细胞增殖并拮抗白细胞介素6（IL-6）的促增殖作用。此外，miR-155靶向基因白细胞介素6受体（IL-6R）并抑制Janus激酶2（JAK）/信号转导子和转录激活子（STAT3）信号通路。
M1-Exos通过传递miR-155并抑制IL-6R/JAK/STAT3信号通路来抑制心肌细胞增殖。本研究为巨噬细胞调节心肌再生和心脏修复提供了新的见解和潜在的治疗策略。
