Dong Zheng, Zhu Jian-Bing, Cheng Shuo, Weng Xin-Yu, Sun Xiao-Lei, Qian Ju-Ying, Zou Yun-Zeng, Sun Ai-Jun, Wang Shi-Jun, Ma Lei-Lei, Ge Jun-Bo
Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China; Key Laboratory of Viral Heart Diseases, National Health Commission, Shanghai, China; Key Laboratory of Viral Heart Diseases, Chinese Academy of Medical Sciences, Shanghai, China; National Clinical Research Center for Interventional Medicine, Shanghai, China; Department of Cardiology, Nanjing Drum Tower Hospital, Nanjing University, Nanjing, China.
Department of Cardiology, The First Affiliated Hospital of Nanchang University, Jiangxi Medical College, Nanchang, China" and "Jiangxi Hypertension Research Institute, Nanchang, China.
Free Radic Biol Med. 2025 Feb 1;227:260-275. doi: 10.1016/j.freeradbiomed.2024.12.008. Epub 2024 Dec 4.
Bruton tyrosine kinase (BTK), which is highly expressed in immune cells, plays a critical role in regulating the function of macrophages. A growing body of evidence has demonstrated that the accumulation of macrophages in cardiac tissue after myocardial infarction (MI) significantly affects wound healing and ventricular remodeling during the early phase of repair after MI. However, the role of BTK in cardiac repair post-MI, especially in macrophage-mediated repair, remains unclear.
MI was induced by permanent left anterior descending (LAD) artery ligation in wild-type (WT) mice and macrophage-specific BTK-knockout (BTK) mice. Expression of BTK and phosphorylated BTK were assessed by western blotting. Then, RNA sequencing and ChIP-qPCR assay were performed to explore potential BTK targets and transcriptional regulatory sites.
BTK, which was mainly expressed in macrophages, was upregulated in mice after MI. Compared with WT mice, BTK mice had significantly greater mortality due to heart rupture, reduced wall thickness and severe impairment of left ventricular (LV) function after MI. In addition, increased matrix metalloproteinase-9 (MMP-9) expression and decreased α-SMA and collagen expression were observed in BTK mice after MI. Further experiments revealed that BTK deficiency in macrophages reduces the expression of VEGF and impairs angiogenesis after MI. By RNA sequencing, we found that Nf-kB family genes, as well as the urokinase-type plasminogen activator (uPA), were significantly upregulated in BTK-deficient macrophages. By ChIP-qPCR analysis, we confirmed that uPA was transcriptionally activated by the Nf-kB p65 subunit. Finally, the application of plasminogen activator inhibitor-1 (PAI-1), an uPA inhibitor, markedly protected against cardiac rupture, lowered the mortality rate, and improved cardiac function by increasing collagen deposition and promoting tissue healing in BTK mice after MI.
The present study identifies PAI-1 as a novel cardioprotective agent for cardiac repair post-MI that increases collagen deposition and promotes tissue healing. A therapeutic strategy targeting BTK may be a promising treatment for cardiac repair post-MI.
布鲁顿酪氨酸激酶（BTK）在免疫细胞中高度表达，在调节巨噬细胞功能方面发挥关键作用。越来越多的证据表明，心肌梗死（MI）后心脏组织中巨噬细胞的积聚在MI后早期修复过程中显著影响伤口愈合和心室重塑。然而，BTK在MI后心脏修复中的作用，尤其是在巨噬细胞介导的修复中的作用仍不清楚。
通过永久性结扎野生型（WT）小鼠和巨噬细胞特异性BTK基因敲除（BTK）小鼠的左前降支（LAD）动脉诱导MI。通过蛋白质免疫印迹法评估BTK和磷酸化BTK的表达。然后，进行RNA测序和染色质免疫沉淀-定量聚合酶链反应（ChIP-qPCR）分析，以探索潜在的BTK靶点和转录调控位点。
BTK主要在巨噬细胞中表达，MI后小鼠体内BTK表达上调。与WT小鼠相比，BTK小鼠因心脏破裂导致的死亡率显著更高，MI后心室壁厚度降低，左心室（LV）功能严重受损。此外，MI后BTK小鼠体内基质金属蛋白酶-9（MMP-9）表达增加，α-平滑肌肌动蛋白（α-SMA）和胶原蛋白表达减少。进一步实验表明，巨噬细胞中BTK缺陷会降低MI后血管内皮生长因子（VEGF）的表达并损害血管生成。通过RNA测序，我们发现BTK缺陷型巨噬细胞中核因子-κB（Nf-κB）家族基因以及尿激酶型纤溶酶原激活剂（uPA）显著上调。通过ChIP-qPCR分析，我们证实uPA是由Nf-κB p65亚基转录激活的。最后，应用uPA抑制剂纤溶酶原激活剂抑制剂-1（PAI-1）可显著预防心脏破裂，降低死亡率，并通过增加MI后BTK小鼠体内胶原蛋白沉积和促进组织愈合来改善心脏功能。
本研究确定PAI-1是一种新型的用于MI后心脏修复的心脏保护剂，可增加胶原蛋白沉积并促进组织愈合。靶向BTK的治疗策略可能是MI后心脏修复的一种有前景的治疗方法。
