PXR激动剂在新型腺嘌呤诱导的HFsnEF小鼠模型中的治疗作用

摘要(中文译文)

射血分数超常的心力衰竭（HFsnEF，LVEF ≥ 65%）是新定义的一种心力衰竭亚型。其病理生理复杂性及缺乏有效的动物模型阻碍了其治疗研究进展。本研究旨在探讨腺嘌呤饮食诱导的HFsnEF小鼠模型的特征，并阐明孕烷X受体（PXR）激动剂的心脏保护作用及其分子机制。采用含0.2%腺嘌呤饮食喂养C57BL/6J小鼠28天以建立HFsnEF模型。通过小动物超声（Vevo 3100）评估心脏功能参数（左心室射血分数、心输出量、室间隔厚度、左心室容积及左心室直径），并通过组织病理学分析心肌损伤及纤维化程度。采用Tunel染色检测细胞凋亡水平。采用免疫荧光、RT-PCR和western blot检测心肌细胞凋亡标志物（p53、Bax、Bcl2、Caspase3及cleave-Caspase3）、心脏毛细血管密度标志物（CD31）及心肌细胞肥大相关标志物（ANP和β-MHC）的表达。在体外实验中，采用腺嘌呤模拟H9c2心肌细胞损伤模型，使用CCK-8检测细胞活力。腺嘌呤饮食成功诱导了小鼠HFsnEF表型，其特征为心脏缩小、射血分数显著升高（≥ 65%）、心输出量降低、收缩期心室后壁特异性增厚、舒张功能受损、心室收缩、心肌纤维化及肥大，以及血压和心率下降。在机制上，Tunel染色及p53、Bax、cleave-Caspase3/Caspase3和Bcl2的表达表明腺嘌呤诱导了心肌细胞凋亡。然而，这些腺嘌呤诱导的变化可被PXR激动剂逆转。本研究首次建立了腺嘌呤饮食诱导的HFsnEF小鼠模型，并揭示PXR激动剂可通过调控p53-Bax/Bcl2凋亡通路减轻心肌损伤，为HFsnEF的机制研究及靶向治疗提供了新依据。

Abstract

Heart failure (HF) with supranormal ejection fraction (HFsnEF, LVEF ≥ 65%) is a newly defined subtype of HF. Its pathophysiological complexity and lack of effective animal models have hindered its treatment research progress. The aim of this study is to explore the characteristics of the HFsnEF mouse model induced by an adenine diet and elucidate the cardioprotective effect of pregnane X receptor (PXR) agonist and its molecular mechanism. C57BL/6J mice were fed with a 0.2% adenine diet for 28 days to establish HFsnEF model. Cardiac function parameters (left ventricular ejection fraction, cardiac output, interventricular septal thickness, left ventricular volume, and left ventricular diameter) were evaluated by small animal ultrasound (Vevo 3100), and the degree of myocardial injury and fibrosis were analyzed by histopathology. Tunel staining was used to detect the level of apoptosis. Immunofluorescence, RT-PCR, and western blot were used to detect the expression of myocardial cell apoptosis markers (p53, Bax, Bcl2, Caspase3, and cleave-Caspase3), cardiac capillary density marker (CD31), and cardiomyocyte hypertrophy-related markers (ANP and β-MHC). In vitro, the adenine was used to simulate the injury model of H9c2 cardiomyocytes. CCK-8 was used to detect cell viability. Adenine diet successfully induced the phenotype of HFsnEF in mice, which was characterized by smaller hearts, significantly increased ejection fraction (≥ 65%), reduced cardiac output, specific ventricular posterior wall thickening during systole, impaired diastolic function, ventricular shrinkage, myocardial fibrosis and hypertrophy, and decreased blood pressure and heart rate. Mechanistically, the Tunel staining and the expression of p53, Bax, cleave-Caspase3/Caspase3, and Bcl2 indicated that adenine induced cardiomyocyte apoptosis. However, these adenine-induced changes were reversed by PXR agonists. This is the first study to establish an HFsnEF mouse model induced by an adenine diet, and reveals that PXR agonists can alleviate myocardial injury by regulating the p53-Bax/Bcl2 apoptosis pathway, providing a new basis for the mechanism and targeted therapy of HFsnEF.

如何引用

FASEB journal : official publication of the Federation of American Societies for Experimental Biology 的其他文献

• 通过单细胞测序和空间组学技术揭示肾小管上皮细胞衰老的异质性及其对肾纤维化的影响
• {"_":"肝脏特异性抑制PLA2G6/iPLAβ改善高脂饮食喂养小鼠的葡萄糖和脂质代谢。","sub":["2"]}
• Telitacicept联合糖皮质激素与单独使用Telitaciccept治疗IgA肾病：一项现实世界的研究
• 慢性葡萄糖激酶激活和抑制对胰腺β细胞功能的对比作用
• 在APP669位点鉴定ADAMTS5为APP切割酶
• 二硫化物交联通过Hsp70介导的泛素连接酶途径诱导Arc/Arg3.1的快速降解
• 通过综合生物信息学和机器学习算法鉴定和验证靶向WT-1的miR-206-3p促进膜性肾病
• 多组学分析鉴定神经胶质细胞功能障碍相关基因作为阿尔茨海默病的治疗靶点和候选药物
• 糖尿病肾病线粒体功能障碍和细胞器串扰的综合见解
• 肝细胞中的CBP/β-Catenin信号在代谢功能障碍相关脂肪性肝炎小鼠模型中MMP-7介导的肝纤维化中起着关键作用