Proline metabolic reprogramming modulates cardiac remodeling induced by pressure overload in the heart. Proline metabolic reprogramming modulates cardiac remodeling induced by pressure overload in the heart

Metabolic reprogramming is critical in the onset of pressure overload-induced cardiac remodeling. Our study reveals that proline dehydrogenase (PRODH), the key enzyme in proline metabolism, reprograms cardiomyocyte metabolism to protect against cardiac remodeling. We induced cardiac remodeling using transverse aortic constriction (TAC) in both cardiac-specific PRODH knockout and overexpression mice. Our results indicate that PRODH expression is suppressed post-TAC. Cardiac-specific PRODH knockout mice exhibited worsened cardiac dysfunction, while mice with PRODH overexpression demonstrated a protective effect. Additionally, we simulated cardiomyocyte hypertrophy in vitro using neonatal rat ventricular myocytes treated with phenylephrine. Through RNA sequencing, metabolomics, and metabolic flux analysis, we elucidated that PRODH overexpression in cardiomyocytes redirects proline catabolism to replenish tricarboxylic acid (TCA) cycle intermediates, enhance energy production, and restore glutathione redox balance. In summary, our findings suggest PRODH as a modulator of cardiac bioenergetics and redox homeostasis duing cardiac remodeling induced by pressure overload. This highlights the potential of PRODH as a therapeutic target for cardiac remodeling. Overall design: To investigate the role of PRODH in the regulation of pressure overload-induced cardiac remodeling, cardiac-specific overexpression of PRODH was achieved through AAV9-mediated delivery system. Two types of viruses, AAV9-Vector and AAV9-PRODH, were injected into mice, and transverse aortic constriction (TAC) surgery was performed. Four weeks post-surgery, cardiac tissues were collected for RNA-seq analysis. The primary aim of our study was to compare the changes between the TAC group and the Sham group in AAV9-Vector mice, as well as to assess the transcriptomic differences between the AAV9-Vector and AAV9-PRODH groups in mice following TAC surgery.

代谢重编程在压力负荷诱导的心肌重构的发生过程中发挥关键作用。本研究发现，作为脯氨酸代谢关键酶的脯氨酸脱氢酶（proline dehydrogenase, PRODH），可通过重编程心肌细胞代谢发挥抗心肌重构的作用。本研究通过横向主动脉缩窄（transverse aortic constriction, TAC）术，在心肌特异性PRODH敲除与过表达小鼠中构建心肌重构模型。结果显示，TAC术后小鼠心肌组织中PRODH的表达被抑制；心肌特异性PRODH敲除小鼠的心脏功能障碍程度加重，而PRODH过表达小鼠则表现出心脏保护效应。此外，本研究采用苯肾上腺素（phenylephrine）处理新生大鼠心室肌细胞，体外模拟心肌细胞肥大模型。通过RNA测序、代谢组学及代谢流分析，本研究阐明：心肌细胞中PRODH过表达可重塑脯氨酸分解代谢途径，补充三羧酸循环（tricarboxylic acid cycle, TCA）中间产物，提升能量生成效率，并恢复谷胱甘肽氧化还原稳态。综上，本研究结果表明，PRODH可调控压力负荷诱导的心肌重构过程中心脏的生物能代谢与氧化还原稳态，提示PRODH有望成为心肌重构治疗的潜在靶点。实验设计概述：为探究PRODH在压力负荷诱导心肌重构调控中的作用，本研究通过腺相关病毒血清型9（AAV9）介导的递送系统，实现小鼠心肌组织中PRODH的特异性过表达。向小鼠注射两种病毒载体：AAV9空载对照与AAV9-PRODH，随后实施横向主动脉缩窄（TAC）手术。术后4周，采集小鼠心脏组织用于RNA测序分析。本研究的主要目的为对比AAV9空载对照小鼠中TAC组与假手术（Sham）组的转录组变化，同时评估TAC术后AAV9空载对照组与AAV9-PRODH过表达组小鼠的转录组差异。