We aimed to determine: 1) the mechanism(s) that enable glucose-6-phosphate dehydrogenase (G6PD) to regulate serum response factor (SRF)- and myocardin (MYOCD)‑driven smooth muscle cell (SMC)-restricted gene expression, a process that aids in the differentiation of SMCs; and 2) whether G6PD-mediated metabolic reprogramming contributes to the pathogenesis of vascular diseases in metabolic syndrome (MetS). Inhibition of G6PD activity increased (>30%) expression of SMC-restricted genes and concurrently decreased (40%) the growth of human and rat SMCs ex vivo. Expression of SMC-restricted genes decreased (>100-fold) across successive passages in primary cultures of SMCs isolated from mouse aorta. G6PD inhibition increased Myh11 (47%) while decreasing (>50%) Sca-1, a stem cell marker, in cells passaged seven times. Similarly, CRISPR-Cas9-mediated expression of the loss-of-function Mediterranean variant of G6PD (S188F; G6PD^S188F) in rats promoted transcription of SMC‑restricted genes. G6PD knockdown or inhibition decreased (48.5%) HDAC activity, enriched (by 3-fold) H3K27ac on the Myocd promoter, and increased Myocd and Myh11 expression. Interestingly, G6PD activity was significantly higher in aortas from JCR rats with MetS than control SD rats. Treating JCR rats with epiandrosterone (30 mg/kg/day), a G6PD inhibitor, increased expression of SMC-restricted genes, suppressed Serpine1 and Epha4, and reduced blood pressure. Moreover, feeding SD control (littermates) and G6PD^S188F rats a high-fat diet for 4 months increased Serpine1 and Epha4 expression and mean arterial pressure in SD but not G6PD^S188F rats. Our findings demonstrate G6PD downregulates transcription of SMC-restricted genes through HDAC-dependent deacetylation and potentially augments the severity of vascular diseases associated with MetS.

中文翻译：

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G6PD 活性有助于调节平滑肌细胞中的组蛋白乙酰化和基因表达以及血管疾病的发病机制

我们旨在确定：1) 使 6-磷酸葡萄糖脱氢酶 (G6PD) 能够调节血清反应因子 (SRF) 和心肌素 (MYOCD) 驱动的平滑肌细胞 (SMC) 限制性基因表达的机制，有助于 SMC 分化的过程；2) G6PD 介导的代谢重编程是否有助于代谢综合征 (MetS) 中血管疾病的发病机制。G6PD 活性的抑制增加 (>30%) SMC 限制基因的表达，同时减少 (40%) 离体人和大鼠 SMC 的生长。在从小鼠主动脉分离的 SMC 的原代培养物中，SMC 限制基因的表达在连续传代中降低（>100 倍）。G6PD 抑制增加 Myh11 (47%)，同时减少 (>50%) Sca-1，干细胞标志物，在细胞传代 7 次。相似地，^S188F）在大鼠中促进了 SMC 限制基因的转录。G6PD 敲低或抑制降低（48.5%）HDAC 活性，在 Myocd 启动子上富集（3 倍）H3K27ac，并增加 Myocd 和 Myh11 表达。有趣的是，患有 MetS 的 JCR 大鼠的主动脉中 G6PD 活性显着高于对照 SD 大鼠。用 G6PD 抑制剂表雄酮（30 mg/kg/天）治疗 JCR 大鼠，可增加 SMC 限制基因的表达，抑制 Serpine1 和 Epha4，并降低血压。此外，喂食 SD 对照（同窝仔）和 G6PD ^S188F大鼠 4 个月的高脂饮食增加了 SD 中 Serpine1 和 Epha4 的表达和平均动脉压，但 G6PD ^S188F没有老鼠。我们的研究结果表明，G6PD 通过 HDAC 依赖性去乙酰化下调 SMC 限制基因的转录，并可能增加与 MetS 相关的血管疾病的严重程度。