P4HA1 expression was modulated using adenoviruses. Endothelial angiogenesis was evaluated through 5-ethynyl-2\'-deoxyuridine incorporation, transwell migration, and tube formation assays in vitro. In vivo experiments measured blood flow and capillary density in the hindlimb ischemia (HLI) model. Glycolytic stress assays, glucose uptake, lactate production, and quantitative reverse transcription-polymerase chain reaction (RT-PCR) were employed to assess glycolytic capacity. Transcriptome sequencing, validated by western blotting and RT-PCR, was utilized to determine underlying mechanisms.
P4HA1 was upregulated in endothelial cells under hypoxia and in the HLI model. P4HA1 overexpression promoted angiogenesis in vitro and in vivo, while its knockdown had the opposite effect. P4HA1 overexpression reduced cellular α-ketoglutarate (α-KG) levels by consuming α-KG during collagen hydroxylation. Downregulation of α-KG reduced the protein level of a DNA dioxygenase, ten-eleven translocation 2 (TET2), and its recruitment to the fructose-1,6-biphosphatase (FBP1) promoter, resulting in decreased FBP1 expression. The decrease in FBP1 enhanced glycolytic metabolism, thereby promoting endothelial angiogenesis.
Hypoxia-induced endothelial P4HA1 overexpression enhanced angiogenesis by promoting glycolytic metabolism reprogramming through the P4HA1/α-KG/TET2/FBP1 pathway. The study\'s findings underscore the significance of P4HA1 in post-ischemic angiogenesis, suggesting its therapeutic potential for post-ischemic tissue repair.
方法:使用腺病毒调节P4HA1表达。通过5-乙炔基-2'-脱氧尿苷掺入评估内皮血管生成,Transwell迁移,和体外试管形成测定。体内实验测量了后肢缺血(HLI)模型中的血流量和毛细血管密度。糖酵解应激测定,葡萄糖摄取,乳酸生产,和定量逆转录聚合酶链反应(RT-PCR)用于评估糖酵解能力。转录组测序,通过蛋白质印迹和RT-PCR验证,被用来确定潜在的机制。
结果:在缺氧和HLI模型中,P4HA1在内皮细胞中上调。P4HA1过表达促进体外和体内血管生成,而它的击倒却产生了相反的效果。P4HA1过表达通过在胶原羟基化过程中消耗α-KG来降低细胞α-酮戊二酸(α-KG)水平。α-KG的下调降低了DNA双加氧酶的蛋白质水平,十-十一易位2(TET2),及其对果糖-1,6-双磷酸酶(FBP1)启动子的募集,导致FBP1表达降低。FBP1的减少增强了糖酵解代谢,从而促进内皮血管生成。
结论:低氧诱导的内皮P4HA1过表达通过P4HA1/α-KG/TET2/FBP1途径促进糖酵解代谢重编程而增强血管生成。这项研究的发现强调了P4HA1在缺血后血管生成中的意义,提示其治疗缺血后组织修复的潜力。