Department of Pathophysiology, School of Medicine, Nantong University, 19 Qixiu Road, Nantong, Jiangsu, 226001, People's Republic of China.
Heart Center of Henan Provincial People's Hospital, Central China Fuwai Hospital, Central China Fuwai Hospital of Zhengzhou University, Zhengzhou, Henan, 450003, People's Republic of China.
BMC Biol. 2023 Apr 7;21(1):75. doi: 10.1186/s12915-023-01580-8.
Angiogenesis plays important roles in physiological and pathologic conditions, but the mechanisms underlying this complex process often remain to be elucidated. In recent years, liquid-liquid phase separation (LLPS) has emerged as a new concept to explain many cellular functions and diseases. However, whether LLPS is involved in angiogenesis has not been studied until now. Here, we investigated the potential role of LLPS in angiogenesis and endothelial function.
We found 1,6-hexanediol (1,6-HD), an inhibitor of LLPS, but not 2,5-hexanediol (2,5-HD) dramatically decreases neovascularization of Matrigel plug and angiogenesis response of murine corneal in vivo. Moreover, 1,6-HD but not 2,5-HD inhibits microvessel outgrowth of aortic ring and endothelial network formation. The endothelial function of migration, proliferation, and cell growth is suppressed by 1,6-HD. Global transcriptional analysis by RNA-sequencing reveals that 1,6-HD specifically blocks cell cycle and downregulates cell cycle-related genes including cyclin A1. Further experimental data show that 1,6-HD treatment greatly reduces the expression of cyclin A1 but with minimal effect on cyclin D1, cyclin E1, CDK2, and CDK4. The inhibitory effect of 1,6-HD on cyclin A1 is mainly through transcriptional regulation because proteasome inhibitors fail to rescue its expression. Furthermore, overexpression of cyclin A1 in HUVECs largely rescues the dysregulated tube formation upon 1,6-HD treatment.
Our data reveal a critical role of LLPS inhibitor 1,6-HD in angiogenesis and endothelial function, which specifically affects endothelial G1/S transition through transcriptional suppression of CCNA1, implying LLPS as a possible novel player to modulate angiogenesis, and thus, it might represent an interesting therapeutic target to be investigated in clinic angiogenesis-related diseases in future.
血管生成在生理和病理条件下发挥着重要作用，但这一复杂过程的机制仍有待阐明。近年来，液-液相分离（LLPS）作为一种新的概念被提出，用以解释许多细胞功能和疾病。然而，LLPS 是否参与血管生成直到现在才被研究。在这里，我们研究了 LLPS 在血管生成和内皮功能中的潜在作用。
我们发现 1,6-己二醇（1,6-HD），一种 LLPS 的抑制剂，但不是 2,5-己二醇（2,5-HD），显著降低了 Matrigel 塞子的新生血管形成和体内小鼠角膜的血管生成反应。此外，1,6-HD 而不是 2,5-HD 抑制了主动脉环的微血管生长和内皮网络形成。1,6-HD 抑制了迁移、增殖和细胞生长的内皮功能。通过 RNA-seq 进行的全转录组分析表明，1,6-HD 特异性阻断细胞周期，并下调包括 cyclin A1 在内的细胞周期相关基因。进一步的实验数据表明，1,6-HD 处理大大降低了 cyclin A1 的表达，但对 cyclin D1、cyclin E1、CDK2 和 CDK4 的影响最小。1,6-HD 对 cyclin A1 的抑制作用主要是通过转录调控，因为蛋白酶体抑制剂不能挽救其表达。此外，在 HUVECs 中过表达 cyclin A1 可在 1,6-HD 处理后很大程度上挽救失调的管状形成。
我们的数据揭示了 LLPS 抑制剂 1,6-HD 在血管生成和内皮功能中的关键作用，它通过转录抑制 CCNA1 特异性影响内皮细胞 G1/S 期转换，暗示 LLPS 可能是一种调节血管生成的新的潜在因子，因此，它可能代表着未来临床上与血管生成相关疾病的一个有趣的治疗靶点。
