Coimbra Luiza B C T, Pinto-Martinez Andrea, Pavan Isadora C B, Melo Everton G, Araujo Thaís L S
Department of Biochemistry, Institute of Chemistry, Universidade de São Paulo, São Paulo, Brazil.
Department of Biochemistry, Institute of Chemistry, Universidade de São Paulo, São Paulo, Brazil; Department of Organic Chemistry, Institute of Chemistry, Universidade Estadual de Campinas - UNICAMP, Campinas, São Paulo, Brazil.
Cell Stress Chaperones. 2025 May 25;30(4):100085. doi: 10.1016/j.cstres.2025.100085.
Heat shock proteins (HSPs) play crucial roles in human endothelial cell functions such as migration and angiogenesis. However, human HSP dynamics under stress conditions such as heat shock (HS) and hypoxia in human endothelial cells (ECs) are enigmatic, and the characteristics of HSPs in ECs after exposure to thermal stress and a low-oxygen environment are unknown. We hypothesized that ECs adapt to HS and hypoxia by modulating chaperome oligomerization and that HSP70 is a major determinant of the endothelial phenotype. HSP70 inhibition with VER-155008 or YM-1 in primary human endothelial cells decreases EC proliferation, migration, and angiogenesis at baseline and after heat shock recovery. We showed that vascular-independent HSC/P70 multimeric complexes in primary human veins (HUVEC) and coronary artery ECs (HCAEC) accumulate after HS and are decreased by hypoxia. HS recovery increases the number of HSP90 dimers, inducible HSP70, and HSP40 macromolecular complexes, whereas HSC70 returns to baseline. We demonstrated that the HS response and hypoxia regulate HSPs through a new layer of complexity, oligomerization, in addition to classical cochaperone/NEF interactions. The biphasic temporal oligomerization of molecular chaperones in the recovery phase provides a novel face of the heat shock response. In addition, shifts in the subcellular location and upregulation of HSP70 were also observed here. The decrease in HSP expression caused by hypoxia raises the possibility that decreased chaperone power contributes to the endothelial dysfunction found in atherosclerosis, thrombosis, and cancer. Together, these results show that HSP70 is pivotal to the healthy endothelial response in veins and coronary arteries, and we revealed human HSP dynamics in the vascular response to proteotoxic stress.
热休克蛋白（HSPs）在人类内皮细胞功能（如迁移和血管生成）中发挥着关键作用。然而，在热休克（HS）和缺氧等应激条件下，人类内皮细胞（ECs）中HSP的动态变化尚不清楚，且暴露于热应激和低氧环境后ECs中HSP的特征也未知。我们推测ECs通过调节伴侣蛋白寡聚化来适应HS和缺氧，且HSP70是内皮细胞表型的主要决定因素。在原代人内皮细胞中用VER-155008或YM-1抑制HSP70会降低基线时以及热休克恢复后的EC增殖、迁移和血管生成。我们发现，原代人静脉（HUVEC）和冠状动脉ECs（HCAEC）中与血管无关的HSC/P70多聚体复合物在HS后会积累，而在缺氧时会减少。HS恢复会增加HSP90二聚体、诱导型HSP70和HSP40大分子复合物的数量，而HSC70则恢复到基线水平。我们证明，除了经典的共伴侣蛋白/核苷酸交换因子（NEF）相互作用外，HS反应和缺氧还通过新的复杂层面——寡聚化来调节HSP。分子伴侣在恢复阶段的双相时间寡聚化展现了热休克反应的新面貌。此外，这里还观察到了HSP70亚细胞定位的改变和上调。缺氧导致的HSP表达下降增加了一种可能性，即伴侣蛋白功能下降促成了动脉粥样硬化、血栓形成和癌症中发现的内皮功能障碍。总之，这些结果表明HSP70对静脉和冠状动脉中健康的内皮反应至关重要，并且我们揭示了人类HSP在血管对蛋白毒性应激反应中的动态变化。
