Xian Tinghui, Liu Yi, Ye Yongsheng, Peng Bohua, Huang Jie, Liang Lin, Zhang Jiaqing, Wu Hao, Lin Zhen
Department of Biochemistry and Molecular Biology, School of Preclinical Medicine, Jinan University, 601 West Huangpu Avenue, Guangzhou, Guangdong, 510632, China.
Department of Oral Implantology, Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medicine, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
Free Radic Biol Med. 2024 Nov 20;225:164-180. doi: 10.1016/j.freeradbiomed.2024.09.046. Epub 2024 Sep 27.
Difficulty in skin wound healing is a concern for diabetic patients across the world. Impaired mitochondrial dysfunction and aging-related vascular dysfunction in human umbilical vein endothelial cells (HUVECs) caused by oxidative stress are major impediments to diabetic wound healing. However, research on skin repair at the mechanistic level by improving mitochondrial function and inhibiting oxidative stress-induced HUVEC senescence remains lacking.
Human saliva effectively inhibits the natural aging of HUVECs through immunodepletion experiments. Histatin 1 (Hst1), a short peptide comprising 38 amino acids, is the primary component of human saliva that prevents HUVEC aging. Based on in vitro findings, Hst1 decreased staining for senescence-associated β-galactosidase activity and expression of mediators of senescence signaling, including p53, p21, and p16. Mechanistically, HUVEC senescence is associated with Hst1-modulated nuclear factor Nrf2 signaling as Hst1 induces ERK-mediated Nrf2 nuclear translocation through NADPH oxidase-dependent ROS regulation, reinforced Nrf2 antioxidant response, and suppressed oxidative stress. RNA sequencing identified that the mitochondrial-related gene set was enriched in the Hst1 group. Coimmunoprecipitation indicated that Hst1 delayed hydrogen peroxide-induced HUVEC senescence by inhibiting mitochondria-associated endoplasmic reticulum (ER) membrane formation mediated by inositol 1,4,5-trisphosphate receptor 1-glucose-regulated protein 75-voltage-dependent anion channel 1 (VDAC1) complex interactions. Furthermore, in aging HUVECs, Hst1 treatment or VDAC1 silencing with small interfering RNA hindered calcium (Ca) transfer from the ER to the mitochondria, thereby ameliorating mitochondrial Ca overload and restoring mitochondrial function. In an in vivo mouse model of diabetes mellitus skin defects, Hst1 facilitated wound healing by stimulating the new blood vessel formation and impeding the expression of senescent biomarkers.
This study proposes a theoretical solution that Hst1 can restore mitochondrial function by inhibiting oxidative stress or cellular senescence, thereby promoting angiogenesis and diabetic wound repair.
皮肤伤口愈合困难是全球糖尿病患者面临的一个问题。氧化应激导致的人脐静脉内皮细胞（HUVECs）线粒体功能障碍和衰老相关血管功能障碍是糖尿病伤口愈合的主要障碍。然而，在通过改善线粒体功能和抑制氧化应激诱导的HUVEC衰老来进行皮肤修复的机制层面的研究仍然缺乏。
通过免疫耗竭实验，人唾液能有效抑制HUVECs的自然衰老。组蛋白1（Hst1）是一种由38个氨基酸组成的短肽，是人唾液中防止HUVEC衰老的主要成分。基于体外研究结果，Hst1减少了衰老相关β-半乳糖苷酶活性的染色以及衰老信号介质（包括p53、p21和p16）的表达。从机制上讲，HUVEC衰老与Hst1调节的核因子Nrf2信号传导有关，因为Hst1通过NADPH氧化酶依赖性ROS调节诱导ERK介导的Nrf2核转位，增强Nrf2抗氧化反应，并抑制氧化应激。RNA测序表明线粒体相关基因集在Hst1组中富集。免疫共沉淀表明，Hst1通过抑制由肌醇1,4,5-三磷酸受体1-葡萄糖调节蛋白75-电压依赖性阴离子通道1（VDAC1）复合物相互作用介导的线粒体相关内质网（ER）膜形成，延缓过氧化氢诱导的HUVEC衰老。此外，在衰老的HUVECs中，Hst1处理或用小干扰RNA沉默VDAC1可阻碍钙（Ca）从内质网转移到线粒体，从而改善线粒体Ca超载并恢复线粒体功能。在糖尿病皮肤缺损的体内小鼠模型中，Hst1通过刺激新血管形成和抑制衰老生物标志物的表达促进伤口愈合。
本研究提出了一种理论解决方案，即Hst1可通过抑制氧化应激或细胞衰老来恢复线粒体功能，从而促进血管生成和糖尿病伤口修复。
