Yang Chun-Tao, Zhao Yu, Xian Ming, Li Jian-Hua, Dong Qi, Bai Hong-Bo, Xu Ji-de, Zhang Mei-Fen
Department of Physiology, Guangzhou Medical University, Guangzhou, P.R. China.
Cell Physiol Biochem. 2014;34(4):1304-17. doi: 10.1159/000366339. Epub 2014 Sep 29.
BACKGROUND/AIM: Delayed wound healing is a common skin complication of diabetes, which is associated with keratinocyte injury and dysfunction. Levels of methylglyoxal (MGO), an α-dicarbonyl compound, are elevated in diabetic skin tissue and plasma, while levels of hydrogen sulfide (H2S), a critical gaseous signaling molecule, are reduced. Interestingly, the gas has shown dermal protection in our previous study. To date, there is no evidence demonstrating whether MGO affects keratinocyte viability and function or H2S donation abolishes these effects and improves MGO-related impairment of wound healing. The current study was conducted to examine the effects of MGO on the injury and function in human skin keratinocytes and then to evaluate the protective action of a novel H2S-releasing molecule.
An N-mercapto-based H2S donor (NSHD)-1 was synthesized and its ability to release H2S was observed in cell medium and cells, respectively. HaCaT cells, a cell line of human skin keratinocyte, were exposed to MGO to establish an in vitro diabetic wound healing model. NSHD-1 was added to the cells before MGO exposure and the improvement of cell function was observed in respect of cellular viability, apoptosis, oxidative stress, mitochondrial membrane potential (MMP) and behavioral function.
Treatment with MGO decreased cell viability, induced cellular apoptosis, increased intracellular reactive oxygen species (ROS) content and depressed MMP in HaCaT cells. The treatment also damaged cell behavioral function, characterized by decreased cellular adhesion and migration. The synthesized H2S-releasing molecule, NSHD-1, was able to increase H2S levels in both cell medium and cells. Importantly, pretreatment with NSHD-1 inhibited MGO-induced decreases in cell viability and MMP, increases in apoptosis and ROS accumulation in HaCaT cells. The pretreatment was also able to improve adhesion and migration function.
These results demonstrate that the novel synthesized H2S donor is able to protect human skin keratinocytes against MGO-induced injury and behavior dysfunction. We believe that more reasonable H2S-releasing molecules will bring relief to patients suffering from delayed wound healing in diabetes mellitus in the future.
背景/目的：伤口愈合延迟是糖尿病常见的皮肤并发症，与角质形成细胞损伤和功能障碍有关。α-二羰基化合物甲基乙二醛（MGO）在糖尿病皮肤组织和血浆中的水平升高，而关键的气体信号分子硫化氢（H2S）水平降低。有趣的是，在我们之前的研究中，这种气体已显示出对皮肤的保护作用。迄今为止，尚无证据表明MGO是否影响角质形成细胞的活力和功能，或者H2S供体是否能消除这些影响并改善与MGO相关的伤口愈合损伤。本研究旨在探讨MGO对人皮肤角质形成细胞损伤和功能的影响，进而评估一种新型H2S释放分子的保护作用。
合成了一种基于N-巯基的H2S供体（NSHD）-1，并分别在细胞培养基和细胞中观察其释放H2S的能力。将人皮肤角质形成细胞系HaCaT细胞暴露于MGO中，建立体外糖尿病伤口愈合模型。在MGO暴露前将NSHD-1添加到细胞中，并从细胞活力、凋亡、氧化应激、线粒体膜电位（MMP）和行为功能方面观察细胞功能的改善情况。
用MGO处理可降低HaCaT细胞的活力，诱导细胞凋亡，增加细胞内活性氧（ROS）含量并降低MMP。该处理还损害了细胞行为功能，其特征为细胞黏附和迁移减少。合成的H2S释放分子NSHD-1能够增加细胞培养基和细胞中的H2S水平。重要的是，用NSHD-1预处理可抑制MGO诱导的HaCaT细胞活力降低和MMP降低、凋亡增加以及ROS积累。该预处理还能够改善黏附和迁移功能。
这些结果表明，新型合成的H2S供体能够保护人皮肤角质形成细胞免受MGO诱导的损伤和行为功能障碍。我们相信，未来更合理的H2S释放分子将为糖尿病伤口愈合延迟的患者带来缓解。
