Ye Jun, Tang Xiaoli, Long Yunzhu, Chu Zhou, Zhou Qing, Lin Bojie
Department of emergency surgery, The affiliated ZhuZhou Hospital of Xiangya School of Medicine, CSU, ZhuZhou, China.
Infectious Department, The affiliated ZhuZhou Hospital of Xiangya School of Medicine, CSU, ZhuZhou, China.
J Cosmet Dermatol. 2021 Feb;20(2):684-690. doi: 10.1111/jocd.13578. Epub 2020 Jul 17.
Hypoxia is of great significance for stem cells to maintain the proliferation and differentiation capacity. As a specialized mesenchymal component of the hair follicle (HF), the dermal papilla cell (DPC) not only regulates HF cycle, but also plays a pivotal role in differentiating hair follicle stem cell(HFSC) into HF. However, whether hypoxia could affect DPCs on proliferation or metabolism remains unclear. In our study, DPCs were cultured in normoxia (20%O ) or hypoxia (5%O ). Cell viability assays were performed, and lactate dehydrogenase (LDH) activity and lactate level in DPCs were detected. After that, LDH was overexpressed or knocked down in DPCs; then, the expression of protein markers (ALP, Ki-67) was assessed by Western blotting, and cell proliferation was also detected after overexpression or knockdown of LDH. Hypoxia did show positive effect on proliferation of DPCs. The LDH activity of DPCs cultured under hypoxic condition was significantly higher than that of cultured under normoxic condition. Overexpression of LDH significantly up-regulates the expression of ALP and Ki-67 compared with knockdown and negative control. Cell proliferation was also promoted in DPCs with elevated LDH. Our findings showed that the proliferation activity of DPCs could be stimulated under hypoxia. Meanwhile, LDH plays an important role in maintaining the activity of DPCs in hypoxic condition.
缺氧对于干细胞维持增殖和分化能力具有重要意义。作为毛囊（HF）的一种特殊间充质成分，真皮乳头细胞（DPC）不仅调节毛囊周期，而且在将毛囊干细胞（HFSC）分化为毛囊方面起关键作用。然而，缺氧是否会影响DPC的增殖或代谢仍不清楚。在我们的研究中，将DPC在常氧（20%O₂）或缺氧（5%O₂）条件下培养。进行细胞活力测定，并检测DPC中的乳酸脱氢酶（LDH）活性和乳酸水平。之后，在DPC中过表达或敲低LDH；然后，通过蛋白质印迹法评估蛋白质标志物（碱性磷酸酶、Ki-67）的表达，并且在过表达或敲低LDH后也检测细胞增殖。缺氧确实对DPC的增殖显示出积极作用。在缺氧条件下培养的DPC的LDH活性明显高于在常氧条件下培养的DPC。与敲低和阴性对照相比，LDH的过表达显著上调碱性磷酸酶和Ki-67的表达。在LDH升高的DPC中细胞增殖也得到促进。我们的研究结果表明，在缺氧条件下DPC的增殖活性可被刺激。同时，LDH在维持缺氧条件下DPC的活性中起重要作用。
