Diabetes, Metabolic Syndrome and Obesity (Apr 2022)
Down-Regulation of miR-138 Alleviates Inflammatory Response and Promotes Wound Healing in Diabetic Foot Ulcer Rats via Activating PI3K/AKT Pathway and hTERT
Abstract
Jian Wang,1,2 Xiaodan Zhao,3 Guichang Tian,2 Xiaochao Liu,2 Chengyan Gui,2 Lin Xu1,4 1School of Medicine, Cheeloo College of Medicine, Shandong University, Jinan, 250012, People’s Republic of China; 2Department of Orthopedics, Qufu Hospital of TCM, Qufu, 273100, People’s Republic of China; 3Image Center, Shandong Provincial Third Hospital, Jinan, 250000, People’s Republic of China; 4Department of Orthopedics, Yantai Affiliated Hospital of Binzhou Medical University, Yantai, 264100, People’s Republic of ChinaCorrespondence: Lin Xu, Department of Orthopedics, Yantai Affiliated Hospital of Binzhou Medical University, Yantai, 264100, People’s Republic of China, Tel +86-13805350031, Email [email protected]; [email protected]: To study the role of miR-138 on the repair of diabetic foot ulcer (DFU) and further to explore its possible mechanism.Materials and Methods: miR-138 inhibitor, IGF-1, LY294002 were used in DFU rat mode, and the mRNA expression of miR-138 was detected. HE staining was used to observe the histological changes of skin ulcer in rats. The level of inflammation, wound healing, and blood vessel formation-related factors were detected by ELISA and immunohistochemical. The expression of VEGF and PI3K/AKT pathway-related proteins were detected by Western blot. To further determine the underlying mechanism of miR-138 in the repair of DFU, telomerase inhibitor BIBR-1232 was used in HUVECs. Dual-luciferase assay was used to determine the target relationship between miR-138 and hTERT. CCK-8, transwell, and tube formation assays were conducted to observe the biological behavior of HUVECs. Inflammatory cytokines and PI3K/AKT pathway-related proteins were also measured by ELISA and Western blot.Results: The mRNA expression of miR-138 in DFU rat was increased and ulcer of diabetic foot rats was improved after silencing miR-138. The results of cellular bioactivity in vitro experiment were consistent with that in vivo. Meanwhile, after silencing miR-138, the level of inflammatory cytokines was decreased, while the level of anti-inflammatory and healing factors was increased in vivo and vitro. Moreover, the ratios of p-PI3K/PI3K and p-AKT/AKT were upregulated after treated with miR-138 inhibitor and miR-138 was negatively regulated the expression of hTERT. However, the inhibitory effect on inflammatory response and the promotion effect on wound healing of miR-138 inhibitor were reversed by LY294002 and BIBR-1232.Conclusion: Down-regulation of miR-138 could alleviate inflammatory response and promote wound healing in DFU rats by activating PI3K/AKT pathway and hTERT.Keywords: miR-138, diabetic foot ulcer, inflammatory response, wound healing, PI3K/AKT pathway, hTERT
