Calcitonin Gene-Related Peptide Attenuates LPS-Induced Acute Kidney Injury by Regulating Sirt1

BACKGROUND: Acute kidney injury (AKI) caused by sepsis is a very dangerous clinical complication. This study explored the effects of calcitonin gene-related peptides (CGRP) on AKI and its mechanisms. MATERIAL/METHODS: We cultured renal proximal tubular epithelial cells (HK-2 cells) and induced AKI models using LPS. Recombinant human CGRP was used to stimulate HK-2 cells and we detected markers of kidney injury (KIM-1 and NGAL) to determine the protective effect of CGRP on HK-2 cells. In addition, we constructed Sirt1-overexpressing lentivirus and small interfering RNA to increase or decrease Sirt1 expression in HK-2 cells to verify that CGRP protects HK-2 cells by regulating Sirt1. RESULTS: After CGRP stimulation of HK-2 cells, LPS-induced HK-2 cell damage was significantly ameliorated, showing a decrease in the expression of KIM-1, NGAL, and inflammatory factors. In addition, Sirt1 was significantly increased in CGRP-stimulated HK-2 cells. After transfection of HK-2 cells with Lenti-Sirt1, inflammation and damage of HK-2 cells were both reduced, indicating that Sirt1 has a protective effect on HK-2 cells and can mediate the protective effect of CGRP on HK-2 cells. Therefore, the protective effect of CGRP on HK-2 cells was also attenuated after reducing Sirt1 in HK-2 cells. Finally, we used CGRP to treat LPS-induced mice and verified the protective effect of CGRP on mouse AKI. CONCLUSIONS: CGRP has a significant anti-inflammatory effect. In the treatment of AKI, CGRP can increase the expression of Sirt1 to exert an anti-inflammatory effect and has a good protective effect on LPS-induced HK-2 cells.