Effects of Long Non-Coding RNA LINC00963 on Renal Interstitial Fibrosis and Oxidative Stress of Rats with Chronic Renal Failure via the Foxo Signaling Pathway

Abstract

Background/Aims: Chronic renal failure (CRF) is usually associated with chronic diseases such as congestive heart failure and diabetes mellitus, the prevalence of which is increased with age. This study is designed to investigate the role of long intergenic non-coding RNA (lincRNA) LINC00963 in renal interstitial fibrosis (RIF) and oxidative stress (OS) of CRF via the forkhead box O (FoxO) signaling pathway. Methods: Microarray data and annotated probe files related to CRF were downloaded by retrieving Gene Expression Omnibus (GEO) database to screen differentially expressed lncRNA. Multi Experiment Matrix (MEM) website and dual-luciferase reporter gene assay were used to predict and verify the target gene of LINC00963, and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis to identify the major signaling pathways involved. A total of 60 Wistar male rats were randomly selected and divided into the sham (n = 10) and model (n = 50) groups. Five rats in the sham group and thirty rats in the model group were sub-categorized into the control, blank, negative control (NC), LINC00963 vector, si-LINC00963, si-FoxO3, and si-LINC00963 + si-FoxO3 groups (n = 5). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis were performed to evaluate the expressions of LINC00963, FoxO3a, TGF-β1, FN, GSH-PX, Bax, and Bcl-2. Measurement of changes in OS indexes including BUN, MDA, GSH-Px, SOD, and Na+-K+-ATP were conducted. Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of inflammatory factors including TNF-α, IL-6, ICAM-1 and FN. TUNEL staining was performed to evaluate cell apoptosis. Results: LINC00963 was highly expressed in CRF rats and FoxO3 was predicted and then verified as a target gene of LINC00963. FoxO3 gene participated in the FOXO signaling pathway. Compared with the blank and NC groups, there were significantly decreased expressions of LINC00963, TGF-β1, FN, and Bax in the si-LINC00963 group, while increased expressions of GSH-PX, FoxO3a, and Bcl-2. The vitality values of BUN and MDA in the si-LINC00963 group declined, while enzymatic activities of GSH-Px, SOD and Na+-K+-ATP elevated in comparison to the blank and NC groups. The levels of TNF-α, IL-6, ICAM-1 and FN, and cell apoptosis rate in the si-LINC00963 group decreased in comparison to the blank and NC groups. All the results in the si-LINC00963 group were opposite in the LINC00963 vector and si-FoxO3 groups. Conclusion: Taken together, we conclude that down-regulation of LINC00963 suppresses RIF and OS of CRF by activating the FoxO signaling pathway.