Knockdown of AMPKα2 impairs epithelial‑mesenchymal transition in rat renal tubular epithelial cells by downregulating ETS1 and RPS6KA1.

Abstract

Epithelial-mesenchymal transition (EMT) serves an important regulatory role in obstructive nephropathy and renal fibrosis. As an intracellular energy sensor, AMP-activated protein kinase (AMPK) is essential in the process of EMT. The aim of the present study was to elucidate changes in the expression levels of AMPKα2 and which AMPKα2 genes play a role during EMT. TGF-β1 was used to induce EMT in normal rat renal tubular epithelial (NRK-52E) cells. The short hairpin AMPKα2 lentivirus was used to interfere with AMPKα2 expression levels in EMT-derived NRK-52E cells and AMPKα2 expression levels and EMT were detected. Differential gene expression levels following AMPKα2 knockdown in EMT-derived NRK-52E cells were assessed via gene microarray. Potential regulatory pathways were analyzed using ingenuity pathway analysis (IPA) and differentially expressed genes were partially verified by reverse transcription-quantitative PCR (RT-qPCR) and western blotting. AMPKα2 was upregulated in TGF-β1-induced EMT-derived NRK-52E cells. EMT progression was significantly inhibited following downregulation of expression levels of AMPKα2 by shAMPKα2 lentivirus. A total of 1,588 differentially expressed genes were detected following AMPKα2 knockdown in NRK-52E cells in which EMT occurred. The ERK/MAPK pathway was significantly impaired following AMPKα2 knockdown, as indicated by IPA analysis. Furthermore, RT-qPCR and western blot results demonstrated that the expression levels of AMPKα2, v-ets erythroblastosis virus E26 oncogene homolog-1 (ETS1) and ribosomal protein S6 kinase A1 (RPS6KA1) were upregulated following EMT in NRK-52E cells, whereas the expression levels of ETS1 and RPS6KA1 were downregulated following AMPKα2 knockdown. It was concluded that AMPKα2 plays a key role in the regulation of rat renal tubular EMT, which may be achieved by modulating ETS1 and RPS6KA1 in the ERK/MAPK pathway.