LncRNA ARAP1‐AS2 promotes high glucose‐induced human proximal tubular cell injury via persistent transactivation of the EGFR by interacting with ARAP1

• Published in: Journal of cellular and molecular medicine Vol. 24; no. 22; pp. 12994 - 13009
• Main Authors: Li, Xin, Ma, Tian‐Kui, Wen, Si, Li, Lu‐Lu, Xu, Li, Zhu, Xin‐Wang, Zhang, Cong‐Xiao, Liu, Nan, Wang, Xu, Fan, Qiu‐Ling
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.11.2020; John Wiley and Sons Inc
• Subjects: Antibodies; Antisense RNA; Biotechnology; Cell growth; Cell injury; Cell proliferation; Diabetes; Diabetes mellitus (non-insulin dependent); Diabetic nephropathy; EGFR/TGF‐β/Smad3 pathway; Endocytosis; Epidermal growth factor; Epidermal growth factor receptors; Epithelial cells; Fibrosis; Glucose; Immunofluorescence; Kinases; Laboratory animals; lncRNA ARAP1‐AS2; Nephropathy; Non-coding RNA; Original; Plasmids; Proteins; proximal tubular cell; Ribonucleic acid; RNA; Signal transduction; Smad3 protein; Transforming growth factor-b; Ubiquitination; United States > US; China; EGFR/TGF-β/Smad3 pathway; proximal tubular cell; diabetic nephropathy; lncRNA ARAP1-AS2
• ISSN: 1582-1838; 1582-4934
• DOI: 10.1111/jcmm.15897

The persistent transactivation of epidermal growth factor receptor (EGFR) causes subsequent activation of the TGF‐β/Smad3 pathway, which is closely associated with fibrosis and cell proliferation in diabetic nephropathy (DN), but the exact mechanism of persistent EGFR transactivation in DN remains unclear. ARAP1, a susceptibility gene for type 2 diabetes, can regulate the endocytosis and ubiquitination of membrane receptors, but the effect of ARAP1 and its natural antisense long non‐coding RNA (lncRNA), ARAP1‐AS2, on the ubiquitination of EGFR in DN is not clear. In this study, we verified that the expression of ARAP1 and ARAP1‐AS2 was significantly up‐regulated in high glucose‐induced human proximal tubular epithelial cells (HK‐2 cells). Moreover, we found that overexpression or knockdown of ARAP1‐AS2 could regulate fibrosis and HK‐2 cell proliferation through EGFR/TGF‐β/Smad3 signalling. RNA pulldown assays revealed that ARAP1‐AS2 directly interacts with ARAP1. Coimmunoprecipitation, dual‐immunofluorescence and ubiquitination assays showed that ARAP1 may maintain persistent EGFR activation by reducing EGFR ubiquitination through competing with Cbl for CIN85 binding. Taken together, our results suggest that the lncRNA ARAP1‐AS2 may promote high glucose‐induced proximal tubular cell injury via persistent EGFR/TGF‐β/Smad3 pathway activation by interacting with ARAP1.