Early growth response protein-1 upregulates long noncoding RNA Arid2-IR to promote extracellular matrix production in diabetic kidney disease.

Diabetic kidney disease (DKD) has surpassed chronic glomerulonephritis as the leading cause of end-stage renal disease. Previously, we showed that early growth response protein-1 (Egr1) plays a key role in DKD by enhancing mesangial cell proliferation and extracellular matrix (ECM) production. The long noncoding RNA (lncRNA) AT-rich interactive domain 2-IR (Arid2-IR) has been identified as a mothers against decapentaplegic homolog 3 (Smad3)-associated lncRNA in unilateral ureteral obstructive kidney disease. However, the effect of Egr1 on Arid2-IR in the development of DKD is still unknown. In this study, we found that Arid2-IR was increased in mice with high-fat diet and streptozotocin-induced type 2 diabetes and in mouse mesangial cells cultured with high glucose to mimic diabetes. Knockdown of Arid2-IR in mouse mesangial cells reduced the high expression levels of collagen-α1(I) (Col1a1) and α-smooth muscle actin (α-SMA) induced by high glucose. Furthermore, Arid2-IR expression changed the increased expression of Col1a1 and α-SMA caused by overexpression of Egr1. Overall, these data suggest that increased Arid2-IR likely contributes to ECM production in DKD and that Egr1 promotes ECM production in DKD partly by upregulating Arid2-IR. Thus, Arid2-IR may be a new target in the treatment of DKD.