Immunoglobulin heavy constant gamma 1 silencing decreases tonicity-responsive enhancer-binding protein expression to alleviate diabetic nephropathy.

Abstract

The molecular mechanisms of diabetic nephropathy (DN) are poorly identified. However, the advantage of an increasing amount on microarray data of diabetic nephropathy intrigued us to explore the mechanisms based on bioinformatics prediction for diabetic nephropathy. Bioinformatics analysis was conducted to screen the hub genes associated with diabetic nephropathy. The average human renal tubular epithelial cells were exposed to high glucose (HG) to generate an in vitro cell model. In addition, a mouse model of diabetic nephropathy was established using a high-fat diet and streptozotocin injection. Finally, the shRNA targeting immunoglobulin heavy constant gamma 1 (IGHG1) was introduced in vitro and in vivo to illustrate its effect on downstream factors and on the development diabetic nephropathy. Bioinformatics analysis revealed that IGHG1, TRIM11 (tripartite motif protein 11), and TonEBP are highly expressed in diabetic nephropathy. In vitro cell experiments demonstrated that IGHG1 positively regulates the expression of TRIM11 and TonEBP (tonicity-responsive enhancer binding protein) in HK2 cells treated with high glucose. Furthermore, TRIM11 upregulates the expression of TonEBP through activation of the MEK/ERK (mitogen-activated protein kinase/extracellular signal-regulated kinase) signaling pathway in HK2 cells treated with high glucose. In vivo, animal experiments further confirmed that silencing IGHG1 could prevent the occurrence and development of diabetic nephropathy. The silencing of IGHG1 alleviated diabetic nephropathy by inhibiting the TRIM11/MEK/ERK axis and by downregulating TonEBP.