Diabetic nephropathy is one of the most common chronic complications of diabetes, and its incidence is also on the rise. It has become the second cause of end-stage renal disease, second only to various glomerulonephritis. Because of its complex metabolic disorders, once it develops into end-stage renal disease, it is often more difficult than the treatment of other renal diseases. Therefore, timely prevention and treatment is of great significance to delaying diabetic nephropathy.

The study found that when the endogenous nicotinamide phosphoribosyl transferase Nampt was overexpressed in the glomerular cells of diabetic mice, the expression of bone morphogenetic protein BMP7 was significantly reduced. It is known that the overexpression of Nampt can activate a variety of inflammatory factors and profibrotic factors, thereby promoting the inflammatory response. Under certain conditions, BMP7 can be expressed in kidney tissue cells, and play an antagonistic effect on the inflammatory fibrosis of kidney tissue through a variety of ways; when kidney damage (including diabetic nephropathy), BMP7 expression and activity decrease. However, the relationship between Nampt and BMP7 is unclear.

In order to further verify the intrinsic relationship between Nampt and BMP7, Nampt's specific inhibitor FK866 and NAD+precursor nicotinamide mononucleotide （NMN）to intervene in the cells, and the results were found in FK866, NMN and FK866+NMN cells in each group , The expression of endogenous Nampt and NF-κB p65 were significantly reduced, while the expression of BMP7 was significantly increased. This shows that when NMN interferes with the endogenous Nampt expression in cells, the expression of BMP7 increases significantly.

It is suggested that in severe diabetic state, BMP7 can be up-regulated by inhibiting the overexpression of endogenous Nampt, thereby alleviating the inflammatory fibrosis of glomerular cells. NMN may affect the expression of BMP7 in cells by interfering with Nampt. It suggests that NMN may play a role in the prevention and treatment of diabetic nephropathy and glomerular fibrosis.