Silencing of TRB3 Ameliorates Diabetic Tubule Interstitial Nephropathy via PI3K/AKT Signaling in Rats

BACKGROUND Nephropathy, a chronic progressive kidney disease often characterized by glomeruli scarring and sclerosis, is a major complication of diabetes mellitus. Development of nephropathologic lesions has been shown to be associated with suppressed AKT phosphorylation and elevated level of apoptosis. Moreover, it has been established that the TRB3 gene is capable of inhibiting AKT phosphorylation and promoting apoptosis. MATERIAL AND METHODS In this study, we injected TRB3 siRNA into Wistar rats with type 1 diabetes, and monitored development of nephropathy in the rats. Urinary albumin excretion and serum creatinine were used as primary indicators, and nephritic histology was also examined. We also measured the serum level of pro-inflammatory cytokines collagen expression, and phosphorylation of PI3K and AKT proteins in the kidneys. RESULTS By silencing the TRB3 gene with siRNA, diabetic-induced nephropathy symptoms were alleviated, such as increased serum creatinine level and urinary albumin secretion. Additionally, histological examination showed lower levels of nephropathic lesions, and samples of the kidneys showed less accumulation of collagen proteins. Levels of serum cytokines, including TNF-α, IL-1β, and IL-6, were also lowered, whereas phosphorylation levels of PI3K and AKT were increased. In summary, TRB3 silencing in diabetic rats had a significant ameliorative effect on their nephropathy. CONCLUSIONS Silencing of TRB3 has a significant ameliorative effect on diabetic nephropathy in rats.