Objective: To observe the characteristics of rat diabetic nephropathy model and the diagnostic value of urinary LN for early DN, and to explore the expression of perilipin (Plin) in the kidneys of DN rats.
Methods: 14 SD male rats were randomly divided into control group (normal diet) and diabetic nephropathy model group (high sugar and high fat diet), 6 rats in control group and 8 rats in model group. A kg dose of 1% streptozotocin (STZ) was injected, and the blood glucose was detected to be ≥16.7mmol/L. The diabetic model was successfully established. After continuing to feed for 6 weeks, the 24-h urine protein was detected to be greater than or equal to 30mg/kg, and the diabetic nephropathy model was successfully established. Coomassie brilliant blue 24h urine protein was detected, ELISA was used to measure urinary laminin, HE staining was used to observe the pathological changes of renal tissue, and Real-time PCR and Western blot were used to detect the expression of perilipin in renal tissue.
Results: The 24-hour urine protein of the model rats was ≥30 mg/kg, and the diabetic nephropathy rat model was successfully made. Compared with the control group, the kidney weight/body weight ratio of the model group was significantly higher (P<0.05), the urine volume and the adhesion of the urinary layer were increased. The protein increased at 5 weeks, and the 24h urine protein increased at 6 weeks, and all three indicators increased with time. Pathological examination of renal tissue showed: glomerular hypertrophy, basement membrane hyperplasia, microangioma formation, The tubular lumen was deformed, epithelial shedding, vacuolar degeneration, a large number of inflammatory cells such as mononuclear cells and lymphocytes infiltrated, and interstitial collagen fibers proliferated. The mRNA and protein expressions of Plin in the kidney tissue of the rats in the model group were significantly increased ( P<0.05).
CONCLUSION: Urinary laminin increases earlier than 24h urinary protein, which can be used as a warning indicator of early diabetic nephropathy. The increased expression of Plin may be involved in the process of diabetic nephropathy, which provides new ideas for further exploring the pathogenesis of diabetic nephropathy.