Effects of calcitriol on peripheral endothelial progenitor cells and renal renovation in rats with chronic renal failure

Urine trace element disorder along with renal function injury in vitamin D deficient diabetic rats and intervention effect of 1α,25-dihydroxyvitamin D3

Introduction

Trace element metabolism disorders are often secondary to disorders of glucose metabolism in diabetes. Although 1α,25-dihydroxyvitamin D3 [1,25(OH)₂D₃] could ameliorate abnormal glucose metabolism in the development of diabetes, the effect on trace element metabolism is unclear. The objective of this study was to evaluate the influence of 1,25(OH)₂D₃ on urinary excretions of trace elements in Zucker diabetic fatty (ZDF) rats.

Methods

At 6 weeks of age, male ZDF (n = 40) rats were subdivided into four groups: diabetic model (ZDF), low-dose (ZDF + VL, 2 μg/kg⋅bw), middle-dose (ZDF + VM, 8 μg/kg⋅bw) and high-dose (ZDF + VH, 16 μg/kg⋅bw) 1,25(OH)₂D₃ groups. Another 10 Zucker lean (ZL) rats served as a control group. All rats were given vitamin D deficient Purina #5008 chow and the intervention groups were given the corresponding dose of 1,25(OH)₂D₃ by gavage on alternate days for 7 weeks. Microalbuminuria (MALB) and urinary creatinine concentration were detected by a biochemical autoanalyzer. Urine trace element concentrations were measured using inductively coupled plasma mass spectrometry (ICP-MS) and were corrected by urinary creatinine.

Results

Throughout the intervention phase, MALB, UACR and urinary creatinine levels in the ZDF group were significantly higher than those in the ZL group, and showed a gradual increase with the prolongation of the intervention time. These changes were reversed in a dose-dependent manner after 1,25(OH)₂D₃ intervention (P < 0.05). Correspondingly, most of the urinary trace element excretions in the ZDF rats were significantly increased compared with the ZL group, and 1,25(OH)₂D₃ intervention significantly reduced the urinary copper (Cu), zinc (Zn), selenium (Se) and molybdenum (Mo) levels in the ZDF rats (P < 0.05), especially in the medium and high dose groups.

Conclusion

1,25(OH)₂D₃ had improvement effects on urinary Cu, Zn, Se, and Mo excretions in ZDF rats, suggesting that it may be related to the reduction of diabetic renal impairment and renal oxidative damage.

Exploring the Effect of Dapagliflozin on Alcoholic Kidney Injury and Renal Interstitial Fibrosis in Rats Based on TIMP-1/MMP-24 Pathway

Objective

To establish a rat model of alcoholic kidney injury and detect the expression of TIMP-1/MMP-24 in the kidneys of rats with alcoholic kidney injury at the molecular pathological level, so as to explore the mechanism of alcohol abuse leading to kidney injury and renal interstitial fibrosis as well as the alleviation of alcohol-induced kidney injury and inhibition of renal interstitial fibrosis by dapagliflozin.

Methods

48 male rats were randomly divided into 4 groups: control group, alcohol group, alcohol + dapagliflozin group, and alcohol + losartan group, each with 12 rats. Different drugs were administered by gavage for modeling and treatment. Six days later, the rats were sacrificed, blood was collected from the heart to separate the serum, and the blood creatinine (Scr) and urea nitrogen (BUN) contents were detected biochemically. After blood collection, the kidney tissue was taken and fixed in10% neutral formalin. The expression of renal tissue inflammatory factors (CRP, IL-6, and TNF-α) and renal fibrosis indexes (LN, HA, and TGF-β1) were detected; MMP-24 and TIMP-1 in the kidney tissue of rats in different treatment groups were detected, and Smad3 expression was also detected.

Results

After treatment, the general condition of the alcohol + dapagliflozin group and the alcohol + losartan group improved to different degrees. The weight first decreased and then gradually increased over time. There was no statistical difference in the weight change between the two groups; Compared with the control group, the Scr level, BUN content, renal index, inflammatory factors, and renal fibrosis indexes in the alcohol group were significantly increased (P < 0.05); after 6 weeks of treatment, in the alcohol + dapagliflozin group and alcohol + losartan group, Scr level, BUN content, kidney index, inflammatory factors, and renal fibrosis indexes were significantly decreased (P < 0.05); the expression of MMP-24 in the kidney tissue of the control group was upregulated, and the expression of TIMP-1 and Smad3 was downregulated; MMP-24 expression was downregulated, and TIMP-1 and Smad3 expression was significantly upregulated (P < 0.05) in the rats of the alcohol group. After dapagliflozin and losartan treatment, MMP-24 expression gradually increased and TIMP-1 and Smad3 expression gradually decreased (P < 0.05).

Conclusion

Long-term large-scale alcohol intake can cause kidney tissue damage and fibrotic lesions. The expression of fibrotic cytokines such as TIMP-1 and Smad3 will increase, and the expression of MMP-24 will be decreased. However, dapagliflozin and losartan have certain therapeutic effects on the abovementioned lesions. The mechanism may be downregulating TIMP-1 and Smad3 and upregulating the expression of MMP-24 and other cytokines in the kidney.