Effects of Aging on Kidney Graft Function, Oxidative Stress and Gene Expression after Kidney Transplantation

Effects of Donor-Recipient Age Difference in Renal Transplantation, an Investigation on Renal Function and Fluid Proteome

Introduction

Our previous study revealed that a young internal environment ameliorated kidney aging by virtue of an animal model of heterochronic parabiosis and a model of heterochronic renal transplantation. In this research, we used proteome to investigate the effects of donor-recipient age difference in clinical renal transplantation.

Methods

This study included 10 pairs of renal transplantation donors and recipients with an age difference of greater than 20 years to their corresponding recipients/donors. All recipients have received transplantation more than 3 years ago. Renal function and the serum/urine proteomes of the donors and recipients were analyzed.

Results

The renal function was similar between the young recipients and the old donors. In contrast, the renal function of the young donors was significantly superior to that of the old recipients. Furthermore, 497 and 975 proteins were identified in the serum and urine proteomes, respectively. The content of SLC3A2 in the blood was found to be related to aging, while the contents of SERPINA1 and SERPINA3 in the urine were related to immune functions after renal transplantation.

Conclusion

This study demonstrated that, in the human body, a younger internal environment could ameliorate kidney aging and provided not only clinical evidence for increasing the age limit of kidney transplant donors but also new information for kidney aging research.

Decreased expression of sirtuin 3 protein correlates with early stage chronic renal allograft dysfunction in a rat kidney model

Chronic renal allograft dysfunction (CRAD) is the primary factor affecting the long-term survival of patients who have undergone renal transplantation. Oxidative stress and inflammation serve an important role in the pathological damage caused by CRAD in the early post-transplantation phase. Previous studies have demonstrated that sirtuin 3 (sirt3) protects cells from oxidative stress and inflammation. A model of renal orthotopic transplantation was established in the current study and kidney samples were harvested from the rats 12 weeks following surgery. Compared with the control groups, there were significantly increased levels of serum creatinine, blood urea nitrogen and 24 h urinary protein in the allograft group (P<0.05). Pathological examinations indicated mononuclear cell infiltration and intimal proliferation in the allograft group, which had a higher Banff score compared with the control groups. There were increased levels of malondialdehyde, decreased sirt3 protein expression and decreased superoxide dismutase enzyme activity in the allograft group compared with the control groups (P<0.05). In addition, there was a negative correlation between the expression of sirt3 and 24 h urinary protein excretion, serum creatinine levels, tubulointerstitial mononuclear cell infiltration, smooth muscle cell migration in the vascular wall and Banff scores. Thus, sirt3 may serve an important protective role in the early stage of CRAD.

Telmisartan combined with probucol effectively reduces urinary protein in patients with type 2 diabetes: A randomized double-blind placebo-controlled multicenter clinical study

BACKGROUND

Persistent proteinuria is an important factor contributing to the progression of diabetic nephropathy. The present randomized double-blind placebo-controlled multicenter clinical study evaluated the efficacy and safety of telmisartan combined with the antioxidant probucol in reducing urinary protein levels in patients with type 2 diabetes (T2D).

METHODS

Patients with T2D and 24-h proteinuria 0.5-3 g were enrolled in the study and randomly assigned to one of two groups: a telmisartan or a probucol + telmisartan group. Both groups were given telmisartan 80 mg q.d. for 48 weeks. The probucol + telmisartan group was given probucol 500 mg b.i.d. for the first 24 weeks, with the dosage then reduced to 250 mg b.i.d. for the remaining 24 weeks. The telmisartan group was given probucol placebo.

RESULTS

In all, 160 patients were enrolled in the present study. The 24-h proteinuria levels were significantly reduced in the probucol + telmisartan compared with telmisartan group. For patients with baseline 24-h proteinuria levels <1.0 g, both treatments resulted in significant reductions in 24-h proteinuria levels after 48 weeks treatment. However, in patients with baseline 24-h proteinuria levels ≥1.0 g, 24-h proteinuria levels after 48 weeks treatment were only reduced in the probucol + telmisartan group. There was no significant difference between the two groups for either adverse cardiovascular or other events.

CONCLUSIONS

In patients with diabetic nephropathy, probucol combined with telmisartan more effectively reduces urinary protein levels than telmisartan alone.