Combination of Tripterygium wilfordii Hook F and angiotensin receptor blocker synergistically reduces excretion of urinary podocytes in patients with type 2 diabetic kidney disease

Abstract

The aim of this study was to investigate whether Tripterygium wilfordii Hook F (TwHF) and irbesartan could synergistically affect the urinary excretion of podocytes and proteins in type 2 diabetic kidney disease (DKD) patients and the underlying mechanisms. Forty DKD patients were divided into a DI group (DKD patients treated with irbesartan alone) and a DTI group (DKD patients treated with Tripterygium wilfordii Hook F and irbesartan). Urinary podocytes were observed by immunofluorescence. Urinary levels of connective tissue growth factor (CTGF) and transforming growth factor-β₁ (TGF-β₁) were detected by enzyme-linked immunosorbent assay. Immunofluorescence indicated that shed podocytes were not detected in urine samples of normal controls, whereas the detection rate of urinary podocytes was 82.5% in DKD patients. Urinary CTGF and TGF-β₁ levels were significantly higher in urinary podocyte-positive DKD patients than in urinary podocyte-negative patients. Furthermore, urinary podocyte excretion was closely correlated with urinary protein excretion and urinary CTGF/TGF-β₁ levels. Treatments with TwHF and irbesartan significantly reduced the urinary excretion of proteins and podocytes, and decreased the urinary levels of CTGF and TGF-β₁. Our results suggest that urinary podocyte excretion might serve as a predictor for DKD progression. TwHF/irbesartan combination could reduce the urinary excretion of proteins and podocytes synergistically in DKD patients, which might result from the synergistic inhibition of CTGF and TGF-β₁ in urine.

Keywords:

• diabetic kidney disease
• Tripterygium wilfordii Hook F
• podocytes
• transforming growth factor-β₁

Acknowledgements

Thanks for the support of Dr. Zhen Li and Xiaofei Xue from the Department of Nephrology, Affiliated Hospital of Medical College, Qingdao University.

Disclosure Statement

All authors declare no financial competing interests. All authors declare no non-financial competing interests.

Additional information

Funding

This work was supported by the Qingdao Municipal Science and Technology Bureau [grant number 07-2-1-4-nsh-2].