Artemether attenuates renal tubular injury by targeting mitochondria in adriamycin nephropathy mice.

Chronic kidney disease (CKD) is complex and current treatment remains limited. As we know, glomerular injury plays a dominant role in kidney disease progression. However, accumulating evidence demonstrated that renal tubules, rather than being victims or bystanders, are major initiators in renal fibrosis progression. Renal tubules are rich in mitochondria and mitochondrial dysfunction may participate in renal tubular phenotypic changes and ultimately promote renal fibrosis. Previous studies have proved that artemether displayed renal protective effects, but the mechanisms remain unclear. In this experiment, we showed that artemether reduced urinary protein/creatinine ratio and attenuated renal tubular injury. Both in vivo and in vitro results indicated that artemether could restore renal tubular phenotypic alterations. Meanwhile, the unbalanced expressions of Bax and Bcl-xL in renal tubules were restored by artemether. In addition, artemether also regulated mitochondrial pyruvate metabolism, increased mitochondrial biogenesis, and improved mitochondrial function. Taken together, this study suggested that artemether could attenuate renal tubular injury by regulating mitochondrial biogenesis and function. It has great potential to be translated to the clinic as a therapeutic agent for treating kidney diseases, especially those associated with renal tubular injury.

Niclosamide ethanolamine protects kidney in adriamycin nephropathy by regulating mitochondrial redox balance.

Chronic kidney disease (CKD) is commonly characterized by proteinuria and leads to progressive glomerulosclerosis and tubulointerstitial fibrosis. Accumulating evidence implicates mitochondrial dysfunction including reactive oxygen species (ROS) overproduction in the pathogenesis of CKD. Mitochondrial function and ROS production are regulated by mitochondrial uncoupling. Niclosamide ethanolamine salt (NEN) is a mild mitochondrial uncoupler, which reduces urinary albumin excretion in mice with diabetic kidney disease. However, its role in nondiabetic kidney disease has not been investigated. Here we show that NEN exerts renoprotective effects in adriamycin induced nondiabetic kidney disease. It reduces urinary protein excretion, restores podocyte function, ameliorates renal pathological injury, and decreases the excretion of the urinary tubular injury biomarkers NGAL and Kim-1. Specifically, NEN uncouples isolated kidney mitochondria, and dose-dependently decreases the renal production and urinary excretion of H2O2. Moreover, NEN increases catalase and PGC-1α expression, which might accelerate H2O2 scavenging. The results of this study provide the first evidence that NEN protects kidney in nondiabetic kidney disease by regulating redox balance.

Astragaloside IV ameliorates early diabetic nephropathy by inhibition of MEK1/2-ERK1/2-RSK2 signaling in streptozotocin-induced diabetic mice.

Objective The aim of this study was to investigate the renoprotective effects and molecular mechanisms of astragaloside IV (AS-IV) in streptozotocin (STZ)-induced diabetic mice. Methods Male C57BL/6 mice were injected intraperitoneally with STZ at 200 mg/kg body weight. AS-IV was administered for 8 consecutive weeks, beginning 1 week after STZ injection. Body weight, 24-hour urinary albumin excretion, and fasting blood glucose were measured. Kidney tissues were examined by histopathological analyses. Total levels and phosphorylation of mitogen-activated protein kinase 1/2 (MEK1/2), extracellular signal-regulated kinases 1 and 2 (ERK1/2), and ribosomal S6 kinase 2 (RSK2) were determined by Western blotting analysis. Results AS-IV treatment significantly reduced albuminuria and serum creatinine levels, ameliorated mesangial matrix expansion and greater foot process width, and decreased the levels of urinary N-acetyl-beta-D-glucosaminidase, neutrophil gelatinase-associated lipocalin, and transforming growth factor-beta 1 in STZ-induced diabetic mice. AS-IV also inhibited renal cortical phosphorylation of MEK1/2, ERK1/2 and RSK2. Conclusion Our results suggest that AS-IV attenuates renal injury in STZ-induced diabetic mice. This effect might be partially associated with inhibition of the activation of the MEK1/2-ERK1/2-RSK2 signaling pathway.

Lisinopril protects against the adriamycin nephropathy and reverses the renalase reduction: potential role of renalase in adriamycin nephropathy.

AIMS: To investigate the potential role of renalase in adriamycin nephropathy and the effect of lisinopril on the regulation of renalase. METHODS: Adriamycin nephropathy was induced in male Wistar rats (n=12) by a single injection of adriamycin at 2 mg/kg body weight. Rats were then randomly assigned to a model group or a treatment group, to which were administered distilled water or the angiotensin converting enzyme inhibitor lisinopril, respectively, for 12 weeks. Six normal rats served as controls. At the end of study, physiological parameters and systolic blood pressure were measured. Glomerulosclerosis and tubulointerstitial injury were assessed by histopathology Renalase protein expression in kidney was quantified by immunohistochemistry and immunoblotting. The serum concentration and urinary excretion of renalase were determined by enzyme-linked immunosorbent assay. RESULTS: In model group rats, proteinuria and systolic blood pressure were elevated. Increased serum renalase concentration was observed; however, renalase protein expression in the kidney was significantly decreased. Compared with the model group, decreased proteinuria, lower systolic blood pressure, and fewer morphologic lesions were detected in the treatment group. Although levels of serum renalase were similar, accumulation of renalase in urine and kidney tissue increased notably in the treatment group compared with the model group. CONCLUSIONS: This study suggests that renalase may be involved in the process of adriamycin-induced renal injuries. Lisinopril may attenuate adriamycin-induced kidney injury by controlling blood pressure, which may be partially attributed to the renalase expression and secretion.