ABSTRACT
Acute kidney injury (AKI) is frequently encountered in clinical practice, particularly secondarily to cardiovascular surgery and administration of nephrotoxic agents, and is increasingly recognized for initiating a transition to chronic kidney disease. Clarifying the pathogenesis of AKI could facilitate the development of novel preventive strategies, because the occurrence of hospital-acquired AKI is often anticipated. Vasohibin-1 (VASH1) was initially identified as an antiangiogenic factor derived from endothelial cells. VASH1 expression in endothelial cells has subsequently been reported to enhance cellular stress tolerance. Considering the importance of maintaining peritubular capillaries in preventing the progression of AKI, the present study aimed to examine whether VASH1 deletion is involved in the pathogenesis of cisplatin-induced AKI. For this, we injected male C57BL/6J wild-type (WT) and VASH1 heterozygous knockout (VASH1+/-) mice intraperitoneally with either 20 mg/kg cisplatin or vehicle solution. Seventy-two hours after cisplatin injection, increased serum creatinine concentrations and renal tubular injury accompanied by apoptosis and oxidative stress were more prominent in VASH1+/- mice than in WT mice. Cisplatin-induced peritubular capillary loss was also accelerated by VASH1 deficiency. Moreover, the increased expression of ICAM-1 in the peritubular capillaries of cisplatin-treated VASH1+/- mice was associated with a more marked infiltration of macrophages into the kidney. Taken together, VASH1 expression could have protective effects on cisplatin-induced AKI probably by maintaining the number and function of peritubular capillaries.
Subject(s)
Acute Kidney Injury/metabolism , Capillaries/metabolism , Cell Cycle Proteins/deficiency , Cisplatin , Kidney Tubules/blood supply , Kidney Tubules/metabolism , Acute Kidney Injury/chemically induced , Acute Kidney Injury/genetics , Acute Kidney Injury/pathology , Animals , Apoptosis , Capillaries/pathology , Capillary Permeability , Cell Cycle Proteins/genetics , Creatinine/blood , Disease Models, Animal , Disease Progression , Heterozygote , Intercellular Adhesion Molecule-1/metabolism , Kidney Tubules/pathology , Macrophages/metabolism , Macrophages/pathology , Male , Mice, Inbred C57BL , Mice, Knockout , Oxidative Stress , Time FactorsABSTRACT
Acute kidney injury (AKI) has been associated with not only higher in-hospital mortality but also the subsequent development of chronic kidney disease (CKD). Recent evidence has suggested the involvement of mitochondrial dysfunction and impaired dynamics in the pathogenesis of AKI. Estrogen-related receptor α (ERRα) is an orphan nuclear receptor that acts as a transcription factor to regulate the transcription of genes required for mitochondrial biogenesis and oxidative phosphorylation. In the present study, we examined the effects of ERRα deficiency on the progression of AKI induced by cisplatin. Male C57BL/6â¯J wild-type and ERRα-/- mice received a single intraperitoneal injection of 20â¯mg/kg cisplatin. Seventy-two hours after the injection, kidney function and morphology were evaluated. ERRα expression was observed in renal tubules, and cisplatin inhibited its translocation into nuclei. ERRα deficiency exacerbated cisplatin-induced renal dysfunction and tubular injury, as well as oxidative stress and apoptosis. ERRα-/- mice kidneys revealed lower mitochondrial DNA content and swollen mitochondria with reduced cristae. In addition, these mice had lower expression of the mitochondrial fusion protein mitofusin-2. The cisplatin-induced decrease in mitochondrial DNA and altered mitochondrial structure were more severe in ERRα-/- mice. In cultured mouse proximal tubular epithelial cells, the ERRα inverse agonist XCT-790 significantly inhibited mitofusin-2 expression and induced mitochondrial fragmentation. Taken together, our findings suggest the involvement of ERRα in the progression of cisplatin-induced AKI probably through impaired mitochondrial dynamics.
