title: Pex11a deficiency is associated with a reduced abundance of functional peroxisomes and aggravated renal interstitial lesions.
abstract: Although proteinuria is known to be associated with the deterioration of chronic kidney disease, the molecular basis of this mechanism is not fully understood. We previously found that Pex11a deficiency was associated with a reduction of functional peroxisomes and impaired fatty acid metabolism in hepatocytes and resulted in steatosis. Proximal tubule cells are rich in peroxisomes. We assessed whether Pex11a deficiency might result in the derangement of peroxisome systems in proximal tubule cells and the aggravation of tubulointerstitial lesions in chronic kidney disease. Histological analyses showed that the number of functional peroxisomes in proximal tubule cells was reduced in Pex11a knockout (Pex11a(-/-)) mice. To clarify whether a decrease in the number of tubular peroxisomes might aggravate interstitial lesions, we assessed 2 models in which proximal tubule cells are overloaded with fatty acids (ie, deoxycorticosterone acetate and salt hypertension and the overload of fatty acid-bound albumin). Deoxycorticosterone acetate -salt-treated Pex11a(-/-) mice exhibited greater interstitial lesions than deoxycorticosterone acetate-salt-treated wild-type mice in terms of tubular lipid accumulation, blood pressure, urinary albumin, urinary N-acetyl-β-d-glucosaminidase, urinary 8-iso-prostane, and the histological evaluation of fibrosis and inflammation. An overload of fatty acid-bound albumin also resulted in more severe tubulointerstitial lesions in Pex11a(-/-) mice than in wild-type mice. Fenofibrate, a peroxisome proliferator-activated receptor-α agonist, restored the abundance of peroxisomes and reduced the tubulointerstitial lesions induced by deoxycorticosterone acetate-salt hypertension. In conclusion, our results indicate that proximal tubule peroxisomes play an important role in proteinuria-induced interstitial lesions. The activation of tubular peroxisomes might be an excellent therapeutic strategy against chronic kidney disease.
authors.affiliation: From the Department of Genomic Medicine, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan. weng@ncvc.go.jp iwai@ncvc.go.jp.
authors.forename: Huachun
authors.initials: H
authors.lastname: Weng
authors.affiliation: From the Department of Genomic Medicine, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan.
authors.forename: Xu
authors.initials: X
authors.lastname: Ji
authors.affiliation: From the Department of Genomic Medicine, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Endo
authors.affiliation: From the Department of Genomic Medicine, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan. weng@ncvc.go.jp iwai@ncvc.go.jp.
authors.forename: Naoharu
authors.initials: N
authors.lastname: Iwai
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005227:Fatty Acids / Q000009:adverse effects / Q000494:pharmacology; D005260:Female; D011345:Fenofibrate / Q000494:pharmacology; D005355:Fibrosis; D006973:Hypertension / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology; D000960:Hypolipidemic Agents / Q000494:pharmacology; D007674:Kidney Diseases / Q000473:pathology* / Q000503:physiopathology*; D007687:Kidney Tubules, Proximal / Q000187:drug effects / Q000473:pathology*; D008297:Male; D008565:Membrane Proteins / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D020675:Peroxisomes / Q000187:drug effects / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D005227:Fatty Acids; D000960:Hypolipidemic Agents; D008565:Membrane Proteins; C469727:Pex11alpha protein, mouse; D017382:Reactive Oxygen Species; D011345:Fenofibrate
keywords: fatty acid–binding proteins; hypertension; peroxisomes; renal insufficiency, chronic