Superoxide overproduction and kidney fibrosis: a new animal model

• Main Authors: Nadia Karina Guimarães-Souza, Liliya Marsovna Yamaleyeva, Baisong Lu, Ana Claudia Mallet de Souza Ramos, Colin Edward Bishop, Karl Erik Andersson
• Format: Article
• Language: English
• Published: Instituto Israelita de Ensino e Pesquisa Albert Einstein
• Series: Einstein (São Paulo)
• Subjects: Insuficiência renal crônica; Inflamação; Camundongos transgênicos; Modelos animais; Estresse oxidativo
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-45082015000100014&lng=en&tlng=en

Objective To establish whether the mutation in the Immp2L gene induces renal fibrosis and whether aging exacerbates renal morphology in mice. Methods Female mutant mice with mutation in the inner mitochondrial membrane peptidase 2-like protein at 3 and 18 months of age were used. Renal fibrosis was analyzed using classic fibrosis score, Masson’s trichrome staining, and analysis of profibrotic markers using real time polymerase chain reaction (superoxide dismutase 1, metalloproteinase-9, erythropoietin, transforming growth factor beta), and immunostaining (fibroblasts and Type IV collagen). Oxidative stress markers were determined by immunohistochemistry. The number of renal apoptotic cells was determined. Renal function was estimated by serum creatinine. Results Young mutant mice had significantly more glomerulosclerosis than age-matched mice (p=0.034). Mutant mice had more tubular casts (p=0.025), collagen deposition (p=0.019), and collagen type IV expression (p<0.001). Superoxide dismutase 1 expression was significantly higher in young mutants (p=0.038). Old mutants exhibited significantly higher expression of the fibroblast marker and macrophage marker (p=0.007 and p=0.012, respectively). The real time polymerase chain reaction of metalloproteinase-9 and erythropoietin were enhanced 2.5- and 6-fold, respectively, in old mutants. Serum creatinine was significantly higher in old mutants (p<0.001). Conclusion This mutation altered renal architecture by increasing the deposition of extracellular matrix, oxidative stress, and inflammation, suggesting a protective role of Immp2L against renal fibrosis.