title: Inhibition of H3K9 histone methyltransferase G9a attenuates renal fibrosis and retains klotho expression.
abstract: H3K9 methyltransferase G9a is reportedly induced by transforming growth factor-β1 (TGF-β1) and has an important role in the development of epithelial-mesenchymal transposition in cancer cells. Since the transcriptional activity of the Klotho gene is regulated by H3K9 modification, we investigated the effects of G9a on renal fibrosis and klotho expression. G9a levels were significantly upregulated by day 7 in the kidneys of unilateral ureteral-obstructed mice, but this was inhibited by TGF-β1-neutralizing antibody. Administration of G9a small interfering RNA not only decreased α-smooth muscle actin and fibronectin but also increased klotho expression in the ureteral-obstructed mice. Similarly, intraperitoneal injection of BIX01294, a specific inhibitor of G9a, showed beneficial effects on renal fibrosis and klotho expression with decreased monomethylation of H3K9 (me1). In in vitro experiments, BIX01294 also inhibited TGF-β1-induced fibrotic changes and klotho downregulation along with suppressed H3K9me1. In human kidney biopsy specimens, areas of G9a immunostaining correlated positively with H3K9me1 levels, as well as fibrotic markers, but correlated negatively with klotho expression. Thus, TGF-β1-induced G9a has an important role in the progression of renal fibrosis and reduced klotho expression through H3K9me1.
authors.affiliation: Department of Nephrology, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Irifuku
authors.affiliation: Department of Nephrology, Hiroshima University Hospital, Hiroshima, Japan. Electronic address: sdoi@hiroshima-u.ac.jp.
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Doi
authors.affiliation: Department of Nephrology, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Sasaki
authors.affiliation: Department of Nephrology, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Doi
authors.affiliation: Department of Nephrology, Hiroshima University Hospital, Hiroshima, Japan; Department of Regeneration and Medicine, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Ayumu
authors.initials: A
authors.lastname: Nakashima
authors.affiliation: Department of Nephrology, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Ueno
authors.affiliation: Department of Nephrology, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Anatomical Pathology, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Arihiro
authors.affiliation: Department of Molecular and Internal Medicine, Graduate School of Biomedical Science, Hiroshima University, Hiroshima, Japan.
authors.forename: Nobuoki
authors.initials: N
authors.lastname: Kohno
authors.affiliation: Department of Nephrology, Hiroshima University Hospital, Hiroshima, Japan. Electronic address: masakit@hiroshima-u.ac.jp.
authors.forename: Takao
authors.initials: T
authors.lastname: Masaki
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D057134:Antibodies, Neutralizing / Q000494:pharmacology; D001381:Azepines / Q000494:pharmacology; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D005353:Fibronectins / Q000235:genetics / Q000378:metabolism; D005355:Fibrosis; D005922:Glomerulonephritis, IGA / Q000378:metabolism / Q000473:pathology; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism*; D006649:Histocompatibility Antigens / Q000235:genetics* / Q000378:metabolism*; D011495:Histone-Lysine N-Methyltransferase / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D006657:Histones / Q000378:metabolism*; D006801:Humans; D007668:Kidney / Q000201:enzymology* / Q000473:pathology; D000090265:Klotho Proteins; D008239:Lysine / Q000378:metabolism; D008297:Male; D008745:Methylation; D051379:Mice; D011799:Quinazolines / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000494:pharmacology; D051381:Rats; D053773:Transforming Growth Factor beta1 / Q000276:immunology / Q000378:metabolism; D014517:Ureteral Obstruction / Q000150:complications
chemical_list: D000199:Actins; D057134:Antibodies, Neutralizing; D001381:Azepines; D004791:Enzyme Inhibitors; D005353:Fibronectins; D005966:Glucuronidase; D006649:Histocompatibility Antigens; D011495:Histone-Lysine N-Methyltransferase; D006657:Histones; D000090265:Klotho Proteins; D008239:Lysine; D011799:Quinazolines; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D053773:Transforming Growth Factor beta1; C518299:BIX 01294; C544013:alpha-smooth muscle actin, mouse; C498862:Acta2 protein, rat; C445405:EHMT2 protein, human
keywords: klotho; methylation of lysine 9 of histone H3; methyltransferase G9a; transforming growth factor-β1; tubulointerstitial fibrosis