title: Rho-kinase regulation of TNF-α-induced nuclear translocation of NF-κB RelA/p65 and M-CSF expression via p38 MAPK in mesangial cells.
abstract: The small GTPase Rho and its downstream effector, Rho-associated coiled-coil containing protein kinase (Rho-kinase), regulate a number of cellular processes, including organization of the actin cytoskeleton, cell adhesion, and migration. While pharmacological inhibitors of Rho-kinase signaling are known to block renal inflammation, the molecular basis for this effect is unclear. Here, we provide evidence that proinflammatory TNF-α promotes mesangial expression of macrophage colony-stimulating factor (M-CSF), a key regulator for the growth and differentiation of mononuclear phagocytes, in a Rho-kinase-dependent manner. Consistent with this observation, TNF-α-mediated renal expression of M-CSF in insulin-resistant db/db mice was downregulated by Rho-kinase inhibition. Small interfering RNA-facilitated knockdown of Rho-kinase isoforms ROCK1 and ROCK2 indicated that both isoforms make comparable contributions to regulation of M-CSF expression in mesangial cells. From a mechanistic standpoint, Western blotting and EMSA showed that Rho-kinase and its downstream target p38 MAPK regulate nuclear translocation of NF-κB RelA/p65 and subsequent DNA binding activity, with no significant effects on IκBα degradation and RelA/p65 phosphorylation. Moreover, we showed that Rho-kinase-mediated cytoskeletal organization is required for the nuclear uptake of RelA/p65. Collectively, these findings identify Rho-kinase as a critical regulator of chemokine expression and macrophage proliferation.
authors.affiliation: Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Matoba
authors.affiliation: Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and daijika@jikei.ac.jp.
authors.forename: Daiji
authors.initials: D
authors.lastname: Kawanami
authors.affiliation: Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
authors.forename: Masami
authors.initials: M
authors.lastname: Tsukamoto
authors.affiliation: Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
authors.forename: Jun
authors.initials: J
authors.lastname: Kinoshita
authors.affiliation: Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ito
authors.affiliation: Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
authors.forename: Sho
authors.initials: S
authors.lastname: Ishizawa
authors.affiliation: Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kanazawa
authors.affiliation: Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Yokota
authors.affiliation: Department of Molecular Biology, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Murai
authors.affiliation: Department of Molecular Biology, Jikei University School of Medicine, Tokyo, Japan.
authors.forename: Senya
authors.initials: S
authors.lastname: Matsufuji
authors.affiliation: Division of Diabetes, Metabolism, and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan; and.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Utsunomiya
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D049109:Cell Proliferation; D018925:Chemokines / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D066298:In Vitro Techniques; D016173:Macrophage Colony-Stimulating Factor / Q000378:metabolism*; D008264:Macrophages / Q000166:cytology; D008297:Male; D050527:Mesangial Cells / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D008815:Mice, Inbred Strains; D023421:Models, Animal; D021381:Protein Transport; D051996:Transcription Factor RelA / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*; D054460:rho-Associated Kinases / Q000378:metabolism*
chemical_list: D000199:Actins; D018925:Chemokines; C498144:Rela protein, mouse; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; D016173:Macrophage Colony-Stimulating Factor; D054460:rho-Associated Kinases; D048051:p38 Mitogen-Activated Protein Kinases
keywords: NF-κB; Rho-kinase; macrophage colony-stimulating factor; p38 MAPK