Musculin/MyoR is expressed in kidney side population cells and can regulate their function

• Published in: The Journal of cell biology 2005-06, Vol.169 (6), p.921-928
• Main Authors: Hishikawa, Keiichi, Marumo, Takeshi, Miura, Shigeki, Nakanishi, Asato, Matsuzaki, Yumi, Shibata, Katsunori, Ichiyanagi, Tomoko, Kohike, Hiroko, Komori, Takuya, Takahashi, Ichiro, Takase, Osamu, Imai, Naohiko, Yoshikawa, Masahiro, Inowa, Toshihiko, Hayashi, Matsuhiko, Nakaki, Toshio, Nakauchi, Hiromitsu, Okano, Hideyuki, Fujita, Toshiro
• Format: Article
• Language: English
• Subjects: Acute kidney failure; Animals; Cell Death - drug effects; Cell Death - physiology; Cell Differentiation - drug effects; Cell Differentiation - physiology; Cell Proliferation - drug effects; Cells; Cells, Cultured; Cytoprotection - drug effects; Cytoprotection - physiology; Disease Models, Animal; Down-Regulation - drug effects; Down-Regulation - physiology; Endothelial cells; Epithelial Cells - cytology; Epithelial Cells - metabolism; Epithelial Cells - transplantation; Gene expression; Gene Expression Regulation - drug effects; Gene Expression Regulation - physiology; Hepatocytes; Interleukin-6 - metabolism; Interleukin-6 - pharmacology; Kidney - cytology; Kidney - metabolism; Kidney cells; Kidney failure; Kidneys; Leukemia Inhibitory Factor; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Muscle Proteins; Muscular system; Regeneration - drug effects; Regeneration - physiology; Renal Insufficiency - metabolism; Renal Insufficiency - physiopathology; Renal Insufficiency - therapy; Skeletal muscle; Stem cells; Stromal cells; Transcription Factors - genetics; Transcription Factors - metabolism
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.200412167

Musculin/MyoR is a new member of basic helix-loop-helix transcription factors, and its expression is limited to skeletal muscle precursors. Here, we report that musculin/MyoR is expressed in adult kidney side population (SP) cells and can regulate their function. SP phenotype can be used to purify stem cell-rich fractions. Microarray analysis clarified that musculin/MyoR was exclusively expressed in kidney SP cells, and the cells resided in the renal interstitial space. Musculin/MyoR-positive cells were decreased in acute renal failure, but infusion of kidney SP cells increased musculin/MyoR-positive cells and improved renal function. Kidney SP cells in reversible acute renal failure expressed a high level of renoprotective factors and leukemia inhibitory factor (LIF), but not in irreversible chronic renal failure. In cultured kidney SP cells, LIF stimulated gene expression of renoprotective factors, and down-regulation of musculin/MyoR augmented LIF-induced gene expression. Our results suggest that musculin/MyoR may play important roles not only in developmental processes but also in regenerative processes in adult tissue.