First Author | Lin F | Year | 2011 |
Journal | Endocrinology | Volume | 152 |
Issue | 10 | Pages | 3668-79 |
PubMed ID | 21862616 | Mgi Jnum | J:177777 |
Mgi Id | MGI:5296267 | Doi | 10.1210/en.2011-1107 |
Citation | Lin F, et al. (2011) The Ca2+/calmodulin-dependent protein kinase kinase, CaMKK2, inhibits preadipocyte differentiation. Endocrinology 152(10):3668-79 |
abstractText | When fed a standard chow diet, CaMKK2 null mice have increased adiposity and larger adipocytes than do wild-type mice, whereas energy balance is unchanged. Here, we show that Ca(2+)/calmodulin-dependent protein kinase kinase 2 (CaMKK2) is expressed in preadipocytes, where it functions as an AMP-activated protein kinase (AMPK)alpha kinase. Acute inhibition or deletion of CaMKK2 in preadipocytes enhances their differentiation into mature adipocytes, which can be reversed by 5-aminoimidazole-4-carboxamide ribonucleotide-mediated activation of AMPK. During adipogenesis, CaMKK2 expression is markedly decreased and temporally accompanied by increases in mRNA encoding the early adipogenic genes CCAAT/enhancer binding protein (C/EBP) beta and C/EBP delta. Preadipocyte factor 1 has been reported to inhibit adipogenesis by up-regulating sex determining region Y-box 9 (Sox9) expression in preadipocytes and Sox9 suppresses C/EBPbeta and C/EBPdelta transcription. We show that inhibition of the CaMKK2/AMPK signaling cascade in preadipocytes reduces preadipocyte factor 1 and Sox9 mRNA resulting in accelerated adipogenesis. We conclude that CaMKK2 and AMPK function in a signaling pathway that participates in the regulation of adiposity. |