| Physiology |
| Phy-PHYSIO -5 |
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Y. W. Chung, Y. Tang, S. C. Hockman, F. Ahmad, V. C. Manganiello |
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Function of Phosphodiesterase 3B in Regulatory Circuits Controlling White versus Brown Adipocyte Differentiation and Mitochondria Biogenesis |
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Cyclic nucleotide phosphodiesterase 3B (PDE3B) has been suggested to be critical in regulating energy metabolism in adipocytes, liver, and pancreatic b cells. In Pde3b-KO mice epididymal white adipose tissue (EWAT) exhibits some phenotypic characteristics of brown adipose tissue (BAT), including enhanced gene expression of peroxisome proliferator activated receptor g coactivator-1 alpha (PGC-1a) and uncoupling protein 1 (UCP1), and increased mitochondria number and size. Mitochondria were isolated from wild-type and PDE3B knock out (KO) mice using discontinuous sucrose gradients, and were studied by electron microscopic (EM) and proteomics techniques. Sucrose gradient and EM data demonstrated two populations of mitochondria, with EWAT containing lighter and smaller mitochondria, and BAT, heavier and bigger mitochondria. EWAT from PDE3B KO contained both populations of mitochondria. Knock out of the Pde3b gene also resulted in increased adipocyte fatty acid oxidation (FAO) and oxygen consumption. Taken together, these results suggested that PDE3B might function as a molecular switch determining white versus brown adipocyte differentiation, and thereby could play an important role in regulation of energy metabolism. |
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