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Transforming growth factor β 1 induces mitogenesis in fetal rat brown adipocytes
Author(s) -
Teruel Teresa,
Valverde Angela M.,
Benito Manuel,
Lorenzo Margarita
Publication year - 1996
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/(sici)1097-4652(199603)166:3<577::aid-jcp12>3.0.co;2-4
Subject(s) - biology , transforming growth factor , dna synthesis , fetus , cell growth , cell cycle , medicine , endocrinology , proliferating cell nuclear antigen , thymidine , fetal bovine serum , microbiology and biotechnology , cell , dna , biochemistry , pregnancy , genetics
The presence of transforming growth factor β 1 (TGF‐β 1 ) for 24 or 48 h stimulated DNA synthesis, the percentage of cells in the S + G 2 /M phases of the cell cycle, and cell number, as compared to quiescent cells. The mitogenic capacity of TGF‐β 1 (1 pM) was similar to that shown by 10% fetal calf serum (FCS). TGF‐β 1 for 48 h increased by 5‐fold the percentage of cells containing ( 3 H)thymidine‐labeled nuclei as compared to quiescent cells. In addition, single fetal brown adipocytes, showing their typical multilocular fat droplets phenotype, become positive for ( 3 H)thymidine‐labeled nuclei in response to TGF‐β 1 . Moreover, TGF‐β 1 induced the mRNA expression of a complete set of proliferation‐related genes, such as c‐fos (30 min), c‐myc and β‐actin (2 h), and H‐ras, cdc2 kinase, and glucose 6‐phosphate dehydrogenase (G6PD) at 4 and 8 h, as compared to quiescent cells. Concurrently, TGF‐β 1 for 12 h increased the protein content of proliferating cellular nuclear antigen (PCNA) by 6‐fold and p21‐ras by 2‐fold. Although our results demonstrate that TGF‐β 1 induces the expression of very early genes related to cell proliferation, TGF‐β 1 could be acting either as a mitogen or as a survival factor to induce proliferation in fetal brown adipocytes. © 1996 Wiley‐Liss, Inc.