Effects of ghrelin on the proliferation and differentiation of 3T3-L1 preadipocytes and its possible mechanisms.
- Author:
Jing LIU
1
;
Han-Hua LIN
;
Pei-Xuan CHENG
;
Xiu-Fen HU
;
Hui-Ling LU
Author Information
- Publication Type:Journal Article
- MeSH: 3T3-L1 Cells; Adipocytes; cytology; drug effects; Animals; CCAAT-Enhancer-Binding Protein-alpha; genetics; Cell Differentiation; drug effects; Cell Proliferation; drug effects; Genes, myc; Ghrelin; pharmacology; Mice; PPAR gamma; genetics; RNA, Messenger; analysis; Stem Cells; cytology; drug effects; Thymidine Kinase; genetics
- From: Chinese Journal of Contemporary Pediatrics 2009;11(1):69-73
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo investigate the effects of ghrelin on the proliferation and differentiation of 3T3-L1 preadipocyte, and study the possible mechanisms.
METHODS3T3-L1 preadipocytes were cultured in vitro. The proliferation potentials of 3T3-L1 preadipocytes that were treated with different concentrations of ghrelin were evaluated by MTT methods. The levels of c-myc and thymidine kinase mRNA were detected using RT-PCR. 3T3-L1 preadipocytes were differentiated into the matured adipocytes with insulin (INS) or ghrelin. The morphological changes of 3T3-L1 adipocytes were observed and the differentiation rate was assayed by oil-red O staining. Total RNA was extracted from adipocytes at various times, and the levels of peroxisome proliferation activated receptor gamma (PPARgamma) and CAAT/enhancer binding protein(C/EBPalpha) mRNA expressions were detected using RT-PCR.
RESULTSGhrelin at concentrations of 10(-7) to 10(-15) mol/L significantly stimulated preadipocyte proliferation (p<0.05). The levels of c-myc and thymidine kinase mRNA significantly increased in 3T3-L1 preadipocytes with 10(-9) mol/L and 10(-11) mol/L ghrelin treatment (p<0.01). The 3T3-L1 preadipocytes treated with 10(-11) mol/L ghrelin had lots of lipid droplets in the cytoplasma, but the differentiation rate was lower than those treated with INS. Ghrelin of 10(-11) mol/L significantly increased the mRNA expression of PPARgamma and C/EBPalpha in the course of 3T3-L1 preadipocyte differentiation, compared with the normal control group (p<0.05). The PPARgamma and C/EBPalpha mRNA expression increased with the prolonged differentiation of preadipocytes induced by ghrelin or INS. There were significant differences in the levels of PPARgamma and C/EBPalpha mRNA expression between the 2nd and 8th days of differentiation(p<0.01).
CONCLUSIONSGhrelin promotes the proliferation and differentiation of 3T3-L1 preadipocytes. The proliferation of 3T3-L1 preadipocytes induced by ghrelin may be associated with increased c-myc levels. Ghrelin may promote differentiation of 3T3-L1 preadipocytes by increasing mRNA expression of PPARgamma and C/EBPalpha, thus enhances the sensitivity of adipocytes to INS.
