Green tea (-)-epigallocatechin gallate inhibits IGF-I and IGF-II stimulation of 3T3-L1 preadipocyte mitogenesis via the 67-kDa laminin receptor, but not AMP-activated protein kinase pathway.
Mol Nutr Food Res
; 56(4): 580-92, 2012 Apr.
Article
in En
| MEDLINE
| ID: mdl-22495985
SCOPE: This study investigated the pathways involved in epigallocatechin gallate (EGCG) modulation of insulin-like growth factor (IGF)-I-stimulated and IGF-II-stimulated mitogenesis in 3T3-L1 preadipocytes. METHODS AND RESULTS: We found that this process was dose and time dependent, and caused by suppression of IGF-I-stimulated and IGF-II-stimulated phosphorylation of p66Shc and mitogen-activated protein kinase (MAPK) pathway proteins, including MEK1 kinase (RAF1), extracellular signal-regulated protein kinase (ERK) kinase (MEK1), and ERK 1 and ERK 2 (ERK1/2), but not phospho-Jun-N-terminal kinase, protein kinase B, p52Shc, or p46Shc. Furthermore, EGCG inhibited the IGF-I-stimulated phosphorylation of the IGF-I receptor-beta (IGF-IR ß), the association of IGF-IR with the p66Shc protein, and the IGF-II-stimulated associations of the IGF-II receptor with G(αi-2) and p66Shc proteins, suggesting that EGCG selectively affects particular types of Shc and MAPK family members. Pretreatment with antiserum against the EGCG receptor (also known as the 67-kDa laminin receptor; 67LR), but not with an adenosine monophosphate (AMP)-activated protein kinase (AMPK) inhibitor, prevented the inhibitory actions of EGCG on IGF-I- and IGF-II-stimulated ERK1/2 phosphorylation and subsequent preadipocyte proliferation. CONCLUSION: The results of this study suggest that EGCG mediates anti-IGF-I and anti-IGF-II signals in preadipocyte mitogenesis via the 67LR but not the AMPK pathway.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Insulin-Like Growth Factor I
/
Insulin-Like Growth Factor II
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Catechin
/
Receptors, Laminin
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Adipocytes
/
Cell Proliferation
Limits:
Animals
Language:
En
Journal:
Mol Nutr Food Res
Journal subject:
CIENCIAS DA NUTRICAO
Year:
2012
Document type:
Article
Affiliation country:
Taiwan
Country of publication:
Germany