These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: 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.
    Author: Ku HC, Liu HS, Hung PF, Chen CL, Liu HC, Chang HH, Tsuei YW, Shih LJ, Lin CL, Lin CM, Kao YH.
    Journal: Mol Nutr Food Res; 2012 Apr; 56(4):580-92. PubMed ID: 22495985.
    Abstract:
    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 β), 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.
    [Abstract] [Full Text] [Related] [New Search]