The critical role of Shc in insulin-like growth factor-I-mediated mitogenesis and differentiation in 3T3-L1 preadipocytes.
Boney CM., Gruppuso PA., Faris RA., Frackelton AR.
Animal Study, published in Mol Endocrinol (2000) — summary generated from the PubMed abstract.
Evidence from laboratory and animal studies provides groundwork for understanding mechanisms and potential before human studies continue.
- Level A · Stronger Clinical Evidence
- Level B · Emerging clinical evidence with positive signals
- Level C · Early human research exploring benefits
- Level D · Scientific groundwork from lab and animal studies
- Emerging · Emerging topic under active research
This page is generated from the PubMed record. The Thai description is an automated summary of bibliographic fields and the abstract, not a full translation, and is not medical advice.
- Study type
- Animal Study
- Journal
- Mol Endocrinol (2000)
- Country
- United States
- Reported sample size
- —
- Source database
- PubMed
- PMID
- 10847583
- DOI
- 10.1210/mend.14.6.0487
Abstract (original English)
Insulin-like growth factor-I (IGF-I) stimulates mitogenesis in proliferating preadipocytes, but when cells reach confluence and become growth arrested, IGF-I stimulates differentiation into adipocytes. IGF-I induces signaling pathways that involve IGF-I receptor-mediated tyrosine phosphorylation of Shc and insulin receptor substrate 1 (IRS-1). Either of these adaptor proteins can lead to activation of the three-kinase cascade ending in activation of the extracellular signal-regulated kinase 1 and -2 (ERK-1 and -2) mitogen-activated protein kinases (MAPKs). Several lines of evidence suggest that activation of MAPK inhibits 3T3-L1 preadipocyte differentiation. We have shown that IGF-I stimulation of MAPK activity is lost as 3T3-L1 preadipocytes begin to differentiate. This change in MAPK signaling coincides with loss of IGF-I-mediated Shc, but not IRS-1, tyrosine phosphorylation. We hypothesized that down-regulation of MAPK via loss of proximal signaling through Shc is an early component in the IGF-I switch from mitogenesis to differentiation in 3T3-L1 preadipocytes. Treatment of subconfluent cells with the MEK inhibitor PD098059 inhibited both IGF-I-activation of MAPK as well as 3H-thymidine incorporation. PD098059, in the presence of differentiation-inducing media, accelerated differentiation in subconfluent cells as measured by expression of adipocyte protein-2 (aP-2), peroxis
What this study does not prove
- • This study does not prove SVF is an approved treatment or a replacement for standard care.
- • This is preclinical work; animal or laboratory results cannot be applied to humans.
Evidence level
Evidence from laboratory and animal studies provides groundwork for understanding mechanisms and potential before human studies continue.
How we grade evidenceBrowse all related research
Filter the research library by this study's title keywords, author, or publication year.