| First Author | Williams KL | Year | 2002 |
| Journal | Am J Physiol Gastrointest Liver Physiol | Volume | 283 |
| Issue | 4 | Pages | G875-85 |
| PubMed ID | 12223347 | Mgi Jnum | J:134606 |
| Mgi Id | MGI:3789404 | Doi | 10.1152/ajpgi.00089.2002 |
| Citation | Williams KL, et al. (2002) Mesenchymal IGF-I overexpression: paracrine effects in the intestine, distinct from endocrine actions. Am J Physiol Gastrointest Liver Physiol 283(4):G875-85 |
| abstractText | Local IGF-I expression is frequently increased in intestinal mesenchyme during adaptive growth of intestinal epithelium, but paracrine growth effects of IGF-I in vivo are not defined. We tested whether overexpression of IGF-I in intestinal mesenchyme increases epithelial growth and if effects are distinct from known effects of circulating IGF-I. SMP8-IGF-I-transgenic (TG) mice overexpress IGF-I driven by an alpha-smooth muscle actin promoter. Mucosal and muscularis growth were assessed in the jejunum, ileum, and colon of SMP8-IGF-I-TG mice and wild-type littermates. Abundance of the SMP8-IGF-I transgene and IGF binding protein (IGFBP)-3 and -5 mRNAs was determined. Mucosal growth was increased in SMP8-IGF-I-TG ileum but not jejunum or colon; muscularis growth was increased throughout the bowel. IGFBP-5 mRNA was increased in SMP8-IGF-I-TG jejunum and ileum and was specifically upregulated in ileal lamina propria. Overexpression of IGF-I in intestinal mesenchymal cells has preferential paracrine effects on the ileal mucosal epithelium and autocrine effects on the muscularis throughout the bowel. Locally expressed IGF-I has distinct actions on IGFBP expression compared with circulating IGF-I. |
