First Author | Inan MS | Year | 2000 |
Journal | Am J Physiol Gastrointest Liver Physiol | Volume | 279 |
Issue | 6 | Pages | G1282-91 |
PubMed ID | 11093952 | Mgi Jnum | J:108661 |
Mgi Id | MGI:3624483 | Doi | 10.1152/ajpgi.2000.279.6.G1282 |
Citation | Inan MS, et al. (2000) Transcription factor NF-kappaB participates in regulation of epithelial cell turnover in the colon. Am J Physiol Gastrointest Liver Physiol 279(6):G1282-91 |
abstractText | The transcription factor nuclear factor (NF)-kappaB regulates the expression of genes that can influence cell proliferation and death. Here we analyze the contribution of NF-kappaB to the regulation of epithelial cell turnover in the colon. Immunohistochemical, immunoblot, and DNA binding analyses indicate that NF-kappaB complexes change as colonocytes mature: p65-p50 complexes predominate in proliferating epithelial cells of the colon, whereas the p50-p50 dimer is prevalent in mature epithelial cells. NF-kappaB1 (p50) knockout mice were used to study the role of NF-kappaB in regulating epithelial cell turnover. Knockout animals lacked detectable NF-kappaB DNA binding activity in isolated epithelial cells and had significantly longer crypts with a more extensive proliferative zone than their wild-type counterparts (as determined by proliferating cell nuclear antigen staining and in vivo bromodeoxyuridine labeling). Gene expression profiling reveals that the NF-kappaB1 knockout mice express the potentially growth-enhancing tumor necrosis factor (TNF)-alpha and nerve growth factor-alpha genes at elevated levels, with in situ hybridization localizing some of the TNF-alpha expression to epithelial cells. TNF-alpha is NF-kappaB regulated, and its upregulation in NF-kappaB1 knockouts may result from an alleviation of p50-p50 repression. NF-kappaB complexes may therefore influence cell proliferation in the colon through their ability to selectively activate and/or repress gene expression. |