First Author | Pritchard MT | Year | 2010 |
Journal | Am J Pathol | Volume | 176 |
Issue | 6 | Pages | 2743-52 |
PubMed ID | 20395449 | Mgi Jnum | J:161334 |
Mgi Id | MGI:4458001 | Doi | 10.2353/ajpath.2010.091186 |
Citation | Pritchard MT, et al. (2010) Hepatic fibrosis is enhanced and accompanied by robust oval cell activation after chronic carbon tetrachloride administration to Egr-1-deficient mice. Am J Pathol 176(6):2743-52 |
abstractText | The transcription factor early growth response (Egr)-1 regulates the expression of genes required for execution of the wound healing response. Multiple cycles of injury, coupled to incomplete wound healing, lead to fibrosis. Therefore, we hypothesized that Egr-1 is required for the development of hepatic fibrosis. To test this hypothesis, we exposed wild-type and egr-1(-/-) mice to acute or chronic carbon tetrachloride (CCl(4)). Acute CCl(4) exposure established a profibrotic milieu in the liver, including activation of hepatic stellate cells as well as expression of type 1 collagen genes and tissue inhibitor of matrix metalloproteinase 1 in both wild-type and egr-1(-/-) mice. This response was exacerbated in egr-1(-/-) mice. After chronic CCl(4) exposure, hepatic fibrosis was established in both genotypes; however, the fibrotic response was profoundly worsened in Egr-1-deficient mice. Importantly, enhanced fibrosis in egr-1(-/-) mice was accompanied by a robust activation of the oval cell response, suggesting more severe liver injury and/or reduced hepatocyte proliferation when compared with wild-type mice. Hepatic expression of genes indicative of oval cell activation, as well as the number of cells expressing A6, a mouse oval cell marker, was greater in egr-1(-/-) mice. Taken together, these data reveal novel roles for Egr-1 as a negative regulator of both CCl(4)-induced hepatic fibrosis and the oval cell response. |