Tags

Type your tag names separated by a space and hit enter

Differential patterns of expression of three C/EBP isoforms, HNF-1, and HNF-4 after partial hepatectomy in rats.
Exp Cell Res. 1993 Sep; 208(1):248-56.EC

Abstract

Regenerating liver provides a system for studying the mechanisms controlling regulated proliferation of differentiated hepatocytes. A set of transcription factors termed hepatocyte nuclear factors (HNF-1, -3, -4) and CCAAT/enhancer binding protein (C/EBP) isoforms are known to regulate several genes predominantly expressed in the liver. To assess whether these factors might be involved in the hepatocyte proliferation program, we have studied the expression of the three C/EBP isoforms C/EBP alpha, C/EBP beta, and C/EBP delta and the two hepatocyte-enriched transcription factors, HNF-1 and HNF-4, in rat liver at various time points after partial hepatectomy and sham operations using transcriptional "run-on" assays and Northern blot and Western blot experiments. We report here that partial hepatectomy in rats leads to dramatic changes in the pattern of expression of some of these genes. The three C/EBP isoforms are differentially regulated in response to partial hepatectomy and are likely to play different roles in determining the proliferation/differentiation state of hepatocytes. In particular, C/EBP alpha expression is rapidly down-regulated, whereas C/EBP delta is induced. C/EBP beta expression is also increased, although an increase is also observed after sham operation. The drastic decrease in C/EBP alpha under these conditions of active DNA synthesis and rapid cell proliferation further supports the concept of a potential incompatibility between high C/EBP alpha protein levels and cell proliferation. The patterns of transcriptional rates of HNF-1 and HNF-4 during the different stages of the regenerative process are similar. However, HNF-1 steady-state mRNA and protein levels are significantly changed while HNF-4 remains virtually unaffected, indicating that post-transcriptional mechanisms are also involved in the regulation of HNF-1 gene expression.

Authors+Show Affiliations

Center for Biotechnology, Karolinska Institute, NOVUM, Huddinge, Sweden.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

8359219

Citation

Flodby, P, et al. "Differential Patterns of Expression of Three C/EBP Isoforms, HNF-1, and HNF-4 After Partial Hepatectomy in Rats." Experimental Cell Research, vol. 208, no. 1, 1993, pp. 248-56.
Flodby P, Antonson P, Barlow C, et al. Differential patterns of expression of three C/EBP isoforms, HNF-1, and HNF-4 after partial hepatectomy in rats. Exp Cell Res. 1993;208(1):248-56.
Flodby, P., Antonson, P., Barlow, C., Blanck, A., Porsch-Hällström, I., & Xanthopoulos, K. G. (1993). Differential patterns of expression of three C/EBP isoforms, HNF-1, and HNF-4 after partial hepatectomy in rats. Experimental Cell Research, 208(1), 248-56.
Flodby P, et al. Differential Patterns of Expression of Three C/EBP Isoforms, HNF-1, and HNF-4 After Partial Hepatectomy in Rats. Exp Cell Res. 1993;208(1):248-56. PubMed PMID: 8359219.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Differential patterns of expression of three C/EBP isoforms, HNF-1, and HNF-4 after partial hepatectomy in rats. AU - Flodby,P, AU - Antonson,P, AU - Barlow,C, AU - Blanck,A, AU - Porsch-Hällström,I, AU - Xanthopoulos,K G, PY - 1993/9/1/pubmed PY - 1993/9/1/medline PY - 1993/9/1/entrez SP - 248 EP - 56 JF - Experimental cell research JO - Exp Cell Res VL - 208 IS - 1 N2 - Regenerating liver provides a system for studying the mechanisms controlling regulated proliferation of differentiated hepatocytes. A set of transcription factors termed hepatocyte nuclear factors (HNF-1, -3, -4) and CCAAT/enhancer binding protein (C/EBP) isoforms are known to regulate several genes predominantly expressed in the liver. To assess whether these factors might be involved in the hepatocyte proliferation program, we have studied the expression of the three C/EBP isoforms C/EBP alpha, C/EBP beta, and C/EBP delta and the two hepatocyte-enriched transcription factors, HNF-1 and HNF-4, in rat liver at various time points after partial hepatectomy and sham operations using transcriptional "run-on" assays and Northern blot and Western blot experiments. We report here that partial hepatectomy in rats leads to dramatic changes in the pattern of expression of some of these genes. The three C/EBP isoforms are differentially regulated in response to partial hepatectomy and are likely to play different roles in determining the proliferation/differentiation state of hepatocytes. In particular, C/EBP alpha expression is rapidly down-regulated, whereas C/EBP delta is induced. C/EBP beta expression is also increased, although an increase is also observed after sham operation. The drastic decrease in C/EBP alpha under these conditions of active DNA synthesis and rapid cell proliferation further supports the concept of a potential incompatibility between high C/EBP alpha protein levels and cell proliferation. The patterns of transcriptional rates of HNF-1 and HNF-4 during the different stages of the regenerative process are similar. However, HNF-1 steady-state mRNA and protein levels are significantly changed while HNF-4 remains virtually unaffected, indicating that post-transcriptional mechanisms are also involved in the regulation of HNF-1 gene expression. SN - 0014-4827 UR - https://www.unboundmedicine.com/medline/citation/8359219/Differential_patterns_of_expression_of_three_C/EBP_isoforms_HNF_1_and_HNF_4_after_partial_hepatectomy_in_rats_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0014-4827(83)71244-9 DB - PRIME DP - Unbound Medicine ER -