TY - JOUR
T1 - Phenobarbital responsiveness as a uniquely sensitive indicator of hepatocyte differentiation status
T2 - Requirement of dexamethasone and extracellular matrix in establishing the functional integrity of cultured primary rat hepatocytes
AU - Sidhu, Jaspreet S.
AU - Liu, Fei
AU - Omiecinski, Curtis J.
N1 - Funding Information:
This research was supported by a grant from the National Institute of General Medical Sciences, GM32281 (CJO), and a Core Center Grant from the National Institute of Environmental Sciences, ES07033.
PY - 2004/1/15
Y1 - 2004/1/15
N2 - We used a serum-free, highly defined primary hepatocyte culture model to investigate the mechanisms whereby dexamethasone (Dex) and extracellular matrix (ECM) coordinate cell differentiation and transcriptional responsiveness to the inducer, phenobarbital (PB). Low nanomolar levels of Dex and dilute concentrations of ECM overlay were essential in the maintenance of normal hepatocyte physiology, as assessed by cell morphology, LDH release, expression of the hepatic nuclear factors C/EBPα, -β, -γ, HNF-1α, -1β, -4α, and RXRα, expression of prototypical hepatic marker genes, including albumin and transferrin, and ultimately, cellular capacity to respond to PB. The loss of hepatocyte integrity produced by deficiency of these components correlated with the activation of several stress signaling pathways including the MAPK, SAPK/JNK, and c-Jun signaling pathways, with resulting nuclear recruitment of the activated protein-1 (AP-1) complex. In Dex-deficient cultures, normal cellular function, including the PB induction response, was largely restored in a dose-dependent manner by reintroduction of nanomolar additions of the hormone, in the presence of ECM. Our results demonstrate critical and cooperative roles for Dex and ECM in establishing hepatocyte integrity and in the coordination of an array of liver-specific functions. These studies further establish the PB gene induction response as an exceptionally sensitive indicator of hepatocyte differentiation status.
AB - We used a serum-free, highly defined primary hepatocyte culture model to investigate the mechanisms whereby dexamethasone (Dex) and extracellular matrix (ECM) coordinate cell differentiation and transcriptional responsiveness to the inducer, phenobarbital (PB). Low nanomolar levels of Dex and dilute concentrations of ECM overlay were essential in the maintenance of normal hepatocyte physiology, as assessed by cell morphology, LDH release, expression of the hepatic nuclear factors C/EBPα, -β, -γ, HNF-1α, -1β, -4α, and RXRα, expression of prototypical hepatic marker genes, including albumin and transferrin, and ultimately, cellular capacity to respond to PB. The loss of hepatocyte integrity produced by deficiency of these components correlated with the activation of several stress signaling pathways including the MAPK, SAPK/JNK, and c-Jun signaling pathways, with resulting nuclear recruitment of the activated protein-1 (AP-1) complex. In Dex-deficient cultures, normal cellular function, including the PB induction response, was largely restored in a dose-dependent manner by reintroduction of nanomolar additions of the hormone, in the presence of ECM. Our results demonstrate critical and cooperative roles for Dex and ECM in establishing hepatocyte integrity and in the coordination of an array of liver-specific functions. These studies further establish the PB gene induction response as an exceptionally sensitive indicator of hepatocyte differentiation status.
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U2 - 10.1016/j.yexcr.2003.09.001
DO - 10.1016/j.yexcr.2003.09.001
M3 - Article
C2 - 14697333
AN - SCOPUS:0347623122
SN - 0014-4827
VL - 292
SP - 252
EP - 264
JO - Experimental Cell Research
JF - Experimental Cell Research
IS - 2
ER -