Transcriptional regulation in hepatic stellate cells

Modulation of gene expression through altered transcription regulates stell ate cell behavior in normal liver and following hepatic injury. Transcripti on factors are generally classified according to conserved motifs within ei ther the activation- or DNA-binding domains of the molecules. Transcription al activity in stellate cells represents a delicate fine tuning of multiple inputs. Activities of these transcription factors are modified by their in tracellular localization, rate and pathway of degradation, oligomerization, and interactions with heterologous factors and chromatin, as well as by po sttranslational modifications, including phosphorylation, glycosylation, an d acetylation. General paradigms of transcriptional control are increasingl y being validated in hepatic stellate cells, particularly involving the tra nscription factors CCAAT/enhancer-binding proteins, c-myb, CREB, nuclear fa ctor kappaB, peroxisome proliferator-activated receptor, and Kruppel-like z inc finger factors. Although there are no simple rules that govern mechanis ms of transcriptional regulation in stellate cells, continued advances win yield new insights into their role in normal liver homeostasis and in the r esponse to injury.