The role of clock genes and rhythmicity in the liver

Abstract

The liver is the important organ to maintain energy homeostasis of an organism. To achieve this, many biochemical reactions run in this organ in a rhythmic fashion. An elegant way to coordinate the temporal expression of genes for metabolic enzymes relies in the link to the circadian timing system. In this fashion not only a maximum of synchronization is achieved, but also anticipation of daily recurring events is possible. Here we will focus on the input and output pathways of the hepatic circadian oscillator and discuss the recently found flexibility of its circadian transcriptional networks.

Chronopharmacokinetics of Erlotinib and Circadian Rhythms of Related Metabolic Enzymes in Lewis Tumor-Bearing Mice

“…Higher Cyp enzyme activities during the dark phase have been previously observed in mouse livers [25]. Zhang et al [26] demonstrated that the mRNA levels of several major Cyp enzymes were more highly expressed at night, which is in line with our current study.…”

Performing a hepatic timing signal: glucocorticoids induce gper1a and gper1b expression and repress gclock1a and gbmal1a in the liver of goldfish

“…The liver, a main regulator of primary metabolism, is one of the most sensitive peripheral oscillators, being synchronized by glucocorticoids (among other signals) in mammals (Reddy et al 2007;Schmutz et al 2012;Albrecht 2012;Sujino et al 2012). In mammalian cell lines or primary cell cultures, glucocorticoids increase Per1 gene expression (Balsalobre et al 2000;Fukuoka et al 2005;Reddy et al 2007).…”

The liver of goldfish as a component of the circadian system: Integrating a network of signals

“…The hepatic oscillator in mammals is one of the most sensitive to different external cues, as feeding time and internal ones, as changes in circulating hormones, including glucocorticoids (Kornmann et al, 2007;Schmutz et al, 2012;Stokkan et al, 2001;Yamamoto et al, 2005). Thus, this organ seems to be an endogenous oscillator where the circadian information converges with the regulation of metabolism (Schmutz et al, 2012).…”