Biomaterial Database

Nonalcoholic fatty liver disease in CLOCK mutant mice. 2020

Xiaoyue Pan, and Joyce Queiroz, and M Mahmood Hussain

Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, New York, USA.

Nonalcoholic fatty liver disease (NAFLD) is becoming a major health issue as obesity increases around the world. We studied the effect of a circadian locomotor output cycles kaput (CLOCK) mutant (ClkΔ19/Δ19) protein on hepatic lipid metabolism in C57BL/6 Clkwt/wt and apolipoprotein E-deficient (Apoe-/-) mice. Both ClkΔ19/Δ19 and ClkΔ19/Δ19 Apoe-/- mice developed a full spectrum of liver diseases (steatosis, steatohepatitis, cirrhosis, and hepatocellular carcinoma) recognized in human NAFLD when challenged with a Western diet, lipopolysaccharide, or CoCl2. We identified induction of CD36 and hypoxia-inducible factor 1α (HIF1α) proteins as contributing factors for NAFLD. Mechanistic studies showed that WT CLOCK protein interacted with the E-box enhancer elements in the promoters of the proline hydroxylase domain (PHD) proteins to increase expression. In ClkΔ19/Δ19 mice, PHD levels were low, and HIF1α protein levels were increased. When its levels were high, HIF1α interacted with the Cd36 promoter to augment expression and enhance fatty acid uptake. Thus, these studies establish a regulatory link among circadian rhythms, hypoxia response, fatty acid uptake, and NAFLD. The mouse models described here may be useful for further mechanistic studies in the progression of liver diseases and in the discovery of drugs for the treatment of these disorders.

UI	MeSH Term	Description	Entries
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D004195	Disease Models, Animal	Naturally-occurring or experimentally-induced animal diseases with pathological processes analogous to human diseases.	Animal Disease Model,Animal Disease Models,Disease Model, Animal
D004742	Enhancer Elements, Genetic	Cis-acting DNA sequences which can increase transcription of genes. Enhancers can usually function in either orientation and at various distances from a promoter.	Enhancer Elements,Enhancer Sequences,Element, Enhancer,Element, Genetic Enhancer,Elements, Enhancer,Elements, Genetic Enhancer,Enhancer Element,Enhancer Element, Genetic,Enhancer Sequence,Genetic Enhancer Element,Genetic Enhancer Elements,Sequence, Enhancer,Sequences, Enhancer
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000072417	Protein Domains	Discrete protein structural units that may fold independently of the rest of the protein and have their own functions.	Peptide Domain,Protein Domain,Domain, Peptide,Domain, Protein,Domains, Peptide,Domains, Protein,Peptide Domains
D000074085	Mice, Knockout, ApoE	Strains of mice that contain genetic disruptions (knockout) of APOLIPOPROTEINS E genes. They are used as models for ATHEROSCLEROSIS research.	Apo E Knockout Mice,ApoE Knockout Mice,Knockout Mice, ApoE,Mice, ApoE Knockout
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus
D056926	CLOCK Proteins	Basic helix-loop-helix (bHLH) domain-containing proteins that contain intrinsic HISTONE ACETYLTRANSFERASE activity and play important roles in CIRCADIAN RHYTHM regulation. Clock proteins combine with Arntl proteins to form heterodimeric transcription factors that are specific for E-BOX ELEMENTS and stimulate the transcription of several E-box genes that are involved in cyclical regulation. This transcriptional activation also sets into motion a time-dependent feedback loop which in turn down-regulates the expression of clock proteins.	CLOCK Protein,Circadian Locomotor Output Cycles Kaput Proteins
D065626	Non-alcoholic Fatty Liver Disease	Fatty liver finding without excessive ALCOHOL CONSUMPTION.	Fatty Liver, Nonalcoholic,NAFLD,Nonalcoholic Fatty Liver Disease,Nonalcoholic Steatohepatitis,Fatty Livers, Nonalcoholic,Liver, Nonalcoholic Fatty,Livers, Nonalcoholic Fatty,Non alcoholic Fatty Liver Disease,Nonalcoholic Fatty Liver,Nonalcoholic Fatty Livers,Nonalcoholic Steatohepatitides,Steatohepatitides, Nonalcoholic,Steatohepatitis, Nonalcoholic