Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
40
pubmed:dateCreated
1996-11-25
pubmed:abstractText
Peroxisomal genetic disorders, such as Zellweger syndrome, are characterized by defects in one or more enzymes involved in the peroxisomal beta-oxidation of very long chain fatty acids and are associated with defective peroxisomal biogenesis. The biologic role of peroxisomal beta-oxidation system, which consists of three enzymes: fatty acyl-CoA oxidase (ACOX), enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase (HD), and thiolase, has been examined in mice by disrupting ACOX gene, which encodes the first and rate-limiting enzyme of this system. Homozygous (ACOX -/-) mice lacked the expression of ACOX protein and accumulate very long chain fatty acids in blood. However, these homozygous mice are viable, but growth-retarded and infertile. During the first 3-4 months of age, the livers of ACOX -/- mice reveal severe microvesicular fatty metamorphosis of hepatocytes. In such steatotic cells, peroxisome assembly is markedly defective; as a result, they contain few or no peroxisomes. Few hepatocytes in 1-3-month-old ACOX -/- mice contain numerous peroxisomes, and these peroxisome-rich hepatocytes show no fatty change. At this stage, the basal mRNA levels of HD, thiolase, and other peroxisome proliferator-induced target genes were elevated in ACOX -/- mouse liver, but these mice, when treated with a peroxisome proliferator, showed no increases in the number of hepatic peroxisomes and in the mRNAs levels of these target genes. Between 4 and 5 months of age, severe steatosis resulted in scattered cell death, steatohepatitis, formation of lipogranulomas, and focal hepatocellular regeneration. In 6-7-month-old animals, the newly emerging hepatocytes, which progressively replaced steatotic cells, revealed spontaneous peroxisome proliferation. These livers showed marked increases in the mRNA levels of the remaining two genes of the beta-oxidation system, suggesting that ACOX gene disruption leads to increased endogenous ligand-mediated transcription levels. These observations demonstrate links among peroxisomal beta-oxidation, development of severe microvesicular fatty liver, peroxisome assembly, cell death, and cell proliferation in liver.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
24698-710
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8798738-Acyl-CoA Oxidase, pubmed-meshheading:8798738-Animals, pubmed-meshheading:8798738-Cell Line, pubmed-meshheading:8798738-Fatty Liver, pubmed-meshheading:8798738-Female, pubmed-meshheading:8798738-Fetal Growth Retardation, pubmed-meshheading:8798738-Homozygote, pubmed-meshheading:8798738-Lipid Metabolism, pubmed-meshheading:8798738-Liver, pubmed-meshheading:8798738-Male, pubmed-meshheading:8798738-Mice, pubmed-meshheading:8798738-Mice, Inbred BALB C, pubmed-meshheading:8798738-Mice, Inbred C57BL, pubmed-meshheading:8798738-Mice, Mutant Strains, pubmed-meshheading:8798738-Microbodies, pubmed-meshheading:8798738-Microscopy, Electron, pubmed-meshheading:8798738-Microsomes, Liver, pubmed-meshheading:8798738-Oxidoreductases, pubmed-meshheading:8798738-Phenotype, pubmed-meshheading:8798738-Pregnancy, pubmed-meshheading:8798738-RNA, Messenger, pubmed-meshheading:8798738-Up-Regulation
pubmed:year
1996
pubmed:articleTitle
Hepatocellular and hepatic peroxisomal alterations in mice with a disrupted peroxisomal fatty acyl-coenzyme A oxidase gene.
pubmed:affiliation
Department of Pathology, Northwestern University Medical School, Chicago, Illinois 60611, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't