Aging lowers steady-state antioxidant enzyme and stress protein expressionin primary hepatocytes

Citation
Dm. Hall et al., Aging lowers steady-state antioxidant enzyme and stress protein expressionin primary hepatocytes, J GERONT A, 56(6), 2001, pp. B259-B267
Citations number
38
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Public Health & Health Care Science","Medical Research General Topics
Journal title
JOURNALS OF GERONTOLOGY SERIES A-BIOLOGICAL SCIENCES AND MEDICAL SCIENCES
ISSN journal
1079-5006 → ACNP
Volume
56
Issue
6
Year of publication
2001
Pages
B259 - B267
Database
ISI
SICI code
1079-5006(200106)56:6<B259:ALSAEA>2.0.ZU;2-F
Abstract
It has been reported that the isolation and culture of primary hepatocytes can compromise cellular ability to constituitively express antioxidant enzy me (AE) genes, making it difficult to study their regulation ex vivo. In th e present study, the steady-state expression of manganese-containing supero xide dismutase, copper- and zinc-containing superoxide dismutase, catalase, and glutathione peroxidase was assessed in primary hepatocytes isolated fr om young and senescent rats and cultured in Matrigel. There was no change i n steady-state superoxide dismutase protein or activity levels in cells col lected from young animals and cultured for 7 days. Catalase expression was initially increased, and then it declined 30%. In contrast, superoxide dism utase expression declined 60% and catalase expression declined 50% in cells from senescent animals. Constitutive and inducible 70-kDa heat shock prote in expression increased coincident with declining AE levels in the young ce lls but not senescent cells. For both age groups, electron micrographs show ed rounded hepatocytes with abundant rough endoplasmic reticulum, mitochond ria, and peroxisomes. Hepatocytes were organized into clusters of 6-12 cell s surrounding a large central lumen devoid of microvilli. Each cluster also contained smaller microvilli-lined lumens between adjacent hepatocytes tha t resembled canniculi. The plasma membranes of these lumens were sealed fro m the extracellular space by junctional complexes. Gap junctions in the pla sma membrane suggest that hepatocytes were capable of intercellular communi cation. We conclude that the Matrigel system can be used to study AE regula tion in primary hepatocytes from young and senescent animals, provided that experiments can be conducted within a time frame of 5-7 days in culture. T hese data also support the hypothesis that aging compromises hepatocellular ability to maintain AE status and upregulate stress protein expression.