What question did this study set out to answer?

Investigate how cell-surface low density lipoprotein (LDL) receptors regulate cholesterol metabolism using human fibroblasts with genetic mutations.

April 1, 1975Journal of Cellular Physiology

Use of mutant fibroblasts in the analysis of the regulation of cholesterol metabolism in human cells

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Authors

MBMichael S. BrownHospital of the University of Pennsylvania PBPatricia G. BrannanUniversity of Lusaka HBH. A. BohmfalkHeidelberg University

Discussion

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Implication

In vitro study reveals defective LDL receptor-mediated cholesterol regulation in familial hypercholesterolemia fibroblasts, highlighting the molecular control of mammalian gene expression.

Key Points

Investigate how cell-surface low density lipoprotein (LDL) receptors regulate cholesterol metabolism using human fibroblasts with genetic mutations.
Cultured and analyzed normal human fibroblasts alongside mutant fibroblasts from individuals homozygous and heterozygous for familial hypercholesterolemia.
Assessed cell-surface LDL receptor binding, the rate of proteolytic LDL degradation, and the suppression of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity across varying LDL concentrations.
Homozygous fibroblasts exhibited a nearly total reduction in LDL receptors, leading to failure of HMG-CoA reductase suppression, cholesterol overproduction, and impaired LDL degradation.
Heterozygous fibroblasts displayed approximately 50 percent of normal LDL receptors, requiring a two- to three-fold higher concentration of extracellular LDL to reach normal rates of cholesterol synthesis and degradation.

Cite This Study

Brown et al. (1975) studied this question.

synapsesocial.com/papers/6a71d3fd31a3df824329d41c https://doi.org/10.1002/jcp.1040850409

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April 1, 1975Journal of Cellular Physiology

Use of mutant fibroblasts in the analysis of the regulation of cholesterol metabolism in human cells

View Full Paper

Ask AI

Bookmark

Authors

MBMichael S. BrownHospital of the University of Pennsylvania PBPatricia G. BrannanUniversity of Lusaka HBH. A. BohmfalkHeidelberg University

Discussion

Member takes

Implication

In vitro study reveals defective LDL receptor-mediated cholesterol regulation in familial hypercholesterolemia fibroblasts, highlighting the molecular control of mammalian gene expression.

Key Points

Investigate how cell-surface low density lipoprotein (LDL) receptors regulate cholesterol metabolism using human fibroblasts with genetic mutations.
Cultured and analyzed normal human fibroblasts alongside mutant fibroblasts from individuals homozygous and heterozygous for familial hypercholesterolemia.
Assessed cell-surface LDL receptor binding, the rate of proteolytic LDL degradation, and the suppression of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity across varying LDL concentrations.
Homozygous fibroblasts exhibited a nearly total reduction in LDL receptors, leading to failure of HMG-CoA reductase suppression, cholesterol overproduction, and impaired LDL degradation.
Heterozygous fibroblasts displayed approximately 50 percent of normal LDL receptors, requiring a two- to three-fold higher concentration of extracellular LDL to reach normal rates of cholesterol synthesis and degradation.

Cite This Study

Brown et al. (1975) studied this question.

synapsesocial.com/papers/6a71d3fd31a3df824329d41c https://doi.org/10.1002/jcp.1040850409

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