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Plasma acylation stimulating protein (ASP) as a predictor of impaired cellular biological response to ASP in patients with hyperapoB
Author(s) -
Zhang Xj,
Katherine Cianflone,
Jacques Genest,
Sniderman Ad
Publication year - 1998
Publication title -
european journal of clinical investigation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 107
eISSN - 1365-2362
pISSN - 0014-2972
DOI - 10.1046/j.1365-2362.1998.00359.x
Subject(s) - stimulation , medicine , receptor , endocrinology , triglyceride , chemistry , fibroblast , biology , biochemistry , cholesterol , in vitro
Background The objective of this study was to examine specific membrane binding of [ 125 I]‐acylation stimulating protein (ASP) in cultured human skin fibroblasts obtained from normal subjects and patients with hyperapoB. ASP is a small basic protein isolated from human plasma that stimulates triglyceride synthesis (TGS) and glucose transport (GT) in human skin fibroblasts and adipocytes. Design In the present study, three groups were studied: normal (N ASP ‐N B ) subjects, hyperapoB subjects with normal plasma ASP (N ASP ‐H B ) and hyperapoB subjects with high plasma ASP (H ASP ‐H B ). Results ASP‐induced TGS in fibroblasts from H ASP ‐H B subjects was significantly less than in the two control groups with normal plasma ASP (N ASP ‐N B and N ASP ‐H B ). Similarly, ASP stimulation of GT was less in H ASP ‐H B fibroblasts than in the N ASP ‐H B fibroblasts or the N ASP ‐N B subjects. Insulin‐induced TGS was similar in all three groups as was insulin‐stimulated GT. As well, protein kinase C‐mediated stimulation was equivalent among the three groups both for GT and for TGS. There was no significant difference in the binding affinity ( K d ) of [ 125 I]‐ASP to intact cells in any group. By contrast, binding of [ 125 I]‐ASP revealed a significantly lower B max of the H ASP ‐H B cell lines than the N ASP ‐N B cells and the N ASP ‐H B cells. Conclusion A decrease in the ASP cell‐surface receptor concentration is responsible for decreased ASP stimulation of TGS, and GT and may contribute to the inefficient post‐prandial triglyceride (TG) clearance in H ASP ‐H B subjects.