In vivo glucosylated LpA-I subfraction. Evidence for structural and functional alterations.
Arterioscler Thromb Vasc Biol
; 17(11): 2830-6, 1997 Nov.
Article
in En
| MEDLINE
| ID: mdl-9409262
ABSTRACT
This study compared the structural and functional properties of glucosylated and non-glucosylated LpA-I particle subfractions (GLpA-I and NGLpA-I, respectively) isolated from patients with poorly controlled type 1 (insulin-dependent) diabetes. Compared with NGLpA-I, GLpA-I showed an enrichment in triglycerides (P < .05) and a depletion in phospholipid (P < .05) content. Moreover, the triglycerides-to-cholesteryl esters ratio was increased (P < .05), suggesting an increased cholesteryl ester transfer protein activity and a possible transport defect that accelerates atherogenesis. The surface-to-core constituents ratio, an indirect estimate of particles size, is lower in GLpA-I (P < .01) than in NGLpA-I, correlating well with a larger median size (P < .05) as seen by electron microscopy. The apolipoprotein (apo) A-I conformation was evaluated through determination of the immunological accessibility of three different domains defining specific epitopes for anti-apo A-I monoclonal antibodies. We observed a marked decreased accessibility for two of these regions, which interestingly have already been implicated in the interaction with cells. Cell culture data suggest that nonenzymatic glycosylation occurring on apo A-I can modify lipoprotein function, since it results in a decreased binding of GLpA-I to HeLa cells and impaired cholesterol efflux from Fu5AH rat hepatoma cells.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Protein Processing, Post-Translational
/
Lipoprotein(a)
/
Diabetes Mellitus, Type 1
Limits:
Animals
/
Humans
/
Male
Language:
En
Journal:
Arterioscler Thromb Vasc Biol
Journal subject:
ANGIOLOGIA
Year:
1997
Document type:
Article
Affiliation country:
France