Osteopontin levels are associated with cholesterol synthesis markers in mildly hypercholesterolaemic patients.
OBJECTIVE
Atherosclerotic lesions are characterized by an accumulation of inflammatory cells and lipids. Osteopontin (OPN) is a cell-binding phosphoprotein, and it seems to promote the development of atherosclerosis. The purpose of our study was to find out whether plasma levels of OPN are associated with cholesterol metabolites in plasma or tissues.


RESULTS
Forty-three normal or mildly hypercholesterolaemic subjects, aged 31 to 69, were studied. The plasma level of OPN correlated negatively with muscle lathosterol (r = -0.52, P < 0.0001) and with the muscle lathosterol to muscle cholesterol ratio (r = -0.48, P = 0.001). Lathosterol concentrations in muscle (P = 0.003) and in relation to cholesterol (P = 0.005) were also significantly different among the OPN tertiles. OPN correlated negatively and significantly with muscle lathosterol in men (r = -0.58, P = 0.001, n = 29) but not in women (r = -0.21, P = 0.48, n = 14). Correspondingly, it also correlated negatively and significantly with the muscle lathosterol to muscle cholesterol ratio (r = -0.60, P = 0.001) in men but not in women (r = -0.13, P = 0.65). Plasma levels of OPN had a non-significant inverse correlation with plasma lathosterol and the plasma lathosterol to plasma cholesterol ratio. Plasma OPN concentrations were not related to plant sterols, cholesterol and 27-hydroxycholesterol.


CONCLUSIONS
Tissue markers of cholesterol synthesis were related to plasma OPN, particularly in men. This suggests that there is interplay between OPN and cholesterol metabolism in human cells.
Luomala
Mari
M
Laboratory of Atherosclerosis Genetics, Centre for Laboratory Medicine, Tampere University Hospital, Finn-Medi 5 7th floor, P.O. Box 2000, 33521, Tampere, Finland. mari.luomala@uta.fi
Päivä
Hannu
H
Thelen
Karin
K
Laaksonen
Reijo
R
Saarela
Marika
M
Mattila
Kari
K
Lütjohann
Dieter
D
Lehtimaki
Terho
T
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D016632:Apolipoprotein A-I / Q000097:blood; D001055:Apolipoproteins B / Q000097:blood; D015415:Biomarkers / Q000097:blood; D002784:Cholesterol / Q000096:biosynthesis / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005387:Finland; D006801:Humans; D006888:Hydroxycholesterols / Q000097:blood; D006937:Hypercholesterolemia / Q000097:blood* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism; D053495:Osteopontin / Q000097:blood*; D010840:Phytosterols / Q000097:blood; D012720:Severity of Illness Index; D012737:Sex Factors; D014280:Triglycerides / Q000097:blood
D016632:Apolipoprotein A-I; D001055:Apolipoproteins B; D015415:Biomarkers; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D006888:Hydroxycholesterols; D010840:Phytosterols; D014280:Triglycerides; D053495:Osteopontin; C076996:27-hydroxycholesterol; D002784:Cholesterol