Methylenetetrahydrofolate reductase gene C677T polymorphism, homocysteine, vitamin B12, and DNA damage in coronary artery disease.
Elevated levels of plasma homocysteine (Hcy), a risk factor for coronary artery disease (CAD), can result from genetic errors, e.g., the methylenetetrahydrofolate reductase (MTHFR) polymorphism, or nutritional deficiencies, e.g., in vitamin B12 and folate. The mechanism by which Hcy induces atherosclerosis is not fully understood. Recently, Hcy has also been observed to induce DNA damage. In this study, we have investigated whether DNA damage is related to the C677T variant in the MTHFR gene and to plasma levels of Hcy, B12, and folate in patients with CAD. Patients ( n=46) with angiographically proven CAD were studied by using the micronucleus (MN) test, an accepted method for evaluating genetic instability. TT patients had plasma Hcy levels higher than those with the CT or CC genotypes (27.8+/-5.2 vs 13.7+/-2.2 and 12.9+/-1.9 micro mol/l, respectively; P=0.02). Patients with multi-vessel disease had higher plasma Hcy levels (11.6+/-1.2, 22.0+/-4.7, 19.3+/-3.9 micromol/l for one-, two- and three-vessel disease, respectively; P=0.05). The MN index increased with the number of affected vessels (8.4+/-0.7, 11.1+/-2.0, 14.2+/-1.7 for one-, two-, and three-vessels disease, respectively; P=0.02) and was significantly higher in subjects with the TT genotype compared with the CC or CT genotypes (15.7+/-2.4 vs 8.9+/-1.7 and 9.9+/-0.8; P=0.02). The MN index was also correlated negatively with plasma B12 concentration ( r=-0.343; P=0.019) and positively with plasma Hcy ( r=0.429, P=0.005). These data indicate that the MN index is associated with the severity of CAD and is related to the MTHFR polymorphism, suggesting an interesting link between coronary atherosclerosis and genetic instability in humans.
Andreassi
Maria Grazia
MG
Laboratory of Cellular Biology, CNR Institute of Clinical Physiology, G. Pasquinucci Hospital, Via Aurelia Sud-Montepepe, 54100 Massa, Italy. andreas@ifc.pi.cnr.it
Botto
Nicoletta
N
Cocci
Franca
F
Battaglia
Debora
D
Antonioli
Elisabetta
E
Masetti
Serena
S
Manfredi
Samantha
S
Colombo
Maria Giovanna
MG
Biagini
Andrea
A
Clerico
Aldo
A
D000368:Aged; D000483:Alleles; D002340:Carotid Artery Diseases / Q000097:blood* / Q000235:genetics*; D017023:Coronary Angiography; D003596:Cytosine / Q000737:chemistry; D004247:DNA / Q000097:blood / Q000235:genetics; D004249:DNA Damage; D004252:DNA Mutational Analysis; D017931:DNA Primers / Q000737:chemistry; D005260:Female; D005492:Folic Acid / Q000097:blood; D005838:Genotype; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D015162:Micronucleus Tests; D008875:Middle Aged; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics* / Q000378:metabolism; D017354:Point Mutation / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012307:Risk Factors; D013936:Thymidine / Q000737:chemistry; D014805:Vitamin B 12 / Q000097:blood*
D017931:DNA Primers; D006710:Homocysteine; D003596:Cytosine; D004247:DNA; D005492:Folic Acid; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D014805:Vitamin B 12; D013936:Thymidine