Peroxisome proliferator-activated receptor gamma polymorphism and periodontitis in pregnant Japanese women.
BACKGROUND
Recent studies suggest an association between maternal periodontitis and preterm birth, although the association remains controversial. It was suggested that mechanisms such as a genetic predisposition for a hyperinflammatory response cause periodontitis and preterm births. Peroxisome proliferator-activated receptor gamma (PPARgamma) is a nuclear hormone receptor and ligand-dependent transcription factor. PPARgamma inhibits the transcriptional activity of the genes that produce proinflammatory mediators and repress periodontitis. Recently, a common polymorphism, proline(PRO)-to-alanine(ALA) mutation at codon12 in exonB (Pro12Ala: rs 1801282) PPARgamma, was reported to reduce the ability to transactivate responsive promoters. In this study, we tested whether the PPARgammaPro12Ala polymorphism was associated with maternal periodontitis and/or preterm birth.


METHODS
Genomic DNA was isolated from the venous blood of pregnant Japanese women (term birth: n = 72; preterm birth: n = 58). The PPARgammaPro12Ala genotype was determined by polymerase chain reaction (PCR)-restriction fragment length polymorphism. Within 5 days after labor, clinical periodontal parameters were evaluated, and periodontopathic bacteria from the subgingival plaque were detected by species-specific PCR.


RESULTS
The mean clinical attachment level (P = 0.012), mean probing depth (P = 0.031), mean gingival index (P = 0.037), and percentages of sites with bleeding on probing (P = 0.041) in women with the PPARgammaPro12Ala genotype were significantly higher than in women with the PPARgammaPro12Pro genotype. However, there was no association between preterm birth and periodontitis.


CONCLUSIONS
We suggest that the PPARgammaPro12Ala polymorphism may represent a genetic susceptibility factor for the clinical measurements of periodontitis in a limited number of pregnant Japanese women, but it probably cannot influence the relationship between periodontitis and preterm birth.
Hirano
Emi
E
Division of Periodontology, Department of Oral Biological Science, Graduate School of Medical and Dental Sciences, Niigata University, Niigata 951-8514, Japan.
Sugita
Noriko
N
Kikuchi
Akira
A
Shimada
Yasuko
Y
Sasahara
Jun
J
Iwanaga
Ruriko
R
Tanaka
Kenichi
K
Yoshie
Hiromasa
H
D000409:Alanine; D019943:Amino Acid Substitution / Q000235:genetics; D016009:Chi-Square Distribution; D004252:DNA Mutational Analysis; D003773:Dental Plaque / Q000382:microbiology; D005260:Female; D006801:Humans; D007564:Japan; D020125:Mutation, Missense; D047495:PPAR gamma / Q000235:genetics*; D010518:Periodontitis / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D011247:Pregnancy; D011248:Pregnancy Complications / Q000235:genetics*; D047928:Premature Birth / Q000235:genetics*; D011392:Proline; D018709:Statistics, Nonparametric
D047495:PPAR gamma; D011392:Proline; D000409:Alanine