Functionally significant SNP MMP8 promoter haplotypes and preterm premature rupture of membranes (PPROM).
Matrix metalloproteinase 8 (MMP8), an enzyme that degrades fibrillar collagens imparting strength to the fetal membranes, is expressed by leukocytes and chorionic cytotrophoblast cells. We identified three single nucleotide polymorphisms (SNPs) at -799C/T, -381A/G and +17C/G from the major transcription start site in the MMP8 gene, and determined the functional significance of these SNPs by analyzing their impact upon MMP8 promoter activity and their association with preterm premature rupture of membranes (PPROM). The minor alleles +17 (G) and -381 (G) were in complete linkage disequilibrium. A promoter fragment containing the three minor alleles had 3-fold greater activity in chorion-like trophoblast cells (BeWo, JEG-3 and HTR-8/SVneo) compared with the major allele promoter construct. Electrophoretic mobility shift assays revealed differences in BeWo nuclear protein binding to oligonucleotides representing the -381 and -799 SNPs, suggesting that the minor alleles have reduced transcription factor binding. A case-control study of African-American neonates using allele-specific primers revealed a statistically significant association between the three minor allele haplotype, which displays the highest MMP8 promoter activity in trophoblast cells, with PPROM with an odds ratio (OR) of 4.63 (P < 0.0001), whereas the major allele promoter appeared to be protective (OR = 0.52, P < 0.0002). None of the minor alleles were individually associated with PPROM. These findings demonstrate the functional significance of SNP haplotypes in the MMP8 gene and associations with obstetrical outcomes.
Wang
Hongyan
H
Center for Research on Reproduction and Women's Health, University of Pennsylvania, 421 Curie Boulevard, Philadephia, PA 19104, USA.
Parry
Samuel
S
Macones
George
G
Sammel
Mary D
MD
Ferrand
Pedro E
PE
Kuivaniemi
Helena
H
Tromp
Gerard
G
Halder
Indrani
I
Shriver
Mark D
MD
Romero
Roberto
R
Strauss
Jerome F
JF
D000483:Alleles; D017398:Alternative Splicing; D001483:Base Sequence; D044383:Black People / Q000235:genetics; D016022:Case-Control Studies; D002460:Cell Line; D002874:Chromosome Mapping; D024202:Electrophoretic Mobility Shift Assay; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000208:ethnology / Q000235:genetics*; D005787:Gene Frequency; D006239:Haplotypes; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008156:Luciferases / Q000378:metabolism; D020784:Matrix Metalloproteinase 8 / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D011247:Pregnancy; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012689:Sequence Homology, Nucleic Acid; D020298:U937 Cells; D001741:Black or African American
D008156:Luciferases; D020784:Matrix Metalloproteinase 8