Functional Significance of MMP3 and TIMP2 Polymorphisms in Cleft Lip/Palate

Area of Science:

• Genetics
• Developmental Biology
• Molecular Biology

Background:

• Matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) genes are implicated in non-syndromic cleft lip with or without cleft palate (NSCL/P).
• Previous studies linked specific promoter polymorphisms in MMP3 and TIMP2 to NSCL/P.
• The functional impact of these polymorphisms remained largely unexplored.

Purpose of the Study:

• To investigate the functional significance of promoter polymorphisms in MMP3 (rs3025058, rs522616) and TIMP2 (rs8179096) in relation to NSCL/P.
• To determine how these genetic variations affect gene transcription and potentially craniofacial development.

Main Methods:

• Analysis of DNA-protein complex formation for MMP3 rs522616.
• Assessment of promoter activity associated with MMP3 and TIMP2 polymorphisms using reporter assays.
• Investigation of nuclear factor kappa B (NF-κB) binding to TIMP2 rs8179096 alleles.

Main Results:

• MMP3 rs522616 allele A demonstrated higher promoter activity than allele G, with its effect modulated by the rs3025058 allele.
• TIMP2 rs8179096 allele T exhibited a 2.5-fold increase in promoter activity compared to allele C.
• Both TIMP2 rs8179096 alleles C and T were found to bind to NF-κB.

Conclusions:

• Promoter polymorphisms in MMP3 and TIMP2 are functional and can alter gene transcription.
• These functional variations may contribute to craniofacial development abnormalities, increasing the risk for NSCL/P.
• The study provides mechanistic insights into the genetic basis of NSCL/P.