A Relative Study Between The MMP-1 Promoter Gene Polymorphism And Periodontitis

Periodontitis is an inflammatory disease, which is initiated and perpetuated by a group of predominantly gram-negative and anaerobic bacteria. As an important host-derived factor, genetic risk factors play the crucial role that it could affect the dynamic equilibrium of bacteria-host interactions. Now many genetic studies and genealogy analysis showed that genetic risk factors are essential for disease initiation, but they are insufficient for the disease progression and outcomes.Periodontitis is characterized by the degradation of periodontal extracelluar matrix ingredient. Degradation of periodontal tissues is mainly mediated by matrix metalloproteinases (MMPs), a family of metal - dependent proteolytic enzymes that degrade extracellular matrix and basement membranes. As a mostly interstitial collagenase, MMP-1 (Fibroblast-type collagenase) gene is expressed by fibroblasts, keratinocytes, endotheial cells, monocytes, osteoblast and chondrocytes. MMP-1 has been identified in inflamed periodontal tissues, gingival cervical fluid(GCF), human gingival fibrobalst(HGF) and rat periodontal ligament cells(PDLC), which is the major proteolytic enzyme that can cleave native interstitial collagens type I and III, which are the most abundant protein components of extracellular matrix in periodontium. The expression level of MMP-1 is regulated at 4 "gates": (1) by transcriptional regulation of MMP genes; (2) by precursor activation; (3) by differences in substrate specificity; (4) by MMP inhibitors. Normally, the expression levels of MMP-1 in most cells are low, but it is readily induced by phorbol esters, growth factors and inflammatory cytokines.A genetic variation in the MMP-1 promoter region can influence the levels of MMP-1 transcription, and hence this gene may be crucial in mediating connective tissue degradation in the pathogenesis of periodontitis. This variation is a single nucleotide polymorphism located at -1607 bp, where an additional guanine (G) creates an Ets binding site, 5'-GGA-3', instead of 5'-GAT-3\ the core binding site for members of the Ets transcription factors. It has been shown that the 2G allele significantly increased the transcriptionactivity of MMP-1 as compared to 1G allele. The presence of the 2G allele has recently been associated with severe chronic periodontitis with the severe chronic periodontitis in a Brazilian population and the development of breast cancer and ovarian cancer. But Itagaki found that there was no significant differences in genotype distributions, allele frequencies, carriage rates and haplotype frequencies in the MMP-1 gene promoter 1G/2G polymorphisms among all groups in Japanese patients with chronic periodontitis. So it is very necessary to examine the distribution of MMP-1 genotypes in a group of Chinese subjects with periodontitis and periodontally healthy subjects, and to evaluate the possible association of the MMP-1 promoter polymorphism with periodontitis in a Chinese population.Many researchers were studying the effects of single nucleotide polymorphism on periodontal treatment. Different subjects showed the different effect in response of periodontal treatment, which could be caused by the expression level of endogenous MMP-1. In periodontitis, when PDLC were stimulated by the inflammatory stimuli and host-derived cytokines, it would product MMP-1. So we speculated that PDLC with different MMP-1 promoter polymorphism could express different level MMP-1 in response of exoteric stimuli, furthermore, result in different process of periodontitis and the diversity of therapy response.Chinese herb has received attention from all over the world. Baicalin, an active ingredient from scutellaric baicalensis georgi (Huang-Chin, HC), which is a traditional Chinese herb, has many pharmaceutical actions, such as anti-inflammation, anti-allergy and anti-oxidants. Our previous research has proved that lOOng/ml Baicalin could inhibit the secretion of pro-MMP-1 and MMP-3 expression in IL-1 P induced HGF and PDLC by cell immunocytochemistry and ELISA. These also suggest that baicalin also play an important role in the prevention and treatment of periodontitis, however the regulate mechanism of MMP-1 in PDLC by baicalin has been undefined. So we would investigate the effects of baicalin on the expression of MMP-l/TIMP-1 mRNA in PDLC.Part one A relative study between the MMP-1 promoter gene polymorphism and periodontitisGenomic DNA was obtained from whole blood samples from 40 aggressive periodontitis (AgP) patients and 52 controls. Genotypes of MMP-1 promoter -1607bp were determined by (polymerase chain reaction - restriction fragmentlength polymorphism (PCR-RFLP). MMP-1 promoter fragment was amplified by polymerase chain reaction, and the polymorphisms were analyzed by restriction endonuclease cleavage. The alleles were detected by polyacrylamide gel electrophoresis and visualized with ethidium bromide. Results: In the controls, the 2G allele was observed with a frequency of 49%, while in the AgP patients; the 2G allele was seen in 68.7%, and the distribution of 2G allele had significantly differences between AgP patients and Healthy controls (X2 =7.194,/7