Association of Fas-670 gene polymorphism with inflammatory bowel disease in Chinese patients

AIM: Recent studies suggest that Fas-mediated apoptosis is involved in the pathogenesis of inflammatory bowel disease (IBD). It has been hypothesized that either increased apoptosis of intestinal epithelium or decreased apoptosis of lamina propria lymphocytes may induce inflammation of gut. The aim of this study was to determine whether the Fas gene promoter polymorphism at position-670 was associated with IBD in Chinese patients.METHODS: Fifty unrelated Chinese patients with IBD (38patients with ulcerative colitis and 12 with Crohn's disease)and 124 healthy controls were genotyped for the Fas-670polymorphism by PCR-restriction fragment length polymorphism method. The PCR product was digested by Mva I restriction enzyme.RESULTS: Distribution of the Fas-670 gene polymorphism was 33% for the AA genotype, 52% for the AG genotype and 15% for the GG genotype in 124 healthy subjects. In patients with IBD, 30% was for the AA genotype, 42% for the AG genotype and 28% for the GG genotype respectively. However, there was no significant difference in the genotype (P= 0.1498), allele frequencies (P= 0.3198)and carriage frequencies (P = 0.4133) between healthy controls and IBD patients. Furthermore, we did not find any difference between the left-sided colitis and total colitis (P = 0.8242).CONCLUSION: Fas-670 polymorphism is not associated with IBD in Chinese patients.

Association of tumor necrosis factor genetic polymorphism with chronic atrophic gastritis and gastric adenocarcinoma in Chinese Han population

AIM:To investigate the association of TNF polymorphisms with chronic atrophic gastritis (CAG) and gastric adenocarcin-oma in Chinese Han patients.METHODS:The TNFa-e 5 microsatellites and 3 RFLP sites were typed using PCR technique,followed by high-voltage denaturing PAGE with silver staining and restriction enzyme digestion respectively in specimens from 53 patients with CAG and 56 patients with agstric daenocarcinoma and 164 healthy controls.The PCR products were cloned and sequenced.RESULTS:The frequency of TNF-β Ncol*1/2 genotype was higher in patients with chronic atrophic gastritis than in healthy controls,but no significant difference was observed(60.38% vs 46.34%,p=0.076).The frequency of TNa10 allele was significantly higher in patients with chronic atrophic gastritis than in healthy controls(19.81% vs 11.89%,p=0.04).However,it did not relate to age,gender,atrophic degree or intestinal metaplasin in patients with chronic atrophic gastritis,The frequency of TNF-β Ncol*1/2 and d2/d6 genotypes were significantly higher in patients with gastric adenocarcinoma than in healthy indiveduals(p>0.05).However,TNF-β Ncol*1/2 and d2/d6 genotypes did not relate to age,gender,grade of differentiation and clinicopathologic state in patients with gastric adenocarcinoma.The frequency of TNFa6b5c1 hapolotype homoaygote was significantly lower in patients with gastric adenocarcinoma than in healthy controls (1.79% vs 15.85%,p=0.006).CONCLUSION:TNFa10 allele may be a risk factor for chronic atrophic gastritis ,TNF-β Ncol*1/2 and d2/d6 genotypes are associated with the suscepotibility to gastric adenocarcinoma,whereas TNFa6b5c1 haplotype homozygote may contribute to the resistance against gastric adenocarcinoma.

Effects of low molecular weight heparin on platelet surface P-selectin expression and serum interleukin-8 production in rats with trinitrobenzene sulphonic acid-induced colitis

AIM:To observe the effects of low molecular weight heparin(LMWH) on platelet surface P-selectin expression and serum interleukin-8 production in rats with trinitrobenzene sulphonic acid (TNBS) induced colitis.METHODS:Colitis was induced in female Sprauge-Dawley rats by colonic administration of 2, 4, 6-TNBS. LMWH, a dalteparin (150U/kg, 300U/kg) was subcutaneously administrated one hour before induction of colitis and went on once a day for 6 days. Then a half dose was given for the next 7 days. Control animals received the same volume of normal saline once a day for 14 days after treated by TNBS.Animals were sacrificed at 24h, days 7 and 14 after induction of colitis. The colon was excised for the evaluation of macroscopic and histological findings and TNF-α immunohistochemical assay. Platelet surface P-selectin expression was determined by radioimmunoassay and serum IL-8 production was assayed by ELISA method.RESULTS:LMWH treatment in a dose of 300U/kg for 14 days significantly improved colonic inflammation by histological examination. Serum IL-8 production in the 300U/kg treatment group was more significantly decreased at day 14 than that at 24h (P<0.05). However, platelet surface P-selectin expression and TNF-α staining in colonic tissue were not significantly different among the three groups.CONCLUSION:LMWH has an anti-infiammatory effect on TNBS induced colitis in rats. The effect is possibly related to inhibition of proinflammatory cytokine IL-8, but not involved platelet surface P-selectin expression.

Cis- and Trans-Cinnamic Acids Have Different Effects on the Catalytic Properties of Arabidopsis Phenylalanine Ammonia Lyases PAL1, PAL2, and PAL4

Abstract: Cis-cinnamic acid (CA) is a naturally occurring compound, presumably converted from trans-CA in higher plants. To investigate the effect of cis-CA on the activity of Arabidopsis phenylalanine ammonia lyase (PAL), AtPAL1, AtPAL2, and AtPAL4 genes were isolated using reverse transcription poly-merase chain reaction. These genes were fused to a glutathione S-transferase gene and overexpressed in a heterologous prokaryotic system of Escherichia coli. The purified PAL1, PAL2 and PAL4 enzymes were characterized biochemically to determine the effects of cis-CA on the kinetic parameter Km. The results showed that cis-CA is a competitive inhibitor for PAL1, but not PAL2 and PAL4, whereas trans-CA acts as a competitive inhibitor for all three PAL isomers, suggesting that cis- and trans-CA have different effects on the catalytic activity of PAL.