Gene variability in matrix metalloproteinases in patients with recurrent aphthous stomatitis.

BACKGROUND: The development of recurrent aphthous stomatitis (RAS), inflammatory disease of oral mucosa, is influenced by both environmental and genetic factors. The aim of this study was to investigate polymorphisms located in seven genes coding different types of matrix metalloproteinases (MMPs)-collagenases (MMP1, MMP8, and MMP13), gelatinases (MMP2 and MMP9), stromelysin (MMP3), and membrane-type metalloproteinase (MMP16) in patients with RAS and healthy controls. METHODS: Totally, 223 subjects were included in this case-control study and their detailed anamnestic, clinical, and laboratory parameters were recorded. Seventy-seven patients with RAS and 146 controls were genotyped for seventeen polymorphisms in the MMPs genes using the real-time polymerase chain reaction (PCR) or PCR with restriction analysis. RESULTS: Allele, genotype, and haplotype frequencies of the studied polymorphisms between RAS patients and controls were similar, except for allele distributions of MMP1 rs1144393, MMP9 rs3918242, and MMP16 rs10429371, which were different between patients with RAS and healthy controls (P = .023, P = .049 and P = .025, all Pcorr  > 0.05, respectively). Moreover, the comparison of genotype frequencies (TT vs CC + CT) of the MMP16 rs10429371 variant showed a marginally significant difference between RAS patients and controls (P = .05, Pcorr  > 0.05, OR = 1.68, 95% CI = 0.95-2.98). CONCLUSIONS: No significant relationship between investigated polymorphisms in seven MMPs genes and RAS development in the Czech population was observed in this study.

Enzymatic antioxidants status in patients with recurrent aphthous stomatitis.

BACKGROUND: Oxidative stress (OS) has been thought to play a main role in the etiopathogenesis of recurrent aphthous stomatitis (RAS), which is one of the most common oral mucosal diseases characterized by recurrent and painful oral ulcers. The aim of this investigation was to evaluate the enzymatic antioxidants status in patients with RAS in the active stage and remission stage. METHODS: Ninety-seven patients with idiopathic minor RAS and 102 race-, age- and gender-matched healthy individuals were recruited. All these subjects were allocated to three groups: RAS patients with active lesion (group A); the same patients in group A in the remission stage of RAS (group B); and healthy individuals without RAS (group C). Following an overnight fast, blood samples were obtained. The serum levels of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSHPx) were measured by the spectrophotometric method. Independent-samples t-test and paired t-test were performed for statistical evaluation. RESULTS: The serum levels of SOD, GSHPx, and CAT (83.9 ± 17.1 U/ml, 6687.2 ± 2629.2 U/ml, 1789.7 ± 593.8 U/l) were found to be significantly lower in group A as compared to those of group B (99.8 ± 11.1 U/ml, 9364.1 ± 1607.9 U/ml, 2789.1 ± 1113.4 U/l; P < 0.05) or group C (97.3 ± 12.1 U/ml, 9246.2 ± 2376.1 U/ml, 2819.0 ± 914.8 U/l; P < 0.05). No significant differences were found between group B and group C with respect to any one of these enzymatic antioxidants (P > 0.05). CONCLUSIONS: Our results indicate that enzymatic antioxidant defense system is impaired in RAS patients with active lesion and seems to play a crucial role in its pathogenesis.

Association of MMP but not TIMP-1 gene polymorphisms with recurrent aphthous stomatitis.

OBJECTIVES: Recurrent aphthous stomatitis (RAS) is a common oral inflammatory disease induced by genetic and environmental factors. Gelatinases (MMP-2 and MMP-9) and their natural inhibitor TIMP-1 are active players in the inflammatory process. We aimed to determine whether inheritance of specific MMP-2, MMP-9, or TIMP-1 gene polymorphisms is associated with RAS susceptibility. SUBJECTS AND METHODS: Ninety-six RAS patients and 153 healthy controls were studied. Five polymorphisms were genotyped: rs17576, rs3918242, and rs11697325 in MMP-9, MMP-2 rs2285053, and TIMP-1 rs6609533. Association was assessed by logistic regression analysis after adjustment for confounding factors. Linkage disequilibrium (LD) was assessed using the Haploview program. RESULTS: MMP-9 rs11697325 was significantly associated with RAS, with an increase in the AA genotype in patients, determined using χ(2) analysis (OR = 2.3, P = 0.006) and adjusted regression analysis (OR = 3.1, P = 0.009). MMP-9 rs11697325 and rs17576 showed strong LD (D' = 0.95), with an increase in the AA haplotype (P = 0.023) and a decrease in the GA haplotype (P = 0.015) in patients. CONCLUSIONS: This is the first study to investigate the association of MMPs or TIMP-1 with RAS. We found a significant association between MMP-9 rs11697325 polymorphisms and RAS. Confirmatory studies in other populations and functional investigations are needed to determine the role of these genes in RAS.

Assessment of the serum paraoxonase activity and oxidant/antioxidant status in patients with recurrent aphthous stomatitis.

OBJECTIVES: Several studies have indicated that recurrent aphthous stomatitis (RAS) is associated with oxidative stress. The aim of this study was to investigate serum paraoxonase (PON) activity and oxidant/antioxidant status in patients with RAS. DESIGN AND METHODS: Thirty-one patients with RAS and 31 healthy controls were enrolled. Serum PON1 and arylesterase activities, total antioxidant capacity, total oxidant status, and oxidative stress index were determined. RESULTS: Serum total antioxidant capacity levels, PON1, and arylesterase activities were significantly lower in RAS than controls (P < 0.001), while total oxidant status levels and oxidative stress index were significantly higher (P < 0.001). PON1 activity had a significant correlation with high-density lipoprotein cholesterol only (r = 0.482, P < 0.05), while there were no correlations with other lipids (P > 0.05) in patients with RAS. CONCLUSIONS: Our results indicate that RAS is associated with decreased PON1 activity and increased oxidative stress that plays a crucial role in the pathogenesis of RAS. Further studies on a larger number of patients are needed to verify these results.

High association of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism with recurrent aphthous stomatitis.

Recurrent aphthous stomatitis (RAS) is a common ulcerative disease of the oral mucosa. Oral ulcers are also the most common feature of Behçet's disease (BD). Association of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism with BD has been reported in Turkish population. The aim of the present study was to investigate the possible association between ACE gene I/D polymorphism and RAS, and evaluate if there was an association with clinical features in a relatively large cohort of Turkish patients. The study included 198 patients affected by RAS and 214 healthy controls. ACE gene I/D polymorphism genotypes were determined using polymerase chain reaction with I and D allele-specific primers. The genotype and allele frequencies of I/D polymorphism showed statistically significant differences between RAS patients and controls (p < 0.0001 and p < 0.0001, respectively). After stratifying RAS patients according to clinical and demographical characteristics, no significant association was observed. In conclusion, the results of this study suggest that I/D polymorphism of the ACE gene was positively associated with predisposition to develop RAS in Turkish population. Further studies with larger populations are recommended.

Association between recurrent aphthous stomatitis and inheritance of a single-nucleotide polymorphism of the NOS2 gene encoding inducible nitric oxide synthase.

BACKGROUND: Recurrent aphthous stomatitis is a common ulcerative disease of the oral mucosa. Recurrent oral aphthous ulceration is also a feature of the more serious and systemic Behçet's disease. Nitric oxide is a free radical synthesized by one of a family of nitric oxide synthase (NOS) enzymes and is an important regulator of inflammation and immunity. Association of NOS3 gene polymorphisms encoding endothelial nitric oxide synthase has been reported in Behçet's disease but not recurrent aphthous stomatitis. The aim of this study was to investigate any association between NOS2 gene polymorphisms that encode inducible nitric oxide synthase and recurrent aphthous stomatitis. METHODS: This is a case control association study. Eighty-three Jordanian recurrent aphthous stomatitis patients and 83 age, gender and ethnically matched controls were genotyped for three NOS2 single-nucleotide polymorphisms, rs10459953, rs1060822 and rs2297518. Chi-squared analysis was used to compare the allele frequencies and genotypes. RESULTS: There was a significant association between recurrent aphthous stomatitis and inheritance of single-nucleotide polymorphism rs2297518 (P = 0.006). Although no direct association was demonstrated between rs10459953 or rs1060822 and recurrent aphthous stomatitis, a strong linkage disequilibrium was identified between rs1060822 and rs2297518. CONCLUSION: Inheritence of a NOS2 single-nucleotide polymorphism rs2297518 is associated with increased risk of recurrent aphthous stomatitis in a Jordanian population. Confirmatory studies in other populations and investigation of other NOS2 gene polymorphisms will enhance our understanding of the functional basis of this association and help elucidate the role of inducible nitric oxide synthase in recurrent aphthous stomatitis.

Endothelial nitric oxide synthase gene polymorphisms are not associated with recurrent aphthous stomatitis.

OBJECTIVE: Recurrent aphthous stomatitis (RAS) is a common ulcerative disease of the oral mucosa. Recurrent oral aphthous ulceration is the most common and consistent feature of the more serious and systemic Behçet's disease (BD). Association of endothelial nitric oxide synthase (eNOS) gene polymorphisms with BD have been reported in different populations. This study aims to investigate if there is an association between these polymorphisms and RAS. METHODS: A case-control association study using 91 Caucasoid RAS patients and 91 ethnically matched systemically healthy controls were genotyped for the -786 and 894 eNOS single nucleotide polymorphisms (SNPs) and a variable number of tandem repeat (VNTR) polymorphism. Chi-square analysis was used to compare the allele and genotype frequencies. RESULTS: No significant difference was found in the distribution of allele and genotype frequencies of the -786 and +894 polymorphisms or the VNTR polymorphism between cases and controls. CONCLUSION: eNOS gene polymorphisms associated with BD are not associated with RAS. This suggests that the oral ulceration common to both conditions may have a different underlying genetic aetiology. Although our data suggests that RAS does not have an association with eNOS, it is still possible that nitric oxide is involved in the disease process. This could still occur through localised and inflammation driven regulation by iNOS.

Clinical assessment of the effect of a matrix metalloproteinase inhibitor on aphthous ulcers.

OBJECTIVE: Aphthous ulceration is a common form of recurrent ulceration of the oral mucosa. Numerous treatments have been tried as a means of relieving pain, disinfecting the ulcer base, and reducing inflammation, but with limited success. Tetracycline and its derivatives have been shown to be inhibitors of matrix metalloproteinases (MMPs), which are part of the inflammatory response and contribute to the breakdown of tissue in the ulcer. Of the commercially available tetracyclines, doxycycline has shown the best inhibition of the MMPs. The aim of this study was to test clinically whether the inhibitory effect of a low-dose doxycycline in a hydrogel on MMPs would speed the recovery of oral ulceration. MATERIAL AND METHODS: Forty-nine patients participated in a randomized, double-blind, placebo-controlled trial. RESULTS: Sixty-eight percent of ulcers had healed by the third day of treatment with the doxycycline gel, whereas only 25% of the patients receiving the placebo reported healing of their ulcers within 3 days. Patients treated with the docycline gel recounted faster reduction in pain during the treatment period than the placebo group did. CONCLUSIONS: Incorporation of low-dose doxycycline in a muco-adhesive gel has been demonstrated to have potential in the treatment of recurrent oral ulceration. It is concluded that MMP enzymes can be inhibited by low doses of doxycycline below levels likely to disrupt the oral flora.

Oxidative stress and myeloperoxidase levels in saliva of patients with recurrent aphthous stomatitis.

OBJECTIVE: Recurrent aphthous stomatitis (RAS) is the most common oral ulcerative condition affecting 5-25% of the general population. The aim of this study was to evaluate the oxidative stress parameters in saliva of patients with RAS and to investigate the relationship among these parameters in either group. MATERIALS AND METHODS: The study involved 50 patients with RAS of whom 24 were male and 26 were female, and 25 healthy controls of whom 13 were male and 12 were female. RESULTS: There was no statistically significant difference in the salivary total antioxidant capacity, total oxidant status, oxidative stress index levels, and myeloperoxidase activity between patients with RAS and those in the control group. CONCLUSIONS: The results show that reactive oxygen species may not play a role in the etiology of RAS.

Purine catabolic enzymes and nitric oxide in patients with recurrent aphthous ulceration.

OBJECTIVES: Recurrent aphthous ulceration (RAU) is one of the most common oral mucosal disorders found in humans. Although the exact etiology of RAU is unkown, local and systemic conditions, and genetic, immunologic, and infectious factors all have been identified as potential etiopathogenic agents. The aim of our study was to compare serum xanthine oxidase (XO) and adenosine deaminase (AD) activities, and malondialdehyde (MDA), nitric oxide (NO) and uric acid (UA) levels in a group of patients affected by RAU and in a group of healthy controls. SUBJECTS AND METHODS: A total of 26 patients with minor RAU were included in the study. Twenty-six healthy volunteers were selected to form the control group. AD and XO activities, and UA, NO, and MDA levels were studied in the serum samples of all patients and controls. RESULTS: Serum XO and AD activities, and MDA, NO, and UA levels were significantly higher in RAU patients than in controls. CONCLUSION: Increased XO and AD activities, NO and UA levels and lipid peroxidation were thought to take part in the pathogenesis of RAU. Hence the effects of XO inhibitors in the treatment of RAU should be evaluated in future studies.

Erythrocyte superoxide dismutase, catalase activities and plasma nitrite and nitrate levels in patients with Behçet disease and recurrent aphthous stomatitis.

Behçet disease (BD) and recurrent aphthous stomatitis (RAS) are two distinct diseases of unknown aetiology which are both characterized by oral aphthae. The aim of this study was to determine the possible association of both diseases with antioxidant status and nitric oxide levels. Twenty-six patients (17 female, nine male) with RAS, 28 patients (17 female, 11 male) with BD and 31 (22 female, nine male) healthy control subjects were included in the study. Blood samples were studied for erythrocyte superoxide dismutase (SOD) and catalase (CAT) activities and plasma nitric oxide (NO) levels. Erythrocyte SOD activity in BD patients was significantly higher than in RAS patients and controls. Although SOD activity in RAS patients was higher than in controls, the difference was not statistically significant. No significant differences in CAT activities or NO levels were found between the three groups. In conclusion, changes in SOD activity may be important in the inflammatory reactions observed in BD and RAS, but NO does not seem to play a primary role in the aetiopathogenesis.

Oxidant/antioxidant status in patients with recurrent aphthous stomatitis.

Recurrent aphthous stomatitis (RAS) is recognized as one of the most common oral mucosal diseases worldwide. The aim of this study was to determine the oxidant/antioxidant status in erythrocyte and plasma samples from patients with RAS in comparison with healthy controls. Twenty-two patients with RAS and 23 healthy controls were recruited. Superoxide dismutase, glutathione peroxidase (GSHPx) and catalase (CAT) activities, and malondialdehyde (MDA) and antioxidant potential (AOP) levels were measured in plasma and erythrocytes from patient with RAS and controls. We found decreased CAT and GSHPx activities and AOP levels in the erythrocytes, and decreased AOP and increased MDA plasma levels in patients with RAS in comparison with control subjects. In summary, this study demonstrated that enzymatic and nonenzymatic antioxidant defence systems are impaired in patients with RAS.

Epidemiological evaluation of recurrent stomatitis, nitrates in drinking water, and cytochrome b5 reductase activity.

OBJECTIVE: Our aim was to examine a possible correlation between drinking water nitrate concentration, recurrent stomatitis, and cytochrome b5 reductase activity. Dietary nitrate can form nitrite in vivo. This can cause methemoglobinemia in the red blood cells. Cytochrome b5 reductase is an enzyme in the red blood cells that reduces methemoglobin back to hemoglobin. METHODS: Five areas were selected in the State of Rajasthan, India, having drinking water nitrate concentration (as nitrate) of 26, 45, 95, 222, and 459 mg of NO3/L. House schedules were prepared in these areas in accordance with a statistically designed protocol. We selected 193 age- and weight-matched persons, representing 10% of the total population in each of these areas. Detailed history was taken for recurrent stomatitis, medical examination was conducted, and blood samples were taken to ascertain cytochrome b5 reductase activity in the selected population. Collected data were statistically analyzed to ascertain a relationship between nitrate concentration, cytochrome b5 reductase activity, and percent stomatitis, using Microsoft Excel software. RESULTS: This study suggests that there is a significant interdependence between drinking water nitrate concentration, cytochrome b5 reductase activity, and recurrent stomatitis. CONCLUSION: Increased cytochrome b5 reductase activity primarily induced by the presence of high nitrate concentration in drinking water could be the cause for recurrent stomatitis.

Effect of tetracyclines on collagenase activity in patients with recurrent aphthous ulcers.

Human neutrophil-type (MMP-8) and fibroblast-type (MMP-1) interstitial collagenase, and their inhibition by tetracyclines in saliva from patients with recurrent aphthous ulcers (RAU) or aphthae, were studied by means of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and enzymological analyses. In the salivary specimens obtained from patients with aphthae, collagenase was found in endogenously active form and was predominantly of MMP-8 type. Topical rinsing treatment with chlortetracycline (Aureomycin) alleviated the discomfort caused by the lesions but did not reduce salivary collagenase amounts; however in vitro, doxycycline inhibited salivary collagenase totally.

Collagenase and stromelysin in recurrent aphthous ulcers (RAU).

Six patients with recurrent aphthous ulcers were studied for the presence of matrix metalloproteinases (MMP) 1, 3, and 8 in the lesions and in the clinically unaffected control mucosa obtained from the opposite side. MMP-type specific antisera were applied in the avidin-biotin-peroxidase complex staining method. Neutrophil-type collagenase (MMP-8) was found intracellularly in the connective tissue under the necrotized epithelium, and also laterally to the ulcer in association with the basement membrane. Fibroblast-type collagenase (MMP-1) and stromelysin (MMP-3) were found in the epithelial cells adjacent to the ulcerous lesion. They were found also in the endothelium of capillary blood vessels and postcapillary venules and also in some macrophage- and fibroblast-like mononuclear cells in the lamina propria laterally to the ulcer. A small number of MMP-1 and MMP-3 positive cells were noted in the control biopsies obtained from the clinically uninvolved control mucosa. These findings suggest regional differences in the distribution of the two main collagenases, implying distinct roles in tissue destruction and remodeling.

[Clinical study of superoxide dismutase in recurrent aphthous ulceration].

Activity of superoxide dismutase (SOD) was determined in erythrocytes obtained from 74 patients with recurrent aphthous ulcerations (RAU) and 100 healthy individuals. The results showed that activity level of SOD in RAU was significantly lower as compared with that in the controls (P less than 0.01). The activity of SOD in 30 cases of RAU at interval period was elevated on reexamination, but it was still lower than that in the controls (P less than 0.01). There is evidence that damage of superoxide radicals (O.2) and decrease of activity of SOD may play important roles in the pathogenesis of RAU. A random double-blind, placebo-controlled, cross-over trial on membrane SOD was carried out in 40 patients with RAU. The results demonstrated that the effective rate of SOD was 90%, being markedly higher than that of placebo. It is suggested that membrane SOD, as a topical medicine, could increase the concentration of SOD on the ulcerous surfaces, prevent O.2-induced injury, decrease capillary permeability, relieve inflammation and improve cure of ulcer.

[Effect of anaprilin on the tyrosine hydroxylase activity of the oral mucosa in dogs with experimental stomatitis]. / Vliianie anaprilina na tirozingidroksilaznuiu aktivnost' slizistoi obolochki polosti rta u sobak pri éksperimental'nom stomatite.

It was shown that in dogs with experimental aphthous stomatitis (ligation of the common bile duct) tyrosine hydroxylase activity and content of catecholamines (CA) in the oral mucosa were increased. Blockade of beta-adrenoreceptors caused by anaprilin (1 mg/kg) led to the further increase of tyrosine hydroxylase activity. A relative decrease of CA content was simultaneously observed.