Interrelationships among MTHFR gene polymorphisms, MTRR gene polymorphisms, and HBV gene BCP 1762/1764 mutations with disease progression in Chronic hepatitis B virus infection patients.

OBJECTIVE: Chronic hepatitis B virus (HBV) infection is a major disease that seriously affects the health of patients. In this paper, the relationship among MTHFR gene polymorphism, MTRR gene polymorphism and 1762/1764 mutation in the BCP region of HBV gene with disease progression in chronic HBV patients was studied. METHODS: A total of 144 chronic HBV infection patients from January 2021 to June 2022 in the Third People's Hospital of Zigong City, were included as the study subjects. These patients were divided into hepatitis B primary liver cancer patients group (PLC) in 51 cases, Non-primary liver cancer patients group (Non-PLC) in 93 cases, Non-PLC is also divided into chronic hepatitis B virus carriers (CHC) in 49 cases, hepatitis B Live cirrhosis(LC) in 44 cases. MTHFR (C677T), MTRR (A66G) and MTHFR (A1298C) genes polymorphisms were detected by PCR-dissolution curve. The level of HBV-DNA was quantified by real-time PCR, and the 1762/1764 mutation site in the BCP region of the HBV gene were detected by ARMS-PCR. Data were statistically analyzed using the SPSS statistical software. RESULTS: The proportion of HBV mutations in BCP region 1762/1764 in PLC group was 82.4%, which was higher than that in LC group (63.6%) and CHC group (51.0%), and the differences were statistically significant (p < 0.05). There were no significant differences in the distribution of MTHFR C677T, MTHFR A1298C and MTRR A66G polymorphisms among CHC, LC and PLC (p > 0.05). The polymorphism distribution of MTHFR C677T, MTRR A66G and MTHFR A1298C genes in patients with chronic hepatitis B virus infection at different stages (CHC, LC and PLC) showed no gender or age differences between and within groups (p > 0.05). Among the patients with MTHFR 677CT + TT, MTRR 66AG + GG and MTHFR 1298AA genotype, the proportion of HBV mutation in BCP region 1762/1764 in PLC group was higher than that in CHC group and LC group, and the differences were statistically significant (p < 0.05). Folate levels in the PLC group were lower than those in the non-PLC group (CHC and LC patients), and the difference was statistically significant compared with the CHC group (p < 0.05). In different MTHFR C677T and MTRR A66G genotypes, the serum GGT activity were statistically significant between mutant PLC and mutant Non-PLC (p < 0.05). CONCLUSION: MTHFR C677T, MTRR A66G and MTHFR A1298C gene polymorphisms distribution have no gender and age differences in chronic hepatitis B virus infection patients. The mutation of HBV gene BCP region 1762/1764 may be associated with the occurrence and development of liver cancer in patients with chronic HBV infection. Single difference of MTHFR C677T, MTHFR A1298C and MTRR A66G gene polymorphisms may have little effect on the disease progression in patients with chronic HBV infection. MTHFR 677CT + TT, MTRR 66AG + GG and MTHFR 1298AA genotype combined with HBV gene BCP region 1762/1764 mutation may be closely related to the occurrence and development of hepatitis B liver cancer.

Association of MTHFR (C677T, A1298C) and MTRR A66G polymorphisms with fatty acids profile and risk of neural tube defects.

OBJECTIVE: This study aims to determine if 5,10-methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and methionine synthase reductase (MTRR A66G) gene polymorphisms were associated with fatty acid (FA) levels in mothers of fetuses with neural tube defects (NTDs) and whether these associations were modified by environmental factors. METHODS: Plasma FA composition was assessed using capillary gas chromatography. Concentrations of studied FA were compared between 42 mothers of NTDs fetuses and 30 controls as a function of each polymorphism by the Kruskal-Wallis nonparametric test. RESULTS: In MTHFR gene C677T polymorphism, cases with (CT + TT) genotype had lower monounsaturated FAs (MUFA) and omega-3 polyunsaturated FA (n-3 PUFA) levels, but higher omega-6 polyunsaturated FAs (n-6 PUFA) and omega-6 polyunsaturated FAs: omega-3 polyunsaturated FAs (n-6:n-3) ratio levels. In MTRR gene A66G polymorphism, cases with (AG + GG) genotype had lower MUFA levels, but higher PUFA and n-6 PUFA levels. Controls with (AG + GG) genotype had lower n-6 PUFA levels. In MTHFR gene C677T polymorphism, cases with smoking spouses and (CT + TT) genotype had lower MUFA and n-3 PUFA levels, but higher PUFA, n-6 PUFA, and n-6:n-3 ratio levels. Cases with (CT + TT) genotype and who used sauna during pregnancy had lower n-3 PUFA levels. In MTRR gene A66G polymorphism, cases with (AG + GG) genotype and who used sauna during pregnancy had higher PUFA and n-6 PUFA levels. CONCLUSIONS: Further research is required to clarify the association of FA metabolism and (MTHFR, MTRR) polymorphisms with NTDs.

MTHFR and MTRR gene polymorphisms in patients with chronic hepatitis B virus infections in Zigong, Sichuan Province.

BACKGROUND: Chronic hepatitis B virus (HBV) infection is a severe disease affecting the physical and economic well-being of patients. The relationship between polymorphisms in the MTHFR gene and disease progression following HBV infection remains a controversial topic. AIM: To study MTHFR and MTRR gene polymorphisms in patients with chronic HBV infections in Zigong, Sichuan Province. SUBJECTS AND METHODS: One hundred and ninety-one patients with chronic HBV infections were divided into three groups: the chronic hepatitis B (CHB) group (n = 71), the hepatitis B-induced liver cirrhosis (LC) group (n = 56), and the hepatitis B-related primary liver cancer (PLC) group (n = 64). The gene polymorphisms were detected using the PCR-melt curve method and analysed. RESULTS: The distributions of MTHFR C677T (CC: 41.2% vs. 41.8%; CT: 50% vs. 45.5%; TT: 8.8% vs. 12.7%; p = 0.714), MTHFR A1298C (AA: 70.6% vs. 72.7%; AC: 26.5% vs. 25.5%; CC: 2.9% vs. 1.8%; p = 1.000), and MTRR A66G (AA: 58.1% vs. 65.5%; AG: 39.0% vs. 29.1%; 2.9% vs. 5.5%; p = 0.353) genetic polymorphisms did not vary between male and female patients from Zigong. In addition, there were no differences in the distributions of MTHFR C677T (CC: 43.4% vs. 38.8%; CT: 49.1% vs. 48.2%; TT: 7.5% vs. 12.9%; p = 0.444), MTHFR A1298C (AA: 76.4% vs. 64.7%; AC: 20.8% vs. 32.9%; CC: 2.8% vs. 2.4%; p = 0.155), and MTRR A66G (AA: 62.3% vs. 57.6%; AG: 34.0% vs. 38.8%; 3.8% vs. 3.5%; p = 0.353) genetic polymorphisms between the patients <60 and >60 years of age. The distributions of MTHFR C677T (CHB vs. LC, p = 0.888; CHB vs. PLC, p = 0.661; PLC vs. LC, p = 0.926), MTHFR A1298C (CHB vs. LC, p = 0.12; CHB vs. PLC, p = 0.263; PLC vs. LC, p = 0.550), and MTRR A66G (CHB vs. LC, p = 0.955; CHB vs. PLC, p = 0.645; PLC vs. LC, p = 0.355) gene polymorphisms were comparable between the CHB, LC, and PLC groups. CONCLUSION: The distributions of MTHFR and MRRR genetic polymorphisms in the population with HBV infections in Zigong, Sichuan Province did not differ in age and sex. The MTHFR and MRRR genetic polymorphisms were comparable between the CHB, LC, and PLC groups.

Global DNA Methylation Levels Viz-a-Viz Genetic and Biochemical Variations in One Carbon Metabolic Pathway: An Exploratory Study from North India.

Despite the importance of one carbon metabolic pathway (OCMP) in modulating the DNA methylation process, only a few population-based studies have explored their relationship among healthy individuals. This study aimed to understand the variations in global DNA methylation levels with respect to selected genetic (CBS 844ins68, MTRR A66G, MTR A2756G, and MTHFR C677T polymorphisms) and biochemical (folate, vitamin B12, and homocysteine) markers associated with OCMP among healthy North Indian adults. The study has been conducted among 1095 individuals of either sex (69.5% females), aged 30-75 years. A sample of 5 mL of blood was collected from each participant. Homocysteine, folate, and vitamin B12 levels were determined using the chemiluminescence technique. Restriction digestion was performed for genotyping MTRR A66G, MTR A2756G, and MTHFR C677T polymorphisms and allele-specific PCR amplification for CBS 844ins68 polymorphism. Global DNA methylation levels were analyzed using ELISA-based colorimetric technique. Of the selected genetic and biochemical markers, the mutant MTRR A66G allele was positively associated with global DNA methylation levels. Further, advanced age was inversely associated with methylation levels. MTRR 66GG genotype group was hypermethylated than other genotypes in folate replete and vitamin B12 deficient group (a condition prevalent among vegetarians), suggesting that the G allele may be more efficient than the wild-type allele in such conditions. Global DNA methylation levels appeared to be more influenced by genetic than biochemical factors. MTRR 66G allele may have a selective advantage in vitamin B12 deficient conditions. Further research should be undertaken to understand how genetics affects epigenetic processes.

MTR, MTRR and CBS Gene Polymorphisms in Recurrent Miscarriages: A Case Control Study from North India.

Background: According to various epidemiological studies, the aetiology of recurrent miscarriages (RMs) is multifactorial. The goal of this study is to learn more about the link between genetic polymorphisms and RM. Aim: To evaluate the association of 5-Methytetrahydrofolate-Homocysteine Methyltransferase (MTR) A2756G, 5-Methytetrahydrofolate-Homocysteine Methyltransferase Reductase (MTRR) A66G and cystathionine beta-synthase (CBS) 844INS68 genetic polymorphisms with RM and also to understand the combined effect of the selected genotypes. Study Setting and Design: This was a hospital-based, case-control, observational study. Materials and Methods: A total of 516 participants were recruited in the present study, of which 200 RM cases and 258 controls were included in the present study. Fasting blood sample (~5ml) was drawn from all the participants and were screened for genetic polymorphisms of MTR A2756G, MTRR A66G and CBS 844INS68. Statistical Analysis: The frequency, odd's ratio and Hardy-Weinberg equilibrium were evaluated. SPSS (version 21.0) was used for the data analysis. Results: MTR A2756G genetic polymorphism was not associated with the risk of RM. The ancestral allele of MTRR A66G and the mutant allele of CBS 844INS68 was causing an increased risk of more than two folds for RM. CBS 844INS68 in combination with MTR A2756G was found to pose an increased risk of more than two folds for RM. Conclusion: Genetic polymorphisms particularly MTRR A66G and CBS 844INS68 seems to be elevating the risk and hence making women susceptible for RM.

Evaluating the Association Between Genetic Polymorphisms Related to Homocysteine Metabolism and Unexplained Recurrent Pregnancy Loss in Women.

Objective: To investigate the relationship between unexplained recurrent pregnancy loss (URPL) and polymorphisms of homocysteine metabolism-related genes in women. Materials and Methods: A case-control study included 90 women with two or more consecutive unexplained pregnancy losses and 92 controlled women without miscarriage history; the female participants were in the age category of 18-35 years. The high-resolution melting technique was used to detect the single-nucleotide variants related to homocysteine metabolism disorder, namely MTHFR C677T, MTHFR A1298C, MTR A2756G, and MTRR A66G polymorphism. Results: The MTHFR C677T polymorphism had significantly correlation with URPL. Indeed, the frequency of the677T allele and genotypes (677CT, 677TT) in the URPL group was significantly higher than that in the control group (p < 0.05). However, the allele, as well as genotype distribution of MTHFR A1298C, MTR A2756G, and MTRR A66G polymorphisms showed no significant difference (p > 0.05). MTHFR 677CT-1298AC genotype combination led to a 9.0-fold increased risk of URPL (OR 9.0; 95% CI, 2.25-35.99; p = 0.001), while the risk increased 10.0-fold (OR 10.0; 95% CI, 1.8-55.53; p = 0.008) when participants had more than the 3 variant loci. Conclusion: The MTHFR C677T polymorphism was a risk factor for URPL, and determining the MTHFR C677T polymorphism had a potential prediction of URPL risk. Moreover, the MTHFR C677T and MTHFR A1298C joint mutants might have a synergistic effect on URPL. Conversely, there is a lack of evidence suggesting the URPL risk of MTHFR A1298C, MTR A2756G, and MTRR A66G polymorphisms.

Screening of six polymorphisms related with folate metabolism in parents of individuals with Down syndrome.

OBJECTIVE: The study aim to investigate MTHFR C677T, MTHFR A1298C, RFC1 A80G, MTR A2756G, CBS 844ins68, MTRR A66G polymorphisms in Down syndrome (DS) parents. METHODS: Polymorphisms were evaluated in 35 mothers and 24 fathers of individuals with free trisomy of chromosome 21 confirmed by karyotype. The control group included 26 mothers and 26 fathers who had no children with DS. The molecular analysis was performed by polymerase chain reaction and restriction fragment length polymorphism (reaction chain polymerase restriction fragment length polymorphism) or polymerase chain reaction. The χ2 test (chi-square) was used to compare allele's differences among the study and the control group. Hardy-Weinberg equilibrium model was performed by χ2 testing. Multiple logistic regression models and binary logistic regression used to determine the association between polymorphisms and parental DS risk. RESULTS: This study did not reveal any significant difference in frequencies of polymorphisms. The haplotype analysis did not reveal linkage disequilibrium. The logistic regression analysis did not demonstrate differences between the groups. However, the binary logistic regression showed a higher frequency of the polymorphic homozygote genotype in DS parent group to codominant and dominant model in the RFC1 A80G. CONCLUSION: In conclusion, although the screening results were significant only to the RFC1 A80G polymorphism, the other determinations of the genetic factors associated with abnormal chromosome segregation could be helpful in future studies, including other polymorphisms involved in folate metabolism.

Acceleration of age-induced proteolysis in the guinea pig lens nucleus by in vivo exposure to hyperbaric oxygen: A mass spectrometry analysis.

Hyperbaric oxygen (HBO) treatment of animals or ocular lenses in culture recapitulates many molecular changes observed in human age-related nuclear cataract. The guinea pig HBO model has been one of the best examples of such treatment leading to dose-dependent development of lens nuclear opacities. In this study, complimentary mass spectrometry methods were employed to examine protein truncation after HBO treatment of aged guinea pigs. Quantitative liquid chromatography-mass spectrometry (LC-MS) analysis of the membrane fraction of guinea pig lenses showed statistically significant increases in aquaporin-0 (AQP0) C-terminal truncation, consistent with previous reports of accelerated loss of membrane and cytoskeletal proteins. In addition, imaging mass spectrometry (IMS) analysis spatially mapped the acceleration of age-related αA-crystallin truncation in the lens nucleus. The truncation sites in αA-crystallin closely match those observed in human lenses with age. Taken together, our results suggest that HBO accelerates the normal lens aging process and leads to nuclear cataract.

Diverse mechanisms activate the PI 3-kinase/mTOR pathway in melanomas: implications for the use of PI 3-kinase inhibitors to overcome resistance to inhibitors of BRAF and MEK.

BACKGROUND: The PI 3-kinase (PI3K) pathway has been implicated as a target for melanoma therapy. METHODS: Given the high degree of genetic heterogeneity in melanoma, we sought to understand the breadth of variation in PI3K signalling in the large NZM panel of early passage cell lines developed from metastatic melanomas. RESULTS: We find the vast majority of lines show upregulation of this pathway, and this upregulation is achieved by a wide range of mechanisms. Expression of all class-IA PI3K isoforms was readily detected in these cell lines. A range of genetic changes in different components of the PI3K pathway was seen in different lines. Coding variants or amplification were identified in the PIK3CA gene, and amplification of the PK3CG gene was common. Deletions in the PIK3R1 and PIK3R2 regulatory subunits were also relatively common. Notably, no genetic variants were seen in the PIK3CD gene despite p110δ being expressed in many of the lines. Genetic variants were detected in a number of genes that encode phosphatases regulating the PI3K signalling, with reductions in copy number common in PTEN, INPP4B, INPP5J, PHLLP1 and PHLLP2 genes. While the pan-PI3K inhibitor ZSTK474 attenuated cell growth in all the lines tested, isoform-selective inhibition of p110α and p110δ inhibited cell growth in only a subset of the lines and the inhibition was only partial. This suggests that functional redundancy exists between PI3K isoforms. Furthermore, while ZSTK474 was initially effective in melanoma cells with induced resistance to vemurafenib, a subset of these cell lines concurrently developed partial resistance to PI3K inhibition. Importantly, mTOR-selective or mTOR/PI3K dual inhibitors effectively inhibited cell growth in all the lines, including those already resistant to BRAF inhibitors and ZSTK474. CONCLUSIONS: Overall, this indicates a high degree of diversity in the way the PI3K pathway is activated in different melanoma cell lines and that mTOR is the most effective point for targeting the growth via the PI3K pathway across all of these cell lines.

Distribution of Methionine Synthase Reductase (MTRR) Gene A66G Polymorphism in Indian Population.

Methionine synthase reductase (MTRR) is an important enzyme of the folate/homocysteine pathway. It is responsible for regulation of methionine enzyme by reductive methylation. A common variant A66G is reported in the FMN-binding domain of the MTRR gene, which leads to substitution of isoleucine by methionine (I22M) in MTRR enzyme with reduced activity. Reduced catalytic activity of enzyme leads to high homocysteine concentration in blood and increases risk for numerous diseases. The frequency of A66G polymorphism varies in different ethnic groups. The present study has been designed to evaluate the frequency of MTRR A66G gene polymorphism in the Eastern UP population by PCR-RFLP method. Along with this we also performed a meta-analysis to evaluate the global prevalence of this polymorphism. Databases were screened to identified the eligible studies. The prevalence of the G allele and GG genotype was determined by the use of prevalence proportion with 95% CI. Open meta-analyst software was used for the meta-analysis. Total 1000 blood samples were analyzed, the frequencies of A and G alleles were 0.35 and 0.65 respectively. Meta-analysis results revealed that the prevalence of G allele and GG genotype were 49.4% (95% CI 40.6-58.1, p ≤ 0.001) and 24.3% (95% CI 17.8-30.9, p ≤ 0.001) respectively. In sub-group meta-analysis, the lowest frequency of G allele was found in South America (32.7%; 95% CI 14.1-51.3, p ≤ 0.001), and highest in Asia (56.4%; 95% CI 39.5-73.3, p ≤ 0.001). The results of the meta-analysis showed that the Asian population has the highest frequency of G allele and highest frequency of the GG genotype was found in the European population.

Association of MTHFR C677T, MTHFR A1298C, and MTRR A66G Polymorphisms with Neural Tube Defects in Tunisian Parents.

OBJECTIVE: This study aims to investigate the association of 5,10-methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and methionine synthase reductase (MTRR A66G) gene polymorphisms with neural tube defects (NTDs) in a Tunisian population. METHODS: Genotyping was performed by polymerase chain reaction with restriction fragment length polymorphisms (PCR-RFLPs) using the restriction enzymes. Allele and genotype frequencies were compared between mothers and fathers of fetuses with NTDs with matched controls based on an association analysis using SPSS software. RESULTS: MTHFR (C677T, A1298C) and MTRR A66G polymorphisms were found to be protector factors for NTD fetuses in the mother group. In addition, a combination of the three wild-type alleles C677/A1298/A66 has increased four-fold the incidence of NTDs (p = 0.004, OR = 3.96, 95% CI: 1.53-10.23). In the father group, MTHFR C677T was a risk factor for NTDs. However, no association was found between MTHFR A1298C, MTRR A66G, and the occurrence of this anomaly. The analysis of MTHFR C677T and MTRR A66G polymorphisms has demonstrated a significant difference in vitamin B12 levels between recessive and dominant genotypes in case mothers (p < 0.05). CONCLUSION: Additional studies are required to better understand the roles of parental gene polymorphisms related to folate-homocysteine metabolism in the pathogenesis of NTD.

Interactions between genetic variants involved in the folate metabolic pathway and serum lipid, homocysteine levels on the risk of recurrent spontaneous abortion.

BACKGROUND: The interaction between folate pathway gene polymorphisms and homocysteine, serum lipid leverls are poorly understood in patients with recurrent spontaneous abortion (RSA). The aim of this study is to explore the effects of folate pathway gene polymorphisms (the 5-10-methylenetetrahydrofolate reductase, MTHTR C677T, MTHFR A1298C and the methionine synthase reductase, MTRR A66G) and their interactions with homocysteine on serum lipid levels in patients with RSA. METHODS: A total of 403 RSA women and 342 healthy women were randomly selected. Genotyping of the MTHFR C677T, A1298C and MTRR A66G were performed by TaqMan-MGB technique. Serum homocysteine, folate, fasting glucose, fasting insulin, Interleukin 6, Tumor necrosis factorα (TNFα) and lipid profiles were measured according to the kits. Continuous variables were analyzed using 2-sample t-tests. Categorical variables were analyzed and compared by χ2 or Fisher's exact tests. Unconditional logistic regression model was applied to test the interactions of gene polymorphisms on RSA. RESULTS: The distribution of genotype of CC, CT TT and T allele of MTHFR C677T, genotype of AA and C allele of MTHFR A1298C, and genotype of AA, AG and G allele of MTRR A66G were different between cases and controls (all p were < 0.05). There were significant interactions between MTHFR C677T-A1298C and MTHFR A1298C-MTRR A66G in RSA group and control group, with ORs of 1.62 (95%CI: 1.28-2.04, p < 0.001) and 1.55 (95%CI: 1.27-1.88, p < 0.001), respectively. Serum TNFα level and insulin resistant status (HOMR-IR) were higher in RSA group than in control group (p = 0.038, 0.001, respectively). All the three gene SNPs except MTRR 66AG gene variant had detrimental effects on HOMA-IR (all p were < 0.05). RSA group who carried the MTHFR 677CT, TT, CT/TT genotypes and MTRR 66AG, AG/GG genotypes had detrimental effects on serum homocysteine levels, the MTHFR 677CT, CT/TT genotype carriers had favorable effects on serum folate levels, the MTHFR 677TT, CT/TT, 1298 AC, AC/CC genotype carriers had detrimental effects on serum low-density lipoprotein cholesterol (LDL-C) levels, and the MTRR 66AG genotype carriers had lower high-density lipoprotein cholesterol (HDL-C) levels than the AA genotype carriers (all p were < 0.05). CONCLUSIONS: Interaction between the MTHFR C677T, A1298C and MTHFR A1298C, MTRR A66G are observed in our RSA group. Besides, all the three gene SNPs except MTRR 66AG gene variant had detrimental effects on HOMA-IR. MTHFR C677T and MTRR A66G gene variants had detrimental effects on serum homocysteine levels and insulin resistance status, while MTHFR C677T, A1298C and MTRR A66G gene variants had detrimental effects on certain serum lipid profiles.

RETRACTED: Peptide-induced formation of protein aggregates and amyloid fibrils in human and guinea pig αA-crystallins under physiological conditions of temperature and pH.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the authors. The senior author contacted the journal in a forthright manner, in an effort to preserve the scientific integrity of the literature, after discovering a significant error in the results reported in the article. The authors were recently made aware of a paper by Kim et al. (Nature Commun. 2019) which shows a spirosome structure (the enzyme aldehyde-alcohol dehydrogenase) present in E. coli (Fig. 5a) that is very similar to the structure the authors thought formed when synthetic alpha A crystallin (66-80) peptide was incubated for 24 h with recombinant guinea pig alpha A insert crystallin (see Kumarasamy et al., Figs. 7C and F, and Fig. 9). Subsequent to publication of their report, the authors later found a number of images that showed what appeared to be the same structure present in samples of their presumably purified recombinant guinea pig alpha A insert crystallin which had been incubated without peptide for 24 h. Hence, the authors now conclude that the structures shown in Figs. 7C and F, and Fig. 9 of their article published in this journal are actually due to E. coli contaminant aldehyde-alcohol dehydrogenase. The authors deeply regret this error and any inconvenience it may have caused.

A novel HLA-A null allele, HLA-A*66:28N.

The novel HLA-A*66:28N allele differs from HLA-A*66:03 by a single nucleotide deletion at codon 185.

Associations Between MTR A2756G, MTRR A66G, and TCN2 C776G Polymorphisms and Risk of Nonsyndromic Cleft Lip With or Without Cleft Palate: A Meta-Analysis.

OBJECTIVE: We conducted a meta-analysis to investigate the associations of methionine synthase (MTR) A2756G, methionine synthase reductase (MTRR) A66G, and transcobalamin 2 (TCN2) C776G gene polymorphisms with nonsyndromic cleft lip with or without cleft palate (NSCL/P). MATERIALS AND METHODS: The PubMed, Web of Science, Embase, and Wiley Online Library databases and the China Biomedical Literature Service System (SinoMed) were searched for relevant articles to explore the associations between the MTR A2756G, MTRR A66G, and TCN2 C776G polymorphisms and the risk of NSCL/P. We performed overall comparisons and stratified analyses according to the ethnicity, type of NSCL/P, and Hardy-Weinberg equilibrium (HWE) of the control group. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were applied to estimate the associations of these gene polymorphisms with NSCL/P risk using fixed-effects or random-effects models incorporating five genetic models. RESULTS: Ultimately, 12 articles were included in this study. The pooled results did not reveal a significant association of the MTR A2756G polymorphism with NSCL/P risk (G vs. A: OR = 0.95, 95% CI = 0.82-1.11, p = 0.55). Similar results were observed for the MTRR A66G polymorphism (G vs. A: OR = 0.99, 95% CI = 0.82-1.18, p = 0.72) and the TCN2 C776G polymorphism (G vs. C: OR = 0.95, 95% CI = 0.86-1.06, p = 0.37). CONCLUSION: In summary, the MTR A2756G, MTRR A66G, and TCN2 C776G polymorphisms might not be associated with NSCL/P risk.

The role of miR-190a-5p contributes to diabetic neuropathic pain via targeting SLC17A6.

INTRODUCTION: MicroRNAs play a key role in neuropathic pain. In a previous study, miR-190a-5p was significantly downregulated in diabetic neuropathic pain (DNP). However, the role and pathological mechanism of miR-190a-5p in DNP still remain unclear. MATERIALS AND METHODS: DNP model was established. The paw withdrawal thresholds were measured to assess the mechanical nociceptive response. Dual-luciferase reporter assay was used to confirm the target gene of microRNA. The expressions of microRNA, gene, and protein were detected by the quantitative real-time polymerase chain reaction or Western blot. The levels of IL-1ß and IL-6 were detected with the enzyme-linked immuno sorbent assay. RESULTS: Compared with the control sample, the expression of miR-190a-5p was decreased and SLC17A6 was increased in the spinal tissue from those developing DNP. The bioinformatics and luciferase reporter assay demonstrated that SLC17A6 is a direct target of miR-190a-5p. Up-regulation of miR-190a-5p and inhibition of SLC17A6 could significantly weaken the painful behavior and reduce IL-1ß and IL-6 level in DNP. CONCLUSION: miR-190a-5p is involved in DNP via targeting SLC17A6, and miR-190a-5p and SLC17A6 may be the therapeutic targets of this disease.

A66G and C524T polymorphisms of methionine synthase reductase gene are linked to the development of acyanotic congenital heart diseases in Egyptian children.

Methionine synthase reductase (MTRR) is one of the main regulatory enzymes in the homocysteine/folate pathway. Genes involved in this pathway may play an important role in the development of congenital heart diseases (CHDs). C524T and A66G polymorphisms of MTRR gene may play an imperative role in the development of acyanotic CHDs. This study carried out on 200 children equally divided into 2 groups: group I: 100 children with acyanotic CHDs; and group II: 100 healthy children served as controls. PCR-RFLP method carried out to amplify the A66G and C524T polymorphisms of MTRR gene digested with Xho1and NdeI enzymes. A significant difference(P=0.015) in genotype frequencies of C524T polymorphism between cases and controls, where CC, CT, and TT were 14.0%, 40.0% and 46.0% in patients compared to 38.0,36.0% and 26.0% in controls. Again, a significant difference (P=0.010) in genotype frequencies of A66G polymorphism between the two groups as AA, AG and GG were 26.0%, 32.0% and42.0% in patients compared to 48.0, 36.0% and 16.0% in controls. Also, MTRR A66G and C524T polymorphisms were associated with a higher CHD risk in the homozygote comparison of wild and mutant genotypes and also in heterozygote and mutant comparison. So A66G and C524T polymorphisms of MTRR gene are associated with increased risk of acyanotic CHDs.

Effect of Green Tea Polyphenol Epigallocatechin-3-gallate on the Aggregation of αA(66-80) Peptide, a Major Fragment of αA-crystallin Involved in Cataract Development.

PURPOSE: Crystallin is a major protein present in eye lens. Peptide fragment αA(66-80) derived from αA-crystallin possesses high aggregation propensity and forms amyloid-like structures. αA(66-80) aggregates are known to interact with soluble crystallins and destabilize native structures that subsequently undergo aggregation. Crystallin aggregation in eye lens leads to reduction in lens opacity, the condition generally referred to as a cataract. Thus, αA(66-80) aggregation appears to be an important event during cataract development, and therefore, inhibition of αA(66-80) aggregation may be an attractive strategy to intervene in cataract development. MATERIALS AND METHODS: αA(66-80) peptide derived from αA-crystallin possesses high aggregation potential and has a crucial role in cataract development. In order to inhibit the aggregation of αA(66-80) peptide, epigallocatechin-3-gallate (EGCG), a major active constituent of green tea, was employed. The inhibitory effect was assessed by Congo Red (CR) spectral shift assay, Thioflavin-T binding assay, transmission electron microscopy and fluorescence microscopy. RESULTS: The inhibitory potential of EGCG toward αA-crystallin was clearly observed as in the presence of EGCG, the αA(66-80) aggregation was considerably inhibited and the pre-formed fibrillary aggregates of αA(66-80) were found to be disassembled. CONCLUSION: In the present study, we are able to successfully demonstrate that EGCG efficiently blocks the aggregation of αA(66-80) peptide in a concentration-dependent manner. Furthermore, it is also evident that EGCG is able to disaggregate pre-formed αA(66-80) aggregates. The study suggests that EGCG can be a potential molecule that can prevent the initiation of cataract as well as be helpful in the disease reversal.

Effect of MTHFR A1298C and MTRR A66G Genetic Mutations on Homocysteine Levels in the Chinese Population: A Systematic Review and Meta-analysis.

BACKGROUND AND OBJECTIVES: The Chinese population typically has inadequate folate intake and no mandatory folic acid fortification. Methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) are the two key regulatory enzymes in the folate/homocysteine (Hcy) metabolism. Hcy has been implicated in the pathogenesis of cardiovascular disease. We conducted a meta-analysis to assess whether the MTHFR gene A1298C and the MTRR gene A66G polymorphisms affect Hcy levels in the Chinese population. METHODS: This analysis included 13 studies with Hcy levels reported as one of the study measurements. Summary estimates of weighted mean differences and 95% confidence intervals (CIs) were obtained using random-effect models. RESULTS: Overall, there were no significant differences in Hcy concentrations between participants with the MTHFR 1298 CC (12 trials, n = 129), AA (n = 2166; ß, -0.51 µmol/L; 95%CI: -2.14, 1.11; P = 0.53), or AC genotype (n = 958; ß, 0.55 µmol/L; 95%CI: -0.72, 1.82; P = 0.40). Consistently, compared to those with the MTRR 66 GG genotype (6 trials, n = 156), similar Hcy concentrations were found in participants with the AA (n = 832; ß, -0.43 µmol/L; 95%CI: -1.04, 0.17; P = 0.16) or AG (n =743; ß, -0.57 µmol/L; 95%CI: -1.46, 0.31; P = 0.21) genotype. Similar results were observed for the dominant and recessive models. CONCLUSIONS: Neither the MTHFR A1298C polymorphism nor the MTRR A66G polymorphism affects Hcy levels in the Chinese population.

Additive Interaction of MTHFR C677T and MTRR A66G Polymorphisms with Being Overweight/Obesity on the Risk of Type 2 Diabetes.

Although both methylenetetrahydrofolate reductase (MTHFR) C677T and methionine synthase reductase (MTRR) A66G polymorphisms have been associated with type 2 diabetes (T2D), their interactions with being overweight/obesity on T2D risk remain unclear. To evaluate the associations of the two polymorphisms with T2D and their interactions with being overweight/obesity on T2D risk, a case-control study of 180 T2D patients and 350 healthy controls was conducted in northern China. Additive interaction was estimated using relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and synergy index (S). After adjustments for age and gender, borderline significant associations of the MTHFR C677T and MTRR A66G polymorphisms with T2D were observed under recessive (OR = 1.43, 95% CI: 0.98-2.10) and dominant (OR = 1.43, 95% CI: 1.00-2.06) models, respectively. There was a significant interaction between the MTHFR 677TT genotype and being overweight/obesity on T2D risk (AP = 0.404, 95% CI: 0.047-0.761), in addition to the MTRR 66AG/GG genotypes (RERI = 1.703, 95% CI: 0.401-3.004; AP = 0.528, 95% CI: 0.223-0.834). Our findings suggest that individuals with the MTHFR 677TT or MTRR 66AG/GG genotypes are more susceptible to the detrimental effect of being overweight/obesity on T2D. Further large-scale studies are still needed to confirm our findings.