Evidence from genetic studies among rs2107538 variant in the CCL5 gene and Saudi patients diagnosed with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a chronic and metabolic disorder that affects the adult population. Chemokines are proinflammatory cytokines that play a role in the development of chronic diseases such as obesity, gestational diabetes, and T2DM. The C-C Motif Chemokine Ligand 5 (CCL5) gene plays a role in antiviral immunity, tumor development, obesity, impaired glucose tolerance, and T2DM. This study aimed to investigate the genetic role of the rs2107538 variant in the CCL5 gene in Saudi patients with T2DM. Sixty subjects with T2DM patients and 60 healthy controls participated in this prospective case-control study. Prior to Sanger sequencing, genomic DNA was extracted and amplified with Polymerase chain reaction (PCR), after which the PCR products were purified. The collected data were used to conduct various statistical analyses to determine the relationship between T2DM and control subjects. The findings of the current study revealed a positive association for most parameters between T2DM and control subjects (p < 0.05). The frequency of genotypes (p = 0.002, AA vs.GG: p = 0.008, GA + AA vs. GG: p = 0.0002) and alleles (A vs. G: p = 0.0007) revealed a strong risk association. Multiple logistic regression with individual effects revealed a link between SBP and HDLc levels (p = 0.03). In patients with T2DM, waist (p = 0.001), TG (p = 0.0007), and LDLc (p = 0.0004) levels were all associated with the ANOVA. Finally, the rs2107538 variant was linked to an increased risk of T2DM in the Saudi Population. The GA and AA genotypes were strongly connected to the T2DM subjects. In order to rule out disease-causing variants in the global population, future research should use a large sample size.     

The polymorphisms in methylenetetrahydrofolate reductase, methionine synthase, methionine synthase reductase, and the risk of colorectal cancer

Polymorphisms in genes involved in folate metabolism may modulate the risk of colorectal cancer (CRC), but data from published studies are conflicting. The current meta-analysis was performed to address a more accurate estimation. A total of 41 (17,552 cases and 26,238 controls), 24(8,263 cases and 12,033 controls), 12(3,758 cases and 5,646 controls), and 13 (5,511 cases and 7,265 controls) studies were finally included for the association between methylenetetrahydrofolate reductase (MTHFR) C677T and A1289C, methione synthase reductase (MTRR) A66G, methionine synthase (MTR) A2756G polymorphisms and the risk of CRC, respectively. The data showed that the MTHFR 677T allele was significantly associated with reduced risk of CRC (OR = 0.93, 95%CI 0.90-0.96), while the MTRR 66G allele was significantly associated with increased risk of CRC (OR = 1.11, 95%CI 1.01-1.18). Sub-group analysis by ethnicity revealed that MTHFR C677T polymorphism was significantly associated with reduced risk of CRC in Asians (OR = 0.80, 95%CI 0.72-0.89) and Caucasians (OR = 0.84, 95%CI 0.76-0.93) in recessive genetic model, while the MTRR 66GG genotype was found to significantly increase the risk of CRC in Caucasians (GG vs. AA: OR = 1.18, 95%CI 1.03-1.36). No significant association was found between MTHFR A1298C and MTR A2756G polymorphisms and the risk of CRC. Cumulative meta-analysis showed no particular time trend existed in the summary estimate. Probability of publication bias was low across all comparisons illustrated by the funnel plots and Egger's test. Collectively, this meta-analysis suggested that MTHFR 677T allele might provide protection against CRC in worldwide populations, while MTRR 66G allele might increase the risk of CRC in Caucasians. Since potential confounders could not be ruled out completely, further studies were needed to confirm these results.     

A study on the immunological vitality of an inflammatory biomarker explored with rs5743708 polymorphism in TLR2 gene among Saudi women confirmed with polycystic ovarian syndrome

IntroductionPolycystic ovary syndrome (PCOS) is an ovarian health condition as well as a long-term endocrine dysfunction that affects reproductive-aged women. Toll-like receptor 2 (TLR2) gene was linked to PCOS and chronic inflammation, and the prevalence of obesity was rising in Saudi women. Previous studies on rs5743708 polymorphism were documented in the obesity as well as in PCOS women.AimIn this study, we investigated the molecular role of rs5743708 polymorphism in TLR2 gene among Saudi women diagnosed with PCOS using the Rotterdam criteria.MethodsBlood samples were collected from 220 Saudi women in this hospital-based case-control study; 110 were PCOS women and remaining 110 were non-PCOS (control women). Biochemical analysis was performed on serum samples, and molecular analysis was performed on EDTA blood. Genotyping for rs5743708 polymorphism was performed with polymerase chain reaction-restriction fragment length polymorphism analysis.ResultsIn both groups, clinical data was calculated using t-test, which revealed both positive (p < 0.05) and negative (p > 0.05) associations. HWE analysis supported the rs5743708 polymorphism (p < 0.05). In the rs5743708 polymorphism, none of the genotypes, genetic models, or allele frequencies were found to be associated with PCOS and non-PCOS women. However, both ANOVA and regression analyses revealed a positive relationship in PCOS with weight and BMI (p < 0.0001).ConclusionThe rs5743708 polymorphism was not associated to PCOS in Saudi women. One of the predictions could be that 42.7% of PCOS and 73.6% of non-PCOS women were obese, and the rs5743708 polymorphism has been linked to both obesity and PCOS in the previous studies. This study suggests screening for additional polymorphisms with a large sample size.     

Knock-down of methylenetetrahydrofolate reductase reduces gastric cancer cell survival: an in vitro study

The present study aimed to investigate the effect of knocking-down methylenetetrahydrofolate reductase (MTHFR) on the survival of the human gastric cancer cell line MKN45. Antisense and small interfering RNA (siRNA) plasmids were used to target MTHFR in MKN45. Meanwhile, we also constructed a wild-type MTHFR plasmid to assess the effect of over-expression of this protein on cell viability. The knock-down of MTHFR decreased cell survival by approximately 30% compared to the control and resulted in cell cycle arrest at the G2 phase. These cells also had lower levels of c-myc compared to control cells, while over-expression of MTHFR increased cell proliferation and induced the down-regulation of p21WAF1 and hMLH1. Inhibiting MTHFR with either antisense or siRNA decreases the viability of methionine-dependent transformed gastric cancer cells and suggests that MTHFR inhibition may be a novel anticancer approach.     

Prevalence of methylenetetrahydrofolate reductase C677T polymorphism in eastern Uttar Pradesh

AIM:

This study was aimed to evaluate the 5, 10-methylenetetrahydrofolate reductase (MTHFR) C677T mutation in eastern Uttar Pradesh population.

MATERIALS AND METHODS:

Polymerase chain reaction (PCR) using specific primers followed by amplicon digestion by Hinf I restriction enzyme was used for MTHFR C677T polymorphism analysis. Total 250 subjects were analyzed.

RESULTS:

The CC genotype was found in 192 subjects, followed by CT in 56 subjects and TT in 2 subject. Genotype frequencies of CC, CT and TT were 0.768, 0.224 and 0.008, respectively. The frequency of C allele was found to be 0.88 and that of T allele was 0.12.

CONCLUSION:

It is evident from the results of the present study that the percentage of homozygous genotype (CC) is highest in the target population.     

A proteomic approach for the characterization of C677T mutation of the human gene methylenetetrahydrofolate reductase

Methylenetetrahydrofolate reductase (MTHFR) catalyzes the conversion of methylenetetrahydrofolate (CH2H4folate) to methyltetrahydrofolate (CH3H4folate). The C677T mutation is a common polymorphism of the human enzyme that leads to the replacement of Ala222Val, thermolability of MTHFR, and mild elevation of plasma homocysteine levels. A mild hyperhomocysteinemia is known to be risk factor for cardiovascular and thrombotic diseases, ischemic stroke, neural tube defects, late on-set dementia, and pregnancy complications. Human plasma of subjects carrying the C677T mutation in the MTHFR gene has been investigated for their protein pattern in order to identify novel molecular hallmarks. 2-D analysis of the plasma protein allowed the identification of a specific pattern associated with the TT mutant genotype. Noteworthy, we found one spot shifted to a more basic pI in mutant individuals, and MS identification corresponded to vitamin D-binding protein (DBP or group component (Gc) globulin). MS/MS peptide sequencing allowed to discriminate different allelic variants in the investigated clinical groups. These data confirmed by molecular genetic analysis highlight the novel association between the C677T MTHFR genotype with the Gc2 polymorphism of the DBP. Moreover, we found a quantitative reduction of Apolipoprotein A-I in mutant individuals, which was associated, in previous studies by others to an increased cardiovascular risk.     

Multiple single-nucleotide polymorphisms in the methylenetetrahydrofolate reductase and its truncated pseudogene of 23 inbred strains of mice

Reduced 5,10-methylenetetrahydrofolate reductase (MTHFR) results in a number of human diseases. To find a model mouse sensitive to these diseases, we analyzed single-nucleotide polymorphisms (SNPs) of the mouse Mthfr using 23 phylogenetically distant strains of mouse. We found five SNPs: two nonsynonymous and three synonymous. The CAST/Ei strain has the nonsynonymous SNP L350V and five strains (NMRI, KJR, SWN2, MSM, and JF1) have the nonsynonymous SNP S22G. The MTHFR activity of CAST/Ei and MSM showed no significant difference in activity or thermostability compared with that of C57BL/6J. We also found a pseudogene segment of the mouse Mthfr that was not present in human and was more frequently variable than the functional gene. These results suggest a possibility that the truncated pseudogene may buffer variations of the mouse Mthfr functional gene, and the mouse has evolved fewer variations of the gene than human.     

Thermodynamics of methylenetetrahydrofolate reduction to methyltetrahydrofolate and its implications for the energy metabolism of homoacetogenic bacteria

The thermodynamics of the methylenetetrahydrofolate reduction to 5-methyltetrahydrofolate was studied with the methylenetetrahydrofolate reductase purified from the homoacetogenic bacterium Peptostreptococcus productus. The equilibrium constants were determined for the forward and backward reactions of methylenetetrahydrofolate reduction with NADH or acetylpyridine adenine dinucleotide (APADH), respectively, as the electron donors. From the equilibrium constants and the known standard redox potentials at pH 7 (E ^o ) of the couples NAD⁺/NADH or APAD⁺/APADH the E ^o of the couple methylene-/methyltetrahydrofolate was determined to be about-200mV. This value is different from values reported before for this couple. The implications for the mechanism of energy conservation of homoacetogens is discussed.Abbreviations FH₄ tetrahydrofolate - CH₂=FH₄ 5,10-methylenetrahydrofolate - CH₃-FH₄ 5-methyltetrahydrofolate - K _eq equilibrium constant - G ^o Gibb's free energy change under standard conditions (all concentrations of reactants = 1 M) - G ^o G ^o at pH 7 ([H⁺]=10^-7 M) - E ^o standard redox potential - G ^o standard redox potential difference of two reactants - E ^o E ^o at pH 7 - R gas constant - F Faraday constant - APAD acetylpyridine adenine dinucleotide (NAD⁺-analogue)     

Prevalence of methylenetetrahydrofolate reductase 677 C-T polymorphism among mothers of Down syndrome children

INTRODUCTION:

The relationship between chromosomal non-disjunction leading to aneuploidy and folate metabolism has drawn attention in the recent years. In this study, we examined the polymorphism in the gene encoding the folate metabolizing enzyme methylenetetrahydrofolate reductase (MTHFR), namely, 677 C-T in women having Down syndrome (DS) children.

MATERIALS AND METHODS:

The prevalence of these variant genotypes (MTHFR 677 C-T polymorphism) in women having DS children (case mothers) (n = 110) was compared with controls (n = 111) from Punjab. Genotyping was done using the polymerase chain reaction method followed by restriction fragment length polymorphism.

RESULTS:

In the present study, 1.8% of case mothers had TT genotype while none of the control mothers showed this genotype. T allele frequency among cases was 0.13 and 0.11 in controls. The Chi-square value showed a non-significant difference between cases and controls.

CONCLUSION:

No association has been observed between 677 C-T polymorphism and risk of non-disjunction in case mothers. Detection of polymorphisms in more genes of folate pathway is required to find out the exact cause of non-disjunction.     

Foot care practices of diabetic patients in Saudi Arabia

Diabetic foot is a serious complication that causes lower extremity amputations. The aim of this study was to identify the patient’s awareness about risk factors for diabetic foot disease and to explore the knowledge and foot care practices among diabetic patients in a Saudi population. This cross-sectional study was conducted in King Khalid University Hospital (KKUH), King Abdulaziz University Hospital (KAUH), King Fahad Medical City, National Guard Hospital, Military Hospital, and Prince Salman Hospital capital city of Saudi Arabia. Patients were eligible if they had diabetes foot disease, signed the consent form, and completed the questionnaire. We selected 350 patients from different hospitals between November-2011 and April-2012. The majority of patients (68%) were selected from King Saud University hospitals. The mean age of patients was 50.87 ± 15.9 years with a range of 20–90 years. The majority of patients were male (64.3%) and had a family history of hypertension (55.4%), high total cholesterol (58.6%), and other diabetes (58.9%). A family history of smoking, a major risk factor for diabetic foot, was found in 20.3% of cases. Sixty percent of the patients were using oral medications, 27.1% were using insulin therapy, 10% were using both oral and insulin therapies, and 10% were on diet. In our study, 19.4% of participants were illiterate while 80.6% had a high school or university level education. Our findings also revealed that some patients had a lack of knowledge concerning diabetic foot disease and future complications. Patients are unaware of the risk factors for diabetes foot and practice poor foot care. Awareness programs should be mandatory in all hospitals and diabetes clinics to help compensate for the lack of awareness and lack of podiatric educational services. Such programs may decrease the risk of diabetes foot disease.