Association of the polymorphisms rs179008 (TLR7), rs2004640 (IRF5), rs1800795 (IL-6) and rs2280788 (CCL5) with systemic lupus erythematosus in women of Mayan ethnicity from Yucatan.

Introduction: IFN-α is the main cytokine in SLE, and single nucleotide polymorphisms (SNP) in different genes could induce it. Aim: To determine the association of rs2004640 (IRF5), rs179008 (TLR7), rs1800795 (IL-6) and rs2280788 (CCL5) with SLE in Mexican women with Mayan ethnicity. Methods: DNA and RNA were isolated from the peripheral blood of 110 patients and 200 healthy control subjects. SNP genotyping and gene expression analysis of IRF5, TLR7, IL-6 and IFN-α were determined by real-time PCR and analyzed with SNP Stat, Stata 10.1 and Graph Pad Prism v5. Results: rs2004640, rs179008, and rs1800795 in both groups were according to Hardy-Weinberg equilibrium. Risk alleles rs179008T and rs2004640T frequencies were higher in controls (p = 0.015 and p = 0.028, respectively), whereas rs179008A frequency was higher in patients (p = 0.015). Allelic combination AGT frequency was higher in patients (p = 0.001). IL-6 rs1800795C > G and CCL5 rs2280788G > C frequencies did not show significant differences (p > 0.05), being rs2280788G (CCL5) monomorphic in controls. SLE patients showed higher TLR7, IRF5, IL6, and IFN-α mRNA levels. IRF5 expression was higher in SLE patients homozygous for rs2004640T (IRF5). Conclusion: This work showed the contribution of TLR7 and IRF5 in SLE pathogenesis in Mayan females from Yucatan.

Copy Number Variation and Frequency of rs179008 in TLR7 Gene Associated with Systemic Lupus Erythematosus in Two Mexican Populations.

Systemic Lupus Erythematosus (SLE) is an autoimmune disease in which genetic factors play a role in the susceptibility to develop it. Genes related to the synthesis of interferons such as TLR7 and genetics factors such as single nucleotide polymorphisms (SNPs) or copies number variation (CNV) in the gene have been involved with the development of the disease. The genetic differences between the populations contribute to the complexity of LES. Mexico has a mestizo population with a genetic load of at least three origins: Amerindian, Caucasian, and African. The mestizo of Yucatán is the only group whose contribution Amerindian is mainly Mayan, geographically distant from other Mexican Amerindians. We analyzed the CNV and the frequency of SNP rs179008 of the TLR7 as genetic risk factors in developing the disease in patients from Yucatán and Central Mexico. Results show that 14% of the cases of the Yucatecan population showed significantly >2 CNV and a higher risk of developing the disease (OR: 34.364), concerning 4% of those coming from Central Mexico (OR: 10.855). T allele and the A/T and T/T risk genotypes of rs179008 were more frequent in patients of Central Mexico than in those of Yucatán (50% vs. 30%, 93% vs. 30%, 4% vs. 1%), and association with susceptibility to develop SLE was observed (OR: 1.5 vs. 0.58, 9.54 vs. 0.66, 12 vs. 0.14). Data support the genetic differences between and within Mexican mestizo populations and the role of the TLR7 in the pathogenesis of SLE.

Genetic variants of PON1, GSTM1, GSTT1, and locus 9p21.3, and the risk for premature coronary artery disease in Yucatan, Mexico.

OBJECTIVE: Genetic variants of PON1, rs70587, rs662, rs854560, GSTM1, and GSTT1 and two single nucleotide polymorphisms (SNP) at 9p21.3 locus, rs1333049, and rs2383207; were evaluated in association with the risk for premature coronary artery disease (CAD) in a population of Yucatan, Mexico. These genes are involved in the inactivation of pro-oxidants and pro-inflammatory mediators, lipid and xenobiotic metabolism, detoxification of reactive oxygen species, and regulation of cellular proliferation playing key roles in the pathogenesis of atherosclerosis. METHODS: We conducted a matched case-control study with 98 CAD cases and 101 healthy controls. Genotyping of PON1 and 9p21.2 SNP was performed by real time-PCR and for GSTM1 and GSTT1 with multiplex-PCR. Odds ratios (OR) were calculated to estimate association and generalized multifactor dimensionality reduction (GMDR) algorithm to identify gene-gene and gene-environment interactions. RESULTS: The distribution of all allele/genotype frequencies in controls was within Hardy-Weinberg expectations (p > .05) except for GSTM1. The allele/genotype frequencies of the GSTT1 null were significantly higher in CAD cases than in controls, suggesting association with higher risk for developing CAD. The other SNPs did not show any significant independent association with premature CAD. GMDR revealed a significant interaction between GSTT1 and LL55 genotype. Likewise, the body mass index (BMI) and smoking also showed an interaction with GSTT1. CONCLUSION: The GSTT1 null allele/genotype is associated with an increased risk of developing premature CAD, the effect of which is not modified by cardiovascular risk factors in the population of Yucatan.

High expression levels of circulating microRNA-122 and microRNA-222 are associated with obesity in children with Mayan ethnicity.

OBJECTIVES: High expression levels (HELs) of microRNA-122 (miR-122) or microRNA-222 (miR-222) have been associated with insulin resistance (IR), which leads to the development of obesity. The association between HELs of circulating miR-122 and miR-222 and the risk of obesity was evaluated in Mexican school-aged children, where childhood obesity is the primary cause of morbidity. METHODS: Anthropometric data, biochemical parameters, and caloric intake were obtained in 50 children with obesity and 49 children with normal weight. The expression of circulating miR-122 and miR-222 was measured by quantitative real-time polymerase chain reaction amplification. Data were analyzed using Student t test, Pearson correlation coefficient, associations with chi-square, and multiple linear and logistic regressions with SPSS software v.23. RESULTS: The mean relative expression for miR-122 and miR-222 was 0.33 and 5.65, respectively, for children with obesity and 0.22 and 3.16, respectively, for children with normal weight. The expression of miR-122 and miR-222 was 1.47 and 1.78-fold higher, respectively, in children with obesity (P = 0.001 and P = 0.025). HELs of both miR-122 and miR-222 were associated with body mass index (BMI), waist to height ratio (WHR), fat percentage, serum high-density lipid levels, triglycerides (TGs), and metabolic index (MI) (P < .001). CONCLUSIONS: The HELs of circulating miR-122 conferred a 3.85-fold increase in the risk for obesity, whereas the HELs of both miR-122 and miR-222 conferred a 3.11-fold increase in the risk for obesity, which were also associated with higher anthropometric or biochemical parameters, such as BMI, WHR, fat percentage, serum high-density lipid levels, TGs, and MI, in Mayan children.

Genetic variation of FTO: rs1421085 T>C, rs8057044 G>A, rs9939609 T>A, and copy number (CNV) in Mexican Mayan school-aged children with obesity/overweight and with normal weight.

OBJECTIVES: Genetic variation of the fat mass and obesity associated gene (FTO) has been identified as a risk factor for obesity and obesity traits. Distribution of FTO single nutleotide polymorphisms (SNPs) rs1421085T>C, rs9939609T>A, rs8057044G>A and copy number variation (CNV) was evaluated in association with childhood obesity or overweight status in children with Mayan ethnicity. METHODS: We included 318 school-aged children with obesity or overweight status (body mass index [BMI]: >85th percentile) and 303 children with normal weight (BMI: 15th-85th percentile). Genotyping was performed using real-time polymerase chain reaction (RT-PCR) with TaqMan probes. The cross-sectional study was carried out using univariate and multivariate logistic regression models adjusted for gender. RESULTS: FTO-SNP rs1421085 showed significant differences between children with obesity and children with normal weight for the heterozygous genotype (P = 0.003) and for allele frequencies (P = 0.023). Adjusting by gender, significant differences were found in frequencies of the hetezygous genotype of SNPs rs9939609 (P = 0.023) and rs1421085 (P = 0.003) as well as in allele frequencies (P = 0.042 and P = 0.013, respectively) between girls with obesity and girls without obesity. In contrast, SNP rs8057044 was significantly different only between heterozygous overweight versus normal weight boys (P = 0.035) and for the allele frequency of rs8057044 (P = 0.021). The mean relative CNV was significantly higher in male overweight children than in boys with normal weight (P = 0.000). CONCLUSIONS: The FTO SNP rs1421085 is a genetic factor associated with obesity in Mayan school-aged children. FTO SNPs rs1421085 and rs9939609 affect genetic susceptibility for obesity only in girls, whereas, SNP rs8057044 and CNV are associated with overweight status only in boys.

Determinación de mutaciones (del E746-A750 exón 19 y L858R exón 21) en el gen receptor del factor de crecimiento epidérmico (EGFR) en muestras de suero y biopsia de carcinoma pulmonar no microcítico (CPNM) / Determination of mutations (del E746-A750 exon 19 and L858R exon 21) in the epidermal growth factor receptor (EGFR) gene in serum samples and in biopsys of non-microcytic lung carcinoma (NMLC)

Resumen Introducción Las mutaciones, del E746-A750 exón 19 y L858R exón 21 del gen EGFR en células tumorales de CPNM representan biomarcadores de respuesta a fármacos inhibidores de tirosina cinasa (ITK). Pacientes con tumores positivos a mutaciones EGFR muestran mejor respuesta y mayor sobrevivencia. Estas mutaciones ocupan el 90% de las mutaciones en cáncer de pulmón. Objetivo Evaluar la frecuencia de las mutaciones del E746-A750 exón 19 y L858R exón 21 del EGFR en muestras de biopsia de CPNM y en muestras de suero de población abierta de Yucatán. Material y métodos Se seleccionaron 19 muestras de biopsia de CNPM tipo adeconocarcinoma y 101 sueros de sujetos sanos. Las mutaciones del E746-A750 y L858R en EGFR se determinaron mediante amplificación por PCR oligo-alelo específica (PCR-ASO). Se calcularon las frecuencias genotípicas y alélicas y su distribución según Hardy Weinberg, utilizando la plataforma SNPstats. Resultados En muestras de suero se determinó el genotipo homocigoto (1/1) en 26.58%, 73.42% el heterocigoto (1/0) y ausencia del genotipo mutante con deleción (0/0) para del E746-A750; en tanto que, para L858R, 21.78% resultó homocigoto (TT), 54.46% heterocigoto (T/G) y 23.76% mutantes GG. En las biopsias, el heterocigoto fue más frecuente en ambas mutaciones 63.16% y 73.68% para del E746-A750 y L858R, respectivamente. Conclusión. La frecuencia de las mutaciones del gen EGFR en las muestras de sueros fue de 36.71% para la deleción del E746-A750 en exón 19 y 50.99% para L858R en exón 21. La distribución de las mutaciones en muestras de biopsia CPNM resultó en 42.11% para cada mutación estudiada.

Abstract Introduction EGFR mutations, del E746-A750 in exon 19 and L858R in exon 21 in tumor cells of NMLC represent biomarkers of response to tyrosine kinase inhibitors (TKI) therapy. Patients with tumors positive for EGFR mutations show better response and greater survival. These mutations occupy 90% of mutations in lung cancer. Objective To evaluate the frequency of mutations del E746-A750-exon 19 and L858R-exon 21 of EGFR gene in NMLC biopsy samples and in serum samples of the general population from Yucatán. Material and methods 19 NMLC biopsy samples of adenocarcinoma type and 101 serum samples from healthy subjects were selected. EGFR mutations del E746-A750 and L858R were determined by allele-specific PCR amplification (PCR-ASO). The genotypic and allelic frequencies; and their distribution according to Hardy Weinberg expectations were calculated using the SNPstats software. Results For serum, EGFR del E746-A750 mutation, homozygous genotype (1/1) was present in 26.58%, heterozygote (1/0) in 73.42% and absence of mutant genotype with deletion (0/0); whereas for L858R mutation, 21.78% were homozygous (TT), 54.46% heterozygous (T/G) and 23.76% GG mutants. For the NMLC biopsies, the heterozygote was the most frequent genotype for both mutations, 63.16% and 73.68% for del E746-A750 and L858R, respectively. Conclusion The frequency of mutations of EGFR gene in serum samples was 36.71% for deletion delE746-A750 in exon 19 and 50.99% for L858R in exon 21. Distribution of mutations in biopsy samples NMLC resulted in 42.11% for each EGFR mutation.

The Paraoxonase 1 Gene c.-108C>T SNP in the Promoter Is Associated with Risk for Glioma in Mexican Patients, but Not the p.L55M or p.Q192R Polymorphisms in the Coding Region.

AIM: To evaluate the association of the paraoxonase 1 (PON1) gene polymorphisms c.-108C>T, p.L55M, and p.Q192R with the risk of glioma in Southeast Mexico. Decreased PON1 activity caused by polymorphisms has been observed in gliomas, thus supporting the theory that PON1 is involved in tumorigenesis in the brain. METHODS: Sixty-seven glioma patients and 58 control individuals were included. Three PON1 polymorphisms were genotyped by real-time PCR allelic discrimination using TaqMan probes: c.-108C>T in the promoter region, p.Q192R and p.L55M, both of which were in the coding region. Allele, genotype, and haplotype frequencies were assessed in cases and controls to test for statistical associations (STATA 10.2 package). RESULTS: Significant differences were found for the PON1 c.-108C>T polymorphism between the cases and controls. Compared to the controls the cases were more likely to be CT heterozygous (p = 0.002) or TT homozygous (p = 0.036); similarly cases were more likely to possess a T allele (p = 0.032). In contrast, the p.L55M and p.Q192R polymorphisms did not show significant differences between the glioma cases and controls (p > 0.05). CONCLUSION: The PON1 c.-108C>T polymorphism in the promoter region is associated with genetic risk for glioma. Conversely, p.L55M and p.Q192R polymorphisms in the coding region do not seem to have an influence in this population.

Copy Number Variation of TLR-7 Gene and its Association with the Development of Systemic Lupus Erythematosus in Female Patients from Yucatan Mexico.

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by the production of autoantibodies against self-antigens, which occurs most often in women between 15 and 40 years of age. The innate immunity is involved in the pathogenesis of SLE through TLR- 7. Genetic factors such as copy number variation (CNV) of target genes may contribute to disease development, but this possible risk has not yet been studied in SLE patients from Yucatan, Mexico. The CNV of TLR-7 gene was determined by quantitative polymerase chain reaction assay using TaqMan probes in 80 SLE women and 150 control subjects. The results showed that 10% of SLE patients exhibited more than two copies of TLR-7 gene, whereas no mRNA overexpression was detected. These data suggested that increased CNV of the TLR-7 gene in Yucatan SLE women can be a risk factor for this disease.

MTHFR/p53 polymorphisms as genetic factors for cervical intraepithelial neoplasia and cervical cancer in HPV-infected Mexican women.

We performed a case-control association study to evaluate the association between common polymorphisms in MTHFR (C677T and A1298C) and the Arg72Pro polymorphism in the p53 gene and the risk for cervical intraepithelial neoplasia (CIN) or invasive cervical cancer (ICC) in Mexican HPV-infected women. We included 131 women with diagnosis of CIN grade I-II and 78 with CIN III or ICC; as controls we also included 274 women with normal Pap smear and negative HPV test. Genotyping for MTHFR and p53 polymorphisms was performed by PCR-RFPLs. HPV was tested by Hybrid Capture II. Odds ratios and 95% confidence intervals were estimated. Genotype frequencies for the 3 studied polymorphisms were distributed according to the Hardy-Weinberg equilibrium. The A1298C-MTHFR polymorphism showed significant differences for the heterozygous AC genotype and the C allele, whereas the AA genotype and A allele resulted to be genetic risk factors for CIN or ICC (p<0.03). The Arg72Pro-p53 polymorphism showed for the genotypes Arg/Pro and Pro/Pro, and for the Pro allele, a significant association only to the risk for CIN (p<0.03). The MTHFR/p53 interaction showed that the genotype combinations AA/ArgArg and AA/ArgPro were associated, respectively, to the risk of ICC and CIN (p<0.05). This study suggests that the A1298C-MTHFR polymorphism contributes to the genetic risk for both CIN and ICC, whereas the Arg72Pro-p53 polymorphism only contributes to the risk for CIN. The MTHFR/p53 genetic combinations AA/ArgArg and AA/ArgPro are associated genetic risk factors for ICC and CIN in Mexican HPV-infected women.

Longitudinal studies of West Nile virus infection in avians, Yucatán State, México.

Following the introduction of West Nile virus (WNV) into North America in 1999, surveillance for evidence of infection with this virus in migratory and resident birds was established in Yucatán State, México in March 2000. Overall, 8611 birds representing 182 species and 14 orders were captured and assayed for antibodies to WNV. Of these, 5066 (59%) birds were residents and 3545 (41%) birds were migrants. Twenty-one (0.24%) birds exhibited evidence of flavivirus infection. Of these, 8 birds had antibodies to WNV by epitope-blocking enzyme-linked immunosorbent assay. Five (0.06%) birds (gray catbird, brown-crested flycatcher, rose-breasted grosbeak, blue bunting and indigo bunting) were confirmed to have WNV infections by plaque reduction neutralization test. The WNV-infected birds were sampled in December 2002 and January 2003. The brown-crested flycatcher and blue bunting presumably were resident birds; the other WNV seropositive birds were migrants. These data provide evidence of WNV transmission among birds in the Yucatán Peninsula.