VNTR (CAG)n polymorphism of the ATXN2 gene and metabolic parameters of cardiovascular risk associated with the degree of obesity in the Amerindian population of Oaxaca.

INTRODUCTION: The ATXN2 gene has a VNTR (CAG)n with locus in exon1. Long alleles within the normal range (22-29 repeats) are associated with severe obesity in people from the United Kingdom, Indonesia and the Caribbean. OBJECTIVE: To analyse the influence of VNTR (CAG)n on metabolic profile in adults with obesity and pre-obesity, as well as to estimate its effect on the risk of developing diabetes. METHODS AND MATERIAL: 255 adults of Chinantec Amerindian ethnic origin were included, who underwent anthropometric and biochemical evaluation. The VNTR was amplified by end-point PCR and by 8% PAGE electrophoresis. RESULTS: Differences were found in the waist/hip circumference index and body mass index in the carriers of genotypes different to the one homozygous for 22 repeats with a Student's t-test value of 0.0041 and 0.0334, respectively. We also found an association with a family history of chronic disease. CONCLUSION: The VNTR of ATXN2 is associated with obesity in Mexican adults of Chinantec ancestry.

New Genetic Polymorphisms as an Epidemiological Factor of Arterial Hypertension in Patients with Hyposodical Diet.

Hypertension is a major public health problem, affecting more than a quarter of the world's population causing serious cardiovascular problems. In recent years, different polymorphisms have been studied and helped to identify some candidate genes and hereditary syndromes associated with the molecular mechanisms involved in the development of hypertension. Therefore, it is important to identify these molecular mechanisms. This review exposes all the genes and polymorphisms that increase or decrease the risk of hypertension in different populations that are related to the renin angiotensin aldosterone system, G protein, salt excretion, aldosterone synthesis, lipid metabolism, mechanism of insulin resistance, vitamin metabolism, purines and sodium reabsorption. This document can be a useful tool in clinical practice, in addition to serving as a support for future research on this topic.

VNTR (CAG)n polymorphism of the ATXN2 gene and metabolic parameters of cardiovascular risk associated with the degree of obesity in the Amerindian population of Oaxaca. / Polimorfismo VNTR (CAG)n del gen ATXN2 y parámetros metabólicos de riesgo cardiovascular asociados con el grado de obesidad en población amerindia de Oaxaca.

INTRODUCTION: The ATXN2 gene has a VNTR (CAG)n with locus in exon1. Long alleles within the normal range (22-29 repeats) are associated with severe obesity in people from the United Kingdom, Indonesia and the Caribbean. OBJECTIVE: To analyse the influence of VNTR (CAG)n on metabolic profile in adults with obesity and pre-obesity, as well as to estimate its effect on the risk of developing diabetes. METHODS AND MATERIAL: 255 adults of Chinantec Amerindian ethnic origin were included, who underwent anthropometric and biochemical evaluation. The VNTR was amplified by end-point PCR and by 8% PAGE electrophoresis. RESULTS: Differences were found in the waist/hip circumference index and body mass index in the carriers of genotypes different to the one homozygous for 22 repeats with a Student's t test value of 0.0041 and 0.0334, respectively. We also found an association with a family history of chronic disease. CONCLUSION: The VNTR of ATXN2 is associated with obesity in Mexican adults of Chinantec ancestry.

CCR2/CCL2 and CMKLR1/RvE1 chemokines system levels are associated with insulin resistance in rheumatoid arthritis.

Rheumatoid arthritis (RA) has been associated with insulin resistance (IR). Due to an excess in storage of white adipose tissue, IR has an inflammatory process that overlaps with RA. This is performed by the activation/migration of monocytes carried out by the CCR2/CCL2 and CMKLR1/RvE1 chemokines systems. Furthermore, these can potentiate chronic inflammation which is the central axis in the immunopathogenesis of RA. We evaluated the association between the relative expression of CCR2 and CMKLR1 and the serum levels of their ligands CCL2 and RvE1, in the context of adiposity status with IR as a comorbidity in RA. We studied 138 controls and 138 RA-patients classified with and without IR. We evaluated adiposity, RA activity, IR status and immunometabolic profiles by routine methods. Insulin, CCL2 and RvE1 serum levels were determined by ELISA. Relative expression of CCR2, CMKLR1 and RPS28 as constitutive gene by SYBR green RT-qPCR and 2-ΔΔCT method. Increased measurements were observed of body adiposity and metabolic status as follows: RA with IR>control group with IR>RA without IR> control group without IR. CCR2 and CMKLR1 relative expression was increased in RA without IR versus control without IR. CCR2: 2.3- and 1.3-fold increase and CMKLR1: 3.5- and 2.7-fold increase, respectively. Whereas, CCR2 expression correlates with CMKLR1 expression (rho = 0.331) and IR status (rho = 0.497 to 0.548). CMKLR1 expression correlates with inflammation markers (rho = 0.224 to 0.418). CCL2 levels were increased in the RA groups but levels of RvE1 were increased in RA without IR. We conclude that in RA with IR, the chemokine receptors expression pattern showed a parallel increase with their respective ligands. RA and IR in conjunction with the pathological distribution of body fat mass might exacerbate chronic inflammation. These results suggest that high CCL2 levels and compensatory RvE1 levels might not be enough to resolve the inflammation by themselves.

Association between nutritional risk markers and polymorphisms rs2291166 in TJP1 and VNTR (CAG)n in ATXN2 in an obese adolescent Mexican population. / Asociación entre marcadores de riesgo nutricionales con los polimorfismos rs2291166 de TJP1 y el VNTR (CAG)n de ATXN2 en población mexicana adolescente con obesidad.

OBJECTIVE: To estimate the correlation between indices of diet quality (DQIs), insulin sensitivity (QUICKI) and resistance (HOMA-IR), waist circumference (WHR) and body mass (BMI) and the alleles and genotypes of the TJP1 SNP rs2291166 and the VNTR of ATXN2 in adolescent patients. SUBJECTS AND METHOD: The study enrolled 85 subjects aged 10-20years, from the city of Tuxtepec, Oaxaca, Mexico, recruited in the period 2017-2018. DQIs, BMI, WHR, HOMA-IR, QUICKI, and diet quality index were measured. The rs2291166 polymorphism in TJP1 was determined by allele-specific PCR and the (CAG)n expansion in ATXN2 was determined by hot start PCR. PCR products were analyzed using 8% PAGE electrophoresis and silver nitrate staining. RESULTS: A correlation was found of indices DQIs, HOMA-IR, WHR and BMI with the heterozygous genotype of the TJP1 SNP rs2291166 and the long and short repeats of the ATXN2 CAG repeat in obese adolescent patients. A very strong positive correlation was seen between the TJP1 SNP and the HOMA-IR index (P<.05). A positive correlation was also found between the ATXN2 CAG repeat and the QUICKI index (P=.000) (P<.05), while the DQIs index correlated more closely with BMI and WHR. CONCLUSIONS: DQIs, TJP1 SNP rs2291166, and ATXN2 CAG repeat are determinants of obesity-related risk parameters such as BMI, WHR, QUICKI, and HOMA-IR in the adolescent population analyzed.

[Glucotransporters: clinical, molecular and genetic aspects]. / Glucotransportadores (GLUT): Aspectos clínicos, moleculares y genéticos.

Oxidation of glucose is the major source of obtaining cell energy, this process requires glucose transport into the cell. However, cell membranes are not permeable to polar molecules such as glucose; therefore its internalization is accomplished by transporter proteins coupled to the cell membrane. In eukaryotic cells, there are two types of carriers coupled to the membrane: 1) cotransporter Na+-glucose (SGLT) where Na+ ion provides motive power for the glucose´s internalization, and 2) the glucotransporters (GLUT) act by facilitated diffusion. This review will focus on the 14 GLUT so far described. Despite the structural homology of GLUT, different genetic alterations of each GLUT cause specific clinical entities. Therefore, the aim of this review is to gather the molecular and biochemical available information of each GLUT as well as the particular syndromes and pathologies related with GLUT´s alterations and their clinical approaches.

Low CD36 and LOX-1 Levels and CD36 Gene Subexpression Are Associated with Metabolic Dysregulation in Older Individuals with Abdominal Obesity.

Background. Obesity study in the context of scavenger receptors has been linked to atherosclerosis. CD36 and LOX-1 are important, since they have been associated with atherogenic and metabolic disease but not fat redistribution. The aim of our study was to determinate the association between CD36 and LOX-1 in presence of age and abdominal obesity. Methods. This is a cross-sectional study that included 151 healthy individuals, clinically and anthropometrically classified into two groups by age (<30 and ≥30 years old) and abdominal obesity (according to World Health Organization guidelines). We excluded individuals with any chronic and metabolic illness, use of medication, or smoking. Fasting blood samples were taken to perform determination of CD36 mRNA expression by real-time PCR, lipid profile and metabolic and low grade inflammation markers by routine methods, and soluble scavenger receptors (CD36 and LOX-1) by ELISA. Results. Individuals ≥30 years old with abdominal obesity presented high atherogenic index, lower soluble scavenger receptor levels, and subexpression of CD36 mRNA (54% less). On the other hand, individuals <30 years old with abdominal adiposity presented higher levels in the same parameters, except LOX-1 soluble levels. Conclusion. In this study, individuals over 30 years of age presented low soluble scavenger receptors levels pattern and CD36 gene subexpression, which suggest the chronic metabolic dysregulation in abdominal obesity.

[High frequency of ancestral allele of the TJP1 polymorphism rs2291166 in Mexican population, conformational effect and applications in surgery and medicine]. / Alta frecuencia del alelo ancestral del polimorfismo rs2291166 de TJP1 en población mexicana, efecto conformacional así como las aplicaciones en cirugía y medicina.

BACKGROUND: TJP1 gene encodes a ZO-1 protein that is required for the recruitment of occludins and claudins in tight junction, and is involved in cell polarisation. It has different variations, the frequency of which has been studied in different populations. In Mexico there are no studies of this gene. These are required because their polymorphisms can be used in studies associated with medicine and surgery. Therefore, the aim of this study was to estimate the frequency of alleles and genotypes of rs2291166 gene polymorphism TJP1 in Mexico Mestizos population, and to estimate the conformational effect of an amino acid change. MATERIAL AND METHODS: A total of 473 individuals were included. The rs2291166 polymorphism was identified PASA PCR-7% PAGE, and stained with silver nitrate. The conformational effect of amino acid change was performed in silico, and was carried out with servers ProtPraram Tool and Search Database with Fasta. RESULTS: The most frequent allele in the two populations is the ancestral allele (T). A genotype distribution similar to other populations was found. The polymorphism is in Hardy-Weinberg, p>0.05. Changing aspartate to alanine produced a conformational change. CONCLUSIONS: The study reveals a high frequency of the ancestral allele at rs2291166 polymorphism in the Mexican population.

Asociación del gen ELMO1 (snp rs1345365) con el desarrollo de diabetes mellitus tipo 2 en población mestiza Mexicana / Association of the ELMO1 gene (snp rs1345365) with development of type 2 diabetes mellitus in the Mexican mestizo population

El locus g.37190613 en 7p14.2-14.1 del gen ELMO1 presenta un polimorfismo el cual consiste en un cambio G>A(rs1345365). Esta variante, entre otras, de ELMO1, ha sido asociada con nefropatía diabética en diferentes poblaciones. En México son limitados los estudios de asociación de diabetes mellitus con genes candidatos. Por ello, el objetivo del presente trabajo fue determinar la asociación del SNP rs1345365 del gen ELMO1 con el desarrollo de diabetes mellitus tipo 2 (DM2). Para ello se analizaron 148 pacientes con DM2, 156 individuos sin diabetes pero con factores de riesgo cardiovascular y 269 personas sanas sin DM2. El polimorfismo se identificó por PASA (PCR AMPLIFICATION ALLELE SPECIFIC) y PAGE teñida con nitrato de plata. La asociación se estableció por diferentes modelos de epidemiología genética; el modelo dominante mostró una asociación positiva (p=0,0006) como factor protector y el para-dominante mostró al estado heterocigoto como factor de riesgo. En conclusión el estudio reveló la asociación del SNP rs1345365 del gen ELMO1 con DM2 en una población mestiza Mexicana.

The g.37190613 locus on 7p14.2-14.1 in the ELMO1 gene has a G>A polymorphism (SNP rs1345365) that has been associated with diabetic nephropathy in different populations. The genetic-association studies in type 2 diabetes mellitus (DM2) on the Mexican population are limited. The aim of this study was to estimate whether the polymorphism G>A of ELMO1 gene is associated with the development of DM2. We included 148 DM2 individuals, 156 individuals with cardiovascular risk factors without diabetes and 269 healthy proband without DM2. The polymorphism was identified by PCR amplification specific allele (PASA), PAGE and silver staining. The association was established by genetic epidemiological models; the dominant model showed a positive association (p=0.0006) as a protective factor, and the para-dominant model to heterozygous, as risk factor. In conclusion, this study revealed the association of the SNP rs1345365 of the ELMO1 gene in a Mexican population.

[Pathogenic mechanisms of neuronal damage in multiple sclerosis]. / Mecanismos patogénicos en el desarrollo de la esclerosis múltiple: ambiente, genes, sistema inmune y estrés oxidativo.

Multiple sclerosis is the most common cause of progressive neurological disability in young adults. This disease involves damage to the myelin sheath that normally insulates the electrical activity of nerve fibers. This leads to a wide range of symptoms as specific nerves become injured and lose their function. Epidemiological and experimental studies show that genetic alterations, antioxidant enzyme abnormalities and autoimmunity are risk factors for developing the disease. Recent evidence suggests that inflammation and oxidative stress within the central nervous system are major causes of ongoing tissue damage. Resident central nervous system cells and invading inflammatory cells release several reactive oxygen and nitrogen species which cause the histopathological features of multiple sclerosis: demyelization and axonal damage. The interplay between inflammatory and neurodegenerative processes results in an intermittent neurological disturbance followed by progressive accumulation of disability. Reductions in inflammation and oxidative stress status are important therapeutic strategies to slow or halt the disease processes. Therefore, several drugs are currently in trial in clinical practice to target this mechanism; particularly the use of supplements such as antioxidants and omega-3 polyunsaturated fatty acids, in order to improve the survival and quality of patients' lives.

Role of the blood-brain barrier in multiple sclerosis.

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system associated with demyelination and axonal loss eventually leading to neurodegeneration. MS exhibits many of the hallmarks of an inflammatory autoimmune disorder including breakdown of the blood-brain barrier (BBB). The BBB is a complex organization of cerebral endothelial cells, pericytes and their basal lamina, which are surrounded and supported by astrocytes and perivascular macrophages. In pathological conditions, lymphocytes activated in the periphery infiltrate the central nervous system to trigger a local immune response that ultimately damages myelin and axons. Cytotoxic factors including pro-inflammatory cytokines, proteases, and reactive oxygen and nitrogen species accumulate and may contribute to myelin destruction. Dysregulation of the BBB and transendothelial migration of activated leukocytes are among the earliest cerebrovascular abnormalities seen in MS brains and parallel the release of inflammatory cytokines. In this review we establish the importance of the role of the BBB in MS. Improvements in our understanding of molecular mechanism of BBB functioning in physiological and pathological conditions could lead to improvement in the quality of life of MS patients.

[Implications in primary health care of medical genetics and genomic in type 2 diabetes mellitus]. / Implicaciones en la atención primaria en salud de la genética y genómica en la diabetes mellitus tipo 2.

Type 2 diabetes mellitus is a complex disease and a global health problem. Therefore, the first level of health care should handle the approaches of medical genetics and genomics to reduce its incidence. The aim is to present perspectives analyzed by our group in two areas of genetics and its clinical application. Emphasis is placed on the coexistence of several genetic forms clinically detectable in patients with diabetes, missing heritability associated with low penetrance, and epigenomics mechanism. It is discussed the effect of genetic variation associated with resistance to insulin, beta-cell dysfunction, shaft incretin, and other points of interest, such as thrifty genotype hypothesis, conformational disease, genetically unknown foods, phenocopies as clinically silent hypercortisolism, molecular phytopharmacology in the clinical management. Finally, the result was displayed in the Mexican population from genetic studies and new findings of clinical importance, such as involvement of melatonin and effect of variations in the number of copies in a genomic region.

La diabetes mellitus tipo 2 es una enfermedad multifactorial y un problema de salud mundial. De ahí que en el primer nivel de atención en salud se deben manejar los abordajes de la genética médica y genómica para disminuir su incidencia. El propósito de este artículo es presentar perspectivas analizadas por nuestro grupo en dos áreas de la genética, así como su aplicación clínica. Se hace hincapié en la coexistencia de varias formas genéticas clínicamente detectables en el paciente diabético, la heredabilidad perdida relacionada con baja penetrancia y fenómenos epigenómicos. Se discute el efecto de la variación genética relacionada con la resistencia a la insulina, la disfunción de las células beta, el eje incretínico, otros puntos de interés como las hipótesis del genotipo ahorrador, la patología conformacional, comidas genéticamente desconocidas, fenocopias como el hipercortisolismo clínicamente silente y la fitofarmacología molecular en el manejo clínico. Finalmente, se muestran resultados de estudios genéticos en población mexicana y nuevos hallazgos de importancia en la clínica, como la participación de la melatonina y el efecto de las variaciones en el número de copias en una región genómica.

[The metabolic and molecular bases of Cockayne syndrome]. / Las bases metabólicas y moleculares del síndrome de Cockayne.

Cockayne is a segmental progeroid syndrome that has autosomal recessive inheritance pattern. It is mainly characterized by Intrauterine growth retardation, severe postnatal growth deficiency, cachectic dwarfism, microcephaly, wizened face, sensorineural hearing loss, cataracts, dental caries, cardiac arrhythmias, hypertension, atherosclerosis, proteinuria, micropenis, renal failure, skeletal abnormalities, skin photosensitivity, decreased subcutaneous adipose tissue, cerebral atrophy, dementia, basal ganglia calcifications, ataxia and apraxia. It has a complex phenotype given by genetic heterogeneity. There are five gene responsible for this syndrome: CSA, CSB, XPB, XPD and XPG, in which various mutations have been found. The biochemical effect of these mutations includes dysfunctional protein of the repair system for oxidative damage to DNA, the complex coupled to transcription and the nucleotide excision repair system. Considering the role played for these proteins and its effects on clinical phenotype when they are deficient, we suggest that these genes might be candidates for analyzing susceptibility to common chronic degenerative diseases related to oxidative stress and aging.

[Proximal pancreatectomy in a case of nesidioblastosis]. / Pancreatectomía proximal en nesidioblastosis.

A 19 moth-old child who presented seizures secondary to intractable hypoglycemia, fulfilling the clinical and biochemical criteria for hyperinsulinism was studied. Histopathological findings of the pancreas showed the presence of small clusters of b cell islets throughout acinar tissue near ducts, in both the head and the proximal third of the body. Proximal pancreatectomy (60%) and distal pancreatic-jejunostomy (Roux-in-Y) were performed. This procedure was effective in reverting hypoglycemia and constitutes the first successful alternative treatment.

Pancreatectomía proximal en nesidioblastosis / Proximal pancreatectomy in case of nesidioblastosis

En 1938 Laidiaw acuñó el término de nesidioblastosis refiriéndose a una neodiferenciación de los islotes de Langerhans, originada del epitelio de los conductos pancreáticos. Se presenta un caso clínico de un niño de 19 meses de edad, con convulsiones secundarias a hipoglucemia intratable. Se diagnosticó hiperinsulinismo con base en criterios clínicos y bioquímicos. Los hallazgos histopatológicos del páncreas mostraron la presencia de racimos de islotes de células P por todo el tejido acinar localizados en cabeza y un tercio proximal del cuerpo. Se realizó el diagnóstico de nesidioblastosis y para su tratamiento se practicó pancreatectomía proximal (60%), con una pancreático yeyunostomía distal (Y en Roux). Después del tratamiento, el paciente tuvo normalización de los niveles séricos de glucosa y de insulina. Se concluye que este procedimiento resultó efectivo al revertir la hipoglucemia, por lo que constituye el primer tratamiento alternativo al método convencional.

A 19 month old child who presented seizures secondary to intractable hypoglycemia, fulfilling the clinical and biochemical criteria for hyperinsulinism was studied. Histopathological findings of the pancreas showed the presence of small clusters of b cell islets throughout acinar tissue near ducts, in both the head and the proximal third of the body. Proximal pancreatectomy (60%) and distal pancreatic jejunostomy (Roux in Y) were performed. This procedure was effective in reverting hypoglycemia and constitutes the first successful alternative treatment.