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The flavanol (-)-epicatechin has exercise-mimetic properties. Besides, several miRNAs play a role in modulating the adaptation of the muscle to different training protocols. However, notwithstanding all information, few studies aimed to determine if (-)-epicatechin can modify the expression of miRNAs related to skeletal muscle development and regeneration. Mice were treated for fifteen days by oral gavage with the flavanol (-)-epicatechin. After treatment, the quadriceps of the mice was dissected, and total RNA was extracted. The expression level of miR-133, -204, -206, -223, -486, and -491 was analyzed by qRT-PCR. We also used bioinformatic analysis to predict the participation of these miRNAs in different skeletal muscle signal transduction pathways. Additionally, we analyzed the level of the myogenic proteins MyoD and myogenin by Western blot and measured the cross-sectional area of muscle fibers stained with E&H. (-)-Epicatechin upregulated the expression of miR-133, -204, -206, -223, and -491 significantly, which was associated with an increase in the level of the myogenic proteins MyoD and Myogenin and an augment in the fiber size. The bioinformatics analysis showed that the studied miRNAs might participate in different signal transduction pathways related to muscle development and adaptation. Our results showed that (-)-epicatechin upregulated miRNAs that participate in skeletal exercise muscle adaptation, induced muscle hypertrophy, and increased the level of myogenic proteins MyoD and MyoG.
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Catequina , MicroRNAs , Camundongos , Animais , Miogenina/genética , Miogenina/metabolismo , Proteína MyoD/genética , Proteína MyoD/metabolismo , Catequina/farmacologia , Músculo Esquelético/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Diferenciação CelularRESUMO
BACKGROUND: Mitochondrial and oxidative stress has been related to obesity and breast cancer being this cancer more frequent and more aggressive in postmenopausal women with obesity. OBJECTIVE: The objective of this study was to investigate whether Mexican-Mestizo postmenopausal women with breast cancer and obesity present different somatic mutations in the mitochondrial DNA (mtDNA) when compared to women with normal body mass index (BMI). SUBJECTS AND METHODS: We included six Mexican-Mestizo postmenopausal women bearing breast cancer and who underwent mastectomy or breast-conserving surgery. BMI was determined in each case. Patients' genomic DNA was isolated from blood leukocytes and tumor tissue samples. Whole mtDNA sequence was determined by MitoChip v2.0 mitochondrial resequencing array, and data were analyzed using the GeneChip Sequence Analysis Software. Tumor mtDNA sequence was compared with matched leukocyte mtDNA sequence. RESULTS: Three women had a normal BMI and three presented obesity. Overall, we found 64 genetic variants: 53.1% were somatic mutations and 46.9% were polymorphisms; 44.1% were in the non-coding region and 55.9% were in genes that encode for mitochondrial proteins. Among the somatic mutations, 67.7% were in patients with normal BMI and 32.3% in patients with obesity. CONCLUSIONS: We did not find a higher frequency of mitochondrial somatic mutations in postmenopausal women with breast cancer and obesity compared to those with normal BMI. However, results could be due to the small number of women studied.
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Neoplasias da Mama/patologia , Genoma Mitocondrial , Obesidade/epidemiologia , Pós-Menopausa , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Neoplasias da Mama/genética , Neoplasias da Mama/cirurgia , DNA Mitocondrial/genética , Feminino , Humanos , Mastectomia/métodos , Mastectomia Segmentar/métodos , México , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo GenéticoRESUMO
Abstract Background Mitochondrial and oxidative stress has been related to obesity and breast cancer being this cancer more frequent and more aggressive in postmenopausal women with obesity. Objective The objective of this study was to investigate whether Mexican-Mestizo postmenopausal women with breast cancer and obesity present different somatic mutations in the mitochondrial DNA (mtDNA) when compared to women with normal body mass index (BMI). Subjects and Methods We included six Mexican-Mestizo postmenopausal women bearing breast cancer and who underwent mastectomy or breast-conserving surgery. BMI was determined in each case. Patients genomic DNA was isolated from blood leukocytes and tumor tissue samples. Whole mtDNA sequence was determined by MitoChip v2.0 mitochondrial resequencing array, and data were analyzed using the GeneChip Sequence Analysis Software. Tumor mtDNA sequence was compared with matched leukocyte mtDNA sequence. Results Three women had a normal BMI and three presented obesity. Overall, we found 64 genetic variants: 53.1% were somatic mutations and 46.9% were polymorphisms; 44.1% were in the non-coding region and 55.9% were in genes that encode for mitochondrial proteins. Among the somatic mutations, 67.7% were in patients with normal BMI and 32.3% in patients with obesity. Conclusions We did not find a higher frequency of mitochondrial somatic mutations in postmenopausal women with breast cancer and obesity compared to those with normal BMI. However, results could be due to the small number of women studied.
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Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , Pós-Menopausa , Genoma Mitocondrial , Obesidade/epidemiologia , Polimorfismo Genético , Neoplasias da Mama/cirurgia , Neoplasias da Mama/genética , DNA Mitocondrial/genética , Mastectomia Segmentar/métodos , Índice de Massa Corporal , Análise de Sequência com Séries de Oligonucleotídeos , Mastectomia/métodos , MéxicoRESUMO
Several studies suggest an important role of Interleukin-27 in the development of atherosclerosis. The aim of this study was to establish whether the IL-27p28 gene polymorphisms are associated with premature coronary artery disease and/or other cardiovascular risk factors. Four IL-27p28 gene polymorphisms were selected and genotyped in 1162 premature coronary artery disease cases and 1107 controls. rs26528 T and rs40837 A alleles were significantly associated with a lower risk of premature coronary artery disease under different inheritance models (Pdominant = 0.046; Pover-dominant = 0.002; Pco-dominant1 = 0.007 for rs26528T; Pover-dominant = 0.008 and Pco-dominant1 = 0.031 for rs40837). The rs40837 A allele was also associated with a lower risk of insulin resistance, in cases (Pover-dominant = 0.037) and controls (Padditive = 0.008; Pdominant = 0.047; Precessive = 0.014; Pco-dominant2 = 0.006), while the rs26528 T allele was associated with a lower risk of insulin resistance only in the control group (Precessive = 0.016; Pco-dominant2 = 0.021). Interleukin-27 plasma levels were measured in 450 controls and 450 cases, and were significantly higher in cases compared to controls (P = 0.004). However, Interleukin-27 plasma levels were not associated with IL-27p28 polymorphisms. Luciferase assays showed that co-transfection of the rs40837 A allele and miR-379-5p significantly decreased luciferase gene expression. Our study shows for the first time, that IL-27p28 gene polymorphisms are associated with premature coronary artery disease and with some metabolic parameters. The rs40837 A allele in presence of miR-379-5p significantly decreased luciferase gene expression.
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BACKGROUND: Polymorphisms of methylenetetrahydrofolate reductase (MTHFR) have been associated with diastolic blood pressure, hypertension, and other cardiovascular diseases; however, results of these studies are still controversial. In this study, we sought to determine whether 2 functional variants (rs1801133 and rs13306560) within the MTHFR are associated with hypertension in Mexican-Mestizos. METHODS AND RESULTS: We performed a case-control study with 1214 subjects including adults and children to test for the association of both single nucleotide polymorphisms with essential hypertension. The adult group included 764 participants (372 patients and 391 controls) and the group of children included 418 participants (209 patients and 209 controls). rs13306560 was associated with essential hypertension in adults (odds ratio, 4.281; 95% confidence interval, 1.841-9.955; P=0.0003) with a statistical power >0.8. In children, none of the polymorphisms was associated with essential hypertension. In addition, we assessed the effect of the rs13306560 polymorphism on the MTHFR promoter region by means of luciferase reporter gene assays using human umbilical vein endothelial cells. Cells transfected with the pMTHFRaLUC construct showed an ≈25% reduction in luciferase activity (P=0.003). Furthermore, the promoter activity was reduced considerably by in vitro methylation of CpG sequences. CONCLUSIONS: Our data suggest that the rs13306560 polymorphism of the MTHFR may be part of the observed hypertension process in Mexican-Mestizo populations, but further studies are warranted. In addition, the allele A of the rs13306560 polymorphism as well as the in vitro methylation of CpGs reduced the promoter activity of the MTHFR regulatory region.
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Predisposição Genética para Doença/genética , Hipertensão/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo de Nucleotídeo Único , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Estudos de Casos e Controles , Criança , Hipertensão Essencial , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , México , Pessoa de Meia-Idade , Razão de Chances , Regiões Promotoras Genéticas/genéticaRESUMO
OBJECTIVE: This study aimed to identify the isotype of human papillomavirus (HPV) in fresh tissue samples of 35 male adults with adult recurrent adult respiratory papillomatosis which may be important to define the precise etiology of the disease, and determine the therapeutic and prophylactic measures. METHODS: A total of 35 adult male patients diagnosed with active RRP who have been treated for several years were included in the study. DNA of patients was extracted from fresh biological samples and analyzed by PCR and a Linear Array® HPV Genotyping system. RESULTS: Most cases (95%) corresponded to adult-onset of RRP. A questionnaire was applied to obtain demographic and clinical data. Using a PCR-based detection system all patients showed the presence of HPV; 80% were positive for HPV-6, 8% for HPV-11 and one for HPV-16. CONCLUSION: Most patients presented HPV-6 and consequently it was not feasible to correlate clinical and demographic characteristics with viral type. Besides, co-infections were not evident. This knowledge may be relevant to delineate therapeutic and preventive measures.
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DNA Viral/genética , Papillomavirus Humano 11/genética , Papillomavirus Humano 16/genética , Papillomavirus Humano 6/genética , Infecções por Papillomavirus/virologia , Infecções Respiratórias/virologia , Adulto , Idoso , Genótipo , Papillomavirus Humano 11/isolamento & purificação , Papillomavirus Humano 16/isolamento & purificação , Papillomavirus Humano 6/isolamento & purificação , Humanos , Masculino , México , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prega Vocal/virologia , Adulto JovemRESUMO
A high proportion of primary percutaneous coronary interventions performed in the setting of acute myocardial infarction, concur with inadequate myocardial perfusion at the microvascular level. This phenomenon, known as "no-reflow" contributes to reperfusion injury, poor prognosis and to unfavorable clinical outcome. In this study, we evaluated the hypothesis that the synthetic 17ß-aminoestrogen Prolame, may confer cardioprotection and prevent against no-reflow. In an open-chest model of 30-min ischemia and 90-min reperfusion, male Wistar rats were randomly assigned to different groups: Control, Prolame, Prolame followed by the nitric oxide synthase inhibitor (L-NAME), and 17ß-estradiol. Areas of risk, infarct size and no-reflow were determined by planimetry with triphenyltetrazolium chloride and thioflavin-S stains. Structural damage of the vasculature was measured as capillary compression in clarified tissue after intra-atrial injection of Microfil. Hemodynamic function was obtained at the end of stabilization, ischemia and reperfusion; nitric oxide (NO·) content was determined indirectly using the Griess reaction. Activation of the eNOS signaling cascade was determined by western blot. Prolame reduced the infarcted area, decreased the zones of no-reflow and capillary compression by activating the PI3K/Akt/eNOS signaling pathway in correlation with NO· increase. Prolame also activated endothelial cells augmenting NO· production, which was inhibited by ICI182780 (a selective estrogen receptor down-regulator), supporting the notion that the cardioprotective effect of Prolame involves the preservation of endothelium through the activation of estrogen receptor downstream signaling. Our results provide evidence that Prolame has potential therapeutic application in patients with AMI, as it prevents from both vascular and cardiac tissue damage.
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Estrenos/farmacologia , Hemodinâmica/efeitos dos fármacos , Infarto do Miocárdio/fisiopatologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Fenômeno de não Refluxo/prevenção & controle , Transdução de Sinais/efeitos dos fármacos , Animais , Western Blotting , Modelos Animais de Doenças , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Humanos , Masculino , Infarto do Miocárdio/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Fenômeno de não Refluxo/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Wistar , Veias UmbilicaisAssuntos
Distrofina/genética , Duplicação Gênica , Fases de Leitura , Adolescente , Biópsia , Estudos de Casos e Controles , Análise Mutacional de DNA , Distrofina/metabolismo , Éxons , Feminino , Humanos , Masculino , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Distrofia Muscular de Duchenne/diagnóstico , Distrofia Muscular de Duchenne/genética , Pele/metabolismo , Pele/patologiaRESUMO
The mammary gland (MG) undergoes functional and metabolic changes during the transition from pregnancy to lactation, possibly by regulation of conserved genes. The objective was to elucidate orthologous genes, chromosome clusters and putative conserved transcriptional modules during MG development. We analyzed expression of 22,000 transcripts using murine microarrays and RNA samples of MG from virgin, pregnant, and lactating rats by cross-species hybridization. We identified 521 transcripts differentially expressed; upregulated in early (78%) and midpregnancy (89%) and early lactation (64%), but downregulated in mid-lactation (61%). Putative orthologous genes were identified. We mapped the altered genes to orthologous chromosomal locations in human and mouse. Eighteen sets of conserved genes associated with key cellular functions were revealed and conserved transcription factor binding site search entailed possible coregulation among all eight block sets of genes. This study demonstrates that the use of heterologous array hybridization for screening of orthologous gene expression from rat revealed sets of conserved genes arranged in chromosomal order implicated in signaling pathways and functional ontology. Results demonstrate the utilization power of comparative genomics and prove the feasibility of using rodent microarrays to identification of putative coexpressed orthologous genes involved in the control of human mammary gland development.
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Duchenne muscular dystrophy is a severe, debilitating and progressive disease that affects 1 in 3,500 live male births in the world. The diagnosis should be confirmed by genetic testing to identify the mutation in the DMD gene or muscle biopsy and immunostaining to demonstrate the absence of dystrophin. Although up to now continues to be an incurable disease, this does not mean it has no treatment. Treatment should be multidisciplinary, looking for the functionality of the patient and avoiding or correcting complications, mainly cardio-respiratory and skeletal. Many proposals have been evaluated and implemented with the aim of improving the quality of life for these patients. The long-term steroids have shown significant benefits, such as prolonging ambulation, reduce the need for spinal surgery, improve cardiorespiratory function and increase survival and the quality of life. This document presents the recommendations based on the experience of the working group and experts worldwide on the diagnosis and treatment with steroids for patients with Duchenne muscular dystrophy.
TITLE: Diagnostico y tratamiento con esteroides de pacientes con distrofia muscular de Duchenne: experiencia y recomendaciones para Mexico.La distrofia muscular de Duchenne es una enfermedad grave, incapacitante y progresiva que afecta a 1 de cada 3.500 recien nacidos varones alrededor del mundo. El diagnostico debera confirmarse mediante pruebas geneticas para identificar la mutacion en el gen DMD, o bien por biopsia muscular e inmunotincion para demostrar la ausencia de distrofina. Aunque actualmente continua siendo una enfermedad incurable, no significa que no tenga tratamiento. Este debe ser multidisciplinario, buscando la funcionalidad del paciente y evitando o corrigiendo las complicaciones, principalmente cardiorrespiratorias y esqueleticas. Se han evaluado e implementado multiples propuestas con la finalidad de mejorar la calidad de vida en estos pacientes. Los esteroides a largo plazo han demostrado importantes beneficios para los pacientes, prolongan la deambulacion, reducen la necesidad de cirugia de columna, mejoran la funcion cardiorrespiratoria, y aumentan la supervivencia y la calidad de vida. En este documento se presentan las recomendaciones con base en la experiencia del grupo de trabajo y de los expertos de ambito mundial sobre el diagnostico y el tratamiento con esteroides para los pacientes con distrofia muscular de Duchenne.
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Corticosteroides/uso terapêutico , Distrofia Muscular de Duchenne/tratamento farmacológico , Corticosteroides/administração & dosagem , Corticosteroides/efeitos adversos , Cuidadores/educação , Terapia Combinada , Diagnóstico Diferencial , Distrofina/genética , Cardiopatias/etiologia , Cardiopatias/prevenção & controle , Humanos , Hiperglicemia/induzido quimicamente , Terapia de Imunossupressão , Incidência , Masculino , México/epidemiologia , Técnicas de Diagnóstico Molecular , Distrofia Muscular de Duchenne/diagnóstico , Distrofia Muscular de Duchenne/epidemiologia , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/reabilitação , Obesidade/induzido quimicamente , Equipe de Assistência ao Paciente , Modalidades de Fisioterapia , Qualidade de Vida , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/prevenção & controle , Terapia RespiratóriaRESUMO
Osteoporosis is characterized by low bone mineral density (BMD). One of the most important factors that influence BMD is the genetic contribution. The collagen type 1 alpha 1 (COL1A1) and the JAGGED (JAG1) have been investigated in relation to BMD. The aim of this study was to investigate the possible association between two single-nucleotide polymorphisms (SNPs) of COL1A1, their haplotypes, and one SNP of JAG1 with BMD in postmenopausal Mexican-Mestizo women. Seven hundred and fifty unrelated postmenopausal women were included. Risk factors were recorded and BMD was measured in lumbar spine, total hip, and femoral neck by dual-energy X-ray absorptiometry. DNA was obtained from blood leukocytes. Two SNPs in COL1A1 (rs1800012 and rs1107946) and one in JAG1 (rs2273061) were studied. Real-time PCR allelic discrimination was used for genotyping. The differences between the means of the BMDs according to genotype were analyzed with covariance. Deviations from Hardy-Weinberg equilibrium were tested. Pairwise linkage disequilibrium between single nucleotide polymorphisms was calculated by direct correlation r (2), and haplotype analysis of COL1A1 was conducted. Under a dominant model, the rs1800012 polymorphism of the COL1A1 showed an association with BMD of the lumbar spine (P = 0.021). In addition, analysis of the haplotype of COL1A1 showed that the G-G haplotype presented a higher BMD in lumbar spine. We did not find an association between the s1107946 and rs2273061 polymorphisms of the COL1A1 and JAG1, respectively. Our results suggest that the rs1800012 polymorphism of the COL1A1, in addition to one haplotype, were significantly associated with BMD variation in Mexican-Mestizo postmenopausal women.
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Densidade Óssea/genética , Proteínas de Ligação ao Cálcio/genética , Colágeno Tipo I/genética , Peptídeos e Proteínas de Sinalização Intercelular/genética , Proteínas de Membrana/genética , Osteoporose/genética , Polimorfismo de Nucleotídeo Único , Absorciometria de Fóton , Análise de Variância , Distribuição de Qui-Quadrado , Cadeia alfa 1 do Colágeno Tipo I , Feminino , Genótipo , Haplótipos , Humanos , Proteína Jagged-1 , México , Pessoa de Meia-Idade , Osteoporose/etnologia , Pós-Menopausa , Fatores de Risco , Proteínas Serrate-Jagged , Inquéritos e QuestionáriosRESUMO
INTRODUCTION: The muscular dystrophies (MDs) result from perturbations in the myofibers. These alterations are induced in part by mechanical stress due to membrane cell fragility, disturbances in mechanotransduction pathways, muscle cell physiology, and metabolism. METHODS: We analyzed 290 biopsies of patients with a clinical diagnosis of muscular dystrophy. Using immunofluorescence staining, we searched for primary and secondary deficiencies of 12 different proteins, including membrane, costamere, cytoskeletal, and nuclear proteins. In addition, we analyzed calpain-3 by immunoblot. RESULTS: We identified 212 patients with varying degrees of protein deficiencies, including dystrophin, sarcoglycans, dysferlin, caveolin-3, calpain-3, emerin, and merosin. Moreover, 78 biopsies showed normal expression of all investigated muscle proteins. The frequency rates of protein deficiencies were as follows: 52.36% dystrophinopathies; 18.40% dysferlinopathies; 14.15% sarcoglycanopathies; 11.32% calpainopathies; 1.89% merosinopathies; 1.42% caveolinopathies; and 0.47% emerinopathies. Deficiencies in lamin A/C and telethonin were not detected. CONCLUSION: We have described the frequency of common muscular dystrophies in Mexico.
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Proteínas de Membrana/metabolismo , Proteínas Musculares/metabolismo , Distrofias Musculares/diagnóstico , Distrofias Musculares/metabolismo , Adolescente , Adulto , Calpaína/metabolismo , Caveolina 3/metabolismo , Criança , Pré-Escolar , Creatina Quinase/sangue , Disferlina , Distrofina/metabolismo , Imunofluorescência , Regulação da Expressão Gênica/fisiologia , Humanos , Lactente , Laminina/metabolismo , México , Pessoa de Meia-Idade , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Distrofias Musculares/epidemiologia , Distrofias Musculares/fisiopatologia , Proteínas Nucleares/metabolismo , Sarcoglicanas/metabolismo , Índice de Gravidade de Doença , Adulto JovemRESUMO
Endothelial cells are susceptible to infection by several pathogens, but little is known about mycobacterial infection. We analyzed some features of mycobacteria-endothelial cell interactions and the innate response to the infection. Intracellular growth in human umbilical vein endothelial cells (HUVECs) of three Mycobacterium species: M. tuberculosis (MTB), M. abscessus (MAB) and M. smegmatis (MSM) was analyzed. M. smegmatis was eliminated; M. abscessus had an accelerate intracellular replication and M. tuberculosis did not replicate or was eliminated. M. abscessus infection induced profound cytoskeleton rearrangements, with M. tuberculosis infection changes were less marked, and with MSM were slight. Nitric oxide (NO) production was induced differentially: M. abscessus induced the highest levels followed by M. tuberculosis and M. smegmatis; the contrary was true for reactive oxygen species (ROS) production. Only M. tuberculosis infection caused beta-1 defensin over-expression. As a whole, our results describe some aspects of the innate response of HUVEC infected by mycobacteria with different virulence and suggest that a strong cytoskeleton mobilization triggers a high NO production in these cells.
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Defensinas/biossíntese , Células Endoteliais/imunologia , Células Endoteliais/microbiologia , Imunidade Inata , Infecções por Mycobacterium/imunologia , Mycobacterium smegmatis/crescimento & desenvolvimento , Carga Bacteriana , Citoesqueleto/ultraestrutura , Defensinas/análise , Células Endoteliais/citologia , Células Endoteliais/ultraestrutura , Feminino , Feto , Interações Hospedeiro-Parasita , Humanos , Microscopia Eletrônica de Varredura , Mycobacterium/crescimento & desenvolvimento , Mycobacterium/patogenicidade , Infecções por Mycobacterium/microbiologia , Mycobacterium smegmatis/patogenicidade , Mycobacterium tuberculosis/crescimento & desenvolvimento , Mycobacterium tuberculosis/patogenicidade , Óxido Nítrico/análise , Gravidez , Cultura Primária de Células , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Veias Umbilicais/citologia , Virulência/imunologiaRESUMO
INTRODUCTION. Dystrophinopathies are X-linked genetic disorders caused by mutations in the DMD gene. Genetic tests are of utmost importance for management and genetic counseling of these diseases. However, the complexity of the DMD gene is a challenge for diagnosis. AIM. To describe recent advances in the diagnosis of dystrophinopathies, after 20 years since the firsts molecular assays for genetic screening for these diseases. DEVELOPMENT. Currently, a variety of strategies such as automated mutation detection, cell-based methods and high throughput haplotyping have been developed to facilitate diagnosis of dystrophinopathies, carrier detection, prenatal and preimplantation diagnosis. CONCLUSION. New technologies have improved early detection and optimal management of dystrophinopathies and have established the basis for future molecular medicine. The most significant advances in dystrophinopathy diagnosis are reviewed herein.
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Distrofina/genética , Doenças Genéticas Ligadas ao Cromossomo X/diagnóstico , Distrofia Muscular de Duchenne/diagnóstico , Portador Sadio , Análise Mutacional de DNA , Bases de Dados Genéticas , Distrofina/metabolismo , Doenças Genéticas Ligadas ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/fisiopatologia , Marcadores Genéticos , Testes Genéticos , Humanos , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/fisiopatologia , Diagnóstico Pré-Implantação/métodosRESUMO
OBJECTIVE: Considering that the Mexican mestizo population seems to be the result of a genetic admixture, we proposed that further research is needed to evaluate the role of ethnicity in conjunction with health-related factors to better understand ethnic differences in bone mineral density (BMD). The aim of this study was to analyze several risk factors related to the development of osteoporosis in postmenopausal Mexican mestizo women. METHODS: We included 567 postmenopausal Mexican mestizo women. A structured questionnaire for risk factors was applied and BMD was measured in total hip and lumbar spine by dual-energy x-ray absorptiometry. Nonconditional logistic regression was used to estimate crude and adjusted odds ratio. RESULTS: Using World Health Organization criteria, 28.7% of postmenopausal women had osteoporosis, 46.4% had osteopenia, and 24.9% had normal BMD. Each clinical risk factor had a different significance for osteopenia/osteoporosis; however, duration of total breast-feeding, body mass index, and number of years since menopause remained significantly associated with osteopenia/osteoporosis after bone density was added to the nonconditional model. Interestingly, extended periods of accumulated breast-feeding for 24 and 36 months were, in both cases, significantly associated with osteopenia/osteoporosis. CONCLUSIONS: Our results confirm the importance of considering the duration of breast-feeding as an important risk factor for osteopenia/osteoporosis. In addition, we find that body mass index is positively associated with BMD. Because of the heterogeneity of the Mexican mestizo population, the risk factor for osteoporosis may not be the same in different ethnic groups.
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Densidade Óssea , Osteoporose Pós-Menopausa/etnologia , Pós-Menopausa , Absorciometria de Fóton , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Doenças Ósseas Metabólicas/epidemiologia , Doenças Ósseas Metabólicas/etnologia , Aleitamento Materno , Feminino , Número de Gestações , Humanos , Modelos Logísticos , México/epidemiologia , Pessoa de Meia-Idade , Razão de Chances , Osteoporose Pós-Menopausa/epidemiologia , Gravidez , Fatores de Risco , Inquéritos e Questionários , Fatores de TempoRESUMO
BACKGROUND: delta-Sarcoglycan (delta-SG) knockout (KO) mice develop skeletal muscle histopathological alterations similar to those in humans with limb muscular dystrophy. Membrane fragility and increased Ca(2+) permeability have been linked to muscle degeneration. However, little is known about the mechanisms by which genetic defects lead to disease. METHODS: Isolated skeletal muscle fibers of wild-type and delta-SG KO mice were used to investigate whether the absence of delta-SG alters the increase in intracellular Ca(2+) during single twitches and tetani or during repeated stimulation. Immunolabeling, electrical field stimulation and Ca(2+) transient recording techniques with fluorescent indicators were used. RESULTS: Ca(2+) transients during single twitches and tetani generated by muscle fibers of delta-SG KO mice are similar to those of wild-type mice, but their amplitude is greatly decreased during protracted stimulation in KO compared to wild-type fibers. This impairment is independent of extracellular Ca(2+) and is mimicked in wild-type fibers by blocking store-operated calcium channels with 2-aminoethoxydiphenyl borate (2-APB). Also, immunolabeling indicates the localization of a delta-SG isoform in the sarcoplasmic reticulum of the isolated skeletal muscle fibers of wild-type animals, which may be related to the functional differences between wild-type and KO muscles. CONCLUSIONS: delta-SG has a role in calcium homeostasis in skeletal muscle fibers. GENERAL SIGNIFICANCE: These results support a possible role of delta-SG on calcium homeostasis. The alterations caused by the absence of delta-SG may be related to the pathogenesis of muscular dystrophy.
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Cálcio/fisiologia , Fibras Musculares Esqueléticas/fisiologia , Músculo Esquelético/metabolismo , Sarcoglicanas/deficiência , Animais , Estimulação Elétrica , Membro Posterior , Humanos , Camundongos , Camundongos Endogâmicos , Camundongos Knockout , Distrofia Muscular Animal/genética , Valores de Referência , Transdução de Sinais/fisiologiaRESUMO
Several studies have emphasized the relevance of dystrophin-associated protein complex (DAPC) to maintain the vascular function. Previously we postulated the presence of an utrophin associated protein complex (UAPC) in endothelium from umbilical cord vessels. In the present work, we demonstrate that utrophin (UTR) indeed forms a complex, with beta-dystroglycan (DG), epsilon-sarcoglycan (SG), caveolin-1 (cav-1), and endothelial nitric oxide synthase (eNOS) in human umbilical vein endothelial cells (HUVEC) by co-immunoprecipitation analysis. Additionally, we observed an increment in the protein levels of epsilon-SG, beta-DG, UTR and cav-1 after mechanical stretching. Interestingly, this stimulus also induced eNOS up-regulation, activation and release from the UAPC, and led to a significant increase in nitric oxide (NO) production. Finally, we propose that UAPC in HUVECs may play an important role in the regulation of vascular tone.
Assuntos
Endotélio Vascular/enzimologia , Óxido Nítrico Sintase Tipo III/metabolismo , Utrofina/metabolismo , Caveolina 1/análise , Caveolina 1/metabolismo , Células Cultivadas , Distroglicanas/análise , Distroglicanas/metabolismo , Endotélio Vascular/química , Endotélio Vascular/citologia , Ativação Enzimática , Humanos , Sarcoglicanas/análise , Sarcoglicanas/metabolismo , Estresse Mecânico , Veias Umbilicais/citologia , Utrofina/análiseRESUMO
The mouse alpha-sarcoglycan gene is expressed in muscle cells during differentiation, but its transcriptional regulation is not understood. We have characterized the promoter region of the mouse alpha-sarcoglycan gene. This region is composed of positive and negative regulatory elements that respond to the myogenic differentiation environment. Accordingly, MyoD transactivates the alpha-sarcoglycan full-length and the proximal promoter. Chromatin immunoprecipitation assays revealed that MyoD, TFIID, and TFIIB interact with the distal promoter in C2C12 myoblasts, a stage at which the alpha-SG promoter appears to drive basal activity. In myotubes, such factors are located concomitantly at the distal promoter and at a DNA region around the proximal promoter. In agreement with these results, TFIID and TFIIB co-immunoprecipitate with MyoD. We conclude that the alpha-SG promoter is activated by MyoD, which interacts with TFIID and TFIIB in a protein complex differentially located at the distal promoter and around the proximal promoter during myogenic cell differentiation.
Assuntos
Desenvolvimento Muscular/genética , Proteína MyoD/metabolismo , Regiões Promotoras Genéticas , Sarcoglicanas/genética , Ativação Transcricional , Animais , Sequência de Bases , Diferenciação Celular/genética , Imunoprecipitação da Cromatina , Regulação da Expressão Gênica , Camundongos , Dados de Sequência Molecular , Fibras Musculares Esqueléticas/metabolismo , Mioblastos/citologia , Mioblastos/metabolismo , Fator de Transcrição TFIIB/metabolismo , Fator de Transcrição TFIID/metabolismoRESUMO
The sarcoglycan-sarcospan complex (alpha-, beta-, gamma-, delta-, epsilon-, and zeta-SG-SSPN), a component of the dystrophin-associated glycoprotein complex (DAGC), is located at the sarcolemma of muscle fibers where it contributes to maintain cell integrity during contraction-relaxation cycles; gamma- and delta-SG are also expressed in the sarcoplasmic reticulum (SR). In this study, we report the identification of a novel isoform of murine delta-SG produced by alternative splicing that we named delta-SG3. This isoform is present at transcript level in several tissues, with its highest expression in skeletal and cardiac muscle. The delta-SG3 protein lacks the last 122 amino acids at the C-terminal, which are replaced by 10 new amino acids (EGFLNMQLAG). Interestingly, double immunofluorescence analysis for delta-SG3 and the dihydropyridine receptor (DHPR) shows a close localization of these two proteins. We propose the subcellular distribution of this novel delta-SG3 isoform at the SR and its involvement in intracellular calcium concentration regulation.