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1.
Mitochondrion ; 43: 30-36, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29674166

RESUMO

The present study on the basis of a detailed bioinformatics analysis proposed a potential role of a miRNA, hsa-miR-19b-2-5p, in regulating the mitochondrial biogenesis. The miRNA has shown to be involved in important biological processes of cellular metabolic, cellular macromolecule biosynthetic processes and gene expression pathways. The miRNA, hsa-miR-19b-2-5p, was predicted to regulate the molecular function of nucleic acid, organic/heterocyclic compound, nucleic acid binding transcription factor activity. The pathway enrichment analysis suggested that this miRNA participated in several metabolic pathways which could be a key to the regulation of the mitochondrial gene expression and biogenesis. In addition, this miRNA targets a total of 112 mitochondria-related genes, establishing further the crucial role of the candidate miRNA in mitochondrial biology.


Assuntos
Regulação da Expressão Gênica , MicroRNAs/metabolismo , Biogênese de Organelas , Biologia Computacional , Humanos , Redes e Vias Metabólicas/genética , MicroRNAs/genética
2.
Sci Rep ; 7(1): 1525, 2017 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-28484249

RESUMO

Here we demonstrate localization of the isoform3 of DNA Methyltransferase1 (DNMT1) enzyme to mitochondria, instead of isoform1 as reported earlier. The fused DNMT1-isoform1, reported earlier to localize in mitochondria, surprisingly showed its exclusive presence inside the nucleus after its ectopic expression; and failed to localize in mitochondria. On the other hand, ectopically expressed DNMT1-isoform3 targeted itself to mitochondria and subsequently methylated CpG regions in the mitochondrial genome. In addition, overexpression of DNMT1-isoform3 affected mitochondrial biology and regulated its function. Under different conditions of oxidative and nutritional stress, this isoform was down-regulated, resulting in hypomethylation of mitochondrial genome. Our study reveals how DNMT1-isoform3, instead of isoform1, is responsible for mtDNA methylation, influencing its biology.


Assuntos
DNA (Citosina-5-)-Metiltransferase 1/metabolismo , Metilação de DNA/genética , Genoma Mitocondrial , Núcleo Celular/metabolismo , DNA Mitocondrial/genética , Regulação da Expressão Gênica , Humanos , Isoenzimas/metabolismo , Mitocôndrias/metabolismo , Modelos Biológicos , Fases de Leitura Aberta/genética , Estresse Oxidativo , Frações Subcelulares/metabolismo , Fatores de Tempo
3.
Gene ; 567(2): 217-24, 2015 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-25943634

RESUMO

MicroRNAs the small (18-22 in length) noncoding RNA molecules are negative regulators of gene expression, modulating biological processes of cell differentiation, survival and death. The latter two phenomena are critical in tumour biology. We provide here the results of human genome wide target prediction of one such microRNA, hsa-miR-24-2, shown to target genes essential for initiating cellular stability and cell survival. The protein-protein interaction study showed important nodes which could affect cell cycle progression and differential oncogenesis. An analysis of hsa-miR-24-2 in sporadic breast tumours showed a negative correlation with metastasis and increasing nodes. The conclusion drawn of hsa-miR-24-2 targeting the genes of cell survival correlated with the methylation profile and resultant transcription factor binding site gain or loss in support of absence of cell survival. In order to accentuate the potential of hsa-miR-24-2 to reduce cellular viability under experimental conditions, in vitro studies in the presence and absence of anti-cancer drugs, such as docetaxel resulted in a significant decrease in cellular viability even at a 200-fold reduced dose of the drug in combination with hsa-miR-24-2.


Assuntos
Antineoplásicos/farmacologia , Sobrevivência Celular/genética , MicroRNAs/fisiologia , Taxoides/farmacologia , Apoptose , Sobrevivência Celular/efeitos dos fármacos , Docetaxel , Resistencia a Medicamentos Antineoplásicos , Expressão Gênica , Células Hep G2 , Humanos , Células MCF-7 , Mapas de Interação de Proteínas , Interferência de RNA
4.
PLoS One ; 9(10): e111177, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25353636

RESUMO

Moderately increased DNA damage due to the exogenous miR-101 (4 fold) over-expression in MCF7 cells was substantiated by an increase in the number of γ-H2AX foci, correlating with a simple-to-do Halo-assay. miR-101 induced mild/moderate DNA damage favoured senescence rather than apoptosis. An experimental support emanated from the induced mild/moderate DNA damage with 1 µM/5 µM etoposide in MCF7 cells, which resulted in an endogenous miR-101 over-expression (10/4 fold, respectively), followed by senescence. On the other hand, the severe DNA damage induced with 10 µM etoposide, resulted in a low (<1 fold) endogenous expression of miR-101 and an elevated percentage of apoptotic cells. Using bioinformatics tools along with in-vitro and in-vivo validations, miR-101 was found to target and downregulate the mRNA expression of UBE2N and SMARCA4, involved in DNA damage repair (DDR) pathways. Recovery of the expression of the two novel targets in anti-miR-101 transfection validated the results. We conclude that a threshold range of over-expressed miR-101, capable of inducing mild/moderate DNA damage, is sensed by cells to become senescent. The observation derives further support from in-silico protein-protein network analysis where the two novel targets showed their involvement in senescence pathway.


Assuntos
Apoptose , Senescência Celular , Dano ao DNA , MicroRNAs/genética , DNA Helicases/genética , DNA Helicases/metabolismo , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Células MCF-7 , MicroRNAs/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Enzimas de Conjugação de Ubiquitina/genética , Enzimas de Conjugação de Ubiquitina/metabolismo
5.
J Clin Microbiol ; 49(10): 3537-44, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21813716

RESUMO

Type-specific detection of human papillomavirus (HPV) is indicated for better risk stratification and clinical management of women testing positive for HPV and for epidemiologic surveillance. MassARRAY spectrometry (MassARRAY; Sequenom) is a novel method for type-specific detection of 15 high-risk oncogenic HPV types: HPV-16, -18, -31, -33, -35, -39, -45, -51, -52, -56, -58, -59, -66, -68, and -73. PreTect HPV-Proofer (Proofer; Norchip) is a type-specific assay that detects E6/E7 mRNA from five high-risk oncogenic HPV types: HPV-16, -18, -31, -33, and -45. The performance of these tests for type-specific identification of HPV was assessed with cervical specimens from 192 cases of cervical cancer in comparison with consensus MY09/MY11 PCR followed by nucleotide sequencing (consensus PCR). The overall HPV detection rates were 94.8% (95% confidence interval [CI], 91.7, 97.9), 83.3% (95% CI, 78.1, 88.5), and 86.5% (95% CI, 81.7, 91.3) for MassARRAY, Proofer, and consensus PCR, respectively. All tests were negative in six (3.1%) of the 192 cases. Considering only the specimens that contained at least one of the five types targeted by Proofer, the detection rates were 96.6%, 91.4%, and 86.9% for MassARRAY, Proofer, and consensus PCR, respectively. MassARRAY detected multiple infections in 14.1%, Proofer detected multiple infections in 3.6%, and consensus PCR failed to detect any multiple infections. The agreement was highest at 86.0% (kappa = 0.76) between MassARRAY and Proofer and lowest at 81.8% (kappa = 0.69) between Proofer and consensus PCR. In conclusion, MassARRAY is a highly sensitive and accurate method for type-specific detection of oncogenic HPV in cervical cancer, with Proofer showing impressive performance.


Assuntos
Técnicas de Diagnóstico Molecular/métodos , Papillomaviridae/classificação , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/diagnóstico , Análise Espectral/métodos , Neoplasias do Colo do Útero/virologia , Virologia/métodos , Adulto , Coinfecção/diagnóstico , Coinfecção/virologia , Feminino , Genótipo , Humanos , Pessoa de Meia-Idade , Papillomaviridae/química , Papillomaviridae/genética , Infecções por Papillomavirus/virologia , Sensibilidade e Especificidade
6.
Infect Genet Evol ; 11(6): 1456-61, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21645645

RESUMO

Vitamin D receptor (VDR) plays an important role in activating immune response against various infectious agents. This study was aimed to investigate the association between VDR gene polymorphisms and different clinical forms of pulmonary tuberculosis (TB) in different population groups. Four common polymorphisms (TaqI, ApaI, BsmI and FokI) of VDR gene were studied in clinically diagnosed TB patients and healthy controls from Sahariya tribe (n=377), Bhil tribe (n=95), Chhattisgarh tribe (n=33), general population from North-Central (NC) (n=1021) and South-Eastern (SE) region (n=646) and Muslims (n=217). Genotyping was carried out using PCR-RFLP method and re-confirmed by direct sequencing. The haplotype analysis was performed on Haploview 4.1 and statistical analysis was done using SPSS 13.0 software. We found that bb genotype of BsmI polymorphism conferred significant risk to smear positive and multiple drug resistant (MDR) TB in tribes [OR (CI)=3.7 (1.5-9.2), p=0.002], SE population [OR (CI)=2.1 (1.4-3.3), p=0.0004] and Muslims [OR (CI)=6.7 (1.1-39), p=0.01]. The subjects with FF genotype of FokI polymorphism appeared less likely (p=0.004) to develop MDR TB in NC population, whereas, those with Ff [OR (CI)=2.5 (1.3-5.0), p=0.004] and ff [OR (CI)=3.4 (1.2-9.3), p=0.01] genotypes were at high risk of MDR and smear positive disease, respectively. Similarly, tt genotype of TaqI polymorphism was found associated with high risk of smear positive TB in NC [OR (CI)=3.6 (0.9-14.2), p=0.05] as well as in SE [OR (CI)=4.7 (1.8-12.3), p=0.00003] population. Interestingly, tt genotype appeared strongly associated [OR (CI)=8.9 (2.7-29), p=0.00001] with high bacillary load outcome. In conclusion, genetic polymorphisms in VDR gene, alone or in combination (haplotypes) are associated with different clinical outcomes in pulmonary TB.


Assuntos
Predisposição Genética para Doença , Islamismo , Polimorfismo de Fragmento de Restrição , Receptores de Calcitriol/genética , Classe Social , Tuberculose Pulmonar/genética , Estudos de Associação Genética , Haplótipos , Humanos , Índia , Desequilíbrio de Ligação
7.
Clin Appl Thromb Hemost ; 17(4): 358-61, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20460344

RESUMO

Hemophilia A is a bleeding disorder caused by heterogeneous mutations of the factor VIII gene. A total of 60 unique mutations have been identified in exon 16. The current study was done with the objective of detecting small mutations in exon 16 of factor VIII gene in Indian cases with hemophilia A and to further analyze structural and functional alterations in protein structure. In all, 40 cases with mild and moderate hemophilia A, negative for intron 22 inversion mutations were screened with single-strand conformational polymorphism (SSCP) for point mutations in the exon 16 region. Two cases from unrelated families showed the presence of a missense mutation due to conversion of CGT to CAT at codon 1781 in which arginine was replaced by histidine residues, resulting in deficiency in A3 domain function. Small mutation detection can be achieved using a low-infrastructure SSCP-DNA sequencing protocol in developing countries. Protein modeling predicts structural and functional changes defining causative mutations.


Assuntos
Éxons , Fator VIII/genética , Hemofilia A/genética , Mutação de Sentido Incorreto , Sequência de Bases , Humanos , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples
8.
Indian J Clin Biochem ; 25(1): 57-63, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23105885

RESUMO

The present study was carried out in the Sahariya tribe of Central India, which reportedly have high prevalence of pulmonary tuberculosis. Total serum LDH and its tissue specific isoforms were estimated in TB patients and matched healthy controls to test the utility of LDH as diagnostic marker for tuberculosis. About 210 sputum positive cases and 328 age and sex matched sputum negative controls were recruited. The spectrophotometeric and densitometric analysis of each LDH isoform was carried out in both cases and controls. The mean values of serum LDH were estimated and compared for each class by t-test. The statistical comparisons were made between sputum negative controls and sputum positive cases by Mann-Whitney's U test. The spectrophotometric estimation of serum LDH revealed significant (P=0.0016) increase in its level in cases (290 IU/L) as compared to controls (248 IU/L). The densitometric analysis of individual LDH isoforms in cases and controls demonstrated significant elevation in LDH1 (P>0.05), LDH2 (P>0.05) and LDH3 (P<0.005) in sputum positive cases in comparison to sputum negative controls. Our study revealed a positive correlation between serum LDH level and the presence of mycobacteria and their load, suggesting utility of LDH as an important diagnostic marker of tuberculosis induced stress, at least in tribal areas lacking access to modern clinical tests.

9.
Indian J Urol ; 24(2): 150-4, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19468388

RESUMO

OBJECTIVE: To understand role of mitochondrial (mt) mutations in genes regulating oxidative phosphorylation (OXPHOS) in pathogenesis of male infertility. Infertility affects approximately 15% of couples trying to conceive. Infertility is frequently attributed to defects of sperm motility and number. Mitochondrion and mitochondrial DNA (mtDNA) play an important role in variety of physiological process. They control the oxidative energy supply and thus are central to growth, development and differentiation. Mitochondrial function is controlled by a fine-tuned crosstalk between mtDNA and nuclear DNA (nDNA). As mitochondria supply energy by OXPHOS, any mutation in mtDNA disrupts adenosine triphosphate (ATP) production and thus result in an impaired spermatogenesis and impaired flagellar movement. As sperm midpiece has few mtDNA copies, thus enhanced number of mutant mtDNA results in early phenotypic defect which manifest as spermatogenic arrest or asthenozoospermia. Oxidative stress and mtDNA mutations are positively correlated and mutations in mitochondrial genome (mt genome) are implicated in the lowered fertilising capacity of the sperm and affects the reproductive potential of an individual. MATERIALS AND METHODS: A thorough review of articles in the last 15 years was cited with reference to the below-mentioned keywords. The articles considered discuss the role of mt genome in the normal functioning of sperm and the factors associated with mt mutations and impact of these mutations on the reproductive potential. RESULTS: Sperm motility is a very important factor for the fertilisation of ova. The energy requirements of sperm are therefore very critical for sperm. Mutations in the mitochondrial genes as COX II, ATPase 6 and 8 play an important role and disrupts ATP production affecting the spermatogenesis and sperm motility. Therefore, the aberrations in mt genome are an important etiopatholgy of male infertility. CONCLUSION: In the context of male infertility, mt mutations, generation of reactive oxygen species and lowered antioxidant capacity are interlinked and constitute a unified pathogenic molecular mechanism. In the era of assisted reproduction technique (ART), it is very important to distinguish between mutations in nuclear and mitochondrial genomes in sperm, as mtDNA mutations are better diagnostic and prognostic markers in infertile men opting for ART.

10.
J Comput Aided Mol Des ; 22(9): 647-60, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17710553

RESUMO

Pyruvate phosphate dikinase (PPDK) is the key enzyme essential for the glycolytic pathway in most common and perilous parasite Entamoeba histolytica. Inhibiting the function of this enzyme could control the wide spread of intestinal infections caused by Entamoeba histolytica in humans. With this objective, we modeled the three dimensional structure of the PPDK protein. We used templates with 51% identity and 67% similarity to employ homology-modeling approach. Stereo chemical quality of protein structure was validated by protein structure validation program PROCHECK and VERIFY3D. Experimental proof available in literature along with the in silico studies indicated Lys21, Arg91, Asp323, Glu325 and Gln337 to be the probable active sites in the target protein. Virtual screening was carried out using the genetic docking algorithm GOLD and a consensus scoring function X-Score to substantiate the prediction. The small molecule libraries (ChemDivision database, Diversity dataset, Kinase inhibitor database) were used for screening process. Along with the high scoring results, the interaction studies provided promising ligands for future experimental screening to inhibit the function of PPDK in Entamoeba histolytica. Further, the phylogeny study was carried out to assess the possibility of using the proposed ligands as inhibitors in related pathogens.


Assuntos
Entamoeba histolytica/enzimologia , Inibidores Enzimáticos/química , Modelos Moleculares , Preparações Farmacêuticas/química , Piruvato Ortofosfato Diquinase/química , Piruvatos/química , Algoritmos , Sequência de Aminoácidos , Animais , Sítios de Ligação , Simulação por Computador , Bases de Dados Factuais , Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Modelos Químicos , Conformação Molecular , Dados de Sequência Molecular , Estrutura Molecular , Filogenia , Conformação Proteica , Piruvato Ortofosfato Diquinase/antagonistas & inibidores , Piruvato Ortofosfato Diquinase/metabolismo , Homologia de Sequência de Aminoácidos
11.
Hum Genet ; 122(5): 535-40, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17701054

RESUMO

In the recent past, we have observed a possible role of 10398A and 16189C mtDNA and PGC1alpha p.Thr394Thr (rs2970847) and p.Gly482Ser (rs8192673) variant genotypes providing susceptibility/protection against type 2 diabetes mellitus (T2DM) in two North Indian population groups. These initial observations encouraged us to look at the candidate genes in combination with -866G/A (rs659366) polymorphism in uncoupling protein 2 (UCP2) in a single study of a relatively large sample size, constituted of both the cohorts, to unravel an interesting outcome of an additive interaction in-between the studied genes. In a total of 1,686 individuals (762 cases and 924 controls) belonging to Indo-European linguistic group from North India, a comparison of risk genotype combinations of: UCP2-866GG, mtDNA 10398A and PGC1alpha p.Thr394Thr or p.Gly482Ser against the protective genotypes: UCP2-866XA, mtDNA 10398G and PGC1alpha p.Thr394Thr (nominal P value = 1.75 x 10(-14), Odds ratio, OR = 5.29, 3.40-8.22 at 95% CI) or PGC1alpha p.Gly482Ser (nominal p value = 4.42 x 10(-24), OR = 8.59, 5.53-13.35 at 95% CI), showed a highly significant difference and increased ORs. In a complex disease, it is always encouraging to find an additive interaction of multiple small effects of the studied candidate gene variations.


Assuntos
DNA Mitocondrial/genética , Diabetes Mellitus Tipo 2/genética , Proteínas de Choque Térmico/genética , Canais Iônicos/genética , Proteínas Mitocondriais/genética , Polimorfismo Genético , Fatores de Transcrição/genética , Adulto , Alelos , Substituição de Aminoácidos , Estudos de Casos e Controles , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Polimorfismo de Nucleotídeo Único , Proteína Desacopladora 2
12.
Hum Genet ; 121(5): 609-14, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17390150

RESUMO

The recent observations that Peroxisome proliferator activated receptor gamma coactivator 1 alpha (PGC1A) is responsible for the induction of reactive oxygen species (ROS) detoxifying agents and that ROS triggers insulin resistance, support the role that this gene could play in the onset of Type 2 diabetes mellitus (T2DM). Two PGC1A variants Thr394Thr (rs2970847) and Gly482Ser (rs8192673) were genotyped in 822 subjects (351 T2DM cases and 471 controls) from two North Indian populations, represented as Group 1 (Kashmir population) and Group 2 (Punjab and Jammu population). Both Groups 1 and 2 showed a significant association of Thr394Thr variant with T2DM after applying Bonferroni corrections (P=0.001 and 0.012, respectively). Logistic regression analysis for Thr394Thr susceptible genotypes together (rs2970847 G/A and A/A) conferred a 1.89-(95%CI 1.25-2.85) fold higher risk for T2DM in Group 1 and 1.81-(95%CI 1.19-2.78) fold risk in Group 2. The susceptible, Ser482 (rs8192673 G/A and A/A) genotypes, gave a 2.04 (95%CI 1.47-3.03) fold higher risk for T2DM in Group 1. Mitochondrial genotype backgrounds observed in association with T2DM (Bhat et al. 2007), when studied in combination with PGC1A variants, showed an increased prevalence in controls with mt10398G and 16189T along with G/G genotype background at the two polymorphic loci of PGC1A. These observations suggest that the two genotype backgrounds together could provide protection against T2DM.


Assuntos
Diabetes Mellitus Tipo 2/genética , Proteínas de Choque Térmico/genética , Polimorfismo Genético , Fatores de Transcrição/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Mitocôndrias/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo
13.
Indian J Biochem Biophys ; 44(6): 437-42, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18320842

RESUMO

Assisted reproductive technique (ART) has revolutionized the management of severe male factor infertility and in some countries 5% babies are conceived through ART/intra cytoplasmic sperm injection (ICSI). However, the carry-home live birth rate after several ART cycles is low (18-25%) and this is financially, physically and emotionally crippling for the couples. Genetic factors could lead to pre or post-implantation failure and thus explain for low ART success rate. Thus, this study was planned to understand, if infertile men harbour genetic abnormalities which may be iatrogenically transmitted by ART and adversely affect growth potential of embryo. Ninety infertile men underwent semen, cytogenetic, Yq microdeletion and mitochondrial mutation analysis. Of these, 14.4% cases harboured cytogenetic abnormality, and 8.89% Yq microdeletions. A high frequency of mitochondrial mutations was found in 23 men with asthenospermia. It is important to understand that through ART genetic abnormalities are transmitted to offspring, resulting in impaired growth and development potential of embryo and poor take-home live birth rate. Thus, genetic analysis is strongly recommend in all men with idiopathic infertility who opt for ART to counsel couples and provide them with most adapted therapeutics.


Assuntos
Núcleo Celular/genética , Genoma , Infertilidade Masculina/genética , Mitocôndrias/genética , Técnicas de Reprodução Assistida , Injeções de Esperma Intracitoplásmicas , Adulto , Deleção Cromossômica , Cromossomos Humanos Y/genética , Amplificação de Genes , Humanos , Técnicas In Vitro , Infertilidade Masculina/diagnóstico , Infertilidade Masculina/terapia , Masculino , Mitocôndrias/patologia , Mutação , Sêmen/química
14.
Cancer Lett ; 249(2): 249-55, 2007 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-17081685

RESUMO

Mitochondria are the major source of Reactive Oxygen Species (ROS) and mtDNA G10398A (Ala-->Thr) polymorphism, proposed to be involved in increased ROS production, has been shown in association with invasive breast cancer in African-American (AA) women [J.A. Canter, A.R. Kallianpur, F.F. Parl, R.C. Millikan, Mitochondrial DNA G10398A polymorphism and invasive breast cancer in African-American women, Cancer Res. 65 (2005) 8028-8033] and prostate cancer in AA men [M.P. Mims, T.G. Hayes, S. Zheng, S.M. Leal, A. Frolov, M.M. Ittmann, et al., Mitochondrial DNA G10398A polymorphism and invasive breast cancer in African-American women, Cancer Res. 66 (2006) 1880; author reply 1880-1881]. The role of mitochondria, however, in cancer development has been in question recently [A. Salas, Y.G. Yao, V. Macaulay, A. Vega, A. Carracedo, H.J. Bandelt, A critical reassessment of the role of mitochondria in tumorigenesis, PLoS Med. 2 (2005) e296], which has made it pertinent to analyze the data and test the hypotheses by conducting fresh case-control studies. This study, therefore, makes an attempt to validate the exclusive presence of mtG10398A (Ala-->Thr) polymorphism in a haplotype constituting mtDNA haplogroup N and its sublineages, imparting this group a higher risk for breast cancer, based on the re-analyses of approximately 1000 complete human mtDNA sequences worldwide and collated information on 2334 individuals belonging to 18 regions in India. The conclusion drawn of mt10398A allele providing a risk towards cancer is confirmed in a case-control comparison study of 124 sporadic breast cancer patients and 273 controls; and 55 squamous cell carcinoma of esophagus, ESCC, and 163 controls, matched for age, ethnicity and sex from north India. It is further apparent from the study that such a mtDNA polymorphism background provides a higher risk for the cancers of the tissues which could be affected by environmental insults directly as in the ESCC, observed with a high acquired (somatic) rate of mutation in p53 when compared to the breast cancer, suggesting that the mtDNA variants that arose as energetic adaptations, influence our health differentially under different environment conditions and a given genetic background of the mt genome.


Assuntos
Neoplasias da Mama/genética , DNA Mitocondrial/genética , Neoplasias Esofágicas/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Neoplasias da Mama/epidemiologia , Estudos de Casos e Controles , Neoplasias Esofágicas/epidemiologia , Feminino , Haplótipos , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Polimorfismo Genético
15.
Hum Genet ; 120(6): 821-6, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17066297

RESUMO

The role of mitochondria in causing diseases is becoming evident as more and more studies are focusing on this organelle of the cell. This is largely attributed to its reactive oxygen species (ROS) production property. In the context of diabetes, ROS is suggested to trigger different forms of insulin resistance involving different mechanisms. The suggestive role of a mtDNA variant G10398A in increasing ROS production and the impaired response to oxidative stress due to T16189C variant is worth addressing as genetic susceptibility factors in type 2 diabetes mellitus (T2DM). A case control study on 312 T2DM cases and ethnically matched 466 controls involving two North Indian populations, referred as cohort 1 and cohort 2 (in a replicative study), was undertaken to test such a genetic association. A statistically significant association was observed for 10398A allele in both the cohorts [cohort1 (OR = 2.67 95% CI 1.77-4.00); cohort2 (OR = 1.76 95%CI 1.12-2.77)]. The analysis of G10398A/T16189C haplotypic combinations revealed that 10398A/16189C haplotype provides a risk in both the cohorts. To sum up the study suggests that 10398A and 16189C alleles provide susceptiblity to T2DM independently as well as together.


Assuntos
DNA Mitocondrial/genética , Diabetes Mellitus Tipo 2/genética , Variação Genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Frequência do Gene , Predisposição Genética para Doença , Haplótipos , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Fatores de Risco
16.
Can J Physiol Pharmacol ; 84(6): 647-54, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16900249

RESUMO

Plasma glucose levels are maintained by a precise balance between glucose production and its use. Liver pyruvate kinase (PK) and phosphoenolpyruvate carboxykinase (PEPCK), 2 key enzymes of glycolysis and gluconeogenesis, respectively, play a crucial role in this glucose homeostasis along with skeletal muscle glucose transporter (GLUT4). In the diabetic state, this balance is disturbed owing to the absence of insulin, the principal factor controlling this regulation. In the present study, alloxan-diabetic animals having high glucose levels of more than 300 mmol/L have been taken and the administration of Trigonella seed powder (TSP) to the diabetic animals was assessed for its effect on the expression of PK and PEPCK in liver and GLUT4 distribution in skeletal muscle of alloxan-diabetic rats. TSP treatment to the diabetic animals resulted in a marked decrease in the plasma glucose levels. Trigonella treatment partially restored the altered expression of PK and PEPCK. TSP treatment also corrected the alterations in the distribution of GLUT4 in the skeletal muscle.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Piruvato Quinase/metabolismo , Trigonella , Animais , Glicemia/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/tratamento farmacológico , Feminino , Fígado/efeitos dos fármacos , Fígado/enzimologia , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Pós/farmacologia , Ratos , Ratos Wistar , Sementes/química , Distribuição Tecidual , Resultado do Tratamento , Trigonella/química
17.
Life Sci ; 78(8): 820-4, 2006 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-16289562

RESUMO

Oral administration of vanadate is an effective treatment for diabetes in animal models. However, vanadate exerts these effects at high doses and several toxic effects are produced. Low doses of vanadate are relatively safe but are unable to elicit any antidiabetic effect. The present study explored the prospect of using low doses of vanadate in combination with Trigonella seed powder (TSP) to evaluate their antidiabetic effect in alloxan-diabetic rats. Alloxan-diabetic rats were treated with insulin, vanadate, TSP and vanadate and TSP in combination for 3 weeks. The effect of these antidiabetic compounds was examined on general physiological parameters and distribution of glucose transporter (GLUT4) in skeletal muscle by immunoblotting and immunohistochemistry. Treatment of alloxan-diabetic rats with insulin, vanadate, TSP and vanadate in combination with TSP revived normoglycemia and restored the disturbances in the distribution of GLUT4 in skeletal muscle. TSP treatment was only partially effective in the restoration of diabetic alterations. The treatment of diabetic rats with combined doses of vanadate and TSP was most effective in the normalization of plasma glucose levels and correction of altered GLUT4 distribution.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Transportador de Glucose Tipo 4/metabolismo , Hipoglicemiantes/uso terapêutico , Trigonella/química , Vanadatos/uso terapêutico , Aloxano , Animais , Glicemia , Fracionamento Celular , Diabetes Mellitus Experimental/metabolismo , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Hipoglicemiantes/farmacocinética , Insulina/farmacologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Extratos Vegetais/farmacocinética , Extratos Vegetais/uso terapêutico , Ratos , Ratos Wistar , Vanadatos/farmacocinética
18.
Hum Genet ; 118(2): 295-300, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16163478

RESUMO

The minor haplotype -3575A/-2849G/-2763C in IL-10 promoter has been defined as a marker of disease resistance to leprosy and its severity in Brazilian population. Our investigation of six single-nucleotide polymorphisms (SNPs) in IL-10 promoter in 282 Indian leprosy patients and 266 healthy controls by direct PCR sequencing, however, showed that the extended haplotype: -3575T/-2849G/-2763C/-1082A/-819C/-592C was associated with resistance to leprosy per se and to the development of severe form of leprosy, using either a binomial (controls vs cases, P=0.01, OR=0.58, CI=0.37-0.89) or ordinal (controls vs paucibacillary vs multibacillary, P=0.004) model. Whereas, IL-10 haplotype -3575T/-2849G/-2763C/-1082A/-819T/-592A was associated with the risk of development of severe form of leprosy (P=0.0002) in contrast to the minor risk haplotype -3575T/-2849A/-2763C in the Brazilian population. The role of IL-10 promoter SNPs in Brazilian and Indian population strongly suggests the involvement of IL-10 locus in the outcome of leprosy.


Assuntos
Imunidade Inata/genética , Interleucina-10/genética , Hanseníase/genética , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas/genética , Brasil , Estudos de Casos e Controles , Análise Mutacional de DNA , Feminino , Marcadores Genéticos , Humanos , Imunidade Inata/imunologia , Indígenas Sul-Americanos , Hanseníase/imunologia , Masculino , Reação em Cadeia da Polimerase , Locos de Características Quantitativas/genética
19.
Int J Cancer ; 116(1): 62-8, 2005 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-15761872

RESUMO

Esophageal squamous cell carcinoma (ESCC) has been reported to show geographical variation in its incidence, even within areas of ethnic homogeneity. Kashmir valley, in north of India, has been described as a high-risk area for ESCC. Here, we make a preliminary attempt to study mutations in exons 5-8 (the DNA binding domain) of the tumor suppressor gene, p53, in 55 ESCC patients from Kashmir. Polymerase chain reaction followed by direct sequencing analysis revealed the presence of mutations in 36.36% (20/55) tumors, assessed for the extent of allelic instability. The 20 mutations, found in 20 patients, comprised of 17 single-base substitutions (11 transitions + 6 transversions) and 3 deletions. The 17 single-base variations represented 12 missense mutations, 2 nonsense mutations and 3 variations located in intron 6, 1 of which resulted in a splicing variant. The patients when compared for the incidence of p53 mutation with various demographic features revealed females to be at increased risk (p = 0.016; OR = 4.13; 95% CI = 1.26-13.46). Comparison of mutation profile with other high-risk areas reflected both differences and similarities indicating coexposure to a unique set of risk factors. This might be due to the special dietary and cultural practices of Kashmir that needs validation, as does the gender-based difference in the incidence of p53 mutation observed in this study.


Assuntos
Carcinoma de Células Escamosas/genética , Neoplasias Esofágicas/genética , Genes p53 , Mutação , Adulto , Idoso , Carcinoma de Células Escamosas/epidemiologia , Neoplasias Esofágicas/epidemiologia , Feminino , Humanos , Índia/epidemiologia , Perda de Heterozigosidade , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Fatores de Risco , Fatores Sexuais
20.
Clin Chim Acta ; 342(1-2): 105-14, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15026271

RESUMO

BACKGROUND: Vanadate treatment to diabetic rats has been reported to correct the altered carbohydrate metabolism and antioxidant status. However, vanadate exerts these effects at relatively high doses and several toxic effects are produced. We used low doses of vanadate in combination with Trigonella foenum graecum seed powder (TSP) and evaluated their effect on the enzyme changes in diabetic rats. METHODS: Alloxan-diabetic rats were treated separately with insulin, vanadate (0.6 mg/ml), TSP and a combined dose of Vanadate (0.2 mg/ml) and TSP for 21 days. At the end of the experimental period, blood glucose levels and activities of pyruvate kinase (PK), phosphoenolpyruvate carboxykinase (PEPCK), glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD) and catalase (CAT) were measured in cytosolic fraction in the liver and kidney. RESULTS: Blood glucose levels increased markedly in diabetic rats. Treatment with antidiabetic compounds resulted in the reduction of glucose levels. Rats treated with combined dose of vanadate and trigonella had glucose levels comparable to control ones. Similar results were obtained with the activities of PK, PEPCK, SOD, GPx, GR, and CAT in liver and kidney of diabetic rats. Combined dose of vanadate and Trigonella was found to be most effective in correcting these alterations. CONCLUSIONS: Lower doses of vanadate could be used in combination with TSP to effectively counter diabetic alterations without any toxic side effects.


Assuntos
Antioxidantes/metabolismo , Glicemia/efeitos dos fármacos , Diabetes Mellitus Experimental/metabolismo , Hipoglicemiantes/farmacologia , Preparações de Plantas/uso terapêutico , Trigonella/química , Vanadatos/farmacologia , Animais , Diabetes Mellitus Experimental/tratamento farmacológico , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Hipoglicemiantes/administração & dosagem , Rim/efeitos dos fármacos , Rim/enzimologia , Rim/metabolismo , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/metabolismo , Fitoterapia , Ratos , Ratos Wistar , Vanadatos/administração & dosagem
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