Human Genetics And Molecular Medicine - Research Publications

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PPARG and ADIPOQ gene polymorphisms increase type 2 diabetes mellitus risk in Asian Indian Sikhs: Pro12Ala still remains as the strongest predictor
(2010) Sanghera, D.K.; Demirci, F.Y.; Been, L.; Ortega, L.; Ralhan, S.; Wander, G.S.; Mehra, N.K.; Singh, J.; Aston, C.E.; Mulvihill, J.J.; Kamboh, I.M.
We have examined the association of 14 tagging single nucleotide polymorphisms (tagSNPs) in peroxisome proliferator activated receptor-? transcripts 1 and 2 (PPARG1 and 2) and 5 tagSNPs in adiponectin (ADIPOQ) genes for their effect on type 2 diabetes mellitus (T2D) risk in Asian Indian Sikhs. A total of 554 T2D cases and 527 normoglycemic controls were examined for association with T2D and other subphenotypes of T2D. With the exception of a strong association of PPARG2/Pro12Ala with T2D (odds ratio, 0.13; 95% confidence interval, 0.03-0.56; P = .0007), no other tagSNP in the PPARG locus revealed any significant association with T2D in this population. Similarly, none of the tagSNPs in the ADIPOQ gene was associated with T2D susceptibility in single-site analysis. However, haplotype analysis provided strong evidence of association of these loci with T2D. Three-site haplotype analysis in the PPARG locus using the 2 marginally associated SNPs (P/rs11715073 and P/rs3892175) in combination with Pro12 Ala (P/rs1801282) revealed a strong association of 1 "risk" (CGC) (P = .003, permutation P = .015) and 1 "protective" (CAC) (P = .001, permutation P = .005) haplotype associated with T2D. However, the major effect still appears to be driven by Pro12Ala, as the association of these haplotypes did not remain significant when analyzed conditional upon Pro12Ala (P = .262). In addition, 2-site haplotype analysis in the ADIPOQ locus using only 2 marginally associated SNPs (AD/rs182052 and AD/rs7649121) revealed a significant protective association of the GA haplotype with T2D (P = .009, permutation P = .026). Multiple linear regression analysis also revealed significant association of an ADIPOQ variant (AD/rs12495941) with total body weight (P = .010), waist (P = .024), and hip (P = .021), although these associations were not significant after adjusting for multiple testing. Our new findings strongly suggest that the genetic variation in PPARG and ADIPOQ loci could contribute to the risk for the development of T2D in Indian Sikhs. Identification of causal SNPs in these important biological and positional candidate genes would help determine the true physiologic significance of these loci in T2D and obesity. ? 2010 Elsevier Inc. All rights reserved.
Directory of human genetic services in India - 2007
(2010) Singh, J.R.; Singh, A.R.; Singh, A.R.
[No abstract available]
Variants in KCNQ1 increase type II diabetes susceptibility in South Asians: A study of 3,310 subjects from India and the US
(2011) Been, L.F.; Ralhan, S.; Wander, G.S.; Mehra, N.K.; Singh, J.; Mulvihill, J.J.; Aston, C.E.; Sanghera, D.K.
Background: Polymorphisms in intron 15 of potassium voltage-gated channel, KQT-like subfamily member 1 (KCNQ1) gene have been associated with type II diabetes (T2D) in Japanese genome-wide association studies (GWAS). More recently a meta-analysis of European GWAS has detected a new independent signal associated with T2D in intron 11 of the KCNQ1 gene. The purpose of this investigation is to examine the role of these variants with T2D in populations of Asian Indian descent from India and the US.Methods: We examined the association between four variants in the KCNQ1 gene with T2D and related quantitative traits in a total of 3,310 Asian Indian participants from two different cohorts comprising 2,431 individuals of the Punjabi case-control cohort from the Sikh Diabetes Study and 879 migrant Asian Indians living in the US.Results: Our data confirmed the association of a new signal at the KCNQ1 locus (rs231362) with T2D showing an allelic odds ratio (OR) of 1.24 95%CI [1.08-1.43], p = 0.002 in the Punjabi cohort. A moderate association with T2D was also seen for rs2237895 in the Punjabi (OR 1.14; p = 0.036) and combined cohorts (meta-analysis OR 1.14; p = 0.018). Three-site haplotype analysis of rs231362, rs2237892, rs2237895 exhibited considerably stronger evidence of association of the GCC haplotype with T2D showing OR of 1.24 95%CI [1.00-1.53], p = 0.001, permutation p = 8 ? 10-4in combined cohorts. The 'C' risk allele carriers of rs2237895 had significantly reduced measures of HOMA-B in the US cohort (p = 0.008) as well as in combined cohort in meta-analysis (p = 0.009).Conclusions: Our investigation has confirmed that the variation within the KCNQ1 locus confers a significant risk to T2D among Asian Indians. Haplotype analysis further suggested that the T2D risk associated with KCNQ1 SNPs may be derived from 'G' allele of rs231362 and 'C' allele of rs2237895 and this appears to be mediated through ? cell function. ? 2011 Been et al; licensee BioMed Central Ltd.
Ring chromosome 22: A review of the literature and first report from India
(2012) Mahajan, S.; Kaur, A.; Singh, Jai Roop
Ring chromosome 22 [r(22)], a rare cytogenetic finding, has been described in nearly 70 cases to date. Cytogenetic investigations were carried out on a 5-year-old male child with microcephaly and intellectual disability. Cytogenetic investigations revealed his karyotype to be 46, XY, r(22). To the best of our knowledge, this is the first report of an r(22) anomaly from India.
A low frequency variant within the GWAS locus of MTNR1B affects fasting glucose concentrations: Genetic risk is modulated by obesity
(2012) Been, L.F.; Hatfield, J.L.; Shankar, A.; Aston, C.E.; Ralhan, S.; Wander, G.S.; Mehra, N.K.; Singh, J.R.; Mulvihill, J.J.; Sanghera, D.K.
Two common variants (rs1387153, rs10830963) in MTNR1B have been reported to have independent effects on fasting blood glucose (FBG) levels with increased risk to type 2 diabetes (T2D) in recent genome-wide association studies (GWAS). In this investigation, we report the association of these two variants, and an additional variant (rs1374645) within the GWAS locus of MTNR1B with FBG, 2h glucose, insulin resistance (HOMA IR), ?-cell function (HOMA B), and T2D in our sample of Asian Sikhs from India. Our cohort comprised 2222 subjects [1201 T2D, 1021 controls]. None of these SNPs was associated with T2D in this cohort. Our data also could not confirm association of rs1387153 and rs10830963 with FBG phenotype. However, upon stratifying data according to body mass index (BMI) (low ? 25 kg/m2 and high > 25 kg/m2) in normoglycemic subjects (n = 1021), the rs1374645 revealed a strong association with low FBG levels in low BMI group (? = -0.073, p = 0.002, Bonferroni p = 0.01) compared to the high BMI group (? = 0.015, p = 0.50). We also detected a strong evidence of interaction between rs1374645 and BMI with respect to FBG levels (p = 0.002). Our data provide new information about the significant impact of another MTNR1B variant on FBG levels that appears to be modulated by BMI. Future confirmation on independent datasets and functional studies will be required to define the role of this variant in fasting glucose variation. ? 2011.
A novel 7 bp deletion in PRPF31 associated with autosomal dominant retinitis pigmentosa with incomplete penetrance in an Indian family
(2012) Saini, S.; Robinson, P.N.; Singh, J.R.; Vanita, V.
To localize and identify the gene linked with non-syndromic autosomal dominant retinitis pigmentosa (adRP) with high but not complete penetrance in an Indian family. A detailed family history and clinical data were recorded. A genome-wide scan by 2-point linkage analysis using nearly 400 fluorescently labeled microsatellite markers in combination with multipoint lod score and haplotype analysis was carried out. Mutation screening was performed in the candidate gene by bidirectional sequence analysis of the amplified products. A maximum 2-point lod score of 3.553 at theta = 0.0 was obtained with marker D19S572. Haplotype analysis placed the RP locus distal to marker D19S572, in close proximity to the gene for pre-mRNA processing factor 31 (PRPF31) at 19q13.42. Mutation screening in all 14 exonic regions and adjacent flanking intronic sequences of PRPF31 revealed a novel 7 bp deletion, c.59_65del7 (p.Gly20AlafsX43), in the first coding exon of PRPF31. This leads to a premature termination codon (PTC) in the next exon, 43 amino acids downstream. The observed 7 bp deletion in PRPF31 was identified in all the tested 10 affected members and in an unaffected individual, consistent with a high, but not the complete penetrance of c.59_65del7 (p.Gly20AlafsX43). This deletion was not observed in other tested six unaffected family members or in 100 ethnically matched control subjects. The present study describes mapping of a locus for non-syndromic adRP at 19q13.42 (RP11 locus) in a family of Indian origin and identifies a novel deletion, c.59_65del7, in PRPF31 within the mapped interval. Since the mutant PRPF31 is truncated relatively close to the N-terminus of the protein, haploinsufficiency rather than aberrant protein formation is likely to be the underlying mechanism of the disease. The present findings further substantiate the role of PRPF31 that encodes a component of the spliceosome complex in relation to ADRP. ? 2012 Elsevier Ltd.
Regulation of GAD65 expression by SMAR1 and p53 upon Streptozotocin treatment
(2012) Singh, Sandeep; Raina, Varsheish; Chavali, Pavithra Lakshminarsimhan; Dubash, Taronish; Kadreppa, Sreenath; Parab, Pradeep; Chattopadhyay, Samit
Background: GAD65 (Glutamic acid decarboxylase 65 KDa isoform) is one of the most important auto-antigens involved in Type 1 diabetes induction. Although it serves as one of the first injury markers of ?-islets, the mechanisms governing GAD65 expression remain poorly understood. Since the regulation of GAD65 is crucial for the proper functioning of insulin secreting cells, we investigated the stress induced regulation of GAD65 transcription.Results: The present study shows that SMAR1 regulates GAD65 expression at the transcription level. Using a novel protein-DNA pull-down assay, we show that SMAR1 binding is very specific to GAD65 promoter but not to the other isoform, GAD67. We show that Streptozotocin (STZ) mediated DNA damage leads to upregulation of SMAR1 and p53 expression, resulting in elevated levels of GAD65, in both cell lines as well as mouse ?-islets. SMAR1 and p53 act synergistically to up-regulate GAD65 expression upon STZ treatment.Conclusion: We propose a novel mechanism of GAD65 regulation by synergistic activities of SMAR1 and p53. ? 2012 Singh et al.; licensee BioMed Central Ltd.
Immunomodulatory and antibacterial effects of cystatin 9 against Francisella tularensis
(2013) Eaves-Pyles, Tonyia; Patel, Jignesh; Arigi, Emma; Cong, Yingzi; Cao, Anthony; Garg, Nisha; Dhiman, Monisha; Pyles, Richard B.; Arulanandam, Bernard; Miller, Aaron L.; Popov, Vsevolod L.; Soong, Lynn; Carlsen, Eric D.; Coletta, Ciro; Szabo, Csaba; Almeida, Igor C.
Cystatin 9 (CST9) is a member of the type 2 cysteine protease inhibitor family, which has been shown to have immunomodulatory effects that restrain inflammation, but its functions against bacterial infections are unknown. Here, we report that purified human recombinant (r)CST9 protects against the deadly bacterium Francisella tularensis (Ft) in vitro and in vivo. Macrophages infected with the Ft human pathogen Schu 4 (S4), then given 50 pg of rCST9 exhibited significantly decreased intracellular bacterial replication and increased killing via preventing the escape of S4 from the phagosome. Further, rCST9 induced autophagy in macrophages via the regulation of the mammalian target of rapamycin (mTOR) signaling pathways. rCST9 promoted the upregulation of macrophage proteins involved in antiinflammation and antiapoptosis, while restraining proinflammatory-associated proteins. Interestingly, the viability and virulence of S4 also was decreased directly by rCST9. In a mouse model of Ft inhalation, rCST9 significantly decreased organ bacterial burden and improved survival, which was not accompanied by excessive cytokine secretion or subsequent immune cell migration. The current report is the first to show the immunomodulatory and antimicrobial functions of rCST9 against Ft. We hypothesize that the attenuation of inflammation by rCST9 may be exploited for therapeutic purposes during infection.
Genome-wide association study identifies a novel locus contributing to type 2 diabetes susceptibility in Sikhs of Punjabi origin from India
(American Diabetes Association Inc., 2013) Saxena, R.; Saleheen, D.; Been, L.F.; Garavito, M.L.; Braun, T.; Bjonnes, A.; Young, R.; Ho, W.K.; Rasheed, A.; Frossard, P.; Sim, X.; Hassanali, N.; Radha, V.; Chidambaram, M.; Liju, S.; Rees, S.D.; Ng, D.P.-K.; Wong, T.-Y.; Yamauchi, T.; Hara, K.; Tanaka, Y.; Hirose, H.; McCarthy, M.I.; Morris, A.P.; Basit, A.; Barnett, A.H.; Katulanda, P.; Matthews, D.; Mohan, V.; Wander, G.S.; Singh, J.R.; Mehra, N.K.; Ralhan, S.; Kamboh, M.I.; Mulvihill, J.J.; Maegawa, H.; Tobe, K.; Maeda, S.; Cho, Y.S.; Ta
We performed a genome-wide association study (GWAS) and a multistage meta-analysis of type 2 diabetes (T2D) in Punjabi Sikhs from India. Our discovery GWAS in 1,616 individuals (842 case subjects) was followed by in silico replication of the top 513 independent single nucleotide polymorphisms (SNPs) (P < 10-3) in Punjabi Sikhs (n = 2,819; 801 case subjects). We further replicated 66 SNPs (P < 10-4) through genotyping in a Punjabi Sikh sample (n = 2,894; 1,711 case subjects). On combined meta-analysis in Sikh populations (n = 7,329; 3,354 case subjects), we identified a novel locus in association with T2D at 13q12 represented by a directly genotyped intronic SNP (rs9552911, P = 1.82 ? 10-8) in the SGCG gene. Next, we undertook in silico replication (stage 2b) of the top 513 signals (P < 10-3) in 29,157 non-Sikh South Asians (10,971 case subjects) and de novo genotyping of up to 31 top signals (P < 10-4) in 10,817 South Asians (5,157 case subjects) (stage 3b). In combined South Asian meta-analysis, we observed six suggestive associations (P < 10-5 to < 10-7), including SNPs at HMG1L1/CTCFL, PLXNA4, SCAP, and chr5p11. Further evaluation of 31 top SNPs in 33,707 East Asians (16,746 case subjects) (stage 3c) and 47,117 Europeans (8,130 case subjects) (stage 3d), and joint meta-analysis of 128,127 individuals (44,358 case subjects) from 27 multiethnic studies, did not reveal any additional loci nor was there any evidence of replication for the new variant. Our findings provide new evidence on the presence of a population-specific signal in relation to T2D, which may provide additional insights into T2D pathogenesis. ? 2013 by the American Diabetes Association.
Innate Immune Responses and Antioxidant/Oxidant Imbalance Are Major Determinants of Human Chagas Disease
(Public Library of Science, 2013) Dhiman, Monisha; Coronado, Yun A.; Vallejo, Cecillia K.; Peterson, John R.; Ejilemele, Adetoun; Nunez, Sonia; Zago, Maria Paola; Spratt, Hiedi; Garg, Nisha Jain
Background:We investigated the pathological and diagnostic role of selected markers of inflammation, oxidant/antioxidant status, and cellular injury in human Chagas disease.Methods:Seropositive/chagasic subjects characterized as clinically-symptomatic or clinically-asymptomatic (n = 116), seronegative/cardiac subjects (n = 102), and seronegative/healthy subjects (n = 45) were analyzed for peripheral blood biomarkers.Results:Seropositive/chagasic subjects exhibited an increase in sera or plasma levels of myeloperoxidase (MPO, 2.8-fold), advanced oxidation protein products (AOPP, 56%), nitrite (5.7-fold), lipid peroxides (LPO, 12-17-fold) and malondialdehyde (MDA, 4-6-fold); and a decline in superoxide dismutase (SOD, 52%) and glutathione (GSH, 75%) contents. Correlation analysis identified a significant (p<0.001) linear relationship between inflammatory markers (AOPP/nitrite: r = 0.877), inflammation and antioxidant/oxidant status (AOPP/glutathione peroxidase (GPX): r = 0.902, AOPP/GSH: r = 0.806, Nitrite/GPX: 0.773, Nitrite/LPO: 0.805, MDA/MPO: 0.718), and antioxidant/oxidant levels (GPX/MDA: r = 0.768) in chagasic subjects. Of these, MPO, LPO and nitrite biomarkers were highly specific and sensitive for distinguishing seropositive/chagasic subjects from seronegative/healthy controls (p<0.001, training and fitting AUC/ROC >0.95). The MPO (r = 0.664) and LPO (r = 0.841) levels were also correlated with clinical disease state in chagasic subjects (p<0.001). Seronegative/cardiac subjects exhibited up to 77% decline in SOD, 3-5-fold increase in LPO and glutamate pyruvate transaminase (GPT) levels, and statistically insignificant change in MPO, AOPP, MDA, GPX, GSH, and creatine kinase (CK) levels.Conclusions:The interlinked effects of innate immune responses and antioxidant/oxidant imbalance are major determinants of human Chagas disease. The MPO, LPO and nitrite are excellent biomarkers for diagnosing seropositive/chagasic subjects, and MPO and LPO levels have potential utility in identifying clinical severity of Chagas disease. ? 2013 Dhiman et al.
MnSOD tg Mice Control Myocardial Inflammatory and Oxidative Stress and Remodeling Responses Elicited in Chronic Chagas Disease
(American Heart Association, 2013)
Background We utilized genetically modified mice equipped with a variable capacity to scavenge mitochondrial and cellular reactive oxygen species to investigate the pathological significance of oxidative stress in Chagas disease. Methods and Results C57BL/6 mice (wild type, MnSODtg, MnSOD+/−, GPx1−/−) were infected with Trypanosoma cruzi and harvested during the chronic disease phase. Chronically infected mice exhibited a substantial increase in plasma levels of inflammatory markers (nitric oxide, myeloperoxidase), lactate dehydrogenase, and myocardial levels of inflammatory infiltrate and oxidative adducts (malondialdehyde, carbonyls, 3‐nitrotyrosine) in the order of wild type=MnSOD+/−>GPx1−/−>MnSODtg. Myocardial mitochondrial damage was pronounced and associated with a >50% decline in mitochondrial DNA content in chronically infected wild‐type and GPx1−/− mice. Imaging of intact heart for cardiomyocytes and collagen by the nonlinear optical microscopy techniques of multiphoton fluorescence/second harmonic generation showed a significant increase in collagen (>10‐fold) in chronically infected wild‐type mice, whereas GPx1−/− mice exhibited a basal increase in collagen that did not change during the chronic phase. Chronically infected MnSODtg mice exhibited a marginal decline in mitochondrial DNA content and no changes in collagen signal in the myocardium. P47phox−/− mice lacking phagocyte‐generated reactive oxygen species sustained a low level of myocardial oxidative stress and mitochondrial DNA damage in response to Trypanosoma cruzi infection. Yet chronically infected p47phox−/− mice exhibited increase in myocardial inflammatory and remodeling responses, similar to that noted in chronically infected wild‐type mice. Conclusions Inhibition of oxidative burst of phagocytes was not sufficient to prevent pathological cardiac remodeling in Chagas disease. Instead, enhancing the mitochondrial reactive oxygen species scavenging capacity was beneficial in controlling the inflammatory and oxidative pathology and the cardiac remodeling responses that are hallmarks of chronic Chagas disease.
Association of GABRA6 1519 T>C (rs3219151) and Synapsin II (rs37733634) gene polymorphisms with the development of idiopathic generalized epilepsy
(Elsevier, 2014) Prasad, D.K.V.; Shaheen, U.; Satyanarayana, U.; Prabha, T.S.; Jyothy, A.; Munshi, A.
The idiopathic generalized epilepsy (IGE) is a neurological disorder which accounts for approximately 30% of all epilepsy cases. Patients identified with IGE syndromes have pharmacoresponsive epilepsies without abnormal neurological symptoms, structural brain lesions and are of unknown origin. A genetic etiology to IGEs has been proposed. Gamma amino butyric acid (GABA), a major inhibitory neurotransmitter acts by binding to transmembrane GABAA and GABAB receptors of both pre- and postsynaptic neurons. Synapsin II (SynII), a neuron specific phosphoprotein plays a major role in synaptogenesis and neurotransmitter release. The present study was carried out with an aim to evaluate the association of GABRA6 (rs3219151) T>C and Syn II (rs37733634) A>G gene polymorphisms with IGE. Molecular analysis revealed that the frequency of 'CC' genotype and 'C'allele of GABRA6 (rs3219151) T>C gene polymorphism was significantly higher in IGE patients compared to healthy controls [CC vs. TT, ?2=26; p<0.001; Odds ratio=3.6 (95% CI; 2.1-5.9); C vs T, ?2=24.7; p<0.001; Odds ratio=1.78 (95% CI; 1.4-2.2)]. The frequency of 'GG' genotype and 'G' allele of the intronic polymorphism A>G in Syn II gene was also found to be significantly associated with the disease when compared to controls [GG vs AA, ?2=64.52; p<0.001; Odds ratio=7.37 (95% CI; 4.4-12.3); G vs. A, ?2=65.78; p<0.001; Odds ratio=2.57 (95% CI; 2.0-3.2)]. The generalized multifactor dimensionality reduction method was employed to detect gene-gene interactions. The gene-gene interaction at two loci involving GABRA6 and Syn II revealed a significant association [?2=36.6, p<0.001, Odds ratio=3.17 (95% CI; 2.2-4.6)] with IGE. Therefore, the present study clearly indicates that both GABRA6 (rs3219151) T>C and Syn II (rs37733634) A>G polymorphisms are important risk factors for the development of IGE in the South Indian population from Andhra Pradesh. The gene-gene interaction studies demonstrated significant interactive effects of these two loci in the development of the disease. ? 2014 Elsevier B.V.
Apolipoprotein C3 gene polymorphisms in Southern Indian patients with nonalcoholic fatty liver disease
(Springer, 2014) Munshi, Anjana
Aim Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in the world today. A previous study has suggested an association of apolipoprotein C3 (APOC3) gene variants with the risk of NAFLD in Asian Indian men living in the Western regions. The present study was carried out with an aim to evaluate the association of demographic features, serum lipid profile and APOC3 gene variants (C-482T and T-455C) NAFLD. Methods One hundred and fifty NAFLD patients and 150 age and gender-matched controls were included in the study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed to detect the genotypes of APOC3. Serum lipid profile was analyzed. Results In the present study, body mass index was not a predictive demographic marker for NAFLD. Serum triglycerides were higher in patients (mean 155.95 ± 59.0) with NAFLD compared to the control group (mean 133.75 ± 44.71) (p = 0.016). APOC3 gene polymorphism T-455C (rs2854116) was significantly associated with NAFLD (p = 0.001). However, we did not find a significant association of C-482T polymorphism (rs2854117) of APOC3 gene with NAFLD. Genotype -455C/C of the SNP, rs2854116 associated significantly with the elevated serum triglycerides in patients. Conclusions The polymorphism T-455C in APOC3 gene and elevated serum triglycerides were associated with NAFLD.
Toca-1 is suppressed by p53 to limit breast cancer cell invasion and tumor metastasis
(BioMed Central Ltd., 2014) Chander, Harish; Brien, Colin D; Truesdell, Peter; Kathleen, Watt; Meens, Jalna; Schick, Colleen; Germain, Doris; Craig, Andrew WB
Introduction: Transducer of Cdc42-dependent actin assembly-1 (Toca-1) recruits actin regulatory proteins to invadopodia, and promotes breast tumor metastasis. Since metastatic breast tumors frequently harbor mutations in the tumor suppressor p53, we tested whether p53 regulates Toca-1 expression. Methods: Normal mammary epithelial cells (HBL-100, MCF10A) and breast cancer cell lines expressing wild-type (WT) p53 (DU4475, MTLn3) were treated with camptothecin or Nutlin-3 to stabilize p53 to test effects on Toca-1 mRNA and protein levels. Chromatin immunoprecipitation (ChIP) assays were performed to identify p53 binding site in Toca-1 gene. Stable silencing of p53 and Toca-1 were performed in MTLn3 cells to test effects on invadopodia and cell invasion in vitro, and tumor metastasis in vivo. Results: We observed that breast cancer cell lines with mutant p53 have high levels of Toca-1 compared to those with WT p53. Stabilization of WT p53 led to further reduction in Toca-1 mRNA and protein levels in normal breast epithelial cells and breast cancer cells. ChIP assays revealed p53 binding within intron 2 of toca1, and reduced histone acetylation within its promoter region upon p53 upregulation or activation. Stable silencing of WT p53 in MTLn3 cells led to increased extracellular matrix degradation and cell invasion compared to control cells. Interestingly, the combined silencing of p53 and Toca-1 led to a partial rescue of these effects of p53 silencing in vitro and reduced lung metastases in mice. In human breast tumors, Toca-1 levels were high in subtypes with frequent p53 mutations, and high Toca-1 transcript levels correlated with increased risk of relapse. Conclusions: Based on these findings, we conclude that loss of p53 tumor suppressor function in breast cancers leads to upregulation of Toca-1, and results in enhanced risk of developing metastatic disease. ? Chander et al.
Association of Serum Trace Elements and Minerals with Genetic Generalized Epilepsy and Idiopathic Intractable Epilepsy
(Springer New York LLC, 2014) Prasad, D.K.V.; Shaheen,Uzma; Satyanarayana,U.; Prabha, T. Surya; Jyothy, Akka|Munshi, Anjana; Prasad, D.K.V.; Shaheen, U.; Satyanarayana, U.; Surya Prabha, T.; Jyothy, A.; Munshi, Anjana
Certain minerals and trace elements are essential for the development of healthy nervous system. Altered serum levels of these elements may lead to the development of various diseases including epilepsy. The present study was designed to evaluate the association of serum calcium, magnesium, zinc and copper in the development of genetic generalized epilepsy [GGE; erstwhile known as idiopathic generalized epilepsy (IGE)] as well as idiopathic intractable epilepsy (IIE), in which seizures persist despite treatment with at least two or three antiepileptic drugs tolerated at reasonable dosage. 200 GGE patients and equal number of healthy controls were recruited for study with their written informed consent. The patients were further divided into responders and non-responders based on their response to antiepileptic drugs. Copper and zinc levels were assayed by atomic absorption spectrophotometer whereas calcium and magnesium were analyzed by Human Star 600 fully automated biochemistry analyzer. The patients with GGE had significant low levels of calcium, magnesium and zinc (1.85???0.33, 0.69???0.13?mmol/L and 11.33???3.32??mol/L respectively) and the corresponding values for controls were 2.27???0.22, 0.89???0.15, 12.71???3.24 (p?
E-selectin gene (S128R) polymorphism in hemorrhagic stroke: Comparison with ischemic stroke
(Elsevier Ireland Ltd, 2014) Das, Satrupa; Roy, Sitara; Kaul, Subhash; Jyothy, Akka; Munshi, Anjana
Increasing evidence suggests that genetic variation in inflammatory genes plays a pivotal role in pathogenesis of stroke. The aim of the present study was to evaluate the association of E-selectin S128R polymorphism with hemorrhagic stroke and also to evaluate the genotypic and allelic variation with ischemic stroke in a South Indian population from Andhra Pradesh. In this study, we recruited 250 hemorrhagic stroke patients along with 250 age and sex matched controls. The genotypes were determined using PCR-RFLP method and the strength of association between genotypes and hemorrhagic stroke was determined by odds ratio with 95% confidence interval (CI) and chi-square analysis. Allelic and genotypic frequencies of the polymorphism differed significantly between hemorrhagic stroke patients and controls (p < 0.001). Significant association was also found following dominant (p < 0.001) and co-dominant (p < 0.001) models. On comparing the genotypic and allelic frequencies between ischemic and hemorrhagic stroke significant difference was found between the two stroke types (p < 0.001). In conclusion, we found the AC genotype to be a significant risk factor for hemorrhagic stroke and we also found significant differences in AC genotype and C allele among the two stroke types. The genotypic and allelic variation between the ischemic and hemorrhagic stroke, suggests that E-selectin S128R mediated amplification of leukocytes onto endothelial cells, leading to secondary damage of brain cells is more pronounced in hemorrhagic stroke. ? 2014 Elsevier Ireland Ltd.
Oxidative stress and inflammation in diabetic complications
(Hindawi Publishing Corporation, 2014) Vikram, Ajit; Tripathi, Durga Nand; Kumar, Ashutosh; Singh, Sandeep
Oxidative Stress Events and Neuronal Dysfunction in Alzheimer’s Disease: Focus on APE1/Ref-1-Mediated Survival Strategies
(Springer, 2014) Kaur, Navrattan; Sarkar, Bibekananda; Mittal, Sunil; Dhiman, Monisha; Taglialatela, Gulio; Perez-polo, Regino J.; Mantha, Anil K.
Alzheimer’s disease (AD) is an important public health problem which affects millions of people worldwide. The major pathological hallmarks associated with AD are the accumulation of amyloid beta (Aβ) in senile plaques and neurofibrillary tangles (NFT) made up of hyperphosphorylated tau proteins. New findings suggest that oligomeric Aβ is a more toxic species than fibrillar Aβ relevant to AD pathology. Although the molecular mechanism(s) underlying the disease is not identified completely, various factors have been implicated in the development of AD. Accumulating evidences point towards the role of oxidative stress and mitochondrial dysfunction in the pathogenesis of AD and recognise them as an early event in AD development. Ageing is considered the greatest risk factor for AD and is linked to oxidative stress which causes accumulation of somatic mutations in mitochondrial DNA (mtDNA) over time and leads to genome instability and mitochondrial dysfunction. Recent studies on AD patients and transgenic mouse models suggest that amyloid precursor protein (APP) and Aβ localise to mitochondria, interact with mitochondrial proteins, disrupt electron transport chain (ETC), increases reactive oxygen species (ROS) level, impair axonal mitochondrial trafficking, thus leading to synaptic damage and cognitive decline associated with AD. It is not known whether accumulation of Aβ is the cause or outcome of declining mitochondrial function in AD. In order to counteract oxidative stress and maintain genome integrity, various DNA repair pathways exist, base excision repair (BER) pathway being the predominant pathway for repairing oxidised base lesions in neuronal cells. APE1 is the central enzyme of the BER pathway, having both repair and redox activities and shown to enhance neuronal survival after oxidative stress. Newer studies are revealing the role of APE1 in maintenance of mitochondrial genome repair and function. In this scenario, antioxidant-based therapy, which could reduce oxidative stress and modulate the activities of APE1, can serve as effective treatment providing neuroprotection in AD. This book chapter summarises some recent developments in understanding the pathogenesis of AD linking Aβ-induced oxidative stress, mitochondrial dysfunction, role of APE1 and phytochemicals toward AD therapeutics.
Association of the genetic variants of insulin receptor substrate 1 (IRS-1) with type 2 diabetes mellitus in a Saudi population
(Humana Press Inc., 2014) Alharbi, Khalid Khalaf; Khan, Imran Ali; Munshi, Anjana; Alharbi, Fawiziah Khalaf; Al-Sheikh, Yazeed; Alnbaheen, May Salem
Type 2 diabetes mellitus (T2DM) is a chronic degenerative disease, phenotypically and genetically heterogeneous, characterized by high levels of glucose and metabolic complications. Insulin receptor substrate 1 (IRS-1) plays a key role in the insulin-stimulated signal transduction pathway. A glycine-to-arginine substitution at codon 972 (G972R) (rs1801278) in the IRS-1 gene has been associated with impaired insulin action. Another SNP rs2943641 in the IRS-1 gene has been found to be associated with T2DM and insulin resistance in genome-wide association studies. The aim of the present study was to evaluate whether rs1801278 and rs2943641 are associated with increased risk of T2DM in the Saudi population. The study included 376 T2DM cases and 380 healthy controls. Genomic DNA was isolated using a commercially available kit supplied by Norgen Biotech Corp. Genotyping was performed by PCR and RFLP analysis. There was a significant difference in the genotypic distribution as well as allelic frequency between the T2DM cases and controls in case of both the polymorphisms for rs1801278 (1.752, 95?% CI 1.002?3.121; p?=?0.04), and for rs2943641 (OR?=?1.482, 95?% CI 1.176?1.867; p?=?0.001). In conclusion, both the (rs1801278 and rs2943641) polymorphisms are associated with T2DM in the Saudi population. ? 2014, Springer Science+Business Media New York.
Breast cancer MicroRNAs: Clinical biomarkers for the diagnosis and treatment strategies
(Springer India, 2014) Shafi, G.; Hasan, T.N.; Syed, N.A.; Paine, A.; Tegner, J.; Munshi, Anjana
Breast cancer is the second most common cancer in females that accounts for the highest cancer-specific deaths worldwide. Although recent advances in clinical management significantly reduced the mortality rate in breast cancer patients, the success rate of the effective therapy remains largely dependent on early detection. It has been demonstrated that gene expression profile may be a useful tool to define the signature of breast cancer as well as to predict the prognosis or response to treatment. The microRNA expression profile is gaining lots of attention to define various types of cancers since they play critical roles in many different cellular processes including metabolism, apoptosis, differentiation, and development. Several studies have shown that microRNA's signatures are associated with the staging, progression, and response to treatment in breast cancer. In addition to this microRNA has been shown to act as oncogenes and tumor suppressor genes. Continued efforts to delineate the microRNA function in mammary physiological and pathological conditions will reveal novel insights into normal cells and breast cancer biology and ultimately provide a new molecular target for alternate therapy. The book chapter covers the role of microRNAs in the diagnosis, staging, progression, prognosis, and response to treatment of breast cancer. ? 2014 Springer India. All rights reserved.