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result(s) for
"Bharadwaj, Dwaipayan"
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Renin-Angiotensin System in Pathogenesis of Atherosclerosis and Treatment of CVD
by
Grechko, Andrey V.
,
Orekhov, Alexander N.
,
Sazonova, Margarita A.
in
Apoptosis
,
Atherosclerosis
,
Blood pressure
2021
Atherosclerosis has complex pathogenesis, which involves at least three serious aspects: inflammation, lipid metabolism alterations, and endothelial injury. There are no effective treatment options, as well as preventive measures for atherosclerosis. However, this disease has various severe complications, the most severe of which is cardiovascular disease (CVD). It is important to note, that CVD is among the leading causes of death worldwide. The renin–angiotensin–aldosterone system (RAAS) is an important part of inflammatory response regulation. This system contributes to the recruitment of inflammatory cells to the injured site and stimulates the production of various cytokines, such as IL-6, TNF-a, and COX-2. There is also an association between RAAS and oxidative stress, which is also an important player in atherogenesis. Angiotensin-II induces plaque formation at early stages, and this is one of the most crucial impacts on atherogenesis from the RAAS. Importantly, while stimulating the production of ROS, Angiotensin-II at the same time decreases the generation of NO. The endothelium is known as a major contributor to vascular function. Oxidative stress is the main trigger of endothelial dysfunction, and, once again, links RAAS to the pathogenesis of atherosclerosis. All these implications of RAAS in atherogenesis lead to an explicable conclusion that elements of RAAS can be promising targets for atherosclerosis treatment. In this review, we also summarize the data on treatment approaches involving cytokine targeting in CVD, which can contribute to a better understanding of atherogenesis and even its prevention.
Journal Article
Genome-wide association study of blood lipids in Indians confirms universality of established variants
by
Giri, Anil K.
,
Basu, Analabha
,
Tandon, Nikhil
in
Adipose tissue
,
Adult
,
Asian Continental Ancestry Group - genetics
2019
Lipids foster energy production and their altered levels have been coupled with metabolic ailments. Indians feature high prevalence of metabolic diseases, yet uncharacterized for genes regulating lipid homeostasis. We performed first GWAS for quantitative lipids (total cholesterol, LDL, HDL, and triglycerides) exclusively in 5271 Indians. Further to corroborate our genetic findings, we investigated DNA methylation marks in peripheral blood in Indians at the identified loci (N = 233) and retrieved gene regulatory features from public domains. Recurrent GWAS loci-CELSR2, CETP, LPL, ZNF259, and BUD13 cropped up as lead signals in Indians, reflecting their universal applicability. Besides established variants, we found certain unreported variants at sub-genome-wide level-QKI, REEP3, TMCC2, FAM129C, FAM241B, and LOC100506207. These variants though failed to attain GWAS significance in Indians, but largely turned out to be active CpG sites in human subcutaneous adipose tissue and showed robust association to two or more lipid traits. Of which, QKI variants showed significant association to all four lipid traits and their designated region was observed to be a key gene regulatory segment denoting active transcription particularly in human subcutaneous adipose tissue. Both established and novel loci were observed to be significantly associated with altered DNA methylation in Indians for specific CpGs that resided in key regulatory elements. Further, gene-based association analysis pinpointed novel GWAS loci-LINC01340 and IQCJ-SCHIP1 for TC; IFT27, IFT88, and LINC02141 for HDL; and TEX26 for TG. Present study ascertains universality of selected known genes and also identifies certain novel loci for lipids in Indians by integrating data from various levels of gene regulation.
Journal Article
Impact of Common Variants of PPARG , KCNJ11 , TCF7L2 , SLC30A8 , HHEX , CDKN2A , IGF2BP2 , and CDKAL1 on the Risk of Type 2 Diabetes in 5,164 Indians
by
Tabassum, Rubina
,
Bhaskar, Seema
,
Dwivedi, Om Prakash
in
Aged
,
Aged, 80 and over
,
Biological and medical sciences
2010
Common variants in PPARG, KCNJ11, TCF7L2, SLC30A8, HHEX, CDKN2A, IGF2BP2, and CDKAL1 genes have been shown to be associated with type 2 diabetes in European populations by genome-wide association studies. We have studied the association of common variants in these eight genes with type 2 diabetes and related traits in Indians by combining the data from two independent case-control studies.
We genotyped eight single nucleotide polymorphisms (PPARG-rs1801282, KCNJ11-rs5219, TCF7L2-rs7903146, SLC30A8-rs13266634, HHEX-rs1111875, CDKN2A-rs10811661, IGF2BP2-rs4402960, and CDKAL1-rs10946398) in 5,164 unrelated Indians of Indo-European ethnicity, including 2,486 type 2 diabetic patients and 2,678 ethnically matched control subjects.
We confirmed the association of all eight loci with type 2 diabetes with odds ratio (OR) ranging from 1.18 to 1.89 (P = 1.6 x 10(-3) to 4.6 x 10(-34)). The strongest association with the highest effect size was observed for TCF7L2 (OR 1.89 [95% CI 1.71-2.09], P = 4.6 x 10(-34)). We also found significant association of PPARG and TCF7L2 with homeostasis model assessment of beta-cell function (P = 6.9 x 10(-8) and 3 x 10(-4), respectively), which looked consistent with recessive and under-dominant models, respectively.
Our study replicates the association of well-established common variants with type 2 diabetes in Indians and shows larger effect size for most of them than those reported in Europeans.
Journal Article
Normative range of blood biochemical parameters in urban Indian school-going adolescents
by
Giri, Anil K.
,
Tandon, Nikhil
,
Bandesh, Khushdeep
in
Adolescence
,
Adolescent
,
Adolescent obesity
2019
Adolescence is the most critical phase of human growth that radically alters physiology of the body and wherein any inconsistency can lead to serious health consequences in adulthood. The timing and pace at which various developmental events occur during adolescence is highly diverse and thus results in a drastic change in blood biochemistry. Monitoring the physiological levels of various biochemical measures in ample number of individuals during adolescence can call up for an early intervention in managing metabolic diseases in adulthood. Today, only a couple of studies in different populations have investigated blood biochemistry in a small number of adolescents however, there is no comprehensive biochemical data available worldwide. In view, we performed a cross-sectional study in a sizeable group of 7,618 Indian adolescents (3,333 boys and 4,285 girls) aged between 11-17 years to inspect the distribution of values of common biochemical parameters that generally prevails during adolescence and we observed that various parameters considerably follow the reported values from different populations being 3.56-6.49mmol/L (fasting glucose), 10.60-199.48pmol/L (insulin), 0.21-3.22nmol/L (C-peptide), 3.85-6.25% (HbA1c), 2.49-5.54mmol/L (total cholesterol), 1.16-3.69mmol/L (LDL), 0.78-1.85mmol/L (HDL), 0.33-2.24mmol/L (triglycerides), 3.56-11.45mmol/L (urea), 130.01-440.15μmol/L (uric acid) and 22.99-74.28μmol/L (creatinine). Barring LDL and triglycerides, all parameters differed significantly between boys and girls (p< 0.001). Highest difference was seen for uric acid (p = 1.3 x10-187) followed by C-peptide (p = 6.6 x10-89). Across all ages during adolescence, glycemic and nitrogen metabolites parameters varied markedly with gender. Amongst lipid parameters, only HDL levels were found to be significantly associated with gender following puberty (p< 0.001). All parameters except urea, differed considerably in obese and lean adolescents (p< 0.0001). The present study asserts that age, sex and BMI are the essential contributors to variability in blood biochemistry during adolescence. Our composite data on common blood biochemical measures will benefit future endeavors to define reference intervals in adolescents especially when the global availability is scarce.
Journal Article
Common variants of FTO and the risk of obesity and type 2 diabetes in Indians
by
NIGAM Shubhanchi
,
VARMA Binuja
,
MAHAJAN Anubha
in
631/208/726/649
,
692/699/2743/137/773
,
692/699/2743/393
2011
Common variants of fat mass and obesity-associated gene (
FTO
, fat mass- and obesity-associated gene) have been shown to be associated with obesity and type 2 diabetes in population of European and non-European ethnicity. However, studies in Indian population have provided inconsistent results. Here, we examined association of eight
FTO
variants (rs1421085, rs8050136, rs9939609, rs9930506, rs1861867, rs9926180, rs2540769 and rs708277) with obesity and type 2 diabetes in 5364 North Indians (2474 type 2 diabetes patients and 2890 non-diabetic controls) in two stages. None of the variants including previously reported intron 1 variants (rs1421085, rs8050136, rs9939609 and rs9930506) showed body mass index (BMI)-dependent/independent association with type 2 diabetes. However, rs1421085, rs8050136 and rs9939609 were associated with obesity status and measures of obesity (BMI, waist circumference and waist-to-hip ratio) in stage 2 and combined study population. Meta-analysis of the two study population results also revealed that rs1421085, rs8050136 and rs9939609 were significantly associated with BMI both under the random- and fixed-effect models (
P
(random/fixed)=0.02/0.0001, 0.004/0.0006 and 0.01/0.01, respectively). In conclusion, common variants of
FTO
were associated with obesity, but not with type 2 diabetes in North Indian population.
Journal Article
Common Variants of FTO Are Associated with Childhood Obesity in a Cross-Sectional Study of 3,126 Urban Indian Children
2012
FTO variants are robustly associated with obesity and related traits in many population and shown to have variable impact during life course. Although studies have shown association of FTO variants with adiposity in adult Indian, its association in Indian children is yet to be confirmed.
Here we examined association of FTO variants (rs9939609 and rs8050136) with obesity and related anthropometric and biochemical traits in 3,126 Indian children (aged 11-17 years) including 2,230 normal-weight and 896 over-weight/obese children. We also compared effects observed in the present study with that observed in previous studies on South Asian adults and children of other ethnic groups.
The variant rs9939609 showed significant association with risk of obesity [OR = 1.21, P = 2.5 × 10(-3)] and its measures BMI, weight, waist circumference and hip circumference [β range = 0.11 to 0.14 Z-score units; P range = 1.3 × 10(-4) to 1.6 × 10(-7)] in children. The observed effect sizes in Indian children were similar to those reported for European children. Variant rs9939609 explained 0.88% of BMI variance in Indian children. The effect sizes of rs9939609 on BMI and WC were ~2 fold higher in children than adults. Interestingly rs9939609 was also associated with serum levels of thyroid stimulating hormone (TSH) [β = 0.10 Z-score, P = 5.8 × 10(-3)]. The other variant rs8050136 was in strong linkage disequilibrium with rs9939609 (r(2) = 0.97) and provided similar association results.
The study provides first report of association of FTO variants with obesity and related anthropometric traits in Indian children with higher impact in children compared to adults. We also demonstrated association of FTO variant with serum levels of TSH, indicating putative influence of FTO in hypothalamic-pituitary-thyroid axis.
Journal Article
Association of variants in genes involved in pancreatic β-cell development and function with type 2 diabetes in North Indians
by
Chavali, Sreenivas
,
Tabassum, Rubina
,
Tandon, Nikhil
in
631/208/726/649
,
631/208/727/2000
,
692/699/2743/137/773
2011
Variants in genes involved in pancreatic β-cell development and function are known to cause monogenic forms of type 2 diabetes and are also associated with complex form. In this study, we studied the genetic association of polymorphisms in such important genes with type 2 diabetes in the high-risk Indians. We genotyped 91 polymorphisms in 19 genes (
ABCC8, HNF1A, HNF1B, HNF4A, INS, INSM1
,
ISL1, KCNJ11, MAFA, MNX1, NEUROD1, NEUROG3, NKX2.2, NKX6.1, PAX4, PAX6, PDX1, USF1
and
WFS1
) in 2025 unrelated North Indians of Indo-European ethnicity comprising of 1019 diabetic and 1006 non-diabetic subjects.
HNF4A
promoter P2 polymorphisms rs1884613 and rs2144908, which are in high linkage disequilibrium, showed significant association with type 2 diabetes (odds ratio (OR)=1.37 (95% confidence interval (CI) 1.19–1.57),
P
=9.4 × 10
−6
for rs1884613 and OR=1.37 (95%CI 1.20–1.57),
P
=6.0 × 10
−6
for rs2144908), as previously shown in other populations. We observed body mass index-dependent association of these variants with type 2 diabetes in normal-weight/lean subjects. Variants in
USF1
,
ABCC8
,
ISL1
and
KCNJ11
showed nominal association, while haplotypes in these genes were significantly associated. rs3812704 upstream of
NEUROG3
significantly increased risk for type 2 diabetes in normal-weight/lean subjects (OR=1.68 (95%CI 1.25–2.24),
P
=4.9 × 10
−4
). Thus, pancreatic β-cell development and function genes contribute to susceptibility to type 2 diabetes in North Indians.
Journal Article
Genetic Variant of AMD1 Is Associated with Obesity in Urban Indian Children
by
Tabassum, Rubina
,
Tandon, Nikhil
,
Ghosh, Saurabh
in
Adenosylmethionine Decarboxylase - genetics
,
Adipose tissue
,
Adiposity - genetics
2012
Hyperhomocysteinemia is regarded as a risk factor for cardiovascular diseases, diabetes and obesity. Manifestation of these chronic metabolic disorders starts in early life marked by increase in body mass index (BMI). We hypothesized that perturbations in homocysteine metabolism in early life could be a link between childhood obesity and adult metabolic disorders. Thus here we investigated association of common variants from homocysteine metabolism pathway genes with obesity in 3,168 urban Indian children.
We genotyped 90 common variants from 18 genes in 1,325 children comprising of 862 normal-weight (NW) and 463 over-weight/obese (OW/OB) children in stage 1. The top signal obtained was replicated in an independent sample set of 1843 children (1,399 NW and 444 OW/OB) in stage 2. Stage 1 association analysis revealed association between seven variants and childhood obesity at P<0.05, but association of only rs2796749 in AMD1 [OR = 1.41, P = 1.5×10(-4)] remained significant after multiple testing correction. Association of rs2796749 with childhood obesity was validated in stage 2 [OR = 1.28, P = 4.2×10(-3)] and meta-analysis [OR = 1.35, P = 1.9×10(-6)]. AMD1 variant rs2796749 was also associated with quantitative measures of adiposity and plasma leptin levels that was also replicated and corroborated in combined analysis.
Our study provides first evidence for the association of AMD1 variant with obesity and plasma leptin levels in children. Further studies to confirm this association, its functional significance and mechanism of action need to be undertaken.
Journal Article
Gene prioritization in Type 2 Diabetes using domain interactions and network analysis
by
Chavali, Sreenivas
,
Bharadwaj, Dwaipayan
,
Tabassum, Rubina
in
Animal Genetics and Genomics
,
Biomedical and Life Sciences
,
Cluster Analysis
2010
Background
Identification of disease genes for Type 2 Diabetes (T2D) by traditional methods has yielded limited success. Based on our previous observation that T2D may result from disturbed protein-protein interactions affected through disrupting modular domain interactions, here we have designed an approach to rank the candidates in the T2D linked genomic regions as plausible disease genes.
Results
Our approach integrates Weight value (Wv) method followed by prioritization using clustering coefficients derived from domain interaction network. Wv for each candidate is calculated based on the assumption that disease genes might be functionally related, mainly facilitated by interactions among domains of the interacting proteins. The benchmarking using a test dataset comprising of both known T2D genes and non-T2D genes revealed that Wv method had a sensitivity and specificity of 0.74 and 0.96 respectively with 9 fold enrichment. The candidate genes having a Wv > 0.5 were called High Weight Elements (HWEs). Further, we ranked HWEs by using the network property-the clustering coefficient (C
i
). Each HWE with a C
i
< 0.015 was prioritized as plausible disease candidates (HWEc) as previous studies indicate that disease genes tend to avoid dense clustering (with an average C
i
of 0.015). This method further prioritized the identified disease genes with a sensitivity of 0.32 and a specificity of 0.98 and enriched the candidate list by 6.8 fold. Thus, from the dataset of 4052 positional candidates the method ranked 435 to be most likely disease candidates. The gene ontology sharing for the candidates showed higher representation of metabolic and signaling processes. The approach also captured genes with unknown functions which were characterized by network motif analysis.
Conclusions
Prioritization of positional candidates is essential for cost-effective and an expedited discovery of disease genes. Here, we demonstrate a novel approach for disease candidate prioritization from numerous loci linked to T2D.
Journal Article
Genome-Wide Association Study of Metabolic Syndrome Reveals Primary Genetic Variants at CETP Locus in Indians
2019
Indians, a rapidly growing population, constitute vast genetic heterogeneity to that of Western population; however they have become a sedentary population in past decades due to rapid urbanization ensuing in the amplified prevalence of metabolic syndrome (MetS). We performed a genome-wide association study (GWAS) of MetS in 10,093 Indian individuals (6617 MetS and 3476 controls) of Indo-European origin, that belong to our previous biorepository of The Indian Diabetes Consortium (INDICO). The study was conducted in two stages—discovery phase (N = 2158) and replication phase (N = 7935). We discovered two variants within/near the CETP gene—rs1800775 and rs3816117—associated with MetS at genome-wide significance level during replication phase in Indians. Additional CETP loci rs7205804, rs1532624, rs3764261, rs247617, and rs173539 also cropped up as modest signals in Indians. Haplotype association analysis revealed GCCCAGC as the strongest haplotype within the CETP locus constituting all seven CETP signals. In combined analysis, we perceived a novel and functionally relevant sub-GWAS significant locus—rs16890462 in the vicinity of SFRP1 gene. Overlaying gene regulatory data from ENCODE database revealed that single nucleotide polymorphism (SNP) rs16890462 resides in repressive chromatin in human subcutaneous adipose tissue as characterized by the enrichment of H3K27me3 and CTCF marks (repressive gene marks) and diminished H3K36me3 marks (activation gene marks). The variant displayed active DNA methylation marks in adipose tissue, suggesting its likely regulatory activity. Further, the variant also disrupts a potential binding site of a key transcription factor, NRF2, which is known for involvement in obesity and metabolic syndrome.
Journal Article