No abstract

Schizophrenia (SCZ) as a severe and complex neuropsychiatric disorder and is characterized by positive symptoms, negative symptoms and cognitive dysfunctions. Genome-wide association studies (GWAS) have identified a strong association between the single nucleotide polymorphism (SNP) rs12807809 upstream of Neurogranin (NRGN) in a European population. This evidence prompted us to conduct an association study among 1005 schizophrenia cases and 1069 controls in a South Indian Population using TaqMan Allelic discrimination method. We observed an association of rs12807809 with SCZ in this study population. Allele frequencies and genotype frequencies of rs12807809 showed significant differences between cases and control subjects [p=0.0019; OR=0.69; 95% CI=(0.55-0.87)] and (p=0.0062). Further Genotype-Phenotype correlation revealed a moderate association of rs12807809 with flat affect (p=0.039) and Hallucinations (p=0.012). The ancestral non-risk C allele contributes to the severity of psychosis (p=0.039) in this population.

Pancreastatin (PST), a chromogranin A (CHGA)-derived potent physiological dysglycemic peptide, regulates glucose/insulin homeostasis. We have identified a non-synonymous functional PST variant (p.Gly297Ser; rs9658664) that occurs in a large section of human populations. Association analysis of this single nucleotide polymorphism with cardiovascular/metabolic diseases states in Indian populations (n≈4300 subjects) displays elevated plasma glucose, glycosylated hemoglobin, diastolic blood pressure and catecholamines in Gly/Ser subjects as compared to wild-type individuals (Gly/Gly). Consistently, the 297Ser allele confers an increased risk (∼1.3-1.6-fold) for type-2 diabetes/hypertension/coronary artery disease/metabolic syndrome. In corroboration, the variant peptide (PST-297S) displays gain-of-potency in several cellular events relevant for cardiometabolic disorders (e.g., increased expression of gluconeogenic genes, increased catecholamine secretion, greater inhibition of insulin-stimulated glucose-uptake) than the wild-type peptide (PST-WT). Computational docking analysis and molecular dynamics simulations show higher affinity binding of PST-297S peptide with glucose-regulated protein 78 (GRP78) and insulin receptor (IR) than PST-WT, providing a mechanistic basis for the enhanced activity of the variant peptide. In vitro binding assays validate these in silico predictions of PST peptides binding to GRP78 and IR. In conclusion, the PST 297Ser allele influences cardiovascular/metabolic phenotypes and emerges as a novel risk factor for type-2 diabetes/hypertension/coronary artery disease in human populations.

No abstract

Pancreastatin (PST), a chromogranin A (CHGA)-derived potent physiological dysglycemic peptide, regulates glucose/insulin homeostasis. We have identified a non-synonymous functional PST variant (p.Gly297Ser; rs9658664) that occurs in a large section of human populations. Association analysis of this single nucleotide polymorphism with cardiovascular/metabolic diseases states in Indian populations (n≈4300 subjects) displays elevated plasma glucose, glycosylated hemoglobin, diastolic blood pressure and catecholamines in Gly/Ser subjects as compared to wild-type individuals (Gly/Gly). Consistently, the 297Ser allele confers an increased risk (~1.3-1.6-fold) for type-2 diabetes/hypertension/coronary artery disease/metabolic syndrome. In corroboration, the variant peptide (PST-297S) displays gain-of-potency in several cellular events relevant for cardiometabolic disorders (<i>e.g.</i>, increased expression of gluconeogenic genes, increased catecholamine secretion, greater inhibition of insulin-stimulated glucose-uptake) than the wild-type peptide (PST-WT). Computational docking analysis and molecular dynamics simulations show higher affinity binding of PST-297S peptide with glucose-regulated protein 78 (GRP78) and insulin receptor (IR) than PST-WT, providing a mechanistic basis for the enhanced activity of the variant peptide. <i>In vitro</i> binding assays validate these <i>in silico</i> predictions of PST peptides binding to GRP78 and IR. In conclusion, the PST 297Ser allele influences cardiovascular/metabolic phenotypes and emerges as a novel risk factor for type-2 diabetes/hypertension/coronary artery disease in human populations.

Pancreastatin (PST), a chromogranin A (CHGA)-derived potent physiological dysglycemic peptide, regulates glucose/insulin homeostasis. We have identified a non-synonymous functional PST variant (p.Gly297Ser; rs9658664) that occurs in a large section of human populations. Association analysis of this single nucleotide polymorphism with cardiovascular/metabolic diseases states in Indian populations (n≈4300 subjects) displays elevated plasma glucose, glycosylated hemoglobin, diastolic blood pressure and catecholamines in Gly/Ser subjects as compared to wild-type individuals (Gly/Gly). Consistently, the 297Ser allele confers an increased risk (~1.3-1.6-fold) for type-2 diabetes/hypertension/coronary artery disease/metabolic syndrome. In corroboration, the variant peptide (PST-297S) displays gain-of-potency in several cellular events relevant for cardiometabolic disorders (<i>e.g.</i>, increased expression of gluconeogenic genes, increased catecholamine secretion, greater inhibition of insulin-stimulated glucose-uptake) than the wild-type peptide (PST-WT). Computational docking analysis and molecular dynamics simulations show higher affinity binding of PST-297S peptide with glucose-regulated protein 78 (GRP78) and insulin receptor (IR) than PST-WT, providing a mechanistic basis for the enhanced activity of the variant peptide. <i>In vitro</i> binding assays validate these <i>in silico</i> predictions of PST peptides binding to GRP78 and IR. In conclusion, the PST 297Ser allele influences cardiovascular/metabolic phenotypes and emerges as a novel risk factor for type-2 diabetes/hypertension/coronary artery disease in human populations.