Subhankar Das

Albany Medical College | AMC

Targeted-deletion of Npr1 gene (coding for guanylyl cyclase/natriuretic peptide receptor-A, GC-A/NPRA) exhibits hypertrophic and proliferative effects in target organs of Npr 1 gene-knockout mice. Fibrosis and hypertrophy are regulated by p21 Cip1 and p27 Kip1 , cell-cycle regulatory proteins that inhibit target cyclin and cyclin-dependent kinase (...

Cell‐cycle regulatory proteins (p21Cip1/p27Kip1) inhibit cyclin and cyclin‐dependent kinase (CDK) complex that promotes fibrosis and hypertrophy. The present study examined the role of CDK blockers, p21Cip1/p27Kip1 in the progression of renal fibrosis and dysfunction using Npr1 (encoding guanylyl cyclase/natriuretic peptide receptor‐A, GC‐A/NPRA) g...

Atrial and brain natriuretic peptides (ANP and BNP) are cardiac hormones that elicit natriuretic, diuretic, vasorelaxant, and antiproliferative responses, all of which contribute to lowering blood pressure and blood volume. ANP and BNP bind to guanylyl cyclase ‐A/natriuretic peptide receptor ‐A (GC‐A/NPRA), which is considered to be the major natri...

The objective of the present study was to determine whether targeted-disruption of Npr1 gene (encoding for guanylyl cyclase/natriuretic peptide receptor-A; GC-A/NPRA) upregulates pro(renin) receptor (P)RR expression and leads to the activation of MAPKs in Npr1 gene-knockout mice. The Npr1 homozygous (Npr1 −/− ; 0-copy), heterozygous (Npr1 +/− ; 1-c...

Atrial and brain natriuretic peptides (ANP and BNP) activate guanylyl cyclase/natriuretic peptide receptor‐a (GC‐A/NPRA), which regulates blood pressure through inhibition of renin‐angiotensin‐aldosterone system (RAAS). The aim of the present study was to determine whether targeted‐disruption of Npr1 (encoding GC‐A/NPRA) upregulates pro(renin) rece...

Cardiac hypertrophy is a major predictor of progressive heart disease and an adverse prognosis. Atrial and brain natriuretic peptides (ANP and BNP) bind to guanylyl cyclase/natriuretic peptide receptor‐A (GC‐A/NPRA) and exert the beneficial effects against hypertension and cardiac hypertrophy. The objective of the present study was to examine the e...

Atrial and brain natriuretic peptides (ANP and BNP) activate guanylyl cyclase/natriuretic peptide receptor‐a (GC‐A/NPRA), which regulates blood pressure through inhibition of renin‐angiotensin‐aldosterone system (RAAS). The present study was aimed to determine whether targeted‐disruption of Npr1 gene (coding for GC‐A/NPRA) upregulates pro(renin) re...

The objective of the present study was to delineate the mechanisms of guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) gene (Npr1) expression in vivo. We utilized all-trans retinoic acid (ATRA) and histone deacetylase (HDAC) inhibitor, sodium butyrate (NaBu) to examine the expression and function of Npr1 using gene-disrupted heterozygous...

Mice lacking functional guanylyl cyclase/natriuretic peptide receptor‐A (GC‐A/NPRA) gene (Npr1) exhibit hypertension, kidney disease, and heart failure. The objective of the present study was to elucidate the effect of all‐trans retinoic acid (ATRA) and histone deacetylase inhibitor, sodium butyrate (NaBu) on attenuation of renal fibrosis and remod...

The objective of this study was to examine whether genetically determined differences in guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) gene (Npr1) affect cardiac expression of pro-inflammatory cytokines, hypertrophic markers, nuclear factor kappa-B (NF-kB), and activating protein-1 (AP-1) in a Npr1 gene-dose-dependent manner. In the p...

Mice lacking functional Npr1 gene (coding for guanylyl cyclase/natriuretic peptide receptor-A, GC-A/NPRA) exhibit hypertension and kidney disease, however, the mechanisms regulating Npr1 expression are not well understood. The objective of the present study was to determine the effect of all- trans retinoic acid (ATRA) on Npr1 gene expression and r...

Guanylyl cyclase/natriuretic peptide receptor‐A (GC‐A/NPRA) is the biological receptor of cardiac hormones atrial and brain natriuretic peptides (ANP and BNP), which plays an important role in maintaining renal and cardiovascular homeostasis. Present study was designed to uncover the regulatory mechanism involved in Npr1 gene (coding for GC‐A/NPRA)...

Objective: The objective of the present study was to elucidate the interactive roles of guanylyl cyclase/natriuretic peptide receptor-A (NPRA) gene (Npr1) and salt diets on cardiac angiotensin II (ANG II), aldosterone and pro-inflammatory cytokines levels in Npr1 gene-targeted (1-copy, 2-copy, 3-copy, 4-copy) mice. Methods: Npr1 genotypes includ...

Atrial natriuretic peptide (ANP) exerts an inhibitory effect on juxtaglomerular (JG) renin synthesis and release by activating guanylyl cyclase/ natriuretic peptide receptor-A (GC-A/NPRA). Renin has also been localized in connecting tubule cells; however, the effect of ANP/NPRA signaling on tubular renin has not been determined. In the present stud...

Mice carrying targeted-disruption of guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) gene ( Npr1 ) exhibits hypertension, cardiac, and kidney hypertrophy, and congestive heart failure. The objective of the present study was to determine the role of (pro)renin receptor (P)RR in the kidneys of Npr1 gene-disrupted (-/-; 0-copy), and wild-t...

Binding of atrial natriuretic peptide (ANP) to its guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) exerts diverse physiological effects by lowering the blood pressure and blood volume. The objective of the present study was to determine the effect of blockade of nuclear factor-kappa B, inhibitory kappa B kinase, and inhibitory kappa B a...

Disruption of the Npr1 gene (coding for GC‐A/NPRA) exhibits increased BP, congestive heart failure, cardiac and renal hypertrophy in mice. The objective of the present study was to evaluate the effect of RAS components in Npr1 gene‐disrupted and gene‐duplicated mice kidney. The study was performed utilizing adult mice aged 6 month with different co...

The present study was aimed at determining the consequences of the disruption of guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) gene (Npr1) on proinflammatory responses of nuclear factor kappa B, inhibitory kappa B kinase, and inhibitory kappa B alpha (NF-κB, IKK, IκBα) in the kidneys of mutant mice. The results showed that the disrupt...

Binding of atrial and brain natriuretic peptides to guanylyl cyclase-A/natriuretic peptide receptor-A produces second messenger cGMP, which plays an important role in maintaining renal and cardiovascular homeostasis. Mice carrying a targeted disruption of the Npr1 gene coding for guanylyl cyclase-A/natriuretic peptide receptor-A exhibit changes tha...

Systemic disruption of guanylyl cyclase‐A/natriuretic peptide receptor‐A (GC‐A/NPRA) gene (Npr1) has been shown to increase blood pressure, marked cardiac hypertrophy, and renal insufficiency in mice. The objective of the present study was to evaluate the consequences of Npr1 gene‐disruption on renal inflammation, collagenesis, and remodeling in nu...

The objective of the present study was to evaluate the effect of Npr1 (coding for Guanylyl Cyclase‐A/Natriuretic Peptide Receptor‐A; GC‐A/NPRA) gene‐disruption in the development of renal hypertrophy and fibrosis. Blood pressure measurement and plasma cytokine assays were performed in 16‐weeks old mice having different copies of Npr1 gene (0‐copy,...

Arsenic, the environmental metalloid toxicant, is known to induce oxidative damage to liver and produce hepatic fibrosis. The theme of our study was to optimize and evaluate the therapeutic efficacy of galactosylated liposomal flavonoidal antioxidant, quercetin (QC), in combating arsenic-induced hepatic fibrogenesis. The rats of the hepatic damage...

Very little evidence exists concerning the possible impairment of children's intellectual function in relation to arsenic exposure in utero and during childhood. We conducted a cross-sectional study among 351 children age 5 to 15 years who were selected from a source population of 7683 people in West Bengal, India, in 2001-2003. Intellectual functi...

This study was conducted to monitor the changes in arsenic concentration during different seasons in a one-year period during 2002-2003 in selected tubewells in an arsenic-affected area in the district of South 24 Parganas in West Bengal, India, and to map the location of the wells. Seasonal variations in concentrations of arsenic in water were mea...

Between 2001 and 2003, the authors studied pregnancy outcomes and infant mortality among 202 married women in West Bengal, India. Reproductive histories were ascertained using structured interviews. Arsenic exposure during each pregnancy, including all water sources used, was assessed; this involved measurements from 409 wells. Odds ratios for spon...

Chronic arsenic exposure is known to produce arsenicosis and cancer. To ascertain whether perturbation of methylation plays a role in such carcinogenesis, the degree of methylation of p53 and p16 gene in DNA obtained from blood samples of people chronically exposed to arsenic and skin cancer subjects was studied. Methylation-specific restriction en...

During 1998–2000, the authors investigated relations between lung function, respiratory symptoms, and arsenic in drinking water among 287 study participants, including 132 with arsenic-caused skin lesions, in West Bengal, India. The source population involved 7,683 participants who had been surveyed for arsenic-related skin lesions in 1995–1996. Re...

Introduction: Noncirrhotic portal fibrosis has been reported to occur in humans due to prolonged intake of arsenic contaminated water. Further, oxystress and hepatic fibrosis have been demonstrated by us in chronic arsenic induced hepatic damage in murine model. Cytokines like tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6) are su...

Various effects of ingested inorganic arsenic in drinking water in adults have been shown in different regions of the world, particularly in South America and Asia. The impact of pre- and postnatal arsenic exposures on pregnancy outcomes and child development are largely unknown. The aim of this investigation is to study reproductive effects includ...

Over 6 million people live in areas of West Bengal, India, where groundwater sources are contaminated with naturally occurring arsenic. The key objective of this nested case-control study was to characterize the dose-response relation between low arsenic concentrations in drinking water and arsenic-induced skin keratoses and hyperpigmentation. We s...

The natural history of people who stop drinking arsenic (As) contaminated water is not known. A cohort follow-up study of 1074 people (As-exposed people 623, control population 451) was therefore carried out in 2000, 5 years after the original clinical examination done on the same population. Clinical examination was done on 559 exposed people out...

Background: Chronic arsenic toxicity, producing various clinical manifestations, is currently epidemic in West Bengal, India, Bangladesh, and other regions of the world. 2,3-Dimercapto-1-propanesulfonate, a chelating agent, increases excretion of arsenic in urine to several times the prechelation concentration but the therapeutic efficacy of 2,3-d...

Picrorhiza kurrooa (Pk) has been used in liver diseases in the Indian indigenous system of medicine. We undertook this study to determine whether Pk extract possesses hepatoprotective function and if so to determine its nature and mechanism. Liver injury was induced in 16 mice by thrice-a-week injection of carbon tetrachloride (CCl4) for nine weeks...