Central Drug Research Institute
Central Drug Research Institute
Chatterjee M.,Central Drug Research Institute
Neuropharmacology | Year: 2012
Ketamine, an NMDA receptor antagonist has been shown to induce aberrant behaviour phenotypes in rodents, some of which are known to simulate the behaviour abnormalities observed in patients suffering from schizophrenia. Thus, developing ketamine-induced animal models became an important tool of choice to study the mechanistic details of some critical symptoms associated with schizophrenia. In this study, our goal was to characterize and correlate the ketamine-induced changes in the behavioural phenotypes to the changes in neurochemical and molecular profile(s) in the brain tissues implicated in the pathophysiology of schizophrenia. We studied the effects of ketamine in mice using 'acute' and 'chronic' treatment regimens along with the 'drug withdrawal' effects on their biochemical and molecular parameters in the pre-frontal cortex, hippocampus, and striatum. Our results demonstrated that the acute and chronic ketamine administration, differentially and site specifically, modulated the levels of acetylcholine, dopamine, serotonin and noradrenaline. In addition, the chronic ketamine doses dramatically suppressed the levels of glycine among some of the amino acids examined and induced alternations in gene expression of the key neurotransmitter receptor systems, including some members of the dopamine and the serotonin receptor families. The acute and chronic ketamine treatment induced "signature" neurochemical and gene-expression patterns that are implicated in the pathophysiology of schizophrenia. Our analyses tend to support the "chronic ketamine" mice model for experimental psychosis as a tool for deeper investigation of the mechanistic paradigm associated with the schizophrenia spectrum disorder and for screening next-generation antipsychotic drugs. Copyright © 2012 Elsevier Ltd. All rights reserved.
Nakka V.P.,Central Drug Research Institute |
Gusain A.,Central Drug Research Institute |
Raghubir R.,Central Drug Research Institute
Neurotoxicity Research | Year: 2010
The endoplasmic reticulum(ER) stress plays a vital role in mediating ischemic neuronal cell death. However, very little is known about the role of ER stress in mediating pathophysiological reactions to acute brain injuries. An attempt was therefore made to assess the role of cerebral ischemia/reperfusion (I/R) induced ER stress and its modulation on outcome of ischemic insult. Focal cerebral ischemia was induced in rats by middle cerebral artery occlusion (MCAO) for 2 h followed by varying time points of reperfusion. The brain loci specific and time-dependent alterations were seen in the expression pattern of molecular markers, i.e., heat-shock protein 70 (HSP70) for cytoplasmic dysfunction, glucose-regulated protein 78 (GRP78), Caspase-12, C/EBP homologous protein/growth arrest andDNA damage-inducible gene 153 (CHOP/GADD153), activating transcription factor 4 (ATF-4), and Processed X-box protein 1 (xbp1) mRNA for ER dysfunction. Further, histological examinations indicated pronounced brain damage, massive neuronal loss, and DNA fragmentation predominantly in the striatum and cortex. The enhanced expression of GRP78, Caspase-12, CHOP/GADD153, ATF4 and processing of xbp1mRNAin the affected brain regions clearly indicate the critical involvement of ER-mediated cell death/survival mechanisms and also collectively demonstrated the activation of unfolded protein response (UPR). Moreover, Salubrinal, a selective inhibitor of eIF2α dephosphorylation was used to counteract ER stress, which significantly increased the phosphorylation of eukaryotic translation initiation factor 2 subunit α (eIF2α), leading to reduced brain damage after I/R injury. Therefore, inhibition of ER stress following I/R injury may be used as key therapeutic target for neuroprotection. © Springer Science+Business Media, LLC 2009.
Chatterjee M.,Central Drug Research Institute |
Verma R.,Central Drug Research Institute |
Ganguly S.,Institute of Molecular Medicine |
Palit G.,Central Drug Research Institute
Neuropharmacology | Year: 2012
Ketamine, an NMDA receptor antagonist has been shown to induce aberrant behaviour phenotypes in rodents, some of which are known to simulate the behaviour abnormalities observed in patients suffering from schizophrenia. Thus, developing ketamine-induced animal models became an important tool of choice to study the mechanistic details of some critical symptoms associated with schizophrenia. In this study, our goal was to characterize and correlate the ketamine-induced changes in the behavioural phenotypes to the changes in neurochemical and molecular profile(s) in the brain tissues implicated in the pathophysiology of schizophrenia. We studied the effects of ketamine in mice using 'acute' and 'chronic' treatment regimens along with the 'drug withdrawal' effects on their biochemical and molecular parameters in the pre-frontal cortex, hippocampus, and striatum. Our results demonstrated that the acute and chronic ketamine administration, differentially and site specifically, modulated the levels of acetylcholine, dopamine, serotonin and noradrenaline. In addition, the chronic ketamine doses dramatically suppressed the levels of glycine among some of the amino acids examined and induced alternations in gene expression of the key neurotransmitter receptor systems, including some members of the dopamine and the serotonin receptor families. The acute and chronic ketamine treatment induced "signature" neurochemical and gene-expression patterns that are implicated in the pathophysiology of schizophrenia. Our analyses tend to support the "chronic ketamine" mice model for experimental psychosis as a tool for deeper investigation of the mechanistic paradigm associated with the schizophrenia spectrum disorder and for screening next-generation antipsychotic drugs. Highlights: Characterization of neurochemical abnormalities induced by ketamine. Evaluation of the construct validity of the ketamine model of experimental psychosis. Abnormalities in neurotransmitter, amino acids and enzyme activity were studied. Chronic ketamine model possesses better construct validity than the acute model. © 2012 Elsevier Ltd. All rights reserved.
Pathak A.,Sanjay Gandhi Post Graduate Institute of Medical Sciences |
Sinha R.A.,Sanjay Gandhi Post Graduate Institute of Medical Sciences |
Mohan V.,Sanjay Gandhi Post Graduate Institute of Medical Sciences |
Mitra K.,Central Drug Research Institute |
Godbole M.M.,Sanjay Gandhi Post Graduate Institute of Medical Sciences
Cerebral Cortex | Year: 2011
Though aberrant neuronal migration in response to maternal thyroid hormone (TH) deficiency before the onset of fetal thyroid function (embryonic day [E] 17.5) in rat cerebral cortex has been described, molecular events mediating morphogenic actions have remained elusive. To investigate the effect of maternal TH deficiency on neocortical development, rat dams were maintained on methimazole from gestational day 6 until sacrifice. Decreased number and length of radial glia, loss of neuronal bipolarity, and impaired neuronal migration were correctible with early (E13-15) TH replacement. Reelin downregulation under hypothyroidism is neither due to enhanced apoptosis in Cajal-Retzius cells nor mediated through brain-derived neurotrophic factor-tyrosine receptor kinase B alterations. Results based on gel shift and chromatin immunoprecipitation assays show the transcriptional control of reelin by TH through the presence of intronic TH response element. Furthermore, hypothyroidism significantly increased TH receptor α1 with decreased reelin, apolipoprotein E receptor 2, very low-density lipoprotein receptor expression, and activation of cytosolic adapter protein disabled 1 that compromised the reelin signaling. Integrins (αV and β1) are significantly decreased without alteration of α3 indicating intact neuroglial recognition but disrupted adhesion and glial endfeet attachment. Results provide mechanistic basis of essentiality of adequate maternal TH levels to ensue proper fetal neocortical cytoarchitecture and importance of early thyroxine replacement. © The Author 2010. Published by Oxford University Press. All rights reserved.
Shaha C.,National Institute of Immunology |
Tripathi R.,National Institute of Immunology |
Prasad Mishra D.,Central Drug Research Institute
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2010
Cellular apoptosis appears to be a constant feature in the adult testis and during early development. This is essential because mammalian spermatogenesis is a complex process that requires precise homeostasis of different cell types. This review discusses the latest information available on male germ cell apoptosis induced by hormones, toxins and temperature in the context of the type of apoptotic pathway either the intrinsic or the extrinsic that may be used under a variety of stimuli. The review also discusses the importance of mechanisms pertaining to cellular apoptosis during testicular development, which is independent of exogenous stimuli. Since instances of germ cell carcinoma have increased over the past few decades, the current status of research on apoptotic pathways in teratocarcinoma cells is included. One other important aspect that is covered in this review is microRNA-mediated control of germ cell apoptosis, a field of research that is going to see intense activity in near future. Since knockout models of various kinds have been used to study many aspects of germ cell development, a comprehensive summary of literature on knockout mice used in reproduction studies is also provided. © 2010 The Royal Society.
Kumar A.,Central Drug Research Institute
Proteomics | Year: 2010
Kaempferol, a flavonoid, promotes osteoblast mineralization in vitro and bone formation in vivo; however, its mechanism of action is yet unknown. We adopted proteomic approach to identify the differential effect of kaempferol on rat primary calvarial osteoblasts during mineralization. The primary rat calvarial osteoblasts were treated with kaempferol (5.0 microM) for 9 days under mineralizing condition that resulted in significant increase in alkaline phosphatase activity and mineralization of the cells. Further, 2-D analysis of the kaempferol-treated osteoblast lysates revealed 18 differentially expressed proteins (nine upregulated and nine downregulated) on the basis of >/<2.0-fold as cut-off (p<0.01) that were then identified by MALDI-TOF MS. These included cytoskeletal proteins, intracellular signaling protein, chaperone, extracellular matrix protein, and proteins involved in glycolysis and cell-matrix interactions. Proteomics data were confirmed by Western blotting and quantitative real-time PCR by randomly selecting two upregulated and two downregulated proteins. Western blot analysis confirmed upregulation of HSP-70 and cytokeratin-14 levels, and downregulation of aldose reductase and caldesmon expression. We further demonstrated that kaempferol treatment inhibits aldose reductase activity in osteoblasts indicating an altered cellular metabolism by decelerating polyol pathway that was associated with the kaempferol-induced osteoblast mineralization. In conclusion, this is a first comprehensive study on the differential regulation of proteins by kaempferol in primary osteoblast, which would further help to elucidate the role of the identified proteins in the process of osteoblast mineralization.
Mondal S.,Central Drug Research Institute |
Panda G.,Central Drug Research Institute
RSC Advances | Year: 2014
The last decade has witnessed a high demand of various synthetic approaches towards bioactive achiral diarylmethanols, diaryl and triarylmethanes and the molecules derived thereof. Their biological and therapeutical relevancy in diverse areas such as antimicrobials, infectious, cardiovascular and nervous system disorders, genital tract diseases, estrogen related disorders and bone remodeling is quite well known. These small molecules have also been the starting materials for the development of a variety of pharmaceutically important compounds. Compounds belonging to this family have not only played a leading role in the development of small molecules as therapeutically useful compounds but also have become one of the mainstays for the development of organic synthesis. However, a comprehensive review which covers their synthesis as well as their biological activity is still lacking. (Two reviews cover the synthesis of chiral diarylmethanols through asymmetric aryl transfer, and three reviews cover the photochemical properties of triarylmethanes, bioconjugation, application of trityl ions and the use of triarylmethanes as dyes.) This review describes the synthesis as well as the biological activities of this group of molecules that came up in the last fifteen years (1995-2013). The current review will cover the various approaches followed for the synthesis of achiral diarylmethanols and the strategies followed for the synthesis of achiral diaryl as well as triarylmethanes. Finally, we will also cover the bioactivities of molecules containing the diaryl and triaryl methane core. © 2014 the Partner Organisations.
Thakur R.,Central Drug Research Institute |
Mishra D.P.,Central Drug Research Institute
Journal of Cellular and Molecular Medicine | Year: 2013
Beta-catenin (β-catenin) is a multifunction protein with a central role in physiological homeostasis. Its abnormal expression leads to various diseases including cancer. In normal physiology, β-catenin either maintains integrity of epithelial tissues or controls transcription of various genes on extracellular instigations. In epithelial tissues, β-catenin functions as a component of the cadherin protein complex and regulates epithelial cell growth and intracellular adhesion. In Wnt signalling, β-catenin is a major transcriptional modulator and plays a crucial role in embryogenesis, stem cell renewal and organ regeneration. Aberrant expression of β-catenin can induce malignant pathways in normal cells and its abnormal activity is also exploited by existing malignant programmes. It acts as an oncogene and modulates transcription of genes to drive cancer initiation, progression, survival and relapse. Abnormal expression and function of β-catenin in cancer makes it a putative drug target. In the past decade, various attempts have been made to identify and characterize various pharmacological inhibitors of β-catenin. Many of these inhibitors are currently being investigated for their anticancer activities in a variety of cancers. The first half of this review will focus on the role of β-catenin in cancer initiation, maintenance, progression and relapse whereas the second half will briefly summarize the recent progress in development of agents for the pharmacological modulation of β-catenin activity in cancer therapeutics. © 2013.
Singh A.P.,Central Drug Research Institute |
Rajender S.,Central Drug Research Institute
Reproductive BioMedicine Online | Year: 2015
A number of physiological events, such as sperm hyperactivation, chemotaxis towards the egg, capacitation and acrosome reaction, are triggered by activation of sperm ion channels in response to a diverse range of chemical cues. Cation channel of sperm (CatSper), a sperm-specific ion channel, is unique in orchestrating the events for fertilization, and seems to be exclusively evolved for sperm function and male fertility. CatSper acts as a polymodal, chemosensory calcium channel and plays a vital role in the regulation of sperm hyperactivation. CatSper knockout models and application of patch clamp recordings have shown that it is indispensable for male fertility, and mutations and deletions in CatSper gene(s) may lead to infertility. In fact, mutations in CatSper1 and 2 have been identified in infertile individuals; however, CatSper3 and 4 have not been explored. Restricted localization and expression of CatSper in sperm offer an added advantage to developing gamete-based safe non-hormonal contraceptives. This review concisely covers identification, structure, function, and mechanism of action of CatSper channels. The functional importance of this complex ion channel in sperm motility and male fertility is highlighted for further research on male fertility, infertility, and contraception. © 2014 Reproductive Healthcare Ltd. Published by Elsevier Inc. All rights reserved.
Mishra P.R.,Central Drug Research Institute
Journal of Biomedical Nanotechnology | Year: 2011
A ciprofloxacin (CFn)-loaded lipid emulsion was developed for treatment of intra-abdominal infections, especially sepsis. Loading efficiency depended on the proportion of chitosan (CH) and sodium deoxycholate (SDC). The average globule size was 225 to 325 nm. Animal survival improved when the prototype formulation was administered to LPS-induced septic mice. At 4 μg/ml, reduction in TNF-α and NO production were observed (P < 0.05) but at lower concentration these changes were not significant (P > 0.05) as compared to positive control (LPS-1 μg/ml). This indicates that chitosan can modify LPS interaction with macrophages, and that formulations have potential to control inflammation associated with sepsis. Copyright © 2011 American Scientific Publishers All rights reserved.