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2.
Elife ; 112022 10 13.
Article in English | MEDLINE | ID: mdl-36226913

ABSTRACT

Escalated and inappropriate levels of aggressive behavior referred to as pathological in psychiatry can lead to violent outcomes with detrimental impact on health and society. Early life stressful experiences might increase the risk of developing pathological aggressive behavior in adulthood, though molecular mechanisms remain elusive. Here, we provide prefrontal cortex and hypothalamus specific transcriptome profiles of peripubertal stress (PPS) exposed Balb/c adult male mice exhibiting escalated aggression and adult female mice resilient to such aberrant behavioral responses. We identify transthyretin (TTR), a well known thyroid hormone transporter, as a key regulator of PPS induced escalated aggressive behavior in males. Brain-region-specific long-term changes in Ttr gene expression and thyroid hormone (TH) availability were evident in PPS induced escalated aggressive male mice, circulating TH being unaltered. Ttr promoter methylation marks were also altered being hypermethylated in hypothalamus and hypomethylated in prefrontal cortex corroborating with its expression pattern. Further, Ttr knockdown in hypothalamus resulted in escalated aggressive behavior in males without PPS and also reduced TH levels and expression of TH-responsive genes (Nrgn, Trh, and Hr). Escalated aggressive behavior along with reduced Ttr gene expression and TH levels in hypothalamus was also evident in next generation F1 male progenies. Our findings reveal that stressful experiences during puberty might trigger lasting escalated aggression by modulating TTR expression in brain. TTR can serve as a potential target in reversal of escalated aggression and related psychopathologies.


Subject(s)
Prealbumin , Sexual Maturation , Animals , Mice , Male , Female , Prealbumin/genetics , Prealbumin/metabolism , Aggression/physiology , Prefrontal Cortex/metabolism , Mice, Inbred BALB C , Thyroid Hormones/metabolism
4.
Neurochem Int ; 149: 105124, 2021 10.
Article in English | MEDLINE | ID: mdl-34245808

ABSTRACT

Brain and neuronal circuits constitute the most complex organ networks in human body. They not only control and coordinate functions of all other organs, but also represent one of the most-affected systems with stress, lifestyle and age. With global increase in aging populations, these neuropathologies have emerged as major concern for maintaining quality of life. Recent era has witnessed a surge in nutritional remediation of brain dysfunctions primarily by "nutraceuticals" that refer to functional foods and supplements with pharmacological potential. Specific dietary patterns with a balanced intake of carbohydrates, fatty acids, vitamins and micronutrients have also been ascertained to promote brain health. Dietary herbs and their phytochemicals with wide range of biological and pharmacological activities and minimal adverse effects have gained remarkable attention as neuro-nutraceuticals. Neuro-nutraceutical potentials of herbs are often expressed as effects on cognitive response, circadian rhythm, neuromodulatory, antioxidant and anti-inflammatory activities that are mediated by effects on gene expression, epigenetics, protein synthesis along with their turnover and metabolic pathways. Epidemiological and experimental evidence have implicated enormous applications of herbal supplementation in neurodegenerative and psychiatric disorders. The present review highlights the identification, experimental evidence and applications of some herbs including Bacopa monniera, Withania somnifera, Curcuma longa, Helicteres angustifolia, Undaria pinnatifida, Haematococcus pluvialis, and Vitis vinifera, as neuro-nutraceuticals.


Subject(s)
Antioxidants/therapeutic use , Brain Diseases/drug therapy , Brain/drug effects , Dietary Supplements , Nootropic Agents/therapeutic use , Plant Preparations/therapeutic use , Animals , Antioxidants/isolation & purification , Antioxidants/pharmacology , Brain/metabolism , Brain Diseases/metabolism , Humans , Nootropic Agents/isolation & purification , Nootropic Agents/pharmacology , Phytochemicals/isolation & purification , Phytochemicals/pharmacology , Phytochemicals/therapeutic use , Plant Preparations/isolation & purification , Plant Preparations/pharmacology
5.
Neurochem Int ; 143: 104928, 2021 02.
Article in English | MEDLINE | ID: mdl-33285273

ABSTRACT

Cognitive abilities are compromised with advancing age posing a great risk for the development of dementia and other related brain disorders. Genetic susceptibility as well as environmental exposures determine the fate of cognitive aging and its transition to pathological states. Emerging epidemiological and observational studies have revealed the importance of lifestyle factors including dietary patterns and nutritional intake in the maintenance of cognitive health and reducing the risk of neurodegenerative disorders. In this context, nutraceutical interventions have gained considerable attention in preventing age-related cognitive deficits and counteracting pathological processes. Nutraceuticals include dietary plants and derivatives, food supplements and processed foods with nutritional and pharmaceutical values. The present review highlights the importance of nutraceuticals in attenuating cognitive aging and its progression to dementia, with specific emphasis on chemical constituents, neurocognitive properties and mechanism of action.


Subject(s)
Cognitive Aging/physiology , Cognitive Aging/psychology , Cognitive Dysfunction/diet therapy , Cognitive Dysfunction/psychology , Dietary Supplements , Aging/physiology , Aging/psychology , Animals , Antioxidants/administration & dosage , Cognition/physiology , Cognitive Dysfunction/physiopathology , Humans
6.
Front Aging Neurosci ; 12: 561925, 2020.
Article in English | MEDLINE | ID: mdl-33244299

ABSTRACT

Cell-based screening of bioactive compounds has served as an important gateway in drug discovery. In the present report, using human neuroblastoma cells and enrolling an extensive three-step screening of 57 phytochemicals, we have identified caffeic acid phenethyl ester (CAPE) as a potent neurodifferentiating natural compound. Analyses of control and CAPE-induced neurodifferentiated cells revealed: (i) modulation of several key proteins (NF200, MAP-2, NeuN, PSD95, Tuj1, GAP43, and GFAP) involved in neurodifferentiation process; and (ii) attenuation of neuronal stemness (HOXD13, WNT3, and Msh-2) and proliferation-promoting (CDC-20, CDK-7, and BubR1) proteins. We anticipated that the neurodifferentiation potential of CAPE may be beneficial for the treatment of neurodegenerative diseases and tested it using the Drosophila model of Alzheimer's disease (AD) and mice model of amnesia/loss of memory. In both models, CAPE exhibited improved disease symptoms and activation of physiological functions. Remarkably, CAPE-treated mice showed increased levels of neurotrophin-BDNF, neural progenitor marker-Nestin, and differentiation marker-NeuN, both in the cerebral cortex and hippocampus. Taken together, we demonstrate the differentiation-inducing and therapeutic potential of CAPE for neurodegenerative diseases.

7.
Neurochem Res ; 45(4): 796-808, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31960226

ABSTRACT

The present study demonstrates the epigenetic mechanisms underlying the effect of Bacoside rich extract of Bacopa monniera-a nootropic herb, on scopolamine treated amnesic mice conferred via chromatin modifying enzymes. The focus of the work was to elucidate the modulation of the chromatin modifying enzymes: DNMT1, DNMT3a, DNMT3b, HDAC2, HDAC5 and CPB in scopolamine induced amnesic mice after treatment with bacoside rich extract of Bacopa monniera (BA) and BA encapsulated in lactoferrin conjugated PEG-PLA-PCL-OH based polymersomes (BAN). We observed remarkable difference between the results obtained after the treatment with BA and BAN. Interestingly BAN was found to be more efficient in downregulating DNA methylation and histone chain deacetylation. Scopolamine treatment showed up-regulation of DNMT1 expression in qRT-PCR by 3.14-fold as compared to the control, which was considerably decreased by 1.5-fold after treatment with BA and remarkably decreased 0.11-fold by BAN treatment. Scopolamine treatment up-regulated the expression of DNMT3a by 1.6-fold while for DNMT3b by 3.13-fold. In DNMT3a and DNMT3b the fold change decreased to 0.64 and 0.76 after BA treatment, whereas the BAN treatment further down-regulated to 0.32- and 0.63-fold, respectively. Similarly scopolamine up-regulated HDAC2 and HDAC5 by 3.12 fold and 3.64-fold, respectively. BA treatment reversed the changes by reducing HDAC2 mRNA to 0.89-fold and HDAC5 mRNA 0.83-fold. BAN further reduced expression of HDAC2 further to 0.39-fold and HDAC5 to 0.31-fold. On the other hand scopolamine down-regulated CBP mRNA expression by 0.28-fold and increased by 1.09 after BA treatment. BAN significantly increased the CPB expression by 1.65-fold as compared to BA treatment. These findings were consolidated by DNMT and HDAC enzyme activity assay, methylation in the promoter region of the memory related genes: ARC and BDNF and Dot blot assay for DNA methylation. The percent activity increase of DNMT and HDAC after scopolamine administration was 375.74 and 240.90 respectively. After treatment with BA the downfall in percent activity was observed as 167.99 in DMNT and 130.57 in HDAC. BAN treatment further decreased the percent enzyme activity of DNMT and HDAC significantly by 30.0 and 61.81 respectively. The potency of BAN in reversing the epigenetic changes of scopolamine induced amnesic mouse brain, can be attributed to the brain specific delivery of BA through polymersomes which are able to cross the blood brain barrier (BBB) via receptor mediated endocytosis.


Subject(s)
Amnesia/drug therapy , Drug Carriers/chemistry , Epigenesis, Genetic/drug effects , Saponins/therapeutic use , Amnesia/chemically induced , Animals , Bacopa/chemistry , DNA (Cytosine-5-)-Methyltransferases/metabolism , Histone Deacetylases/metabolism , Lactoferrin/chemistry , Male , Mice , Polyesters/chemistry , Polyethylene Glycols/chemistry , Scopolamine
8.
Sci Rep ; 9(1): 13990, 2019 Sep 30.
Article in English | MEDLINE | ID: mdl-31570736

ABSTRACT

Memory loss is one of the most tragic symptoms of Alzheimer's disease. Our laboratory has recently demonstrated that 'i-Extract' of Ashwagandha (Withania somnifera) restores memory loss in scopolamine (SC)-induced mice. The prime target of i-Extract is obscure. We hypothesize that i-Extract may primarily target muscarinic subtype acetylcholine receptors that regulate memory processes. The present study elucidates key target(s) of i-Extract via cellular, biochemical, and molecular techniques in a relevant amnesia mouse model and primary hippocampal neuronal cultures. Wild type Swiss albino mice were fed i-Extract, and hippocampal cells from naïve mice were treated with i-Extract, followed by muscarinic antagonist (dicyclomine) and agonist (pilocarpine) treatments. We measured dendritic formation and growth by immunocytochemistry, kallikrein 8 (KLK8) mRNA by reverse transcription polymerase chain reaction (RT-PCR), and levels of KLK8 and microtubule-associated protein 2, c isoform (MAP2c) proteins by western blotting. We performed muscarinic receptor radioligand binding. i-Extract stimulated an increase in dendrite growth markers, KLK8 and MAP2. Scopolamine-mediated reduction was significantly reversed by i-Extract in mouse cerebral cortex and hippocampus. Our study identified muscarinic receptor as a key target of i-Extract, providing mechanistic evidence for its clinical application in neurodegenerative cognitive disorders.


Subject(s)
Memory/drug effects , Nerve Regeneration/drug effects , Neuroprotective Agents/pharmacology , Plant Extracts/pharmacology , Receptor, Muscarinic M1/drug effects , Withania/chemistry , Animals , Blotting, Western , Dendrites/drug effects , Dendrites/physiology , Dicyclomine/pharmacology , Female , Male , Mice , Mice, Transgenic , Pilocarpine/pharmacology , Receptor, Muscarinic M1/agonists , Receptor, Muscarinic M1/antagonists & inhibitors , Reverse Transcriptase Polymerase Chain Reaction , Scopolamine/pharmacology
9.
Neurochem Int ; 129: 104510, 2019 10.
Article in English | MEDLINE | ID: mdl-31348967

ABSTRACT

The maladaptive form of aggressive behavior confers risk for violence and criminal incidences with profound impact on society. Although considerable research has been devoted to elucidate the etiology of aggression, molecular correlates of sex differences remains largely unexplored. Also, little attention has been given to whether males and females respond differently to similar causal factor of aggression. Here, we show the possible association of brain region specific neural activity (c-Fos expression) and monoamine oxidase A (MAOA) epigenetic state with sexual dimorphism in peripubertal stress (PPS) induced adulthood aggression. While PPS adult males exhibited escalated aggression, females spent maximal time in social exploration. c-Fos expression was brain region and sex specific. In the PPS adult cohort, only males showed elevated c-Fos expression in the prefrontal cortex, indicative of their hyper-responsive behavior. MAOA expression and enzyme activity was reduced in hypothalamus and increased in prefrontal cortex of hyper-aggressive male mice. Investigation into the underlying mechanisms revealed hypomethylation in prefrontal cortex and hypermethylation in hypothalamus of MAOA promoter negatively correlating with the expression pattern. On the other hand, binding of Sirt1 to MAOA promoter was diametrically opposite being increased in prefrontal cortex and reduced in hypothalamus. In females, neither expression nor epigenetic state of MAOA gene was significantly altered between control and PPS adult mice. Our study revealed novel epigenetic correlates of sexual dimorphism in stress induced aggressive psychopathology. However, given the multi-factorial nature with environmental influences, further studies are warranted to uncover the biological hub.


Subject(s)
Hypothalamus/enzymology , Monoamine Oxidase/genetics , Nerve Tissue Proteins/genetics , Prefrontal Cortex/enzymology , Promoter Regions, Genetic , Sex Characteristics , Stress, Psychological/genetics , Aggression , Agonistic Behavior , Animals , Base Sequence , Clorgyline/pharmacology , DNA Methylation , Fear , Female , Male , Mice , Mice, Inbred BALB C , Monoamine Oxidase/analysis , Monoamine Oxidase Inhibitors/pharmacology , Nerve Tissue Proteins/analysis , Odorants , Selegiline/pharmacology , Sirtuin 1/metabolism
10.
Nanoscale ; 10(37): 17781-17798, 2018 Sep 27.
Article in English | MEDLINE | ID: mdl-30215650

ABSTRACT

In the present study, engineered lactoferrin (Lf)-conjugated pH and redox-sensitive polymersomes derived from the triblock copolymer polyethylene glycol-S-S-polylactic acid-polycaprolactone (PEG-S-S-PLA-PCL-OH) have been used to deliver bacosides to the brain. Bacosides are classified as triterpenoid saponins and are used in Indian Ayurveda for reversal of amnesia; however, no study has extensively demonstrated their efficacy as a nano-formulation in an animal model. The polymer was synthesized by ring opening polymerization of lactide and ε-caprolactone. The nanoparticles obtained by nanoprecipitation showed a core-shell morphology, with an average size of 110 nm, by transmission electron microscopy (TEM). The colloidal stability, hemocompatibility and cytocompatibility of the polymersomes proved their biocompatibility. pH and disulfide linkages in the polymeric chain accelerated the disintegration of the polymersomes at pH 6.6 and at pH 6.6 with glutathione (GSH) in comparison to pH 7.4, supporting their degradation behavior. Supermagnetic iron oxide nanoparticles (SPIONs, 74.99 µg mg-1 polymer) encapsulated into the polymersomes demonstrated their uptake in a mouse model by MRI. Furthermore, bacosides encapsulated in the polymersomes (10% loading) showed significant memory loss reversal in chemically induced amnesic mice, supported by the gene expression profiles of Arc, BDNF and CREB as well as by histopathology.


Subject(s)
Brain/drug effects , Drug Carriers/chemistry , Lactoferrin/chemistry , Saponins/administration & dosage , Triterpenes/administration & dosage , Animals , Bacopa/chemistry , Blood-Brain Barrier , Brain-Derived Neurotrophic Factor/metabolism , Cell Line , Cyclic AMP Response Element-Binding Protein/metabolism , Cytoskeletal Proteins/metabolism , Humans , Hydrogen-Ion Concentration , Male , Mice , Nerve Tissue Proteins/metabolism , Oxidation-Reduction , Plant Extracts/chemistry , Polyesters , Polyethylene Glycols , Polymers
11.
Sci Rep ; 8(1): 9928, 2018 07 02.
Article in English | MEDLINE | ID: mdl-29967374

ABSTRACT

The multitude of molecular pathways underlying memory impairment in neurological disorders and aging-related disorders has been a major hurdle against therapeutic targeting. Over the years, neuronal growth promoting factors, intracellular kinases, and specific transcription factors, particularly cyclic AMP response element-binding protein (CREB), have emerged as crucial players of memory storage, and their disruption accompanies many cognitive disabilities. However, a molecular link that can influence these major players and can be a potential recovery target has been elusive. Recent reports suggest that extracellular cues at the synapses might evoke an intracellular signaling cascade and regulate memory function. Herein, we report novel function of an extracellular serine protease, kallikrein 8 (KLK8/Neuropsin) in regulating the expression of microtubule associated dendrite growth marker microtubule-associated protein (MAP2)c, dendrite architecture and protein kinase A (PKA)-CREB signaling. Both knockdown of KLK8 via siRNA transfection in mouse primary hippocampal neurons and via intra-hippocampal administration of KLK8 antisense oligonucleotides in vivo reduced expression of MAP2c, dendrite length, dendrite branching and spine density. The KLK8 mediated MAP2c deficiency in turn inactivated PKA and downstream transcription factor phosphorylated CREB (pCREB), leading to downregulation of memory-linked genes and consequent impaired memory consolidation. These findings revealed a protease associated novel pathway of memory impairment in which KLK8 may act as a "regulator of regulators", suggesting its exploration as an important therapeutic target of memory disorders.


Subject(s)
Dendrites/metabolism , Hippocampus/metabolism , Kallikreins/metabolism , Memory Disorders/metabolism , Microtubule-Associated Proteins/metabolism , Neural Cell Adhesion Molecule L1/metabolism , Signal Transduction , Animals , Cyclic AMP Response Element-Binding Protein/metabolism , Cyclic AMP-Dependent Protein Kinases/metabolism , Dendrites/physiology , Gene Expression Regulation , Hippocampus/physiopathology , Male , Memory , Memory Disorders/genetics , Memory Disorders/physiopathology , Mice , Microtubule-Associated Proteins/genetics , Proteolysis
13.
BMC Genomics ; 18(1): 417, 2017 05 30.
Article in English | MEDLINE | ID: mdl-28558688

ABSTRACT

BACKGROUND: Restriction site associated DNA sequencing (RADseq) has the potential to be a broadly applicable, low-cost approach for high-quality genetic linkage mapping in forest trees lacking a reference genome. The statistical inference of linear order must be as accurate as possible for the correct ordering of sequence scaffolds and contigs to chromosomal locations. Accurate maps also facilitate the discovery of chromosome segments containing allelic variants conferring resistance to the biotic and abiotic stresses that threaten forest trees worldwide. We used ddRADseq for genetic mapping in the tree Quercus rubra, with an approach optimized to produce a high-quality map. Our study design also enabled us to model the results we would have obtained with less depth of coverage. RESULTS: Our sequencing design produced a high sequencing depth in the parents (248×) and a moderate sequencing depth (15×) in the progeny. The digital normalization method of generating a de novo reference and the SAMtools SNP variant caller yielded the most SNP calls (78,725). The major drivers of map inflation were multiple SNPs located within the same sequence (77% of SNPs called). The highest quality map was generated with a low level of missing data (5%) and a genome-wide threshold of 0.025 for deviation from Mendelian expectation. The final map included 849 SNP markers (1.8% of the 78,725 SNPs called). Downsampling the individual FASTQ files to model lower depth of coverage revealed that sequencing the progeny using 96 samples per lane would have yielded too few SNP markers to generate a map, even if we had sequenced the parents at depth 248×. CONCLUSIONS: The ddRADseq technology produced enough high-quality SNP markers to make a moderately dense, high-quality map. The success of this project was due to high depth of coverage of the parents, moderate depth of coverage of the progeny, a good framework map, an optimized bioinformatics pipeline, and rigorous premapping filters. The ddRADseq approach is useful for the construction of high-quality genetic maps in organisms lacking a reference genome if the parents and progeny are sequenced at sufficient depth. Technical improvements in reduced representation sequencing (RRS) approaches are needed to reduce the amount of missing data.


Subject(s)
Chromosome Mapping/methods , DNA Restriction Enzymes/metabolism , Quercus/genetics , Sequence Analysis, DNA , Genotyping Techniques , Polymorphism, Single Nucleotide
14.
Aging Dis ; 7(2): 121-9, 2016 Mar.
Article in English | MEDLINE | ID: mdl-27114845

ABSTRACT

Age-associated cognitive decline is an inevitable phenomenon that predisposes individuals for neurological and psychiatric disorders eventually affecting the quality of life. Scientists have endeavored to identify the key molecular switches that drive cognitive decline with advancing age. These newly identified molecules are then targeted as recovery of cognitive aging and related disorders. Cognitive decline during aging is multi-factorial and amongst several factors influencing this trajectory, gene expression changes are pivotal. Identifying these genes would elucidate the neurobiological underpinnings as well as offer clues that make certain individuals resilient to withstand the inevitable age-related deteriorations. Our laboratory has focused on this aspect and investigated a wide spectrum of genes involved in crucial brain functions that attribute to senescence induced cognitive deficits. We have recently identified master switches in the epigenome regulating gene expression alteration during brain aging. Interestingly, these factors when manipulated by chemical or genetic strategies successfully reverse the age-related cognitive impairments. In the present article, we review findings from our laboratory and others combined with supporting literary evidences on molecular switches of brain aging and their potential as recovery targets.

15.
Neurochem Int ; 95: 109-18, 2016 May.
Article in English | MEDLINE | ID: mdl-26361721

ABSTRACT

Rapidly increasing aging population and environmental stressors are the two main global concerns of the modern society. These have brought in light rapidly increasing incidence of a variety of pathological conditions including brain tumors, neurodegenerative & neuropsychiatric disorders, and new challenges for their treatment. The overlapping symptoms, complex etiology and lack of full understanding of the brain structure and function to-date further complicate these tasks. On the other hand, several herbal reagents with a long history of their use have been asserted to possess neurodifferentiation, neuroregenerative and neuroprotective potentials, and hence been recommended as supplement to enhance and maintain brain health and function. Although they have been claimed to function by holistic approach resulting in maintaining body homeostasis and brain health, there are not enough laboratory studies in support to these and mechanism(s) of such beneficial activities remain largely undefined. One such herb is Ashwagandha, also called "Queen of Ayurveda" for its popular use in Indian traditional home medicine because of its extensive benefits including anticancer, anti-stress and remedial potential for aging and neurodegenerative pathologies. However, active principles and underlying mechanism(s) of action remain largely unknown. Here we provide a review on the effects of Ashwagandha extracts and active principles, and underlying molecular mechanism(s) for brain pathologies. We highlight our findings on the nootropic potential of Ashwagandha leaves. The effects of Ashwagandha leaf extracts are multidimensional ranging from differentiation of neuroblastoma and glioma cells, reversal of Alzheimer and Parkinson's pathologies, protection against environmental neurotoxins and enhancement of memory.


Subject(s)
Neurodegenerative Diseases/drug therapy , Nootropic Agents/therapeutic use , Plant Extracts/therapeutic use , Plant Leaves , Plant Roots , Animals , Humans , Medicine, Ayurvedic , Neurodegenerative Diseases/metabolism , Nootropic Agents/chemistry , Nootropic Agents/isolation & purification , Plant Extracts/chemistry , Plant Extracts/isolation & purification
16.
Article in English | MEDLINE | ID: mdl-26413129

ABSTRACT

Preclinical studies on animal models have discerned the antiamnesic and memory-enhancing potential of Bacopa monniera (Brahmi) crude extract and standardized extracts. These studies primarily focus on behavioral consequences. However, lack of information on molecular underpinnings has limited the clinical trials of the potent herb in human subjects. In recent years, researchers highlight plasticity markers as molecular correlates of amnesia and being crucial to design therapeutic targets. In the present report, we have investigated the effect of a special extract of B. monniera (CDRI-08) on the expression of key neuronal (BDNF and Arc) and glial (GFAP) plasticity markers in the cerebrum of scopolamine induced amnesic mice. Pre- and postadministration of CDRI-08 ameliorated amnesic effect of scopolamine by decreasing acetyl cholinesterase activity and drastically upregulating the mRNA and protein expression of BDNF, Arc, and GFAP in mouse cerebrum. Interestingly, the plant extract per se elevated BDNF and Arc expression as compared to control but GFAP was unaltered. In conclusion, our findings provide the first molecular evidence for antiamnesic potential of CDRI-08 via enhancement of both neuronal and glial plasticity markers. Further investigations on detailed molecular pathways would encourage therapeutic application of the extract in memory disorders.

17.
J Neurochem ; 134(4): 642-51, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25982413

ABSTRACT

The amnesic potential of scopolamine is well manifested through synaptic plasticity gene expression changes and behavioral paradigms of memory impairment. However, the underlying mechanism remains obscure and consequently ideal therapeutic target is lacking. In this context, chromatin-modifying enzymes, which regulate memory gene expression changes, deserve major attention. Therefore, we analyzed the expression of chromatin-modifying enzymes and recovery potential of enzyme modulators in scopolamine-induced amnesia. Scopolamine administration drastically up-regulated DNA methyltransferases (DNMT1) and HDAC2 expression while CREB-binding protein (CBP), DNMT3a and DNMT3b remained unaffected. HDAC inhibitor sodium butyrate and DNMT inhibitor Aza-2'deoxycytidine recovered scopolamine-impaired hippocampal-dependent memory consolidation with concomitant increase in the expression of synaptic plasticity genes Brain-derived neurotrophic factor (BDNF) and Arc and level of histone H3K9 and H3K14 acetylation and decrease in DNA methylation level. Sodium butyrate showed more pronounced effect than Aza-2'deoxycytidine and their co-administration did not exhibit synergistic effect on gene expression. Taken together, we showed for the first time that scopolamine-induced up-regulation of chromatin-modifying enzymes, HDAC2 and DNMT1, leads to gene expression changes and consequent decline in memory consolidation. Our findings on the action of scopolamine as an epigenetic modulator can pave a path for ideal therapeutic targets. We propose the following putative pathway for scopolamine-mediated memory impairment; scopolamine up-regulates hippocampal DNMT1 and HDAC2 expression, induces methylation and deacetylation of BDNF and Arc promoter, represses gene expression and eventually impairs memory consolidation. On the other hand, Aza-2 and NaB inhibit DNMT1 and HDAC2 respectively, up-regulate BDNF and Arc expression and recover memory consolidation. We elucidate the action of scopolamine as an epigenetic modulator and hope that DNMT1 and HDAC2 would be ideal therapeutic targets for memory disorders.


Subject(s)
Chromatin/enzymology , DNA (Cytosine-5-)-Methyltransferases/biosynthesis , Hippocampus/enzymology , Histone Deacetylase 2/biosynthesis , Memory Disorders/enzymology , Scopolamine/toxicity , Animals , DNA (Cytosine-5-)-Methyltransferase 1 , Gene Expression Regulation , Hippocampus/drug effects , Male , Memory Disorders/chemically induced , Mice , Neuronal Plasticity/drug effects , Neuronal Plasticity/physiology
18.
Mol Neurobiol ; 51(3): 1130-8, 2015.
Article in English | MEDLINE | ID: mdl-24965600

ABSTRACT

Neuropsin (NP) is a serine protease, implicated in synaptic plasticity and memory acquisition through cleavage of synaptic adhesion molecule, L1CAM. However, NP has not been explored during brain aging that entails drastic deterioration of plasticity and memory with selective regional vulnerability. Therefore, we have analysed the expression of NP and correlated with its function via analysis of endogenous cleavage of L1CAM and level of dendritic marker MAP2c in different regions of the aging mouse brain. While NP expression gradually decreased in the cerebral cortex during aging, it showed a sharp rise in both olfactory bulb and hippocampus in adult and thereafter declined in old age. NP expression was moderate in young medulla, but undetectable in midbrain and cerebellum. It was positively correlated with L1CAM cleavage and MAP2c level in different brain regions during aging. Taken together, our study shows age-dependent regional variation in NP expression and its positive correlation with MAP2c level, suggesting the involvement of NP in MAP2c mediated alterations in dendritic morphology during aging.


Subject(s)
Aging/metabolism , Brain/metabolism , Dendrites/metabolism , Kallikreins/biosynthesis , Microtubule-Associated Proteins/biosynthesis , Aging/pathology , Animals , Brain/pathology , Dendrites/pathology , Gene Expression Regulation , Male , Mice
19.
PLoS One ; 6(11): e27265, 2011.
Article in English | MEDLINE | ID: mdl-22096544

ABSTRACT

BACKGROUND: Scopolamine is a well-known cholinergic antagonist that causes amnesia in human and animal models. Scopolamine-induced amnesia in rodent models has been widely used to understand the molecular, biochemical, behavioral changes, and to delineate therapeutic targets of memory impairment. Although this has been linked to the decrease in central cholinergic neuronal activity following the blockade of muscarinic receptors, the underlying molecular and cellular mechanism(s) particularly the effect on neuroplasticity remains elusive. In the present study, we have investigated (i) the effects of scopolamine on the molecules involved in neuronal and glial plasticity both in vivo and in vitro and (ii) their recovery by alcoholic extract of Ashwagandha leaves (i-Extract). METHODOLOGY/PRINCIPAL FINDINGS: As a drug model, scopolamine hydrobromide was administered intraperitoneally to mice and its effect on the brain function was determined by molecular analyses. The results showed that the scopolamine caused downregulation of the expression of BDNF and GFAP in dose and time dependent manner, and these effects were markedly attenuated in response to i-Extract treatment. Similar to our observations in animal model system, we found that the scopolamine induced cytotoxicity in IMR32 neuronal and C6 glioma cells. It was associated with downregulation of neuronal cell markers NF-H, MAP2, PSD-95, GAP-43 and glial cell marker GFAP and with upregulation of DNA damage--γH2AX and oxidative stress--ROS markers. Furthermore, these molecules showed recovery when cells were treated with i-Extract or its purified component, withanone. CONCLUSION: Our study suggested that besides cholinergic blockade, scopolamine-induced memory loss may be associated with oxidative stress and Ashwagandha i-Extract, and withanone may serve as potential preventive and therapeutic agents for neurodegenerative disorders and hence warrant further molecular analyses.


Subject(s)
Brain/drug effects , Plant Extracts/pharmacology , Plant Leaves/chemistry , Scopolamine/toxicity , Triterpenes/pharmacology , Withania/chemistry , Animals , Brain/metabolism , Brain-Derived Neurotrophic Factor/metabolism , Cell Line , Cell Line, Tumor , DNA Damage/drug effects , Glial Fibrillary Acidic Protein , Mice , Nerve Tissue Proteins/metabolism , Oxidative Stress/drug effects , Withanolides
20.
Middle East Afr J Ophthalmol ; 18(2): 192-4, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21731335

ABSTRACT

Amniotic band syndrome manifests at birth with a variety of malformations ranging from constriction ring to defects incompatible to life, in various parts of the body. Although some theories have been proposed for the development of this syndrome, the exact cause remains unknown. The median facial cleft is an extremely rare manifestation of amniotic band syndrome with a relative paucity of reports available in the literature. Here, we report one such case.

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