Publications by authors named "Ansuman Chattopadhyay"

48 Publications

Bacopasaponins with cytotoxic activity against human breast cancer cells in vitro.

Mol Biol Rep 2021 Mar 10;48(3):2497-2505. Epub 2021 Apr 10.

Department of Zoology, Visva-Bharati, Santiniketan, West Bengal, 731235, India.

Globally, breast cancer is a serious concern that exhibits a persistent rise in its incidence and related mortality even after significant advancement in the field of cancer research. To find an alternative cure for the disease from natural resources we selected Bacopa monniera, a perennial ethnomedicinal plant popularly used for boosting memory and mental health. We isolated four different types of dammarane saponins, namely bacopasaponins C-F (1-4) from the plant and evaluated their toxic effects on two different types of human breast cancer cell lines-a hormone-responsive MCF7 and a triple-negative MDA-MB-231. Interestingly, MTT assay revealed a dose-dependent toxic effect of all four types of bacopasaponins on both of these cell lines, 4 being the most effective with 48 h-inhibitory concentration (IC) of 32.44 and 30 µM in MCF7 and MDA-MB-231 respectively. Further, 4 caused significant alterations in normal cytomorphology and induction of apoptosis in both of these cell lines after 48 h of treatment. No caspase-8 activity was detected in these cell lines when exposed to 4 for 2, 24, and 48 h; instead, Western blotting analysis confirmed involvement of either caspase-9 (MCF7) or both caspase-9 and caspase-3 (MDA-MB-231) in the process of apoptosis indicating the occurrence of intrinsic mode. Additionally, at comparable effective doses to cancer, bacopasaponins showed much less toxicity in normal human peripheral blood lymphocytes (≥ 85% cell survival). Overall, the findings project bacopasaponin F, a natural constituent of Bacopa monniera, as an efficient and safer alternative for breast cancer therapeutics.
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http://dx.doi.org/10.1007/s11033-021-06284-2DOI Listing
March 2021

Identifying Molecular Signatures of Distinct Modes of Collective Migration in Response to the Microenvironment Using Three-Dimensional Breast Cancer Models.

Cancers (Basel) 2021 Mar 20;13(6). Epub 2021 Mar 20.

Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261, USA.

Collective cell migration is a key feature of transition of ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC) among many other cancers, yet the microenvironmental factors and underlying mechanisms that trigger collective migration remain poorly understood. Here, we investigated two microenvironmental factors, tumor-intrinsic hypoxia and tumor-secreted factors (secretome), as triggers of collective migration using three-dimensional (3D) discrete-sized microtumor models that recapitulate hallmarks of DCIS-IDC transition. Interestingly, the two factors induced two distinct modes of collective migration: directional and radial migration in the 3D microtumors generated from the same breast cancer cell line model, T47D. Without external stimulus, large (600 µm) T47D microtumors exhibited tumor-intrinsic hypoxia and directional migration, while small (150 µm), non-hypoxic microtumors exhibited radial migration only when exposed to the secretome of large microtumors. To investigate the mechanisms underlying hypoxia- and secretome-induced directional vs. radial migration modes, we performed differential gene expression analysis of hypoxia- and secretome-induced migratory microtumors compared with non-hypoxic, non-migratory small microtumors as controls. We propose unique gene signature sets related to tumor-intrinsic hypoxia, hypoxia-induced epithelial-mesenchymal transition (EMT), as well as hypoxia-induced directional migration and secretome-induced radial migration. Gene Set Enrichment Analysis (GSEA) and protein-protein interaction (PPI) network analysis revealed enrichment and potential interaction between hypoxia, EMT, and migration gene signatures for the hypoxia-induced directional migration. In contrast, hypoxia and EMT were not enriched in the secretome-induced radial migration, suggesting that complete EMT may not be required for radial migration. Survival analysis identified unique genes associated with low survival rate and poor prognosis in TCGA-breast invasive carcinoma dataset from our tumor-intrinsic hypoxia gene signature (CXCR4, FOXO3, LDH, NDRG1), hypoxia-induced EMT gene signature (EFEMP2, MGP), and directional migration gene signature (MAP3K3, PI3K3R3). NOS3 was common between hypoxia and migration gene signature. Survival analysis from secretome-induced radial migration identified ATM, KCNMA1 (hypoxia gene signature), and KLF4, IFITM1, EFNA1, TGFBR1 (migration gene signature) to be associated with poor survival rate. In conclusion, our unique 3D cultures with controlled microenvironments respond to different microenvironmental factors, tumor-intrinsic hypoxia, and secretome by adopting distinct collective migration modes and their gene expression analysis highlights the phenotypic heterogeneity and plasticity of epithelial cancer cells.
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http://dx.doi.org/10.3390/cancers13061429DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8004051PMC
March 2021

Fibrosis Distinguishes Critical Limb Ischemia Patients from Claudicants in a Transcriptomic and Histologic Analysis.

J Clin Med 2020 Dec 8;9(12). Epub 2020 Dec 8.

Department of Surgery, University of Pittsburgh Medical Centre, Pittsburgh, PA 15217, USA.

Most patients with critical limb ischemia (CLI) from peripheral arterial disease (PAD) do not have antecedent intermittent claudication (IC). We hypothesized that transcriptomic analysis would identify CLI-specific pathways, particularly in regards to fibrosis. Derivation cohort data from muscle biopsies in PAD and non-PAD (controls) was obtained from the Gene Expression Omnibus (GSE120642). Transcriptomic analysis indicated CLI patients (N = 16) had a unique gene expression profile, when compared with non-PAD controls (N = 15) and IC (N = 20). Ninety-eight genes differed between controls and IC, 2489 genes differed between CLI and controls, and 2783 genes differed between CLI and IC patients. Pathway enrichment analysis showed that pathways associated with TGFβ, collagen deposition, and VEGF signaling were enriched in CLI but not IC. Receiver operating curve (ROC) analysis of nine fibrosis core gene expression revealed the areas under the ROC (AUC) were all >0.75 for CLI. Furthermore, the fibrosis area (AUC = 0.81) and % fibrosis (AUC = 0.87) in validation cohort validated the fibrosis discrimination CLI from IC and control (all n = 12). In conclusion, transcriptomic analysis identified fibrosis pathways, including those involving TGFβ, as a novel gene expression feature for CLI but not IC. Fibrosis is an important characteristic of CLI, which we confirmed histologically, and may be a target for novel therapies in PAD.
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http://dx.doi.org/10.3390/jcm9123974DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7763090PMC
December 2020

Activation of endothelial Wnt/β-catenin signaling by protective astrocytes repairs BBB damage in ischemic stroke.

Prog Neurobiol 2021 Apr 26;199:101963. Epub 2020 Nov 26.

Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA; The Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA. Electronic address:

The role of astrocytes in dysregulation of blood-brain barrier (BBB) function following ischemic stroke is not well understood. Here, we investigate the effects of restoring the repair properties of astrocytes on the BBB after ischemic stroke. Mice deficient for NHE1, a pH-sensitive Na/H exchanger 1, in astrocytes have reduced BBB permeability after ischemic stroke, increased angiogenesis and cerebral blood flow perfusion, in contrast to wild-type mice. Bulk RNA-sequencing transcriptome analysis of purified astrocytes revealed that ∼177 genes were differentially upregulated in mutant astrocytes, with Wnt7a mRNA among the top genes. Using a Wnt reporter line, we confirmed that the pathway was upregulated in cerebral vessels of mutant mice after ischemic stroke. However, administration of the Wnt/β-catenin inhibitor, XAV-939, blocked the reparative effects of Nhe1-deficient astrocytes. Thus, astrocytes lacking pH-sensitive NHE1 protein are transformed from injurious to "protective" by inducing Wnt production to promote BBB repair after ischemic stroke.
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http://dx.doi.org/10.1016/j.pneurobio.2020.101963DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7925353PMC
April 2021

Combined effect of arsenic and fluoride at environmentally relevant concentrations in zebrafish (Danio rerio) brain: Alterations in stress marker and apoptotic gene expression.

Chemosphere 2021 Apr 21;269:128678. Epub 2020 Oct 21.

Department of Zoology, Visva-Bharati, Santiniketan, 731235, West Bengal, India. Electronic address:

Arsenic and fluoride are two naturally occurring toxicants to which various organisms including a major part of the human populations are co-exposed to. However, interactions between them inside body are quite complicated and needs proper evaluation. Inconclusive reports regarding their combined effects on brain prompted us to conduct this study where we investigated their individual as well as combined effects on female zebrafish brain at environmentally relevant concentrations (50 μgL arsenic trioxide and 15 mgL sodium fluoride) after different time intervals (15, 30 and 60 days). Persistent near-basal level of GSH, least increased MDA content and catalase activity portrayed arsenic and fluoride co-exposure as less toxic which was corroborated with far less damage caused in the histoarchitecture of optic tectum region in midbrain. Stress-responsive genes viz., Nrf2 and Hsp70 were overexpressed after individual as well as combined exposures, indicating a common cellular response to combat the formed oxidative stresses. Biphasic response of AChE upon individual exposure confirmed their neurotoxic effects too. Expression profile of p53 (unaltered), Bax (lower or near-basal) and Bcl2 (comparatively higher), along with absence of DNA fragmentation indicated no induction of apoptosis in the co-exposed group. Tissue accumulation of arsenic and fluoride was significantly less in the brain of co-exposed zebrafish when compared to their individual exposures. This preliminary study indicates an antagonistic effect of these two toxicants in zebrafish brain and needs further studies involving oxidative stress independent markers to understand the detailed molecular mechanism.
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http://dx.doi.org/10.1016/j.chemosphere.2020.128678DOI Listing
April 2021

Calcium and Vitamin D Supplementation Effectively Alleviates Dental and Skeletal Fluorosis and Retain Elemental Homeostasis in Mice.

Biol Trace Elem Res 2020 Oct 14. Epub 2020 Oct 14.

Department of Zoology, Visva-Bharati, Santiniketan, West Bengal, 731235, India.

Fluoride (F) is an essential trace element, but chronic exposure beyond the permissible limit (1.5 ppm) effectuates dental and skeletal fluorosis. Although 200 million people across the world are suffering from toxic manifestations of F, till now proper treatment is not available. In this study, we assessed the effectiveness of calcium and vitamin D supplementation for alleviation of fluorosis. Swiss albino mice were divided into 6 groups; group I-control group (received drinking water ˂ 0.5 ppm F; within the permissible limit), group II-treated with 15 ppm of sodium fluoride (NaF) for 4 months, group III-treated with 15 ppm of NaF for 8 months through drinking water. Group IV-orally treated with 15 ppm NaF for 4 months, thereafter received only drinking water for next 4 months, group V-orally treated with 15 ppm NaF for 4 months, thereafter received drinking water supplemented with calcium and vitamin D (2.5-g calcium kg diet and 1000 IU vitamin D kg diet) for next 4 months, and group VI was treated with 15 ppm of NaF through drinking water as well as supplemented with calcium and vitamin D for 4 months. NaF treatment caused dental fluorosis, skeletal fluorosis, and alteration of bone's metal profile. Substitution of NaF-containing water with normal drinking water reduced the severity of fluorosis but supplementation of calcium and vitamin D effectively alleviated dental and skeletal fluorosis, reduced F deposition, and retained elemental homeostasis of the bone. Our findings strongly support that calcium and vitamin D act as redeemer of fluorosis. Graphical Abstract.
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http://dx.doi.org/10.1007/s12011-020-02435-xDOI Listing
October 2020

Shinorine ameliorates chromium induced toxicity in zebrafish hepatocytes through the facultative activation of Nrf2-Keap1-ARE pathway.

Aquat Toxicol 2020 Nov 9;228:105622. Epub 2020 Sep 9.

Department of Zoology, Visva-Bharati, Santiniketan 731235, West Bengal, India. Electronic address:

Hexavalent chromium, a heavy metal toxicant, abundantly found in the environment showed hepatotoxic potential in zebrafish liver and instigated the Nrf2-Keap1-ARE pathway as a cellular stress response as reported in our previous studies. In the present study we have evaluated the ameliorating effect of shinorine, a mycosporine like amino acid (MAAs) and a mammalian Keap1 antagonist against chromium induced stress in zebrafish hepatocytes. Shinorine was found to be effective in increasing the cell viability of chromium treated hepatocytes through curtailing the cellular ROS content. Trigonelline, an Nrf2 inhibitor was found to reduce the viability of hepatocyte cultures co-exposed to shinorine and chromium. In other words, trigonelline being an Nrf2 blocker neutralised the alleviating effect of shinorine. This indicated that shinorine mediated cyto-protection in Cr [VI]-intoxicated cells is Nrf2 dependent. Further, qRT-PCR analysis revealed comparatively higher expression of nfe2l2 and nqo1 in shinorine + chromium treated hepatocytes than cells exposed to chromium alone indicating a better functioning of Nrf2-Keap1-Nqo1 axis. To further confirm if shinorine can lead to disruption of Nrf2-Keap1 interaction in zebrafish hepatocytes and render cytoprotection to chromium exposure, our in silico analysis through molecular docking revealed that shinorine could bind to the active amino acid residues of the DGR domain, responsible for Nrf2-Keap1 interaction of all the three Keap1s evaluated. This is the first report about shinorine that ameliorates chromium induced toxicity through acting as an Nrf2-Keap1 interaction disruptor. We additionally carried out in-silico pharmacokinetic and ADMET studies to evaluate druglikeness of shinorine whose promising results indicated its potential to be developed as an ideal therapeutic candidate against toxicant induced pathological conditions.
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http://dx.doi.org/10.1016/j.aquatox.2020.105622DOI Listing
November 2020

Chronic exposure to environmentally relevant concentration of fluoride alters Ogg1 and Rad51 expressions in mice: Involvement of epigenetic regulation.

Ecotoxicol Environ Saf 2020 Oct 11;202:110962. Epub 2020 Jul 11.

Department of Zoology, Visva-Bharati, Santiniketan, 731235, West Bengal, India. Electronic address:

Chronic exposure to fluoride (F) beyond the permissible limit (1.5 ppm) is known to cause detrimental health effects by induction of oxidative stress-mediated DNA damage overpowering the DNA repair machinery. In the present study, we assessed F induced oxidative stress through monitoring biochemical parameters and looked into the effect of chronic F exposure on two crucial DNA repair genes Ogg1 and Rad51 having important role against ROS induced DNA damages. To address this issue, we exposed Swiss albino mice to an environmentally relevant concentration of fluoride (15 ppm NaF) for 8 months. Results revealed histoarchitectural damages in liver, brain, kidney and spleen. Depletion of GSH, increase in lipid peroxidation and catalase activity in liver and brain confirmed the generation of oxidative stress. qRT-PCR result showed that expressions of Ogg1 and Rad51 were altered after F exposure in the affected organs. Promoter hypermethylation was associated with the downregulation of Rad51. F-induced DNA damage and the compromised DNA repair machinery triggered intrinsic pathway of apoptosis in liver and brain. The present study indicates the possible association of epigenetic regulation with F induced neurotoxicity.
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http://dx.doi.org/10.1016/j.ecoenv.2020.110962DOI Listing
October 2020

Apoptosis of hematopoietic progenitor-derived adipose tissue-resident macrophages contributes to insulin resistance after myocardial infarction.

Sci Transl Med 2020 07;12(553)

Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA.

Patients with insulin resistance have high risk of cardiovascular disease such as myocardial infarction (MI). However, it is not known whether MI can initiate or aggravate insulin resistance. We observed that patients with ST-elevation MI and mice with MI had de novo hyperglycemia and features of insulin resistance, respectively. In mouse models of both myocardial and skeletal muscle injury, we observed that the number of visceral adipose tissue (VAT)-resident macrophages decreased because of apoptosis after these distant organ injuries. Patients displayed a similar decrease in VAT-resident macrophage numbers and developed systemic insulin resistance after ST-elevation MI. Loss of VAT-resident macrophages after MI injury led to systemic insulin resistance in non-diabetic mice. Danger signaling-associated protein high mobility group box 1 was released by the dead myocardium after MI in rodents and triggered macrophage apoptosis via Toll-like receptor 4. The VAT-resident macrophage population in the steady state in mice was transcriptomically distinct from macrophages in the brain, skin, kidney, bone marrow, lungs, and liver and was derived from hematopoietic progenitor cells just after birth. Mechanistically, VAT-resident macrophage apoptosis and de novo insulin resistance in mouse models of MI were linked to diminished concentrations of macrophage colony-stimulating factor and adiponectin. Collectively, these findings demonstrate a previously unappreciated role of adipose tissue-resident macrophages in sensing remote organ injury and promoting MI pathogenesis.
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http://dx.doi.org/10.1126/scitranslmed.aaw0638DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7813555PMC
July 2020

Targeting NAD Biosynthesis Overcomes Panobinostat and Bortezomib-Induced Malignant Glioma Resistance.

Mol Cancer Res 2020 07 1;18(7):1004-1017. Epub 2020 Apr 1.

Department of Neurosurgery, University of Pittsburgh, Pittsburgh, Pennsylvania.

To improve therapeutic responses in patients with glioma, new combination therapies that exploit a mechanistic understanding of the inevitable emergence of drug resistance are needed. Intratumoral heterogeneity enables a low barrier to resistance in individual patients with glioma. We reasoned that targeting two or more fundamental processes that gliomas are particularly dependent upon could result in pleiotropic effects that would reduce the diversity of resistant subpopulations allowing convergence to a more robust therapeutic strategy. In contrast to the cytostatic responses observed with each drug alone, the combination of the histone deacetylase inhibitor panobinostat and the proteasome inhibitor bortezomib synergistically induced apoptosis of adult and pediatric glioma cell lines at clinically achievable doses. Resistance that developed was examined using RNA-sequencing and pharmacologic screening of resistant versus drug-naïve cells. Quinolinic acid phosphoribosyltransferase (QPRT), the rate-determining enzyme for synthesis of NAD from tryptophan, exhibited particularly high differential gene expression in resistant U87 cells and protein expression in all resistant lines tested. Reducing QPRT expression reversed resistance, suggesting that QPRT is a selective and targetable dependency for the panobinostat-bortezomib resistance phenotype. Pharmacologic inhibition of either NAD biosynthesis or processes such as DNA repair that consume NAD or their simultaneous inhibition with drug combinations, specifically enhanced apoptosis in treatment-resistant cells. Concomitantly, vulnerabilities to known drugs were observed. IMPLICATIONS: These data provide new insights into mechanisms of treatment resistance in gliomas, hold promise for targeting recurrent disease, and provide a potential strategy for further exploration of next-generation inhibitors.
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http://dx.doi.org/10.1158/1541-7786.MCR-19-0669DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7335346PMC
July 2020

Environmental exposure of arsenic and fluoride and their combined toxicity: A recent update.

J Appl Toxicol 2020 05 22;40(5):552-566. Epub 2019 Dec 22.

Department of Zoology, Visva-Bharati University, Santiniketan, West Bengal, India.

Environmental exposure to arsenic (As) and fluoride (F) in the recent year has been increased because of excessive use of naturally contaminated ground water. Surface water is also regularly contaminated with these elements in various industrial areas. Arsenicosis and fluorosis upon individual exposure of As and F are reported in many studies. A syndrome of endemic As poisoning and fluorosis occurs during concurrent exposure of As and F. Previous reports showed synergistic, antagonistic and independent effects of these two compounds, although few recent reports also revealed antagonistic effects after co-exposure. Interaction during intestinal absorption and influence of F on As metabolism might be the cause of antagonism. The synergism/antagonism is thought to depend on the dose and duration of the co-exposure. However, the detailed mechanism is still not fully understood and needs further studies. Removal technologies of As and F from contaminated water is available but removal of such contaminants from food is yet to be developed. Antioxidants are useful to mitigate the toxic effects of As and F. This review focused on the effect of co-exposure, amelioration as well as removal techniques of As and F.
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http://dx.doi.org/10.1002/jat.3931DOI Listing
May 2020

Environmentally relevant concentration of chromium induces nuclear deformities in erythrocytes and alters the expression of stress-responsive and apoptotic genes in brain of adult zebrafish.

Sci Total Environ 2020 Feb 19;703:135622. Epub 2019 Nov 19.

Department of Zoology, Visva-Bharati, Santiniketan 731235, West Bengal, India. Electronic address:

Heavy metal contamination of water body has become a serious threat to aquatic life forms specially to fish. Hexavalent chromium (Cr [VI]) is one of the most potent heavy metal toxicant. It is present in aquatic environment at concentrations beyond permissible limit. Considering the fact that toxic effects are function of the exposure concentration, studies involving toxicological risk assessment should be done at environmentally relevant concentration. Therefore we studied the toxic effects of Cr [VI] to zebrafish at an environmentally relevant concentration (2 mg L). We monitored the genotoxic potential of Cr [VI] in erythrocytes through a simple reliable microscopic assay and found an increase in frequency of micronucleated erythrocytes along with erythrocytes with blebbed, lobed and notched nuclei. In addition, Cr [VI] induced neurotoxicity, being a least reported event was also investigated. Histological alterations in brain, elevated GSH and MDA content and increased catalase activity indicated oxidative stress-mediated damage. This was further confirmed through expressional alteration of Ucp2. Upregulation of Nrf2, Nqo1 and Ho1 clearly indicated the involvement of Nrf2-ARE system in stress response against Cr [VI] induced neurotoxicity. The transcriptional induction of apoptotic genes such as Bax, Caspase 9 and Caspase 3 along with downregulation of Bcl2 indicated that the cytoprotective system failed to counter the induced stress. Interestingly, there was upregulation of AChE gene, which could be correlated with the upregulated apoptotic genes. This study provides an insight on the neurotoxic stress of Cr [VI] on the zebrafish yet at an environmentally relevant concentration. Moreover the induction of nuclear anomalies in the erythrocytes can serve as extremely sensitive endpoints of toxicological stress indicators of aquatic contaminants like Cr [VI].
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http://dx.doi.org/10.1016/j.scitotenv.2019.135622DOI Listing
February 2020

Nrf2-ARE signaling in cellular protection: Mechanism of action and the regulatory mechanisms.

J Cell Physiol 2020 04 23;235(4):3119-3130. Epub 2019 Sep 23.

Department of Zoology, Toxicology and Cancer Biology Laboratory, Visva-Bharati, Santiniketan, West Bengal, India.

Oxidative stress is the increase in cellular oxidant concentration in comparison to antioxidant titer. Toxic insults and many other diseased conditions are mediated through the formation of such condition. Once the redox equilibrium is disrupted, the cellular antioxidant system functions to bring back the cell to redox homeostasis state. The field players of the cytoprotective machinery are the xenobiotic-metabolizing enzymes that are transcriptionally controlled by upstream regulatory pathways like the Nrf2-ARE pathway and AhR-XRE pathway. The importance of Nrf2 lies in the fact that it is activated by a variety of compounds and has a wide range of inducers including metals, organic toxicants and so forth. The present review article aims to discuss the role of Nrf2 in cellular protection and also intends to illuminate the regulatory mechanisms that control Nrf2 itself. This can add to our knowledge of how the cell reacts and survives against such stressed conditions.
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http://dx.doi.org/10.1002/jcp.29219DOI Listing
April 2020

Mixture effect of arsenic and fluoride at environmentally relevant concentrations in zebrafish (Danio rerio) liver: Expression pattern of Nrf2 and related xenobiotic metabolizing enzymes.

Aquat Toxicol 2019 Aug 3;213:105219. Epub 2019 Jun 3.

Department of Zoology, Visva-Bharati, Santiniketan, 731235, West Bengal, India. Electronic address:

Nrf2 is a crucial transcription factor that regulates the expression of cytoprotective enzymes and controls cellular redox homeostasis. Both arsenic and fluoride are potent toxicants that are known to induce Nrf2. They are reported to coexist in many areas of the world leading to complex mixture effects in exposed organisms. The present study investigated the expression of Nrf2 and related xenobiotic metabolizing enzymes along with other stress markers such as histopathological alterations, catalase activity, reduced glutathione content and lipid peroxidation in zebrafish liver as a function of combined exposure to environmentally relevant concentrations of arsenic (37.87 μgL or 5.05 × 10 M) and fluoride (6.8 mg L or 3.57 × 10 M) for 60 days. The decrease in the total reduced glutathione level was evident in all treatment conditions. Hyperactivity of catalase along with conspicuous elevation in reactive oxygen species, malondialdehyde content and histo-architectural anomalies signified the presence of oxidative stress in the treatment groups. Nrf2 was seen to be induced at both transcriptional and translational levels in case of both individual and co-exposure. The same pattern was observed in case of its nuclear translocation also. From the results of qRT-PCR it was evident that at each time point co-exposure to arsenic and fluoride seemed to alter the gene expression of Cu/Zn Sod, Mn Sod, Gpx and Nqo1 just like their individual exposure but at a very low magnitude. In conclusion, this study demonstrates for the first time the differential expression and activity of Nrf2 and other stress response genes in the zebrafish liver following individual and combined exposure to arsenic and fluoride.
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http://dx.doi.org/10.1016/j.aquatox.2019.06.002DOI Listing
August 2019

Molecular Biology Information Service: an innovative medical library-based bioinformatics support service for biomedical researchers.

Brief Bioinform 2020 05;21(3):876-884

University of Pittsburgh, Health Sciences Library System.

Biomedical researchers are increasingly reliant on obtaining bioinformatics training in order to conduct their research. Here we present a model that academic institutions may follow to provide such training for their researchers, based on the Molecular Biology Information Service (MBIS) of the Health Sciences Library System, University of Pittsburgh (Pitt). The MBIS runs a four-facet service with the following goals: (1) identify, procure and implement commercially licensed bioinformatics software, (2) teach hands-on workshops using bioinformatics tools to solve research questions, (3) provide in-person and email consultations on software/databases and (4) maintain a web portal providing overall guidance on the access and use of bioinformatics resources and MBIS-created webtools. This paper describes these facets of MBIS activities from 2006 to 2018, including outcomes from a survey measuring attitudes of Pitt researchers about MBIS service and performance.
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http://dx.doi.org/10.1093/bib/bbz035DOI Listing
May 2020

R430: A potent inhibitor of DNA and RNA viruses.

Sci Rep 2018 11 9;8(1):16662. Epub 2018 Nov 9.

Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, 3811 O'Hara Street, Pittsburgh, PA, 15213, USA.

Acyclovir (ACV) is an effective antiviral agent for treating lytic Herpes Simplex virus, type 1 (HSV-1) infections, and it has dramatically reduced the mortality rate of herpes simplex encephalitis. However, HSV-1 resistance to ACV and its derivatives is being increasingly documented, particularly among immunocompromised individuals. The burgeoning drug resistance compels the search for a new generation of more efficacious anti-herpetic drugs. We have previously shown that trans-dihydrolycoricidine (R430), a lycorane-type alkaloid derivative, effectively inhibits HSV-1 infections in cultured cells. We now report that R430 also inhibits ACV-resistant HSV-1 strains, accompanied by global inhibition of viral gene transcription and enrichment of H3K27me3 methylation on viral gene promoters. Furthermore, we demonstrate that R430 prevents HSV-1 reactivation from latency in an ex vivo rodent model. Finally, among a panel of DNA viruses and RNA viruses, R430 inhibited Zika virus with high therapeutic index. Its therapeutic index is comparable to standard antiviral drugs, though it has greater toxicity in non-neuronal cells than in neuronal cells. Synthesis of additional derivatives could enable more efficacious antivirals and the identification of active pharmacophores.
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http://dx.doi.org/10.1038/s41598-018-33904-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6226428PMC
November 2018

Environmentally relevant concentration of chromium activates Nrf2 and alters transcription of related XME genes in liver of zebrafish.

Chemosphere 2019 Jan 18;214:35-46. Epub 2018 Sep 18.

Department of Zoology, Visva-Bharati, Santiniketan-731235, West Bengal, India. Electronic address:

Fish is an excellent model to decipher the mechanism of toxicity of aquatic contaminants such as hexavalent chromium (Cr [VI]). The present study looked into the manifestation of stress in liver of zebrafish exposed to an environmentally relevant concentration (2 mgL), and the functioning of the cytoprotective machinery that pacifies the formed stress. The results lead us to hypothesize that oxidative stress plays a key role in chromium-induced toxicity resulting in lipid peroxidation and extensive changes in tissue ultrastructure. In treated fish, production of reactive oxygen species, increase in reduced glutathione content and increase in malondialdehyde content along with enhanced catalase activity were evident. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) was found to increase both at transcriptional and translational level and its translocation into the nucleus was confirmed by fluorescence-based immunohistochemical studies. The mRNA levels of genes like Nqo1, Cyp1a and Cu/Zn Sod were found to increase whereas Ho1, Hsp70 and Ucp2 were down-regulated. The sensitivity of these genes towards Cr [VI] validates their candidature as important biomarkers of Cr [VI] exposure in zebrafish.
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http://dx.doi.org/10.1016/j.chemosphere.2018.09.104DOI Listing
January 2019

Peptide vaccine immunotherapy biomarkers and response patterns in pediatric gliomas.

JCI Insight 2018 04 5;3(7). Epub 2018 Apr 5.

Department of Neurological Surgery.

Low-grade gliomas (LGGs) are the most common brain tumor affecting children. We recently reported an early phase clinical trial of a peptide-based vaccine, which elicited consistent antigen-specific T cell responses in pediatric LGG patients. Additionally, we observed radiologic responses of stable disease (SD), partial response (PR), and near-complete/complete response (CR) following therapy. To identify biomarkers of clinical response in peripheral blood, we performed RNA sequencing on PBMC samples collected at multiple time points. Patients who showed CR demonstrated elevated levels of T cell activation markers, accompanied by a cytotoxic T cell response shortly after treatment initiation. At week 34, patients with CR demonstrated both IFN signaling and Poly-IC:LC adjuvant response patterns. Patients with PR demonstrated a unique, late monocyte response signature. Interestingly, HLA-V expression, before or during therapy, and an early monocytic hematopoietic response were strongly associated with SD. Finally, low IDO1 and PD-L1 expression before treatment and early elevated levels of T cell activation markers were associated with prolonged progression-free survival. Overall, our data support the presence of unique peripheral immune patterns in LGG patients associated with different radiographic responses to our peptide vaccine immunotherapy. Future clinical trials, including our ongoing phase II LGG vaccine immunotherapy, should monitor these response patterns.
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http://dx.doi.org/10.1172/jci.insight.98791DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5928860PMC
April 2018

Relaxin reverses inflammatory and immune signals in aged hearts.

PLoS One 2018 18;13(1):e0190935. Epub 2018 Jan 18.

Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America.

Background: 'Healthy' aging drives structural and functional changes in the heart including maladaptive electrical remodeling, fibrosis and inflammation, which lower the threshold for cardiovascular diseases such as heart failure (HF) and atrial fibrillation (AF). Despite mixed results in recent clinical trials, Relaxin-therapy for 2-days could reduce mortality by 37% at 180-days post-treatment, in patients with acute decompensated HF. Relaxin's short life-span (hours) but long-lasting protective actions led us to test the hypothesis that relaxin acts at a genomic level to reverse maladaptive remodeling in aging and HF.

Methods And Results: Young (9-month) and aged (24-month), male and female F-344/Brown Norway rats were treated with relaxin (0.4 mg/kg/day) for 2-weeks delivered by subcutaneous osmotic mini-pumps or with sodium acetate (controls). The genomic effects of aging and relaxin were evaluated by extracting RNA from the left ventricles and analyzing genomic changes by RNA-sequencing, Ingenuity Pathway Analysis, MetaCore and tissue immunohistochemistry. We found that aging promotes a native inflammatory response with distinct sex-differences and relaxin suppresses transcription of multiple genes and signaling pathways associated with inflammation and HF in both genders. In addition, aging significantly increased: macrophage infiltration and atrial natriuretic peptide levels in female ventricles, and activation of the complement cascade, whereas relaxin reversed these age-related effects.

Conclusion: These data support the hypothesis that relaxin alters gene transcription and suppresses inflammatory pathways and genes associated with HF and aging. Relaxin's suppression of inflammation and fibrosis supports its potential as a therapy for cardiovascular and inflammation-related diseases, such as HF, AF and diabetes.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0190935PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5773192PMC
February 2018

Estradiol up-regulates L-type Ca channels via membrane-bound estrogen receptor/phosphoinositide-3-kinase/Akt/cAMP response element-binding protein signaling pathway.

Heart Rhythm 2018 05 9;15(5):741-749. Epub 2018 Jan 9.

Department of Medicine, Heart and Vascular Institute, University of Pittsburgh, Pittsburgh, Pennsylvania. Electronic address:

Background: In long QT syndrome type 2, women are more prone than men to the lethal arrhythmia torsades de pointes. We previously reported that 17β-estradiol (E2) up-regulates L-type Ca channels and current (I) (∼30%) in rabbit ventricular myocytes by a classic genomic mechanism mediated by estrogen receptor-α (ERα). In long QT syndrome type 2 (I blockade or bradycardia), the higher Ca influx via I causes Ca overload, spontaneous sarcoplasmic reticulum Ca release, and reactivation of I that triggers early afterdepolarizations and torsades de pointes.

Objective: The purpose of this study was to investigate the molecular mechanisms whereby E2 up-regulates I, which are poorly understood.

Methods: H9C2 and rat myocytes were incubated with E2 ± ER antagonist, or inhibitors of downstream transcription factors, for 24 hours, followed by western blots of Cav1.2α1C and voltage-clamp measurements of I.

Results: Incubation of H9C2 cells with E2 (10-100 nM) increased I density and Cav1.2α1C expression, which were suppressed by the ER antagonist ICI182,780 (1 μM). Enhanced I and Cav1.2α1C expression by E2 was suppressed by inhibitors of phosphoinositide-3-kinase (Pi3K) (30 μM LY294002; P <.05) and Akt (5 μM MK2206) but not of mitogen-activated protein kinase (5 μM U0126) or protein kinase A (1 μM KT5720). E2 incubation increased p-CREB via the Pi3K/Akt pathway, reached a peak in 20 minutes (3-fold), and leveled off to 1.5-fold 24 hours later. Furthermore, a CREB decoy oligonucleotide inhibited E2-induced Cav1.2α1C expression, whereas membrane-impermeable E2 (E2-bovine serum albumin) was equally effective at Cav1.2α1C up-regulation as E2.

Conclusion: Estradiol up-regulates Cav1.2α1C and I via plasma membrane ER and by activating Pi3K, Akt, and CREB signaling. The promoter regions of the CACNA1C gene (human-rabbit-rat) contain adjacent/overlapping binding sites for p-CREB and ERα, which suggests a synergistic regulation by these pathways.
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http://dx.doi.org/10.1016/j.hrthm.2018.01.019DOI Listing
May 2018

(Linn.)-mediated green silver nanoparticles trigger caspase 9-dependent cell death in MCF7 and MDA-MB-231 cells.

Breast Cancer (Dove Med Press) 2017 18;9:265-278. Epub 2017 Apr 18.

Molecular Genetics Laboratory, Department of Zoology, Visva-Bharati, Santiniketan, West Bengal.

Introduction: Leaf extract of or mint plant was used as reducing agent for the synthesis of green silver nanoparticles (GSNPs) as a cost-effective, eco-friendly process compared to that of chemical synthesis. The existence of nanoparticles was characterized by ultraviolet-visible spectrophotometry, dynamic light scattering, Fourier transform infrared spectroscopy, X-ray diffraction, energy-dispersive X-ray analysis, atomic-force microscopy and transmission electron microscopy analyses, which ascertained the formation of spherical GSNPs with a size range of 3-9 nm. Anticancer activities against breast cancer cell lines (MCF7 and MDA-MB-231) were studied and compared with those of chemically synthesized (sodium borohydride [NaBH]-mediated) silver nanoparticles (CSNPs).

Materials And Methods: Cell survival of nanoparticle-treated and untreated cells was studied by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Cell-cycle analyses were carried out using fluorescence-activated cell sorting. Cell morphology was observed by fluorescence microscopy. Expression patterns of PARP1, P53, P21, Bcl2, Bax and cleaved caspase 9 as well as caspase 3 proteins in treated and untreated MCF7 and MDA-MB-231 cells were studied by Western blot method.

Results: MTT assay results showed that -mediated GSNPs exhibited significant cytotoxicity toward breast cancer cells (MCF7 and MDA-MB-231), which were at par with that of CSNPs. Cell cycle analyses of MCF7 cells revealed a significant increase in sub-G1 cell population, indicating cytotoxicity of GSNPs. On the other hand, human peripheral blood lymphocytes showed significantly less cytotoxicity compared with MCF7 and MDA-MB-231 cells when treated with the same dose. Expression patterns of proteins suggested that GSNPs triggered caspase 9-dependent cell death in both cell lines. The Ames test showed that GSNPs were nonmutagenic in nature.

Conclusion: GSNPs synthesized using may be considered as a promising anticancer agent in breast cancer therapy. They are less toxic and nonmutagenic and mediate caspase 9-dependent apoptosis in MCF7 and MDA-MB-231 cells.
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http://dx.doi.org/10.2147/BCTT.S130952DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5402903PMC
April 2017

Silver Nanoparticles as Antibacterial and Anticancer Materials Against Human Breast, Cervical and Oral Cancer Cells.

J Nanosci Nanotechnol 2017 Feb;17(2):968-76

Silver nanoparticles contribute a giant share to the realm of modern nanobiotechnology. Their utility as antimicrobial agents is also well documented. Green synthesis of nanoparticle has several advantages over its chemical synthesis. In the present study, Thuja occidentalis leaf extract mediated silver nanoparticles were prepared without using a stabilizing agent and tested for their anticancer and anti-microbial activity. Thuja occidentalis leaf extract mediated silver nanoparticles were prepared under ambient conditions which showed a narrow size distribution within the range of 10–15 nm, with average particle size of 12.7 nm. Interestingly, these nanoparticles exhibited anti-cancer activity against human breast (MCF 7, MDA MB 231) and cervical cancer (HeLa) as well as mouth epidermoid carcinoma (KB) cell lines at a concentration range of 6.25–50 μg/mL. Contrarily, they are compatible with human peripheral blood mononuclear cells and rat hepatocytes. Moreover, their efficient inhibitory effect was witnessed against Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium and Pseudomonas aeruginosa with inhibitory concentration at 5–10 μg/mL. The prepared nanoparticles were highly biocompatible and have strong potential in the development of non-toxic chemotherapy with antibacterial attributes.
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http://dx.doi.org/10.1166/jnn.2017.12636DOI Listing
February 2017

CCAAT/Enhancer-binding protein β promotes pathogenesis of EAE.

Cytokine 2017 04 12;92:24-32. Epub 2017 Jan 12.

Division of Rheumatology & Clinical Immunology, University of Pittsburgh, Pittsburgh, PA, USA. Electronic address:

The CCAAT/Enhancer Binding Protein β (C/EBPβ) transcription factor is activated by multiple inflammatory stimuli, including IL-17 and LPS, and C/EBPβ itself regulates numerous genes involved in inflammation. However, the role of C/EBPβ in driving autoimmunity is not well understood. Here, we demonstrate that Cebpb mice are resistant to EAE. Cebpb mice exhibited reduced lymphocyte and APC infiltration into CNS following EAE induction. Furthermore, MOG-induced Th17 cytokine production was impaired in draining LN, indicating defects in Th17 cell priming. In vitro Th17 polarization studies indicated that T cell responses are not inherently defective, instead supporting the known roles for C/EBPβ in myeloid lineage cell activation as the likely mechanism for defective Th17 priming in vivo. However, we did uncover an unexpected role for C/EBPβ in regulating ll23r expression in APCs. ChIP assays confirmed that C/EBPβ binds directly to the Il23r gene promoter in dendritic cells and Th17 cells. These data establish C/EBPβ as a key driver of autoimmune inflammation in EAE, and propose a novel role for C/EBPβ in regulation of IL-23R expression.
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http://dx.doi.org/10.1016/j.cyto.2017.01.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5337143PMC
April 2017

Transcriptome analyses identify key cellular factors associated with HIV-1-associated neuropathogenesis in infected men.

AIDS 2017 03;31(5):623-633

aDepartment of Infectious Diseases & Microbiology, Graduate School of Public Health, University of Pittsburgh bComputer Science Department, School of Computer Science, Carnegie Mellon University cMolecular Biology Information Service, University of Pittsburgh dComputational Biology and Machine Learning Department, Carnegie Mellon University, Pittsburgh, Pennsylvania eDepartment of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois fDepartment of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland gDepartment of Neurology, David Geffen School of Medicine, University of California Los Angeles, California hDepartment of Psychiatry, Rush University Medical Center, Chicago, Illinois iDepartment of Neurology, Johns Hopkins Bayview Medical Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.

Objective: HIV-1 viral proteins and host inflammatory factors have a direct role in neuronal toxicity in vitro; however, the contribution of these factors in vivo in HIV-1-associated neurocognitive disorder (HAND) is not fully understood. We applied novel Systems Biology approaches to identify specific cellular and viral factors and their related pathways that are associated with different stages of HAND.

Design: A cross-sectional study of individuals enrolled in the Multicenter AIDS Cohort Study including HIV-1-seronegative (N = 36) and HIV-1-seropositive individuals without neurocognitive symptoms (N = 16) or with mild neurocognitive disorder (MND) (N = 8) or HIV-associated dementia (HAD) (N = 16).

Methods: A systematic evaluation of global transcriptome of peripheral blood mononuclear cells (PBMCs) obtained from HIV-1-seronegative individuals and from HIV-1-positive men without neurocognitive symptoms, or MND or HAD was performed.

Results: MND and HAD were associated with specific changes in mRNA transcripts and microRNAs in PBMCs. Comparison of upstream regulators and TimePath analyses identified specific cellular factors associated with MND and HAD, whereas HIV-1 viral proteins played a greater role in HAD. In addition, expression of specific microRNAs - miR-let-7a, miR-124, miR-15a and others - were found to correlate with mRNA gene expression and may have a potential protective role in asymptomatic HIV-1-seropositive individuals by regulating cellular signal transduction pathways downstream of chemokines and cytokines.

Conclusion: These results identify signature transcriptome changes in PBMCs associated with stages of HAND and shed light on the potential contribution of host cellular factors and viral proteins in HAND development.
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http://dx.doi.org/10.1097/QAD.0000000000001379DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5389669PMC
March 2017

Differential modulation of cellular antioxidant status in zebrafish liver and kidney exposed to low dose arsenic trioxide.

Ecotoxicol Environ Saf 2017 Jan 10;135:173-182. Epub 2016 Oct 10.

Environmental Toxicology Laboratory, Department of Zoology, School of Life Sciences, Visva-Bharati University, Santiniketan, West Bengal 731235, India. Electronic address:

Zebrafish were exposed to a nonlethal dose (1/350LC; 50µg/L) of AsO and sampled at 7, 15, 30, 60 and 90 days of treatment. The oxidative stress response was assessed in terms of time-dependent histopathological changes, lipid peroxidation, GSH status, activities of detoxification enzymes and expression of antioxidant genes in liver and kidney. AsO treatment enhanced lipid peroxidation except at day 90 in liver and day 30 in kidney. Glutathione depleted significantly in the liver except on day 30; whereas in kidney, it increased initially but thereafter depleted significantly. The liver GST activity was high until day 30, low on day 60 and high on day 90. On the other hand, activity of GST in kidney remained high throughout the exposure. GR activity in liver decreased initially but augmented from 30 days onwards whereas in kidney it remained high until 30 days of exposure. Significant increase in GPx and CAT activities in liver and kidney confirmed oxidative stress in zebrafish which correlated with mRNA expression of antioxidant genes. Upregulation in mRNA level of Cu-Zn Sod in liver and kidney was prominent. Gpx1 upregulation was more conspicuous in kidney as compared to liver while the pattern of Cat expression was almost similar in both the organs. Among the mitochondrial genes, expression of Cox1 was significantly high only after 90 days in liver, while in kidney it enhanced at 7, 30 and 60 days of arsenic exposure. Ucp2 was upregulated in liver after 15 days of exposure but significantly downregulated at day 90; in kidney it remained unchanged at other time points except at day 90. An overall increased expression of Bcl2 further confirmed AsO induced oxidative stress in zebrafish liver and kidney. The pattern of mRNA expression of Nrf2 was not uniform and was in accordance to its downstream antioxidant genes. Present findings elucidate that low dose of AsO exposure induces a time dependent differential modulation of antioxidant status in liver and kidney of zebrafish in a tissue-specific manner.
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http://dx.doi.org/10.1016/j.ecoenv.2016.09.025DOI Listing
January 2017

search.bioPreprint: a discovery tool for cutting edge, preprint biomedical research articles.

F1000Res 2016 16;5:1396. Epub 2016 Jun 16.

Health Sciences Library System, University of Pittsburgh, Pittsburgh, USA.

The time it takes for a completed manuscript to be published traditionally can be extremely lengthy. Article publication delay, which occurs in part due to constraints associated with peer review, can prevent the timely dissemination of critical and actionable data associated with new information on rare diseases or developing health concerns such as Zika virus. Preprint servers are open access online repositories housing preprint research articles that enable authors (1) to make their research immediately and freely available and (2) to receive commentary and peer review prior to journal submission. There is a growing movement of preprint advocates aiming to change the current journal publication and peer review system, proposing that preprints catalyze biomedical discovery, support career advancement, and improve scientific communication. While the number of articles submitted to and hosted by preprint servers are gradually increasing, there has been no simple way to identify biomedical research published in a preprint format, as they are not typically indexed and are only discoverable by directly searching the specific preprint server websites. To address this issue, we created a search engine that quickly compiles preprints from disparate host repositories and provides a one-stop search solution. Additionally, we developed a web application that bolsters the discovery of preprints by enabling each and every word or phrase appearing on any web site to be integrated with articles from preprint servers. This tool, search.bioPreprint, is publicly available at http://www.hsls.pitt.edu/resources/preprint.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4957174PMC
http://dx.doi.org/10.12688/f1000research.8798.2DOI Listing
August 2016

Structurally Characterized Zn2+ Selective Ratiometric Fluorescence Probe in 100 % Water for HeLa Cell Imaging: Experimental and Computational Studies.

J Fluoresc 2016 Jan;26(1):87-103

Fluorescence recognition of Zn2+ in 100% aqueous medium using 2-((1, 3 dihydroxy-2-(hydroxymethyl)propan-2 ylimino) methyl) phenol (SALTM) as ratiometric probe is reported. Moreover, SALTM can discriminate Zn2+ from Cd2+very effectively. The binding constant and detection limit of the probe for Zn2+ is 2.2×10(4) M(-1/2) and 2.79×10(-8) M respectively.Interestingly, corresponding naphthalene derivative(HNTM) having less water solubility fails to be a ratiometric sensor. SALTM can detect intracellular Zn2+ in HeLa cervical cancer cells under fluorescence microscope. Moreover, DFT and TD-DFT studies support experimental findings.
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http://dx.doi.org/10.1007/s10895-015-1688-9DOI Listing
January 2016

Temporal transcriptional response to latency reversing agents identifies specific factors regulating HIV-1 viral transcriptional switch.

Retrovirology 2015 Oct 6;12:85. Epub 2015 Oct 6.

Department of Infectious Diseases and Microbiology, Graduate School of Public Health, University of Pittsburgh/GSPH, Room A435, Crabtree Hall, 130 DeSoto Street, Pittsburgh, PA, 15261, USA.

Background: Latent HIV-1 reservoirs are identified as one of the major challenges to achieve HIV-1 cure. Currently available strategies are associated with wide variability in outcomes both in patients and CD4(+) T cell models. This underlines the critical need to develop innovative strategies to predict and recognize ways that could result in better reactivation and eventual elimination of latent HIV-1 reservoirs.

Results And Discussion: In this study, we combined genome wide transcriptome datasets post activation with Systems Biology approach (Signaling and Dynamic Regulatory Events Miner, SDREM analyses) to reconstruct a dynamic signaling and regulatory network involved in reactivation mediated by specific activators using a latent cell line. This approach identified several critical regulators for each treatment, which were confirmed in follow-up validation studies using small molecule inhibitors. Results indicate that signaling pathways involving JNK and related factors as predicted by SDREM are essential for virus reactivation by suberoylanilide hydroxamic acid. ERK1/2 and NF-κB pathways have the foremost role in reactivation with prostratin and TNF-α, respectively. JAK-STAT pathway has a central role in HIV-1 transcription. Additional evaluation, using other latent J-Lat cell clones and primary T cell model, also confirmed that many of the cellular factors associated with latency reversing agents are similar, though minor differences are identified. JAK-STAT and NF-κB related pathways are critical for reversal of HIV-1 latency in primary resting T cells.

Conclusion: These results validate our combinatorial approach to predict the regulatory cellular factors and pathways responsible for HIV-1 reactivation in latent HIV-1 harboring cell line models. JAK-STAT have a role in reversal of latency in all the HIV-1 latency models tested, including primary CD4(+) T cells, with additional cellular pathways such as NF-κB, JNK and ERK 1/2 that may have complementary role in reversal of HIV-1 latency.
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http://dx.doi.org/10.1186/s12977-015-0211-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4594640PMC
October 2015

Sodium fluoride affects zebrafish behaviour and alters mRNA expressions of biomarker genes in the brain: Role of Nrf2/Keap1.

Environ Toxicol Pharmacol 2015 Sep 14;40(2):352-9. Epub 2015 Jul 14.

Molecular Genetics Laboratory, Department of Zoology (Centre for Advanced Studies), Visva-Bharati, Santiniketan 731 235, West Bengal, India. Electronic address:

Sodium fluoride (NaF), used as pesticides and for industrial purposes are deposited in the water bodies and therefore affects its biota. Zebrafish exposed to NaF in laboratory condition showed hyperactivity and frequent surfacing activity, somersaulting and vertical swimming pattern as compared to the control group. Reactive oxygen species level was elevated and glutathione level was depleted along with increased malondialdehyde content in the brain. Levels of glutathione-s-transferase (GST), catalase (CAT) and superoxide dismutase were also elevated in the treatment groups. Expression of mRNA of nuclear factor erythroid 2 related factor 2 (Nrf2) and its inhibitor Kelch-like ECH-associated protein 1 (Keap1) during stress condition were observed along with Gst, Cat, NADPH: quinone oxidoreductase 1(Nqo1) and p38. Except Keap1, all other genes exhibited elevated expression. Nrf2/Keap1 proteins had similar expression pattern as their corresponding mRNA. The findings in this study might help to understand the molecular mechanism of fluoride induced neurotoxicity in fish.
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http://dx.doi.org/10.1016/j.etap.2015.07.003DOI Listing
September 2015

Lysine triggered ratiometric conversion of dynamic to static excimer of a pyrene derivative: aggregation-induced emission, nanomolar detection and human breast cancer cell (MCF7) imaging.

Chem Commun (Camb) 2015 Jul;51(57):11455-8

Department of Chemistry, The University of Burdwan, Golapbag, Burdwan, India.

A simple pyrene based probe (A3) derived from pyrene-1-carboxaldehyde and 2-amino-1-phenylpropan-1-ol shows unique optical response triggered by the concentration of lysine (Lys). This allows selective nanomolar detection of Lys via a cascade of processes, dynamic to static-excimer conversion in a ratiometric manner followed by aggregation-induced emission (AIE). Imaging of Lys in the human breast cancer cell (MCF7) has been achieved.
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http://dx.doi.org/10.1039/c5cc02389kDOI Listing
July 2015