%0 Journal Article %J J Med Virol %D 2022 %T Age-stratified adeno-associated virus serotype 3 neutralizing and total antibody prevalence in hemophilia A patients from India. %A Daniel, Hubert D-J %A Kumar, Sanjay %A Kannangai, Rajesh %A J, Farzana %A Joel, Joseph N %A Abraham, Aby %A Lakshmi, Kavitha M %A Agbandje-McKenna, Mavis %A Coleman, Kirsten E %A Srivastava, Arun %A Srivastava, Alok %A Abraham, Asha M %K Adult %K Animals %K Antibodies, Neutralizing %K Antibodies, Viral %K Child %K Dependovirus %K Genetic Vectors %K Hemophilia A %K Humans %K Prevalence %K Serogroup %X

Gene therapy using an adeno-associated virus (AAV) vector offers a new treatment option for individuals with monogenetic disorders. The major bottleneck is the presence of pre-existing anti-AAV antibodies, which impacts its use. Even very low titers of neutralizing antibodies (NAb) to capsids from natural AAV infections have been reported to inhibit the transduction of intravenously administered AAV in animal models and are associated with limited efficacy in human trials. Assessing the level of pre-existing NAb is important for determining the primary eligibility of patients for AAV vector-based gene therapy clinical trials. Techniques used to screen AAV-antibodies include AAV capsid enzyme-linked immunosorbent assay (ELISA) and transduction inhibition assay (TIA) for detecting total capsid-binding (TAb) and Nab, respectively. In this study, we screened 521 individuals with hemophilia A from India for TAb and NAb using ELISA and TIA, respectively. The prevalence of TAb and NAb in hemophilia A patients from India were 96% and 77.5%, respectively. There was a significant increase in anti-AAV3 NAb prevalence with age in the hemophilia A patient group from India. There was a trend in anti-AAV3 TAb positivity between the pediatric age group (94.4%) and the adult age group (97.4%).

%B J Med Virol %V 94 %P 4542-4547 %8 2022 Sep %G eng %N 9 %R 10.1002/jmv.27859 %0 Journal Article %J J Vis Exp %D 2022 %T CRISPR/Cas9 Gene Editing of Hematopoietic Stem and Progenitor Cells for Gene Therapy Applications. %A Venkatesan, Vigneshwaran %A Christopher, Abisha Crystal %A Karuppusamy, Karthik V %A Babu, Prathibha %A Alagiri, Manoj Kumar K %A Thangavel, Saravanabhavan %K Animals %K CRISPR-Cas Systems %K Gene Editing %K Genetic Therapy %K Hematopoietic Stem Cell Transplantation %K Hematopoietic Stem Cells %K Mice %X

CRISPR/Cas9 is a highly versatile and efficient gene-editing tool adopted widely to correct various genetic mutations. The feasibility of gene manipulation of hematopoietic stem and progenitor cells (HSPCs) in vitro makes HSPCs an ideal target cell for gene therapy. However, HSPCs moderately lose their engraftment and multilineage repopulation potential in ex vivo culture. In the present study, ideal culture conditions are described that improves HSPC engraftment and generate an increased number of gene-modified cells in vivo. The current report displays optimized in vitro culture conditions, including the type of culture media, unique small molecule cocktail supplementation, cytokine concentration, cell culture plates, and culture density. In addition to that, an optimized HSPC gene-editing procedure, along with the validation of the gene-editing events, are provided. For in vivo validation, the gene-edited HSPCs infusion and post-engraftment analysis in mouse recipients are displayed. The results demonstrated that the culture system increased the frequency of functional HSCs in vitro, resulting in robust engraftment of gene-edited cells in vivo.

%B J Vis Exp %8 2022 08 09 %G eng %N 186 %R 10.3791/64064 %0 Journal Article %J Sci Rep %D 2022 %T Erythroid lineage-specific lentiviral RNAi vectors suitable for molecular functional studies and therapeutic applications. %A Bagchi, Abhirup %A Devaraju, Nivedhitha %A Chambayil, Karthik %A Rajendiran, Vignesh %A Venkatesan, Vigneshwaran %A Sayed, Nilofer %A Pai, Aswin Anand %A Nath, Aneesha %A David, Ernest %A Nakamura, Yukio %A Balasubramanian, Poonkuzhali %A Srivastava, Alok %A Thangavel, Saravanabhavan %A Mohankumar, Kumarasamypet M %A Velayudhan, Shaji R %K Animals %K Cell Line, Tumor %K Cell Lineage %K DNA-Binding Proteins %K Genetic Vectors %K Humans %K Lentivirus %K Mice %K RNA Interference %K RNA, Small Interfering %K Transcription Factors %K Transduction, Genetic %X

Numerous genes exert multifaceted roles in hematopoiesis. Therefore, we generated novel lineage-specific RNA interference (RNAi) lentiviral vectors, H23B-Ery-Lin-shRNA and H234B-Ery-Lin-shRNA, to probe the functions of these genes in erythroid cells without affecting other hematopoietic lineages. The lineage specificity of these vectors was confirmed by transducing multiple hematopoietic cells to express a fluorescent protein. Unlike the previously reported erythroid lineage RNAi vector, our vectors were designed for cloning the short hairpin RNAs (shRNAs) for any gene, and they also provide superior knockdown of the target gene expression with a single shRNA integration per cell. High-level lineage-specific downregulation of BCL11A and ZBTB7A, two well-characterized transcriptional repressors of HBG in adult erythroid cells, was achieved with substantial induction of fetal hemoglobin with a single-copy lentiviral vector integration. Transduction of primary healthy donor CD34 cells with these vectors resulted in >80% reduction in the target protein levels and up to 40% elevation in the γ-chain levels in the differentiated erythroid cells. Xenotransplantation of the human CD34 cells transduced with H23B-Ery-Lin-shBCL11A LV in immunocompromised mice showed ~ 60% reduction in BCL11A protein expression with ~ 40% elevation of γ-chain levels in the erythroid cells derived from the transduced CD34 cells. Overall, the novel erythroid lineage-specific lentiviral RNAi vectors described in this study provide a high-level knockdown of target gene expression in the erythroid cells, making them suitable for their use in gene therapy for hemoglobinopathies. Additionally, the design of these vectors also makes them ideal for high-throughput RNAi screening for studying normal and pathological erythropoiesis.

%B Sci Rep %V 12 %P 14033 %8 2022 08 18 %G eng %N 1 %R 10.1038/s41598-022-13783-0 %0 Journal Article %J Methods Mol Biol %D 2022 %T Genome Engineering of Hematopoietic Stem Cells Using CRISPR/Cas9 System. %A Devaraju, Nivedhitha %A Rajendiran, Vignesh %A Ravi, Nithin Sam %A Mohankumar, Kumarasamypet M %K Animals %K CRISPR-Cas Systems %K Gene Editing %K Hematopoietic Stem Cell Transplantation %K Hematopoietic Stem Cells %K Mice %K Transplantation, Autologous %X

Ex vivo genetic manipulation of autologous hematopoietic stem and progenitor cells (HSPCs) is a viable strategy for the treatment of hematologic and primary immune disorders. Targeted genome editing of HSPCs using the CRISPR-Cas9 system provides an effective platform to edit the desired genomic locus for therapeutic purposes with minimal off-target effects. In this chapter, we describe the detailed methodology for the CRISPR-Cas9 mediated gene knockout, deletion, addition, and correction in human HSPCs by viral and nonviral approaches. We also present a comprehensive protocol for the analysis of genome modified HSPCs toward the erythroid and megakaryocyte lineage in vitro and the long-term multilineage reconstitution capacity in the recently developed NBSGW mouse model that supports human erythropoiesis.

%B Methods Mol Biol %V 2429 %P 307-331 %8 2022 %G eng %R 10.1007/978-1-0716-1979-7_20 %0 Journal Article %J Nat Commun %D 2022 %T Intermittent scavenging of storage lesion from stored red blood cells by electrospun nanofibrous sheets enhances their quality and shelf-life. %A Pandey, Subhashini %A Mahato, Manohar %A Srinath, Preethem %A Bhutani, Utkarsh %A Goap, Tanu Jain %A Ravipati, Priusha %A Vemula, Praveen Kumar %K Acridines %K Animals %K Drug-Related Side Effects and Adverse Reactions %K Erythrocytes %K Humans %K Mice %K Nanofibers %K Research Personnel %X

Transfusion of healthy red blood cells (RBCs) is a lifesaving process. However, upon storing RBCs, a wide range of damage-associate molecular patterns (DAMPs), such as cell-free DNA, nucleosomes, free-hemoglobin, and poly-unsaturated-fatty-acids are generated. DAMPs can further damage RBCs; thus, the quality of stored RBCs declines during the storage and limits their shelf-life. Since these DAMPs consist of either positive or negative charged species, we developed taurine and acridine containing electrospun-nanofibrous-sheets (Tau-AcrNFS), featuring anionic, cationic charges and an DNA intercalating group on their surfaces. We show that Tau-AcrNFS are efficient in scavenging DAMPs from stored human and mice RBCs ex vivo. We find that intermittent scavenging of DAMPs by Tau-AcrNFS during the storage reduces the loss of RBC membrane integrity and reduces discocytes-to-spheroechinocytes transformation in stored-old-RBCs. We perform RBC-transfusion studies in mice to reveal that intermittent removal of DAMPs enhances the quality of stored-old-RBCs equivalent to freshly collected RBCs, and increases their shelf-life by ~22%. Such prophylactic technology may lead to the development of novel blood bags or medical device, and may therefore impact healthcare by reducing transfusion-related adverse effects.

%B Nat Commun %V 13 %P 7394 %8 2022 Dec 01 %G eng %N 1 %R 10.1038/s41467-022-35269-3 %0 Journal Article %J Theranostics %D 2022 %T Microbial metabolite restricts 5-fluorouracil-resistant colonic tumor progression by sensitizing drug transporters via regulation of FOXO3-FOXM1 axis. %A Ghosh, Sweta %A Singh, Rajbir %A Vanwinkle, Zachary Matthew %A Guo, Haixun %A Vemula, Praveen Kumar %A Goel, Ajay %A Haribabu, Bodduluri %A Jala, Venkatakrishna Rao %K Animals %K Antimetabolites, Antineoplastic %K ATP Binding Cassette Transporter, Subfamily G, Member 2 %K Azoxymethane %K Cell Line, Tumor %K Colonic Neoplasms %K Coumarins %K Drug Resistance, Neoplasm %K Fluorouracil %K Forkhead Box Protein M1 %K Forkhead Box Protein O3 %K Gastrointestinal Microbiome %K Humans %K Mice %K Neoplasm Proteins %X

The survival rate of colorectal cancer patients is adversely affected by the selection of tumors resistant to conventional anti-cancer drugs such as 5-fluorouracil (5FU). Although there is mounting evidence that commensal gut microbiota is essential for effective colon cancer treatment, the detailed molecular mechanisms and the role of gut microbial metabolites remain elusive. The goal of this study is to decipher the impact and mechanisms of gut microbial metabolite, urolithin A (UroA) and its structural analogue, UAS03 on reversal of 5FU-resistant (5FUR) colon cancers. We have utilized the SW480 and HCT-116 parental (5FU-sensitive) and 5FUR colon cancer cells to examine the chemosensitization effects of UroA or UAS03 by using both and models. The effects of mono (UroA/UAS03/5FU) and combinatorial therapy (UroA/UAS03 + 5FU) on cell proliferation, apoptosis, cell migration and invasion, regulation of epithelial mesenchymal transition (EMT) mediators, expression and activities of drug transporters, and their regulatory transcription factors were examined using molecular, cellular, immunological and flowcytometric methods. Further, the anti-tumor effects of mono/combination therapy (UroA or UAS03 or 5FU or UroA/UAS03 + 5FU) were examined using pre-clinical models of 5FUR-tumor xenografts in NRGS mice and azoxymethane (AOM)-dextran sodium sulfate (DSS)-induced colon tumors. Our data showed that UroA or UAS03 in combination with 5FU significantly inhibited cell viability, proliferation, invasiveness as well as induced apoptosis of the 5FUR colon cancer cells compared to mono treatments. Mechanistically, UroA or UAS03 chemosensitized the 5FUR cancer cells by downregulating the expression and activities of drug transporters (MDR1, BCRP, MRP2 and MRP7) leading to a decrease in the efflux of 5FU. Further, our data suggested the UroA or UAS03 chemosensitized 5FUR cancer cells to 5FU treatment through regulating FOXO3-FOXM1 axis. Oral treatment with UroA or UAS03 in combination with low dose i.p. 5FU significantly reduced the growth of 5FUR-tumor xenografts in NRGS mice. Further, combination therapy significantly abrogated colonic tumors in AOM-DSS-induced colon tumors in mice. In summary, gut microbial metabolite UroA and its structural analogue UAS03 chemosensitized the 5FUR colon cancers for effective 5FU chemotherapy. This study provided the novel characteristics of gut microbial metabolites to have significant translational implications in drug-resistant cancer therapeutics.

%B Theranostics %V 12 %P 5574-5595 %8 2022 %G eng %N 12 %R 10.7150/thno.70754 %0 Journal Article %J Hum Gene Ther %D 2022 %T Preferential Expansion of Human CD34CD133CD90 Hematopoietic Stem Cells Enhances Gene-Modified Cell Frequency for Gene Therapy. %A Christopher, Abisha Crystal %A Venkatesan, Vigneshwaran %A Karuppusamy, Karthik V %A Srinivasan, Saranya %A Babu, Prathibha %A Azhagiri, Manoj Kumar K %A Chambayil, Karthik %A Bagchi, Abhirup %A Rajendiran, Vignesh %A Ravi, Nithin Sam %A Kumar, Sanjay %A Marepally, Srujan Kumar %A Mohankumar, Kumarasamypet Murugesan %A Srivastava, Alok %A Velayudhan, Shaji R %A Thangavel, Saravanabhavan %K Animals %K Antigens, CD34 %K Fetal Blood %K Genetic Therapy %K Hematopoietic Stem Cell Transplantation %K Hematopoietic Stem Cells %K Humans %K Mice %K Mice, Inbred NOD %K Mice, SCID %X

CD34CD133CD90 hematopoietic stem cells (HSCs) are responsible for long-term multilineage hematopoiesis, and the high frequency of gene-modified HSCs is crucial for the success of hematopoietic stem and progenitor cell (HSPC) gene therapy. However, the culture and gene manipulation steps of HSPC graft preparation significantly reduce the frequency of HSCs, thus necessitating large doses of HSPCs and reagents for the manipulation. In this study, we identified a combination of small molecules, Resveratrol, UM729, and SR1 that preferentially expands CD34CD133CD90 HSCs over other subpopulations of adult HSPCs in culture. The preferential expansion enriches the HSCs in culture, enhances the adhesion, and results in a sixfold increase in the long-term engraftment in NSG mice. Further, the culture-enriched HSCs are more responsive to gene modification by lentiviral transduction and gene editing, increasing the frequency of gene-modified HSCs up to 10-fold . The yield of gene-modified HSCs obtained by the culture enrichment is similar to the sort-purification of HSCs and superior to Cyclosporin-H treatment. Our study addresses a critical challenge of low frequency of gene modified HSCs in HSPC graft by developing and demonstrating a facile HSPC culture condition that increases the frequency of gene-modified cells . This strategy will improve the outcome of HSPC gene therapy and also simplify the gene manipulation process.

%B Hum Gene Ther %V 33 %P 188-201 %8 2022 02 %G eng %N 3-4 %R 10.1089/hum.2021.089 %0 Journal Article %J J Cell Sci %D 2022 %T S. mediterranea ETS-1 regulates the function of cathepsin-positive cells and the epidermal lineage landscape via basement membrane remodeling. %A Dubey, Vinay Kumar %A Sarkar, Souradeep R %A Lakshmanan, Vairavan %A Dalmeida, Rimple %A Gulyani, Akash %A Palakodeti, Dasaradhi %K Animals %K Basement Membrane %K Cathepsins %K Cell Differentiation %K Epidermis %K Humans %K Matrix Metalloproteinases %K Mediterranea %K Planarians %K Transcription Factors %X

Extracellular matrix (ECM) is an important component of stem cell niche. Remodeling of ECM mediated by ECM regulators, such as matrix metalloproteinases (MMPs) plays a vital role in stem cell function. However, the mechanisms that modulate the function of ECM regulators in the stem cell niche are understudied. Here, we explored the role of the transcription factor (TF) ETS-1, which is expressed in the cathepsin-positive cell population, in regulating the expression of the ECM regulator, mt-mmpA, thereby modulating basement membrane thickness. In planarians, the basement membrane around the gut/inner parenchyma is thought to act as a niche for pluripotent stem cells. It has been shown that the early epidermal progenitors migrate outwards from this region and progressively differentiate to maintain the terminal epidermis. Our data shows that thickening of the basement membrane in the absence of ets-1 results in defective migration of stem cell progeny. Furthermore, the absence of ets-1 leads to a defective epidermal progenitor landscape, despite its lack of expression in those cell types. Together, our results demonstrate the active role of ECM remodeling in regulating tissue homeostasis and regeneration in the planarian Schmidtea mediterranea. This article has an associated First Person interview with one of the co-first authors of the paper.

%B J Cell Sci %V 135 %8 2022 10 15 %G eng %N 20 %R 10.1242/jcs.259900 %0 Journal Article %J Mol Cell %D 2021 %T Proteome plasticity in response to persistent environmental change. %A Domnauer, Matthew %A Zheng, Fan %A Li, Liying %A Zhang, Yanxiao %A Chang, Catherine E %A Unruh, Jay R %A Conkright-Fincham, Juliana %A McCroskey, Scott %A Florens, Laurence %A Zhang, Ying %A Seidel, Christopher %A Fong, Benjamin %A Schilling, Birgit %A Sharma, Rishi %A Ramanathan, Arvind %A Si, Kausik %A Zhou, Chuankai %K Acclimatization %K Adaptation, Physiological %K Animals %K Environmental Exposure %K Gene Expression Regulation, Fungal %K Hot Temperature %K Proteome %K Saccharomycetales %K Stress, Physiological %K Transcriptome %X

Temperature is a variable component of the environment, and all organisms must deal with or adapt to temperature change. Acute temperature change activates cellular stress responses, resulting in refolding or removal of damaged proteins. However, how organisms adapt to long-term temperature change remains largely unexplored. Here we report that budding yeast responds to long-term high temperature challenge by switching from chaperone induction to reduction of temperature-sensitive proteins and re-localizing a portion of its proteome. Surprisingly, we also find that many proteins adopt an alternative conformation. Using Fet3p as an example, we find that the temperature-dependent conformational difference is accompanied by distinct thermostability, subcellular localization, and, importantly, cellular functions. We postulate that, in addition to the known mechanisms of adaptation, conformational plasticity allows some polypeptides to acquire new biophysical properties and functions when environmental change endures.

%B Mol Cell %V 81 %P 3294-3309.e12 %8 2021 08 19 %G eng %N 16 %R 10.1016/j.molcel.2021.06.028 %0 Journal Article %J Proc Natl Acad Sci U S A %D 2021 %T A regulatory network of microRNAs confers lineage commitment during early developmental trajectories of B and T lymphocytes. %A Nikhat, Sameena %A Yadavalli, Anurupa D %A Prusty, Arpita %A Narayan, Priyanka K %A Palakodeti, Dasaradhi %A Murre, Cornelis %A Pongubala, Jagan M R %K Animals %K B-Lymphocytes %K Cell Differentiation %K Cell Lineage %K Gene Expression %K Gene Expression Profiling %K Gene Regulatory Networks %K Hematopoietic Stem Cells %K Mice %K MicroRNAs %K Myeloid Cells %K T-Lymphocytes %X

The commitment of hematopoietic multipotent progenitors (MPPs) toward a particular lineage involves activation of cell type-specific genes and silencing of genes that promote alternate cell fates. Although the gene expression programs of early-B and early-T lymphocyte development are mutually exclusive, we show that these cell types exhibit significantly correlated microRNA (miRNA) profiles. However, their corresponding miRNA targetomes are distinct and predominated by transcripts associated with natural killer, dendritic cell, and myeloid lineages, suggesting that miRNAs function in a cell-autonomous manner. The combinatorial expression of miRNAs miR-186-5p, miR-128-3p, and miR-330-5p in MPPs significantly attenuates their myeloid differentiation potential due to repression of myeloid-associated transcripts. Depletion of these miRNAs caused a pronounced de-repression of myeloid lineage targets in differentiating early-B and early-T cells, resulting in a mixed-lineage gene expression pattern. De novo motif analysis combined with an assay of promoter activities indicates that B as well as T lineage determinants drive the expression of these miRNAs in lymphoid lineages. Collectively, we present a paradigm that miRNAs are conserved between developing B and T lymphocytes, yet they target distinct sets of promiscuously expressed lineage-inappropriate genes to suppress the alternate cell-fate options. Thus, our studies provide a comprehensive compendium of miRNAs with functional implications for B and T lymphocyte development.

%B Proc Natl Acad Sci U S A %V 118 %8 2021 11 16 %G eng %N 46 %R 10.1073/pnas.2104297118 %0 Journal Article %J Eur J Neurosci %D 2021 %T A salience hypothesis of stress in PTSD. %A Chakraborty, Prabahan %A Chattarji, Sumantra %A Jeanneteau, Freddy %K Animals %K Brain-Derived Neurotrophic Factor %K Glucocorticoids %K Stress Disorders, Post-Traumatic %X

Attention to key features of contexts and things is a necessary tool for all organisms. Detecting these salient features of cues, or simply, salience, can also be affected by exposure to traumatic stress, as has been widely reported in individuals suffering from post-traumatic stress disorder (PTSD). Interestingly, similar observations have been robustly replicated across many animal models of stress as well. By using evidence from such rodent stress paradigms, in the present review, we explore PTSD through the lens of salience processing. In this context, we propose that interaction between the neurotrophin brain-derived neurotrophic factor (BDNF) and glucocorticoids determines the long lasting cellular and behavioural consequences of stress salience. We also describe the dual effect of glucocorticoid therapy in the amelioration of PTSD symptoms. Finally, by integrating in vivo observations at multiple scales of plasticity, we propose a unifying hypothesis that pivots on a crucial role of glucocorticoid signalling in dynamically orchestrating stress salience.

%B Eur J Neurosci %V 54 %P 8029-8051 %8 2021 12 %G eng %N 11 %R 10.1111/ejn.15526 %0 Journal Article %J Stress %D 2021 %T The same stress has divergent effects on social versus asocial manifestations of anxiety-like behavior over time. %A Saxena, Kapil %A Chakraborty, Prabahan %A Chattarji, Sumantra %K Amygdala %K Animals %K Anxiety %K Anxiety Disorders %K Behavior, Animal %K Disease Models, Animal %K Male %K Rats %K Social Behavior %K Stress, Psychological %X

Stress may lead to augmented anxiety, which may, with time culminate in some form of anxiety disorder. Behavioral alterations related to increased anxiety can be broadly classified into two types-social, affecting interactions between individuals, and self-oriented, affecting the anxious individual only. While a growing body of literature now exists describing the effects of stress-induced anxiety on self-oriented behavior in animal models of anxiety disorders, the effects of such aberrant anxiety on social behavior has largely remained uncharacterized in these models. This study aims to fill this gap in our understanding by examining changes in social behavior following a single 2-hour episode of immobilization stress, which has been shown to cause delayed structural and functional changes in the amygdala. To this end, we examined social behavior, measured as active social interactions, anogenital sniffing, nose-to-nose contacts, allogrooming, actively following and crawling under, as well as self-oriented asocial behavior, manifested as self-grooming and rearing, in adult male rats. Stressed animals showed reduced social interaction 1 day after immobilization stress and this decrease was persistent for at least 10 days after stress. In contrast, individualistic behaviors were impaired only 10 days, but not 1 day later. Together, these results not only show that the same single episode of stress can elicit divergent effects on social and asocial measures of anxiety in the same animal, but also suggest that enhanced social anxiety soon after stress may also serve as an early indicator of its delayed behavioral effects.

%B Stress %V 24 %P 474-480 %8 2021 07 %G eng %N 4 %R 10.1080/10253890.2020.1855421 %0 Journal Article %J PLoS Pathog %D 2021 %T Strategies to target SARS-CoV-2 entry and infection using dual mechanisms of inhibition by acidification inhibitors. %A Prabhakara, Chaitra %A Godbole, Rashmi %A Sil, Parijat %A Jahnavi, Sowmya %A Gulzar, Shah-E-Jahan %A van Zanten, Thomas S %A Sheth, Dhruv %A Subhash, Neeraja %A Chandra, Anchal %A Shivaraj, Akshatha %A Panikulam, Patricia %A U, Ibrahim %A Nuthakki, Vijay Kumar %A Puthiyapurayil, Theja Parassini %A Ahmed, Riyaz %A Najar, Ashaq Hussain %A Lingamallu, Sai Manoz %A Das, Snigdhadev %A Mahajan, Bhagyashri %A Vemula, Praveen %A Bharate, Sandip B %A Singh, Parvinder Pal %A Vishwakarma, Ram %A Guha, Arjun %A Sundaramurthy, Varadharajan %A Mayor, Satyajit %K Ammonium Chloride %K Angiotensin-Converting Enzyme 2 %K Animals %K Antiviral Agents %K Cell Line %K Chlorocebus aethiops %K Chloroquine %K Clathrin %K COVID-19 %K Drug Synergism %K Endocytosis %K Endosomes %K Humans %K Hydrogen-Ion Concentration %K Hydroxychloroquine %K Macrolides %K Niclosamide %K Protein Binding %K Protein Domains %K SARS-CoV-2 %K Spike Glycoprotein, Coronavirus %K Vero Cells %K Virus Internalization %X

Many viruses utilize the host endo-lysosomal network for infection. Tracing the endocytic itinerary of SARS-CoV-2 can provide insights into viral trafficking and aid in designing new therapeutic strategies. Here, we demonstrate that the receptor binding domain (RBD) of SARS-CoV-2 spike protein is internalized via the pH-dependent CLIC/GEEC (CG) endocytic pathway in human gastric-adenocarcinoma (AGS) cells expressing undetectable levels of ACE2. Ectopic expression of ACE2 (AGS-ACE2) results in RBD traffic via both CG and clathrin-mediated endocytosis. Endosomal acidification inhibitors like BafilomycinA1 and NH4Cl, which inhibit the CG pathway, reduce the uptake of RBD and impede Spike-pseudoviral infection in both AGS and AGS-ACE2 cells. The inhibition by BafilomycinA1 was found to be distinct from Chloroquine which neither affects RBD uptake nor alters endosomal pH, yet attenuates Spike-pseudovirus entry. By screening a subset of FDA-approved inhibitors for functionality similar to BafilomycinA1, we identified Niclosamide as a SARS-CoV-2 entry inhibitor. Further validation using a clinical isolate of SARS-CoV-2 in AGS-ACE2 and Vero cells confirmed its antiviral effect. We propose that Niclosamide, and other drugs which neutralize endosomal pH as well as inhibit the endocytic uptake, could provide broader applicability in subverting infection of viruses entering host cells via a pH-dependent endocytic pathway.

%B PLoS Pathog %V 17 %P e1009706 %8 2021 07 %G eng %N 7 %R 10.1371/journal.ppat.1009706 %0 Journal Article %J Proc Natl Acad Sci U S A %D 2020 %T Reply to Negri et al.: Air pollution and health impacts on bees: Signs of causation. %A Thimmegowda, Geetha G %A Brockmann, Axel %A Dhandapany, Perundurai S %A Olsson, Shannon B %K Air Pollution %K Animals %K Bees %K Health %B Proc Natl Acad Sci U S A %V 117 %P 26578-26579 %8 2020 10 27 %G eng %N 43 %R 10.1073/pnas.2017972117 %0 Journal Article %J Proc Natl Acad Sci U S A %D 2020 %T Stress-induced modulation of endocannabinoid signaling leads to delayed strengthening of synaptic connectivity in the amygdala. %A Yasmin, Farhana %A Colangeli, Roberto %A Morena, Maria %A Filipski, Sarah %A van der Stelt, Mario %A Pittman, Quentin J %A Hillard, Cecilia J %A Teskey, G Campbell %A McEwen, Bruce S %A Hill, Matthew N %A Chattarji, Sumantra %K Administration, Oral %K Amidohydrolases %K Animals %K Basolateral Nuclear Complex %K Cannabinoid Receptor Antagonists %K Disease Models, Animal %K Emotions %K Endocannabinoids %K Enzyme Inhibitors %K Excitatory Postsynaptic Potentials %K Humans %K Male %K Rats %K Receptor, Cannabinoid, CB1 %K Signal Transduction %K Stress, Psychological %X

Even a brief exposure to severe stress strengthens synaptic connectivity days later in the amygdala, a brain area implicated in the affective symptoms of stress-related psychiatric disorders. However, little is known about the synaptic signaling mechanisms during stress that eventually culminate in its delayed impact on the amygdala. Hence, we investigated early stress-induced changes in amygdalar synaptic signaling in order to prevent its delayed effects. Whole-cell recordings in basolateral amygdala (BLA) slices from rats revealed higher frequency of miniature excitatory postsynaptic currents (mEPSCs) immediately after 2-h immobilization stress. This was replicated by inhibition of cannabinoid receptors (CBR), suggesting a role for endocannabinoid (eCB) signaling. Stress also reduced -arachidonoylethanolamine (AEA), an endogenous ligand of CBR. Since stress-induced activation of fatty acid amide hydrolase (FAAH) reduces AEA, we confirmed that oral administration of an FAAH inhibitor during stress prevents the increase in synaptic excitation in the BLA soon after stress. Although stress also caused an immediate reduction in synaptic inhibition, this was not prevented by FAAH inhibition. Strikingly, FAAH inhibition during the traumatic stressor was also effective 10 d later on the delayed manifestation of synaptic strengthening in BLA neurons, preventing both enhanced mEPSC frequency and increased dendritic spine-density. Thus, oral administration of an FAAH inhibitor during a brief stress prevents the early synaptic changes that eventually build up to hyperexcitability in the amygdala. This framework is of therapeutic relevance because of growing interest in targeting eCB signaling to prevent the gradual development of emotional symptoms and underlying amygdalar dysfunction triggered by traumatic stress.

%B Proc Natl Acad Sci U S A %V 117 %P 650-655 %8 2020 01 07 %G eng %N 1 %R 10.1073/pnas.1910322116 %0 Journal Article %J Nat Commun %D 2019 %T Efficient allelic-drive in Drosophila. %A Guichard, Annabel %A Haque, Tisha %A Bobik, Marketta %A Xu, Xiang-Ru S %A Klanseck, Carissa %A Kushwah, Raja Babu Singh %A Berni, Mateus %A Kaduskar, Bhagyashree %A Gantz, Valentino M %A Bier, Ethan %K Agriculture %K Alleles %K Animals %K Animals, Genetically Modified %K CRISPR-Cas Systems %K DNA End-Joining Repair %K DNA Mutational Analysis %K Drosophila %K Female %K Gene Drive Technology %K Gene Editing %K Inheritance Patterns %K Male %K Mosaicism %K RNA, Guide %X

Gene-drive systems developed in several organisms result in super-Mendelian inheritance of transgenic insertions. Here, we generalize this "active genetic" approach to preferentially transmit allelic variants (allelic-drive) resulting from only a single or a few nucleotide alterations. We test two configurations for allelic-drive: one, copy-cutting, in which a non-preferred allele is selectively targeted for Cas9/guide RNA (gRNA) cleavage, and a more general approach, copy-grafting, that permits selective inheritance of a desired allele located in close proximity to the gRNA cut site. We also characterize a phenomenon we refer to as lethal-mosaicism that dominantly eliminates NHEJ-induced mutations and favors inheritance of functional cleavage-resistant alleles. These two efficient allelic-drive methods, enhanced by lethal mosaicism and a trans-generational drive process we refer to as "shadow-drive", have broad practical applications in improving health and agriculture and greatly extend the active genetics toolbox.

%B Nat Commun %V 10 %P 1640 %8 2019 04 09 %G eng %N 1 %R 10.1038/s41467-019-09694-w %0 Journal Article %J Nat Commun %D 2019 %T Enhancement of the gut barrier integrity by a microbial metabolite through the Nrf2 pathway. %A Singh, Rajbir %A Chandrashekharappa, Sandeep %A Bodduluri, Sobha R %A Baby, Becca V %A Hegde, Bindu %A Kotla, Niranjan G %A Hiwale, Ankita A %A Saiyed, Taslimarif %A Patel, Paresh %A Vijay-Kumar, Matam %A Langille, Morgan G I %A Douglas, Gavin M %A Cheng, Xi %A Rouchka, Eric C %A Waigel, Sabine J %A Dryden, Gerald W %A Alatassi, Houda %A Zhang, Huang-Ge %A Haribabu, Bodduluri %A Vemula, Praveen K %A Jala, Venkatakrishna R %K Animals %K Basic Helix-Loop-Helix Transcription Factors %K Caco-2 Cells %K Coumarins %K Epithelial Cells %K Gene Expression Regulation %K HT29 Cells %K Humans %K Intestinal Mucosa %K Macrophages %K Mice %K Mice, Inbred C57BL %K Mice, Knockout %K NF-E2-Related Factor 2 %K Receptors, Aryl Hydrocarbon %K Specific Pathogen-Free Organisms %K Tight Junction Proteins %X

The importance of gut microbiota in human health and pathophysiology is undisputable. Despite the abundance of metagenomics data, the functional dynamics of gut microbiota in human health and disease remain elusive. Urolithin A (UroA), a major microbial metabolite derived from polyphenolics of berries and pomegranate fruits displays anti-inflammatory, anti-oxidative, and anti-ageing activities. Here, we show that UroA and its potent synthetic analogue (UAS03) significantly enhance gut barrier function and inhibit unwarranted inflammation. We demonstrate that UroA and UAS03 exert their barrier functions through activation of aryl hydrocarbon receptor (AhR)- nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent pathways to upregulate epithelial tight junction proteins. Importantly, treatment with these compounds attenuated colitis in pre-clinical models by remedying barrier dysfunction in addition to anti-inflammatory activities. Cumulatively, the results highlight how microbial metabolites provide two-pronged beneficial activities at gut epithelium by enhancing barrier functions and reducing inflammation to protect from colonic diseases.

%B Nat Commun %V 10 %P 89 %8 2019 01 09 %G eng %N 1 %R 10.1038/s41467-018-07859-7 %0 Journal Article %J Elife %D 2018 %T Extinction recall of fear memories formed before stress is not affected despite higher theta activity in the amygdala. %A Rahman, Mohammed Mostafizur %A Shukla, Ashutosh %A Chattarji, Sumantra %K Amygdala %K Animals %K Extinction, Psychological %K Fear %K Male %K Memory %K Mental Recall %K Prefrontal Cortex %K Rats, Sprague-Dawley %K Stress, Physiological %K Theta Rhythm %X

Stress is known to exert its detrimental effects not only by enhancing fear, but also by impairing its extinction. However, in earlier studies stress exposure preceded both processes. Thus, compared to unstressed animals, stressed animals had to extinguish fear memories that were strengthened by prior exposure to stress. Here, we dissociate the two processes to examine if stress specifically impairs the acquisition and recall of fear extinction. Strikingly, when fear memories were formed before stress exposure, thereby allowing animals to initiate extinction from comparable levels of fear, recall of fear extinction was unaffected. Despite this, we observed a persistent increase in theta activity in the BLA. Theta activity in the mPFC, by contrast, was normal. Stress also disrupted mPFC-BLA theta-frequency synchrony and directional coupling. Thus, in the absence of the fear-enhancing effects of stress, the expression of fear during and after extinction reflects normal regulation of theta activity in the mPFC, not theta hyperactivity in the amygdala.

%B Elife %V 7 %8 2018 08 13 %G eng %R 10.7554/eLife.35450 %0 Journal Article %J PLoS One %D 2018 %T Local release of tacrolimus from hydrogel-based drug delivery system is controlled by inflammatory enzymes in vivo and can be monitored non-invasively using in vivo imaging. %A Dzhonova, Dzhuliya %A Olariu, Radu %A Leckenby, Jonathan %A Dhayani, Ashish %A Vemula, Praveen Kumar %A Prost, Jean-Christophe %A Banz, Yara %A Taddeo, Adriano %A Rieben, Robert %K Animals %K Drug Delivery Systems %K Humans %K Hydrogels %K Immunosuppressive Agents %K Inflammation %K Male %K Rats %K Rats, Inbred BN %K Rats, Inbred Lew %K Tacrolimus %X

BACKGROUND: Local drug delivery systems that adjust the release of immunosuppressive drug in response to the nature and intensity of inflammation represent a promising approach to reduce systemic immunosuppression and its side effects in allotransplantation. Here we aimed to demonstrate that release of tacrolimus from triglycerol monostearate hydrogel is inflammation-dependent in vivo. We further report that by loading the hydrogel with a near-infrared dye, it is possible to monitor drug release non-invasively in an in vivo model of vascularized composite allotransplantation.

MATERIALS AND METHODS: Inflammation was induced by local challenge with lipopolysaccharides in naïve rats 7 days after injection of tacrolimus-loaded hydrogel in the hind limb. Tacrolimus levels in blood and tissues were measured at selected time points. A near-infrared dye was encapsulated in the hydrogel together with tacrolimus in order to monitor hydrogel deposits and drug release in vitro and in vivo in a model of vascularized composite allotransplantation.

RESULTS: Injection of lipopolysaccharides led to increased blood and skin tacrolimus levels (p = 0.0076, day 7 vs. day 12 in blood, and p = 0.0007 in treated limbs, 48 h after injection compared to controls). Moreover, lipopolysaccharides-injected animals had higher tacrolimus levels in treated limbs compared to contralateral limbs (p = 0.0003 for skin and p = 0.0053 for muscle). Imaging of hydrogel deposits and tacrolimus release was achieved by encapsulating near-infrared dye in the hydrogel for 160 days. The correlation of tacrolimus and near-infrared dye release from hydrogel was R2 = 0.6297 and R2 = 0.5619 in blood and grafts of transplanted animals respectively and R2 = 0.6066 in vitro.

CONCLUSIONS: Here we demonstrate the inflammation-responsiveness of a tacrolimus-loaded hydrogel in vivo. Moreover, we show that encapsulating a near-infrared dye in the hydrogel provides a reliable correlation of tacrolimus and dye release from the hydrogel, and an accessible non-invasive method for monitoring drug release from hydrogel deposits.

%B PLoS One %V 13 %P e0203409 %8 2018 %G eng %N 8 %R 10.1371/journal.pone.0203409 %0 Journal Article %J Methods Mol Biol %D 2018 %T Quantification of Neurotransmitters from Intact and Regenerating Planarians Using UHPLC-MS/SRM Method. %A Rangiah, Kannan %A Palakodeti, Dasaradhi %K Animals %K Chromatography, High Pressure Liquid %K Neurotransmitter Agents %K Planarians %K Regeneration %K Stem Cells %K Tandem Mass Spectrometry %X

Freshwater planarian species S. mediterranea is an emerging stem cell model because of its capability of regenerating large portions of missing body parts. It is one of the best model systems available to address the basic biological mechanisms in the regeneration processes. Absolute quantification of metabolites from planarians is imperative to understand their role in the regeneration processes. Here we describe a stable isotope dilution ultrahigh performance liquid chromatography/mass spectrometry/selected reaction monitoring (UHPLC-MS/SRM) assay for a sensitive and quantitative assessment of neurotransmitters (NTs) in planaria. We used this method for the simultaneous quantification of 16 NTs from both intact and regenerating planarians.

%B Methods Mol Biol %V 1774 %P 555-570 %8 2018 %G eng %R 10.1007/978-1-4939-7802-1_25 %0 Journal Article %J Behav Brain Res %D 2018 %T Repeated social stress leads to contrasting patterns of structural plasticity in the amygdala and hippocampus. %A Patel, D %A Anilkumar, S %A Chattarji, S %A Buwalda, B %K Amygdala %K Animals %K Atrophy %K Avoidance Learning %K CA1 Region, Hippocampal %K Dendritic Spines %K Dominance-Subordination %K Male %K Neuronal Plasticity %K Prefrontal Cortex %K Pyramidal Cells %K Rats, Wistar %K Stress, Psychological %X

Previous studies have demonstrated that repeated immobilization and restraint stress cause contrasting patterns of dendritic reorganization as well as alterations in spine density in amygdalar and hippocampal neurons. Whether social and ethologically relevant stressors can induce similar patterns of morphological plasticity remains largely unexplored. Hence, we assessed the effects of repeated social defeat stress on neuronal morphology in basolateral amygdala (BLA), hippocampal CA1 and infralimbic medial prefrontal cortex (mPFC). Male Wistar rats experienced social defeat stress on 5 consecutive days during confrontation in the resident-intruder paradigm with larger and aggressive Wild-type Groningen rats. This resulted in clear social avoidance behavior one day after the last confrontation. To assess the morphological consequences of repeated social defeat, 2 weeks after the last defeat, animals were sacrificed and brains were stained using a Golgi-Cox procedure. Morphometric analyses revealed that, compared to controls, defeated Wistar rats showed apical dendritic decrease in spine density on CA1 but not BLA. Sholl analysis demonstrated a significant dendritic atrophy of CA1 basal dendrites in defeated animals. In contrast, basal dendrites of BLA pyramidal neurons exhibited enhanced dendritic arborization in defeated animals. Social stress failed to induce lasting structural changes in mPFC neurons. Our findings demonstrate for the first time that social defeat stress elicits divergent patterns of structural plasticity in the hippocampus versus amygdala, similar to what has previously been reported with repeated physical stressors. Therefore, brain region specific variations may be a universal feature of stress-induced plasticity that is shared by both physical and social stressors.

%B Behav Brain Res %V 347 %P 314-324 %8 2018 07 16 %G eng %R 10.1016/j.bbr.2018.03.034 %0 Journal Article %J Development %D 2017 %T Co-expression of Tbx6 and Sox2 identifies a novel transient neuromesoderm progenitor cell state. %A Javali, Alok %A Misra, Aritra %A Leonavicius, Karolis %A Acharyya, Debalina %A Vyas, Bhakti %A Sambasivan, Ramkumar %K Animals %K Body Patterning %K Cell Differentiation %K Cell Lineage %K Embryonic Stem Cells %K Gene Expression Regulation, Developmental %K Mesoderm %K Mice %K Mice, Transgenic %K Neural Tube %K SOXB1 Transcription Factors %K Spinal Cord %K Transcription Factors %X

Elongation of the body axis is a key aspect of body plan development. Bipotential neuromesoderm progenitors (NMPs) ensure axial growth of embryos by contributing both to the spinal cord and mesoderm. The current model for the mechanism controlling NMP deployment invokes Tbx6, a T-box factor, to drive mesoderm differentiation of NMPs. Here, we identify a new population of Tbx6 cells in a subdomain of the NMP niche in mouse embryos. Based on co-expression of a progenitor marker, Sox2, we identify this population as representing a transient cell state in the mesoderm-fated NMP lineage. Genetic lineage tracing confirms the presence of the NMP cell state. Furthermore, we report a novel aspect of the documented mutant phenotype, namely an increase from two to four ectopic neural tubes, corresponding to the switch in NMP niche, thus highlighting the importance of function in NMP fate decision. This study emphasizes the function of Tbx6 as a bistable switch that turns mesoderm fate 'on' and progenitor state 'off', and thus has implications for the molecular mechanism driving NMP fate choice.

%B Development %V 144 %P 4522-4529 %8 2017 12 15 %G eng %N 24 %R 10.1242/dev.153262 %0 Journal Article %J Development %D 2017 %T Cytoplasmic poly (A)-binding protein critically regulates epidermal maintenance and turnover in the planarian . %A Bansal, Dhiru %A Kulkarni, Jahnavi %A Nadahalli, Kavana %A Lakshmanan, Vairavan %A Krishna, Srikar %A Sasidharan, Vidyanand %A Geo, Jini %A Dilipkumar, Shilpa %A Pasricha, Renu %A Gulyani, Akash %A Raghavan, Srikala %A Palakodeti, Dasaradhi %K Animals %K Cell Lineage %K Cell Proliferation %K Cytoplasm %K Epidermis %K Epithelium %K Extracellular Matrix %K Gene Knockdown Techniques %K Homeostasis %K Models, Biological %K Planarians %K Poly(A)-Binding Protein I %K Regeneration %K RNA, Messenger %K Wound Healing %X

Identifying key cellular events that facilitate stem cell function and tissue organization is crucial for understanding the process of regeneration. Planarians are powerful model system to study regeneration and stem cell (neoblast) function. Here, using planaria, we show that the initial events of regeneration, such as epithelialization and epidermal organization are critically regulated by a novel cytoplasmic poly A-binding protein, SMED-PABPC2. Knockdown leads to defects in epidermal lineage specification, disorganization of epidermis and ECM, and deregulated wound healing, resulting in the selective failure of neoblast proliferation near the wound region. Polysome profiling suggests that epidermal lineage transcripts, including , are translationally regulated by SMED-PABPC2 Together, our results uncover a novel role for SMED-PABPC2 in the maintenance of epidermal and ECM integrity, critical for wound healing and subsequent processes for regeneration.

%B Development %V 144 %P 3066-3079 %8 2017 09 01 %G eng %N 17 %R 10.1242/dev.152942 %0 Journal Article %J Cell Mol Life Sci %D 2017 %T Exosomes: mobile platforms for targeted and synergistic signaling across cell boundaries. %A Vyas, Neha %A Dhawan, Jyotsna %K Animals %K Cell Communication %K Cell Membrane %K Exosomes %K Humans %K Models, Biological %K RNA %K Signal Transduction %X

Intercellular communications play a vital role during tissue patterning, tissue repair, and immune reactions, in homeostasis as well as in disease. Exosomes are cell-derived secreted vesicles, extensively studied for their role in intercellular communication. Exosomes have the intrinsic ability to package multiple classes of proteins and nucleic acids within their lumens and on their membranes. Here, we explore the hypothesis that exosomal targeting may represent a cellular strategy that has evolved to deliver specific combinations of signals to specific target cells and influence normal or pathological processes. This review aims to evaluate the available evidence for this hypothesis and to identify open questions whose answers will illuminate our understanding and applications of exosome biology.

%B Cell Mol Life Sci %V 74 %P 1567-1576 %8 2017 05 %G eng %N 9 %R 10.1007/s00018-016-2413-9 %0 Journal Article %J Biochemistry %D 2017 %T Horse Liver Alcohol Dehydrogenase: Zinc Coordination and Catalysis. %A Plapp, Bryce V %A Savarimuthu, Baskar Raj %A Ferraro, Daniel J %A Rubach, Jon K %A Brown, Eric N %A Ramaswamy, S %K 2,2'-Dipyridyl %K Adenosine Diphosphate Ribose %K Alcohol Dehydrogenase %K Animals %K Catalytic Domain %K Crystallography, X-Ray %K Formamides %K Horses %K Kinetics %K Liver %K Models, Molecular %K NAD %K Phenanthrolines %K Protein Binding %K Protein Conformation %K Water %K Zinc %X

During catalysis by liver alcohol dehydrogenase (ADH), a water bound to the catalytic zinc is replaced by the oxygen of the substrates. The mechanism might involve a pentacoordinated zinc or a double-displacement reaction with participation by a nearby glutamate residue, as suggested by studies of human ADH3, yeast ADH1, and some other tetrameric ADHs. Zinc coordination and participation of water in the enzyme mechanism were investigated by X-ray crystallography. The apoenzyme and its complex with adenosine 5'-diphosphoribose have an open protein conformation with the catalytic zinc in one position, tetracoordinated by Cys-46, His-67, Cys-174, and a water molecule. The bidentate chelators 2,2'-bipyridine and 1,10-phenanthroline displace the water and form a pentacoordinated zinc. The enzyme-NADH complex has a closed conformation similar to that of ternary complexes with coenzyme and substrate analogues; the coordination of the catalytic zinc is similar to that found in the apoenzyme, except that a minor, alternative position for the catalytic zinc is ∼1.3 Å from the major position and closer to Glu-68, which could form the alternative coordination to the catalytic zinc. Complexes with NADH and N-1-methylhexylformamide or N-benzylformamide (or with NAD and fluoro alcohols) have the classical tetracoordinated zinc, and no water is bound to the zinc or the nicotinamide rings. The major forms of the enzyme in the mechanism have a tetracoordinated zinc, where the carboxylate group of Glu-68 could participate in the exchange of water and substrates on the zinc. Hydride transfer in the Michaelis complexes does not involve a nearby water.

%B Biochemistry %V 56 %P 3632-3646 %8 2017 07 18 %G eng %N 28 %R 10.1021/acs.biochem.7b00446 %0 Journal Article %J Methods Mol Biol %D 2017 %T Mimicking Muscle Stem Cell Quiescence in Culture: Methods for Synchronization in Reversible Arrest. %A Arora, Reety %A Rumman, Mohammed %A Venugopal, Nisha %A Gala, Hardik %A Dhawan, Jyotsna %K Actins %K Adult Stem Cells %K Animals %K Biomarkers %K Cell Culture Techniques %K Cell Differentiation %K Cell Line %K Cell Proliferation %K Fluorescent Antibody Technique %K Humans %K Mice %K Microscopy, Fluorescence %K Muscle, Skeletal %K Myoblasts %K Resting Phase, Cell Cycle %K Satellite Cells, Skeletal Muscle %K Stem Cells %X

Growing evidence supports the view that in adult stem cells, the defining stem cell features of potency and self-renewal are associated with the quiescent state. Thus, uncovering the molecular logic of this reversibly arrested state underlies not only a fundamental understanding of adult tissue dynamics but also hopes for therapeutic regeneration and rejuvenation of damaged or aging tissue. A key question concerns how adult stem cells use quiescence to establish or reinforce the property of self-renewal. Since self-renewal is largely studied by assays that measure proliferation, the concept of self-renewal programs imposed during non-proliferating conditions is counterintuitive. However, there is increasing evidence generated by deconstructing the quiescent state that highlights how programs characteristic of this particular cell cycle exit may enhance stem cell capabilities, through both cell-intrinsic and extrinsic programs.Toward this end, culture models that recapitulate key aspects of stem cell quiescence are useful for molecular analysis to explore attributes and regulation of the quiescent state. In this chapter, we review the different methods used to generate homogeneous populations of quiescent muscle cells, largely by manipulating culture conditions that feed into core signaling programs that regulate the cell cycle. We also provide detailed protocols developed or refined in our lab over the past two decades.

%B Methods Mol Biol %V 1556 %P 283-302 %8 2017 %G eng %R 10.1007/978-1-4939-6771-1_15 %0 Journal Article %J G3 (Bethesda) %D 2016 %T Genome-Wide Analysis of Polyadenylation Events in Schmidtea mediterranea. %A Lakshmanan, Vairavan %A Bansal, Dhiru %A Kulkarni, Jahnavi %A Poduval, Deepak %A Krishna, Srikar %A Sasidharan, Vidyanand %A Anand, Praveen %A Seshasayee, Aswin %A Palakodeti, Dasaradhi %K 3' Untranslated Regions %K Animals %K Computational Biology %K Genome, Helminth %K Genome-Wide Association Study %K High-Throughput Nucleotide Sequencing %K MicroRNAs %K Molecular Sequence Annotation %K Platyhelminths %K Poly A %K Polyadenylation %K Reproducibility of Results %K RNA Interference %K RNA Processing, Post-Transcriptional %K RNA, Messenger %X

In eukaryotes, 3' untranslated regions (UTRs) play important roles in regulating posttranscriptional gene expression. The 3'UTR is defined by regulated cleavage/polyadenylation of the pre-mRNA. The advent of next-generation sequencing technology has now enabled us to identify these events on a genome-wide scale. In this study, we used poly(A)-position profiling by sequencing (3P-Seq) to capture all poly(A) sites across the genome of the freshwater planarian, Schmidtea mediterranea, an ideal model system for exploring the process of regeneration and stem cell function. We identified the 3'UTRs for ∼14,000 transcripts and thus improved the existing gene annotations. We found 97 transcripts, which are polyadenylated within an internal exon, resulting in the shrinking of the ORF and loss of a predicted protein domain. Around 40% of the transcripts in planaria were alternatively polyadenylated (ApA), resulting either in an altered 3'UTR or a change in coding sequence. We identified specific ApA transcript isoforms that were subjected to miRNA mediated gene regulation using degradome sequencing. In this study, we also confirmed a tissue-specific expression pattern for alternate polyadenylated transcripts. The insights from this study highlight the potential role of ApA in regulating the gene expression essential for planarian regeneration.

%B G3 (Bethesda) %V 6 %P 3035-3048 %8 2016 10 13 %G eng %N 10 %R 10.1534/g3.116.031120 %0 Journal Article %J Cell Rep %D 2016 %T Sterile Inflammation Enhances ECM Degradation in Integrin β1 KO Embryonic Skin. %A Kurbet, Ambika S %A Hegde, Samarth %A Bhattacharjee, Oindrila %A Marepally, Srujan %A Vemula, Praveen K %A Raghavan, Srikala %K Animals %K Extracellular Matrix %K Inflammation %K Integrin beta1 %K Macrophages %K Mice %K Mice, Knockout %K Signal Transduction %K Skin %X

Epidermal knockout of integrin β1 results in complete disorganization of the basement membrane (BM), resulting in neonatal lethality. Here, we report that this disorganization is exacerbated by an early embryonic inflammatory response involving the recruitment of tissue-resident and monocyte-derived macrophages to the dermal-epidermal junction, associated with increased matrix metalloproteinase activity. Remarkably, the skin barrier in the integrin β1 knockout animals is intact, suggesting that this inflammatory response is initiated in a sterile environment. We demonstrate that the molecular mechanism involves de novo expression of integrin αvβ6 in the basal epidermal cells, which activates a TGF-β1 driven inflammatory cascade resulting in upregulation of dermal NF-κB in a Tenascin C-dependent manner. Importantly, treatment of β1 KO embryos in utero with small molecule inhibitors of TGF-βR1 and NF-κB results in marked rescue of the BM defects and amelioration of immune response, revealing an unconventional immuno-protective role for integrin β1 during BM remodeling.

%B Cell Rep %V 16 %P 3334-3347 %8 2016 09 20 %G eng %N 12 %R 10.1016/j.celrep.2016.08.062 %0 Journal Article %J Analyst %D 2015 %T A quantitative metabolomics peek into planarian regeneration. %A Natarajan, Nivedita %A Ramakrishnan, Padma %A Lakshmanan, Vairavan %A Palakodeti, Dasaradhi %A Rangiah, Kannan %K Animals %K Calibration %K Chromatography, High Pressure Liquid %K Limit of Detection %K Metabolomics %K Planarians %K Reference Standards %K Regeneration %K Reproduction, Asexual %K Species Specificity %K Tandem Mass Spectrometry %X

The fresh water planarian species Schmidtea mediterranea is an emerging stem cell model because of its capability to regenerate a whole animal from a small piece of tissue. It is one of the best model systems to address the basic mechanisms essential for regeneration. Here, we are interested in studying the roles of various amines, thiols and nucleotides in planarian regeneration, stem cell function and growth. We developed mass spectrometry based quantitative methods and validated the differential enrichment of 35 amines, 7 thiol metabolites and 4 nucleotides from both intact and regenerating planarians. Among the amines, alanine in sexual and asparagine in asexual are the highest (>1000 ng/mg) in the intact planarians. The levels of thiols such as cysteine and GSH are 651 and 1107 ng mg(-1) in planarians. Among the nucleotides, the level of cGMP is the lowest (0.03 ng mg(-1)) and the level of AMP is the highest (187 ng mg(-1)) in both of the planarian strains. We also noticed increasing levels of amines in both anterior and posterior regenerating planarians. The blastema from day 3 regenerating planarians also showed higher amounts of many amines. Interestingly, the thiol (cysteine and GSH) levels are well maintained during planarian regeneration. This suggests an inherent and effective mechanism to control induced oxidative stress because of the robust regeneration and stem cell proliferation. Like in intact planarians, the level of cGMP is also very low in regenerating planarians. Surprisingly, the levels of amines and thiols in head regenerating blastemas are ∼3 times higher compared to those for tail regenerating blastemas. Thus our results strongly indicate the potential roles of amines, thiols and nucleotides in planarian regeneration.

%B Analyst %V 140 %P 3445-64 %8 2015 May 21 %G eng %N 10 %R 10.1039/c4an02037e %0 Journal Article %J Biochem Biophys Res Commun %D 1975 %T Metal substitutions incarbonic anhydrase: a halide ion probe study. %A Smith, R J %A Bryant, R G %K Animals %K Binding Sites %K Cadmium %K Carbonic Anhydrases %K Cattle %K Humans %K Hydrogen-Ion Concentration %K Magnetic Resonance Spectroscopy %K Mercury %K Protein Binding %K Protein Conformation %K Zinc %B Biochem Biophys Res Commun %V 66 %P 1281-6 %8 1975 Oct 27 %G eng %N 4 %R 10.1016/0006-291x(75)90498-2