@article {2463, title = {Whole genome sequencing delineates regulatory, copy number, and cryptic splice variants in early onset cardiomyopathy.}, journal = {NPJ Genom Med}, volume = {7}, year = {2022}, month = {2022 Mar 14}, pages = {18}, abstract = {

Cardiomyopathy (CMP) is a heritable disorder. Over 50\% of cases are gene-elusive on clinical gene panel testing. The contribution of variants in non-coding DNA elements that result in cryptic splicing and regulate gene expression has not been explored. We analyzed whole-genome sequencing (WGS) data in a discovery cohort of 209 pediatric CMP patients and 1953 independent replication genomes and exomes. We searched for protein-coding variants, and non-coding variants predicted to affect the function or expression of genes. Thirty-nine percent of cases harbored pathogenic coding variants in known CMP genes, and 5\% harbored high-risk loss-of-function (LoF) variants in additional candidate CMP genes. Fifteen percent harbored high-risk regulatory variants in promoters and enhancers of CMP genes (odds ratio 2.25, p = 6.70 {\texttimes} 10 versus controls). Genes involved in α-dystroglycan glycosylation (FKTN, DTNA) and desmosomal signaling (DSC2, DSG2) were most highly enriched for regulatory variants (odds ratio 6.7-58.1). Functional effects were confirmed in patient myocardium and reporter assays in human cardiomyocytes, and in zebrafish CRISPR knockouts. We provide strong evidence for the genomic contribution of functionally active variants in new genes and in regulatory elements of known CMP genes to early onset CMP.

}, issn = {2056-7944}, doi = {10.1038/s41525-022-00288-y}, author = {Lesurf, Robert and Said, Abdelrahman and Akinrinade, Oyediran and Breckpot, Jeroen and Delfosse, Kathleen and Liu, Ting and Yao, Roderick and Persad, Gabrielle and McKenna, Fintan and Noche, Ramil R and Oliveros, Winona and Mattioli, Kaia and Shah, Shreya and Miron, Anastasia and Yang, Qian and Meng, Guoliang and Yue, Michelle Chan Seng and Sung, Wilson W L and Thiruvahindrapuram, Bhooma and Lougheed, Jane and Oechslin, Erwin and Mondal, Tapas and Bergin, Lynn and Smythe, John and Jayappa, Shashank and Rao, Vinay J and Shenthar, Jayaprakash and Dhandapany, Perundurai S and Semsarian, Christopher and Weintraub, Robert G and Bagnall, Richard D and Ingles, Jodie and Mel{\'e}, Marta and Maass, Philipp G and Ellis, James and Scherer, Stephen W and Mital, Seema} } @article {2248, title = {Allosteric inhibition of MTHFR prevents futile SAM cycling and maintains nucleotide pools in one-carbon metabolism.}, journal = {J Biol Chem}, volume = {295}, year = {2020}, month = {2020 11 20}, pages = {16037-16057}, abstract = {

Methylenetetrahydrofolate reductase (MTHFR) links the folate cycle to the methionine cycle in one-carbon metabolism. The enzyme is known to be allosterically inhibited by SAM for decades, but the importance of this regulatory control to one-carbon metabolism has never been adequately understood. To shed light on this issue, we exchanged selected amino acid residues in a highly conserved stretch within the regulatory region of yeast MTHFR to create a series of feedback-insensitive, deregulated mutants. These were exploited to investigate the impact of defective allosteric regulation on one-carbon metabolism. We observed a strong growth defect in the presence of methionine. Biochemical and metabolite analysis revealed that both the folate and methionine cycles were affected in these mutants, as was the transsulfuration pathway, leading also to a disruption in redox homeostasis. The major consequences, however, appeared to be in the depletion of nucleotides. C isotope labeling and metabolic studies revealed that the deregulated MTHFR cells undergo continuous transmethylation of homocysteine by methyltetrahydrofolate (CHTHF) to form methionine. This reaction also drives SAM formation and further depletes ATP reserves. SAM was then cycled back to methionine, leading to futile cycles of SAM synthesis and recycling and explaining the necessity for MTHFR to be regulated by SAM. The study has yielded valuable new insights into the regulation of one-carbon metabolism, and the mutants appear as powerful new tools to further dissect out the intersection of one-carbon metabolism with various pathways both in yeasts and in humans.

}, keywords = {Adenosine Triphosphate, Allosteric Regulation, Humans, Methylation, Methylenetetrahydrofolate Reductase (NADPH2), S-Adenosylmethionine, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins}, issn = {1083-351X}, doi = {10.1074/jbc.RA120.015129}, author = {Bhatia, Muskan and Thakur, Jyotika and Suyal, Shradha and Oniel, Ruchika and Chakraborty, Rahul and Pradhan, Shalini and Sharma, Monika and Sengupta, Shantanu and Laxman, Sunil and Masakapalli, Shyam Kumar and Bachhawat, Anand Kumar} } @article {2110, title = {Cortical neurons derived from human pluripotent stem cells lacking FMRP display altered spontaneous firing patterns.}, journal = {Mol Autism}, volume = {11}, year = {2020}, month = {2020 Jun 19}, pages = {52}, abstract = {

BACKGROUND: Fragile X syndrome (FXS), a neurodevelopmental disorder, is a leading monogenetic cause of intellectual disability and autism spectrum disorder. Notwithstanding the extensive studies using rodent and other pre-clinical models of FXS, which have provided detailed mechanistic insights into the pathophysiology of this disorder, it is only relatively recently that human stem cell-derived neurons have been employed as a model system to further our understanding of the pathophysiological events that may underlie FXS. Our study assesses the physiological properties of human pluripotent stem cell-derived cortical neurons lacking fragile X mental retardation protein (FMRP).

METHODS: Electrophysiological whole-cell voltage- and current-clamp recordings were performed on two control and three FXS patient lines of human cortical neurons derived from induced pluripotent stem cells. In addition, we also describe the properties of an isogenic pair of lines in one of which FMR1 gene expression has been silenced.

RESULTS: Neurons lacking FMRP displayed bursts of spontaneous action potential firing that were more frequent but shorter in duration compared to those recorded from neurons expressing FMRP. Inhibition of large conductance Ca-activated K currents and the persistent Na current in control neurons phenocopies action potential bursting observed in neurons lacking FMRP, while in neurons lacking FMRP pharmacological potentiation of voltage-dependent Na channels phenocopies action potential bursting observed in control neurons. Notwithstanding the changes in spontaneous action potential firing, we did not observe any differences in the intrinsic properties of neurons in any of the lines examined. Moreover, we did not detect any differences in the properties of miniature excitatory postsynaptic currents in any of the lines.

CONCLUSIONS: Pharmacological manipulations can alter the action potential burst profiles in both control and FMRP-null human cortical neurons, making them appear like their genetic counterpart. Our studies indicate that FMRP targets that have been found in rodent models of FXS are also potential targets in a human-based model system, and we suggest potential mechanisms by which activity is altered.

}, issn = {2040-2392}, doi = {10.1186/s13229-020-00351-4}, author = {Das Sharma, Shreya and Pal, Rakhi and Reddy, Bharath Kumar and Selvaraj, Bhuvaneish T and Raj, Nisha and Samaga, Krishna Kumar and Srinivasan, Durga J and Ornelas, Loren and Sareen, Dhruv and Livesey, Matthew R and Bassell, Gary J and Svendsen, Clive N and Kind, Peter C and Chandran, Siddharthan and Chattarji, Sumantra and Wyllie, David J A} } @article {2115, title = {A field-based quantitative analysis of sublethal effects of air pollution on pollinators.}, journal = {Proc Natl Acad Sci U S A}, volume = {117}, year = {2020}, month = {2020 Aug 25}, pages = {20653-20661}, abstract = {

While the impact of air pollution on human health is well studied, mechanistic impacts of air pollution on wild systems, including those providing essential ecosystem services, are largely unknown, but directly impact our health and well-being. India is the world{\textquoteright}s largest fruit producer, second most populous country, and contains 9 of the world{\textquoteright}s 10 most polluted cities. Here, we sampled Giant Asian honey bees, , at locations with varying air pollution levels in Bangalore, India. We observed significant correlations between increased respirable suspended particulate matter (RSPM) deposition and changes in bee survival, flower visitation, heart rate, hemocyte levels, and expression of genes related to lipid metabolism, stress, and immunity. Lab-reared exposed to these same sites also exhibited similar molecular and physiological differences. Our study offers a quantitative analysis on the current impacts of air pollution on insects, and indicates the urgency for more nonhuman studies to accurately assess the effects of pollution on our natural world.

}, issn = {1091-6490}, doi = {10.1073/pnas.2009074117}, author = {Thimmegowda, Geetha G and Mullen, Susan and Sottilare, Katie and Sharma, Ankit and Mohanta, Saptashi Soham and Brockmann, Axel and Dhandapany, Perundurai S and Olsson, Shannon B} } @article {2209, title = {Reply to Negri et al.: Air pollution and health impacts on bees: Signs of causation.}, journal = {Proc Natl Acad Sci U S A}, volume = {117}, year = {2020}, month = {2020 10 27}, pages = {26578-26579}, keywords = {Air Pollution, Animals, Bees, Health}, issn = {1091-6490}, doi = {10.1073/pnas.2017972117}, author = {Thimmegowda, Geetha G and Brockmann, Axel and Dhandapany, Perundurai S and Olsson, Shannon B} } @article {1984, title = {Novel Series of Methyl 3-(Substituted Benzoyl)-7-Substituted-2-Phenylindolizine-1-Carboxylates as Promising Anti-Inflammatory Agents: Molecular Modeling Studies.}, journal = {Biomolecules}, volume = {9}, year = {2019}, month = {2019 Oct 28}, abstract = {

The cyclooxygenase-2 (COX-2) enzyme is considered to be an important target for developing novel anti-inflammatory agents. Selective COX-2 inhibitors offer the advantage of lower adverse effects that are commonly associated with non-selective COX inhibitors. In this work, a novel series of methyl 3-(substituted benzoyl)-7-substituted-2-phenylindolizine-1-carboxylates was synthesized and evaluated for COX-2 inhibitory activity. Compound was identified as the most active compound of the series with an IC of 6.71 M, which is comparable to the IC of indomethacin, a marketed non-steroidal anti-inflammatory drug (NSAID). Molecular modeling and crystallographic studies were conducted to further characterize the compounds and gain better understanding of the binding interactions between the compounds and the residues at the active site of the COX-2 enzyme. The pharmacokinetic properties and potential toxic effects were predicted for all the synthesized compounds, which indicated good drug-like properties. Thus, these synthesized compounds can be considered as potential lead compounds for developing effective anti-inflammatory therapeutic agents.

}, issn = {2218-273X}, doi = {10.3390/biom9110661}, author = {Venugopala, Katharigatta N and Al-Attraqchi, Omar H A and Tratrat, Christophe and Nayak, Susanta K and Morsy, Mohamed A and Aldhubiab, Bandar E and Attimarad, Mahesh and Nair, Anroop B and Sreeharsha, Nagaraja and Venugopala, Rashmi and Haroun, Michelyne and Girish, Meravanige B and Chandrashekharappa, Sandeep and Alwassil, Osama I and Odhav, Bharti} } @article {1738, title = {Sustained correction of associative learning deficits after brief, early treatment in a rat model of Fragile X Syndrome.}, journal = {Sci Transl Med}, volume = {11}, year = {2019}, month = {2019 May 29}, abstract = {

Fragile X Syndrome (FXS) is one of the most common monogenic forms of autism and intellectual disability. Preclinical studies in animal models have highlighted the potential of pharmaceutical intervention strategies for alleviating the symptoms of FXS. However, whether treatment strategies can be tailored to developmental time windows that define the emergence of particular phenotypes is unknown. Similarly, whether a brief, early intervention can have long-lasting beneficial effects, even after treatment cessation, is also unknown. To address these questions, we first examined the developmental profile for the acquisition of associative learning in a rat model of FXS. Associative memory was tested using a range of behavioral paradigms that rely on an animal{\textquoteright}s innate tendency to explore novelty. knockout (KO) rats showed a developmental delay in their acquisition of object-place recognition and did not demonstrate object-place-context recognition paradigm at any age tested (up to 23 weeks of age). Treatment of KO rats with lovastatin between 5 and 9 weeks of age, during the normal developmental period that this associative memory capability is established, prevents the emergence of deficits but has no effect in wild-type animals. Moreover, we observe no regression of cognitive performance in the FXS rats over several months after treatment. This restoration of the normal developmental trajectory of cognitive function is associated with the sustained rescue of both synaptic plasticity and altered protein synthesis. The findings provide proof of concept that the impaired emergence of the cognitive repertoire in neurodevelopmental disorders may be prevented by brief, early pharmacological intervention.

}, issn = {1946-6242}, doi = {10.1126/scitranslmed.aao0498}, author = {Asiminas, Antonis and Jackson, Adam D and Louros, Susana R and Till, Sally M and Spano, Teresa and Dando, Owen and Bear, Mark F and Chattarji, Sumantra and Hardingham, Giles E and Osterweil, Emily K and Wyllie, David J A and Wood, Emma R and Kind, Peter C} } @article {1189, title = {Local injections of tacrolimus-loaded hydrogel reduce systemic immunosuppression-related toxicity in vascularized composite allotransplantation.}, journal = {Transplantation}, year = {2018}, month = {2018 May 23}, abstract = {

BACKGROUND: Routine application of vascularized composite allotransplantation (VCA) is hampered by immunosuppression-related health comorbidities. To mitigate these we developed an inflammation-responsive hydrogel for local immunosuppression. Here we report on its long-term effect on graft survival, immunological and toxicological impact.

METHODS: Brown Norway-to-Lewis rat hind limb transplantations were treated either systemically with daily injections of 1 mg/kg tacrolimus or with subcutaneous intragraft injections of hydrogel containing 7 mg tacrolimus, every 70 days. Animals were monitored for rejection or other pathology for 280 days. Systemic and graft tacrolimus levels, regulatory T cells, and donor cell chimerism were measured periodically. At endpoint, markers for kidney, liver and metabolic state were compared to na{\"\i}ve age-matched rats.

RESULTS: Both daily systemic tacrolimus and subcutaneous intragraft tacrolimus hydrogel at 70 day intervals were able to sustain graft survival for \>280 days in 5 out of 6 recipients. In the hydrogel group, 1 graft progressed to grade 3 rejection at postoperative day (POD) 149. In systemic tacrolimus group, 1 animal was euthanized due to lymphoma on POD 275. Hydrogel treatment provided stable graft- and reduced systemic tacrolimus levels, and a 4 times smaller total tacrolimus dose compared with systemic immunosuppression. Hydrogel-treated animals showed preserved kidney function, absence of malignancies or opportunistic infections and increased hematopoietic chimerism compared to systemic immunosuppression.

CONCLUSIONS: Our findings demonstrate that localized immunosuppression with tacrolimus hydrogel is a long-term safe and reliable treatment. It may reduce the burden of systemic immunosuppression in VCA, potentially boosting the clinical application of this surgical intervention.

}, issn = {1534-6080}, doi = {10.1097/TP.0000000000002283}, author = {Dzhonova, Dzhuliya V and Olariu, Radu and Leckenby, Jonathan and Banz, Yara and Prost, Jean-Christophe and Dhayani, Ashish and Vemula, Praveen K and Voegelin, Esther and Taddeo, Adriano and Rieben, Robert} } @article {1592, title = {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.}, journal = {PLoS One}, volume = {13}, year = {2018}, month = {2018}, pages = {e0203409}, abstract = {

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 na{\"\i}ve 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.

}, keywords = {Animals, Drug Delivery Systems, Humans, Hydrogels, Immunosuppressive Agents, Inflammation, Male, Rats, Rats, Inbred BN, Rats, Inbred Lew, Tacrolimus}, issn = {1932-6203}, doi = {10.1371/journal.pone.0203409}, author = {Dzhonova, Dzhuliya and Olariu, Radu and Leckenby, Jonathan and Dhayani, Ashish and Vemula, Praveen Kumar and Prost, Jean-Christophe and Banz, Yara and Taddeo, Adriano and Rieben, Robert} } @article {1202, title = {Facile Synthesis of Highly Sensitive, Red-Emitting, Fluorogenic Dye for Microviscosity and Mitochondrial Imaging in Embryonic Stem Cells}, journal = {ChemistrySelect}, volume = {2}, year = {2017}, pages = {4609-4616}, abstract = {

Abstract Bright, sensitive fluorescent probes that respond to changes in the cellular microenvironment are extremely valuable for imaging cellular dynamics. We report a simple, one-step synthesis of a new hemicaynine (HC-1) dye as a sensitive, red-emitting (λmax-610 nm) fluorogenic probe for micro-viscosity and local order in diverse environments, including live cells. HC-1 responds to increasing micro-viscosity through changes in fluorescence intensity and lifetime, and is sensitive enough to report dynamic micellar self-assembly. While HC-1 shows properties of a molecular {\textquoteleft}rotor{\textquoteright}, time-dependent density functional theoretical analysis reveals that in HC-1, an inhibition of photo-isomerization in viscous environment is the likely cause of fluorescence enhancement. HC-1 localizes to mitochondria in live cells and responds to mitochondrial ordering through a significant increase in fluorescence. Strikingly, we show that HC-1 is also a sensitive probe for the spatial heterogeneity of mitochondrial organization in embryonic stem cells as well as dynamic remodeling of the mitochondria in early-differentiated cells.

}, keywords = {Embryonic Stem Cells, Live cell imaging, Microviscosity, Mitochondrial fluorescent probe, Photoisomerization}, doi = {10.1002/slct.201700463}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/slct.201700463}, author = {Raja Sufi O. and Sivaraman Gandhi and Mukherjee Ananya and Duraisamy Chellappa and Gulyani Akash} } @article {1206, title = {{One enzyme, many reactions: structural basis for the various reactions catalyzed by naphthalene 1,2-dioxygenase}}, journal = {IUCrJ}, volume = {4}, year = {2017}, month = {Sep}, pages = {648{\textendash}656}, abstract = {

Rieske nonheme iron oxygenases (ROs) are a well studied class of enzymes. Naphthalene 1,2-dioxygenase (NDO) is used as a model to study ROs. Previous work has shown how side-on binding of oxygen to the mononuclear iron provides this enzyme with the ability to catalyze stereospecific and regiospecific {\i}t cis}-dihydroxylation reactions. It has been well documented that ROs catalyze a variety of other reactions, including mono-oxygenation, desaturation, O- and N-dealkylation, sulfoxidation {\i}t etc}. NDO itself catalyzes a variety of these reactions. Structures of NDO in complex with a number of different substrates show that the orientation of the substrate in the active site controls not only the regiospecificity and stereospecificity, but also the type of reaction catalyzed. It is proposed that the mononuclear iron-activated dioxygen attacks the atoms of the substrate that are most proximal to it. The promiscuity of delivering two products (apparently by two different reactions) from the same substrate can be explained by the possible binding of the substrate in slightly different orientations aided by the observed flexibility of residues in the binding pocket.

}, keywords = {2-dioxygenase, deoxygenation, monooxygenation, naphthalene 1, substrate orientation, sulfoxidation}, doi = {10.1107/S2052252517008223}, url = {https://doi.org/10.1107/S2052252517008223}, author = {Ferraro, Daniel J. and Okerlund, Adam and Brown, Eric and Ramaswamy, S.} } @article {1171, title = {Melatonin and Human Cardiovascular Disease.}, journal = {J Cardiovasc Pharmacol Ther}, year = {2016}, month = {2016 Jul 21}, abstract = {

The possible therapeutic role of melatonin in the pathophysiology of coronary artery disorder (CAD) is increasingly being recognized. In humans, exogenous melatonin has been shown to decrease nocturnal hypertension, improve systolic and diastolic blood pressure, reduce the pulsatility index in the internal carotid artery, decrease platelet aggregation, and reduce serum catecholamine levels. Low circulating levels of melatonin are reported in individuals with CAD, arterial hypertension, and congestive heart failure. This review assesses current literature on the cardiovascular effects of melatonin in humans. It can be concluded that melatonin deserves to be considered in clinical trials evaluating novel therapeutic interventions for cardiovascular disorders.

}, issn = {1940-4034}, doi = {10.1177/1074248416660622}, author = {Pandi-Perumal, Seithikurippu R and BaHammam, Ahmed S and Ojike, Nwakile I and Akinseye, Oluwaseun A and Kendzerska, Tetyana and Buttoo, Kenneth and Dhandapany, Perundurai S and Brown, Gregory M and Cardinali, Daniel P} } @article {398, title = {Conserved hippocampal cellular pathophysiology but distinct behavioural deficits in a new rat model of FXS.}, journal = {Hum Mol Genet}, volume = {24}, year = {2015}, month = {2015 Nov 1}, pages = {5977-84}, abstract = {

Recent advances in techniques for manipulating genomes have allowed the generation of transgenic animals other than mice. These new models enable cross-mammalian comparison of neurological disease from core cellular pathophysiology to circuit and behavioural endophenotypes. Moreover they will enable us to directly test whether common cellular dysfunction or behavioural outcomes of a genetic mutation are more conserved across species. Using a new rat model of Fragile X Syndrome, we report that Fmr1 knockout (KO) rats exhibit elevated basal protein synthesis and an increase in mGluR-dependent long-term depression in CA1 of the hippocampus that is independent of new protein synthesis. These defects in plasticity are accompanied by an increase in dendritic spine density selectively in apical dendrites and subtle changes in dendritic spine morphology of CA1 pyramidal neurons. Behaviourally, Fmr1 KO rats show deficits in hippocampal-dependent, but not hippocampal-independent, forms of associative recognition memory indicating that the loss of fragile X mental retardation protein (FMRP) causes defects in episodic-like memory. In contrast to previous reports from mice, Fmr1 KO rats show no deficits in spatial reference memory reversal learning. One-trial spatial learning in a delayed matching to place water maze task was also not affected by the loss of FMRP in rats. This is the first evidence for conservation across mammalian species of cellular and physiological hippocampal phenotypes associated with the loss of FMRP. Furthermore, while key cellular phenotypes are conserved they manifest in distinct behavioural dysfunction. Finally, our data reveal novel information about the selective role of FMRP in hippocampus-dependent associative memory.

}, issn = {1460-2083}, doi = {10.1093/hmg/ddv299}, author = {Till, Sally M and Asiminas, Antonis and Jackson, Adam D and Katsanevaki, Danai and Barnes, Stephanie A and Osterweil, Emily K and Bear, Mark F and Chattarji, Sumantra and Wood, Emma R and Wyllie, David J A and Kind, Peter C} }