Publications by authors named "Xiao-Yan Wen"

71 Publications

HACS1 signaling adaptor protein recognizes a motif in the paired immunoglobulin receptor B cytoplasmic domain.

Commun Biol 2020 Nov 13;3(1):672. Epub 2020 Nov 13.

Department of Biology, York University, 4700 Keele Street, Toronto, M3J 1P3, ON, Canada.

Hematopoietic adaptor containing SH3 and SAM domains-1 (HACS1) is a signaling protein with two juxtaposed protein-protein interaction domains and an intrinsically unstructured region that spans half the sequence. Here, we describe the interaction between the HACS1 SH3 domain and a sequence near the third immunoreceptor tyrosine-based inhibition motif (ITIM3) of the paired immunoglobulin receptor B (PIRB). From surface plasmon resonance binding assays using a mouse and human PIRB ITIM3 phosphopeptides as ligands, the HACS1 SH3 domain and SHP2 N-terminal SH2 domain demonstrated comparable affinities in the micromolar range. Since the PIRB ITIM3 sequence represents an atypical ligand for an SH3 domain, we determined the NMR structure of the HACS1 SH3 domain and performed a chemical shift mapping study. This study showed that the binding site on the HACS1 SH3 domain for PIRB shares many of the same amino acids found in a canonical binding cleft normally associated with polyproline ligands. Molecular modeling suggests that the respective binding sites in PIRB ITIM3 for the HACS1 SH3 domain and the SHP2 SH2 domain are too close to permit simultaneous binding. As a result, the HACS1-PIRB partnership has the potential to amalgamate signaling pathways that influence both immune and neuronal cell fate.
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http://dx.doi.org/10.1038/s42003-020-01397-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7666139PMC
November 2020

Zebrafish hhatla is involved in cardiac hypertrophy.

J Cell Physiol 2021 May 14;236(5):3700-3709. Epub 2020 Oct 14.

Zebrafish Centre for Advanced Drug Discovery, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Li Ka Shing Knowledge Institute, Toronto, Ontario, Canada.

Cardiac hypertrophy is a compensatory response to pathological stimuli, ultimately progresses to cardiomyopathy, heart failure, or sudden death. Although many signaling pathways have been reported to be involved in the hypertrophic process, it is still not fully clear about the underlying molecular mechanisms for cardiac hypertrophy. Hedgehog acyltransferase-like (Hhatl), a sarcoplasmic reticulum-resident protein, exhibits high expression in the heart and muscle. However, the biological role of Hhatl in the heart remains unknown. In this study, we first found that the expression level of Hhatl is markedly decreased in cardiac hypertrophy. We further studied the role of hhatla, homolog of Hhatl with the zebrafish model. The depletion of hhatla in zebrafish leads to cardiac defects, as well as an enhanced level of hypertrophic markers. Besides, we found that calcineurin signaling participates in hhatla depletion-induced cardiac hypertrophy. Together, these results demonstrate a critical role for hhatla in cardiac hypertrophy.
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http://dx.doi.org/10.1002/jcp.30106DOI Listing
May 2021

ndufa7 plays a critical role in cardiac hypertrophy.

J Cell Mol Med 2020 11 29;24(22):13151-13162. Epub 2020 Sep 29.

Zebrafish Centre for Advanced Drug Discovery, Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.

Cardiac hypertrophy is a common pathological change in patients with progressive cardiac function failure, which can be caused by hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM) or arterial hypertension. Despite years of study, there is still limited knowledge about the underlying molecular mechanisms for cardiac hypertrophy. NDUFA7, a subunit of NADH:ubiquinone oxidoreductase (complex I), has been reported to be a novel HCM associated gene. However, the biological role of NDUFA7 in heart remains unknown. In this study, we found that NDUFA7 exhibited high expression in the heart, and its level was significantly decreased in mice model of cardiac hypertrophy. Moreover, we demonstrated that ndufa7 knockdown in developing zebrafish embryos resulted in cardiac development and functional defects, associated with increased expression of pathological hypertrophy biomarkers nppa (ANP) and nppb (BNP). Mechanistic study demonstrated that ndufa7 depletion promoted ROS production and calcineurin signalling activation. Moreover, NDUFA7 depletion contributed to cardiac cell hypertrophy. Together, these results report for the first time that ndufa7 is implicated in pathological cardiac hypertrophy.
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http://dx.doi.org/10.1111/jcmm.15921DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7701565PMC
November 2020

Building the vertebrate codex using the gene breaking protein trap library.

Elife 2020 08 11;9. Epub 2020 Aug 11.

Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, United States.

One key bottleneck in understanding the human genome is the relative under-characterization of 90% of protein coding regions. We report a collection of 1200 transgenic zebrafish strains made with the gene-break transposon (GBT) protein trap to simultaneously report and reversibly knockdown the tagged genes. Protein trap-associated mRFP expression shows previously undocumented expression of 35% and 90% of cloned genes at 2 and 4 days post-fertilization, respectively. Further, investigated alleles regularly show 99% gene-specific mRNA knockdown. Homozygous GBT animals in , , , and phenocopied established mutants. 204 cloned lines trapped diverse proteins, including 64 orthologs of human disease-associated genes with 40 as potential new disease models. Severely reduced skeletal muscle Ca transients in GBT homozygous animals validated the ability to explore molecular mechanisms of genetic diseases. This GBT system facilitates novel functional genome annotation towards understanding cellular and molecular underpinnings of vertebrate biology and human disease.
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http://dx.doi.org/10.7554/eLife.54572DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7486118PMC
August 2020

The Canadian Rare Diseases Models and Mechanisms (RDMM) Network: Connecting Understudied Genes to Model Organisms.

Am J Hum Genet 2020 02;106(2):143-152

Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada. Electronic address:

Advances in genomics have transformed our ability to identify the genetic causes of rare diseases (RDs), yet we have a limited understanding of the mechanistic roles of most genes in health and disease. When a novel RD gene is first discovered, there is minimal insight into its biological function, the pathogenic mechanisms of disease-causing variants, and how therapy might be approached. To address this gap, the Canadian Rare Diseases Models and Mechanisms (RDMM) Network was established to connect clinicians discovering new disease genes with Canadian scientists able to study equivalent genes and pathways in model organisms (MOs). The Network is built around a registry of more than 500 Canadian MO scientists, representing expertise for over 7,500 human genes. RDMM uses a committee process to identify and evaluate clinician-MO scientist collaborations and approve 25,000 Canadian dollars in catalyst funding. To date, we have made 85 clinician-MO scientist connections and funded 105 projects. These collaborations help confirm variant pathogenicity and unravel the molecular mechanisms of RD, and also test novel therapies and lead to long-term collaborations. To expand the impact and reach of this model, we made the RDMM Registry open-source, portable, and customizable, and we freely share our committee structures and processes. We are currently working with emerging networks in Europe, Australia, and Japan to link international RDMM networks and registries and enable matches across borders. We will continue to create meaningful collaborations, generate knowledge, and advance RD research locally and globally for the benefit of patients and families living with RD.
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http://dx.doi.org/10.1016/j.ajhg.2020.01.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7010971PMC
February 2020

Protocol development for discovery of angiogenesis inhibitors via automated methods using zebrafish.

PLoS One 2019 15;14(11):e0221796. Epub 2019 Nov 15.

Zebrafish Centre for Advanced Drug Discovery, Keenan Research Center, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Unity Health Toronto, Toronto, Ontario, Canada.

Their optical clarity as larvae and embryos, small size, and high fecundity make zebrafish ideal for whole animal high throughput screening. A high-throughput drug discovery platform (HTP) has been built to perform fully automated screens of compound libraries with zebrafish embryos. A Tg(kdrl:EGFP) line, marking endothelial cell cytoplasm, was used in this work to help develop protocols and functional algorithms for the system, with the intent of screening for angiogenesis inhibitors. Indirubin 3' Monoxime (I3M), a known angiogenesis inhibitor, was used at various concentrations to validate the protocols. Consistent with previous studies, a dose dependant inhibitory effect of I3M on angiogenesis was confirmed. The methods and protocols developed here could significantly increase the throughput of drug screens, while limiting human errors. These methods are expected to facilitate the discovery of novel anti-angiogenesis compounds and can be adapted for many other applications in which samples have a good fluorescent signal.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0221796PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6857904PMC
March 2020

Bi-allelic GOT2 Mutations Cause a Treatable Malate-Aspartate Shuttle-Related Encephalopathy.

Am J Hum Genet 2019 09 15;105(3):534-548. Epub 2019 Aug 15.

On behalf of "United for Metabolic Diseases," 1105AZ Amsterdam, the Netherlands; Department of Laboratory Medicine, Translational Metabolic Laboratory, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands. Electronic address:

Early-infantile encephalopathies with epilepsy are devastating conditions mandating an accurate diagnosis to guide proper management. Whole-exome sequencing was used to investigate the disease etiology in four children from independent families with intellectual disability and epilepsy, revealing bi-allelic GOT2 mutations. In-depth metabolic studies in individual 1 showed low plasma serine, hypercitrullinemia, hyperlactatemia, and hyperammonemia. The epilepsy was serine and pyridoxine responsive. Functional consequences of observed mutations were tested by measuring enzyme activity and by cell and animal models. Zebrafish and mouse models were used to validate brain developmental and functional defects and to test therapeutic strategies. GOT2 encodes the mitochondrial glutamate oxaloacetate transaminase. GOT2 enzyme activity was deficient in fibroblasts with bi-allelic mutations. GOT2, a member of the malate-aspartate shuttle, plays an essential role in the intracellular NAD(H) redox balance. De novo serine biosynthesis was impaired in fibroblasts with GOT2 mutations and GOT2-knockout HEK293 cells. Correcting the highly oxidized cytosolic NAD-redox state by pyruvate supplementation restored serine biosynthesis in GOT2-deficient cells. Knockdown of got2a in zebrafish resulted in a brain developmental defect associated with seizure-like electroencephalography spikes, which could be rescued by supplying pyridoxine in embryo water. Both pyridoxine and serine synergistically rescued embryonic developmental defects in zebrafish got2a morphants. The two treated individuals reacted favorably to their treatment. Our data provide a mechanistic basis for the biochemical abnormalities in GOT2 deficiency that may also hold for other MAS defects.
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http://dx.doi.org/10.1016/j.ajhg.2019.07.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6732527PMC
September 2019

The Novel Small Molecule TRVA242 Stabilizes Neuromuscular Junction Defects in Multiple Animal Models of Amyotrophic Lateral Sclerosis.

Neurotherapeutics 2019 10;16(4):1149-1166

Department of Neuroscience, Université de Montréal, Montréal, Quebec, Canada.

Amyotrophic lateral sclerosis (ALS) is a debilitating neurodegenerative disorder in which the neuromuscular junction progressively degenerates, leading to movement difficulties, paralysis, and eventually death. ALS is currently being treated by only two FDA-approved drugs with modest efficacy in slowing disease progression. Often, the translation of preclinical findings to bedside terminates prematurely as the evaluation of potential therapeutic compounds focuses on a single study or a single animal model. To circumscribe these issues, we screened 3,765 novel small molecule derivatives of pimozide, a recently identified repurposed neuroleptic for ALS, in Caenorhabditis elegans, confirmed the hits in zebrafish and validated the most active compounds in mouse genetic models. Out of the 27 small molecules identified from the high-throughput screen in worms, 4 were found to recover locomotor defects in C. elegans and genetic zebrafish models of ALS. TRVA242 was identified as the most potent compound as it significantly improved efficiency in rescuing locomotor, motorneuron, and neuromuscular junction synaptic deficits in a C. elegans TDP-43 model and in multiple zebrafish genetic (TDP-43, SOD1, and C9ORF72) models of ALS. The actions of TRVA242 were also conserved in a mammalian model as it also stabilized neuromuscular junction deficits in a mouse SOD1 model of ALS. Compounds such as TRVA242 therefore represent new potential therapeutics for the treatment of ALS.
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http://dx.doi.org/10.1007/s13311-019-00765-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6985319PMC
October 2019

Furanoic Lipid F-6, A Novel Anti-Cancer Compound that Kills Cancer Cells by Suppressing Proliferation and Inducing Apoptosis.

Cancers (Basel) 2019 Jul 9;11(7). Epub 2019 Jul 9.

Program in Translational Medicine, Peter Gilgan Centre for Research and Learning (PGCRL), The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada.

Identifying novel anti-cancer drugs is important for devising better cancer treatment options. In a series of studies designed to identify novel therapeutic compounds, we recently showed that a C-20 fatty acid (12,15-epoxy-13,14-dimethyleicosa-12,14-dienoic acid, a furanoic acid or F-6) present in the lipid fraction of the secretions of the Arabian Gulf catfish skin (; AGCS) robustly induces neutrophil extracellular trap formation. Here, we demonstrate that a lipid mix (Ft-3) extracted from AGCS and F-6, a component of Ft-3, dose dependently kill two cancer cell lines (leukemic K-562 and breast MDA MB-231). Pure F-6 is approximately 3.5 to 16 times more effective than Ft-3 in killing these cancer cells, respectively. Multiplex assays and network analyses show that F-6 promotes the activation of MAPKs such as Erk, JNK, and p38, and specifically suppresses JNK-mediated c-Jun activation necessary for AP-1-mediated cell survival pathways. In both cell lines, F-6 suppresses PI3K-Akt-mTOR pathway specific proteins, indicating that cell proliferation and Akt-mediated protection of mitochondrial stability are compromised by this treatment. Western blot analyses of cleaved caspase 3 (cCasp3) and poly ADP ribose polymerase (PARP) confirmed that F-6 dose-dependently induced apoptosis in both of these cell lines. In 14-day cell recovery experiments, cells treated with increasing doses of F-6 and Ft-3 fail to recover after subsequent drug washout. In summary, this study demonstrates that C-20 furanoic acid F-6, suppresses cancer cell proliferation and promotes apoptotic cell death in leukemic and breast cancer cells, and prevents cell recovery. Therefore, F-6 is a potential anti-cancer drug candidate.
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http://dx.doi.org/10.3390/cancers11070960DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6678287PMC
July 2019

Validation of a CRISPR-Mediated CFTR Correction Strategy for Preclinical Translation in Pigs.

Hum Gene Ther 2019 09 18;30(9):1101-1116. Epub 2019 Jun 18.

Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada.

Early efforts in cystic fibrosis (CF) gene therapy faced major challenges in delivery efficiency and sustained therapeutic gene expression. Recent advancements in engineered site-specific endonucleases such as clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 make permanent CF transmembrane conductance regulator () gene correction possible. However, because of safety concerns of the CRISPR/Cas9 system and challenges in delivery to inflamed CF airway, CRISPR-based gene correction strategies need to be tested in proper animal models. In this study, we aimed at creating vectors for testing gene correction in pig models. We constructed helper-dependent adenoviral (HD-Ad) vectors to deliver CRISPR/Cas9 and a donor template (a 6 kb or 8.7 kb human expression cassette) into cultured pig cells. We demonstrated precise integration of each donor into the safe harbor through Cas9-induced homology directed repair with 3 kb homology arms. In addition, we showed that both and were persistently expressed in transduced cells. Furthermore, we created a CFTR-deficient cell line for testing CFTR correction. We detected hCFTR mRNA and protein expression in cells transduced with the hCFTR vector. We also demonstrated CFTR function in the CF cells transduced with the HD-Ad delivering the CRISPR-Cas9 system and hCFTR donor at late cellular passages using the membrane potential sensitive dye-based assay (FLIPR). Combined with our previous report on gene delivery to pig airway basal cells, these data provide the feasibility of testing CRISPR/Cas9-mediated permanent human CFTR correction through HD-Ad vector delivery in pigs.
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http://dx.doi.org/10.1089/hum.2019.074DOI Listing
September 2019

Non-steric-zipper models for pathogenic α-synuclein conformers.

APL Bioeng 2018 Jun 1;2(2):026105. Epub 2018 May 1.

Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada.

Parkinson's disease neurodegenerative brain tissue exhibits two biophysically distinct α-synuclein fiber isoforms-single stranded fibers that appear to be steric-zippers and double-stranded fibers with an undetermined structure. Herein, we describe a β-helical homology model of α-synuclein that exhibits stability in probabilistic and Monte Carlo simulations as a candidate for stable prional dimer conformers in equilibrium with double-stranded fibers and cytotoxic pore assemblies. Molecular models of β-helical pore assemblies are consistent with α-synuclein transfected rat immunofluorescence epitope maps. Atomic force microscopy reveals that α-synuclein peptides aggregate into anisotropic fibrils lacking the density or circumference of a steric-zipper. Moreover, fibrillation was blocked by mutations designed to hinder β-helical but not steric-zipper conformations. β-helical species provide a structural basis for previously described biophysical properties that are incompatible with a steric-zipper, provide pathogenic mechanisms for familial human α-synuclein mutations, and offer a direct cytotoxic target for therapeutic development.
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http://dx.doi.org/10.1063/1.5023460DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6481714PMC
June 2018

Glutaminase Deficiency Caused by Short Tandem Repeat Expansion in .

N Engl J Med 2019 04;380(15):1433-1441

From Amsterdam University Medical Centers, University of Amsterdam, Departments of Clinical Chemistry, Pediatrics, and Clinical Genetics, Emma Children's Hospital, Amsterdam Gastroenterology and Metabolism (A.B.P.K., R.L., J.K., J. Meijer, L.A.T., M.T., M.W., R.J.A.W., H.R.W., C.D.M.K.), and United for Metabolic Diseases (A.B.P.K., R.J.A.W., H.R.W., C.D.M.K.), Amsterdam, and the Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht (J.J.F.A.V., J.H.V.), and the Project MinE ALS Sequencing Consortium (J.J.F.A.V., J.H.V.), Utrecht - all in the Netherlands; the Departments of Biochemistry and Molecular Biology and Medical Genetics, Cumming School of Medicine, and Alberta Children's Hospital Research Institute, University of Calgary, Calgary (M.T.-G.), Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute (P.A.R., M.J.J., M.S.K., J. MacIsaac, W.W.W., C.D.M.K.), the Faculty of Pharmaceutical Sciences (B.I.D., G.E.B.W., C.J.R.), and the Departments of Medical Genetics (C.M., I.-S.R.-B., W.W.W.) and Pediatrics (C.D.M.K.), University of British Columbia, Vancouver, the Zebrafish Centre for Advanced Drug Discovery, St. Michael's Hospital and University of Toronto (K.B.-A., F.K., M.L., Y.W., X.-Y.W.), the Centre for Applied Genomics, Genetics and Genome Biology, the Hospital for Sick Children (C.N., S.W.S., B.T., R.K.C.Y.), and the Department of Molecular Genetics (C.N., S.W.S., R.K.C.Y.), the McLaughlin Centre (S.W.S.), and the Departments of Medicine, Physiology, and Laboratory Medicine and Pathobiology, Institute of Medical Science (X.-Y.W.), University of Toronto, Toronto, and the Division of Medical Genetics, Department of Pediatrics, Children's Hospital Eastern Ontario, University of Ottawa, Ottawa (J.S.W., M.T.G.) - all in Canada; the Departments of Medicine and Physiology, National University of Singapore (M.A.P.), and the Translational Laboratory in Genetic Medicine, Agency for Science, Technology, and Research (M.A.P., B.S., X.X., J.Z.) - both in Singapore; Uppsala University, Department of Chemistry-Biomedical Center, Uppsala, Sweden (D.D.); Illumina, San Diego, CA (E.D., M.A.E.); Gene Structure and Disease Section, Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD (B.H., D.K., K.U.); and the Department of Clinical Inherited Metabolic Disorders, Birmingham Children's Hospital, Birmingham, United Kingdom (S.S.).

We report an inborn error of metabolism caused by an expansion of a GCA-repeat tract in the 5' untranslated region of the gene encoding glutaminase () that was identified through detailed clinical and biochemical phenotyping, combined with whole-genome sequencing. The expansion was observed in three unrelated patients who presented with an early-onset delay in overall development, progressive ataxia, and elevated levels of glutamine. In addition to ataxia, one patient also showed cerebellar atrophy. The expansion was associated with a relative deficiency of messenger RNA transcribed from the expanded allele, which probably resulted from repeat-mediated chromatin changes upstream of the repeat. Our discovery underscores the importance of careful examination of regions of the genome that are typically excluded from or poorly captured by exome sequencing.
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http://dx.doi.org/10.1056/NEJMoa1806627DOI Listing
April 2019

Sialic acid catabolism by N-acetylneuraminate pyruvate lyase is essential for muscle function.

JCI Insight 2018 12 20;3(24). Epub 2018 Dec 20.

Department of Neurology, Donders Institute for Brain, Cognition, and Behavior, Radboud University Medical Center, Nijmegen, Netherlands.

Sialic acids are important components of glycoproteins and glycolipids essential for cellular communication, infection, and metastasis. The importance of sialic acid biosynthesis in human physiology is well illustrated by the severe metabolic disorders in this pathway. However, the biological role of sialic acid catabolism in humans remains unclear. Here, we present evidence that sialic acid catabolism is important for heart and skeletal muscle function and development in humans and zebrafish. In two siblings, presenting with sialuria, exercise intolerance/muscle wasting, and cardiac symptoms in the brother, compound heterozygous mutations [chr1:182775324C>T (c.187C>T; p.Arg63Cys) and chr1:182772897A>G (c.133A>G; p.Asn45Asp)] were found in the N-acetylneuraminate pyruvate lyase gene (NPL). In vitro, NPL activity and sialic acid catabolism were affected, with a cell-type-specific reduction of N-acetyl mannosamine (ManNAc). A knockdown of NPL in zebrafish resulted in severe skeletal myopathy and cardiac edema, mimicking the human phenotype. The phenotype was rescued by expression of wild-type human NPL but not by the p.Arg63Cys or p.Asn45Asp mutants. Importantly, the myopathy phenotype in zebrafish embryos was rescued by treatment with the catabolic products of NPL: N-acetyl glucosamine (GlcNAc) and ManNAc; the latter also rescuing the cardiac phenotype. In conclusion, we provide the first report to our knowledge of a human defect in sialic acid catabolism, which implicates an important role of the sialic acid catabolic pathway in mammalian muscle physiology, and suggests opportunities for monosaccharide replacement therapy in human patients.
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http://dx.doi.org/10.1172/jci.insight.122373DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6338320PMC
December 2018

Nuclear Factor (Erythroid-Derived 2)-Like 2 Regulates the Hepatoprotective Effects of Remote Ischemic Conditioning in Hemorrhagic Shock.

Antioxid Redox Signal 2019 05 20;30(14):1760-1773. Epub 2018 Dec 20.

1 Department of Surgery, St. Michael's Hospital, Toronto, Ontario, Canada.

Aims: Remote ischemic conditioning (RIC) protects against organ ischemia/reperfusion injury in experimental and clinical settings. We have demonstrated that RIC prevents liver and lung inflammation/injury after hemorrhagic shock/resuscitation (S/R). In this study, we used a murine model of S/R to investigate the role of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in mediating hepatoprotection.

Results: The combination of RIC with S/R caused a synergistic rise in Nrf2 and its translocation to the nucleus in the liver. Increased activation of Nrf2 by RIC augmented heme oxygenase-1 (HO-1) and autophagy and exerted hepatoprotection, concurrent with reductions in S/R-induced TNF-α (tumor necrosis factor alpha) and IL-6 (interleukin-6). In Nrf2 knockout (KO) animals, RIC did not exert hepatoprotection, and it failed to upregulate HO-1 and autophagy. Further, resuscitating wildtype (WT) animals with blood from donor WT animals undergoing RIC was hepatoprotective, but not in Nrf2 KO recipient animals. Interestingly, RIC blood from Nrf2 KO donor animals was also not protective when used to resuscitate WT animals, suggesting a role for Nrf2 both in the afferent arm of RIC where protective factors are generated and also in the efferent arm where organ protection is exerted. Finally, RIC plasma prevented oxidant-induced zebrafish mortality, but not in Nrf2a morpholino knockdown fish.

Innovation: Activation of Nrf2 is an essential mechanism underlying the hepatoprotective effects of RIC. Nrf2 appears to play a role in the afferent limb of RIC protection, as its absence precludes the generation of the protective humoral factors induced by RIC.

Conclusion: Our studies demonstrate the critical role of Nrf2 in the ability of RIC to prevent organ injury after S/R.
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http://dx.doi.org/10.1089/ars.2018.7541DOI Listing
May 2019

Dual effects of human neutrophil peptides in a mouse model of pneumonia and ventilator-induced lung injury.

Respir Res 2018 Sep 29;19(1):190. Epub 2018 Sep 29.

The State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510000, Guangdong, China.

Background: Pneumonia is a major cause of high morbidity and mortality in critically illness, and frequently requires support with mechanical ventilation. The latter can lead to ventilator-induced lung injury characterized by neutrophil infiltration. The cationic human neutrophil peptides (HNP) stored in neutrophils can kill microorganisms, but excessive amount of HNP released during phagocytosis may contribute to inflammatory responses and worsen lung injury. Based on our previous work, we hypothesized that blocking the cell surface purinergic receptor P2Y will attenuate the HNP-induced inflammatory responses while maintaining their antimicrobial activity in pneumonia followed by mechanical ventilation.

Methods: Plasma HNP levels were measured in patients with pneumonia who received mechanical ventilation and in healthy volunteers. FVB littermate control and HNP transgenic (HNP) mice were randomized to receive P. aeruginosa intranasally. The P2Y antagonist (MRS2578) or vehicle control was given after P. aeruginosa instillation. Additional mice underwent mechanical ventilation at either low pressure (LP) or high pressure (HP) ventilation 48 h after pneumonia, and were observed for 24 h.

Results: Plasma HNP concentration increased in patients with pneumonia as compared to healthy subjects. The bacterial counts in the bronchoalveolar lavage fluid (BALF) were lower in HNP mice than in FVB mice 72 h after P. aeruginosa instillation. However, upon receiving HP ventilation, HNP mice had higher levels of cytokines and chemokines in BALF than FVB mice. These inflammatory responses were attenuated by the treatment with MRS2578 that did not affect the microbial effects of HNP.

Conclusions: HNP exerted dual effects by exhibiting antimicrobial activity in pneumonia alone condition while enhancing inflammatory responses in pneumonia followed by HP mechanical ventilation. Blocking P2Y can attenuate the inflammation without affecting the antibacterial property of HNP. The P2Y receptor may be a novel therapeutic target in attenuation of the leukocyte-mediated excessive host responses in inflammatory lung diseases.
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http://dx.doi.org/10.1186/s12931-018-0869-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6162902PMC
September 2018

Simultaneous ultra-high frequency photoacoustic microscopy and photoacoustic radiometry of zebrafish larvae .

Photoacoustics 2018 Dec 1;12:14-21. Epub 2018 Sep 1.

Department of Physics, Ryerson University, Toronto, M5B 2K3, Canada.

With their optically transparent appearance, zebrafish larvae are readily imaged with optical-resolution photoacoustic (PA) microscopy (OR-PAM). Previous OR-PAM studies have mapped endogenous chromophores (e.g. melanin and hemoglobin) within larvae; however, anatomical features cannot be imaged with OR-PAM alone due to insufficient optical absorption. We have previously reported on the photoacoustic radiometry (PAR) technique, which can be used simultaneously with OR-PAM to generate images dependent upon the optical attenuation properties of a sample. Here we demonstrate application of the duplex PAR/PA technique for label-free imaging of the anatomy and vasculature of zebrafish larvae in vivo at 200 and 400 MHz ultrasound detection frequencies. We then use the technique to assess the effects of anti-angiogenic drugs on the development of the larval vasculature. Our results demonstrate the effectiveness of simultaneous PAR/PA for acquiring anatomical images of optically transparent samples in vivo, and its potential applications in assessing drug efficacy and embryonic development.
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http://dx.doi.org/10.1016/j.pacs.2018.08.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6139000PMC
December 2018

Integrating glycomics and genomics uncovers SLC10A7 as essential factor for bone mineralization by regulating post-Golgi protein transport and glycosylation.

Hum Mol Genet 2018 09;27(17):3029-3045

Department of Child Health, University Hospital of Wales, Cardiff, UK.

Genomics methodologies have significantly improved elucidation of Mendelian disorders. The combination with high-throughput functional-omics technologies potentiates the identification and confirmation of causative genetic variants, especially in singleton families of recessive inheritance. In a cohort of 99 individuals with abnormal Golgi glycosylation, 47 of which being unsolved, glycomics profiling was performed of total plasma glycoproteins. Combination with whole-exome sequencing in 31 cases revealed a known genetic defect in 15 individuals. To identify additional genetic factors, hierarchical clustering of the plasma glycomics data was done, which indicated a subgroup of four patients that shared a unique glycomics signature of hybrid type N-glycans. In two siblings, compound heterozygous mutations were found in SLC10A7, a gene of unknown function in human. These included a missense mutation that disrupted transmembrane domain 4 and a mutation in a splice acceptor site resulting in skipping of exon 9. The two other individuals showed a complete loss of SLC10A7 mRNA. The patients' phenotype consisted of amelogenesis imperfecta, skeletal dysplasia, and decreased bone mineral density compatible with osteoporosis. The patients' phenotype was mirrored in SLC10A7 deficient zebrafish. Furthermore, alizarin red staining of calcium deposits in zebrafish morphants showed a strong reduction in bone mineralization. Cell biology studies in fibroblasts of affected individuals showed intracellular mislocalization of glycoproteins and a defect in post-Golgi transport of glycoproteins to the cell membrane. In contrast to yeast, human SLC10A7 localized to the Golgi. Our combined data indicate an important role for SLC10A7 in bone mineralization and transport of glycoproteins to the extracellular matrix.
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http://dx.doi.org/10.1093/hmg/ddy213DOI Listing
September 2018

Zebrafish heart failure models: opportunities and challenges.

Amino Acids 2018 Jul 3;50(7):787-798. Epub 2018 May 3.

Zebrafish Centre for Advanced Drug Discovery, Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada.

Heart failure is a complex pathophysiological syndrome of pumping functional failure that results from injury, infection or toxin-induced damage on the myocardium, as well as genetic influence. Gene mutations associated with cardiomyopathies can lead to various pathologies of heart failure. In recent years, zebrafish, Danio rerio, has emerged as an excellent model to study human cardiovascular diseases such as congenital heart defects, cardiomyopathy, and preclinical development of drugs targeting these diseases. In this review, we will first summarize zebrafish genetic models of heart failure arose from cardiomyopathy, which is caused by mutations in sarcomere, calcium or mitochondrial-associated genes. Moreover, we outline zebrafish heart failure models triggered by chemical compounds. Elucidation of these models will improve the understanding of the mechanism of pathogenesis and provide potential targets for novel therapies.
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http://dx.doi.org/10.1007/s00726-018-2578-7DOI Listing
July 2018

Histone acetyltransferase 7 (KAT7)-dependent intragenic histone acetylation regulates endothelial cell gene regulation.

J Biol Chem 2018 03 6;293(12):4381-4402. Epub 2018 Feb 6.

From the Departments of Medical Biophysics and

Although the functional role of chromatin marks at promoters in mediating cell-restricted gene expression has been well characterized, the role of intragenic chromatin marks is not well understood, especially in endothelial cell (EC) gene expression. Here, we characterized the histone H3 and H4 acetylation profiles of 19 genes with EC-enriched expression via locus-wide chromatin immunoprecipitation followed by ultra-high-resolution (5 bp) tiling array analysis in ECs non-ECs throughout their genomic loci. Importantly, these genes exhibit differential EC enrichment of H3 and H4 acetylation in their promoter in ECs non-ECs. Interestingly, VEGFR-2 and VEGFR-1 show EC-enriched acetylation across broad intragenic regions and are up-regulated in non-ECs by histone deacetylase inhibition. It is unclear which histone acetyltransferases (KATs) are key to EC physiology. Depletion of KAT7 reduced VEGFR-2 expression and disrupted angiogenic potential. Microarray analysis of KAT7-depleted ECs identified 263 differentially regulated genes, many of which are key for growth and angiogenic potential. KAT7 inhibition in zebrafish embryos disrupted vessel formation and caused loss of circulatory integrity, especially hemorrhage, all of which were rescued with human KAT7. Notably, perturbed EC-enriched gene expression, especially the VEGFR-2 homologs, contributed to these vascular defects. Mechanistically, KAT7 participates in transcription by mediating RNA polymerase II binding, H3 lysine 14, and H4 acetylation in its intragenic region. Collectively, our findings support the importance of differential histone acetylation at both promoter and intragenic regions of EC genes and reveal a previously underappreciated role of KAT7 and intragenic histone acetylation in regulating VEGFR-2 and endothelial function.
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http://dx.doi.org/10.1074/jbc.RA117.001383DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5868248PMC
March 2018

Neuroleptics as therapeutic compounds stabilizing neuromuscular transmission in amyotrophic lateral sclerosis.

JCI Insight 2017 11 16;2(22). Epub 2017 Nov 16.

Department of Neuroscience, Université de Montréal, Montréal, Canada.

Amyotrophic lateral sclerosis (ALS) is a rapidly progressing, fatal disorder with no effective treatment. We used simple genetic models of ALS to screen phenotypically for potential therapeutic compounds. We screened libraries of compounds in C. elegans, validated hits in zebrafish, and tested the most potent molecule in mice and in a small clinical trial. We identified a class of neuroleptics that restored motility in C. elegans and in zebrafish, and the most potent was pimozide, which blocked T-type Ca2+ channels in these simple models and stabilized neuromuscular transmission in zebrafish and enhanced it in mice. Finally, a short randomized controlled trial of sporadic ALS subjects demonstrated stabilization of motility and evidence of target engagement at the neuromuscular junction. Simple genetic models are, thus, useful in identifying promising compounds for the treatment of ALS, such as neuroleptics, which may stabilize neuromuscular transmission and prolong survival in this disease.
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http://dx.doi.org/10.1172/jci.insight.97152DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5752378PMC
November 2017

Characterization of the first knock-out aldh7a1 zebrafish model for pyridoxine-dependent epilepsy using CRISPR-Cas9 technology.

PLoS One 2017 20;12(10):e0186645. Epub 2017 Oct 20.

Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, Toronto, Canada.

Pyridoxine dependent epilepsy (PDE) is caused by likely pathogenic variants in ALDH7A1 (PDE-ALDH7A1) and inherited autosomal recessively. Neurotoxic alpha-amino adipic semialdehyde (alpha-AASA), piperideine 6-carboxylate and pipecolic acid accumulate in body fluids. Neonatal or infantile onset seizures refractory to anti-epileptic medications are clinical features. Treatment with pyridoxine, arginine and lysine-restricted diet does not normalize neurodevelopmental outcome or accumulation of neurotoxic metabolites. There is no animal model for high throughput drug screening. For this reason, we developed and characterized the first knock-out aldh7a1 zebrafish model using CRISPR-Cas9 technology. Zebrafish aldh7a1 mutants were generated by using a vector free method of CRISPR-Cas9 mutagenesis. Genotype analysis of aldh7a1 knock-out zebrafish was performed by high resolution melt analysis, direct sequencing and QIAxcel system. Electroencephalogram was performed. Alpha-AASA, piperideine 6-carboxylate and pipecolic acid, were measured by liquid chromatography-tandem mass spectrometry. Our knock-out aldh7a1 zebrafish has homozygous 5 base pair (bp) mutation in ALDH7A1. Knock-out aldh7a1 embryos have spontaneous rapid increase in locomotion and a rapid circling swim behavior earliest 8-day post fertilization (dpf). Electroencephalogram revealed large amplitude spike discharges compared to wild type. Knock-out aldh7a1 embryos have elevated alpha-AASA, piperideine 6-carboxylate and pipecolic acid compared to wild type embryos at 3 dpf. Knock-out aldh7a1 embryos showed no aldh7a1 protein by western blot compared to wild type. Our knock-out aldh7a1 zebrafish is a well characterized model for large-scale drug screening using behavioral and biochemical features and accurately recapitulates the human PDE-ALDH7A1 disease.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0186645PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5650160PMC
November 2017

Activated NK cells cause placental dysfunction and miscarriages in fetal alloimmune thrombocytopenia.

Nat Commun 2017 08 9;8(1):224. Epub 2017 Aug 9.

Toronto Platelet Immunobiology Group, Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, ON, Canada, M5B 1W8.

Miscarriage and intrauterine growth restriction (IUGR) are devastating complications in fetal/neonatal alloimmune thrombocytopenia (FNAIT). We previously reported the mechanisms for bleeding diatheses, but it is unknown whether placental, decidual immune cells or other abnormalities at the maternal-fetal interface contribute to FNAIT. Here we show that maternal immune responses to fetal platelet antigens cause miscarriage and IUGR that are associated with vascular and immune pathologies in murine FNAIT models. Uterine natural killer (uNK) cell recruitment and survival beyond mid-gestation lead to elevated NKp46 and CD107 expression, perforin release and trophoblast apoptosis. Depletion of NK cells restores normal spiral artery remodeling and placental function, prevents miscarriage, and rescues hemorrhage in neonates. Blockade of NK activation receptors (NKp46, FcɣRIIIa) also rescues pregnancy loss. These findings shed light on uNK antibody-dependent cell-mediated cytotoxicity of invasive trophoblasts as a pathological mechanism in FNAIT, and suggest that anti-NK cell therapies may prevent immune-mediated pregnancy loss and ameliorate FNAIT.Fetal/neonatal alloimmune thrombocytopenia (FNAIT) is a gestational disease caused by maternal immune responses against fetal platelets. Using a FNAIT mouse model and human trophoblast cell lines, here the authors show that uterine natural killer cell-mediated trophoblast apoptosis contributes to FNAIT pathogenesis.
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http://dx.doi.org/10.1038/s41467-017-00269-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5550461PMC
August 2017

Development of a zebrafish sepsis model for high-throughput drug discovery.

Mol Med 2017 07 7;23:134-148. Epub 2017 Jun 7.

Zebrafish Centre for Advanced Drug Discovery, St. Michael's Hospital, 209 Victoria St, Toronto, Ontario, Canada M5B 1T8.

Sepsis is a leading cause of death worldwide. Current treatment modalities remain largely supportive. Intervention strategies focused on inhibiting specific mediators of the inflammatory host response have been largely unsuccessful, a consequence of an inadequate understanding of the complexity and heterogeneity of the innate immune response. Moreover, the conventional drug development pipeline is time consuming and expensive and the low success rates associated with cell-based screens underline the need for whole organism screening strategies, especially for complex pathological processes. Here, we established an LPS-induced zebrafish endotoxemia model, which exhibits the major hallmarks of human sepsis including, edema and tissue/organ damage, increased vascular permeability and vascular leakage accompanied by an altered expression of cellular junction proteins, increased cytokine expression, immune cell activation and ROS production, reduced circulation and increased platelet aggregation. We tested the suitability of the model for phenotype-based drug screening using three primary readouts: mortality, vascular leakage, and ROS production. Preliminary screening identified fasudil, a drug known to protect against vascular leakage in murine models, as a lead hit thereby validating the utility of our model for sepsis drug screens. This zebrafish sepsis model has the potential to rapidly analyze sepsis associated pathologies and cellular processes in the whole organism, as well as to screen and validate large numbers of compounds that can modify sepsis pathology in .
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http://dx.doi.org/10.2119/molmed.2016.00188DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5522968PMC
July 2017

Effect of empagliflozin on cardiac biomarkers in a zebrafish model of heart failure: clues to the EMPA-REG OUTCOME trial?

Mol Cell Biochem 2017 Sep 8;433(1-2):97-102. Epub 2017 Apr 8.

Zebrafish Centre for Advanced Drug Discovery, Keenan Research Centre for Biomedical Science of St. Michael's Hospital, Department of Medicine and Physiology, University of Toronto, 209 Victoria Street, LKSKI Rm 519, Toronto, ON, M5B 1T8, Canada.

The sodium-glucose cotransporter 2 (SGLT2) inhibitor empagliflozin was recently reported to reduce heart failure-associated hospitalizations and cardiovascular mortality amongst individuals with type 2 diabetes at high cardiovascular risk. We sought to elucidate the underlying mechanism(s) for these protective effects using a validated zebrafish heart failure model to evaluate the impact of empagliflozin on the expression of biomarkers of heart failure and mortality. We used aristolochic acid (AA) to induce heart failure in developing cmlc2::GFP transgenic zebrafish embryos and monitored BNP signaling in nppb::Luc transgenic zebrafish with a luciferase reporter assay. Empagliflozin markedly reduced the morphological and functional cardiac changes induced by AA; dampened AA-enhanced expression of brain natriuretic peptide and atrial natriuretic peptide; and reduced embryonic mortality. Furthermore, morpholino-mediated knockdown of the slc5A2 gene mimicked the changes evoked by empagliflozin in developing zebrafish embryos previously exposed to AA. We report herein the first mechanistic data demonstrating a salutary benefit of SGLT2 inhibition on critical pathways of heart failure signaling. These findings provide important translational clues to the cardiovascular benefits documented in the EMPA-REG OUTCOME study.
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http://dx.doi.org/10.1007/s11010-017-3018-9DOI Listing
September 2017

Disruption of alters endocardial and myocardial fusion during zebrafish cardiac assembly.

Biol Open 2017 Mar 15;6(3):348-357. Epub 2017 Mar 15.

Zebrafish Centre for Advanced Drug Discovery & Keenan Research Centre for Biomedical Science, Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada M5B 1T8

Cardiac development in vertebrates is a finely tuned process regulated by a set of conserved signaling pathways. Perturbations of these processes are often associated with congenital cardiac malformations. Platelet-derived growth factor receptor α (PDGFRα) is a highly conserved tyrosine kinase receptor, which is essential for development and organogenesis. Disruption of function in murine models is embryonic lethal due to severe cardiovascular defects, suggesting a role in cardiac development, thus necessitating the use of alternative models to explore its precise function. In this study, we generated a zebrafish mutant line by gene trapping, in which the Pdgfra protein is truncated and fused with mRFP (Pdgfra-mRFP). Our results demonstrate that mutants have defects in cardiac morphology as a result of abnormal fusion of myocardial precursors. Expression analysis of the developing heart at later stages suggested that Pdgfra-mRFP is expressed in the endocardium. Further examination of the endocardium in mutants revealed defective endocardial migration to the midline, where cardiac fusion eventually occurs. Together, our data suggests that is required for proper medial migration of both endocardial and myocardial precursors, an essential step required for cardiac assembly and development.
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http://dx.doi.org/10.1242/bio.021212DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5374395PMC
March 2017

A Novel Model of Traumatic Brain Injury in Adult Zebrafish Demonstrates Response to Injury and Treatment Comparable with Mammalian Models.

J Neurotrauma 2017 04 20;34(7):1382-1393. Epub 2016 Dec 20.

1 Institute of Medical Sciences, University of Toronto , Ontario, Canada .

Traumatic brain injury (TBI) is a leading cause of death and morbidity in industrialized countries with considerable associated health care costs. The cost and time associated with pre-clinical development of TBI therapeutics is lengthy and expensive with a poor track record of successful translation to the clinic. The zebrafish is an emerging model organism in research with unique technical and genomic strengths in the study of disease and development. Its high degree of genetic homology and cell signaling pathways relative to mammalian species and amenability to high and medium throughput assays has potential to accelerate the rate of therapeutic drug identification. Accordingly, we developed a novel closed-head model of TBI in adult zebrafish using a targeted, pulsed, high-intensity focused ultrasound (pHIFU) to induce mechanical injury of the brain. Western blot results indicated altered microtubule and neurofilament expression as well as increased expression of cleaved caspase-3 and beta APP (β-APP; p < 0.05). We used automated behavioral tracking software to evaluate locomotor deficits 24 and 48 h post-injury. Significant behavioral impairment included decreased swim distance and velocity (p < 0.05), as well as heightened anxiety and altered group social dynamics. Responses to injury were pHIFU dose-dependent and modifiable with MK-801, MDL-28170, or temperature modulation. Together, results indicate that the zebrafish exhibits responses to injury and intervention similar to mammalian TBI pathophysiology and suggest the potential for use to rapidly evaluate therapeutic compounds with high efficiency.
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http://dx.doi.org/10.1089/neu.2016.4497DOI Listing
April 2017

New Exploration of Chinese Herbal Medicines in Hepatology.

Evid Based Complement Alternat Med 2016 20;2016:3056438. Epub 2016 Jul 20.

Division of Gastroenterology and Hepatology, Department of Internal Medicine, Edward Doisy Research Center, Saint Louis University School of Medicine, St. Louis, MO 63104, USA.

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http://dx.doi.org/10.1155/2016/3056438DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4971296PMC
August 2016

Simple animal models for amyotrophic lateral sclerosis drug discovery.

Expert Opin Drug Discov 2016 Aug 13;11(8):797-804. Epub 2016 Jun 13.

b Department of Neuroscience , FRQS Groupe de recherche sur le système nerveux central and CRCHUM, University of Montréal , Montréal , Canada.

Introduction: Simple animal models have enabled great progress in uncovering the disease mechanisms of amyotrophic lateral sclerosis (ALS) and are helping in the selection of therapeutic compounds through chemical genetic approaches.

Areas Covered: Within this article, the authors provide a concise overview of simple model organisms, C. elegans, Drosophila and zebrafish, which have been employed to study ALS and discuss their value to ALS drug discovery. In particular, the authors focus on innovative chemical screens that have established simple organisms as important models for ALS drug discovery.

Expert Opinion: There are several advantages of using simple animal model organisms to accelerate drug discovery for ALS. It is the authors' particular belief that the amenability of simple animal models to various genetic manipulations, the availability of a wide range of transgenic strains for labelling motoneurons and other cell types, combined with live imaging and chemical screens should allow for new detailed studies elucidating early pathological processes in ALS and subsequent drug and target discovery.
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http://dx.doi.org/10.1080/17460441.2016.1196183DOI Listing
August 2016

Restrictions on the Importation of Zebrafish into Canada Associated with Spring Viremia of Carp Virus.

Zebrafish 2016 07 1;13 Suppl 1:S153-63. Epub 2016 Jun 1.

4 Department of Cell and Systems Biology, University of Toronto , Toronto, Canada .

The zebrafish model system is helping researchers improve the health and welfare of people and animals and has become indispensable for advancing biomedical research. As genetic engineering is both resource intensive and time-consuming, sharing successfully developed genetically modified zebrafish lines throughout the international community is critical to research efficiency and to maximizing the millions of dollars in research funding. New restrictions on importation of zebrafish into Canada based on putative susceptibility to infection by the spring viremia of carp virus (SVCV) have been imposed on the scientific community. In this commentary, we review the disease profile of SVCV in fish, discuss the findings of the Canadian government's scientific assessment, how the interpretations of their assessment differ from that of the Canadian research community, and describe the negative impact of these regulations on the Canadian research community and public as it pertains to protecting the health of Canadians.
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http://dx.doi.org/10.1089/zeb.2016.1286DOI Listing
July 2016