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1.
Gene Ther ; 31(3-4): 195-196, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38172433
2.
Gene Ther ; 30(10-11): 737, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37938351
5.
Nat Hum Behav ; 3(3): 204-206, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30886904

ABSTRACT

Human enhancement technologies are opening tremendous opportunities but also challenges to the core of what it means to be human. We argue that the goal of human enhancement should be to enhance quality of life and well-being not only of individuals but also of the communities they inhabit.

6.
Med Sport Sci ; 62: 119-128, 2017.
Article in English | MEDLINE | ID: mdl-28571016

ABSTRACT

Despite being prohibited by the World Anti-Doping Agency (WADA), blood manipulations such as the use of recombinant human erythropoietin and blood transfusions are a well-known method used by athletes to enhance performance. Direct detection of illicit blood manipulation has been partially successful due to the short detection window of the substances/methods, sample collection timing, and the use of sophisticated masking strategies. In response, WADA introduced the athlete biological passport (ABP) in 2009, which is an individualised longitudinal monitoring approach that tests primarily haematologic biomarkers of doping in order to identify atypical variability in response(s) in athletes, highlighting a potential doping violation. Although the implementation of the ABP has been an encouraging step forward in the quest for clean/drug-free sport, this detection method has some limitations. To reduce the risk of being detected by the ABP method, athletes are now resorting to microdoses of prohibited blood boosting substances to prevent abnormal fluctuations in haematologic biomarkers, thereby reducing the sensitivity of the ABP detection method. Recent studies from numerous laboratories, including our own, have confirmed the potential of transcriptomic microarrays, which can reveal distinct changes in gene expression after blood manipulations, to enhance the ABP. There is, therefore, an urgent need to intensify research efforts that involve transcriptomics and other state-of-the-art molecular methods, collectively known as "omics", e.g., proteomics (proteins) and metabolomics (metabolites), in order to identify new and even more robust molecular signatures of blood manipulation that can be used in combination with the ABP and, intriguingly, even as a stand-alone test.


Subject(s)
Doping in Sports/prevention & control , Substance Abuse Detection/methods , Biomarkers/blood , Humans , Metabolomics , Proteomics , Sports , Substance Abuse Detection/trends , Transcriptome
9.
Neurosci Lett ; 590: 35-9, 2015 Mar 17.
Article in English | MEDLINE | ID: mdl-25636690

ABSTRACT

Transcriptomic studies of murine D3 embryonic stem (ES) cells deficient in the purinergic biosynthetic function hypoxanthine guanine phosphoribosyltransferase (HPRT) and undergoing dopaminergic neuronal differentiation has demonstrated a marked shift from neuronal to glial gene expression and aberrant expression of multiple genes also known to be aberrantly expressed in Alzheimer's and other CNS disorders. Such genetic dysregulations may indicate some shared pathogenic metabolic mechanisms in diverse CNS diseases.


Subject(s)
Alzheimer Disease/genetics , Hypoxanthine Phosphoribosyltransferase/deficiency , Lesch-Nyhan Syndrome/genetics , Purines/biosynthesis , Transcriptome , Alzheimer Disease/metabolism , Animals , Cell Differentiation , Cell Line , Dopaminergic Neurons/cytology , Dopaminergic Neurons/metabolism , Embryonic Stem Cells/cytology , Embryonic Stem Cells/metabolism , Lesch-Nyhan Syndrome/metabolism , Mice , Neuroglia/cytology , Neuroglia/metabolism
10.
PLoS One ; 8(10): e74967, 2013.
Article in English | MEDLINE | ID: mdl-24130677

ABSTRACT

The mechanisms by which mutations of the purinergic housekeeping gene hypoxanthine guanine phosphoribosyltransferase (HPRT) cause the severe neurodevelopmental Lesch Nyhan Disease (LND) are poorly understood. The best recognized neural consequences of HPRT deficiency are defective basal ganglia expression of the neurotransmitter dopamine (DA) and aberrant DA neuronal function. We have reported that HPRT deficiency leads to dysregulated expression of multiple DA-related developmental functions and cellular signaling defects in a variety of HPRT-deficient cells, including human induced pluripotent stem (iPS) cells. We now describe results of gene expression studies during neuronal differentiation of HPRT-deficient murine ESD3 embryonic stem cells and report that HPRT knockdown causes a marked switch from neuronal to glial gene expression and dysregulates expression of Sox2 and its regulator, genes vital for stem cell pluripotency and for the neuronal/glial cell fate decision. In addition, HPRT deficiency dysregulates many cellular functions controlling cell cycle and proliferation mechanisms, RNA metabolism, DNA replication and repair, replication stress, lysosome function, membrane trafficking, signaling pathway for platelet activation (SPPA) multiple neurotransmission systems and sphingolipid, sulfur and glycan metabolism. We propose that the neural aberrations of HPRT deficiency result from combinatorial effects of these multi-system metabolic errors. Since some of these aberrations are also found in forms of Alzheimer's and Huntington's disease, we predict that some of these systems defects play similar neuropathogenic roles in diverse neurodevelopmental and neurodegenerative diseases in common and may therefore provide new experimental opportunities for clarifying pathogenesis and for devising new potential therapeutic targets in developmental and genetic disease.


Subject(s)
Embryonic Stem Cells/cytology , Embryonic Stem Cells/enzymology , Hypoxanthine Phosphoribosyltransferase/metabolism , Neurons/cytology , Animals , Blotting, Western , Cell Differentiation/genetics , Cell Differentiation/physiology , Dopamine/metabolism , Hypoxanthine Phosphoribosyltransferase/genetics , Mice , Mice, Knockout , Neurons/enzymology , Signal Transduction
11.
Bioanalysis ; 4(13): 1667-80, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22831482

ABSTRACT

Technical advances are being made in many areas of biotechnology and genetics that are facilitating the detection of doping in sport. These improvements have been catalyzed by the need to counter the ever-increasing sophistication of the community of athletes and their retinues who are intent on the illicit use of physical, pharmacological and genetic tools and methods to enhance athletic performance, in contravention of established international ethical and legal standards and of international treaty. The methods described in this article present a partial and general picture of only some of these advances.


Subject(s)
Doping in Sports/prevention & control , Pharmaceutical Preparations/blood , Substance Abuse Detection/methods , Substance Abuse Detection/trends , Aptamers, Nucleotide/chemistry , Athletic Performance , Biological Assay/methods , Biomarkers/blood , Biomarkers/urine , Chromatography, High Pressure Liquid/methods , Doping in Sports/legislation & jurisprudence , Female , Gas Chromatography-Mass Spectrometry/methods , Genetic Enhancement/methods , Humans , International Cooperation/legislation & jurisprudence , Male
14.
Proc Natl Acad Sci U S A ; 109(9): 3377-82, 2012 Feb 28.
Article in English | MEDLINE | ID: mdl-22331909

ABSTRACT

Lesch-Nyhan disease (LND) is an X-linked genetic disorder caused by mutations of the hypoxanthine guanine phosphoribosyltransferase (HPRT) purine biosynthesis gene and characterized by aberrant purine metabolism, deficient basal ganglia dopamine levels, dystonia, and severe neurobehavioral manifestations, including compulsive self-injurious behavior. Although available evidence has identified important roles for purinergic signaling in brain development, the mechanisms linking HPRT deficiency, purinergic pathways, and neural dysfunction of LND are poorly understood. In these studies aimed at characterizing purinergic signaling in HPRT deficiency, we used a lentivirus vector stably expressing an shRNA targeted to the HPRT gene to produce HPRT-deficient human CVB induced pluripotent stem cells and human HUES11 embryonic stem cells. Both CVB and HUES11 cells show >99% HPRT knockdown and demonstrate markedly decreased expression of the purinergic P2Y1 receptor mRNA. In CVB cells, P2Y1 mRNA and protein down-regulation by HPRT knockdown is refractory to activation by the P2Y1 receptor agonist ATP and shows aberrant purinergic signaling, as reflected by marked deficiency of the transcription factor pCREB and constitutive activation of the MAP kinases phospho-ERK1/2. Moreover, HPRT-knockdown CVB cells also demonstrate marked reduction of phosphorylated ß-catenin. These results indicate that the housekeeping gene HPRT regulates purinergic signaling in pluripotent human stem cells, and that this regulation occurs at least partly through aberrant P2Y1-mediated expression and signaling. We propose that such mechanisms may play a role in the neuropathology of HPRT-deficiency LND and may point to potential molecular targets for modulation of this intractable neurological phenotype.


Subject(s)
Hypoxanthine Phosphoribosyltransferase/physiology , Neurogenesis/physiology , Pluripotent Stem Cells/enzymology , Purines/metabolism , Adenosine Triphosphate/pharmacology , Cell Line , Fibroblasts/enzymology , Gene Knockdown Techniques , Genes, Essential , Genetic Vectors/genetics , Glycogen Synthase Kinase 3/physiology , Glycogen Synthase Kinase 3 beta , Humans , Lentivirus/genetics , Lesch-Nyhan Syndrome/enzymology , MAP Kinase Signaling System/physiology , Male , Mitogen-Activated Protein Kinase 1/physiology , Mitogen-Activated Protein Kinase 3/physiology , Purinergic P2Y Receptor Agonists/pharmacology , RNA, Messenger/genetics , RNA, Small Interfering/genetics , Receptors, Purinergic P2Y1/genetics , Receptors, Purinergic P2Y1/physiology , beta Catenin/metabolism
15.
Hum Mol Genet ; 21(3): 609-22, 2012 Feb 01.
Article in English | MEDLINE | ID: mdl-22042773

ABSTRACT

Mutations in the gene encoding the purine biosynthetic enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT) cause the intractable neurodevelopmental Lesch-Nyhan disease (LND) associated with aberrant development of brain dopamine pathways. In the current study, we have identified an increased expression of the microRNA miR181a in HPRT-deficient human dopaminergic SH-SY5Y neuroblastoma cells. Among the genes potentially regulated by miR181a are several known to be required for neural development, including Engrailed1 (En1), Engrailed2 (En2), Lmx1a and Brn2. We demonstrate that these genes are down-regulated in HPRT-deficient SH-SY5Y cells and that over-expression of miR181a significantly reduces endogenous expression of these genes and inhibits translation of luciferase plasmids bearing the En1/2 or Lmx1a 3'UTR miRNA-binding elements. Conversely, inhibition of miR181a increases the expression of these genes and enhances translation of luciferase constructs bearing the En1/2 and Lmx1a 3'UTR miRNA-binding sequences. We also demonstrate that key neurodevelopmental genes (e.g. Nurr1, Pitx3, Wnt1 and Mash1) known to be functional partners of Lmx1a and Brn2 are also markedly down-regulated in SH-SY5Y cells over-expressing miR181a and in HPRT-deficient cells. Our findings in SH-SY5Y cells demonstrate that HPRT deficiency is accompanied by dysregulation of some of the important pathways that regulate the development of dopaminergic neurons and dopamine pathways and that this defect is associated with and possibly due at least partly to aberrant expression of miR181a. Because aberrant expression of miR181a is not as apparent in HPRT-deficient LND fibroblasts, the relevance of the SH-SY5Y neuroblastoma cells to human disease remains to be proven. Nevertheless, we propose that these pleiotropic neurodevelopment effects of miR181a may play a role in the pathogenesis of LND.


Subject(s)
Dopaminergic Neurons/metabolism , Gene Expression Regulation , Hypoxanthine Phosphoribosyltransferase/deficiency , Lesch-Nyhan Syndrome/genetics , MicroRNAs/metabolism , 3' Untranslated Regions , Cell Line, Tumor , Cells, Cultured , Down-Regulation , Fibroblasts/metabolism , Gene Knockdown Techniques , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , Hypoxanthine Phosphoribosyltransferase/antagonists & inhibitors , Hypoxanthine Phosphoribosyltransferase/genetics , LIM-Homeodomain Proteins/genetics , LIM-Homeodomain Proteins/metabolism , Lesch-Nyhan Syndrome/metabolism , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , POU Domain Factors/genetics , POU Domain Factors/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism
16.
J Am Coll Cardiol ; 58(16): 1715-27, 2011 Oct 11.
Article in English | MEDLINE | ID: mdl-21982317

ABSTRACT

OBJECTIVES: We sought to assess the in vivo importance of scavenger receptor (SR)-mediated uptake of oxidized low-density lipoprotein (OxLDL) in atherogenesis and to test the efficacy of human antibody IK17-Fab or IK17 single-chain Fv fragment (IK17-scFv), which lacks immunologic properties of intact antibodies other than the ability to inhibit uptake of OxLDL by macrophages, to inhibit atherosclerosis. BACKGROUND: The unregulated uptake of OxLDL by macrophage SR contributes to foam cell formation, but the importance of this pathway in vivo is uncertain. METHODS: Cholesterol-fed low-density lipoprotein receptor knockout (LDLR(-/-)) mice were treated with intraperitoneal infusion of human IK17-Fab (2.5 mg/kg) 3 times per week for 14 weeks. Because anti-human antibodies developed in these mice, LDLR(-/-)/low-density lipoprotein receptor Rag 1 double-knockout mice (lacking the ability to make immunoglobulins due to loss of T- and B-cell function) were treated with an adenoviral vector encoding adenovirus expressed (Adv)-IK17-scFv or control adenovirus-enhanced green fluorescent protein vector intravenously every 2 weeks for 16 weeks. RESULTS: In LDLR(-/-) mice, infusion of IK17-Fab was able to sustain IK17 plasma levels for the first 8 weeks, but these diminished afterward due to increasing murine anti-IK17 antibody titers. Despite this, after 14 weeks, a 29% decrease in en face atherosclerosis was noted compared with phosphate-buffered saline-treated mice. In LDLR(-/-)/low-density lipoprotein receptor Rag 1 double-knockout mice, sustained levels of plasma IK17-scFv was achieved by Adv-IK17-scFv-mediated hepatic expression, which led to a 46% reduction (p < 0.001) in en face atherosclerosis compared with adenovirus-enhanced green fluorescent protein vector. Importantly, peritoneal macrophages isolated from Adv-IK17-scFv treated mice had decreased lipid accumulation compared with adenovirus-enhanced green fluorescent protein-treated mice. CONCLUSIONS: These data support an important role for SR-mediated uptake of OxLDL in the pathogenesis of atherosclerosis and demonstrate that oxidation-specific antibodies reduce the progression of atherosclerosis, suggesting their potential in treating cardiovascular disease in humans.


Subject(s)
Antibodies/chemistry , Atherosclerosis/immunology , Atherosclerosis/pathology , Foam Cells/metabolism , Lipoproteins, LDL/metabolism , Adenoviridae/metabolism , Animals , Atherosclerosis/therapy , Disease Progression , Green Fluorescent Proteins/metabolism , Homeodomain Proteins/genetics , Humans , Immunoglobulin Fragments/chemistry , Macrophages/cytology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Receptors, LDL/genetics , Recombinant Proteins/chemistry
17.
PLoS One ; 6(1): e16572, 2011 Jan 28.
Article in English | MEDLINE | ID: mdl-21305049

ABSTRACT

We have used microarray-based methods of global gene expression together with quantitative PCR and Western blot analysis to identify dysregulation of genes and aberrant cellular processes in human fibroblasts and in SH-SY5Y neuroblastoma cells made HPRT-deficient by transduction with a retrovirus stably expressing an shRNA targeted against HPRT. Analysis of the microarray expression data by Gene ontology (GO) and Gene Set Enrichment Analysis (GSEA) as well as significant pathway analysis by GeneSpring GX10 and Panther Classification System reveal that HPRT deficiency is accompanied by aberrations in a variety of pathways known to regulate neurogenesis or to be implicated in neurodegenerative disease, including the canonical Wnt/ß-catenin and the Alzheimer's disease/presenilin signaling pathways. Dysregulation of the Wnt/ß-catenin pathway is confirmed by Western blot demonstration of cytosolic sequestration of ß-catenin during in vitro differentiation of the SH-SY5Y cells toward the neuronal phenotype. We also demonstrate that two key transcription factor genes known to be regulated by Wnt signaling and to be vital for the generation and function of dopaminergic neurons; i.e., Lmx1a and Engrailed 1, are down-regulated in the HPRT knockdown SH-SY5Y cells. In addition to the Wnt signaling aberration, we found that expression of presenilin-1 shows severely aberrant expression in HPRT-deficient SH-SY5Y cells, reflected by marked deficiency of the 23 kDa C-terminal fragment of presenilin-1 in knockdown cells. Western blot analysis of primary fibroblast cultures from two LND patients also shows dysregulated presenilin-1 expression, including aberrant proteolytic processing of presenilin-1. These demonstrations of dysregulated Wnt signaling and presenilin-1 expression together with impaired expression of dopaminergic transcription factors reveal broad pleitropic neuro-regulatory defects played by HPRT expression and suggest new directions for investigating mechanisms of aberrant neurogenesis and neuropathology in LND and potential new targets for restoration of effective signaling in this neuro-developmental defect.


Subject(s)
Hypoxanthine Phosphoribosyltransferase/deficiency , Neurogenesis/genetics , Presenilin-1/metabolism , Signal Transduction/genetics , Wnt Proteins/metabolism , Cell Line, Tumor , Dopamine , Gene Expression Profiling/methods , Humans , Lesch-Nyhan Syndrome , Transcription Factors
18.
Cold Spring Harb Protoc ; 2010(7): pdb.prot5420, 2010 Jul 01.
Article in English | MEDLINE | ID: mdl-20647353

ABSTRACT

INTRODUCTION: A major obstacle to in vivo delivery of lentivirus or other retroviral vectors is their lability in the presence of serum. In vivo, these viral particles are rapidly destroyed by nonspecific complement-mediated degradation mechanisms. The eventual effective use of retroviral vectors for in vivo gene delivery would be greatly facilitated by the development of methods to protect the viral particles from such degradation. This protocol describes methods for the production of complement-stabilized lentiviral vectors either by pseudotyping the viral particles with a fusion envelope protein containing the complement-regulatory protein CD55 (decay accelerating factor, DAF) or by coassembly with the native DAF protein. An in vitro serum inactivation assay is also described.


Subject(s)
Complement Inactivator Proteins/pharmacology , Gene Transfer Techniques , Genetic Vectors/genetics , Lentivirus/classification , Lentivirus/genetics , Virus Inactivation , Cell Line , Filtration , Humans , Immunoassay , Plasmids/genetics , Serotyping , Transfection , Virus Inactivation/drug effects
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