101
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Kolitz S, Hasson T, Towfic F, Funt JM, Bakshi S, Fowler KD, Laifenfeld D, Grinspan A, Artyomov MN, Birnberg T, Schwartz R, Komlosh A, Hayardeny L, Ladkani D, Hayden MR, Zeskind B, Grossman I. Gene expression studies of a human monocyte cell line identify dissimilarities between differently manufactured glatiramoids. Sci Rep 2015; 5:10191. [PMID: 25998228 PMCID: PMC4441120 DOI: 10.1038/srep10191] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 04/02/2015] [Indexed: 11/09/2022] Open
Abstract
Glatiramer Acetate (GA) has provided safe and effective treatment for multiple sclerosis (MS) patients for two decades. It acts as an antigen, yet the precise mechanism of action remains to be fully elucidated, and no validated pharmacokinetic or pharmacodynamic biomarkers exist. In order to better characterize GA’s biological impact, genome-wide expression studies were conducted with a human monocyte (THP-1) cell line. Consistent with previous literature, branded GA upregulated anti-inflammatory markers (e.g. IL10), and modulated multiple immune-related pathways. Despite some similarities, significant differences were observed between expression profiles induced by branded GA and Probioglat, a differently-manufactured glatiramoid purported to be a generic GA. Key results were verified using qRT-PCR. Genes (e.g. CCL5, adj. p < 4.1 × 10−5) critically involved in pro-inflammatory pathways (e.g. response to lipopolysaccharide, adj. p = 8.7 × 10−4) were significantly induced by Probioglat compared with branded GA. Key genes were also tested and confirmed at the protein level, and in primary human monocytes. These observations suggest differential biological impact by the two glatiramoids and warrant further investigation.
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Affiliation(s)
| | - Tal Hasson
- Teva Pharmaceutical Industries, Petach Tikva, Israel
| | | | | | - Shlomo Bakshi
- Teva Pharmaceutical Industries, Petach Tikva, Israel
| | | | | | | | | | - Tal Birnberg
- Teva Pharmaceutical Industries, Petach Tikva, Israel
| | | | | | | | - David Ladkani
- Teva Pharmaceutical Industries, Petach Tikva, Israel
| | | | | | - Iris Grossman
- Teva Pharmaceutical Industries, Petach Tikva, Israel
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102
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Østergaard ME, Thomas G, Koller E, Southwell AL, Hayden MR, Seth PP. Biophysical and biological characterization of hairpin and molecular beacon RNase H active antisense oligonucleotides. ACS Chem Biol 2015; 10:1227-33. [PMID: 25654188 DOI: 10.1021/cb500880f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Antisense oligonucleotides (ASOs) are single stranded, backbone modified nucleic acids, which mediate cleavage of complementary RNA by directing RNase H cleavage in cell culture and in animals. It has generally been accepted that the single stranded state in conjunction with the phosphorothioate modified backbone is necessary for cellular uptake and transport to the active compartment. Herein, we examine the effect of using hairpin structured ASOs to (1) determine if an ASO agent requires a single stranded conformation for efficient RNA knock down, (2) use a fluorophore-quencher labeled ASO to evaluate which moieties the ASO interacts with in cells and examine if cellular distribution can be determined with such probes, and (3) evaluate if self-structured ASOs can improve allele selective silencing between closely related huntingtin alleles. We show that hairpin shaped ASOs can efficiently down-regulate RNA in vitro, but potency correlates strongly negatively with increasing stability of the hairpin structure. Furthermore, self-structured ASOs can efficiently reduce huntingtin mRNA in the central nervous system of mice.
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Affiliation(s)
| | - George Thomas
- Isis Pharmaceuticals, 2855
Gazelle Court, Carlsbad, California, United States
| | - Erich Koller
- Isis Pharmaceuticals, 2855
Gazelle Court, Carlsbad, California, United States
| | - Amber L. Southwell
- Centre
for Molecular Medicine and Therapeutics, Child and Family Research
Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Michael R. Hayden
- Centre
for Molecular Medicine and Therapeutics, Child and Family Research
Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Punit P. Seth
- Isis Pharmaceuticals, 2855
Gazelle Court, Carlsbad, California, United States
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103
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Jan A, Karasinska JM, Kang MH, de Haan W, Ruddle P, Kaur A, Connolly C, Leavitt BR, Sorensen PH, Hayden MR. Direct intracerebral delivery of a miR-33 antisense oligonucleotide into mouse brain increases brain ABCA1 expression. [Corrected]. Neurosci Lett 2015; 598:66-72. [PMID: 25957561 DOI: 10.1016/j.neulet.2015.05.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 04/25/2015] [Accepted: 05/02/2015] [Indexed: 11/24/2022]
Abstract
The ATP-binding cassette transporter A1 (ABCA1) is a membrane bound protein that serves to efflux cholesterol and phospholipids onto lipid poor apolipoproteins during HDL biogenesis. Increasing the expression and activity of ABCA1 have beneficial effects in experimental models of various neurologic and cardiovascular diseases including Alzheimer's disease. Despite the beneficial effects of liver X receptor (LXR) agonists--compounds that increase ABCA1 expression--in preclinical studies, their therapeutic utility is limited by systemic adverse effects on lipid metabolism. Interestingly, microRNA-33 (miR-33) inhibition increases ABCA1 expression and activity in rodents and non-human primates without severe metabolic adverse effects. Herein, we demonstrate that treatment of cultured mouse neurons, astrocytes and microglia with an antisense oligonucleotide (ASO) targeting miR-33 increased ABCA1 expression, which was accompanied by increased cholesterol efflux and apoE secretion in astrocytic cultures. We also show that intracerebral delivery of an ASO targeting miR-33 leads to increased ABCA1 expression in cerebral cortex or subcortical structures such as hippocampus. These findings highlight an effective strategy for increasing brain ABCA1 expression/activity for relevant mechanistic studies. [Corrected]
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Affiliation(s)
- Asad Jan
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, 950 West 28th Avenue, Vancouver, BC V5Z 4H4, Canada; BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC V5Z 1L3, Canada
| | - Joanna M Karasinska
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, 950 West 28th Avenue, Vancouver, BC V5Z 4H4, Canada; BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC V5Z 1L3, Canada
| | - Martin H Kang
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, 950 West 28th Avenue, Vancouver, BC V5Z 4H4, Canada
| | - Willeke de Haan
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, 950 West 28th Avenue, Vancouver, BC V5Z 4H4, Canada
| | - Piers Ruddle
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, 950 West 28th Avenue, Vancouver, BC V5Z 4H4, Canada
| | - Achint Kaur
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, 950 West 28th Avenue, Vancouver, BC V5Z 4H4, Canada
| | - Colum Connolly
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, 950 West 28th Avenue, Vancouver, BC V5Z 4H4, Canada
| | - Blair R Leavitt
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, 950 West 28th Avenue, Vancouver, BC V5Z 4H4, Canada
| | - Poul H Sorensen
- BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC V5Z 1L3, Canada
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, 950 West 28th Avenue, Vancouver, BC V5Z 4H4, Canada.
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104
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Southwell AL, Skotte NH, Caron N, Kordasiewicz H, Oestergaard M, Doty CN, Villanueva EB, Xie Y, Felczak B, Freier SM, Swayze EE, Seth PP, Frank Bennet C, Hayden MR. 696. Pre-Clinical Evaluation of Allele-Specific Mutant Huntingtin Gene Silencing Antisense Oligonucleotides. Mol Ther 2015. [DOI: 10.1016/s1525-0016(16)34305-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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105
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Bates GP, Dorsey R, Gusella JF, Hayden MR, Kay C, Leavitt BR, Nance M, Ross CA, Scahill RI, Wetzel R, Wild EJ, Tabrizi SJ. Huntington disease. Nat Rev Dis Primers 2015; 1:15005. [PMID: 27188817 DOI: 10.1038/nrdp.2015.5] [Citation(s) in RCA: 846] [Impact Index Per Article: 94.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Huntington disease is devastating to patients and their families - with autosomal dominant inheritance, onset typically in the prime of adult life, progressive course, and a combination of motor, cognitive and behavioural features. The disease is caused by an expanded CAG trinucleotide repeat (of variable length) in HTT, the gene that encodes the protein huntingtin. In mutation carriers, huntingtin is produced with abnormally long polyglutamine sequences that confer toxic gains of function and predispose the protein to fragmentation, resulting in neuronal dysfunction and death. In this Primer, we review the epidemiology of Huntington disease, noting that prevalence is higher than previously thought, geographically variable and increasing. We describe the relationship between CAG repeat length and clinical phenotype, as well as the concept of genetic modifiers of the disease. We discuss normal huntingtin protein function, evidence for differential toxicity of mutant huntingtin variants, theories of huntingtin aggregation and the many different mechanisms of Huntington disease pathogenesis. We describe the genetic and clinical diagnosis of the condition, its clinical assessment and the multidisciplinary management of symptoms, given the absence of effective disease-modifying therapies. We review past and present clinical trials and therapeutic strategies under investigation, including impending trials of targeted huntingtin-lowering drugs and the progress in development of biomarkers that will support the next generation of trials. For an illustrated summary of this Primer, visit: http://go.nature.com/hPMENh.
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Affiliation(s)
- Gillian P Bates
- Department of Medical and Molecular Genetics, King's College London, London, UK
| | - Ray Dorsey
- Department of Neurology, University of Rochester Medical Center, Rochester, New York, USA
| | - James F Gusella
- Molecular Neurogenetics Unit, Center for Human Genetic Research, Massachusetts General Hospital, and Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Chris Kay
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Blair R Leavitt
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Martha Nance
- Struthers Parkinson's Center, Golden Valley, Minneapolis, Minnesota, USA; and Hennepin County Medical Center, Minneapolis, Minnesota, USA
| | - Christopher A Ross
- Division of Neurobiology, Department of Psychiatry and Departments of Neurology, Pharmacology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Rachael I Scahill
- Department of Neurodegenerative Disease, University College London Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Ronald Wetzel
- Department of Structural Biology and Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Edward J Wild
- Department of Neurodegenerative Disease, University College London Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Sarah J Tabrizi
- Department of Neurodegenerative Disease, University College London Institute of Neurology, Queen Square, London WC1N 3BG, UK
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106
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Brunham LR, Hayden MR. Human genetics of HDL: Insight into particle metabolism and function. Prog Lipid Res 2015; 58:14-25. [DOI: 10.1016/j.plipres.2015.01.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 12/22/2014] [Accepted: 01/07/2015] [Indexed: 10/24/2022]
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107
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Kaur A, Patankar JV, de Haan W, Ruddle P, Wijesekara N, Groen AK, Verchere CB, Singaraja RR, Hayden MR. Loss of Cyp8b1 improves glucose homeostasis by increasing GLP-1. Diabetes 2015; 64:1168-79. [PMID: 25338812 DOI: 10.2337/db14-0716] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Besides their role in facilitating lipid absorption, bile acids are increasingly being recognized as signaling molecules that activate cell-signaling receptors. Targeted disruption of the sterol 12α-hydroxylase gene (Cyp8b1) results in complete absence of cholic acid (CA) and its derivatives. Here we investigate the effect of Cyp8b1 deletion on glucose homeostasis. Absence of Cyp8b1 results in improved glucose tolerance, insulin sensitivity, and β-cell function, mediated by absence of CA in Cyp8b1(-/-) mice. In addition, we show that reduced intestinal fat absorption in the absence of biliary CA leads to increased free fatty acids reaching the ileal L cells. This correlates with increased secretion of the incretin hormone GLP-1. GLP-1, in turn, increases the biosynthesis and secretion of insulin from β-cells, leading to the improved glucose tolerance observed in the Cyp8b1(-/-) mice. Thus, our data elucidate the importance of Cyp8b1 inhibition on the regulation of glucose metabolism.
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Affiliation(s)
- Achint Kaur
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jay V Patankar
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Willeke de Haan
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Piers Ruddle
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Nadeeja Wijesekara
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Albert K Groen
- Departments of Pediatrics and Laboratory Medicine, Center for Liver, Digestive and Metabolic Diseases, University Medical Center Groningen, Groningen, the Netherlands
| | - C Bruce Verchere
- Departments of Surgery and Pathology and Laboratory Medicine, Child & Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Roshni R Singaraja
- A*STAR (Agency for Science, Technology and Research) Institute and Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
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108
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Mattis VB, Tom C, Akimov S, Saeedian J, Østergaard ME, Southwell AL, Doty CN, Ornelas L, Sahabian A, Lenaeus L, Mandefro B, Sareen D, Arjomand J, Hayden MR, Ross CA, Svendsen CN. HD iPSC-derived neural progenitors accumulate in culture and are susceptible to BDNF withdrawal due to glutamate toxicity. Hum Mol Genet 2015; 24:3257-71. [PMID: 25740845 DOI: 10.1093/hmg/ddv080] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 03/02/2015] [Indexed: 12/12/2022] Open
Abstract
Huntington's disease (HD) is a fatal neurodegenerative disease, caused by expansion of polyglutamine repeats in the Huntingtin gene, with longer expansions leading to earlier ages of onset. The HD iPSC Consortium has recently reported a new in vitro model of HD based on the generation of induced pluripotent stem cells (iPSCs) from HD patients and controls. The current study has furthered the disease in a dish model of HD by generating new non-integrating HD and control iPSC lines. Both HD and control iPSC lines can be efficiently differentiated into neurons/glia; however, the HD-derived cells maintained a significantly greater number of nestin-expressing neural progenitor cells compared with control cells. This cell population showed enhanced vulnerability to brain-derived neurotrophic factor (BDNF) withdrawal in the juvenile-onset HD (JHD) lines, which appeared to be CAG repeat-dependent and mediated by the loss of signaling from the TrkB receptor. It was postulated that this increased death following BDNF withdrawal may be due to glutamate toxicity, as the N-methyl-d-aspartate (NMDA) receptor subunit NR2B was up-regulated in the cultures. Indeed, blocking glutamate signaling, not just through the NMDA but also mGlu and AMPA/Kainate receptors, completely reversed the cell death phenotype. This study suggests that the pathogenesis of JHD may involve in part a population of 'persistent' neural progenitors that are selectively vulnerable to BDNF withdrawal. Similar results were seen in adult hippocampal-derived neural progenitors isolated from the BACHD model mouse. Together, these results provide important insight into HD mechanisms at early developmental time points, which may suggest novel approaches to HD therapeutics.
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Affiliation(s)
- Virginia B Mattis
- The Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd, 8400 AHSP, Los Angeles, CA 90048, USA
| | - Colton Tom
- The Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd, 8400 AHSP, Los Angeles, CA 90048, USA
| | - Sergey Akimov
- Division of Neurobiology, Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jasmine Saeedian
- The Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd, 8400 AHSP, Los Angeles, CA 90048, USA
| | | | - Amber L Southwell
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada and
| | - Crystal N Doty
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada and
| | - Loren Ornelas
- The Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd, 8400 AHSP, Los Angeles, CA 90048, USA
| | - Anais Sahabian
- The Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd, 8400 AHSP, Los Angeles, CA 90048, USA
| | - Lindsay Lenaeus
- The Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd, 8400 AHSP, Los Angeles, CA 90048, USA
| | - Berhan Mandefro
- The Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd, 8400 AHSP, Los Angeles, CA 90048, USA
| | - Dhruv Sareen
- The Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd, 8400 AHSP, Los Angeles, CA 90048, USA
| | | | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada and
| | - Christopher A Ross
- Division of Neurobiology, Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Clive N Svendsen
- The Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd, 8400 AHSP, Los Angeles, CA 90048, USA
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109
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Sturrock A, Laule C, Wyper K, Milner RA, Decolongon J, Dar Santos R, Coleman AJ, Carter K, Creighton S, Bechtel N, Bohlen S, Reilmann R, Johnson HJ, Hayden MR, Tabrizi SJ, Mackay AL, Leavitt BR. A longitudinal study of magnetic resonance spectroscopy Huntington's disease biomarkers. Mov Disord 2015; 30:393-401. [PMID: 25690257 DOI: 10.1002/mds.26118] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 10/06/2014] [Accepted: 10/23/2014] [Indexed: 11/10/2022] Open
Abstract
Putaminal metabolites examined using cross-sectional magnetic resonance spectroscopy (MRS) can distinguish pre-manifest and early Huntington's Disease (HD) individuals from controls. An ideal biomarker, however, will demonstrate longitudinal change over short durations. The objective here was to evaluate longitudinal in vivo brain metabolite profiles in HD over 24 months. Eighty-four participants (30 controls, 25 pre-manifest HD, 29 early HD) recruited as part of TRACK-HD were imaged at baseline, 12 months, and 24 months using 3T MRS of left putamen. Automated putaminal volume measurement was performed simultaneously. To quantify partial volume effects, spectroscopy was performed in a second, white matter voxel adjacent to putamen in six subjects. Subjects underwent TRACK-HD motor assessment. Statistical analyses included linear regression and one-way analysis of variance (ANOVA). At all time-points N-acetyl aspartate and total N-acetyl aspartate (NAA), neuronal integrity markers, were lower in early HD than in controls. Total NAA was lower in pre-manifest HD than in controls, whereas the gliosis marker myo-inositol (MI) was robustly elevated in early HD. Metabolites were stable over 24 months with no longitudinal change. Total NAA was not markedly different in adjacent white matter than putamen, arguing against partial volume confounding effects in cross-sectional group differences. Total NAA correlations with disease burden score suggest that this metabolite may be useful in identifying neurochemical responses to therapeutic agents. We demonstrate almost consistent group differences in putaminal metabolites in HD-affected individuals compared with controls over 24 months. Future work establishing spectroscopy as an HD biomarker should include multi-site assessments in large, pathologically diverse cohorts.
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Affiliation(s)
- Aaron Sturrock
- Centre for Molecular Medicine & Therapeutics, Vancouver, Canada; Centre for Huntington Disease, University of British Columbia (UBC) Hospital, Vancouver, Canada
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110
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Southwell AL, Franciosi S, Villanueva EB, Xie Y, Winter LA, Veeraraghavan J, Jonason A, Felczak B, Zhang W, Kovalik V, Waltl S, Hall G, Pouladi MA, Smith ES, Bowers WJ, Zauderer M, Hayden MR. Anti-semaphorin 4D immunotherapy ameliorates neuropathology and some cognitive impairment in the YAC128 mouse model of Huntington disease. Neurobiol Dis 2015; 76:46-56. [PMID: 25662335 DOI: 10.1016/j.nbd.2015.01.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 12/15/2014] [Accepted: 01/25/2015] [Indexed: 11/18/2022] Open
Abstract
Huntington disease (HD) is an inherited, fatal neurodegenerative disease with no disease-modifying therapy currently available. In addition to characteristic motor deficits and atrophy of the caudate nucleus, signature hallmarks of HD include behavioral abnormalities, immune activation, and cortical and white matter loss. The identification and validation of novel therapeutic targets that contribute to these degenerative cellular processes may lead to new interventions that slow or even halt the course of this insidious disease. Semaphorin 4D (SEMA4D) is a transmembrane signaling molecule that modulates a variety of processes central to neuroinflammation and neurodegeneration including glial cell activation, neuronal growth cone collapse and apoptosis of neural precursors, as well as inhibition of oligodendrocyte migration, differentiation and process formation. Therefore, inhibition of SEMA4D signaling could reduce CNS inflammation, increase neuronal outgrowth and enhance oligodendrocyte maturation, which may be of therapeutic benefit in the treatment of several neurodegenerative diseases, including HD. To that end, we evaluated the preclinical therapeutic efficacy of an anti-SEMA4D monoclonal antibody, which prevents the interaction between SEMA4D and its receptors, in the YAC128 transgenic HD mouse model. Anti-SEMA4D treatment ameliorated neuropathological signatures, including striatal atrophy, cortical atrophy, and corpus callosum atrophy and prevented testicular degeneration in YAC128 mice. In parallel, a subset of behavioral symptoms was improved in anti-SEMA4D treated YAC128 mice, including reduced anxiety-like behavior and rescue of cognitive deficits. There was, however, no discernible effect on motor deficits. The preservation of brain gray and white matter and improvement in behavioral measures in YAC128 mice treated with anti-SEMA4D suggest that this approach could represent a viable therapeutic strategy for the treatment of HD. Importantly, this work provides in vivo demonstration that inhibition of pathways initiated by SEMA4D constitutes a novel approach to moderation of neurodegeneration.
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Affiliation(s)
- Amber L Southwell
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | - Sonia Franciosi
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | - Erika B Villanueva
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | - Yuanyun Xie
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | | | | | | | - Boguslaw Felczak
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | - Weining Zhang
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | - Vlad Kovalik
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | - Sabine Waltl
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | - George Hall
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | - Mahmoud A Pouladi
- Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, 138648, Singapore; Department of Medicine, National University of Singapore, Singapore
| | | | | | | | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, BC V5Z 4H4, Canada.
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111
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Hayden MR, Pena S, Mundlos S. Clinical Exome/Genome Reports-Announcement. Clin Genet 2015. [DOI: 10.1111/cge.12556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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112
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Aharony I, Ehrnhoefer DE, Shruster A, Qiu X, Franciosi S, Hayden MR, Offen D. A Huntingtin-based peptide inhibitor of caspase-6 provides protection from mutant Huntingtin-induced motor and behavioral deficits. Hum Mol Genet 2015; 24:2604-14. [PMID: 25616965 DOI: 10.1093/hmg/ddv023] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Accepted: 01/21/2015] [Indexed: 11/14/2022] Open
Abstract
Over the past decade, increasing evidence has implied a significant connection between caspase-6 activity and the pathogenesis of Huntington's disease (HD). Consequently, inhibiting caspase-6 activity was suggested as a promising therapeutic strategy to reduce mutant Huntingtin toxicity, and to provide protection from mutant Huntingtin-induced motor and behavioral deficits. Here, we describe a novel caspase-6 inhibitor peptide based on the huntingtin caspase-6 cleavage site, fused with a cell-penetrating sequence. The peptide reduces mutant Huntingtin proteolysis by caspase-6, and protects cells from mutant Huntingtin toxicity. Continuous subcutaneous administration of the peptide protected pre-symptomatic BACHD mice from motor deficits and behavioral abnormalities. Moreover, administration of the peptide in an advanced disease state resulted in the partial recovery of motor performance, and an alleviation of depression-related behavior and cognitive deficits. Our findings reveal the potential of substrate-based caspase inhibition as a therapeutic strategy, and present a promising agent for the treatment of HD.
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Affiliation(s)
- Israel Aharony
- Neuroscience Laboratory, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Israel and
| | - Dagmar E Ehrnhoefer
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Adi Shruster
- Neuroscience Laboratory, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Israel and
| | - Xiaofan Qiu
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Sonia Franciosi
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Daniel Offen
- Neuroscience Laboratory, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Israel and
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Sanders SS, Hou J, Sutton LM, Garside VC, Mui KKN, Singaraja RR, Hayden MR, Hoodless PA. Huntingtin interacting proteins 14 and 14-like are required for chorioallantoic fusion during early placental development. Dev Biol 2015; 397:257-66. [PMID: 25478910 DOI: 10.1016/j.ydbio.2014.11.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 09/01/2014] [Accepted: 11/12/2014] [Indexed: 11/17/2022]
Abstract
Huntington disease (HD) is an adult-onset neurodegenerative disease characterized by motor, cognitive, and psychiatric symptoms that is caused by a CAG expansion in the HTT gene. Palmitoylation is the addition of saturated fatty acids to proteins by DHHC palmitoylacyl transferases. HTT is palmitoylated by huntingtin interacting proteins 14 and 14-like (HIP14 and HIP14L or ZDHHC17 and 13 respectively). Mutant HTT is less palmitoylated and this reduction of palmitoylation accelerates its aggregation and increases cellular toxicity. Mouse models deficient in either Hip14 (Hip14(-/-)) or Hip14l (Hip14l(-/-)) develop HD-like phenotypes. The biological function of HTT palmitoylation and the role that loss of HTT palmitoylation plays in the pathogenesis of HD are unknown. To address these questions mice deficient for both genes were created. Loss of Hip14 and Hip14l leads to early embryonic lethality at day embryonic day 10-11 due to failed chorioallantoic fusion. The chorion is thickened and disorganized and the allantois does not fuse correctly with the chorion and forms a balloon-like shape compared to Hip14l(-/-); Hip14(+/+) littermate control embryos. Interestingly, the Hip14(-/-) ; Hip14(-/-) embryos share many features with the Htt(-/-) embryos, including folding of the yolk sac, a bulb shaped allantois, and a thickened and disorganized chorion. This may be due to a decrease in HTT palmitoylation. In Hip14(-/-); Hip14l(-/-) mouse embryonic fibroblasts show a 25% decrease in HTT palmitoylation compared to wild type cells. This is the first description of a double PAT deficient mouse model where loss of a PAT or multiple PATs results in embryonic lethality in mammals. These results reinforce the physiological importance of palmitoylation during embryogenesis.
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Affiliation(s)
- Shaun S Sanders
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, 950 28th Avenue West, Vancouver, British Columbia, Canada V5Z 4H4
| | - Juan Hou
- Terry Fox Laboratory, BC Cancer Agency, 675 10th Ave West, Vancouver, British Columbia, Canada V5Z 1L3
| | - Liza M Sutton
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, 950 28th Avenue West, Vancouver, British Columbia, Canada V5Z 4H4
| | - Victoria C Garside
- Terry Fox Laboratory, BC Cancer Agency, 675 10th Ave West, Vancouver, British Columbia, Canada V5Z 1L3
| | - Katherine K N Mui
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, 950 28th Avenue West, Vancouver, British Columbia, Canada V5Z 4H4
| | - Roshni R Singaraja
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, 950 28th Avenue West, Vancouver, British Columbia, Canada V5Z 4H4
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, 950 28th Avenue West, Vancouver, British Columbia, Canada V5Z 4H4.
| | - Pamela A Hoodless
- Terry Fox Laboratory, BC Cancer Agency, 675 10th Ave West, Vancouver, British Columbia, Canada V5Z 1L3
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114
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Wong BKY, Ehrnhoefer DE, Graham RK, Martin DDO, Ladha S, Uribe V, Stanek LM, Franciosi S, Qiu X, Deng Y, Kovalik V, Zhang W, Pouladi MA, Shihabuddin LS, Hayden MR. Partial rescue of some features of Huntington Disease in the genetic absence of caspase-6 in YAC128 mice. Neurobiol Dis 2015; 76:24-36. [PMID: 25583186 DOI: 10.1016/j.nbd.2014.12.030] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 12/22/2014] [Accepted: 12/31/2014] [Indexed: 12/13/2022] Open
Abstract
Huntington Disease (HD) is a progressive neurodegenerative disease caused by an elongated CAG repeat in the huntingtin (HTT) gene that encodes a polyglutamine tract in the HTT protein. Proteolysis of the mutant HTT protein (mHTT) has been detected in human and murine HD brains and is implicated in the pathogenesis of HD. Of particular importance is the site at amino acid (aa) 586 that contains a caspase-6 (Casp6) recognition motif. Activation of Casp6 occurs presymptomatically in human HD patients and the inhibition of mHTT proteolysis at aa586 in the YAC128 mouse model results in the full rescue of HD-like phenotypes. Surprisingly, Casp6 ablation in two different HD mouse models did not completely prevent the generation of this fragment, and therapeutic benefits were limited, questioning the role of Casp6 in the disease. We have evaluated the impact of the loss of Casp6 in the YAC128 mouse model of HD. Levels of the mHTT-586 fragment are reduced but not absent in the absence of Casp6 and we identify caspase 8 as an alternate enzyme that can generate this fragment. In vivo, the ablation of Casp6 results in a partial rescue of body weight gain, normalized IGF-1 levels, a reversal of the depression-like phenotype and decreased HTT levels. In the YAC128/Casp6-/- striatum there is a concomitant reduction in p62 levels, a marker of autophagic activity, suggesting increased autophagic clearance. These results implicate the HTT-586 fragment as a key contributor to certain features of HD, irrespective of the enzyme involved in its generation.
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Affiliation(s)
- Bibiana K Y Wong
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada; Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Dagmar E Ehrnhoefer
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Rona K Graham
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada; Research Center on Aging, Department of Physiology and Biophysics, University of Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada
| | - Dale D O Martin
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Safia Ladha
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Valeria Uribe
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Lisa M Stanek
- Genzyme, a Sanofi Company, Framingham, MA 01701, USA
| | - Sonia Franciosi
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Xiaofan Qiu
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Yu Deng
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Vlad Kovalik
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Weining Zhang
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada
| | - Mahmoud A Pouladi
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada; Translational Laboratory in Genetic Medicine, Agency for Science, Technology and Research, 138648, Singapore; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 138648, Singapore
| | | | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V5Z 4H4, Canada.
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115
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Abstract
Low HDL is a risk factor for the development of type 2 diabetes. Hepatic ABCA1 is the rate-limiting protein in HDL biogenesis, and mice lacking hepatic ABCA1 (ABCA1(-l/-l)) have very low plasma HDL concentrations. To investigate the role of hepatic ABCA1 in glucose tolerance and β-cell function, we used ABCA1(-l/-l) mice, which showed impaired glucose tolerance without changes in insulin sensitivity. Insulin secretion was reduced following glucose gavage. Ex vivo, glucose stimulated insulin secretion from β-cells from wild-type (WT) and ABCA1(-l/-l) mice was similar. Insulin secretion was, however, reduced upon addition of ABCA1(-l/-l) serum to the medium compared with WT serum, whereas islets lacking β-cell ABCA1 were not affected differently by ABCA1(-l/-l) or WT serum. After high-fat feeding, WT and ABCA1(-l/-l) mice showed no difference in glucose tolerance or insulin secretion, and serum from ABCA1(-l/-l) and WT mice fed a high-fat diet did not affect insulin secretion differently. We conclude that hepatic ABCA1 improves glucose tolerance by improving β-cell function through both HDL production and interaction with β-cell ABCA1. The beneficial effect of hepatic ABCA1 is decreased under metabolic stress. Increasing hepatic ABCA1 may represent a novel therapeutic strategy for improving glucose homeostasis in diabetes.
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Affiliation(s)
- Willeke de Haan
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Joanna M Karasinska
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Piers Ruddle
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
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Southwell AL, Skotte NH, Kordasiewicz HB, Østergaard ME, Watt AT, Carroll JB, Doty CN, Villanueva EB, Petoukhov E, Vaid K, Xie Y, Freier SM, Swayze EE, Seth PP, Bennett CF, Hayden MR. In vivo evaluation of candidate allele-specific mutant huntingtin gene silencing antisense oligonucleotides. Mol Ther 2014; 22:2093-2106. [PMID: 25101598 PMCID: PMC4429695 DOI: 10.1038/mt.2014.153] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 07/23/2014] [Indexed: 11/08/2022] Open
Abstract
Huntington disease (HD) is a dominant, genetic neurodegenerative disease characterized by progressive loss of voluntary motor control, psychiatric disturbance, and cognitive decline, for which there is currently no disease-modifying therapy. HD is caused by the expansion of a CAG tract in the huntingtin (HTT) gene. The mutant HTT protein (muHTT) acquires toxic functions, and there is significant evidence that muHTT lowering would be therapeutically efficacious. However, the wild-type HTT protein (wtHTT) serves vital functions, making allele-specific muHTT lowering strategies potentially safer than nonselective strategies. CAG tract expansion is associated with single nucleotide polymorphisms (SNPs) that can be targeted by gene silencing reagents such as antisense oligonucleotides (ASOs) to accomplish allele-specific muHTT lowering. Here we evaluate ASOs targeted to HD-associated SNPs in acute in vivo studies including screening, distribution, duration of action and dosing, using a humanized mouse model of HD, Hu97/18, that is heterozygous for the targeted SNPs. We have identified four well-tolerated lead ASOs that potently and selectively silence muHTT at a broad range of doses throughout the central nervous system for 16 weeks or more after a single intracerebroventricular (ICV) injection. With further validation, these ASOs could provide a therapeutic option for individuals afflicted with HD.
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Affiliation(s)
- Amber L Southwell
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Niels H Skotte
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | | | | | | | - Jeffrey B Carroll
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham, Washington, USA
| | - Crystal N Doty
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Erika B Villanueva
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Eugenia Petoukhov
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kuljeet Vaid
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Yuanyun Xie
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | | | | | | | | | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada.
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117
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Semaka A, Kay C, Belfroid RDM, Bijlsma EK, Losekoot M, van Langen IM, van Maarle MC, Oosterloo M, Hayden MR, van Belzen MJ. A new mutation for Huntington disease following maternal transmission of an intermediate allele. Eur J Med Genet 2014; 58:28-30. [PMID: 25464109 DOI: 10.1016/j.ejmg.2014.11.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 11/12/2014] [Indexed: 10/24/2022]
Abstract
New mutations for Huntington disease (HD) originate from CAG repeat expansion of intermediate alleles (27-35 CAG). Expansions of such alleles into the pathological range (≥ 36 CAG) have been exclusively observed in paternal transmission. We report the occurrence of a new mutation that defies the paternal expansion bias normally observed in HD. A maternal intermediate allele with 33 CAG repeats expanded in transmission to 48 CAG repeats causing a de novo case of HD in the family. Retrospectively, the mother presented with cognitive decline, but HD was never considered in the differential diagnosis. She was diagnosed with dementia and testing for HD was only performed after her daughter had been diagnosed. This observation of an intermediate allele expanding into the full penetrance HD range after maternal transmission has important implications for genetic counselling of females with intermediate repeats.
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Affiliation(s)
- Alicia Semaka
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
| | - Chris Kay
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
| | - René D M Belfroid
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Emilia K Bijlsma
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Monique Losekoot
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Irene M van Langen
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Merel C van Maarle
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands
| | - Mayke Oosterloo
- Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
| | - Martine J van Belzen
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands.
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118
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Kolitz SE, Towfic F, Grossman I, Hayden MR, Zeskind B. Use of genetic technologies to compare medicines. Clin Genet 2014; 86:441-6. [PMID: 25046029 DOI: 10.1111/cge.12462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 07/14/2014] [Accepted: 07/16/2014] [Indexed: 11/27/2022]
Abstract
In order to ensure that patients receive the safest and most effective medicines possible, it is often necessary to compare medicines and assess the extent to which they are similar in their clinical impact. Full clinical trials with appropriate endpoints remain the only method to compare the clinical impact of two medicines with absolute certainty. Other available methods (including physicochemical analysis, genomics, and transcriptomics) can provide partial information about certain aspects of a medicine's biological impact, with possible clinical implications. Especially for biologics and non-biological complex drugs, which are more difficult to characterize by physicochemical means than small molecules, genomics and transciptomic studies can yield valuable insights for physicians, regulators, and drug developers. In this review, we cite and summarize a variety of studies that exemplify the emerging science of applying genomics and transcriptomics technologies to compare medicines. We discuss key aspects of experimental design, conduct of genetic assays, and advanced data analysis, all of which are critical for the successful execution of such studies. Finally, we propose new areas for which such studies can be applied to maximize patient benefit and reduce safety issues.
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Affiliation(s)
- S E Kolitz
- Immuneering Corporation, Cambridge, MA, USA
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119
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Ratovitski T, Nakamura M, D'Ambola J, Chighladze E, Liang Y, Wang W, Graham R, Hayden MR, Borchelt DR, Hirschhorn RR, Ross CA. N-Terminal Proteolysis of Full-Length Mutant Huntingtin in an Inducible PC12 Cell Model of Huntington’s Disease. Cell Cycle 2014; 6:2970-81. [DOI: 10.4161/cc.6.23.4992] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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120
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Stanek LM, Yang W, Angus S, Sardi PS, Hayden MR, Hung GH, Bennett CF, Cheng SH, Shihabuddin LS. Antisense oligonucleotide-mediated correction of transcriptional dysregulation is correlated with behavioral benefits in the YAC128 mouse model of Huntington's disease. J Huntingtons Dis 2014; 2:217-28. [PMID: 25063516 DOI: 10.3233/jhd-130057] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Huntington's disease (HD) is a neurological disorder caused by mutations in the huntingtin (HTT) gene, the product of which leads to selective and progressive neuronal cell death in the striatum and cortex. Transcriptional dysregulation has emerged as a core pathologic feature in the CNS of human and animal models of HD. It is still unclear whether perturbations in gene expression are a consequence of the disease or importantly, contribute to the pathogenesis of HD. OBJECTIVE To examine if transcriptional dysregulation can be ameliorated with antisense oligonucleotides that reduce levels of mutant Htt and provide therapeutic benefit in the YAC128 mouse model of HD. METHODS Quantitative real-time PCR analysis was used to evaluate dysregulation of a subset of striatal genes in the YAC128 mouse model. Transcripts were then evaluated following ICV delivery of antisense oligonucleotides (ASO). Rota rod and Porsolt swim tests were used to evaluate phenotypic deficits in these mice following ASO treatment. RESULTS Transcriptional dysregulation was detected in the YAC128 mouse model and appears to progress with age. ICV delivery of ASOs directed against mutant Htt resulted in reduction in mutant Htt levels and amelioration in behavioral deficits in the YAC128 mouse model. These improvements were correlated with improvements in the levels of several dysregulated striatal transcripts. CONCLUSIONS The role of transcriptional dysregulation in the pathogenesis of Huntington's disease is not well understood, however, a wealth of evidence now strongly suggests that changes in transcriptional signatures are a prominent feature in the brains of both HD patients and animal models of the disease. Our study is the first to show that a therapeutic agent capable of improving an HD disease phenotype is concomitantly correlated with normalization of a subset of dysregulated striatal transcripts. Our data suggests that correction of these disease-altered transcripts may underlie, at least in part, the therapeutic efficacy shown associated with ASO-mediated correction of HD phenotypes and may provide a novel set of early biomarkers for evaluating future therapeutic concepts for HD.
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Affiliation(s)
| | - Wendy Yang
- Genzyme, a Sanofi Company, Framingham, MA, USA
| | | | | | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
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121
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Brunham LR, Kang MH, Van Karnebeek C, Sadananda SN, Collins JA, Zhang LH, Sayson B, Miao F, Stockler S, Frohlich J, Cassiman D, Rabkin SW, Hayden MR. Clinical, Biochemical, and Molecular Characterization of Novel Mutations in ABCA1 in Families with Tangier Disease. JIMD Rep 2014; 18:51-62. [PMID: 25308558 DOI: 10.1007/8904_2014_348] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 07/28/2014] [Accepted: 07/30/2014] [Indexed: 01/22/2023] Open
Abstract
Tangier disease is a rare, autosomal recessive disorder caused by mutations in the ABCA1 gene and is characterized by near absence of plasma high-density lipoprotein cholesterol, accumulation of cholesterol in multiple tissues, peripheral neuropathy, and accelerated atherosclerosis. Here we report three new kindreds with Tangier disease harboring both known and novel mutations in ABCA1. One patient was identified to be homozygous for a nonsense mutation, p.Gln1038*. In a remarkably large Tangier disease pedigree with four affected siblings, we identified compound heterozygosity for previously reported missense variants, p.Arg937Val and p.Thr940Met, and show that both of these mutations result in significantly impaired cholesterol efflux in transfected cells. In a third pedigree, the proband was identified to be compound heterozygous for two novel mutations, a frameshift (p.Ile1200Hisfs*4) and an intronic variant (c.4176-11T>G), that lead to the creation of a cryptic splice site acceptor and premature truncation, p.Ser1392Argfs*6. We demonstrate that this mutation arose de novo, the first demonstration of a pathogenic de novo mutation in ABCA1 associated with Tangier disease. We also report results of glucose tolerance testing in a Tangier disease kindred for the first time, showing a gene-dose relationship between ABCA1 activity and glucose tolerance and suggesting that Tangier disease patients may have substantially impaired islet function. Our findings provide insight into the diverse phenotypic manifestations of this rare disorder, expand the list of pathogenic mutations in ABCA1, and increase our understanding of how specific mutations in this gene lead to abnormal cellular and physiological phenotypes.
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Affiliation(s)
- Liam R Brunham
- Translational Laboratory in Genetic Medicine, Association for Science, Technology and Research, Singapore, Singapore,
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122
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Martin DDO, Ladha S, Ehrnhoefer DE, Hayden MR. Autophagy in Huntington disease and huntingtin in autophagy. Trends Neurosci 2014; 38:26-35. [PMID: 25282404 DOI: 10.1016/j.tins.2014.09.003] [Citation(s) in RCA: 211] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 09/08/2014] [Accepted: 09/09/2014] [Indexed: 01/20/2023]
Abstract
Autophagy is an important biological process that is essential for the removal of damaged organelles and toxic or aggregated proteins by delivering them to the lysosome for degradation. Consequently, autophagy has become a primary target for the treatment of neurodegenerative diseases that involve aggregating proteins. In Huntington disease (HD), an expansion of the polyglutamine (polyQ) tract in the N-terminus of the huntingtin (HTT) protein leads to protein aggregation. However, HD is unique among the neurodegenerative proteinopathies in that autophagy is not only dysfunctional but wild type (wt) HTT also appears to play several roles in regulating the dynamics of autophagy. Herein, we attempt to integrate the recently described novel roles of wtHTT and altered autophagy in HD.
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Affiliation(s)
- Dale D O Martin
- Centre for Molecular Medicine and Therapeutics (CMMT), Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada.
| | - Safia Ladha
- Centre for Molecular Medicine and Therapeutics (CMMT), Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Dagmar E Ehrnhoefer
- Centre for Molecular Medicine and Therapeutics (CMMT), Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics (CMMT), Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada.
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123
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Skotte NH, Southwell AL, Østergaard ME, Carroll JB, Warby SC, Doty CN, Petoukhov E, Vaid K, Kordasiewicz H, Watt AT, Freier SM, Hung G, Seth PP, Bennett CF, Swayze EE, Hayden MR. Allele-specific suppression of mutant huntingtin using antisense oligonucleotides: providing a therapeutic option for all Huntington disease patients. PLoS One 2014; 9:e107434. [PMID: 25207939 PMCID: PMC4160241 DOI: 10.1371/journal.pone.0107434] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 08/11/2014] [Indexed: 01/10/2023] Open
Abstract
Huntington disease (HD) is an inherited, fatal neurodegenerative disorder caused by a CAG repeat expansion in the huntingtin gene. The mutant protein causes neuronal dysfunction and degeneration resulting in motor dysfunction, cognitive decline, and psychiatric disturbances. Currently, there is no disease altering treatment, and symptomatic therapy has limited benefit. The pathogenesis of HD is complicated and multiple pathways are compromised. Addressing the problem at its genetic root by suppressing mutant huntingtin expression is a promising therapeutic strategy for HD. We have developed and evaluated antisense oligonucleotides (ASOs) targeting single nucleotide polymorphisms that are significantly enriched on HD alleles (HD-SNPs). We describe our structure-activity relationship studies for ASO design and find that adjusting the SNP position within the gap, chemical modifications of the wings, and shortening the unmodified gap are critical for potent, specific, and well tolerated silencing of mutant huntingtin. Finally, we show that using two distinct ASO drugs targeting the two allelic variants of an HD-SNP could provide a therapeutic option for all persons with HD; allele-specifically for roughly half, and non-specifically for the remainder.
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Affiliation(s)
- Niels H. Skotte
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Amber L. Southwell
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Jeffrey B. Carroll
- Behavioral Neuroscience Program, Department of Psychology, Western Washington University, Bellingham, Washington, United States of America
| | - Simon C. Warby
- Center for Advanced Research in Sleep Medicine, Department of Psychiatry, University of Montréal, Montréal, Quebec, Canada
| | - Crystal N. Doty
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Eugenia Petoukhov
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kuljeet Vaid
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Andrew T. Watt
- ISIS Pharmaceuticals, Carlsbad, California, United States of America
| | - Susan M. Freier
- ISIS Pharmaceuticals, Carlsbad, California, United States of America
| | - Gene Hung
- ISIS Pharmaceuticals, Carlsbad, California, United States of America
| | - Punit P. Seth
- ISIS Pharmaceuticals, Carlsbad, California, United States of America
| | - C. Frank Bennett
- ISIS Pharmaceuticals, Carlsbad, California, United States of America
| | - Eric E. Swayze
- ISIS Pharmaceuticals, Carlsbad, California, United States of America
| | - Michael R. Hayden
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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Carleton BC, Ross CJ, Pussegoda K, Bhavsar AP, Visscher H, Lee JW, Brooks B, Rassekh SR, Dubé MPP, Hayden MR. Genetic Markers of Cisplatin-Induced Hearing Loss in Children. Clin Pharmacol Ther 2014; 96:296-8. [DOI: 10.1038/clpt.2014.92] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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125
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Singaraja RR, Tietjen I, Hovingh GK, Franchini PL, Radomski C, Wong K, vanHeek M, Stylianou IM, Lin L, Wang L, Mitnaul L, Hubbard B, Winther M, Mattice M, Legendre A, Sherrington R, Kastelein JJ, Akinsanya K, Plump A, Hayden MR. Identification of four novel genes contributing to familial elevated plasma HDL cholesterol in humans. J Lipid Res 2014; 55:1693-701. [PMID: 24891332 PMCID: PMC4109763 DOI: 10.1194/jlr.m048710] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 06/01/2014] [Indexed: 01/15/2023] Open
Abstract
While genetic determinants strongly influence HDL cholesterol (HDLc) levels, most genetic causes underlying variation in HDLc remain unknown. We aimed to identify novel rare mutations with large effects in candidate genes contributing to extreme HDLc in humans, utilizing family-based Mendelian genetics. We performed next-generation sequencing of 456 candidate HDLc-regulating genes in 200 unrelated probands with extremely low (≤10th percentile) or high (≥90th percentile) HDLc. Probands were excluded if known mutations existed in the established HDLc-regulating genes ABCA1, APOA1, LCAT, cholesteryl ester transfer protein (CETP), endothelial lipase (LIPG), and UDP-N-acetyl-α-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 2 (GALNT2). We identified 93 novel coding or splice-site variants in 72 candidate genes. Each variant was genotyped in the proband's family. Family-based association analyses were performed for variants with sufficient power to detect significance at P < 0.05 with a total of 627 family members being assessed. Mutations in the genes glucokinase regulatory protein (GCKR), RNase L (RNASEL), leukocyte immunoglobulin-like receptor 3 (LILRA3), and dynein axonemal heavy chain 10 (DNAH10) segregated with elevated HDLc levels in families, while no mutations associated with low HDLc. Taken together, we have identified mutations in four novel genes that may play a role in regulating HDLc levels in humans.
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Affiliation(s)
- Roshni R. Singaraja
- Xenon Pharmaceuticals Inc., Burnaby, BC, Canada
- A*STAR Institute and Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Ian Tietjen
- Xenon Pharmaceuticals Inc., Burnaby, BC, Canada
| | - G. Kees Hovingh
- Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | | | | | | | | | | | - Linus Lin
- Merck Research Laboratories, Rahway, NJ
| | | | | | | | | | | | | | | | - John J. Kastelein
- Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | | | | | - Michael R. Hayden
- A*STAR Institute and Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Centre for Molecular Medicine and Therapeutics, and Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada
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126
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Lee JW, Aminkeng F, Bhavsar AP, Shaw K, Carleton BC, Hayden MR, Ross CJD. The emerging era of pharmacogenomics: current successes, future potential, and challenges. Clin Genet 2014; 86:21-8. [PMID: 24684508 PMCID: PMC4233969 DOI: 10.1111/cge.12392] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 03/24/2014] [Accepted: 03/27/2014] [Indexed: 12/20/2022]
Abstract
The vast range of genetic diversity contributes to a wonderful array of human traits and characteristics. Unfortunately, a consequence of this genetic diversity is large variability in drug response between people, meaning that no single medication is safe and effective in everyone. The debilitating and sometimes deadly consequences of adverse drug reactions (ADRs) are a major and unmet problem of modern medicine. Pharmacogenomics can uncover associations between genetic variation and drug safety and has the potential to predict ADRs in individual patients. Here we review pharmacogenomic successes leading to changes in clinical practice, as well as clinical areas probably to be impacted by pharmacogenomics in the near future. We also discuss some of the challenges, and potential solutions, that remain for the implementation of pharmacogenomic testing into clinical practice for the significant improvement of drug safety.
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Affiliation(s)
- J W Lee
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, The University of British Columbia, Vancouver, BC, Canada; Child & Family Research Institute, Vancouver, BC, Canada
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127
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128
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Brown AMK, Renaud Y, Ross C, Hansen M, Mongrain I, Valois D, Carleton BC, Hayden MR, Dubé MP, Tardif JC, Phillips MS. Development of a broad-based ADME panel for use in pharmacogenomic studies. Pharmacogenomics 2014; 15:1185-95. [DOI: 10.2217/pgs.14.81] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: To optimally address the interindividual variability observed in pharmacokinetic drug response, we have created a custom genotyping panel that interrogates most of the key genetic variations present in a set of 181 prioritized genes responsible for the absorption, distribution, metabolism and excretion (ADME) of many therapeutic agents. This consensus list of genes and variants was based on the ADME core and extended gene lists compiled by a group of pharmaceutical companies as having relevance. Although these pharmacokinetic genes and pathways are well known, tools that can interrogate a large number of these genes simultaneously within a single experiment are not currently available. Methods: Using novel design strategies, we have developed an optimized and validated ADME genotyping panel, encompassing approximately 3000 variants, that has broad applicability to any study or clinical trial that would benefit from the evaluation of an extensive list of ADME genes. Results & conclusion: Over the course of three design iterations, overall assay conversion rates were improved from 83 to 97% resulting in a panel that fills in many of the gaps in coverage present on currently available commercial genotyping assays. The utility of the assay has been demonstrated by the screening of more than 1000 samples resulting in the discovery of novel pharmacogenomic associations. The assay, and the underlying methods, will continue to be a valuable tool for use in future pharmacogenomic studies. Original submitted 28 November 2013; Revision submitted 13 May 2014
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Affiliation(s)
- Andrew MK Brown
- Beaulieu-Saucier Université de Montréal Pharmacogenomics Centre, Montréal, QC, Canada
- Montreal Heart Institute Research Centre, Montréal, QC, Canada
- Université de Montréal, Montréal, QC, Canada
- Current affiliation: Ontario Institute for Cancer Research, Toronto, ON, Canada
| | - Yannick Renaud
- Beaulieu-Saucier Université de Montréal Pharmacogenomics Centre, Montréal, QC, Canada
- Montreal Heart Institute Research Centre, Montréal, QC, Canada
| | - Colin Ross
- Division of Translational Therapeutics, Department of Pediatrics & Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | | | - Ian Mongrain
- Beaulieu-Saucier Université de Montréal Pharmacogenomics Centre, Montréal, QC, Canada
- Montreal Heart Institute Research Centre, Montréal, QC, Canada
| | - Diane Valois
- Beaulieu-Saucier Université de Montréal Pharmacogenomics Centre, Montréal, QC, Canada
- Montreal Heart Institute Research Centre, Montréal, QC, Canada
| | - Bruce C Carleton
- Division of Translational Therapeutics, Department of Pediatrics & Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada
- Pharmaceutical Outcomes Programme, BC Children's Hospital, Vancouver, BC, Canada
| | - Michael R Hayden
- Centre for Molecular Medicine & Therapeutics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Marie-Pierre Dubé
- Beaulieu-Saucier Université de Montréal Pharmacogenomics Centre, Montréal, QC, Canada
- Montreal Heart Institute Research Centre, Montréal, QC, Canada
- Université de Montréal, Montréal, QC, Canada
| | - Jean-Claude Tardif
- Beaulieu-Saucier Université de Montréal Pharmacogenomics Centre, Montréal, QC, Canada
- Montreal Heart Institute Research Centre, Montréal, QC, Canada
- Université de Montréal, Montréal, QC, Canada
| | - Michael S Phillips
- Beaulieu-Saucier Université de Montréal Pharmacogenomics Centre, Montréal, QC, Canada
- Montreal Heart Institute Research Centre, Montréal, QC, Canada
- Université de Montréal, Montréal, QC, Canada
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129
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Shaw K, Amstutz U, Hildebrand C, Rassekh SR, Hosking M, Neville K, Leeder JS, Hayden MR, Ross CJ, Carleton BC. VKORC1 and CYP2C9 genotypes are predictors of warfarin-related outcomes in children. Pediatr Blood Cancer 2014; 61:1055-62. [PMID: 24474498 DOI: 10.1002/pbc.24932] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 12/16/2013] [Indexed: 11/10/2022]
Abstract
BACKGROUND Despite substantial evidence supporting a pharmacogenetic approach to warfarin therapy in adults, evidence on the importance of genetics in warfarin therapy in children is limited, particularly for clinical outcomes. We assessed the contribution of CYP2C9/VKORC1/CYP4F2 genotypes and variation in other genes involved in vitamin K and coagulation pathways to warfarin dose and related clinical outcomes in children. PROCEDURE Clinical and genetic data for 93 children (age ≤ 18 years) who received warfarin therapy were obtained. DNA was genotyped for 93 selected single nucleotide polymorphisms using a custom assay. RESULTS With a median age of 4.8 years, our cohort included more young children than most previous studies. Overall, 76.3% of dose variability was explained by weight, indication, VKORC1-1639G/A and CYP2C9 *2/*3, with genotypes accounting for 21.1% of variability. There was a strong correlation (R(2) = 0.68; P < 0.001) between actual and predicted warfarin dose using a pediatric genotype-based dosing model. VKORC1 genotype had a significant impact on time to therapeutic international normalized ratio (INR) (P = 0.047) and time to over-anticoagulation (INR > 4; P = 0.024) during the initiation of therapy. CYP2C9*3 carriers were also at increased risk of major bleeding while receiving warfarin (adjusted OR = 11.28). An additional variant in CYP2C9 (rs7089580) was significantly associated with warfarin dose (P = 0.020) in a multivariate clinical and genetic model. CONCLUSIONS This study confirms the importance of VKORC1/CYP2C9 genotypes for warfarin dosing in a young pediatric cohort and demonstrates an impact of genetic factors on clinical outcomes in children. Furthermore, we identified an additional variant in CYP2C9 of potential relevance for warfarin dosing in children.
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Affiliation(s)
- Kaitlyn Shaw
- Department of Pediatrics, Faculty of Medicine, University of British Columbia (UBC), Vancouver, BC, Canada; Pharmaceutical Outcomes Programme, B.C. Children's Hospital, Vancouver, BC, Canada
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130
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Kolodziejczyk K, Parsons MP, Southwell AL, Hayden MR, Raymond LA. Striatal synaptic dysfunction and hippocampal plasticity deficits in the Hu97/18 mouse model of Huntington disease. PLoS One 2014; 9:e94562. [PMID: 24728353 PMCID: PMC3984157 DOI: 10.1371/journal.pone.0094562] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 03/18/2014] [Indexed: 01/01/2023] Open
Abstract
Huntington disease (HD) is a fatal neurodegenerative disorder caused by a CAG repeat expansion in the gene (HTT) encoding the huntingtin protein (HTT). This mutation leads to multiple cellular and synaptic alterations that are mimicked in many current HD animal models. However, the most commonly used, well-characterized HD models do not accurately reproduce the genetics of human disease. Recently, a new ‘humanized’ mouse model, termed Hu97/18, has been developed that genetically recapitulates human HD, including two human HTT alleles, no mouse Hdh alleles and heterozygosity of the HD mutation. Previously, behavioral and neuropathological testing in Hu97/18 mice revealed many features of HD, yet no electrophysiological measures were employed to investigate possible synaptic alterations. Here, we describe electrophysiological changes in the striatum and hippocampus of the Hu97/18 mice. At 9 months of age, a stage when cognitive deficits are fully developed and motor dysfunction is also evident, Hu97/18 striatal spiny projection neurons (SPNs) exhibited small changes in membrane properties and lower amplitude and frequency of spontaneous excitatory postsynaptic currents (sEPSCs); however, release probability from presynaptic terminals was unaltered. Strikingly, these mice also exhibited a profound deficiency in long-term potentiation (LTP) at CA3-to-CA1 synapses. In contrast, at 6 months of age we found only subtle alterations in SPN synaptic transmission, while 3-month old animals did not display any electrophysiologically detectable changes in the striatum and CA1 LTP was intact. Together, these data reveal robust, progressive deficits in synaptic function and plasticity in Hu97/18 mice, consistent with previously reported behavioral abnormalities, and suggest an optimal age (9 months) for future electrophysiological assessment in preclinical studies of HD.
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Affiliation(s)
- Karolina Kolodziejczyk
- Department of Psychiatry, Brain Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Matthew P. Parsons
- Department of Psychiatry, Brain Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Amber L. Southwell
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael R. Hayden
- Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lynn A. Raymond
- Department of Psychiatry, Brain Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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131
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Butland SL, Sanders SS, Schmidt ME, Riechers SP, Lin DTS, Martin DDO, Vaid K, Graham RK, Singaraja RR, Wanker EE, Conibear E, Hayden MR. The palmitoyl acyltransferase HIP14 shares a high proportion of interactors with huntingtin: implications for a role in the pathogenesis of Huntington's disease. Hum Mol Genet 2014; 23:4142-60. [PMID: 24705354 DOI: 10.1093/hmg/ddu137] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
HIP14 is the most highly conserved of 23 human palmitoyl acyltransferases (PATs) that catalyze the post-translational addition of palmitate to proteins, including huntingtin (HTT). HIP14 is dysfunctional in the presence of mutant HTT (mHTT), the causative gene for Huntington disease (HD), and we hypothesize that reduced palmitoylation of HTT and other HIP14 substrates contributes to the pathogenesis of the disease. Here we describe the yeast two-hybrid (Y2H) interactors of HIP14 in the first comprehensive study of interactors of a mammalian PAT. Unexpectedly, we discovered a highly significant overlap between HIP14 interactors and 370 published interactors of HTT, 4-fold greater than for control proteins (P = 8 × 10(-5)). Nearly half of the 36 shared interactors are already implicated in HD, supporting a direct link between HIP14 and the disease. The HIP14 Y2H interaction set is significantly enriched for palmitoylated proteins that are candidate substrates. We confirmed that three of them, GPM6A, and the Sprouty domain-containing proteins SPRED1 and SPRED3, are indeed palmitoylated by HIP14; the first enzyme known to palmitoylate these proteins. These novel substrates functions might be affected by reduced palmitoylation in HD. We also show that the vesicular cargo adapter optineurin, an established HTT-binding protein, co-immunoprecipitates with HIP14 but is not palmitoylated. mHTT leads to mislocalization of optineurin and aberrant cargo trafficking. Therefore, it is possible that optineurin regulates trafficking of HIP14 to its substrates. Taken together, our data raise the possibility that defective palmitoylation by HIP14 might be an important mechanism that contributes to the pathogenesis of HD.
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Affiliation(s)
- Stefanie L Butland
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Shaun S Sanders
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Mandi E Schmidt
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Sean-Patrick Riechers
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin-Buch 13125, Germany
| | - David T S Lin
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Dale D O Martin
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Kuljeet Vaid
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Rona K Graham
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Roshni R Singaraja
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Erich E Wanker
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin-Buch 13125, Germany
| | - Elizabeth Conibear
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
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132
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Sanders SS, Mui KKN, Sutton LM, Hayden MR. Identification of binding sites in Huntingtin for the Huntingtin Interacting Proteins HIP14 and HIP14L. PLoS One 2014; 9:e90669. [PMID: 24651384 PMCID: PMC3947954 DOI: 10.1371/journal.pone.0090669] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 02/04/2014] [Indexed: 11/26/2022] Open
Abstract
Huntington disease is an adult onset neurodegenerative disease characterized by motor, cognitive, and psychiatric dysfunction, caused by a CAG expansion in the HTT gene. Huntingtin Interacting Protein 14 (HIP14) and Huntingtin Interacting Protein 14-like (HIP14L) are palmitoyl acyltransferases (PATs), enzymes that mediate the post-translational addition of long chain fatty acids to proteins in a process called palmitoylation. HIP14 and HIP14L interact with and palmitoylate HTT and are unique among PATs as they are the only two that have an ankyrin repeat domain, which mediates the interaction between HIP14 and HTT. These enzymes show reduced interaction with and palmitoylation of mutant HTT, leading to increased mutant HTT inclusion formation and toxicity. The interaction between HIP14 and HTT goes beyond that of only an enzyme–substrate interaction as HTT is essential for the full enzymatic activity of HIP14. It is important to further understand and characterize the interactions of HTT with HIP14 and HIP14L to guide future efforts to target and enhance this interaction and increase enzyme activity to remediate palmitoylation of HTT and their substrates, as well as to understand the relationship between the three proteins. HIP14 and HIP14L have been previously shown to interact with HTT amino acids 1–548. Here the interaction of HIP14 and HIP14L with N- and C-terminal HTT 1–548 deletion mutations was assessed. We show that HTT amino acids 1–548 were sufficient for full interaction of HTT with HIP14 and HIP14L, but partial interaction was also possible with HTT 1–427 and HTT 224–548. To further characterize the binding domain we assessed the interaction of HIP14-GFP and HIP14L-GFP with 15Q HTT 1-548Δ257-315. Both enzymes showed reduced but not abolished interaction with 15Q HTT 1-548Δ257-315. This suggests that two potential binding domains exist, one around residues 224 and the other around 427, for the PAT enzymes HIP14 and HIP14L.
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Affiliation(s)
- Shaun S. Sanders
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Katherine K. N. Mui
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Liza M. Sutton
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael R. Hayden
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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133
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Cui X, Chopp M, Cui Y, Wang Y, Roberts C, Karasinska JM, Hayden MR, Chen J. Abstract W P205: Specific Deficiency of Brain ABCA1 Increases Inflammation and White Matter Damage and Worsens Functional Outcome After Stroke. Stroke 2014. [DOI: 10.1161/str.45.suppl_1.wp205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
ATP-binding cassette transporter A1 (ABCA1) plays a critical role in HDL-cholesterol production and has been identified as a potent anti-inflammatory molecule in macrophages and other immune cells. However, direct experimental support of this hypothesis in cerebral ischemia is lacking. Using specific deficiency of brain ABCA1 mice, we therefore tested whether ABCA1 plays a role in neuro-inflammation and white matter damage after stroke.
Methods:
Adult male brain ABCA1 knockout control (floxed, ABCA1
fl/fl
) and brain ABCA1 knockout (floxed, nestin-Cre positive, ABCA1
-B/-B
) mice were subjected to permanent extraluminal distal middle cerebral artery occlusion (dMCAo) by transcranial ligation of distal MCA with a 10-0 filament. Animals were sacrificed 7 days after MCAo. A battery of functional outcomes, infarct volume, and immunostaining for analysis of inflammation and white matter damage were performed.
Results:
There is no significant difference in blood level of total cholesterol, triglyceride and HDL before and after MCAo between ABCA1
-B/-B
and ABCA1
fl/fl
mice. However, ABCA1
-B/-B
mice showed: 1) increased infarct volume (21.67%±2.95%, n=14, p=0.022) compared with ABCA1
fl/fl
(11.57%±1.58%, n=9); 2) decreased functional outcome evaluated by the adhesive removal and basket tests performed at 1, 3 and 7 days after MCAo (p<0.05); 3) increased inflammation in the ischemic brain, including: (a) decreased the number of CD163 (M2 macrophage marker, anti-inflammatory) positive cells, but an increased the ratio of ED1 (M1 macrophage marker, pro-inflammatory)/CD163 positive cells; (
b
) increased matrix metalloproteinase-9 (MMP-9) expression measured by immunostaining; (
c
) increased number of NFkB positive cells; 4) increased white matter damage: decreased density of Luxol Fast Blue (myelin marker, p<0.01) and Bielshowsky silver (axon marker, p<0.05) compared to ABCA1fl/fl mice.
Conclusions:
Specific deficiency of brain ABCA1 increases inflammation and white matter damage in the ischemic brain, which may play important roles in increasing infarct volume and decreasing functional outcome after stroke. These data indicate that ABCA1 plays an important role in inhibiting neuro-inflammation in the ischemic brain after stroke.
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Affiliation(s)
- Xu Cui
- Neurology Rsch, Henry Ford Hosp, Detroit, MI
| | | | - Yisheng Cui
- Neurology Rsch, Henry Ford Hosp, Detroit, MI
| | - Yun Wang
- Cntr for Neuropsychiatric Rsch, National Health Rsch Institutes, Taiwan, China
| | | | - Joanna M Karasinska
- Dept of Med Genetics, Cntr for Molecular Medicine and Therapeutics, Univ of British Columbia, Vancouver, Canada
| | - Michael R Hayden
- Dept of Med Genetics, Cntr for Molecular Medicine and Therapeutics, Univ of British Columbia, Vancouver, Canada
| | - Jieli Chen
- Neurology Rsch, Henry Ford Hosp, Detroit, MI
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134
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Martin DDO, Heit RJ, Yap MC, Davidson MW, Hayden MR, Berthiaume LG. Identification of a post-translationally myristoylated autophagy-inducing domain released by caspase cleavage of huntingtin. Hum Mol Genet 2014; 23:3166-79. [PMID: 24459296 DOI: 10.1093/hmg/ddu027] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Huntington disease (HD) is a debilitating neurodegenerative disease characterized by the loss of motor control and cognitive ability that ultimately leads to death. It is caused by the expansion of a polyglutamine tract in the huntingtin (HTT) protein, which leads to aggregation of the protein and eventually cellular death. Both the wild-type and mutant form of the protein are highly regulated by post-translational modifications including proteolysis, palmitoylation and phosphorylation. We now demonstrate the existence of a new post-translational modification of HTT: the addition of the 14 carbon fatty acid myristate to a glycine residue exposed on a caspase-3-cleaved fragment (post-translational myristoylation) and that myristoylation of this fragment is altered in a physiologically relevant model of mutant HTT. Myristoylated HTT553-585-EGFP, but not its non-myristoylated variant, initially localized to the ER, induced the formation of autophagosomes and accumulated in abnormally large autophagolysosomal/lysosomal structures in a variety of cell types, including neuronal cell lines under nutrient-rich conditions. Our results suggest that accumulation of myristoylated HTT553-586 in cells may alter the rate of production of autophagosomes and/or their clearance through the heterotypic autophagosomal/lysosomal fusion process. Overall, our novel observations establish a role for the post-translational myristoylation of a caspase-3-cleaved fragment of HTT, highly similar to the Barkor/ATG14L autophagosome-targeting sequence domain thought to sense, maintain and/or promote membrane curvature in the regulation of autophagy. Abnormal processing or production of this myristoylated HTT fragment might be involved in the pathophysiology of HD.
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Affiliation(s)
- Dale D O Martin
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, 950 West 28th Avenue, Vancouver, BC, Canada
| | - Ryan J Heit
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Megan C Yap
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Michael W Davidson
- National High Magnetic Field Laboratory and Department of Biological Science, Florida State University, 1800 East Paul Dirac Drive, Tallahassee, FL 32310, USA
| | - Michael R Hayden
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, 950 West 28th Avenue, Vancouver, BC, Canada
| | - Luc G Berthiaume
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
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135
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de Haan W, Bhattacharjee A, Ruddle P, Kang MH, Hayden MR. ABCA1 in adipocytes regulates adipose tissue lipid content, glucose tolerance, and insulin sensitivity. J Lipid Res 2014; 55:516-23. [PMID: 24443560 DOI: 10.1194/jlr.m045294] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Adipose tissue contains one of the largest reservoirs of cholesterol in the body. Adipocyte dysfunction in obesity is associated with intracellular cholesterol accumulation, and alterations in cholesterol homeostasis have been shown to alter glucose metabolism in cultured adipocytes. ABCA1 plays a major role in cholesterol efflux, suggesting a role for ABCA1 in maintaining cholesterol homeostasis in the adipocyte. However, the impact of adipocyte ABCA1 on adipose tissue function and glucose metabolism is unknown. Our aim was to determine the impact of adipocyte ABCA1 on adipocyte lipid metabolism, body weight, and glucose metabolism in vivo. To address this, we used mice lacking ABCA1 specifically in adipocytes (ABCA1(-ad/-ad)). When fed a high-fat, high-cholesterol diet, ABCA1(-ad/-ad) mice showed increased cholesterol and triglyceride stores in adipose tissue, developed enlarged fat pads, and had increased body weight. Associated with these phenotypic changes, we observed significant changes in the expression of genes involved in cholesterol and glucose homeostasis, including ldlr, abcg1, glut-4, adiponectin, and leptin. ABCA1(-ad/-ad) mice also demonstrated impaired glucose tolerance, lower insulin sensitivity, and decreased insulin secretion. We conclude that ABCA1 in adipocytes influences adipocyte lipid metabolism, body weight, and whole-body glucose homeostasis.
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Affiliation(s)
- Willeke de Haan
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
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136
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Towfic F, Funt JM, Fowler KD, Bakshi S, Blaugrund E, Artyomov MN, Hayden MR, Ladkani D, Schwartz R, Zeskind B. Comparing the biological impact of glatiramer acetate with the biological impact of a generic. PLoS One 2014; 9:e83757. [PMID: 24421904 PMCID: PMC3885444 DOI: 10.1371/journal.pone.0083757] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 11/07/2013] [Indexed: 11/19/2022] Open
Abstract
For decades, policies regarding generic medicines have sought to provide patients with economical access to safe and effective drugs, while encouraging the development of new therapies. This balance is becoming more challenging for physicians and regulators as biologics and non-biological complex drugs (NBCDs) such as glatiramer acetate demonstrate remarkable efficacy, because generics for these medicines are more difficult to assess. We sought to develop computational methods that use transcriptional profiles to compare branded medicines to generics, robustly characterizing differences in biological impact. We combined multiple computational methods to determine whether differentially expressed genes result from random variation, or point to consistent differences in biological impact of the generic compared to the branded medicine. We applied these methods to analyze gene expression data from mouse splenocytes exposed to either branded glatiramer acetate or a generic. The computational methods identified extensive evidence that branded glatiramer acetate has a more consistent biological impact across batches than the generic, and has a distinct impact on regulatory T cells and myeloid lineage cells. In summary, we developed a computational pipeline that integrates multiple methods to compare two medicines in an innovative way. This pipeline, and the specific findings distinguishing branded glatiramer acetate from a generic, can help physicians and regulators take appropriate steps to ensure safety and efficacy.
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Affiliation(s)
- Fadi Towfic
- Immuneering Corporation, Cambridge, Massachusetts, United States of America
| | - Jason M. Funt
- Immuneering Corporation, Cambridge, Massachusetts, United States of America
| | - Kevin D. Fowler
- Immuneering Corporation, Cambridge, Massachusetts, United States of America
| | - Shlomo Bakshi
- Teva Pharmaceutical Industries, Petach Tikva, Israel
| | | | - Maxim N. Artyomov
- Immuneering Corporation, Cambridge, Massachusetts, United States of America
| | | | - David Ladkani
- Teva Pharmaceutical Industries, Petach Tikva, Israel
| | | | - Benjamin Zeskind
- Immuneering Corporation, Cambridge, Massachusetts, United States of America
- * E-mail:
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137
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Kastelein JJP, Ross CJD, Hayden MR. From mutation identification to therapy: discovery and origins of the first approved gene therapy in the Western world. Hum Gene Ther 2013; 24:472-8. [PMID: 23578007 DOI: 10.1089/hum.2013.063] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- John J P Kastelein
- Department of Vascular Medicine, Academic Medical Centre, University of Amsterdam, The Netherlands.
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138
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Parsons MP, Kang R, Buren C, Dau A, Southwell AL, Doty CN, Sanders SS, Hayden MR, Raymond LA. Bidirectional control of postsynaptic density-95 (PSD-95) clustering by Huntingtin. J Biol Chem 2013; 289:3518-28. [PMID: 24347167 DOI: 10.1074/jbc.m113.513945] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Huntington disease is associated with early alterations in corticostriatal synaptic function that precede cell death, and it is postulated that ameliorating such changes may delay clinical onset and/or prevent neurodegeneration. Although many of these synaptic alterations are thought to be attributable to a toxic gain of function of the mutant huntingtin protein, the role that nonpathogenic huntingtin (HTT) plays in synaptic function is relatively unexplored. Here, we compare the immunocytochemical localization of a major postsynaptic scaffolding protein, PSD-95, in striatal neurons from WT mice and mice overexpressing HTT with 18 glutamine repeats (YAC18, nonpathogenic). We found that HTT overexpression resulted in a palmitoylation- and BDNF-dependent increase in PSD-95 clustering at synaptic sites in striatal spiny projection neurons (SPNs) co-cultured with cortical neurons. Surprisingly, the latter effect was mediated presynaptically, as HTT overexpression in cortical neurons alone was sufficient to increase PSD-95 clustering in the postsynaptic SPNs. In contrast, antisense oligonucleotide knockdown of HTT in WT co-cultures resulted in a significant reduction of PSD-95 clustering in SPNs. Notably, despite these bidirectional changes in PSD-95 clustering, we did not observe an alteration in basal electrophysiological measures of AMPA and NMDA receptors. Thus, unlike in previous studies in the hippocampus, enhanced or decreased PSD-95 clustering alone was insufficient to drive AMPA or NMDA receptors into or out of SPN synapses. In all, our results demonstrate that nonpathogenic HTT can indeed influence synaptic protein localization and uncover a novel role of HTT in PSD-95 distribution.
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Affiliation(s)
- Matthew P Parsons
- From the Department of Psychiatry and Brain Research Centre, University of British Columbia, Vancouver, British Columbia V6T 1Z3 and
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139
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Milnerwood AJ, Parsons MP, Young FB, Singaraja RR, Franciosi S, Volta M, Bergeron S, Hayden MR, Raymond LA. Memory and synaptic deficits in Hip14/DHHC17 knockout mice. Proc Natl Acad Sci U S A 2013; 110:20296-301. [PMID: 24277827 PMCID: PMC3864353 DOI: 10.1073/pnas.1222384110] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Palmitoylation of neurotransmitter receptors and associated scaffold proteins regulates their membrane association in a rapid, reversible, and activity-dependent fashion. This makes palmitoylation an attractive candidate as a key regulator of the fast, reversible, and activity-dependent insertion of synaptic proteins required during the induction and expression of long-term plasticity. Here we describe that the constitutive loss of huntingtin interacting protein 14 (Hip14, also known as DHHC17), a single member of the broad palmitoyl acyltransferase (PAT) family, produces marked alterations in synaptic function in varied brain regions and significantly impairs hippocampal memory and synaptic plasticity. The data presented suggest that, even though the substrate pool is overlapping for the 23 known PAT family members, the function of a single PAT has marked effects upon physiology and cognition. Moreover, an improved understanding of the role of PATs in synaptic modification and maintenance highlights a potential strategy for intervention against early cognitive impairments in neurodegenerative disease.
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Affiliation(s)
- Austen J. Milnerwood
- Department of Psychiatry and
- Brain Research Centre, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
| | - Matthew P. Parsons
- Department of Psychiatry and
- Brain Research Centre, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
| | - Fiona B. Young
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada V5Z 4H4; and
| | - Roshni R. Singaraja
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada V5Z 4H4; and
| | - Sonia Franciosi
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada V5Z 4H4; and
| | - Mattia Volta
- Centre for Applied Neurogenetics and Translational Neuroscience, Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 2B5
| | - Sabrina Bergeron
- Centre for Applied Neurogenetics and Translational Neuroscience, Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada V6T 2B5
| | - Michael R. Hayden
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada V5Z 4H4; and
| | - Lynn A. Raymond
- Department of Psychiatry and
- Brain Research Centre, University of British Columbia, Vancouver, BC, Canada V6T 1Z3
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140
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Kang MH, Zhang LH, Wijesekara N, de Haan W, Butland S, Bhattacharjee A, Hayden MR. Regulation of ABCA1 protein expression and function in hepatic and pancreatic islet cells by miR-145. Arterioscler Thromb Vasc Biol 2013; 33:2724-32. [PMID: 24135019 DOI: 10.1161/atvbaha.113.302004] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 10/04/2013] [Indexed: 12/18/2022]
Abstract
OBJECTIVE The ATP-binding cassette transporter A1 (ABCA1) protein maintains cellular cholesterol homeostasis in several different tissues. In the liver, ABCA1 is crucial for high-density lipoprotein biogenesis, and in the pancreas ABCA1 can regulate insulin secretion. In this study, our aim was to identify novel microRNAs that regulate ABCA1 expression in these tissues. APPROACH AND RESULTS We combined multiple microRNA prediction programs to identify 8 microRNAs that potentially regulate ABCA1. A luciferase reporter assay demonstrated that 5 of these microRNAs (miR-148, miR-27, miR-144, miR-145, and miR-33a/33b) significantly repressed ABCA1 3'-untranslated region activity with miR-145 resulting in one of the larger decreases. In hepatic HepG2 cells, miR-145 can regulate both ABCA1 protein expression levels and cholesterol efflux function. In murine islets, an increase in miR-145 expression decreased ABCA1 protein expression, increased total islet cholesterol levels, and decreased glucose-stimulated insulin secretion. Inhibiting miR-145 produced the opposite effect of increasing ABCA1 protein levels and improving glucose-stimulated insulin secretion. Finally, increased glucose levels in media significantly decreased miR-145 levels in cultured pancreatic beta cells. These findings suggest that miR-145 is involved in glucose homeostasis and is regulated by glucose concentration. CONCLUSIONS Our studies demonstrate that miR-145 regulates ABCA1 expression and function, and inhibiting this microRNA represents a novel strategy for increasing ABCA1 expression, promoting high-density lipoprotein biogenesis in the liver, and improving glucose-stimulated insulin secretion in islets.
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Affiliation(s)
- Martin H Kang
- From the Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
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141
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Semaka A, Kay C, Doty CN, Collins JA, Tam N, Hayden MR. High frequency of intermediate alleles on Huntington disease-associated haplotypes in British Columbia's general population. Am J Med Genet B Neuropsychiatr Genet 2013; 162B:864-71. [PMID: 24038799 DOI: 10.1002/ajmg.b.32193] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 07/11/2013] [Indexed: 11/08/2022]
Abstract
Intermediate alleles (27-35 CAG, IAs) for Huntington disease (HD) usually do not confer the disease phenotype but are prone to CAG repeat instability. Consequently, offspring are at-risk of inheriting an expanded allele in the HD range (≥36 CAG). IAs that expand into a new mutation have been hypothesized to be more susceptible to instability compared to IAs identified on the non-HD side of a family from the general population. Frequency estimates for IAs are limited and have largely been determined using clinical samples of HD or related disorders, which may result in an ascertainment bias. This study aimed to establish the frequency of IAs in a sample of a British Columbia's (B.C.) general population with no known association to HD and examine the haplotype of new mutation and general population IAs. CAG sizing was performed on 1,600 DNA samples from B.C.'s general population. Haplotypes were determined using 22 tagging SNPs across the HTT gene. 5.8% of individuals were found to have an IA, of which 60% were on HD-associated haplotypes. There was no difference in the haplotype distribution of new mutation and general population IAs. These findings suggest that IAs are relatively frequent in the general population and are often found on haplotypes associated with expanded CAG lengths. There is likely no difference in the propensity of new mutation and general population IAs to expand into the disease range given that they are both found on disease-associated haplotypes. These findings have important implications for clinical practice.
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Affiliation(s)
- Alicia Semaka
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
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142
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Wan J, Savas JN, Roth AF, Sanders SS, Singaraja RR, Hayden MR, Yates JR, Davis NG. Tracking brain palmitoylation change: predominance of glial change in a mouse model of Huntington's disease. Chem Biol 2013; 20:1421-34. [PMID: 24211138 PMCID: PMC3880188 DOI: 10.1016/j.chembiol.2013.09.018] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 08/28/2013] [Accepted: 09/08/2013] [Indexed: 11/25/2022]
Abstract
Protein palmitoylation, a reversible lipid modification of proteins, is widely used in the nervous system, with dysregulated palmitoylation being implicated in a variety of neurological disorders. Described below is ABE/SILAM, a proteomic strategy that couples acyl-biotinyl exchange (ABE) purification of palmitoyl-proteins to whole animal stable isotope labeling (SILAM) to provide an accurate tracking of palmitoylation change within rodent disease models. As a first application, we have used ABE/SILAM to look at Huntington's disease (HD), profiling palmitoylation change in two HD-relevant mouse mutants: the transgenic HD model mouse YAC128 and the hypomorphic Hip14-gt mouse, which has sharply reduced expression for HIP14 (Zdhhc17), a palmitoyl-transferase implicated in the HD disease process. Rather than mapping to the degenerating neurons themselves, the biggest disease changes instead map to astrocytes and oligodendrocytes (i.e., the supporting glial cells).
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Affiliation(s)
- Junmei Wan
- Department of Pharmacology, Wayne State University, Detroit, MI 48201, USA
| | - Jeffrey N. Savas
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Amy F. Roth
- Department of Pharmacology, Wayne State University, Detroit, MI 48201, USA
| | - Shaun S. Sanders
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4 Canada
| | - Roshni R. Singaraja
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4 Canada
| | - Michael R. Hayden
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia V5Z 4H4 Canada
| | - John R. Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Nicholas G. Davis
- Department of Pharmacology, Wayne State University, Detroit, MI 48201, USA
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143
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Fisher ER, Hayden MR. Multisource ascertainment of Huntington disease in Canada: prevalence and population at risk. Mov Disord 2013; 29:105-14. [PMID: 24151181 DOI: 10.1002/mds.25717] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 08/23/2013] [Accepted: 09/11/2013] [Indexed: 12/12/2022] Open
Abstract
There is uncertainty surrounding the accuracy of prevalence estimates for Huntington's disease (HD). The aims of this study were to provide a best estimate of the prevalence and population at risk for HD in the province of British Columbia (BC), Canada, in 2012. HD patients with a clinical and/or genetic diagnosis of HD and individuals at risk for HD were ascertained from multiple sources. Clinical and genetic data were obtained from all available medical, social service, and genetic testing records. Six hundred and thirty-one HD patients and 3,763 individuals at 25% or 50% risk for HD were identified. Prevalence of HD was estimated at 13.7 per 100,000 (95% confidence interval [CI]: 12.6-14.8 per 100,000) in the general population, and 17.2 per 100,000 (95% CI: 15.8-18.6 per 100,000) in the Caucasian population. The population at 25% to 50% risk was estimated at 81.6 per 100,000 (95% CI: 79.0-84.2 per 100,000) individuals. These figures suggest there may be up to 4,700 individuals affected with HD and 14,000 at 50% risk for HD in Canada as well as up to 43,000 individuals affected with HD and 123,000 at 50% risk for HD in the United States. This is the first direct assessment of HD epidemiology in Canada in over three decades. These findings suggest that underascertainment may have led to previous underestimates of prevalence, namely, in Caucasian populations, and will aid in the planning of appropriate resource allocation and service delivery for the HD community.
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Affiliation(s)
- Emily R Fisher
- Center for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
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144
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Franciosi S, Shim Y, Lau M, Hayden MR, Leavitt BR. A systematic review and meta-analysis of clinical variables used in Huntington disease research. Mov Disord 2013; 28:1987-94. [PMID: 24142393 DOI: 10.1002/mds.25663] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 06/24/2013] [Accepted: 08/11/2013] [Indexed: 11/12/2022] Open
Abstract
Treatment effect in Huntington disease (HD) clinical trials has relied on primary outcome measures such as total motor score or functional rating scales. However, these measures have limited sensitivity, particularly in pre- to early stages of the disease. We performed a systematic review of HD clinical studies to identify endpoints that correlate with disease severity. Using standard HD keywords and terms, we identified 749 published studies from 1993 to 2011 based on the availability of demographic, biochemical, and clinical measures. The average and variability of each measure was abstracted and stratified according to pre-far, pre-close, early, mild, moderate, and severe HD stages. A fixed-effect meta-analysis on selected variables was conducted at various disease stages. A total of 1,801 different clinical variables and treatment outcomes were identified. Unified Huntington Disease Rating Scale (UHDRS) Motor, UHDRS Independence, and Trail B showed a trend toward separation between HD stages. Other measures, such as UHDRS Apathy, Verbal Fluency, and Symbol Digit, could only distinguish between pre- and early stages of disease and later stages, whereas other measures showed little correlation with increasing HD stages. Using cross-sectional data from published HD clinical trials, we have identified potential endpoints that could be used to track HD disease progression and treatment effect. Longitudinal studies, such as TRACK-HD, are critical for assessing the value of potential markers of disease progression for use in future HD therapeutic trials. A list of variables, references used in this meta-analysis, and database is available at http://www.cmmt.ubc.ca/research/investigators/leavitt/publications.
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Affiliation(s)
- Sonia Franciosi
- Center for Molecular Medicine and Therapeutics and Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
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145
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Ehrnhoefer DE, Skotte NH, Ladha S, Nguyen YTN, Qiu X, Deng Y, Huynh KT, Engemann S, Nielsen SM, Becanovic K, Leavitt BR, Hasholt L, Hayden MR. p53 increases caspase-6 expression and activation in muscle tissue expressing mutant huntingtin. Hum Mol Genet 2013; 23:717-29. [PMID: 24070868 DOI: 10.1093/hmg/ddt458] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Activation of caspase-6 in the striatum of both presymptomatic and affected persons with Huntington's disease (HD) is an early event in the disease pathogenesis. However, little is known about the role of caspase-6 outside the central nervous system (CNS) and whether caspase activation might play a role in the peripheral phenotypes, such as muscle wasting observed in HD. We assessed skeletal muscle tissue from HD patients and well-characterized mouse models of HD. Cleavage of the caspase-6 specific substrate lamin A is significantly increased in skeletal muscle obtained from HD patients as well as in muscle tissues from two different HD mouse models. p53, a transcriptional activator of caspase-6, is upregulated in neuronal cells and tissues expressing mutant huntingtin. Activation of p53 leads to a dramatic increase in levels of caspase-6 mRNA, caspase-6 activity and cleavage of lamin A. Using mouse embryonic fibroblasts (MEFs) from YAC128 mice, we show that this increase in caspase-6 activity can be mitigated by pifithrin-α (pifα), an inhibitor of p53 transcriptional activity, but not through the inhibition of p53's mitochondrial pro-apoptotic function. Remarkably, the p53-mediated increase in caspase-6 expression and activation is exacerbated in cells and tissues of both neuronal and peripheral origin expressing mutant huntingtin (Htt). These findings suggest that the presence of the mutant Htt protein enhances p53 activity and lowers the apoptotic threshold, which activates caspase-6. Furthermore, these results suggest that this pathway is activated both within and outside the CNS in HD and may contribute to both loss of CNS neurons and muscle atrophy.
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Affiliation(s)
- Dagmar E Ehrnhoefer
- Centre for Molecular Medicine and Therapeutics (CMMT), Department of Medical Genetics, CFRI, University of British Columbia, 950 West 28th Avenue, Vancouver, BC V5Z 4H4, Canada
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146
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Østergaard ME, Southwell AL, Kordasiewicz H, Watt AT, Skotte NH, Doty CN, Vaid K, Villanueva EB, Swayze EE, Bennett CF, Hayden MR, Seth PP. Rational design of antisense oligonucleotides targeting single nucleotide polymorphisms for potent and allele selective suppression of mutant Huntingtin in the CNS. Nucleic Acids Res 2013; 41:9634-50. [PMID: 23963702 PMCID: PMC3834808 DOI: 10.1093/nar/gkt725] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Autosomal dominant diseases such as Huntington’s disease (HD) are caused by a gain of function mutant protein and/or RNA. An ideal treatment for these diseases is to selectively suppress expression of the mutant allele while preserving expression of the wild-type variant. RNase H active antisense oligonucleotides (ASOs) or small interfering RNAs can achieve allele selective suppression of gene expression by targeting single nucleotide polymorphisms (SNPs) associated with the repeat expansion. ASOs have been previously shown to discriminate single nucleotide changes in targeted RNAs with ∼5-fold selectivity. Based on RNase H enzymology, we enhanced single nucleotide discrimination by positional incorporation of chemical modifications within the oligonucleotide to limit RNase H cleavage of the non-targeted transcript. The resulting oligonucleotides demonstrate >100-fold discrimination for a single nucleotide change at an SNP site in the disease causing huntingtin mRNA, in patient cells and in a completely humanized mouse model of HD. The modified ASOs were also well tolerated after injection into the central nervous system of wild-type animals, suggesting that their tolerability profile is suitable for advancement as potential allele-selective HD therapeutics. Our findings lay the foundation for efficient allele-selective downregulation of gene expression using ASOs—an outcome with broad application to HD and other dominant genetic disorders.
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Affiliation(s)
- Michael E Østergaard
- Isis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA 92010, USA and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, V5Z 4H4, Canada
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147
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Houge G, Bruland O, Bjørnevoll I, Hayden MR, Semaka A. De novo Huntington disease caused by 26-44 CAG repeat expansion on a low-risk haplotype. Neurology 2013; 81:1099-100. [PMID: 23946314 DOI: 10.1212/wnl.0b013e3182a4a4af] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Gunnar Houge
- From the Center for Medical Genetics and Molecular Medicine (G.H., O.B.), Haukeland University Hospital, Bergen; Section for Medical Genetics (I.B.), Department of Pathology, St. Olavs Hospital, Trondheim, Norway; Centre for Molecular Medicine and Therapeutics (M.R.H., A.S.), Vancouver; and University of British Columbia (M.R.H., A.S.), Vancouver, Canada
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148
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Singaraja R, van Capelleveen J, Hovingh K, Zhang L, Dallinga-Thie G, Tietjen I, Wong K, Kastelein JJ, Hayden MR. Abstract 155: Mutations In ABCA8 Result In HDL Deficiency And Cholesterol Efflux Defects. Circ Res 2013. [DOI: 10.1161/res.113.suppl_1.a155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The molecular basis of extreme HDL-C levels is incompletely understood. To identify mutations in novel putative HDL genes, we sequenced select genes in 80 unrelated individuals with extreme low HDLc (HDL %ile≤10th) and as controls, 120 individuals with high HDL (HDL %ile≥90th). We identified two variants in ABCA8 in subjects with low HDL-C levels. The E18-2T>C mutation is located in a highly conserved region and gives rise to a disruption of a splice site. The G>C variant occurs at a site conserved in vertebrates, at position 64425884 (build HG18), and results in Pro609Arg substitution. No ABCA8 mutations were identified in HHDL individuals. These represent the first mutations identified in ABCA8, which belongs to the family of ATP binding cassette transporters. Family expansion followed by genotyping identified additional mutation carriers and first degree relative controls in whom segregation analyses were performed. Compared with controls, mutation carriers showed a significant 32.6% decrease in plasma HDLc levels and decreased HDL percentiles (HDLc: controls = 1.23±0.26, mutation carriers = 0.83±0.37, mmol/L, p=0.0007; HDL%ile: controls = 41.8±21.2, mutation carriers = 17.3±19.2, p=0.004, n=23 controls and 12 carriers). No changes in LDLc, triglycerides or BMI were observed. Since mutations in ABCA8 reduce plasma HDLc levels, we assessed the role of ABCA8 in lipid efflux. Cholesterol efflux to lipid-free APOA-I was significantly reduced by 62.1% in fibroblasts from the proband with the E18-2 T>C mutation. In comparison, fibroblasts from heterozygous ABCA1 mutation carriers showed a 30-60% decrease in efflux to APOA-I depending on mutation severity. Wild type and P609R ABCA8 cDNA clones were generated from human liver RNA. A significant ~200% increase in cholesterol efflux to lipid free APOA-I was observed with wild type ABCA8, further suggesting that ABCA8 is a lipid transporter. A significant 75% decrease in the efflux of cholesterol to lipid-free APOA-I (p=0.02) was observed with the mutant P609R ABCA8 protein compared to wild-type. We show here that ABCA8 is a cholesterol transporter, and that mutations in ABCA8 are a novel cause for reduced plasma HDLc levels in humans.
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Pussegoda K, Ross CJ, Visscher H, Yazdanpanah M, Brooks B, Rassekh SR, Zada YF, Dubé MP, Carleton BC, Hayden MR. Replication of TPMT and ABCC3 genetic variants highly associated with cisplatin-induced hearing loss in children. Clin Pharmacol Ther 2013; 94:243-51. [PMID: 23588304 PMCID: PMC4006820 DOI: 10.1038/clpt.2013.80] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 04/04/2013] [Indexed: 01/12/2023]
Abstract
Cisplatin is a widely used chemotherapeutic agent for the treatment of solid tumors. A serious complication of cisplatin treatment is permanent hearing loss. The aim of this study was to replicate previous genetic findings in an independent cohort of 155 pediatric patients. Associations were replicated for genetic variants in TPMT (rs12201199, P = 0.0013, odds ratio (OR) 6.1) and ABCC3 (rs1051640, P = 0.036, OR 1.8). A predictive model combining variants in TPMT, ABCC3, and COMT with clinical variables (patient age, vincristine treatment, germ-cell tumor, and cranial irradiation) significantly improved the prediction of hearing-loss development as compared with using clinical risk factors alone (area under the curve (AUC) 0.786 vs. 0.708, P = 0.00048). The novel combination of genetic and clinical factors predicted the risk of hearing loss with a sensitivity of 50.3% and a specificity of 92.7%. These findings provide evidence to support the importance of TPMT, COMT, and ABCC3 in the prediction of cisplatin-induced hearing loss in children.
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Affiliation(s)
- K Pussegoda
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
- Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - CJ Ross
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
- Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- Division of Translational Therapeutics, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
| | - H Visscher
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
- Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - M Yazdanpanah
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
- Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Clinical Genomics Network, University of British Columbia, Vancouver, British Columbia, Canada
| | - B Brooks
- Department of Audiology and Speech Pathology, British Columbia Children’s Hospital, Vancouver, British Columbia, Canada
| | - SR Rassekh
- Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- Division of Pediatric Hematology/Oncology/Bone Marrow Transplant, Department of Pediatrics, British Columbia Children’s Hospital, Vancouver, British Columbia, Canada
| | - YF Zada
- Montreal Heart Institute Research Centre and Université de Montreal, Montreal, Quebec, Canada
| | - M-P Dubé
- Montreal Heart Institute Research Centre and Université de Montreal, Montreal, Quebec, Canada
| | - BC Carleton
- Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- Division of Translational Therapeutics, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
- Pharmaceutical Outcomes Programme, British Columbia Children’s Hospital, Vancouver, British Columbia, Canada
| | - MR Hayden
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada
- Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
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150
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Visscher H, Ross CJD, Rassekh SR, Sandor GSS, Caron HN, van Dalen EC, Kremer LC, van der Pal HJ, Rogers PC, Rieder MJ, Carleton BC, Hayden MR. Validation of variants in SLC28A3 and UGT1A6 as genetic markers predictive of anthracycline-induced cardiotoxicity in children. Pediatr Blood Cancer 2013; 60:1375-81. [PMID: 23441093 DOI: 10.1002/pbc.24505] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 01/24/2013] [Indexed: 12/14/2022]
Abstract
BACKGROUND The use of anthracyclines as effective antineoplastic drugs is limited by the occurrence of cardiotoxicity. Multiple genetic variants predictive of anthracycline-induced cardiotoxicity (ACT) in children were recently identified. The current study was aimed to assess replication of these findings in an independent cohort of children. PROCEDURE . Twenty-three variants were tested for association with ACT in an independent cohort of 218 patients. Predictive models including genetic and clinical risk factors were constructed in the original cohort and assessed in the current replication cohort. RESULTS . We confirmed the association of rs17863783 in UGT1A6 and ACT in the replication cohort (P = 0.0062, odds ratio (OR) 7.98). Additional evidence for association of rs7853758 (P = 0.058, OR 0.46) and rs885004 (P = 0.058, OR 0.42) in SLC28A3 was found (combined P = 1.6 × 10(-5) and P = 3.0 × 10(-5), respectively). A previously constructed prediction model did not significantly improve risk prediction in the replication cohort over clinical factors alone. However, an improved prediction model constructed using replicated genetic variants as well as clinical factors discriminated significantly better between cases and controls than clinical factors alone in both original (AUC 0.77 vs. 0.68, P = 0.0031) and replication cohort (AUC 0.77 vs. 0.69, P = 0.060). CONCLUSIONS . We validated genetic variants in two genes predictive of ACT in an independent cohort. A prediction model combining replicated genetic variants as well as clinical risk factors might be able to identify high- and low-risk patients who could benefit from alternative treatment options.
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Affiliation(s)
- H Visscher
- Centre for Molecular Medicine and Therapeutics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada
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