Effects of Exogenous NUB1 Expression in the Striatum of HDQ175/Q7 Mice.
Reducing mutant huntingtin (mHTT) in neurons may be a therapy for Huntington's disease (HD). Elevating NUB1 protein reduced mHTT levels in cell and fly models of HD through a proteasome dependent mechanism.



To examine the effects of augmenting NUB1 in HD mouse striatum on mHTT levels.



Striata of HDQ175/Q7 mice were injected at 3 months of age with recombinant AAV2/9 coding for NUB1 or GFP under the control of the neuron specific human synapsin 1 promoter and examined 6 months post-injection for levels of huntingtin, the striatal markers DARPP32 and PDE10A, the astrocyte marker GFAP, and the autophagy and mHTT aggregate marker P62 using immunolabeling of brain sections and Western blot assay of striatal subcellular fractions.



By Western blot human HD brain had only one of the two variants of NUB1 present in human control brain. In striatum of WT and HD mice NUB1 was localized in medium size neurons and enriched in the nucleus of large neurons. In the striatum of NUB1 injected HD mice, there was widespread neuronal distribution of exogenous NUB1 labeling and protein levels were ∼2.5-fold endogenous levels. DARPP32 and GFAP distribution and levels were unchanged but PDE10A levels were lower in crude homogenates and P62 was increased in nuclear enriched P1 fractions. Elevating NUB1 did not change levels of full-length mHTT or the number and size of mHTT (S830) positive nuclear inclusions.



Findings suggest that increasing NUB1 protein in striatal neurons of HDQ175/Q7 mice in vivo may be relatively safe but is ineffective in reducing mHTT. Increased NUB1 expression in HD striatum alters PDE10A and P62 which are known to be influenced by mHTT.
Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
Petr
P
Vodicka
Department of Medicine and The RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA, USA.
Kathryn
K
Chase
Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
Maria
M
Iuliano
Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
Dana T
DT
Valentine
Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
Ellen
E
Sapp
Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.|State Key Laboratory of Medical Neurobiology, School of Life Sciences, Fudan University, China.
Boxun
B
Lu
Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
Kimberly B
KB
Kegel-Gleason
Department of Neurology, Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA, USA.
Miguel
M
Sena-Esteves
Department of Medicine and The RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA, USA.
Neil
N
Aronin
Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
Marian
M
DiFiglia
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D003342:Corpus Striatum / Q000378:metabolism*; D044842:Cullin Proteins / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32 / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000235:genetics*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D000071058:Huntingtin Protein / Q000235:genetics* / Q000378:metabolism; D006816:Huntington Disease / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D010727:Phosphoric Diester Hydrolases / Q000235:genetics / Q000378:metabolism; D016704:Synapsins / Q000235:genetics / Q000378:metabolism; D051758:Transcription Factor TFIIH; D014157:Transcription Factors / Q000378:metabolism; D014161:Transduction, Genetic; D018911:Trinucleotide Repeats / Q000235:genetics*
D048868:Adaptor Proteins, Signal Transducing; C503646:Cul3 protein, mouse; D044842:Cullin Proteins; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; C490981:Gtf2h1 protein, mouse; D000071058:Huntingtin Protein; C486597:Nub1 protein, mouse; C497929:Ppp1r1b protein, mouse; D016704:Synapsins; D014157:Transcription Factors; D049452:Green Fluorescent Proteins; D051758:Transcription Factor TFIIH; C492284:Pde10a protein, mouse; D010727:Phosphoric Diester Hydrolases
Adeno-associated virus; Huntington’s disease; NUB1; NUB1L; P62; aggregates; huntingtin; neurodegeneration; striatum