Genetic and Pathological Assessment of hnRNPA1, hnRNPA2/B1, and hnRNPA3 in Familial and Sporadic Amyotrophic Lateral Sclerosis

Background: Mutations in the genes encoding the heterogeneous nuclear ribonucleoproteins hnRNPA1 and hnRNPA2/B1 have been reported in a multisystem proteinopathy that includes amyotrophic lateral sclerosis (ALS) and inclusion body myopathy associated with Paget disease of the bone and frontotemporal dementia. Mutations were also described in the prion-like domain of hnRNPA1 in patients with classic ALS. Another hnRNP protein, hnRNPA3, has been found to be associated with the ALS/frontotemporal dementia protein C9orf72. Objective: To further assess their role in ALS, we examined these hnRNPs in spinal cord tissue from sporadic (SALS) and familial ALS (FALS) patients, including C9orf72 repeat expansion-positive patients, and controls. We also sought to determine the prevalence of HNRNPA1, HNRNPA2B1, and HNRNPA3 mutations in Australian ALS patients. Methods: Immunostaining was used to assess hnRNPs in ALS patient spinal cords. Mutation analysis of the HNRNPA1, HNRNPA2B1, and HNRNPA3 genes was performed in FALS and of their prion-like domains in SALS patients. Results: Immunostaining of spinal motor neurons of ALS patients with the C9orf72 repeat expansion showed significant mislocalisation of hnRNPA3, and no differences in hnRNPA1 or A2/B1 localisation, compared to controls. No novel or known mutations were identified in HNRNPA1, HNRNPA2B1, or HNRNPA3 in Australian ALS patients. Conclusions: hnRNPA3 pathology was identified in motor neurons of ALS patients with C9orf72 repeat expansions, implicating hnRNPA3 in the pathogenesis of C9orf72-linked ALS. hnRNPA3 warrants further investigation into the pathogenesis of ALS linked to C9orf72. This study also determined that HNRNP mutations are not a common cause of FALS and SALS in Australia.

[1]  D. Rowe,et al.  The genotype–phenotype landscape of familial amyotrophic lateral sclerosis in Australia , 2017, Clinical genetics.

[2]  T. Arzberger,et al.  Reduced hnRNPA3 increases C9orf72 repeat RNA levels and dipeptide‐repeat protein deposition , 2016, EMBO reports.

[3]  Bruce L. Miller,et al.  GGGGCC repeat expansion in C9orf72 compromises nucleocytoplasmic transport , 2015, Nature.

[4]  F. Gage,et al.  Modifiers of C9orf72 dipeptide repeat toxicity connect nucleocytoplasmic transport defects to FTD/ALS , 2015, Nature Neuroscience.

[5]  Sean J. Miller,et al.  The C9orf72 repeat expansion disrupts nucleocytoplasmic transport , 2015, Nature.

[6]  Murray Grossman,et al.  Frontotemporal lobar degeneration: defining phenotypic diversity through personalized medicine , 2015, Acta Neuropathologica.

[7]  Denis C. Bauer,et al.  Mutation analysis of MATR3 in Australian familial amyotrophic lateral sclerosis , 2015, Neurobiology of Aging.

[8]  Satoshi O. Suzuki,et al.  Loss of hnRNPA1 in ALS spinal cord motor neurons with TDP‐43‐positive inclusions , 2015, Neuropathology : official journal of the Japanese Society of Neuropathology.

[9]  P. Scheltens,et al.  No mutations in hnRNPA1 and hnRNPA2B1 in Dutch patients with amyotrophic lateral sclerosis, frontotemporal dementia, and inclusion body myopathy , 2014, Neurobiology of Aging.

[10]  Brian D. Freibaum,et al.  TDP-43 suppresses CGG repeat-induced neurotoxicity through interactions with HnRNP A2/B1. , 2014, Human molecular genetics.

[11]  D. Hannequin,et al.  hnRNPA2B1 and hnRNPA1 mutations are rare in patients with “multisystem proteinopathy” and frontotemporal lobar degeneration phenotypes , 2014, Neurobiology of Aging.

[12]  Fabian A. Buske,et al.  NGSANE: a lightweight production informatics framework for high-throughput data analysis , 2014, Bioinform..

[13]  Adriano Chiò,et al.  State of play in amyotrophic lateral sclerosis genetics , 2013, Nature Neuroscience.

[14]  G. Comi,et al.  Analysis of hnRNPA1, A2/B1, and A3 genes in patients with amyotrophic lateral sclerosis , 2013, Neurobiology of Aging.

[15]  Michael Benatar,et al.  Prion-like domain mutations in hnRNPs cause multisystem proteinopathy and ALS , 2013, Nature.

[16]  C. Broeckhoven,et al.  hnRNP A3 binds to GGGGCC repeats and is a constituent of p62-positive/TDP43-negative inclusions in the hippocampus of patients with C9orf72 mutations , 2013, Acta Neuropathologica.

[17]  Johannes E. Schindelin,et al.  Fiji: an open-source platform for biological-image analysis , 2012, Nature Methods.

[18]  M. Fay.  Confidence intervals that match Fisher's exact or Blaker's exact tests. , 2010, Biostatistics.

[19]  C. Béroud,et al.  Human Splicing Finder: an online bioinformatics tool to predict splicing signals , 2009, Nucleic acids research.

[20]  Xun Hu,et al.  Mutations in FUS, an RNA Processing Protein, Cause Familial Amyotrophic Lateral Sclerosis Type 6 , 2009, Science.

[21]  J. Trojanowski,et al.  Absence of heterogeneous nuclear ribonucleoproteins and survival motor neuron protein in TDP-43 positive inclusions in frontotemporal lobar degeneration , 2007, Acta Neuropathologica.

[22]  Bruce L. Miller,et al.  Ubiquitinated TDP-43 in Frontotemporal Lobar Degeneration and Amyotrophic Lateral Sclerosis , 2006, Science.

[23]  E. Buratti,et al.  TDP-43 Binds Heterogeneous Nuclear Ribonucleoprotein A/B through Its C-terminal Tail , 2005, Journal of Biological Chemistry.

[24]  S H Appel,et al.  Prevalence and patterns of cognitive impairment in sporadic ALS , 2005, Neurology.

[25]  S. Gabriel,et al.  The Structure of Haplotype Blocks in the Human Genome , 2002, Science.

[26]  Trent P Munro,et al.  Heterogeneous Nuclear Ribonucleoprotein A3, a Novel RNA Trafficking Response Element-binding Protein* , 2002, The Journal of Biological Chemistry.

[27]  M. Swash,et al.  El Escorial revisited: Revised criteria for the diagnosis of amyotrophic lateral sclerosis , 2000, Amyotrophic lateral sclerosis and other motor neuron disorders : official publication of the World Federation of Neurology, Research Group on Motor Neuron Diseases.