Understanding the relationship between cerebellum and the frontal-cortex region of C9orf72-related amyotrophic lateral sclerosis: A comparative analysis of genetic features

PLoS One. 2024 May 16;19(5):e0301267. doi: 10.1371/journal.pone.0301267. eCollection 2024.

Abstract

Background: Amyotrophic lateral sclerosis (ALS) is a relentlessly progressive and fatal neurodegenerative diseases for which at present no cure is available. Despite the extensive research the progress from diagnosis to prognosis in ALS and frontotemporal dementia (FTD) has been slow which represents suboptimal understanding of disease pathophysiological processes. In recent studies, several genes have been associated with the ALS and FTD diseases such as SOD1, TDP43, and TBK1, whereas the hexanucleotide GGGGCC repeat expansion (HRE) in C9orf72 gene is a most frequent cause of ALS and FTD, that has changed the understanding of these diseases.

Methods: The goal of this study was to identify and spatially determine differential gene expression signature differences between cerebellum and frontal cortex in C9orf72-associated ALS (C9-ALS), to study the network properties of these differentially expressed genes, and to identify miRNAs targeting the common differentially expressed genes in both the tissues. This study thus highlights underlying differential cell susceptibilities to the disease mechanisms in C9-ALS and suggesting therapeutic target selection in C9-ALS.

Results: In this manuscript, we have identified that the genes involved in neuron development, protein localization and transcription are mostly enriched in cerebellum of C9-ALS patients, while the UPR-related genes are enriched in the frontal cortex. Of note, UPR pathway genes were mostly dysregulated both in the C9-ALS cerebellum and frontal cortex. Overall, the data presented here show that defects in normal RNA processing and the UPR pathway are the pathological hallmarks of C9-ALS. Interestingly, the cerebellum showed more strong transcriptome changes than the frontal cortex.

Conclusion: Interestingly, the cerebellum region showed more significant transcriptomic changes as compared to the frontal cortex region suggesting its active participation in the disease process. This nuanced understanding may offer valuable insights for the development of targeted therapeutic strategies aimed at mitigating disease progression in C9-ALS.

Publication types

  • Comparative Study

MeSH terms

  • Aged
  • Amyotrophic Lateral Sclerosis* / genetics
  • Amyotrophic Lateral Sclerosis* / metabolism
  • Amyotrophic Lateral Sclerosis* / pathology
  • C9orf72 Protein* / genetics
  • C9orf72 Protein* / metabolism
  • Cerebellum* / metabolism
  • Cerebellum* / pathology
  • Female
  • Frontal Lobe* / metabolism
  • Frontal Lobe* / pathology
  • Frontotemporal Dementia / genetics
  • Frontotemporal Dementia / metabolism
  • Frontotemporal Dementia / pathology
  • Humans
  • Male
  • MicroRNAs / genetics
  • MicroRNAs / metabolism
  • Middle Aged

Substances

  • C9orf72 protein, human

Grants and funding

K.P. sincerely thanks the Indian Council of Medical Research (ICMR) New Delhi, India for providing the Senior Research Fellowship grant (BMI/11(63)/2020). VK sincerely thanks Indian Council of Medical Research (ICMR) New Delhi, India (Grant No. DHR/Neuro/2020-NCD-I). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.