Downregulation of SF3B2 protects CNS neurons in models of multiple sclerosis

Ann Clin Transl Neurol. 2023 Feb;10(2):246-265. doi: 10.1002/acn3.51717. Epub 2022 Dec 27.

Abstract

Objective: Neurodegeneration induced by inflammatory stress in multiple sclerosis (MS) leads to long-term neurological disabilities that are not amenable to current immunomodulatory therapies.

Methods and results: Here, we report that neuronal downregulation of Splicing factor 3b subunit 2 (SF3B2), a component of U2 small nuclear ribonucleoprotein (snRNP), preserves retinal ganglion cell (RGC) survival and axonal integrity in experimental autoimmune encephalomyelitis (EAE)-induced mice. By employing an in vitro system recapitulating the inflammatory environment of MS lesion, we show that when SF3B2 levels are downregulated, cell viability and axon integrity are preserved in cortical neurons against inflammatory toxicity. Notably, knockdown of SF3B2 suppresses the expression of injury-response and necroptosis genes and prevents activation of Sterile Alpha and TIR Motif Containing 1 (Sarm1), a key enzyme that mediates programmed axon degeneration.

Interpretation: Together, these findings suggest that the downregulation of SF3B2 is a novel potential therapeutic target to prevent secondary neurodegeneration in MS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Armadillo Domain Proteins / genetics
  • Armadillo Domain Proteins / metabolism
  • Axons / pathology
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism
  • Disease Models, Animal
  • Down-Regulation
  • Encephalomyelitis, Autoimmune, Experimental* / pathology
  • Mice
  • Multiple Sclerosis* / genetics
  • Multiple Sclerosis* / pathology
  • RNA Splicing Factors* / genetics
  • Retinal Ganglion Cells* / metabolism
  • Retinal Ganglion Cells* / pathology

Substances

  • Armadillo Domain Proteins
  • Cytoskeletal Proteins
  • RNA Splicing Factors
  • SARM1 protein, mouse
  • SF3B2 protein, human
  • Sf3b2 protein, mouse

Grants and funding

This work was funded by Dr. Miriam and Sheldon G. Adelson Medical Foundation; Merkin Family Foundation; Race to Erase MS .