A Specific Mini-Intrabody Mediates Lysosome Degradation of Mutant Huntingtin

Adv Sci (Weinh). 2023 Nov;10(31):e2301120. doi: 10.1002/advs.202301120. Epub 2023 Sep 8.

Abstract

Accumulation of misfolded proteins leads to many neurodegenerative diseases that can be treated by lowering or removing mutant proteins. Huntington's disease (HD) is characterized by the intracellular accumulation of mutant huntingtin (mHTT) that can be soluble and aggregated in the central nervous system and causes neuronal damage and death. Here, an intracellular antibody (intrabody) fragment is generated that can specifically bind mHTT and link to the lysosome for degradation. It is found that delivery of this peptide by either brain injection or intravenous administration can efficiently clear the soluble and aggregated mHTT by activating the lysosomal degradation pathway, resulting in amelioration of gliosis and dyskinesia in HD knock-in (KI-140Q) mice. These findings suggest that the small intrabody peptide linked to lysosomes can effectively lower mutant proteins and provide a new approach for treating neurodegenerative diseases that are caused by the accumulation of mutant proteins.

Keywords: HD KI-140Q mice; SM3; intravenous injection; lysosome; mini-intrabody; mutant huntingtin; stereotaxic injection.

MeSH terms

  • Animals
  • Huntingtin Protein / genetics
  • Huntingtin Protein / metabolism
  • Huntington Disease* / metabolism
  • Lysosomes / metabolism
  • Mice
  • Mutant Proteins
  • Nerve Tissue Proteins
  • Neurodegenerative Diseases*
  • Peptides

Substances

  • Huntingtin Protein
  • Mutant Proteins
  • Nerve Tissue Proteins
  • Peptides
  • Htt protein, mouse