Rapid iPSC inclusionopathy models shed light on formation, consequence, and molecular subtype of α-synuclein inclusions

Neuron. 2024 Sep 4;112(17):2886-2909.e16. doi: 10.1016/j.neuron.2024.06.002. Epub 2024 Jul 29.

Abstract

The heterogeneity of protein-rich inclusions and its significance in neurodegeneration is poorly understood. Standard patient-derived iPSC models develop inclusions neither reproducibly nor in a reasonable time frame. Here, we developed screenable iPSC "inclusionopathy" models utilizing piggyBac or targeted transgenes to rapidly induce CNS cells that express aggregation-prone proteins at brain-like levels. Inclusions and their effects on cell survival were trackable at single-inclusion resolution. Exemplar cortical neuron α-synuclein inclusionopathy models were engineered through transgenic expression of α-synuclein mutant forms or exogenous seeding with fibrils. We identified multiple inclusion classes, including neuroprotective p62-positive inclusions versus dynamic and neurotoxic lipid-rich inclusions, both identified in patient brains. Fusion events between these inclusion subtypes altered neuronal survival. Proteome-scale α-synuclein genetic- and physical-interaction screens pinpointed candidate RNA-processing and actin-cytoskeleton-modulator proteins like RhoA whose sequestration into inclusions could enhance toxicity. These tractable CNS models should prove useful in functional genomic analysis and drug development for proteinopathies.

Keywords: CRISPR screen; Lewy body; Parkinson’s disease; Rab protein; RhoA; actin cytoskeleton; aggregation; dementia with Lewy bodies; glia; iPSC; inclusion; lipid; neurodegeneration; neuron; p62; piggyBac; proximity labeling; synucleinopathy; ubiquitin; α-synuclein.

MeSH terms

  • Brain / metabolism
  • Brain / pathology
  • Humans
  • Inclusion Bodies* / metabolism
  • Inclusion Bodies* / pathology
  • Induced Pluripotent Stem Cells* / metabolism
  • Neurons / metabolism
  • Neurons / pathology
  • Synucleinopathies / genetics
  • Synucleinopathies / metabolism
  • Synucleinopathies / pathology
  • alpha-Synuclein* / genetics
  • alpha-Synuclein* / metabolism

Substances

  • alpha-Synuclein