RRC ID 84145
Author Riordan R, Saxton A, Han M, McMillan PJ, Kow RL, Liachko NF, Kraemer BC.
Title TMEM106B C-terminal fragments aggregate and drive neurodegenerative proteinopathy in transgenic Caenorhabditis elegans.
Journal Alzheimers Dement
Abstract INTRODUCTION:Genetic variation in the lysosomal and transmembrane protein 106B (TMEM106B) modifies risk for several neurodegenerative disorders, especially frontotemporal lobar degeneration (FTLD). The C-terminal (CT) domain of TMEM106B occurs as fibrillar protein deposits in the brains of dementia patients.
METHODS:To determine the TMEM CT aggregation propensity and neurodegenerative potential, we generated transgenic Caenorhabditis elegans expressing the human TMEM CT fragment aggregating in FTLD cases.
RESULTS:Pan-neuronal expression of human TMEM CT in C. elegans causes severe neuronal dysfunction driving neurodegeneration.  Cytosolic aggregation of TMEM CT proteins accompanied by behavioral dysfunction and neurodegeneration. Loss of pgrn-1 did not modify TMEM CT phenotypes suggesting TMEM CT aggregation occurs downstream of PGRN loss of function. The mechanistic drivers of TMEM106B proteinopathy appear distinct from known modifiers of tauopathy.
DISCUSSION:Our data demonstrate that TMEM CT aggregation can kill neurons. TMEM106B transgenic C.elegans provide a useful model for characterizing TMEM106B proteinopathy-mediated neurodegeneration in FTLD.
HIGHLIGHTS:Pan-neuronal expression of human TMEM106B C-terminal fragments (TMEM CT) in C. elegans neurons drives a suite of disease-related phenotypes useful for modeling the molecular and cellular features of TMEM106B neuropathology. TMEM CT expression results in extensive TMEM aggregation and accumulation of highly detergent insoluble protein species. TMEM CT expression causes moderate to severe neuronal dysfunction dependent on TMEM CT abundance as measured by stereotypical behavioral readouts. TMEM CT expression drives significant neurodegenerative changes. Dendra2 tagged TMEM exhibits similar properties to untagged TMEM allowing ready visualization of the protein. TMEM CT aggregates accumulate adjacent to but not within lysosomes. PGRN loss of function does not impact TMEM CT toxicity. Modifiers of tau and TDP-43 proteinopathies have little impact on TMEM CT-related neurodegenerative phenotypes.
Volume 21(2)
Pages e14468
Published 2025-2-1
DOI 10.1002/alz.14468
PMID 39711302
PMC PMC11848199
MeSH Animals Animals, Genetically Modified Caenorhabditis elegans Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / metabolism Disease Models, Animal Frontotemporal Lobar Degeneration* / genetics Frontotemporal Lobar Degeneration* / metabolism Frontotemporal Lobar Degeneration* / pathology Humans Membrane Proteins* / genetics Membrane Proteins* / metabolism Nerve Tissue Proteins* / genetics Nerve Tissue Proteins* / metabolism Neurodegenerative Diseases* / genetics Neurodegenerative Diseases* / metabolism Neurodegenerative Diseases* / pathology Neurons / metabolism Neurons / pathology
Resource
C.elegans tm985