Dataset Information

Directly Reprogrammed Neurons Express MAPT and APP Splice Variants Pertinent to Ageing and Neurodegeneration.

ABSTRACT: Neurons produced by reprogramming of other cell types are used to study cellular mechanisms of age-related neurodegenerative diseases. To model Alzheimer's disease and other tauopathies, it is essential that alternative splicing of the MAPT transcript in these neurons produces the relevant tau isoforms. Human neurons derived from induced pluripotent stem cells, however, express tau isoform compositions characteristic of foetal neurons rather than of adult neurons unless cultured in vitro for extended time periods. In this study, we characterised the dynamics of the MAPT and APP alternative splicing during a developmental time-course of porcine and murine cerebral cortices. We found age-dependent and species-specific isoform composition of MAPT, including 3R and 4R isoforms in the porcine adult brain similar to that of the adult human brain. We converted adult and embryonic fibroblasts directly into induced neurons and found similar developmental patterns of isoform composition, notably, the 3R and 4R isoforms relevant to the pathogenesis of Alzheimer's disease. Also, we observed cell-type-specific isoform expression of APP transcripts during the conversion. The approach was further used to generate induced neurons from transgenic pigs carrying Alzheimer's disease-causing mutations. We show that such neurons authentically model the first crucial steps in AD pathogenesis.

SUBMITTER: Habekost M

PROVIDER: S-EPMC8018937 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:IntroductionThe neurodevelopmental disorder fragile X syndrome (FXS) is the most common monogenic cause of intellectual disability associated with autism spectrum disorder. Inaccessibility to developing human brain cells is a major barrier to studying FXS. Direct-to-neural precursor reprogramming provides a unique platform to investigate the developmental profile of FXS-associated phenotypes throughout neural precursor and neuron generation, at a temporal resolution not afforded by post-mortem tissue and in a patient-specific context not represented in rodent models. Direct reprogramming also circumvents the protracted culture times and low efficiency of current induced pluripotent stem cell strategies.MethodsWe have developed a chemically modified mRNA (cmRNA) -based direct reprogramming protocol to generate dorsal forebrain precursors (hiDFPs) from FXS patient-derived fibroblasts, with subsequent differentiation to glutamatergic cortical neurons and astrocytes.ResultsWe observed differential expression of mature neuronal markers suggesting impaired neuronal development and maturation in FXS- hiDFP-derived neurons compared to controls. FXS- hiDFP-derived cortical neurons exhibited dendritic growth and arborization deficits characterized by reduced neurite length and branching consistent with impaired neuronal maturation. Furthermore, FXS- hiDFP-derived neurons exhibited a significant decrease in the density of pre- and post- synaptic proteins and reduced glutamate-induced calcium activity, suggesting impaired excitatory synapse development and functional maturation. We also observed a reduced yield of FXS- hiDFP-derived neurons with a significant increase in FXS-affected astrocytes.DiscussionThis study represents the first reported derivation of FXS-affected cortical neurons following direct reprogramming of patient fibroblasts to dorsal forebrain precursors and subsequently neurons that recapitulate the key molecular hallmarks of FXS as it occurs in human tissue. We propose that direct to hiDFP reprogramming provides a unique platform for further study into the pathogenesis of FXS as well as the identification and screening of new drug targets for the treatment of FXS.

Dataset Information

Directly Reprogrammed Neurons Express MAPT and APP Splice Variants Pertinent to Ageing and Neurodegeneration.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets