Studying the neuroprotective roles of meningothelial cells in a bioprinted model of the subarachnoid space
Description: BackgroundCerebrospinal fluid (CSF) flow promotes the export of neurotoxic metabolites such as amyloid beta (Abeta) peptides or tau- and alpha-synuclein-containing exosomes related to Alzheimer’s (AD) or Parkinson’s disease (PD) from the brain. The age-dependent slowdown of CSF flow and diminished export of neurotoxic metabolites has recently been linked to progression of AD and PD. Covering the structures of the central nervous system, the meninges form the interface between CSF and neuronal tissue. Besides providing physical protection to the brain, the meninges are also an important hub for immunological processes and involved in CSF clearance. Specialized macrophages as well as endocytically active cells referred to as leptomeningeal/meningothelial cells (MECs) are postulated to be involved in CSF maintenance through direct uptake of neurotoxic substances.Working HypothesisWe hypothesize that through their large contact surface with CSF, their strong endocytic activity and their large capacity for protein secretion, MECs contribute to the removal of toxic metabolites and debris from the brain either by direct endocytosis or by providing soluble endocytosis receptors for neighboring meningeal macrophages. During age-related slowing of CSF flow, which impairs neurotoxic metabolites export from the brain, the endocytic clearance capacity of MECs may become essential for preventing neurotoxic metabolite accumulation.Specific AimsWe aim to define how CSF flow dynamics affect clearance of AD-associated Abeta as well as exosome uptake by MECs. We will also study how MEC energy metabolism linked to endocytic activity is affected by low CSF flow conditions encountered during aging. Moreover, we will elucidate the crosstalk between MECs and meningeal macrophages in CSF clearance and validate our findings in vivo.Experimental Design and MethodsWe combine state-of-the art 3D bioprinting with a robust, miniaturized perfusion system and culture of primary human MECs and macrophages to generate a 3D model of the subarachnoid space amenable to live cell imaging. Using single cell RNASeq, we characterize MEC and macrophage cell populations in these 3D co-cultures. We employ lentiviral transduction of genetically encoded fluorescent biosensors and combine confocal live cell imaging with advanced image processing. Using CRISPR technology, we generate knock-out cell lines lacking MFG-E8 and integrin alphaVbeta3 implicated in endocytosis and employ low light measurements of luciferase-based sensors to monitor endocytic activity. Finally, we intrathecally inject mice with fluorescent tracers to verify our findings in vivo.Expected Value of the ProjectThe project will extend our understanding of CSF homeostasis and define the contribution of MECs relative to other meningeal cell types to this process especially under age-related CSF flow conditions. Moreover, elucidating the crosstalk between hitherto understudied MECs and the better-defined meningeal macrophages will likely foster new research into this important border tissue protecting the brain. Finally, as insufficient toxic metabolite clearance is linked to neurodegenerative processes, our research might also point to new therapeutic strategies to target neurodegenerative disorders including PD and AD.
Amount: CHF 599,900
Funding type: research
Funder scheme: Project funding
Start date: 2024-06-01
End date: 2028-05-31
Investigator: Neutzner, Albert
Institution: University of Basel – BS
Funded outputs count: 1
Funder award ID: 10000243
OpenAlex ID: G5237922725