David Pitt, MD

Multiple Sclerosis (MS) is a common inflammatory disease of the central nervous system. MS has a prominent, neurodegenerative component that is most visible in the progressive phase of the disease. Neurodegeneration in MS is poorly understood and currently not treatable. Our research goal is to decipher the molecular and cellular mechanisms of MS-related neurodegeneration and to translate these insights into therapies.

Defining the Contribution of Astrocytes and Oligodendrocytes to Genetic MS Susceptibility

We are systematically identifying the MS risk variants that are active in astrocytes and oligodendrocytes and the genes that they perturb. For this, we are generating chromatin accessibility profiles of astrocytes/oligodendrocytes isolated from MS lesions and intersect these profiles with MS risk variants. The resulting list of variants and variant-dependent genes will provide a roadmap of astroglia/oligodendroglia pathways that are dysregulated by MS risk variants and are ikely to contribute to glia-mediated MS susceptibility.

Identifying Cellular Phenotypes and Generate Spatial and Functional Maps of their Interactions in MS Lesions

We are combining single nuclear RNA sequencing (sNuc-Seq) of MS lesion tissue with highly multiplexed tissue imaging to identify and localize cellular subpopulations within MS lesions and determine their molecular interactions. We are thus generating spatial and functional maps that provide unprecedented insight into the in situ-funcionality of lesional cellular subpopulations.

Astrocyte-Derived Exosomes as Biomarkers for MS Progression and Remyelination

Current MS research focuses increasingly on disease progression and myelin repair, and there is a surge of clinical trials that test potentially neuroprotective or remyelinating compounds. These trials face the fundamental challenge that MS progression and remyelination are difficult to quantity in vivo. We are exploring the potential of astrocyte-derived exosomes to monitor and predict disease progression, remyelination and treatment responses.

Innovative Techniques in our Lab include:

· Highly multiplexed imaging: Individual, histological sections are labeled with 40+ antibodies to capture cellular subpopulations in MS lesions, place them within the context of the lesion environment, and identify their specific interaction networks.

· Computational pipeline (Ilastik, CellProfiler, histoCAT, PHATE, and Pseudotime) for cellular segmentation, identiication o cellular phenotypes, and spatial analysis.

· Purification of astrocyte and oligodendrocyte nuclei from MS, Alzheimer's, and Parkinson's tissue for transcriptomal and genomic profiling with sNuc-Seq and ATAC-Seq.

· CRISPR/Cas9 genome editing of MS patient-derived iPSCs.

· Generation of iPSC-derived astrocytes.

· Purification and quantification of exosomes from patient plasma.