Abstract TP284: Transcriptome Profiling of Peripheral Blood Mononuclear Cells in Moyamoya Disease

Abstract

Objectives: Moyamoya Disease (MMD) is a progressive occlusive cerebrovascular disease with unknown etiology and pathogenesis. Studies have reported dysregulation in extracellular matrix-related molecules and increased circulating inflammatory cytokines/chemokines in MMD patients, suggesting a role of immune responses in the development of MMD. In this study, we utilized single-cell RNA sequencing (scRNA-seq) to investigate the circulating transcriptome immune cell signatures in MMD. Methods: Whole blood samples were collected from bilateral MMD (n=3), non-MMD patients (n=2, aneurysm, or cavernous malformation) and healthy controls (HC) (n=2). Peripheral blood mononuclear cells (PBMCs) were isolated and cryopreserved. Single Cell 3’ Gene Expression libraries were generated and sequenced. Data were demultiplexed and mapped using the CellRanger. Differentially expressed genes (DEGs) were identified and top biological functions and pathways in each cell type were analyzed. Results: ScRNA-seq data showed differences in several key cell types between MMD and HC, such as CD8+ NKT, Naïve CD8+ T, CD4+ NKT, Naïve B cells and non-classical monocytes. Further analyses of DEGs for CD8+ NKT, Naïve CD8+ T and CD4+ NKT highlighted in MMD revealed a predicted activation in cell death and predicted inhibition in cell viability, cell movement, proliferation, and migration. In addition, eIF2 (eukaryotic initiation factor-2) activation was detected in all three cell types, most prominently in CD8+ NKT cells. Pathway analysis revealed an inhibition in natural killer cell signaling and autophagy pathways. Conclusion: In this study, we identified circulating immune cell signatures in MMD and highlighted the role of CD8+ NKT cells, Naïve CD8+ T cells and CD4+ NKT cells. These cell types manifest distinct pathological processes involved in cellular stress, including inhibition of natural killer cell signaling and disruption in autophagy, which can lead to impaired cytotoxic functions. Active investigations address validation of key cell-type and genes with additional patient cohort. This investigation elucidates the intricate immune responses associated with MMD, providing integral insights for discerning the disease's pathophysiology.