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Gjoneska, E.

Publications and source records attributed to Gjoneska, E..

3 recordsLinked to original sources

Immune receptor LAG3 regulates microglia function duringAlzheimer's disease

Alzheimers Disease (AD) remains the leading cause of dementia globally, yet the exact etiology is not well defined and effective treatments remain unavailable. Here, we report that deletion of the immune checkpoint receptor lymphocyte activation gene 3 (Lag3) in a familial AD mouse model, 5xFAD+, can rescue molecular, cellular and behavioral phenotypes of neurodegeneration. Specifically, we demonstrate that amyloidosis and microgliosis in the 5xFAD+ mice are significantly reduced by Lag3 deletion. Moreover, we show that Lag3 deletion attenuates deficits in neurodegeneration-related behavioral phenotypes in the 5xFAD+ mice. Transcriptional profiling reveals that Lag3 deletion suppresses aberrant overexpression of disease associated microglia (DAM) genes in 5xFAD+ microglia, effectively restoring homeostatic transcriptional programs. Finally, we observe reduced CD8+ T cell infiltration in the brain of 5xFAD+ animals after Lag3 deletion which likely mediates molecular, cellular and behavioral effects resulting from microglia DAM gene activation. Our results highlight a previously unrecognized role for Lag3 in AD as a critical regulator of microglia function and suggest Lag3 might be a viable target for novel AD therapeutic interventions. HighlightsO_LIImmune receptor Lag3 deletion ameliorates amyloidosis and microgliosis during AD C_LIO_LILag3 deletion attenuates deficits in neurodegeneration-related behavioral phenotypes C_LIO_LILag3 deletion reverses aberrant activation of DAM genes and restores microglia homeostasis C_LIO_LILag3 inhibition presents a viable approach for novel AD therapeutic interventions C_LI

neuroscience↗

Alzheimer's Disease Risk Allele APOE4 Interacts with Arsenic Exposure to Drive Microglial Dysfunction

Alzheimers disease (AD) is influenced by both genetic risk and environmental exposures, but how these factors interact in human microglia remains unclear. Here, we investigate whether the late-onset AD risk allele APOE4 impacts microglial vulnerability to arsenite exposure. To that end, we used CRISPR/Cas9 to generate an isogenic APOE4+/+ iPSC-derived transcription factor-induced microglia-like cells (iTFM). We demonstrate that APOE4+/+ iTFM exhibit decreased survival following arsenite exposure, as evidenced by a lower LC50 compared to APOE3+/+ controls. Transcriptomic profiling identified arsenite concentration as the primary driver of gene expression changes, while genotype contributed a secondary, distinct component of the response. Weighted gene co-expression network analysis revealed genotype-dependent modules enriched for phagocytic and oxidative stress pathways, including KEAP1-NFE2L2 signaling. These transcriptomic changes were further supported by functional assays. APOE4+/+ iTFM had a high proportion of phagocytic cells and altered mitochondrial phenotypes including increased mitochondrial mass, reduced membrane potential, and reduced superoxide production, all of which were further perturbed by low dose arsenite exposure. These results support a gene-environment interaction-dependent increase in microglial vulnerability via reshaping of transcriptional and functional stress responses, and provide a human cell-based framework for studying environmentally mediated microglial contributions to AD.

neuroscience↗

Epigenome-wide study uncovers tau pathology-driven changes of chromatin organization in the aging human brain

Accumulation of tau and amyloid-{beta} are two pathologic hallmarks of Alzheimers disease (AD). Here, we conducted an epigenome-wide association study using the H3K9 acetylation (H3K9Ac) mark in 669 aged human prefrontal cortices: in contrast to amyloid-{beta}, tau protein burden had a broad effect on the epigenome, affecting 5,590 out of 26,384 H3K9Ac domains. Tau-related alterations aggregated in large genomic segments reflecting spatial chromatin organization, and the magnitude of these effects correlated with the segments nuclear lamina association. We confirmed the functional relevance of these chromatin changes by demonstrating (1) consistent transcriptional changes in three independent datasets and (2) similar findings in two AD mouse models. Finally, we found that tau overexpression in iPSC-derived neurons disrupted chromatin organization and that these effects could be blocked by a small molecule predicted to reverse the tau effect. Thus, we report large-scale tau-driven chromatin rearrangements in the aging human brain that may be reversible with HSP90 inhibitors.

neuroscience↗