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Boreland, A. J.

Publications and source records attributed to Boreland, A. J..

4 recordsLinked to original sources

Identification of alcohol use disorder-associated and ethanol-responsive proteins and candidate biomarkers using human cortical organoids

Genome-wide association studies of alcohol use disorder (AUD) have identified >100 loci, yet the functional impact and the downstream molecular mechanisms are not well understood. As functional effectors of genes, proteins provide direct insight into disease mechanisms. However, most proteomic alterations in postmortem human brains of AUD likely reflect a combination of inherited susceptibility (AUD-associated), the consequences of alcohol exposure (ethanol-responsive), other environmental and lifestyle factors, as well as sample preparation. Here, we profiled the proteome of human microglia-containing cortical organoids derived from human induced pluripotent stem cells from individuals with AUD (n=11) and without (n=5), paired with or without intermittent ethanol exposure. To maximize statistical power, donors were selected based on high or low genetic liability for AUD as measured by polygenic scores. Among 8,952 proteins that passed quality control, 1,038 were AUD-associated and 718 were ethanol-responsive. AUD-associated proteins were enriched for neuronal signaling, immune, mitochondrial, and extracellular matrix pathways, whereas ethanol-responsive proteins were enriched for RNA processing, ribosome biogenesis, protein translation, vesicle trafficking, and membrane transport pathways. Twenty ethanol-responsive proteins were replicated in a postmortem human prefrontal cortex proteomic dataset. Using UK Biobank plasma proteomics data, we identified 26 candidate AUD-associated biomarkers and 9 candidate ethanol-responsive biomarkers. We also found that major proteomic variation was significantly correlated with AUD polygenic scores. Together, these findings reveal distinct proteomic signatures of inherited susceptibility to AUD and ethanol exposure, providing new insights into mechanisms underlying AUD and identifying candidate circulating biomarkers for further investigation.

cell biology↗

Ethanol induces neuroimmune dysregulation and soluble TREM2 generation in a human iPSC neuron, astrocyte, microglia triculture model

Alcohol use disorders (AUDs) affect substantial populations worldwide and increase the risk of developing cognitive impairments and alcohol-associated dementia. While chronic inflammatory signaling likely plays an important role in alcohol-associated neurological sequalae, the precise mechanisms underlying alcohol-associated neuropathology remain enigmatic. We hypothesize that alcohol leads to neuroimmune dysregulation among neurons, astrocytes, and microglia; and is perpetuated by innate immune signaling pathways involving cell-cell signaling. To investigate how alcohol dysregulates neuroimmune interactions in a human context, we constructed a triculture model comprising neurons, astrocytes, and microglia derived from human induced pluripotent stem cells. After exposure to ethanol, we observed significant differential gene expression relating to innate immune pathways, inflammation, and microglial activation. Microglial activation was confirmed with morphological analysis and expression of CD68, a lysosomal-associated membrane protein and marker for phagocytic microglial activation. A striking finding in our study was the elevation of TREM2 expression and, specifically, TREM2 alternative splice variants that are predicted to give rise to soluble TREM2. TREM2 has been reported to be a risk factor for Alzheimers disease. These results suggest that ethanol exposure in the brain may lead to increased microglial activation and production of soluble isoform named TREM2219 through alternate splicing. Deciphering the molecular and cellular mechanisms underpinning ethanol-related neuroimmune dysregulation within a human context promises to shed light on the etiology of AUD-related disorders, potentially contributing to the development of effective therapeutic strategies. HighlightsO_LIWe prepared a "triculture" of human iPSC-derived neurons, astrocytes and microglia C_LIO_LIEthanol treatment produces substantial changes in gene expression with prominent effects on neuroimmune signaling C_LIO_LISeveral microglia-specific genes are induced by ethanol in tricultures but not in cultures of microglia alone C_LIO_LITREM2 expression is increased following ethanol treatment and results indicate a differential splicing of isoforms, encoding a soluble form of TREM2 C_LI

neuroscience↗

Dysregulated neuroimmune interactions and sustained type I interferon signaling after human immunodeficiency virus type 1 infection of human iPSC derived microglia and cerebral organoids

Human immunodeficiency virus type-1 (HIV-1) associated neurocognitive disorder (HAND) affects up to half of HIV-1 positive patients with long term neurological consequences, including dementia. There are no effective therapeutics for HAND because the pathophysiology of HIV-1 induced glial and neuronal functional deficits in humans remains enigmatic. To bridge this knowledge gap, we established a model simulating HIV-1 infection in the central nervous system using human induced pluripotent stem cell (iPSC) derived microglia combined with sliced neocortical organoids. Upon incubation with two replication-competent macrophage-tropic HIV-1 strains (JRFL and YU2), we observed that microglia not only became productively infected but also exhibited inflammatory activation. RNA sequencing revealed a significant and sustained activation of type I interferon signaling pathways. Incorporating microglia into sliced neocortical organoids extended the effects of aberrant type I interferon signaling in a human neural context. Collectively, our results illuminate the role of persistent type I interferon signaling in HIV-1 infected microglial in a human neural model, suggesting its potential significance in the pathogenesis of HAND. Highlights of the workO_LIHIV-1 productively infects iPSC-derived microglia and triggers inflammatory activation. C_LIO_LIHIV-1 infection of microglia results in sustained type I interferon signaling. C_LIO_LIMicroglia infected by HIV-1 incorporate into sliced neocortical organoids with persistent type I interferon signaling and disease risk gene expression. C_LI

neuroscience↗

Developing Human Pluripotent Stem Cell-Based Cerebral Organoids with a Controllable Microglia Ratio for Modeling Brain Development and Pathology

Microglia, as brain-resident macrophages, play critical roles in brain development, homeostasis, and disease. Microglia in animal models cannot accurately model the properties of human microglia due to notable transcriptomic and functional differences between human and other animal microglia. Efficient generation of microglia from human pluripotent stem cells (hPSCs) provides unprecedented opportunities to study the function and behavior of human microglia. Particularly, incorporating hPSCs-derived microglia into brain organoids facilitates their development in a 3-dimensional context, mimicking the brain environment. However, an optimized method that integrates an appropriate amount of microglia into brain organoids at a proper time point, resembling in vivo brain development, is still lacking. Here, we report the development of a new brain region-specific, microglia-containing organoid model by co-culturing hPSCs-derived primitive neural progenitor cells (pNPCs) and primitive macrophage progenitors (PMPs). In these organoids, hPSCs-derived pNPCs and PMPs interact with each other and develop into functional neurons, astroglia, and microglia, respectively. Importantly, the numbers of human microglia in the organoids can be controlled, resulting in a cell type ratio similar to that seen in the human brain. Using super-resolution microscopy, we demonstrate that these human microglia are able to phagocytize neural progenitor cells (NPCs) and apoptotic cells, as well as to prune synapses at different developmental stages of the organoids. Furthermore, these human microglia respond to Zika virus infection of the organoids, as indicated by amoeboid-like morphology, increased expression of gene transcripts encoding inflammatory cytokines, and excessive pruning of synaptic materials. Together, our findings establish a new microglia-containing brain organoid model that will serve to study human microglial function in a variety of neurological disorders.

neuroscience↗