Project description:Microglia play vital roles in the emergence and preservation of a healthy brain microenvironment with their impaired functions highlighted in neurodevelopmental and neurodegenerative disorders. However, investigating the microglia function in health and disease states has been challenging due to the lack of easily accessible human models. Here, we develop a method to generate functional microglia inside human cortical organoids (hCOs) from human embryonic stem cells (hESCs) and apply this system to dissect the role of microglia under inflammation induced by amyloid- (A). The overexpression of the myeloid-specific transcription factor PU.1 generated microglia-like cells in hCOs, producing mhCOs (microglia-containing hCOs) and engrafted in the mouse brain. Single-cell transcriptomics reveals that mhCOs acquire a microglia cell cluster with an intact complement/chemokine system. Functionally, microglia in mhCOs protect parenchyma from cellular and molecular damage caused by A. A-induced expression of genes associated with apoptosis, ferroptosis, and Alzheimer’s disease (AD) stage III genes was attenuated in mhCOs. Finally, we determined the function of AD-associated genes highly expressed in microglia in response to A by using pooled CRISPRi coupled with single-cell RNA sequencing in mhCOs. Together, mhCOs represent an innovative platform to investigate neurodegenerative disorders and serve to develop therapeutics in the future.
Project description:Microglia play vital roles in the emergence and preservation of a healthy brain microenvironment with their impaired functions highlighted in neurodevelopmental and neurodegenerative disorders. However, investigating the microglia function in health and disease states has been challenging due to the lack of easily accessible human models. Here, we develop a method to generate functional microglia inside human cortical organoids (hCOs) from human embryonic stem cells (hESCs) and apply this system to dissect the role of microglia under inflammation induced by amyloid- (A). The overexpression of the myeloid-specific transcription factor PU.1 generated microglia-like cells in hCOs, producing mhCOs (microglia-containing hCOs) and engrafted in the mouse brain. Single-cell transcriptomics reveals that mhCOs acquire a microglia cell cluster with an intact complement/chemokine system. Functionally, microglia in mhCOs protect parenchyma from cellular and molecular damage caused by A. A-induced expression of genes associated with apoptosis, ferroptosis, and Alzheimer’s disease (AD) stage III genes was attenuated in mhCOs. Finally, we determined the function of AD-associated genes highly expressed in microglia in response to A by using pooled CRISPRi coupled with single-cell RNA sequencing in mhCOs. Together, mhCOs represent an innovative platform to investigate neurodegenerative disorders and serve to develop therapeutics in the future.
Project description:Glioblastoma (GBM) remains one of the most aggressive and lethal brain tumors, with conventional treatment approaches yielding only modest survival improvements. Although chimeric antigen receptor (CAR) T cell therapy has revolutionized the treatment of hematologic malignancies, its clinical benefits in GBM have been limited. To address this challenge, we developed a novel therapeutic strategy employing CAR-engineered microglia (MG). Utilizing human cortical organoids incorporating microglia (mhCOs), we isolated endogenous MG and genetically modified them to express a CAR targeting EGFRvIII, a predominant de novo mutation frequently observed in GBM. To further characterize the engineered microglia and elucidate their transcriptional landscape, four distinct mhCO-derived samples were analyzed via single-cell RNA sequencing (scRNAseq). This dataset provides comprehensive insights into the cellular heterogeneity, CAR expression profiles, and potential immunomodulatory functions of the modified microglia, thereby underpinning their therapeutic promise in targeting GBM.
Project description:To investigate the influence of transcription factor knockouts in cell fate decision-making, we performed a CROP-seq screen of 20 transcription factors in brain organoids.
Project description:<p>Lipids are critical for the structure, signaling, and metabolism of the central nervous system (CNS), yet their roles during human brain development remain underexplored due to limited tissue availability. X-linked adrenoleukodystrophy (ALD), a peroxisomal disorder caused by ABCD1 mutations, disrupts very long-chain fatty acid (VLCFA) degradation, leading to axonal degeneration and demyelination. To investigate lipid dynamics in CNS development and ALD pathogenesis, we generated human induced pluripotent stem cell (hiPSC)-derived cortical and spinal cord organoids and performed lipidomics over 200 days. Lipidomic analysis revealed a dynamic lipidome, with changes in lipid abundance, saturation, and chain length reflecting neurodevelopment. ALD hiPSC-derived organoids exhibited significant lipid alterations over time, including elevated VLCFA levels and reductions in brain-relevant lipids, such as sulfatides and gangliosides, in cortical organoids. These findings provide a foundational resource for studying lipid dynamics in CNS development and emphasize the value of organoids for understanding ALD and other CNS diseases.</p>
Project description:Isolation of glia from Alzheimer's mice reveals inflammation and dysfunction. Reactive astrocytes and microglia are associated with amyloid plaques in Alzheimer's disease (AD). Yet, not much is known about the molecular alterations underlying this reactive phenotype. To get an insight into the molecular changes underlying AD induced astrocyte and microglia reactivity, we performed a transcriptional analysis on acutely isolated astrocytes and microglia from the cortex of aged controls and APPswe/PS1dE9 AD mice. As expected, both cell types acquired a proinflammatory phenotype, which confirms the validity of our approach. Interestingly, we observed that the immune alteration in astrocytes was relatively more pronounced than in microglia. Concurrently, our data reveal that astrocytes display a reduced expression of neuronal support genes and genes involved in neuronal communication. The microglia showed a reduced expression of phagocytosis and/or endocytosis genes. Co-expression analysis of a human AD expression data set and the astrocyte and microglia data sets revealed that the inflammatory changes in astrocytes were remarkably comparable in mouse and human AD, whereas the microglia changes showed less similarity. Based on these findings we argue that chronically proinflammatory astrocyte and microglia phenotypes, showing a reduction of genes involved in neuronal support and neuronal signaling, are likely to contribute to the neuronal dysfunction and cognitive decline in AD. 2 cell types from 2 conditions: cortical microglia and cortical astrocytes from 15-18 month old APPswe/PS1dE9 mice compared to wildtype littermates. Biological replicates: microglia from APPswe/PS1dE9, N=7, microglia from WT, N=7, astrocytes from APPswe/PS1dE9, N=4, microglia from WT, N=4