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Brüstle, O.

Publications and source records attributed to Brüstle, O..

7 recordsLinked to original sources

Glia-enriched human brain organoids for studying developmental alterations in leukodystrophies

Leukodystrophies (LKD) comprise mostly inherited white matter disorders whose developmental origins and underlying pathomechanisms remain poorly understood. Progress has been limited by restricted access to human primary tissue and by the inability of animal models to fully recapitulate human neurodevelopment. Human induced pluripotent stem cell-derived neural organoids provide an alternative approach, but most culture systems do not capture later, glia-rich developmental stages relevant to these diseases. Recent studies have shown that appropriate patterning cues and long in vitro differentiation can generate neuroglial spheroids comprising multiple neuronal and macroglial populations, including mature oligodendrocytes. Here, we adapt the human oligodendrocyte (hOLS) spheroid platform to establish 3D models of globoid cell leukodystrophy (GLD), 4H leukodystrophy (4H), and Canavan disease (CD). Here we adapt this organoid platform to establish 3D models of globoid cell leukodystrophy (GLD), 4H leukodystrophy (4H), and Canavan disease (CD). Across 150 days of differentiation, hOLS from different genetic backgrounds displayed largely comparable growth kinetics and developmental trajectories, comprising multiple neuroglial cell types with predominantly ventral forebrain and midbrain identities. Comparison of LKD and control hOLS revealed both shared and disease-specific alterations, with prominent transcriptional changes in lysosomal, metabolic, and stress-response pathways. Lineage-resolved pathway analysis further identified signatures across individual LKDs, including mitochondrial and translational stress in GLD glial lineages, disruption of RNA metabolic and cell-cycle pathways in 4H, and prominent astrocyte-centered metabolic dysregulation in CD. Our results establish hOLS as a human 3D in vitro platform for studying the impact of LKD-associated genetic variants on early neural development and for dissecting lineage-specific disease vulnerability.

neuroscience↗

In vitro programming and pseudounipolarization of human iPSC-derived sensory neurons

Ectopic expression of NGN1, BRN3A and ISLET1 (NBI) from a safe harbor locus in induced pluripotent stem cells (iPSCs) yielded robust differentiation into functional sensory neurons (iNBI-SNs) within seven days. Single nucleus transcriptomics identified peripheral sensory neuron profiles of nociceptors and mechanoreceptors. Electrophysiological studies showed that more than 98 % of iNBI-SNs display TTX-resistant sodium currents and that they establish functional connections to excitatory CNS neurons. iNBI-SNs derived from patients with inherited erythromelalgia, a pain disorder associated with gain-of-function mutations in the Nav1.7 sodium channel showed pathologically increased firing rates which could be partially rescued with a Nav1.7 inhibitor. Notably, iNBI-SNs acquire a characteristic pseudounipolar morphology upon co-culture with embryonic rodent DRG cells. Taken together, NBI-based forward programming of iPSCs represents a robust approach for the generation of human sensory neurons suitable for developmental, disease- and therapy-related studies.

neuroscience↗

Mapping human microglial morphological diversity via handcrafted and deep learning-derived image features

Microglia play critical roles in brain health and disease by adopting a spectrum of dynamic activation states. However, capturing this continuous heterogeneity in a scalable way remains a major challenge. To address this, we developed an imaging and data analysis framework to map the activation landscape of human iPSC-derived microglia (iMG) at single-cell resolution. We combined high-content imaging using two complementary strategies: a hypothesis-driven immunofluorescence (IF) panel targeting key activation markers (NF-{kappa}B, ASC, CD45) and a discovery-oriented, pan-morphological Cell Painting (CP) assay. Diverse phenotypes were captured through handcrafted and representation learning-based features. To classify cells, we applied Gaussian Mixture Models (GMMs) to image-derived features, enabling soft probabilistic assignments that capture transitional states between phenotypes. Compared to graph-based methods like the Leiden algorithm, GMMs provided comparable classification performance while offering a more nuanced and biologically interpretable view of microglial heterogeneity. We demonstrate that deep learning features from the targeted IF panel are most powerful, achieving high classification accuracy and strong correlation with biological states such as functional NLRP3 inflammasome activation. Our model system provides a robust and scalable platform for quantifying microglial heterogeneity, offering a new tool to identify novel disease-associated states and compounds that precisely modulate microglial phenotypes for therapeutic discovery.

neuroscience↗

Blockade of rheumatoid arthritis synovial fluid-induced sensory neuron activation by JAK inhibitors

ObjectiveClinical studies suggest that compared to anti-TNF treatment, JAK inhibitors (JAKi) are superior in reducing pain in rheumatoid arthritis (RA). The underlying mechanisms for this observation are still unknown. Sensory neurons transmit noxious signals from inflamed joints to the central nervous system, where a pain percept is generated. We investigated whether JAKi exert direct effects on sensory neurons. MethodsIn-house and public RNA sequencing datasets of sensory neurons were analysed for relevant JAK/STAT and cytokine-receptor gene expression. Human induced pluripotent stem cell (IPSC)-derived sensory neurons were stimulated with serum and synovial fluid (SF) from individuals with RA, or with selected cytokines that were found in RA SF by Luminex. Phosphorylation of STAT3 (pSTAT3) was assessed by Western blot. Sensory neuron activation was examined by recording neuronal firing using multi-electrode array and measuring expression levels of pain-relevant genes with STAT3-binding sites. ResultsCell-free RA synovial fluid induced pSTAT3 in IPSC-derived sensory neurons, an effect which was completely blocked by the JAKi tofacitinib. Compared to paired serum, RA SF was enriched for the JAK/STAT cytokines IL-6, IL-11, LIF, IFN-alpha and IFN-beta, with their requisite receptors present on sensory neurons. Stimulation of IPSC- derived sensory neurons with these recombinant cytokines recapitulated pSTAT3 induction in these cells. Furthermore, IL-6+sIL-6R or LIF upregulated expression of pain-relevant genes which was blocked by tofacitinib. Finally, we provided evidence that LIF can induce neuronal sensitisation. ConclusionOur data indicate that JAKi can act directly on sensory neurons, providing a potential mechanistic explanation for their suggested superior analgesic properties.

immunology↗

Machine learning-aided multidimensional phenotyping of Parkinson's disease patient stem cell-derived midbrain dopaminergic neurons

Combining multiple Parkinsons disease (PD) relevant cellular phenotypes might increase the accuracy of midbrain dopaminergic (mDA) in vitro models. We differentiated patient-derived induced pluripotent stem cells (iPSCs) with a LRRK2 G2019S mutation, isogenic control and genetically unrelated iPSCs into mDA neurons. Using automated fluorescence microscopy in 384-well plate format, we identified elevated levels of -synuclein and Serine 129 phosphorylation (pS129), reduced dendritic complexity, and mitochondrial dysfunction. Next, we measured additional image-based phenotypes and used machine learning (ML) to accurately classify mDA neurons according to their genotype. Additionally, we show that chemical compound treatments, targeting LRRK2 kinase activity or -synuclein levels, are detectable when using ML classification based on multiple image-based phenotypes. We validated our approach using a second isogenic patient derived SNCA gene triplication mDA neuronal model. This phenotyping and classification strategy improves the exploitability of mDA neurons for disease modelling and the identification of novel PD drug targets.

neuroscience↗

Anthrax Toxin as a Molecular Platform to Target Nociceptive Neurons and Modulate Pain

Bacterial toxins are able to act on neurons to modulate signaling and function. Here, we find that nociceptive sensory neurons that mediate pain are enriched in the receptor for anthrax toxins, ANTXR2. Anthrax Edema Toxin (ET) induced cAMP and PKA signaling in Nav1.8+ nociceptive neurons and modulated pain in vivo. Peripherally administered ET mediated mechanical allodynia in naive mice and during B. anthracis infection. Intrathecally administered ET produced analgesic effects, potently blocking pain-like behaviors in multiple mouse models of inflammatory and chronic neuropathic pain. Nociceptor-specific ablation of ANTXR2 attenuated ET-induced signaling and analgesia. Modified anthrax toxin successfully delivered exogenous protein cargo into nociceptive neurons, illustrating utility of the anthrax toxin system as a molecular platform to target pain. ET further induced signaling in human iPSC-derived sensory neurons. Our findings highlight novel interactions between a bacterial toxin and nociceptors that may be utilized for developing new pain therapeutics. SUMMARYANTXR2 expression on nociceptive neurons allows selective targeting and modulation of pain by native and engineered anthrax toxins.

neuroscience↗

Formation of the substantia nigra requires Reelin-mediated fast, laterally-directed migration of dopaminergic neurons

Midbrain dopaminergic (mDA) neurons migrate to form the laterally-located substantia nigra pars compacta (SN) and medially-located ventral tegmental area (VTA), but little is known about the underlying cellular and molecular processes. Reelin signaling regulates tangential migration of SN-mDA neurons, but whether Reelin acts directly on SN-mDA neurons and how it affects their cellular morphology and migratory behavior has not been explored. Here we visualize the dynamic cell morphologies of tangentially migrating SN-mDA neurons with 3D-time-lapse imaging and identify two distinct migration modes. Slow migration is the default mode in SN-mDA neurons, while fast, laterally-directed migration occurs infrequently and is strongly associated with bipolar cell morphology. By speci1cally inactivating Reelin signaling in mDA neurons we demonstrate its direct role in SN-mDA tangential migration. We show that Reelin signaling promotes laterally-biased movements in mDA neurons during their slow migration mode, stabilizes leading process morphology and increases the probability of fast, laterally-directed migration.

developmental biology↗