Biology subjects

Dooves, S.

Publications and source records attributed to Dooves, S..

3 recordsLinked to original sources

bioRxiv2026

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↗

bioRxiv2022

Cortical interneuron development is affected in leukodystrophy 4H

4H leukodystrophy is a rare genetic disorder classically characterized by hypomyelination, hypodontia and hypogonadotropic hypogonadism. With the discovery that 4H is caused by mutations that affect RNA polymerase III, mainly involved in the transcription of small non-coding RNAs, also patients with atypical presentations with mainly a neuronal phenotype were identified. Pathomechanisms of 4H brain abnormalities are still unknown and research is hampered by a lack of preclinical models. We aimed to identify cells and pathways that are affected by 4H mutations using induced pluripotent stem cell models. RNA sequencing analysis on induced pluripotent stem cell-derived cerebellar cells revealed several differentially expressed genes between 4H patients and control samples, including reduced ARX expression. As ARX is involved in early brain and interneuron development, we studied and confirmed interneuron changes in primary tissue of 4H patients. Subsequently, we studied interneuron changes in more depth and analyzed induced pluripotent stem cell-derived cortical neuron cultures for changes in neuronal morphology, synaptic balance, network activity and myelination. We showed a decreased percentage of GABAergic synapses in 4H, which correlated to increased neuronal network activity. Treatment of cultures with GABA antagonists led to a significant increase in neuronal network activity in control cells but not in 4H cells, also pointing to lack of inhibitory activity in 4H. Myelination and oligodendrocyte maturation in cultures with 4H neurons was normal, and treatment with sonic hedgehog agonist SAG did not improve 4H related neuronal phenotypes. qPCR analysis revealed increased expression of parvalbumin interneuron marker ERBB4, suggesting that the development rather than generation of interneurons may be affected in 4H. Together, these results indicate that interneurons are involved, possibly parvalbumin interneurons, in disease mechanisms of 4H leukodystrophy.

neuroscience↗

bioRxiv2019

Human and mouse iPSC-derived astrocyte subtypes reveal vulnerability in Vanishing White Matter

Astrocytes gained attention as important players in neurological disease, including a number of leukodystrophies. Several studies explored the generation of induced pluripotent stem cell-derived astrocytes for drug screening and regenerative studies. Developing robust models of patient induced pluripotent stem cells is challenged by high variability due to diverse genetic backgrounds and long-term culture procedures. While human models are of special interest, mouse-based models have the advantage that for them these issues are less pronounced. Here we present astrocyte differentiation protocols for both human and mouse induced pluripotent stem cells to specifically induce grey and white matter astrocytes. Both subtypes expressed astrocyte-associated markers, had typical astrocyte morphologies, and gave a reactive response to stress. Importantly, the grey and white matter-like astrocytes differed in size, complexity of processes, and expression profile, conform primary grey and white matter astrocytes. The newly presented mouse and human stem cell-based models for the leukodystrophy Vanishing White Matter replicated earlier findings, such as increased proliferation, decreased OPC maturation and modulation by hyaluronidase. We studied intrinsic astrocyte subtype vulnerability in Vanishing White Matter in both human and mouse cells. Oligodendrocyte maturation was specifically inhibited in cultures with Vanishing White Matter white matter-like astrocytes. By performing RNA sequencing, we found more differentially regulated genes in the white than in the grey matter-like astrocytes. Human and mouse astrocytes showed the same affected pathways, although human white matter-like astrocytes presented human-specific disease mechanisms involved in Vanishing White Matter. Using both human and mouse induced pluripotent stem cells, our study presents protocols to generate white and grey matter-like astrocytes, and shows astrocyte subtype-specific defects in Vanishing White Matter. While mouse induced pluripotent stem cell-based cultures may be less suitable to mimic human astrocyte subtype- or patient-specific changes, they might more robustly represent disease mutation-related cellular phenotypes as the cells are derived from inbred mice and the protocols are faster. The presented models give new tools to generate astrocyte subtypes for in vitro disease modeling and in vivo regenerative applications.

neuroscience↗