Li Wang

All Publications

• The new frontier in understanding human and mammalian brain development NATURE Nowakowski, T. J., Nano, P. R., Matho, K. S., Chen, X., Corrigan, E. K., Ding, W., Gao, Y., Heffel, M., Jayakumar, J., Kaplan, H. S., Kronman, F. N., Kovner, R., Mannens, C. C. A., Song, M., Steyert, M. R., Venkatesan, S., Wallace, J. L., Wang, L., Werner, J. M., Zhang, D., Yuan, G., Zuo, G., Ament, S. A., Colantuoni, C., Dulac, C., Fan, R., Gillis, J., Kriegstein, A. R., Krienen, F. M., Kim, Y., Linnarsson, S., Mitra, P. P., Pollen, A. A., Sestan, N., Tward, D. J., Van Velthoven, C. T. J., Yao, Z., Bhaduri, A., Zeng, H. 2025; 647 (8088): 51-59

  Abstract

  Neurodevelopmental disorders that cause cognitive, behavioural or motor impairments affect around 15% of children and adolescents worldwide1, with diagnoses of profound autism and attention deficit hyperactivity disorder increasing in the USA and contributing to a major economic burden2,3. Yet the origins and mechanisms of these conditions remain poorly understood, limiting progress in therapies. Comprehensive cell atlases of the developing human brain, alongside those of model organisms such as mice and non-human primates, are now providing high-resolution measures of gene expression, cell-type abundance and spatial distribution. In this Perspective, we highlight recent studies that have identified novel developmental cell populations, revealed conserved and divergent patterns of cell genesis, migration and maturation across species, and begun testing hypotheses that link them to processes ranging from transcriptional control of cell fate specification to the emergence of complex behaviours. We present remaining conceptual and technical challenges and provide an outlook on how further studies of human and mammalian brain development can empower a deeper understanding of neurodevelopmental and neuropsychiatric disorders. Future efforts expanding to additional developmental stages, including adolescence, as well as whole-brain, multimodal and cross-species integration, will yield new insights into how development shapes the brain. These atlases promise to serve as essential references for unravelling mechanisms of brain function and disease vulnerability, and for advancing precision medicine.

  View details for DOI 10.1038/s41586-025-09652-1

  View details for Web of Science ID 001609450500001

  View details for PubMedID 41193845

  View details for PubMedCentralID 10129867

• Spatial dynamics of brain development and neuroinflammation NATURE Zhang, D., Rubio Rodriguez-Kirby, L. A., Lin, Y., Wang, W., Song, M., Wang, L., Wang, L., Kanatani, S., Jimenez-Beristain, T., Dang, Y., Zhong, M., Kukanja, P., Bao, S., Wang, S., Chen, X., Gao, F., Wang, D., Xu, H., Ma, C., Lou, X., Liu, Y., Chen, J., Sestan, N., Uhlen, P., Kriegstein, A., Zhao, H., Castelo-Branco, G., Fan, R. 2025; 647 (8088): 213-227

  Abstract

  The ability to spatially map multiple layers of omics information across developmental timepoints enables exploration of the mechanisms driving brain development1, differentiation, arealization and disease-related alterations. Here we used spatial tri-omic sequencing, including spatial ATAC-RNA-protein sequencing and spatial CUT&Tag-RNA-protein sequencing, alongside multiplexed immunofluorescence imaging (co-detection by indexinng (CODEX)) to map dynamic spatial remodelling during brain development and neuroinflammation. We generated a spatiotemporal tri-omic atlas of the mouse brain from postnatal day 0 (P0) to P21 and compared corresponding regions with the human developing brain. In the cortex, we identified temporal persistence and spatial spreading of chromatin accessibility for a subset of layer-defining transcription factors. In the corpus callosum, we observed dynamic chromatin priming of myelin genes across subregions and identified a role for layer-specific projection neurons in coordinating axonogenesis and myelination. In a lysolecithin neuroinflammation mouse model, we detected molecular programs shared with developmental processes. Microglia exhibited both conserved and distinct programs for inflammation and resolution, with transient activation observed not only at the lesion core but also at distal locations. Overall, this study reveals common and differential mechanisms underlying brain development and neuroinflammation, providing a rich resource for investigating brain development, function and disease.

  View details for DOI 10.1038/s41586-025-09663-y

  View details for Web of Science ID 001609450500013

  View details for PubMedID 41193846

  View details for PubMedCentralID PMC12589135

• Single-cell analysis of dup15q syndrome reveals developmental and postnatal molecular changes in autism. Nature communications Perez, Y., Velmeshev, D., Wang, L., White, M. L., Siebert, C., Baltazar, J., Zuo, G., Moriano, J. A., Chen, S., Steffen, D. M., Dutton, N. G., Wang, S., Wick, B., Haeussler, M., Chamberlain, S., Alvarez-Buylla, A., Kriegstein, A. 2025; 16 (1): 6177

  Abstract

  Duplication 15q (dup15q) syndrome is a leading genetic cause of autism spectrum disorder, offering a key model for studying autism-related mechanisms. Using single-cell and single-nucleus RNA sequencing of cortical organoids from dup15q patient-derived iPSCs and post-mortem brain samples, we identify increased glycolysis, disrupted layer-specific marker expression, and aberrant morphology in deep-layer neurons during fetal-stage organoid development. In adolescent-adult postmortem brains, upper-layer neurons exhibit heightened transcriptional burden related to synaptic signaling, a pattern shared with idiopathic autism. Using spatial transcriptomics, we confirm these cell-type-specific disruptions in brain tissue. By gene co-expression network analysis, we reveal disease-associated modules that are well preserved between postmortem and organoid samples, suggesting metabolic dysregulation that may lead to altered neuron projection, synaptic dysfunction, and neuron hyperexcitability in dup15q syndrome.

  View details for DOI 10.1038/s41467-025-61184-4

  View details for PubMedID 40615364

  View details for PubMedCentralID PMC12227528

• Molecular and cellular dynamics of the developing human neocortex. Nature Wang, L., Wang, C., Moriano, J. A., Chen, S., Zuo, G., Cebrián-Silla, A., Zhang, S., Mukhtar, T., Wang, S., Song, M., de Oliveira, L. G., Bi, Q., Augustin, J. J., Ge, X., Paredes, M. F., Huang, E. J., Alvarez-Buylla, A., Duan, X., Li, J., Kriegstein, A. R. 2025

  Abstract

  The development of the human neocortex is highly dynamic, involving complex cellular trajectories controlled by gene regulation1. Here we collected paired single-nucleus chromatin accessibility and transcriptome data from 38 human neocortical samples encompassing both the prefrontal cortex and the primary visual cortex. These samples span five main developmental stages, ranging from the first trimester to adolescence. In parallel, we performed spatial transcriptomic analysis on a subset of the samples to illustrate spatial organization and intercellular communication. This atlas enables us to catalogue cell-type-specific, age-specific and area-specific gene regulatory networks underlying neural differentiation. Moreover, combining single-cell profiling, progenitor purification and lineage-tracing experiments, we have untangled the complex lineage relationships among progenitor subtypes during the neurogenesis-to-gliogenesis transition. We identified a tripotential intermediate progenitor subtype-tripotential intermediate progenitor cells (Tri-IPCs)-that is responsible for the local production of GABAergic neurons, oligodendrocyte precursor cells and astrocytes. Notably, most glioblastoma cells resemble Tri-IPCs at the transcriptomic level, suggesting that cancer cells hijack developmental processes to enhance growth and heterogeneity. Furthermore, by integrating our atlas data with large-scale genome-wide association study data, we created a disease-risk map highlighting enriched risk associated with autism spectrum disorder in second-trimester intratelencephalic neurons. Our study sheds light on the molecular and cellular dynamics of the developing human neocortex.

  View details for DOI 10.1038/s41586-024-08351-7

  View details for PubMedID 39779846

  View details for PubMedCentralID 6704245

• A conserved molecular logic for neurogenesis to gliogenesis switch in the cerebral cortex. Proceedings of the National Academy of Sciences of the United States of America Liang, X. G., Hoang, K., Meyerink, B. L., Kc, P., Paraiso, K., Wang, L., Jones, I. R., Zhang, Y., Katzman, S., Finn, T. S., Tsyporin, J., Qu, F., Chen, Z., Visel, A., Kriegstein, A., Shen, Y., Pilaz, L. J., Chen, B. 2024; 121 (20): e2321711121

  Abstract

  During development, neural stem cells in the cerebral cortex, also known as radial glial cells (RGCs), generate excitatory neurons, followed by production of cortical macroglia and inhibitory neurons that migrate to the olfactory bulb (OB). Understanding the mechanisms for this lineage switch is fundamental for unraveling how proper numbers of diverse neuronal and glial cell types are controlled. We and others recently showed that Sonic Hedgehog (Shh) signaling promotes the cortical RGC lineage switch to generate cortical oligodendrocytes and OB interneurons. During this process, cortical RGCs generate intermediate progenitor cells that express critical gliogenesis genes Ascl1, Egfr, and Olig2. The increased Ascl1 expression and appearance of Egfr+ and Olig2+ cortical progenitors are concurrent with the switch from excitatory neurogenesis to gliogenesis and OB interneuron neurogenesis in the cortex. While Shh signaling promotes Olig2 expression in the developing spinal cord, the exact mechanism for this transcriptional regulation is not known. Furthermore, the transcriptional regulation of Olig2 and Egfr has not been explored. Here, we show that in cortical progenitor cells, multiple regulatory programs, including Pax6 and Gli3, prevent precocious expression of Olig2, a gene essential for production of cortical oligodendrocytes and astrocytes. We identify multiple enhancers that control Olig2 expression in cortical progenitors and show that the mechanisms for regulating Olig2 expression are conserved between the mouse and human. Our study reveals evolutionarily conserved regulatory logic controlling the lineage switch of cortical neural stem cells.

  View details for DOI 10.1073/pnas.2321711121

  View details for PubMedID 38713624

  View details for PubMedCentralID PMC11098099

• Single-cell analysis of prenatal and postnatal human cortical development. Science (New York, N.Y.) Velmeshev, D., Perez, Y., Yan, Z., Valencia, J. E., Castaneda-Castellanos, D. R., Wang, L., Schirmer, L., Mayer, S., Wick, B., Wang, S., Nowakowski, T. J., Paredes, M., Huang, E. J., Kriegstein, A. R. 2023; 382 (6667): eadf0834

  Abstract

  We analyzed >700,000 single-nucleus RNA sequencing profiles from 106 donors during prenatal and postnatal developmental stages and identified lineage-specific programs that underlie the development of specific subtypes of excitatory cortical neurons, interneurons, glial cell types, and brain vasculature. By leveraging single-nucleus chromatin accessibility data, we delineated enhancer gene regulatory networks and transcription factors that control commitment of specific cortical lineages. By intersecting our results with genetic risk factors for human brain diseases, we identified the cortical cell types and lineages most vulnerable to genetic insults of different brain disorders, especially autism. We find that lineage-specific gene expression programs up-regulated in female cells are especially enriched for the genetic risk factors of autism. Our study captures the molecular progression of cortical lineages across human development.

  View details for DOI 10.1126/science.adf0834

  View details for PubMedID 37824647

  View details for PubMedCentralID PMC11005279

• LIF signaling regulates outer radial glial to interneuron fate during human cortical development. Cell stem cell Andrews, M. G., Siebert, C., Wang, L., White, M. L., Ross, J., Morales, R., Donnay, M., Bamfonga, G., Mukhtar, T., McKinney, A. A., Gemenes, K., Wang, S., Bi, Q., Crouch, E. E., Parikshak, N., Panagiotakos, G., Huang, E., Bhaduri, A., Kriegstein, A. R. 2023; 30 (10): 1382-1391.e5

  Abstract

  Radial glial (RG) development is essential for cerebral cortex growth and organization. In humans, the outer radial glia (oRG) subtype is expanded and gives rise to diverse neurons and glia. However, the mechanisms regulating oRG differentiation are unclear. oRG cells express leukemia-inhibitory factor (LIF) receptors during neurogenesis, and consistent with a role in stem cell self-renewal, LIF perturbation impacts oRG proliferation in cortical tissue and organoids. Surprisingly, LIF treatment also increases the production of inhibitory interneurons (INs) in cortical cultures. Comparative transcriptomic analysis identifies that the enhanced IN population resembles INs produced in the caudal ganglionic eminence. To evaluate whether INs could arise from oRGs, we isolated primary oRG cells and cultured them with LIF. We observed the production of INs from oRG cells and an increase in IN abundance following LIF treatment. Our observations suggest that LIF signaling regulates the capacity of oRG cells to generate INs.

  View details for DOI 10.1016/j.stem.2023.08.009

  View details for PubMedID 37673072

  View details for PubMedCentralID PMC10591955

• A cross-species proteomic map reveals neoteny of human synapse development. Nature Wang, L., Pang, K., Zhou, L., Cebrián-Silla, A., González-Granero, S., Wang, S., Bi, Q., White, M. L., Ho, B., Li, J., Li, T., Perez, Y., Huang, E. J., Winkler, E. A., Paredes, M. F., Kovner, R., Sestan, N., Pollen, A. A., Liu, P., Li, J., Piao, X., García-Verdugo, J. M., Alvarez-Buylla, A., Liu, Z., Kriegstein, A. R. 2023; 622 (7981): 112-119

  Abstract

  The molecular mechanisms and evolutionary changes accompanying synapse development are still poorly understood1,2. Here we generate a cross-species proteomic map of synapse development in the human, macaque and mouse neocortex. By tracking the changes of more than 1,000 postsynaptic density (PSD) proteins from midgestation to young adulthood, we find that PSD maturation in humans separates into three major phases that are dominated by distinct pathways. Cross-species comparisons reveal that human PSDs mature about two to three times slower than those of other species and contain higher levels of Rho guanine nucleotide exchange factors (RhoGEFs) in the perinatal period. Enhancement of RhoGEF signalling in human neurons delays morphological maturation of dendritic spines and functional maturation of synapses, potentially contributing to the neotenic traits of human brain development. In addition, PSD proteins can be divided into four modules that exert stage- and cell-type-specific functions, possibly explaining their differential associations with cognitive functions and diseases. Our proteomic map of synapse development provides a blueprint for studying the molecular basis and evolutionary changes of synapse maturation.

  View details for DOI 10.1038/s41586-023-06542-2

  View details for PubMedID 37704727

  View details for PubMedCentralID PMC10576238

• Editorial: Identifying genetics-based mechanisms and treatments for neurodevelopmental and psychiatric disorders through data integration. Frontiers in genetics Pang, K., Wang, L., Chang, S. 2023; 14: 1186489

  View details for DOI 10.3389/fgene.2023.1186489

  View details for PubMedID 37077543

  View details for PubMedCentralID PMC10106741

• Non-muscle myosins control the integrity of cortical radial glial endfeet. PLoS biology Wang, L., Kriegstein, A. R. 2023; 21 (2): e3002032

  Abstract

  Radial glial cells, the stem cells of the cerebral cortex, extend a long basal fiber that ends in basal endfeet. A new study in PLOS Biology found that non-muscle myosins control basal endfoot integrity to regulate interneuron organization.

  View details for DOI 10.1371/journal.pbio.3002032

  View details for PubMedID 36854254

  View details for PubMedCentralID PMC9974232

• Tropism of SARS-CoV-2 for human cortical astrocytes. Proceedings of the National Academy of Sciences of the United States of America Andrews, M. G., Mukhtar, T., Eze, U. C., Simoneau, C. R., Ross, J., Parikshak, N., Wang, S., Zhou, L., Koontz, M., Velmeshev, D., Siebert, C. V., Gemenes, K. M., Tabata, T., Perez, Y., Wang, L., Mostajo-Radji, M. A., de Majo, M., Donohue, K. C., Shin, D., Salma, J., Pollen, A. A., Nowakowski, T. J., Ullian, E., Kumar, G. R., Winkler, E. A., Crouch, E. E., Ott, M., Kriegstein, A. R. 2022; 119 (30): e2122236119

  Abstract

  The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) readily infects a variety of cell types impacting the function of vital organ systems, with particularly severe impact on respiratory function. Neurological symptoms, which range in severity, accompany as many as one-third of COVID-19 cases, indicating a potential vulnerability of neural cell types. To assess whether human cortical cells can be directly infected by SARS-CoV-2, we utilized stem-cell-derived cortical organoids as well as primary human cortical tissue, both from developmental and adult stages. We find significant and predominant infection in cortical astrocytes in both primary tissue and organoid cultures, with minimal infection of other cortical populations. Infected and bystander astrocytes have a corresponding increase in inflammatory gene expression, reactivity characteristics, increased cytokine and growth factor signaling, and cellular stress. Although human cortical cells, particularly astrocytes, have no observable ACE2 expression, we find high levels of coronavirus coreceptors in infected astrocytes, including CD147 and DPP4. Decreasing coreceptor abundance and activity reduces overall infection rate, and increasing expression is sufficient to promote infection. Thus, we find tropism of SARS-CoV-2 for human astrocytes resulting in inflammatory gliosis-type injury that is dependent on coronavirus coreceptors.

  View details for DOI 10.1073/pnas.2122236119

  View details for PubMedID 35858406

  View details for PubMedCentralID PMC9335272

• Phospholipid-flippase chaperone CDC50A is required for synapse maintenance by regulating phosphatidylserine exposure. The EMBO journal Li, T., Yu, D., Oak, H. C., Zhu, B., Wang, L., Jiang, X., Molday, R. S., Kriegstein, A., Piao, X. 2021; 40 (21): e107915

  Abstract

  Synaptic refinement is a critical physiological process that removes excess synapses to establish and maintain functional neuronal circuits. Recent studies have shown that focal exposure of phosphatidylserine (PS) on synapses acts as an "eat me" signal to mediate synaptic pruning. However, the molecular mechanism underlying PS externalization at synapses remains elusive. Here, we find that murine CDC50A, a chaperone of phospholipid flippases, localizes to synapses, and that its expression depends on neuronal activity. Cdc50a knockdown leads to phosphatidylserine exposure at synapses and subsequent erroneous synapse removal by microglia partly via the GPR56 pathway. Taken together, our data support that CDC50A safeguards synapse maintenance by regulating focal phosphatidylserine exposure at synapses.

  View details for DOI 10.15252/embj.2021107915

  View details for PubMedID 34585770

  View details for PubMedCentralID PMC8561630

• Mitochondria Control Cortical Cell Fate after Mitosis. Developmental cell Wang, L., Kriegstein, A. 2020; 55 (2): 120-122

  Abstract

  During brain development, the daughter cells of neural stem cells have to make a choice - either to become new stem cells or to differentiate into neurons. In a recent issue of Science, Iwata et al. (2020) show that these fate decisions can be determined after mitosis by mitochondrial remodeling.

  View details for DOI 10.1016/j.devcel.2020.09.028

  View details for PubMedID 33108754

• Origins and Proliferative States of Human Oligodendrocyte Precursor Cells. Cell Huang, W., Bhaduri, A., Velmeshev, D., Wang, S., Wang, L., Rottkamp, C. A., Alvarez-Buylla, A., Rowitch, D. H., Kriegstein, A. R. 2020; 182 (3): 594-608.e11

  Abstract

  Human cerebral cortex size and complexity has increased greatly during evolution. While increased progenitor diversity and enhanced proliferative potential play important roles in human neurogenesis and gray matter expansion, the mechanisms of human oligodendrogenesis and white matter expansion remain largely unknown. Here, we identify EGFR-expressing "Pre-OPCs" that originate from outer radial glial cells (oRGs) and undergo mitotic somal translocation (MST) during division. oRG-derived Pre-OPCs provide an additional source of human cortical oligodendrocyte precursor cells (OPCs) and define a lineage trajectory. We further show that human OPCs undergo consecutive symmetric divisions to exponentially increase the progenitor pool size. Additionally, we find that the OPC-enriched gene, PCDH15, mediates daughter cell repulsion and facilitates proliferation. These findings indicate properties of OPC derivation, proliferation, and dispersion important for human white matter expansion and myelination.

  View details for DOI 10.1016/j.cell.2020.06.027

  View details for PubMedID 32679030

  View details for PubMedCentralID PMC7415734

• Coexpression enrichment analysis at the single-cell level reveals convergent defects in neural progenitor cells and their cell-type transitions in neurodevelopmental disorders. Genome research Pang, K., Wang, L., Wang, W., Zhou, J., Cheng, C., Han, K., Zoghbi, H. Y., Liu, Z. 2020; 30 (6): 835-848

  Abstract

  A large number of genes have been implicated in neurodevelopmental disorders (NDDs), but their contributions to NDD pathology are difficult to decipher without understanding their diverse roles in different brain cell types. Here, we integrated NDD genetics with single-cell RNA sequencing data to assess coexpression enrichment patterns of various NDD gene sets. We identified midfetal cortical neural progenitor cell development-more specifically, the ventricular radial glia-to-intermediate progenitor cell transition at gestational week 10-as a key point of convergence in autism spectrum disorder (ASD) and epilepsy. Integrated Gene Ontology-based analysis further revealed that ASD genes activate neural differentiation and inhibit cell cycle during the transition, whereas epilepsy genes function as downstream effectors in the same processes, offering one possible explanation for the high comorbidity rate of the two disorders. This approach provides a framework for investigating the cell-type-specific pathophysiology of NDDs.

  View details for DOI 10.1101/gr.254987.119

  View details for PubMedID 32554779

  View details for PubMedCentralID PMC7370880

• Nr2f1 heterozygous knockout mice recapitulate neurological phenotypes of Bosch-Boonstra-Schaaf optic atrophy syndrome and show impaired hippocampal synaptic plasticity. Human molecular genetics Chen, C. A., Wang, W., Pedersen, S. E., Raman, A., Seymour, M. L., Ruiz, F. R., Xia, A., van der Heijden, M. E., Wang, L., Yin, J., Lopez, J., Rech, M. E., Lewis, R. A., Wu, S. M., Liu, Z., Pereira, F. A., Pautler, R. G., Zoghbi, H. Y., Schaaf, C. P. 2020; 29 (5): 705-715

  Abstract

  Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) has been identified as an autosomal-dominant disorder characterized by a complex neurological phenotype, with high prevalence of intellectual disability and optic nerve atrophy/hypoplasia. The syndrome is caused by loss-of-function mutations in NR2F1, which encodes a highly conserved nuclear receptor that serves as a transcriptional regulator. Previous investigations to understand the protein's role in neurodevelopment have mostly used mouse models with constitutive and tissue-specific homozygous knockout of Nr2f1. In order to represent the human disease more accurately, which is caused by heterozygous NR2F1 mutations, we investigated a heterozygous knockout mouse model and found that this model recapitulates some of the neurological phenotypes of BBSOAS, including altered learning/memory, hearing defects, neonatal hypotonia and decreased hippocampal volume. The mice showed altered fear memory, and further electrophysiological investigation in hippocampal slices revealed significantly reduced long-term potentiation and long-term depression. These results suggest that a deficit or alteration in hippocampal synaptic plasticity may contribute to the intellectual disability frequently seen in BBSOAS. RNA-sequencing (RNA-Seq) analysis revealed significant differential gene expression in the adult Nr2f1+/- hippocampus, including the up-regulation of multiple matrix metalloproteases, which are known to be critical for the development and the plasticity of the nervous system. Taken together, our studies highlight the important role of Nr2f1 in neurodevelopment. The discovery of impaired hippocampal synaptic plasticity in the heterozygous mouse model sheds light on the pathophysiology of altered memory and cognitive function in BBSOAS.

  View details for DOI 10.1093/hmg/ddz233

  View details for PubMedID 31600777

  View details for PubMedCentralID PMC7104670

• Neurexophilin4 is a selectively expressed α-neurexin ligand that modulates specific cerebellar synapses and motor functions. eLife Meng, X., McGraw, C. M., Wang, W., Jing, J., Yeh, S. Y., Wang, L., Lopez, J., Brown, A. M., Lin, T., Chen, W., Xue, M., Sillitoe, R. V., Jiang, X., Zoghbi, H. Y. 2019; 8

  Abstract

  Neurexophilins are secreted neuropeptide-like glycoproteins, and neurexophilin1 and neurexophilin3 are ligands for the presynaptic cell adhesion molecule α-neurexin. Neurexophilins are more selectively expressed in the brain than α-neurexins, however, which led us to ask whether neurexophilins modulate the function of α-neurexin in a context-specific manner. We characterized the expression and function of neurexophilin4 in mice and found it to be expressed in subsets of neurons responsible for feeding, emotion, balance, and movement. Deletion of Neurexophilin4 caused corresponding impairments, most notably in motor learning and coordination. We demonstrated that neurexophilin4 interacts with α-neurexin and GABAARs in the cerebellum. Loss of Neurexophilin4 impaired cerebellar Golgi-granule inhibitory neurotransmission and synapse number, providing a partial explanation for the motor learning and coordination deficits observed in the Neurexophilin4 null mice. Our data illustrate how selectively expressed Neurexophilin4, an α-neurexin ligand, regulates specific synapse function and modulates cerebellar motor control.

  View details for DOI 10.7554/eLife.46773

  View details for PubMedID 31524598

• A kinome-wide RNAi screen identifies ERK2 as a druggable regulator of Shank3 stability. Molecular psychiatry Wang, L., Adamski, C. J., Bondar, V. V., Craigen, E., Collette, J. R., Pang, K., Han, K., Jain, A., Y Jung, S., Liu, Z., Sifers, R. N., Holder, J. L., Zoghbi, H. Y. 2019

  Abstract

  Neurons are sensitive to changes in the dosage of many genes, especially those regulating synaptic functions. Haploinsufficiency of SHANK3 causes Phelan-McDermid syndrome and autism, whereas duplication of the same gene leads to SHANK3 duplication syndrome, a disorder characterized by neuropsychiatric phenotypes including hyperactivity and bipolar disorder as well as epilepsy. We recently demonstrated the functional modularity of Shank3, which suggests that normalizing levels of Shank3 itself might be more fruitful than correcting pathways that function downstream of it for treatment of disorders caused by alterations in SHANK3 dosage. To identify upstream regulators of Shank3 abundance, we performed a kinome-wide siRNA screen and identified multiple kinases that potentially regulate Shank3 protein stability. Interestingly, we discovered that several kinases in the MEK/ERK2 pathway destabilize Shank3 and that genetic deletion and pharmacological inhibition of ERK2 increases Shank3 abundance in vivo. Mechanistically, we show that ERK2 binds Shank3 and phosphorylates it at three residues to promote its poly-ubiquitination-dependent degradation. Altogether, our findings uncover a druggable pathway as a potential therapeutic target for disorders with reduced SHANK3 dosage, provide a rich resource for studying Shank3 regulation, and demonstrate the feasibility of this approach for identifying regulators of dosage-sensitive genes.

  View details for DOI 10.1038/s41380-018-0325-9

  View details for PubMedID 30696942

• An autism-linked missense mutation in SHANK3 reveals the modularity of Shank3 function. Molecular psychiatry Wang, L., Pang, K., Han, K., Adamski, C. J., Wang, W., He, L., Lai, J. K., Bondar, V. V., Duman, J. G., Richman, R., Tolias, K. F., Barth, P., Palzkill, T., Liu, Z., Holder, J. L., Zoghbi, H. Y. 2019

  Abstract

  Genome sequencing has revealed an increasing number of genetic variations that are associated with neuropsychiatric disorders. Frequently, studies limit their focus to likely gene-disrupting mutations because they are relatively easy to interpret. Missense variants, instead, have often been undervalued. However, some missense variants can be informative for developing a more profound understanding of disease pathogenesis and ultimately targeted therapies. Here we present an example of this by studying a missense variant in a well-known autism spectrum disorder (ASD) causing gene SHANK3. We analyzed Shank3's in vivo phosphorylation profile and identified S685 as one phosphorylation site where one ASD-linked variant has been reported. Detailed analysis of this variant revealed a novel function of Shank3 in recruiting Abelson interactor 1 (ABI1) and the WAVE complex to the post-synaptic density (PSD), which is critical for synapse and dendritic spine development. This function was found to be independent of Shank3's other functions such as binding to GKAP and Homer. Introduction of this human ASD mutation into mice resulted in a small subset of phenotypes seen previously in constitutive Shank3 knockout mice, including increased allogrooming, increased social dominance, and reduced pup USV. Together, these findings demonstrate the modularity of Shank3 function in vivo. This modularity further indicates that there is more than one independent pathogenic pathway downstream of Shank3 and correcting a single downstream pathway is unlikely to be sufficient for clear clinical improvement. In addition, this study illustrates the value of deep biological analysis of select missense mutations in elucidating the pathogenesis of neuropsychiatric phenotypes.

  View details for DOI 10.1038/s41380-018-0324-x

  View details for PubMedID 30610205

• PAK1 regulates ATXN1 levels providing an opportunity to modify its toxicity in spinocerebellar ataxia type 1. Human molecular genetics Bondar, V. V., Adamski, C. J., Onur, T. S., Tan, Q., Wang, L., Diaz-Garcia, J., Park, J., Orr, H. T., Botas, J., Zoghbi, H. Y. 2018; 27 (16): 2863-2873

  Abstract

  Spinocerebellar ataxia type 1 (SCA1) is caused by the expansion of a trinucleotide repeat that encodes a polyglutamine tract in ataxin-1 (ATXN1). The expanded polyglutamine in ATXN1 increases the protein's stability and results in its accumulation and toxicity. Previous studies have demonstrated that decreasing ATXN1 levels ameliorates SCA1 phenotypes and pathology in mouse models. We rationalized that reducing ATXN1 levels through pharmacological inhibition of its modulators could provide a therapeutic avenue for SCA1. Here, through a forward genetic screen in Drosophila we identified, p21-activated kinase 3 (Pak3) as a modulator of ATXN1 levels. Loss-of-function of fly Pak3 or Pak1, whose mammalian homologs belong to Group I of PAK proteins, reduces ATXN1 levels, and accordingly, improves disease pathology in a Drosophila model of SCA1. Knockdown of PAK1 potently reduces ATXN1 levels in mammalian cells independent of the well-characterized S776 phosphorylation site (known to stabilize ATXN1) thus revealing a novel molecular pathway that regulates ATXN1 levels. Furthermore, pharmacological inhibition of PAKs decreases ATXN1 levels in a mouse model of SCA1. To explore the potential of using PAK inhibitors in combination therapy, we combined the pharmacological inhibition of PAK with MSK1, a previously identified modulator of ATXN1, and examined their effects on ATXN1 levels. We found that inhibition of both pathways results in an additive decrease in ATXN1 levels. Together, this study identifies PAK signaling as a distinct molecular pathway that regulates ATXN1 levels and presents a promising opportunity to pursue for developing potential therapeutics for SCA1.

  View details for DOI 10.1093/hmg/ddy200

  View details for PubMedID 29860311

  View details for PubMedCentralID PMC6077814

• A Mild PUM1 Mutation Is Associated with Adult-Onset Ataxia, whereas Haploinsufficiency Causes Developmental Delay and Seizures. Cell Gennarino, V. A., Palmer, E. E., McDonell, L. M., Wang, L., Adamski, C. J., Koire, A., See, L., Chen, C. A., Schaaf, C. P., Rosenfeld, J. A., Panzer, J. A., Moog, U., Hao, S., Bye, A., Kirk, E. P., Stankiewicz, P., Breman, A. M., McBride, A., Kandula, T., Dubbs, H. A., Macintosh, R., Cardamone, M., Zhu, Y., Ying, K., Dias, K. R., Cho, M. T., Henderson, L. B., Baskin, B., Morris, P., Tao, J., Cowley, M. J., Dinger, M. E., Roscioli, T., Caluseriu, O., Suchowersky, O., Sachdev, R. K., Lichtarge, O., Tang, J., Boycott, K. M., Holder, J. L., Zoghbi, H. Y. 2018; 172 (5): 924-936.e11

  Abstract

  Certain mutations can cause proteins to accumulate in neurons, leading to neurodegeneration. We recently showed, however, that upregulation of a wild-type protein, Ataxin1, caused by haploinsufficiency of its repressor, the RNA-binding protein Pumilio1 (PUM1), also causes neurodegeneration in mice. We therefore searched for human patients with PUM1 mutations. We identified eleven individuals with either PUM1 deletions or de novo missense variants who suffer a developmental syndrome (Pumilio1-associated developmental disability, ataxia, and seizure; PADDAS). We also identified a milder missense mutation in a family with adult-onset ataxia with incomplete penetrance (Pumilio1-related cerebellar ataxia, PRCA). Studies in patient-derived cells revealed that the missense mutations reduced PUM1 protein levels by ∼25% in the adult-onset cases and by ∼50% in the infantile-onset cases; levels of known PUM1 targets increased accordingly. Changes in protein levels thus track with phenotypic severity, and identifying posttranscriptional modulators of protein expression should identify new candidate disease genes.

  View details for DOI 10.1016/j.cell.2018.02.006

  View details for PubMedID 29474920

  View details for PubMedCentralID PMC5832058

• Otud7a Knockout Mice Recapitulate Many Neurological Features of 15q13.3 Microdeletion Syndrome. American journal of human genetics Yin, J., Chen, W., Chao, E. S., Soriano, S., Wang, L., Wang, W., Cummock, S. E., Tao, H., Pang, K., Liu, Z., Pereira, F. A., Samaco, R. C., Zoghbi, H. Y., Xue, M., Schaaf, C. P. 2018; 102 (2): 296-308

  Abstract

  15q13.3 microdeletion syndrome is characterized by a wide spectrum of neurodevelopmental disorders, including developmental delay, intellectual disability, epilepsy, language impairment, abnormal behaviors, neuropsychiatric disorders, and hypotonia. This syndrome is caused by a deletion on chromosome 15q, which typically encompasses six genes. Here, through studies on OTU deubiquitinase 7A (Otud7a) knockout mice, we identify OTUD7A as a critical gene responsible for many of the cardinal phenotypes associated with 15q13.3 microdeletion syndrome. Otud7a-null mice show reduced body weight, developmental delay, abnormal electroencephalography patterns and seizures, reduced ultrasonic vocalizations, decreased grip strength, impaired motor learning/motor coordination, and reduced acoustic startle. We show that OTUD7A localizes to dendritic spines and that Otud7a-null mice have decreased dendritic spine density compared to their wild-type littermates. Furthermore, frequency of miniature excitatory postsynaptic currents (mEPSCs) is reduced in the frontal cortex of Otud7a-null mice, suggesting a role of Otud7a in regulation of dendritic spine density and glutamatergic synaptic transmission. Taken together, our results suggest decreased OTUD7A dosage as a major contributor to the neurodevelopmental phenotypes associated with 15q13.3 microdeletion syndrome, through the misregulation of dendritic spine density and activity.

  View details for DOI 10.1016/j.ajhg.2018.01.005

  View details for PubMedID 29395075

  View details for PubMedCentralID PMC5985472