Neural Progenitor Cells Research Articles

Prenatal Maternal Stress Suppresses Embryonic Neurogenesis via Elevated Glucocorticoid Levels.

Although it is known that prenatal maternal stress (PNMS) has negative influence on nervous system development in offspring, there has been no solid evidence showing the effect of PNMS on early neurogenesis during development. In this study, we established a chick embryo model to investigate how PNMS affects early neurogenesis by mimicking an intrauterine environment with high dexamethasone (Dex) levels. The results showed that Dex-mimicked PNMS significantly suppressed the development of gastrula embryos and increased the risks of neural tube defects and cranial deformity. Using immunofluorescence staining and Western blots to determine the expression levels of pHIS3, PCNA/Sox2, we found that PNMS significantly inhibited the proliferation of neural progenitor cells, and the downregulation of TGFβ signaling pathway might be responsible for the inhibition. Furthermore, immunofluorescence staining and Western blots manifested that PNMS could suppress the differentiation of neural progenitor cells to neuronal lineages, but promote them to transform into neuroglial cells, which might be due to the restriction of expressions of key genes (BMP4, SHH, Wnt3a, Slug, and Msx1) related to neural differentiation. In summary, our data reveal that PNMS dramatically impacts the earliest stages of neural development, thereby greatly increasing the risk of physical and mental health problems in childhood or adulthood.

Lipid Priming of Adipose Mesenchymal Stromal Cells with Docosahexaenoic Acid: Impact on Cell Differentiation, Senescence and the Secretome Neuroregulatory Profile.

Priming strategies that improve the functionality of MSCs may be required to address issues limiting successful clinical translation of MSC therapies. For conditions requiring high trophic support such as brain and spinal cord injuries, priming MSCs to produce higher levels of trophic factors may be instrumental to facilitate translation of current MSC therapies. We developed and tested a novel molecular priming paradigm using docosahexaenoic acid (DHA) to prime adipose tissue-derived mesenchymal stromal cells (ASCs) to enhance the secretome neuroregulatory potential. Comprehensive dose-response and time-course assays were carried to determine an optimal priming protocol. Secretome total protein measurements were taken in association with cell viability, density and morphometric assessments. Cell identity and differentiation capacity were studied by flow cytometry and lineage-specific markers. Cell growth was assessed by trypan-blue exclusion and senescence was probed over time using SA-β-gal, morphometry and gene expression. Secretomes were tested for their ability to support differentiation and neurite outgrowth of human neural progenitor cells (hNPCs). Neuroregulatory proteins in the secretome were identified using multiplex membrane arrays. Priming with 40µM DHA for 72h significantly enhanced the biosynthetic capacity of ASCs, producing a secretome with higher protein levels and increased metabolic viability. DHA priming enhanced ASCs adipogenic differentiation and adapted their responses to replicative senescence induction. Furthermore, priming increased concentrations of neurotrophic factors in the secretome promoting neurite outgrowth and modulating the differentiation of hNPCs. These results provide proof-of-concept evidence that DHA priming is a viable strategy to improve the neuroregulatory profile of ASCs.

Construction of a Prognostic Model for Mitochondria and Macrophage Polarization Correlation in Glioma Based on Single-Cell and Transcriptome Sequencing.

Numerous diseases are associated with the interplay of mitochondrial and macrophage polarization. However, the correlation of mitochondria-related genes (MRGs) and macrophage polarization-related genes (MPRGs) with the prognosis of glioma remains unclear. This study aimed to examine this relationship based on bioinformatic analysis. Glioma-related datasets (TCGA-GBMLGG, mRNA-seq-325, mRNA-seq-693, GSE16011, GSE4290, and GSE138794) were included in this study. The intersection genes were obtained by overlapping differentially expressed genes (DEGs) from differential expression analysis in GSE16011, key module genes from WGCNA, and MRGs. Subsequently, the intersection genes were further screened to obtain prognostic genes. Following this, a risk model was developed and verified. After that, independent prognostic factors were identified, followed by the construction of a nomogram and subsequent evaluation of its predictive ability. Furthermore, immune microenvironment analysis and expression validation were implemented. The GSE138794 dataset was utilized to evaluate the expression of prognostic genes at a cellular level, followed by conducting an analysis on cell-to-cell communication. Finally, the results were validated in different datasets and tissue samples from patients. ECI2, MCCC2, OXCT1, SUCLG2, and CPT2 were identified as prognostic genes for glioma. The risk model constructed based on these genes in TCGA-GBMLGG demonstrated certain accuracy in predicting the occurrence of glioma. Additionally, the nomogram constructed based on risk score and grade exhibited strong performance in predicting patient survival. Significant differences were observed in the proportion of 27 immune cell types (e.g., activated B cells and macrophages) and the expression of 32 immune checkpoints (e.g., CD70, CD200, and CD48) between the two risk groups. Single-cell RNA sequencing showed that CPT2, ECI2, and SUCLG2 were highly expressed in oligodendrocytes, neural progenitor cells, and BMDMs, respectively. The results of cell-cell communication analysis revealed that both oligodendrocytes and BMDMs exhibited a substantial number of interactions with high strength. This study revealed five genes associated with the prognosis of glioma (ECI2, MCCC2, OXCT1, SUCLG2, and CPT2), providing novel insights into individualized treatment and prognosis.

SMPD4 mediated sphingolipid metabolism regulates brain and primary cilia development.

Genetic variants in multiple sphingolipid biosynthesis genes cause human brain disorders. A recent study collected patients from twelve unrelated families with variants in the gene SMPD4, a neutral sphingomyelinase which metabolizes sphingomyelin into ceramide at an early stage of the biosynthesis pathway. These patients have severe developmental brain malformations including microcephaly and cerebellar hypoplasia. The disease mechanism of SMPD4 was not known and we pursued a new mouse model. We hypothesized that the role of SMPD4 in producing ceramide is important for making primary cilia, a crucial organelle mediating cellular signaling. We found that the mouse model has cerebellar hypoplasia due to failure of Purkinje cell development. Human induced pluripotent stem cells exhibit neural progenitor cell death and have shortened primary cilia which is rescued by adding exogenous ceramide. SMPD4 production of ceramide is crucial for human brain development.

Stem Cells Treatment for Subarachnoid Hemorrhage.

Subarachnoid hemorrhage (SAH) refers to bleeding in the subarachnoid space, which is a serious neurologic emergency. However, the treatment effects of SAH are limited. In recent years, stem cell (SC) therapy has gradually become a very promising therapeutic method and advanced scientific research area for SAH. The SCs used for SAH treatment are mainly bone marrow mesenchymal stem cells (BMSCs), umbilical cord mesenchymal stem cells (hUC-MSCs), dental pulp stem cells (DPSCs), neural stem cells (NSCs)/neural progenitor cell (NPC), and endothelial progenitor cell (EPC). The mechanisms mainly included differentiation and migration of SCs for tissue repair; alleviating neuronal apoptosis; anti-inflammatory effects; and blood-brain barrier (BBB) protection. The dosage of SCs was generally 106 orders of magnitude. The administration methods included intravenous injection, nasal, occipital foramen magnum, and intraventricular administration. The administration time is generally 1 hour after SAH modeling, but it may be as late as 24 hours or 6 days. Existing studies have confirmed the neuroprotective effect of SCs in the treatment of SAH. SC has great potential application value in SAH treatment, a few case reports have provided support for this. However, the relevant research is still insufficient and there is still a lack of clinical research on the SC treatment for SAH to further evaluate the effectiveness and safety before it can go from experiment to clinical application.

Widespread Gene Editing in the Brain via In Utero Delivery of mRNA Using Acid-Degradable Lipid Nanoparticles.

In utero gene editing with mRNA-based therapeutics has the potential to revolutionize the treatment of neurodevelopmental disorders. However, a critical bottleneck in clinical application has been the lack of mRNA delivery vehicles that can efficiently transfect cells in the brain. In this report, we demonstrate that in utero intracerebroventricular (ICV) injection of densely PEGylated lipid nanoparticles (ADP-LNPs) containing an acid-degradable PEG-lipid can safely and effectively deliver mRNA for gene editing enzymes to the fetal mouse brain, resulting in successful transfection and editing of brain cells. ADP-LNPs containing Cre mRNA transfected 30% of the fetal brain cells in Ai9 mice and had no detectable adverse effects on fetal development and postnatal growth. In addition, ADP-LNPs efficiently transfected neural stem and progenitor cells in Ai9 mice with Cre mRNA, which subsequently proliferated and caused over 40% of the cortical neurons and 60% of the hippocampal neurons to be edited in treated mice 10 weeks after birth. Furthermore, using Angelman syndrome, a paradigmatic neurodevelopmental disorder, as a disease model, we demonstrate that ADP-LNPs carrying Cas9 mRNA and gRNA induced indels in 21% of brain cells within 7 days postpartum, underscoring the precision and potential of this approach. These findings demonstrate that LNP/mRNA complexes have the potential to be a transformative tool for in utero treatment of neurodevelopmental disorders and set the stage for a frontier in treating neurodevelopmental disorders that focuses on curing genetic diseases before birth.

Neural crest lineage in the protovertebrate model Ciona.

Neural crest cells are multipotent progenitors that produce defining features of vertebrates such as the 'new head'1. Here we use the tunicate, Ciona, to explore the evolutionary origins of neural crest since this invertebrate chordate is among the closest living relatives of vertebrates2-4. Previous studies identified two potential neural crest cell types in Ciona, sensory pigment cells and bipolar tail neurons5,6. Recent findings suggest that bipolartail neurons are homologous to cranial sensory ganglia rather than derivatives of neural crest7,8. Here we show that the pigment cell lineage also produces neural progenitor cells that form regions of the juvenile nervous system following metamorphosis. Neural progenitors are also a major derivative of neural crest in vertebrates, suggesting that the last common ancestor of tunicates and vertebrates contained a multipotent progenitor population at the neural plate border. It would therefore appear that a key property of neural crest, multipotentiality, preceded the emergence of vertebrates.

Modeling Glioma Intratumoral Heterogeneity with Primary Human Neural Stem and Progenitor Cells.

Glioblastoma multiforme (GBM) is a deadly form of glioma notable for its significant intratumoral heterogeneity, which is believed to drive therapy resistance. GBM has been observed to mimic a neural stem cell hierarchy reminiscent of normal brain development. However, it is still unclear how cell-of-origin shapes intratumoral heterogeneity. Here, we develop a model of glioma initiation using neural stem and progenitor cells (NSPCs) purified from fetal human brain tissue. We previously described a method to prospectively isolate and culture tripotent neural stem cells (NSCs), bipotent glial progenitor cells (GPCs), and unipotent oligodendrocyte precursor cells (OPCs). We transduced these isogenic lines with dominant-negative TP53 R175H and NF1 knockdown, a commonly-used genetic model of GBM in mice. These reprogrammed lines robustly engrafted when transplanted into the brains of immunodeficient mice, and showed significant expansion over time. Engrafted cells were reextracted from the mouse brain for single cell RNA sequencing (scRNA-seq), in order to quantify how the cell-of-origin modulates the cellular subtypes found in the resulting tumor. This result revealed the strong influence the cell-of-origin plays in glioma heterogeneity. Our platform is highly adaptable and allows for modular and systematic interrogation of how cell-of-origin shape the tumor landscape.

Stage-specific expression patterns and co-targeting relationships among miRNAs in the developing mouse cerebral cortex

microRNAs are crucial regulators of brain development, however, miRNA regulatory networks are not sufficiently well characterized. By performing small RNA-seq of the mouse embryonic cortex at E14, E17, and P0 as well as in neural progenitor cells and neurons, here we detected clusters of miRNAs that were co-regulated at distinct developmental stages. miRNAs such as miR-92a/b acted as hubs during early, and miR-124 and miR-137 during late neurogenesis. Notably, validated targets of P0 hub miRNAs were enriched for downregulated genes related to stem cell proliferation, negative regulation of neuronal differentiation and RNA splicing, among others, suggesting that miRNAs are particularly important for modulating transcriptional programs of crucial factors that guide the switch to neuronal differentiation. As most genes contain binding sites for more than one miRNA, we furthermore constructed a co-targeting network where numerous miRNAs shared more targets than expected by chance. Using luciferase reporter assays, we demonstrated that simultaneous binding of miRNA pairs to neurodevelopmentally relevant genes exerted an enhanced transcriptional silencing effect compared to single miRNAs. Taken together, we provide a comprehensive resource of miRNA longitudinal expression changes during murine corticogenesis. Furthermore, we highlight several potential mechanisms through which miRNA regulatory networks can shape embryonic brain development.

Suppressing DUSP16 overexpression induced by ELK1 promotes neural progenitor cell differentiation in mouse models of Alzheimer's disease.

Emerged evidence indicated that stimulating hippocampal neurogenesis is a potential strategy for restoring cognition in AD. Mitogen-activated protein kinases (MAPKs) play an essential role in neurogenesis. Meanwhile, the enzymatic power of the phosphatases is much greater than that of kinases. Dual-specificity phosphatase 16 (DUSP16), known to as a phosphatase negatively regulate MAPKs, may be implicated in neural differentiation. Nevertheless, the effect of DUSP16 on cognitive disorders by stimulating neural progenitor cell (NPC) differentiation in AD mice remains unclear. Our study demonstrates an association between DUSP16 SNPs and clinical progression in individuals with mild cognitive impairment (MCI). Besides, increased DUSP16 expression was detected in both 3xTg and SAMP8 mouse models of AD, accompanied by NPC neural differentiation impairments. By silencing DUSP16, the induction of neural differentiation, synaptic transmission, and cognitive benefits were observed in both AD mice. Furthermore, DUSP16 was involved in the process of NPC differentiation through regulating c-Jun N-terminal kinase (JNK) phosphorylation and SOX2 expression. Moreover, ETS transcription factor (ELK1) was involved in the DUSP16 transcription, which resulted in the upregulation of DUSP16 at the state of AD. Our data uncovers a potential regulatory role for DUSP16 in adult hippocampal neurogenesis (AHN) and provides a possibility to find a novel strategy for AD intervention.

RSPO/LGR signaling regulates proliferation of adult hippocampal neural stem cells.

In the dentate gyrus of the adult hippocampus, neurogenesis from neural stem cells (NSCs) is regulated by Wnt signals from the local microenvironment. The Wnt/β-catenin pathway is active in NSCs, where it regulates proliferation and fate commitment, and subsequently its activity is strongly attenuated. The mechanisms controlling Wnt activity are poorly understood. In stem cells from adult peripheral tissues, secreted R-spondin proteins (RSPO1-4) interact with LGR4-6 receptors and control Wnt signaling strength. Here, we found that RSPO1-3 and LGR4-6 are expressed in the adult dentate gyrus and in cultured NSCs isolated from the adult mouse hippocampus. LGR4-5 expression decreased in cultured NSCs upon differentiation, concomitantly with the reported decrease in Wnt activity. Treatment with RSPO1-3 increased NSC proliferation and the expression of Cyclin D1, but did not induce the expression of Axin2 or RNF43, two well-described Wnt target genes. However, RSPOs enhanced the effect of Wnt3a on Axin2 and RNF43 expression, as well as on Wnt/β-catenin reporter activity, indicating that they can potentiate Wnt activity in NSCs. Moreover, RSPO1-3 were found to be expressed by cultured dentate gyrus astrocytes, a crucial component of the neurogenic niche. In co-culture experiments, the astrocyte-induced proliferation of NSCs was prevented by RSPO2 knockdown in astrocytes and LGR5 knockdown in hippocampal NSCs. Additionally, RSPO2 knockdown in the adult mouse dentate gyrus reduced proliferation of neural stem and progenitor cells in vivo. Altogether, our results indicate that RSPO/LGR signaling is present in the dentate gyrus and plays a crucial role in regulating neural precursor cell proliferation.

Shh signaling directs dorsal ventral patterning in the regenerating X. tropicalis spinal cord.

Tissue development and regeneration rely on the deployment of embryonic signals to drive progenitor activity and thus generate complex cell diversity and organization. One such signal is Sonic Hedgehog (Shh), which establishes the dorsal-ventral (D/V) axis of the spinal cord during embryogenesis. However, the existence of this D/V axis and its dependence on Shh signaling during regeneration varies by species. Here we investigate the function of Shh signaling in patterning the D/V axis during spinal cord regeneration in Xenopus tropicalis tadpoles. We find that neural progenitor markers Msx1/2, Nkx6.1, and Nkx2.2 are confined to dorsal, intermediate and ventral spatial domains, respectively, in both the uninjured and regenerating spinal cord. These domains are altered by perturbation of Shh signaling. Additionally, we find that these D/V domains are more sensitive to Shh perturbation during regeneration than uninjured tissue. The renewed sensitivity of these neural progenitor cells to Shh signals represents a regeneration specific response and raises questions about how responsiveness to developmental patterning cues is regulated in mature and regenerating tissues.

Harnessing the role of aberrant cell signaling pathways in glioblastoma multiforme: a prospect towards the targeted therapy.

Glioblastoma Multiforme (GBM), designated as grade IV by the World Health Organization, is the most aggressive and challenging brain tumor within the central nervous system. Around 80% of GBM patients have a poor prognosis, with a median survival of 12-15months. Approximately 90% of GBM cases originate from normal glial cells via oncogenic processes, while the remainder arise from low-grade tumors. GBM is notorious for its heterogeneity, high recurrence rates, invasiveness, and aggressive behavior. Its malignancy is driven by increased invasive migration, proliferation, angiogenesis, and reduced apoptosis. Throughout various stages of central nervous system (CNS) development, pivotal signaling pathways, including Wnt/β-catenin, Sonic hedgehog signaling (Shh), PI3K/AKT/mTOR, Ras/Raf/MAPK/ERK, STAT3, NF-КB, TGF-β, and Notch signaling, orchestrate the growth, proliferation, differentiation, and migration of neural progenitor cells in the brain. Numerous upstream and downstream regulators within these signaling pathways have been identified as significant contributors to the development of human malignancies. Disruptions or aberrant activations in these pathways are linked to gliomagenesis, enhancing the invasiveness, progression, and aggressiveness of GBM, along with epithelial to mesenchymal transition (EMT) and the presence of glioma stem cells (GSCs). Traditional GBM treatment involves surgery, radiotherapy, and chemotherapy with Temozolomide (TMZ). However, most patients experience tumor recurrence, leading to low survival rates. This review provides an overview of the major cell signaling pathways involved in gliomagenesis. Furthermore, we explore the signaling pathways leading to therapy resistance and target key molecules within these signaling pathways, paving the way for the development of novel therapeutic approaches.

Optical coherence tomography enables longitudinal evaluation of cell graft-directed remodeling in stroke lesions.

Stem cell grafting can promote glial repair of adult stroke injuries during the subacute wound healing phase, but graft survival and glial repair outcomes are perturbed by lesion severity and mode of injury. To better understand how stroke lesion environments alter the functions of cell grafts, we employed optical coherence tomography (OCT) to longitudinally image mouse cortical photothrombotic ischemic strokes treated with allogeneic neural progenitor cell (NPC) grafts. OCT angiography, signal intensity, and signal decay resulting from optical scattering were assessed at multiple timepoints across two weeks in mice receiving an NPC graft or an injection of saline at two days after stroke. OCT scattering information revealed pronounced axial lesion contraction that naturally occurred throughout the subacute wound healing phase that was not modified by either NPC or saline treatment. By analyzing OCT signal intensity along the coronal plane, we observed dramatic contraction of the cortex away from the imaging window in the first week after stroke which impaired conventional OCT angiography but which enabled the detection of NPC graft-induced glial repair. There was moderate, but variable, NPC graft survival at photothrombotic strokes at two weeks which was inversely correlated with acute stroke lesion sizes as measured by OCT prior to treatment, suggesting a prognostic role for OCT imaging and reinforcing the dominant effect of lesion size and severity on graft outcome. Overall, our findings demonstrate the utility of OCT imaging for both tracking and predicting natural and treatment-directed changes in ischemic stroke lesion cores.

Lineage tracing of Shh+ floor plate cells and dynamics of dorsal-ventral gene expression in the regenerating axolotl spinal cord.

Both development and regeneration depend on signaling centers, which are sources of locally secreted tissue-patterning molecules. As many signaling centers are decommissioned before the end of embryogenesis, a fundamental question is how signaling centers can be re-induced later in life to promote regeneration after injury. Here, we use the axolotl salamander model (Ambystoma mexicanum) to address how the floor plate is assembled for spinal cord regeneration. The floor plate is an archetypal vertebrate signaling center that secretes Shh ligand and patterns neural progenitor cells during embryogenesis. Unlike mammals, axolotls continue to express floor plate genes (including Shh) and downstream dorsal-ventral patterning genes in their spinal cord throughout life, including at steady state. The parsimonious hypothesis that Shh+ cells give rise to functional floor plate cells for regeneration had not been tested. Using HCR in situ hybridization and mathematical modeling, we first quantified the behaviors of dorsal-ventral spinal cord domains, identifying significant increases in gene expression level and floor plate size during regeneration. Next, we established a transgenic axolotl to specifically label and fate map Shh+ cells in vivo. We found that labeled Shh+ cells gave rise to regeneration floor plate, and not to other neural progenitor domains, after tail amputation. Thus, despite changes in domain size and downstream patterning gene expression, Shh+ cells retain their floor plate identity during regeneration, acting as a stable cellular source for this regeneration signaling center in the axolotl spinal cord.

The transcription elongation factors Spt4 and Spt5 control neural progenitor proliferation and are implicated in neuronal remodeling during Drosophila mushroom body development.

Spt4 and Spt5 form the DRB sensitivity inducing factor (DSIF) complex that regulates transcription elongation at multiple steps including promotor-proximal pausing, processivity and termination. Although this implicated a general role in transcription, several studies pointed to smaller sets of target genes and indicated a more specific requirement in certain cellular contexts. To unravel common or distinct functions of Spt4 and Spt5 in vivo, we generated knock-out alleles for both genes in Drosophila melanogaster. Using the development of the mushroom bodies as a model, we provided evidence for two common functions of Spt4 and Spt5 during mushroom body development, namely control of cell proliferation of neural progenitor cells and remodeling of axonal projections of certain mushroom body neurons. This latter function is not due to a general requirement of Spt4 and Spt5 for axon pathfinding of mushroom body neurons, but due to distinct effects on the expression of genes controlling remodeling.

An integrative systems-biology approach defines mechanisms of Alzheimer's disease neurodegeneration.

Despite years of intense investigation, the mechanisms underlying neuronal death in Alzheimer's disease, the most common neurodegenerative disorder, remain incompletely understood. To define relevant pathways, we integrated the results of an unbiased, genome-scale forward genetic screen for age-associated neurodegeneration in Drosophila with human and Drosophila Alzheimer's disease-associated multi-omics. We measured proteomics, phosphoproteomics, and metabolomics in Drosophila models of Alzheimer's disease and identified Alzheimer's disease human genetic variants that modify expression in disease-vulnerable neurons. We used a network optimization approach to integrate these data with previously published Alzheimer's disease multi-omic data. We computationally predicted and experimentally demonstrated how HNRNPA2B1 and MEPCE enhance tau-mediated neurotoxicity. Furthermore, we demonstrated that the screen hits CSNK2A1 and NOTCH1 regulate DNA damage in Drosophila and human iPSC-derived neural progenitor cells. Our work identifies candidate pathways that could be targeted to ameliorate neurodegeneration in Alzheimer's disease.

TAOK2 Drives Opposing Cilia Length Deficits in 16p11.2 Deletion and Duplication Carriers.

Copy number variation (CNV) in the 16p11.2 (BP4-BP5) genomic locus is strongly associated with autism. Carriers of 16p11.2 deletion and duplication exhibit several common behavioral and social impairments, yet, show opposing brain structural changes and body mass index. To determine cellular mechanisms that might contribute to these opposing phenotypes, we performed quantitative tandem mass tag (TMT) proteomics on human dorsal forebrain neural progenitor cells (NPCs) differentiated from induced pluripotent stem cells (iPSC) derived from 16p11.2 CNV carriers. Differentially phosphorylated proteins between unaffected individuals and 16p11.2 CNV carriers were significantly enriched for centrosomal and cilia proteins. Deletion patient-derived NPCs show increased primary cilium length compared to unaffected individuals, while stunted cilium growth was observed in 16p11.2 duplication NPCs. Through cellular shRNA and overexpression screens in human iPSC derived NPCs, we determined the contribution of genes within the 16p11.2 locus to cilium length. TAOK2, a serine threonine protein kinase, and PPP4C, a protein phosphatase, were found to regulate primary cilia length in a gene dosage-dependent manner. We found TAOK2 was localized at centrosomes and the base of the primary cilium, and NPCs differentiated from TAOK2 knockout iPSCs had longer cilia. In absence of TAOK2, there was increased pericentrin at the basal body, and aberrant accumulation of IFT88 at the ciliary distal tip. Further, pharmacological inhibition of TAO kinase activity led to increased ciliary length, indicating that TAOK2 negatively controls primary cilium length through its catalytic activity. These results implicate aberrant cilia length in the pathophysiology of 16p11.2 CNV, and establish the role of TAOK2 kinase as a regulator of primary cilium length.

Comparative single-cell multiome identifies evolutionary changes in neural progenitor cells during primate brain development.

Understanding the cellular and genetic mechanisms driving human-specific features of cortical development remains a challenge. We generated a cell-type resolved atlas of transcriptome and chromatin accessibility in the developing macaque and mouse prefrontal cortex (PFC). Comparing with published human data, our findings demonstrate that although the cortex cellular composition is overall conserved across species, progenitor cells show significant evolutionary divergence in cellular properties. Specifically, human neural progenitors exhibit extensive transcriptional rewiring in growth factor and extracellular matrix (ECM) pathways. Expression of the human-specific progenitor marker ITGA2 in the fetal mouse cortex increases the progenitor proliferation and the proportion of upper-layer neurons. These transcriptional divergences are primarily driven by altered activity in the distal regulatory elements. The chromatin regions with human-gained accessibility are enriched with human-specific sequence changes and polymorphisms linked to intelligence and neuropsychiatric disorders. Our results identify evolutionary changes in neural progenitors and putative gene regulatory mechanisms shaping primate brain evolution.

MARK2 variants cause autism spectrum disorder via the downregulation of WNT/β-catenin signaling pathway.

Microtubule affinity-regulating kinase 2 (MARK2) contributes to establishing neuronal polarity and developing dendritic spines. Although large-scale sequencing studies have associated MARK2 variants with autism spectrum disorder (ASD), the clinical features and variant spectrum in affected individuals with MARK2 variants, early developmental phenotypes in mutant human neurons, and the pathogenic mechanism underlying effects on neuronal development have remained unclear. Here, we report 31 individuals with MARK2 variants and presenting with ASD, other neurodevelopmental disorders, and distinctive facial features. Loss-of-function (LoF) variants predominate (81%) in affected individuals, while computational analysis and invitro expression assay of missense variants supported the effect of MARK2 loss. Using proband-derived and CRISPR-engineered isogenic induced pluripotent stem cells (iPSCs), we show that MARK2 loss leads to early neuronal developmental and functional deficits, including anomalous polarity and dis-organization in neural rosettes, as well as imbalanced proliferation and differentiation in neural progenitor cells (NPCs). Mark2+/- mice showed abnormal cortical formation and partition and ASD-like behavior. Through the use of RNA sequencing (RNA-seq) and lithium treatment, we link MARK2 loss to downregulation of the WNT/β-catenin signaling pathway and identify lithium as a potential drug for treating MARK2-associated ASD.