Progressive Defects Research Articles

Fission yeast essential nuclear pore protein Nup211 regulates the expression of genes involved in cytokinesis.

Nuclear pore proteins control nucleocytoplasmic transport; however, certain nucleoporins play regulatory roles in activities such as transcription and chromatin organization. The fission yeast basket nucleoporin Nup211 is implicated in mRNA export and is essential for cell viability. Nup211 preferentially associates with heterochromatin, however, it is unclear whether it plays a role in regulating transcription. To better understand its functions, we constructed a nup211 "shut-off" strain and observed that Nup211 depletion led to severe defects in cell cycle progression, including septation and cytokinesis. Using RNA-Seq and RT-qPCR, we revealed that loss of Nup211 significantly altered the mRNA levels of a set of genes crucial for cell division. Using domain analysis and CRISPR/cas9 technology, we determined that the first 655 residues of Nup211 are sufficient for viability. This truncated protein was detected at the nuclear periphery. Furthermore, exogenous expression of this domain in nup211 shut-off cells effectively restored both cell morphology and transcript abundance for some selected genes. Our findings unveil a novel role for Nup211 in regulating gene expression.

Generation of an iPSC cell line (VANYHHi001-A) from a patient with cardiac arrythmias carrying CACNA1D, SCN5A, and DSP variants

Progressive cardiac conduction defect often associated with variants in sodium voltage-gated channel SCN5A gene and variants in the L-type calcium voltage-gated channel CACNA1D gene are implicated in sinoatrial node dysfunction. We generated an induced pluripotent stem cell line (iPSC) from a 13-year-old patient with history of conduction system disease and ventricular tachycardia, carrying variants in SCN5A (c.2618C > G), CACNA1D (c.3786G > T), and DSP (c.1582C > G). The generated iPSC line exhibited pluripotency markers, differentiated into the three embryonic germ layers, and maintained a normal karyotype. This iPSC line offers insights into the pathophysiological mechanisms of cardiac arrhythmias and personalized therapies development.

CHLOROQUINE INDUCED MACULAR TOXICITY IN A PATIENT LATER DEVELOPING SECTOR RETINITIS PIGMENTOSA: A CASE REPORT.

To describe how underlying retinal diseases, such as retinitis pigmentosa, increase the risk of chloroquine-induced macular toxicity. Observational case report. We present the case of a 57-year-old woman being annually followed-up in the Ophthalmology service due to a systemic treatment with chloroquine (CQ). The explorations were successive normal, until a 10:2 visual field (VF) shows central defects in both eyes. Despite CQ treatment is discontinued, 10:2 VF reveal slowly progressive macular defects. During follow-up, fundus examination disclosed bone spicules in the inferonasal middle periphery: the electroretinogram (ERG) shows slow amplitude responses under scotopic conditions and the electrooculogram (EOG) also shows pathological responses. Therefore, the diagnosis of sector retinitis pigmentosa plus chloroquine maculopathy is made. Currently, the slow but constant progression of both peripheral and central defects is evident, despite having discontinued CQ treatment more than 15 years ago. Underlying retinal diseases seem to increase the risk of photoreceptor damage when undergoing a toxic insult. Thus, we hypothesize a potential interplay between retinal dystrophies and toxic maculopathy induced by CQ, and the influence of each of them in the evolution and prognosis of the other.

New evidence of vascular defects in neurodegenerative diseases revealed by single cell RNA sequencing.

Neurodegenerative diseases (NDs) involve the progressive loss of neuronal structure or function in the brain and spinal cord. Despite their diverse etiologies, NDs manifest similar pathologies. Emerging research identifies vascular defects as a previously neglected hallmark of NDs. The development and popularization of single-cell RNA sequencing (scRNA-seq) technologies have significantly advanced our understanding of brain vascular cell types and their molecular characteristics, including gene expression changes at the single-cell level in NDs. These unprecedented insights deepen our understanding of the pathogenic mechanisms underlying NDs. However, the occurrence and role of vascular defects in disease progression remain largely unexplored. In this paper, we systematically summarize recent advances in the structure and organization of the central nervous system vasculature in mice, healthy individuals, and patients with NDs, focussing primarily on disease-specific alterations in vascular cell types or subtypes. Combining scRNA-seq with pathology evidence, we propose that vascular defects, characterized by disruptions in cell types and structural integrity, may serve as common early features of NDs. Finally, we discuss several pathways through which vascular defects in NDs lead to neuronal degeneration. A deeper understanding of the causes and contributions of vascular defects to NDs aids in elucidating the pathogenic mechanisms and developing meaningful therapeutic interventions.

Combined biomaterial scaffold and neuromodulation strategy to promote tissue repair and corticospinal connectivity after spinal cord injury in a rodent model

Spinal cord injury (SCI) damages the trauma site, leading to progressive and secondary structural defects rostral and caudal to the injury. Interruption of ascending and descending pathways produce motor, sensory, and autonomic impairments, driving the need for effective therapies. In this study, we address lesion site repair and promoting descending projections using a combined biomaterial-neuromodulation strategy in a rat model of cervical contusion SCI. To promote tissue repair, we used Chitosan fragmented physical hydrogel suspension (Cfphs), a biomaterial formulation optimized to mitigate inflammation and support tissue remodeling. To promote descending projections, we targeted the corticospinal motor system with dual motor cortex–trans-spinal direct current neuromodulation to promote spared corticospinal tract (CST) axon sprouting rostral and caudal to SCI. Cfphs, injected into the lesion site acutely, was followed by 10 days of daily neuromodulation. Analysis was made at the chronic phase, 8-weeks post-SCI. Compared with SCI only, Cfphs alone or in combination with neuromodulation prevented cavity formation, by promoting tissue remodeling at the injury site, abrogated astrogliosis surrounding the newly formed tissue, and enabled limited CST axon growth into the remodeled injury site. Cfphs alone significantly reduced CST axon dieback and was accompanied by preserving more CST axon gray matter projections rostral to SCI. Cfphs + neuromodulation produced sprouting rostral and caudal to injury. Our findings show that our novel biomaterial-neuromodulation combinatorial strategy achieves significant injury site tissue remodeling and promoted CST projections rostral and caudal to SCI.

Argonaute protein CSR-1 restricts localization of holocentromere protein HCP-3, the C. elegans CENP-A homolog.

Chromosome segregation errors caused by centromere malfunction can lead to chromosome instability and aneuploidy. In Caenorhabditis elegans, the Argonaute protein CSR-1 is essential for proper chromosome segregation, although the specific mechanisms are not fully understood. Here, we investigated how CSR-1 regulates centromere and kinetochore function in C. elegans embryos. We found that depletion of CSR-1 results in defects in mitotic progression and chromosome positioning relative to the spindle pole. Knockdown of CSR-1 does not affect mRNA and protein levels of the centromeric histone H3 variant and CENP-A homolog HCP-3 but does increase the localization of HCP-3 and some kinetochore proteins to the mitotic chromosomes. Such elevation of HCP-3 chromatin localization depends on EGO-1, which is an upstream factor in the CSR-1 RNA interference (RNAi) pathway, and PIWI domain activity of CSR-1. Our results suggest that CSR-1 restricts the level of HCP-3 at the holocentromeres, prevents erroneous kinetochore assembly and thereby promotes accurate chromosome segregation. Our work sheds light on the role of CSR-1 in regulating deposition of HCP-3 on chromatin and centromere function in embryos.

Role of male gonad-enriched microRNAs in sperm production in Caenorhabditis elegans.

Germ cell development and gamete production in animals require small RNA pathways. While studies indicate that microRNAs (miRNAs) are necessary for normal sperm production and function, the specific roles for individual miRNAs are largely unknown. Here, we use small RNA sequencing (RNA-seq) of dissected gonads and functional analysis of new loss-of-function alleles to identify functions for miRNAs in the control of fecundity and sperm production in Caenorhabditis elegans males and hermaphrodites. We describe a set of 29 male gonad-enriched miRNAs and identify a set of individual miRNAs (mir-58.1 and mir-235) and a miRNA cluster (mir-4807-4810.1) that are required for optimal sperm production at 20°C and a set of miRNAs (mir-49, mir-57, mir-83, mir-261, and mir-357/358) that are required for sperm production at 25°C. We observed defects in meiotic progression in mutants missing mir-58.1, mir-83, mir-235, and mir-4807-4810.1, which may contribute to the observed defects in sperm production. Further, analysis of multiple mutants of these miRNAs suggested genetic interactions between these miRNAs. This study provides insights on the regulatory roles of miRNAs that promote optimal sperm production and fecundity in males and hermaphrodites.

Utility of an Untargeted Metabolomics Approach Using a 2D GC-GC-MS Platform to Distinguish Relapsing and Progressive Multiple Sclerosis.

Multiple sclerosis (MS) is the most common inflammatory neurodegenerative disease of the central nervous system (CNS) in young adults and results in progressive neurological defects. The relapsing-remitting phenotype (RRMS) is the most common disease course in MS, which ultimately progresses to secondary progressive MS (SPMS), while primary progressive MS (PPMS) is a type of MS that worsens gradually over time without remissions. There is a gap in knowledge regarding whether the relapsing form can be distinguished from the progressive course, or healthy subjects (HS) based on an altered serum metabolite profile. In this study, we performed global untargeted metabolomics with the 2D GC-GC-MS platform to identify altered metabolites between RRMS, PPMS, and HS. We profiled 235 metabolites in the serum of patients with RRMS (n = 41), PPMS (n = 31), and HS (n = 91). A comparison of RRMS and HS patients revealed 22 significantly altered metabolites at p < 0.05 (false-discovery rate [FDR] = 0.3). The PPMS and HS comparisons revealed 28 altered metabolites at p < 0.05 (FDR = 0.2). Pathway analysis using MetaboAnalyst revealed enrichment of four metabolic pathways in both RRMS and PPMS (hypergeometric test p < 0.05): (1) galactose metabolism; (2) amino sugar and nucleotide sugar metabolism; (3) phenylalanine, tyrosine, and tryptophan biosynthesis; and (4) aminoacyl-tRNA biosynthesis. The Qiagen IPA enrichment test identified the sulfatase 2 (SULF2) (p = 0.0033) and integrin subunit beta 1 binding protein 1 (ITGB1BP1) (p = 0.0067) genes as upstream regulators of altered metabolites in the RRMS vs. HS groups. However, in the PPMS vs. HS comparison, valine was enriched in the neurodegeneration of brain cells (p = 0.05), and heptadecanoic acid, alpha-ketoisocaproic acid, and glycerol participated in inflammation in the CNS (p = 0.03). Overall, our study suggests that RRMS and PPMS may contribute metabolic fingerprints in the form of unique altered metabolites for discriminating MS disease from HS, with the potential for constructing a metabolite panel for progressive autoimmune diseases such as MS.

Diverse somatic Transformer and sex chromosome karyotype pathways regulate gene expression in Drosophila gonad development.

The somatic sex determination gene transformer (tra) is required for the highly sexually dimorphic development of most somatic cells, including those of the gonads. In addition, somatic tra is required for the germline development even though it is not required for sex determination within germ cells. Germ cell autonomous gene expression is also necessary for their sex determination. To understand the interplay between these signals, we compared the phenotype and gene expression of larval wild-type gonads and the sex-transformed tra gonads. XX larval ovaries transformed into testes were dramatically smaller than wild-type, with significant reductions in germ cell number, likely due to altered geometry of the stem cell niche. Additionally, there was a defect in progression into spermatocyte stages. XY larval testes transformed into ovaries had excessive germ cells, possibly due to the earlier onset of cell division. We suggest that germ cells are neither fully female nor male following somatic sex transformation, with certain pathways characteristic of each sex expressed in tra mutants. We found multiple patterns of somatic and germline gene expression control exclusively due to tra, exclusively due to sex chromosome karyotype, but usually due to a combination of these factors showing tra and sex chromosome karyotype pathways regulate gene expression during Drosophila gonad development.

The Drosophila histone methyltransferase SET1 coordinates multiple signaling pathways in regulating male germline stem cell maintenance and differentiation.

Many tissue-specific adult stem cell lineages maintain a balance between proliferation and differentiation. Here, we study how the H3K4me3 methyltransferase Set1 regulates early-stage male germ cells in Drosophila. Early-stage germline-specific knockdown of Set1 results in temporally progressive defects, arising as germ cell loss and developing into overpopulated early-stage germ cells. These germline defects also impact the niche architecture and cyst stem cell lineage non-cell-autonomously. Additionally, wild-type Set1, but not the catalytically inactive Set1, rescues the Set1 knockdown phenotypes, highlighting the functional importance of the methyltransferase activity of Set1. Further, RNA-sequencing experiments reveal key signaling pathway components, such as the JAK-STAT pathway gene Stat92E and the BMP pathway gene Mad, which are upregulated upon Set1 knockdown. Genetic interaction assays support the functional relationships between Set1 and JAK-STAT or BMP pathways, as both Stat92E and Mad mutations suppress the Set1 knockdown phenotypes. These findings enhance our understanding of the balance between proliferation and differentiation in an adult stem cell lineage. The phenotype of germ cell loss followed by over-proliferation when inhibiting a histone methyltransferase also raises concerns about using their inhibitors in cancer therapy.

Mis-localization of endogenous TDP-43 leads to ALS-like early-stage metabolic dysfunction and progressive motor deficits

BackgroundThe key pathological signature of ALS/ FTLD is the mis-localization of endogenous TDP-43 from the nucleus to the cytoplasm. However, TDP-43 gain of function in the cytoplasm is still poorly understood since TDP-43 animal models recapitulating mis-localization of endogenous TDP-43 from the nucleus to the cytoplasm are missing.MethodsCRISPR/Cas9 technology was used to generate a zebrafish line (called CytoTDP), that mis-locates endogenous TDP-43 from the nucleus to the cytoplasm. Phenotypic characterization of motor neurons and the neuromuscular junction was performed by immunostaining, microglia were immunohistochemically localized by whole-mount tissue clearing and muscle ultrastructure was analyzed by scanning electron microscopy. Behavior was investigated by video tracking and quantitative analysis of swimming parameters. RNA sequencing was used to identify mis-regulated pathways with validation by molecular analysis.ResultsCytoTDP fish have early larval phenotypes resembling clinical features of ALS such as progressive motor defects, neurodegeneration and muscle atrophy. Taking advantage of zebrafish’s embryonic development that solely relys on yolk usage until 5 days post fertilization, we demonstrated that microglia proliferation and activation in the hypothalamus is independent from food intake. By comparing CytoTDP to a previously generated TDP-43 knockout line, transcriptomic analyses revealed that mis-localization of endogenous TDP-43, rather than TDP-43 nuclear loss of function, leads to early onset metabolic dysfunction.ConclusionsThe new TDP-43 model mimics the ALS/FTLD hallmark of progressive motor dysfunction. Our results suggest that functional deficits of the hypothalamus, the metabolic regulatory center, might be the primary cause of weight loss in ALS patients. Cytoplasmic gain of function of endogenous TDP-43 leads to metabolic dysfunction in vivo that are reminiscent of early ALS clinical non-motor metabolic alterations. Thus, the CytoTDP zebrafish model offers a unique opportunity to identify mis-regulated targets for therapeutic intervention early in disease progression.

Biallelic variants in TMIE and PDE6B genes mimic Usher syndrome

In the case of consanguineous families, comorbidity cannot be ruled out. Here, we reported a child of eleven years-old who presented profound congenital hearing impairment and progressive visual defect who was suspected to have Usher syndrome. We searched for mutations in Usher syndrome genes but we failed to detect any. We then performed whole exome sequencing to identify the causality of their phenotype. Interestingly, we found two homozygous missense variants, p.(Arg84Trp) in TMIE, responsible for deafness and p.(His337Arg) in PDE6B, responsible for retinitis pigmentosa. The combination of both variants mimics Usher syndrome. This article highlights the importance of genetics in avoiding clinical misdiagnosis, which is important for genetic counseling and in the perspective of gene therapy.

Clinical risk factors associated with cardiac events in children with BrS-SCN5A

Abstract Introduction between 20-30% of patients with Brugada syndrome (BrS) are carriers of deleterious genetic variants in the SCN5A gene. However, the risk factors for cardiac events in these patients remain under consideration, especially in the paediatric population, with many risk factors being still undetermined. Objectives to investigate and evaluate individual clinical risk factors associated with cardiac events in children with BrS-SCN5A. Methods a Spanish retrospective single-centre paediatric cohort study was conducted including 41 BrS patients under 21 years of age carrying rare variants in the SCN5A gene. Demographic, clinical, genetic, and therapeutic variables were collected. Descriptive and univariate analyses were performed to identify independent risk factors for cardiac events. Outcomes were defined as cardiac syncope, ventricular tachycardia/fibrillation (VT/VF), sudden cardiac death (SCD), and appropriate shock in ICD. Results Nearly 20% of BrS-SCN5A patients presented with cardiac events. Five patients showing cardiogenic syncope, 4-SCD, 3-VT and 2 appropriate shocks in the ICD. The presence of bradycardia and bradyarrhythmia in baseline EKG (P&amp;lt;0.05), AV block type 1 (P&amp;lt;0.02), type 1 Brugada pattern in fever EKG (P&amp;lt;0.02), atrial fibrillation(P&amp;lt;0.05), arrhythmias in febrile episodes (P&amp;lt;0.05), progressive cardiac conduction defect (PCCD; P&amp;lt;0.001), sick sinus syndrome (SSS; P=0.001) and overlap phenotype (P&amp;lt;0.001) were predictor of cardiac events in this cohort. Conclusions We have identified several statistically significant independent risk factors associated with cardiac events and worse phenotype severity in BrS-SCN5A children from a single-centre Spanish cohort. These results may help to improve prognosis assessment, establish accurate risk stratification, and prevent SCD in children with BrS-SCN5A. Future studies in large cohorts of different ethnicities are crucial to strengthen our risk factors in paediatric cohorts at high risk of malignant arrhythmias.

Glaucoma progression due to refraining examination amid the pandemic of COVID-19.

Some patients refrained from seeking an ophthalmologist due to the anxiety and morbidity associated with the coronavirus disease (COVID-19) pandemic. We investigated progressive visual field defects in patients with glaucoma who refrained from ophthalmological examinations. This was a retrospective study. We analyzed data from 886 patients with glaucoma who visited Inouye Eye Hospital in June 2022 and were followed-up prior to January 2020. We examined the number of times patients canceled visits between January 2020 and May 2022 due to coronavirus concerns. We assessed the mean deviation (MD) values of the Humphrey Visual Field Assessment (HFA) program 30-2 SITA Standard values after visit interruptions for worsening beyond the MD values predicted by the MD slope. Factors influencing this difference were analyzed using logistic regression analysis. The study included 374 men and 512 women. The mean age was 68.7 ± 12.0years. Visit interruptions occurred in 146 patients (16.5%), with 95 (65.1%) rescheduling once, 27 (18.5%) twice, and 24 (16.4%) three or more times. Among 90 patients who underwent HFA regularly, 50 (55.6%) experienced worse-than-expected MD values and 12 (13.3%) deteriorated by 2dB or more. Longer interruptions and high intraocular pressure before interruption worsened the MD values by 2dB or more. Patients with glaucoma with visit interruptions due to the pandemic should be monitored for the progression of visual field impairment.

Competing Endogenous RNAs Crosstalk in Hippocampus: A Potential Mechanism for Neuronal Developing Defects in Down Syndrome.

Down syndrome (DS) is the most example of aneuploidy, resulting from an additional copy of all or part of chromosome 21. Competing endogenous RNAs (ceRNAs) play important roles in neuronal development and neurological defects. This study aimed to identify hub genes and synergistic crosstalk among ceRNAs in the DS fetal hippocampus as potential targets for the treatment of DS-related neurodegenerative diseases. We profiled differentially expressed long non-coding RNAs (DElncRNAs), differentially expressed circular RNAs (DEcircRNAs), differentially expressed microRNAs (DEmiRNAs), and differentially expressed messenger RNAs (DEmRNAs) in hippocampal samples from patients with or without DS. Functional enrichment analysis and gene set enrichment analysis were performed, and chromosome 21-related ceRNA and protein-protein interaction networks were constructed. Additionally, the correlations between lncRNA-mRNA and miRNA-mRNA expression in the samples and HEK293T cells were validated. Our finding of changes in the expression of some key genes and ncRNAs on chromosome 21 in DS might not fully conform to the gene dosage hypothesis. Moreover, we found that four lncRNAs (MIR99AHG, PLCB4, SNHG14, GIGYF2) and one circRNA (hsa_circ_0061697) may competitively bind with three miRNAs (hsa-miR-548b-5p, miR-730-5p, and hsa-miR-548i) and subsequently regulate five mRNAs (beta-1,3-galactosyltransferase 5 [B3GALT5], helicase lymphoid-specific [HELLS], thrombospondin-2 [THBS2], glycinamide ribonucleotide transformylase [GART], clathrin heavy chain like 1 [CLTCL1]). These RNAs, whether located on chromosome 21 or not, interact with each other and might activate the PI3K/Akt/mTOR and Wnt signaling pathways, which are involved in autophagosome formation and tau hyperphosphorylation, possibly leading to adverse consequences of trisomy 21. These findings provide researchers with a better understanding of the fundamental molecular mechanisms underlying DS-related progressive defects in neuronal development.

The pancancer overexpressed NFYCAntisense 1 controls cell cycle mitotic progression through in cis and in trans modes of action

Antisense RNAs (asRNAs) represent an underappreciated yet crucial layer of gene expression regulation. Generally thought to modulate their sense genes in cis through sequence complementarity or their act of transcription, asRNAs can also regulate different molecular targets in trans, in the nucleus or in the cytoplasm. Here, we performed an in-depth molecular characterization of NFYCAntisense1 (NFYC-AS1), the asRNA transcribed head-to-head to NFYC subunit of the proliferation-associated NF-Y transcription factor. Our results show that NFYC-AS1 is a prevalently nuclear asRNA peaking early in the cell cycle. Comparative genomics suggests a narrow phylogenetic distribution, with a probable origin in the common ancestor of mammalian lineages. NFYC-AS1 is overexpressed pancancer, preferentially in association with RB1 mutations. Knockdown of NFYC-AS1 by antisense oligonucleotides impairs cell growth in lung squamous cell carcinoma and small cell lung cancer cells, a phenotype recapitulated by CRISPR/Cas9-deletion of its transcription start site. Surprisingly, expression of the sense gene is affected only when endogenous transcription of NFYC-AS1 is manipulated. This suggests that regulation of cell proliferation is at least in part independent of the in cis transcription-mediated effect on NFYC and is possibly exerted by RNA-dependent in trans effects converging on the regulation of G2/M cell cycle phase genes. Accordingly, NFYC-AS1-depleted cells are stuck in mitosis, indicating defects in mitotic progression. Overall, NFYC-AS1 emerged as a cell cycle-regulating asRNA with dual action, holding therapeutic potential in different cancer types, including the very aggressive RB1-mutated tumors.

Loss of mitochondrial DNA is associated with reduced DNA content variability in Saccharomyces cerevisiae.

DNA content measurement by fluorescence-assisted cell sorting (FACS) provides information on cell cycle progression and DNA content variability. Saccharomyces cerevisiae mutants with DNA content variability that was reduced relative to wild-type strains had defects in mitochondrial DNA (mtDNA) maintenance and mitochondrial gene expression and were correlated with strains found to lack mtDNA ([ rho 0 ] cells) by genome sequencing and fluorescence microscopy. In contrast, mutants with increased variability had defects in cell cycle progression, which may indicate a loss of coordination between mtDNA and nuclear DNA replication. Thus, FACS measurement of DNA content variability can provide insight into cell-to-cell heterogeneity in mtDNA copy number.

A Progressive Feature Fusion-Based Manhole Cover Defect Recognition Method

A Progressive Feature Fusion-Based Manhole Cover Defect Recognition Method

PRSS50-mediated inhibition of MKP3/ERK signaling is crucial for meiotic progression and sperm quality.

Serine protease 50 (PRSS50/TSP50) is highly expressed in spermatocytes. Our study investigated its role in testicular development and spermatogenesis. Initially, PRSS50 knockdown was observed to impair DNA synthesis in spermatocytes. To further explore this, we generated PRSS50 knockout ( Prss50 -/- ) mice ( Mus musculus), which exhibited abnormal spermatid nuclear compression and reduced male fertility. Furthermore, dysplastic seminiferous tubules and decreased sex hormones were observed in 4-week-old Prss50 -/- mice, accompanied by meiotic progression defects and increased apoptosis of spermatogenic cells. Mechanistic analysis indicated that PRSS50 deletion resulted in increased phosphorylation of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) and elevated levels of MAP kinase phosphatase 3 (MKP3), a specific ERK antagonist, potentially accounting for testicular dysplasia in adolescent Prss50 -/- mice. Taken together, these findings suggest that PRSS50 plays an important role in testicular development and spermatogenesis, with the MKP3/ERK signaling pathway playing a significant role in this process.

The AP-2 complex interacts with γ-TuRC and regulates the proliferative capacity of neural progenitors.

Centrosomes are organelles that nucleate microtubules via the activity of gamma-tubulin ring complexes (γ-TuRC). In the developing brain, centrosome integrity is central to the progression of the neural progenitor cell cycle, and its loss leads to microcephaly. We show that NPCs maintain centrosome integrity via the endocytic adaptor protein complex-2 (AP-2). NPCs lacking AP-2 exhibit defects in centrosome formation and mitotic progression, accompanied by DNA damage and accumulation of p53. This function of AP-2 in regulating the proliferative capacity of NPCs is independent of its role in clathrin-mediated endocytosis and is coupled to its association with the GCP2, GCP3, and GCP4 components of γ-TuRC. We find that AP-2 maintains γ-TuRC organization and regulates centrosome function at the level of MT nucleation. Taken together, our data reveal a novel, noncanonical function of AP-2 in regulating the proliferative capacity of NPCs and open new avenues for the identification of novel therapeutic strategies for the treatment of neurodevelopmental and neurodegenerative disorders with AP-2 complex dysfunction.