Differentiation Of Neural Cells Research Articles

FBLN2 is associated with Goldenhar syndrome and is essential for cranial neural crest cell development.

Goldenhar syndrome, a rare craniofacial malformation, is characterized by developmental anomalies in the first and second pharyngeal arches. Its etiology is considered to be heterogenous, including both genetic and environmental factors that remain largely unknown. To further elucidate the genetic cause in a five-generation Goldenhar syndrome pedigree and exploit the whole-exome sequencing (WES) data of this pedigree, we generated collapsed haplotype pattern markers based on WES and employed rare variant nonparametric linkage analysis. FBLN2 was identified as a candidate gene via analysis of WES data across the significant linkage region. A fbln2 knockout zebrafish line was established by CRISPR/Cas9 to examine the gene's role in craniofacial cartilage development. fbln2 was expressed specifically in the mandible during the zebrafish early development, while fbln2 knockout zebrafish exhibited craniofacial malformations with abnormal chondrocyte morphologies. Functional studies revealed that fbln2 knockout caused abnormal chondrogenic differentiation, apoptosis, and proliferation of cranial neural crest cells (CNCCs), and downregulated the bone morphogenic protein (BMP) signaling pathway in the zebrafish model. This study demonstrates the role of FBLN2 in CNCC development and BMP pathway regulation, and highlights FBLN2 as a candidate gene for Goldenhar syndrome, which may have implications for the selection of potential screening targets and the development of treatments for conditions like microtia-atresia.

Aligned polycaprolactone/polyaniline electrospun nanofibers for directing neural stem cell differentiation and neuron arrangement

The use of engineered biomimetic substrates combined with neural stem cells (NSCs) constitutes a promising approach to develop reliable in vitro models of the nervous tissue. The fabrication of scaffolds with suitable compositional, topographical, and electrical properties is crucial for directing neural cell adhesion, differentiation, and arrangement. Herein, we propose the development of electroconductive polycaprolactone/polyaniline (PCL/PANI) electrospun mats as functional substrates for NSC culture. A rotating drum collector was employed to obtain fibers with aligned geometry. According to the results, the increase in alignment contributed to the reduction of fiber diameter and the increase of scaffold mechanical properties in terms of elastic modulus and tensile strength. In vitro experiments demonstrated the ability of PCL/PANI membranes to support NSC attachment and growth, as well as significantly foster neuronal differentiation. Furthermore, the presence of an aligned pattern was shown to effectively influence the arrangement of NSC-derived neurons, confirming the potential of this substrate for the design of a physiologically relevant culture platform for in vitro investigation of the nervous tissue.

An injectable hydrogel loaded with GMSCs-derived neural lineage cells promotes recovery after stroke.

Ischemic stroke is a devastating medical condition with poor prognosis due to the lack of effective treatment modalities. Transplantation of human neural stem cells or primary neural cells is a promising treatment approach, but this is hindered by limited suitable cell sources and low in vitro expansion capacity. This study aimed i) to use small molecules to reprogram gingival mesenchymal stem cells (GMSCs) commitment to the neural lineage cells in vitro, and ii) to use hyaluronic acid (HA) hydrogel scaffolds seeded with GMSCs-derived neural lineage cells to treat ischemic stroke invivo. Neural induction was carried out with a small molecule cocktail-based one-step culture protocol over a period of 24 hours. The induced cells were analyzed for expression of neural markers with immunocytochemistry and qRT-PCR. The SD rats (n=100) were subjected to the middle cerebral artery occlusion (MCAO) reperfusion ischemic stroke model. Then, after 8 days post-MCAO, the modelled rats were randomly assigned to six study groups (n=12 per group): (i) GMSCs, (ii) GMSCs-derived neural lineage cells, (iii) HA and GMSCs-derived neural lineage cells, (iv) HA, (v) PBS, and (vi) sham transplantation control, and received their respective transplantation. Evaluation of post-stroke recovery were performed by the behavioral tests and histological assessments. The morphologically altered nature of neural lineages has been observed of the GMSCs treated with small molecules compared to the untreated controls. As shown by the qRT-PCR and immunocytochemistry, small molecules further signifcantly enhanced the experession level of neural markers of GMSCs as compared with the untreated controls (all p<0.05). Intracerebral injection of self-assembling HA hydrogel carrying GMSCs-derived neural lineage cells promoted the recovery of neural function and reduced ischemic damage in rats with ischemic stroke, as demonstrated by histological examination and behavioral assessments (all p<0.05). In conclusion, the small molecule cocktail significantly enhanced the differentiation of GMSCs into neural lineage cells. The HA hydrogel was found to facilitate the proliferation and differentiation of GMSCs-derived neural lineage cells. Furthermore, HA hydrogel seeded with GMSCs-derived neural lineage cells could promote tissue repair and functional recovery in rats with ischemic stroke and may be a promising alternative treatment modality for stroke.

Abstract PS02-05: Trajectories and predictors of peripheral neuropathy after neoadjuvant chemotherapy in a prospective cohort of 11,014 patients with early breast cancer

Abstract Background Peripheral neuropathy (PN) is a debilitating adverse event in patients with early breast cancer (BC) receiving (neo)adjuvant chemotherapy (CT). We harnessed the CANTO cohort study to detail clinical trajectories and explore clinical and genetic predictors of PN. Methods CANTO (CANcer TOxicities - NCT01993498) prospectively enrolled invasive stage I-III BC patients (pts) of 26 French comprehensive cancer centers. Pts were assessed at diagnosis, 3-6 (M6), 12 (M12), 36 (M36), and 60 (M60) months after treatment, defined as completion of surgery, CT or radiotherapy, whichever comes last. At each time point, PN events including paresthesia, sensory and motor neuropathy were collected according to NCI-CTC v4.0 criteria. A genome-wide association study (GWAS) was conducted to identify genetic predictors of PN, using Illumina GSA BeadChips. Minimac4/1000G was used to impute additional single nucleotide polymorphisms (SNPs). After stringent quality control measures, 1,894,475 SNPs with a minor allele frequency (MAF) &amp;gt;0.05 were evaluated. Longitudinal trajectories of PN events were descriptively examined. Statistical associations between each SNP and PN events measured at different time points, and between SNPs and trajectories, were performed with logistic regression assuming a log-additive genetic model. All analyses were adjusted for key clinical parameters and the first ten axes of principal component analysis of the genetic data to control for population stratification. Results Of 12,012 included pts (data lock Aug. 2022), 11,014 (91.7%) were analyzed. Age was &amp;lt; 50 and &amp;gt;65 in 3407 and 2759 pts (31% and 25%, respectively). Overweight/obesity and diabetes were recorded in 5328 (48%) and 458 pts (4%). A neurologic history was observed in 1360 pts (13%). Stage 0-I and II-III were observed in 5356 (49%) and 5512 pts (51%), and 4011 pts had an axillary dissection (37%). CT was administered in 5790 pts (53%), including a taxane (tax) in 5542 pts (96%). Shortly, all grade and grade 2+ PN was observed in 29% and 12%; 27% and 10%; 20% and 10%; 13% and 10% of pts at M6, M12, M36 and M60, respectively. We derived 5 trajectories of overall PN, deemed “never”, “always”, “appears”, “transient” and “disappears”, in respectively 54%, 10%, 9%, 7% and 19% of the pts. Similar trajectories were built for the 3 categories of PN events. We built 9 predictive nomograms including key clinical parameters and time of analysis. E.g., grade 2+ PN at M6 was independently predicted by a medical history of carpal tunnel syndrome, past neurologic history and exposure to tax. Grade 2+ PN at M36 was predicted by past neurologic history and exposure to tax, and largely by previous PN at M6 or M12. The GWAS analysis included 7633 pts (84%). Four independent SNPs adding predictive value to the clinical nomograms were identified at a suggestive level of association (p &amp;lt; 1e-6), including one SNP in the NCAM1 gene (involved in neurogenesis) for M6 PN (OR=1.40, 95%CI 1.23-1.60, p=4.8e-7, see table) and one SNP in the CLDN11 gene (regulates oligodendrocytes) for M12 sensory PN (OR=1.32; 95%CI 1.17-1.49, p=7.5e-6). For rare ( &amp;lt; 5%) toxicities, 10 independent suggestive SNPs were identified, including one SNP in the NELL1 gene (neural cell growth regulation and differentiation) for the “always” trajectory (OR=1.61, 95%CI 1.31-1.99, p=7.6e-6) and one SNP in the KCNIP1 gene (neuronal sensor) for M36 motor PN (OR=1.5, 95%CI 1.7-3.5, p=3.1e-07). Conclusions Risk of early peripheral neuropathy is associated with previous neurological history and taxane exposure. Patients with PN at M6 or M12 are highly exposed to long-term PN. Some key SNPs may add independent predictive value for specific PN endpoints. Exploratory results of interest were produced for rarer toxicities and typical clinical trajectories. Detailed results will be presented at the meeting. All PN, M6 Multivariate analyses of the risk of peripheral neuropathy, all grades, at M6, without and with GWAS input. Citation Format: Youenn Drouet, Emilie Thomas, Florence Lerebours, Barbara Pistilli, Olivier Trédan, Christelle Jouannaud, Marion Fournier, Philippe Rouanet, Laurence Vanlemmens, CHARLES COUTANT, Asma Dhaini Merimeche, Baptiste Sauterey, Christelle Levy, Mario Campone, Carole Tarpin, Marie-Ange Mouret-Reynier, Olivier Rigal, Thierry Petit, Sophie Guillermet, Antoine Arnaud, Mahmoud Ibrahim, Sylvie Giacchetti, Florence Dalenc, Johanna Wassermann, Olivier Arsène, Ariane Darut-Jouve, Sibille Everhard, Ines Vaz Luis, Anne-Laure Martin, Fabrice André, Jean-François Deleuze, Alain Viari, Matthieu Carton, Paul Cottu. Trajectories and predictors of peripheral neuropathy after neoadjuvant chemotherapy in a prospective cohort of 11,014 patients with early breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS02-05.

Size-Optimized Layered Double Hydroxide Nanoparticles Promote Neural Progenitor Cells Differentiation of Embryonic Stem Cells Through the Regulation of M6A Methylation.

The committed differentiation fate regulation has been a difficult problem in the fields of stem cell research, evidence showed that nanomaterials could promote the differentiation of stem cells into specific cell types. Layered double hydroxide (LDH) nanoparticles possess the regulation function of stem cell fate, while the underlying mechanism needs to be investigated. In this study, the process of embryonic stem cells (ESCs) differentiate to neural progenitor cells (NPCs) by magnesium aluminum LDH (MgAl-LDH) was investigated. MgAl-LDH with diameters of 30, 50, and 100 nm were synthesized and characterized, and their effects on the cytotoxicity and differentiation of NPCs were detected in vitro. Dot blot and MeRIP-qPCR were performed to detect the level of m6A RNA methylation in nanoparticles-treated cells. Our work displayed that LDH nanoparticles of three different sizes were biocompatible with NPCs, and the addition of MgAl-LDH could significantly promote the process of ESCs differentiate to NPCs. 100 nm LDH has a stronger effect on promoting NPCs differentiation compared to 30 nm and 50 nm LDH. In addition, dot blot results indicated that the enhanced NPCs differentiation by MgAl-LDH was closely related to m6A RNA methylation process, and the major modification enzyme in LDH controlled NPCs differentiation may be the m6A RNA methyltransferase METTL3. The upregulated METTL3 by LDH increased the m6A level of Sox1 mRNA, enhancing its stability. This work reveals that MgAl-LDH nanoparticles can regulate the differentiation of ESCs into NPCs by increasing m6A RNA methylation modification of Sox1.

Biocompatible antibiotic-coupled nickel-titanium nanoparticles as a potential coating material for biomedical devices

The challenges facing metallic implants for reconstructive surgery include the leaching of toxic metal ions, a mismatch in elastic modulus between the implant and the treated tissue, and the risk of infection. These problems can be addressed by passivating the metal surface with an organic substrate and incorporating antibiotic molecules. Nitinol (NiTi), a nickel-titanium alloy, is used in devices for biomedical applications due to its shape memory and superelasticity. However, unmodified NiTi carries a risk of localized nickel toxicity and inadequately supports angiogenesis or neuroregeneration due to limited cell adhesion, poor biomineralization, and little antibacterial activity. To address these challenges, NiTi nanoparticles were modified using self-assembled phosphonic acid monolayers and functionalized with the antibiotics ceftriaxone and vancomycin via the formation of an amide. Surface modifications were monitored to confirm that phosphonic acid modifications were present on NiTi nanoparticles and 100% of the samples formed ordered films. Modifications were stable for more than a year. Elemental composition showed the presence of nickel, titanium, and phosphorus (1.9% for each sample) after surface modifications. Dynamic light scattering analysis suggested some agglomeration in solution. However, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy confirmed a particle size distribution of <100 nm, the even distribution of nanoparticles on coverslips, and elemental composition before and after cell culture. B35 neuroblastoma cells exhibited no inhibition of survival and extended neurites of approximately 100 μm in total length when cultured on coverslips coated with only poly-l-lysine or with phosphonic acid-modified NiTi, indicating high biocompatibility. The ability to support neural cell growth and differentiation makes modified NiTi nanoparticles a promising coating for surfaces in metallic bone and nerve implants. NiTi nanoparticles functionalized with ceftriaxone inhibited Escherichia coli and Serratia marcescens (SM6) at doses of 375 and 750 μg whereas the growth of Bacillus subtilis was inhibited by a dose of only 37.5 μg. NiTi-vancomycin was effective against B. subtilis at all doses even after mammalian cell culture. These are common bacteria associated with infected implants, further supporting the potential use of functionalized NiTi in coating reconstructive implants.

Harnessing developmental dynamics of spinal cord extracellular matrix improves regenerative potential of spinal cord organoids

Neonatal spinal cord tissues exhibit remarkable regenerative capabilities as compared to adult spinal cord tissues after injury, but the role of extracellular matrix (ECM) in this process has remained elusive. Here, we found that early developmental spinal cord had higher levels of ECM proteins associated with neural development and axon growth, but fewer inhibitory proteoglycans, compared to those of adult spinal cord. Decellularized spinal cord ECM from neonatal (DNSCM) and adult (DASCM) rabbits preserved these differences. DNSCM promoted proliferation, migration, and neuronal differentiation of neural progenitor cells (NPCs) and facilitated axonal outgrowth and regeneration of spinal cord organoids more effectively than DASCM. Pleiotrophin (PTN) and Tenascin (TNC) in DNSCM were identified as contributors to these abilities. Furthermore, DNSCM demonstrated superior performance as a delivery vehicle for NPCs and organoids in spinal cord injury (SCI) models. This suggests that ECM cues from early development stages might significantly contribute to the prominent regeneration ability in spinal cord.

Reduced mTORC1-signaling in progenitor cells leads to retinal lamination deficits.

Neuronal lamination is a hallmark of the mammalian central nervous system (CNS) and underlies connectivity and function. Initial formation of this tissue architecture involves the integration of various signaling pathways that regulate the differentiation and migration of neural progenitor cells. Here, we demonstrate that mTORC1 mediates critical roles during neuronal lamination using the mouse retina as a model system. Down-regulation of mTORC1-signaling in retinal progenitor cells by conditional deletion of Rptor led to decreases in proliferation and increased apoptosis during embryogenesis. These developmental deficits preceded aberrant lamination in adult animals which was best exemplified by the fusion of the outer and inner nuclear layer and the absence of an outer plexiform layer. Moreover, ganglion cell axons originating from each Rptor-ablated retina appeared to segregate to an equal degree at the optic chiasm with both contralateral and ipsilateral projections displaying overlapping termination topographies within several retinorecipient nuclei. In combination, these visual pathway defects led to visually mediated behavioral deficits. This study establishes a critical role for mTORC1-signaling during retinal lamination and demonstrates that this pathway regulates diverse developmental mechanisms involved in driving the stratified arrangement of neurons during CNS development.

Synergistic Effect of Electrical and Biochemical Stimulation on Human iPSC-Derived Neural Differentiation in a Microfluidic Electrode Array Chip.

Neural differentiation is crucial for advancing our understanding of the nervous system and developing treatments for neurological disorders. The advanced methods and the ability to manipulate the alignment, proliferation, and differentiation of stem cells are essential for studying neuronal development and synaptic interactions. However, the utilization of human induced pluripotent stem cells (iPSCs) for disease modeling of neurodegenerative conditions may be constrained by the prolonged duration and uncontrolled cell differentiation required for functional neural cell differentiation. Here, we developed a microfluidic chip to enhance the differentiation and maturation of specific neural lineages by placing aligned microelectrodes on the glass surface to regulate the neural differentiation of human iPSCs. The utilization of electrical stimulation (ES) in conjunction with neurotrophic factors (NF) significantly enhanced the efficiency in generating functional neurons from human iPSCs. We also observed that the simultaneous application of NF and ES to human iPSCs promoted their differentiation and maturation into functional neurons while increasing synaptic interactions. Our research demonstrated the effect of combining NF and ES on human iPSC-derived neural differentiation.

Aberrant DNA methylation distorts developmental trajectories in atypical teratoid/rhabdoid tumors.

Atypical teratoid/rhabdoid tumors (AT/RTs) are pediatric brain tumors known for their aggressiveness and aberrant but still unresolved epigenetic regulation. To better understand their malignancy, we investigated how AT/RT-specific DNA hypermethylation was associated with gene expression and altered transcription factor binding and how it is linked to upstream regulation. Medulloblastomas, choroid plexus tumors, pluripotent stem cells, and fetal brain were used as references. A part of the genomic regions, which were hypermethylated in AT/RTs similarly as in pluripotent stem cells and demethylated in the fetal brain, were targeted by neural transcriptional regulators. AT/RT-unique DNA hypermethylation was associated with polycomb repressive complex 2 and linked to suppressed genes with a role in neural development and tumorigenesis. Activity of the several NEUROG/NEUROD pioneer factors, which are unable to bind to methylated DNA, was compromised via the suppressed expression or DNA hypermethylation of their target sites, which was also experimentally validated for NEUROD1 in medulloblastomas and AT/RT samples. These results highlight and characterize the role of DNA hypermethylation in AT/RT malignancy and halted neural cell differentiation.

TARGET ONCOGENIC RECEPTORS IN TUMOURS, FROM ITS INITIAL CLINICAL BREAKTHROUGHS TO CURRENT CLINICAL STANDARD THERAPY

Epidermal growth factor (EGF) is a polypeptide hormone originally isolated from mouse submaxillary gland, which is a potent mitogen for a wide variety of culture cells of both epithelial and mesenchymal origin, and its important role in the proliferation, differentiation, and survival of neural and glial precursor cells. The physiological effects of EGF are mediated by an EGF receptor with tyrosine-specific protein kinase activity. The traditionally accepted view is that normal epidermal growth factor receptor (EGFR) is no tumorigenic, whereas mutated EGFR such as an oncogenic receptor EGFRvIII is oncogenic. In recent, it has been implicated that EGF could be beneficial for burn, wound healing, diabetic foot ulcer, and show an attractive perspective. In addition, cosmetic containing EGF would be effective in improving the plasticity of skin, helps in anti-aging and whitening, and controls the amount of erythema and sebum in the skin. In our team we have successfully prepared a series of 350 bottles of Shampoo liquid and 26 bottles of recombinant human EGF (rhEGF) spray, and 4 bottles of EGF-Silvadence ointment. The initial results indicated that prepared rhEGF is safe and available in clinical use. On the other hand, progress on the interaction of EGF with its altered oncogenic receptor signaling through its downstream molecules such Ras/Raf/MAPK (see figure in the full text, George Zhu,1991) and/or PI3k/akt pathway in the development of some cancers such as A431 human epidermoid carcinoma cells, brain glioblastoma, breast, pancreas and lung cancers. In addition to a series of gefitinib, erlotinib, osimertinib and the CIMA vax-EGF vaccine, an antioncogenic receptor antibody based fusion protein [for example Cetuximab-based IL-10 fusion protein, CmAb-(IL10)2] provide a potential strategy to improve cancer immunotherapy. Peer Review History: Received 1 December 2023; Revised 26 January 2024; Accepted 2 March; Available online 15 March 2024 Academic Editor: Dr. Tamer Elhabibi, Suez Canal University, Egypt, tamer_hassan@pharm.suez.edu.eg Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 8.0/10 Reviewers: Dr. Bilge Ahsen KARA, Ankara Gazi Mustafa Kemal Hospital, Turkey, ahsndkyc@gmail.com Dr. Asia Selman Abdullah, University of Basrah, Iraq, asia_abdullah65@yahoo.com

ZEB2 alleviates Hirschsprung’s-associated enterocolitis by promoting the proliferation and differentiation of enteric neural precursor cells via the Notch-1/Jagged-2 pathway

BackgroundHirschsprung’s-associated enterocolitis (HAEC) is a prevalent complication of Hirschsprung’s disease (HSCR). Zinc finger E-box binding homeobox 2 (ZEB2) and Notch-1/Jagged-2 are dysregulated in HSCR, but their role in HAEC progression remains poorly understood. We aimed to explore the role and underlying mechanism of enteric neural precursor cells (ENPCs) and the ZEB2/Notch-1/Jagged-2 pathway in HAEC development. MethodsColon tissues were collected from HSCR and HAEC patients. ENPCs were isolated from the HAEC group and stimulated by lipopolysaccharide (LPS). The expressions of ZEB2/Notch-1/Jagged-2 were measured using RT-qPCR and Western blot. Immunofluorescence and cell counting kit-8 assays were performed to assess the differentiation and proliferation of ENPCs. Inflammatory factors were measured by ELISA kits. Co-immunoprecipitation and bioinformatic analysis were used to explore the interaction between ZEB2 and Notch-1. Small interfering RNA and overexpression vectors were used to investigate the role and mechanism of ZEB2 and Notch-1 in regulating ENPCs' proliferation and differentiation during HAEC progression. ResultsWe observed increased LPS in the colon tissues of HAEC, with downregulated ZEB2 expression and upregulated Notch-1/Jagged-2 expression. ZEB2 interacts with Notch-1. LPS treatment downregulated ZEB2 expression, upregulated Notch-1/Jagged-2 expression, and induced proliferation and differentiation disorders in ENPCs, which were reversed by the knockdown of Notch-1. Furthermore, overexpression of ZEB2 inhibited Notch-1/Jagged-2 signaling and ameliorated inflammation and dysfunction in LPS-induced ENPCs. Notch-1 overexpression enhanced LPS-induced dysfunction, but this effect was antagonized by the overexpression of ZEB2. ConclusionOverexpression of ZEB2 ameliorates LPS-induced ENPCs' dysfunction via the Notch-1/Jagged-2 pathway, thus playing a role in HAEC.

The long coiled-coil protein NECC2 regulates oxLDL-induced endothelial oxidative damage and exacerbates atherosclerosis development in apolipoprotein E −/− mice

Oxidized low density lipoprotein (oxLDL)-induced endothelial oxidative damage promotes the development of atherosclerosis. Caveolae play an essential role in maintaining the survival and function of vascular endothelial cell (VEC). It is reported that the long coiled-coil protein NECC2 is localized in caveolae and is associated with neural cell differentiation and adipocyte formation, but its role in VECs needs to be clarified. Our results showed NECC2 expression increased in the endothelium of plaque-loaded aortas and oxLDL-treated HUVECs. Down-regulation of NECC2 by NECC2 siRNA or compound YF-307 significantly inhibited oxLDL-induced VEC apoptosis and the adhesion factors expression. Remarkably, inhibition of NECC2 expression in the endothelium of apoE−/− mice by adeno-associated virus (AAV)-carrying NECC2 shRNA or compound YF-307 alleviated endothelium injury and restricted atherosclerosis development. The immunoprecipitation results confirmed that NECC2 interacted with Tyk2 and caveolin-1(Cav-1) in VECs, and NECC2 further promoted the phosphorylation of Cav-1 at Tyr14 b y activating Tyk2 phosphorylation. On the other hand, inhibiting NECC2 levels suppressed oxLDL-induced phosphorylation of Cav-1, uptake of oxLDL by VECs, accumulation of intracellular reactive oxygen species and activation of NF-κB. Our findings suggest that NECC2 may contribute to oxLDL-induced VEC injury and atherosclerosis via modulating Cav-1 phosphorylation through Tyk2. This work provides a new concept and drug target for treating atherosclerosis.

Genetic architecture of the structural connectome

Myelinated axons form long-range connections that enable rapid communication between distant brain regions, but how genetics governs the strength and organization of these connections remains unclear. We perform genome-wide association studies of 206 structural connectivity measures derived from diffusion magnetic resonance imaging tractography of 26,333 UK Biobank participants, each representing the density of myelinated connections within or between a pair of cortical networks, subcortical structures or cortical hemispheres. We identify 30 independent genome-wide significant variants after Bonferroni correction for the number of measures studied (126 variants at nominal genome-wide significance) implicating genes involved in myelination (SEMA3A), neurite elongation and guidance (NUAK1, STRN, DPYSL2, EPHA3, SEMA3A, HGF, SHTN1), neural cell proliferation and differentiation (GMNC, CELF4, HGF), neuronal migration (CCDC88C), cytoskeletal organization (CTTNBP2, MAPT, DAAM1, MYO16, PLEC), and brain metal transport (SLC39A8). These variants have four broad patterns of spatial association with structural connectivity: some have disproportionately strong associations with corticothalamic connectivity, interhemispheric connectivity, or both, while others are more spatially diffuse. Structural connectivity measures are highly polygenic, with a median of 9.1 percent of common variants estimated to have non-zero effects on each measure, and exhibited signatures of negative selection. Structural connectivity measures have significant genetic correlations with a variety of neuropsychiatric and cognitive traits, indicating that connectivity-altering variants tend to influence brain health and cognitive function. Heritability is enriched in regions with increased chromatin accessibility in adult oligodendrocytes (as well as microglia, inhibitory neurons and astrocytes) and multiple fetal cell types, suggesting that genetic control of structural connectivity is partially mediated by effects on myelination and early brain development. Our results indicate pervasive, pleiotropic, and spatially structured genetic control of white-matter structural connectivity via diverse neurodevelopmental pathways, and support the relevance of this genetic control to healthy brain function.

BRG1 establishes the neuroectodermal chromatin landscape to restrict dorsal cell fates.

Cell fate decisions are achieved with gene expression changes driven by lineage-specific transcription factors (TFs). These TFs depend on chromatin remodelers including the Brahma-related gene 1 (BRG1)-associated factor (BAF) complex to activate target genes. BAF complex subunits are essential for development and frequently mutated in cancer. Thus, interrogating how BAF complexes contribute to cell fate decisions is critical for human health. We examined the requirement for the catalytic BAF subunit BRG1 in neural progenitor cell (NPC) specification from human embryonic stem cells. During the earliest stages of differentiation, BRG1 was required to establish chromatin accessibility at neuroectoderm-specific enhancers. Depletion of BRG1 dorsalized NPCs and promoted precocious neural crest specification and enhanced neuronal differentiation. These findings demonstrate that BRG1 mediates NPC specification by ensuring proper expression of lineage-specific TFs and appropriate activation of their transcriptional programs.

Rho kinase inhibitor Y27632 promotes survival of human induced pluripotent stem cells during differentiation into functional midbrain dopaminergic progenitor cells in vitro

To improve the efficiency of induced differentiation of primitive neural epithelial cells derived from human induced pluripotent stem cells (hiPSCs-NECs) into functional midbrain dopaminergic progenitor cells (DAPs). HiPSCs were cultured in mTeSRTM medium containing DMH1 (10 μmol/L), SB431542 (10 μmol/L), SHH (200 ng/mL), FGF8 (100 ng/mL), purmorphamine (2 μmol/L), CHIR99021 (3 μmol/L), and N2 (1%) for 12 days to induce their differentiation into primitive neuroepithelial cells (NECs). The hiPSCs-NECs were digested with collagenase Ⅳ and then cultured in neurobasal medium supplemented with 1% N2, 2% B27-A, BDNF (10 ng/mL), GDNF (10 ng/mL), AA, TGF-β, cAMP, and 1% GlutaMax in the presence of different concentrations of Rho kinase inhibitor Y27632, and the culture medium was changed the next day to remove Y27632. Continuous induction was performed until day 28 to obtain DAPs. Human iPSCs expressed the pluripotency markers OCT4, SOX2, Nanog, and SSEA1 and were positive for alkaline phosphatase staining. The hiPSCs-NECs were obtained on day 13 in the form of neural rosettes expressing neuroepithelial markers SOX2, nestin, and PAX6. In digested hiPSCs-NECs, the addition of 5 μmol/L Y27632 significantly promoted survival of the adherent cells, increased cell viability and the proportion of S-phase cells (P < 0.01), and reduced the rate of apoptotic cells (P < 0.05). On day 28 of induction, the obtained cells highly expressed the specific markers of DAPS (TH, FOXA2, NURR1, and Tuj1). Treatment with Y27632 (5 μmol/L) for 24 h significantly promotes the survival of human iPSCs-NECs during their differentiation into DPAs without affecting the cell differentiation, which indirectly enhances the efficiency of cell differentiation.

Assessment of SOX10 expression in 437 canine neoplasms of different embryologic origins.

Several members of the SRY-related HMG-box (SOX) protein family are implicated in tumorigenesis, metastasis, and regulation of the tumor microenvironment. SOX10, which is involved in neural crest cell migration and differentiation, has long been recognized a sensitive and specific immunohistochemical (IHC) marker in the diagnosis of melanoma in humans. However, expression of SOX10 in other tumor types has infrequently been evaluated in humans until recently and has not been thoroughly investigated in the dog. Our aim was to characterize the expression of SOX10 in canine neoplasms to objectively assess its value as a diagnostic IHC marker. Immunohistochemistry for SOX10 was performed on 437 archived, formalin-fixed paraffin-embedded tissues from representative canine neoplasms of ectodermal (15 tumor types), mesodermal (13 tumor types), endodermal (8 tumor types), and mixed/unknown (7 tumor types) embryologic origin. Oral and cutaneous tumors of melanocytic origin were used as positive controls. Intense SOX10 immunolabeling was observed in most tumors of ectodermal origin, including consistent expression in mammary carcinomas, and gliomas. Embryonal and hair follicle neoplasms inconsistently exhibited strong nuclear immunolabeling. Oral fibrosarcomas and undifferentiated oral sarcomas both inconsistently exhibited moderate to strong nuclear immunolabeling. Neoplasms of mesodermal and endodermal origin lacked immunolabeling. Salivary carcinomas, representing an unknown/mixed embryologic origin, were strongly labeled. SOX10 expression is not limited to melanomas, but is expressed by canine tumors of diverse tissues and embryologic derivation. Importantly, expression of SOX10 by a subset of oral sarcomas impairs its value as a marker for spindle cell oral melanomas.

Controlled Assembly and Disassembly of Higher-Order Peptide Nanotubes.

The controlled peptide self-assembly and disassembly are not only implicated in many cellular processes but also possess huge application potential in a wide range of biotechnology and biomedicine. β-sheet peptide assemblies possess high kinetic stability, so it is usually hard to disassemble them rapidly. Here, we reported that both the self-assembly and disassembly of a designed short β-sheet peptide IIIGGHK could be well harnessed through the variations of concentration, pH, and mechanical stirring. Microscopic imaging, neutron scattering, and infrared spectroscopy were used to track the assembly and disassembly processes upon these stimuli, especially the interconversion between thin, left-handed protofibrils and higher-order nanotubes with superstructural right-handedness. The underlying rationale for these controlled disassembly processes mainly lies in the fact that the specific His-His interactions between protofibrils were responsive to these stimuli. By taking advantage of the peptide self-assembly and disassembly, the encapsulation of the hydrophobic drug curcumin and its rapid release upon stimuli were achieved. Additionally, the peptide hydrogels facilitated the differentiation of neural cells while maintaining low cell cytotoxicity. We believe that such dynamic and reversible structural transformation in this work provides a distinctive paradigm for controlling the peptide self-assembly and disassembly, thus laying a foundation for practical applications of peptide assemblies.

CUL4B mutations impair human cortical neurogenesis through PP2A-dependent inhibition of AKT and ERK

Mutation in CUL4B gene is one of the most common causes for X-linked intellectual disability (XLID). CUL4B is the scaffold protein in CUL4B-RING ubiquitin ligase (CRL4B) complex. While the roles of CUL4B in cancer progression and some developmental processes like adipogenesis, osteogenesis, and spermatogenesis have been studied, the mechanisms underlying the neurological disorders in patients with CUL4B mutations are poorly understood. Here, using 2D neuronal culture and cerebral organoids generated from the patient-derived induced pluripotent stem cells and their isogenic controls, we demonstrate that CUL4B is required to prevent premature cell cycle exit and precocious neuronal differentiation of neural progenitor cells. Moreover, loss-of-function mutations of CUL4B lead to increased synapse formation and enhanced neuronal excitability. Mechanistically, CRL4B complex represses transcription of PPP2R2B and PPP2R2C genes, which encode two isoforms of the regulatory subunit of protein phosphatase 2 A (PP2A) complex, through catalyzing monoubiquitination of H2AK119 in their promoter regions. CUL4B mutations result in upregulated PP2A activity, which causes inhibition of AKT and ERK, leading to premature cell cycle exit. Activation of AKT and ERK or inhibition of PP2A activity in CUL4B mutant organoids rescues the neurogenesis defect. Our work unveils an essential role of CUL4B in human cortical development.

Single-cell multiomics decodes regulatory programs for mouse secondary palate development

Perturbations in gene regulation during palatogenesis can lead to cleft palate, which is among the most common congenital birth defects. Here, we perform single-cell multiome sequencing and profile chromatin accessibility and gene expression simultaneously within the same cells (n = 36,154) isolated from mouse secondary palate across embryonic days (E) 12.5, E13.5, E14.0, and E14.5. We construct five trajectories representing continuous differentiation of cranial neural crest-derived multipotent cells into distinct lineages. By linking open chromatin signals to gene expression changes, we characterize the underlying lineage-determining transcription factors. In silico perturbation analysis identifies transcription factors SHOX2 and MEOX2 as important regulators of the development of the anterior and posterior palate, respectively. In conclusion, our study charts epigenetic and transcriptional dynamics in palatogenesis, serving as a valuable resource for further cleft palate research.