HNRNPU's multi-tasking is essential for proper cortical development.

Heterogeneous nuclear ribonucleoprotein U (HNRNPU) is a nuclear protein that plays a crucial role in various biological functions, such as RNA splicing and chromatin organization. HNRNPU/scaffold attachment factor A (SAF-A) activities are essential for regulating gene expression, DNA replication, genome integrity, and mitotic fidelity. These functions are critical to ensure the robustness of developmental processes, particularly those involved in shaping the human brain. As a result, HNRNPU is associated with various neurodevelopmental disorders (HNRNPU-related neurodevelopmental disorder, HNRNPU-NDD) characterized by developmental delay and intellectual disability. Our research demonstrates that the loss of HNRNPU function results in the death of both neural progenitor cells and post-mitotic neurons, with a higher sensitivity observed in the former. We reported that HNRNPU truncation leads to the dysregulation of gene expression and alternative splicing of genes that converge on several signaling pathways, some of which are likely to be involved in the pathology of HNRNPU-related NDD.

Using multi-organ culture systems to study Parkinson's disease.

In recent years, it has been revealed that Parkinson's disease pathology may begin to manifest in the gastrointestinal track at a much earlier time point than in the brain. This paradigm shift has been suggested following evidence in humans that has been reproduced in animal models. Since rodent models cannot recapitulate many of the human disease features, human induced pluripotent stem cells derived from Parkinson's patients have been used to generate brain organoids, greatly contributing to our understanding of the disease pathophysiology. To understand the multifaced aspects of Parkinson's disease, it may be desirable to expand the complexity of these models, to include different brain regions, vasculature, immune cells as well as additional diverse organ-specific organoids such as gut and intestine. Furthermore, the contribution of gut microbiota to disease progression cannot be underestimated. Recent biotechnological advances propose that such combinations may be feasible. Here we discuss how this need can be met and propose that additional brain diseases can benefit from this approach.

A Quality Improvement Initiative Is Associated With Reduced Time to Administer Biologics and Small Molecules and Emergency Room Visits in Inflammatory Bowel Disease.

BACKGROUND: Delays in biologic or small molecule medication administration are associated with increased adverse events, hospitalization, and surgery in inflammatory bowel disease (IBD). We evaluated the impact of a quality improvement (QI) intervention on the time to administration of biologics or small molecules (TABS) in IBD. METHODS: Data were retrospectively extracted for IBD patients prescribed biologics or small molecules from a convenience sample of providers participating in an accredited QI educational intervention (baseline cohort). Subsequent to the intervention, data were prospectively collected from patients prescribed these medications (postintervention cohort). Dates related to steps between a treatment decision to medication administration were collected. The primary outcome compared TABS in baseline and postintervention cohorts. RESULTS: Eighteen physicians provided survey and patient data for 200 patients in each cohort (n=400). The median time to medication administration (TABS) decreased from baseline to postintervention cohorts (30 vs. 26 d, P=0.04). Emergency room visits before medication administration also decreased (25.5% vs. 12.5%, P=0.001). Similar numerical TABS reductions were observed in subgroups limited to physicians providing patients to both cohorts and for individual medications prescribed. Primary contributors to delays included filling prescriptions subsequent to insurance approval and dispensation subsequent to this. CONCLUSIONS: A QI intervention successfully reduced medication administration times (TABS) by accelerating provider-dependent steps. This intervention was associated with reduced emergency room visits. We propose TABS as a quality metric to assess the effective delivery of therapies in IBD. Further evaluation of QI interventions, patient education on prescription drug insurance, and quality metrics are warranted.

Proteomics insights into infantile neuronal ceroid lipofuscinosis (CLN1) point to the involvement of cilia pathology in the disease.

Mutations in the depalmitoylation enzyme, palmitoyl protein thioesterase (PPT1), result in the early onset neurodegenerative disease known as Infantile Neuronal Ceroid Lipofuscinosis. Here, we provide proteomic evidence suggesting that PPT1 deficiency could be considered as a ciliopathy. Analysis of membrane proteins from brain enriched for acylated proteins from neonate Ppt1 knock out and control mice revealed a list of 88 proteins with differential expression levels. Amongst them, we identified Rab3IP, which regulates ciliogenesis in concert with Rab8 and Rab11. Immunostaining analysis revealed that PPT1 is localized in the cilia. Indeed, an unbiased proteomics analysis on isolated cilia revealed 660 proteins, which differed in their abundance levels between wild type and Ppt1 knock out. We demonstrate here that Rab3IP, Rab8 and Rab11 are palmitoylated, and that palmitoylation of Rab11 is required for correct intracellular localization. Cells and brain preparations from Ppt1-/- mice exhibited fewer cells with cilia and abnormally longer cilia, with both acetylated tubulin and Rab3IP wrongly distributed along the length of cilia. Most importantly, the analysis revealed a difference in the distribution and levels of the modified proteins in cilia in the retina of mutant mice versus the wildtype, which may be important in the early neurodegenerative phenotype. Overall, our results suggest a novel link between palmitoylated proteins, cilial organization and the pathophysiology of Neuronal Ceroid Lipofuscinosis.

Notch Activation by Shootin1 Opposing Activities on 2 Ubiquitin Ligases.

The evolutionarily conserved Notch pathway plays an important role in regulation of stem cell renewal and cell fate determination in numerous organs, and as such is a key pathway in normal health and disease processes. Canonical Notch signaling is usually activated by cell contact where transmembrane ligands such as Delta-like and Jagged bind to Notch receptors. Notch activation results in the translocation of the cleaved Notch intracellular domain (NICD) into the nucleus and subsequent activation of transcription. Poly-ubiquitination leading to proteosome degradation of pathway components is one mean of regulating the Notch pathway. Here, we identified that Shootin1 exhibits the surprising propensity of activating the pathway either by interacting with LNX1/2 and promoting poly-ubiquitination of Numb or by complexing with Itch and impairing poly-ubiquitination of NICD. Within the developing brain Shootin1 modulates neuroblasts cell fate by executing 2 opposing activities on ubiquitin ligases, which control Notch signaling on 2 different levels.

Protein S Regulates Neural Stem Cell Quiescence and Neurogenesis.

Neurons are continuously produced in brains of adult mammalian organisms throughout life-a process tightly regulated to ensure a balanced homeostasis. In the adult brain, quiescent Neural Stem Cells (NSCs) residing in distinct niches engage in proliferation, to self-renew and to give rise to differentiated neurons and astrocytes. The mechanisms governing the intricate regulation of NSC quiescence and neuronal differentiation are not completely understood. Here, we report the expression of Protein S (PROS1) in adult NSCs, and show that genetic ablation of Pros1 in neural progenitors increased hippocampal NSC proliferation by 47%. We show that PROS1 regulates the balance of NSC quiescence and proliferation, also affecting daughter cell fate. We identified the PROS1-dependent downregulation of Notch1 signaling to correlate with NSC exit from quiescence. Notch1 and Hes5 mRNA levels were rescued by reintroducing Pros1 into NCS or by supplementation with purified PROS1, suggesting the regulation of Notch pathway by PROS1. Although Pros1-ablated NSCs show multilineage differentiation, we observed a 36% decrease in neurogenesis, coupled with a similar increase in astrogenesis, suggesting PROS1 is instructive for neurogenesis, and plays a role in fate determination, also seen in aged mice. Rescue experiments indicate PROS1 is secreted by NSCs and functions by a NSC-endogenous mechanism. Our study identifies a duple role for PROS1 in stem-cell quiescence and as a pro-neurogenic factor, and highlights a unique segregation of increased stem cell proliferation from enhanced neuronal differentiation, providing important insight into the regulation and control of NSC quiescence and differentiation. Stem Cells 2017;35:679-693.

Self-Reported Training Adequacy, Experience, and Comfort Level in Performing Schizophrenia-Related Clinical Skills among Psychiatry Residents and Fellows.

OBJECTIVE: In the context of an educational program on schizophrenia for psychiatry trainees, this survey study analyzed associations between self-reported training adequacy, experience in providing patient care, and comfort level in performing schizophrenia-related clinical skills. The influence of the education on comfort level was also assessed for each skill. METHODS: Survey respondents were psychiatry residents and fellows who participated in a schizophrenia education program at an in-person workshop or through online videos recorded at the workshop. In a pre-program survey, participants reported their experience in providing schizophrenia patient care and rated their training adequacy and comfort level for performing seven clinical skills involved in diagnosing and treating schizophrenia. The post-program survey included items for reassessing comfort level in performing the skills. RESULTS: Across the seven clinical skills, the proportion of respondents (n = 79) who agreed or strongly agreed that their training was adequate ranged from 29 to 88 %. The proportion of high ratings for comfort level in skill performance ranged from 45 to 83 %. Comfort level was significantly associated with training adequacy for all seven clinical skills and with experience in providing patient care for four skills. For all skills, comfort level ratings were significantly higher after versus before the educational workshop. Commonly indicated needs for further training included education on new therapies, exposure to a broader range of patients, and opportunities for longitudinal patient management. CONCLUSIONS: Psychiatry trainees' self-reported, disease-specific training adequacy, experiences, and comfort level have unique applications for developing and evaluating graduate medical curriculum.

The spinal muscular atrophy with pontocerebellar hypoplasia gene VRK1 regulates neuronal migration through an amyloid-ß precursor protein-dependent mechanism.

Spinal muscular atrophy with pontocerebellar hypoplasia (SMA-PCH) is an infantile SMA variant with additional manifestations, particularly severe microcephaly. We previously identified a nonsense mutation in Vaccinia-related kinase 1 (VRK1), R358X, as a cause of SMA-PCH. VRK1-R358X is a rare founder mutation in Ashkenazi Jews, and additional mutations in patients of different origins have recently been identified. VRK1 is a nuclear serine/threonine protein kinase known to play multiple roles in cellular proliferation, cell cycle regulation, and carcinogenesis. However, VRK1 was not known to have neuronal functions before its identification as a gene mutated in SMA-PCH. Here we show that VRK1-R358X homozygosity results in lack of VRK1 protein, and demonstrate a role for VRK1 in neuronal migration and neuronal stem cell proliferation. Using shRNA in utero electroporation in mice, we show that Vrk1 knockdown significantly impairs cortical neuronal migration, and affects the cell cycle of neuronal progenitors. Expression of wild-type human VRK1 rescues both proliferation and migration phenotypes. However, kinase-dead human VRK1 rescues only the migration impairment, suggesting the role of VRK1 in neuronal migration is partly noncatalytic. Furthermore, we found that VRK1 deficiency in human and mouse leads to downregulation of amyloid-ß precursor protein (APP), a known neuronal migration gene. APP overexpression rescues the phenotype caused by Vrk1 knockdown, suggesting that VRK1 affects neuronal migration through an APP-dependent mechanism.

Continuing Medical Education Improves Gastroenterologists' Compliance with Inflammatory Bowel Disease Quality Measures.

BACKGROUND: Low rates of compliance with quality measures for inflammatory bowel disease (IBD) have been reported for US gastroenterologists. AIMS: We assessed the influence of quality improvement (QI) education on compliance with physician quality reporting system (PQRS) measures for IBD and measures related to National Quality Strategy (NQS) priorities. METHODS: Forty community-based gastroenterologists participated in the QI study; 20 were assigned to educational intervention and control groups, respectively. At baseline, randomly selected charts of patients with moderate-to-severe ulcerative colitis were retrospectively reviewed for the gastroenterologists' performance of 8 PQRS IBD measures and 4 NQS-related measures. The intervention group participated in a series of accredited continuing medical education (CME) activities focusing on QI. Follow-up chart reviews were conducted 6 months after the CME activities. Independent t tests were conducted to compare between-group differences in baseline-to-follow-up rates of documented compliance with each measure. RESULTS: The analysis included 299 baseline charts and 300 follow-up charts. The intervention group had significantly greater magnitudes of improvement than the control group for the following measures: assessment of IBD type, location, and activity (+14 %, p = 0.009); influenza vaccination (+13 %, p = 0.025); pneumococcal vaccination (+20 %, p = 0.003); testing for latent tuberculosis before anti-TNF-α therapy (+10 %, p = 0.028); assessment of hepatitis B virus status before anti-TNF-α therapy (+9 %, p = 0.010); assessment of side effects (+17 %, p = 0.048), and counseling patients about cancer risks (+13 %, p = 0.013). CONCLUSIONS: QI-focused CME improves community-based gastroenterologists' compliance with IBD quality measures and measures aligned with NQS priorities.

Shootin1 acts in concert with KIF20B to promote polarization of migrating neurons.

Shootin1 has been ascribed a role in regulating polarization of primary hippocampal neurons. To better understand the possible role of Shootin1 in the developing brain, we identified a member of the kinesin superfamily, KIF20B, as a novel Shootin1 interacting protein and a potential mediator of Shootin1 interaction with microtubules. KIF20B/Shootin1 binding was mapped to a 57 aa KIF20B sequence, which was used as a dominant-negative fragment. Direct interaction between that peptide (MBD) and Shootin1 was confirmed by surface plasmon resonance-based technology and the affinity was determined in the 10⁻7 m range. The proteins are expressed in the developing brain and formed a complex in vivo based on coimmunoprecipitation experiments and coimmunostaining in primary neurons. In primary hippocampal neurons Kif20b knockdown reduced Shootin1 mobilization to the developing axon, as evidenced by immunostaining and fluorescence recovery after photobleaching analysis, suggesting that Shootin1 is a novel KIF20B cargo. shRNA targeting of Shootin1 reduced PIP3 accumulation in the growth cone, as did Kif20b shRNA. In the developing mouse brain, Kif20b knockdown or expression of the KIF20B minimal binding domain inhibited neuronal migration, and in vivo migration assays suggested that Shootin1/Kif20b acts in the same genetic pathway. Time-lapse imaging of multipolar cells in the subventricular zone revealed that downregulating levels of either Shootin1 or Kif20b hindered the transition from multipolar to bipolar cells. Collectively, our data demonstrate the importance of the Shootin1/KIF20B interaction to the dynamic process of pyramidal neuronal polarization and migration.

Tau's role in the developing brain: implications for intellectual disability.

Microdeletions encompassing the MAPT (Tau) locus resulting in intellectual disability raised the hypothesis that Tau may regulate early functions in the developing brain. Our results indicate that neuronal migration was inhibited in mouse brains following Tau reduction. In addition, the leading edge of radially migrating neurons was aberrant in spite of normal morphology of radial glia. Furthermore, intracellular mitochondrial transport and morphology were affected. In early postnatal brains, a portion of Tau knocked down neurons reached the cortical plate. Nevertheless, they exhibited far less developed dendrites and a striking reduction in connectivity evident by the size of boutons. Our novel results strongly implicate MAPT as a dosage-sensitive gene in this locus involved in intellectual disability. Furthermore, our results are likely to impact our understanding of other diseases involving Tau.

Ndel1 palmitoylation: a new mean to regulate cytoplasmic dynein activity.

Regulated activity of the retrograde molecular motor, cytoplasmic dynein, is crucial for multiple biological activities, and failure to regulate this activity can result in neuronal migration retardation or neuronal degeneration. The activity of dynein is controlled by the LIS1-Ndel1-Nde1 protein complex that participates in intracellular transport, mitosis, and neuronal migration. These biological processes are subject to tight multilevel modes of regulation. Palmitoylation is a reversible posttranslational lipid modification, which can dynamically regulate protein trafficking. We found that both Ndel1 and Nde1 undergo palmitoylation in vivo and in transfected cells by specific palmitoylation enzymes. Unpalmitoylated Ndel1 interacts better with dynein, whereas the interaction between Nde1 and cytoplasmic dynein is unaffected by palmitoylation. Furthermore, palmitoylated Ndel1 reduced cytoplasmic dynein activity as judged by Golgi distribution, VSVG and short microtubule trafficking, transport of endogenous Ndel1 and LIS1 from neurite tips to the cell body, retrograde trafficking of dynein puncta, and neuronal migration. Our findings indicate, to the best of our knowledge, for the first time that Ndel1 palmitoylation is a new mean for fine-tuning the activity of the retrograde motor cytoplasmic dynein.

Mark/Par-1 marking the polarity of migrating neurons.

Proper brain development requires the orchestrated migration of neurons from their place of birth to their final positioning, where they will form appropriate connections with their target cells. These events require coordinated activity of multiple elements of the cytoskeleton, in which the MARK/Par-1 polarity kinase plays an important role. Here, the various roles and modes of regulation of MARK/Par-1 are reviewed. MARK/Par-1 participates in axon formation in primary hippocampal neurons. Balanced levels of MARK/Par-1 are required for proper radial migration, as well as for migration in the rostral migratory stream. Normal neuronal migration requires at least two of MARK/Par-1 substrates, DCX and tau. Overall, the positioning of MARK/Par-1 at the crosstalk of regulating cytoskeletal dynamics allows its participation in neuronal polarity decisions.

Growth of Remote Therapeutic Monitoring Lands New Opportunities for Case Management.

PURPOSE/OBJECTIVES: An increase in the use of remote therapeutic monitoring (RTM) has been spurred by nationwide factors including the COVID-19 pandemic, authorized reimbursement of RTM by the Centers for Medicare & Medicaid Services, and more frequent use of big data analytics in health care delivery. This article discusses the use of RTM by care teams at the point of care and explores the role of the case manager in RTM to address patients' unmet needs. PRIMARY PRACTICE SETTINGS: Although RTM may be utilized across inpatient and outpatient levels of care, this article focuses on outpatient care such as community clinics, provider groups, and home health care. FINDINGS/CONCLUSIONS: When implemented along with care management interventions, RTM applications have the potential to improve patient adherence, enhance communication between patients and their providers, streamline resource allocation, and address social determinants of health impacting patient care and outcomes. IMPLICATIONS FOR CASE MANAGEMENT PRACTICE: RTM reimbursement models are rapidly evolving, utilizing real-world and patient-reported data to identify and initiate timely, individualized solutions that meet the holistic needs of each patient. Use of an RTM system allows the case manager to build rapport with the patient while quickly identifying care gaps and delivering appropriate interventions that can maximize patient outcomes. RTM can drive savings and bring revenue to the system or practice while providing salient documentation of social determinants of health that can be addressed with validation of proven care coordination interventions.

MARK2/Par-1 guides the directionality of neuroblasts migrating to the olfactory bulb.

In rodents and most other mammals studied, neuronal precursors generated in the subventricular zone (SVZ) migrate to the adult olfactory bulb (OB) to differentiate into interneurons called granule and periglomerular cells. How the newborn cells navigate in the postnatal forebrain to reach precisely their target area is largely unknown. However, it is often thought that postnatal neurogenesis recapitulates the neuronal development occurring during embryogenesis. During brain development, intracellular kinases are key elements for controlling cell polarization as well as the coupling between polarization and cellular movement. We show here that the polarity kinase MARK2 maintains its expression in the postnatal SVZ-OB system. We therefore investigated the potential role of this kinase in adjusting postnatal neuroblast migration. We employed mouse brain slices maintained in culture, in combination with lentiviral vector injections designed to label neuronal precursors with GFP and to diminish the expression of MARK2. Time-lapse video microscopy was used to monitor neuroblast migration in the postnatal forebrain from SVZ precursors to cells populating the OB. We found that reduced MARK2 expression resulted in altered migratory patterns and stalled neuroblasts in the rostral migratory stream (RMS). In agreement with the observed migratory defects, we report a diminution of the proportion of cells reaching the OB layers. Our study reveals the involvement of MARK2 in the maintenance of the migratory direction in postnatally-generated neuroblasts and consequently on the control of the number of newly-generated neurons reaching and integrating the appropriate target circuits.

Evidence of shared transcriptomic dysregulation of HNRNPU-related disorder between human organoids and embryonic mice.

Generating effective therapies for neurodevelopmental disorders has remained elusive. An emerging drug discovery approach for neurodevelopmental disorders is to characterize transcriptome-wide dysregulation in an appropriate model system and screen therapeutics based on their capacity to restore functionally relevant expression patterns. We characterized transcriptomic dysregulation in a human model of HNRNPU-related disorder to explore the potential of such a paradigm. We identified widespread dysregulation in functionally relevant pathways and then compared dysregulation in a human model to transcriptomic differences in embryonic and perinatal mice to determine whether dysregulation in an in vitro human model is partially replicated in an in vivo model of HNRNPU-related disorder. Strikingly, we find enrichment of co-dysregulation between 45-day-old human organoids and embryonic, but not perinatal, mice from distinct models of HNRNPU-related disorder. Thus, hnRNPU deficient human organoids may only be suitable to model transcriptional dysregulation in certain cell types within a specific developmental time window.

LIS1 RNA-binding orchestrates the mechanosensitive properties of embryonic stem cells in AGO2-dependent and independent ways.

Lissencephaly-1 (LIS1) is associated with neurodevelopmental diseases and is known to regulate the molecular motor cytoplasmic dynein activity. Here we show that LIS1 is essential for the viability of mouse embryonic stem cells (mESCs), and it governs the physical properties of these cells. LIS1 dosage substantially affects gene expression, and we uncovered an unexpected interaction of LIS1 with RNA and RNA-binding proteins, most prominently the Argonaute complex. We demonstrate that LIS1 overexpression partially rescued the extracellular matrix (ECM) expression and mechanosensitive genes conferring stiffness to Argonaute null mESCs. Collectively, our data transforms the current perspective on the roles of LIS1 in post-transcriptional regulation underlying development and mechanosensitive processes.

Brain Organization and Human Diseases.

The cortex is a highly organized structure that develops from the caudal regions of the segmented neural tube. Its spatial organization sets the stage for future functional arealization. Here, we suggest using a developmental perspective to describe and understand the etiology of common cortical malformations and their manifestation in the human brain.

Heterogeneous nuclear ribonucleoprotein U (HNRNPU) safeguards the developing mouse cortex.

HNRNPU encodes the heterogeneous nuclear ribonucleoprotein U, which participates in RNA splicing and chromatin organization. Microdeletions in the 1q44 locus encompassing HNRNPU and other genes and point mutations in HNRNPU cause brain disorders, including early-onset seizures and severe intellectual disability. We aimed to understand HNRNPU's roles in the developing brain. Our work revealed that HNRNPU loss of function leads to rapid cell death of both postmitotic neurons and neural progenitors, with an apparent higher sensitivity of the latter. Further, expression and alternative splicing of multiple genes involved in cell survival, cell motility, and synapse formation are affected following Hnrnpu's conditional truncation. Finally, we identified pharmaceutical and genetic agents that can partially reverse the loss of cortical structures in Hnrnpu mutated embryonic brains, ameliorate radial neuronal migration defects and rescue cultured neural progenitors' cell death.