Comparative study of enriched dopaminergic neurons from siblings with Gaucher disease discordant for parkinsonism

Inducible pluripotent stem cells (iPSCs) derived from patient samples have significantly enhanced our ability to model neurological diseases. Comparative studies of dopaminergic (DA) neurons differentiated from iPSCs derived from siblings with Gaucher disease discordant for parkinsonism provides a valuable avenue to explore genetic modifiers contributing to GBA1 -associated parkinsonism in disease-relevant cells. However, such studies are often complicated by the inherent heterogeneity in differentiation efficiency among iPSC lines derived from different individuals. To address this technical challenge, we devised a selection strategy to enrich dopaminergic (DA) neurons expressing tyrosine hydroxylase (TH). A neomycin resistance gene (neo) was inserted at the C-terminus of the TH gene following a T2A self-cleavage peptide, placing its expression under the control of the TH promoter. This allows for TH+ DA neuron enrichment through geneticin selection. This method enabled us to generate comparable, high-purity DA neuron cultures from iPSC lines derived from three sisters that we followed for over a decade: one sibling is a healthy individual, and the other two have Gaucher disease (GD) with GBA1 genotype N370S/c.203delC+R257X (p.N409S/c.203delC+p.R296X). Notably, the younger sister with GD later developed Parkinson disease (PD). A comprehensive analysis of these high-purity DA neurons revealed that although GD DA neurons exhibited decreased levels of glucocerebrosidase (GCase), there was no substantial difference in GCase protein levels or lipid substrate accumulation between DA neurons from the GD and GD/PD sisters, suggesting that the PD discordance is related to of other genetic modifiers.

Molecular profiling of human substantia nigra identifies diverse neuron types associated with vulnerability in Parkinson's disease

Parkinson's disease (PD) is characterized pathologically by the loss of dopaminergic (DA) neurons in the substantia nigra (SN). Whether cell types beyond DA neurons in the SN show vulnerability in PD remains unclear. Through transcriptomic profiling of 315,867 high-quality single nuclei in the SN from individuals with and without PD, we identified cell clusters representing various neuron types, glia, endothelial cells, pericytes, fibroblasts, and T cells and investigated cell type-dependent alterations in gene expression in PD. Notably, a unique neuron cluster marked by the expression of RIT2, a PD risk gene, also displayed vulnerability in PD. We validated RIT2-enriched neurons in midbrain organoids and the mouse SN. Our results demonstrated distinct transcriptomic signatures of the RIT2-enriched neurons in the human SN and implicated reduced RIT2 expression in the pathogenesis of PD. Our study sheds light on the diversity of cell types, including DA neurons, in the SN and the complexity of molecular and cellular changes associated with PD pathogenesis.

Disruption of lysosomal proteolysis in astrocytes facilitates midbrain organoid proteostasis failure in an early-onset Parkinson's disease model

Accumulation of advanced glycation end products (AGEs) on biopolymers accompanies cellular aging and drives poorly understood disease processes. Here, we studied how AGEs contribute to development of early onset Parkinson's Disease (PD) caused by loss-of-function of DJ1, a protein deglycase. In induced pluripotent stem cell (iPSC)-derived midbrain organoid models deficient for DJ1 activity, we find that lysosomal proteolysis is impaired, causing AGEs to accumulate, α-synuclein (α-syn) phosphorylation to increase, and proteins to aggregate. We demonstrated these processes are at least partly driven by astrocytes, as DJ1 loss reduces their capacity to provide metabolic support and triggers acquisition of a pro-inflammatory phenotype. Consistently, in co-cultures, we find that DJ1-expressing astrocytes are able to reverse the proteolysis deficits of DJ1 knockout midbrain neurons. In conclusion, astrocytes' capacity to clear toxic damaged proteins is critical to preserve neuronal function and their dysfunction contributes to the neurodegeneration observed in a DJ1 loss-of-function PD model.

Development of ELIP to Assess Physical Literacy for Emerging Adults: A Methodological and Epistemological Challenge

Purpose: Following increased interest in physical literacy (PL), development of appropriate tools for assessment has become an important next step for its operationalization. To forward the development of such tools, the objective of this study was to build the foundations of the Évaluation de la Littératie Physique (ELIP), designed to help reduce existing tensions in approaches to PL assessment that may be resulting in a low uptake into applied settings. Methods: We followed two steps: (1) the development of the first version of ELIP by deploying a Delphi method (n = 30); and (2) the modification of items through cognitive interviews with emerging adults (n = 32). Results: The expert consensus highlighted four dimensions of PL to be assessed-physical; affective; cognitive; and social-with new perspectives, including a preference for broad motor tests over fitness. Conclusion: Results offer new insights into the assessment of emerging adults' PL, but ELIP still requires further work concerning validity, reliability, and sensitivity.

Novel human pluripotent stem cell-derived hypothalamus organoids demonstrate cellular diversity

The hypothalamus is a region of the brain that plays an important role in regulating body functions and behaviors. There is a growing interest in human pluripotent stem cells (hPSCs) for modeling diseases that affect the hypothalamus. Here, we established an hPSC-derived hypothalamus organoid differentiation protocol to model the cellular diversity of this brain region. Using an hPSC line with a tyrosine hydroxylase (TH)-TdTomato reporter for dopaminergic neurons (DNs) and other TH-expressing cells, we interrogated DN-specific pathways and functions in electrophysiologically active hypothalamus organoids. Single-cell RNA sequencing (scRNA-seq) revealed diverse neuronal and non-neuronal cell types in mature hypothalamus organoids. We identified several molecularly distinct hypothalamic DN subtypes that demonstrated different developmental maturities. Our in vitro 3D hypothalamus differentiation protocol can be used to study the development of this critical brain structure and can be applied to disease modeling to generate novel therapeutic approaches for disorders centered around the hypothalamus.

The Impact of Physical Activity Restrictions on Health-Related Fitness in Children with Congenital Heart Disease

Children with congenital heart disease (CHD) are often restricted from some types of physical activity (PA) despite the lack of evidence regarding the need to restrict recreational PA, apart from those with rhythm disorders. This study retrospectively investigated the associations between parent-reported activity restrictions (on-going need to restrict exertion, body contact or competition) and measures of health-related fitness among 236 children (8.2 ± 2.1 years, range 4−12 years) treated for single ventricle (n = 104), tetralogy of Fallot (n = 48), transposition of the great arteries (n = 47) or atrial septal defect (n = 37). Body mass index (BMI), moderate-to-vigorous physical activity (MVPA; 7 day accelerometry), strength, flexibility, and movement skill assessment results were collected from the baseline assessment research records for two studies completed in Ontario, Canada. A subset of 62 children also had physician-reported activity restrictions. Regression models empirically tested the goodness of fit between the dependent and independent variables. Participants with body contact restrictions from both parents and physicians had significantly higher BMI z-scores (0.23 ± 1.19 vs. −0.32 ± 0.85; t = 2.55; p = 0.04 and 0.66 ± 1.33 vs. −0.02 ± 0.98; t = 2.25; p = 0.02 for CDC and WHO scores, respectively). Otherwise, BMI z-score was not associated with patient variables (p > 0.36; sex, cardiac diagnosis, age, or activity restriction). Children with any type of parent-reported restriction (0.98 ± 2.06 vs. −0.08 ± 1.99; t = 3.77; p = 0.0002) were less flexible. Movement skill (TGMD-2) scores were 50% lower (25.1 ± 31.2 vs. 52.6 ± 28.6; F = 6.93; p = 0.009) among children with parent-reported competitive sport restrictions. Weekly MVPA (p > 0.18) and strength (p > 0.05) were not associated with activity restriction. Children whose parents reported PA restrictions were less flexible, and had decreased movement skill and increased BMI z-scores if the restrictions impacted competitive sport or body contact, respectively. Future research is recommended to confirm these results among larger samples of children who have both parent- and physician-specified PA restrictions.

Proteomic profiling dataset of chemical perturbations in multiple biological backgrounds

While gene expression profiling has traditionally been the method of choice for large-scale perturbational profiling studies, proteomics has emerged as an effective tool in this context for directly monitoring cellular responses to perturbations. We previously reported a pilot library containing 3400 profiles of multiple perturbations across diverse cellular backgrounds in the reduced-representation phosphoproteome (P100) and chromatin space (Global Chromatin Profiling, GCP). Here, we expand our original dataset to include profiles from a new set of cardiotoxic compounds and from astrocytes, an additional neural cell model, totaling 5300 proteomic signatures. We describe filtering criteria and quality control metrics used to assess and validate the technical quality and reproducibility of our data. To demonstrate the power of the library, we present two case studies where data is queried using the concept of "connectivity" to obtain biological insight. All data presented in this study have been deposited to the ProteomeXchange Consortium with identifiers PXD017458 (P100) and PXD017459 (GCP) and can be queried at https://clue.io/proteomics .

Canadian Assessment of Physical Literacy in grades 7-9 (12-16 years): Preliminary validity and descriptive results

Background: The Canadian Assessment of Physical Literacy (CAPL) accurately and reliably assesses the physical literacy level of young children. However, in preliminary analyses ceiling effects were noted among 183 older children. The purposes of this study were to assess the validity of a modified CAPL designed for older children (CAPL 789) and to offer descriptive results.Methods: CAPL 789 assessed the physical literacy of Canadian children in grades 7-9. Data were collected from schools and recreation facilities in the provinces of Alberta and Ontario (Canada), yielding a new sample of 245 participants (129 girls, 13.7 ± 0.9 years). Descriptive statistics were calculated for all CAPL domains. Age and gender effects were examined to support the validity.Results: Physical competence score (/32) increased with age (F = 4.90, p < 0.05), the means in grades 7-9 being 18.9 ± 3.2, 20.9 ± 4.4 and 21.2 ± 3.4, respectively. Girls scored significantly higher (t = -2.29, p < 0.05) than boys (6.6 ± 1.2 vs 6.3 ± 1.3) in the knowledge assessment (/10).Conclusion: The CAPL 789 was feasible among children from grades 7-9. Additional research is required to establish the psychometric properties in children 12 to 16 years.

New Reference Values for Cardiopulmonary Exercise Testing in Children

INTRODUCTION

Cardiopulmonary exercise testing is an essential tool to assess cardiorespiratory fitness (CRF) in children. There is a paucity of adequate pediatric reference values that are independent of body size and pubertal stage. The purpose of this study is to provide Z score equations for several maximal and submaximal CRF parameters derived from a prospectively recruited sample of healthy children.

METHODS

In this cross-sectional multicenter study, we prospectively recruited 228 healthy children 12 to 17 yr old in local schools. We performed a symptom-limited cardiopulmonary exercise testing progressive ramp protocol on an electronically braked cycle ergometer. Eighteen CRF parameters were analyzed. We tested several regression models to obtain prediction curves that minimized residual association with age, body size, and pubertal stage. Both the predicted mean and the predicted SD were modeled to account for heteroscedasticity.

RESULTS

We identified nonlinear association of CRF parameters with body size and significant heteroscedasticity. To normalize CRF parameters, the use of a single body size variable was not sufficient. We therefore used multivariable models with various combination of height, corrected body mass, and age. Final prediction models yielded adjusted CRF parameters that were independent of age, sex, body mass, height, body mass index, and Tanner stages.

CONCLUSIONS

We present Z score equations for several CRF parameters derived from a healthy pediatric population. These reference values provide updated predicted means and range of normality that are independent of sex and body size. Further testing is needed to assess if these reference values increase sensitivity and specificity to identify abnormal cardiorespiratory response in children with chronic diseases.

Compact radio emission indicates a structured jet was produced by a binary neutron star merger

The binary neutron star merger event GW170817 was detected through both electromagnetic radiation and gravitational waves. Its afterglow emission may have been produced by either a narrow relativistic jet or an isotropic outflow. High-spatial-resolution measurements of the source size and displacement can discriminate between these scenarios. We present very-long-baseline interferometry observations, performed 207.4 days after the merger by using a global network of 32 radio telescopes. The apparent source size is constrained to be smaller than 2.5 milli-arc seconds at the 90% confidence level. This excludes the isotropic outflow scenario, which would have produced a larger apparent size, indicating that GW170817 produced a structured relativistic jet. Our rate calculations show that at least 10% of neutron star mergers produce such a jet.

A Possible Method to Control Prolongations of Bleeding Time under Antiplatelet Therapy with Ticlopidine

The interactions of oral and i.v. administrations of corticosteroids with the effects of ticlopidine were studied, in a search for an antidote for possible excessive prolongations of bleeding time induced by antiaggregating agents. Indeed, the results show that an i.v. injection of methylprednisolone or an oral treatment with prednisolone counteract the prolongation of bleeding time but do not interfere with the inhibition of platelet aggregation brought about by ticlopidine. This could be ascribed to a vasoconstrictive effect of corticosteroids, possibly through reduction of vascular prostacyclin release. If this mode of action was confirmed, this useful finding would essentially apply to ticlopidine, but not to cyclooxygenase inhibitors such as aspirin which, by themselves, abolish prostacyclin production.

A model of genital herpes simplex virus Type 1 infection in Rhesus Macaques

BACKGROUND

Although HSV-2 is the major cause of genital lesions, HSV-1 accounts for half of new cases in developed countries.

METHODS

Three healthy SHIV-SF162P3-infected Indian rhesus macaques were inoculated with 4×108 pfu of HSV-1 twice, with the second inoculation performed after the vaginal mucosa was gently abraded with a cytobrush.

RESULTS

HSV-1 DNA was detected in vaginal swabs 5 days after the second but not the first inoculation in all three macaques. An increase in inflammatory cytokines was detected in the vaginal fluids of the animals with no or intermittent shedding. Higher frequency of blood α4 β7high CD4+ T cells was measured in the animals with consistent and intermitted shedding, while a decrease in the frequency of CD69+ CD4+ T cells was present in all animals.

CONCLUSIONS

This macaque model of genital HSV-1 could be useful to study the impact of the growing epidemic of genital HSV-1 on HIV infection.

Aspirin Dose and Prevention of Coronary Abnormalities in Kawasaki Disease

BACKGROUND

Acetylsalicylic acid (ASA) is part of the recommended treatment of Kawasaki disease (KD). Controversies remain regarding the optimal dose of ASA to be used. We aimed to evaluate the noninferiority of ASA at an antiplatelet dose in acute KD in preventing coronary artery (CA) abnormalities.

METHODS

This is a multicenter, retrospective, nonrandomized cohort study including children 0 to 10 years of age with acute KD between 2004 and 2015 from 5 institutions, of which 2 routinely use low-dose ASA (3-5 mg/kg per day) and 3 use high-dose ASA (80 mg/kg per day). Outcomes were CA abnormalities defined as a CA diameter with a z score ≥2.5. We assessed the risk difference of CA abnormalities according to ASA dose. All subjects received ASA and intravenous immunoglobulin within 10 days of fever onset.

RESULTS

There were 1213 subjects included, 848 in the high-dose and 365 in the low-dose ASA group. There was no difference in the risk of CA abnormalities in the low-dose compared with the high-dose ASA group (22.2% vs 20.5%). The risk difference adjusted for potential confounders was 0.3% (95% confidence interval [CI]: -4.5% to 5.0%). The adjusted risk difference for CA abnormalities persisting at the 6-week follow-up was -1.9% (95% CI: -5.3% to 1.5%). The 95% CI of the risk difference of CA abnormalities adjusted for confounders was within the prespecified 5% margin considered to be noninferior.

CONCLUSIONS

In conjunction with intravenous immunoglobulin, low-dose ASA in acute KD is not inferior to high-dose ASA for reducing the risk of CA abnormalities.

Glucocorticoid compounds modify smoothened localization and hedgehog pathway activity

The Hedgehog signaling pathway is linked to a variety of diseases, notably a range of cancers. The first generation of drug screens identified Smoothened (Smo), a membrane protein essential for signaling, as an attractive drug target. Smo localizes to the primary cilium upon pathway activation, and this transition is critical for the response to Hedgehog ligands. In a high content screen directly monitoring Smo distribution in Hedgehog-responsive cells, we identified different glucocorticoids as specific modulators of Smo ciliary accumulation. One class promoted Smo accumulation, conferring cellular hypersensitivity to Hedgehog stimulation. In contrast, a second class inhibited Smo ciliary localization and signaling activity by both wild-type Smo, and mutant forms of Smo, SmoM2, and SmoD473H, that are refractory to previously identified Smo antagonists. These findings point to the potential for developing glucocorticoid-based pharmacological modulation of Smo signaling to treat mutated drug-resistant forms of Smo, an emerging problem in long-term cancer therapy. They also raise a concern about potential crosstalk of glucocorticoid drugs in the Hedgehog pathway, if therapeutic administration exceeds levels associated with on-target transcriptional mechanisms of glucocorticoid action.

Selective identification of hedgehog pathway antagonists by direct analysis of smoothened ciliary translocation

Hedgehog (Hh) signaling promotes tumorigenesis. The accumulation of the membrane protein Smoothened (Smo) within the primary cilium (PC) is a key event in Hh signal transduction, and many pharmacological inhibitors identified to date target Smo's actions. Smo ciliary translocation is inhibited by some pathway antagonists, while others promote ciliary accumulation, an outcome that can lead to a hypersensitive state on renewal of Hh signaling. To identify novel inhibitory compounds acting on the critical mechanistic transition of Smo accumulation, we established a high content screen to directly analyze Smo ciliary translocation. Screening thousands of compounds from annotated libraries of approved drugs and other agents, we identified several new classes of compounds that block Sonic hedgehog-driven Smo localization within the PC. Selective analysis was conducted on two classes of Smo antagonists. One of these, DY131, appears to inhibit Smo signaling through a common binding site shared by previously reported Smo agonists and antagonists. Antagonism by this class of compound is competed by high doses of Smo-binding agonists such as SAG and impaired by a mutation that generates a ligand-independent, oncogenic form of Smo (SmoM2). In contrast, a second antagonist of Smo accumulation within the PC, SMANT, was less sensitive to SAG-mediated competition and inhibited SmoM2 at concentrations similar to those that inhibit wild-type Smo. Our observations identify important differences among Hh antagonists and the potential for development of novel therapeutic approaches against mutant forms of Smo that are resistant to current therapeutic strategies.

CXCR1 deficiency does not alter liver regeneration after partial hepatectomy in mice

Previous studies have shown that CXC chemokines containing Glu-Leu-Arg (ELR) in their amino-terminus stimulate hepatocyte proliferation and liver regeneration after partial hepatectomy. These ELR+CXC chemokines bind to two receptors, CXCR1 and CXCR2. Previous work has shown that CXCR2 is involved in the proliferative effects of CXC chemokines. However, the function of CXCR1 during the regenerative response has not been studied. The aim of the current study was to investigate the role of CXCR1 in liver regeneration after partial hepatectomy. C57BL/6 (wild type) or CXCR1-/- mice were subjected to 70% partial hepatectomy or sham surgery and sacrificed on day 2 and 4 after operation. There were no significant differences in liver-to-body weight ratio or hepatocyte proliferation. The data suggest that CXCR1 does not mediate the proliferative effects of ELR+ CXC chemokines during liver regeneration after partial hepatectomy.

Using surveillance data for action: lessons learnt from the second generation HIV/AIDS surveillance project in Pakistan

Although many countries are now collecting useful, high-quality HIV surveillance data, more efforts are put into the collection of data than into ensuring it is deployed effectively. The Canada-Pakistan HIV/AIDS surveillance project has strengthened and expanded the existing national AIDS control programme surveillance system in Pakistan through a comprehensive estimate of the size and location of some of the most at-risk populations (sex workers and injection drug users) and annual assessments of their sociodemographic characteristics, behaviours and HIV prevalence. The country now uses second generation surveillance data at a broad level to lobby for policy change, mobilize resources, improve programming and measure the success of prevention through an integrated national effort. This article aims to share the experiences and lessons learnt in the development of a second generation surveillance system for HIV/AIDS in Pakistan.