Midbrain organoids mimic early embryonic neurodevelopment and recapitulate LRRK2-p.Gly2019Ser-associated gene expression.

Human brain organoid models that recapitulate the physiology and complexity of the human brain have a great potential for in vitro disease modeling, in particular for neurodegenerative diseases, such as Parkinson disease. In the present study, we compare single-cell RNA-sequencing data of human midbrain organoids to the developing human embryonic midbrain. We demonstrate that the in vitro model is comparable to its in vivo equivalents in terms of developmental path and cellular composition. Moreover, we investigate the potential of midbrain organoids for modeling early developmental changes in Parkinson disease. Therefore, we compare the single-cell RNA-sequencing data of healthy-individual-derived midbrain organoids to their isogenic LRRK2-p.Gly2019Ser-mutant counterparts. We show that the LRRK2 p.Gly2019Ser variant alters neurodevelopment, resulting in an untimely and incomplete differentiation with reduced cellular variability. Finally, we present four candidate genes, APP, DNAJC6, GATA3, and PTN, that might contribute to the LRRK2-p.Gly2019Ser-associated transcriptome changes that occur during early neurodevelopment.

Microglia integration into human midbrain organoids leads to increased neuronal maturation and functionality.

The human brain is a complex, three-dimensional structure. To better recapitulate brain complexity, recent efforts have focused on the development of human-specific midbrain organoids. Human iPSC-derived midbrain organoids consist of differentiated and functional neurons, which contain active synapses, as well as astrocytes and oligodendrocytes. However, the absence of microglia, with their ability to remodel neuronal networks and phagocytose apoptotic cells and debris, represents a major disadvantage for the current midbrain organoid systems. Additionally, neuroinflammation-related disease modeling is not possible in the absence of microglia. So far, no studies about the effects of human iPSC-derived microglia on midbrain organoid neural cells have been published. Here we describe an approach to derive microglia from human iPSCs and integrate them into iPSC-derived midbrain organoids. Using single nuclear RNA Sequencing, we provide a detailed characterization of microglia in midbrain organoids as well as the influence of their presence on the other cells of the organoids. Furthermore, we describe the effects that microglia have on cell death and oxidative stress-related gene expression. Finally, we show that microglia in midbrain organoids affect synaptic remodeling and increase neuronal excitability. Altogether, we show a more suitable system to further investigate brain development, as well as neurodegenerative diseases and neuroinflammation.

Prescribing Patterns of Oral Opioid Analgesic for Long Bone Fracture at Tertiary Care Children's Hospital Emergency Departments and Urgent Cares.

OBJECTIVES: Disparities in opioid prescribing in children can lead to underprescribing and poorly controlled pain. On the contrary, unnecessary overprescribing can increase the risk for misuse, abuse, and diversion. The primary objective of this study was to compare the demographics and clinical characteristics of children with an extremity fracture who did and did not receive an opioid prescription from a tertiary care children's hospital. METHODS: This was a retrospective cohort study of children younger than 22 years with extremity fracture evaluated at a tertiary care children's hospital emergency department (ED) and surrounding satellite locations (3 EDs and 4 urgent cares), from January 1, 2017, to December 31, 2017. RESULTS: There were 3325 patients younger than 22 years who were seen for evaluation of an extremity fracture. The overall median age of patients was 8 years (interquartile range [IQR], 4-11), and 1976 (59.4%) were male. Patients with extremity fractures who received opioid analgesics were older than those who did not receive opioids (median age of 10 years [IQR, 6-13 years] vs 7 years [IQR, 4-11 years], P < 0.001). There was a significant difference found between insurance types, specifically those patients receiving Medicaid and private insurance. Patients who received opioid analgesics had a higher initial pain score (7 [IQR, 4-9] vs 5 [IQR, 2-7], P < 0.001), were more likely to have an physician (MD/DO) provider (P < 0.001), and were more likely to present to the ED (P < 0.001). CONCLUSIONS: Younger patients, patients with Medicaid insurance, patients treated by an advanced care provider, and patients who presented to an urgent care were less likely to receive opioid analgesics upon discharge. These findings demonstrate that more standardization and guidance on opioid prescribing are needed in pediatrics, to both adequately treat pain and reduce harms from overprescribing of opioid analgesics.

Prescribing Patterns of Oral Opioid Analgesic for Acute Pain at a Tertiary Care Children's Hospital Emergency Departments and Urgent Cares.

OBJECTIVES: Despite Centers for Disease Control and Prevention guidelines on adult opioid prescribing, there is a paucity of evidence and no guidelines to inform opioid prescribing in pediatrics. To develop guidelines on pediatric prescribing, it is imperative to evaluate current practice on opioid use. The objectives were to describe prescribing patterns of opioids for acute pain at a children's hospital and to compare clinical characteristics of patients who received less or greater than 3 days. METHODS: A retrospective review of oral opioid analgesics prescribed for acute pain at a tertiary care children's hospital emergency department and urgent care from January 1, 2017, to December 31, 2017. Patients younger than 22 years who received an opioid prescription upon discharge were included. Patients with hematology/oncology or chronic pain diagnosis were excluded. RESULTS: Opioids were prescribed for a median of 2.2 days (interquartile range, 1.4-3.0 days). Most opioids were prescribed for ≤3 days (1326; 79.3%), and there were 44 (2.6%) prescriptions for >7 days. Twenty-two opioid formulations were prescribed. Single-ingredient oxycodone was the most commonly prescribed (877; 52.5%); there were 724 (43.3%) acetaminophen combination products. Common diagnoses were orthopedic (973; 58.2%), surgery/burn/trauma (195; 11.7%), and ear/nose/throat (143; 8.6%). Patients who received >3 days of opioids were younger (P < 0.001), and there was no differences in sex, ethnicity, insurance, or provider qualifications. CONCLUSIONS: Overall, prescribing patterns for the duration of opioid analgesics were ≤3 days, with a median of 2 days. There was a large range of days prescribed, with variations in prescribing characteristics among patients and providers.

Highly scalable and standardized organ-on-chip platform with TEER for biological barrier modeling.

The development of new therapies is hampered by the lack of predictive, and patient-relevant in vitro models. Organ-on-chip (OOC) technologies can potentially recreate physiological features and hold great promise for tissue and disease modeling. However, the non-standardized design of these chips and perfusion control systems has been a barrier to quantitative high-throughput screening (HTS). Here we present a scalable OOC microfluidic platform for applied kinetic in vitro assays (AKITA) that is applicable for high, medium, and low throughput. Its standard 96-well plate and 384-well plate layouts ensure compatibility with existing laboratory workflows and high-throughput data collection and analysis tools. The AKITA plate is optimized for the modeling of vascularized biological barriers, primarily the blood-brain barrier, skin, and lung, with precise flow control on a custom rocker. The integration of trans-epithelial electrical resistance (TEER) sensors allows rapid and repeated monitoring of barrier integrity over long time periods. Together with automated liquid handling and compound permeability testing analyses, we demonstrate the flexibility of the AKITA platform for establishing human-relevant models for preclinical drug and precision medicine's efficacy, toxicity, and permeability under near-physiological conditions.

Omics data integration suggests a potential idiopathic Parkinson's disease signature.

The vast majority of Parkinson's disease cases are idiopathic. Unclear etiology and multifactorial nature complicate the comprehension of disease pathogenesis. Identification of early transcriptomic and metabolic alterations consistent across different idiopathic Parkinson's disease (IPD) patients might reveal the potential basis of increased dopaminergic neuron vulnerability and primary disease mechanisms. In this study, we combine systems biology and data integration approaches to identify differences in transcriptomic and metabolic signatures between IPD patient and healthy individual-derived midbrain neural precursor cells. Characterization of gene expression and metabolic modeling reveal pyruvate, several amino acid and lipid metabolism as the most dysregulated metabolic pathways in IPD neural precursors. Furthermore, we show that IPD neural precursors endure mitochondrial metabolism impairment and a reduced total NAD pool. Accordingly, we show that treatment with NAD precursors increases ATP yield hence demonstrating a potential to rescue early IPD-associated metabolic changes.

Impaired neuron differentiation in GBA-associated Parkinson's disease is linked to cell cycle defects in organoids.

The mechanisms underlying Parkinson's disease (PD) etiology are only partially understood despite intensive research conducted in the field. Recent evidence suggests that early neurodevelopmental defects might play a role in cellular susceptibility to neurodegeneration. To study the early developmental contribution of GBA mutations in PD we used patient-derived iPSCs carrying a heterozygous N370S mutation in the GBA gene. Patient-specific midbrain organoids displayed GBA-PD relevant phenotypes such as reduction of GCase activity, autophagy impairment, and mitochondrial dysfunction. Genome-scale metabolic (GEM) modeling predicted changes in lipid metabolism which were validated with lipidomics analysis, showing significant differences in the lipidome of GBA-PD. In addition, patient-specific midbrain organoids exhibited a decrease in the number and complexity of dopaminergic neurons. This was accompanied by an increase in the neural progenitor population showing signs of oxidative stress-induced damage and premature cellular senescence. These results provide insights into how GBA mutations may lead to neurodevelopmental defects thereby predisposing to PD pathology.

Treating Parkinson's Disease with Human Bone Marrow Mesenchymal Stem Cell Secretome: A Translational Investigation Using Human Brain Organoids and Different Routes of In Vivo Administration.

Parkinson's disease (PD) is the most common movement disorder, characterized by the progressive loss of dopaminergic neurons from the nigrostriatal system. Currently, there is no treatment that retards disease progression or reverses damage prior to the time of clinical diagnosis. Mesenchymal stem cells (MSCs) are one of the most extensively studied cell sources for regenerative medicine applications, particularly due to the release of soluble factors and vesicles, known as secretome. The main goal of this work was to address the therapeutic potential of the secretome collected from bone-marrow-derived MSCs (BM-MSCs) using different models of the disease. Firstly, we took advantage of an optimized human midbrain-specific organoid system to model PD in vitro using a neurotoxin-induced model through 6-hydroxydopamine (6-OHDA) exposure. In vivo, we evaluated the effects of BM-MSC secretome comparing two different routes of secretome administration: intracerebral injections (a two-site single administration) against multiple systemic administration. The secretome of BM-MSCs was able to protect from dopaminergic neuronal loss, these effects being more evident in vivo. The BM-MSC secretome led to motor function recovery and dopaminergic loss protection; however, multiple systemic administrations resulted in larger therapeutic effects, making this result extremely relevant for potential future clinical applications.

An Acute Care Sepsis Response System Targeting Improved Antibiotic Administration.

BACKGROUND AND OBJECTIVES: Pediatric sepsis quality improvement in emergency departments has been well described and associated with improved survival. Acute care (non-ICU inpatient) units differ in important ways, and optimal approaches to improving sepsis processes and outcomes in this setting are not yet known. Our objective was to increase the proportion of acute care sepsis cases in our health system with initial antibiotic order-to-administration time ≤60 minutes by 20% from a baseline of 43% to 52% by December 2020. METHODS: Employing the Model for Improvement with broad stakeholder engagement, we developed and implemented interventions aimed at effective intervention for sepsis cases on acute care units. We analyzed process and outcome metrics over time using statistical process control charts. We used descriptive statistics to explore differences in antibiotic order-to-administration time and inform ongoing improvement. RESULTS: We cared for 187 patients with sepsis over the course of our initiative. The proportion within our goal antibiotic order-to-administration time rose from 43% to 64% with evidence of special cause variation after our interventions. Of all patients, 66% experienced ICU transfer and 4% died. CONCLUSIONS: We successfully decreased antibiotic order-to-administration time. We also introduced a novel model for sepsis response systems that integrates interventions designed for the complexities of acute care settings. We demonstrated impactful local improvements in the acute care setting where quality improvement reports and success have previously been limited.

The Parkinson's-disease-associated mutation LRRK2-G2019S alters dopaminergic differentiation dynamics via NR2F1.

Increasing evidence suggests that neurodevelopmental alterations might contribute to increase the susceptibility to develop neurodegenerative diseases. We investigate the occurrence of developmental abnormalities in dopaminergic neurons in a model of Parkinson's disease (PD). We monitor the differentiation of human patient-specific neuroepithelial stem cells (NESCs) into dopaminergic neurons. Using high-throughput image analyses and single-cell RNA sequencing, we observe that the PD-associated LRRK2-G2019S mutation alters the initial phase of neuronal differentiation by accelerating cell-cycle exit with a concomitant increase in cell death. We identify the NESC-specific core regulatory circuit and a molecular mechanism underlying the observed phenotypes. The expression of NR2F1, a key transcription factor involved in neurogenesis, decreases in LRRK2-G2019S NESCs, neurons, and midbrain organoids compared to controls. We also observe accelerated dopaminergic differentiation in vivo in NR2F1-deficient mouse embryos. This suggests a pathogenic mechanism involving the LRRK2-G2019S mutation, where the dynamics of dopaminergic differentiation are modified via NR2F1.

Reproducible generation of human midbrain organoids for in vitro modeling of Parkinson's disease.

The study of human midbrain development and midbrain related diseases, like Parkinson's disease (PD), is limited by deficiencies in the currently available and validated laboratory models. Three dimensional midbrain organoids represent an innovative strategy to recapitulate some aspects of the complexity and physiology of the human midbrain. Nevertheless, also these novel organoid models exhibit some inherent weaknesses, including the presence of a necrotic core and batch-to-batch variability. Here we describe an optimized approach for the standardized generation of midbrain organoids that addresses these limitations, while maintaining key features of midbrain development like dopaminergic neuron and astrocyte differentiation. Moreover, we have established a novel time-efficient, fit for purpose analysis pipeline and provided proof of concept for its usage by investigating toxin induced PD.

Machine learning-assisted neurotoxicity prediction in human midbrain organoids.

INTRODUCTION: Brain organoids are highly complex multi-cellular tissue proxies, which have recently risen as novel tools to study neurodegenerative diseases such as Parkinson's disease (PD). However, with increasing complexity of the system, usage of quantitative tools becomes challenging. OBJECTIVES: The primary objective of this study was to develop a neurotoxin-induced PD organoid model and to assess the neurotoxic effect on dopaminergic neurons using microscopy-based phenotyping in a high-content fashion. METHODS: We describe a pipeline for a machine learning-based analytical method, allowing for detailed image-based cell profiling and toxicity prediction in brain organoids treated with the neurotoxic compound 6-hydroxydopamine (6-OHDA). RESULTS: We quantified features such as dopaminergic neuron count and neuronal complexity and built a machine learning classifier with the data to optimize data processing strategies and to discriminate between different treatment conditions. We validated the approach with high content imaging data from PD patient derived midbrain organoids. CONCLUSIONS: The here described model is a valuable tool for advanced in vitro PD modeling and to test putative neurotoxic compounds.

A Strategy for the Renovation of a Clinical Pathways Program.

INTRODUCTION: Clinical pathways (CPs) translate best available evidence to the local care context and intend to inform clinical decision-making, optimize care, and decrease variation. This article describes a CPs program improvement process at a free-standing academic children's hospital. Aims: (1) improve the pathway development process; (2) identify and address gaps; (3) strengthen measurement; (4) increase efficiency in cycle time to build a pathway; (5) increase multidisciplinary participation; (6) integrate into the electronic health record ; and (7) and increase pathway utilization. METHODS: We renovated the CP program using a structured, improvement process. A series of internal stakeholder and external colleague interviews informed the process. To improve the program, we developed and implemented different interventions. RESULTS: The streamlined process reduced the overall time for completion from a median of 15 to 5 months (measured from the date of first meeting with the clinical improvement team to approval), a 70% increase in efficiency. Between 1994 and 2015, the hospital had 33 CPs. There was a 78% increase in the total number of pathways after the renovation with 26 additional pathways. CONCLUSIONS: Renovation of the CP program led to early success through an improved development process, alleviation of programmatic gaps, inclusion of measures within each pathway, increased timely completion, multidisciplinary involvement, integration into the electronic health record, and improved utilization. Initial results are encouraging, and the lessons learned should be helpful to other programs. Further program development is ongoing, focusing on continued improvements in implementation and overall program measures.

3D Cultures of Parkinson's Disease-Specific Dopaminergic Neurons for High Content Phenotyping and Drug Testing.

Parkinson's disease (PD)-specific neurons, grown in standard 2D cultures, typically only display weak endophenotypes. The cultivation of PD patient-specific neurons, derived from induced pluripotent stem cells carrying the LRRK2-G2019S mutation, is optimized in 3D microfluidics. The automated image analysis algorithms are implemented to enable pharmacophenomics in disease-relevant conditions. In contrast to 2D cultures, this 3D approach reveals robust endophenotypes. High-content imaging data show decreased dopaminergic differentiation and branching complexity, altered mitochondrial morphology, and increased cell death in LRRK2-G2019S neurons compared to isogenic lines without using stressor agents. Treatment with the LRRK2 inhibitor 2 (Inh2) rescues LRRK2-G2019S-dependent dopaminergic phenotypes. Strikingly, a holistic analysis of all studied features shows that the genetic background of the PD patients, and not the LRRK2-G2019S mutation, constitutes the strongest contribution to the phenotypes. These data support the use of advanced in vitro models for future patient stratification and personalized drug development.

Neural Stem Cells of Parkinson's Disease Patients Exhibit Aberrant Mitochondrial Morphology and Functionality.

Emerging evidence suggests that Parkinson's disease (PD), besides being an age-associated disorder, might also have a neurodevelopment component. Disruption of mitochondrial homeostasis has been highlighted as a crucial cofactor in its etiology. Here, we show that PD patient-specific human neuroepithelial stem cells (NESCs), carrying the LRRK2-G2019S mutation, recapitulate key mitochondrial defects previously described only in differentiated dopaminergic neurons. By combining high-content imaging approaches, 3D image analysis, and functional mitochondrial readouts we show that LRRK2-G2019S mutation causes aberrations in mitochondrial morphology and functionality compared with isogenic controls. LRRK2-G2019S NESCs display an increased number of mitochondria compared with isogenic control lines. However, these mitochondria are more fragmented and exhibit decreased membrane potential. Functional alterations in LRRK2-G2019S cultures are also accompanied by a reduced mitophagic clearance via lysosomes. These findings support the hypothesis that preceding mitochondrial developmental defects contribute to the manifestation of the PD pathology later in life.

Impaired serine metabolism complements LRRK2-G2019S pathogenicity in PD patients.

Parkinson's disease (PD) is a multifactorial disorder with complex etiology. The most prevalent PD associated mutation, LRRK2-G2019S is linked to familial and sporadic cases. Based on the multitude of genetic predispositions in PD and the incomplete penetrance of LRRK2-G2019S, we hypothesize that modifiers in the patients' genetic background act as susceptibility factors for developing PD. To assess LRRK2-G2019S modifiers, we used human induced pluripotent stem cell-derived neuroepithelial stem cells (NESCs). Isogenic controls distinguish between LRRK2-G2019S dependent and independent cellular phenotypes. LRRK2-G2019S patient and healthy mutagenized lines showed altered NESC self-renewal and viability, as well as impaired serine metabolism. In patient cells, phenotypes were only partly LRRK2-G2019S dependent, suggesting a significant contribution of the genetic background. In this context we identified the gene serine racemase (SRR) as a novel patient-specific, developmental, genetic modifier contributing to the aberrant phenotypes. Its enzymatic product, d-serine, rescued altered cellular phenotypes. Susceptibility factors in the genetic background, such as SRR, could be new targets for early PD diagnosis and treatment.

Stakeholder Perspectives on Optimizing Communication in a School-Centered Asthma Program.

BACKGROUND: School-centered asthma programs (SAPs) can be an effective intervention to improve asthma control for underserved populations but little is known about how key stakeholders communicate within these programs. Therefore, our aim was to identify key components of effective communication in a SAP. METHODS: Primary care providers (PCPs), parents and school nurses associated with a SAP in Denver, Colorado participated in interviews and focus groups about their views on effective communication. Interview and focus group guides were developed using an appreciative inquiry approach and transcripts were analyzed via an iterative coding approach. RESULTS: We conducted 3 focus groups with school nurses (N = 13), interviews with parents (N = 12) and PCPs (N = 10). Stakeholders identified multiple themes that enable communication, namely personal relationships, clear roles, integration of technology, adequate resources, and accessibility. CONCLUSIONS: Communication in SAPs is most effective when there are clearly delineated roles with the school being the focal point for education and monitoring of asthmatic students and PCPs being the focal point for diagnosis and changes in care. Communication should take place using modern technology that is integrated into existing workflow. Information sharing is most likely to be successful if there is deliberate relationship building.

FACS-Assisted CRISPR-Cas9 Genome Editing Facilitates Parkinson's Disease Modeling.

Genome editing and human induced pluripotent stem cells hold great promise for the development of isogenic disease models and the correction of disease-associated mutations for isogenic tissue therapy. CRISPR-Cas9 has emerged as a versatile and simple tool for engineering human cells for such purposes. However, the current protocols to derive genome-edited lines require the screening of a great number of clones to obtain one free of random integration or on-locus non-homologous end joining (NHEJ)-containing alleles. Here, we describe an efficient method to derive biallelic genome-edited populations by the use of fluorescent markers. We call this technique FACS-assisted CRISPR-Cas9 editing (FACE). FACE allows the derivation of correctly edited polyclones carrying a positive selection fluorescent module and the exclusion of non-edited, random integrations and on-target allele NHEJ-containing cells. We derived a set of isogenic lines containing Parkinson's-disease-associated mutations in α-synuclein and present their comparative phenotypes.

Rapid and robust generation of long-term self-renewing human neural stem cells with the ability to generate mature astroglia.

Induced pluripotent stem cell bear the potential to differentiate into any desired cell type and hold large promise for disease-in-a-dish cell-modeling approaches. With the latest advances in the field of reprogramming technology, the generation of patient-specific cells has become a standard technology. However, directed and homogenous differentiation of human pluripotent stem cells into desired specific cell types remains an experimental challenge. Here, we report the development of a novel hiPSCs-based protocol enabling the generation of expandable homogenous human neural stem cells (hNSCs) that can be maintained under self-renewing conditions over high passage numbers. Our newly generated hNSCs retained differentiation potential as evidenced by the reliable generation of mature astrocytes that display typical properties as glutamate up-take and expression of aquaporin-4. The hNSC-derived astrocytes showed high activity of pyruvate carboxylase as assessed by stable isotope assisted metabolic profiling. Moreover, using a cell transplantation approach, we showed that grafted hNSCs were not only able to survive but also to differentiate into astroglial in vivo. Engraftments of pluripotent stem cells derived from somatic cells carry an inherent tumor formation potential. Our results demonstrate that hNSCs with self-renewing and differentiation potential may provide a safer alternative strategy, with promising applications especially for neurodegenerative disorders.