Mitochondrial biogenesis and electrical properties of hPSC-derived motor neurons

Human pluripotent stem cells (hPSCs), including human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) hold great promise in the fields of drug development and regenerative medicine. If iPSCs reprogrammed from patient cells replicate what is seen in vivo they may be used as a model of disease. A process that is disrupted in many neurodegenerative diseases is mitochondrial biogenesis. One of these diseases is amyotrophic lateral sclerosis (ALS), which is characterized by loss of motor neurons in the brain and spinal cord. Differentiation of hPSCs into motor neurons offers a way to study a previous unavailable cell type and may further our understanding of human motor neuron biology. The aims of the present study were to differentiate motor neurons from hESCs and iPSCs in low oxygen conditions and to explore mitochondrial biogenesis and electrical maturation during this process. After three weeks of treatment with retinoic acid and purmorphamine, a sonic hedgehog agonist, cells increased expression of post mitotic spinal motor neuron markers. One week later electrophysiological analysis revealed voltage-gated currents and action potential generation. Mitochondrial biogenesis signaling and expression of respiratory chain proteins increased with motor neuron differentiation. Respiration analysis revealed a decrease in glycolysis in motor neurons compared to neural stem cells. Interestingly, this was not accompanied by an increase in basal respiration or mitochondrial mass. These findings enhance our understanding of motor neuron mitochondrial biogenesis, a process impaired in ALS

Improved workflow for quantification of left ventricular volumes and mass using free-breathing motion corrected cine imaging.

BACKGROUND: Traditional cine imaging for cardiac functional assessment requires breath-holding, which can be problematic in some situations. Free-breathing techniques have relied on multiple averages or real-time imaging, producing images that can be spatially and/or temporally blurred. To overcome this, methods have been developed to acquire real-time images over multiple cardiac cycles, which are subsequently motion corrected and reformatted to yield a single image series displaying one cardiac cycle with high temporal and spatial resolution. Application of these algorithms has required significant additional reconstruction time. The use of distributed computing was recently proposed as a way to improve clinical workflow with such algorithms. In this study, we have deployed a distributed computing version of motion corrected re-binning reconstruction for free-breathing evaluation of cardiac function. METHODS: Twenty five patients and 25 volunteers underwent cardiovascular magnetic resonance (CMR) for evaluation of left ventricular end-systolic volume (ESV), end-diastolic volume (EDV), and end-diastolic mass. Measurements using motion corrected re-binning were compared to those using breath-held SSFP and to free-breathing SSFP with multiple averages, and were performed by two independent observers. Pearson correlation coefficients and Bland-Altman plots tested agreement across techniques. Concordance correlation coefficient and Bland-Altman analysis tested inter-observer variability. Total scan plus reconstruction times were tested for significant differences using paired t-test. RESULTS: Measured volumes and mass obtained by motion corrected re-binning and by averaged free-breathing SSFP compared favorably to those obtained by breath-held SSFP (r = 0.9863/0.9813 for EDV, 0.9550/0.9685 for ESV, 0.9952/0.9771 for mass). Inter-observer variability was good with concordance correlation coefficients between observers across all acquisition types suggesting substantial agreement. Both motion corrected re-binning and averaged free-breathing SSFP acquisition and reconstruction times were shorter than breath-held SSFP techniques (p \u3c 0.0001). On average, motion corrected re-binning required 3 min less than breath-held SSFP imaging, a 37 % reduction in acquisition and reconstruction time. CONCLUSIONS: The motion corrected re-binning image reconstruction technique provides robust cardiac imaging that can be used for quantification that compares favorably to breath-held SSFP as well as multiple average free-breathing SSFP, but can be obtained in a fraction of the time when using cloud-based distributed computing reconstruction

The impact of smoke exposure on the clinical phenotype of alpha-1 antitrypsin deficiency in Ireland: exploiting a national registry to understand a rare disease.

Individuals with Alpha-1 antitrypsin deficiency (AATD) have mutations in the SERPINA1 gene causing genetic susceptibility to early onset lung and liver disease that may result in premature death. Environmental interactions have a significant impact in determining the disease phenotype and outcome in AATD. The aim of this study was to assess the impact of smoke exposure on the clinical phenotype of AATD in Ireland. Clinical demographics and available thoracic computerised tomography (CT) imaging were detected from 139 PiZZ individuals identified from the Irish National AATD Registry. Clinical information was collected by questionnaire. Data was analysed to assess AATD disease severity and evaluate predictors of clinical phenotype. Questionnaires were collected from 107/139 (77%) and thoracic CT evaluation was available in 72/107 (67.2%). 74% of respondents had severe Chronic Obstructive Pulmonary Disease (COPD) (GOLD stage C or D). Cigarette smoking was the greatest predictor of impairment in FEV1 and DLCO (%predicted) and the extent of emphysema correlated most significantly with DLCO. Interestingly the rate of FEV1 decline was similar in ex-smokers when compared to never-smokers. Passive smoke exposure in childhood resulted in a greater total pack-year smoking history. Radiological evidence of bronchiectasis was a common finding and associated with increasing age. The Irish National AATD Registry facilitates clinical and basic science research of this condition in Ireland. This study illustrates the detrimental effect of smoke exposure on the clinical phenotype of AATD in Ireland and the benefit of immediate smoking cessation at any stage of lung disease

Prenatal Buprenorphine/Naloxone or Methadone Use on Neonatal Outcomes in Michigan

Background: Maternal opioid exposure during pregnancy has various effects on neonatal health. Buprenorphine/naloxone and methadone are examples of medications for opioid use disorder (MOUD) used for the treatment of opioid use disorder (OUD). Research comparing the impacts of these MOUD modalities on neonatal outcomes when used to treat pregnant people with OUD remains limited. We evaluated the differences in outcomes between neonates with in-utero exposure to buprenorphine/naloxone versus methadone. Methodology: We performed a retrospective cohort chart review between October 15, 2008, and October 15, 2019, evaluating mother/neonate dyads at two medical centers in Michigan. The charts of female patients, aged 18+, with OUD and buprenorphine/naloxone or methadone treatment, were examined. The charts of the corresponding neonates were also examined. Multiple regression analysis was performed. Results: In total, 343 mother/infant dyads were included: 99 patients were treated with buprenorphine/naloxone and 232 patients were treated with methadone. The buprenorphine/naloxone group had significant differences in maternal age, hepatitis status, asthma, gestational age in weeks, neonatal intensive care unit (NICU) length of stay (LOS), neonatal opioid withdrawal syndrome (NOWS) peak score, birth head circumference, and birth weight compared to the methadone group at baseline. Adjusted multivariable regression analysis demonstrated neonates with exposure to buprenorphine/naloxone had a NOWS peak score 3.079 points less (95% confidence interval (CI): -4.525, 1.633; p = 0.001) and NICU LOS 8.955 days less (95% CI: -14.399, -3.511; p = 0.001) than neonates exposed to methadone. Conclusions: Neonates with in-utero exposure to buprenorphine/naloxone had significantly lower NOWS scores and shorter NICU LOS compared to neonates with in-utero exposure to methadone. These findings demonstrate that buprenorphine/naloxone is potentially a more favorable treatment for the reduction in metrics representing adverse neonatal outcomes in pregnant people with OUD than methadone

Centering Community Voices in Mining Governance

Peru has shifted away from centralized mining management to governance among government, companies, and communities. Various mechanisms facilitate community participation, including the mining canon, dialogues, and corporate social responsibility programs. Even with these laws and mechanisms, mining pollution and conflicts continue. In this study, we ask: how do communities perceive and participate in mining governance? And what are some alternative ways, driven by community priorities, to address governance in mining contexts? We collected 53 semi-structured with agricultural actors in two Peruvian districts with mining activity and analyzed those perspectives through the lens of community-centered governance. Our analyses revealed how centering community priorities in data collection and analysis illuminates context-specific factors that shape community attitudes toward mining and highlights community-driven approaches to addressing mining governance. Such community driven approaches could include integrating understandings of local livelihoods and historical contexts, implementing transparent participatory processes, and improving laws to give communities decision-making power over mining development

Evidence of Natural Bluetongue Virus Infection among African Carnivores

Bluetongue is an International Office of Epizootics List A disease described as the century\u27s most economically devastating affliction of sheep. Bluetongue (BLU) viruses were thought to infect only ruminants, shrews, and some rodents, but recently, inadvertent administration of BLU virus-contaminated vaccine resulted in mortality and abortion among domestic dogs. We present evidence of natural BLU virus infection among African carnivores that dramatically widens the spectrum of susceptible hosts. We hypothesize that such infection occurred after ingestion of meat and organs from BLU virus infected prey species. The effect of BLU virus on endangered carnivores such as the cheetah and African wild dog requires urgent investigation. Also, the role of carnivores in the epizootiology of this disease needs elucidation

Radiation-free CMR diagnostic heart catheterization in children.

BACKGROUND: Children with heart disease may require repeated X-Ray cardiac catheterization procedures, are more radiosensitive, and more likely to survive to experience oncologic risks of medical radiation. Cardiovascular magnetic resonance (CMR) is radiation-free and offers information about structure, function, and perfusion but not hemodynamics. We intend to perform complete radiation-free diagnostic right heart catheterization entirely using CMR fluoroscopy guidance in an unselected cohort of pediatric patients; we report the feasibility and safety. METHODS: We performed 50 CMR fluoroscopy guided comprehensive transfemoral right heart catheterizations in 39 pediatric (12.7 ± 4.7 years) subjects referred for clinically indicated cardiac catheterization. CMR guided catheterizations were assessed by completion (success/failure), procedure time, and safety events (catheterization, anesthesia). Pre and post CMR body temperature was recorded. Concurrent invasive hemodynamic and diagnostic CMR data were collected. RESULTS: During a twenty-two month period (3/2015 - 12/2016), enrolled subjects had the following clinical indications: post-heart transplant 33%, shunt 28%, pulmonary hypertension 18%, cardiomyopathy 15%, valvular heart disease 3%, and other 3%. Radiation-free CMR guided right heart catheterization attempts were all successful using passive catheters. In two subjects with septal defects, right and left heart catheterization were performed. There were no complications. One subject had six such procedures. Most subjects (51%) had undergone multiple (5.5 ± 5) previous X-Ray cardiac catheterizations. Retained thoracic surgical or transcatheter implants (36%) did not preclude successful CMR fluoroscopy heart catheterization. During the procedure, two subjects were receiving vasopressor infusions at baseline because of poor cardiac function, and in ten procedures, multiple hemodynamic conditions were tested. CONCLUSIONS: Comprehensive CMR fluoroscopy guided right heart catheterization was feasible and safe in this small cohort of pediatric subjects. This includes subjects with previous metallic implants, those requiring continuous vasopressor medication infusions, and those requiring pharmacologic provocation. Children requiring multiple, serial X-Ray cardiac catheterizations may benefit most from radiation sparing. This is a step toward wholly CMR guided diagnostic (right and left heart) cardiac catheterization and future CMR guided cardiac intervention. TRIAL REGISTRATION: ClinicalTrials.gov NCT02739087 registered February 17, 2016

Reflections on the Formation and Growth of the SURE Network: a National Disciplinary Network to Enhance Undergraduate Research in the Sciences

The Science Undergraduate Research Experience (SURE) Network is an academic network comprised of nine Higher Education Institutions (HEI) in Ireland that seeks to enhance the profile of, and practices in, undergraduate research in the Sciences within the Technological Higher Education Sector. This paper presents the reflections of the network\u27s leaders on the formation and growth of the network over the period from 2015, just prior to its establishment, to 2020 when the network hosted its seventh undergraduate research conference, published its second undergraduate journal issue, and initiated a coordinated community of practice in response to the Covid-19 crisis. The paper presents the motivations of the leaders for establishing and joining the SURE network, their interpretation of how involvement in the network enhances practice in their own HEI, their reflections on how their own personal development was enhanced, their interpretation of the factors that have contributed to the success of the network, and the direction in which they see the network going in the future. The collective reflections of the leaders of the SURE Network, as presented in this paper, provide importance guidance for those seeking to establish similar academic networks, both in the area of undergraduate research and elsewhere

Inhibition of pluripotency networks by the Rb tumor suppressor restricts reprogramming and tumorigenesis

Mutations in the retinoblastoma tumor suppressor gene Rb are involved in many forms of human cancer. In this study, we investigated the early consequences of inactivating Rb in the context of cellular reprogramming. We found that Rb inactivation promotes the reprogramming of differentiated cells to a pluripotent state. Unexpectedly, this effect is cell cycle independent, and instead reflects direct binding of Rb to pluripotency genes, including Sox2 and Oct4, which leads to a repressed chromatin state. More broadly, this regulation of pluripotency networks and Sox2 in particular is critical for the initiation of tumors upon loss of Rb in mice. These studies therefore identify Rb as a global transcriptional repressor of pluripotency networks, providing a molecular basis for previous reports about its involvement in cell fate pliability, and implicate misregulation of pluripotency factors such as Sox2 in tumorigenesis related to loss of Rb function

Inhibition of pluripotency networks by the Rb tumor suppressor restricts reprogramming and tumorigenesis

Mutations in the retinoblastoma tumor suppressor gene Rb are involved in many forms of human cancer. In this study, we investigated the early consequences of inactivating Rb in the context of cellular reprogramming. We found that Rb inactivation promotes the reprogramming of differentiated cells to a pluripotent state. Unexpectedly, this effect is cell cycle independent, and instead reflects direct binding of Rb to pluripotency genes, including Sox2 and Oct4, which leads to a repressed chromatin state. More broadly, this regulation of pluripotency networks and Sox2 in particular is critical for the initiation of tumors upon loss of Rb in mice. These studies therefore identify Rb as a global transcriptional repressor of pluripotency networks, providing a molecular basis for previous reports about its involvement in cell fate pliability, and implicate misregulation of pluripotency factors such as Sox2 in tumorigenesis related to loss of Rb function