Neuroanatomical distribution of fluorophores within adult RXFP3 Cre-tdTomato/YFP mouse brain.

Relaxin-family peptide 3 receptor (RXFP3) is activated by relaxin-3 in the brain to influence arousal and related functions, such as feeding and stress responses. Two transgenic mouse lines have recently been developed that co-express different fluorophores within RXFP3-expressing neurons: either yellow fluorescent protein (YFP; RXFP3-Cre/YFP mice) or tdTomato (RXFP3-Cre/tdTomato mice). To date, the characteristics of neurons that express RXFP3-associated fluorophores in these mice have only been investigated in the bed nucleus of the stria terminalis and the hypothalamic arcuate nucleus. To better determine the utility of these fluorophore-expressing mice for further research, we characterised the neuroanatomical distribution of fluorophores throughout the brain of these mice and compared this to the published distribution of Rxfp3 mRNA (detected by in situ hybridisation) in wildtype mice. Coronal sections of RXFP3-Cre/YFP (n = 8) and RXFP3-Cre/tdTomato (n = 8) mouse brains were imaged, and the density of fluorophore-expressing cells within various brain regions/nuclei was qualitatively assessed. Comparisons with our previously reported RXFP3 mRNA distribution revealed that of 212 brain regions that contained either fluorophore or RXFP3 mRNA, approximately half recorded densities that were within two qualitative measurements of each other (on a 9-point scale), including hippocampal dentate gyrus and amygdala subregions. However, many brain areas with likely non-authentic, false-positive, or false-negative fluorophore expression were also detected, including the cerebellum. Therefore, this study provides a guide to which brain regions should be prioritized for future study of RXFP3 in these mice, to better understand the neuroanatomy and function of this intriguing, neuronal peptide receptor.

Novel insights on genetics and epigenetics as clinical targets for paediatric astrocytoma.

Paediatric and adult astrocytomas are notably different, where clinical treatments used for adults are not as effective on children with the same form of cancer and these treatments lead to adverse long-term health concerns. Integrative omics-based studies have shown the pathology and fundamental molecular characteristics differ significantly and cannot be extrapolated from the more widely studied adult disease. Recent clinical advances in our understanding of paediatric astrocytomas, with the aid of next-generation sequencing and epigenome-wide profiling, have led to the identification of key canonical mutations that vary based on the tumour location and age of onset. These driver mutations, in particular the identification of the recurrent histone H3 mutations in high-grade tumours, have confirmed the important role epigenetic dysregulations play in cancer progression. This review summarises the current updates of the classification, epidemiology, pathogenesis and clinical management of paediatric astrocytoma based on their grades and the ongoing clinical trials. It also provides novel insights on genetic and epigenetic alterations as diagnostic biomarkers, highlighting the potential of targeting these pathways as therapeutics for this devastating childhood cancer.

Injury patterns and mortality associated with near-hanging in children.

BACKGROUND: The pathophysiology of near-hanging in children is different from that of adults due to anatomic, physiologic, and injury-related mechanisms, with evidence suggesting that blunt cerebrovascular injuries (BCVI) and cervical spine injuries (CSI) are uncommon. We sought to estimate the incidence of secondary injuries and their association with mortality in pediatric near-hanging victims. METHODS: We performed a retrospective observational study of children (≤17 years) with a diagnosis code for hanging between October 1, 2015 and February 28, 2023 who presented to one of 47 geographically diverse US children's hospitals. We evaluated the incidence of the following secondary injuries: cerebral edema, pneumothorax, pulmonary edema, BCVI, and CSI. We performed Fisher's exact test with Bonferroni correction to identify associations between intentionality, sex, age, and secondary injuries with mortality. RESULTS: We included 1929 children, of whom 33.8% underwent neuroimaging, 45.9% underwent neck imaging, and 38.7% underwent neck angiography. The most common injury was cerebral edema (24.0%), followed by pulmonary edema (3.2%) and pneumothorax (2.8%). CSI (2.1%) and BCVI (0.9%) occurred infrequently. Cerebral edema, pneumothorax, pulmonary edema, and younger age (≤12 years) were associated with mortality. CONCLUSIONS: In this multi-center study of pediatric near-hanging victims, BCVI and CSI occurred rarely and were not associated with mortality. While children in our study underwent neck imaging more frequently than head imaging, cerebral edema occurred more often than other injury types and imparted the highest mortality risk. Given the rarity of BCVI and CSI, a selective approach to neck imaging may be warranted in pediatric near-hanging events.

Prevalence and Characteristics of Diagnostic Error in Pediatric Critical Care: A Multicenter Study.

OBJECTIVES: Effective interventions to prevent diagnostic error among critically ill children should be informed by diagnostic error prevalence and etiologies. We aimed to determine the prevalence and characteristics of diagnostic errors and identify factors associated with error in patients admitted to the PICU. DESIGN: Multicenter retrospective cohort study using structured medical record review by trained clinicians using the Revised Safer Dx instrument to identify diagnostic error (defined as missed opportunities in diagnosis). Cases with potential errors were further reviewed by four pediatric intensivists who made final consensus determinations of diagnostic error occurrence. Demographic, clinical, clinician, and encounter data were also collected. SETTING: Four academic tertiary-referral PICUs. PATIENTS: Eight hundred eighty-two randomly selected patients 0-18 years old who were nonelectively admitted to participating PICUs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 882 patient admissions, 13 (1.5%) had a diagnostic error up to 7 days after PICU admission. Infections (46%) and respiratory conditions (23%) were the most common missed diagnoses. One diagnostic error caused harm with a prolonged hospital stay. Common missed diagnostic opportunities included failure to consider the diagnosis despite a suggestive history (69%) and failure to broaden diagnostic testing (69%). Unadjusted analysis identified more diagnostic errors in patients with atypical presentations (23.1% vs 3.6%, p = 0.011), neurologic chief complaints (46.2% vs 18.8%, p = 0.024), admitting intensivists greater than or equal to 45 years old (92.3% vs 65.1%, p = 0.042), admitting intensivists with more service weeks/year (mean 12.8 vs 10.9 wk, p = 0.031), and diagnostic uncertainty on admission (77% vs 25.1%, p < 0.001). Generalized linear mixed models determined that atypical presentation (odds ratio [OR] 4.58; 95% CI, 0.94-17.1) and diagnostic uncertainty on admission (OR 9.67; 95% CI, 2.86-44.0) were significantly associated with diagnostic error. CONCLUSIONS: Among critically ill children, 1.5% had a diagnostic error up to 7 days after PICU admission. Diagnostic errors were associated with atypical presentations and diagnostic uncertainty on admission, suggesting possible targets for intervention.

A randomised controlled trial assessing the potential of palmitoylethanolamide (PEA) to act as an adjuvant to resistance training in healthy adults: a study protocol.

BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) and analgesics are used frequently by athletes either prophylactically for the prevention of pain, or to accelerate recovery following an injury. However, these types of pain management strategies have been shown to inhibit signalling pathways (e.g., cyclooxygenase-2) that may hinder muscular adaptations such as hypertrophy and strength. Nutraceuticals such as palmitoylethanolamide (PEA) have analgesic properties that act via different mechanisms to NSAIDS/analgesics. Furthermore, PEA has been shown to have a positive effect on sleep and may contribute positively to muscle hypertrophy via PKB activation. Although PEA has not been widely studied in the athletic or recreationally active population, it may provide an alternative solution for pain management if it is found not to interfere with, or enhance training adaptations. Therefore, the study aim is to investigate the effects of daily PEA supplementation (Levagen + ®) with resistance training on lean body mass, strength, power and physical performance and outcomes of recovery (e.g., sleep) compared to placebo. METHODS: This double-blind, randomised controlled study will take place over an 11-week period (including 8-weeks of progressive resistance training). Participants for this study will be 18-35 years old, healthy active adults that are not resistance trained. Participants will attend a familiarisation (week 0), pre-testing (week 1) and final-testing (week 11). At the pre-testing and final-testing weeks, total lean body mass (dual-energy X-ray absorptiometry; DXA), total mid-thigh cross sectional area (pQCT), maximal muscular strength (1 repetition maximum bench press, isometric mid-thigh pull) and power (countermovement jump and bench throw) will be assessed. Additionally, circulating inflammatory cytokines and anabolic hormones, sleep quality and quantity (ActiGraph), pain and subjective wellbeing (questionnaires) will also be examined. DISCUSSION: This study is designed to investigate the effects that PEA may have on pre-to post intervention changes in total body and regional lean muscle mass, strength, power, sleep, subjective wellbeing, and pain associated with resistance training and menstruation compared with the placebo condition. Unlike other NSAIDs and analgesics, which may inhibit muscle protein synthesis and training adaptations, PEA which provides analgesia via alternative mechanisms may provide an alternative pain management solution. It is therefore important to determine if this analgesic compound interferes with or enhances training adaptations so that athletes and active individuals can make an informed decision on their pain management strategies. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR: ACTRN12621001726842p).

Organisation of enkephalin inputs and outputs of the central nucleus of the amygdala in mice.

The central nucleus of the amygdala (CeA) is a key hub integrating sensory inputs and modulating behavioural outputs. The CeA is a complex structure with discrete subdivisions, high peptidergic heterogeneity and broad CNS afferent and efferent projections. While several neuropeptide systems within the CeA have been examined in detail, less is known about CeA preproenkephalin (ppENK) cells. Here, we used a recently developed transgenic Penk-Cre mouse line to advance our understanding of the efferent and afferent connectivity of ppENK in the CeA. First, to determine the fidelity of Cre expression in Penk-Cre transgenic mice, we conducted RNAscope in the CeA of Penk-Cre mice. Our analysis revealed that 96.6 % of CeA Cre+ neurons co-expressed pENK mRNA, and 99.7 % of CeA pENK+ neurons co-expressed Cre mRNA, indicating faithful recapitulation of Cre expression in CeA ppENK-expressing cells, supporting the fidelity of the Penk-Cre reporter mouse. Anterograde tracing of CeAPenk cells showed strong efferent projections to the extended amygdala, midbrain and hindbrain PBN and NTS. Retrograde tracing of Penk afferents to the CeA were more restricted, with primary innervation originating within the amygdala complex and bed nucleus of the stria terminalis, and minor innervation from the parabrachial nucleus and nucleus of the solitary tract. Together, our data provide a comprehensive map of ENKergic efferent and afferent connectivity of the CeA in Penk-Cre mice. Further, we highlight both the utility and limitations of the Penk-Cre mice to study the function of CeA, PBN and NTS ppENK cells.

Association of Diagnostic Stewardship for Blood Cultures in Critically Ill Children With Culture Rates, Antibiotic Use, and Patient Outcomes: Results of the Bright STAR Collaborative.

Importance: Blood culture overuse in the pediatric intensive care unit (PICU) can lead to unnecessary antibiotic use and contribute to antibiotic resistance. Optimizing blood culture practices through diagnostic stewardship may reduce unnecessary blood cultures and antibiotics. Objective: To evaluate the association of a 14-site multidisciplinary PICU blood culture collaborative with culture rates, antibiotic use, and patient outcomes. Design, Setting, and Participants: This prospective quality improvement (QI) collaborative involved 14 PICUs across the United States from 2017 to 2020 for the Bright STAR (Testing Stewardship for Antibiotic Reduction) collaborative. Data were collected from each participating PICU and from the Children's Hospital Association Pediatric Health Information System for prespecified primary and secondary outcomes. Exposures: A local QI program focusing on blood culture practices in the PICU (facilitated by a larger QI collaborative). Main Outcomes and Measures: The primary outcome was blood culture rates (per 1000 patient-days/mo). Secondary outcomes included broad-spectrum antibiotic use (total days of therapy and new initiations of broad-spectrum antibiotics ≥3 days after PICU admission) and PICU rates of central line-associated bloodstream infection (CLABSI), Clostridioides difficile infection, mortality, readmission, length of stay, sepsis, and severe sepsis/septic shock. Results: Across the 14 PICUs, the blood culture rate was 149.4 per 1000 patient-days/mo preimplementation and 100.5 per 1000 patient-days/mo postimplementation, for a 33% relative reduction (95% CI, 26%-39%). Comparing the periods before and after implementation, the rate of broad-spectrum antibiotic use decreased from 506 days to 440 days per 1000 patient-days/mo, respectively, a 13% relative reduction (95% CI, 7%-19%). The broad-spectrum antibiotic initiation rate decreased from 58.1 to 53.6 initiations/1000 patient-days/mo, an 8% relative reduction (95% CI, 4%-11%). Rates of CLABSI decreased from 1.8 to 1.1 per 1000 central venous line days/mo, a 36% relative reduction (95% CI, 20%-49%). Mortality, length of stay, readmission, sepsis, and severe sepsis/septic shock were similar before and after implementation. Conclusions and Relevance: Multidisciplinary diagnostic stewardship interventions can reduce blood culture and antibiotic use in the PICU. Future work will determine optimal strategies for wider-scale dissemination of diagnostic stewardship in this setting while monitoring patient safety and balancing measures.

Co-Expression Networks Unveiled Long Non-Coding RNAs as Molecular Targets of Drugs Used to Treat Bipolar Disorder.

Long non-coding RNAs (lncRNAs) may play a role in psychiatric diseases including bipolar disorder (BD). We investigated mRNA-lncRNA co-expression patterns in neuronal-like cells treated with widely prescribed BD medications. The aim was to unveil insights into the complex mechanisms of BD medications and highlight potential targets for new drug development. Human neuronal-like (NT2-N) cells were treated with either lamotrigine, lithium, quetiapine, valproate or vehicle for 24 h. Genome-wide mRNA expression was quantified for weighted gene co-expression network analysis (WGCNA) to correlate the expression levels of mRNAs with lncRNAs. Functional enrichment analysis and hub lncRNA identification was conducted on key co-expressed modules associated with the drug response. We constructed lncRNA-mRNA co-expression networks and identified key modules underlying these treatments, as well as their enriched biological functions. Processes enriched in key modules included synaptic vesicle cycle, endoplasmic reticulum-related functions and neurodevelopment. Several lncRNAs such as GAS6-AS1 and MIR100HG were highlighted as driver genes of key modules. Our study demonstrates the key role of lncRNAs in the mechanism(s) of action of BD drugs. Several lncRNAs have been suggested as major regulators of medication effects and are worthy of further investigation as novel drug targets to treat BD.

Cytokine-inducible SH2 domain containing protein contributes to regulation of adiposity, food intake, and glucose metabolism.

The cytokine-inducible SH2 domain containing protein (CISH) is the founding member of the suppressor of cytokine signaling (SOCS) family of negative feedback regulators and has been shown to be a physiological regulator of signaling in immune cells. This study sought to investigate novel functions for CISH outside of the immune system. Mice deficient in CISH were generated and analyzed using a range of metabolic and other parameters, including in response to a high fat diet and leptin administration. CISH knockout mice possessed decreased body fat and showed resistance to diet-induced obesity. This was associated with reduced food intake, but unaltered energy expenditure and microbiota composition. CISH ablation resulted in reduced basal expression of the orexigenic Agrp gene in the arcuate nucleus (ARC) region of the brain. Cish was basally expressed in the ARC, with evidence of co-expression with the leptin receptor (Lepr) gene in Agrp-positive neurons. CISH-deficient mice also showed enhanced leptin responsiveness, although Cish expression was not itself modulated by leptin. CISH-deficient mice additionally exhibited improved insulin sensitivity on a high-fat diet, but not glucose tolerance despite reduced body weight. These data identify CISH as an important regulator of homeostasis through impacts on appetite control, mediated at least in part by negative regulation of the anorexigenic effects of leptin, and impacts on glucose metabolism.

Opioid Analgesia and Opioid-Induced Adverse Effects: A Review.

Opioids are widely used as therapeutic agents against moderate to severe acute and chronic pain. Still, these classes of analgesic drugs have many potential limitations as they induce analgesic tolerance, addiction and numerous behavioural adverse effects that often result in patient non-compliance. As opium and opioids have been traditionally used as painkillers, the exact mechanisms of their adverse reactions over repeated use are multifactorial and not fully understood. Older adults suffer from cancer and non-cancer chronic pain more than younger adults, due to the physiological changes related to ageing and their reduced metabolic capabilities and thus show an increased number of adverse reactions to opioid drugs. All clinically used opioids are µ-opioid receptor agonists, and the major adverse effects are directly or potentially connected to this receptor. Multifunctional opioid ligands or peripherally restricted opioids may elicit fewer adverse effects, as shown in preclinical studies, but these results need reproducibility from further extensive clinical trials. The current review aims to overview various mechanisms involved in the adverse effects induced by opioids, to provide a better understanding of the underlying pathophysiology and, ultimately, to help develop an effective therapeutic strategy to better manage pain.

Targeted Temperature Management Protocol in a Pediatric Intensive Care Unit: A Quality Improvement Project.

BACKGROUND: In patients with acute neurological injury, abrupt temperature change exacerbates increased intracranial pressures and negatively affects perfusion pressure and cerebral blood flow. Critical care nurses must provide coordinated and effective interventions to maintain normothermia without precipitating shivering immediately after acute neurological injury in pediatric patients. OBJECTIVE: To improve hyperthermia management in a 40-bed pediatric intensive care unit, an interdisciplinary pediatric critical care team developed, implemented, and evaluated a targeted temperature management protocol. METHODS: The project was guided by the organization's plan-do-study-act quality improvement process. Quality improvement was assessed retrospectively using electronic medical records of patients meeting eligibility criteria. Samples of pediatric patients who received temperature interventions were compared before and after protocol implementation. The protocol included environmental, pharmacological, and body surface cooling device interventions, as well as use of a bedside shivering assessment scale and stepwise interventions to prevent and control shivering. RESULTS: Before implementation of the targeted temperature management protocol, 64% of patients had documented temperatures higher than 37.5 °C, and body surface cooling devices were used in 10% of patients. After protocol implementation, more than 80% of patients had documented temperatures higher than 37.5 °C, and body surface cooling devices were used in 62% of patients. Four patients (6%) before and 5 patients (31%) after protocol implementation were treated with body surface cooling without requiring use of neuromuscular blockade. CONCLUSIONS: Creation and implementation of a targeted temperature management protocol increased nurses' documented use of body surface cooling to manage hyperthermia in pediatric intensive care unit patients with acute neurological injury.

Farmed Mussels: A Nutritive Protein Source, Rich in Omega-3 Fatty Acids, with a Low Environmental Footprint.

The world's ever-growing population presents a major challenge in providing sustainable food options and in reducing pressures on the Earth's agricultural land and freshwater resources. Current estimates suggest that agriculture contributes ~30% of global greenhouse gas (GHG) emissions. Additionally, there is an increased demand for animal protein, the production of which is particularly polluting. Therefore, the climate-disrupting potential of feeding the planet is likely to substantially worsen in the future. Due to the nutritional value of animal-based protein, it is not a simple solution to recommend a wholesale reduction in production/consumption of animal proteins. Rather, employing strategies which result in the production of low carbon animal protein may be part of the solution to reduce the GHGs associated with our diets without compromising diet quality. We suggest that farmed mussels may present a partial solution to this dilemma. Mussel production has a relatively low GHG production and does not put undue pressure on land or fresh water supplies. By drawing comparisons to other protein sources using the Australian Food and Nutrient Database and other published data, we demonstrate that they are a sustainable source of high-quality protein, long-chain omega-3 fatty acids, phytosterols, and other key micronutrients such as B-12 and iron. The aim of this review is to summarise the current knowledge on the health benefits and potential risks of increasing the consumption of farmed mussels.

Serum Biomarkers of Regeneration and Plasticity are Associated with Functional Outcome in Pediatric Neurocritical Illness: An Exploratory Study.

BACKGROUND/OBJECTIVE: Pediatric neurocritical care survivorship is frequently accompanied by functional impairments. Lack of prognostic biomarkers is a barrier to early identification and management of impairment. We explored the association between blood biomarkers and functional impairment in children with acute acquired brain injury. METHODS: This study is a secondary analysis of a randomized control trial evaluating early versus usual care rehabilitation in the pediatric intensive care unit (PICU). Forty-four children (17 [39%] female, median age 11 [interquartile range 6-13] years) with acute acquired brain injury admitted to the PICU were studied. A single center obtained serum samples on admission days 0, 1, 3, 5, and the day closest to hospital discharge. Biomarkers relevant to brain injury (neuron specific enolase [NSE], S100b), inflammation (interleukin [IL-6], C-reactive protein), and regeneration (brain-derived neurotrophic factor [BDNF], vascular endothelial growth factor [VEGF]) were collected. Biomarkers were analyzed using a Luminex® bioassay. Functional status scale (FSS) scores were abstracted from the medical record. New functional impairment was defined as a (worse) FSS score at hospital discharge compared to pre-PICU (baseline). Individual biomarker fluorescence index (FI) values for each sample collection day were correlated with new functional impairment using Spearman rank correlation coefficient (ρ). Trends in repeated measures of biomarker FI over time were explored graphically, and the association between repeated measures of biomarker FI and new functional impairment was analyzed using covariate adjusted linear mixed-effect models. RESULTS: Functional impairment was inversely correlated with markers of regeneration and plasticity including BDNF at day 3 (ρ = - 0.404, p = .015), day 5 (ρ = - 0.549, p = 0.005) and hospital discharge (ρ = - 0.420, p = 0.026) and VEGF at day 1 (ρ = - 0.282, p = 0.008) and hospital discharge (ρ = - 0.378, p = 0.047), such that lower levels of both markers at each time point were associated with greater impairment. Similarly, repeated measures of BDNF and VEGF were inversely correlated with new functional impairment (B = - 0.001, p = 0.001 and B = - 0.001, p = 0.003, respectively). NSE, a biomarker of acute brain injury, showed a positive correlation between day 0 levels and new functional impairment (ρ = 0.320, p = 0.044). CONCLUSIONS: Blood-based biomarkers of regeneration and plasticity may hold prognostic utility for functional impairment among pediatric patients with neurocritical illness and warrant further investigation.

Comparison of Two Assessment Tools for Hospitalized Subjects With Asthma.

BACKGROUND: Pediatric Asthma Assessment tools used to guide the weaning of inhaled therapies during inpatient hospitalization require further evaluation and validation. This study aimed to compare 2 asthma assessment tools: an asthma scale versus an asthma score. METHODS: A prospective, physician-blinded, comparison study was conducted in 2 separate 6-week phases of patients > 2 y old admitted to a tertiary care children's hospital with status asthmaticus between July and November 2014. The asthma scale categorized 5 components (oxygen, auscultation, dyspnea, breathing frequency, and pulse oximetry) into 1 of 3 respiratory assessments: mild, moderate, or severe. The asthma score used a sum of the components, resulting in a score of 1-15. Study tool predictability was measured using a metric based on hours on continuous albuterol, with area under the curve ≥ 0.8 indicating good predictability. Agreement between clinicians was measured using the Cohen kappa statistic. Study tool clinical correlation was measured using Spearman coefficient. Usability was evaluated using web-based surveys. RESULTS: Phase 1 included 1,971 assessments (97 unique subjects), whereas phase 2 included 607 assessments (69 unique subjects). Using the continuous albuterol metric, predictability of the asthma scale had an area under the curve of 0.62 versus the asthma score area under the curve of 0.80. Agreement early in hospitalization for the asthma scale was kappa = 0.34 (95% CI 0.18-0.5; n = 84) versus kappa = 0.55 (95% CI 0.35-0.76; n = 44) for the asthma score. Agreement late in hospitalization for the asthma scale was kappa = 0.38 (95% CI 0.17-0.59; n = 66) versus kappa = 0.41 (95% CI 0.13-0.69; n = 33) for the asthma score. Clinical correlation for the asthma scale (no. = 1,908) was r = 0.57 (P < .001) versus r = 0.80 (P < .001) for the asthma score (no. = 558). Mean asthma scale usability was 3.38 versus 3.68 for the asthma score. CONCLUSIONS: The asthma score showed better clinical predictability and clinical correlation compared to the asthma scale. Numerical scores provided more objective assessments compared to categorical scores. Validated scoring tools such as the asthma score are crucial to the success of management of inpatient asthma care.

Pioglitazone and Deoxyribonucleoside Combination Treatment Increases Mitochondrial Respiratory Capacity in m.3243A>G MELAS Cybrid Cells.

The lack of effective treatments for mitochondrial disease has seen the development of new approaches, including those that aim to stimulate mitochondrial biogenesis to boost ATP generation above a critical disease threshold. Here, we examine the effects of the peroxisome proliferator-activated receptor γ (PPARγ) activator pioglitazone (PioG), in combination with deoxyribonucleosides (dNs), on mitochondrial biogenesis in cybrid cells containing >90% of the m.3243A>G mutation associated with mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). PioG + dNs combination treatment increased mtDNA copy number and mitochondrial mass in both control (CON) and m.3243A>G (MUT) cybrids, with no adverse effects on cell proliferation. PioG + dNs also increased mtDNA-encoded transcripts in CON cybrids, but had the opposite effect in MUT cybrids, reducing the already elevated transcript levels. Steady-state levels of mature oxidative phosphorylation (OXPHOS) protein complexes were increased by PioG + dNs treatment in CON cybrids, but were unchanged in MUT cybrids. However, treatment was able to significantly increase maximal mitochondrial oxygen consumption rates and cell respiratory control ratios in both CON and MUT cybrids. Overall, these findings highlight the ability of PioG + dNs to improve mitochondrial respiratory function in cybrid cells containing the m.3243A>G MELAS mutation, as well as their potential for development into novel therapies to treat mitochondrial disease.

Differential Level of RXFP3 Expression in Dopaminergic Neurons Within the Arcuate Nucleus, Dorsomedial Hypothalamus and Ventral Tegmental Area of RXFP3-Cre/tdTomato Mice.

RXFP3 (relaxin-family peptide 3 receptor) is the cognate G-protein-coupled receptor for the neuropeptide, relaxin-3. RXFP3 is expressed widely throughout the brain, including the hypothalamus, where it has been shown to modulate feeding behavior and neuroendocrine activity in rodents. In order to better characterize its potential mechanisms of action, this study determined whether RXFP3 is expressed by dopaminergic neurons within the arcuate nucleus (ARC) and dorsomedial hypothalamus (DMH), in addition to the ventral tegmental area (VTA). Neurons that express RXFP3 were visualized in coronal brain sections from RXFP3-Cre/tdTomato mice, which express the tdTomato fluorophore within RXFP3-positive cells, and dopaminergic neurons in these areas were visualized by simultaneous immunohistochemical detection of tyrosine hydroxylase-immunoreactivity (TH-IR). Approximately 20% of ARC neurons containing TH-IR coexpressed tdTomato fluorescence, suggesting that RXFP3 can influence the dopamine pathway from the ARC to the pituitary gland that controls prolactin release. The ability of prolactin to reduce leptin sensitivity and increase food consumption therefore represents a potential mechanism by which RXFP3 activation influences feeding. A similar proportion of DMH neurons containing TH-IR expressed RXFP3-related tdTomato fluorescence, consistent with a possible RXFP3-mediated regulation of stress and neuroendocrine circuits. In contrast, RXFP3 was barely detected within the VTA. TdTomato signal was absent from the ARC and DMH in sections from Rosa26-tdTomato mice, suggesting that the cells identified in RXFP3-Cre/tdTomato mice expressed authentic RXFP3-related tdTomato fluorescence. Together, these findings identify potential hypothalamic mechanisms through which RXFP3 influences neuroendocrine control of metabolism, and further highlight the therapeutic potential of targeting RXFP3 in feeding-related disorders.

Modulation of high fat diet-induced microbiome changes, but not behaviour, by minocycline.

An emerging novel therapeutic agent for major depressive disorder, minocycline, has the potential to influence both gut microbiome and inflammatory status. The present study showed that chronic high fat diet feeding led to changes in both behaviour and the gut microbiome in male mice, without an overt inflammatory response. The diet-induced behavioural changes were characterised as increased immobility in the forced swim test and changes in locomotor activities in the open field test. Minocycline significantly altered the gut microbiome, rendering a community distinctly different to both untreated healthy and diet-affected states. In contrast, minocycline did not reverse high fat diet-induced changes in behaviour.