RESUMEN
OBJECTIVE: Recreational gamma-hydroxybutyrate (GHB) use is rising in Australia. We aimed to describe ED presentation patterns related to GHB over time and the impact this has on ED resource use. METHODS: Retrospective review of prospective data collection from two clinical toxicology units based in Queensland and New South Wales. RESULTS: There were 751 GHB-related presentations to the two units (Newcastle, 127; Princess Alexandria, 624), with marked increases in presentations occurring in 2019 and 2023. The major intervention was intubation, with 95 (13%) patients intubated. CONCLUSION: GHB presentations to ED are rising and the impact on acute bed space and clinical resources is significant.
RESUMEN
Vitamin D signals through the vitamin D receptor (VDR) to induce its end-organ effects. Hepatic stellate cells control development of liver fibrosis in response to stressors and vitamin D signaling decreases fibrogenesis. VDR expression in hepatocytes is low in healthy liver, and the role of VDR in hepatocyte proliferation is unclear. Hepatocyte-VDR null mice (hVDR) were used to assess the role of VDR and vitamin D signaling in hepatic regeneration. hVDR mice have impaired liver regeneration and impaired hepatocyte proliferation associated with significant differential changes in bile salts. Notably, mice lacking hepatocyte VDR had significant increases in expression of conjugated bile acids after partial hepatectomy, consistent with failure to normalize hepatic function by the 14-day time point tested. Real-time PCR of hVDR and control livers showed significant changes in expression of cell-cycle genes including cyclins D1 and E1 and cyclin-dependent kinase 2. Gene expression profiling of hepatocytes treated with vitamin D or control showed regulation of groups of genes involved in liver proliferation, hepatitis, liver hyperplasia/hyperproliferation, and liver necrosis/cell death. Together, these studies demonstrate an important functional role for VDR in hepatocytes during liver regeneration. Combined with the known profibrotic effects of impaired VDR signaling in stellate cells, the studies provide a mechanism whereby vitamin D deficiency would both reduce hepatocyte proliferation and permit fibrosis, leading to significant liver compromise.
Asunto(s)
Ácidos y Sales Biliares , Proliferación Celular , Hepatectomía , Hepatocitos , Regeneración Hepática , Ratones Noqueados , Receptores de Calcitriol , Animales , Regeneración Hepática/efectos de los fármacos , Regeneración Hepática/fisiología , Receptores de Calcitriol/metabolismo , Receptores de Calcitriol/genética , Masculino , Ratones , Hepatocitos/metabolismo , Hepatocitos/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Ácidos y Sales Biliares/metabolismo , Hígado/metabolismo , Ciclina D1/metabolismo , Ciclina D1/genética , Ciclina E/metabolismo , Ciclina E/genética , Quinasa 2 Dependiente de la Ciclina/metabolismo , Quinasa 2 Dependiente de la Ciclina/genética , Ratones Endogámicos C57BL , Vitamina D/farmacología , Transducción de Señal/efectos de los fármacos , Proteínas OncogénicasRESUMEN
INTRODUCTION: Antivenom is first line treatment for snake envenomation worldwide, despite few placebo controlled clinical trials demonstrating effectiveness. We aimed to investigate whether early antivenom in red-bellied black snake (Pseudechis porphyriacus) bites would prevent systemic myotoxicity. METHODS: We undertook a multicentre randomized placebo-controlled trial of antivenom for red-bellied black snake bites with patients recruited from the Australian Snakebite Project (July 2014 to June 2020). In addition, we report all patients with red-bellied black snake bites during the same period, comparing the same outcomes. Patients over 2 years of age with definite red-bellied black snake bites and early systemic effects were randomized to receive 50 per cent glucose (placebo) or tiger snake antivenom within 6 hours post-bite, or in the cohort group received antivenom determined by the treating clinician. The primary outcome was the proportion of patients with myotoxicity (peak creatine kinase activity >1,000 U/L). Secondary outcomes were: area under the curve of total creatine kinase elevation over 48 hours, presence of venom post-antivenom, and adverse reactions. We analyzed both the randomized control trial patients and the combination of randomized control trial and cohort patients. RESULTS: Fifteen patients were recruited to the randomized controlled trial, and a cohort of 68 patients who were not randomized were included in the analysis. After treatment, two of seven patients given placebo had a peak creatine kinase activity >1,000 U/L versus none of the eight given antivenom (difference in favour of antivenom; 29 per cent; 95 per cent confidence interval:-18 per cent to +70 per cent; P = 0.2). The median area under the curve of total creatine kinase elevation over 48 hours in patients given placebo was 0 U/L*h (interquartile range: 0-124 U/L*h), which was not significantly different to those given antivenom: 197 U/L*h (interquartile range: 0-66,353 U/L*h; P = 0.26). Venom was not detected post-antivenom in six patients with measured venom concentrations given antivenom. Two patients given antivenom had immediate hypersensitivity reactions, one severe anaphylaxis, and another had serum sickness. Combining randomized and not randomized patients, three of 36 (8 per cent) administered antivenom less than 6 hours post-bite had a peak creatine kinase activity >1,000 U/L versus 17/47 (36 per cent) patients not receiving antivenom less than 6 hours post-bite (difference in favour of antivenom 29 per cent; 95 per cent confidence interval: 8 per cent to 44 per cent; P < 0.004). Overall, 13/36 (36 per cent) patients administered antivenom within 6 hours had hypersensitivity reactions, six severe anaphylaxis (17 per cent). DISCUSSION: We found that early antivenom was effective in red-bellied black snake bites, and only three patients need to be given antivenom within 6 hours to prevent myotoxicity in one (number needed to treat = 3). However, one in three patients administered antivenom developed a hypersensitivity reaction, and one in six had severe anaphylaxis. The major limitation of this study was the small number of patients recruited to the randomized controlled trial. CONCLUSION: Administration of antivenom in red-bellied black snake envenomation within 6 hours post-bite appeared to decrease the proportion of patients with myotoxicity, but a third of patients had adverse reactions.
Asunto(s)
Antivenenos , Venenos Elapídicos , Mordeduras de Serpientes , Humanos , Mordeduras de Serpientes/tratamiento farmacológico , Antivenenos/uso terapéutico , Masculino , Femenino , Adulto , Estudios Prospectivos , Persona de Mediana Edad , Animales , Venenos Elapídicos/antagonistas & inhibidores , Miotoxicidad/tratamiento farmacológico , Adulto Joven , Australia , Elapidae , Adolescente , Resultado del Tratamiento , Creatina Quinasa/sangre , AncianoRESUMEN
Despite numerous female contraceptive options, nearly half of all pregnancies are unintended. Family planning choices for men are currently limited to unreliable condoms and invasive vasectomies with questionable reversibility. Here, we report the development of an oral contraceptive approach based on transcriptional disruption of cyclical gene expression patterns during spermatogenesis. Spermatogenesis involves a continuous series of self-renewal and differentiation programs of spermatogonial stem cells (SSCs) that is regulated by retinoic acid (RA)-dependent activation of receptors (RARs), which control target gene expression through association with corepressor proteins. We have found that the interaction between RAR and the corepressor silencing mediator of retinoid and thyroid hormone receptors (SMRT) is essential for spermatogenesis. In a genetically engineered mouse model that negates SMRT-RAR binding (SMRTmRID mice), the synchronized, cyclic expression of RAR-dependent genes along the seminiferous tubules is disrupted. Notably, the presence of an RA-resistant SSC population that survives RAR de-repression suggests that the infertility attributed to the loss of SMRT-mediated repression is reversible. Supporting this notion, we show that inhibiting the action of the SMRT complex with chronic, low-dose oral administration of a histone deacetylase inhibitor reversibly blocks spermatogenesis and fertility without affecting libido. This demonstration validates pharmacologic targeting of the SMRT repressor complex for non-hormonal male contraception.
Asunto(s)
Proteínas de Unión al ADN , Proteínas Represoras , Humanos , Femenino , Masculino , Animales , Ratones , Proteínas de Unión al ADN/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Proteínas Co-Represoras/genética , Co-Represor 2 de Receptor Nuclear/genética , Tretinoina/farmacología , Anticoncepción , Co-Represor 1 de Receptor NuclearRESUMEN
The nuclear receptor corepressor (NCoR) forms a complex with histone deacetylase 3 (HDAC3) that mediates repressive functions of unliganded nuclear receptors and other transcriptional repressors by deacetylation of histone substrates. Recent studies provide evidence that NCoR/HDAC3 complexes can also exert coactivator functions in brown adipocytes by deacetylating and activating PPARγ coactivator 1α (PGC1α) and that signaling via receptor activator of nuclear factor kappa-B (RANK) promotes the formation of a stable NCoR/HDAC3/PGC1ß complex that coactivates nuclear factor kappa-B (NFκB)- and activator protein 1 (AP-1)-dependent genes required for osteoclast differentiation. Here, we demonstrate that activation of Toll-like receptor (TLR) 4, but not TLR3, the interleukin 4 (IL4) receptor nor the Type I interferon receptor, also promotes assembly of an NCoR/HDAC3/PGC1ß coactivator complex. Receptor-specific utilization of TNF receptor-associated factor 6 (TRAF6) and downstream activation of extracellular signal-regulated kinase 1 (ERK1) and TANK-binding kinase 1 (TBK1) accounts for the common ability of RANK and TLR4 to drive assembly of an NCoR/HDAC3/PGC1ß complex in macrophages. ERK1, the p65 component of NFκB, and the p300 histone acetyltransferase (HAT) are also components of the induced complex and are associated with local histone acetylation and transcriptional activation of TLR4-dependent enhancers and promoters. These observations identify a TLR4/TRAF6-dependent signaling pathway that converts NCoR from a corepressor of nuclear receptors to a coactivator of NFκB and AP-1 that may be relevant to functions of NCoR in other developmental and homeostatic processes.
Asunto(s)
Histonas , Factor 6 Asociado a Receptor de TNF , Activación Transcripcional , Proteínas Co-Represoras/genética , Histonas/genética , Histonas/metabolismo , Factor 6 Asociado a Receptor de TNF/genética , Factor 6 Asociado a Receptor de TNF/metabolismo , Factor de Transcripción AP-1/metabolismo , Receptor Toll-Like 4/metabolismo , Transducción de Señal , FN-kappa B/genética , FN-kappa B/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismoRESUMEN
Mitochondrial dysfunction is a characteristic trait of human and rodent obesity, insulin resistance and fatty liver disease. Here we show that high-fat diet (HFD) feeding causes mitochondrial fragmentation in inguinal white adipocytes from male mice, leading to reduced oxidative capacity by a process dependent on the small GTPase RalA. RalA expression and activity are increased in white adipocytes after HFD. Targeted deletion of RalA in white adipocytes prevents fragmentation of mitochondria and diminishes HFD-induced weight gain by increasing fatty acid oxidation. Mechanistically, RalA increases fission in adipocytes by reversing the inhibitory Ser637 phosphorylation of the fission protein Drp1, leading to more mitochondrial fragmentation. Adipose tissue expression of the human homolog of Drp1, DNM1L, is positively correlated with obesity and insulin resistance. Thus, chronic activation of RalA plays a key role in repressing energy expenditure in obese adipose tissue by shifting the balance of mitochondrial dynamics toward excessive fission, contributing to weight gain and metabolic dysfunction.
Asunto(s)
Resistencia a la Insulina , Proteínas de Unión al GTP ral , Animales , Humanos , Masculino , Ratones , Adipocitos Blancos/metabolismo , Tejido Adiposo/metabolismo , Obesidad/etiología , Obesidad/metabolismo , Aumento de Peso , Proteínas de Unión al GTP ral/metabolismoRESUMEN
BACKGROUND: Cardiac metabolic dysfunction is a hallmark of heart failure (HF). Estrogen-related receptors ERRα and ERRγ are essential regulators of cardiac metabolism. Therefore, activation of ERR could be a potential therapeutic intervention for HF. However, in vivo studies demonstrating the potential usefulness of ERR agonist for HF treatment are lacking, because compounds with pharmacokinetics appropriate for in vivo use have not been available. METHODS: Using a structure-based design approach, we designed and synthesized 2 structurally distinct pan-ERR agonists, SLU-PP-332 and SLU-PP-915. We investigated the effect of ERR agonist on cardiac function in a pressure overload-induced HF model in vivo. We conducted comprehensive functional, multi-omics (RNA sequencing and metabolomics studies), and genetic dependency studies both in vivo and in vitro to dissect the molecular mechanism, ERR isoform dependency, and target specificity. RESULTS: Both SLU-PP-332 and SLU-PP-915 significantly improved ejection fraction, ameliorated fibrosis, and increased survival associated with pressure overload-induced HF without affecting cardiac hypertrophy. A broad spectrum of metabolic genes was transcriptionally activated by ERR agonists, particularly genes involved in fatty acid metabolism and mitochondrial function. Metabolomics analysis showed substantial normalization of metabolic profiles in fatty acid/lipid and tricarboxylic acid/oxidative phosphorylation metabolites in the mouse heart with 6-week pressure overload. ERR agonists increase mitochondria oxidative capacity and fatty acid use in vitro and in vivo. Using both in vitro and in vivo genetic dependency experiments, we show that ERRγ is the main mediator of ERR agonism-induced transcriptional regulation and cardioprotection and definitively demonstrated target specificity. ERR agonism also led to downregulation of cell cycle and development pathways, which was partially mediated by E2F1 in cardiomyocytes. CONCLUSIONS: ERR agonists maintain oxidative metabolism, which confers cardiac protection against pressure overload-induced HF in vivo. Our results provide direct pharmacologic evidence supporting the further development of ERR agonists as novel HF therapeutics.
Asunto(s)
Insuficiencia Cardíaca , Ratones , Animales , Cardiomegalia/metabolismo , Mitocondrias/metabolismo , Miocitos Cardíacos/metabolismo , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Ácidos Grasos/metabolismoRESUMEN
Oncogenic lesions in pancreatic ductal adenocarcinoma (PDAC) hijack the epigenetic machinery in stromal components to establish a desmoplastic and therapeutic resistant tumor microenvironment (TME). Here we identify Class I histone deacetylases (HDACs) as key epigenetic factors facilitating the induction of pro-desmoplastic and pro-tumorigenic transcriptional programs in pancreatic stromal fibroblasts. Mechanistically, HDAC-mediated changes in chromatin architecture enable the activation of pro-desmoplastic programs directed by serum response factor (SRF) and forkhead box M1 (FOXM1). HDACs also coordinate fibroblast pro-inflammatory programs inducing leukemia inhibitory factor (LIF) expression, supporting paracrine pro-tumorigenic crosstalk. HDAC depletion in cancer-associated fibroblasts (CAFs) and treatment with the HDAC inhibitor entinostat (Ent) in PDAC mouse models reduce stromal activation and curb tumor progression. Notably, HDAC inhibition (HDACi) enriches a lipogenic fibroblast subpopulation, a potential precursor for myofibroblasts in the PDAC stroma. Overall, our study reveals the stromal targeting potential of HDACi, highlighting the utility of this epigenetic modulating approach in PDAC therapeutics.
Asunto(s)
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Animales , Ratones , Línea Celular Tumoral , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Páncreas/metabolismo , Carcinoma Ductal Pancreático/tratamiento farmacológico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Fibroblastos/metabolismo , Carcinogénesis/patología , Microambiente TumoralRESUMEN
Oncogenic lesions in pancreatic ductal adenocarcinoma (PDAC) hijack the epigenetic machinery in stromal components to establish a desmoplastic and therapeutic resistant tumor microenvironment (TME). Here we identify Class I histone deacetylases (HDACs) as key epigenetic factors facilitating the induction of pro-desmoplastic and pro-tumorigenic transcriptional programs in pancreatic stromal fibroblasts. Mechanistically, HDAC-mediated changes in chromatin architecture enable the activation of pro-desmoplastic programs directed by serum response factor (SRF) and forkhead box M1 (FOXM1). HDACs also coordinate fibroblast pro-inflammatory programs inducing leukemia inhibitory factor (LIF) expression, supporting paracrine pro-tumorigenic crosstalk. HDAC depletion in cancer-associated fibroblasts (CAFs) and treatment with the HDAC inhibitor entinostat (Ent) in PDAC mouse models reduce stromal activation and curb tumor progression. Notably, HDAC inhibition (HDACi) enriches a lipogenic fibroblast subpopulation, a potential precursor for myofibroblasts in the PDAC stroma. Overall, our study reveals the stromal targeting potential of HDACi, highlighting the utility of this epigenetic modulating approach in PDAC therapeutics.
RESUMEN
The nuclear receptor co-repressor (NCoR) complex mediates transcriptional repression dependent on histone deacetylation by histone deacetylase 3 (HDAC3) as a component of the complex. Unexpectedly, we found that signaling by the receptor activator of nuclear factor κB (RANK) converts the NCoR/HDAC3 co-repressor complex to a co-activator of AP-1 and NF-κB target genes that are required for mouse osteoclast differentiation. Accordingly, the dominant function of NCoR/HDAC3 complexes in response to RANK signaling is to activate, rather than repress, gene expression. Mechanistically, RANK signaling promotes RNA-dependent interaction of the transcriptional co-activator PGC1ß with the NCoR/HDAC3 complex, resulting in the activation of PGC1ß and inhibition of HDAC3 activity for acetylated histone H3. Non-coding RNAs Dancr and Rnu12, which are associated with altered human bone homeostasis, promote NCoR/HDAC3 complex assembly and are necessary for RANKL-induced osteoclast differentiation in vitro. These findings may be prototypic for signal-dependent functions of NCoR in other biological contexts.
Asunto(s)
Osteoclastos , ARN , Humanos , Ratones , Animales , Proteínas Co-Represoras/genética , Osteoclastos/metabolismo , Ligando RANK/genética , Co-Represor 1 de Receptor Nuclear/genética , Co-Represor 1 de Receptor Nuclear/metabolismo , Expresión GénicaRESUMEN
INTRODUCTION: Controversy exists with regard to risk of secondary exposure of health care workers caring for patients who have ingested an organophosphate insecticide. We aim to report clinical effects of staff members caring for an organophosphate poisoned patient. INCIDENT: A 76-year-old male presented to the Emergency Department exhibiting a cholinergic toxidrome requiring atropine, intubation and mechanical ventilation. METHODS: We undertook a retrospective chart review of any Emergency Department presentations for medical assessment in relation to the incident and conducted telephone interviews of any healthcare workers who did not present but were deemed to be closely involved with patient care. We collected data including age, gender, symptoms reported and plasma cholinesterase activity measurement. RESULTS: We collected data from 13 individuals, of whom nine presented for medical assessment, including the patient's spouse. Five additional staff members were interviewed, having been identified via Emergency Department rostering documentation. The 13 healthcare workers comprised five nurses, four paramedics and four doctors. Dizziness and nausea were reported in two and the patient's spouse reported one episode of vomiting. Of the nine patients who had plasma cholinesterase activity measured, none were below the laboratory reference range, including those who experienced symptoms. CONCLUSIONS: We found no clinical nor biochemical evidence of toxicity in healthcare workers caring for a critically ill patient with organophosphate ingestion. These findings are consistent with previously published guidelines advocating standard/Level D personal protective equipment. We believe that emergency departments should not be closed as a safety measure.
Asunto(s)
Intoxicación por Organofosfatos , Intoxicación , Masculino , Humanos , Anciano , Intoxicación por Organofosfatos/terapia , Estudios Retrospectivos , Organofosfatos , Personal de Salud , Colinesterasas , ColinérgicosRESUMEN
Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy in need of new therapeutic options. Using unbiased analyses of super-enhancers (SEs) as sentinels of core genes involved in cell-specific function, here we uncover a druggable SE-mediated RNA-binding protein (RBP) cascade that supports PDAC growth through enhanced mRNA translation. This cascade is driven by a SE associated with the RBP heterogeneous nuclear ribonucleoprotein F, which stabilizes protein arginine methyltransferase 1 (PRMT1) to, in turn, control the translational mediator ubiquitin-associated protein 2-like. All three of these genes and the regulatory SE are essential for PDAC growth and coordinately regulated by the Myc oncogene. In line with this, modulation of the RBP network by PRMT1 inhibition reveals a unique vulnerability in Myc-high PDAC patient organoids and markedly reduces tumor growth in male mice. Our study highlights a functional link between epigenetic regulation and mRNA translation and identifies components that comprise unexpected therapeutic targets for PDAC.
Asunto(s)
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Masculino , Animales , Ratones , ARN , Epigénesis Genética , Secuencias Reguladoras de Ácidos Nucleicos , Neoplasias Pancreáticas/genética , Carcinoma Ductal Pancreático/genética , Metiltransferasas , Proteínas de Unión al ARN/genéticaRESUMEN
BACKGROUND: New onset atrial fibrillation (NOAF) is the most common arrhythmia affecting critically ill patients with sepsis. NOAF is associated with increased intensive care unit mortality, increased hospital mortality, development of heart failure and increased risk of permanent atrial fibrillation and thromboembolic events such as stroke. The pathophysiology of NOAF has been outlined, however, a knowledge gap exists regarding the association between abnormalities in coagulation and immune biomarkers, and the risk of developing NOAF in patients with sepsis. METHODS AND ANALYSIS: This protocol describes a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guideline (PRISMA-P) and the Meta-Analyses and Systematic Reviews of Observational Studies guideline (MOOSE). We will conduct the literature search in Medline, Scopus and Cochrane Library. We will include studies that report data in adult patients (>18 years) with sepsis that develop NOAF. We will extract data from studies that report at least one coagulation or immune biomarker. Risk of bias will be assessed by using the Newcastle Ottawa Scale (NOS) and Risk of Bias 2 tool (RoB2) for non-randomized and randomized trials respectively. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach will be utilized in assessing the quality of evidence. DISCUSSION: This systematic review and meta-analysis will explore the scientific literature regarding the association between coagulation and immune activation in critically ill patients with sepsis, who develop NOAF. The findings will add to the existing knowledge base of NOAF in sepsis, highlight areas of uncertainty and identify future areas of interest to guide and improve management strategies for NOAF. TRIAL REGISTRATION: Registration details. CRD42022385225 (PROSPERO).
Asunto(s)
Fibrilación Atrial , Trastornos de la Coagulación Sanguínea , Ciervos , Sepsis , Animales , Fibrilación Atrial/complicaciones , Enfermedad Crítica , Revisiones Sistemáticas como Asunto , Metaanálisis como Asunto , Sepsis/complicaciones , Estudios Observacionales como AsuntoRESUMEN
Colorectal cancer (CRC) is driven by genomic alterations in concert with dietary influences, with the gut microbiome implicated as an effector in disease development and progression. While meta-analyses have provided mechanistic insight into patients with CRC, study heterogeneity has limited causal associations. Using multi-omics studies on genetically controlled cohorts of mice, we identify diet as the major driver of microbial and metabolomic differences, with reductions in α diversity and widespread changes in cecal metabolites seen in high-fat diet (HFD)-fed mice. In addition, non-classic amino acid conjugation of the bile acid cholic acid (AA-CA) increased with HFD. We show that AA-CAs impact intestinal stem cell growth and demonstrate that Ileibacterium valens and Ruminococcus gnavus are able to synthesize these AA-CAs. This multi-omics dataset implicates diet-induced shifts in the microbiome and the metabolome in disease progression and has potential utility in future diagnostic and therapeutic developments.
Asunto(s)
Neoplasias Colorrectales , Microbioma Gastrointestinal , Microbiota , Animales , Ratones , Ácidos y Sales Biliares , MetabolomaRESUMEN
While the world is rapidly transforming into a superaging society, pharmaceutical approaches to treat sarcopenia have hitherto not been successful due to their insufficient efficacy and failure to specifically target skeletal muscle cells (skMCs). Although electrical stimulation (ES) is emerging as an alternative intervention, its efficacy toward treating sarcopenia remains unexplored. In this study, we demonstrate a silver electroceutical technology with the potential to treat sarcopenia. First, we developed a high-throughput ES screening platform that can simultaneously stimulate 15 independent conditions, while utilizing only a small number of human-derived primary aged/young skMCs (hAskMC/hYskMC). The in vitro screening showed that specific ES conditions induced hypertrophy and rejuvenation in hAskMCs, and the optimal ES frequency in hAskMCs was different from that in hYskMCs. When applied to aged mice in vivo, specific ES conditions improved the prevalence and thickness of Type IIA fibers, along with biomechanical attributes, toward a younger skMC phenotype. This study is expected to pave the way toward an electroceutical treatment for sarcopenia with minimal side effects and help realize personalized bioelectronic medicine.
Asunto(s)
Sarcopenia , Animales , Humanos , Ratones , Fibras Musculares Esqueléticas , Músculo Esquelético/fisiología , Fenotipo , Sarcopenia/terapia , PlataRESUMEN
Mitochondrial dysfunction is a characteristic trait of human and rodent obesity, insulin resistance, and fatty liver disease. Here we report that mitochondria undergo fragmentation and reduced oxidative capacity specifically in inguinal white adipose tissue after feeding mice high fat diet (HFD) by a process dependent on the small GTPase RalA. RalA expression and activity are increased in white adipocytes from mice fed HFD. Targeted deletion of Rala in white adipocytes prevents the obesity-induced fragmentation of mitochondria and produces mice resistant to HFD-induced weight gain via increased fatty acid oxidation. As a result, these mice also exhibit improved glucose tolerance and liver function. In vitro mechanistic studies revealed that RalA suppresses mitochondrial oxidative function in adipocytes by increasing fission through reversing the protein kinase A-catalyzed inhibitory Ser637phosphorylation of the mitochondrial fission protein Drp1. Active RalA recruits protein phosphatase 2A (PP2Aa) to specifically dephosphorylate this inhibitory site on Drp1, activating the protein, thus increasing mitochondrial fission. Adipose tissue expression of the human homolog of Drp1, DNML1, is positively correlated with obesity and insulin resistance in patients. Thus, chronic activation of RalA plays a key role in repressing energy expenditure in obese adipose tissue by shifting the balance of mitochondrial dynamics towards excessive fission, contributing to weight gain and related metabolic dysfunction.
RESUMEN
Successful phytoremediation of acidic metal-contaminated mine tailings requires amendments to condition tailings properties prior to plant establishment. This conditioning process is complex and includes multiple changes in tailings bio-physico-chemical properties. The objective of this project is to identify relationships between tailings properties, the soil microbiome, and plant stress response genes during growth of Atriplex lentiformis in compost-amended (10 %, 15 %, 20 % w/w) mine tailings. Analyses include RNA-Seq for plant root gene expression, 16S rRNA amplicon sequencing for bacterial/archaeal communities, metal concentrations in both tailings and plant organs, and phenotypic measures of plant stress. Zn accumulation in A. lentiformis leaves varied with compost levels and was the highest in the intermediate treatment (15 %, TC15). Microbial analysis identified Alicyclobacillus, Hydrotalea, and Pseudolabrys taxa with the highest relative abundance in TC15, and these taxa were strongly associated with Zn accumulation. Furthermore, we identified 190 root genes with significant gene expression changes. These root genes were associated with different pathways including, abscisic acid and auxin signaling, defense responses, ion channels, metal ion binding, oxidative stress, transcription regulation, and transmembrane transport. However, root gene expression changes were not driven by the increasing levels of compost. For example, there were 15 genes that were up-regulated in TC15, whereas 106 genes were down-regulated in TC15. The variables analyzed explained 86 % of the variance in Zn accumulation in A. lentiformis leaves. Importantly, Zn accumulation was driven by Zn shoot concentrations, leaf stress symptoms, plant root genes, and microbial taxa. Therefore, our results suggest there are strong plant-microbiome associations that drive Zn accumulation in A. lentiformis and different plant gene pathways are involved in alleviating varying levels of metal stress. Future work is needed to gain a mechanistic understanding of these plant-microbiome interactions to optimize phytoremediation strategies as they will govern the success or failure of the revegetation process.
Asunto(s)
Atriplex , Metales Pesados , Contaminantes del Suelo , Zinc/análisis , Genes de Plantas , Suelo/química , ARN Ribosómico 16S/genética , Metales/análisis , Plantas/metabolismo , Ácidos , Biodegradación Ambiental , Contaminantes del Suelo/análisis , Metales Pesados/análisisRESUMEN
Molecular classification of gastric cancer (GC) identified a subgroup of patients showing chemoresistance and poor prognosis, termed SEM (Stem-like/Epithelial-to-mesenchymal transition/Mesenchymal) type in this study. Here, we show that SEM-type GC exhibits a distinct metabolic profile characterized by high glutaminase (GLS) levels. Unexpectedly, SEM-type GC cells are resistant to glutaminolysis inhibition. We show that under glutamine starvation, SEM-type GC cells up-regulate the 3 phosphoglycerate dehydrogenase (PHGDH)-mediated mitochondrial folate cycle pathway to produce NADPH as a reactive oxygen species scavenger for survival. This metabolic plasticity is associated with globally open chromatin structure in SEM-type GC cells, with ATF4/CEBPB identified as transcriptional drivers of the PHGDH-driven salvage pathway. Single-nucleus transcriptome analysis of patient-derived SEM-type GC organoids revealed intratumoral heterogeneity, with stemness-high subpopulations displaying high GLS expression, a resistance to GLS inhibition, and ATF4/CEBPB activation. Notably, coinhibition of GLS and PHGDH successfully eliminated stemness-high cancer cells. Together, these results provide insight into the metabolic plasticity of aggressive GC cells and suggest a treatment strategy for chemoresistant GC patients.
Asunto(s)
Fosfoglicerato-Deshidrogenasa , Neoplasias Gástricas , Humanos , Fosfoglicerato-Deshidrogenasa/genética , Fosfoglicerato-Deshidrogenasa/metabolismo , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/genética , Línea Celular Tumoral , Glutamina/metabolismo , NutrientesRESUMEN
AIM: We aimed to describe the severity of clonidine poisonings in a paediatric population referred to a tertiary toxicology service. METHODS: We undertook a retrospective review of all presentations of clonidine poisoning in children or adolescents reported to a tertiary toxicology service from March 2014 to February 2020. Cases were divided into young children (0-6 years), older children (7-11 years) and adolescents (12-17 years). We report clinical effects: bradycardia, hypotension and abnormal Glasgow coma score (GCS), based on standard paediatric observation charts, interventions, length of emergency department stay, proportion admitted to a medical ward or paediatric intensive care unit. RESULTS: We identified 111 clonidine poisonings, 41 young children, 9 older children and 61 adolescents. There were more females in the adolescent group and slightly more males in the younger age groups. The median dose ingested was 13 mcg/kg (interquartile range: 7-38 mcg/kg), which varied across ages. Clonidine alone was ingested in 78 cases (70%) and co-ingestion was more common in adolescents (24/61; 39%). Thirty-seven patients (33%) were admitted and 23 (21%) were admitted to paediatric intensive care unit. Median length of emergency department stay was 16.4 h, longer for adolescents. At least one abnormal observation occurred in 101 of 111 (91%) cases: 76 of 106 (72%) bradycardia, 76 of 110 (69%) hypotension and 4 of 99 (4%) GCS < 9. Thirteen (12%) had severe bradycardia, more common in young children and 23 (21%) had severe hypotension, more common in adolescents. For 27 children (0-11 years) ingesting 5-10 mcg/kg, 3 (11%) had severe bradycardia or severe hypotension and 1 received naloxone (4%). No cases ingesting <5 mcg/kg developed moderate/severe bradycardia or hypotension. Four cases received naloxone with no significant change, two patients got atropine with a transient response. One patient was intubated to facilitate safe inter-hospital transfer. CONCLUSION: Paediatric clonidine poisoning commonly results in bradycardia, hypotension and decreased GCS, but rarely severe or requiring major interventions. Children ingesting <5 mcg/kg do not require admission.
Asunto(s)
Hipotensión , Intoxicación , Masculino , Femenino , Niño , Humanos , Adolescente , Preescolar , Clonidina , Bradicardia/inducido químicamente , Atropina , Hipotensión/inducido químicamente , Naloxona , Estudios RetrospectivosRESUMEN
Over the last decades, epidemiology and functional studies have started to reveal a pivotal role of vitamin D in both type 1 and type 2 diabetes pathogenesis. Acting through the vitamin D receptor (VDR), vitamin D regulates insulin secretion in pancreatic islets and insulin sensitivity in multiple peripheral metabolic organs. In vitro studies and both T1D and T2D animal models showed that vitamin D can improve glucose homeostasis by enhancing insulin secretion, reducing inflammation, reducing autoimmunity, preserving beta cell mass, and sensitizing insulin action. Conversely, vitamin D deficiency has been shown relevant in increasing T1D and T2D incidence. While clinical trials testing the hypothesis that vitamin D improves glycemia in T2D have shown conflicting results, subgroup and meta-analyses support the idea that raising serum vitamin D levels may reduce the progression from prediabetes to T2D. In this review, we summarize current knowledge on the molecular mechanisms of vitamin D in insulin secretion, insulin sensitivity, and immunity, as well as the observational and interventional human studies investigating the use of vitamin D as a treatment for diabetes.