RESUMO
Multiple neurodegenerative diseases are characterized by aberrant proteinaceous accumulations of tau. Here, we report a RING-in-between-RING-type E3 ligase, TRIAD3A, that functions as an autophagy adaptor for tau. TRIAD3A(RNF216) is an essential gene with mutations causing age-progressive neurodegeneration. Our studies reveal that TRIAD3A E3 ligase catalyses mixed K11/K63 polyubiquitin chains and self-assembles into liquid-liquid phase separated (LLPS) droplets. Tau is ubiquitinated and accumulates within TRIAD3A LLPS droplets and, via LC3 interacting regions, targets tau for autophagic degradation. Unexpectedly, tau sequestered within TRIAD3A droplets rapidly converts to fibrillar aggregates without the transitional liquid phase of tau. In vivo studies show that TRIAD3A decreases the accumulation of phosphorylated tau in a tauopathy mouse model, and a disease-associated mutation of TRIAD3A increases accumulation of phosphorylated tau, exacerbates gliosis and increases pathological tau spreading. In human Alzheimer disease brain, TRIAD3A co-localizes with tau amyloid in multiple histological forms, suggesting a role in tau proteostasis. TRIAD3A is an autophagic adaptor that utilizes E3 ligase and LLPS as a mechanism to capture cargo and appears especially relevant to neurodegenerative diseases.
Assuntos
Autofagia , Ubiquitina-Proteína Ligases , Proteínas tau , Proteínas tau/metabolismo , Proteínas tau/genética , Animais , Humanos , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Camundongos , Fosforilação , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Doença de Alzheimer/genética , Ubiquitinação , Encéfalo/metabolismo , Encéfalo/patologia , Modelos Animais de Doenças , Camundongos Transgênicos , Células HEK293 , Mutação , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Feminino , Masculino , Separação de FasesRESUMO
BACKGROUND: Limited access to specialist medical services is a major barrier to healthcare in rural areas. We compared rural-urban specialist doctor consultations outside hospital by older adults (≥ 60 years) across South Australia. METHODS: Cross-sectional data were available from the South Australia's Department of Health. The Modified Monash Model (MM1-7) of remoteness was used to categorize data into rural (MM 3-4), remote (MM5-7), and urban (MM1-MM2) of participants in urban and non-urban South Australia. The analysis was conducted on older adults (n = 20,522), self-reporting chronic physical and common mental health conditions. RESULTS: Specialist doctor consultation in the past 4 weeks was 14.6% in our sample. In multivariable analysis, increasing age (odds ratio 1.3, 95% CI: 1.2-1.4), higher education (odds ratio 1.5, 95% CI: 1.3-1.9), physical health conditions [diabetes (odds ratio 1.2, 95% CI: 1.1-1.3); cancer (odds ratio1.8, 95% CI: 1.7-2.0); heart disease (odds ratio 1.9, 95% CI: 1.6-2.1)], and common mental disorders [depression (odds ratio 1.3, 95% CI: 1.1-1.5); anxiety (odds ratio 1.4, 95% CI: 1.1-1.6)] were associated with higher specialist care use. Specialist care use among rural (odds ratio 0.8, 95% CI: 0.6-0.9), and remote (odds ratio 0.8, 95% CI: 0.7-0.9) older people was significantly lower than their urban counterparts after controlling for age, education, and chronic disease. CONCLUSION: Our findings demonstrate a disparity in the use of out of hospital specialist medical services between urban and non-urban areas.
Assuntos
Especialização , Humanos , Idoso , Masculino , Feminino , Austrália do Sul , Estudos Transversais , Pessoa de Meia-Idade , Especialização/estatística & dados numéricos , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Medicina/estatística & dados numéricos , Idoso de 80 Anos ou mais , Serviços de Saúde Rural/estatística & dados numéricos , Doença Crônica/terapia , Encaminhamento e Consulta/estatística & dados numéricosRESUMO
BACKGROUND: The demand for mental health services in Australia is substantial and has grown beyond the capacity of the current workforce. As a result, it is currently difficult for many to access secondary healthcare providers. Within the secondary healthcare sector, however, peer workers who have lived experience of managing mental health conditions have been increasingly employed to intentionally use their journey of recovery in supporting others living with mental health conditions and their communities. Currently, the presence of peer workers in primary care has been limited, despite the potential benefits of providing supports in conjunction with GPs and secondary healthcare providers. METHODS: This stepped-wedge cluster randomised controlled trial (RCT) aims to evaluate a lived experience peer support intervention for accessing mental health care in primary care (PS-PC). Four medical practices across Australia will be randomly allocated to switch from control to intervention, until all practices are delivering the PS-PC intervention. The study will enrol 66 patients at each practice (total sample size of 264). Over a period of 3-4 months, 12 h of practical and emotional support provided by lived experience peer workers will be available to participants. Scale-based questionnaires will inform intervention efficacy in terms of mental health outcomes (e.g., self-efficacy) and other health outcomes (e.g., healthcare-related costs) over four time points. Other perspectives will be explored through scales completed by approximately 150 family members or carers (carer burden) and 16 peer workers (self-efficacy) pre- and post-intervention, and 20 medical practice staff members (attitudes toward peer workers) at the end of each study site's involvement in the intervention. Interviews (n = 60) and six focus groups held toward the end of each study site's involvement will further explore the views of participants, family members or carers, peer workers, and practice staff to better understand the efficacy and acceptability of the intervention. DISCUSSION: This mixed-methods, multi-centre, stepped-wedge controlled study will be the first to evaluate the implementation of peer workers in the primary care mental health care sector. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12623001189617. Registered on 17 November 2023, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=386715.
Assuntos
Transtornos Mentais , Serviços de Saúde Mental , Grupo Associado , Atenção Primária à Saúde , Ensaios Clínicos Controlados Aleatórios como Assunto , Humanos , Transtornos Mentais/terapia , Transtornos Mentais/psicologia , Saúde Mental , Estudos Multicêntricos como Assunto , Apoio Social , AustráliaRESUMO
BACKGROUND: Establishing a new medical school is a significant venture involving many complex political, social, economic, educational, and organisational considerations. The published literature on the process of establishing a new medical school is, however, under-developed with minimal empirical research and no explicit reference to theory. This research sought to address these gaps and establish an empirical and theoretical evidence-base for the process of new medical school establishment in diverse contexts, particularly medically under-served areas. METHODS: A Critical Realist Multiple Case Study was undertaken to examine the establishment of new medical schools across three continents. Data were collected between 2016 and 2018 through observational data gathered on site visits to three medical schools in medically under-served areas, relevant documents/audio-visual materials, and semi-structured interviews with key founding personnel. Data were analysed using the Critical Realist approach. Institutional Entrepreneurship theory was applied, adapted, and extended to explore and explain the phenomenon of new medical school establishment in diverse contexts. RESULTS: This study identifies eight critical success factors underpinning new medical school establishment. Framed as the Eight C's Framework (8CF), these factors include Context (field conditions), Catalysts (institutional entrepreneurs), Conducing (helping to bring about a particular situation or outcome), Collecting (resources), Connecting (relationships), Convincing (rationales), Challenges, and Consequences (outcomes). 8CF highlights that new medical schools are successfully established when Catalysts act within their Contexts to undertake the tasks of Conducing, Convincing, Collecting, and Connecting in order to produce desired Consequences and overcome Challenges. CONCLUSIONS: The Eight C's Framework is a theory-based, empirically supported framework that can be applied across different contexts to strategically guide the successful establishment of new medical schools. Founding leaders and stakeholders could use 8CF to ensure their establishment efforts are underpinned by theory and scholarship.
RESUMO
AIM OF THE STUDY: Neuronal pentraxin-2 (NPTX2) is a synaptic protein responsible for modulating plasticity at excitatory synapses. While the role of NPTX2 as a novel synaptic biomarker in cognitive disorders has been elucidated recently, its role in idiopathic normal pressure hydrocephalus (iNPH) is not yet understood. CLINICAL RATIONALE FOR STUDY: To determine if NPTX2 predicts cognition in patients with iNPH, and whether it could serve as a predictive marker for shunt outcomes. MATERIAL AND METHODS: 354 iNPH patients underwent cerebrospinal fluid drainage (CSF) as part of the tap test or extended lumbar drainage. Demographic and clinical measures including age, Evans Index (EI), Montreal Cognitive Assessment (MoCA) score, Functional Activities Questionnaire (FAQ) score, and baseline and post-shunt surgery Timed Up and Go (TUG) test scores were ascertained. CSF NPTX2 concentrations were measured using an ELISA. CSF ß-amyloid 1-40 (Aß1-40), ß-amyloid 1-42 (Aß1-42), and phosphorylated tau-181 (pTau-181) were measured by chemiluminescent assays. Spearman's correlation was used to determine the correlation between CSF NPTX2 concentrations and age, EI, MoCA and FAQ, TUG, Aß1-40/Aß1-42 ratio, and pTau-181 concentrations. Logistic regression was used to determine if CSF NPTX2 values were a predictor of short-term improvement post-CSF drainage or long-term improvement post-shunt surgery. RESULTS: There were 225 males and 129 females with a mean age of 77.7 years (± 7.06). Average CSF NPTX2 level in all iNPH patients was 559.97 pg/mL (± 432.87). CSF NPTX2 level in those selected for shunt surgery was 505.61 pg/mL (± 322.38). NPTX2 showed modest correlations with pTau-181 (r = 0.44, p < 0.001) with a trend for Aß42/Aß40 ratio (r = -0.1, p = 0.053). NPTX2 concentrations did not correlate with age (r = -0.012, p = 0.83) or MoCA score (r = 0.001, p = 0.87), but correlated negatively with FAQ (r = -0.15, p = 0.019). CONCLUSIONS: While CSF NPTX2 values correlate with neurodegeneration, they do not correlate with cognitive or functional measures in iNPH. CSF NPTX2 cannot serve as a predictor of either short-term or long-term improvement after CSF drainage. CLINICAL IMPLICATIONS: These results suggest that synaptic degeneration is not a core feature of iNPH pathophysiology.
Assuntos
Proteína C-Reativa , Hidrocefalia de Pressão Normal , Proteínas do Tecido Nervoso , Masculino , Feminino , Humanos , Idoso , Hidrocefalia de Pressão Normal/cirurgia , Hidrocefalia de Pressão Normal/líquido cefalorraquidiano , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidiano , Biomarcadores/líquido cefalorraquidiano , CogniçãoRESUMO
BACKGROUND: Analgesic tolerance due to long-term use of morphine remains a challenge for pain management. Morphine acts on µ-opioid receptors and downstream of the phosphatidylinositol 3-kinase signaling pathway to activate the mammalian target of rapamycin (mTOR) pathway. Rheb is an important regulator of growth and cell-cycle progression in the central nervous system owing to its critical role in the activation of mTOR. The hypothesis was that signaling via the GTP-binding protein Rheb in the dorsal horn of the spinal cord is involved in morphine-induced tolerance. METHODS: Male and female wild-type C57BL/6J mice or transgenic mice (6 to 8 weeks old) were injected intrathecally with saline or morphine twice daily at 12-h intervals for 5 consecutive days to establish a tolerance model. Analgesia was assessed 60 min later using the tail-flick assay. After 5 days, the spine was harvested for Western blot or immunofluorescence analysis. RESULTS: Chronic morphine administration resulted in the upregulation of spinal Rheb by 4.27 ± 0.195-fold (P = 0.0036, n = 6), in turn activating mTOR by targeting rapamycin complex 1 (mTORC1). Genetic overexpression of Rheb impaired morphine analgesia, resulting in a tail-flick latency of 4.65 ± 1.10 s (P < 0.0001, n = 7) in Rheb knock-in mice compared to 10 s in control mice (10 ± 0 s). Additionally, Rheb overexpression in spinal excitatory neurons led to mTORC1 signaling overactivation. Genetic knockout of Rheb or inhibition of mTORC1 signaling by rapamycin potentiated morphine-induced tolerance (maximum possible effect, 52.60 ± 9.56% in the morphine + rapamycin group vs. 16.60 ± 8.54% in the morphine group; P < 0.0001). Moreover, activation of endogenous adenosine 5'-monophosphate-activated protein kinase inhibited Rheb upregulation and retarded the development of morphine-dependent tolerance (maximum possible effect, 39.51 ± 7.40% in morphine + metformin group vs. 15.58 ± 5.79% in morphine group; P < 0.0001). CONCLUSIONS: This study suggests spinal Rheb as a key molecular factor for regulating mammalian target of rapamycin signaling.
Assuntos
Proteínas Monoméricas de Ligação ao GTP , Feminino , Masculino , Camundongos , Animais , Proteínas Monoméricas de Ligação ao GTP/genética , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Morfina/farmacologia , Sirolimo/farmacologia , Camundongos Endogâmicos C57BL , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Dor , Mamíferos/metabolismoRESUMO
Sleep and circadian rhythm disruption (SCRD) is commonly observed in aging, especially in individuals who experience progressive cognitive decline to mild cognitive impairment (MCI) and Alzheimer's disease (AD). However, precise molecular mechanisms underlying the association between SCRD and aging are not fully understood. Orexin A is a well-characterized "sleep neuropeptide" that is expressed in hypothalamic neurons and evokes wake behavior. The importance of Orexin is exemplified in narcolepsy where it is profoundly down-regulated. Interestingly, the synaptic immediate early gene NPTX2 is co-expressed in Orexin neurons and is similarly reduced in narcolepsy. NPTX2 is also down-regulated in CSF of some cognitively normal older individuals and predicts the time of transition from normal cognition to MCI. The association between Orexin and NPTX2 is further evinced here where we observe that Orexin A and NPTX2 are highly correlated in CSF of cognitively normal aged individuals and raises the question of whether SCRD that are typically attributed to Orexin A loss of function may be modified by concomitant NPTX2 down-regulation. Is NPTX2 an effector of sleep or simply a reporter of orexin-dependent SCRD? To address this question, we examined NPTX2 KO mice and found they retain Orexin expression in the brain and so provide an opportunity to examine the specific contribution of NPTX2 to SCRD. Our results reveal that NPTX2 KO mice exhibit a disrupted circadian onset time, coupled with increased activity during the sleep phase, suggesting difficulties in maintaining states. Sleep EEG indicates distinct temporal allocation shifts across vigilance states, characterized by reduced wake and increased NREM time. Evident sleep fragmentation manifests through alterations of event occurrences during Wake and NREM, notably during light transition periods, in conjunction with an increased frequency of sleep transitions in NPTX2 KO mice, particularly between Wake and NREM. EEG spectral analysis indicated significant shifts in power across various frequency bands in the wake, NREM, and REM states, suggestive of disrupted neuronal synchronicity. An intriguing observation is the diminished occurrence of sleep spindles, one of the earliest measures of human sleep disruption, in NPTX2 KO mice. These findings highlight the effector role of NPTX2 loss of function as an instigator of SCRD and a potential mediator of sleep disruption in aging.
RESUMO
How neuronal signaling affects brain myelination remains poorly understood. We show dysregulated neuronal RHEB-mTORC1-DLK1 axis impairs brain myelination. Neuronal Rheb cKO impairs oligodendrocyte differentiation/myelination, with activated neuronal expression of the imprinted gene Dlk1. Neuronal Dlk1 cKO ameliorates myelination deficit in neuronal Rheb cKO mice, indicating that activated neuronal Dlk1 expression contributes to impaired myelination caused by Rheb cKO. The effect of Rheb cKO on Dlk1 expression is mediated by mTORC1; neuronal mTor cKO and Raptor cKO and pharmacological inhibition of mTORC1 recapitulate elevated neuronal Dlk1 expression. We demonstrate that both a secreted form of DLK1 and a membrane-bound DLK1 inhibit the differentiation of cultured oligodendrocyte precursor cells into oligodendrocytes expressing myelin proteins. Finally, neuronal expression of Dlk1 in transgenic mice reduces the formation of mature oligodendrocytes and myelination. This study identifies Dlk1 as an inhibitor of oligodendrocyte myelination and a mechanism linking altered neuronal signaling with oligodendrocyte dysfunction.
Assuntos
Bainha de Mielina , Proteína Enriquecida em Homólogo de Ras do Encéfalo , Transdução de Sinais , Animais , Camundongos , Diferenciação Celular/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos Transgênicos , Bainha de Mielina/metabolismo , Oligodendroglia/metabolismo , Transdução de Sinais/fisiologia , Proteína Enriquecida em Homólogo de Ras do Encéfalo/metabolismoRESUMO
OBJECTIVE: This study examined whether cerebrospinal fluid (CSF) baseline levels of the synaptic protein NPTX2 predict time to onset of symptoms of mild cognitive impairment (MCI), both alone and when accounting for traditional CSF Alzheimer's disease (AD) biomarker levels. Longitudinal NPTX2 levels were also examined. METHODS: CSF was collected longitudinally from 269 cognitively normal BIOCARD Study participants (mean baseline age = 57.7 years; mean follow-up = 16.3 years; n = 77 progressed to MCI/dementia). NPTX2 levels were measured from 3 correlated peptides using quantitative parallel reaction monitoring mass spectrometry. Levels of Aß42 /Aß40 , p-tau181 , and t-tau were measured from the same CSF specimens using Lumipulse automated electrochemiluminescence assays. RESULTS: In Cox regression models, lower baseline NPTX2 levels were associated with an earlier time to MCI symptom onset (hazard ratio [HR] = 0.76, SE = 0.09, p = 0.023). This association was significant for progression within 7 years (p = 0.036) and after 7 years from baseline (p = 0.001). Baseline NPTX2 levels improved prediction of time to MCI symptom onset after accounting for baseline AD biomarker levels (p < 0.01), and NPTX2 did not interact with the CSF AD biomarkers or APOE-ε4 genetic status. In linear mixed effects models, higher baseline p-tau181 and t-tau levels were associated with higher baseline levels of NPTX2 (both p < 0.001) and greater rates of NPTX2 declines over time. INTERPRETATION: NPTX2 may be a valuable prognostic biomarker during preclinical AD that provides additive and independent prediction of MCI onset among individuals who are cognitively normal. We hypothesize that NPTX2-mediated circuit homeostasis confers resilience during the early phase of AD. ANN NEUROL 2023;94:620-631.
Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Pessoa de Meia-Idade , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Biomarcadores/líquido cefalorraquidiano , Cognição/fisiologia , Disfunção Cognitiva/líquido cefalorraquidiano , Disfunção Cognitiva/diagnóstico , Progressão da Doença , Fragmentos de Peptídeos/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidianoRESUMO
The calcium-selective ion channel Orai1 has a complex role in bone homeostasis, with defects in both bone production and resorption detected in Orai1 germline knock-out mice. To determine whether Orai1 has a direct, cell-intrinsic role in osteoblast differentiation and function, we bred Orai1 flox/flox (Orai1fl/fl) mice with Runx2-cre mice to eliminate its expression in osteoprogenitor cells. Interestingly, Orai1 was expressed in a mosaic pattern in Orai1fl/fl-Runx2-cre bone. Specifically, antibody labeling for Orai1 in vertebral sections was uniform in wild type animals, but patchy regions in Orai1fl/fl-Runx2-cre bone revealed Orai1 loss while in other areas expression persisted. Nevertheless, by micro-CT, bones from Orai1fl/fl-Runx2-cre mice showed reduced bone mass overall, with impaired bone formation identified by dynamic histomorphometry. Cortical surfaces of Orai1fl/fl-Runx2-cre vertebrae however exhibited patchy defects. In cell culture, Orai1-negative osteoblasts showed profound reductions in store-operated Ca2+ entry, exhibited greatly decreased alkaline phosphatase activity, and had markedly impaired substrate mineralization. We conclude that defective bone formation observed in the absence of Orai1 reflects an intrinsic role for Orai1 in differentiating osteoblasts.
Assuntos
Canais de Cálcio , Subunidade alfa 1 de Fator de Ligação ao Core , Osteoblastos , Animais , Camundongos , Cálcio/metabolismo , Canais de Cálcio/genética , Canais de Cálcio/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Camundongos Knockout , Proteína ORAI1/genética , Proteína ORAI1/metabolismo , Osteoblastos/metabolismoRESUMO
Cocaine-induced changes in the expression of the glutamate-related scaffolding protein Homer2 influence this drug's psychostimulant and rewarding properties. In response to neuronal activity, Homer2 is phosphorylated on S117/S216 by calcium-calmodulin kinase IIα (CaMKIIα), which induces a rapid dissociation of mGlu5-Homer2 scaffolds. Herein, we examined the requirement for Homer2 phosphorylation in cocaine-induced changes in mGlu5-Homer2 coupling, to include behavioral sensitivity to cocaine. For this, mice with alanine point mutations at (S117/216)-Homer2 (Homer2AA/AA ) were generated, and we determined their affective, cognitive and sensorimotor phenotypes, as well as cocaine-induced changes in conditioned reward and motor hyperactivity. The Homer2AA/AA mutation prevented activity-dependent phosphorylation of S216 Homer2 in cortical neurons, but Homer2AA/AA mice did not differ from wild-type (WT) controls with respect to Morris maze performance, acoustic startle, spontaneous or cocaine-induced locomotion. Homer2AA/AA mice exhibited signs of hypoanxiety similar to the phenotype of transgenic mice with a deficit in signal-regulated mGluR5 phosphorylation (Grm5AA/AA ). However, opposite of Grm5AA/AA mice, Homer2AA/AA mice were less sensitive to the aversive properties of high-dose cocaine under both place-conditioning and taste-conditioning procedures. Acute injection with cocaine caused dissociation of mGluR5 and Homer2 in striatal lysates from WT, but not Homer2AA/AA mice, suggesting a molecular basis for the deficit in cocaine aversion. These findings indicate that CaMKIIα-dependent phosphorylation of Homer2 gates the negative motivational valence of high-dose cocaine via regulation of mGlu5 binding, furthering an important role for dynamic changes in mGlu5-Homer interactions in addiction vulnerability.
Assuntos
Cocaína , Camundongos , Animais , Cocaína/farmacologia , Camundongos Knockout , Fosforilação , Camundongos Transgênicos , Condicionamento PsicológicoRESUMO
Complement overactivation mediates microglial synapse elimination in neurological diseases such as Alzheimer's disease (AD) and frontotemporal dementia (FTD), but how complement activity is regulated in the brain remains largely unknown. We identified that the secreted neuronal pentraxin Nptx2 binds complement C1q and thereby regulates its activity in the brain. Nptx2-deficient mice show increased complement activity, C1q-dependent microglial synapse engulfment, and loss of excitatory synapses. In a neuroinflammation culture model and in aged TauP301S mice, adeno-associated virus (AAV)-mediated neuronal overexpression of Nptx2 was sufficient to restrain complement activity and ameliorate microglia-mediated synapse loss. Analysis of human cerebrospinal fluid (CSF) samples from a genetic FTD cohort revealed reduced concentrations of Nptx2 and Nptx2-C1q protein complexes in symptomatic patients, which correlated with elevated C1q and activated C3. Together, these results show that Nptx2 regulates complement activity and microglial synapse elimination in the brain and that diminished Nptx2 concentrations might exacerbate complement-mediated neurodegeneration in patients with FTD.
Assuntos
Demência Frontotemporal , Microglia , Humanos , Camundongos , Animais , Idoso , Microglia/metabolismo , Complemento C1q/genética , Complemento C1q/metabolismo , Demência Frontotemporal/genética , Demência Frontotemporal/metabolismo , Sinapses/metabolismo , Proteínas do Sistema Complemento/metabolismoRESUMO
INTRODUCTION: It is now 25 years since the Riverland health service began its partnership with Flinders University to create the Parallel Rural Community Curriculum (PRCC) in rural South Australia. What started as a workforce program quickly became a successful disruptive technology for broader pedagogy in medical education. Despite more graduates of the PRCC choosing rural practice compared with their urban rotation-based colleagues, local medical workforce crises have persisted. METHODS: In February 2021, the Local Health Network decided to implement the National Rural Generalist Pathway in its local region. It created the Riverland Academy of Clinical Excellence (RACE) as its vehicle for taking responsibility for training its own health professional workforce. RESULTS: RACE has increased the region's medical workforce by over 20% in 1 year. It gained accreditation as a provider of junior doctor and advanced skills training and recruited five interns (all of whom had previously undertaken 1-year rural clinical school placements), six second year and above doctors, and four advanced skills registrars. RACE has linked with GPEx Rural Generalist registrars and formed a Public Health Unit from those registrars who also have MPH qualifications. RACE and Flinders University are expanding teaching facilities in the region and enabling medical students to complete their MD in the region. DISCUSSION: Health services can facilitate vertical integration of rural medical education, supporting a full pathway to rural practice. Providing length of training contracts is proving attractive for junior doctors who are interested in establishing a rural home base for their training.
Assuntos
Educação Médica , Serviços de Saúde Rural , Humanos , População Rural , Recursos Humanos , Mão de Obra em Saúde , Área de Atuação ProfissionalRESUMO
BACKGROUND: Memory deficits are central to many neuropsychiatric diseases. During acquisition of new information, memories can become vulnerable to interference, yet mechanisms that underlie interference are unknown. METHODS: We describe a novel transduction pathway that links the NMDA receptor (NMDAR) to AKT signaling via the immediate early gene Arc and evaluate its role in memory. The signaling pathway is validated using biochemical tools and transgenic mice, and function is evaluated in assays of synaptic plasticity and behavior. The translational relevance is evaluated in human postmortem brain. RESULTS: Arc is dynamically phosphorylated by CaMKII (calcium/calmodulin-dependent protein kinase II) and binds the NMDAR subunits NR2A/NR2B and a previously unstudied PI3K (phosphoinositide 3-kinase) adapter p55PIK (PIK3R3) in vivo in response to novelty or tetanic stimulation in acute slices. NMDAR-Arc-p55PIK recruits p110α PI3K and mTORC2 (mechanistic target of rapamycin complex 2) to activate AKT. NMDAR-Arc-p55PIK-PI3K-mTORC2-AKT assembly occurs within minutes of exploratory behavior and localizes to sparse synapses throughout hippocampal and cortical regions. Studies using conditional (Nestin-Cre) p55PIK deletion mice indicate that NMDAR-Arc-p55PIK-PI3K-mTORC2-AKT functions to inhibit GSK3 and mediates input-specific metaplasticity that protects potentiated synapses from subsequent depotentiation. p55PIK conditional knockout mice perform normally in multiple behaviors including working memory and long-term memory tasks but exhibit deficits indicative of increased vulnerability to interference in both short-term and long-term paradigms. The NMDAR-AKT transduction complex is reduced in postmortem brain of individuals with early Alzheimer's disease. CONCLUSIONS: A novel function of Arc mediates synapse-specific NMDAR-AKT signaling and metaplasticity that contributes to memory updating and is disrupted in human cognitive disease.
Assuntos
Doença de Alzheimer , Camundongos , Humanos , Animais , Doença de Alzheimer/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , N-Metilaspartato/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Transdução de Sinais , Hipocampo/metabolismo , Camundongos Transgênicos , Camundongos Knockout , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismoRESUMO
OBJECTIVE: Perinatal emotional well-being is more than the presence or absence of depressive and anxiety disorders; it encompasses a wide range of factors that contribute to emotional well-being. This study compares perinatal well-being between women living in metropolitan and rural regions. DESIGN: Prospective, longitudinal cohort. PARTICIPANTS/SETTING: Eight hundred and six women from Victoria and Western Australia recruited before 20 weeks of pregnancy and followed up to 12 months postpartum. MAIN OUTCOME MEASURES: Rurality was assessed using the Modified Monash Model (MM Model) with 578 in metropolitan cities MM1, 185 in regional and large rural towns MM2-MM3 and 43 in rural to remote MM4-MM7. The Structured Clinical Interview for DSM-IV (SCID-IV) was administered at recruitment to assess depression, and symptoms of depression and anxiety were measured using the Edinburgh Post-natal Depression Scale and the State and Trait Anxiety Scale, respectively. Other measures included stressful events, diet, exercise, partner support, parenting and sleep. RESULTS: The prevalence of depressive disorders did not differ across rurality. There was also no difference in breastfeeding cessation, exercise, sleep or partner support. Women living in rural communities and who also had depression reported significantly higher parenting stress than metropolitan women and lower access to parenting activities. CONCLUSIONS: Our study suggests while many of the challenges of the perinatal period were shared between women in all areas, there were important differences in parenting stress and access to activities. Furthermore, these findings suggest that guidelines and interventions designed for perinatal mental health should consider rurality.
Assuntos
Saúde Mental , População Rural , Gravidez , Feminino , Humanos , Estudos Prospectivos , Vitória/epidemiologia , Depressão/epidemiologia , Depressão/psicologiaRESUMO
Verifying causal effects of neural circuits is essential for proving a direct circuit-behavior relationship. However, techniques for tagging only active neurons with high spatiotemporal precision remain at the beginning stages. Here we develop the soma-targeted Cal-Light (ST-Cal-Light) which selectively converts somatic calcium rise triggered by action potentials into gene expression. Such modification simultaneously increases the signal-to-noise ratio of reporter gene expression and reduces the light requirement for successful labeling. Because of the enhanced efficacy, the ST-Cal-Light enables the tagging of functionally engaged neurons in various forms of behaviors, including context-dependent fear conditioning, lever-pressing choice behavior, and social interaction behaviors. We also target kainic acid-sensitive neuronal populations in the hippocampus which subsequently suppress seizure symptoms, suggesting ST-Cal-Light's applicability in controlling disease-related neurons. Furthermore, the generation of a conditional ST-Cal-Light knock-in mouse provides an opportunity to tag active neurons in a region- or cell-type specific manner via crossing with other Cre-driver lines. Thus, the versatile ST-Cal-Light system links somatic action potentials to behaviors with high temporal precision, and ultimately allows functional circuit dissection at a single cell resolution.
Assuntos
Corpo Celular , Neurônios , Animais , Camundongos , Neurônios/metabolismo , Potenciais de Ação/fisiologia , Hipocampo/fisiologia , Cálcio/metabolismoRESUMO
BACKGROUND: Hepatocellular carcinoma (HCC) early diagnosis remains a challenge to date. Alpha-feto protein, though less sensitive remains widely used for both diagnosis and prognosis. Recently however, a number of molecular biomarkers have been suggested as alternatives to Alpha feto protein, especially for early diagnosis. OBJECTIVE: To determine the role of the long non-coding RNA, LIPCAR in the pathogenesis and early diagnosis of hepatocellular carcinoma. METHODS: Quantitative real-time PCR, and Fluorescence in situ hybridization assays were conducted to determine LIPCAR expression in HCC vs normal blood samples, and HCC cell lines vs normal liver cell lines. Transfection was done to upregulate LIPCAR in one HCC cell line, and used to study cell proliferation, migration, apoptosis and epithelial-mesenchymal transformation. Animal experiment was finally done to determine its effect on metastasis. RESULTS: LIPCAR was significantly upregulated in HCC blood samples and HCC cell lines compared to their respective normal ones. Its overexpression promoted hepatocellular carcinoma cell proliferation, and migration, while inhibiting apoptosis. Its overexpression also promoted epithelial-mesenchymal transformation in hepatocellular carcinoma cells, and metastasis in vivo. CONCLUSION: The study demonstrated that the lncRNA, LIPCAR is significantly upregulated in hepatocellular carcinoma patients and that its upregulation promotes HCC proliferation, migration, and metastases.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , RNA Longo não Codificante , Humanos , Animais , RNA Longo não Codificante/genética , Carcinoma Hepatocelular/genética , Regulação para Cima , Hibridização in Situ Fluorescente , Neoplasias Hepáticas/genética , Proliferação de Células/genéticaRESUMO
Calcium signalling in platelets through store operated Ca2+ entry (SOCE) or receptor-operated Ca2+ entry (ROCE) mechanisms is crucial for platelet activation and function. Orai1 proteins have been implicated in platelet's SOCE. In this study we evaluated the contribution of Orai1 proteins to these processes using washed platelets from adult mice from both genders with platelet-specific deletion of the Orai1 gene (Orai1flox/flox; Pf4-Cre termed as Orai1Plt-KO) since mice with ubiquitous Orai1 deficiency show early lethality. Platelet aggregation as well as Ca2+ entry and release were measured in vitro following stimulation with collagen, collagen related peptide (CRP), thromboxane A2 analogue U46619, thrombin, ADP and the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) inhibitor thapsigargin, respectively. SOCE and aggregation induced by Thapsigargin up to a concentration of 0.3 µM was abrogated in Orai1-deficient platelets. Receptor-operated Ca2+-entry and/or platelet aggregation induced by CRP, U46619 or thrombin were partially affected by Orai1 deletion depending on the gender. In contrast, ADP-, collagen- and CRP-induced aggregation was comparable in Orai1Plt-KO platelets and control cells over the entire concentration range. Our results reinforce the indispensability of Orai1 proteins for SOCE in murine platelets, contribute to understand its role in agonist-dependent signalling and emphasize the importance to analyse platelets from both genders.
Assuntos
Plaquetas , Cálcio , Proteína ORAI1 , Animais , Feminino , Masculino , Camundongos , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacologia , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/metabolismo , Difosfato de Adenosina/metabolismo , Adenosina Trifosfatases/metabolismo , Plaquetas/metabolismo , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Sinalização do Cálcio , Colágeno/metabolismo , Proteína ORAI1/metabolismo , Peptídeos/metabolismo , Molécula 1 de Interação Estromal/metabolismo , Tapsigargina/farmacologia , Trombina/farmacologia , Tromboxano A2/metabolismoRESUMO
The mechanistic target of rapamycin (mTOR) signals through the mTOR complex 1 (mTORC1) and the mTOR complex 2 to maintain cellular and organismal homeostasis. Failure to finely tune mTOR activity results in metabolic dysregulation and disease. While there is substantial understanding of the molecular events leading mTORC1 activation at the lysosome, remarkably little is known about what terminates mTORC1 signaling. Here, we show that the AAA + ATPase Thorase directly binds mTOR, thereby orchestrating the disassembly and inactivation of mTORC1. Thorase disrupts the association of mTOR to Raptor at the mitochondria-lysosome interface and this action is sensitive to amino acids. Lack of Thorase causes accumulation of mTOR-Raptor complexes and altered mTORC1 disassembly/re-assembly dynamics upon changes in amino acid availability. The resulting excessive mTORC1 can be counteracted with rapamycin in vitro and in vivo. Collectively, we reveal Thorase as a key component of the mTOR pathway that disassembles and thus inhibits mTORC1.