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1.
Genes Dev ; 32(9-10): 602-619, 2018 05 01.
Article in English | MEDLINE | ID: mdl-29802123

ABSTRACT

Lipid peroxidation is the process by which oxygen combines with lipids to generate lipid hydroperoxides via intermediate formation of peroxyl radicals. Vitamin E and coenzyme Q10 react with peroxyl radicals to yield peroxides, and then these oxidized lipid species can be detoxified by glutathione and glutathione peroxidase 4 (GPX4) and other components of the cellular antioxidant defense network. Ferroptosis is a form of regulated nonapoptotic cell death involving overwhelming iron-dependent lipid peroxidation. Here, we review the functions and regulation of lipid peroxidation, ferroptosis, and the antioxidant network in diverse species, including humans, other mammals and vertebrates, plants, invertebrates, yeast, bacteria, and archaea. We also discuss the potential evolutionary roles of lipid peroxidation and ferroptosis.


Subject(s)
Antioxidants/metabolism , Biological Evolution , Cell Death/physiology , Iron/metabolism , Lipid Peroxidation , Animals , Humans , Reactive Oxygen Species/metabolism , Species Specificity
2.
J Neurosci ; 41(49): 10034-10053, 2021 12 08.
Article in English | MEDLINE | ID: mdl-34663629

ABSTRACT

Traumatic brain injury (TBI) results in disrupted brain function following impact from an external force and is a risk factor for sporadic Alzheimer's disease (AD). Although neurologic symptoms triggered by mild traumatic brain injuries (mTBI), the most common form of TBI, typically resolve rapidly, even an isolated mTBI event can increase the risk to develop AD. Aberrant accumulation of amyloid Ɵ peptide (AƟ), a cleaved fragment of amyloid precursor protein (APP), is a key pathologic outcome designating the progression of AD following mTBI and has also been linked to impaired axonal transport. However, relationships among mTBI, amyloidogenesis, and axonal transport remain unclear, in part because of the dearth of human models to study the neuronal response following mTBI. Here, we implemented a custom-microfabricated device to deform neurons derived from human-induced pluripotent stem cells, derived from a cognitively unimpaired male individual, to mimic the mild stretch experienced by neurons during mTBI. Although no cell lethality or cytoskeletal disruptions were observed, mild stretch was sufficient to stimulate rapid amyloidogenic processing of APP. This processing led to abrupt cessation of APP axonal transport and progressive formation of aberrant axonal accumulations that contained APP, its processing machinery, and amyloidogenic fragments. Consistent with this sequence of events, stretch-induced defects were abrogated by reducing amyloidogenesis either pharmacologically or genetically. In sum, we have uncovered a novel and manipulable stretch-induced amyloidogenic pathway directly responsible for APP axonal transport dysregulation. Our findings may help to understand and ultimately mitigate the risk of developing AD following mTBI.SIGNIFICANCE STATEMENT Mild traumatic brain injury is a risk factor for sporadic Alzheimer's disease (AD). Increased amyloid Ɵ peptide generation after injury may drive this risk. Here, by using a custom-built device to impose mild stretch to human neurons, we found that stretch triggers amyloid precursor protein (APP) cleavage, and thus amyloid Ɵ peptide generation, consequently disrupting APP axonal transport. Compellingly, protecting APP from cleavage was sufficient to spare axonal transport dysregulation and the consequent aberrant axonal accumulation of APP. Supporting such protective mechanism, the expression of the AD-protective APPA673T genetic variant conferred protection against stretch-induced APP axonal transport phenotypes. Our data reveal potential subcellular pathways contributing to the development of AD-associated phenotypes following mild traumatic brain injury, and putative strategies for intervening in these pathways.


Subject(s)
Amyloid beta-Protein Precursor/metabolism , Axonal Transport/physiology , Neurons/metabolism , Neurons/pathology , Alzheimer Disease/etiology , Brain Concussion/complications , Brain Concussion/metabolism , Brain Concussion/pathology , Cell Culture Techniques/methods , Humans , Induced Pluripotent Stem Cells , Male
3.
FASEB J ; 35(3): e21407, 2021 03.
Article in English | MEDLINE | ID: mdl-33583084

ABSTRACT

The obesity epidemic has increased type II diabetes mellitus (T2DM) across developed countries. Cardiac T2DM risks include ischemic heart disease, heart failure with preserved ejection fraction, intolerance to ischemia-reperfusion (I-R) injury, and refractoriness to cardioprotection. While opioids are cardioprotective, T2DM causes opioid receptor signaling dysfunction. We tested the hypothesis that sustained opioid receptor stimulus may overcome diabetes mellitus-induced cardiac dysfunction via membrane/mitochondrial-dependent protection. In a murine T2DM model, we investigated effects of morphine on cardiac function, I-R tolerance, ultrastructure, subcellular cholesterol expression, mitochondrial protein abundance, and mitochondrial function. T2DM induced 25% weight gain, hyperglycemia, glucose intolerance, cardiac hypertrophy, moderate cardiac depression, exaggerated postischemic myocardial dysfunction, abnormalities in mitochondrial respiration, ultrastructure and Ca2+ -induced swelling, and cell death were all evident. Morphine administration for 5 days: (1) improved glucose homeostasis; (2) reversed cardiac depression; (3) enhanced I-R tolerance; (4) restored mitochondrial ultrastructure; (5) improved mitochondrial function; (6) upregulated Stat3 protein; and (7) preserved membrane cholesterol homeostasis. These data show that morphine treatment restores contractile function, ischemic tolerance, mitochondrial structure and function, and membrane dynamics in type II diabetic hearts. These findings suggest potential translational value for short-term, but high-dose morphine administration in diabetic patients undergoing or recovering from acute ischemic cardiovascular events.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/metabolism , Mitochondria, Heart/drug effects , Morphine/pharmacology , Myocardial Infarction/drug therapy , Animals , Humans , Mice , Mitochondria, Heart/metabolism , Myocardial Infarction/etiology , Myocardial Reperfusion Injury/drug therapy , Myocardial Reperfusion Injury/metabolism , Myocardium/metabolism , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Signal Transduction/drug effects , Signal Transduction/physiology
4.
Proc Natl Acad Sci U S A ; 116(13): 5872-5877, 2019 03 26.
Article in English | MEDLINE | ID: mdl-30850523

ABSTRACT

Nanoscale multipoint structure-function analysis is essential for deciphering the complexity of multiscale biological and physical systems. Atomic force microscopy (AFM) allows nanoscale structure-function imaging in various operating environments and can be integrated seamlessly with disparate probe-based sensing and manipulation technologies. Conventional AFMs only permit sequential single-point analysis; widespread adoption of array AFMs for simultaneous multipoint study is challenging owing to the intrinsic limitations of existing technological approaches. Here, we describe a prototype dispersive optics-based array AFM capable of simultaneously monitoring multiple probe-sample interactions. A single supercontinuum laser beam is utilized to spatially and spectrally map multiple cantilevers, to isolate and record beam deflection from individual cantilevers using distinct wavelength selection. This design provides a remarkably simplified yet effective solution to overcome the optical cross-talk while maintaining subnanometer sensitivity and compatibility with probe-based sensors. We demonstrate the versatility and robustness of our system on parallel multiparametric imaging at multiscale levels ranging from surface morphology to hydrophobicity and electric potential mapping in both air and liquid, mechanical wave propagation in polymeric films, and the dynamics of living cells. This multiparametric, multiscale approach provides opportunities for studying the emergent properties of atomic-scale mechanical and physicochemical interactions in a wide range of physical and biological networks.


Subject(s)
Microscopy, Atomic Force/methods , Animals , Mice , Myocytes, Cardiac/ultrastructure , Nanotechnology/methods , Optical Imaging/methods , Polymers/chemistry , Structure-Activity Relationship , Surface Properties
5.
Intern Med J ; 51(10): 1567-1579, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34105222

ABSTRACT

Ambient (outdoor) air pollution is a key risk factor for health for which effective policy plays an important preventative role. Australian federal and related state air quality standards have historically relied on international evidence for guidance, which may not accurately reflect the Australian context. However, there has been a large increase in Australian epidemiological studies over recent years. The aim of this study is to provide an updated systematic literature review of peer-reviewed epidemiological studies that examined the health impacts of outdoor air pollution in Australia, including short- and long-term exposure. Following PRISMA guidelines, we conducted a systematic literature review. Broad search terms were applied to two databases (PubMed and Web of Science) and Google Scholar. Quality assessment and risk of bias were assessed using standard metrics. Included studies were summarised by tabulating key study characteristics, grouped by health outcomes. In total, 72 studies were included in the review. Sixty-four (89%) studies used daily or hourly pollutant concentrations to examine short-term exposure impacts, of which 59 (92%) revealed significant associations with one or more health outcomes, including cardio-respiratory, all-cause mortality or morbidity and birth outcomes. Eight (11%) studies used annual average pollutant concentrations to investigate the long-term exposure finding significant associations with asthma, reduced lung function, atopy and cardio-respiratory mortality across five studies. The remaining three studies found no significant association with asthma, mortality and a range of self-reported diseases, respectively. Ambient air pollution has substantial health impacts in Australia. The body of domestic evidence has increased markedly since national air quality standards were first set in the 1990s, which could be drawn on by policy-makers when revising the existing standards, or considering new standards.


Subject(s)
Air Pollutants , Air Pollution , Air Pollutants/adverse effects , Air Pollution/adverse effects , Air Pollution/analysis , Australia/epidemiology , Environmental Exposure/adverse effects , Environmental Exposure/analysis , Epidemiologic Studies , Humans , Risk Factors
6.
Int J Mol Sci ; 22(15)2021 Jul 30.
Article in English | MEDLINE | ID: mdl-34360984

ABSTRACT

Dopamine D1 receptor (D1R) function is regulated by membrane/lipid raft-resident protein caveolin-1 (Cav1). We examined whether altered expression of Cav1 in the dorsal striatum would affect self-administration of methamphetamine, an indirect agonist at the D1Rs. A lentiviral construct expressing Cav1 (LV-Cav1) or containing a short hairpin RNA against Cav1 (LV-shCav1) was used to overexpress or knock down Cav1 expression respectively, in the dorsal striatum. Under a fixed-ratio schedule, LV-Cav1 enhanced and LV-shCav1 reduced responding for methamphetamine in an extended access paradigm compared to LV-GFP controls. LV-Cav1 and LV-shCav1 also produced an upward and downward shift in a dose-response paradigm, generating a drug vulnerable/resistant phenotype. LV-Cav1 and LV-shCav1 did not alter responding for sucrose. Under a progressive-ratio schedule, LV-shCav1 generally reduced positive-reinforcing effects of methamphetamine and sucrose as seen by reduced breakpoints. Western blotting confirmed enhanced Cav1 expression in LV-Cav1 rats and reduced Cav1 expression in LV-shCav1 rats. Electrophysiological findings in LV-GFP rats demonstrated an absence of high-frequency stimulation (HFS)-induced long-term potentiation (LTP) in the dorsal striatum after extended access methamphetamine self-administration, indicating methamphetamine-induced occlusion of plasticity. LV-Cav1 prevented methamphetamine-induced plasticity via increasing phosphorylation of calcium calmodulin kinase II, suggesting a mechanism for addiction vulnerability. LV-shCav1 produced a marked deficit in the ability of HFS to produce LTP and, therefore, extended access methamphetamine was unable to alter striatal plasticity, indicating a mechanism for resistance to addiction-like behavior. Our results demonstrate that Cav1 expression and knockdown driven striatal plasticity assist with modulating addiction to drug and nondrug rewards, and inspire new strategies to reduce psychostimulant addiction.


Subject(s)
Amphetamine-Related Disorders/metabolism , Caveolin 1/metabolism , Corpus Striatum/metabolism , Long-Term Potentiation , Amphetamine-Related Disorders/genetics , Amphetamine-Related Disorders/physiopathology , Animals , Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism , Caveolin 1/genetics , Corpus Striatum/drug effects , Male , Methamphetamine/toxicity , Rats , Rats, Long-Evans , Reward
7.
J Neurosci ; 39(43): 8576-8583, 2019 10 23.
Article in English | MEDLINE | ID: mdl-31527120

ABSTRACT

Type 2 diabetes mellitus (T2DM) is a risk factor for the development of late-onset Alzheimer's disease (AD). However, the mechanism underlying the development of late-onset AD is largely unknown. Here we show that levels of the endothelial-enriched protein caveolin-1 (Cav-1) are reduced in the brains of T2DM patients compared with healthy aging, and inversely correlated with levels of Ɵ-amyloid (AƟ). Depletion of Cav-1 is recapitulated in the brains of db/db (Leprdb ) diabetic mice and corresponds with recognition memory deficits as well as the upregulation of amyloid precursor protein (APP), BACE-1, a trending increase in Ɵ-amyloid AƟ42/40 ratio and hyperphosphorylated tau (p-tau) species. Importantly, we show that restoration of Cav-1 levels in the brains of male db/db mice using adenovirus overexpressing Cav-1 (AAV-Cav-1) rescues learning and memory deficits and reduces pathology (i.e., APP, BACE-1 and p-tau levels). Knocking down Cav-1 using shRNA in HEK cells expressing the familial AD-linked APPswe mutant variant upregulates APP, APP carboxyl terminal fragments, and AƟ levels. In turn, rescue of Cav-1 levels restores APP metabolism. Together, these results suggest that Cav-1 regulates APP metabolism, and that depletion of Cav-1 in T2DM promotes the amyloidogenic processing of APP and hyperphosphorylation of tau. This may suggest that depletion of Cav-1 in T2DM underlies, at least in part, the development of AD and imply that restoration of Cav-1 may be a therapeutic target for diabetic-associated sporadic AD.SIGNIFICANCE STATEMENT More than 95% of the Alzheimer's patients have the sporadic late-onset form (LOAD). The cause for late-onset Alzheimer's disease is unknown. Patients with Type 2 diabetes mellitus have considerably higher incidence of cognitive decline and AD compared with the general population, suggesting a common mechanism. Here we show that the expression of caveolin-1 (Cav-1) is reduced in the brain in Type 2 diabetes mellitus. In turn, reduced Cav-1 levels induce AD-associated neuropathology and learning and memory deficits. Restoration of Cav-1 levels rescues these deficits. This study unravels signals underlying LOAD and suggests that restoration of Cav-1 may be an effective therapeutic target.


Subject(s)
Alzheimer Disease/metabolism , Brain/pathology , Caveolin 1/genetics , Diabetes Mellitus, Type 2/metabolism , Alzheimer Disease/genetics , Alzheimer Disease/pathology , Amyloid beta-Peptides/genetics , Amyloid beta-Peptides/metabolism , Amyloid beta-Protein Precursor/genetics , Amyloid beta-Protein Precursor/metabolism , Animals , Brain/metabolism , Caveolin 1/metabolism , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/pathology , Disease Models, Animal , Male , Mice , Phosphorylation
8.
Am J Physiol Gastrointest Liver Physiol ; 318(3): G531-G541, 2020 03 01.
Article in English | MEDLINE | ID: mdl-31961720

ABSTRACT

Cirrhotic cardiomyopathy is a clinical syndrome in patients with liver cirrhosis characterized by blunted cardiac contractile responses to stress and/or heart rate-corrected QT (QTc) interval prolongation. Caveolin-3 (Cav-3) plays a critical role in cardiac protection and is an emerging therapeutic target for heart disease. We investigated the protective role of cardiac-specific overexpression (OE) of Cav-3 in cirrhotic cardiomyopathy. Biliary fibrosis was induced in male Cav-3 OE mice and transgene negative (TGneg) littermates by feeding a diet containing 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC; 0.1%) for 3 wk. Liver pathology and blood chemistries were assessed, and stress echocardiography, telemetry, and isolated heart perfusion studies to assess adrenergic responsiveness were performed. Cav-3 OE mice showed a similar degree of hyperdynamic contractility, pulmonary hypertension, and QTc interval prolongation as TGneg mice after 3 wk of DDC diet. Blunted systolic responses were shown in both DDC-fed Cav-3 OE and TGneg hearts after in vivo isoproterenol challenge. However, QTc interval prolongation after in vivo isoproterenol challenge was significantly less in DDC-fed Cav-3 OE hearts compared with DDC-fed TGneg hearts. In ex vivo perfused hearts, where circulatory factors are absent, isoproterenol challenge showed hearts from DDC-fed Cav-3 OE mice had better cardiac contractility and relaxation compared with DDC-fed TGneg hearts. Although Cav-3 OE in the heart did not prevent cardiac alterations in DDC-induced biliary fibrosis, cardiac expression of Cav-3 reduced QTc interval prolongation after adrenergic stimulation in cirrhosis.NEW & NOTEWORTHY Prevalence of cirrhotic cardiomyopathy is up to 50% in cirrhotic patients, and liver transplantation is the only treatment. However, cirrhotic cardiomyopathy is associated with perioperative morbidity and mortality after liver transplantation; therefore, management of cirrhotic cardiomyopathy is crucial for successful liver transplantation. This study shows cardiac myocyte specific overexpression of caveolin-3 (Cav-3) provides better cardiac contractile responses and less corrected QT prolongation during adrenergic stress in a cirrhotic cardiomyopathy model, suggesting beneficial effects of Cav-3 expression in cirrhotic cardiomyopathy.


Subject(s)
Cardiomyopathies/metabolism , Caveolin 3/metabolism , Liver Cirrhosis, Biliary/metabolism , Myocardium/metabolism , Action Potentials , Animals , Cardiomyopathies/pathology , Cardiomyopathies/physiopathology , Cardiomyopathies/prevention & control , Caveolin 3/genetics , Disease Models, Animal , Heart Rate , Isolated Heart Preparation , Liver Cirrhosis, Biliary/chemically induced , Liver Cirrhosis, Biliary/pathology , Male , Mice, Inbred C57BL , Mice, Transgenic , Myocardial Contraction , Myocardium/pathology , Pyridines , Signal Transduction , Time Factors , Up-Regulation
9.
FASEB J ; 33(6): 7545-7554, 2019 06.
Article in English | MEDLINE | ID: mdl-30894019

ABSTRACT

Interventions that preserve motor neurons or restore functional motor neuroplasticity may extend longevity in amyotrophic lateral sclerosis (ALS). Delivery of neurotrophins may potentially revive degenerating motor neurons, yet this approach is dependent on the proper subcellular localization of neurotrophin receptor (NTR) to plasmalemmal signaling microdomains, termed membrane/lipid rafts (MLRs). We previously showed that overexpression of synapsin-driven caveolin-1 (Cav-1) (SynCav1) increases MLR localization of NTR [e.g., receptor tyrosine kinase B (TrkB)], promotes hippocampal synaptic and neuroplasticity, and significantly improves learning and memory in aged mice. The present study crossed a SynCav1 transgene-positive (SynCav1+) mouse with the mutant human superoxide dismutase glycine to alanine point mutation at amino acid 93 (hSOD1G93A) mouse model of ALS. When compared with hSOD1G93A, hSOD1G93A/SynCav1+ mice exhibited greater body weight and longer survival as well as better motor function. Microscopic analyses of hSOD1G93A/SynCav1+ spinal cords revealed preserved spinal cord α-motor neurons and preserved mitochondrial morphology. Moreover, hSOD1G93A/SynCav1+ spinal cords contained more MLRs (cholera toxin subunit B positive) and MLR-associated TrkB and Cav-1 protein expression. These findings demonstrate that SynCav1 delays disease progression in a mouse model of ALS, potentially by preserving or restoring NTR expression and localization to MLRs.-Sawada, A., Wang, S., Jian, M., Leem, J., Wackerbarth, J., Egawa, J., Schilling, J. M., Platoshyn, O., Zemljic-Harpf, A., Roth, D. M., Patel, H. H., Patel, P. M., Marsala, M., Head, B. P. Neuron-targeted caveolin-1 improves neuromuscular function and extends survival in SOD1G93A mice.


Subject(s)
Caveolin 1/physiology , Muscle, Skeletal/physiology , Nervous System Physiological Phenomena , Superoxide Dismutase-1/genetics , Animals , Body Weight , Caveolin 1/metabolism , Electric Stimulation , Humans , Longevity , Male , Mice , Mice, Transgenic , Motor Neurons/cytology , Survival Rate
10.
Cereb Cortex ; 28(9): 3255-3266, 2018 09 01.
Article in English | MEDLINE | ID: mdl-28981594

ABSTRACT

A delicate interneuronal communication between pre- and postsynaptic membranes is critical for synaptic plasticity and the formation of memory. Evidence shows that membrane/lipid rafts (MLRs), plasma membrane microdomains enriched in cholesterol and sphingolipids, organize presynaptic proteins and postsynaptic receptors necessary for synaptic formation and signaling. MLRs establish a cell polarity that facilitates transduction of extracellular cues to the intracellular environment. Here we show that neuron-targeted overexpression of an MLR protein, caveolin-1 (SynCav1), in the adult mouse hippocampus increased the number of presynaptic vesicles per bouton, total excitatory type I glutamatergic synapses, number of same-dendrite multiple-synapse boutons, increased myelination, increased long-term potentiation, and increased MLR-localized N-methyl-d-aspartate receptor subunits (GluN1, GluN2A, and GluN2B). Immunogold electron microscopy revealed that Cav-1 localizes to both the pre- and postsynaptic membrane regions as well as in the synaptic cleft. These findings, which are consistent with a significant increase in ultrastructural and functional synaptic plasticity, provide a fundamental framework that underlies previously demonstrated improvements in learning and memory in adult and aged mice by SynCav1. Such observations suggest that Cav-1 and MLRs alter basic aspects of synapse biology that could serve as potential therapeutic targets to promote neuroplasticity and combat neurodegeneration in a number of neurological disorders.


Subject(s)
Caveolin 1/metabolism , Hippocampus/physiology , Neuronal Plasticity/physiology , Neurons/physiology , Animals , Mice , Mice, Inbred C57BL
11.
Mol Pharmacol ; 93(4): 277-285, 2018 04.
Article in English | MEDLINE | ID: mdl-29358220

ABSTRACT

Caveolins have been recognized over the past few decades as key regulators of cell physiology. They are ubiquitously expressed and regulate a number of processes that ultimately impact efficiency of cellular processes. Though not critical to life, they are central to stress adaptation in a number of organs. The following review will focus specifically on the role of caveolin in stress adaptation in the heart, brain, and eye, three organs that are susceptible to acute and chronic stress and that show as well declining function with age. In addition, we consider some novel molecular mechanisms that may account for this stress adaptation and also offer potential to drive the future of caveolin research.


Subject(s)
Adaptation, Physiological/physiology , Caveolins/metabolism , Cell Physiological Phenomena/physiology , Stress, Physiological/physiology , Animals , Cell Death/physiology , Cell Proliferation/physiology , Humans , Oxidative Stress/physiology
12.
FASEB J ; 31(8): 3403-3411, 2017 08.
Article in English | MEDLINE | ID: mdl-28450301

ABSTRACT

Studies in vitro and in vivo demonstrate that membrane/lipid rafts and caveolin (Cav) organize progrowth receptors, and, when overexpressed specifically in neurons, Cav-1 augments neuronal signaling and growth and improves cognitive function in adult and aged mice; however, whether neuronal Cav-1 overexpression can preserve motor and cognitive function in the brain trauma setting is unknown. Here, we generated a neuron-targeted Cav-1-overexpressing transgenic (Tg) mouse [synapsin-driven Cav-1 (SynCav1 Tg)] and subjected it to a controlled cortical impact model of brain trauma and measured biochemical, anatomic, and behavioral changes. SynCav1 Tg mice exhibited increased hippocampal expression of Cav-1 and membrane/lipid raft localization of postsynaptic density protein 95, NMDA receptor, and tropomyosin receptor kinase B. When subjected to a controlled cortical impact, SynCav1 Tg mice demonstrated preserved hippocampus-dependent fear learning and memory, improved motor function recovery, and decreased brain lesion volume compared with wild-type controls. Neuron-targeted overexpression of Cav-1 in the adult brain prevents hippocampus-dependent learning and memory deficits, restores motor function after brain trauma, and decreases brain lesion size induced by trauma. Our findings demonstrate that neuron-targeted Cav-1 can be used as a novel therapeutic strategy to restore brain function and prevent trauma-associated maladaptive plasticity.-Egawa, J., Schilling, J. M., Cui, W., Posadas, E., Sawada, A., Alas, B., Zemljic-Harpf, A. E., Fannon-Pavlich, M. J., Mandyam, C. D., Roth, D. M., Patel, H. H., Patel, P. M., Head, B. P. Neuron-specific caveolin-1 overexpression improves motor function and preserves memory in mice subjected to brain trauma.


Subject(s)
Brain Injuries, Traumatic/metabolism , Caveolin 1/metabolism , Memory/physiology , Neurons/metabolism , Animals , Brain Injuries, Traumatic/physiopathology , Caveolin 1/genetics , Conditioning, Psychological , Fear , Gene Expression Regulation/physiology , Genetic Therapy , Genotype , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Neuronal Plasticity/physiology
13.
Horm Behav ; 104: 130-137, 2018 08.
Article in English | MEDLINE | ID: mdl-29505763

ABSTRACT

Contribution to Special Issue on Fast effects of steroids. Estrogen receptors α and Ɵ (ERα and ERƟ) have a unique relationship with metabotropic glutamate receptors (mGluRs) in the female rodent brain such that estradiol is able to recruit intracellular G-protein signaling cascades to influence neuronal physiology, structure, and ultimately behavior. While this association between ERs and mGluRs exists in many cell types and brain regions, its effects are perhaps most striking in the nucleus accumbens (NAc). This review will discuss the original characterization of ER/mGluR signaling and how estradiol activity in the NAc confers increased sensitivity to drugs of abuse in females through this mechanism.


Subject(s)
Receptors, Estrogen/metabolism , Receptors, Metabotropic Glutamate/metabolism , Substance-Related Disorders/metabolism , Animals , Brain/drug effects , Brain/metabolism , Estradiol/pharmacology , Female , Neurons/drug effects , Neurons/metabolism , Rodentia , Sex Characteristics , Signal Transduction/drug effects , Signal Transduction/physiology , Substance-Related Disorders/etiology
14.
Lab Invest ; 97(3): 256-267, 2017 03.
Article in English | MEDLINE | ID: mdl-28165468

ABSTRACT

Thy-1-negative lung fibroblasts are resistant to apoptosis. The mechanisms governing this process and its relevance to fibrotic remodeling remain poorly understood. By using either sorted or transfected lung fibroblasts, we found that Thy-1 expression is associated with downregulation of anti-apoptotic molecules Bcl-2 and Bcl-xL, as well as increased levels of cleaved caspase-9. Addition of rhFasL and staurosporine, well-known apoptosis inducers, caused significantly increased cleaved caspase-3, -8, and PARP in Thy-1-transfected cells. Furthermore, rhFasL induced Fas translocation into lipid rafts and its colocalization with Thy-1. These in vitro results indicate that Thy-1, in a manner dependent upon its glycophosphatidylinositol anchor and lipid raft localization, regulates apoptosis in lung fibroblasts via Fas-, Bcl-, and caspase-dependent pathways. In vivo, Thy-1 deficient (Thy1-/-) mice displayed persistence of myofibroblasts in the resolution phase of bleomycin-induced fibrosis, associated with accumulation of collagen and failure of lung fibrosis resolution. Apoptosis of myofibroblasts is decreased in Thy1-/- mice in the resolution phase. Collectively, these findings provide new evidence regarding the role and mechanisms of Thy-1 in initiating myofibroblast apoptosis that heralds the termination of the reparative response to bleomycin-induced lung injury. Understanding the mechanisms regulating fibroblast survival/apoptosis should lead to novel therapeutic interventions for lung fibrosis.


Subject(s)
Apoptosis/physiology , Fibroblasts/metabolism , Lung Injury/metabolism , Membrane Microdomains/metabolism , Thy-1 Antigens/metabolism , fas Receptor/metabolism , Animals , Apoptosis/drug effects , Apoptosis/genetics , Bleomycin , Caspase 9/metabolism , Cell Line , Embryo, Mammalian/cytology , Fas Ligand Protein/pharmacology , Fibroblasts/drug effects , Immunoblotting , Lung Injury/chemically induced , Lung Injury/prevention & control , Mice, Inbred C57BL , Mice, Knockout , Microscopy, Confocal , Myofibroblasts/drug effects , Myofibroblasts/metabolism , Protein Binding , Proto-Oncogene Proteins c-bcl-2/metabolism , Pulmonary Fibrosis/genetics , Pulmonary Fibrosis/metabolism , Pulmonary Fibrosis/prevention & control , Rats , Signal Transduction/drug effects , Signal Transduction/genetics , Staurosporine/pharmacology , Thy-1 Antigens/genetics , bcl-X Protein/metabolism
15.
J Neurophysiol ; 117(1): 436-444, 2017 01 01.
Article in English | MEDLINE | ID: mdl-27832597

ABSTRACT

Schizophrenia is a debilitating psychiatric disorder manifested in early adulthood. Disrupted-in-schizophrenia-1 (DISC1) is a susceptible gene for schizophrenia (Hodgkinson et al. 2004; Millar et al. 2000; St Clair et al. 1990) implicated in neuronal development, brain maturation, and neuroplasticity (Brandon and Sawa 2011; Chubb et al. 2008). Therefore, DISC1 is a promising candidate gene for schizophrenia, but the molecular mechanisms underlying its role in the pathogenesis of the disease are still poorly understood. Interestingly, caveolin-1 (Cav-1), a cholesterol binding and scaffolding protein, regulates neuronal signal transduction and promotes neuroplasticity. In this study we examined the role of Cav-1 in mediating DISC1 expression in neurons in vitro and the hippocampus in vivo. Overexpressing Cav-1 specifically in neurons using a neuron-specific synapsin promoter (SynCav1) increased expression of DISC1 and proteins involved in synaptic plasticity (PSD95, synaptobrevin, synaptophysin, neurexin, and syntaxin 1). Similarly, SynCav1-transfected differentiated human neurons derived from induced pluripotent stem cells (hiPSCs) exhibited increased expression of DISC1 and markers of synaptic plasticity. Conversely, hippocampi from Cav-1 knockout (KO) exhibited decreased expression of DISC1 and proteins involved in synaptic plasticity. Finally, SynCav1 delivery to the hippocampus of Cav-1 KO mice and Cav-1 KO neurons in culture restored expression of DISC1 and markers of synaptic plasticity. Furthermore, we found that Cav-1 coimmunoprecipitated with DISC1 in brain tissue. These findings suggest an important role by which neuron-targeted Cav-1 regulates DISC1 neurobiology with implications for synaptic plasticity. Therefore, SynCav1 might be a potential therapeutic target for restoring neuronal function in schizophrenia. NEW & NOTEWORTHY: The present study is the first to demonstrate that caveolin-1 can regulate DISC1 expression in neuronal models. Furthermore, the findings are consistent across three separate neuronal models that include rodent neurons (in vitro and in vivo) and human differentiated neurons derived from induced pluripotent stem cells. These findings justify further investigation regarding the modulatory role by caveolin on synaptic function and as a potential therapeutic target for the treatment of schizophrenia.


Subject(s)
Caveolin 1/metabolism , Gene Expression Regulation/genetics , Nerve Tissue Proteins/metabolism , Neurons/metabolism , Animals , Caveolin 1/genetics , Cells, Cultured , Hippocampus/cytology , Humans , Immunoprecipitation , Luminescent Proteins/genetics , Luminescent Proteins/metabolism , Mice , Mice, Inbred C57BL , Mice, Transgenic , Rats , Synapses/metabolism , Synapsins/genetics , Synapsins/metabolism , Transduction, Genetic , Red Fluorescent Protein
16.
Cell Mol Neurobiol ; 37(4): 571-585, 2017 May.
Article in English | MEDLINE | ID: mdl-27383839

ABSTRACT

Traumatic brain injury (TBI) is one of the leading causes of death of young people in the developed world. In the United States alone, 1.7 million traumatic events occur annually accounting for 50,000 deaths. The etiology of TBI includes traffic accidents, falls, gunshot wounds, sports, and combat-related events. TBI severity ranges from mild to severe. TBI can induce subtle changes in molecular signaling, alterations in cellular structure and function, and/or primary tissue injury, such as contusion, hemorrhage, and diffuse axonal injury. TBI results in blood-brain barrier (BBB) damage and leakage, which allows for increased extravasation of immune cells (i.e., increased neuroinflammation). BBB dysfunction and impaired homeostasis contribute to secondary injury that occurs from hours to days to months after the initial trauma. This delayed nature of the secondary injury suggests a potential therapeutic window. The focus of this article is on the (1) pathophysiology of TBI and (2) potential therapies that include biologics (stem cells, gene therapy, peptides), pharmacological (anti-inflammatory, antiepileptic, progrowth), and noninvasive (exercise, transcranial magnetic stimulation). In final, the review briefly discusses membrane/lipid rafts (MLR) and the MLR-associated protein caveolin (Cav). Interventions that increase Cav-1, MLR formation, and MLR recruitment of growth-promoting signaling components may augment the efficacy of pharmacologic agents or already existing endogenous neurotransmitters and neurotrophins that converge upon progrowth signaling cascades resulting in improved neuronal function after injury.


Subject(s)
Blood-Brain Barrier/drug effects , Brain Injuries, Traumatic/physiopathology , Brain Injuries, Traumatic/therapy , Caveolins/metabolism , Inflammation/drug therapy , Animals , Blood-Brain Barrier/physiopathology , Brain Injuries, Traumatic/metabolism , Disease Models, Animal , Humans , Treatment Outcome
17.
BMC Health Serv Res ; 17(1): 374, 2017 05 30.
Article in English | MEDLINE | ID: mdl-28558763

ABSTRACT

BACKGROUND: Heightened fiscal constraints, increases in the chronic disease burden and in consumer expectations are among several factors contributing to the global interest in evidence-informed health policy. The present article builds on previous work that explored how the Australian Federal Government applied five instruments of policy, or policy levers, to implement a series of reforms under the Australian National Mental Health Strategy (NMHS). The present article draws on theoretical insights from political science to analyse the relative successes and failures of these levers, as portrayed in formal government evaluations of the NMHS. METHODS: Documentary analysis of six evaluation documents corresponding to three National Mental Health Plans was undertaken. Both the content and approach of these government-funded, independently conducted evaluations were appraised. RESULTS: An overall improvement was apparent in the development and application of policy levers over time. However, this finding should be interpreted with caution due to variations in evaluation approach according to Plan and policy lever. Tabulated summaries of the success and failure of each policy initiative, ordered by lever type, are provided to establish a resource that could be consulted for future policy-making. CONCLUSIONS: This analysis highlights the complexities of health service reform and underscores the limitations of narrowly focused empirical approaches. A theoretical framework is provided that could inform the evaluation and targeted selection of appropriate policy levers in mental health.


Subject(s)
Health Planning/organization & administration , Health Policy , Mental Health Services/organization & administration , Australia , Chronic Disease , Government , Humans , Mental Health , Policy Making , Politics , Program Evaluation
18.
PLoS Genet ; 10(10): e1004609, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25340560

ABSTRACT

The mechanisms involved in the recognition of microbial pathogens and activation of the immune system have been extensively studied. However, the mechanisms involved in the recovery phase of an infection are incompletely characterized at both the cellular and physiological levels. Here, we establish a Caenorhabditis elegans-Salmonella enterica model of acute infection and antibiotic treatment for studying biological changes during the resolution phase of an infection. Using whole genome expression profiles of acutely infected animals, we found that genes that are markers of innate immunity are down-regulated upon recovery, while genes involved in xenobiotic detoxification, redox regulation, and cellular homeostasis are up-regulated. In silico analyses demonstrated that genes altered during recovery from infection were transcriptionally regulated by conserved transcription factors, including GATA/ELT-2, FOXO/DAF-16, and Nrf/SKN-1. Finally, we found that recovery from an acute bacterial infection is dependent on ELT-2 activity.


Subject(s)
Caenorhabditis elegans Proteins/biosynthesis , GATA Transcription Factors/biosynthesis , Immunity, Innate/genetics , Infections/genetics , Wound Healing/genetics , Animals , Caenorhabditis elegans , Caenorhabditis elegans Proteins/genetics , Computer Simulation , Disease Models, Animal , GATA Transcription Factors/genetics , Inactivation, Metabolic , Infections/immunology , Infections/microbiology , Salmonella enterica/pathogenicity , Transcriptome
19.
Health Res Policy Syst ; 15(1): 84, 2017 Oct 02.
Article in English | MEDLINE | ID: mdl-28969650

ABSTRACT

BACKGROUND: In order to understand and measure the policy impact of research we need a definition of research impact that is suited to the task. This article systematically reviewed both peer-reviewed and grey literature for definitions of research impact to develop a definition of research impact that can be used to investigate how public health research influences policy. METHOD: Keyword searches of the electronic databases Web of Science, ProQuest, PubMed, EMBASE, CINAHL, Informit, PsycINFO, The Cochrane Database of Systematic Reviews and Google Scholar were conducted between August 2015 and April 2016. Keywords included 'definition' and 'policy' and 'research impact' or 'research evidence'. The search terms 'health', public health' or 'mental health' and 'knowledge transfer' or 'research translation' were used to focus the search on relevant health discipline approaches. Studies included in the review described processes, theories or frameworks associated with public health, health services or mental health policy. RESULTS: We identified 108 definitions in 83 publications. The key findings were that literature on research impact is growing, but only 23% of peer-reviewed publications on the topic explicitly defined the term and that the majority (76%) of definitions were derived from research organisations and funding institutions. We identified four main types of definition, namely (1) definitions that conceptualise research impacts in terms of positive changes or effects that evidence can bring about when transferred into policies (example Research Excellence Framework definition), (2) definitions that interpret research impacts as measurable outcomes (Research Councils UK), and (3) bibliometric and (4) use-based definitions. We identified four constructs underpinning these definitions that related to concepts of contribution, change, avenues and levels of impact. CONCLUSION: The dominance of bureaucratic definitions, the tendency to discuss but not define the concept of research impact, and the heterogeneity of definitions confirm the need for conceptual clarity in this area. We propose a working definition of research impact that can be used in a range of health policy contexts.


Subject(s)
Health Policy , Peer Review, Health Care , Public Health , Health Services , Humans , Serial Publications
20.
Am J Physiol Cell Physiol ; 311(6): C854-C865, 2016 Dec 01.
Article in English | MEDLINE | ID: mdl-27707689

ABSTRACT

Autophagy is a dynamic recycling process responsible for the breakdown of misfolded proteins and damaged organelles, providing nutrients and energy for cellular renovation and homeostasis. Loss of autophagy is associated with cardiovascular diseases. Caveolin-3 (Cav-3), a muscle-specific isoform, is a structural protein within caveolae and is critical to stress adaptation in the heart. Whether Cav-3 plays a role in regulating autophagy to modulate cardiac stress responses remains unknown. In the present study, we used HL-1 cells, a cardiac muscle cell line, with stable Cav-3 knockdown (Cav-3 KD) and Cav-3 overexpression (Cav-3 OE) to study the impact of Cav-3 in regulation of autophagy. We show that traditional stimulators of autophagy (i.e., rapamycin and starvation) result in upregulation of the process in Cav-3 OE cells while Cav-3 KD cells have a blunted response. Cav-3 coimmunoprecipitated with beclin-1 and Atg12, showing an interaction of caveolin with autophagy-related proteins. In the heart, autophagy may be a major regulator of protection from ischemic stress. We found that Cav-3 KD cells have a decreased expression of autophagy markers [beclin-1, light chain (LC3-II)] after simulated ischemia and ischemia-reperfusion (I/R) compared with WT, whereas OE cells showed increased expression. Moreover, Cav-3 KD cells showed increased cell death and higher level of apoptotic proteins (cleaved caspase-3 and cytochrome c) with suppressed mitochondrial function in response to simulated ischemia and I/R, whereas Cav-3 OE cells were protected and had preserved mitochondrial function. Taken together, these results indicate that autophagy regulates adaptation to cardiac stress in a Cav-3-dependent manner.


Subject(s)
Autophagy/physiology , Caveolin 3/metabolism , Ischemia/metabolism , Ischemia/pathology , Myocardial Reperfusion Injury/metabolism , Myocardial Reperfusion Injury/pathology , Animals , Apoptosis Regulatory Proteins/metabolism , Caspase 3/metabolism , Caveolae/metabolism , Cytochromes c/metabolism , Heart/physiology , Mice , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/pathology , Reperfusion/methods
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