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1.
J Biol Chem ; 298(7): 102148, 2022 07.
Article in English | MEDLINE | ID: mdl-35716778

ABSTRACT

Depletion of exogenous inositol in yeast results in rising levels of phosphatidic acid (PA) and is correlated with increased expression of genes containing the inositol-dependent upstream activating sequence promoter element (UASINO). INO1, encoding myo-inositol 3-phosphate synthase, is the most highly regulated of the inositol-dependent upstream activating sequence-containing genes, but its mechanism of regulation is not clear. In the current study, we determined the relative timing and kinetics of appearance of individual molecular species of PA following removal of exogenous inositol in actively growing wild type, pah1Δ, and ole1ts strains. We report that the pah1Δ strain, lacking the PA phosphatase, exhibits a delay of about 60 min in comparison to wildtype before initiating derepression of INO1 expression. The ole1ts mutant on the other hand, defective in fatty acid desaturation, when grown at a semirestrictive temperature, exhibited reduced synthesis of PA species 34:1 and elevated synthesis of PA species 32:1. Importantly, we found these changes in the fatty acid composition in the PA pool of the ole1ts strain were associated with reduced expression of INO1, indicating that synthesis of PA 34:1 is involved in optimal expression of INO1 in the absence of inositol. Using deuterium-labeled glycerol in short-duration labeling assays, we found that changes associated with PA species 34:1 were uniquely correlated with increased expression of INO1 in all three strains. These data indicate that the signal for activation of INO1 transcription is not necessarily the overall level of PA but rather levels of a specific species of newly synthesized PA 34:1.


Subject(s)
Gene Expression Regulation, Fungal , Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae , Fatty Acids/metabolism , Inositol/metabolism , Phosphatidic Acids/metabolism , Saccharomyces cerevisiae/enzymology , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/metabolism
2.
J Addict Med ; 16(3): 333-339, 2022.
Article in English | MEDLINE | ID: mdl-34483278

ABSTRACT

OBJECTIVES: Treatment of hepatitis C virus infection (HCV) with direct acting antiviral therapy is encouraged regardless of substance use status. Patients with substance use disorder are at risk of HCV reinfection after cure. Follow up viral load testing (FUVL) with HCV RNA is recommended. We investigated factors associated with adoption of FUVL in real-world clinical settings. METHODS: Medical records of all patients with SUD who achieved HCV cure with direct acting antivirals at a multidisciplinary addiction treatment program between 2014 and 2019 were reviewed as part of a quality improvement initiative. Demographic and clinical characteristics including SUD treatment, urine toxicology results, and medical service use were collected. Factors associated with FUVL were analyzed and the rate of HCV reinfection was determined. RESULTS: Among 149 patients, 58.4% received FUVL. Receipt of FUVL was associated with engagement in ongoing primary medical care after cure (AOR 4.39, 95% CI [1.67, 11.49]). The HCV reinfection rate among those who received FUVL was 1.95 per 100 person-years of follow up (95% CI [0.64, 5.98]). There was no significant difference in the percentage of negative urine toxicology results before and after cure. CONCLUSIONS: Over half of a cohort of patients with substance use disorder cured of HCV received FUVL. The relationship between FUVL and engagement in primary medical and substance use treatment highlights the importance of integrated systems in providing longitudinal care for patients cured of HCV. Standardized interventions that facilitate FUVL testing and management of infectious complications of SUD in addiction treatment settings are needed.


Subject(s)
Hepatitis C, Chronic , Hepatitis C , Substance-Related Disorders , Antiviral Agents/adverse effects , Follow-Up Studies , Hepacivirus , Hepatitis C/drug therapy , Hepatitis C/epidemiology , Hepatitis C, Chronic/drug therapy , Humans , Primary Health Care , Reinfection , Substance-Related Disorders/drug therapy , Substance-Related Disorders/therapy , Viral Load
3.
J Cell Sci ; 133(21)2020 11 05.
Article in English | MEDLINE | ID: mdl-33033181

ABSTRACT

Lipid droplets (LDs) are implicated in conditions of lipid and protein dysregulation. The fat storage-inducing transmembrane (FIT; also known as FITM) family induces LD formation. Here, we establish a model system to study the role of the Saccharomyces cerevisiae FIT homologues (ScFIT), SCS3 and YFT2, in the proteostasis and stress response pathways. While LD biogenesis and basal endoplasmic reticulum (ER) stress-induced unfolded protein response (UPR) remain unaltered in ScFIT mutants, SCS3 was found to be essential for proper stress-induced UPR activation and for viability in the absence of the sole yeast UPR transducer IRE1 Owing to not having a functional UPR, cells with mutated SCS3 exhibited an accumulation of triacylglycerol within the ER along with aberrant LD morphology, suggesting that there is a UPR-dependent compensatory mechanism that acts to mitigate lack of SCS3 Additionally, SCS3 was necessary to maintain phospholipid homeostasis. Strikingly, global protein ubiquitylation and the turnover of both ER and cytoplasmic misfolded proteins is impaired in ScFITΔ cells, while a screen for interacting partners of Scs3 identifies components of the proteostatic machinery as putative targets. Together, our data support a model where ScFITs play an important role in lipid metabolism and proteostasis beyond their defined roles in LD biogenesis.This article has an associated First Person interview with the first author of the paper.


Subject(s)
Membrane Lipids , Saccharomyces cerevisiae , Endoplasmic Reticulum/genetics , Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum Stress/genetics , Homeostasis , Membrane Lipids/metabolism , Proteostasis , Saccharomyces cerevisiae/genetics , Unfolded Protein Response/genetics
4.
Mediators Inflamm ; 2020: 3270513, 2020.
Article in English | MEDLINE | ID: mdl-32410850

ABSTRACT

Vascular adhesion protein-1 (VAP-1) is an ectoenzyme that functions as a copper-containing amine oxidase and is involved in leukocyte adhesion at sites of inflammation. Inhibition of VAP-1 oxidative deamination has become an attractive target for anti-inflammatory therapy with demonstrated efficacy in rodent models of inflammation. A previous comparison of purified recombinant VAP-1 from mouse, rat, monkey, and human gene sequences predicted that rodent VAP-1 would have higher affinity for smaller hydrophilic substrates/inhibitors because of its narrower and more hydrophilic active site channel. An optimized in vitro oxidative deamination fluorescence assay with benzylamine (BA) was used to compare inhibition of five known inhibitors in recombinant mouse, rat, and human VAP-1. Human VAP-1 was more sensitive compared to rat or mouse VAP-1 (lowest IC50 concentration) to semicarbazide but was least sensitive to hydralazine and LJP-1207. Hydralazine had a lower IC50 in rats compared to humans, although not significant. However, the IC50 of hydralazine was significantly higher in the rat compared to mouse VAP-1. The larger hydrophobic compounds from Astellas (compound 35c) and Boehringer Ingelheim (PXS-4728A) were hypothesized to have higher binding affinity for human VAP-1 compared to rodent VAP-1 since the channel in human VAP-1 is larger and more hydrophobic than that in rodent VAP-1. Although the sensitivity of these two inhibitors was the lowest in the mouse enzyme, we found no significant differences between mouse, rat, and human VAP-1. Michaelis-Menten kinetics of the small primary amines phenylethylamine and tyramine were also compared to the common marker substrate BA demonstrating that BA had the highest affinity among the substrates. Rat VAP-1 had the highest affinity for all three substrates and mouse VAP-1 had intermediate affinity for BA and phenylethylamine, but tyramine was not a substrate for mouse VAP-1 under these assay conditions. These results suggest that comparing oxidative deamination in mouse and rat VAP-1 may be important if using these species for preclinical efficacy models.


Subject(s)
Amine Oxidase (Copper-Containing)/chemistry , Benzylamines/chemistry , Cell Adhesion Molecules/chemistry , Allylamine/analogs & derivatives , Allylamine/pharmacology , Animals , Benzamides/pharmacology , Haplorhini , Humans , Hydrophobic and Hydrophilic Interactions , Inflammation , Inhibitory Concentration 50 , Insecta , Kinetics , Mice , Oxygen/chemistry , Rats , Recombinant Proteins/chemistry , Species Specificity , Substrate Specificity
5.
Drug Discov Today ; 25(2): 292-304, 2020 02.
Article in English | MEDLINE | ID: mdl-31809750

ABSTRACT

Retinal photoreceptors continually endure stresses associated with prolonged light exposure and the metabolic demands of dark adaptation. Although healthy photoreceptors are able to withstand these stresses for several decades, the disease-affected retina functions at a reduced capacity and is at an increased risk for dysfunction. To alleviate cellular and metabolic stressors in degenerative retinal diseases, a new class of drugs that modulate the metabolic activity of the retina have been developed. A clinical candidate in this class (emixustat) has been shown to reduce retinal pathology in various animal models of human retinal disease and is currently under clinical study. Here, we describe the pharmacological properties of emixustat, its mechanisms of action, and potential for use in the treatment of specific retinal diseases.


Subject(s)
Phenyl Ethers/therapeutic use , Propanolamines/therapeutic use , Retinal Diseases/drug therapy , Stress, Physiological , Animals , Humans , Retina/metabolism , Retinal Diseases/metabolism
6.
Invest Ophthalmol Vis Sci ; 60(14): 4924-4930, 2019 11 01.
Article in English | MEDLINE | ID: mdl-31770432

ABSTRACT

Purpose: In the dark, photoreceptor outer segments contain high levels of cyclic guanosine 3'-5' monophosphate (cGMP), which binds to ion channels, holding them open and allowing an influx of cations. Ion pumping activity, which balances cation influx, uses considerable amounts of adenosine triphosphate (ATP) and oxygen. Light reduces cation influx and thereby lowers metabolic demand. Blood vessels are compromised in the diabetic retina and may not be able to meet the higher metabolic demand in darkness. Emixustat is a visual cycle modulator (VCM) that reduces chromophore levels and, therefore, may mimic light conditions. We evaluated the effect of emixustat on oxygen consumption and cation influx in dark conditions. Methods: Cation influx was measured in rats using Mn2+-magnetic resonance imaging (MEMRI). Retinal oxygen profiles were recorded to evaluate oxygen consumption. In the MEMRI protocol, animals were treated with either emixustat or vehicle. In the oxygen protocol, animals were untreated or treated with emixustat. Results: In vehicle-treated animals, cation channel activity increased in the dark. Emixustat treatment reduced cation channel activity; activity was comparable to vehicle-treated controls in light conditions. In vehicle-treated animals, minimum retinal oxygen tension decreased as the retina recovered from a photobleach, indicating that more oxygen was being consumed. Emixustat treatment prevented the decrease in oxygen pressure after photobleach. Conclusions: Emixustat reduced the cation influx and retinal oxygen consumption associated with dark conditions. VCMs are a promising potential treatment for ischemic retinal neovascularization, such as that in diabetic retinopathy.


Subject(s)
Dark Adaptation/physiology , Manganese/metabolism , Oxygen Consumption/physiology , Phenyl Ethers/pharmacology , Propanolamines/pharmacology , Retina/drug effects , Animals , Magnetic Resonance Imaging , Male , Rats , Rats, Inbred BN , Rats, Long-Evans , Retina/metabolism , cis-trans-Isomerases/antagonists & inhibitors
7.
Subst Abus ; 40(2): 132-135, 2019.
Article in English | MEDLINE | ID: mdl-30714880

ABSTRACT

Background: Despite the clear success of office-based buprenorphine treatment in increasing availability of effective treatment for opioid use disorder, constraints on its effectiveness include high attrition and limited high-quality behavioral care in many areas. Web-based interventions may be a novel strategy for providing evidence-based behavioral care to individuals receiving office-based buprenorphine maintenance. This report describes modification and initial pilot testing of Web-based training in cognitive-behavioral therapy (CBT4CBT) specifically for use with individuals in office-based buprenorphine. Methods: Twelve-week randomized pilot trial evaluating effects of CBT4CBT-Buprenophine in retaining participants and reducing drug use with respect to standard office-based buprenorphine alone was carried out. Twenty individuals meeting DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition) criteria for current opioid use disorder were randomized to standard buprenorphine treatment or buprenorphine plus access to CBT4CBT-Buprenorphine. Results: There were promising findings regarding rates of urine toxicology screens negative for opioids (91% versus 64%; P = .05, effect size d = 0.88) and all drugs (82% versus 30%; P = .004, d = 1.2). Individuals randomized to CBT4CBT-Buprenorphine completed a mean of 82.6 (SD = 4.4) days of treatment (of a possible 84) compared with 68.6 (SD = 32.6) for those assigned to standard buprenorphine treatment. Conclusions: Although preliminary and limited by the small sample size, this trial suggests the feasibility and promise of validated, Web-based interventions, tailored for this specific patient population, for improving outcomes in office-based buprenorphine.


Subject(s)
Analgesics, Opioid/therapeutic use , Buprenorphine/therapeutic use , Cognitive Behavioral Therapy/methods , Internet-Based Intervention , Opiate Substitution Treatment , Opioid-Related Disorders/therapy , Retention in Care , Adult , Ambulatory Care , Combined Modality Therapy , Female , Humans , Male , Middle Aged , Pilot Projects , Treatment Outcome
8.
J Biol Chem ; 292(45): 18713-18728, 2017 11 10.
Article in English | MEDLINE | ID: mdl-28924045

ABSTRACT

In the yeast Saccharomyces cerevisiae, the Opi1p repressor controls the expression of INO1 via the Opi1p/Ino2p-Ino4p regulatory circuit. Inositol depletion favors Opi1p interaction with both Scs2p and phosphatidic acid at the endoplasmic reticulum (ER) membrane. Inositol supplementation, however, favors the translocation of Opi1p from the ER into the nucleus, where it interacts with the Ino2p-Ino4p complex, attenuating transcription of INO1 A strain devoid of Scs2p (scs2Δ) and a mutant, OPI1FFAT, lacking the ability to interact with Scs2p were utilized to examine the specific role(s) of the Opi1p-Scs2p interaction in the regulation of INO1 expression and overall lipid metabolism. Loss of the Opi1p-Scs2p interaction reduced INO1 expression and conferred inositol auxotrophy. Moreover, inositol depletion in strains lacking this interaction resulted in Opi1p being localized to sites of lipid droplet formation, coincident with increased synthesis of triacylglycerol. Supplementation of choline to inositol-depleted growth medium led to decreased TAG synthesis in all three strains. However, in strains lacking the Opi1p-Scs2p interaction, Opi1p remained in the nucleus, preventing expression of INO1 These data support the conclusion that a specific pool of phosphatidic acid, associated with lipid droplet formation in the perinuclear ER, is responsible for the initial rapid exit of Opi1p from the nucleus to the ER and is required for INO1 expression in the presence of choline. Moreover, the mitochondria-specific phospholipid, cardiolipin, was significantly reduced in both strains compromised for Opi1p-Scs2p interaction, indicating that this interaction is required for the transfer of phosphatidic acid from the ER to the mitochondria for cardiolipin synthesis.


Subject(s)
Endoplasmic Reticulum/metabolism , Membrane Proteins/metabolism , Mitochondrial Membranes/metabolism , Myo-Inositol-1-Phosphate Synthase/metabolism , Phosphatidic Acids/metabolism , Repressor Proteins/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/metabolism , Biological Transport , Cardiolipins/metabolism , Cell Nucleus/metabolism , Choline/metabolism , Gene Deletion , Gene Expression Regulation, Bacterial , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Lipid Droplets , Lipid Metabolism , Membrane Proteins/genetics , Mutation , Myo-Inositol-1-Phosphate Synthase/genetics , Phosphorylation , Protein Processing, Post-Translational , Recombinant Fusion Proteins/metabolism , Repressor Proteins/genetics , Saccharomyces cerevisiae/cytology , Saccharomyces cerevisiae/growth & development , Saccharomyces cerevisiae Proteins/genetics
9.
J Subst Abuse Treat ; 75: 49-53, 2017 04.
Article in English | MEDLINE | ID: mdl-28237054

ABSTRACT

With the advent of the direct acting antivirals (DAA), or all oral HCV treatment regimens, there exists a great opportunity to provide HCV treatment to people who inject drugs (PWID) enrolled in an opioid treatment program (OTP). This retrospective study conducted in the context of routine clinical care explores the outcomes of HCV treatment with DAAs in PWID enrolled in an OTP. Our study showed treatment outcomes among our first 75 patients treated with DAAs were nearly equivalent to patients in the general population. Ninety-eight percent of patients completing treatment obtained a sustained virologic response, with 10 patients lost to follow-up. Ninety-nine percent of patients adhered to HCV treatment. Ongoing drug use occurred in 23% of patients, however this did not alter HCV treatment outcomes. Treating HCV infection with DAAs in PWID onsite in an OTP is feasible.


Subject(s)
Antiviral Agents/therapeutic use , Hepatitis C/drug therapy , Opioid-Related Disorders/drug therapy , Substance Abuse, Intravenous/drug therapy , Adult , Antiviral Agents/administration & dosage , Connecticut , Female , Harm Reduction , Hepatitis C/complications , Humans , Male , Opiate Substitution Treatment/methods , Opioid-Related Disorders/complications , Retrospective Studies , Substance Abuse Treatment Centers , Substance Abuse, Intravenous/complications , Treatment Outcome
10.
Proc Natl Acad Sci U S A ; 113(52): 15102-15107, 2016 12 27.
Article in English | MEDLINE | ID: mdl-27956601

ABSTRACT

The recent accumulation of newly discovered fungal-bacterial mutualisms challenges the paradigm that fungi and bacteria are natural antagonists. To understand the mechanisms that govern the establishment and maintenance over evolutionary time of mutualisms between fungi and bacteria, we studied a symbiosis of the fungus Rhizopus microsporus (Mucoromycotina) and its Burkholderia endobacteria. We found that nonhost R. microsporus, as well as other mucoralean fungi, interact antagonistically with endobacteria derived from the host and are not invaded by them. Comparison of gene expression profiles of host and nonhost fungi during interaction with endobacteria revealed dramatic changes in expression of lipid metabolic genes in the host. Analysis of the host lipidome confirmed that symbiosis establishment was accompanied by specific changes in the fungal lipid profile. Diacylglycerol kinase (DGK) activity was important for these lipid metabolic changes, as its inhibition altered the fungal lipid profile and caused a shift in the host-bacterial interaction into an antagonism. We conclude that adjustments in host lipid metabolism during symbiosis establishment, mediated by DGKs, are required for the mutualistic outcome of the Rhizopus-Burkholderia symbiosis. In addition, the neutral and phospholipid profiles of R. microsporus provide important insights into lipid metabolism in an understudied group of oleaginous Mucoromycotina. Lastly, our study revealed that the DGKs involved in the symbiosis form a previously uncharacterized clade of DGK domain proteins.


Subject(s)
Burkholderia/metabolism , Lipid Metabolism , Rhizopus/genetics , Symbiosis , Biological Evolution , Diacylglycerol Kinase/metabolism , Gene Expression Regulation, Fungal , Genetic Markers , Lipids/chemistry , MAP Kinase Signaling System , Phylogeny , Polymerase Chain Reaction , Up-Regulation
11.
Elife ; 4: e07485, 2015 Nov 26.
Article in English | MEDLINE | ID: mdl-26609809

ABSTRACT

Maintenance of energy homeostasis depends on the highly regulated storage and release of triacylglycerol primarily in adipose tissue, and excessive storage is a feature of common metabolic disorders. CIDEA is a lipid droplet (LD)-protein enriched in brown adipocytes promoting the enlargement of LDs, which are dynamic, ubiquitous organelles specialized for storing neutral lipids. We demonstrate an essential role in this process for an amphipathic helix in CIDEA, which facilitates embedding in the LD phospholipid monolayer and binds phosphatidic acid (PA). LD pairs are docked by CIDEA trans-complexes through contributions of the N-terminal domain and a C-terminal dimerization region. These complexes, enriched at the LD-LD contact site, interact with the cone-shaped phospholipid PA and likely increase phospholipid barrier permeability, promoting LD fusion by transference of lipids. This physiological process is essential in adipocyte differentiation as well as serving to facilitate the tight coupling of lipolysis and lipogenesis in activated brown fat.


Subject(s)
Adipocytes, Brown/metabolism , Apoptosis Regulatory Proteins/metabolism , Lipid Droplets/metabolism , Phosphatidic Acids/metabolism , Animals , Apoptosis Regulatory Proteins/chemistry , Binding Sites , Cell Line , Mice , Protein Binding , Protein Structure, Secondary
12.
PLoS One ; 10(5): e0124940, 2015.
Article in English | MEDLINE | ID: mdl-25970164

ABSTRACT

Increased exposure to blue or visible light, fluctuations in oxygen tension, and the excessive accumulation of toxic retinoid byproducts places a tremendous amount of stress on the retina. Reduction of visual chromophore biosynthesis may be an effective method to reduce the impact of these stressors and preserve retinal integrity. A class of non-retinoid, small molecule compounds that target key proteins of the visual cycle have been developed. The first candidate in this class of compounds, referred to as visual cycle modulators, is emixustat hydrochloride (emixustat). Here, we describe the effects of emixustat, an inhibitor of the visual cycle isomerase (RPE65), on visual cycle function and preservation of retinal integrity in animal models. Emixustat potently inhibited isomerase activity in vitro (IC50 = 4.4 nM) and was found to reduce the production of visual chromophore (11-cis retinal) in wild-type mice following a single oral dose (ED50 = 0.18 mg/kg). Measure of drug effect on the retina by electroretinography revealed a dose-dependent slowing of rod photoreceptor recovery (ED50 = 0.21 mg/kg) that was consistent with the pattern of visual chromophore reduction. In albino mice, emixustat was shown to be effective in preventing photoreceptor cell death caused by intense light exposure. Pre-treatment with a single dose of emixustat (0.3 mg/kg) provided a ~50% protective effect against light-induced photoreceptor cell loss, while higher doses (1-3 mg/kg) were nearly 100% effective. In Abca4-/- mice, an animal model of excessive lipofuscin and retinoid toxin (A2E) accumulation, chronic (3 month) emixustat treatment markedly reduced lipofuscin autofluorescence and reduced A2E levels by ~60% (ED50 = 0.47 mg/kg). Finally, in the retinopathy of prematurity rodent model, treatment with emixustat during the period of ischemia and reperfusion injury produced a ~30% reduction in retinal neovascularization (ED50 = 0.46mg/kg). These data demonstrate the ability of emixustat to modulate visual cycle activity and reduce pathology associated with various biochemical and environmental stressors in animal models. Other attributes of emixustat, such as oral bioavailability and target specificity make it an attractive candidate for clinical development in the treatment of retinal disease.


Subject(s)
Phenyl Ethers/pharmacology , Propanolamines/pharmacology , Reperfusion Injury/drug therapy , Retinal Degeneration/drug therapy , Retinal Rod Photoreceptor Cells/drug effects , Retinopathy of Prematurity/drug therapy , cis-trans-Isomerases/antagonists & inhibitors , ATP-Binding Cassette Transporters/deficiency , ATP-Binding Cassette Transporters/genetics , Animals , Disease Models, Animal , Electroretinography , Gene Expression , Light , Lipofuscin/antagonists & inhibitors , Lipofuscin/metabolism , Mice , Mice, Inbred BALB C , Neovascularization, Pathologic/metabolism , Neovascularization, Pathologic/pathology , Neovascularization, Pathologic/prevention & control , Reperfusion Injury/genetics , Reperfusion Injury/metabolism , Reperfusion Injury/pathology , Retinal Degeneration/genetics , Retinal Degeneration/metabolism , Retinal Degeneration/pathology , Retinal Pigment Epithelium/drug effects , Retinal Pigment Epithelium/metabolism , Retinal Pigment Epithelium/pathology , Retinal Rod Photoreceptor Cells/metabolism , Retinal Rod Photoreceptor Cells/pathology , Retinoids/antagonists & inhibitors , Retinoids/metabolism , Retinopathy of Prematurity/genetics , Retinopathy of Prematurity/metabolism , Retinopathy of Prematurity/pathology , cis-trans-Isomerases/genetics , cis-trans-Isomerases/metabolism
13.
Dev Cell ; 29(6): 729-39, 2014 Jun 23.
Article in English | MEDLINE | ID: mdl-24960695

ABSTRACT

Membrane phospholipids typically contain fatty acids (FAs) of 16 and 18 carbon atoms. This particular chain length is evolutionarily highly conserved and presumably provides maximum stability and dynamic properties to biological membranes in response to nutritional or environmental cues. Here, we show that the relative proportion of C16 versus C18 FAs is regulated by the activity of acetyl-CoA carboxylase (Acc1), the first and rate-limiting enzyme of FA de novo synthesis. Acc1 activity is attenuated by AMPK/Snf1-dependent phosphorylation, which is required to maintain an appropriate acyl-chain length distribution. Moreover, we find that the transcriptional repressor Opi1 preferentially binds to C16 over C18 phosphatidic acid (PA) species: thus, C16-chain containing PA sequesters Opi1 more effectively to the ER, enabling AMPK/Snf1 control of PA acyl-chain length to determine the degree of derepression of Opi1 target genes. These findings reveal an unexpected regulatory link between the major energy-sensing kinase, membrane lipid composition, and transcription.


Subject(s)
Acetyltransferases/metabolism , Fatty Acids/metabolism , Gene Expression Regulation, Fungal , Membrane Lipids/metabolism , Myo-Inositol-1-Phosphate Synthase/genetics , Phospholipids/metabolism , Repressor Proteins/metabolism , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae/metabolism , AMP-Activated Protein Kinases/genetics , AMP-Activated Protein Kinases/metabolism , Acetyltransferases/genetics , Endoplasmic Reticulum/metabolism , Mutation/genetics , Myo-Inositol-1-Phosphate Synthase/metabolism , Phosphorylation , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/metabolism , Repressor Proteins/genetics , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/growth & development , Saccharomyces cerevisiae Proteins/metabolism
14.
BMC Psychiatry ; 14: 30, 2014 Feb 05.
Article in English | MEDLINE | ID: mdl-24495599

ABSTRACT

BACKGROUND: Mental health patients can feel anxious about losing the support of staff and patients when discharged from hospital and often discontinue treatment, experience relapse and readmission to hospital, and sometimes attempt suicide. The benefits of peer support in mental health services have been identified in a number of studies with some suggesting clinical and economic gains in patients being discharged. METHODS: This pilot randomised controlled trial with economic evaluation aimed to explore whether peer support in addition to usual aftercare for patients during the transition from hospital to home would increase hope, reduce loneliness, improve quality of life and show cost effectiveness compared with patients receiving usual aftercare only, with follow-up at one and three-months post-discharge. RESULTS: A total of 46 service users were recruited to the study; 23 receiving peer support and 23 in the care-as-usual arm. While this pilot trial found no statistically significant benefits for peer support on the primary or secondary outcome measures, there is an indication that hope may be further increased in those in receipt of peer support. The total cost per case for the peer support arm of the study was £2154 compared to £1922 for the control arm. The mean difference between costs was minimal and not statistically significant. However, further analyses demonstrated that peer support has a reasonably high probability of being more cost effective for a modest positive change in the measure of hopelessness. Challenges faced in recruitment and follow-up are explored alongside limitations in the delivery of peer support. CONCLUSIONS: The findings suggest there is merit in conducting further research on peer support in the transition from hospital to home consideration should be applied to the nature of the patient population to whom support is offered; the length and frequency of support provided; and the contact between peer supporters and mental health staff. There is no conclusive evidence to support the cost effectiveness of providing peer support, but neither was it proven a costly intervention to deliver. The findings support an argument for a larger scale trial of peer support as an adjunct to existing services. TRIAL REGISTRATION: Current Controlled Trials ISRCTN74852771.


Subject(s)
Directive Counseling/economics , Mentally Ill Persons/psychology , Patient Discharge , Self-Help Groups/economics , Adolescent , Adult , Aged , Cost-Benefit Analysis , Hope , Hospitals, Psychiatric , Humans , Male , Mental Health , Middle Aged , Peer Group , Quality of Life , Young Adult
15.
Chem Phys Lipids ; 180: 23-43, 2014 May.
Article in English | MEDLINE | ID: mdl-24418527

ABSTRACT

This article focuses on discoveries of the mechanisms governing the regulation of glycerolipid metabolism and stress response signaling in response to the phospholipid precursor, inositol. The regulation of glycerolipid lipid metabolism in yeast in response to inositol is highly complex, but increasingly well understood, and the roles of individual lipids in stress response are also increasingly well characterized. Discoveries that have emerged over several decades of genetic, molecular and biochemical analyses of metabolic, regulatory and signaling responses of yeast cells, both mutant and wild type, to the availability of the phospholipid precursor, inositol are discussed.


Subject(s)
Glycerol/metabolism , Inositol/metabolism , Lipid Metabolism , Saccharomyces cerevisiae/metabolism , Stress, Physiological , Humans , Inositol/biosynthesis , Mutation , Saccharomyces cerevisiae/cytology , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/physiology
16.
J Psychosoc Nurs Ment Health Serv ; 52(1): 31-40, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24305905

ABSTRACT

This article describes the preparation, selection, training, and support of a group of people with lived experience of mental distress/illness and mental health service use to work as peer support workers (PSWs). The PSWs were recruited to provide support alongside conventional aftercare to service users discharged from acute psychiatric units in London, England. Training was delivered over 12 weekly, 1-day sessions from April to July 2010. Supervision and support were provided by a peer support coordinator and a training facilitator. The overall view of the training by those who went on to work as PSWs was that it was a valuable, challenging, yet positive experience that provided them with a good preparation for the role. A key area for improvement concerned the strength of emotional involvement and feelings PSWs had for their peers, especially in regard to ending the support relationship. Skilled, sensitive supervision and support is essential for the success of such roles.


Subject(s)
Mental Disorders/nursing , Mental Disorders/rehabilitation , Mental Health Services/organization & administration , Peer Group , Personnel Selection/organization & administration , Staff Development/organization & administration , Adult , Female , Humans , Male , Mental Disorders/psychology , Middle Aged , Pilot Projects , Program Evaluation , Social Support , United Kingdom , Volunteers/organization & administration
17.
J Cult Divers ; 20(3): 120-4, 2013.
Article in English | MEDLINE | ID: mdl-24279127

ABSTRACT

The concept of diversity varies widely in its definition, conceptualization and connotations. Addressing issues of diversity within a college of nursing is necessary if the cultures of our academic units are to change and become more inclusive. The article provides an overview of how this CON began to address changing its culture to one of a more inclusive nature and across all groups represented within the college, not bound only by ethnicity and gender. The process described in this article may provide an example for others to follow.


Subject(s)
Cultural Diversity , Education, Nursing/organization & administration , Faculty, Nursing/supply & distribution , Organizational Culture , Advisory Committees , Humans , Organizational Innovation , United States
18.
J Nucl Med Technol ; 41(4): 289-91, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24159008

ABSTRACT

With increasing volumes of complex imaging cases and rising economic pressure on physician staffing, timely reporting will become progressively challenging. Current and planned iterations of PACS and electronic medical record systems do not offer workflow management tools to coordinate delivery of imaging interpretations with the needs of the patient and ordering physician. The adoption of a server-based enterprise collaboration software system by our Division of Nuclear Medicine has significantly improved our efficiency and quality of service.


Subject(s)
Computers , Cooperative Behavior , Positron-Emission Tomography/statistics & numerical data , Safety , Software , Tomography, X-Ray Computed/statistics & numerical data , Communication , Quality Control
19.
J Biol Chem ; 288(39): 27861-71, 2013 Sep 27.
Article in English | MEDLINE | ID: mdl-23943620

ABSTRACT

Depriving wild type yeast of inositol, a soluble precursor for phospholipid, phosphoinositide, and complex sphingolipid synthesis, activates the protein kinase C (PKC)-MAPK signaling pathway, which plays a key role in the activation of NAD(+)-dependent telomeric silencing. We now report that triggering PKC-MAPK signaling by inositol deprivation or by blocking inositol-containing sphingolipid synthesis with aureobasidin A results in increased telomeric silencing regulated by the MAPK, Slt2p, and the NAD(+)-dependent deacetylase, Sir2p. Consistent with the dependence on NAD(+) in Sir2p-regulated silencing, we found that inositol depletion induces the expression of BNA2, which is required for the de novo synthesis of NAD(+). Moreover, telomeric silencing is greatly reduced in bna2Δ and npt1Δ mutants, which are defective in de novo and salvage pathways for NAD(+) synthesis, respectively. Surprisingly, however, omitting nicotinic acid from the growth medium, which reduces cellular NAD(+) levels, leads to increased telomeric silencing in the absence of inositol and/or at high temperature. This increase in telomeric silencing in response to inositol starvation is correlated to chronological life span extension but is Sir2p-independent. We conclude that activation of the PKC-MAPK signaling by interruption of inositol sphingolipid synthesis leads to increased Sir2p-dependent silencing and is dependent upon the de novo and salvage pathways for NAD(+) synthesis but is not correlated with cellular NAD(+) levels.


Subject(s)
Inositol/metabolism , MAP Kinase Signaling System , Protein Kinase C/metabolism , Saccharomyces cerevisiae/enzymology , Silent Information Regulator Proteins, Saccharomyces cerevisiae/metabolism , Sirtuin 2/metabolism , Telomere/ultrastructure , Enzyme Activation , Gene Expression Regulation, Fungal , Gene Silencing , Genes, Reporter , Mutation , Saccharomyces cerevisiae/metabolism , Sphingolipids/metabolism , Temperature
20.
Ind Biotechnol (New Rochelle N Y) ; 9(4): 215-228, 2013 Aug.
Article in English | MEDLINE | ID: mdl-24678285

ABSTRACT

Genome-scale metabolic models are built using information from an organism's annotated genome and, correspondingly, information on reactions catalyzed by the set of metabolic enzymes encoded by the genome. These models have been successfully applied to guide metabolic engineering to increase production of metabolites of industrial interest. Congruity between simulated and experimental metabolic behavior is influenced by the accuracy of the representation of the metabolic network in the model. In the interest of applying the consensus model of Saccharomyces cerevisiae metabolism for increased productivity of triglycerides, we manually evaluated the representation of fatty acid, glycerophospholipid, and glycerolipid metabolism in the consensus model (Yeast v6.0). These areas of metabolism were chosen due to their tightly interconnected nature to triglyceride synthesis. Manual curation was facilitated by custom MATLAB functions that return information contained in the model for reactions associated with genes and metabolites within the stated areas of metabolism. Through manual curation, we have identified inconsistencies between information contained in the model and literature knowledge. These inconsistencies include incorrect gene-reaction associations, improper definition of substrates/products in reactions, inappropriate assignments of reaction directionality, nonfunctional ß-oxidation pathways, and missing reactions relevant to the synthesis and degradation of triglycerides. Suggestions to amend these inconsistencies in the Yeast v6.0 model can be implemented through a MATLAB script provided in theSupplementary Materials, Supplementary Data S1(Supplementary Data are available online at www.liebertpub.com/ind).

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