Post-translational S-glutathionylation of cofilin increases actin cycling during cocaine seeking

Neuronal defense against oxidative damage is mediated primarily by the glutathione redox system. Traditionally considered a mechanism to protect proteins from irreversible oxidation, mounting evidence supports a role for protein S-glutathionylation in cell signaling in response to changes in intracellular redox status. Here we determined the specific sites on the actin binding protein cofilin that undergo S-glutathionylation. In addition, we show that S-glutathionylation of cofilin reduces its capacity to depolymerize F-actin. We further describe an assay to determine the S-glutathionylation of target proteins in brain tissue from behaving rodents. Using this technique, we show that cofilin in the rat nucleus accumbens undergoes S-glutathionylation during 15-minutes of cued cocaine seeking in the absence of cocaine. Our findings demonstrate that cofilin S-glutathionylation is increased in response to cocaine-associated cues and that increased cofilin S-glutathionylation reduces cofilin-dependent depolymerization of F-actin. Thus, S-glutathionylation of cofilin may serve to regulate actin cycling in response to drug-conditioned cues.

Abstract 514: Proteomic Characterization of Extracellular Matrix Regulation in Human Aortic Valve Development and Disease

We present the first report of the collagen protein interactome in human aortic valve (AV) development and disease. AV disease affects up to 13% of the world population. As no therapies are available, patients must “watch and wait” until surgical valve replacement is necessary to prevent heart failure. Extracellular matrix (ECM) forms the basis for correct valve function but alterations of the ECM scaffold during development and disease are not well defined. Here, we report ECM protein regulation from a cohort of 26 valvular tissues in four pathological categories: normal functioning AVs, pediatric end-stage congenital aortic valve stenosis (CAVS), adult end-stage fibrocalcific aortic valve stenosis (FAVS), and a pulmonic Ross operation valve. A novel proteomic method was used to target ECM proteins, primarily collagens, for sequence analysis from FFPE 5-μm thin tissue sections. Collagens represented 19/49 proteins identified (39%); A total of 46/49 ECM proteins (94%) were implicated in direct interactions in collagen synthesis, regulation or modification. Data suggested dynamic regulation of collagen types during age and disease, e.g., Col15a1 was found only in normal AV, whereas Col4a1 was reported only in patients younger than 5 years. Upstream regulators of the collagen interactome included COLQ1, IGFBP2, and SPARC. Detailed peptide sequence analysis reported 70 specific collagen peptide sequences containing up to multiple hydroxylated prolines (HYP), a post-translational modification critical to stabilizing the collagen triple helix. Quantitative data analysis on HYP peptides reported differential regulation across patient categories – i.e., Col3a1 peptides show 52% increased HYP in CAVS compared to age matched normal valve. Interestingly, the pulmonic Ross valve represented unique collagen HYP signatures distinct from all other aortic valve tissues. Tissue from pediatric end-stage CAVS patients showed a higher percentage of hydroxylated peptides compared to non-hydroxylated peptides (33%) as compared to normal (25%) or adult end-stage FAVS (16%). We anticipate that the completed study will be useful to targeted therapies aiming to inhibit fibrosis and ECM remodeling, and may better inform engineered options for valve replacement.

Isoflavone ME-344 Disrupts Redox Homeostasis and Mitochondrial Function by Targeting Heme Oxygenase 1

ME-344 is a second-generation isoflavone with unusual cytotoxic properties that is in clinical testing in cancer. To identify targets that contribute to its anticancer activity and therapeutic index, we used lung cancer cell lines that are naturally sensitive or resistant to ME-344. Drug-induced apoptosis was linked with enhanced levels of reactive oxygen species and this initiated a nuclear erythroid factor 2-like 2 signaling response, downstream of which, heme oxygenase 1 (HO-1) was also found to be time-dependently inhibited by ME-344. ME-344 specifically bound to, and altered, HO-1 structure and increased HO-1 translocation from the rough endoplasmic reticulum to mitochondria, but only in drug-sensitive cells. These effects did not occur in either drug-resistant or primary lung fibroblasts with lower HO-1 basal levels. HO-1 was confirmed as a drug target by using surface plasmon resonance technology and through interaction with a clickable ME-344 compound (M2F) and subsequent proteomic analyses, showing direct binding of ME-344 with HO-1. Proteomic analysis showed that clusters of mitochondrial proteins, including voltage-dependent anion-selective channels, were also impacted by ME-344. Human lung cancer biopsies expressed higher levels of Nrf2 and HO-1 compared with normal tissues. Overall, our data show that ME-344 inhibits HO-1 and impacts its mitochondrial translocation. Other mitochondrial proteins are also affected, resulting in interference in tumor cell redox homeostasis and mitochondrial function. These factors contribute to a beneficial therapeutic index and support continued clinical development of ME-344. SIGNIFICANCE: A novel cytotoxic isoflavone is shown to inhibit heme oxygenase, a desirable yet elusive target that disrupts redox homeostasis causing cell death.

Effectiveness of dietetic consultation for lowering blood lipid levels in the management of cardiovascular disease risk: A systematic review and meta-analysis of randomised controlled trials

AIM

Evidence of the effectiveness of dietetic consultation for the management of cardiovascular disease (CVD) risk factors has not been previously synthesised. A systematic review and four meta-analyses evaluated the effectiveness of dietetic consultation for lowering blood lipid levels in high-risk individuals in primary health-care settings.

METHODS

Of the 4860 records identified, 10 eligible randomised controlled trials (RCTs, n = 1530) were evaluated for reporting blood lipid outcomes following dietetic consultation (DN)-defined as at least one exclusive individual face-to-face consultation with a dietitian and comparators (C)-defined as no nutrition intervention or usual or minimal care provided by physicians and/or nurses.

RESULTS

DN groups were effective for lowering blood lipid levels across nine studies reporting total cholesterol (TC) and LDL; and across five of six studies reporting triglycerides (TG). Between-group differences were not consistently assessed, with significance levels reported in four studies all in favour of DN, P < 0.05. Meta-analyses for TC and LDL (seven studies) confirmed DN and C groups were equally effective, P > 0.05; and for TG (six studies) DN groups were significantly more effective than C groups, P < 0.05).

CONCLUSIONS

This review provides RCT evidence that dietetic counselling is effective for lowering TG levels and at least as effective as usual and minimal care for improving cholesterol levels in high-risk individuals in primary health care. However, more adequate reporting of methods and greater consistency in timing interventions and data collection will enhance the quality of the evidence and increase confidence in the health benefits of dietetic counselling for the management of CVD risk.

Extracellular Matrix Imaging of Breast Tissue Pathologies by MALDI-Imaging Mass Spectrometry

PURPOSE

A new method accessing proteins from extracellular matrix by imaging mass spectrometry (ECM IMS) has been recently reported. ECM IMS is evaluated for use in exploring breast tissue pathologies.

EXPERIMENTAL DESIGN

A tissue microarray (TMA) is analyzed that has 176 cores of biopsies and lumpectomies spanning breast pathologies of inflammation, hyperplasia, fibroadenoma, invasive ductal carcinoma, and invasive lobular carcinoma and normal adjacent to tumor (NAT). NAT is compared to subtypes by area under the receiver operating curve (ROC) >0.7. A lumpectomy is also characterized for collagen organization by microscopy and stromal protein distribution by IMS. LC-based high-resolution accurate mass (HRAM) proteomics is used to identify proteins from the lumpectomy.

RESULTS

TMA analysis shows distinct spectral signatures reflecting a heterogeneous tissue microenvironment. Ninety-four peaks show an ROC > 0.7 compared to NAT; NAT has overall higher intensities. Lumpectomy analysis by IMS visualizes a complex central tumor region with distal tumor regions. A total of 39 stromal proteins are identified by HRAM LC-based proteomics. Accurate mass matches between image data and LC-based proteomics demonstrate a heterogeneous collagen type environment in the central tumor.

CONCLUSIONS

Data portray the heterogeneous stromal microenvironment of breast pathologies, including alteration of multiple collagen-type patterns. ECM IMS is a promising new tool for investigating the stromal microenvironment of breast tissue including cancer.

Questionnaires that measure the quality of relationships between patients and primary care providers: a systematic review

Background

International guidance on models of care stress the importance of good quality, continuous patient-provider relationships to support high quality and efficient care and hospital avoidance. However, assessing the quality of patient-provider relationships is challenging due to its experiential nature. The aim of this study was to undertake a systematic review to identify questionnaires previously developed or used to assess the quality of continuous relationships between patients and their provider in primary care.

Methods

MEDLINE, PubMed, Cumulative Index of Nursing and Allied Health Literature (CINAHL) and SCOPUS databases were searched for English language studies published between 2009 and 2017. Key terms used identified studies conducted in the primary care setting examining relationships between patients and providers. Studies that focused on the conceptualisation, development, testing or review of a questionnaire, or studies that used a questionnaire for assessing the quality of continuous relationships between patients and providers were eligible. Studies that did not assess quality via a questionnaire, only assessed single aspects of relationships, only assessed single encounters, assessed transitions between settings or assessed relationships using an index were excluded. Information on validity testing of each relevant questionnaire identified from articles was reviewed to inform recommendations for future research and evaluation.

Results

Twenty-seven studies met the eligibility criteria, including 14 unique questionnaires. The questionnaires were diverse in length, scope, focus and level of validity testing. Five questionnaires were considered not feasible for future use due to size and lack of development work. Three questionnaires were considered strongest candidates for use in future work based on being relevant to the topic and primary care setting, freely available in English and not needing additional pilot work prior to use. These three questionnaires were the Care Continuity Across Levels of Care Scale, the Nijmegan Continuity Questionnaire and the Patient-Doctor Depth of Relationship Tool.

Conclusions

This study provides an overview of 14 unique questionnaires that have been used to assess the quality of continuous relationships between patients and primary care providers. The decision to use one of the questionnaires in future work requires careful consideration, including the scope, length, validation testing, accessibility of the questionnaires and their alignment with the initiative being evaluated.

Nitration and Glycation Turn Mature NGF into a Toxic Factor for Motor Neurons: A Role for p75NTR and RAGE Signaling in ALS

INTRODUCTION

Glycating stress can occur together with oxidative stress during neurodegeneration and contribute to the pathogenic mechanism. Nerve growth factor (NGF) accumulates in several neurodegenerative diseases. Besides promoting survival, NGF can paradoxically induce cell death by signaling through the p75 neurotrophin receptor (p75^NTR). The ability of NGF to induce cell death is increased by nitration of its tyrosine residues under conditions associated with increased peroxynitrite formation.

AIMS

Here we investigated whether glycation also changes the ability of NGF to induce cell death and assessed the ability of post-translational modified NGF to signal through the receptor for advanced glycation end products (RAGEs). We also explored the potential role of RAGE-p75^NTR interaction in the motor neuron death occurring in amyotrophic lateral sclerosis (ALS) models.

RESULTS

Glycation promoted NGF oligomerization and ultimately allowed the modified neurotrophin to signal through RAGE and p75^NTR to induce motor neuron death at low physiological concentrations. A similar mechanism was observed for nitrated NGF. We provide evidence for the interaction of RAGE with p75^NTR at the cell surface. Moreover, we observed that post-translational modified NGF was present in the spinal cord of an ALS mouse model. In addition, NGF signaling through RAGE and p75^NTR was involved in astrocyte-mediated motor neuron toxicity, a pathogenic feature of ALS.

INNOVATION

Oxidative modifications occurring under stress conditions can enhance the ability of mature NGF to induce neuronal death at physiologically relevant concentrations, and RAGE is a new p75^NTR coreceptor contributing to this pathway.

CONCLUSION

Our results indicate that NGF-RAGE/p75^NTR signaling may be a therapeutic target in ALS. Antioxid. Redox Signal. 28, 1587-1602.

Mapping Extracellular Matrix Proteins in Formalin-Fixed, Paraffin-Embedded Tissues by MALDI Imaging Mass Spectrometry

Collagens and elastin form the fundamental framework of all tissues and organs, and their expression and post-translational processing are tightly regulated in disease and health. Because of their unique structural composition and properties, it is a recognized challenge to access these protein structures within the complex tissue microenvironment to understand how localized changes modulate tissue health. We describe a new workflow using a combination of matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) with matrix metalloproteinase (MMP) enzymes to access and report on spatial localization of collagen and elastin sequences in formalin-fixed, paraffin-embedded (FFPE) tissues. The developed technology provides new access to collagens and elastin sequences localized to tissue features that were previously unattainable. This high-throughput technological advance should be applicable to any tissue regardless of disease type, tissue origin, or disease status and is thus relevant to all research: basic, translational, or clinical.

HDAC1 localizes to the mitochondria of cardiac myocytes and contributes to early cardiac reperfusion injury

RATIONALE

Recent evidence indicates that histone deacetylase enzymes (HDACs) contribute to ischemia reperfusion (I/R) injury, and pan-HDAC inhibitors have been shown to be cardioprotective when administered either before an ischemic insult or during reperfusion. We have shown previously that selective inhibition of class I HDACs provides superior cardioprotection when compared to pan-HDAC inhibition in a pretreatment model, but selective class I HDAC inhibition has not been tested during reperfusion, and specific targets of class I HDACs in I/R injury have not been identified.

OBJECTIVE

We hypothesized that selective inhibition of class I HDACs with the drug MS-275 (entinostat) during reperfusion would improve recovery from I/R injury in the first hour of reperfusion.

METHODS AND RESULTS

Hearts from male Sprague-Dawley rats were subjected to ex vivo I/R injury±MS-275 class I HDAC inhibition during reperfusion alone. MS-275 significantly attenuated I/R injury, as indicated by improved LV function and tissue viability at the end of reperfusion. Unexpectedly, we observed that HDAC1 is present in the mitochondria of cardiac myocytes, but not fibroblasts or endothelial cells. We then designed mitochondria-restricted and mitochondria-excluded HDAC inhibitors, and tested both in our ex vivo I/R model. The selective inhibition of mitochondrial HDAC1 attenuated I/R injury to the same extent as MS-275, whereas the mitochondrial-excluded inhibitor did not. Further assays demonstrated that these effects are attributable to a decrease in SDHA activity and subsequent metabolic ROS production in reperfusion.

CONCLUSIONS

We demonstrate for the first time that HDAC1 is present within the mitochondria of cardiac myocytes, and mitochondrial HDAC1 contributes significantly to I/R injury within the first hour of reperfusion.

Effectiveness of Dietetic Consultations in Primary Health Care: A Systematic Review of Randomized Controlled Trials

BACKGROUND

A dietetic consultation is a structured process aimed at supporting individual patients to modify their dietary behaviors to improve health outcomes. The body of evidence on the effectiveness of nutrition care provided by dietitians in primary health care settings has not previously been synthesized. This information is important to inform the role of dietitians in primary health care service delivery.

OBJECTIVE

The aim of this systematic review was to evaluate the evidence of the effectiveness of individual consultations provided exclusively by dietitians in primary care to support adult patients to modify dietary intake and improve health outcomes.

STUDY DESIGN

ProQuest Family Health, Scopus, PubMed Central, Medline, the Cumulative Index to Nursing and Allied Health Literature, and Cochrane databases were searched for English language systematic reviews or randomized controlled trials published before October 2016. The key terms used identified the provision of nutrition care exclusively by a dietitian in a primary health care setting aimed at supporting adult patients to modify dietary behaviors and/or improve biomarkers of health. Interventions delivered to patients aged younger than 18 years, in hospital, via telephone only, in a group or lecture setting, or by a multidisciplinary team were excluded. The methodologic quality of each study was appraised using the Cochrane Risk of Bias tool and the body of evidence was assessed using the Academy of Nutrition and Dietetics Evidence Analysis Manual.

MAIN OUTCOME MEASURES

Outcomes included the effectiveness of dietetic interventions in terms of anthropometry, clinical indicators, and dietary intake. A statistically significant between-group difference was used to indicate intervention effectiveness (P<0.05).

RESULTS

Twenty-six randomized controlled studies met eligibility criteria, representing 5,500 adults receiving dietetic consultations in a primary care setting. Eighteen of 26 included studies showed statistically significant differences in dietary, anthropometric, or clinical indicators between intervention and comparator groups. When focusing specifically on each study's stated aim, significant improvements favoring the intervention compared with control were found for the following management areas: glycemic control (four out of four studies), dietary change (four out of four studies), anthropometry (four out of seven studies), cholesterol (two out of eight studies), triglycerides (one out of five), and blood pressure (zero out of three) studies.

CONCLUSIONS

Dietetic consultations for adults in primary care settings appear to be effective for improvement in diet quality, diabetes outcomes (including blood glucose and glycated haemoglobin values), and weight loss outcomes (eg, changes in weight and waist circumference) and to limit gestational weight gain (Grade II: Fair evidence). Research evaluated in this review does not provide consistent support for the effectiveness of direct dietetic counseling alone in achieving outcomes relating to plasma lipid levels and blood pressure (Grade III: Limited evidence). Therefore, to more effectively control these cardiovascular disease risk factors, future research might explore novel nutrition counseling approaches as well as dietitians functioning as part of multidisciplinary teams.

Effectiveness of group-based self-management education for individuals with Type 2 diabetes: a systematic review with meta-analyses and meta-regression

AIMS

Patient education for the management of Type 2 diabetes can be delivered in various forms, with the goal of promoting and supporting positive self-management behaviours. This systematic review aimed to determine the effectiveness of group-based interventions compared with individual interventions or usual care for improving clinical, lifestyle and psychosocial outcomes in people with Type 2 diabetes.

METHODS

Six electronic databases were searched. Group-based education programmes for adults with Type 2 diabetes that measured glycated haemoglobin (HbA_1c ) and followed participants for ≥ 6 months were included. The primary outcome was HbA_1c , and secondary outcomes included fasting blood glucose, weight, body mass index, waist circumference, blood pressure, blood lipid profiles, diabetes knowledge and self-efficacy.

RESULTS

Fifty-three publications describing 47 studies were included (n = 8533 participants). Greater reductions in HbA_1c occurred in group-based education compared with controls at 6-10 months [n = 30 studies; mean difference (MD) = 3 mmol/mol (0.3%); 95% confidence interval (CI): -0.48, -0.15; P = 0.0002], 12-14 months [n = 27 studies; MD = 4 mmol/mol (0.3%); 95% CI: -0.49, -0.17; P < 0.0001], 18 months [n = 3 studies; MD = 8 mmol/mol (0.7%); 95% CI: -1.26, -0.18; P = 0.009] and 36-48 months [n = 5 studies; MD = 10 mmol/mol (0.9%); 95% CI: -1.52, -0.34; P = 0.002], but not at 24 months. Outcomes also favoured group-based education for fasting blood glucose, body weight, waist circumference, triglyceride levels and diabetes knowledge, but not at all time points. Interventions facilitated by a single discipline, multidisciplinary teams or health professionals with peer supporters resulted in improved outcomes in HbA_1c when compared with peer-led interventions.

CONCLUSIONS

Group-based education interventions are more effective than usual care, waiting list control and individual education at improving clinical, lifestyle and psychosocial outcomes in people with Type 2 diabetes.

Abstract 141: Class I Histone Deacetylases Localize to Cardiac Myocyte Mitochondria and Contribute to Ischemia Reperfusion Injury

Approximately half of the damage done to the heart by a myocardial infarction occurs during reperfusion of the ischemic region while the patient is in the care of the treatment team. While many different adjuvant treatments have been explored in an attempt to attenuate this ischemia-reperfusion (I/R) injury, little progress has been made in translating novel therapies to the clinic. Recently, it was discovered that epigenetic enzymes contribute to reperfusion-induced damage, but little is known about the exact mechanism by which they exacerbate I/R injury. Previously, we have shown that class I histone deacetylase (HDACs) activity acutely exacerbates I/R injury, and that inhibition of class I HDACs with MS-275 (entinostat) preserves left-ventricular (LV) function and substantially reduces the area of infarcted tissue in isolated rat hearts subjected to ischemia-reperfusion (IR) injury. Notably, this protective effect occurs whether MS-275 is given as a pretreatment or during the reperfusion phase alone. Given the acute nature of this protective effect, we hypothesized that class I HDACs mediate reperfusion injury by modulating the acetylation state of non-histone proteins in signaling cascades that are essential to cell survival. To examine this, hearts from male Sprague-Dawley rats were subjected to ex vivo I/R injury +/- class I HDAC inhibition during reperfusion. We then performed mass spectrometry to analyze the changes in the acetylome between sham and I/R groups with and without class I HDAC inhibition. Unexpectedly, mass spectrometry analysis revealed significant changes in the acetylation state of multiple mitochondrial enzymes. Further biochemical studies show that class I HDACs localize to cardiac mitochondria and may directly modulate mitochondrial acetylation. Interestingly, these effects are correlated with a reduction in the mitochondrial respiratory capacity and mitochondrial oxidative stress during reperfusion. This study is the first to identify a class I HDAC that localizes to the mitochondria and emphasizes the importance of exploring class I HDAC inhibitors for protection against ischemia-reperfusion injury.

Passive interventions in primary healthcare waiting rooms are effective in promoting healthy lifestyle behaviours: an integrative review

Primary healthcare waiting rooms have the potential to provide health-promoting environments to support healthy lifestyle behaviours such as smoking cessation, weight management and safe contraception. Passive interventions are cost-effective and continually available within an environment or setting, allowing individuals to interact, engage and learn about topics. The aim of this study was to undertake an integrative review to investigate the effectiveness of passive health-related waiting room interventions in improving healthy lifestyle behaviours, as well as precursors to behaviour change. The integrative review encompassed five phases: problem identification, literature search, data evaluation, data analysis and presentation of results. Quantitative, qualitative and mixed methods studies were included. Of the 9205 studies originally identified, 33 publications were included and grouped under four areas: knowledge about a health condition or behaviour, attitudes and intentions towards a health condition or behaviour, healthcare use and interactions, and health-related behaviours. Overall, the passive interventions had a general positive influence on knowledge, intentions, healthcare use and behaviours. Variable outcomes were reported regarding attitude towards a health topic. Few studies were assessed as both high quality and the highest suitability to assess effectiveness of interventions. Consideration of the clinical significance of improvements is warranted before implementation of future interventions. Overall, passive waiting room interventions appear to be effective in promoting healthy lifestyle behaviours.

Abstract 443: Class I Histone Deacetylases Mediate Cardiac I/R Injury and Modify the Mitochondrial Acetylome

Although rapid reperfusion of ischemic tissue is the treatment of choice for myocardial infarction, a significant amount of damage occurs as a result of reperfusion itself. The role of epigenetic enzymes in modulating this damage has become an area of interest in basic cardiac research. Previously, we have shown that pharmacological inhibition of the class I histone deacetylases (HDACs) with MS-275 (entinostat) preserves left-ventricular (LV) function and substantially reduces the area of infarcted tissue in isolated rat hearts subjected to ischemia-reperfusion (IR) injury. Interestingly, we have also observed that class I HDAC inhibition during 60 minutes of reperfusion alone is sufficient to protect cardiac tissue viability following I/R injury. Therefore, we hypothesized that class I HDACs mediate reperfusion injury by modulating acetylation of non-canonical pathways. To examine this, hearts from male Sprague-Dawley rats were subjected to I/R injury +/- class I HDAC inhibition during reperfusion. We then performed mass spectrometry to analyze the changes in the acetylome between sham and I/R groups with and without class I HDAC inhibition. Unexpectedly, mass spectrometry analysis revealed significant changes in the acetylation state of multiple mitochondrial enzymes. Further biochemical studies show that class I HDACs localize to the mitochondrial fraction of cardiac tissue homogenates and may modulate mitochondrial acetylation by direct or indirect mechanisms. This study emphasizes the importance of exploring class I HDAC inhibitors for protection against ischemia-reperfusion injury.

Chronic intermittent ethanol exposure and withdrawal leads to adaptations in nucleus accumbens core postsynaptic density proteome and dendritic spines

Alcohol use disorder is a chronic relapsing brain disease characterized by the loss of ability to control alcohol (ethanol) intake despite knowledge of detrimental health or personal consequences. Clinical and pre-clinical models provide strong evidence for chronic ethanol-associated alterations in glutamatergic signaling and impaired synaptic plasticity in the nucleus accumbens (NAc). However, the neural mechanisms that contribute to aberrant glutamatergic signaling in ethanol-dependent individuals in this critical brain structure remain unknown. Using an unbiased proteomic approach, we investigated the effects of chronic intermittent ethanol (CIE) exposure on neuroadaptations in postsynaptic density (PSD)-enriched proteins in the NAc of ethanol-dependent mice. Compared with controls, CIE exposure significantly changed expression levels of 50 proteins in the PSD-enriched fraction. Systems biology and functional annotation analyses demonstrated that the dysregulated proteins are expressed at tetrapartite synapses and critically regulate cellular morphology. To confirm this latter finding, the density and morphology of dendritic spines were examined in the NAc core of ethanol-dependent mice. We found that CIE exposure and withdrawal differentially altered dendrite diameter and dendritic spine density and morphology. Through the use of quantitative proteomics and functional annotation, these series of experiments demonstrate that ethanol dependence produces neuroadaptations in proteins that modify dendritic spine morphology. In addition, these studies identified novel PSD-related proteins that contribute to the neurobiological mechanisms of ethanol dependence that drive maladaptive structural plasticity of NAc neurons.

A Novel Quantitative Mass Spectrometry Platform for Determining Protein O-GlcNAcylation Dynamics

Over the past decades, protein O-GlcNAcylation has been found to play a fundamental role in cell cycle control, metabolism, transcriptional regulation, and cellular signaling. Nevertheless, quantitative approaches to determine in vivo GlcNAc dynamics at a large-scale are still not readily available. Here, we have developed an approach to isotopically label O-GlcNAc modifications on proteins by producing (13)C-labeled UDP-GlcNAc from (13)C6-glucose via the hexosamine biosynthetic pathway. This metabolic labeling was combined with quantitative mass spectrometry-based proteomics to determine protein O-GlcNAcylation turnover rates. First, an efficient enrichment method for O-GlcNAc peptides was developed with the use of phenylboronic acid solid-phase extraction and anhydrous DMSO. The near stoichiometry reaction between the diol of GlcNAc and boronic acid dramatically improved the enrichment efficiency. Additionally, our kinetic model for turnover rates integrates both metabolomic and proteomic data, which increase the accuracy of the turnover rate estimation. Other advantages of this metabolic labeling method include in vivo application, direct labeling of the O-GlcNAc sites and higher confidence for site identification. Concentrating only on nuclear localized GlcNAc modified proteins, we are able to identify 105 O-GlcNAc peptides on 42 proteins and determine turnover rates of 20 O-GlcNAc peptides from 14 proteins extracted from HeLa nuclei. In general, we found O-GlcNAcylation turnover rates are slower than those published for phosphorylation or acetylation. Nevertheless, the rates widely varied depending on both the protein and the residue modified. We believe this methodology can be broadly applied to reveal turnovers/dynamics of protein O-GlcNAcylation from different biological states and will provide more information on the significance of O-GlcNAcylation, enabling us to study the temporal dynamics of this critical modification for the first time.

Development of a validated questionnaire to measure the self-perceived competence of primary health professionals in providing nutrition care to patients with chronic disease

BACKGROUND

Nutrition is an important aspect of chronic disease prevention and management by primary health professionals, including GPs, dietitians, practice nurses, diabetes educators and exercise professionals. In order to better understand how to improve the delivery of nutrition care, it is important to have valid and reliable tools to measure self-perceived competence.

OBJECTIVE

This study aimed to develop a valid, structured, questionnaire that measures the self-perceived competence of primary health professionals to provide nutrition care to patients with chronic disease.

METHODS

The development of the questionnaire was carried out in four stages (1): preparation of scope and structure, through a literature review and consultation with an expert reference group (2); development of questionnaire items, which were refined through feedback from the reference group and 18 primary health professionals (3); investigation of internal consistency and concurrent validity through a pilot study on 118 primary health professionals (4) and investigation of test-retest reliability through a pilot study on 33 primary health professionals who completed the questionnaire twice, 2-3 weeks apart.

RESULTS

Stages 1 and 2 resulted in four constructs and 35 questions in the questionnaire. Stage 3 confirmed internal consistency, with Cronbach's α ranging from 0.88 to 0.98 for each construct and 0.98 for all items combined. Dietitians scored significantly higher than speech pathologists (P < 0.05) in each construct, confirming concurrent validity. Stage 4 confirmed test-retest reliability, with correlation coefficients ranging from 0.89 to 0.94 for each construct and 0.95 for all items combined.

CONCLUSION

The NUTrition COMPetence (NUTCOMP) questionnaire is a valid, reliable and suitable tool that can be used to directly inform professional development and identify opportunities to support safe and effective practice.

Changes in Protein Expression and Lysine Acetylation Induced by Decreased Glutathione Levels in Astrocytes

Astrocytes and neurons form a highly specialized functional unit, and the loss or gain of astrocytic functions can influence the initiation and progression of different neurodegenerative diseases. Neurons depend on the antioxidant protection provided by neighboring astrocytes. Glutathione (γ-l-glutamyl-l-cysteinyl-glycine) is a major component of the antioxidant system that defends cells against the toxic effects of reactive oxygen/nitrogen species. A decline in glutathione levels has been observed in aging and neurodegenerative diseases, and it aggravates the pathology in an amyotrophic lateral sclerosis-mouse model. Using a SILAC-based quantitative proteomic approach, we analyzed changes in global protein expression and lysine acetylation in primary astrocyte cultures obtained from wild-type mice or those deficient in the glutamate-cysteine ligase modifier subunit (GCLM). GCLM knockout astrocytes display an ∼80% reduction in total glutathione levels. We identified potential molecular targets and novel sites of acetylation that are affected by the chronic decrease in glutathione levels and observed a response mediated by Nrf2 activation. In addition, sequence analysis of peptides displaying increased acetylation in GCLM knockout astrocytes revealed an enrichment of cysteine residues in the vicinity of the acetylation site, which suggests potential crosstalk between lysine-acetylation and cysteine modification. Regulation of several metabolic and antioxidant pathways was observed at the level of protein expression and lysine acetylation, revealing a coordinated response involving transcriptional and posttranslational regulation.

Exploring G protein-coupled receptor signaling networks using SILAC-based phosphoproteomics

The type 1 parathyroid hormone receptor (PTH1R) is a key regulator of calcium homeostasis and bone turnover. Here, we employed SILAC-based quantitative mass spectrometry and bioinformatic pathways analysis to examine global changes in protein phosphorylation following short-term stimulation of endogenously expressed PTH1R in osteoblastic cells in vitro. Following 5min exposure to the conventional agonist, PTH(1-34), we detected significant changes in the phosphorylation of 224 distinct proteins. Kinase substrate motif enrichment demonstrated that consensus motifs for PKA and CAMK2 were the most heavily upregulated within the phosphoproteome, while consensus motifs for mitogen-activated protein kinases were strongly downregulated. Signaling pathways analysis identified ERK1/2 and AKT as important nodal kinases in the downstream network and revealed strong regulation of small GTPases involved in cytoskeletal rearrangement, cell motility, and focal adhesion complex signaling. Our data illustrate the utility of quantitative mass spectrometry in measuring dynamic changes in protein phosphorylation following GPCR activation.

Intracellular protein O-GlcNAc modification integrates nutrient status with transcriptional and metabolic regulation

The inducible, nutrient-sensitive posttranslational modification of protein Ser/Thr residues with O-linked β-N-acetylglucosamine (O-GlcNAc) occurs on histones, transcriptional regulators, metabolic enzymes, oncogenes, tumor suppressors, and many critical intermediates of growth factor signaling. Cycling of O-GlcNAc modification on and off of protein substrates is catalyzed by the actions of O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively. To date, there are less than 150 publications addressing the role of O-GlcNAc modification in cancer and over half were published in the last 2 years. These studies have clearly established that increased expression of OGT and hyper-O-GlcNAcylation is common to human cancers of breast, prostate, colon, lung, and pancreas. Furthermore, attenuating OGT activity reduces tumor growth in vitro and metastasis in vivo. This chapter discusses the structure and function of the O-GlcNAc cycling enzymes, mechanisms by which protein O-GlcNAc modification sense changes in nutrient status, the influence of O-GlcNAc cycling enzymes on glucose metabolism, and provides an overview of recent observations regarding the role of O-GlcNAcylation in cancer.

"I wish they could be in my shoes": patients' insights into tertiary health care for type 2 diabetes mellitus

BACKGROUND

Insightful accounts of patient experience within a health care system can be valuable for facilitating improvements in service delivery.

OBJECTIVE

The aim of this study was to explore patients' perceptions and experiences regarding a tertiary hospital Diabetes and Endocrinology outpatient service for the management of type 2 diabetes mellitus (T2DM).

METHOD

Nine patients participated in discovery interviews with an independent trained facilitator. Patients' stories were synthesized thematically using a constant comparative approach.

RESULTS

Three major themes were identified from the patients' stories: 1) understanding T2DM and diabetes management with subthemes highlighting that specialist care is highly valued by patients who experience a significant burden of diabetes on daily life and who may have low health literacy and low self confidence; 2) relationships with practitioners were viewed critical and perceived lack of empathy impacted the effectiveness of care; and 3) impact of health care systems on service delivery with lack of continuity of care relating to the tertiary hospital model and limitations with appointment bookings negatively impacting on patient experience.

DISCUSSION

The patients' stories suggest that the expectation of establishing a productive, ongoing relationship with practitioners is highly valued. Tertiary clinics for T2DM are well placed to incorporate novel technological approaches for monitoring and follow-up, which may overcome many of the perceived barriers of traditional service delivery.

CONCLUSION

Investing in strategies that promote patient-practitioner relationships may enhance effectiveness of treatment for T2DM by meeting patient expectations of personalized care. Future changes in service delivery would benefit from incorporating patients as key stakeholders in service evaluation.

O-GlcNAc modification of the runt-related transcription factor 2 (Runx2) links osteogenesis and nutrient metabolism in bone marrow mesenchymal stem cells

Runx2 is the master switch controlling osteoblast differentiation and formation of the mineralized skeleton. The post-translational modification of Runx2 by phosphorylation, ubiquitinylation, and acetylation modulates its activity, stability, and interactions with transcriptional co-regulators and chromatin remodeling proteins downstream of osteogenic signals. Characterization of Runx2 by electron transfer dissociation tandem mass spectrometry revealed sites of O-linked N-acetylglucosamine (O-GlcNAc) modification, a nutrient-responsive post-translational modification that modulates the action of numerous transcriptional effectors. O-GlcNAc modification occurs in close proximity to phosphorylated residues and novel sites of arginine methylation within regions known to regulate Runx2 transactivation. An interaction between Runx2 and the O-GlcNAcylated, O-GlcNAc transferase enzyme was also detected. Pharmacological inhibition of O-GlcNAcase (OGA), the enzyme responsible for the removal of O-GlcNAc from Ser/Thr residues, enhanced basal (39.9%) and BMP2/7-induced (43.3%) Runx2 transcriptional activity in MC3T3-E1 pre-osteoblasts. In bone marrow-derived mesenchymal stem cells differentiated for 6 days in osteogenic media, inhibition of OGA resulted in elevated expression (24.3%) and activity (65.8%) of alkaline phosphatase (ALP) an early marker of bone formation and a transcriptional target of Runx2. Osteogenic differentiation of bone marrow-derived mesenchymal stem cells in the presence of BMP2/7 for 8 days culminated in decreased OGA activity (39.0%) and an increase in the abundance of O-GlcNAcylated Runx2, as compared with unstimulated cells. Furthermore, BMP2/7-induced ALP activity was enhanced by 35.6% in bone marrow-derived mesenchymal stem cells differentiated in the presence of the OGA inhibitor, demonstrating that direct or BMP2/7-induced inhibition of OGA is associated with increased ALP activity. Altogether, these findings link O-GlcNAc cycling to the Runx2-dependent regulation of the early ALP marker under osteoblast differentiation conditions.

Obesity bias among health and non-health students attending an Australian university and their perceived obesity education

OBJECTIVE

This study compared the level of prejudice against obese individuals (obesity bias) among final-year health and non-health students, and associated obesity education.

METHODS

Cross-sectional online survey of 479 final-year students (292 health and 187 non-health) from Griffith University, Australia. Implicit and explicit obesity bias was measured using validated tools, and perceived obesity education ranked from "none" to "excellent." Data were analyzed quantitatively using analysis of variance and independent sample t tests. Statistical significance was set at P < .05.

RESULTS

Students' mean age was 26.2 ± 7.6 years and body mass index was 23.2 ± 4.7 kg/m(2). Health and non-health students exhibited significant levels of obesity bias. Non-health students were more likely to suggest that obese individuals lacked willpower (P = .03). Students' self-reported obesity education varied considerably. Those who reported a higher level of genetics-related obesity education were less likely to believe that obese individuals were "bad" (P = .002) or to show concern about putting on weight (P = .01).

CONCLUSIONS AND IMPLICATIONS

Obesity bias exists in health students in Australia and is similar to non-health students' obesity bias levels. Students' self-reported genetics-related obesity education may be associated with obesity bias. Modifications to existing health curricula should be considered to reduce obesity bias among future health professionals.