Oxaloacetate Enhances Neuronal Cell Bioenergetic Fluxes and Infrastructure

"This is the peer reviewed version of the following article: Wilkins, Heather M. et al. “Oxaloacetate Enhances Neuronal Cell Bioenergetic Fluxes and Infrastructure.” Journal of neurochemistry 137.1 (2016): 76–87., which has been published in final form at 10.1111/jnc.13545. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."We tested how the addition of oxaloacetate (OAA) to SH-SY5Y cells affected bioenergetic fluxes and infrastructure, and compared the effects of OAA to malate, pyruvate, and glucose deprivation. OAA displayed pro-glycolysis and pro-respiration effects. OAA pro-glycolysis effects were not a consequence of decarboxylation to pyruvate because unlike OAA, pyruvate lowered the glycolysis flux. Malate did not alter glycolysis flux and reduced mitochondrial respiration. Glucose deprivation essentially eliminated glycolysis and increased mitochondrial respiration. OAA increased, while malate decreased, the cell NAD+/NADH ratio. Cytosolic malate dehydrogenase 1 (MDH1) protein increased with OAA treatment, but not with malate or glucose deprivation. Glucose deprivation increased protein levels of ATP citrate lyase, an enzyme which produces cytosolic OAA, while OAA altered neither ATP citrate lyase mRNA nor protein levels. OAA, but not glucose deprivation, increased COX2, PGC1α, PGC1β, and PRC protein levels. OAA increased total and phosphorylated SIRT1 protein. We conclude that adding OAA to SH-SY5Y cells can support or enhance both glycolysis and respiration fluxes. These effects appear to depend, at least partly, on OAA causing a shift in the cell redox balance to a more oxidized state, that it is not a glycolysis pathway intermediate, and possibly its ability to act in an anaplerotic fashion

A phase II experience with neoadjuvant irinotecan (CPT-11), 5-fluorouracil (5-FU) and leucovorin (LV) for colorectal liver metastases

<p>Abstract</p> <p>Background</p> <p>Chemotherapy may improve survival in patients undergoing resection of colorectal liver metastases (CLM). Neoadjuvant chemotherapy may help identify patients with occult extrahepatic disease (averting unnecessary metastasectomy), and it provides <it>in vivo </it>chemosensitivity data.</p> <p>Methods</p> <p>A phase II trial was initiated in which patients with resectable CLM received CPT-11, 5-FU and LV for 12 weeks. Metastasectomy was performed unless extrahepatic disease appeared. Postoperatively, patients with stable or responsive disease received the same regimen for 12 weeks. Patients with progressive disease received either second-line chemotherapy or best supportive care. The primary endpoint was disease-free survival (DFS); secondary endpoints included overall survival (OS) and safety.</p> <p>Results</p> <p>35 patients were accrued. During preoperative chemotherapy, 16 patients (46%) had grade 3/4 toxicities. Resection was not possible in 5 patients. One patient died of arrhythmia following surgery, and 1 patient had transient liver failure. During the postoperative treatment phase, 12 patients (55%) had grade 3/4 toxicities. Deep venous thrombosis (DVT) occurred in 11 patients (34%) at various times during treatment. Of those who underwent resection, median DFS was 23.0 mo. and median OS has not been reached. The overall survival from time of diagnosis of liver metastases was 51.6 mo for the entire cohort.</p> <p>Conclusion</p> <p>A short course of chemotherapy prior to hepatic metastasectomy may serve to select candidates best suited for resection and it may also direct postoperative systemic treatment. Given the significant incidence of DVT, alternative systemic neoadjuvant regimens should be investigated, particularly those that avoid the use of a central venous line.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov NCT00168155.</p

A polymorphism associated with depressive disorders differentially regulates brain derived neurotrophic factor promoter IV activity

PMCID: PMC3712170Peer reviewedPublisher PD

Mitochondrial DNA Manipulations Affect Tau Oligomerization

Background:Mitochondrial dysfunction and tau aggregation occur in Alzheimer’s disease (AD), and exposing cells or rodents to mitochondrial toxins alters their tau. Objective:To further explore how mitochondria influence tau, we measured tau oligomer levels in human neuronal SH-SY5Y cells with different mitochondrial DNA (mtDNA) manipulations. Methods:Specifically, we analyzed cells undergoing ethidium bromide-induced acute mtDNA depletion, ρ0 cells with chronic mtDNA depletion, and cytoplasmic hybrid (cybrid) cell lines containing mtDNA from AD subjects. Results:We found cytochrome oxidase activity was particularly sensitive to acute mtDNA depletion, evidence of metabolic re-programming in the ρ0 cells, and a relatively reduced mtDNA content in cybrids generated through AD subject mitochondrial transfer. In each case tau oligomer levels increased, and acutely depleted and AD cybrid cells also showed a monomer to oligomer shift. Conclusion:We conclude a cell’s mtDNA affects tau oligomerization. Overlapping tau changes across three mtDNA-manipulated models establishes the reproducibility of the phenomenon, and its presence in AD cybrids supports its AD-relevance

Tensions and paradoxes in electronic patient record research: a systematic literature review using the meta-narrative method

Background: The extensive and rapidly expanding research literature on electronic patient records (EPRs) presents challenges to systematic reviewers. This literature is heterogeneous and at times conflicting, not least because it covers multiple research traditions with different underlying philosophical assumptions and methodological approaches. Aim: To map, interpret and critique the range of concepts, theories, methods and empirical findings on EPRs, with a particular emphasis on the implementation and use of EPR systems. Method: Using the meta-narrative method of systematic review, and applying search strategies that took us beyond the Medline-indexed literature, we identified over 500 full-text sources. We used ‘conflicting’ findings to address higher-order questions about how the EPR and its implementation were differently conceptualised and studied by different communities of researchers. Main findings: Our final synthesis included 24 previous systematic reviews and 94 additional primary studies, most of the latter from outside the biomedical literature. A number of tensions were evident, particularly in relation to: [1] the EPR (‘container’ or ‘itinerary’); [2] the EPR user (‘information-processer’ or ‘member of socio-technical network’); [3] organizational context (‘the setting within which the EPR is implemented’ or ‘the EPR-in-use’); [4] clinical work (‘decision-making’ or ‘situated practice’); [5] the process of change (‘the logic of determinism’ or ‘the logic of opposition’); [6] implementation success (‘objectively defined’ or ‘socially negotiated’); and [7] complexity and scale (‘the bigger the better’ or ‘small is beautiful’). Findings suggest that integration of EPRs will always require human work to re-contextualize knowledge for different uses; that whilst secondary work (audit, research, billing) may be made more efficient by the EPR, primary clinical work may be made less efficient; that paper, far from being technologically obsolete, currently offers greater ecological flexibility than most forms of electronic record; and that smaller systems may sometimes be more efficient and effective than larger ones. Conclusions: The tensions and paradoxes revealed in this study extend and challenge previous reviews and suggest that the evidence base for some EPR programs is more limited than is often assumed. We offer this paper as a preliminary contribution to a much-needed debate on this evidence and its implications, and suggest avenues for new research

A Possible Role for Metallic Ions in the Carbohydrate Cluster Recognition Displayed by a Lewis Y Specific Antibody

BACKGROUND:Lewis Y (Le(y)) is a blood group-related carbohydrate that is expressed at high surface densities on the majority of epithelial carcinomas and is a promising target for antibody-based immunotherapy. A humanized Le(y)-specific antibody (hu3S193) has shown encouraging safety, pharmacokinetic and tumor-targeting properties in recently completed Phase I clinical trials. METHODOLOGY/PRINCIPAL FINDINGS:We report the three-dimensional structures for both the free (unliganded) and bound (Le(y) tetrasaccharide) hu3S193 Fab from the same crystal grown in the presence of divalent zinc ions. There is no evidence of significant conformational changes occurring in either the Le(y) carbohydrate antigen or the hu3S193 binding site, which suggests a rigid fit binding mechanism. In the crystal, the hu3S193 Fab molecules are coordinated at their protein-protein interface by two zinc ions and in solution aggregation of Fab can be initiated by zinc, but not magnesium ions. Dynamic light scattering revealed that zinc ions could initiate a sharp transition from hu3S193 Fab monomers to large multimeric aggregates in solution. CONCLUSIONS/SIGNIFICANCE:Zinc ions can mediate interactions between hu3S193 Fab in crystals and in solution. Whether metallic ion mediated aggregation of antibody occurs in vivo is not known, but the present results suggest that similar clustering mechanisms could occur when hu3S193 binds to Le(y) on cells, particularly given the high surface densities of antigen on the target tumor cells

Integration of a nationally procured electronic health record system into user work practices

BACKGROUND: Evidence suggests that many small- and medium-scale Electronic Health Record (EHR) implementations encounter problems, these often stemming from users' difficulties in accommodating the new technology into their work practices. There is the possibility that these challenges may be exacerbated in the context of the larger-scale, more standardised, implementation strategies now being pursued as part of major national modernisation initiatives. We sought to understand how England's centrally procured and delivered EHR software was integrated within the work practices of users in selected secondary and specialist care settings. METHODS: We conducted a qualitative longitudinal case study-based investigation drawing on sociotechnical theory in three purposefully selected sites implementing early functionality of a nationally procured EHR system. The complete dataset comprised semi-structured interview data from a total of 66 different participants, 38.5 hours of non-participant observation of use of the software in context, accompanying researcher field notes, and hospital documents (including project initiation and lessons learnt reports). Transcribed data were analysed thematically using a combination of deductive and inductive approaches, and drawing on NVivo8 software to facilitate coding. RESULTS: The nationally led "top-down" implementation and the associated focus on interoperability limited the opportunity to customise software to local needs. Lack of system usability led users to employ a range of workarounds unanticipated by management to compensate for the perceived shortcomings of the system. These had a number of knock-on effects relating to the nature of collaborative work, patterns of communication, the timeliness and availability of records (including paper) and the ability for hospital management to monitor organisational performance. CONCLUSIONS: This work has highlighted the importance of addressing potentially adverse unintended consequences of workarounds associated with the introduction of EHRs. This can be achieved with customisation, which is inevitably somewhat restricted in the context of attempts to implement national solutions. The tensions and potential trade-offs between achieving large-scale interoperability and local requirements is likely to be the subject of continuous debate in England and beyond with no easy answers in sight

How accurate appraisal of behavioral costs and benefits guides adaptive pain coping

Coping with pain is a complex phenomenon encompassing a variety of behavioral responses and a large network of underlying neural circuits. Whether pain coping is adaptive or maladaptive depends on the type of pain (e.g., escapable or inescapable), personal factors (e.g., individual experiences with coping strategies in the past), and situational circumstances. Keeping these factors in mind, costs and benefits of different strategies have to be appraised and will guide behavioral decisions in the face of pain. In this review we present pain coping as an unconscious decision-making process during which accurately evaluated costs and benefits lead to adaptive pain coping behavior. We emphasize the importance of passive coping as an adaptive strategy when dealing with ongoing pain and thus go beyond the common view of passivity as a default state of helplessness. In combination with passive pain coping, we highlight the role of the reward system in reestablishing affective homeostasis and discuss existing evidence on a behavioral and neural level. We further present neural circuits involved in the decision-making process of pain coping when circumstances are ambiguous and, therefore, costs and benefits are difficult to anticipate. Finally, we address the wider implications of this topic by discussing its relevance for chronic pain patients