[13C]bicarbonate labelled from hyperpolarized [1-13C]pyruvate is an in vivo marker of hepatic gluconeogenesis in fasted state

Hyperpolarized [1-13C]pyruvate enables direct in vivo assessment of real-time liver enzymatic activities by 13C magnetic resonance. However, the technique usually requires the injection of a highly supraphysiological dose of pyruvate. We herein demonstrate that liver metabolism can be measured in vivo with hyperpolarized [1-13C]pyruvate administered at two- to three-fold the basal plasma concentration. The flux through pyruvate dehydrogenase, assessed by 13C-labeling of bicarbonate in the fed condition, was found to be saturated or partially inhibited by supraphysiological doses of hyperpolarized [1-13C]pyruvate. The [13C]bicarbonate signal detected in the liver of fasted rats nearly vanished after treatment with a phosphoenolpyruvate carboxykinase (PEPCK) inhibitor, indicating that the signal originates from the flux through PEPCK. In addition, the normalized [13C]bicarbonate signal in fasted untreated animals is dose independent across a 10-fold range, highlighting that PEPCK and pyruvate carboxylase are not saturated and that hepatic gluconeogenesis can be directly probed in vivo with hyperpolarized [1-13C]pyruvate.

Crosstalk between basal extracellular matrix adhesion and building of apical architecture during morphogenesis

ABSTRACT Tissues build complex structures like lumens and microvilli to carry out their functions. Most of the mechanisms used to build these structures rely on cells remodelling their apical plasma membranes, which ultimately constitute the specialised compartments. In addition to apical remodelling, these shape changes also depend on the proper attachment of the basal plasma membrane to the extracellular matrix (ECM). The ECM provides cues to establish apicobasal polarity, and it also transduces forces that allow apical remodelling. However, physical crosstalk mechanisms between basal ECM attachment and the apical plasma membrane remain understudied, and the ones described so far are very diverse, which highlights the importance of identifying the general principles. Here, we review apicobasal crosstalk of two well-established models of membrane remodelling taking place during Drosophila melanogaster embryogenesis: amnioserosa cell shape oscillations during dorsal closure and subcellular tube formation in tracheal cells. We discuss how anchoring to the basal ECM affects apical architecture and the mechanisms that mediate these interactions. We analyse this knowledge under the scope of other morphogenetic processes and discuss what aspects of apicobasal crosstalk may represent widespread phenomena and which ones are used to build subsets of specialised compartments.

Cannabidiol Decreases Metalloproteinase Activity and Normalizes Angiogenesis Factor Expression in UVB-Irradiated Keratinocytes from Psoriatic Patients

The development of psoriasis is associated with the consequences of oxidative stress and inflammation leading to metabolic changes locally, in the skin cells, and systemically, in the blood. Therefore, the aim of this study was to analyze the effect of psoriasis vulgaris (PsV) and psoriatic arthritis (PsA) on the basal plasma/keratinocyte levels of matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs), and angiogenesis factors, as well as to evaluate the effect of CBD on these parameters in keratinocytes isolated from psoriatic/healthy individuals with and without in vitro irradiation by UVB. A quantitative chemiluminescent method of detection based on an ELISA protocol and zymography technique was used during analysis. It was shown that activity levels of MMP-9 and TIMP-2 in PsA plasma were higher than in PsV. Changes in the proteolytic activity were accompanied by an increase in markers of angiogenesis (angiopoietin-2, HGF, VEGF, TNFα, PDGF, FGF), where in the specific case of angiopoietin-2 and TNFα, the overexpression in PsV was significantly stronger than in PsA. CBD application to keratinocytes partially restored levels of MMP-1/2/3/7 and TIMP-1/2 (in an effect which was particularly enhanced by UVB irradiation), as well as levels of the examined angiogenic factors except TNFα (levels of which were increased in psoriatic keratinocytes and decreased in healthy keratinocytes). Presented results indicate that CBD may be suggested as an antiangiogenic factor that reduces the proinflammatory action of UVB in psoriatic keratinocytes and partially has a protective effect for healthy keratinocytes.

TMEM16F and dynamins control expansive plasma membrane reservoirs

Cells can expand their plasma membrane laterally by unfolding membrane undulations and by exocytosis. Here, we describe a third mechanism involving invaginations held shut by the membrane adapter, dynamin. Compartments open when Ca activates the lipid scramblase, TMEM16F, anionic phospholipids escape from the cytoplasmic monolayer in exchange for neutral lipids, and dynamins relax. Deletion of TMEM16F or dynamins blocks expansion, with loss of dynamin expression generating a maximally expanded basal plasma membrane state. Re-expression of dynamin2 or its GTPase-inactivated mutant, but not a lipid binding mutant, regenerates reserve compartments and rescues expansion. Dynamin2-GFP fusion proteins form punctae that rapidly dissipate from these compartments during TMEM16F activation. Newly exposed compartments extend deeply into the cytoplasm, lack numerous organellar markers, and remain closure-competent for many seconds. Without Ca, compartments open slowly when dynamins are sequestered by cytoplasmic dynamin antibodies or when scrambling is mimicked by neutralizing anionic phospholipids and supplementing neutral lipids. Activation of Ca-permeable mechanosensitive channels via cell swelling or channel agonists opens the compartments in parallel with phospholipid scrambling. Thus, dynamins and TMEM16F control large plasma membrane reserves that open in response to lateral membrane stress and Ca influx.

Yoga as an Adjunct for Management of Opioid Dependence Syndrome: A Nine-Month Follow-Up Case Report

Opioid dependence syndrome (ODS) is a chronic relapsing remitting condition associated with significant impairment and mortality risk. Opioid substitution therapy is used worldwide, but long-term retention rates are low and there is risk of misuse and diversion. Yoga practice can improve quality of life, reduce chronic pain, and enhance endogenous opioids (beta-endorphins). We describe a case of ODS where yoga was added to the conventional management and who was followed up for 9 months. Assessments were done for clinical symptoms, urine drug screening, plasma beta-endorphins, and Buprenorphine dosage. We observed an improvement in his clinical symptoms and reduction in the requirements for Buprenorphine. A slight increase in basal plasma beta-endorphin levels was also observed at the 9-month follow-up (from 2.02 pmol/L at baseline to 6.51 pmol/L).

Hemodialysis exacerbates proteolytic imbalance and pro-fibrotic platelet dysfunction

Multi-organ fibrosis among end stage renal disease (ESRD) patients cannot be explained by uremia alone. Despite mitigation of thrombosis during hemodialysis (HD), subsequent platelet dysfunction and tissue dysregulation are less understood. We comprehensively profiled plasma and platelets from ESRD patients before and after HD to examine HD-modulation of platelets beyond thrombotic activation. Basal plasma levels of proteolytic regulators and fibrotic factors were elevated in ESRD patients compared to healthy controls, with isoform-specific changes during HD. Platelet lysate (PL) RNA transcripts for growth and coagulative factors were elevated post-HD, with upregulation correlated to HD vintage. Platelet secretome correlations to plasma factors reveal acutely induced pro-fibrotic platelet phenotypes in ESRD patients during HD characterized by preferentially enhanced proteolytic enzyme translation and secretion, platelet contribution to inflammatory response, and increasing platelet dysfunction with blood flow rate (BFR) and Vintage. Compensatory mechanisms of increased platelet growth factor synthesis with acute plasma matrix metalloproteinase (MMP) and tissue inhibitor of MMPs (TIMP) increases show short-term mode-switching between dialysis sessions leading to long-term pro-fibrotic bias. Chronic pro-fibrotic adaptation of platelet synthesis were observed through changes in differential secretory kinetics of heterogenous granule subtypes. We conclude that chronic and acute platelet responses to HD contribute to a pro-fibrotic milieu in ESRD.

Stress Hormones as Predictors of Response to Cognitive Behavior Therapy in Panic Disorder

Objective: Data regarding the potential association between the outcome of psychotherapy of panic disorder (PD) and biological parameters are few. In 21 (16 females) consecutively referred, medication-free, acutely ill PD outpatients, without comorbidities, except agoraphobia, we systematically explored for potential neuroendocrine and clinical correlates of response to a brief cognitive behavior therapy (CBT). Methods: Cortisol and adrenocorticotropic hormone (ACTH) basal plasma levels were measured. Measures of psychopathology: (a) Symptom Checklist–90-Revised (SCL-90-R), (b) Clinical Global Impressions-Improvement (CGI-I) Scale, (c) Agoraphobic Cognitions Questionnaire (ACQ), and (d) Mobility Inventory (MI)-alone subscale. Results: Nonresponders to CBT (CGI-I >2; N = 6) – as compared to the responders (CGI-I ≤2; N = 15) – demonstrated significantly higher cortisol and ACTH basal plasma concentrations. These differences were much stronger when only female patients (nonresponders = 4; responders = 12) were taken into consideration. Regarding psychopathology, nonresponders to CBT suffered from more severe agoraphobia (MI-alone) at baseline. On the contrary, more intense manifestations of anger (SCL-90-R) at baseline were associated with a better treatment outcome. Response to CBT was associated with significant reductions in all SCL-90-R subscales, more pronounced for “phobic anxiety” and “anxiety” subscales. Conclusions: This study suggests that in acutely ill, medication-free PD patients, response to CBT may be associated with certain hormonal and clinical parameters at baseline.