Ca2+ Homeostasis in the Endoplasmic Reticulum: Coexistence of High and Low [Ca2+] Subcompartments in Intact HeLa Cells

Two recombinant aequorin isoforms with different Ca2+ affinities, specifically targeted to the endoplasmic reticulum (ER), were used in parallel to investigate free Ca2+ homeostasis in the lumen of this organelle. Here we show that, although identically and homogeneously distributed in the ER system, as revealed by both immunocytochemical and functional evidence, the two aequorins measured apparently very different concentrations of divalent cations ([Ca2+]er or [Sr2+]er). Our data demonstrate that this contradiction is due to the heterogeneity of the [Ca2+] of the aequorin-enclosing endomembrane system. Because of the characteristics of the calibration procedure used to convert aequorin luminescence into Ca2+ concentration, the [Ca2+]er values obtained at steady state tend, in fact, to reflect not the average ER values, but those of one or more subcompartments with lower [Ca2+]. These subcompartments are not generated artefactually during the experiments, as revealed by the dynamic analysis of the ER structure in living cells carried out by means of an ER-targeted green fluorescent protein. When the problem of ER heterogeneity was taken into account (and when Sr2+ was used as a Ca2+ surrogate), the bulk of the organelle was shown to accumulate free [cation2+]er up to a steady state in the millimolar range. A theoretical model, based on the existence of multiple ER subcompartments of high and low [Ca2+], that closely mimics the experimental data obtained in HeLa cells during accumulation of either Ca2+ or Sr2+, is presented. Moreover, a few other key problems concerning the ER Ca2+ homeostasis have been addressed with the following conclusions: (a) the changes induced in the ER subcompartments by receptor generation of InsP3 vary depending on their initial [Ca2+]. In the bulk of the system there is a rapid release whereas in the small subcompartments with low [Ca2+] the cation is simultaneously accumulated; (b) stimulation of Ca2+ release by receptor-generated InsP3 is inhibited when the lumenal level is below a threshold, suggesting a regulation by [cation2+]er of the InsP3 receptor activity (such a phenomenon had already been reported, however, but only in subcellular fractions analyzed in vitro); and (c) the maintenance of a relatively constant level of cytosolic [Ca2+], observed when the cells are incubated in Ca2+-free medium, depends on the continuous release of the cation from the ER, with ensuing activation in the plasma membrane of the channels thereby regulated (capacitative influx)

Burned or engaged teachers? The role of mindfulness, self-efficacy, teacher and students’ relationships, and the mediating role of intrapersonal and interpersonal mindfulness

This study had the goal to examine factors that are associated with burnout and engagement among teachers from diverse educational stages. Among these factors, we analyzed socio-demographic aspects, such as gender, age and years of experience, and other psychological teacher-related variables like teacher’s self-efficacy and teacher-student relationships. We also considered the potential mediating role of mindfulness in these relationships. The sample was made up by 425 Spanish teachers who answered an online survey. We administered the following measures: Revised version of the Teacher’s Burnout Questionnaire, Utrecht Work Engagement Scale, Mindfulness in Teaching Scale –which distinguished between intrapersonal and interpersonal mindfulness-, Teacher’s Sense of Self-efficacy Scale, and some questions related to the relationships between students and teachers in the classroom. We conducted a mediational analysis through structural equation modeling (SEM). Our findings indicated that both intrapersonal and interpersonal mindfulness mediated the relation between self-efficacy, which played a direct and an indirect role, the teacher-student relationship, and burnout and engagement. The socio-demographic variables of gender and years of experience played a significant role in mindfulness. The teachers with more self-efficacy were more likely to pay attention to their daily activity and to show more receptivity with their students, which resulted in lower burnout and more engagement. In addition, better relationships with students led to higher intrapersonal mindfulness levels, which mediated the relation with burnout and engagement. These relations varied depending on specific burnout and engagement dimensions. We discuss the implications of these findings for improving teachers´ implication in the education field. © 2021, The Author(s)

Validation of the Spanish versions of the long (26 items) and short (12 items) forms of the Self-Compassion Scale (SCS)

Background: Self-compassion is a key psychological construct for assessing clinical outcomes in mindfulness-based interventions. the aim of this study was to validate the Spanish versions of the long (26 item) and short (12 item) forms of the Self-Compassion Scale (SCS).Methods: the translated Spanish versions of both subscales were administered to two independent samples: Sample 1 was comprised of university students (n = 268) who were recruited to validate the long form, and Sample 2 was comprised of Aragon Health Service workers (n = 271) who were recruited to validate the short form. in addition to SCS, the Mindful Attention Awareness Scale (MAAS), the State-Trait Anxiety Inventory-Trait (STAI-T), the Beck Depression Inventory (BDI) and the Perceived Stress Questionnaire (PSQ) were administered. Construct validity, internal consistency, test-retest reliability and convergent validity were tested.Results: the Confirmatory Factor Analysis (CFA) of the long and short forms of the SCS confirmed the original six-factor model in both scales, showing goodness of fit. Cronbach's a for the 26 item SCS was 0.87 (95% CI = 0.85-0.90) and ranged between 0.72 and 0.79 for the 6 subscales. Cronbach's a for the 12-item SCS was 0.85 (95% CI = 0.81-0.88) and ranged between 0.71 and 0.77 for the 6 subscales. the long (26-item) form of the SCS showed a test-retest coefficient of 0.92 (95% CI = 0.89-0.94). the Intraclass Correlation (ICC) for the 6 subscales ranged from 0.84 to 0.93. the short (12-item) form of the SCS showed a test-retest coefficient of 0.89 (95% CI: 0.87-0.93). the ICC for the 6 subscales ranged from 0.79 to 0.91. the long and short forms of the SCS exhibited a significant negative correlation with the BDI, the STAI and the PSQ, and a significant positive correlation with the MAAS. the correlation between the total score of the long and short SCS form was r = 0.92.Conclusion: the Spanish versions of the long (26-item) and short (12-item) forms of the SCS are valid and reliable instruments for the evaluation of self-compassion among the general population. These results substantiate the use of this scale in research and clinical practice.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Miguel Servet Hosp, Aragon Inst Hlth Sci I CS, Dept Psychiat, Zaragoza, SpainPrimary Care Prevent & Hlth Promot Res Network Re, Zaragoza, SpainBit&Brain Technol, Zaragoza, Spain12 Octubre Res Inst, Madrid, SpainUniv Zaragoza, Fac Hlth Sci & Sports, Huesca, SpainLozano Blesa Univ, Clin Hosp, Zaragoza, SpainUniversidade Federal de São Paulo UNIFESP, Escola Paulista Med, Dept Prevent Med, Ctr Mindfulness & Hlth Promot, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Escola Paulista Med, Dept Prevent Med, Ctr Mindfulness & Hlth Promot, São Paulo, BrazilWeb of Scienc

The dynamics of mitochondrial Ca2+ fluxes

AbstractWe have investigated the kinetics of mitochondrial Ca2+ influx and efflux and their dependence on cytosolic [Ca2+] and [Na+] using low-Ca2+-affinity aequorin. The rate of Ca2+ release from mitochondria increased linearly with mitochondrial [Ca2+] ([Ca2+]M). Na+-dependent Ca2+ release was predominant al low [Ca2+]M but saturated at [Ca2+]M around 400μM, while Na+-independent Ca2+ release was very slow at [Ca2+]M below 200μM, and then increased at higher [Ca2+]M, perhaps through the opening of a new pathway. Half-maximal activation of Na+-dependent Ca2+ release occurred at 5–10mM [Na+], within the physiological range of cytosolic [Na+]. Ca2+ entry rates were comparable in size to Ca2+ exit rates at cytosolic [Ca2+] ([Ca2+]c) below 7μM, but the rate of uptake was dramatically accelerated at higher [Ca2+]c. As a consequence, the presence of [Na+] considerably reduced the rate of [Ca2+]M increase at [Ca2+]c below 7μM, but its effect was hardly appreciable at 10μM [Ca2+]c. Exit rates were more dependent on the temperature than uptake rates, thus making the [Ca2+]M transients to be much more prolonged at lower temperature. Our kinetic data suggest that mitochondria have little high affinity Ca2+ buffering, and comparison of our results with data on total mitochondrial Ca2+ fluxes indicate that the mitochondrial Ca2+ bound/Ca2+ free ratio is around 10- to 100-fold for most of the observed [Ca2+]M range and suggest that massive phosphate precipitation can only occur when [Ca2+]M reaches the millimolar range

Efficacy of a mindful-eating programme to reduce emotional eating in patients suffering from overweight or obesity in primary care settings: a cluster-randomised trial protocol

Introduction Little is known about the applicability of mindfulness-based interventions in Spanish adults with overweight/obesity. The objective of the present study protocol is to describe the methods that will be used in a cluster randomised trial (CRT) that aims to evaluate the effectiveness of a mindfulness eating (ME) programme to reduce emotional eating (EE) in adults with overweight/obesity in primary care (PC) settings. Methods and analysis A CRT will be conducted with approximately 76 adults with overweight/obesity from four PC health centres (clusters) in the city of Zaragoza, Spain. Health centres matched to the average per capita income of the assigned population will be randomly allocated into two groups: ME +treatment as usual (TAU)'' and TAU alone''. The ME programme will be composed of seven sessions delivered by a clinical psychologist, and TAU will be offered by general practitioners. The primary outcome will be EE measured by the Dutch Eating Behaviour Questionnaire (DEBQ) at post test as primary endpoint. Other outcomes will be external and restrained eating (DEBQ), binge eating (Bulimic Investigatory Test Edinburgh), eating disorder (Eating Attitude Test), anxiety (General Anxiety Disorder-7), depression (Patient Health Questionnaire-9), mindful eating (Mindful Eating Scale), dispositional mindfulness (Five Facet Mindfulness Questionnaire) and self-compassion (Self-Compassion Scale). Anthropometric measures, vital signs and blood tests will be taken. A primary intention-to-treat analysis on EE will be conducted using linear mixed models. Supplementary analyses will include secondary outcomes and 1-year follow-up measures; adjusted models controlling for sex, weight status and levels of anxiety and depression; the complier average causal effect of treatment; and the clinical significance of improvements. Ethics and dissemination Positive results of this study may have a significant impact on one of the most important current health-related problems. Approval was obtained from the Ethics Committee of the Regional Authority. The results will be submitted to peer-reviewed journals, and reports will be sent to participants

Effectiveness of attachment-based compassion therapy to reduce psychological distress in university students: a randomised controlled trial protocol

IntroductionHigher education, particularly university, is a challenge for many students that can lead to their mental health being seriously affected. The stress to which they are subject throughout their time at university can lead to anxiety and depression. “Third wave” psychotherapies, including compassion-based therapy, have been used to improve psychological outcomes, such as stress, anxiety, emotional distress and well-being. There are some signs that third wave psychotherapies reduce psychological distress in university students, but more and higher-quality studies are needed. In this randomised controlled trial (RCT), we hypothesise that the provision of attachment-based compassion therapy (ABCT) will be more effective than an active control group based on relaxation therapy for improving psychological distress in university students.Methods and analysisA two-arm RCT will be conducted involving 140 university undergraduate and postgraduate students from the University of Zaragoza and the National University of Distance Education (UNED) who reside in the autonomous community of Aragon, Spain. Interventions with either ABCT or relaxation therapy will be implemented, with an allocation ratio of 1:1 between groups. Both interventions will last six weeks and consist of six weekly group sessions lasting 1.5 h each. Data will be collected before and after the intervention, and there will be a follow-up at six months. The primary outcome will be psychological distress at post-intervention. Secondary outcomes will be depression, anxiety, stress and burnout symptoms, affectivity and emotional regulation. Attachment style, experiential avoidance, compassion (for others/oneself) and mindfulness skills will be measured as potential mechanistic variables. Intention-to-treat analysis will be performed using linear mixed regression models. The clinical significance of improvements will be calculated. Potential side effects will be monitored by an independent clinical psychologist.Ethics and disseminationThis study was approved by the Clinical Research Ethics Committee of Aragón. Participant data will remain anonymous, and results will be submitted to peer-reviewed open-access journals and disseminated via conferences.Clinical Trial RegistrationClinicalTrials.gov, identifier NCT05197595

Attachment-based compassion therapy and adapted mindfulness-based stress reduction for the treatment of depressive, anxious and adjustment disorders in mental health settings: A randomised controlled clinical trial protocol

Introduction Depressive, anxiety and adjustment disorders are highly prevalent among mental health outpatients. The lack of funding for mental health problems produces inefficient results and a high burden of disease. New cost-effective group interventions aimed at treating these symptoms might be an appropriate solution to reduce the healthcare burden in mental health units. Mindfulness-based interventions (MBIs) have shown significant reductions in anxious, depressive and adjustment symptomatology. Recent research highlights the influence of compassion as a key mechanism of change. However, MBIs only address compassion implicitly, whereas compassion-based protocols consider it a core aspect of psychotherapy. In this randomised controlled trial, we hypothesise that the provision of attachment-based compassion therapy (ABCT), which is a compassion-based protocol, will be more effective than mindfulness-based stress reduction (MBSR), which is a conventional MBI programme, for the treatment of depressive, anxious and adaptive symptoms in patients in mental health settings. Methods and analysis Approximately 90 patients suffering from depressive, anxious or adjustment disorders recruited from Spanish mental health settings will be randomised to receive 8 weekly 2 hours group sessions of ABCT, 8 weekly 2.5 hours group sessions of adapted MBSR (with no full-day silent retreat) or treatment as usual (TAU), with a 1:1:1 allocation rate. Patients in the ABCT and adapted MBSR groups will also receive TAU. The main outcome will be general affective distress measured by means of the Depression Anxiety Stress Scales-21'' at post-test as primary endpoint. Other outcomes will be quality of life, mindfulness, self-compassion and the use of healthcare services. There will be a 6-month follow-up assessment. Intention-to-treat analysis will be conducted using linear mixed models. Per-protocol and secondary outcome analyses will be performed. A data monitoring committee comprising the trial manager, the ABCT and MBSR teachers and an independent clinical psychologist will monitor for possible negative side effects. Ethics and dissemination Approval was obtained from the Ethics Committee of the General University Hospital of Castellón, Spain. The results will be submitted to peer-reviewed specialised journals, and brief reports will be sent to participants on request

Effects of attachment-based compassion therapy (ABCT) on brain-derived neurotrophic factor and low-grade inflammation among fibromyalgia patients: A randomized controlled trial

Fibromyalgia (FM) is a disabling syndrome characterized by chronic pain associated with fatigue. Its pathogenesis is unknown, but alterations in central sensitization, involving an imbalance of brain-derived neurotrophic factor (BDNF) and inflammatory biomarkers, appear to be implicated. The aim of this study was to evaluate the impact of attachment-based compassion therapy (ABCT) on levels of BDNF, the inflammatory markers TNF-a, IL-6, IL-10, and the C-reactive protein (CRP), analysing whether biomarkers play a mediating/moderating role in improvements in FM functional status. Thirty-four female patients with FM participated in a RCT and were assigned to ABCT or relaxation therapy. Blood extractions were conducted at baseline and post-intervention, with self-report assessments of functional status (FIQ) at baseline, post-intervention and 3-month follow-up. A pro-inflammatory composite was obtained by summing up IL-6, TNF-a and CRP normalized values. Non-parametric tests, analysis of variance and regression models were used to evaluate treatment and mediation/moderation. Compared to relaxation therapy, ABCT showed significant improvements in FIQ and decreases in BDNF, CRP, and pro-inflammatory composite. Changes in BDNF had a mediating role in FIQ. ABCT seems to reduce BDNF and appears to have anti-inflammatory effects in FM patients. Reductions in BDNF could be a mechanism of FM functional status improvement