Highly specific and non-invasive imaging of Piezo1-dependent activity across scales using GenEPi

Mechanosensing is a ubiquitous process to translate external mechanical stimuli into biological responses. Piezo1 ion channels are directly gated by mechanical forces and play an essential role in cellular mechanotransduction. However, readouts of Piezo1 activity are mainly examined by invasive or indirect techniques, such as electrophysiological analyses and cytosolic calcium imaging. Here, we introduce GenEPi, a genetically-encoded fluorescent reporter for non-invasive optical monitoring of Piezo1-dependent activity. We demonstrate that GenEPi has high spatiotemporal resolution for Piezo1-dependent stimuli from the single-cell level to that of the entire organism. GenEPi reveals transient, local mechanical stimuli in the plasma membrane of single cells, resolves repetitive contraction-triggered stimulation of beating cardiomyocytes within microtissues, and allows for robust and reliable monitoring of Piezo1-dependent activity in vivo. GenEPi will enable non-invasive optical monitoring of Piezo1 activity in mechanochemical feedback loops during development, homeostatic regulation, and disease

Standardization of the NEO-PI-3 in the Greek general population

BACKGROUND: The revised NEO Personality Inventory (NEO-PI-3) includes 240 items corresponding to the Big Five personality traits (Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness to Experience) and subordinate dimensions (facets). It is suitable for use with adolescents and adults (12 years or older). The aim of the current study was to validate the Greek translation of the NEO-PI-3 in the general Greek population. MATERIAL AND METHODS: The study sample included 734 subjects from the general Greek population of whom 59.4% were females and 40.6% males aged 40.80 +/- 11.48. The NEO-PI-3 was translated into Greek and back-translated into English, and the accuracy of the translation was confirmed and established. The statistical analysis included descriptive statistics, confirmatory factorial analysis (CFA), the calculation of Cronbach's alpha, and the calculation of Pearson product-moment correlations. Sociodemographics groups were compared by ANOVA. RESULTS: Most facets had Cronbach's alpha above 0.60. Confirmatory factor analysis showed acceptable loading of the facets on their own hypothesized factors and very good estimations of Cronbach's alphas for the hypothesized factors, so it was partially supportive of the five-factor structure of the NEO-PI-3.The factors extracted with Procrustes rotation analysis can be considered reasonably homologous to the factors of the American normative sample. Correlations between dimensions were as expected and similar to those reported in the literature. DISCUSSION: The literature suggests that overall, the psychometric properties of NEO-PI-3 scales have been found to generalize across ages, cultures, and methods of measurement. In accord with this, the results of the current study confirm the reliability of the Greek translation and adaptation of the NEO-PI-3. The inventory has comparable psychometric properties in its Greek version in comparison to the original and other national translations, and it is suitable for clinical as well as research use

Development of the Risk Assessment Suicidality Scale (RASS): A population-based study

Background: Suicide and suicide attempts are significant and costly public health problems. In order to prevent suicidal and other self-injurious behaviors, research on the multiple factors involved in these behaviors with comprehensive and user-friendly instruments is necessary. The aim of the current study was to construct a self-report instrument with emphasis on items describing suicide-related behavior itself rather than strongly related clinical features on the basis of a general population study. Methods: Twelve items comprising a new scale were applied to 734 subjects from the general population (40.6% males and 59.4% females) aged 40.8 ± 11.5 along with the STAI and the CES-D. Results: The scoring method was developed on the basis of frequency table of responses to the individual scale items. The factor analysis returned 3 factors explaining 59.19% of total variance (Intention, Life, and History). The Cronbach's alpha was 0.85 for the Intention, 0.69 for the Life and 0.52 for the History subscale. Limitation: The findings need replication in clinical and epidemiologic studies. Conclusion: The RASS is a reliable and valid instrument which might prove valuable in the assessment of suicidal risk in the general population as well as in mental patients. © 2012 Elsevier B.V. All rights reserved

Extracellular mechanical forces drive endocardial cell volume decrease during zebrafish cardiac valve morphogenesis.

Organ morphogenesis involves dynamic changes of tissue properties while cells adapt to their mechanical environment through mechanosensitive pathways. How mechanical cues influence cell behaviors during morphogenesis remains unclear. Here, we studied the formation of the zebrafish atrioventricular canal (AVC) where cardiac valves develop. We show that the AVC forms within a zone of tissue convergence associated with the increased activation of the actomyosin meshwork and cell-orientation changes. We demonstrate that tissue convergence occurs with a reduction of cell volume triggered by mechanical forces and the mechanosensitive channel TRPP2/TRPV4. Finally, we show that the extracellular matrix component hyaluronic acid controls cell volume changes. Together, our data suggest that multiple force-sensitive signaling pathways converge to modulate cell volume. We conclude that cell volume reduction is a key cellular feature activated by mechanotransduction during cardiovascular morphogenesis. This work further identifies how mechanical forces and extracellular matrix influence tissue remodeling in developing organs

Standardization of the TEMPS-A in the Greek general population

BACKGROUND: The current study evaluates the reliability and factor-structure replicability of the Temperament Evaluation of Memphis, Pisa, Paris and San Diego Autoquestionnaire (TEMPS-A) in its Greek Version. METHODS: The TEMPS-A was administered to a convenient sample of 734 subjects from the general Greek population (436 females; 59.4% and 298 males; 40.6%). Their mean age was 40.80+/-11.48 years (range 25-67 years). The analysis included the calculation of Chronbach's alpha, the calculation of the threshold to define dominant temperaments (+2 standard deviations or 95th percentile), confirmatory factor analysis and the calculation of Pearson correlation coefficients between the temperament scales scores. Analysis of Covariance with age as covariate and post-hoc t-test was used to search for differences in temperament scores between males and females. Also a table of percentile values corresponding to a raw score was created. RESULTS: Internal consistency was excellent for the various temperaments (0.72-0.88). The factor analysis confirmed the five factor solution as the best factor solution. All TEMPS items were included in the final version of the scale in the Greek language. LIMITATIONS: The study sample included subjects from the general population, but it is a convenient and not representative sample. Although the authors tried to select them on the basis of being mentally healthy and without a psychiatric history, there is always a degree of uncertainty. There is also always the possibility some of them to manifest a mental disorder in the future, thus being currently in a premorbid state. CONCLUSION: The Greek version of the TEMPS-A, has good internal consistency and factor structure similar to what was found in other translations. Overall our results are in accord with the literature and in line with theoretical considerations as well as with empirical evidence

Highly specific and non-invasive imaging of Piezo1-dependent activity across scales using GenEPi

Mechanosensing is a ubiquitous process to translate external mechanical stimuli into biological responses. Piezo1 ion channels are directly gated by mechanical forces and play an essential role in cellular mechanotransduction. However, readouts of Piezo1 activity are mainly examined by invasive or indirect techniques, such as electrophysiological analyses and cytosolic calcium imaging. Here, we introduce GenEPi, a genetically-encoded fluorescent reporter for non-invasive optical monitoring of Piezo1-dependent activity. We demonstrate that GenEPi has high spatiotemporal resolution for Piezo1-dependent stimuli from the single-cell level to that of the entire organism. GenEPi reveals transient, local mechanical stimuli in the plasma membrane of single cells, resolves repetitive contraction-triggered stimulation of beating cardiomyocytes within microtissues, and allows for robust and reliable monitoring of Piezo1-dependent activity in vivo. GenEPi will enable non-invasive optical monitoring of Piezo1 activity in mechanochemical feedback loops during development, homeostatic regulation, and disease

Author Correction: Highly specific and non-invasive imaging of Piezo1-dependent activity across scales using GenEPi

Correction to: Nature Communications, published online 19 July 2023 In the original version of this article, the given and family names of Armando Del Rio Hernandez were incorrectly structured. The name was displayed correctly in all versions at the time of publication. In this article the affiliation details for Nordine Helassa were incorrectly given as ‘7. Centre for Cardiovascular Science, Department of Cardiovascular Science and Metabolic Medicine, Institute of Life Course and Medical Sciences, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, UK.’ but should have been ‘7. Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK.’. The original article has been corrected