Melatonin reshapes the mitochondrial network and promotes intercellular mitochondrial transfer via tunneling nanotubes after ischemic-like injury in hippocampal HT22 cells

Mitochondrial dysfunction is considered one of the hallmarks of ischemia/reperfusion injury. Mitochondria are plastic organelles that undergo continuous biogenesis, fusion, and fission. They can be transferred between cells through tunneling nanotubes (TNTs), dynamic structures that allow the exchange of proteins, soluble molecules, and organelles. Maintaining mitochondrial dynamics is crucial to cell function and survival. The present study aimed to assess the effects of melatonin on mitochondrial dynamics, TNT formation, and mitochondria transfer in HT22 cells exposed to oxygen/glucose deprivation followed by reoxygenation (OGD/R). The results showed that melatonin treatment during the reoxygenation phase reduced mitochondrial reactive oxygen species (ROS) production, improved cell viability, and increased the expression of PGC1α and SIRT3. Melatonin also preserved the expression of the membrane translocase proteins TOM20 and TIM23, and of the matrix protein HSP60, which are involved in mitochondrial biogenesis. Moreover, it promoted mitochondrial fusion and enhanced the expression of MFN2 and OPA1. Remarkably, melatonin also fostered mitochondrial transfer between injured HT22 cells through TNT connections. These results provide new insights into the effect of melatonin on mitochondrial network reshaping and cell survival. Fostering TNTs formation represents a novel mechanism mediating the protective effect of melatonin in ischemia/reperfusion injury

Automatic Detection of Myotonia using a Sensory Glove with Resistive Flex Sensors and Machine Learning Techniques

This paper deals with the automatic detection of Myotonia from a task based on the sudden opening of the hand. Data have been gathered from 44 subjects, divided into 17 controls and 27 myotonic patients, by measuring a 2-point articulation of each finger thanks to a calibrated sensory glove equipped with a Resistive Flex Sensor (RFS). RFS gloves are proven to be reliable in the analysis of motion for myotonic patients, which is a relevant task for the monitoring of the disease and subsequent treatment. With the focus on a healthy VS pathological comparison, customized features were extracted, and several classifications entailing motion data from single fingers, single articulations and aggregations were prepared. The pipeline employed a Correlation-based feature selector followed by a SVM classifier. Results prove that it’s possible to detect Myotonia, with aggregated data from four fingers and upper/lower articulations providing the most promising accuracies (91.1%

Role of melatonin in HT22 cells challenged with serum deprivation

In vitro serum deprivation (SD) is one model for investigating the molecular mechanisms underlying apoptosis as well as autophagy, which generally function as defense strategies upon cell injury by eliminating damaged organelles [1]. Furthermore, SD injury in vitro is widely used to mimic the ischemic environment [2]. In serum deprived conditions, cells show different parameters of apoptosis and autophagy. Melatonin (MLT), a lipophilic indole secreted by pineal and non-pineal cells, is a well-known potent free radical scavenger acting as neuroprotective molecule that prevents apoptotic cell death in several models of neurodegenerative diseases. In the present study we investigated the neuroprotective effects of MLT during SD condition on mouse hippocampal HT22 cells, considering that intracellular ROS are usually linked to autophagy and apoptosis. To explore potential effects of combining SD with melatonin we studied clonogenic survival of HT22 cells. Clonogenic assay demonstrated a significative (p< 0.01) reduction of HT22 total cell numbers challenged for 24h with SD, whereas the pre-treatment with 200nM of MLT for 24hr noticeably reduced this effect of about 30%. In HT22 starved cells the percentage of MitoTracker Red (MTR) positive cells doubled (P< 0.05) if compared to the control condition, suggesting that SD induced a remodelling of mitochondrial network. It is noteworthy that MLT pre-treatment produced a MTR positivity similar to that of controls. We next investigated whether melatonin was able to influence the autophagic pathway. Autophagy was detected by measuring the aggregation of LC3B protein coupled to green fluorescence protein (GFP). Confocal images show that SD induced an increase in the GFP-LC3 puncta, whereas the melatonin treatment reduces these aggregations. Taken together, our results suggest that MLT treatment may play protective roles against cellular modifications induced by SD treatment in HT22 cells

Rapamycin Re-Directs Lysosome Network, Stimulates ER-Remodeling, Involving Membrane CD317 and Affecting Exocytosis, in Campylobacter Jejuni-Lysate-Infected U937 Cells.

The Gram-negative Campylobacter jejuni is a major cause of foodborne gastroenteritis in humans worldwide. The cytotoxic effects of Campylobacter have been mainly ascribed to the actions of the cytolethal distending toxin (CDT): it is mandatory to put in evidence risk factors for sequela development, such as reactive arthritis (ReA) and Guillain-Barré syndrome (GBS). Several researches are directed to managing symptom severity and the possible onset of sequelae. We found for the first time that rapamycin (RM) is able to largely inhibit the action of C. jejuni lysate CDT in U937 cells, and to partially avoid the activation of specific sub-lethal effects. In fact, we observed that the ability of this drug to redirect lysosomal compartment, stimulate ER-remodeling (highlighted by ER-lysosome and ER-mitochondria contacts), protect mitochondria network, and downregulate CD317/tetherin, is an important component of membrane microdomains. In particular, lysosomes are involved in the process of the reduction of intoxication, until the final step of lysosome exocytosis. Our results indicate that rapamycin confers protection against C. jejuni bacterial lysate insults to myeloid cells

Fas Signalling Promotes Intercellular Communication in T Cells

Cell-to-cell communication is a fundamental process for development and maintenance of multicellular organisms. Diverse mechanisms for the exchange of molecular information between cells have been documented, such as the exchange of membrane fragments (trogocytosis), formation of tunneling nanotubes (TNTs) and release of microvesicles (MVs). In this study we assign to Fas signalling a pivotal role for intercellular communication in CD4+ T cells. Binding of membrane-bound FasL to Fas expressing target cells triggers a well-characterized pro-apoptotic signalling cascade. However, our results, pairing up flow cytometric studies with confocal microscopy data, highlight a new social dimension for Fas/FasL interactions between CD4+ T cells. Indeed, FasL enhances the formation of cell conjugates (8 fold of increase) in an early time-frame of stimulation (30 min), and this phenomenon appears to be a crucial step to prime intercellular communication. Our findings show that this communication mainly proceeds along a cytosolic material exchange (ratio of exchange >10, calculated as ratio of stimulated cells signal divided by that recorded in control cells) via TNTs and MVs release. In particular, inhibition of TNTs genesis by pharmacological agents (Latruculin A and Nocodazole) markedly reduced this exchange (inhibition percentage: >40% and >50% respectively), suggesting a key role for TNTs in CD4+ T cells communication. Although MVs are present in supernatants from PHA-activated T cells, Fas treatment also leads to a significant increase in the amount of released MVs. In fact, the co-culture performed between MVs and untreated cells highlights a higher presence of MVs in the medium (1.4 fold of increase) and a significant MVs uptake (6 fold of increase) by untreated T lymphocytes. We conclude that Fas signalling induces intercellular communication in CD4+ T cells by different mechanisms that seem to start concomitantly with the main pathway (programmed cell death) promoted by FasL

Genome-wide analysis identifies genetic effects on reproductive success and ongoing natural selection at the FADS locus

: Identifying genetic determinants of reproductive success may highlight mechanisms underlying fertility and identify alleles under present-day selection. Using data in 785,604 individuals of European ancestry, we identified 43 genomic loci associated with either number of children ever born (NEB) or childlessness. These loci span diverse aspects of reproductive biology, including puberty timing, age at first birth, sex hormone regulation, endometriosis and age at menopause. Missense variants in ARHGAP27 were associated with higher NEB but shorter reproductive lifespan, suggesting a trade-off at this locus between reproductive ageing and intensity. Other genes implicated by coding variants include PIK3IP1, ZFP82 and LRP4, and our results suggest a new role for the melanocortin 1 receptor (MC1R) in reproductive biology. As NEB is one component of evolutionary fitness, our identified associations indicate loci under present-day natural selection. Integration with data from historical selection scans highlighted an allele in the FADS1/2 gene locus that has been under selection for thousands of years and remains so today. Collectively, our findings demonstrate that a broad range of biological mechanisms contribute to reproductive success

Genome-wide analysis identifies 12 loci influencing human reproductive behavior.

The genetic architecture of human reproductive behavior-age at first birth (AFB) and number of children ever born (NEB)-has a strong relationship with fitness, human development, infertility and risk of neuropsychiatric disorders. However, very few genetic loci have been identified, and the underlying mechanisms of AFB and NEB are poorly understood. We report a large genome-wide association study of both sexes including 251,151 individuals for AFB and 343,072 individuals for NEB. We identified 12 independent loci that are significantly associated with AFB and/or NEB in a SNP-based genome-wide association study and 4 additional loci associated in a gene-based effort. These loci harbor genes that are likely to have a role, either directly or by affecting non-local gene expression, in human reproduction and infertility, thereby increasing understanding of these complex traits

IL RUOLO DELLE MAP KINASI NELLA RISPOSTA DI Trichoplax adhaerens A STRESS TERMICO

Trichoplax adhaerens è l’unica specie sino a oggi descritta del phylum Placozoa. Si tratta di organismi marini bentonici, piccoli (< 1 mm), piatti e asimmetrici, lentamente mobili tramite movimento ciliare su fondali duri poco profondi. Trichoplax è caratterizzato dall’organizzazione più semplice, forse la più primitiva, tra i metazoi: il corpo piatto consta di due pseudoepiteli privi di lamina basale, tra cui è compreso un reticolo cellulare sinciziale. La specie si riproduce per scissione binaria: la riproduzione sessuale non è ancora stata accertata, ma in coltura è frequente la formazione di oociti putativi in animali apparentemente in fase di degenerazione. Nonostante la semplicità strutturale, Trichoplax possiede un genoma complesso che comprende geni di tutte le principali famiglie di geni dei metazoi. Considerato che tutti i componenti essenziali delle vie di segnalazione BMP/TGF e JAK/STAT risultano incomplete per la mancanza di componenti molecolari fondamentali per la trasduzione del segnale, ci si è proposti di studiare il possibile ruolo delle vie di segnalazione MAPK e STAT nel mediare la risposta a stress termico. Colture massive (150-250 individui) mantenute a 22 °C sono state sottoposte a stress termico mediante: esposizione a 30 °C, a 14 °C o a 8 °C fino ai primi segni di sofferenza degli animali (4,30 h, 24 h, 4,30 h rispettivamente), quindi lisate con tampone di lisi PBS (11:9). Sono state effettuate analisi di Western Blotting con anticorpi anti p-MAPKs e p-STATs. I risultati preliminari mostrano che Trichoplax in risposta a stress termico attiva una via di segnalazione simile a quelle MAPK e STAT che giocano nei metazoi un ruolo fondamentale per la sopravvivenza. Vie di segnalazione MAPKs e STATs quindi potrebbero essere state già attive e funzionali negli stadi iniziali dell’evoluzione dei metazoi

A T T I DELLA SOCIETÀ DEI NATURALISTI E MATEMATICI DI MODENA

Trichoplax adhaerens è l’unica specie sino a oggi descritta del phylum Placozoa. Si tratta di organismi marini bentonici, piccoli (< 1 mm), piatti e asimmetrici, lentamente mobili tramite movimento ciliare su fondali duri poco profondi. Trichoplax è caratterizzato dall’organizzazione più semplice, forse la più primitiva, tra i metazoi: il corpo piatto consta di due pseudoepiteli privi di lamina basale, tra cui è compreso un reticolo cellulare sinciziale. La specie si riproduce per scissione binaria: la riproduzione sessuale non è ancora stata accertata, ma in coltura è frequente la formazione di oociti putativi in animali apparentemente in fase di degenerazione. Nonostante la semplicità strutturale, Trichoplax possiede un genoma complesso che comprende geni di tutte le principali famiglie di geni dei metazoi. Considerato che tutti i componenti essenziali delle vie di segnalazione BMP/TGF e JAK/STAT risultano incomplete per la mancanza di componenti molecolari fondamentali per la trasduzione del segnale, ci si è proposti di studiare il possibile ruolo delle vie di segnalazione MAPK e STAT nel mediare la risposta a stress termico. Colture massive (150-250 individui) mantenute a 22 °C sono state sottoposte a stress termico mediante: esposizione a 30 °C, a 14 °C o a 8 °C fino ai primi segni di sofferenza degli animali (4,30 h, 24 h, 4,30 h rispettivamente), quindi lisate con tampone di lisi PBS (11:9). Sono state effettuate analisi di Western Blotting con anticorpi anti p-MAPKs e p-STATs. I risultati preliminari mostrano che Trichoplax in risposta a stress termico attiva una via di segnalazione simile a quelle MAPK e STAT che giocano nei metazoi un ruolo fondamentale per la sopravvivenza. Vie di segnalazione MAPKs e STATs quindi potrebbero essere state già attive e funzionali negli stadi iniziali dell’evoluzione dei metazo