Role of Protein Tyrosine Phosphatase Receptor, Type Gamma (PTPRG) in the regulation of endothelial permeability.

The vascular endothelium is a selective barrier that regulates, through paracellular and/or transcellular routes, the transport of macro-molecules and cells across the vessels. Modifications of endothelial cell barrier permeability are involved in many physio-pathological events, such as acute inflammatory response and cancer. Several signalling molecules regulate endothelial permeability, regulating actin cytoskeleton dynamics and/or junctional complex disassembly. Although the role of protein kinases in the regulation of endothelial permeability during physio-pathological conditions is well established, the involvement of protein phosphatases in endothelial cells function still remains poorly defined. In a recent study, our laboratory showed that the Protein Tyrosine Phosphatase Receptor, type gamma (PTPRG), which belongs to the protein tyrosine phosphatases receptor-like family, has a negative role on the regulation of recruitment of human primary monocytes. Indeed, activation of PTPRG tyr-phosphatase activity by means of two Trojan fusion proteins, namely TAT-ICD, that encompasses the complete intracellular active enzymatic domain of PTPRG, and P1-WD (P1-wedge domain), which activates the endogenous PTPRG activity, inhibits signalling pathways controlling integrin activation by chemoattractants. In this study, by taking advantage of TAT-ICD and P1-WD, we investigated the role of PTPRG in the regulation of endothelial permeability. We provided evidence showing that PTPRG activation induces a time- and dose-dependent increase of permeability of endothelial cell monolayers. To corroborate these data, we evaluated the function of ZO-1, a tight junction-associated protein. The data indicated a dose-dependent reduction of ZO-1 expression upon PTPRG activation. Since ZO-1 protein expression critically regulates the stability of tight junctions, these data support the role of PTPRG in the regulation of endothelial permeability. We speculated that PTPRG activity may modulate, directly or indirectly, the phosphorylation state of signalling events controlling the expression and function of junctional proteins involved in the control of endothelial permeability

Culture medium geometry. The dominant factor affecting in vitro RF exposure dosimetry

Biological experiments that expose living cells or tissues to RF energy must have an aqueous medium to provide essential water, ions, nutrients, and growth factors. However, as we show here, the medium inherently functions as a receiving antenna that conveys RF energy to the biological entity in a manner entirely determined by exposure vessel geometry, orientation to the incident RF flux, frequency, and dielectric properties of the medium. We show for two common experimental arrangements that basic antenna theory can predict electromagnetic energy patterns that agree well with those otherwise obtained by computationally intensive methods that require specialized resources

Threatening levels of cumulative stress due to hydroclimatic extremes in the 21st century

Summary Wet and dry hydroclimatic extremes can pose severe stress to human societies under global warming. A new metric of cumulative stress due to hydroclimatic extremes is introduced, expressed in "equivalent reference stress years (ERSY)" i.e. the mean annual stress (e.g. potential for damage) in present climate conditions. 21st century climate projections show that, under the high-end RCP8.5 greenhouse gas scenario, by 2100, increases in wet and dry extremes add ~155 ERSY over global land areas (~125 for wet and ~30 for dry extremes), with wet hotspots over Asia, Eastern Africa and the Americas, and dry hotspots throughout Central and South America, Europe, West Africa and coastal Australia. Consideration of population exposure yields potential stress hotspots exceeding 400 added ERSY over Africa, North America, and Australia. The hydroclimatic stress is considerably reduced under the RCP2.6 scenario

The role of autophagy in epileptogenesis and in epilepsy-induced neuronal alterations

Abstract Recent evidence suggests that autophagy alterations are present in a variety of neurological disorders. These range from neurodegenerative diseases to acute neurological insults. Thus, despite a role of autophagy was investigated in a variety of neurological diseases, only recently these studies included epilepsy. This was fostered by the evidence that rapamycin, a powerful autophagy inducer, strongly modulates a variety of seizure models and epilepsies. These findings were originally interpreted as the results of the inhibition exerted by rapamycin on the molecular complex named ‘‘mammalian Target of Rapamycin’’ (mTOR). Recently, an increasing number of papers demonstrated that mTOR inhibition produces a strong activation of the autophagy machinery. In this way, it is now increasingly recognized that what was once defined as mTORpathy in epileptogenesis may be partially explained by abnormalities in the autophagy machinery. The present review features a brief introductory statement about the autophagy machinery and discusses the involvement of autophagy in seizures and epilepsies. An emphasis is posed on evidence addressing both pros and cons making it sometime puzzling and sometime evident, the role of autophagy in the epileptic brain

Highlights of New Strategies to Increase the Efficacy of Transition Metal Complexes for Cancer Treatments

Although important progress has been made, cancer still remains a complex disease to treat. Serious side effects, the insurgence of resistance and poor selectivity are some of the problems associated with the classical metal-based anti-cancer therapies currently in clinical use. New treatment approaches are still needed to increase cancer patient survival without cancer recurrence. Herein, we reviewed two promising-at least in our opinion-new strategies to increase the efficacy of transition metal-based complexes. First, we considered the possibility of assembling two biologically active fragments containing different metal centres into the same molecule, thus obtaining a heterobimetallic complex. A critical comparison with the monometallic counterparts was done. The reviewed literature has been divided into two groups: the case of platinum; the case of gold. Secondly, the conjugation of metal-based complexes to a targeting moiety was discussed. Particularly, we highlighted some interesting examples of compounds targeting cancer cell organelles according to a third-order targeting approach, and complexes targeting the whole cancer cell, according to a second-order targeting strategy

Direct Monitoring of the Calcium Concentration in the Sarcoplasmic and Endoplasmic Reticulum of Skeletal Muscle Myotubes

Direct monitoring of the free Ca2+ concentration in the sarcoplasmic reticulum (SR) was carried out in rat skeletal myotubes transfected with a specifically targeted aequorin chimera (srAEQ). Myotubes were also transfected with a chimeric aequorin (erAEQ) that we have demonstrated previously is retained in the endoplasmic reticulum (ER). Immunolocalization analysis showed that although both recombinant proteins are distributed in an endomembrane network identifiable with immature SR, the erAEQ protein was retained also in the perinuclear membrane. The difficulty of measuring [Ca2+] in 100-1000 microM range was overcome with the use of the synthetic coelenterazine analogue, coelenterazine n. We demonstrate that the steady state levels of [Ca2+] measured with srAEQ is around 300 microM, whereas that measured with erAEQ is significantly lower, i.e. around 200 microM. The effects of caffeine, high KCl, and nicotinic receptor stimulation, in the presence or absence of external calcium or after blockade of the Ca-ATPase, were investigated with both chimeras. The kinetics of [Ca2+] changes revealed by the erAEQ were similar, but not identical, neither quantitatively nor qualitatively, to those monitored with the srAEQ, indicating that at this stage of muscle development, differences exist between SR and ER in their mechanisms of Ca2+ handling. The functional implications of these findings are discussed

In/disciplinate: soggettività precarie nell’università italiana

“Negli ultimi anni studiose e studiosi hanno lavorato, e stanno lavorando, sul nesso tra precarietà e accademia, con diversi approcci e diverse focalizzazioni: mobilità, genere, carriera, mobilitazione politica, per nominarne solo alcuni. Ci sembra giunto il momento di mettere a confronto i diversi lavori di ricerca empirica, attraverso un ciclo di seminari che, pur mantenendo il filo rosso del comune oggetto di ricerca, si articoli in maniera itinerante, connettendo reti e persone in giro per l’Italia al fine di creare un dibattito ampio e condiviso e, soprattutto, plurale. Gli scopi sono tanti e diversi. Si tratta di sviluppare un lavoro di auto-riflessione critica all’interno dell’accademia, di condividere e rendere disponibili riflessioni teoriche ed empiriche su questo ambito di studi, di riconnettere reti di scambio e di confronto, di attivare dibattito e, non da ultimo, di saperne di più di quello che accade nel posto – nei posti – dove lavoriamo, in forme e modalità diverse”

Optimization and validation of a LC-HRMS method for aflatoxins determination in urine samples

Mycotoxins’ exposure by inhalation and/or dermal contact can occur in different branches of industry especially where heavily dusty settings are present and the handling of dusty commodities is performed. This study aims to explore the possible contribution of the occupational exposure to aflatoxins by analysing urine samples for the presence of aflatoxins B1 and M1 and aflatoxin B1-N7-guanine adduct. The study was conducted in 2017 on two groups of volunteers, the workers group, composed by personnel employed in an Italian feed plant (n = 32), and a control group (n = 29), composed by the administrative employees of the same feed plant; a total of 120 urine samples were collected and analysed. A screening method and a quantitative method with high-resolution mass spectrometry determination were developed and fully validated. Limits of detections were 0.8 and 1.5 pg/mLurine for aflatoxin B1 and M1, respectively. No quantitative determination was possible for the adduct aflatoxin B1-N7-guanine. Aflatoxin B1 and its adduct were not detected in the analysed samples, and aflatoxin M1, instead, was found in 14 samples (12%) within the range 1.9–10.5 pg/mLurine. Only one sample showed a value above the limit of quantification (10.5 pg/mLurine). The absence of a statistical difference between the mean values for workers and the control group which were compared suggests that in this specific setting, no professional exposure occurs. Furthermore, considering the very low level of aflatoxin M1 in the collected urine samples, the contribution from the diet to the overall exposure is to be considered negligible

Biomonitoring data for assessing aflatoxins and ochratoxin a exposure by italian feedstuffs workers

Mycotoxins exposure by inhalation and/or dermal contact is possible in different branches of industry especially where heavily dusty settings are present and the handling of dusty commodities is performed. This study aims to explore the validity of the biomonitoring as a tool to investigate the intake of mycotoxins in a population of workers operating in an Italian feed plant. Serum samples were collected for the determination of aflatoxins B1 (AFB1), AFB1-Lysine adduct and ochratoxin A (OTA). A method based on liquid-liquid extraction coupled with high resolution mass spectrometry determination was developed and fully validated. For AFB1, a high number of non-detected samples (90%) was found and no statistical difference was observed comparing workers and control group. None of the analyzed samples showed the presence of AFB1-Lysine adduct. For OTA, the 100% of the analyzed samples was positive with a 33% of the samples showing a concentration higher than the limit of quantification (LOQ), but no statistical difference was highlighted between the average levels of exposed and control groups. In conclusion, the presence of AFB1 and OTA in serum cannot be attributable to occupational exposure