Cues to opening mechanisms from in silico electric field excitation of cx26 hemichannel and in vitro mutagenesis studies in HeLa transfectans

Connexin channels play numerous essential roles in virtually every organ by mediating solute exchange between adjacent cells, or between cytoplasm and extracellular milieu. Our understanding of the structure-function relationship of connexin channels relies on X-ray crystallographic data for human connexin 26 (hCx26) intercellular gap junction channels. Comparison of experimental data and molecular dynamics simulations suggests that the published structures represent neither fully-open nor closed configurations. To facilitate the search for alternative stable configurations, we developed a coarse grained (CG) molecular model of the hCx26 hemichannel and studied its responses to external electric fields. When challenged by a field of 0.06 V/nm, the hemichannel relaxed toward a novel configuration characterized by a widened pore and an increased bending of the second transmembrane helix (TM2) at the level of the conserved Pro87. A point mutation that inhibited such transition in our simulations impeded hemichannel opening in electrophysiology and dye uptake experiments conducted on HeLa tranfectants. These results suggest that the hCx26 hemichannel uses a global degree of freedom to transit between different configuration states, which may be shared among the whole connexin family

The cold chain and the COVID-19 pandemic: an unusual increase in histamine content in fish samples collected in Southern Italy during lockdown

Objectives We analysed 900 samples of fresh (250) and processed (650) fish products collected in Sicily (Southern Italy) in 2020 during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic (hereafter: COVID-19). Materials and methods The samples were divided temporally based on five phases relating to the various restrictions imposed by the Italian government in this period. The validated method of ultra-high performance liquid chromatography (UHPLC) combined with a diode array detector (DAD) was then employed for the analysis. Results The samples collected during the Phase I lockdown period and after it had ended (Phase II) revealed significant increases in the mean histamine levels: 41.89±87.58 mg/kg -1 and 24.91±76.76 mg/kg -1, respectively. The 11 (1.3% of the total) fresh fish samples that were identified as being non-compliant with EC Reg. 2073/2005 were only found during these two periods. All the processed samples were always compliant. The histamine values decreased as the restrictions eased, achieving a mean value of 11.16±9.3 mgkg -1 (Phase III). Conclusions There was an increase in the incidence of fish samples that were non-compliant with EC Reg. 2073/2005 compared to previous surveillance data. These results provide a first report on the effect of lockdown measures on food safety and the cold chain. Our findings must cause food safety operators to intensify their controls over fresh fish products in such periods to safeguard consumer health. Further studies are required to evaluate whether the same trend would be observed with other food contaminants

Polyphenols of white lupin (Lupinus albus L.) seeds cultivated in Southern Italy by a LC-HRMS method

: In this work we examined the contents of 14 polyphenols in white lupin (Lupinus albus L.) samples cultivated in Southern Italy by the optimisation and validation of a LC-HRMS method. The validation of the LC-HRMS method showed linearity results r2 > 0.989 and recovery values between 71 and 119% for a very wide range of concentrations. Ellagic acid was the most abundant polyphenol, with mean concentrations of 16271.86 ± 19798.53 μg/Kg, followed by apigenin (2749.51 ± 889.95 μg/Kg). A significant variability in ellagic acid contents was found between the areas of cultivation examined (p < 0.05). As far as we know, this work provides the first data on the polyphenols contents of white lupins cultivated in Italy. The comparison with other study confirms the role of the cultivation area for the determination of the polyphenol's contents. The study also confirms white lupins as a promising source of antioxidant and anti-inflammatory substances in a balanced diet

Toxic metals in Loggerhead sea turtles (Caretta caretta) stranded freshly dead along Sicilian coasts

Abstract Background: The Loggerhead sea turtle (Caretta caretta) is a marine reptile belonging to a monophyletic group of chelonians. As these animals are long-lived, they have the ability to accumulate pollutants. Aim: To collect epidemiological data on toxic metals in marine Loggerhead sea turtles. Materials and Methods: Forty Loggerhead sea turtles comprising 25 males and 15 females stranded freshly dead between 2013 and 2018 along the coasts of Sicily, Southern Italy, were examined for arsenic, cadmium, and lead accumulation in muscle and adipose tissues by means of a validated ICP-MS method. A modified K index as a growth condition factor, namely Fulton's K index, was used. Samples were tested in duplicate. A Wilcoxon rank sum test was carried out to evaluate metal contents differences between muscle and adipose tissues and between genders. Results: The Fulton's K index suggested a good body condition of the C. caretta recovered with mean values of 5.34±3.40 (n=40; ±SD). Detectable concentrations of lead were found in 70% of the samples analysed with mean values of 0.65±1.67 mg/kg wet weight and 0.51±1.29 mg/kg wet weight in muscle and adipose tissues, respectively. No significant differences in arsenic, cadmium, and lead were detected between genders. In addition, no significant correlation was found between modified K index and concentrations of arsenic, cadmium, and lead. Clinical relevance: Findings on muscle and adipose tissues suggest chronic exposure of Caretta caretta to high concentrations of especially lead which might negatively affect health and welfare of these marine turtles although body condition was good

Determination of Mycotoxins in Plant-Based Meat Alternatives (PBMAs) and Ingredients after Microwave Cooking

In this study, we investigate the role of microwave cooking in reducing mycotoxin contamination in plant-based food matrices, with a focus on veggie burgers (purchased and home-made) and their ingredients (soybean, potatoes, zucchini, carrots). Two different conditions were studied (Max–Min) that were 800 W for 60 s and 800 W for 90 s, respectively. The degradation patterns of aflatoxins (AFB1, AFB2, AFG1, AFG2), fumonisins (FB1, FB2, FB3), trichothecenes (T2, HT2, ZEA), and ochratoxin A (OTA) were studied. The extraction procedures were conducted with the QuEChERS extraction, and the analyses were conducted with liquid chromatography–tandem mass spectrometry (LC-MS/MS). Principal component analysis (PCA) showed that degradation under microwave cooking varies considerably across different food matrices and cooking conditions. This study provides valuable insights into the degradation of mycotoxins during microwave cooking and underscores the need for more research in this area to ensure food safety

Oleuropein aglycone induces autophagy via the AMPK/mTOR signalling pathway: A mechanistic insight

The healthy effects of plant polyphenols, some of which characterize the so-called Mediterranean diet, have been shown to arise from epigenetic and biological modifications resulting, among others, in autophagy stimulation. Our previous work highlighted the beneficial effects of oleuropein aglycone (OLE), the main polyphenol found in the extra virgin olive oil, against neurodegeneration both in cultured cells and in model organisms, focusing, in particular, autophagy activation. In this study we investigated more in depth the molecular and cellular mechanisms of autophagy induction by OLE using cultured neuroblastoma cells and an OLE-fed mouse model of amylod beta (Aβ) deposition. We found that OLE triggers autophagy in cultured cells through the Ca(2+)-CAMKKβ–AMPK axis. In particular, in these cells OLE induces a rapid release of Ca(2+) from the SR stores which, in turn, activates CAMKKβ, with subsequent phosphorylation and activation of AMPK. The link between AMPK activation and mTOR inhibition was shown in the OLE-fed animal model in which we found that decreased phospho-mTOR immunoreactivity and phosphorylated mTOR substrate p70 S6K levels match enhanced phospho-AMPK levels, supporting the idea that autophagy activation by OLE proceeds through mTOR inhibition. Our results agree with those reported for other plant polyphenols, suggesting a shared molecular mechanism underlying the healthy effects of these substances against ageing, neurodegeneration, cancer, diabetes and other diseases implying autophagy dysfunction

Digital interaction: where are we going?

In the framework of the AVI 2018 Conference, the interuniversity center ECONA has organized a thematic workshop on "Digital Interaction: where are we going?". Six contributions from the ECONA members investigate different perspectives around this thematic

Fatty Acids Composition of Stomach Oil of Scopoli’s Shearwater (Calonectris diomedea) from Linosa’s Colony

Calonectris diomedea is a Procellariforms seabird having a very representative colony in Linosa Island (Southern Italy). The adult forms of C. diomedea produce a pasty oil from their proven- triculus to feed their chicks during the rearing period. In this work, we examined the fatty acids composition of the stomach oil of C. diomedea from Linosa Island by gas chromatography with flame ionization detection (GC-FID). The samples were collected at 20 and 70 days after hatching. Twenty different fatty acids (FAs) were identified. Saturated fatty acids (SFA) were the most abundant in percentage (41.6%) at day 20 followed by polyunsaturated fatty acids (PUFA, 38.7%) and monounsat- urated fatty acids (MUFA, 19.7%). MUFAs were the most abundant in samples collected at day 70 (53.8%), followed by SFAs (36.6%) and PUFAs (9.8%). Oleic acid (C18:1ω9) in the samples on day 70 was 4 times higher than that in the samples on day 20. The Principal Component Analysis (PCA) verified a clear separation of the stomach oil samples in two groups, according to the day of sampling. The results obtained confirm the role of FAs analysis of stomach oil to understand the ecology and breeding behaviour of C. diomedea, highlighting a resemblance with signatures recorded in marine organisms of Linosa Island