DNA oxidative damage is one of the main concerns being implicated in severe cell alterations, promoting different types of human disorders and diseases. For their characteristics, male gametes are the most sensitive cells to the accumulation of damaged DNA. We have recently reported the relevance of arginine residues in the Cu(II)-induced DNA breakage of sperm H1 histones. In this work, we have extended our previous findings investigating the involvement of human sperm nuclear basic proteins on DNA oxidative damage in healthy males presenting copper and chromium excess in their semen. We found in 84% of those males an altered protamines/histones ratio and a different DNA binding mode even for those presenting a canonical protamines/histones ratio. Furthermore, all the sperm nuclear basic proteins from these samples that resulted were involved in DNA oxidative damage, supporting the idea that these proteins could promote the Fenton reaction in DNA proximity by increasing the availability of these metals near the binding surface of DNA. In conclusion, our study reveals a new and unexpected behavior of human sperm nuclear basic proteins in oxidative DNA damage, providing new insights for understanding the mechanisms related to processes in which oxidative DNA damage is implicated.

SARS-CoV-2 has become one of the most studied viruses of the last century. It was assumed that the only possible host for these types of viruses was mammalian eukaryotic cells. Our recent studies show that microorganisms in the human gastrointestinal tract affect the severity of COVID-19 and for the first time provide indications that the virus might replicate in gut bacteria. In order to further support these findings, in the present work, cultures of bacteria from the human microbiome and SARS-CoV-2 were analyzed by electron and fluorescence microscopy. The images presented in this article, in association with the nitrogen (15N) isotope-labeled culture medium experiment, suggest that SARS-CoV-2 could also infect bacteria in the gut microbiota, indicating that SARS-CoV-2 could act as a bacteriophage. Our results add new knowledge to the understanding of the mechanisms of SARS-CoV-2 infection and fill gaps in the study of the interactions between SARS-CoV-2 and non-mammalian cells. These findings could be useful in suggesting specific new pharmacological solutions to support the vaccination campaign.

Reverse transcriptase polymerase chain reaction (RT-PCR) negative results in the upper respiratory tract represent a major concern for the clinical management of coronavirus disease 2019 (COVID-19) patients. Herein, we report the case of a 43-years-old man with a strong clinical suspicion of COVID-19, who resulted in being negative to multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RT-PCR tests performed on different oropharyngeal and nasopharyngeal swabs, despite serology having confirmed the presence of SARS-CoV-2 IgM. The patient underwent a chest computed tomography (CT) that showed typical imaging findings of COVID-19 pneumonia. The presence of viral SARS-CoV-2 was confirmed only by performing a SARS-CoV-2 RT-PCR test on stool. Performing of SARS-CoV-2 RT-PCR test on fecal samples can be a rapid and useful approach to confirm COVID-19 diagnosis in cases where there is an apparent discrepancy between COVID-19 clinical symptoms coupled with chest CT and SARS-CoV-2 RT-PCR tests’ results on samples from the upper respiratory tract.

Many diatom species produce polyunsaturated aldehydes, such as decadienal, which compromise embryonic and larval development in benthic organisms. Here newly fertilized Paracentrotus lividus sea urchins were exposed to low concentration of decadienal and the expression levels of sixteen genes, implicated in a broad range of functional responses, were followed by Real Time qPCR in order to identify potential decadienal targets. We show that at low decadienal concentrations the sea urchin Paracentrotus lividus places in motion different classes of genes to defend itself against this toxic aldehyde, activating hsp60 and two proteases, hat and BP10, at the blastula stage and hsp56 and several other genes (14-3-3ε, p38 MAPK, MTase, and GS) at the prism stage. At this latter stage all genes involved in skeletogenesis (Nec, uni, SM50 and SM30) were also down-expressed, following developmental abnormalities that mainly affected skeleton morphogenesis. Moreover, sea urchin embryos treated with increasing concentrations of decadienal revealed a dose-dependent response of activated target genes. Finally, we suggest that this orchestrated defense system against decadienal represents part of the chemical defensome of P. lividus affording protection from environmental toxicants.

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This study aims to assess the effects induced by 24 hr exposure to a subtoxic copper concentration on the reproductive system (gonads, spermatozoa, and protamine-like[PL] proteins) of Mytilus galloprovincialis. Inductively coupled plasma-mass spectrometry indicated accumulation of this metal in gonads, spermatozoa, and PL proteins of exposed mussels. Further, real-time polymerase chain reaction analyses showed altered expression levels of mt10 and PL proteins genes in spermatozoa and gonads, respectively, of exposed mussels. Protamine-like proteins, which represent the main basic component of sperm chromatin of this organism, showed a higher DNA binding affinity and a different DNA binding mode in exposed mussels. Moreover, an increased amount of NaCl was required for the release from sperm nuclei of PL-III, the main PL protein component. Finally, PL proteins extracted from exposed mussels promoted DNA oxidative damage in the presence of H 2 O 2. These results demonstrate that the tolerable copper amount could also affect the properties of PL proteins and determine the negative effects on the reproductive system of this organism. These analyses could be useful to develop quick and efficient chromatin-based genotoxicity tests for pollution biomonitoring programs.

Here we report the industrial pollution effects due to cadmium on the reproductive health of Mytilus galloprovincialis. Mussels were removed from the biofouling of a Conatex panel after one year exposition at a polluted site near a disposal metallurgical factory. A high cadmium bioaccumulation was observed in the testis of mussels housed at the polluted site, with respect to a control site, as determined by inductively coupled plasma-mass spectrometry, along with a 10 fold increase in metallothionein 20 kDa gene (mt20) expression levels determined by qPCR. Furthermore, mussels transferred into laboratory tanks from the reference site, and exposed to 1.5, 5 and 10 µM CdCl, revealed a 1.7, 3.2 and 4.5 fold expression increase in the testis mt20, respectively, and a positive correlation with cadmium bioaccumulation was found. To evaluate a potential detrimental risk of such alterations on spermatozoa, we carried out electrophoretic analyses on their protamine-like proteins. As determined by AU-PAGE, after 1.5 µM CdCl exposure, protamine-like proteins also display major alterations with respect to those obtained after 5 and 10 µM CdCl exposure. All protamine-like proteins isolated from the polluted biofouling were in an aggregated form and displayed the same reduced DNA binding affinity of the protamine-like proteins obtained after 1.5 µM CdCl as demonstrated EMSA with sperm genomic DNA. Our results contribute to the studies concerning cadmium induced testis alterations and highlight protamine-like proteins' analysis as an emerging biotechnique for cadmium impact assessment on Mytilus galloprovincialis, for the sensitivity of the in vivo and in vitro changes of protamine-like proteins' state and their DNA binding affinity.

In this work, we describe results of the reproductive health monitoring studies in Mytilus galloprovincialis following spermatozoa hsp70 expression and protamine-like protein properties. Mussels control (ctr) were released within cages for 30 days in three different marine sites near Naples (Campania, Italy): Bagnoli south (BAs) and Bagnoli north (BAn), both close to a disposal metallurgical factory and in Capo Miseno (CM). Studies of hsp70 gene expression carried out, by RT-qPCR, in mussel spermatozoa have shown varied expression levels, particularly 5, 13, and 15-fold more than ctr in CM, BAs, and BAn, respectively, indicating highest involvement of stress proteins in spermatozoa of mussels in Bagnoli. In order to evaluate the possible risk on Mytilus galloprovincialis sustainability loss, electrophoretic analyses were performed on protamine-like proteins (PL) of collected spermatozoa. The results showed that CM PL were apparently unaltered with respect to ctr PL, while BAs and BAn PL appeared in part in the form of peptides and in part as bands with low mobility. Further, CM and BAs PL showed, by electrophoretic mobility shift assay, a decrease in DNA binding ability and a change in their DNA binding mode. The results of this investigation show the usefulness of the study of alterations of spermatozoa hsp70 expression and protamine-like protein properties for eco-toxicological evaluation using Mytilus galloprovincialis as a bioindicator.