Identification of Mortalin as the Main Interactor of Mycalin A, a Poly-Brominated C-15 Acetogenin Sponge Metabolite, by MS-Based Proteomics.

Mycalin A (MA) is a polybrominated C-15 acetogenin isolated from the marine sponge Mycale rotalis. Since this substance displays a strong antiproliferative bioactivity towards some tumour cells, we have now directed our studies towards the elucidation of the MA interactome through functional proteomic approaches, (DARTS and t-LIP-MS). DARTS experiments were performed on Hela cell lysates with the purpose of identifying MA main target protein(s); t-LiP-MS was then applied for an in-depth investigation of the MA-target protein interaction. Both these techniques exploit limited proteolysis coupled with MS analysis. To corroborate LiP data, molecular docking studies were performed on the complexes. Finally, biological and SPR analysis were conducted to explore the effect of the binding. Mortalin (GRP75) was identified as the MA's main interactor. This protein belongs to the Hsp70 family and has garnered significant attention due to its involvement in certain forms of cancer. Specifically, its overexpression in cancer cells appears to hinder the pro-apoptotic function of p53, one of its client proteins, because it becomes sequestered in the cytoplasm. Our research, therefore, has been focused on the possibility that MA might prevent this sequestration, promoting the re-localization of p53 to the nucleus and facilitating the apoptosis of tumor cells.

Targeting phosphoglycerate kinases by tatridin A, a natural sesquiterpenoid endowed with anti-cancer activity, using a proteomic platform.

Tatridin A (TatA) is a germacrane sesquiterpenoid containing one E-double bond and one Z-double bond in its 10-membered ring, which is fused to a 3-methylene-dihydrofuran-2-one moiety. Tatridin A bioactivity has been poorly investigated despite its interesting chemical structure. Here, a functional proteomic platform was adapted to disclose its most reliable targets in leukemia monocytic cells, and phosphoglycerate kinases were recognized as the most affine enzymes. Through a combination of limited proteolysis and molecular docking, it has been discovered that tatridin A interacts with the active domains of phosphoglycerate kinase 1, altering its hinge region, and it can be accountable for tatridin A inhibition potency on enzyme activity. A more detailed tatridin A biological profile showed that it is also fully active against gastric cancer cells, downregulating the mRNA levels of chemokine receptor 4 and ß-catenin and inhibiting the invasiveness of living KATO III cells as a direct consequence of phosphoglycerate kinase 1 antagonism.

SARS-CoV-2 RNA in Wastewater and Bivalve Mollusk Samples of Campania, Southern Italy.

SARS-CoV-2 can be detected in the feces of infected people, consequently in wastewater, and in bivalve mollusks, that are able to accumulate viruses due to their ability to filter large amounts of water. This study aimed to monitor SARS-CoV-2 RNA presence in 168 raw wastewater samples collected from six wastewater treatment plants (WWTPs) and 57 mollusk samples obtained from eight harvesting sites in Campania, Italy. The monitoring period spanned from October 2021 to April 2022, and the results were compared and correlated with the epidemiological situation. In sewage, the ORF1b region of SARS-CoV-2 was detected using RT-qPCR, while in mollusks, three targets-RdRp, ORF1b, and E-were identified via RT-dPCR. Results showed a 92.3% rate of positive wastewater samples with increased genomic copies (g.c.)/(day*inhabitant) in December-January and March-April 2022. In the entire observation period, 54.4% of mollusks tested positive for at least one SARS-CoV-2 target, and the rate of positive samples showed a trend similar to that of the wastewater samples. The lower SARS-CoV-2 positivity rate in bivalve mollusks compared to sewages is a direct consequence of the seawater dilution effect. Our data confirm that both sample types can be used as sentinels to detect SARS-CoV-2 in the environment and suggest their potential use in obtaining complementary information on SARS-CoV-2.

Helicobacter pylori Pathogen-Associated Molecular Patterns: Friends or Foes?

Microbial infections are sensed by the host immune system by recognizing signature molecules called Pathogen-Associated Molecular Patterns-PAMPs. The binding of these biomolecules to innate immune receptors, called Pattern Recognition Receptors (PRRs), alerts the host cell, activating microbicidal and pro-inflammatory responses. The outcome of the inflammatory cascade depends on the subtle balance between the bacterial burn and the host immune response. The role of PRRs is to promote the clearance of the pathogen and to limit the infection by bumping inflammatory response. However, many bacteria, including Helicobacter pylori, evolved to escape PRRs' recognition through different camouflages in their molecular pattern. This review examines all the different types of H. pylori PAMPs, their roles during the infection, and the mechanisms they evolved to escape the host recognition.