Mucomics is the study of mucus and its biochemical properties. This discipline has gained increasing attention due to the critical roles mucus plays in protection, adhesion, and communication across species. Ethical restrictions on vertebrate research have driven the interest in invertebrate models such as mollusks. Mollusks produce large amounts of mucus which has several functions, including immune defense, digestion, and environmental adaptation. Mollusks—terrestrial, freshwater, or marine—are valuable models for investigating mucus composition and its responses to environmental stressors, including heavy metal contamination. Histochemical and glycomic techniques have revealed variations in mucin glycosylation patterns that influence mucus functionality, such as its viscoelastic and adhesive properties. Bivalves and gastropods, widely used as bioindicators and generally not subject to regulatory constraints in experimental use, accumulate pollutants in their mucus, reflecting environmental health. Investigative techniques such as lectin histochemistry, proteomic, and glycomic analyses provide insights into the impact of contaminants on mucus composition. Further research on molluscan mucins can enhance understanding of their physiological roles, environmental interactions, and potential biomedical applications. By integrating molecular and histochemical approaches, mucomic studies offer a comprehensive perspective on mucus function, advancing both ecological monitoring and biotechnological applications.

Microplastics (MPs) pose an increasing and significant threat to marine biodiversity and there is a current need to determine the effects of exposure on benthic sessile invertebrates. This study examines the filtration capacity and retention of MP particles, as well as their physiological impacts in the marine sponge Spongia officinalis, a bioindicator species. The findings revealed a very high filtration capacity for MPs within the size range of 1-5 μm, along with a rapid turnover rate, as a large portion of particles were expelled within 48 h of exposure. Histological analyses detected MP particles within the cellular structures of the analyzed tissues, indicating that MPs of this size can penetrate cellular barriers. In terms of physiological effects, detoxification activity was activated during the depuration phase, and lipid peroxidation was observed during both the exposure and depuration phases. Overall, this study provides critical insights into the filtration and retention capacity, intercellular integration of MP particles, and the physiological effects of MP exposure in S. officinalis, providing a baseline for future research.

An in situ analysis of mucin secretions along the annual cycle was performed on the striped Venus clam, Chamelea gallina. Individuals of both sexes from an exploited stock of Margherita di Savoia (Southern Adriatic Sea, Central Mediterranean Sea) were made in June 2020 and 2021, and in January 2021 and 2022, representative of summer and winter seasons, respectively. Tissues from the foot and the gills were analyzed for histochemical and lectin-histochemical analyses. Staining with Periodic Acid-Schiff, Alcian Blue pH 2.5 and High-Iron-Diamine indicated that mucins from both the foot and the gills were acidic, mostly sulfated. Lectin-binding analyses with PNA, SBA, WGA, LTA, UEA-I, AAA, SNA, MAA-II and ConA indicated the presence of N-acetyl-glycosaminylated, mannosylated and fucosylated residuals in the saccharidic chains. In the gills, the amount of acidic and glycosaminylated residuals was higher in summer in both sexes, whereas fucosylation was similar along the sampling period and mannosylation was never observed. In the foot, both surface epithelial and subepidermal secreting cells increased sulfation in winter in males, but not in females. Glycosaminylation and fucosylation were observed only in the surface cells of males. Mannosylated residuals were observed in all the foot cell types in both sexes. It is hypothesized that the observed qualitative and quantitative variations in mucin secretion is linked to the reproductive cycle.

The integrity of esophageal epithelial cells in patients with gastroesophageal reflux disease (GERD) or GERD-like symptoms is the first mechanism of protection to decrease the sensitivity to gastric reflux and heartburn symptoms. We investigated the protective effects of Poliprotect^® (PPRO), a CE-marked medical device, on esophageal epithelial integrity using in vitro and ex vivo models. In vitro, the protective effects of PPRO were tested on Caco-2 cells. PPRO demonstrated safety and protection against oxidative damage induced by hydrogen peroxide. It also preserved epithelial integrity by maintaining transepithelial electrical resistance (TEER) against damage from calcium removal or bile acid exposure (taurodeoxycholic acid, TDCA). Ex vivo, esophageal biopsies from patients subjected to endoscopy were mounted in Ussing chambers and exposed to damaging agents (HCl or HCl + TDCA). Untreated biopsies (control) showed significant loss of epithelial resistance (up to −33%). In contrast, low concentrations of PPRO (50–100 µg/mL) provided strong protection against these damages (p < 0.001), even after 60 min of washing. Histological analysis confirmed the barrier-enhancing effect of PPRO. Overall, PPRO effectively protected the esophageal epithelium from damage in both models, suggesting its potential role in alleviating GERD or GERD-like symptoms by strengthening mucosal barriers and reducing epithelial sensitivity to reflux.

Aluminum is the most abundant metal in the Earth's crust and is widely used in everyday life. In sea waters, the presence of dissolved Al is naturally limited to a few micrograms per litre, however anthropogenic activities tend to alter its concentration. Toxic effects caused by this metal have already been demonstrated on several taxa, as well as a direct correlation with various diseases, including neurodegenerative ones. Since bivalves proved good bioindicators for environmental and possibly human health, we tested by histochemical methods the effects of Aluminum on the muciparous tissues of the striped venus clam, Chamelea gallina. Aluminum chloride at concentrations of 25, 50, and 200 µM, respectively were administered to experimental groups of twenty clams housed under controlled conditions. Image analysis of tissues stained by conventional and lectin-histochemistry indicated both qualitative and quantitative alterations of the mucous secretion produced by the gills and feet epithelia of the clams. The acidity and viscosity of the mucus itself is altered, with possible repercussions on the health and survival of animals.