Universidade Federal de Ciências da Saúde de Porto Alegre

Maternal malnutrition, including obesity, can have long-term adverse effects on offspring health, potentially mediated by epigenetic mechanisms such as microRNAs (miRNAs). These miRNAs play a critical role in regulating gene expression and may contribute to the developmental programming of offspring outcomes. This systematic review aimed to explore the association between maternal obesity during pregnancy and miRNA alterations in offspring, focusing on evidence from animal models. A comprehensive search of the Embase, PubMed, and Scopus databases identified 811 articles, 15 of which met the inclusion criteria. Our analysis revealed significant variability in the miRNAs and target tissues studied. Across the reviewed studies, 35 miRNAs were identified as differentially expressed in offspring exposed to maternal high-fat diet during pregnancy. These alterations were predominantly observed in the brain, liver, cardiac tissue, and adipose tissue, affecting processes related to insulin signaling, development and growth, immune response, and lipid metabolism. The observed miRNA alterations support the hypothesis that a maternal high-fat diet may induce a programmed epigenetic signature in offspring.

Rapid biodegradation of low-density polyethylene (LDPE) by the insect larvae Galleria mellonella motivates the understanding of the role of the larval microbiota in this process. In this study, the effect of the LDPE ingestion by these animals under normal or reduced microbiota conditions was evaluated and a rigorous protocol was designed to assess the gut and salivary glands microbial communities from G. mellonella larvae submitted to different diets. Microbiota depleted larvae showed decreased of LDPE consumption and their frass and cocoon presented changes in chemical features when compared to control larvae. High-throughput sequencing of 16S rRNA gene and ITS region reveled that beeswax-fed and LDPE-fed larvae exhibit similar bacterial community compositions, with an increased abundance of LDPE-biodegrading genera (Rhizobium and Sphingobium) in gut and salivary glands. Additionally, we report for the first time the presence of archaeal communities in both organs, and fungal communities in the salivary glands of G. mellonella. In beeswax-fed larvae, the phylum Ascomycota, known to include genera associated with PE biodegradation, was predominant. Another novel finding is the identification of the ciliate Aspidisca in salivary glands of beeswax-fed larvae, previously reported as a hydrocarbon-biodegrader. Functional prediction analysis demonstrated several enzymes potentially involved in LDPE digestion and allowed us to propose a hypothetical PE biodegradation pathway in G. mellonella larvae, involving a synergistic interaction between larval and microbial enzymes. Our results suggest that feeding on LDPE or beeswax selectively enriches microorganisms associated with hydrocarbons and LDPE biodegradation, indicating the innate capability of G. mellonella to biodegrade plastics.

Hepatopulmonary syndrome (HPS) is characterized by liver abnormalities, hypoxemia, and intrapulmonary vasodilatation. Currently, liver transplant is the only effective treatment, as there are no established pharmacological therapies for HPS. Bile duct ligation (BDL) is an experimental model widely used to study the pathophysiology of HPS, as it replicates disease abnormalities. This study aimed to evaluate the effects of melatonin (MLT) or physical exercise (EX) on BDL-induced HPS. Twenty-six male Wistar rats were divided into 4 groups: control (CO), BDL, BDL + MLT, and BDL + EX. Starting on day 15, MLT (20 mg/kg) was administered intraperitoneally once daily, and the EX protocol was implemented, consisting of swimming sessions in a 50-cm-deep tank every other day. All animals were euthanized on day 29, when blood, liver, and lung samples were collected for analysis. The BDL group showed significant liver damage, as evidenced by elevated liver enzyme levels, the presence of fibrous septa and nodules in the liver, an increased diameter of intrapulmonary vessels, impaired gas exchange in arterial blood gas analysis, increased oxidative stress, and DNA damage. The BDL + MLT and BDL + EX groups showed liver parenchyma restructuring, reduced intrapulmonary vasodilatation, improved gas exchange, and reduced oxidative stress and DNA damage compared with the BDL group. Our results suggest that both MLT and EX exert beneficial effects on BDL-induced HPS, reducing liver and lung abnormalities, improving antioxidant defenses, and decreasing DNA damage through modulation of the antioxidant system.