Molecular Targets to Alleviate Enteric Neuropathy and Gastrointestinal Dysfunction.

Enteric neuropathy underlies long-term gastrointestinal (GI) dysfunction associated with several pathological conditions. Our previous studies have demonstrated that structural and functional changes in the enteric nervous system (ENS) result in persistent alterations of intestinal functions long after the acute insult. These changes lead to aberrant immune response and chronic dysregulation of the epithelial barrier. Damage to the ENS is prognostic of disease progression and plays an important role in the recurrence of clinical manifestations. This suggests that the ENS is a viable therapeutic target to alleviate chronic intestinal dysfunction. Our recent studies in preclinical animal models have progressed into the development of novel therapeutic strategies for the treatment of enteric neuropathy in various chronic GI disorders. We have tested the anti-inflammatory and neuroprotective efficacy of novel compounds targeting specific molecular pathways. Ex vivo studies in human tissues freshly collected after resection surgeries provide an understanding of the molecular mechanisms involved in enteric neuropathy. In vivo treatments in animal models provide data on the efficacy and the mechanisms of actions of the novel compounds and their combinations with clinically used therapies. These novel findings provide avenues for the development of safe, cost-effective, and highly efficacious treatments of GI disorders.

Asperuloside Enhances Taste Perception and Prevents Weight Gain in High-Fat Fed Mice.

Asperuloside is an iridoid glycoside found in many medicinal plants that has produced promising anti-obesity results in animal models. In previous studies, three months of asperuloside administration reduced food intake, body weight, and adipose masses in rats consuming a high fat diet (HFD). However, the mechanisms by which asperuloside exerts its anti-obesity properties were not clarified. Here, we investigated homeostatic and nutrient-sensing mechanisms regulating food intake in mice consuming HFD. We confirmed the anti-obesity properties of asperuloside and, importantly, we identified some mechanisms that could be responsible for its therapeutic effect. Asperuloside reduced body weight and food intake in mice consuming HFD by 10.5 and 12.8% respectively, with no effect on mice eating a standard chow diet. Fasting glucose and plasma insulin were also significantly reduced. Mechanistically, asperuloside significantly reduced hypothalamic mRNA ghrelin, leptin, and pro-opiomelanocortin in mice consuming HFD. The expression of fat lingual receptors (CD36, FFAR1-4), CB1R and sweet lingual receptors (TAS1R2-3) was increased almost 2-fold by the administration of asperuloside. Our findings suggest that asperuloside might exert its therapeutic effects by altering nutrient-sensing receptors in the oral cavity as well as hypothalamic receptors involved in food intake when mice are exposed to obesogenic diets. This signaling pathway is known to influence the subtle hypothalamic equilibrium between energy homeostasis and reward-induced overeating responses. The present pre-clinical study demonstrated that targeting the gustatory system through asperuloside administration could represent a promising and effective new anti-obesity strategy.

Micro RNA Expression after Ingestion of Fucoidan; A Clinical Study.

Fucoidans are a class of fucose-rich sulfated polysaccharides derived from brown macroalgae that exert a range of biological activities in vitro and in vivo. To generate an unbiased assessment of pathways and processes affected by fucoidan, a placebo-controlled double-blind pilot study was performed in healthy volunteers. Blood samples were taken immediately before and 24 h after ingestion of a single dose of 1 g of Undaria pinnatifida fucoidan (UPF) or placebo. Levels of isolated miRNAs were analyzed using Taqman Open Array Human MicroRNA panels. Out of 754 miRNAs screened, UPF affected a total of 53 miRNAs. Pathway analysis using the TALOS data analysis tool predicted 29 different pathways and processes that were largely grouped into cell surface receptor signaling, cancer-related pathways, the majority of which were previously associated with fucoidans. However, this analysis also identified nine pathways and processes that have not been associated with fucoidans before. Overall, this study illustrates that even a single dose of fucoidans has the potential to affect the expression of genes related to fundamental cellular processes. Moreover, it confirms previous data that fucoidans influence immunity, cancer cells, inflammation, and neurological function.

Pathway Analysis of Fucoidan Activity Using a Yeast Gene Deletion Library Screen.

Fucoidan, the sulfated fucose-rich polysaccharide derived from brown macroalgae, was reported to display some anti-cancer effects in in vitro and in vivo models that included apoptosis and cell cycle arrest. The proposed mechanisms of action involve enhanced immune surveillance and direct pro-apoptotic effects via the activation of cell signaling pathways that remain largely uncharacterized. This study aimed to identify cellular pathways influenced by fucoidan using an unbiased genetic approach to generate additional insights into the anti-cancer effects of fucoidan. Drug⁻gene interactions of Undaria pinnatifida fucoidan were assessed by a systematic screen of the entire set of 4,733 halpoid Saccharomyces cerevsiae gene deletion strains. Some of the findings were confirmed using cell cycle analysis and DNA damage detection in non-immortalized human dermal fibroblasts and colon cancer cells. The yeast deletion library screen and subsequent pathway and interactome analysis identified global effects of fucoidan on a wide range of eukaryotic cellular processes, including RNA metabolism, protein synthesis, sorting, targeting and transport, carbohydrate metabolism, mitochondrial maintenance, cell cycle regulation, and DNA damage repair-related pathways. Fucoidan also reduced clonogenic survival, induced DNA damage and G1-arrest in colon cancer cells, while these effects were not observed in non-immortalized human fibroblasts. Our results demonstrate global effects of fucoidan in diverse cellular processes in eukaryotic cells and further our understanding about the inhibitory effect of Undaria pinnatifida fucoidan on the growth of human cancer cells.

The microgenderome revealed: sex differences in bidirectional interactions between the microbiota, hormones, immunity and disease susceptibility.

Sex differences in immunity are well described in the literature and thought to be mainly driven by sex hormones and sex-linked immune response genes. The gastrointestinal tract (GIT) is one of the largest immune organs in the body and contains multiple immune cells in the GIT-associated lymphoid tissue, Peyer's patches and elsewhere, which together have profound effects on local and systemic inflammation. The GIT is colonised with microbial communities composed of bacteria, fungi and viruses, collectively known as the GIT microbiota. The GIT microbiota drives multiple interactions locally with immune cells that regulate the homeostatic environment and systemically in diverse tissues. It is becoming evident that the microbiota differs between the sexes, both in animal models and in humans, and these sex differences often lead to sex-dependent changes in local GIT inflammation, systemic immunity and susceptibility to a range of inflammatory diseases. The sexually dimorphic microbiome has been termed the 'microgenderome'. Herein, we review the evidence for the microgenderome and contemplate the role it plays in driving sex differences in immunity and disease susceptibility. We further consider the impact that biological sex might play in the response to treatments aimed at manipulating the GIT microbiota, such as prebiotics, live biotherapeutics, (probiotics, synbiotics and bacteriotherapies) and faecal microbial transplant. These alternative therapies hold potential in the treatment of both psychological (e.g., anxiety, depression) and physiological (e.g., irritable bowel disease) disorders differentially affecting males and females.