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Signal Transduction and Targeted Therapy Aug 2023As a family of cationic host defense peptides, defensins are mainly synthesized by Paneth cells, neutrophils, and epithelial cells, contributing to host defense. Their... (Review)
Review
As a family of cationic host defense peptides, defensins are mainly synthesized by Paneth cells, neutrophils, and epithelial cells, contributing to host defense. Their biological functions in innate immunity, as well as their structure and activity relationships, along with their mechanisms of action and therapeutic potential, have been of great interest in recent years. To highlight the key research into the role of defensins in human and animal health, we first describe their research history, structural features, evolution, and antimicrobial mechanisms. Next, we cover the role of defensins in immune homeostasis, chemotaxis, mucosal barrier function, gut microbiota regulation, intestinal development and regulation of cell death. Further, we discuss their clinical relevance and therapeutic potential in various diseases, including infectious disease, inflammatory bowel disease, diabetes and obesity, chronic inflammatory lung disease, periodontitis and cancer. Finally, we summarize the current knowledge regarding the nutrient-dependent regulation of defensins, including fatty acids, amino acids, microelements, plant extracts, and probiotics, while considering the clinical application of such regulation. Together, the review summarizes the various biological functions, mechanism of actions and potential clinical significance of defensins, along with the challenges in developing defensins-based therapy, thus providing crucial insights into their biology and potential clinical utility.
Topics: Animals; Humans; Paneth Cells; Inflammatory Bowel Diseases; Defensins
PubMed: 37574471
DOI: 10.1038/s41392-023-01553-x -
Science (New York, N.Y.) Aug 2023The mammalian gut secretes a family of multifunctional peptides that affect appetite, intestinal secretions, and motility whereas others regulate the microbiota. We have...
The mammalian gut secretes a family of multifunctional peptides that affect appetite, intestinal secretions, and motility whereas others regulate the microbiota. We have found that peptide YY (PYY), but not endocrine PYY, acts as an antimicrobial peptide (AMP) expressed by gut epithelial paneth cells (PC). PC-PYY is packaged into secretory granules and is secreted into and retained by surface mucus, which optimizes PC-PYY activity. Although PC-PYY shows some antibacterial activity, it displays selective antifungal activity against virulent hyphae-but not the yeast form. PC-PYY is a cationic molecule that interacts with the anionic surfaces of fungal hyphae to cause membrane disruption and transcriptional reprogramming that selects for the yeast phenotype. Hence, PC-PYY is an antifungal AMP that contributes to the maintenance of gut fungal commensalism.
Topics: Animals; Antifungal Agents; Antimicrobial Peptides; Candida; Paneth Cells; Peptide Fragments; Peptide YY; Symbiosis; Humans; Mice
PubMed: 37535745
DOI: 10.1126/science.abq3178 -
Nature Communications Sep 2023Declined numbers and weakened functions of intestinal stem cells (ISCs) impair the integrity of the intestinal epithelium during aging. However, the impact of intestinal...
Declined numbers and weakened functions of intestinal stem cells (ISCs) impair the integrity of the intestinal epithelium during aging. However, the impact of intestinal microbiota on ISCs in this process is unclear. Here, using premature aging mice (telomerase RNA component knockout, Terc), natural aging mice, and in vitro colonoid models, we explore how heat-inactivated Bifidobacterium adolescentis (B. adolescentis) affects colon senescence. We find that B. adolescentis could mitigate colonic senescence-related changes by enhancing intestinal integrity and stimulating the regeneration of Lgr5 ISCs via Wnt/β-catenin signaling. Furthermore, we uncover the involvement of Paneth-like cells (PLCs) within the colonic stem-cell-supporting niche in the B. adolescentis-induced ISC regeneration. In addition, we identify soluble polysaccharides (SPS) as potential effective components of B. adolescentis. Overall, our findings reveal the role of heat-inactivated B. adolescentis in maintaining the ISCs regeneration and intestinal barrier, and propose a microbiota target for ameliorating colon senescence.
Topics: Mice; Animals; Bifidobacterium adolescentis; Hot Temperature; Intestines; Stem Cells; Intestinal Mucosa; Colon
PubMed: 37777508
DOI: 10.1038/s41467-023-41827-0 -
Cell Reports Sep 2023Lipolysis-stimulated lipoprotein receptor (LSR) is a multi-functional protein that is best known for its roles in assembly of epithelial tricellular tight junctions and...
Lipolysis-stimulated lipoprotein receptor (LSR) is a multi-functional protein that is best known for its roles in assembly of epithelial tricellular tight junctions and hepatic clearance of lipoproteins. Here, we investigated whether LSR contributes to intestinal epithelium homeostasis and pathogenesis of intestinal disease. By using multiple conditional deletion mouse models and ex vivo cultured organoids, we find that LSR elimination in intestinal stem cells results in the disappearance of Paneth cells without affecting the differentiation of other cell lineages. Mechanistic studies reveal that LSR deficiency increases abundance of YAP by modulating its phosphorylation and proteasomal degradation. Using gain- and loss-of-function studies, we show that LSR protects against necrotizing enterocolitis through enhancement of Paneth cell differentiation in small-intestinal epithelium. Thus, this study identifies LSR as an upstream negative regulator of YAP activity, an essential factor for Paneth cell differentiation, and a potential therapeutic target for necrotizing enterocolitis.
Topics: Mice; Animals; Paneth Cells; Receptors, Lipoprotein; Enterocolitis, Necrotizing; Cell Differentiation; Intestines; Intestinal Mucosa
PubMed: 37703178
DOI: 10.1016/j.celrep.2023.113118 -
Journal of Animal Science and... Aug 2023A healthy intestine plays an important role in the growth and development of farm animals. In small intestine, Paneth cells are well known for their regulation of... (Review)
Review
A healthy intestine plays an important role in the growth and development of farm animals. In small intestine, Paneth cells are well known for their regulation of intestinal microbiota and intestinal stem cells (ISCs). Although there has been a lot of studies and reviews on human and murine Paneth cells under intestinal homeostasis or disorders, little is known about Paneth cells in farm animals. Most farm animals possess Paneth cells in their small intestine, as identified by various staining methods, and Paneth cells of various livestock species exhibit noticeable differences in cell shape, granule number, and intestinal distribution. Paneth cells in farm animals and their antimicrobial peptides (AMPs) are susceptible to multiple factors such as dietary nutrients and intestinal infection. Thus, the comprehensive understanding of Paneth cells in different livestock species will contribute to the improvement of intestinal health. This review first summarizes the current status of Paneth cells in pig, cattle, sheep, horse, chicken and rabbit, and points out future directions for the investigation of Paneth cells in the reviewed animals.
PubMed: 37582766
DOI: 10.1186/s40104-023-00905-5 -
Cells Jul 2023Crohn's disease (CD) is a chronic inflammatory bowel disease marked by relapsing, transmural intestinal inflammation driven by innate and adaptive immune responses.... (Review)
Review
Crohn's disease (CD) is a chronic inflammatory bowel disease marked by relapsing, transmural intestinal inflammation driven by innate and adaptive immune responses. Autophagy is a multi-step process that plays a critical role in maintaining cellular homeostasis by degrading intracellular components, such as damaged organelles and invading bacteria. Dysregulation of autophagy in CD is revealed by the identification of several susceptibility genes, including , , , , , , and , that are involved in autophagy. In this review, the role of altered autophagy in the mucosal innate immune response in the context of CD is discussed, with a specific focus on dendritic cells, macrophages, Paneth cells, and goblet cells. Selective autophagy, such as xenophagy, ERphagy, and mitophagy, that play crucial roles in maintaining intestinal homeostasis in these innate immune cells, are discussed. As our understanding of autophagy in CD pathogenesis evolves, the development of autophagy-targeted therapeutics may benefit subsets of patients harboring impaired autophagy.
Topics: Humans; Crohn Disease; Inflammatory Bowel Diseases; Immunity, Innate; Intestines; Autophagy
PubMed: 37443813
DOI: 10.3390/cells12131779 -
Gut Microbes Dec 2023Classically, Axin1 is considered a regulator of Wnt/β-catenin signaling. However, Axin1's roles in host-microbial interactions have been unknown. Our recent study has...
Classically, Axin1 is considered a regulator of Wnt/β-catenin signaling. However, Axin1's roles in host-microbial interactions have been unknown. Our recent study has demonstrated that deletion of intestinal epithelial Axin1 in epithelial cells and Paneth cells protects the host against colitis by enhancing . Loss of intestinal epithelial or Paneth cell Axin1 results in increased Wnt/β-catenin signaling, proliferation, and cell migration. This is associated with morphologically altered goblet and Paneth cells, including increased Muc2 and decreased lysozyme. Axin1 deletion specifically enriched . in Axin1 knockout mice is the driver of protection against DSS-induced inflammation. Here, we feature several significant conceptual changes, such as differences between Axin1 and Axin2, Axin1 in innate immunity and microbial homeostasis, and Axin1 reduction of . We discuss an important trend in the field related to Paneth cells and tissue-specific Axin1 manipulation of microbiome in health and inflammation.
Topics: Animals; Mice; Axin Protein; beta Catenin; Colitis; Gastrointestinal Microbiome; Inflammation; Microbiota; Paneth Cells
PubMed: 38010886
DOI: 10.1080/19490976.2023.2286674 -
Nature Communications Jul 2023TET2/3 play a well-known role in epigenetic regulation and mouse development. However, their function in cellular differentiation and tissue homeostasis remains poorly...
TET2/3 play a well-known role in epigenetic regulation and mouse development. However, their function in cellular differentiation and tissue homeostasis remains poorly understood. Here we show that ablation of TET2/3 in intestinal epithelial cells results in a murine phenotype characterized by a severe homeostasis imbalance in the small intestine. Tet2/3-deleted mice show a pronounced loss of mature Paneth cells as well as fewer Tuft and more Enteroendocrine cells. Further results show major changes in DNA methylation at putative enhancers, which are associated with cell fate-determining transcription factors and functional effector genes. Notably, pharmacological inhibition of DNA methylation partially rescues the methylation and cellular defects. TET2/3 loss also alters the microbiome, predisposing the intestine to inflammation under homeostatic conditions and acute inflammation-induced death. Together, our results uncover previously unrecognized critical roles for DNA demethylation, possibly occurring subsequently to chromatin opening during intestinal development, culminating in the establishment of normal intestinal crypts.
Topics: Animals; Mice; Cell Differentiation; Dioxygenases; DNA Methylation; DNA-Binding Proteins; Epigenesis, Genetic; Homeostasis; Inflammation; Intestine, Small
PubMed: 37414790
DOI: 10.1038/s41467-023-39512-3 -
Nature Communications Sep 2023Intestinal stem cells (ISCs) maintain the epithelial lining of the intestines, but mechanisms regulating ISCs and their niche after damage remain poorly understood....
Intestinal stem cells (ISCs) maintain the epithelial lining of the intestines, but mechanisms regulating ISCs and their niche after damage remain poorly understood. Utilizing radiation injury to model intestinal pathology, we report here that the Interleukin-33 (IL-33)/ST2 axis, an immunomodulatory pathway monitored clinically as an intestinal injury biomarker, regulates intrinsic epithelial regeneration by inducing production of epidermal growth factor (EGF). Three-dimensional imaging and lineage-specific RiboTag induction within the stem cell compartment indicated that ISCs expressed IL-33 in response to radiation injury. Neighboring Paneth cells responded to IL-33 by augmenting production of EGF, which promoted ISC recovery and epithelial regeneration. These findings reveal an unknown pathway of niche regulation and crypt regeneration whereby the niche responds dynamically upon injury and the stem cells orchestrate regeneration by regulating their niche. This regenerative circuit also highlights the breadth of IL-33 activity beyond immunomodulation and the therapeutic potential of EGF administration for treatment of intestinal injury.
Topics: Humans; Interleukin-33; Epidermal Growth Factor; Imaging, Three-Dimensional; Immunomodulation; Radiation Injuries
PubMed: 37669929
DOI: 10.1038/s41467-023-40993-5 -
Internal and Emergency Medicine Sep 2023The intestinal mucosa represents the most extensive human barrier having a defense function against microbial and food antigens. This barrier is represented externally... (Review)
Review
The intestinal mucosa represents the most extensive human barrier having a defense function against microbial and food antigens. This barrier is represented externally by a mucus layer, consisting mainly of mucins, antimicrobial peptides, and secretory immunoglobulin A (sIgA), which serves as the first interaction with the intestinal microbiota. Below is placed the epithelial monolayer, comprising enterocytes and specialized cells, such as goblet cells, Paneth cells, enterochromaffin cells, and others, each with a specific protective, endocrine, or immune function. This layer interacts with both the luminal environment and the underlying lamina propria, where mucosal immunity processes primarily take place. Specifically, the interaction between the microbiota and an intact mucosal barrier results in the activation of tolerogenic processes, mainly mediated by FOXP3 regulatory T cells, underlying intestinal homeostasis. Conversely, the impairment of the mucosal barrier function, the alteration of the normal luminal microbiota composition (dysbiosis), or the imbalance between pro- and anti-inflammatory mucosal factors may result in inflammation and disease. Another crucial component of the intestinal barrier is the gut-vascular barrier, formed by endothelial cells, pericytes, and glial cells, which regulates the passage of molecules into the bloodstream. The aim of this review is to examine the various components of the intestinal barrier, assessing their interaction with the mucosal immune system, and focus on the immunological processes underlying homeostasis or inflammation.
Topics: Humans; Immunity, Mucosal; Endothelial Cells; Intestinal Mucosa; Inflammation; Homeostasis
PubMed: 37402104
DOI: 10.1007/s11739-023-03329-1