Search Results (57)

Radiation-induced intestinal injury (RIII), a severe complication of abdominopelvic radiotherapy, causes intestinal ischemia, ulcers, and necrosis, severely impacting patients’ quality of life. Currently, effective treatments are limited, and a specific cure remains elusive. Our previous research showed that lactoferrin (LF) can promote intestinal stem cell (ISC) proliferation and tissue repair; however, its oral administration is limited by rapid degradation in the gastric environment. In this study, we developed LF-loaded liposomal nanoparticles (Lip-LF) using a simple ethanol injection method. The optimal formulation (cholesterol/egg yolk lecithin ratio 2:8, LF concentration 12.5 mg/mL) achieved a drug-loading capacity of 6.8% and a narrow size distribution (0.2 < PDI < 0.4). In vitro experiments demonstrated that Lip-LF protected LF from pepsin degradation in simulated gastric fluid (SGF), retaining over 80% integrity after 120 min, while releasing in simulated intestinal fluid (SIF). In vivo imaging revealed prolonged gastrointestinal retention of Lip-LF compared to free LF. In a murine model of RIII (12 Gy whole-body irradiation), Lip-LF significantly restored villus counts, increased crypt height, and promoted goblet-cell regeneration. Immunohistochemical and qPCR analyses revealed enhanced ISCs proliferation and upregulation of repair-associated genes, including Pcna and Olfm4. These findings demonstrate that Lip-LF protects LF from gastric degradation and enhances its targeted delivery to the intestine, improving its therapeutic efficacy in repairing RIII. Lip-LF thus offers a promising strategy for managing RIII. Full article

The objective of our study was to verify the intervention effect of Bacillus amyloliquefaciens SC06 on NE by constructing a C. perfringens-induced intestinal damage mouse model. A total of 40 mice were randomly assigned to four treatments: CON (basal diet), CP (basal diet + C. perfringens), SC06 + CP (basal diet + SC06 + C. perfringens) and SC06 (basal diet + SC06). Our findings indicated that SC06 supplementation was effective in maintaining the integrity of the intestinal barrier, enhancing the antioxidant capacity of the intestine, reducing the generation of an inflammatory response, and suppressing enterocyte apoptosis in the presence of C. perfringens. Furthermore, SC06 supplementation enhanced the prefoliation of intestinal stem cells (ISC) and prompted their differentiation into goblet cells and Paneth cells. Moreover, our findings indicate that SC06 promotes the proliferation of C. perfringens-induced jejunum organoids and the expression of genes and proteins associated with ISC differentiation and regeneration. The mechanism by which SC06 modulates ISCs has been validated, and the results align with those obtained in vivo. In conclusion, the findings demonstrated that SC06 stimulates the proliferation and differentiation of ISCs through the activation of the Wnt/β-catenin signaling pathway, thereby accelerating epithelial regeneration and repair. Full article

Intestinal regeneration is essential for maintaining epithelial integrity and repairing mucosal damage caused by inflammation, infections, or injuries. Traditional Chinese Medicine (TCM) has long utilized herbal remedies for gastrointestinal disorders, and accumulating evidence highlights that natural compounds derived from TCM possess significant regenerative potential. This review summarizes the multifaceted mechanisms by which these bioactive compounds promote intestinal healing. Key actions include the stimulation of intestinal stem cell (ISC) proliferation and differentiation, the modulation of inflammatory responses, the reinforcement of epithelial barrier integrity, the attenuation of oxidative stress, and the reshaping of the gut microbiota. Representative compounds such as Astragalus polysaccharides, berberine, curcumin, puerarin, and flavonoids like quercetin exhibit these effects through signaling pathways, including HIF-1, Wnt/β-catenin, NF-κB, Nrf2, and IL-22. Evidence from in vitro organoid models and in vivo studies in colitis, radiation injury, antibiotic-associated diarrhea, and intestinal dysmotility and diarrhea models demonstrates that these compounds enhance crypt villus regeneration, preserve tight junctions, and improve clinical outcomes. The holistic, multi-target actions of Chinese medicine-derived natural products make them promising candidates for therapeutic strategies aimed at intestinal repair. Further clinical validation and mechanistic studies are warranted to facilitate their integration into modern gastrointestinal medicine. Full article

Enteroendocrine cells (EECs) are specialized secretory cells in the gut epithelium that differentiate from intestinal stem cells (ISCs). Mature EECs secrete incretin hormones that stimulate pancreatic insulin secretion and regulate appetite. Decreased EEC numbers and impaired secretion of the incretin glucagon-like peptide-1 (GLP1) have been implicated in obesity-associated metabolic complications. Gut microbial metabolites of dietary tryptophan (TRP) were recently shown to modulate ISC proliferation and differentiation. However, their specific effects on EEC differentiation are not known. We hypothesized that the gut microbial metabolites of dietary tryptophan counteract impaired GLP1 production and function in obesity by stimulating EEC differentiation from ISCs. We utilized complementary models of human and rat intestines to determine the effects of obesity or TRP metabolites on EEC differentiation. EEC differentiation was assessed by the EEC marker chromogranin A (CHGA) levels in the intestinal mucosa of normal versus obese rats. The effects of TRP metabolites on EEC differentiation were determined in human intestinal organoids treated with indole, a primary TRP metabolite, or the culture supernatant of Lactobacillus acidophilus grown in TRP media (LA-CS-TRP). Our results showed that the mRNA and protein levels of CHGA, the EEC marker, were significantly decreased (~60%) in the intestinal mucosa of high-fat-diet-induced obese rat intestines. The expression of the transcription factors that direct the ISC differentiation towards the EEC lineage was also decreased in obesity. In human organoids, treatment with indole or LA-CS-TRP significantly increased (more than 2-fold) CHGA levels, which were blocked by the aryl hydrocarbon receptor (AhR) antagonist CH-223191. Thus, the stimulation of EEC differentiation by colonic microbial metabolites highlights a novel therapeutic role of TRP metabolites in obesity and associated metabolic disorders. Full article

Pesticide residues in foods can disturb the intestinal barrier and microbiota, even at a very low dose; however, studies on direct consequences on intestinal health are still lacking. Here, we evaluated the damage of imidacloprid (IMI) to the intestine and the resulting defense against enterotoxigenic Escherichia coli (ETEC) in C57BL/6J mice. After 8-week exposure to 0.06 mg /kg bodyweight/day, IMI significantly damaged intestinal structure and intestinal integrity, characterized by an increased permeability to FITC-dextran and decreased mRNA expression of tight junction proteins, as well as more broken villi and lower proportions of goblet cells and paneth cells. These were related to the suppression of the self-renewal of intestinal stem cells (ISCs), as evidenced by significantly decreased Sox9+ ISCs and increased apoptosis. Furthermore, the impaired intestinal integrity in mice exposed to low doses of IMI directly increased the susceptibility to ETEC infection and even caused death. On the other hand, exposure to 0.6 mg IMI/kg bodyweight/day lead to significantly increased contents of IL-1β and TNFα both in the intestine and serum, and significantly decreased Th1 cell and IFN-γ contents in the lamina propria during the ETEC infection. Our study suggested that the intestinal damage induced by pesticide residues would significantly decrease the defense ability of the intestine, which suggests a novel perspective when evaluating the long-term effects of food contaminates on intestinal health at low doses without significant toxicological injuries. Full article

Intestinal stem cells (ISCs) maintain epithelial renewal through their proliferation and differentiation capabilities, responding to various intestinal insults. However, the impact of iturin A, a natural antimicrobial peptide, on ISC viability and its potential to mitigate heat-stable enterotoxin b (STb)-induced intestinal damage remains unclear. Our recent study demonstrated that oral administration of iturin A enhances tight junction protein expression, accelerates crypt-villus regeneration, and restores epithelial barrier integrity in STb-exposed mice. Furthermore, iturin A promotes ISC proliferation and differentiation, significantly increasing the numbers of goblet and Paneth cells in the jejunum following STb exposure. Notably, iturin A regulates intestinal homeostasis by scavenging reactive oxygen species (ROS), while elevating total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX) levels in both serum and jejunal mucosa. Mechanistically, iturin A facilitates nuclear factor-erythroid 2- related factor 2 (Nrf2) release by disrupting Kelch-like ECH-associated protein 1 (Keap1), leading to the upregulation of the antioxidant enzyme glutathione peroxidase 4 (GPX4). In conclusion, our findings indicate that iturin A alleviates oxidative stress induced by STb through modulation of the Keap1/Nrf2 pathway and promotes ISC differentiation into goblet and Paneth cells, thereby enhancing resistance to STb-induced damage. Full article

In cell biology, the stem cell niche is the dynamic microenvironment in which stem cells reside and receive signals that determine their behavior and fate. The stem cell niche has largely been a theoretical construct due to the difficulty in identifying and manipulating individual stem cells and their surroundings. Recent technical advances have made it possible to characterize the niches that maintain and control stem cell activity in several organs, including the small intestine. Although the small intestine has a relatively simple architecture, it has an extraordinary capacity for fast self-renewal. Thus, the organ is a unique model for studying intestinal stem cells (ISCs) and their niche. The intestinal epithelium maintains the intestine, enabling it to perform its absorption, secretion, and barrier functions. ISCs reside at the base of crypts adjacent to Paneth cells. In vivo, ISCs are surrounded by the microenvironment that makes up the niche, which provides a variety of stimuli that determine the fate of the cells. Research on stem cell niches is beginning to deepen our understanding of ISC regulation at the cellular and molecular levels and is expected to provide insights that can be applied to ISC therapy. Intestinal organoids originate from a group of crypt base ISCs. These organoids possess a three-dimensional (3D) cell structure made up of the lumen facing inward. Therefore, 3D intestinal organoids are often digested and seeded in a two-dimensional (2D) manner to form confluent organoid monolayers. Here, we not only review our current understanding of ISC niches with a focus on systems that are well-characterized at the cellular and mechanistic levels, but we also summarize the current applications of intestinal organoids. Full article

As a prevalent mycotoxin found in cereal foods and feed, deoxynivalenol (DON) disrupts the orderly regeneration of intestinal epithelial tissue by interfering with the intracellular antioxidant defense system. However, the potential of mulberry leaf-derived Morin, a natural flavonoid active substance with clearing reactive oxygen species (ROS), to mitigate DON-induced intestinal oxidative damage remains unclear. Our investigation demonstrates that Morin effectively reverses the decline in growth performance and repairs damaged jejunal structures and barrier function under DON exposure. Furthermore, the proliferation and differentiation of intestinal stem cells (ISCs) is enhanced significantly after Morin intervention. Importantly, Morin increases the levels of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX) in the serum and jejunal tissue, while reducing the accumulation of ROS and malondialdehyde (MDA). Molecular interaction analysis further confirms that Morin targets inhibition of Keap1 to activate the Nrf2-mediated antioxidant system. In summary, our results suggest that Morin alleviates the oxidative damage induced by DON by regulating the Keap1/Nrf2 pathway, thereby restoring the proliferation and differentiation activity of ISC, which provides new insights into Morin mitigating DON damage. Full article

Fermented feed is extensively used in animal production due to their improved palatability and efficient utilization. This study aimed to explore the effects of fermented feed on growth performance and gut health, particularly through the modulation of intestinal stem cells (ISCs). Twenty-four 28-day-old male weaned piglets were randomly assigned into two groups (n = 12): piglets in a control group fed a basal diet, and an experimental group fed a basal diet replaced with 6% fermented mixed feed (FMF) for 28 days. The results indicated that FMF significantly elevated the growth rate, feed intake, and nutrient digestibility of piglets (p < 0.05). Furthermore, FMF supplementation increased the jejunal villus height, transepithelial electrical resistance (TEER) values, and the expression of tight junction proteins (ZO-1 and Claudin1) (p < 0.05). Immunohistochemistry (IHC) analysis revealed that FMF increased the number of Olfm4⁺ ISCs and PCNA⁺ mitotic cells in jejunal crypts, facilitating the differentiation of ISCs into enterocytes (Villin), goblet cells (MUC2), and enteroendocrine cells (CHGA). Conversely, the protein expression of Cleaved Caspase-3 was decreased in the FMF group (p < 0.05). Notably, the Wnt/β-catenin signaling pathway, including FZD7 and Active β-catenin, was significantly upregulated in the jejunum after FMF supplementation. Consistent with these findings, intestinal organoids derived from jejunal crypts in the FMF group demonstrated enhanced growth and increased expression of Lgr5, PCNA, KRT20, and β-catenin (p < 0.05). These results suggest that fermented feed promotes intestinal development by enhancing ISC proliferation and differentiation via activation of the Wnt/β-catenin signaling pathway. Full article

The intestinal area is composed of diverse cell types that harmonize gut homeostasis, which is influenced by both endogenous and exogenous factors. Notably, the environment of the intestine is exposed to several types of mechanical forces, including shear stress generated by fluid flow, compression and stretch generated by luminal contents and peristaltic waves of the intestine, and stiffness attributed to the extracellular matrix. These forces play critical roles in the regulation of cell proliferation, differentiation, and migration. Many efforts have been made to simulate the actual intestinal environment in vitro. The three-dimensional organoid culture system has emerged as a powerful tool for studying the mechanism of the intestinal epithelial barrier, mimicking rapidly renewing epithelium from intestinal stem cells (ISCs) in vivo. However, many aspects of how mechanical forces, such as shear stress, stiffness, compression, and stretch forces, influence the intestinal area remain unresolved. Here, we review the recent studies elucidating the impact of mechanical forces on intestinal immunity, interaction with the gut microbiome, and intestinal diseases. Full article

Bisphenol A (BPA) and diisobutyl (DIBP) phthalate are widely used as typical plasticizers in food packaging. Plasticizers can be released from polymers, migrate into food, and be ingested by humans, leading to various health problems. However, little research has investigated the combined toxicity of BPA and DIBP, particularly their intestinal toxicity. Our goal is to analyse the combined toxicity of BPA (50 mg/kg) and DIBP (500 mg/kg) on the intestines of KM mice. Additionally, we tried to find natural products that can inhibit or prevent the combined toxicity of BPA and DIBP. The results indicated that the combination of BPA and DIBP exposure resulted in a reduction of beneficial flora, an increase in D-Lac levels (136 ± 14 μmol/L), an increase in intestinal permeability, activation of the notch pathway, and a decline in intestinal stem cells (ISCs) to goblet cells, compared to single-exposure sources. Nevertheless, Rubus chingii Hu phenolic extract (RHPE) (200, 400 and 600 mg/kg) ameliorated the BPA and DIBP-induced intestinal microbiota disruption and intestinal mucosal barrier impairment by inhibiting the overactivation of the notch pathway. The results of this study highlight the potential risks to human health posed by the combination of BPA and DIBP and may help explain the potential pathways of enterotoxicity caused by combined ingestion. Full article

Understanding the regulation of somatic stem cells, both during homeostasis and in response to environmental challenges like injury, infection, chemical exposure, and nutritional changes, is critical because their dysregulation can result in tissue degeneration or tumorigenesis. The use of models such as the Drosophila and mammalian adult intestines offers valuable insights into tissue homeostasis and regeneration, advancing our knowledge of stem cell biology and cancer development. This review highlights significant findings from recent studies, unveiling the molecular mechanisms that govern self-renewal, proliferation, differentiation, and regeneration of intestinal stem cells (ISCs). These insights not only enhance our understanding of normal tissue maintenance but also provide critical perspectives on how ISC dysfunction can lead to pathological conditions such as colorectal cancer (CRC). Full article

The intestines are in a constant state of motion and self-renewal. The mechanical breakdown of food facilitates intestinal movement and aids digestion. It is believed that mechanical stimulation, triggered by changes in osmotic pressure within the intestines, plays a crucial role in regulating gastrointestinal motility. While TRPs and PIEZO1/2 have been identified as mechanosensitive ion channels involved in this process, there still exist numerous unidentified channels with similar properties. In this study, we demonstrate that the TMEM63B expressed in intestinal stem cells contributes to the regulation of intestinal motility and digestion. The deletion of TMEM63B in intestinal stem cells not only decelerates intestinal motility and impairs digestion but also attenuates the proliferation of intestinal stem cells and exacerbates DSS-induced colitis in mice. Collectively, our findings unveil the pivotal role of TMEM63B in governing optimal digestive function and modulating intestinal motility. Full article

Heavy ion radiation, prevalent in outer space and relevant for radiotherapy, is densely ionizing and poses a risk to intestinal stem cells (ISCs), which are vital for maintaining intestinal homeostasis. Earlier studies have shown that heavy-ion radiation can cause chronic oxidative stress, persistent DNA damage, cellular senescence, and the development of a senescence-associated secretory phenotype (SASP) in mouse intestinal mucosa. However, the specific impact on different cell types, particularly Lgr5⁺ intestinal stem cells (ISCs), which are crucial for maintaining cellular homeostasis, GI function, and tumor initiation under genomic stress, remains understudied. Using an ISCs-relevant mouse model (Lgr5⁺ mice) and its GI tumor surrogate (Lgr5⁺Apc^1638N/+ mice), we investigated ISCs-specific molecular alterations after high-LET radiation exposure. Tissue sections were assessed for senescence and SASP signaling at 2, 5 and 12 months post-exposure. Lgr5+ cells exhibited significantly greater oxidative stress following ²⁸Si irradiation compared to γ-ray or controls. Both Lgr5⁺ cells and Paneth cells showed signs of senescence and developed a senescence-associated secretory phenotype (SASP) after ²⁸Si exposure. Moreover, gene expression of pro-inflammatory and pro-growth SASP factors remained persistently elevated for up to a year post-²⁸Si irradiation. Additionally, p38 MAPK and NF-κB signaling pathways, which are critical for stress responses and inflammation, were also upregulated after ²⁸Si radiation. Transcripts involved in nutrient absorption and barrier function were also altered following irradiation. In Lgr5⁺Apc^1638N/+ mice, tumor incidence was significantly higher in those exposed to ²⁸Si radiation compared to the spontaneous tumorigenesis observed in control mice. Our results indicate that high-LET ²⁸Si exposure induces persistent DNA damage, oxidative stress, senescence, and SASP in Lgr5⁺ ISCs, potentially predisposing astronauts to altered nutrient absorption, barrier function, and GI carcinogenesis during and after a long-duration outer space mission. Full article

There are different stress resistance among different breeds of pigs. Changes in intestinal stem cells (ISCs) are still unclear among various breeds of piglets after early weaning. In the current study, Taoyuan Black and Duroc piglets were slaughtered at 21 days of age (early weaning day) and 24 days of age (3 days after early weaning) for 10 piglets in each group. The results showed that the rate of ISC-driven epithelial renewal in local Taoyuan Black pigs hardly changed after weaning for 3 days. However, weaning stress significantly reduced the weight of the duodenum and jejunum in Duroc piglets. Meanwhile, the jejunal villus height, tight junction-related proteins (ZO-1, Occludin, and Claudin1), as well as the trans-epithelial electrical resistance (TEER) values, were down-regulated after weaning for 3 days in Duroc piglets. Moreover, compared with Unweaned Duroc piglets, the numbers of Olfm4⁺ ISC cells, PCNA⁺ mitotic cells, SOX9⁺ secretory progenitor cells, and Villin⁺ absorptive cells in the jejunum were reduced significantly 3 days after weaning. And ex vivo jejunal crypt-derived organoids exhibited growth disadvantages in weaned Duroc piglets. Notably, the Keap1/Nrf2 signaling activities and the expression of HO-1 were significantly depressed in weaned Duroc piglets compared to Unweaned Duroc piglets. Thus, we can conclude that ISCs of Duroc piglets were more sensitive to weaning stress injury than Taoyuan Black piglets, and Keap1/Nrf2 signaling is involved in this process. Full article