Intestinal Epithelial Proliferation Research Articles

Effects of supplemental fulvic acid on survival, growth performance, digestive ability and immunity of large yellow croaker (Larimichthys crocea) larvae.

A 30-day feeding trial was designed to evaluate the effect of supplemental fulvic acid (FA) on survival, growth performance, digestive ability and immunity of large yellow croaker (Larimichthys crocea) larvae (initial body weight 11.33 ± 0.57mg). Four isonitrogenous and isolipids diets containing 0.00%, 0.01%, 0.02% and 0.04% FA were formulated, respectively. Results showed that the supplementation of 0.04% FA significantly improved survival rate of large yellow croaker larvae. Meanwhile, supplemental FA significantly increased final body weight and specific growth rate. Based on the specific growth rate, the optimal supplementation was 0.0135% FA. Larvae fed the diet with 0.01% FA had significantly higher villus height than the control. The supplementation of 0.01%-0.02% FA significantly increased the muscular thickness of intestine. Moreover, supplementation of FA significantly increased mRNA expression of intestinal epithelial proliferation and barrier genes (pcna, zo-1 and zo-2). Diets supplemented with 0.02%-0.04% FA significantly increased the activity of trypsin in the intestinal segment, while 0.01%-0.02% FA significantly increased the activity of trypsin in the pancreatic segment. Compared with the control, supplementation of FA remarkably increased activities of alkaline phosphatase and leucine aminopeptidase in the brush border membrane of intestine. Larvae fed the diet with 0.01% FA significantly increased activities of lysozyme and total nitric oxide synthase. Furthermore, the supplementation of 0.01% to 0.02% FA significantly decreased the mRNA expression of pro-inflammatory cytokines (tnf-α and il-6). Concurrently, supplemental FA significantly increased anti-inflammatory cytokine (il-10) mRNA expression level. In conclusion, this study indicated that the supplementation of FA could improve the survival rate and growth performance of larvae by promoting intestinal development, digestive enzymes activities and innate immunity.

Secreted Aeromonas GlcNAc binding protein GbpA stimulates epithelial cell proliferation in the zebrafish intestine

ABSTRACT In response to microbiota colonization, the intestinal epithelia of many animals exhibit increased rates of cell proliferation. We used gnotobiotic larval zebrafish to identify a secreted factor from the mutualist Aeromonas veronii that is sufficient to promote intestinal epithelial cell proliferation. This secreted A. veronii protein is a homologue of the Vibrio cholerae GlcNAc binding protein GbpA, which was identified as a chitin-binding colonization factor in mice. GbpA was subsequently shown to be a lytic polysaccharide monooxygenase (LPMO) that can degrade recalcitrant chitin. Our phenotypic characterization of gbpA deficient A. veronii found no alterations in these cells’ biogeography in the zebrafish intestine and only a modest competitive disadvantage in chitin-binding and colonization fitness when competed against the wild-type strain. These results argue against the model of GbpA being a secreted adhesin that binds simultaneously to bacterial cells and GlcNAc, and instead suggests that GbpA is part of a bacterial GlcNAc utilization program. We show that the host proliferative response to GbpA occurs in the absence of bacteria upon exposure of germ-free zebrafish to preparations of native GbpA secreted from either A. veronii or V. cholerae or recombinant A. veronii GbpA. Furthermore, domain 1 of A. veronii GbpA, containing the predicted LPMO activity, is sufficient to stimulate intestinal epithelial proliferation. We propose that intestinal epithelial tissues upregulate their rates of renewal in response to secreted bacterial GbpA proteins as an adaptive strategy for coexisting with bacteria that can degrade glycan constituents of the protective intestinal lining.

MiR-542-5p targets c-myc and negates the cell proliferation effect of SphK1 in intestinal epithelial cells.

Intestinal epithelial barrier defects occur commonly during a variety of pathological conditions, though their underlying mechanisms are not completely understood. Sphingosine-1-phosphate (S1P) has been shown to be a critical regulator of proliferation and of maintenance of an intact intestinal epithelial barrier, as is also sphingosine kinase 1 (SphK1), the rate-limiting enzyme for S1P synthesis. SphK1 has been shown to modulate its effect on intestinal epithelial proliferation through increased levels of c-myc. We conducted genome-wide profile analysis to search for differential microRNA expression related to overexpressed SphK1 demonstrating adjusted expression of microRNA 542-5p (miR-542-5p). Here, we show that miR-542-5p is regulated by SphK1 activity and is an effector of c-myc translation that ultimately serves as a critical regulator of the intestinal epithelial barrier. miR-542-5p directly regulates c-myc translation through direct binding to the c-myc mRNA. Exogenous S1P analogs administered in vivo protect murine intestinal barrier from damage due to mesenteric ischemia reperfusion, and damaged intestinal tissue had increased levels of miR-542-5p. These results indicate that miR-542-5p plays a critical role in the regulation of S1P-mediated intestinal barrier function, and may highlight a novel role in potential therapies.

A dietary change to a high-fat diet initiates a rapid adaptation of the intestine.

Long-term impacts of diet have been well studied; however, the immediate response of the intestinal epithelium to a change in nutrients remains poorly understood. We use physiological metrics and single-cell transcriptomics to interrogate the intestinal epithelial cell response to a high-fat diet (HFD). Within 1day of HFD exposure, mice exhibit altered whole-body physiology and increased intestinal epithelial proliferation. Single-cell transcriptional analysis on day 1 reveals a cell-stress response in intestinal crypts and a shift toward fatty acid metabolism. By 3days of HFD, computational trajectory analysis suggests an emergence of progenitors, with a transcriptional profile shifting from secretory populations toward enterocytes. Furthermore, enterocytes upregulate lipid absorption genes and show increased lipid absorption invivo over 7days of HFD. These findings demonstrate the rapid intestinal epithelial response to a dietary change and help illustrate the essential ability of animals to adapt to shifting nutritional environments.

Secondary bile acids mediate high-fat diet-induced upregulation of R-spondin 3 and intestinal epithelial proliferation.

A high-fat diet (HFD) contributes to the increased incidence of colorectal cancer, but the mechanisms are unclear. We found that R-spondin 3 (Rspo3), a ligand for leucine-rich, repeat-containing GPCR 4 and 5 (LGR4 and LGR5), was the main subtype of R-spondins and was produced by myofibroblasts beneath the crypts in the intestine. HFD upregulated colonic Rspo3, LGR4, LGR5, and β-catenin gene expression in specific pathogen-free rodents, but not in germ-free mice, and the upregulations were prevented by the bile acid (BA) binder cholestyramine or antibiotic treatment, indicating mediation by both BA and gut microbiota. Cholestyramine or antibiotic treatments prevented HFD-induced enrichment of members of the Lachnospiraceae and Rumincoccaceae, which can transform primary BA into secondary BA. Oral administration of deoxycholic acid (DCA), or inoculation of a combination of the BA deconjugator Lactobacillus plantarum and 7α-dehydroxylase-containing Clostridium scindens with an HFD to germ-free mice increased serum DCA and colonic Rspo3 mRNA levels, indicating that formation of secondary BA by gut microbiota is responsible for HFD-induced upregulation of Rspo3. In primary myofibroblasts, DCA increased Rspo3 mRNA via TGR5. Finally, we showed that cholestyramine or conditional deletion of Rspo3 prevented HFD- or DCA-induced intestinal proliferation. We conclude that secondary BA is responsible for HFD-induced upregulation of Rspo3, which, in turn, mediates HFD-induced intestinal epithelial proliferation.

Effects of Chitosan-Coated Microdiet on Dietary Physical Properties, Growth Performance, Digestive Enzyme Activities, Antioxidant Capacity, and Inflammation Response of Large Yellow Croaker (Larimichthys crocea) Larvae.

A 30-day feeding trial was designed to investigate the physical properties of chitosan-coated microdiet (CCD) and the effect of CCD on survival, growth performance, activities of digestive enzymes, intestinal development, antioxidant capacity, and inflammatory response of large yellow croaker larvae (initial weight: 3.81 ± 0.20 mg). Four isonitrogenous (50% crude protein) and isolipidic (20% crude lipid) microdiets were prepared with different concentrations of chitosan wall material by spray drying method (0.00%, 0.30%, 0.60%, and 0.90%, weight (chitosan) : volume (acetic acid)). Results showed that the lipid encapsulation efficiency (control: 60.52%, Diet1: 84.63%, Diet2: 88.06%, Diet3: 88.65%) and nitrogen retention efficiency (control: 63.76%, Diet1: 76.14%, Diet2: 79.52%, Diet3: 84.68%) correlated positively with the concentration of wall material (P < 0.05). Furthermore, the loss rate of CCD was significantly lower than the uncoated diet. Larvae fed the diet with 0.60% CCD had significantly higher specific growth rate (13.52 and 9.95%/day) and survival rate (14.73 and 12.58%) compared to the control group (P < 0.05). Larvae fed the diet with 0.30% CCD had significantly higher trypsin activity in pancreatic segments than the control group (4.47 and 3.05 U/mg protein) (P < 0.05). Larvae fed the diet with 0.60% CCD had significantly higher activity of leucine aminopeptidase (7.29 and 4.77 mU/mg protein) and alkaline phosphatase (83.37 and 46.09 U/mg protein) in the brush border membrane than those of the control group (P < 0.05). The intestinal epithelial proliferation- and differentiation-related factors (zo-1, zo-2, and pcna) in larvae fed the diet with 0.30% CCD had higher expression than those of the control group (P < 0.05). When the concentration of wall material reached 0.90%, the larvae had significantly higher superoxide dismutase activity than that of the control group (27.27 and 13.72 U/mg protein) (P < 0.05). Meanwhile, malondialdehyde contents were significantly lower in larvae fed the diet with 0.90% CCD than that of the control group (8.79 and 6.79 nmol/mg protein) (P < 0.05). 0.30%~0.60% CCD significantly increased the activity of total nitric oxide synthase (2.31, 2.60, and 2.05 mU/mg protein) and inducible nitric oxide synthase (1.91, 2.01, and 1.63 mU/mg protein) and had significantly higher transcriptional levels of inflammatory factor genes (il-1β, tnf-α, and il-6) than those of the control group (P < 0.05). The results indicated chitosan-coated microdiet had great potential in feeding large yellow croaker larvae in addition to reducing nutrition loss.

Bacillus subtilis programs the differentiation of intestinal secretory lineages to inhibit Salmonella infection.

The role of intestinal microbiota on fate determination of intestinal epithelial cells has not been extensively examined. In this study, we explore the effect of Bacillus subtilis on programmed intestinal epithelial differentiation. We find that B.subtilis stimulates the differentiation of intestinal secretory cells. Moreover, B.subtilis inhibits the Notch pathway to reduce the expression of hairy and enhancer of split 1, thereby shifting intestinal stem cell differentiation toward a secretory cell fate. Moreover, we demonstrate that the programming effect of B.subtilis on intestinal differentiation is Toll-like receptor 2 pathway dependent. B.subtilis is associated with increased numbers of Paneth and goblet cells in the intestine. This results in the production of antimicrobial peptides to protect the intestinal mucosal barrier against Salmonella typhimurium. This study demonstrates that B.subtilis contributes to the differentiation of secretory cells by affecting Notch pathway signaling to maintain the intestinal barrier.

Differential influence of YAP1 and TAZ on differentiation of intestinal epithelial cell: A review.

Intestinal cell stemness, proliferation and differentiation are complex processes all occurring in distinct compartments of the crypt that need to be closely regulated to ensure proper epithelial renewal. The involvement of the Hippo pathway in intestinal epithelial proliferation and regeneration after injury via the regulation of its effectors YAP1 and TAZ has been well-documented over the last decade. The implication of YAP1 and TAZ on intestinal epithelial cell differentiation is less clear. Using intestinal cell models in which the expression of YAP1 and TAZ can be modulated, our group showed that YAP1 inhibits differentiation of the two main intestinal epithelial cell types, goblet and absorptive cells through a specific mechanism involving the repression of prodifferentiation transcription factor CDX2 expression. Further analysis provided evidence that the repressive effect of YAP1 on intestinal differentiation is mediated by regulation of the Hippo pathway by Src family kinase activity. Interestingly, the TAZ paralog does not seem to be involved in this process, which provides another example of the lack of perfect complementarity of the two main Hippo effectors.

Effects of Dietary Indole-3-carboxaldehyde Supplementation on Growth Performance, Intestinal Epithelial Function, and Intestinal Microbial Composition in Weaned Piglets.

As a microbial tryptophan metabolite, indole-3-carboxaldehyde (ICA) has been suggested to confer benefits to host, such as regulation of intestinal barrier function. This study aimed to elucidate the role of ICA in modulating intestinal homeostasis via using a weaned pig model. Twenty-four weaned piglets were randomly allocated into three groups: the control group (a basal diet), ICA100 group (the basal diet supplemented with 100 mg/kg ICA), and ICA200 group (the basal diet supplemented with 200 mg/kg ICA). The experiment lasted 14 d, and pigs from the control and ICA100 groups were slaughtered. The results showed no significant differences in the average daily gain (ADG) and average daily feed intake (ADFI) among the three groups (P > 0.05). However, the ICA100 group had a lower feed to gain ratio (F:G) (P < 0.05). Dietary ICA supplementation did not alter the villus height, crypt depth, and villus height/crypt depth ratio in the small intestine, and did not change the intestinal permeability and antioxidant parameters (P > 0.05). Intriguingly, ICA treatment significantly increased the jejunal, ileal and colonic indexes in piglets (P < 0.05). Besides, the expression of proliferating cell nuclear antigen (PCNA) in the intestine was up-regulated by ICA treatment. Moreover, in vitro experiments demonstrated that 15 μM ICA significantly accelerated the proliferation activity of IPEC-J2 cells, and increased the expression of the ICA receptor aryl hydrocarbon receptor (AHR) and the proliferation markers PCNA and Cyclin D1 (P < 0.05). In addition, dietary ICA supplementation modulated the intestinal flora, increasing the richness estimators and diversity index, decreasing the abundances of phylum Fibrobacterota and genera Alloprevotella, Prevotella, and Parabacteroides, and enriching the abundance of genera Butyrivibrio. These data reveal a beneficial role for the microbial metabolite ICA on intestinal epithelial proliferation, rather than intestinal barrier function, in weaned piglets.

β-Hydroxybutyrate suppresses colorectal cancer.

Colorectal cancer (CRC) is among the most frequent forms of cancer, and new strategies for its prevention and therapy are urgently needed1. Here we identify a metabolite signalling pathway that provides actionable insights towards this goal. We perform a dietary screen in autochthonous animal models of CRC and find that ketogenic diets exhibit a strong tumour-inhibitory effect. These properties of ketogenic diets are recapitulated by the ketone body β-hydroxybutyrate (BHB), which reduces the proliferation of colonic crypt cells and potently suppresses intestinal tumour growth. We find that BHB acts through the surface receptor Hcar2and induces the transcriptional regulator Hopx, thereby altering gene expression and inhibiting cell proliferation. Cancer organoid assays and single-cell RNA sequencing of biopsies from patients with CRC provide evidence that elevated BHB levels and active HOPX are associated with reduced intestinal epithelial proliferation in humans. This study thus identifies a BHB-triggered pathway regulating intestinal tumorigenesis and indicates that oral or systemic interventions with a single metabolite may complement current prevention and treatment strategies for CRC.

JAM-A signals through the Hippo pathway to regulate intestinal epithelial proliferation

SummaryJAM-A is a tight-junction-associated protein that contributes to regulation of intestinal homeostasis. We report that JAM-A interacts with NF2 and LATS1, functioning as an initiator of the Hippo signaling pathway, well-known for regulation of proliferation. Consistent with these findings, we observed increased YAP activity in JAM-A-deficient intestinal epithelial cells (IEC). Furthermore, overexpression of a dimerization-deficient mutant, JAM-A-DL1, failed to initiate Hippo signaling, phenocopying JAM-A-deficient IEC, whereas overexpression of JAM-A-WT activated Hippo signaling and suppressed proliferation. Lastly, we identify EVI1, a transcription factor reported to promote cellular proliferation, as a contributor to the pro-proliferative phenotype in JAM-A-DL1 overexpressing IEC downstream of YAP. Collectively, our findings establish a new role for JAM-A as a cell-cell contact sensor, raising implications for understanding the contribution(s) of JAM-A to IEC proliferation in the mammalian epithelium.

Ketone body \u03b2-hydroxybutyrate ameliorates colitis by promoting M2 macrophage polarization through the STAT6-dependent signaling pathway

BackgroundKetone body β-hydroxybutyrate (BHB) has received more and more attentions, because it possesses a lot of beneficial, life-preserving effects in the fields of clinical science and medicine. However, the role of BHB in intestinal inflammation has not yet been investigated.MethodsColonic mucosa of inflammatory bowel disease (IBD) patients and healthy controls were collected for evaluation of BHB level. Besides, the therapeutic effect of exogenous BHB in a murine model of acute dextran sulfate sodium (DSS)-induced colitis were assessed by body weight change, colon length, disease activity index, and histopathological sections. The regulatory effectors of BHB were analyzed by RT-qPCR, immunofluorescence, and microbe analysis in vivo. Moreover, the molecular mechanism of BHB was further verified in bone marrow-derived macrophages (BMDMs).ResultsIn this study, significantly reduced BHB levels were found in the colonic mucosa from IBD patients and correlated with IBD activity index. In addition, we demonstrated that the administration of exogenous BHB alleviated the severity of acute experimental colitis, which was characterized by less weight loss, disease activity index, colon shortening, and histology scores, as well as decreased crypt loss and epithelium damage. Furthermore, BHB resulted in significantly increased colonic expression of M2 macrophage-associated genes, including IL-4Ra, IL-10, arginase 1 (Arg-1), and chitinase-like protein 3, following DSS exposure, suggesting an increased M2 macrophage skewing in vivo. Moreover, an in vitro experiment revealed that the addition of BHB directly promoted STAT6 phosphorylation and M2 macrophage-specific gene expression in IL-4-stimulated macrophages. Besides, we found that BHB obviously increased M2 macrophage-induced mucosal repair through promoting intestinal epithelial proliferation. However, the enhancement effect of BHB on M2 macrophage-induced mucosal repair and anti-inflammation was completely inhibited by the STAT6 inhibitor AS1517499.ConclusionsIn summary, we show that BHB promotes M2 macrophage polarization through the STAT6-dependent signaling pathway, which contributes to the resolution of intestinal inflammation and the repair of damaged intestinal tissues. Our finding suggests that exogenous BHB supplement may be a useful therapeutic approach for IBD treatment.

Milk-Derived Small Extracellular Vesicles Promote Recovery of Intestinal Damage by Accelerating Intestinal Stem Cell-Mediated Epithelial Regeneration.

Milk-derived small extracellular vesicles (M-sEVs) are critical bioactive components in milk. They are considered to be regulators in milk that may have promising applications. Understanding their biological effects would be important in nutrition. Intestinal organoids and mice are used to explore the effects of M-sEVs on intestinal regeneration. M-sEVs could be absorbed by intestinal epithelia and upregulate expression of the microRNAs (miRNAs) expressed in milk: miR-148a, miR-22, miR-30, and miR-29a. Interestingly, M-sEVs promote proliferation of intestinal epithelia and repairs the epithelial damage that is caused by tumor necrosis factor-α in intestinal organoids. M-sEVs ameliorate intestinal mucosa damage in mice caused by treatment with dextran sulfate sodium, as well as increasing expression of the intestinal stem cells (ISC) markers leucine-rich repeat containing G-protein-coupled receptor 5 (Lgr5), olfactomedin 4 (Olfm4), and Achaete-Scute Family BHLH Transcription Factor 2 (Ascl2) and stimulating intestinal epithelial proliferation to repair epithelial damage. Furthermore, miR-29 is more abundant in M-sEVs-treated mice, and miR-29 could upregulate expression of ISC marker genes and accelerates intestinal regeneration to recover damaged intestinal epithelia. We reveal thatM-sEVs and miR-29 can accelerate intestinal stem cell-mediated epithelial regeneration and repair epithelial damage.

Immunohistochemical Expression of CDX2 in Gastric Carcinoma.

Background & Objective:Gastric cancer (GC) persists to be a major health issue globally, and the need to investigate new molecular markers for improving the survival of patients continues. CDX2 is a homeobox caudal protein family member encoded by the CDX2 gene and is probably playing a role in intestinal epithelial differentiation and proliferation. This study aimed to assess the expression of this protein in gastric cancer cells in addition to its correlation with multiple clinicopathological parameters. Methods:This observational retrospective study was carried out on 80 gastric cancer cases in Erbil, Iraq. CDX2 protein immunoexpression in tumor cells, as well as its correlation with several clinicopathological criteria, were investigated.Results:CDX2 was detected in 38.75% of GC patients. We found a significant correlation between CDX2 expression and the age of patients (P=0.02). Even though the protein was more expressed in tumors with negative lymphovascular invasion and intestinal GC, there was no significant correlation between the expression of this protein and invasion. In addition, CDX2 expression was not significantly correlated with patient gender, tumor grade, nodal status, and tumor stage. Conclusion:CDX2 expression was observed to be downregulated in younger patients. It could be due to the higher frequency of diffuse GC, in which CDX2 is expressed less than the intestinal type, in younger individuals.

Effect of Bacillus coagulans on maintaining the integrity intestinal mucosal barrier in broilers

Bacillus coagulans (B. coagulans), a spore-forming bacteria, has been further studied for its high tolerance to extreme environmental stressors and probiotic characteristics. But the modulatory effect of B. coagulans on the intestinal mucosal barrier remains unclear. To investigate the effects of B. coagulans on intestinal mucosal barrier, 1-day-old broiler chickens were orally administrated with 108 CFU/mL B. coagulans for consecutive 42 days. In this study, the body weight, jejunum villus height and crypt depth of broiler chickens were significantly increased after B. coagulans treatment. B. coagulans also increased the contents of total protein (TP) and albumin (ALB) in serum, and reduced the contents of low-density lipoprotein (LDL-C), blood urea nitrogen (BUN) and triglyceride (TG). In addition, B. coagulans improved the intestinal flora, significantly increasing the relative abundance of beneficial bacteria in the intestine. The ability of B. coagulans to enhance innate immunity is observed by the increased number of goblet cells and the decreased mRNA expression of IL-1β, IL-6, TNF-α, and sIgA content. Moreover, B. coagulans promoted intestinal epithelial proliferation through the Wnt/β-catenin signaling pathway. This study demonstrated that B. coagulans could maintain the intestinal mucosal barrier by improving the intestinal flora, enhancing innate immunity and promoting intestinal epithelial proliferation.

DNA Methylome Mapping Identifies Epigenetic Abnormalities in Intestinal Lymphocyte Regulation in Human Necrotizing Enterocolitis.

Epigenetic changes occur in response to environmental factors during the pathogenesis of necrotizing enterocolitis (NEC) in animal models, but the DNA methylation signature in human patients with NEC has not been examined. To illustrate the signature and function of DNA methylation in the intestine of human NEC. DNA methyltransferases (DNMTs) were compared between intestinal tissue with NEC and control. Genome-wide DNA methylation was analyzed by reduced representation bisulfite sequencing (RRBS). The biological functions of the potential methylation regulated genes were analyzed by Gene Ontology. Gene methylation and expression were confirmed by bisulfite genomic sequencing (BGS) and RT-qPCR. By screening the expression of DNMTs, we identified a marked reduction in DNMT3A at both the mRNA and protein levels in NEC. Genome-wide variation of DNA methylation was detected in NEC lesions. The CG methylation level in almost all unique regions except CpG islands (CGIs) was lower in NEC compared with control. A total of 287 differentially methylated regions (DMRs) were identified across the whole genome in NEC, 123 of them are located on the CGI in the promoter. The DMR-associated genes were linked to intestinal epithelial permeability, platelet aggregation, and lymphocyte proliferation. Four genes (ZNF335, MPL, RASAL3, and KDM6A) with roles in the regulation of lymphocytes that may predispose the intestine to imbalanced immune processes were further confirmed to be hypermethylated and transcriptionally downregulated. These findings underscore the novel relationship between epigenetic changes and lymphocyte regulation in human NEC, which may have potential diagnostic and therapeutic relevance for NEC.

Qingchang Wenzhong Decoction Accelerates Intestinal Mucosal Healing Through Modulation of Dysregulated Gut Microbiome, Intestinal Barrier and Immune Responses in Mice.

Inflammatory bowel disease (IBD), a group of multifactorial and inflammatory infirmities, is closely associated with dysregulation of gut microbiota and host metabolome, but effective treatments are currently limited. Qingchang Wenzhong Decoction (QCWZD) is an effective and classical traditional herbal prescription for the treatment of IBD and has been proved to attenuate intestinal inflammation in a model of acute colitis. However, the role of QCWZD in recovery phase of colitis is unclear. Here, we demonstrated that mice treated with QCWZD showed a faster recovery from dextran sulfate sodium (DSS)-induced epithelial injury, accompanied by reduced mucosal inflammation and attenuated intestinal dysbiosis using bacterial 16S rRNA amplicon sequencing compared to those receiving sterile water. The protective effects of QCWZD are gut microbiota dependent, as demonstrated by fecal microbiome transplantation and antibiotics treatment. Gut microbes transferred from QCWZD-treated mice displayed a similar role in mucosal protection and epithelial regeneration as QCWZD on colitis in mice, and depletion of the gut microbiota through antibiotics treatments diminished the beneficial effects of QCWZD on colitis mice. Moreover, metabolomic analysis revealed metabolic profiles alternations in response to the gut microbiota reprogrammed by QCWZD intervention, especially enhanced tryptophan metabolism, which may further accelerate intestinal stem cells-mediated epithelial regeneration to protect the integrity of intestinal mucosa through activation of Wnt/β-catenin signals. Collectively, our results suggested that orally administrated QCWZD accelerates intestinal mucosal healing through the modulation of dysregulated gut microbiota and metabolism, thus regulating intestinal stem cells-mediated epithelial proliferation, and hold promise for novel microbial-based therapies in the treatment of IBD.

Sepsis induces variation of intestinal barrier function in different phase through nuclear factor kappa B signaling.

The intestinal barrier function disrupted in sepsis, while little is known about the variation in different phases of sepsis. In this study, mouse models of sepsis were established by caecal ligation and puncture (CLP). The H&E staining of sections and serum diamine oxidase concentration were evaluated at different timepoint after CLP. TUNEL assay and EdU staining were performed to evaluate the apoptosis and proliferation of intestinal epithelium. Relative protein expression was assessed by Western blotting and serum concentrations of pro-inflammatory cytokines was measured by ELISA. The disruption of intestinal barrier worsened in the first 24 h after the onset of sepsis and gradually recovered over the next 24 h. The percentage of apoptotic cell increased in the first 24 h and dropped at 48 h, accompanied with the proliferative rate of intestinal epithelium inhibited in the first 6 h and regained in the later period. Furthermore, the activity of nuclear factor kappa B (NF-κB) presented similar trend with the intestinal barrier function, shared positive correction with apoptosis of intestinal epithelium. These findings reveal the conversion process of intestinal barrier function in sepsis and this process is closely correlated with the activity of NF-κB signaling.

MiR-802 regulates Paneth cell function and enterocyte differentiation in the mouse small intestine

The intestinal epithelium is a complex structure that integrates digestive, immunological, neuroendocrine, and regenerative functions. Epithelial homeostasis is maintained by a coordinated cross-talk of different epithelial cell types. Loss of integrity of the intestinal epithelium plays a key role in inflammatory diseases and gastrointestinal infection. Here we show that the intestine-enriched miR-802 is a central regulator of intestinal epithelial cell proliferation, Paneth cell function, and enterocyte differentiation. Genetic ablation of mir-802 in the small intestine of mice leads to decreased glucose uptake, impaired enterocyte differentiation, increased Paneth cell function and intestinal epithelial proliferation. These effects are mediated in part through derepression of the miR-802 target Tmed9, a modulator of Wnt and lysozyme/defensin secretion in Paneth cells, and the downstream Wnt signaling components Fzd5 and Tcf4. Mutant Tmed9 mice harboring mutations in miR-802 binding sites partially recapitulate the augmented Paneth cell function of mice lacking miR-802. Our study demonstrates a broad miR-802 network that is important for the integration of signaling pathways of different cell types controlling epithelial homeostasis in the small intestine.

Efficacy and Safety of Systemic and Locoregional Cisplatin Chronotherapy in Rats with Ovarian Carcinoma.

AimAlterations in circadian rhythms caused by tumor growth are thought to be clinically relevant as they affect the prognosis and treatment response. We aimed to evaluate the chronotherapeutic approach in rats with ovarian cancer receiving cisplatin intravenously (IV) or with hyperthermic intraperitoneal chemoperfusion (HIPEC) and to assess daily variations in tumor and intestinal epithelium proliferation.MethodsIn the pilot study, we used 12 intact rats and 12 rats with transplantable ovarian cancer, which were euthanized at ZT0 (08:00, lights on), ZT6, ZT12 and ZT18. In the main study, we used 45 rats with transplantable ovarian cancer. Animals were randomized into five groups: control, HIPEC with cisplatin at ZT0 (08:00), HIPEC with cisplatin at ZT12 (20:00), IV cisplatin at ZT0 and IV cisplatin at ZT12. We assessed the proliferation rate of tumor and small intestinal epithelium, apoptosis in small intestinal epithelium, and levels of γ-H2AX (DNA damage/repair marker) in kidneys and liver. Survival was calculated in each group.ResultsAscitic ovarian cancer disrupted daily variations in intestinal epithelium proliferation and DNA damage/repair in rats. Ovarian carcinoma exhibited no daily variation in mitotic activity. In animals receiving IV cisplatin, massive cell damage in the renal medulla and cystic changes within renal tubules were observed, unlike in rats receiving HIPEC. Tumor mitotic activity was lower in morning-treated groups. The median survival of rats in the control group was 8.5 days (95% CI 6.0–22.0), in HIPEC at ZT0 40.5 days (95% CI 28.0–47.0, p<0.001) and in HIPEC at ZT12 32.0 days (95% CI 28.0–37.0, p<0.001).ConclusionIn a rat model, ovarian tumor growth disrupted daily variations in intestinal epithelium proliferation and caused genotoxic stress in tumor-free tissues. HIPEC with cisplatin at ZT0 had a better efficacy/toxicity profile than HIPEC with cisplatin at ZT12 and IV administration at both time points.