Effect of sialyllactose on growth performance and intestinal epithelium functions in weaned pigs challenged by enterotoxigenic Escherichia Coli

Background:Sialyllactose(SL)is one of the most abundant oligosaccharides present in porcine breast milk.However,little is known about its effect on growth performance and intestinal health in weaned pigs.This study was conducted to explore the protective effect of SL on intestinal epithelium in weaned pigs upon enterotoxigenic Escherichia coli(ETEC)challenge.Methods:Thirty-two pigs were randomly divided into four treatments.Pigs fed with a basal diet or basal diet containing SL(5.0 g/kg)were orally infused with ETEC or culture medium.Results:SL supplementation elevated the average daily gain(ADG)and feed efficiency in the ETEC-challenged pigs(P<0.05).SL also improved the digestibilities of dry matter(DM),gross energy(GE),and ash in non-challenged pigs(P<0.05).Moreover,SL not only elevated serum concentrations of immunoglobulins(IgA,IgG,and IgM),but also significantly decreased the serum concentrations of inflammatory cytokines(TNF-α,IL-1β,and IL-6)upon ETEC challenge(P<0.05).Interestingly,SL increased the villus height,the ratio of villus height to crypt depth(V:C),and the activities of mucosal sucrase and maltase in the jejunum and ileum(P<0.05).SL also elevated the concentrations of microbial metabolites(e.g.acetic acid,propanoic acid,and butyric acid)and the abundance of Lactobacillus,Bifidobacterium,and Bacillus in the cecum(P<0.05).Importantly,SL significantly elevated the expression levels of jejunal zonula occludins-1(ZO-1),occluding,and fatty acid transport protein-4(FATP4)in the ETEC-challenged pigs(P<0.05).Conclusions:SL can alleviate inflammation and intestinal injury in weaned pigs upon ETEC challenge,which was associated with suppressed secretion of inflammatory cytokines and elevated serum immunoglobulins,as well as improved intestinal epithelium functions and microbiota.

Adhesion and immunomodulatory effects of Bifidobacterium lactis HN019 on intestinal epithelial cells INT-407

AIM:To elucidate the adherence and immunomodulatory properties of a probiotic strain Bifidobacterium lactis(B.lactis) HN019.METHODS:Adhesion assays of B.lactis HN019 and Salmonella typhimurium(S.typhimurium) ATCC 14028 to INT-407 cells were carried out by detecting copies of species-specific genes with real-time polymerase chain reaction.Morphological study was further conducted by transmission electron microscopy.Interleukin-1β(IL-1β),interleukin-8,and tumor necrosis factor-α(TNF-α) gene expression were assessed while enzyme linked immunosorbent assay was used to detect IL-8 protein secretion.RESULTS:The attachment of S.typhimurium ATCC 14028 to INT407 intestinal epithelial cells was inhibited significantly by B.lactis HN019.B.lactis HN019 could be internalized into the INT-407 cells and attenuated IL-8 mRNA level at both baseline and S.typhimuriuminduced pro-inflammatory responses.IL-8 secretion was reduced while IL-1β and TNF-α mRNA expression level remained unchanged at baseline after treated with B.lactis HN019.CONCLUSION:B.lactis HN019 does not up-regulate the intestinal epithelium expressed pro-inflammatory cytokine,it showed the potential to protect enterocytes from an acute inflammatory response induced by enteropathogen.

Hepatocyte nuclear factor 4-alpha involvement in liver and intestinal inflammatory networks

Hepatocyte nuclear factor 4-alpha (HNF4-&#x003b1;) is a nuclear receptor regulating metabolism, cell junctions, differentiation and proliferation in liver and intestinal epithelial cells. Mutations within the HNF4A gene are associated with human diseases such as maturity-onset diabetes of the young. Recently, HNF4A has also been described as a susceptibility gene for ulcerative colitis in genome-wide association studies. In addition, specific HNF4A genetic variants have been identified in pediatric cohorts of Crohn&#x02019;s disease. Results obtained from knockout mice supported that HNF4-&#x003b1; can protect the intestinal mucosae against inflammation. However, the exact molecular links behind HNF4-&#x003b1; and inflammatory bowel diseases remains elusive. In this review, we will summarize the current knowledge about the role of HNF4-&#x003b1; and its isoforms in inflammation. Specific nature of HNF4-&#x003b1; P1 and P2 classes of isoforms will be summarized. HNF4-&#x003b1; role as a hepatocyte mediator for cytokines relays during liver inflammation will be integrated based on documented examples of the literature. Conclusions that can be made from these earlier liver studies will serve as a basis to extrapolate correlations and divergences applicable to intestinal inflammation. Finally, potential functional roles for HNF4-&#x003b1; isoforms in protecting the intestinal mucosae from chronic and pathological inflammation will be presented.

Chronic low vitamin intake potentiates cisplatin-induced intestinal epithelial cell apoptosis in WNIN rats

AIM： To investigate if cisplatin alters vitamin status and if VR modulates cisplatin induced intestinal apoptosis and oxidative stress in Wistar/NIN （WNIN） male rats.METHODS： Weanling, WNIN male rats （n = 12 per group） received adlibitum for 17 wk： control diet （20% protein） or the same with 50% vitamin restriction. They were then sub-divided into two groups of six rats each and administered cisplatin （2.61 mg/kg bodyweight） once a week for three wk or PBS （vehicle control）. Intestinal epithelial cell （IEC） apoptosis was monitored by morphometry, Annexin-V binding, M30 cytodeath assay and DNA fragmentation. Structural and functional integrity of the villus were assessed by villus height / crypt depth ratio and activities of alkaline phosphatase, lys, ala-dipeptidyl amino-peptidase, respectively. To assess the probable mechanism（s） of altered apoptosis, oxidative stress parameters, caspase-3 activity, and expression of Bcl-2 and Bax were determined.RESULTS： Cisplatin per se decreased plasma vitamin levels and they were the lowest in VR animals treated with cisplatin. As expected VR increased only villus apoptosis, whereas cisplatin increased stem cell apoptosis in the crypt. However, cisplatin treatment of VR rats increased apoptosis both in villus and crypt regions and was associated with higher levels of TBARS, protein carbonyls and caspase-3 activity, but lower GSH concentrations. VR induced decrease in Bcl-2 expression was further lowered by cisplatin. Bax expression, unaffected by VR was increased on cisplatin treatment. Mucosal functional integrity was severely compromised in cisplatin treated VR-rats.CONCLUSION： Low intake of vitamins increases the sensitivity of rats to cisplatin and promotes intestinal epithelial cell apoptosis.

Towards a multiscale model of colorectal cancer

Colorectal cancer (CRC) is one of the best characterised cancers, with extensive data documenting the sequential gene mutations that underlie its development. Complementary datasets are also being generated describing changes in protein and RNA expression, tumour biology and clinical outcome. Both the quantity and the variety of information are inexorably increasing and there is now an accompanying need to integrate these highly disparate datasets. In this article we aim to explain why we believe that mathematical modelling represents a natural tool or language with which to integrate these data and, in so doing, to provide insight into CRC.

Mechanism of iron on the intestinal epithelium development in suckling piglets

This study aimed to investigate the mechanism of iron on intestinal epithelium development of suckling piglets. Compared with newborn piglets, 7-day-old and 21-day-old piglets showed changes in the morphology of the jejunum, increased proliferation,differentiated epithelial cells, and expanded enteroids. Intestinal epithelium maturation markers and iron metabolism genes were significantly changed. These results suggest that lactation is a critical stage in intestinal epithelial development, accompanied by changes in iron metabolism. In addition, deferoxamine(DFO) treatment inhibited the activity of intestinal organoids at passage 4(P4) of 0-day-old piglets, but no significant difference was observed in epithelial maturation markers at passage 1(P1) and P4,and only argininosuccinate synthetase 1(Ass1) and β-galactosidase(Gleb) were up-regulated at passage 7(P7). These results in vitro show that iron deficiency may not directly affect intestinal epithelium development through intestinal stem cells(ISCs). The iron supplementation significantly down-regulated the m RNA expression of interleukin-22 receptor subunit alpha-2(IL-22RA2)in the jejunum of piglets. Furthermore, the m RNA expression of IL-22 in 7-day-old piglets was significantly higher than that in0-day-old piglets. Adult epithelial markers were significantly up-regulated in organoids treated with recombinant murine cytokine IL-22. Thus, IL-22 may play a key role in iron-affecting intestinal epithelium development.

Patient-derived organoids for therapy personalization in inflammatory bowel diseases

Inflammatory bowel diseases(IBDs)are chronic inflammatory disorders of the intestinal tract that have emerged as a growing problem in industrialized countries.Knowledge of IBD pathogenesis is still incomplete,and the most widely-accepted interpretation considers genetic factors,environmental stimuli,uncontrolled immune responses and altered intestinal microbiota composition as determinants of IBD,leading to dysfunction of the intestinal epithelial functions.In vitro models commonly used to study the intestinal barrier do not fully reflect the proper intestinal architecture.An important innovation is represented by organoids,3D in vitro cell structures derived from stem cells that can self-organize into functional organ-specific structures.Organoids may be generated from induced pluripotent stem cells or adult intestinal stem cells of IBD patients and therefore retain their genetic and transcriptomic profile.These models are powerful pharmacological tools to better understand IBD pathogenesis,to study the mechanisms of action on the epithelial barrier of drugs already used in the treatment of IBD,and to evaluate novel target-directed molecules which could improve therapeutic strategies.The aim of this review is to illustrate the potential use of organoids for therapy personalization by focusing on the most significant advances in IBD research achieved through the use of adult stem cells-derived intestinal organoids.

Oral delivery of ferroptosis inducers for effective treatment of hepatic fibrosis

Liver fibrosis is characterized by the excessive accumulation of extracellular matrix(ECM),which is primarily produced by activated hepatic stellate cells(HSCs).However,effective therapies for hepatic fibrosis are currently lacking.Artesunate is a promising anti-fibrotic drug candidate,but its clinical application is hindered by limited absorption.Here,we present a novel oral delivery platform that enhances the HSCs uptake of artesunate and induces potent ferroptosis.The platform is vitamin Adecorated nanoparticles encapsulated with artesunate.The multifunctional ligand vitamin A interacts with retinol-binding proteins that are highly expressed on the intestinal epithelium to promote transcytosis,highly expressed on the surface of HSCs but lowly expressed in normal hepatocytes.After oral administration,this oral delivery platform enhances transepithelial transport in the intestine,improves drug accumulation in the liver,and continuously increases HSCs uptake of artesunate.Upon drug release in HSCs,artesunate depletes glutathione peroxidase 4 and glutathione,effectively initiating ferroptosis.In vivo experiments demonstrate that this strategy induces pronounced ferroptosis,efficiently relieving liver fibrosis.This work provides a proof-ofconcept demonstration that an oral delivery strategy for ferroptosis inducers may be beneficial for liver fibrosis treatment.

BMP signaling in homeostasis, transformation and inflammatory response of intestinal epithelium

Intestine is the organ for food digestion, nutrient absorption and pathogen defense, in which processes intestinal epithelium plays a central role. Intestinal epithelium undergoes fast turnover, and its homeostasis is regulated by multiple signaling pathways,including Wnt, Notch, Hippo and BMP pathways. BMP signaling has been shown to negatively regulate self-renewal of Lgr5^+ intestinal stem cells, constrains the expansion of intestinal epithelium, therefore attenuating colorectal cancer formation. BMPs and their receptors are expressed in both epithelial and mesenchymal cells, suggesting a two-way interaction between the mesenchyme and epithelium. In this review, we summarize the current understanding of the function of BMP signaling in homeostasis, cancerous transformation and inflammatory response of intestinal epithelium.

The interaction among gut microbes,the intestinal barrier and short chain fatty acids

The mammalian gut is inhabited by a massive and complicated microbial community, in which the hostachieves a stable symbiotic environment through the interdependence, coordination, reciprocal constraintsand participation in an immune response. The interaction between the host gut and themicrobiota is essential for maintaining and achieving the homeostasis of the organism. Consequently, guthomeostasis is pivotal in safeguarding the growth and development and potential productive performanceof the host. As metabolites of microorganisms, short chain fatty acids are not only the preferredenergy metabolic feedstock for host intestinal epithelial cells, but also exert vital effects on antioxidantsand the regulation of intestinal community homeostasis. Herein, we summarize the effects of intestinalmicroorganisms on the host gut and the mechanisms of action of short chain fatty acids on the fourintestinal barriers of the organism, which will shed light on the manipulation of the intestinal communityto achieve precise nutrition for specific individuals and provide a novel perspective for theprevention and treatment of diseases.

Intestinal stem cells and intestinal organoids

The intestinal epithelium is one of the most rapidly renewing tissues,which is fueled by stem cells at the base of the crypts.Strategies of genetic lineage tracing and organoids,which capture major features of original tissues,are powerful avenues for exploring the biology of intestinal stem cells in vivo and in vitro,respectively.The combination of intestinal organoideculturing system and genetic modification approaches provides an attractive platform to uncover the mechanism of colorectal cancer and genetic disorders in the human minigut.Here,we will provide a comprehensive overview of studies on intestinal epithelium and intestinal stem cells.We will also review the applications of organoids and genetic markers in intestinal research studies.Furthermore,we will discuss the advantages and drawbacks of organoids as disease models compared with mice models and cell lines.

Chiral mesoporous silica nano-screws as an efficient biomimetic oral drug delivery platform through multiple topological mechanisms

In the microscale, bacteria with helical body shapes have been reported to yield advantages in many bio-processes. In the human society, there are also wisdoms in knowing how to recognize and make use of helical shapes with multi-functionality. Herein, we designed atypical chiral mesoporous silica nano-screws(CMSWs) with ideal topological structures(e.g., small section area, relative rough surface,screw-like body with three-dimension chirality) and demonstrated that CMSWs displayed enhanced bioadhesion, mucus-penetration and cellular uptake(contributed by the macropinocytosis and caveolaemediated endocytosis pathways) abilities compared to the chiral mesoporous silica nanospheres(CMSSs)and chiral mesoporous silica nanorods(CMSRs), achieving extended retention duration in the gastrointestinal(GI) tract and superior adsorption in the blood circulation(up to 2.61-and 5.65-times in AUC).After doxorubicin(DOX) loading into CMSs, DOX@CMSWs exhibited controlled drug release manners with pH responsiveness in vitro. Orally administered DOX@CMSWs could efficiently overcome the intestinal epithelium barrier(IEB), and resulted in satisfactory oral bioavailability of DOX(up to 348%).CMSWs were also proved to exhibit good biocompatibility and unique biodegradability. These findings displayed superior ability of CMSWs in crossing IEB through multiple topological mechanisms and would provide useful information on the rational design of nano-drug delivery systems.

Inflammation and intestinal leakiness in older HIVD individuals with fish oil treatment

Fish oil is a natural product that has shown efficacy for managing inflammatory conditions with few side effects.There is emerging evidence that crosstalks between gut epithelial cells and immune cells contribute to chronic infectious diseases.HIV-infected(HIVt)older adults show age-related co-morbidities at a younger age than their uninfected counterparts.Persistent inflammation related to the chronic viral infection and its sequelae is thought to contribute to this disparity.However,little is known about whether fish oil reduces intestinal inflammation in HIV t patients.We measure inflammation and gut barrier function in HIV t older adults(median age Z 52,N Z 33),following 12 weeks of fish oil supplementation(a total daily dose of 1.6 g of omega-3 fatty acids).We showed a reduction in inflammation and gut permeability as measured by CD14,inflammatory cytokines,lipopolysaccharide,and lipopolysaccharide binding protein.The results indicate that older HIV t adults may benefit from a diet supplemented with the omega-3 fatty acids found in fish oil.