Villus Epithelial Cells Research Articles

Distinct Treatment Outcomes between MVID Patient-Modeled Mice Suggest Epithelial Cell Maturation Is Influenced by MYO5B Functional State

Background and aims: Microvillus inclusion disease (MVID) is a devastating congenital diarrhea and malnutrition disorder caused by different point mutations in Myosin Vb (MYO5B). Specific genotype-dependent epithelial phenotypes or treatment options have not been fully investigated. Using tamoxifen-inducible epithelial-specific MYO5B-deficient (Myo5bΔIEC) mice, we have reported that MYO5B loss disrupts progenitor cell differentiation and that Lyso-Phosphatidic Acid (LPA) signaling and Notch inhibition can ameliorate the differentiation defects. We recently generated another MVID patient-modeled mouse strain, Vil1-CreERT2;Myo5bflox/G519R (Myo5b(G519R)). This study compared the epithelial pathophysiology and the effects of drug treatment between Myo5b(G519R) and Myo5bΔIEC mice. Methods: The MVID model mice and littermate controls received a single dose of tamoxifen, and their intestinal tissues were harvested on day 4 post-tamoxifen. For treatment: the small chemical LPAR5 agonist, Compound-1, or vehicle were given intraperitoneally once a day. Another set of mice received the Notch2-targeted inhibitor, Nirogacestat, on days 1 and 3. Digital image analysis scripts were developed for segmentation of immunostained tissues. Staining intensities and localization (membrane vs. cytoplasm) of markers were assessed in >300,000 epithelial cells per section. Results: Epithelial transcriptional signatures were analyzed by RNA-sequencing of enteroids generated from jejunal crypts of Myo5b(G519R) and Myo5bΔIEC mice. Enteroids from both mice showed significant upregulation of Notch signaling mediators and the downregulation of tuft cell markers and mitochondrial metabolic genes compared to control enteroids. Immunostaining of tissue sections consistently demonstrated that functional Myo5b loss decreases tuft cell numbers and mitochondrial densities in crypt and villus epithelial cells. In the vehicle treated MVID mouse tissues, sodium transporters of enterocytes, such as Na+/H+ exchanger (NHE)3 and Na+-dependent glucose transporter (SGLT)1, were mislocalized from the apical membrane and colocalized with lysosomal markers similar to what is observed in MVID patient tissues. Compound-1 treatment increased the apical localization of NHE3 and SGLT1 both in Myo5b(G519R) and Myo5bΔIEC mouse small intestines, whereas Nirogacestat improved localizations only in Myo5bΔIEC but not Myo5b(G519R) mouse tissues. Conclusions: Functional MYO5B loss, caused by the point mutation at G519R or total knockout directly disrupts Notch signaling and energy metabolic pathways in the epithelial cells, resulting in differentiation defects and malnutrition. The distinct treatment effcacies between the two MVID mouse models suggest that the total loss and impaired function of MYO5B differentially affect epithelial cell functions. NIH R01DK128190, RC2DK118640. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Expression and distribution of erythropoietin, vascular endothelial growth factor (VEGF) and VEGF receptor 2 in small intestine of yaks at different ages.

This study aimed to detect the expression and distribution of vascular endothelial growth factor (VEGF), VEGF receptor 2 (VEGFR-2), and erythropoietin (EPO) proteins in small intestinal tissues of 50-day-old, newborn, and adult yaks. The results provide basic data for the study of the relationship between adaptability and age of plateau yak. Small intestine tissues from healthy adult, 50-day-old, and newborn yak were collected and embedded in paraffin sections. Histological features were observed by haematoxylin and eosin staining. The expression of VEGF, VEGFR-2, and EPO proteins were detected by immunohistochemical staining. Immunohistochemical results showed that of the expression VEGF, VEGFR-2, and EPO were detected in the small intestinal villi of yaks at all ages. The EPO expression level in the jejunum and duodenal villous epithelial cells of newborn yaks was significantly higher than that of 50-day-old and adult yaks. The EPO expression level in ileum villous epithelial cells of 50-day-old yaks was significantly higher than that of newborn and adult yaks. VEGF expression in newborn yak ileum and jejunum epithelial cells of the intestinal villus were significantly higher than in the 50-day-old and adult. In the 50-day-old yaks, the duodenal intestinal villus epithelial cells expression levels were higher than in the adult and newborn yaks. The expression level of VEGFR-2 in the ileum, jejunum and duodenal villous epithelial cells of 50-day-old yak was significantly higher than in that of adult and newborn yak. The expression and distribution characteristics of EPO, VEGF, and VEGFR-2 in yak intestinal tissues of different ages indicate that these proteins may be involved in the physiological regulation of yak intestines in hypoxic environments. It may be an important regulatory protein in yak adaptation to a high altitude and low oxygen environment.

The relationship between SOD1 and Hsp70 expression in broiler ileum throughout post-hatching development

Heat shock proteins (Hsps) are molecular chaperones that play critical functions in the survival and development of cells. Hsps influence adaptive and innate immune responses and may promote cross-talk between the two systems. Superoxide dismutases (SODs) are metalloenzymes that play an essential role in the body's defense against oxidative stress by efficiently removing excess reactive oxygen species. This study is an experimental study that was conducted to determine the relationship between SOD1 and Hsp70 expression in the ileum during the post-hatching development of the broiler. In the study, samples were taken from ileum tissue of 0-, 21- and 42-day-old broilers were used as material. While the Hsp70 immunoreactivity observed in the epithelial cells was specific to a few cells on day 0, it was detected in more villus epithelial cells on days 21 and 42. The Hsp70 expression in the ileum increased from the age 0 to up to day 42, especially in villus epithelial cells. In sections stained by SOD1, the ileum's villus epithelial cells and smooth muscle cells showed an intracytoplasmic reaction. From day 21 to day 42, a regular increase in SOD1 expression was detected in the crypt and villus epithelial cells. As a remarkable finding, a more intense intracytoplasmic staining was detected in villus epithelial cells located at the apex of intestinal villi. In conclusion, it was observed that SOD1 and Hsp70 expression increased in the ileum tissue throughout post-hatching development in broilers with a positive correlation with age. Based on the histological findings, it can be concluded that SOD1 and Hsp70 play a critical protective role in the small intestine after hatching and contribute to the rapid development of the intestine.

Broiler İleumunda Kuluçka Sonrası Farklı Dönemlerin TLR4 ve VEGF Ekspresyon Paternleri Üzerine Etkisi

This study is aimed to evaluate the relationship between VEGF and TLR4 expression in the ileum during broiler post-hatching development. The material for the study was taken from the ileum tissue of 7-, 21-, and 42-day-old broilers. In tissue sections VEGF and TLR4 expression were demonstrated by Streptavidin-biotin complex immunohistochemistry method. Beginning on the 7th day after hatching, the number of stained cells and staining intensity in the epithelial cells lining the villus intestinalis increased in TLR4 immunostaining. On the 7th day following hatching, TLR4 protein expression was not seen in crypt epithelial cells. At day 21, crypt epithelial cells began to stain and gave a more intense immunoreaction at day 42. In VEGF-stained sections, the ileum villus epithelial cells, crypt, and smooth muscle tissue showed a brown intracytoplasmic response. The expression of the VEGF protein in the upper villus epithelial cells started to increase on the 7th day, and it stained intensely, especially on the 42nd day. In addition, it was observed that the staining intensity of the tunica muscularis layer was the same on the 7th and 21st days, and increased on the 42nd day. It was remarkable that goblet cells gave negative results in both immunostaining. In summary it seen that TLR4 and VEGF expression were found to be increase in this study from the 7th to the 42nd day following hatching. Thus, it was concluded that angiogenesis mechanisms and the development of innate and adaptive defense systems continue throughout the post-hatching period.

Complete genomic sequence analysis and intestinal tissue localization of a porcine Kobuvirus variant in China.

Porcine kobuvirus (PKV) infection is very common in both healthy pigs and diarrhea pigs throughout the world. However, there is no proof that it causes diarrhea, and little is known about its role in diarrhea. There are only a few reports concerning porcine kobuvirus separation at present, which makes investigating its invasion and pathogenesis mechanisms difficult. This study sequenced the entire genome of a porcine kobuvirus strain termed "Wuhan2020" after it was isolated from intestinal tissue samples of healthy piglets. The analysis results revealed that it shared the most resemblance with the WUH1 strain (89.5%) and belonged to the same evolutionary branch as the Hungarian strain S-1-SUN. The PKV was located using the in situ hybridization (ISH) approach, which revealed that it was colonized in intestinal villus epithelial cells and lymphocytes in the Peyer's patch. In general, we analyzed the genetic evolution of PKV, discovered PKV susceptible cells and determined PKV localization in the intestine of infected pigs, providing a reference for future research.

Transcriptome Profile Analysis of Intestinal Upper Villus Epithelial Cells and Crypt Epithelial Cells of Suckling Piglets.

Simple SummaryTo investigate the genetic reprogramming that drives intestinal epithelial cells (IECs) maturation along the crypt-villus axis, entCerocytes were sequentially isolated from the villus tip to the crypts of porcine small intestine. The present study obtained the intestinal upper villus epithelial cells (F1) and crypt epithelial cells (F3) of 21-day suckling piglets using the divalent chelation and precipitation technique. By mRNA high-throughput sequencing analysis of F1 and F3, it was shown that a total of 672 unigenes were differentially expressed between F1 and F3, including 224 highly expressed and 448 minimally expressed unigenes. The greatest number of differentially expressed genes enriched in signal transduction, e.g., Wnt, Hippo, TGF-beta, mTOR, PI3K-Akt, and MAPK signaling pathways, were closely related to the differentiation, proliferation, maturation and apoptosis of IECs. Our results provide important information for identifying new regulators of IECs differentiation and maturation. Moreover, they can also provide insights into the regulatory mechanisms underlying intestinal epithelial cell renewal and the rapid repair of intestinal mucosal oxidative damage.It is well known that the small intestinal epithelial cells of mammals rapidly undergo differentiation, maturation, and apoptosis. However, few studies have defined the physiological state and gene expression changes of enterocytes along the crypt-villus axis in suckling piglets. In the present study, we obtained the intestinal upper villus epithelial cells (F1) and crypt epithelial cells (F3) of 21-day suckling piglets using the divalent chelation and precipitation technique. The activities of alkaline phosphatase, sucrase, and lactase of F1 were significantly higher (p < 0.05) than those of F3. To explore the differences at the gene transcription level, we compared the global transcriptional profiles of F1 and F3 using RNA-seq analysis technology. A total of 672 differentially expressed genes (DEGs) were identified between F1 and F3, including 224 highly expressed and 448 minimally expressed unigenes. Functional analyses indicated that some DEGs were involved in the transcriptional regulation of nutrient transportation (SLC15A1, SLC5A1, and SLC3A1), cell differentiation (LGR5, HOXA5 and KLF4), cell proliferation (PLK2 and TGFB3), transcriptional regulation (JUN, FOS and ATF3), and signaling transduction (WNT10B and BMP1), suggesting that these genes were related to intestinal epithelial cell maturation and cell renewal. Gene Ontology (GO) enrichment analysis showed that the DEGs were mainly associated with binding, catalytic activity, enzyme regulator activity, and molecular transducer activity. Furthermore, KEGG pathway analysis revealed that the DGEs were categorized into 284 significantly enriched pathways. The greatest number of DEGs enriched in signal transduction, some of which (Wnt, Hippo, TGF-beta, mTOR, PI3K-Akt, and MAPK signaling pathways) were closely related to the differentiation, proliferation, maturation and apoptosis of intestinal epithelial cells. We validated the expression levels of eight DEGs in F1 and F3 using qRT-PCR. The present study revealed temporal and regional changes in mRNA expression between F1 and F3 of suckling piglets, which provides insights into the regulatory mechanisms underlying intestinal epithelial cell renewal and the rapid repair of intestinal mucosal damage.

DDAVP Downregulates the AQP3-Mediated Glycerol Transport via V1aR in Human Colon HCT8 Cells

Vasopressin (AVP) plays a key function in controlling body water and salt balance through the activation of the vasopressin receptors V1aR and V2R. Abnormal secretion of AVP can cause the syndrome of inappropriate antidiuresis that leads to hyponatremia, which is an electrolyte disorder often observed in the elderly hospitalized and oncologic patients. Beyond kidneys, the colonic epithelium modulates water and salt homeostasis. The water channel AQP3, expressed in villus epithelial cells is implicated in water absorption across human colonic surface cells. Here, the action of dDAVP, a stable vasopressin analog, was evaluated on the AQP3 expression and function using human colon HCT8 cells as an experimental model. Confocal and Western Blotting analysis revealed that HCT8 cells express both V1aR and V2R. Long-term (72 h) treatment with dDAVP reduced glycerol uptake and cell viability. These effects were prevented by SR49059, a synthetic antagonist of V1aR, but not by tolvaptan, a specific V2R antagonist. Of note, the SR49059 action was impaired by DFP00173, a selective inhibitor of AQP3. Interestingly, compared to the normal colonic mucosa, in the colon of patients with adenocarcinoma, the expression of V1aR was significantly decreased. These findings were confirmed by gene expression analysis with RNA-Seq data. Overall, data suggest that dDAVP, through the V1aR dependent pathway, reduces AQP3 mediated glycerol uptake, a process that is reversed in adenocarcinoma, suggesting that the AVP-dependent AQP3 pathway may represent a novel target in colon diseases associated with abnormal cell growth.

Physicochemical Characteristics and Antidiabetic Properties of the Polysaccharides from Pseudostellaria heterophylla.

This study aimed to investigate the Pseudostellaria heterophylla polysaccharides (PF40) physicochemical and antidiabetic characteristics. The ultraviolet–visible (UV) spectra, Fourier transform infrared radiation (FT-IR) spectra, nuclear magnetic resonance (NMR) spectra, zeta potential, surface characteristics, and conformational and thermal stability properties of PF40 were characterized. X-ray diffraction (XRD) and scanning electron microscopy (SEM), combined with Congo red test, revealed that PF40 powder has mainly existed in amorphous form with triple-helix conformation. The single-molecular structure of PF40 exhibited a multi-branched structure extending from the center to the periphery by scanning probe microscopy (SPM) scanning. The monosaccharide residue of PF40 was an α-pyranoid ring and exhibits good stability below 168 °C. Experimental studies on antidiabetic characteristics found that PF40 could significantly improve STZ-induced intestinal mucosal damage and reduce the apoptosis of villus epithelial cells. PF40 combined with metformin could significantly improve the symptoms of insulin resistance in type 2 diabetes mellitus (T2DM) rats, the molecular mechanism might be through inhibiting the expression of RORγ protein and increasing Foxp3 protein in the jejunum of T2DM rats, and then restoring the STZ-induced imbalance of T helper 17(Th17)/ regulatory T cells (Treg) cells, thereby maintaining intestinal immune homeostasis. Results identified in this study provided important information regarding the structure and antidiabetic characteristics of Pseudostellaria heterophylla polysaccharides, which can contribute to the development of Pseudostellaria heterophylla polysaccharides for industrial purposes in the future.

BMP gradient along the intestinal villus axis controls zonated enterocyte and goblet cell states.

Intestinal epithelial cells derive from stem cells at the crypt base and travel along the crypt-villus axis to die at the villus tip. The two dominant villus epithelial cell types, absorptive enterocytes and mucous-secreting goblet cells, are mature when they exit crypts. Murine enterocytes switch functional cell states during migration along the villus. Here, we ask whether this zonation is driven by the bone morphogenetic protein (BMP) gradient, which increases toward the villus. Using human intestinal organoids, we show that BMP signaling controls the expression of zonated genes in enterocytes. We find that goblet cells display similar zonation involving antimicrobial genes. Using an inducible Bmpr1a knockout mouse model, we confirm that BMP controls these zonated genes invivo. Our findings imply that local manipulation of BMP signal strength may be used to reset the enterocyte "rheostat" of carbohydrate versus lipid uptake and to control the antimicrobial response through goblet cells.

Intestinal Deletion of 3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase Promotes Expansion of the Resident Stem Cell Compartment.

The intestine occupies the critical interface between cholesterol absorption and excretion. Surprisingly little is known about the role of de novo cholesterol synthesis in this organ, and its relationship to whole body cholesterol homeostasis. Here, we investigate the physiological importance of this pathway through genetic deletion of the rate-limiting enzyme. Mice lacking 3-hydroxy-3-methylglutaryl-coenzyme A reductase (Hmgcr) in intestinal villus and crypt epithelial cells were generated using a Villin-Cre transgene. Plasma lipids, intestinal morphology, mevalonate pathway metabolites, and gene expression were analyzed. Mice with intestine-specific loss of Hmgcr were markedly smaller at birth, but gain weight at a rate similar to wild-type littermates, and are viable and fertile into adulthood. Intestine lengths and weights were greater relative to body weight in both male and female Hmgcr intestinal knockout mice. Male intestinal knockout had decreased plasma cholesterol levels, whereas fasting triglycerides were lower in both sexes. Lipidomics revealed substantial reductions in numerous nonsterol isoprenoids and sterol intermediates within the epithelial layer, but cholesterol levels were preserved. Hmgcr intestinal knockout mice also showed robust activation of SREBP-2 (sterol-regulatory element binding protein-2) target genes in the epithelium, including the LDLR (low-density lipoprotein receptor). At the cellular level, loss of Hmgcr is compensated for quickly after birth through a dramatic expansion of the stem cell compartment, which persists into adulthood. Loss of Hmgcr in the intestine is compatible with life through compensatory increases in intestinal absorptive surface area, LDLR expression, and expansion of the resident stem cell compartment.

OP14 Interpreting genome-wide association studies of Inflammatory Bowel Disease through the lens of single-cell sequencing

Abstract Background Inflammatory bowel disease (IBD) is a complex disease characterised by chronic inflammation of the digestive tract. Genome-wide association studies (GWAS) have identified 241 risk loci significantly associated with the two common forms of IBD, Crohn’s disease and ulcerative colitis. The vast majority of these risk loci reside in non-coding regions of the genome, and we only know which gene is dysregulated to increase risk of disease for a minority. This knowledge gap makes it difficult to draw insights into disease pathology and identify new candidate drug targets. Methods To improve biological insights from IBD GWAS, we generated single cell RNA-sequencing data from ileal biopsies ascertained from 25 CD patients with active ileal inflammation and 26 non-IBD controls. We identified 49 different cell types among the ~140K sequenced cells (Fig.1), including all major immune, enterocyte, secretory and mesenchymal populations. Our optimized single-cell dissociation protocol preserves the top of villus epithelial cells, which are inherently prone to anoikis, enabling generation of high-quality transcriptomes for the first time. Fig. 1 Single-cell atlas of terminal ileum biopsies from Crohn’s disease and non-IBD individuals. Results We identified 797 unique genes differentially expressed between CD patients and controls, with notable expression differences in stem cell, secretory, and enterocyte populations. Genes involved in antigen presentation and interferon-gamma signaling were enriched among those most frequently dysregulated cell types. In an attempt to identify which of these expression differences are likely causal of disease, rather than simply a consequence of it, we integrated results from the latest IBD GWAS to assess the extent to which genes captured disease heritability, and in which cell-types. Genes specifically expressed in Tregs, monocytes and IL10RA-negative monocyte-derived macrophages captured a significant fraction of disease heritability, strongly implicating these cell types in disease pathogenesis. We investigated which genes were driving these enrichment signals and identified candidate effector genes at many IBD risk loci. Reassuringly, many confirmed IBD effector genes known to have a role in the normal functioning of these cell types were found, including NOD2, IL18RAP, IL23R, NCF4, and IL2RA. Conclusion Single-cell analysis combined with IBD genetics has generated strong evidence for a causal role of novel disease mechanisms that have therapeutic potential. Further experiments are underway to validate this finding. At ECCO we will present an updated version of this analysis, including genetic mapping of gene-regulation across cell types to identify IBD effector genes and causal variants.

Adaptive differentiation promotes intestinal villus recovery.

Loss of differentiated cells to tissue damage is a hallmark of many diseases. In slow-turnover tissues, long-lived differentiated cells can re-enter the cell cycle or transdifferentiate to another cell type to promote repair. Here, we show that in a high-turnover tissue, severe damage to the differentiated compartment induces progenitors to transiently acquire a unique transcriptional and morphological postmitotic state. We highlight this in an acute villus injury model in the mouse intestine, where we identified a population of progenitor-derived cells that covered injured villi. These atrophy-induced villus epithelial cells (aVECs) were enriched for fetal markers but were differentiated and lineage committed. We further established a role for aVECs in maintaining barrier integrity through the activation of yes-associated protein (YAP). Notably, loss of YAP activity led to impaired villus regeneration. Thus, we define a key repair mechanism involving the activation of a fetal-like program during injury-induced differentiation, a process we term "adaptive differentiation."

Abstract 123: Intestinal Deletion Of 3-hydroxy-3-methylglutaryl-coenzyme A Reductase Promotes Expansion Of The Resident Stem Cell Compartment

While the intestine is the critical interface between cholesterol absorption and excretion, surprisingly little is known about the role of de novo cholesterol synthesis in this organ and how it affects whole body cholesterol homeostasis. The mevalonate pathway is most well-known for the production of cholesterol, but it is also required for the production of essential non-sterol isoprenoids. 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), the rate-limiting enzyme in the mevalonate pathway, is regulated by a three-protein complex made up of INSIG, SCAP, and SREBP2. Intestine specific knockouts of Scap and Srebp2 both result in severe enteropathy and reduced mouse survival. Here, we assessed the hypothesis that Hmgcr is required for enterocyte viability. Mice harboring floxed alleles for Hmgcr were bred with the Villin-Cre transgene to specifically knock out this enzyme in the villus and crypt epithelial cells of the small intestine (i-KO). The i-KO mice are viable through adulthood and fertile. Hmgcr is efficiently deleted based on analysis via drop digital PCR and qPCR. RNA sequencing shows reduction in all SREBP2 target genes throughout the mevalonate pathway in intestinal epithelial cells. Lipidomics confirms substantial reductions in abundance of all sterol and non-sterol isoprenoids, except 7-dehydrocholesterol and cholesterol. Cholesterol is likely maintained through reabsorption of biliary cholesterol or increased uptake from the circulation. Circulating cholesterol levels and cholesterol absorption are not altered in i-KO mice, but triglyceride absorption is increased through compensatory changes in bile acid composition and intestinal growth. At the cellular level, the intestine rapidly compensates for loss of Hmgcr via dramatic expansion of the stem cell compartment within the crypts. In conclusion, the mechanisms by which the intestine compensates for genetic loss of Hmgcr include altered triglyceride absorption, bile acid composition, increased absorptive surface area, and expansion of the resident stem cell compartment. Together these studies provide insight into the effects of HMGCR knockout in intestinal development and lipid metabolism.

Histopathological Effects of NaCl Overconcentration in the Gills and Internal Organs of Cyprinus carpio L.

This study aimed to assess the toxic effect of the overconcentration of salt (NaCl) in farmed common carp fish, Cyprinus carpio L. in floating cages in Al-Saqlawiyah Rgion in Iraq. The salt was used at 13.8% which led to fish mortality reached to 70% through 96 hours of exposure. The fishes exhibited lethargy during 10 minutes with abnormal nervous signs and imbalance swimming with progressive decreases in opercular movement frequency. The gills appeared as cooked gill lesion with excessive mucus secretion and congestion in the hepatic, gastrointestinal and kidney tissues. Microscopical examination of gills showed hyper trophy in both pillar cells and mucus cells, variable in severity code of both epithelial hyperplasia and occlusion of lamellar space as well as epithelial cells lifting had been determined and vacuolar degeneration in hepatic cells with severe multifocal infiltration of inflammatory cells and necrosis in liver. Histopathological analysis of kidneys revealed interstitial nephritis while in the intestine, the microscopic examination exhibited hydropic degeneration of mucoid cells, hyperplasia of enterocytes and desquamation of the epithelial cells of villi. The conclusion of this study was that histopathological analysis can be used as biological indicators for evaluation of effects of NaCl overconcentration in fish organs.

Epidermal growth factor promotes intestinal secretory cell differentiation in weaning piglets via Wnt/β-catenin signalling

Small intestinal epithelium homeostasis involves four principal cell types: enterocytes, goblet, enteroendocrine and Paneth cells. Epidermal growth factor (EGF) has been shown to affect enterocyte differentiation. This study determined the effect of dietary EGF on goblet, enteroendocrine and Paneth cell differentiation in piglet small intestine and potential mechanisms. Forty-two weaned piglets were used in a 2 × 3 factorial design; the major factors were time post-weaning (days 7 and 14) and dietary treatment (0, 200 or 400 µg/kg EGF supplementation). The numbers of goblet and enteroendocrine cells were generally greater with the increase in time post-weaning. Moreover, the supplementation of 200 µg/kg EGF increased (P < 0.01) the number of goblet and enteroendocrine cells in villus and crypt of the piglet small intestine as compared with the control. Dietary supplementation with 200 µg/kg EGF enhanced (P < 0.05) abundances of differentiation-related genes atonal homologue 1, mucin 2 and intestinal trefoil factor 3 messenger RNA (mRNA) as compared with the control. Piglets fed 200 or 400 µg/kg EGF diet had increased (P < 0.05) abundances of growth factor-independent 1, SAM pointed domain containing ETS transcription factor and pancreatic and duodenal homeobox 1 mRNA, but decreased the abundance (P < 0.01) of E74 like ETS transcription factor 3 mRNA as compared with the control. Animals receiving 400 µg/kg EGF diets had enhanced (P < 0.05) abundances of neurogenin3 and SRY-box containing gene 9 mRNA as compared with the control. The mRNA abundance and protein expression of lysozyme, a marker of Paneth cell, were also increased (P < 0.05) in those animals. As compared with the control, dietary supplementation with 200 µg/kg EGF increased the abundance of EGF receptor mRNA and the ratio of non-phospho(p)-β-catenin/β-catenin (P < 0.05) in villus epithelial cells at days 7 and 14. This ratio in crypt epithelial cells was higher (P < 0.05) on the both 200 and 400 µg/kg EGF groups during the same period. Our results demonstrated that dietary EGF stimulated goblet, enteroendocrine and Paneth cell differentiation in piglets during the post-weaning period, partly through EGFR and Wnt/β-catenin signalling.

Dietary zinc source impacts intestinal morphology and oxidative stress in young broilers

Zinc is an essential nutritional trace element for all forms of life as it plays an important role in numerous biological processes. In poultry, zinc is provided by in-feed supplementation, mainly as zinc oxide or zinc sulfate. Alternatively zinc can be supplemented as organic sources, which are characterized by using an organic ligand that may be an amino acid, peptide, or protein to bind zinc and have a higher bioavailability than inorganic zinc sources. There are limited number of studies directly comparing the effects of inorganic vs. organic zinc sources on performance and intestinal health in broilers. Therefore, a digestibility and a performance study were conducted to evaluate and compare the effect of an amino acid-complexed zinc source vs. an inorganic zinc source on intestinal health. The experiment consisted of 2 treatments: either a zinc amino acid complex or zinc sulfate was added to a wheat–rye based diet at 60 ppm Zn, with 10 replicates (34 broilers per pen) per treatment. Effects on performance, intestinal morphology, microbiota composition, and oxidative stress were measured. Supplementing zinc amino acid complexes improved the zinc digestibility coefficient as compared to supplementation with zinc sulfate. Broilers supplemented with zinc amino acid complexes had a significantly lower feed conversion ratio in the starter phase compared to birds supplemented with zinc sulfate. A significantly higher villus length was observed in broilers supplemented with zinc amino acid complexes at days 10 and 28. Supplementation with zinc amino acid complexes resulted in a decreased abundance of several genera belonging to the phylum of Proteobacteria. Plasma malondialdehyde levels and glutathione peroxidase activity showed an improved oxidative status in broilers supplemented with zinc amino acid complexes. In conclusion, zinc supplied in feed as amino acid complex is more readily absorbed, potentially conferring a protective effect on villus epithelial cells in the starter phase.

Evaluation of the tetrodotoxin uptake ability of pufferfish Takifugu rubripes tissues according to age using an in vitro tissue slice incubation method

The tetrodotoxin (TTX) uptake ability of pufferfish Takifugu rubripes tissues and its growth-associated changes were investigated using an in vitro tissue slice incubation method. Tissue slices prepared from the liver, skin, and intestine of a non-toxic cultured adult T. rubripes (20 months old) and incubated with incubation buffer containing 25 μg/mL TTX for 1–48 h showed a time-dependent increase in the TTX content in all tissues. The TTX contents of the skin and intestine slices were comparable to or slightly higher than that of the liver slices, with a similar transition pattern, suggesting similar TTX uptake ability among the skin, intestine, and liver. The TTX uptake ability of the liver and intestine did not differ significantly between young (8 months old) and adult (20 months old) fish, but the skin slices of young fish took up approximately twice as much TTX as that of adult fish, suggesting that the TTX uptake ability of the skin is involved in the growth-dependent changes in the toxin distribution inside the body in T. rubripes. To estimate the TTX uptake pathway in each tissue, an immunohistochemical technique was used to observe temporal changes in the intra-tissue microdistribution of TTX during incubation. The findings suggested that TTX is transferred and accumulates from pancreatic exocrine cells to hepatic parenchymal cells in the liver, from connective tissues to basal cells in the skin, and from villi epithelial cells via the lamina propria to the muscle layer in the intestine.

Modification effects of SanWei GanJiang Powder on liver and intestinal damage through reversing bile acid homeostasis

BackgroundSanwei Ganjiang Powder (SWGJ), derived from traditional Chinese medicine (TCM), has long demonstrated its effectiveness in long-term liver damage therapy. Recent studies indicated that it can also regulate the intestinal tract, although the underlying molecular mechanisms of this remain mysterious. The aim of the study is to investigate the mechanisms of SWGJ against dysbacteriosis and carbon tetrachloride (CCl4)-induced gut-liver axis damage underlying bile acid enterohepatic circulation. MethodsTo observe the regulatory effects of SWGJ on Liver and Intestinal Damage, we explored two animal models. In model 1, sixty BALB/c mice were subjected to oral gavage with 12 g/kg of ceftriaxone sodium for 10d; during this time, SWGJ, bifendate and bifico were sequentially administered over 7d. In model 2, the model of chronic liver injury was induced by subcutaneous injection of 40% CCl4 oil solution twice per week for 8 weeks. From the 3rd week, SWGJ, bifendate and bifico were sequentially administered for 6 weeks. Intestinal flora (16S rDNA analysis), histology (H&E staining), tight connections (Immunohistochemistry, IHC), ultrastructure (Transmission electron microscopy, TEM), inflammatory cytokines and LPS (Enzyme-linked immunosorbent assay, ELISA) of the intestines were assessed, and liver function was also evaluated by methods including ALT, AST and H&E staining. The levels of protein associated with bile acid metabolism were assessed by western blot. ResultsIn model 1, SWGJ significantly decreased the activity of inflammatory cytokines and LPS compared with the ceftriaxone sodium group. In addition, SWGJ improved symptoms of intestinal flora imbalance; further, ZO-1 and occludin in the cytoplasm of intestinal villus epithelial cells was increased, and the histopathology of the ileum was improved. Notably, the expression of ALT and AST was significant increased, and disordered hepatic lobule structures were clearly observed in liver histopathology in model group; SWGJ can significantly improve these changes. Furthermore, the levels of proteins related to bile acid synthesis, such as CYP7A1, were significantly upregulated in the SWGJ group compared with the model, and proteins related to excretion and reabsorption, such as NTCP, Mrp2 and BESP, were also upregulated. Importantly, SWGJ increased the nuclear expression of nuclear factor-E2-related factor-2 (Nrf2). Similar results appeared in model 2. ConclusionThis study suggests that SWGJ may elicit significant effects on the treatment of gut-liver axis damage, potential mechanisms at least partially involve bile acid enterohepatic, and increasing of the nuclear Nrf2 levels.

Lessening of porcine epidemic diarrhoea virus susceptibility in piglets after editing of the CMP-N-glycolylneuraminic acid hydroxylase gene with CRISPR/Cas9 to nullify N-glycolylneuraminic acid expression.

The porcine epidemic diarrhoea virus (PEDV) devastates the health of piglets but may not infect piglets whose CMP-N-glycolylneuraminic acid hydroxylase (CMAH) gene is mutated (knockouts, KO) by using CRISPR/Cas9 gene editing techniques. This hypothesis was tested by using KO piglets that were challenged with PEDV. Two single-guide RNAs targeting the CMAH gene and Cas9 mRNA were microinjected into the cytoplasm of newly fertilized eggs. Four live founders generated and proven to be biallelic KO, lacking detectable N-glycolylneuraminic acid (NGNA). The founders were bred, and homozygous offspring were obtained. Two-day-old (in exps. I, n = 6, and III, n = 15) and 3-day-old (in exp. II, n = 9) KO and wild-type (WT, same ages in respective exps.) piglets were inoculated with TCID50 1x103 PEDV and then fed 20 mL of infant formula (in exps. I and II) or sow’s colostrum (in exp. III) every 4 hours. In exp. III, the colostrum was offered 6 times and was then replaced with Ringer/5% glucose solution. At 72 hours post-PEDV inoculation (hpi), the animals either deceased or euthanized were necropsied and intestines were sampled. In all 3 experiments, the piglets showed apparent outward clinical manifestations suggesting that infection occurred despite the CMAH KO. In exp. I, all 6 WT piglets and only 1 of 6 KO piglets died at 72 hpi. Histopathology and immunofluorescence staining showed that the villus epithelial cells of WT piglets were severely exfoliated, but only moderate exfoliation and enterocyte vacuolization was observed in KO piglets. In exp. II, delayed clinical symptoms appeared, yet the immunofluorescence staining/histopathologic inspection (I/H) scores of the two groups differed little. In exp. III, the animals exhibited clinical and pathological signs after inoculation similar to those in exp. II. These results suggest that porcine CMAH KO with nullified NGNA expression are not immune to PEDV but that this KO may lessen the severity of the infection and delay its occurrence.

Lysophosphatidic acid signaling restores mislocalization of brush border proteins in MYO5B deficient mice

Background &amp; AimMyosin Vb (MYO5B) is an essential trafficking protein for membrane protein recycling in gastrointestinal (GI) epithelial cells and its mutation causes the congenital diarrheal disease, microvillus inclusion disease (MVID). Our group has reported that MYO5B loss results in a decrease in the brush border localization of nutrient transporters and enzymes, but CFTR expression is maintained, causing malabsorption and secretory diarrhea in MVID patients and MYO5B KO mice. Activation of lysophosphatidic acid (LPA) receptors (LPA2 and LPA5) can inhibit CFTR and activate NHE3 in the intestinal epithelium. This study tested whether LPA treatment reverses the functional expression of apical proteins in MYO5B knockout (KO) mice.MethodsAdult tamoxifen‐induced, intestine‐specific, MYOB KO mice (VilCreERT2;Myo5bflox/flox) and littermate control mice were treated with LPA (18:1 at 1 or 3 mg/kg/day) or vehicle, orally or intraperitoneally for 4 days after a single injection of tamoxifen (2 mg/mouse, i.p.). Apical transporter activities in jejunum and ileum were measured by an Üssing chamber system and the localization of apical proteins were evaluated immunostaining with whole‐slide imaging and digital image analysis.ResultsFollowing tamoxifen injection, F‐actin‐positive inclusions appeared in the upper small intestine of VilCreERT2;Myo5bflox/flox mice and the brush border localization of phospho‐ezrin, SGLT1, NHE3, DRA, PEPT1, alkaline phosphatase, and DPPIV were lost throughout the intestine. Treatment with LPA partially restored apical localization of phospho‐ezrin, SGLT1, NHE3, alkaline phosphatase, and DPPIV particularly in villus epithelial cells. Consistent with these observations, SGLT1‐dependent short‐circuit current (Isc) was 3 times higher in LPA (3 mg/kg)‐treated jejunum and ileum than that of vehicle‐treated VilCreERT2;Myo5bflox/flox mice. LPA dose‐dependently decreased CFTR‐dependent Isc in the steady state, but had no effect on CFTR dependence in carbachol‐ and forskolin‐stimulated Isc, which was increased by MYO5B loss.ConclusionsThese results suggest that LPA signaling may modulate a MYO5B‐independent trafficking mechanism for some brush border proteins in the small intestine, demonstrating a therapeutic potential for LPA in the treatment of MVID.Support or Funding InformationSupported by The Christine Volpe FoundationThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.