Small Intestinal Villi Research Articles

Lactiplantibacillus argentoratensis AGMB00912 protects weaning mice from ETEC infection and enhances gut health.

Maintaining a healthy intestinal environment, optimal epithelial barrier integrity, and balanced gut microbiota composition are essential for the growth performance of weaning pigs. We identified Lactiplantibacillus argentoratensis AGMB00912 (LA) in healthy porcine feces as having antimicrobial activity against pathogens and enhanced short-chain fatty acid (SCFA) production. Herein, we assess the protective role of LA using a weaning mouse model with enterotoxigenic Escherichia coli (ETEC) infection. LA treatment improves feed intake and weight gain and alleviates colon shortening. Furthermore, LA inhibits intestinal damage, increases the small intestine villus height compared with the ETEC group, and enhances SCFA production. Using the Kyoto Encyclopedia of Genes and Genomes and other bioinformatic tools, including InterProScan and COGNIZER, we validated the presence of SCFA-producing pathways of LA and Lactiplantibacillus after whole genome sequencing. LA mitigates ETEC-induced shifts in the gut microbiota, decreasing the proportion of Escherichia and Enterococcus and increasing SCFA-producing bacteria, including Kineothrix, Lachnoclostridium, Roseuburia, Lacrimispora, Jutongia, and Blautia. Metabolic functional prediction analysis revealed enhanced functions linked to carbohydrate, amino acid, and vitamin biosynthesis, along with decreased functions associated with infectious bacterial diseases compared to the ETEC group. LA mitigates the adverse effects of ETEC infection in weaning mice, enhances growth performance and intestinal integrity, rebalances gut microbiota, and promotes beneficial metabolic functions. These findings validate the functionality of LA in a small animal model, supporting its potential application in improving the health and growth performance of weaning pigs.

The Skin Histopathology of Pro- and Parabiotics in a Mouse Model of Atopic Dermatitis.

As it has been revealed that the activation of human immune cells through the activity of intestinal microorganisms such as pro- and prebiotics plays a vital role, controlling the proliferation of beneficial bacteria and suppressing harmful bacteria in the intestine has become essential. The importance of probiotics, especially for skin health and the immune system, has led to the emergence of products in various forms, including probiotics, prebiotics, and parabiotics. In particular, atopic dermatitis (AD) produces hypersensitive immunosuppressive substances by promoting the differentiation and activity of immune regulatory T cells. As a result, it has been in the Th1 and Th2 immune balance through a mechanism that suppresses skin inflammation or allergic immune responses caused by bacteria. Furthermore, an immune mechanism has recently emerged that simultaneously controls the expression of IL-17 produced by Th17. Therefore, the anti-atopic effect was investigated by administering doses of anti-atopic candidate substances (Lactobacilus sakei CVL-001, Lactobacilus casei MCL, and Lactobacilus sakei CVL-001 Lactobacilus casei MCL mixed at a ratio of 4:3) in an atopy model using 2,4-dinitrochlorobenzene and observing symptom changes for 2 weeks to confirm the effect of pro-, para-, and mixed biotics on AD. First, the body weight and feed intake of the experimental animals were investigated, and total IgG and IgM were confirmed through blood biochemical tests. Afterward, histopathological staining was performed using H&E staining, Toluidine blue staining, Filaggrin staining, and CD8 antibody staining. In the treatment group, the hyperproliferation of the epidermal layer, the inflammatory cell infiltration of the dermal layer, the expression of CD8, the expression of filaggrin, and the secretion of mast cells were confirmed to be significantly reduced. Lastly, small intestine villi were observed through a scanning microscope, and scoring evaluation was performed through skin damage. Through these results, it was confirmed that AD was reduced when treated with pro-, para-, and mixed biotics containing probiotics and parabiotics.

Effects of Adding Sphingomonas Z392 to Drinking Water on Growth Performance, Intestinal Histological Structure, and Microbial Community of Broiler Chickens.

Probiotics are a prominent alternative to antibiotics in antimicrobial-free broiler farming. To assess the effect of Sphingomonas sp. Z392 (isolated and identified) on broiler growth, 600 one-day-old Kebao broiler chickens were randomly divided into a control group and an experimental group. Each group had three replicates, with 100 broiler chickens being raised in each replicate. Regarding the experimental group of broiler chickens, 4.0 × 105 CFU/mL of Sphingomonas Z392 was added to their drinking water. Then, the changes in broiler body weight, the EPI, intestinal histological structure, and gut microbiota were examined. The results show that the supplementation of the broilers' drinking water with 4 × 105 CFU/mL of Sphingomonas Z392 resulted in an increase in the relative abundance of Lactobacillus, Bacteroides, Lachnospiraceae, Aminobacterium, Oribacterium, Christensenellaceae, Faecalibacterium, Barnesiella, Ruminococcus, Parabacteroides, Phascolarctobacterium, Butyricicoccaceae, and Caproiciproducens, which have been reported to be positively correlated with the improved digestion and absorption of broiler chickens. The relative abundance of Odoribacter, Alistipes, Parabacteroides, and Rikenellaceae increased, and these have been reported to be negatively correlated with the occurrence of intestinal diseases. The relative abundance of Campylobacter, Shigella Castellani, Bilophila, Campylobacter, Clostridia, and Anaerotruncus decreased, and these have been reported to be positively correlated with the occurrence of intestinal diseases. At the same time, the following also increased: the integrity of small intestinal villus morphology; the number of goblet cells in small intestinal epithelial cells; the health of the mitochondria in the cytoplasm of jejunal villous epithelial cells; the number of lysosomes in the cytoplasm of goblet cells in the small intestinal epithelium, ileal villous epithelial cells, and mitochondria in the cytoplasm of large intestinal villous epithelial cells; the VH/CD of the ileum; and digestive, absorption, and defense capabilities. In particular, the final weight increased by 4.33%, and the EPI increased by 10.10%. Therefore, the supplementation of broiler drinking water with Sphingomonas generated better economic benefits from the broiler chickens.

Effect of N-acetyl-L-cysteine administration in drinking water of broilers exposed to heat stress on performances, intestinal integrity, and oxidative status

Supplementing the diet of broiler with N-acetyl-L-cysteine (NAC) has been shown to support small intestinal integrity, and as a precursor of L-cysteine, it may also support antioxidant functions. As heat-stressed chickens suffer from intestinal disturbances caused by oxidative stress and at the same time increase water consumption, it was hypothesised that NAC supplemented via the drinking water could reinforce finisher broiler productivity under heat stress. Hence, three hundred 15-day-old male Ross 308 broilers were assigned to three treatments until 39 days of age: thermoneutral (TN), heat-stressed (HS), or HS + NAC. NAC was administered to the drinking water at 1000 mg/L starting on day 20. At 22 days, a chronic cyclic heat stress model was initiated in the HS and HS + NAC groups. On day 39, birds were euthanized and sampled for physiological measurements. Heat stress significantly decreased weight gain and feed intake from 22 to 39 days but did not affect feed efficiency. Rectal temperature and respiration rate significantly increased in heat-stressed broilers on days 23, 30, and 38. Also, ileal mucosal malondialdehyde (MDA) and plasma MDA levels were significantly higher in the HS group and the HS + NAC group, respectively, as compared to the TN group, whereas MDA levels in lung tissue were lower in both HS groups. Small intestinal villus height was significantly lower and serum FITC-d levels were significantly higher in the HS group compared to the TN group, without the effect of NAC supplementation. Furthermore, hepatic gene transcript of glutamate-cysteine ligase catalytic subunit was upregulated under heat stress conditions which may reflect higher glutathione synthesis, whereas in HS + NAC birds cystathionine-beta synthase-like (CBSL) mRNA level was dramatically reduced, indicating decreased transsulfuration activity. In conclusion, the administration of 1000 mg/L NAC in drinking water did not alleviate the reduced performances of heat-stressed finisher broilers. Nevertheless, it resulted in the downregulation of CBSL expression, suggesting a potential methionine-sparing effect.

Partially Differentiated Ileal and Rectal Human CFTR-F508del Enteroids Secrete Fluid in Response to cAMP and cGMP: Targeted Preclinical Studies of Pharmaco-Therapy of CF Constipation

Introduction: Treatment of Cystic Fibrosis (CF) patients with Trikafta is prolonging life. This has allowed the importance of other causes of morbidity in these patients to become clearer and to emphasize the need to improve their quality of life by developing additional treatments. Chronic constipation is one such continuing unsolved medical issue for patients with CF even on Trikafta. In general, approaches to treat chronic constipation include increasing intestinal fluid secretion that involves inhibiting intestinal NaCl absorption and/or stimulating intestinal Cl secretion, with inhibition of the latter being the primary defect in CF. Drug development efforts have mostly aimed to improve CFTR function and control pancreatic insuffciency. We have recently reported an enterocyte population in the human ileal and colon that is present between the crypt Cl− secretory cells and the mature small intestinal villus or colonic surface Na+ absorptive cells that contain both DRA and CFTR. This population is called partially differentiated enterocytes. This study was undertaken to derive a strategy to stimulate intestinal fluid secretion from partially differentiated enterocytes in the F508del-CF-patient population by enhancing residual CFTR F508del activity using drugs that stimulate cAMP and cGMP. Methods: Ileal and rectal enteroids from F508del CF patients and healthy subjects (HS/normal) were studied. Enteroids were maintained in growth media containing Wnt3A, R-spondin, and Noggin (undifferentiated/UD); induced to partially differentiate (3d-DF) or fully differentiate (6d-DF) by removal of growth factors (Wnt3A and R-spondin) for 3 or 6 days, respectively. Forskolin-induced swelling (FIS) assay and live cell microscopy were used to determine fluid secretion in enteroids. A relative increase in organoid surface area over a time series of 60 min was measured to quantify FIS response. mRNA expression was determined using qRT-PCR. Results: Compared to HS enteroids, F508del enteroids had significantly higher mRNA expression of LGR5, and Ki67 in the UD state. Expression of goblet cell marker MUC2 and enteroendocrine (EEC) marker ChgA increased with differentiation in both HS and F508del, while 6d-DF F508del enteroids had a significantly higher ChgA compared to 6d-DF enteroids from HS. UD F508del enteroids had significantly higher expression of phosphodiesterase-3a (PDE3a) than HS enteroids, which further increased with differentiation, but did not change in HS. While UD and 6d-DF F508del rectal and ileal enteroids did not swell when exposed to cAMP (forskolin) and cGMP (linaclotide), 3d-DF F508del enteroids showed a swelling response when exposed to cAMP (forskolin) and cGMP (linaclotide). Fluid secretion from 3d-DF F508del enteroids was ~50% (cAMP) and ~67% (cGMP) of the response of intestinal enteroids from HS enteroids. Combinations of CFTR correctors and potentiators mimicking the makeup of Trikafta only partially enhanced fluid secretion in F508del CF enteroids as compared to HS. However, cGMP (linaclotide) additively enhanced Trikafta-induced fluid secretion from 3d-DF F508del enteroids. Conclusions: CFTR F508del can be stimulated by cAMP and cGMP in partially differentiated enterocyte populations. Our findings identify a novel role of the partially differentiated ileal and rectal enterocyte populations which behave in a way that offers the potential to improve treatment for CF constipation. Funding: This study is partly supported by Cystic Fibrosis Foundation grant CF-SINGH20G0, National Institutes of Health grants R01-DK-116352 and P30-DK-89502 (the Hopkins Basic and Translational Research Digestive Diseases Research Core Center). 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.

Effects of coated sodium butyrate on the growth performance, serum biochemistry, antioxidant capacity, intestinal morphology, and intestinal microbiota of broiler chickens.

This study examined the impact of adding coated sodium butyrate (CSB) to the diet on the growth performance, serum biochemistry, antioxidant capacity, intestinal morphology, and cecal microbiota of yellow-feathered broiler chickens. In this study, 240 yellow-feathered broiler chickens at 26 days old were divided into two groups: the control group (CON group) received a standard diet, and the experimental group (CSB group) received a diet with 0.5 g/kg of a supplement called CSB. Each group had 6 replicates, with 20 chickens in each replicate, and the experiment lasted for 36 days. Compared to the CON group, the CSB group showed a slight but insignificant increase in average daily weight gain during the 26-62 day period, while feed intake significantly decreased. The CSB group exhibited significant increases in serum superoxide dismutase, catalase, and total antioxidant capacity. Additionally, the CSB group had significant increases in total protein and albumin content, as well as a significant decrease in blood ammonia levels. Compared to the CON group, the CSB group had significantly increased small intestine villus height and significantly decreased jejunal crypt depth. The abundance of Bacteroidetes and Bacteroides in the cecal microbiota of the CSB group was significantly higher than that of the CON group, while the abundance of Proteobacteria, Deferribacteres, and Epsilonbacteraeota was significantly lower than that of the CON group. These results suggest that adding CSB to the diet can improve the growth performance and antioxidant capacity of yellow-feathered broiler chickens while maintaining intestinal health.

Classification of celiac disease using novel approach of three-level DWT decomposition and linear support vector machine

In the medical field, the requirement for automated medical diagnosis software has risen as the application uses machine learning to facilitate health analysis from different data points from a patient comparing it with massive amounts of medical data to diagnose and prevent disease. The automated system can run multiple tests simultaneously and thus resulting to faster turnaround time and enables timely patient care along with higher accuracy and reliability. The irregularities in the small intestine villi’s structure cause various autoimmune disorders. So, this work aims to find a novel technique for the feature extraction of upper endoscopy images of celiac disease. We employed CLAHE (Contrast Limited Adaptive Histogram Equalization) for the preprocessing step and the Sobel operator with gradient magnitude for the segmentation of the enhanced image. In this manuscript, we have proposed a novel approach by calculating texture features through gray level co-occurrence matrix and frequency analysis using 3-level discrete wavelet transform decomposition on endoscopy images that renders novelty to the work. Thereafter, linear SVM (support vector machine) with PCA (Principal Component Analysis) is used for classification. The ensemble approach attains accuracy, sensitivity, and specificity of 78.49 %, 90.32 %, and 77.27% respectively. The outcomes achieved with the suggested approach are compared with some state-of-the-art methods using the same dataset. The results are promising due to high sensitivity for the treatment of untreated celiac disease and can prove boom to the medical industry by assisting clinicians to diagnose the disease at an early stage.

Evaluation of the Immunity Responses in Mice to Recombinant Bacillus subtilis Displaying Newcastle Disease Virus HN Protein Truncations.

Bacillus subtilis, a probiotic bacterium with engineering potential, is widely used for the expression of exogenous proteins. In this study, we utilized the integrative plasmid pDG364 to integrate the hemagglutinin-neuraminidase (HN) gene from Newcastle disease virus (NDV) into the genome of the B. subtilis 168 model strain. We successfully constructed a recombinant B. subtilis strain (designated B. subtilis RH) that displays a truncated HN antigen fragment on the surface of its spores and further evaluated its immunogenic effects in mice. Using ELISA, we quantified the levels of IgG in serum and secretory IgA (sIgA) in intestinal contents. The results revealed that the recombinant B. subtilis RH elicited robust specific mucosal and humoral immune responses in mice. Furthermore, B. subtilis RH demonstrated potential mucosal immune adjuvant properties by fostering the development of immune organs and augmenting the number of lymphocytes in the small intestinal villi. Additionally, the strain significantly upregulated the relative expression of inflammatory cytokines such as IL-1β, IL-6, IL-10, TNF-α, and IFN-γ in the small intestinal mucosa. In conclusion, the B. subtilis RH strain developed in this study exhibits promising mucosal immunogenic effects. It holds potential as a candidate for an anti-NDV mucosal subunit vaccine and offers a novel preventive strategy for the poultry industry against this disease.

Citric Acid Promotes Immune Function by Modulating the Intestinal Barrier.

Amidst increasing concern about antibiotic resistance resulting from the overuse of antibiotics, there is a growing interest in exploring alternative agents. One such agent is citric acid, an organic compound commonly used for various applications. Our research findings indicate that the inclusion of citric acid can have several beneficial effects on the tight junctions found in the mouse intestine. Firstly, the study suggests that citric acid may contribute to weight gain by stimulating the growth of intestinal epithelial cells (IE-6). Citric acid enhances the small intestinal villus-crypt ratio in mice, thereby promoting intestinal structural morphology. Additionally, citric acid has been found to increase the population of beneficial intestinal microorganisms, including Bifidobacterium and Lactobacillus. It also promotes the expression of important protein genes such as occludin, ZO-1, and claudin-1, which play crucial roles in maintaining the integrity of the tight junction barrier in the intestines. Furthermore, in infected IEC-6 cells with H9N2 avian influenza virus, citric acid augmented the expression of genes closely associated with the influenza virus infection. Moreover, it reduces the inflammatory response caused by the viral infection and thwarted influenza virus replication. These findings suggest that citric acid fortifies the intestinal tight junction barrier, inhibits the replication of influenza viruses targeting the intestinal tract, and boosts intestinal immune function.

Comparison of Spermophilus dauricus gastrointestinal phenotypic flexibility between hibernating and non-hibernating seasons

Traits of the gastrointestinal (GI) tract are phenotypically flexible and seem to reflect the ecological features of animals. The Daurian ground squirrel (Spermophilus dauricus) is a typical fat-storing, hibernating animal. However, information on seasonal GI plasticity in this species is limited. The aim of the present study was to characterize the morphology, histology, and genetic regulation involved in GI motility in the ground squirrel during non-hibernating and hibernating seasons. The morphological and histological results showed that the body weight, total fresh weight, and total net fresh weight of the GI tract in summer and autumn were higher than those in spring and the winter hibernation season, although the total length of the gut did not change seasonally. The fresh weight and net fresh weight of the small intestine, cecum, and large intestine were significantly greater in autumn and summer than in winter, but the lengths of these segments showed no significant seasonal differences. The mucosal and muscular layer thicknesses of the stomach, illum, cecum, and colon were greater in autumn or summer than in winter, and the small intestine diameter and villus height were decreased in winter compared to those in the spring or summer. Moreover, the expression of nNOS and NPY genes in the small intestine in autumn and winter was higher than that in spring or summer. VIP expression in winter was the highest across seasons; in contrast, CHRM2 expression in autumn was the highest across seasons. These results indicate that morphological and histological traits of the gut, as well motility adjustments, exhibit seasonal plasticity in the ground squirrel, and these are especially affected by the hibernating cycle. This work will expand our knowledge of GI phenotypic plasticity in hibernating rodent species.

The impact of gut microbiota on vascularization of the small intestine

The commensal microbiota resides in a mutualistic relationship within the mammalian gut. It significantly influences the formation of capillary networks in the small intestine, not only during development but also in adulthood. Mucosal capillaries in small intestinal villus structures play a critical role for the uptake of dietary nutrients and immune regulation. Emerging studies have elucidated how the composition of gut microbiota can influence not only postnatal gut development regarding immune tolerance, nutrient absorption, and morphology but also the development and maintenance of blood and lymphatic capillaries within the small intestine. In particular, the analysis of gnotobiotic mouse models affirmed the importance of the gut microbiota, or even only single gut bacteria, in the remodeling of the small intestinal capillaries. Here, different epithelial-to-endothelial cross talk pathways, e.g. Paneth cell-derived signals, Toll-like receptor signaling, or tissue factor–protease activated receptor-1 signaling, have been reported to affect intestinal villus vascular remodeling in a microbiota-dependent fashion. In this review article, we will provide a comprehensive overview on the relevant microbiota–host interaction pathways, which have been revealed to influence angiogenesis and vascular remodeling in the small intestine.

Effects of LED Light Colors on the Growth Performance, Intestinal Morphology, Cecal Short-Chain Fatty Acid Concentrations and Microbiota in Broilers

This study aimed to explore the effects of light-emitting diode (LED) light colors on growth, intestinal morphology, and cecal microbiota in broilers. A total of 360 healthy male Arbor Acres (AA) broilers with similar weights were selected and divided into four groups with six replicates in each group and 15 broilers in each replicate: LED white light (W), LED green light (G), LED blue light (B), and LED blue–green composite light (BG). The experimental period was 42 d, the light cycle of each treatment group was 23L:1D (23 h of light, one hour of darkness) from 1 to 3 d, and the light cycle from 4 to 42 d was 16L:8D; light intensity was 20 Lux. The results showed that the average daily feed intake and final weight of broilers receiving the B group were the highest in 21 d and 42 d compared with other groups. The average daily feed intake of the BG group was lower than that of the B group. In the same light color, small intestine villus height grows with age. On days 21 and 42, compared with other groups, the ileal villus height was higher, the crypt depth was lower, and the V/C ratio (villus to crypt ratio) was higher in the BG group. The combination of blue–green composite light was beneficial to increase the content of propionate, isobutyrate, butyrate, isovalerate, and valerate in the cecum of 21-day-old broilers and the content of isobutyrate in the cecum of 42-day-old broilers, and a decrease in cecal short-chain fatty acid concentrations with age. The B group and the BG group had higher abundances of Bacteroidetes at day 21 of age and lower abundances of Phascolarctobacterium at day 42. However, no cecal microbiota differences were detected by the Bonferroni-corrected test. In general, our research results showed that light color could promote the growth of broilers by affecting intestinal morphology, microbiota abundance (needs to be validated by further experiments), and cecal short-chain fatty acid concentrations. And blue and blue–green composite lights are more suitable for broiler growth.

Synergetic Role of Energy and Oat with Enzymes on Physiological Performance of Broiler

This study was conducted in poultry fields at College of Agriculture / University of Anbar’s Animal Production Department from 2/9/2022 to 14/10/2022 (42 days). This study examined the physiological effects of high energy and oats on grill performance. Three hundred one-day-old (unsexed) chicks were distributed in a completely randomised design to ten treatments with three replicates (10 chicks per replicate). All diets were designed to meet the same requirements. Broilers received water and feed ad libitum. Treatments were as follows: T1 birds fed diets for three phases (starter, grower, and finisher) without any addition, T2 birds fed diet (starter 3100 Kcal /kg feed) + 5% oat + 0.01 mg multienzyme, T3 birds fed diet (starter 3000 Kcal/kg feed) + 5% oat + 200 mg multienzyme, T4 birds fed starter 2900 Kcal/kg feed + 5% oat + 200 mg multienzyme, T5 birds fed diet (grower 3200 Kcal/kg feed) + 5% oat + 200 mg multienzyme, and T6 birds fed diet The 5% oat hull groups had higher small intestine villus height and CD than the control group (p < 0.05). T6 group glucose is higher than control group glucose. T10 group and control group total protein differ significantly (P>0.05). The control group’s albumin, MDA, and GPT levels are not significantly different from the other groups. Dietary oat hull increased Glutamic-Oxaloacetic Transaminase (GOT) activity in T6 compared to control group, but control group had higher ALP activity.

Pectin Modulates Calcium Absorption in Polarized Caco-2 Cells via a Pathway Distinct from Vitamin D Stimulation.

Pectin, a type of soluble fiber, promotes morphological changes in the small intestinal villi. Although its physiological significance is unknown, we hypothesized that changes in villus morphology enhance the efficiency of nutrient absorption in the small intestine and investigated the effect of pectin derived from persimmon on calcium absorption using polarized Caco-2 cells. In polarized Caco-2 cells, pectin altered the mRNA expression levels of substances involved in calcium absorption and the regulation of intracellular calcium concentration and significantly reduced calcium absorption. Although this was comparable to the results of absorption and permeability associated with the addition of active vitamin D, the simultaneous action of pectin and active vitamin D did not show any additive effects. Furthermore, as active vitamin D significantly increases the activity of intestinal alkaline phosphatase (ALP), which is known to be involved in the regulation of intestinal absorption of calcium and lipids, we also investigated the effect of pectin on intestinal ALP activity. As a result, it was found that, unlike the effect of active vitamin D, pectin significantly reduced intestinal ALP activity. These results suggest that pectin stimulates polarized Caco-2 cells through a mechanism distinct from the regulation of calcium absorption by vitamin D, modulating total calcium absorption from the elongated villi through morphological changes in the small intestine by suppressing it at the cellular level.

Quantitative analyses of T cell motion in tissue reveals factors driving T cell search in tissues.

T cells are required to clear infection, and T cell motion plays a role in how quickly a T cell finds its target, from initial naive T cell activation by a dendritic cell to interaction with target cells in infected tissue. To better understand how different tissue environments affect T cell motility, we compared multiple features of T cell motion including speed, persistence, turning angle, directionality, and confinement of T cells moving in multiple murine tissues using microscopy. We quantitatively analyzed naive T cell motility within the lymph node and compared motility parameters with activated CD8 T cells moving within the villi of small intestine and lung under different activation conditions. Our motility analysis found that while the speeds and the overall displacement of T cells vary within all tissues analyzed, T cells in all tissues tended to persist at the same speed. Interestingly, we found that T cells in the lung show a marked population of T cells turning at close to 180o, while T cells in lymph nodes and villi do not exhibit this "reversing" movement. T cells in the lung also showed significantly decreased meandering ratios and increased confinement compared to T cells in lymph nodes and villi. These differences in motility patterns led to a decrease in the total volume scanned by T cells in lung compared to T cells in lymph node and villi. These results suggest that the tissue environment in which T cells move can impact the type of motility and ultimately, the efficiency of T cell search for target cells within specialized tissues such as the lung.

OC 19.5 Epithelial Neuropilin-1 is Regulated by the Gut Microbiota Promoting Vascularization of Small Intestinal Villus Structures

OC 19.5 Epithelial Neuropilin-1 is Regulated by the Gut Microbiota Promoting Vascularization of Small Intestinal Villus Structures

Exosome-coated polydatin nanoparticles in the treatment of radiation-induced intestinal damage.

This study aimed to develop an exosome-coated polydatin (PD) nanoparticles (exo-PD) for improving the water solubility and bioavailability of polydatin and explore its salutary effects on intestinal radiation injury. Exosomes (exo) were extracted from the medium of human amniotic fluid stem cells (hAFSc). Mice were divided into control group, irradiation (IR) group, irradiation+PD (IR+PD) group, irradiation+exo (IR+exo) group and irradiation+exo-PD (IR+exo-PD) group. The results of characterization of protein markers, particle size, morphology and cellular uptake ability confirmed that exosomes were effectively isolated using ultracentrifugation. Compared with the IR group, exo-PD improved cell viability, prolonged survival of mice, improved leukocyte count and reduced diarrhea rate. Histological results showed that the exo-PD group had significant improvements in small intestinal villus length and crypt number and less crypt cell damage. exo-PD could reduce IL-1α and IL-6 levels, reduced γ-H2AX expression, increased mitochondrial membrane potential, enhanced oxidative phosphorylation, and delayed cellular senescence. exo-PD could alleviate intestinal injury by improving mitochondrial function through PI3K-AKT pathway. The exo-PD was able to reduce radiation damage to intestinal cells and could be a potential candidate for salvage of intestinal radiation damage.

Commensal bacteria weaken the intestinal barrier by suppressing epithelial neuropilin-1 and Hedgehog signaling

The gut microbiota influences intestinal barrier integrity through mechanisms that are incompletely understood. Here we show that the commensal microbiota weakens the intestinal barrier by suppressing epithelial neuropilin-1 (NRP1) and Hedgehog (Hh) signaling. Microbial colonization of germ-free mice dampens signaling of the intestinal Hh pathway through epithelial Toll-like receptor (TLR)-2, resulting in decreased epithelial NRP1 protein levels. Following activation via TLR2/TLR6, epithelial NRP1, a positive-feedback regulator of Hh signaling, is lysosomally degraded. Conversely, elevated epithelial NRP1 levels in germ-free mice are associated with a strengthened gut barrier. Functionally, intestinal epithelial cell-specific Nrp1 deficiency (Nrp1ΔIEC) results in decreased Hh pathway activity and a weakened gut barrier. In addition, Nrp1ΔIEC mice have a reduced density of capillary networks in their small intestinal villus structures. Collectively, our results reveal a role for the commensal microbiota and epithelial NRP1 signaling in the regulation of intestinal barrier function through postnatal control of Hh signaling.

Reconstruction of the cell pseudo-space from single-cell RNA sequencing data with scSpace

Tissues are highly complicated with spatial heterogeneity in gene expression. However, the cutting-edge single-cell RNA-seq technology eliminates the spatial information of individual cells, which contributes to the characterization of cell identities. Herein, we propose single-cell spatial position associated co-embeddings (scSpace), an integrative method to identify spatially variable cell subpopulations by reconstructing cells onto a pseudo-space with spatial transcriptome references (Visium, STARmap, Slide-seq, etc.). We benchmark scSpace with both simulated and biological datasets, and demonstrate that scSpace can accurately and robustly identify spatially variated cell subpopulations. When employed to reconstruct the spatial architectures of complex tissue such as the brain cortex, the small intestinal villus, the liver lobule, the kidney, the embryonic heart, and others, scSpace shows promising performance on revealing the pairwise cellular spatial association within single-cell data. The application of scSpace in melanoma and COVID-19 exhibits a broad prospect in the discovery of spatial therapeutic markers.

In vivo tracing of immunostimulatory raw starch microparticles after mucosal administration

Raw starch microparticles (SMPs) proved efficient antigen carriers with adjuvant properties when administered via the mucosal route; however, the underlying mechanisms associated with this bioactivity are unknown. In the present study, we explored the mucoadhesion properties, fate, and toxicity of starch microparticles after mucosal administration. Nasally administered microparticles were mainly retained in nasal turbinates, reaching the nasal-associated lymphoid tissue; this step is facilitated by the ability of the microparticles to penetrate through the mucous epithelium. Likewise, we found intraduodenally administered SMPs on the small intestinal villi, follicle-associated epithelium, and Peyer's patches. Furthermore, under simulated gastric and intestinal pH conditions, we detected mucoadhesion between the SMPs and mucins, regardless of microparticle swelling. SMPs' mucoadhesion and translocation to mucosal immune responses induction sites explain the previously reported role of these microparticles as vaccine adjuvants and immunostimulants.