Intestinal Muscle Layers Research Articles

Effect of Probiotics on Improving Intestinal Mucosal Permeability and Inflammation after Surgery.

We explored the mechanisms underlying the improvement of postoperative ileus (POI) following probiotic pretreatment. We assessed intestinal permeability, inflammation, tight junction (TJ) protein expression in the gut epithelium, and plasma interleukin (IL)-17 levels in a guinea pig model of POI. Guinea pigs were divided into control, POI, and probiotic groups. The POI and probiotic groups underwent surgery, but the probiotic group received probiotics before the procedure. The ileum and proximal colon were harvested. Intestinal permeability was measured via horseradish peroxidase permeability. Inflammation was evaluated via leukocyte count in the intestinal wall muscle layer, and calprotectin expression in each intestinal wall layer was analyzed immunohistochemically. TJ proteins were analyzed using immunohistochemical staining, and plasma IL-17 levels were measured using an enzyme-linked immunosorbent assay. The POI group exhibited increased intestinal permeability and inflammation, whereas probiotic pretreatment reduced the extent of these POI-induced changes. Probiotics restored the expression of TJ proteins occludin and zonula occludens-1 in the proximal colon, which were increased in the POI group. Calprotectin expression significantly increased in the muscle layer of the POI group and was downregulated in the probiotic group; however, no distinct differences were observed between the mucosal and submucosal layers. Plasma IL-17 levels did not significantly differ among the groups. Probiotic pretreatment may relieve POI by reducing intestinal permeability and inflammation and TJ protein expression in the gut epithelium. These findings suggest a potential therapeutic approach for POI management.

MATERIAL PROPERTIES OF THE EMBRYONIC SMALL INTESTINE DURING BUCKLING MORPHOGENESIS.

During embryonic development, tissues undergo dramatic deformations as functional morphologies are stereotypically sculpted from simple rudiments. Formation of healthy, functional organs therefore requires tight control over the material properties of embryonic tissues during development, yet the biological basis of embryonic tissue mechanics is poorly understood. The present study investigates the mechanics of the embryonic small intestine, a tissue that is compactly organized in the body cavity by a mechanical instability during development, wherein differential elongation rates between the intestinal tube and its attached mesentery create compressive forces that buckle the tube into loops with wavelength and curvature that are tightly conserved for a given species. Focusing on the intestinal tube, we combined micromechanical testing with histologic analyses and enzymatic degradation experiments to conclude that elastic fibers closely associated with intestinal smooth muscle layers are responsible for the bending stiffness of the tube, and for establishing its pronounced mechanical anisotropy. These findings provide insights into the developmental role of elastic fibers in controlling tissue stiffness, and raise new questions on the physiologic function of elastic fibers in the intestine during adulthood.

Optimizing valine supplementation in low-fish meal diets for enhanced growth, digestion, antioxidant capacity, and intestinal health of triploid rainbow trout (Oncorhynchus mykiss)

This study evaluates the effects of valine on the growth, digestion, antioxidant capacity, and intestinal health of triploid rainbow trout (Oncorhynchus mykiss) fed a low fish meal diet (10 %). The trouts with an initial body weight of 15.08±0.20 g were fed with five different isonitrogenous and isoenergetic diets containing levels of valine: 0.86 % (G1), 1.79 % (G2), 2.43 % (G3), 3.02 % (G4), and 3.68 % (G5) for 56 days. The results showed that the weight growth rate and specific growth rate of the 2.43 % group were significantly higher than those of the 0.86 % control group (P<0.05). The intestinal villus length and muscle layer thickness propria were significantly increased in the 3.02 % group compared to the control group (P<0.05). The activities of intestinal protease, amylase, superoxide dismutase, catalase, and lysozyme in the 2.43 % group were significantly higher than those in the control group (P<0.05). The levels of interleukin-8 and tumor necrosis factor-alpha were lowest in the 3.02 % group, while the IL-10 level was highest in the 3.02 % group (P<0.05). Elevated levels of valine in the dietary regimen correlated positively with the upregulation of pivotal genes associated with antioxidant mechanisms, notably nuclear factor erythroid 2-related factor 2 (Nrf2), NAD(P)H: quinone oxidoreductase 1 (NQO1), and thioredoxin (Trx). Additionally, the expression of genes implicated in the synthesis of tight junction proteins, including occludin, claudin 7b, and claudin 15, exhibited significant augmentation with escalating valine concentrations in the feed. In conclusion, dietary valine enhanced the growth, digestive and absorptive capabilities, antioxidant capacity, and intestinal health of O. mykiss. An analysis based on a quadratic curve model, which incorporates specific rates of growth and weight gain, establishes that the optimal dietary valine requirement for triploid O. mykiss consuming a 10 % fish meal diet ranges between 2.43 % and 2.69 %.

Effects of dietary astaxanthin on growth performance, immunity, and tissue composition in largemouth bass, Micropterus salmoides

This study examined the effects of feeding largemouth bass (Micropterus salmoides) with diets containing different doses of astaxanthin (0, 50, 100, 150, and 200 mg/kg) for 8 weeks. The results showed that the values of weight gain significantly increased from 620.32 ± 50.38% to 826.14 ± 33.49% as dietary astaxanthin levels increased from 0 mg/kg to 100 mg/kg. When the astaxanthin level exceeded 150mg/kg, the weight gain rate showed a downward trend, but there was no significant difference among of the 100, 150 and 200 mg/kg groups. The feed conversion ratio (FCR) and protein efficiency ratio (PER) were also improved by adding astaxanthin to diets (P &amp;lt; 0.05). Meanwhile, adding astaxanthin to the feed increased the length and thickness of intestinal villus and muscle layer thickness (P &amp;lt; 0.05). The astaxanthin supplementation increased the expression of the NF-E2-related factor (Nrf2) gene and reduced malondialdehyde (MDA) content and the expression of apoptosis genes Caspase-9 and Caspase-3 (P &amp;lt; 0.05), indicating that it has a good antioxidant ability. Furthermore, adding astaxanthin increased the content of non-specific immune markers and decreased the expression levels of the inflammatory factors interleukin-15 (IL-15) and tumor necrosis factor-α (TNF-α). Moreover, fish fed diets with astaxanthin exhibited lower blood cortisol levels (P &amp;lt; 0.05). The proportions of C20:4n6 (ARA) and C20:5n3 (EPA) in the liver decreased with increasing dietary astaxanthin levels. Based on WGR and SGR values, the optimal addition level of astaxanthin in largemouth bass feed is 134.8 mg/kg ~ 135.75 mg/kg. In summary, the appropriate dietary astaxanthin enhanced the antioxidant capacity and immune response of largemouth bass and had a positive effect on its intestinal health.

Evaluation of starvation status in the early developmental stages of black rockfish (Sebastes schlegelii) based on morphological and histological characteristics.

Assessing the nutritional status and identifying major causes of mortality in larvae experiencing varying degrees of starvation are crucial for establishing appropriate feeding protocols and enhancing the welfare of hatchery-reared fish. The black rockfish Sebastes schlegelii is an important species in aquaculture and stock enhancement efforts in China, Japan, and Korea. This study aimed to identify optimal diagnostic morphometric indicators of starvation in newly hatched (0-6 days post-hatch, DPH) and postlarval stages (27-37 DPH) of this valuable fish species through histological analyses. Our findings revealed that certain morphometric parameters, including body length, the ratios of eye diameter to head height, body height to body length, and abdomen height to body height, exhibit sensitivity to starvation during both larval and postlarval stages. Particularly, the ratios of body height to body length and abdomen height to body height emerged as the most sensitive morphometric indicators of starvation. Histological examinations of the digestive system revealed rapid alterations in the morphology of hepatic parenchymal cells, accompanied by a significant decrease in the number of lipid cells in the liver during episodes of food deprivation. Starvation induced cellular degeneration in the digestive organs, manifested by reduced heights of epithelial cells and mucosal layers in the intestine, oesophagus, and stomach, along with degeneration and separation of muscle fibers. Among these variables, the height of the intestinal submucosa and muscle layer emerged as the most sensitive indicators reflecting nutritional conditions in newly hatched larvae. In contrast, the height of intestinal striated borders and mucosal folds proved to be the most sensitive indicators in the postlarval stage. Furthermore, the height of intestinal epithelial cells and the number of lipid vacuoles in enterocytes exhibited high sensitivity to food deprivation in both newly hatched larvae and postlarvae. These findings underscore the varying resilience of fish to starvation during different developmental phases and highlight the utility of morphological sensitivity characteristics as reliable diagnostic indices for assessing nutritional status in relation to starvation or suboptimal feeding during the early developmental stages of black rockfish in hatchery-reared processes.

Single-cell analysis of shared signatures and transcriptional diversity during zebrafish development

During development, animals generate distinct cell populations with specific identities, functions, and morphologies. We mapped transcriptionally distinct populations across 489,686 cells from 62 stages during wild-type zebrafish embryogenesis and early larval development (3-120h post-fertilization). Using these data, we identified the limited catalog of gene expression programs reused across multiple tissues and their cell-type-specific adaptations. We also determined the duration each transcriptional state is present during development and identify unexpected long-term cycling populations. Focused clustering and transcriptional trajectory analyses of non-skeletal muscle and endoderm identified transcriptional profiles and candidate transcriptional regulators of understudied cell types and subpopulations, including the pneumatic duct, individual intestinal smooth muscle layers, spatially distinct pericyte subpopulations, and recently discovered best4+ cells. To enable additional discoveries, we make this comprehensive transcriptional atlas of early zebrafish development available through our website, Daniocell.

Dietary effects of supplementing Clostridium butyricum culture or sodium butyrate in low fishmeal diet on growth, serum indicators, intestinal histology and microbiota of largemouth bass (Micropterus salmoides)

The present study aimed to evaluate the dietary effects of Clostridium butyricum culture (CC) or sodium butyrate (SB) on the growth, feed utilization, serum indicators, intestinal histology and microbiota of largemouth bass (Micropterus salmoides). CC and coated SB (50%) were supplemented to a low fish meal diet (245 g/kg) (control diet) at the inclusion levels of 1 g/kg and 2 g/kg, to form five iso-nitrogenous and iso-lipidic diets (control, CC-1, CC-2, SB-1, and SB-2). Then, the five diets were fed to largemouth bass with initial body weight of 70.2 ± 0.1 g. After 8 weeks of feeding, dietary supplementation of 1 g/kg CC increased the weight gain (WG) by 7.4% (P < 0.05), and decreased the feed conversion ratio by 0.09 (P < 0.05), while dietary SB just numerically improved the WG (P > 0.05), when compared to the control. The muscle composition was not significantly affected by the inclusion of CC or SB (P > 0.05). Dietary inclusion of CC or SB significantly reduced serum diamine oxidase activity and increased lysozyme activity (P < 0.05), while the decreased D-lactic acid level was observed only in the two SB groups (P < 0.05). In intestinal histology, the 1.0 g/kg CC group presented significantly higher intestinal villus height, width and muscle layer thickness than the control group (P < 0.05). The intestinal microbiota analysis showed that dietary CC or SB (1 g/kg) increased the abundance of Fusobacteriota and Cetobacterium, decreased the abundance of Proteobacteria and Aeromonas. In conclusion, the supplementation of CC in low fish meal diet promoted the growth performance, feed utilization, and both CC and SB supplementation positively modulated the intestinal microorganism community of largemouth bass.

Liraglutide modulates morpho-functional and inflammatory gastrointestinal responses in rats.

Obesity impairs homeostatic control of energy and is associated with chronic low-grade inflammation. Effects of glucagon-like peptide-1, the target in the gastrointestinal tract for anti-obesity drugs such as Liraglutide, were not properly associated with inflammation markers. This study investigated the effects of Liraglutide on metabolic and gastrointestinal parameters in a rat model of obesity. Twenty-six Wistar rats with obesity were randomly distributed to receive saline (n = 10), 400 μg (n = 8), or 1200 μg of Liraglutide/kg/day (n = 8), subcutaneously for 30 consecutive days, once a day. Weight gain, feeding efficiency, caloric consumption, gastric motility, adiposity, histomorphometric, murinometric, biochemical parameters and cytokines TNF-α and TGF-β1 in duodenal tissue were measured. Data were analysed by ANOVA, followed by Bonferroni post hoc or Kruskal-Wallis test, followed by Dunn's multiple comparison test. Liraglutide-treated animals had better feeding efficiency and higher caloric intake in a dose-dependent manner. Higher doses slowed gastric emptying and diminished the amplitude of gastric contractions. These effects were accompanied by decreases in intestinal muscle layer thickness and crypt depth. Liraglutide significantly reduced retroperitoneal and visceral white adipose tissue depots. High-dose treatment decreased levels of TNF-α and enhanced levels of TGF-β1 in duodenal tissue. Liraglutide treatment provided significant reductions in total cholesterol, triglyceride and hepatic transaminases. Liraglutide reduced fat accumulation, improved metabolic parameters and downregulated levels of inflammatory signalling in duodenal tissue. Liraglutide at high doses controlled obesity-related outcomes, and such effects seemed to be driven by its action on glucagon-like peptide-1 receptors in the gastrointestinal tract slowing gastric motility.

Behçet's disease with intestinal involvement: a case report and review of the literature

BackgroundBehçet’s disease (BD) is a chronic systemic disease characterized by vasculitis as the basic pathological change. BD is rare, and gastrointestinal involvement occurs in 3% to 25% of affected patients. This article describes a rare case of intestinal BD along with a literature review of intestinal involvement in BD.Case presentationA 50-year-old Han woman from China presented with a > 6-month history of distending pain in the right upper abdomen. Because of mechanical obstruction secondary to stricture formation from an ileocecal ulcer, she underwent radical right colon resection, and postoperative pathologic examination indicated an ileocecal ulcer. The patient was readmitted to the hospital 6 months postoperatively for recurrence of the same symptoms. Colonoscopy indicated obvious narrowing of the anastomosis with an oval-shaped deep ulcer that could not be passed by the endoscope. Pathologic examination showed acute and chronic inflammation of the anastomotic mucosa and granulation tissue. In addition, gastroscopy showed a 3.0- × 4.0-cm giant ulcer at the junction of the descending bulb along with a sinus tract. Moreover, total gastrointestinal computed tomography angiography showed significant thickening of the intestinal wall near the transverse colon, forming a sinus tract at the junction of the antrum and duodenum with a length of about 1.3 cm and width of about 0.2 cm. Further inquiry regarding the patient’s medical history revealed that she had developed repeated oral ulcers 3 years previously and repeated eye inflammation 5 years previously. Specimens of the right half of the colon removed 6 months previously were sent to Run Run Shaw Hospital Affiliated to Zhejiang University for consultation. The pathologic examination revealed vasculitis in the submucosa and subserosa, and the patient was finally diagnosed with BD. She began treatment with adalimumab, and repeat gastroenteroscopy revealed that the intestinal ulcer had significantly improved.ConclusionsAn oval-shaped deep intestinal ulcer is a characteristic lesion in patients with BD and may involve the intestinal muscle layer. This case emphasizes that BD is a vasculitis affecting multiple organs and can present with a single, deep, clean-edged intestinal ulcer that penetrates the bowel wall to form a sinus tract. Therefore, careful examination and differential diagnosis should be carried out to prevent a poor prognosis. Adalimumab is effective for patients with intestinal BD.

Effects of taurine supplementation in low fishmeal diet on growth, immunity and intestinal health of Litopenaeus vannamei

This experiment investigated the impact of taurine supplementation in low fishmeal diets on growth, antioxidant capacity, immunity and intestinal health of Litopenaeus vannamei. In this experiment, five diets were formulated, of which the high fishmeal diet contained 25% fishmeal (HF) and the remaining four diets were a mixture of soybean protein concentrate and Clostridium autoethanogenum protein (CAP) replacing 15% fishmeal and supplemented with 0%, 0.2%, 0.4% and 0.6% taurine (LF, T1, T2, T3). A total of 800 healthy shrimp (0.32 ± 0.00 g) were randomly allocated into 5 groups, with each group consisting of 4 replicates and 40 shrimp per replicate. The shrimp were fed four times a day for 51 days. The results showed that there was no significant difference in weight gain rate and survival (P＞0.05). Dietary taurine supplementation significantly improved the antioxidant capacity of shrimp. Compared with LF group, the mRNA expression of alf (anti-lipopolysaccharide factor) and cru (crustins) in HF group were significantly up-regulated (P＜0.05). Compared with the HF and LF groups, the mRNA expression of pen3 (penaeidins 3) in T1, T2 and T3 groups was significantly up-regulated, and the mRNA expression of dorsal in T2 group was significantly up-regulated (P＜0.05). The mRNA expression of bcl-2 (B-cell lymphoma-2) in T2 group was significantly up-regulated than that in other groups (P＜0.05). The mRNA expression of cyt-c (cytochrome c) in LF group was significantly up-regulated than that in other groups (P＜0.05). Compared with LF group, the mRNA expression of tnf-a (tumor necrosis factor-alpha) in HF, T2 and T3 groups was significantly down-regulated (P＜0.05). The mRNA expression of caspase8 in HF and T2 group was significantly down-regulated than that in other groups (P＜0.05). Compared with LF group, the mRNA expression of caspase3 in T1 groups was significantly down-regulated (P＜0.05). Intestinal H&E stained sections showed that dietary taurine supplementation improved intestinal mucosal folds height, width and muscle layer thickness. In general, dietary taurine supplementation can improve the antioxidant capacity, immunity and intestinal health of Litopenaeus vannamei, and the optimal supplemental level is 0.4%.

Muscle hypertrophy and neuroplasticity in the small bowel in short bowel syndrome

Short bowel syndrome (SBS) is a severe, life-threatening condition and one of the leading causes of intestinal failure in children. Here we were interested in changes in muscle layers and especially in the myenteric plexus of the enteric nervous system (ENS) of the small bowel in the context of intestinal adaptation. Twelve rats underwent a massive resection of the small intestine to induce SBS. Sham laparotomy without small bowel transection was performed in 10 rats. Two weeks after surgery, the remaining jejunum and ileum were harvested and studied. Samples of human small bowel were obtained from patients who underwent resection of small bowel segments due to a medical indication. Morphological changes in the muscle layers and the expression of nestin, a marker for neuronal plasticity, were studied. Following SBS, muscle tissue increases significantly in both parts of the small bowel, i.e., jejunum and ileum. The leading pathophysiological mechanism of these changes is hypertrophy. Additionally, we observed an increased nestin expression in the myenteric plexus in the remaining bowel with SBS. Our human data also showed that in patients with SBS, the proportion of stem cells in the myenteric plexus had risen by more than twofold. Our findings suggest that the ENS is tightly connected to changes in intestinal muscle layers and is critically involved in the process of intestinal adaptation to SBS.

Transcriptome analysis of mesenchymal stromal cells of the large and small intestinal smooth muscle layers reveals a unique gastrointestinal stromal signature

Mesenchymal stromal cells in the muscle layer of the large intestine are essential for the regulation of intestinal motility. They form electrogenic syncytia with the smooth muscle and interstitial cells of Cajal (ICCs) to regulate smooth muscle contraction. Mesenchymal stromal cells are present in the muscle layer throughout the gastrointestinal tract. However, their area-specific characteristics remain ambiguous.In this study, we compared mesenchymal stromal cells from the large and small intestinal muscle layers. Histological analysis using immunostaining showed that the cells in the large and small intestines were morphologically distinct. We established a method to isolate mesenchymal stromal cells from wild-type mice with platelet-derived growth factor receptor-alpha (PDGFRα) as a marker on the cell surface and performed RNAseq. Transcriptome analysis revealed that PDGFRα+ cells in the large intestine exhibited increased expression levels of collagen-related genes, whereas PDGFRα+ cells in the small intestine exhibited increased expression levels of channel/transporter genes, including Kcn genes. These results suggest that mesenchymal stromal cells differ morphologically and functionally depending on gastrointestinal tract. Further investigations of the cellular properties of mesenchymal stromal cells in the gastrointestinal tract will aid in optimizing methods for the prevention and treatment of gastrointestinal diseases.

Effect of dietary phenylalanine on growth performance and intestinal health of triploid rainbow trout (Oncorhynchus mykiss) in low fishmeal diets.

This study aimed to investigate the effects of phenylalanine on the growth, digestive capacity, antioxidant capability, and intestinal health of triploid rainbow trout (Oncorhynchus mykiss) fed a low fish meal diet (15%). Five isonitrogenous and isoenergetic diets with different dietary phenylalanine levels (1.82, 2.03, 2.29, 2.64, and 3.01%) were fed to triplicate groups of 20 fish (initial mean body weight of 36.76 ± 3.13 g). The weight gain rate and specific growth rate were significantly lower (p < 0.05) in the 3.01% group. The trypsin activity in the 2.03% group was significantly higher than that in the control group (p < 0.05). Amylase activity peaked in the 2.64% treatment group. Serum superoxide dismutase, catalase, and lysozyme had the highest values in the 2.03% treatment group. Liver superoxide dismutase and catalase reached their maximum values in the 2.03% treatment group, and lysozyme had the highest value in the 2.29% treatment group. Malondialdehyde levels in both the liver and serum were at their lowest in the 2.29% treatment group. Interleukin factors IL-1β and IL-6 both reached a minimum in the 2.03% group and were significantly lower than in the control group, while IL-10 reached a maximum in the 2.03% group (p < 0.05). The tight junction protein-related genes occludin, claudin-1, and ZO-1 all attained their highest levels in the 2.03% treatment group and were significantly higher compared to the control group (p < 0.05). The intestinal villi length and muscle layer thickness were also improved in the 2.03% group (p < 0.05). In conclusion, dietary phenylalanine effectively improved the growth, digestion, absorption capacity, antioxidant capacity, and intestinal health of O. mykiss. Using a quadratic curve model analysis based on WGR, the dietary phenylalanine requirement of triploid O. mykiss fed a low fish meal diet (15%) was 2.13%.

A62 IDENTIFICATION OF SPECIFIC COLONIC DEEP MUSCLE LAYER MACROPHAGES SUBSETS BY THE CD64 (FCΓRI) MARKER

Abstract Background Although intestinal muscle layer macrophages have been suggested to play an important role in the colonic transit by interacting with the myenteric plexus neurons, they have not been fully characterized. CD64 (FcγRI) is one of the most generally used markers for intestinal macrophages, but several studies suggested existence of a subpopulation of macrophages that lack CD64. In addition, the muscle layer macrophage subsets currently identified are considered to be same in the small intestine and colon, although this has not been formally tested. Purpose In this study, we aim to identify and characterize the subsets of muscle layer macrophages by CD64 marker. We hypothesize that colon specific CD64-macrophages have a different role from CD64+ conventional macrophages. Method The muscle layers of small intestine (ileum) and colon were separated from SPF mice and cells from each muscle layer were analyzed by flow cytometry and fluorescent staining. The muscle layer macrophages were gated withCD45+, F4/80+, CD11b+ and Ly6c-, and analyzed with CD64 and MHCⅡmarkers by flow cytometry. In additional experiments, fluorescent staining with CD64 and F4/80 was assessed in whole-mount tissue of the separated muscle layer. Result(s) Within the macrophage population from the colon muscle layer, we found not only CD64+ cells, a conventional marker of macrophage, but also CD64- cell population (CD45+, F4/80+, CD11b+, Ly6c-). However, in the small intestine, this CD64- cell population was barely detectable. In addition, colonic CD64+ cells had mostly high expression of MHCⅡ marker, while CD64- cells had low expression of MHCⅡ. A similar pattern was found when we examined intestinal and colonic tissues by immunofluorescent staining. Conclusion(s) We identified a colon-specific CD64- subset of macrophage in muscle layer. Additional experiments are needed to characterize their immunomodulatory properties. Please acknowledge all funding agencies by checking the applicable boxes below None Disclosure of Interest None Declared CLIINICAL PRACTICE

An Engineered Living Intestinal Muscle Patch Produces Macroscopic Contractions that can Mix and Break Down Artificial Intestinal Contents.

The intestinal muscle layers execute various gut wall movements to achieve controlled propulsion and mixing of intestinal content. Engineering intestinal muscle layers with complex contractile function is critical for developing bioartificial intestinal tissue to treat patients with short bowel syndrome. Here, the first demonstration of a living intestinal muscle patch capable of generating three distinct motility patterns and displaying multiple digesta manipulationsis reported. Assessment of contractility, cellular morphology, and transcriptome profile reveals that successful generation of the contracting muscle patch relies on both biological factors in a serum-free medium and environmental cues from an elastic electrospun gelatin scaffold. By comparing gene-expression patterns among samples, it is shown that biological factors from the medium strongly affect ion-transport activities, while the scaffold unexpectedly regulates cell-cell communication. Analysis of ligandreceptor interactome identifies scaffold-driven changes in intercellular communication, and 78% of the upregulated ligand-receptor interactions are involved in the development and function of enteric neurons. The discoveries highlight the importance of combining biomolecular and biomaterial approaches for tissue engineering. The living intestinal muscle patch represents a pivotal advancement for building functional replacement intestinal tissue. It offers a more physiological model for studying GI motility and for preclinical drug discovery.

Digestive function and serum biochemical parameters of juvenile Cyprinus carpio in response to substitution of dietary soybean meal with sesame seed (Sesamum indicum) cake

A feeding trial was designed to evaluate effects of soybean meal replacement (SBM) with sesame seed cake (SSC) at 0 (SSC0), 25 (SSC25), 50 (SSC50), 75 (SSC75), and 100 (SSC100) % in isoproteic (30%) and isolipidic (8%) diets on the growth performance, digestive function and serum and hematological parameters in Cyprinus carpio. Four hundred and fifty common carp juveniles (83.09 g) were randomly distributed into 15 tanks with a flow-through system. Triplicate groups of fish were hand-fed one of the diets to visual satiation thrice daily for 90 days. The survival rate, growth performance and somatic indices did not show significant differences between treatments. Among feed utilization indicators, nitrogen retention efficiency was significantly higher in SSC25 than in other treatments. Lipid retention efficiency significantly increased from SSC50 to SSC100. The number of white blood cells was significantly higher in SSC0 than other treatments. Significantly higher hemoglobin was observed in SSC75 as compared to SS0 and SSC25. Serum biochemical parameters did not significantly differ between dietary treatments. Dietary SSC resulted in significant increase in calcium ADC and activity of digestive trypsin, chymotrypsin, lipase, α-amylase, and alkaline phosphatase. Significantly higher villi height and intestinal muscle layer width were observed in fish fed the SSC75 diet. The villi width in SSC25 and SSC50 was significantly less than in SSC0. Comparable growth performance, feed utilization, apparent digestibility, digestive function, hematological and serum factors indicated the possibility of 75–100% substitution of SBM by SSC in the diet of juvenile C. carpio.

Deconvoluted DSC curves of intestinal muscle layer following warm and cold ischaemic injury

Increasingly evidence seems that from the biological samples—mainly the summation of DSC scans of the human blood plasma—can be separated into main and well-known components by deconvolution method. This fact alone could be an important advance in thermoanalytical research, but mostly, it has not been detected in soft tissues yet. The other main reason was that in our previous studies, the histological examinations did not show any significant abnormalities in the intestinal wall muscle layer. Thus, the aim of current research was to measure the small intestinal muscular tissue scans by deconvolution method following different long warm and cold ischaemia animal experiments. Retrospectively, DSC curves obtained from the thermoanalysis of intestinal tissue in animal experiments investigated by deconvolution mathematical methods. Different warm ischaemic insults caused mild decrease after 3 and 6 h in Tm3 and Tm4 transitions in the myosin assigned transition and actin filament transition. After cold storage, the separated 5 melting components appeared in similar order, but the decreases were lesser than after warm ischaemia. Meanwhile, the calorimetric enthalpy which is a good monitor of intervention is decreased in a time-dependent manner after 1 and 3 h in warm and cold ischaemia cases. In contrast, the enthalpy increased above the control value after 6-h warm or cold tissue damage. These results confirmed that both warm and cold ischaemic injuries are detectable by deconvolution of DSC curves in the muscular intestinal layers.

NR4A1 modulates intestinal smooth muscle cell phenotype and dampens inflammation-associated intestinal remodeling.

Stricture formation is a common complication of Crohn's disease (CD), driven by enhanced deposition of extracellular matrix (ECM) and expansion of the intestinal smooth muscle layers. Nuclear receptor subfamily 4 group A member 1 (NR4A1) is an orphan nuclear receptor that exhibits anti-proliferative effects in smooth muscle cells (SMCs). We hypothesized that NR4A1 regulates intestinal SMC proliferation and muscle thickening in the context of inflammation. Intestinal SMCs isolated from Nr4a1+/+ and Nr4a1-/- littermates were subjected to shotgun proteomic analysis, proliferation, and bioenergetic assays. Proliferation was assessed in the presence and absence of NR4A1 agonists, cytosporone-B (Csn-B) and 6-mercaptopurine (6-MP). In vivo, we compared colonic smooth muscle thickening in Nr4a1+/+ and Nr4a1-/- mice using the chronic dextran sulfate sodium (DSS) model of colitis. Second, SAMP1/YitFc mice (a model of spontaneous ileitis) were treated with Csn-B and small intestinal smooth muscle thickening was assessed. SMCs isolated from Nr4a1-/- mice exhibited increased abundance of proteins related to cell proliferation, metabolism, and ECM production, whereas Nr4a1+/+ SMCs highly expressed proteins related to the regulation of the actin cytoskeleton and contractile processes. SMCs isolated from Nr4a1-/- mice exhibited increased proliferation and alterations in cellular metabolism, whereas activation of NR4A1 attenuated proliferation. In vivo, Nr4a1-/- mice exhibited increased colonic smooth muscle thickness following repeated cycles of DSS. Activating NR4A1 with Csn-B, in the context of established inflammation, reduced ileal smooth muscle thickening in SAMP1/YitFc mice. Targeting NR4A1 may provide a novel approach to regulate intestinal SMC phenotype, limiting excessive proliferation that contributes to stricture development in CD.

Atropine-functionalized gold nanoparticles binding to muscarinic receptors after passage across the intestinal epithelium.

Gold nanoparticles have a high potential to be a treatment of diseases by their specific drug delivery properties and multivalent receptor stimulation. For the present project, spherical gold nanoparticles were synthesized and functionalized with the muscarinic receptor antagonist atropine (Au-MUDA-AT NPs). The diameter of the gold core could precisely be controlled by using different synthetic methods and reducing agents resulting in functionalized gold nanoparticles with diameters ranging from 8 to 16 nm. The ability to interact with intestinal muscarinic receptors is size-dependent. When using intestinal chloride secretion induced by the stable acetylcholine derivative, carbachol, as read-out, the strongest inhibition, i.e. the most efficient blockade of muscarinic receptors, was observed with 13 nm sized Au-MUDA-AT NPs. Functional experiments indicate that Au-MUDA-AT NPs with a diameter of 14 nm are able to pass the intestinal mucosa in a time-dependent manner after administration to the intestinal lumen. For example, luminally administered Au-MUDA-AT NPs inhibited contractions of the small intestinal longitudinal muscle layer induced by electrical stimulation of myenteric neurons. A similar inhibition of basolateral epithelial receptors was observed after luminal administration of Au-MUDA-AT NPs when using carbachol-induced chloride secretion across the intestinal epithelium as a test system. Thus, Au-MUDA-AT NPs might be a therapeutic tool for the modulation of intestinal secretion and motility after oral application in the future.

Temporal and spatial development of intestinal smooth muscle layers of human embryos and fetuses.

The sequential occurrence of three layers of smooth muscle layers (SML) in human embryos and fetus is not known. Here, we investigated the process of gut SML development in human embryos and fetuses and compared the morphology of SML in fetuses and neonates. The H&E, Masson trichrome staining, and Immunohistochemistry were conducted on 6-12 gestation week human embryos and fetuses and on normal neonatal intestine. We showed that no lumen was seen in 6-7th gestation week embryonic gut, neither gut wall nor SML was developed in this period. In 8-9th gestation week embryonic and fetal gut, primitive inner circular SML (IC-SML) was identified in a narrow and discontinuous gut lumen with some vacuoles. In 10th gestation week fetal gut, the outer longitudinal SML (OL-SML) in gut wall was clearly identifiable, both the inner and outer SML expressed α-SMA. In 11-12th gestation week fetal gut, in addition to the IC-SML and OL-SML, the muscularis mucosae started to develop as revealed by α-SMA immune-reactivity beneath the developing mucosal epithelial layer. Comparing with the gut of fetuses of 11-12th week of gestation, the muscularis mucosae, IC-SML, and OL-SML of neonatal intestine displayed different morphology, including branching into glands of lamina propria in mucosa and increased thickness. In conclusions, in the human developing gut between week-8 to week-12 of gestation, the IC-SML develops and forms at week-8, followed by the formation of OL-SML at week-10, and the muscularis mucosae develops and forms last at week-12.