Functional Expression of Transient Receptor Potential and Piezo1 Channels in Cultured Interstitial Cells of Human-Bladder Lamina Propria

The interstitial cells in bladder lamina propria (LP-ICs) are believed to be involved in sensing/afferent signaling in bladder mucosa. Transient receptor potential (TRP) cation channels act as mechano- or chemo-sensors and may underlie some of the sensing function of bladder LP-ICs. We aimed to investigate the molecular and functional expression of TRP channels implicated in bladder sensory function and Piezo1/Piezo2 channels in cultured LP-ICs of the human bladder. Bladder tissues were obtained from patients undergoing cystectomy. LP-ICs were isolated and cultured, and used for real-time reverse transcription-quantitative polymerase chain reaction, immunocytochemistry, and calcium-imaging experiments. At the mRNA level, TRPA1, TRPV2, and Piezo1 were expressed most abundantly. Immunocytochemical staining showed protein expression of TRPA1, TRPV1, TRPV2, TRPV4, TRPM8, as well as Piezo1 and Piezo2. Calcium imaging using channel agonists/antagonists provided evidence for functional expression of TRPA1, TRPV2, TRPV4, Piezo1, but not of TRPV1 or TRPM8. Activation of these channels with their agonist resulted in release of adenosine triphosphate (ATP) from LP-ICs. Inhibition of TRPV2, TRPV4 and Piezo1 blocked the stretch induced intracellular Ca2+ increase. Whereas inhibition of TRPA1 blocked H2O2 evoked response in LP-ICs. Our results suggest LP-ICs of the bladder can perceive stretch or chemical stimuli via activation of TRPV2, TRPV4, Piezo1 and TRPA1 channels. LP-ICs may work together with urothelial cells for perception and transduction of mechanical or chemical signals in human-bladder mucosa.

Facilitation of colonic T cell immune responses is associated with an exacerbation of dextran sodium sulfate–induced colitis in mice lacking microsomal prostaglandin E synthase-1

Background Microsomal prostaglandin E synthase-1 (mPGES-1) is a key enzyme that acts downstream of cyclooxygenase and plays a major role in inflammation by converting prostaglandin (PG) H2 to PGE2. The present study investigated the effect of genetic deletion of mPGES-1 on the development of immunologic responses to experimental colitis induced by dextran sodium sulfate (DSS), a well-established model of inflammatory bowel disease (IBD). Methods Colitis was induced in mice lacking mPGES-1 (mPGES-1−/− mice) and wild-type (WT) mice by administering DSS for 7 days. Colitis was assessed by body weight loss, diarrhea, fecal bleeding, and histological features. The colonic expression of mPGES-1 was determined by real-time PCR, western blotting, and immunohistochemistry. The impact of mPGES-1 deficiency on T cell immunity was determined by flow cytometry and T cell depletion in vivo. Results After administration of DSS, mPGES-1−/− mice exhibited more severe weight loss, diarrhea, and fecal bleeding than WT mice. Histological analysis further showed significant exacerbation of colonic inflammation in mPGES-1−/− mice. In WT mice, the colonic expression of mPGES-1 was highly induced on both mRNA and protein levels and colonic PGE2 increased significantly after DSS administration. Additionally, mPGES-1 protein was localized in the colonic mucosal epithelium and infiltrated inflammatory cells in underlying connective tissues and the lamina propria. The abnormalities consistent with colitis in mPGES-1−/− mice were associated with higher expression of colonic T-helper (Th)17 and Th1 cytokines, including interleukin 17A and interferon-γ. Furthermore, lack of mPGES-1 increased the numbers of Th17 and Th1 cells in the lamina propria mononuclear cells within the colon, even though the number of suppressive regulatory T cells also increased. CD4+ T cell depletion effectively reduced symptoms of colitis as well as colonic expression of Th17 and Th1 cytokines in mPGES-1−/− mice, suggesting the requirement of CD4+ T cells in the exacerbation of DSS-induced colitis under mPGES-1 deficiency. Conclusions These results demonstrate that mPGES-1 is the main enzyme responsible for colonic PGE2 production and deficiency of mPGES-1 facilitates the development of colitis by affecting the development of colonic T cell–mediated immunity. mPGES-1 might therefore impact both the intestinal inflammation and T cell–mediated immunity associated with IBD.

Ontogeny of RORγt+ cells in the intestine of newborns and its role in the development of experimental necrotizing enterocolitis

Background Neonates possess an immature and plastic immune system, which is a major cause of some diseases in newborns. Necrotizing enterocolitis (NEC) is a severe and devastating intestinal disease that typically affects premature infants. However, the development of intestinal immune cells in neonates and their roles in the pathological process of NEC have not been elucidated. Results We examined the ontogeny of intestinal lamina propria lymphocytes in the early life of mice and found a high percentage of RORγt+ cells (containing inflammatory Th17 and ILC3 populations) during the first week of life. Importantly, the proportion of RORγt+ cells of intestinal lamina propria further increased in both NEC mice and patients tissue than the control. Furthermore, the application of GSK805, a specific antagonist of RORγt, inhibited IL-17A release and ameliorated NEC severity. Conclusions Our data reveal the high proportion of RORγt+ cells in newborn mice may directly contribute to the development of NEC.

Histological Feature of Uterus and Uterine Tube During Late Period of Pregnancy in Rabbits

Current work was conducted to investigate the histological architecture of the uterine tube and uterus during the period of late pregnancy in rabbits. Twelve adult local breed rabbits were used. The samples from different parts of the uterine tube were prepared for histological study after staining with H&E, Masson’s trichrome and combine Alcian blue (pH2.5)-PAS. The pre ampulla was a narrow tube and its tunica mucosa had slightly long simple mucosal folds lined by pseudostratified columnar epithelium, the ampulla had a wide lumen and its tunica mucosa displayed several highly tall branched mucosal folds with few short simple folds while the isthmus was the narrowest region and its tunica mucosa displayed few of tall and short simple mucosal folds. The mucosa of three parts of the uterine tube was lined by pseudostratified columnar epithelium which is composed of three types of cells: mucous secretory cells, non-secretory cells and basal cells, the mucous secretory cells were the predominant type and revealed secretory activities. The lamina propria-submucosa of the uterine tube was composed of cellular connective tissue and tunica muscularis. The uterus had a very thick wall with well-recognized endometrium and myometrium, the endometrium was composed of many-branched and simple endometrial folds that were covered by multinucleated syncytial cells and simple cuboidal epithelial cells. Lamina propria was composed of loose connective tissue had scattered groups of well growing simple uterine glands that showed secretory activities. The current result showed that the uterus during the late period of pregnancy was differed from those of non-pregnant rabbits, while the uterine tube at late pregnancy has a structure that appeared prepared for the next physiological period.

Ultrastructural characteristics of the rats laryngeal mucosa and cartilage on the 7 and 14 days of the experimental opioid effect

Background and objective. Our main task was to study the ultrastructural organization of the laryngeal mucosa and cartilage on the seventh and fourteenth day of opioid exposure. Methods. The material for the study were mature, outbred male rats in the number of 32 animals, weighing 80g, aged 4.5 months. Animals were injected intramuscularly with Nalbuphine once a day at the same time (10-11 hours in the morning) for 14 days. The initial dose of Nalbuphine was 8 mg / kg during the first week, 15 mg / kg during the second week of the experimental study. Thus, we created the conditions for chronic opioid exposure. Animals were divided into 3 experimental groups: 1 – control group; 2 - animals that received the drug for 7 days; 3 - animals that received the drug for 14 days). All animals were kept in a vivarium. Animal care, labeling and all other manipulations were carried out taking into account the issues of bioethical norms. Before collecting necropsy material, the animal was removed from the experiment with diethyl ether. The the larynx mucosa and rats cartilage were used as the material for ultrastructural examination. Ultrastructural capsule was prepared according to conventional methods. Results. As a result of experimental opioid exposure at the end of 7 days we found alternative changes in the epithelial cells of different parts of the larynx, dyscirculatory changes in blood vessels of lamina propria and submucosa, as well as the destruction of chondrocytes of hyaline and elastic cartilages. The hemocapillaries of lamina propria and submucosa, especially in the ventricles of the larynx and in the subchondral region, were dilated, overflowing with erythrocytes. In the laryngeal mucosa and submucosal base of the laryngeal ventricles, in addition to the overflow of hemocapillaries with erythrocytes, a moderate accumulation of perivascular transudate was noted. At the end of the 14th day of the experimental opioid effect, a pronounced hemocapillaries injury was found, which was accompanied by an increase in the permeability of the vascular wall. In addition to blood plasma, erythrocytes were visualized in the enlarged lumens of hemocapillaries. The development of degenerative changes of endothelial cells, which were accompanied by inhomogeneous dilation of the tubules of the smooth and granular endoplasmic reticulum, was noted. The main substance of the connective tissue of the mucous membrane and submucosal base, especially around the vessels was impregnated with transudate.

IgA Plasma Cells Are Long-Lived Residents of Gut and Bone Marrow That Express Isotype- and Tissue-Specific Gene Expression Patterns

Antibody secreting plasma cells are made in response to a variety of pathogenic and commensal microbes. While all plasma cells express a core gene transcription program that allows them to secrete large quantities of immunoglobulin, unique transcriptional profiles are linked to plasma cells expressing different antibody isotypes. IgA expressing plasma cells are generally thought of as short-lived in mucosal tissues and they have been understudied in systemic sites like the bone marrow. We find that IgA+ plasma cells in both the small intestine lamina propria and the bone marrow are long-lived and transcriptionally related compared to IgG and IgM expressing bone marrow plasma cells. IgA+ plasma cells show signs of shared clonality between the gut and bone marrow, but they do not recirculate at a significant rate and are found within bone marrow plasma cells niches. These data suggest that systemic and mucosal IgA+ plasma cells are from a common source, but they do not migrate between tissues. However, comparison of the plasma cells from the small intestine lamina propria to the bone marrow demonstrate a tissue specific gene transcription program. Understanding how these tissue specific gene networks are regulated in plasma cells could lead to increased understanding of the induction of mucosal versus systemic antibody responses and improve vaccine design.

Colonic Mucosa Barrier Defects in Collagenous and Ischemic Colitis

Aims The subepithelial myofibroblasts (SEMFs) and the subepithelial band of macrophages (SEBM) are major components of the colonic mucosa barrier. Although their role in homeostasis is widely recognized, their contribution to disease states is largely unknown. The aim of the study was to explore histological characteristics of SEMFs and SEBM in collagenous and ischemic colitis.Methods Ten colonic biopsies of collagenous colitis, 10 of ischemic colitis and 10 control biopsies of normal mucosa were examined. SEMFs, SEBM and lamina propria macrophages were identified immunohistochemically by aSMA and CD68 respectively.ResultsIn collagenous colitis, SEMFs were rarely detectable in the collagenous band while in the lower lamina propria cell processes were formed. SEBM was preserved in areas with a collagenous layer up to 20μm. In thicker layers, it was fragmented and gradually disappeared in parallel with engulfment of enlarged macrophages. In the lower lamina propria macrophages were usually increased.In ischemic colitis, rounding, disintegration and extinction of SEMFs constituted successive alterations coinciding with crypt shrinkage and denudation. SEBM displayed total or almost total abolishment in areas with crypt damage and stroma fibrosis but also in sights with minimal changes.ConclusionIn collagenous colitis, alterations of mucosa barrier are related to collagenous layer thickness. SEMFs changes probably reflect derangement of differentiation and migration while SEMB alterations seem to be compensated by macrophage activation and numerical increase in lamina propria. The striking damage of mucosa barrier in ischemic colitis is indicative of its high sensitivity to hypoxia and hypoperfusion. The histological differences between collagenous colitis and ischemic colitis may be proven of differential diagnostic significance.