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European Journal of Pharmaceutics and... Apr 2022Gastrointestinal (GI) mucus is continuously secreted and lines the entire length of the GI tract. Essential for health, it keeps the noxious luminal content away from...
Gastrointestinal (GI) mucus is continuously secreted and lines the entire length of the GI tract. Essential for health, it keeps the noxious luminal content away from the epithelium. Our aim was to characterize the composition and structure of mucus throughout the various GI segments in dog. Mucus was collected from the stomach, small intestine (duodenum, jejunum, ileum), and large intestine (cecum, proximal and distal colon) from dogs. Composition was determined by multi-omics. Structural properties were investigated using cryoSEM and rheology. GI mucus contained 74-95% water and maintained a pH around 6.5. The proteome was similar across the different GI segments. The highest abundant secreted gel-forming mucin in the gastric mucus was mucin 5AC, whether mucin 2 had highest abundance in the intestinal mucus. Lipid and metabolite abundance was generally higher in the jejunal mucus than the colonic mucus. CryoSEM microscopy revealed smaller pore size in small intestinal mucus, which increased in the large intestine. All mucus samples showed shear-thinning behavior and characteristics of gel-like structure. In conclusion, the mucus is a highly viscous and hydrated material. These data provide an important baseline for future studies on human and canine intestinal diseases and the dog model in drug absorption.
Topics: Animals; Colon; Dogs; Gastrointestinal Tract; Intestinal Mucosa; Intestine, Small; Mucus; Stomach
PubMed: 35227857
DOI: 10.1016/j.ejpb.2022.02.019 -
Cell Host & Microbe Dec 2022The human distal small intestine (ileum) has a distinct microbiota, but human studies investigating its composition and function have been limited by the inaccessibility...
The human distal small intestine (ileum) has a distinct microbiota, but human studies investigating its composition and function have been limited by the inaccessibility of the ileum without purging and/or deep intubation. We investigated inherent instability, temporal dynamics, and the contribution of fed and fasted states using stoma samples from cured colorectal cancer patients as a non-invasive access route to the otherwise inaccessible small and large intestines. Sequential sampling of the ileum before and after stoma formation indicated that ileostoma microbiotas represented that of the intact small intestine. Ileal and colonic stoma microbiotas were confirmed as distinct, and two types of instability in ileal host-microbial relationships were observed: inter-digestive purging followed by the rapid postprandial blooming of bacterial biomass and sub-strain appearance and disappearance within individual taxa after feeding. In contrast to the relative stability of colonic microbiota, the human small intestinal microbiota biomass and its sub-strain composition can be highly dynamic.
Topics: Humans; Adult; Gastrointestinal Microbiome; Ileum; Microbiota; Intestine, Small; Colon
PubMed: 36318918
DOI: 10.1016/j.chom.2022.10.002 -
American Journal of Physiology. Cell... May 2021The development of alternative in vitro culture methods has increased in the last decade as three-dimensional organoids of various tissues, including those of the small... (Comparative Study)
Comparative Study
The development of alternative in vitro culture methods has increased in the last decade as three-dimensional organoids of various tissues, including those of the small and large intestines. Due to their multicellular composition, organoids offer advantages over traditionally used immortalized or primary cell lines. However, organoids must be accurate models of their tissues of origin. This study compared gene expression profiles with respect to markers of specific cell types (stem cells, enterocytes, goblet, and enteroendocrine cells) and barrier maturation (tight junctions) of colonoid and enteroid cultures with their tissues of origin and colonoids with enteroids. Colonoids derived from three healthy pigs formed multilobed structures with a monolayer of cells similar to the crypt structures in colonic tissue. Colonoid and enteroid gene expression signatures were more similar to those found for the tissues of their origin than to each other. However, relative to their derived tissues, organoids had increased gene expression levels of stem cell markers and encoding sex-determining region Y-box 9 and leucine-rich repeat-containing G protein-coupled rector 5, respectively. In contrast, expression levels of and encoding occludin and zonula occludens 1, respectively, were decreased. Expression levels of the cell lineage markers , , and encoding atonal homolog 1, chromogranin A, and mucin 2, respectively, were decreased in colonoids, whereas and encoding sodium-glucose transporter 1 and aminopeptidase A, respectively, were decreased in enteroids. These results indicate colonoid and enteroid cultures were predominantly comprised of undifferentiated cell types with decreased barrier maturation relative to their tissues of origin.
Topics: Animals; Biomarkers; Cell Differentiation; Cell Lineage; Cell Proliferation; Colon; Gene Expression Regulation; Ileum; Intestinal Mucosa; Male; Organoids; Phenotype; Signal Transduction; Sus scrofa; Time Factors; Tissue Culture Techniques; Transcriptome
PubMed: 33760661
DOI: 10.1152/ajpcell.00420.2020 -
Journal of Gastrointestinal and Liver... Jun 2015New research has addressed many of the early concerns of computed tomographic colonography (CTC) and these studies are now beginning to shape clinical practices. A... (Review)
Review
New research has addressed many of the early concerns of computed tomographic colonography (CTC) and these studies are now beginning to shape clinical practices. A review of the literature demonstrates that the sensitivity of CTC in screening for large polyps (>/= 1cm) or cancers in the large intestine is as high as that of conventional optical colonoscopy, however, the sensitivity decreases with the diameter of the polyp. Despite this, CTC is well tolerated, more acceptable to patients than optical colonoscopy and therefore may improve colorectal cancer screening compliance. This review not only describes the diagnostic accuracy and sensitivity of CTC, and the evolving role of CTC as a primary colon cancer screening option, but also the recent studies that have demonstrated the additional value of CTC utilization for practicing clinicians.
Topics: Colon; Colonic Neoplasms; Colonography, Computed Tomographic; Colonoscopy; Humans; Predictive Value of Tests; Prognosis; Radiographic Image Interpretation, Computer-Assisted; Reproducibility of Results; Surgeons
PubMed: 26114182
DOI: 10.15403/jgld.2014.1121.242.blws -
World Journal of Gastroenterology Nov 2010Colonic motility subserves large bowel functions, including absorption, storage, propulsion and defaecation. Colonic motor dysfunction remains the leading hypothesis to... (Review)
Review
Colonic motility subserves large bowel functions, including absorption, storage, propulsion and defaecation. Colonic motor dysfunction remains the leading hypothesis to explain symptom generation in chronic constipation, a heterogeneous condition which is extremely prevalent in the general population, and has huge socioeconomic impact and individual suffering. Physiological testing plays a crucial role in patient management, as it is now accepted that symptom-based assessment, although important, is unsatisfactory as the sole means of directing therapy. Colonic manometry provides a direct method for studying motor activities of the large bowel, and this review provides a contemporary understanding of how this technique has enhanced our knowledge of normal colonic motor physiology, as well as helping to elucidate pathophysiological mechanisms underlying constipation. Methodological approaches, including available catheter types, placement technique and recording protocols, are covered, along with a detailed description of recorded colonic motor activities. This review also critically examines the role of colonic manometry in current clinical practice, and how manometric assessment may aid diagnosis, classification and guide therapeutic intervention in the constipated individual. Most importantly, this review considers both adult and paediatric patients. Limitations of the procedure and a look to the future are also addressed.
Topics: Adult; Child; Colon; Constipation; Gastrointestinal Motility; Humans; Manometry
PubMed: 21049550
DOI: 10.3748/wjg.v16.i41.5162 -
JCI Insight Oct 2018Crohn's disease (CD) is highly heterogeneous, due in large part to variability in cellular processes that underlie the natural history of CD, thereby confounding...
BACKGROUND
Crohn's disease (CD) is highly heterogeneous, due in large part to variability in cellular processes that underlie the natural history of CD, thereby confounding effective therapy. There is a critical need to advance understanding of the cellular mechanisms that drive CD heterogeneity.
METHODS
We performed small RNA sequencing of adult colon tissue from CD and NIBD controls. Colonic epithelial cells and immune cells were isolated from colonic tissues, and microRNA-31 (miR-31) expression was measured. miR-31 expression was measured in colonoid cultures generated from controls and patients with CD. We performed small RNA-sequencing of formalin-fixed paraffin-embedded colon and ileum biopsies from treatment-naive pediatric patients with CD and controls and collected data on disease features and outcomes.
RESULTS
Small RNA-sequencing and microRNA profiling in the colon revealed 2 distinct molecular subtypes, each with different clinical associations. Notably, we found that miR-31 expression was a driver of these 2 subtypes and, further, that miR-31 expression was particularly pronounced in epithelial cells. Colonoids revealed that miR-31 expression differences are preserved in this ex vivo system. In adult patients, low colonic miR-31 expression levels at the time of surgery were associated with worse disease outcome as measured by need for an end ileostomy and recurrence of disease in the neoterminal ileum. In pediatric patients, lower miR-31 expression at the time of diagnosis was associated with future development of fibrostenotic ileal CD requiring surgeryCONCLUSIONS. These findings represent an important step forward in designing more effective clinical trials and developing personalized CD therapies.
FUNDING
This work was supported by CCF Career Development Award (SZS), R01-ES024983 from NIEHS (SZS and TSF), 1R01DK104828-01A1 from NIDDK (SZS and TSF), P01-DK094779-01A1 from NIDDK (SZS), P30-DK034987 from NIDDK (SZS), 1-16-ACE-47 ADA Pathway Award (PS), UNC Nutrition Obesity Research Center Pilot & Feasibility Grant P30DK056350 (PS), CCF PRO-KIIDS NETWORK (SZS and PS), UNC CGIBD T32 Training Grant from NIDDK (JBB), T32 Training Grant (5T32GM007092-42) from NIGMS (MH), and SHARE from the Helmsley Trust (SZS). The UNC Translational Pathology Laboratory is supported, in part, by grants from the National Cancer Institute (3P30CA016086) and the UNC University Cancer Research Fund (UCRF) (PS).
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Biomarkers; Biopsy; Child; Child, Preschool; Cohort Studies; Colectomy; Colon; Crohn Disease; Epithelial Cells; Female; Gene Expression Profiling; Humans; Ileostomy; Ileum; Intestinal Mucosa; Male; MicroRNAs; Middle Aged; Prognosis; Recurrence; Reoperation; Sequence Analysis, RNA; Treatment Outcome; Up-Regulation; Young Adult
PubMed: 30282822
DOI: 10.1172/jci.insight.122788 -
American Journal of Veterinary Research Oct 2013To determine the effect of large colon ischemia and reperfusion on concentrations of the inflammatory neutrophilic protein calprotectin and other clinicopathologic...
OBJECTIVE
To determine the effect of large colon ischemia and reperfusion on concentrations of the inflammatory neutrophilic protein calprotectin and other clinicopathologic variables in jugular and colonic venous blood in horses.
ANIMALS
6 healthy horses.
PROCEDURES
Horses were anesthetized, and ischemia was induced for 1 hour followed by 4 hours of reperfusion in a segment of the pelvic flexure of the large colon. Blood samples were obtained before anesthesia, before induction of ischemia, 1 hour after the start of ischemia, and 1, 2, and 4 hours after the start of reperfusion from jugular veins and veins of the segment of the large colon that underwent ischemia and reperfusion. A sandwich ELISA was developed for detection of equine calprotectin. Serum calprotectin concentrations and values of blood gas, hematologic, and biochemical analysis variables were determined.
RESULTS
Large colon ischemia caused metabolic acidosis, a significant increase in lactate and potassium concentrations and creatine kinase activities, and a nonsignificant decrease in glucose concentrations in colonic venous blood samples. Values of these variables after reperfusion were similar to values before ischemia. Ischemia and reperfusion induced activation of an inflammatory response characterized by an increase in neutrophil cell turnover rate in jugular and colonic venous blood samples and calprotectin concentrations in colonic venous blood samples.
CONCLUSIONS AND CLINICAL RELEVANCE
Results of this study suggested that large colon ischemia and reperfusion caused local and systemic inflammation in horses. Serum calprotectin concentration may be useful as a marker of this inflammatory response.
Topics: Acidosis; Animals; Blood Gas Analysis; Colon; Creatine Kinase; Enzyme-Linked Immunosorbent Assay; Hematologic Tests; Horse Diseases; Horses; Jugular Veins; Lactic Acid; Leukocyte L1 Antigen Complex; Potassium; Reperfusion Injury; Statistics, Nonparametric; Time Factors
PubMed: 24066912
DOI: 10.2460/ajvr.74.10.1281 -
Medical Engineering & Physics Feb 2016This paper presents a method of characterizing the distribution of colorectal morphometrics. It uses three-dimensional region growing and topological thinning algorithms...
This paper presents a method of characterizing the distribution of colorectal morphometrics. It uses three-dimensional region growing and topological thinning algorithms to determine and visualize the luminal volume and centreline of the colon, respectively. Total and segmental lengths, diameters, volumes, and tortuosity angles were then quantified. The effects of body orientations on these parameters were also examined. Variations in total length were predominately due to differences in the transverse colon and sigmoid segments, and did not significantly differ between body orientations. The diameter of the proximal colon was significantly larger than the distal colon, with the largest value at the ascending and cecum segments. The volume of the transverse colon was significantly the largest, while those of the descending colon and rectum were the smallest. The prone position showed a higher frequency of high angles and consequently found to be more torturous than the supine position. This study yielded a method for complete segmental measurements of healthy colorectal anatomy and its tortuosity. The transverse and sigmoid colons were the major determinant in tortuosity and morphometrics between body orientations. Quantitative understanding of these parameters may potentially help to facilitate colonoscopy techniques, accuracy of polyp spatial distribution detection, and design of novel endoscopic devices.
Topics: Asymptomatic Diseases; Colon; Colonoscopy; Female; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Prone Position; Rectum; Robotics; Supine Position; Tomography, X-Ray Computed
PubMed: 26762775
DOI: 10.1016/j.medengphy.2015.11.018 -
American Journal of Physiology.... Oct 2021Digestive functions of the colon depend on sensory-motor reflexes in the enteric nervous system (ENS), initiated by intrinsic primary afferent neurons (IPANs). IPAN...
Digestive functions of the colon depend on sensory-motor reflexes in the enteric nervous system (ENS), initiated by intrinsic primary afferent neurons (IPANs). IPAN terminals project to the mucosal layer of the colon, allowing communication with epithelial cells comprising the colon lining. The chemical nature and functional significance of this epithelial-neural communication in regard to secretion and colon motility are of high interest. Colon epithelial cells can produce and release neuroactive substances such as ATP and 5-hydroxytryptamine (5-HT), which can activate receptors on adjacent nerve fibers, including IPAN subtypes. In this study, we examined if stimulation of epithelial cells alone is sufficient to activate neural circuits that control colon motility. Optogenetics and calcium imaging were used in ex vivo preparations of the mouse colon to selectively stimulate the colon epithelium, measure changes in motility, and record activity of neurons within the myenteric plexus. Light-mediated activation of epithelial cells lining the distal, but not proximal, colon caused local contractions and increased the rate of colonic migrating motor complexes. Epithelial-evoked local contractions in the distal colon were reduced by both ATP and 5-HT receptor antagonists. Our findings indicate that colon epithelial cells likely use purinergic and serotonergic signaling to initiate activity in myenteric neurons, produce local contractions, and facilitate large-scale coordination of ENS activity responsible for whole colon motility patterns. Using an all-optical approach to measure real-time cell-to-cell communication responsible for colon functions, we show that selective optogenetic stimulation of distal colon epithelium produced activity in myenteric neurons, as measured with red genetically encoded calcium indicators. The epithelial-induced neural response led to local contractions, mediated by both purinergic and serotonergic signaling, and facilitated colonic motor complexes that propagate from proximal to distal colon.
Topics: Adenosine Triphosphate; Animals; Calcium Signaling; Colon; Female; Gastrointestinal Motility; Intestinal Mucosa; Male; Mice; Muscle Contraction; Myenteric Plexus; Optogenetics; Serotonin
PubMed: 34468219
DOI: 10.1152/ajpgi.00026.2021 -
The FEBS Journal Feb 2019Cytoplasmic dynein-1 is a large minus-end-directed microtubule motor complex involved in membrane trafficking, organelle positioning, and microtubule organization. The...
Cytoplasmic dynein-1 is a large minus-end-directed microtubule motor complex involved in membrane trafficking, organelle positioning, and microtubule organization. The roles of dynein light intermediate chains (DLICs; DLIC1 and DLIC2) within the complex are, however, still largely undefined. In this study, we investigated the possible roles of DLICs in epithelial homeostasis and colon cancer development. Mutant clonal analysis of Drosophila Dlic in the follicular epithelium of Drosophila ovary showed defects in nuclear positioning, epithelial integrity, and apical cell polarity. Consistently, knockdown of human DLIC1 and DLIC2 in colon carcinoma cells resulted in damaged epithelial organization, disturbed lumen formation, and impaired apical polarity establishment in three-dimensional cell culture. Depletion of DLIC1 and DLIC2 led to reduced proliferation, enhanced apoptosis rates, disrupted mitotic spindle assembly, and induction of G2/M arrest in cell cycle progression. Moreover, reduced levels of DLIC1 in contrast to DLIC2 impaired the migratory ability. On the other hand, immunohistochemical examination of human colorectal tissue samples and further colorectal cancer dataset analysis showed a significant upregulation for DLIC1 in tumors, whereas DLIC2 expression was unchanged. In addition, the overexpression of DLIC1 caused increased proliferation, decreased apoptosis and enhanced migration, whereas DLIC2 overexpression did not result in any significant changes. Together, these results indicate that DLIC1 and DLIC2 contribute to the establishment and maintenance of epithelial homeostasis. Furthermore, these findings present the first evidence that DLIC1 and DLIC2 have distinct roles in colon cancer development and that DLIC1 may contribute to proliferative overgrowth and migratory characteristics.
Topics: Animals; Apoptosis; Case-Control Studies; Cell Movement; Cell Proliferation; Cells, Cultured; Colon; Colonic Neoplasms; Cytoplasmic Dyneins; Drosophila; G2 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Humans; Up-Regulation
PubMed: 30657258
DOI: 10.1111/febs.14755