scispace - formally typeset
Search or ask a question
Journal ArticleDOI

A comparative histochemical study of the distribution of mucins in the gastrointestinal tracts of three insectivorous mammals

TL;DR: Similarities between the insectivores of this study and other distantly related species suggest that mixed mucin goblet cells are essential for the formation of the biofilm, irrespective of their diet or taxonomy.
About: This article is published in Acta Histochemica.The article was published on 2013-07-01 and is currently open access. It has received 18 citations till now. The article focuses on the topics: Sialomucins & Mucin.

Summary (3 min read)

Introduction

  • The entire gastrointestinal (GI) mucosal surface from the stomach to the colon is covered with a mucous layer (Atuma et al., 2001) .
  • These animals belong to three different superorders viz.

Animals

  • Intact GI specimens, of animals that were previously fixed by perfusion with 4% paraformaldehyde, were obtained from the Department of Zoology and Entomology at the University of Pretoria.
  • Ethical clearance for the use of these specimens was obtained from the animal ethics committees of the Universities of Pretoria and Stellenbosch.
  • Nature conservation permits were also obtained prior to commencement of this study.

Harvesting of tissue and histochemical methods

  • Tissue was harvested from corresponding GI regions in each species.
  • In the latter two species tissue was therefore harvested from the stomach, duodenum, and two areas corresponding to the presumed position of the middle and distal small intestines and colon.
  • Each of the four slides had four sections.
  • In AF-AB staining, sialomucins stain blue, mixed sulfo-and sialomucins stain blue/purple and sulfomucins stain purple.
  • These images were photographed in a systematic way by capturing every second field of view across the entire length of the tissue section.

Measurement and quantification protocol

  • Image analysis software, NIS Elements Basic Research (Version 3.10), was used to measure the following parameters from each of the stained sections:.
  • The total length of each tissue section in mm was measured from the micrographs captured using the 2.5× objective lens.
  • The systematic approach used to capture images from two tissue sections on each slide ensured that at least 50% of the tissue was analyzed.
  • The data were expressed as the total number of mucin specific goblet cells counted in the surface epithelial-and crypt areas (mm 2 ) respectively, as well as in the sum of the areas covered by the surface epithelium and crypt areas (mm 2 ).
  • Mucous secreting cells of the stomach and Brunner's glands were not quantified owing to the difficulty of distinguishing between individual cells and thus only the staining characteristics are described.

Statistical data analysis

  • Statistical analyses were performed using the Statistica data analysis software system, version 10 (StatSoft, Inc. Tulsa, OK, USA).
  • The number of goblet cells/mm 2 for each GI region was analyzed using the F-test ANOVA and Fisher's Least Significant Difference (LSD) test.
  • The intestinal regions portrayed on the graphs were the duodenum, middle and distal small intestines and the large intestine.
  • The large intestine of A. spinosissimus comprises the caecum and the colon.
  • The labeling of the intestinal regions on the graphs was done in such a manner as to compare A. spinosissimus with the species without caeca.

Quantification of mucin secreting goblet cells AB-PAS technique

  • The total number of goblet cells per total area (mm 2 ) quantified with the AB-PAS technique illustrates the overall distribution of the neutral and acid mucin secreting goblet cells throughout the GITs of all three insectivorous species (Fig. 2A ).
  • Both the surface epithelial and crypt areas revealed similar trends to that observed in Fig. 2A .
  • With the exception of C. cyanea, the largest number of goblet cells was located mainly in the crypt areas (Table 1 ).
  • The total number of neutral mucin-containing goblet cells is significantly greater throughout the intestinal tract of C. cyanea than in the other two species (p < 0.01) (Fig. 2B ) and this trend is similar for both the surface epithelium and crypt regions (Table 1 ).
  • In A. hottentotus, the number of neutral mucins in the surface epithelial area increased towards the large intestine with a simultaneous decrease of cells in the crypts.

AF-AB and HID-AB techniques

  • The results of the AF-AB and HID-AB techniques revealed that A. spinosissimus and C. cyanea had the largest number of acid mucins distributed throughout their GITs however, this result was not significant.
  • The overall trend in all three species indicated that the number of acid mucins increased significantly (p < 0.01) towards the distal GI regions (Fig. 3A ), with the largest number of cells in the crypt areas (Tables 2 and 3 ).
  • A. hottentotus had significantly more (p < 0.01) sialomucin secreting goblet cells than A. spinosissimus and C. cyanea (Fig. 3B ), whereas C. cyanea had significantly more (p < 0.01) sulfomucin secreting goblet cells than the other insectivores (Fig. 3C ).
  • C. cyanea had relatively equal numbers of both weakly and strongly sulfated goblet cells (Table 2 ) which revealed a similar distribution pattern than the overall trend seen in Fig. 3C .
  • The Y-axis is expressed as log 10 in order to represent the large differences in goblet cell number between the different regions and species on the same graph.

Discussion

  • In all the mammalian species (mouse, rat, hamster, gerbil, guinea pig, rabbit, cat, dog, rhesus monkey, baboon and human) examined by Sheahan and Jervis (1976) , neutral mucins were the predominant type expressed throughout the entire gastric epithelium.
  • This is consistent with the observations made in the Brunner's glands of all three species in the present study.
  • Abundant sulfomucins and sialomucins were present in the small intestine of the dog (Sheahan and Jervis, 1976) , and equal amounts of sulfomucins and sialomucins were present in the African elephant and the horseshoe bat, the latter being an insectivorous species (Kotzé and Coetzee, 1994; Scillitani et al., 2007) .
  • As in the small intestine, mixed (acid and neutral) mucins are the predominant type of mucin in the large intestine of the three insectivorous species of the present study.
  • The former authors observed that acid mucin secreting goblet cells were abundant in the intestinal epithelium, but most prominent in the large intestine, with a decrease of neutral mucins towards the large intestine.

Conclusion

  • Mucins have become an important element in the study of GI physiology, pathology and even taxonomy (Scillitani et al., 2007; Cao and Wang, 2009) .
  • The different types of mucins (neutral, sulfomucins and sialomucins) have also been implicated in the colonization of the biofilm in the GIT.
  • In addition, mucins may function as epitopes with which bacteria can interact to colonize the mucosal layer (Deplancke and Gaskins, 2001) .
  • Therefore it is important to determine the composition of the different types of mucins in the mucosal layer, which affects the colonization of microflora.
  • In the present study mixed (neutral and acid) mucins were found predominantly in the GITs of all three insectivores, whereas mixed acid (sulfomucins and sialomucins) mucins were most prominent in A. spinosissimus and large numbers of sulfomucins and sialomucins were present in C. cyanea and A. hottentotus respectively.

Did you find this useful? Give us your feedback

Figures (4)
Citations
More filters
Journal ArticleDOI
TL;DR: It is concluded that Zn in the form of ZnO appears to have specific effects on the innate and adaptive gut associated immune system of piglets and might contribute to the positive effects of ZN on the prevention of postweaning diarrhea.
Abstract: The aim of this study was to evaluate age-related changes and the effect of dietary Zn concentration on morphological and immunological characteristics in the gastrointestinal tract of piglets. A total of 96 purebred Landrace piglets were weaned at the age of 26 ± 1 d, and randomly allocated into 3 treatment groups fed with low (57 mg Zn/kg), medium (164 mg Zn/kg), and high (2425 mg Zn/kg) dietary Zn (ZnO). Piglets (4 males and 4 females per treatment group) were killed at 33 ± 1, 40 ± 1, 47 ± 1, and 54 ± 1 d of age. In the jejunum, villus height, crypt depth, and the number of goblet cells producing neutral, acidic, sulfated, and sialylated mucins were measured. Intraepithelial lymphocytes were characterized by flow cytometry and the gene expression of mucin 2 (MUC2), mucin 20 (MUC20), β-defensin 3, and trefoil factor 3 (TFF3) was determined by reverse transcription quantitative PCR. Villus height and crypt depth in the jejunum showed age related differences (P < 0.01), whereas the dietary concentrations of Zn had no effect. The mucin types were modified mainly by age, and dietary Zn had no effect in the proximal jejunum. In the distal jejunum, age and Zn had effects on the mucin types. The abundance of sulfomucins decreased (P < 0.001) and sialomucins increased with age (P < 0.001), while high dietary ZnO reduced the sulfomucins (P < 0.001) and increased the sialomucins (P < 0.05) in the crypts. The phenotypes of lymphocytes in the epithelium of the proximal jejunum showed relatively constant percentages of T-cells, as well as natural killer cells. High dietary Zn treatment led to a reduced abundance of CD8(+) γδ T-cells (P < 0.05). The apportionment of different cytotoxic T-cell was age dependent. Although the percentage of CD4(-)CD8β(+) increased (P < 0.01), the relative amount of CD4(+)CD8β(+) decreased with age (P < 0.05). The expression of MUC2 and MUC20 was not influenced by age or dietary Zn concentration. High Zn intakes resulted in a reduced gene expression of β-defensin 3 (P < 0.05), but did not affect the expression of TFF3. It is concluded that Zn in the form of ZnO appears to have specific effects on the innate and adaptive gut associated immune system of piglets. These might contribute to the positive effects of Zn on the prevention of postweaning diarrhea.

42 citations

Journal ArticleDOI
TL;DR: The simple GI tract of P. pipistrellus showed an anatomical reduction of tissue enabling for a short retention time and a reduction of the load carried during flight: short GI tract, lack of lymphoid tissue, missing of glands in certain regions, and a distinct pattern of mucus distribution, indicating different physiological functions of these areas.
Abstract: Bats have a very high mass-specific energy demand due to small size and active flight. European bat species are mostly insectivorous and the morphology of the gastrointestinal tract should be adapted accordingly. This study investigated the general anatomy by histology and the function by analysing carbohydrate distribution in particular of the mucus of the GI tract of the insectivorous bat Pipistrellus pipistrellus. The GI tracts of three individuals were dissected, fixed in formaldehyde, and embedded in paraffin wax. The tissues and cells of the GI tract of P. pipistrellus were analysed by classical (Acid Alizarin Blue, Haematoxylin-Eosin, and Masson Goldner Trichrome), histochemical (periodic acid-Schiff, Alcian blue at pH 2.5) and lectin histochemical (lectins WGA and HPA) staining procedures. The GI tract of P. pipistrellus was organised into the typical mammalian layers. The short, narrow, and thin-walled esophagus was simple with a folded stratified squamous epithelium without glands but mucous surface cells secreting neutral mucus. The stomach was globular shaped without specialisation. Mucous surface cells produced neutral mucus whereas neck and parietal cells secreted a mixture of neutral and acid mucus. Chief cell surface was positive for N-acetylglucosamine and the cytoplasm for N-acetylgalactosamine residues. The intestine lacked a caecum and appendix. The small intestine was divided into duodenum, jejunum‑ileum and ileum‑colon. The epithelium consisted of columnar enterocytes and goblet cells. The large intestine was short, only represented by the descending colon-rectum. It lacked villi and the mucosa had only crypts of LieberkA¼hn. Towards the colon-rectum, goblet cells produced mucus with N-acetylglucosamine residues increasing in acidity except in colon-rectum where acidity was highest in the base of crypts. Along the tube the surface of enterocytes was positive for N-acetylglucosamine and N-acetylgalactosamine. All over the mucus filling the lumen of the GI tract was positive for N-acetylglucosamine and increased in acidity in all parts except of the stomach. In conclusion, the simple GI tract showed an anatomical reduction of tissue enabling for a short retention time and a reduction of the load carried during flight: short GI tract, lack of lymphoid tissue, missing of glands in certain regions, and a distinct pattern of mucus distribution, indicating different physiological functions of these areas. The GI tract of P. pipistrellus was typical for an insectivorous species probably representing the ancestral condition.

29 citations

Journal ArticleDOI
TL;DR: The study showed that the total mean percentage of mucous cells in the stomach as well as the total amount of neutral goblet Cells in the colon were most affected by ART and a HCD, suggesting that the quality of the biofilm may be altered and should be considered when ART is prescribed to obese patients.

11 citations


Cites methods from "A comparative histochemical study o..."

  • ...…q i N d m q p a o e i i w f t e g t t f Stains such as ABPAS and ABAF have previously been used sucessfully to determine types of mucin secreting cells in histological ections in various studies (Boonzaier et al., 2013; Mandal et al., 013; Pélissier et al., 2010; Sharma et al., 1995; Ullah, 2012)....

    [...]

  • ...The goblet cells in the colon were uantified by counting the absolute number of cells as described reviously by Boonzaier et al. (2013) and Johnson et al. (2016)....

    [...]

  • ...Stains such as ABPAS and ABAF have previously been used sucessfully to determine types of mucin secreting cells in histological ections in various studies (Boonzaier et al., 2013; Mandal et al., 013; Pélissier et al., 2010; Sharma et al., 1995; Ullah, 2012)....

    [...]

  • ...Colon Colonic goblet cells were analysed according to the methods xplained by Boonzaier et al. (2013) and Johnson et al. (2016)....

    [...]

Journal ArticleDOI
TL;DR: The role played by thyroid hormones in healing of indomethacin induced gastric ulcers is confirmed and increased numbers of bothneutral and acidic goblet cells and the increase in expression of both neutral and acidic mucins during healing of IndomethACin induced ulcers are demonstrated.
Abstract: Gastric ulcers are mucosal discontinuities that may extend into the mucosa, submucosa or even deeper. They result from an imbalance between mucosal aggressors and protective mechanisms that include the mucus bicarbonate layer. Thyroid hormones have been shown to accelerate gastric ulcer healing in part by increasing the adherent mucus levels. However, the effects of thyroid hormones on goblet cell numbers and expression of neutral and acidic mucins during ulcer healing have not been investigated. Thirty six adult male Wistar rats were randomly divided into six groups each with six animals. Group 1 (normal control) and group 2 (negative control) were given normal saline for eight weeks. Groups 3 and 4 were given 100 μg/kg per day per os of thyroxine so as to induce hyperthyroidism. Groups 5 and 6 received 0.01% (w/v) Propylthiouracil (PTU) for 8 weeks so as to induce hypothyroidism. After thyroid hormonal levels were confirmed using radioimmunoassay and immunoradiometric assays, ulcer induction was done using 40 mg/kg intragastric single dose of Indomethacin in groups 2, 3 and 5. Stomachs were extracted after day 3 and 7 of ulcer induction for histological examination. Histochemistry was carried out using Periodic Acid Shiff and Alcian Blue. The number of acidic and neutral goblet cells were determined by counting numbers per field. Mucin expression (%) was determined using Quick Photo Industrial software version 3.1. The numbers of neutral goblet cells (cells/field) increased significantly (P < 0.05) in the ulcer+thyroxine (14.67 ± 0.33), thyroxine (17.04 ± 1.71) and ulcer+PTU (12.89 ± 1.06) groups compared to the normal control (10.78 ± 1.07) at day 3. For the acidic goblet cells, differences between treatment groups were more pronounced at day 7 between the ulcer+thyroxine (22.56 ± 1.26) and thyroxine (22.89 ± 0.80). We further showed that percentage expression of both neutral and acidic mucins was significantly higher in the ulcer+thyroxine (9.23 ± 0.17 and 6.57 ± 0.35 respectively) and thyroxine groups (9.66 ± 0.21 and 6.33 ± 0.38 respectively) as compared to the normal control group (4.08 ± 0.20 and 4.38 ± 0.11 respectively) at day 3 after ulcer induction. This study confirms the role played by thyroid hormones in healing of indomethacin induced gastric ulcers. The study further demonstrates increased numbers of both neutral and acidic goblet cells and the increase in expression of both neutral and acidic mucins during healing of indomethacin induced ulcers.

11 citations


Cites background from "A comparative histochemical study o..."

  • ...These mucins are histochemically classified into acidic and neutral mucins [16, 17]....

    [...]

Journal ArticleDOI
TL;DR: The distribution of mucin secreting cells in the gastrointestinal tracts of the Eastern spiny mouse, King jird and Libyan jird, which inhabit the dry and hot deserts of Saudi Arabia, is similar to previously reported results for small mammals not living under arid conditions.

10 citations

References
More filters
Book
01 Oct 1990
TL;DR: Light Microscopy, Enzyme Histochemistry, and Immunocytochemical Techniques: Diagnostic Cytopathology, Specimen Collection and Preparation.
Abstract: Light Microscopy. Fixation and Fixatives. Tissue Processing, Microtomy and Paraffin Sections. Frozen and Related Sections. The Theory of Staining and It Practical Implications. The Haematoxylins and Eosin. Connective Tissue and Stains. Proteins and Nucleic Acids. Amyloid. Carbohydrates. Lipids. Pigments and Minerals. The Neuroendocrine System. Micro-Organisms. Bone. Techniques in Neuropathology. Cytoplasmic Granules, Organelles and Special Tissues. Enzyme Histochemistry. Enzyme Histochemistry: Diagnostic Applications. Immunofluorescent Techniques. Immunocytochemical Techniques. Immunocytochemistry in Diagnostic Tumour Pathology. In-Situ Hybridisation. Diagnostic Cytopathology, Specimen Collection and Preparation. Diagnostic Cytopathology, Cell Appearances. Resin Embedding Media. Electron Microscopy 1: Instrumentation and Image Formation. Electron Microscopy 2: Practical Procedures. Electron Microscopy 3: Diagnostic Applications. Quantitation in Histopathology. Safety in the Histopathology Laboratory. Audit in Histopathology. Museum and Other Demonstration Techniques.

7,129 citations

Journal ArticleDOI
01 May 1993-Taxon
TL;DR: Wilson and Reeder's Mammal Species of the World as discussed by the authors is the classic reference book on the taxonomic classification and distribution of more than 5400 species of mammals that exist today.
Abstract: Wilson and Reeder's Mammal Species of the World is the classic reference book on the taxonomic classification and distribution of the more than 5400 species of mammals that exist today. The third edition includes detailed information on nomenclature and, for the first time, common names. Each concise entry covers type locality, distribution, synonyms, and major reference sources. The systematic arrangement of information indicates evolutionary relationships at both the ordinal and the family level. This indispensable reference work belongs in public and academic libraries throughout the world and on the shelf of every biologist who works with mammals.

5,477 citations

Journal ArticleDOI
TL;DR: A new large-scale phylogeny of squamate reptiles is presented that includes new, resurrected, and modified subfamilies within gymnophthalmid and scincid lizards, and boid, colubrid, and lamprophiid snakes.
Abstract: The extant squamates (>9400 known species of lizards and snakes) are one of the most diverse and conspicuous radiations of terrestrial vertebrates, but no studies have attempted to reconstruct a phylogeny for the group with large-scale taxon sampling. Such an estimate is invaluable for comparative evolutionary studies, and to address their classification. Here, we present the first large-scale phylogenetic estimate for Squamata. The estimated phylogeny contains 4161 species, representing all currently recognized families and subfamilies. The analysis is based on up to 12896 base pairs of sequence data per species (average = 2497 bp) from 12 genes, including seven nuclear loci (BDNF, c-mos, NT3, PDC, R35, RAG-1, and RAG-2), and five mitochondrial genes (12S, 16S, cytochrome b, ND2, and ND4). The tree provides important confirmation for recent estimates of higher-level squamate phylogeny based on molecular data (but with more limited taxon sampling), estimates that are very different from previous morphology-based hypotheses. The tree also includes many relationships that differ from previous molecular estimates and many that differ from traditional taxonomy. We present a new large-scale phylogeny of squamate reptiles that should be a valuable resource for future comparative studies. We also present a revised classification of squamates at the family and subfamily level to bring the taxonomy more in line with the new phylogenetic hypothesis. This classification includes new, resurrected, and modified subfamilies within gymnophthalmid and scincid lizards, and boid, colubrid, and lamprophiid snakes.

1,381 citations

Journal ArticleDOI
TL;DR: This review highlights the central role played by mucins in accommodating the resident commensal flora and limiting infectious disease, interplay between underlying innate and adaptive immunity and mucins, and the strategies used by successful mucosal pathogens to subvert or avoid the mucin barrier, with a particular focus on bacteria.

996 citations

Frequently Asked Questions (1)
Q1. What contributions have the authors mentioned in the paper "A comparative histochemical study of the distribution of mucins in the gastrointestinal tracts of three insectivorous mammals" ?

The distribution of mucous secreting goblet cells was examined in the gastrointestinal tracts of three insectivores namely: Acomys spinosissimus ( Southern African spiny mouse ), Crocidura cyanea ( Reddish gray musk shrew ) and Amblysomus hottentotus ( Hottentot golden mole ) in order to improve their understanding of the quality and composition of the protective intestinal biofilm.