Non-digestive Organs Research Articles

The gastric mucosa of Atlantic salmon (Salmo salar) is abundant in highly active chitinases.

Atlantic salmon (Salmo salar) possesses a genome containing 10 genes encoding chitinases, yet their functional roles remain poorly understood. In other fish species, chitinases have been primarily linked to digestion, but also to other functions, as chitinase-encoding genes are transcribed in a variety of non-digestive organs. In this study, we investigated the properties of two chitinases belonging to the family 18 glycoside hydrolase group, namely Chia.3 and Chia.4, both isolated from the stomach mucosa. Chia.3 and Chia.4, exhibiting 95% sequence identity, proved inseparable using conventional chromatographic methods, necessitating their purification as a chitinase pair. Biochemical analysis revealed sustained chitinolytic activity against β-chitin for up to 24 h, spanning a pH range of 2 to 6. Moreover, subsequent in vitro investigations established that this chitinase pair efficiently degrades diverse chitin-containing substrates into chitobiose, highlighting the potential of Atlantic salmon to utilize novel chitin-containing feed sources. Analysis of the gastric matrix proteome demonstrates that the chitinases are secreted and rank among the most abundant proteins in the gastric matrix. This finding correlates well with the previously observed high transcription of the corresponding chitinase genes in Atlantic salmon stomach tissue. By shedding light on the secreted chitinases in the Atlantic salmon's stomach mucosa and elucidating their functional characteristics, this study enhances our understanding of chitinase biology in this species. Moreover, the observed capacity to effectively degrade chitin-containing materials implies the potential utilization of alternative feed sources rich in chitin, offering promising prospects for sustainable aquaculture practices.

Accumulation of polystyrene nanoplastics and triclosan by a model tooth-carp fish, Aphaniops hormuzensis (Teleostei: Aphaniidae)

The presence and effects of nanoplastics (NPs; <1 μm) in the aquatic environment are a growing concern. In this study, a model tooth-carp fish, Aphaniops hormuzensis, has been exposed to different concentrations of fluorescent polystyrene nanoplastics (PS-NP) in its diet (up to 5 mg kg−1) over periods of 28 d and the particle accumulation in different tissues determined. Accumulation was observed in both digestive and non-digestive organs, with concentrations greater in the gut, liver and gill (up to 400 μg kg−1 dw) than in the skin and muscle (<180 μg kg−1 dw), but no dependency on exposure time or dose was evident. The presence of the organic contaminant, triclosan (TCS), in the diet and at concentrations up to 0.5 μg kg−1 did not affect PS-NP uptake by A. hormuzensis, while TCS accumulation in the whole body increased with time (up to 10 μg kg−1) and, likewise, appeared to be unaffected by the presence of PS-NPs. These observations suggest that the two contaminants do not interact with each other or that any interactions have no impact on accumulation. The results of this study add to the growing body of evidence that NPs can be translocated by aquatic organisms after ingestion, and reveal that, for the species and conditions employed, nanoplastics are accumulated more readily than a widely used organic chemical.

Is digestive cathepsin D the rule in decapod crustaceans?

Cathepsin D is an aspartic endopetidase with typical characteristics of lysosomal enzymes. Cathepsin D activity has been reported in the gastric fluid of clawed lobsters where it acts as an extracellular digestive enzyme. Here we investigate whether cathepsin D is unique in clawed lobsters or, instead, common in decapod crustaceans. Eleven species of decapods belonging to six infraorders were tested for cathepsin D activity in the midgut gland, the muscle tissue, the gills, and when technically possible, in the gastric fluid. Cathepsin D activity was present in the midgut gland of all 11 species and in the gastric fluid from the seven species from which samples could be taken. All sampled species showed higher activities in the midgut glands than in non-digestive organs and the activity was highest in the clawed lobster. Cathepsin D mRNA was obtained from tissue samples of midgut gland, muscle, and gills. Analyses of deduced amino acid sequence confirmed molecular features of lysosomal cathepsin D and revealed high similarity between the enzymes from Astacidea and Caridea on one side, and the enzymes from Penaeoidea, Anomura, and Brachyura on the other side. Our results support the presence of cathepsin D activity in the midgut glands and in the gastric fluids of several decapod species suggesting an extracellular function of this lysosomal enzyme. We discuss whether cathepsin D may derive from the lysosomal-like vacuoles of the midgut gland B-cells and is released into the gastric lumen upon secretion by these cells.

Microbiota in the coelomic fluid of two common coastal starfish species and characterization of an abundant Helicobacter-related taxon

Marine invertebrates associate with diverse microorganisms. Microorganisms even inhabit coelomic fluid (CF), namely, the fluid filling the main body cavity of echinoderms. The CF microbiota potentially impacts host health and disease. Here, we analysed the CF microbiota in two common coastal starfish species, Patiria pectinifera and Asterias amurensis. Although microbial community structures were highly variable among individual starfish, those of P. pectinifera were compositionally similar to those in the surrounding seawater. By contrast, many A. amurensis individuals harboured unique microbes in the CF, which was dominated by the unclassified Thiotrichales or previously unknown Helicobacter-related taxon. In some individuals, the Helicobacter-related taxon was the most abundant genus-level taxon, accounting for up to 97.3% of reads obtained from the CF microbial community. Fluorescence in situ hybridization using a Helicobacter-related-taxon-specific probe suggested that probe-reactive cells in A. amurensis were spiral-shaped, morphologically similar to known Helicobacter species. Electron microscopy revealed that the spiral cells had a prosthecate-like polar appendage that has never been reported in Helicobacter species. Although culture of Helicobacter-related taxon was unsuccessful, this is the first report of the dominance of a Helicobacter-related taxon in invertebrates and non-digestive organs, reshaping our knowledge of the phylogeography of Helicobacter-related taxa.

Intermediate filament proteins of digestive organs: physiology and pathophysiology.

Intermediate filament proteins (IFs), such as cytoplasmic keratins in epithelial cells and vimentin in mesenchymal cells and the nuclear lamins, make up one of the three major cytoskeletal protein families. Whether in digestive organs or other tissues, IFs share several unique features including stress-inducible overexpression, abundance, cell-selective and differentiation state expression, and association with >80 human diseases when mutated. Whereas most IF mutations cause disease, mutations in simple epithelial keratins 8, 18, or 19 or in lamin A/C predispose to liver disease with or without other tissue manifestations. Keratins serve major functions including protection from apoptosis, providing cellular and subcellular mechanical integrity, protein targeting to subcellular compartments, and scaffolding and regulation of cell-signaling processes. Keratins are essential for Mallory-Denk body aggregate formation that occurs in association with several liver diseases, whereas an alternate type of keratin and lamin aggregation occurs upon liver involvement in porphyria. IF-associated diseases have no known directed therapy, but high-throughput drug screening to identify potential therapies is an appealing ongoing approach. Despite the extensive current knowledge base, much remains to be discovered regarding IF physiology and pathophysiology in digestive and nondigestive organs.

Vitamin A Supplementation Transiently Increases Retinol Concentrations in Extrahepatic Organs of Neonatal Rats Raised under Vitamin A–Marginal Conditions

Background: Vitamin A (VA; retinol) supplementation is recommended for children aged >6 mo in countries with high rates of malnutrition, but the distribution and retention of VA in body tissues have not been extensively explored.Objective: We sought to determine the distribution and retention of VA in tissues of neonatal rats raised under VA-marginal conditions.Methods: Sprague-Dawley neonatal rats (n= 104; 63 males) nursed by mothers fed a VA-marginal diet (0.35 mg retinol equivalents/kg diet) were randomized and treated on postnatal day 4 with an oral dose of either VA (6 μg retinyl palmitate/g body weight) or canola oil as control. Pups (n= 4/group) were killed at 13 time points from 30 min to 24 d after dose administration. The total retinol concentration and mass were determined in all collected organs.Results: In the control group, plasma VA was marginal (0.8 μmol/L), whereas liver VA was deficient (<70 nmol/g). Nonetheless, the liver contained most (∼76%) of the total VA mass in the body, whereas extrahepatic nondigestive organs together contained ∼13%. White adipose tissue (WAT), which was nearly absent before postnatal day 12, contained only ∼1%. In VA-supplemented neonates, the mean total retinol concentrations in all organs were significantly greater than in control pups. However, this increase lasted for only ∼1 d in most extrahepatic tissues, with the exception of WAT, in which it lasted 18 d.Conclusions: Extrahepatic organs in neonatal rats raised under VA-marginal conditions store relatively little VA, and the scarcity of adipose tissue may predispose neonates to a low-VA status. The effect of VA supplementation on VA content in most extrahepatic organs is transient. A more frequent supplementation along with other nutritional interventions may be necessary for maintaining a steady supply of retinol to the rapidly developing extrahepatic organs.

Comprehensive assessment of the global and regional vascular responses to food ingestion in humans using novel rapid MRI.

Ingestion of food is known to increase mesenteric blood flow. It is not clear whether this increased flow demand is compensated by a rise in cardiac output (CO) alone or by redistribution of blood flow from other organs. We used a new comprehensive imaging method to assess the human cardiovascular response to food ingestion. Following a 12-h fast, blood flow in segments of the aorta and in organ-specific arteries, and ventricular volumes were assessed in 20 healthy adults using MRI at rest and following ingestion of a high-energy liquid meal. Systemic vascular resistance (SVR) fell substantially and CO rose significantly. Blood pressure remained stable. These changes were predominantly driven by a rapid fall in mesenteric vascular resistance, resulting in over four times more intestinal blood flow. Renal vascular resistance also declined but less dramatically. No changes in blood flow to the celiac territory, the brain, or the limbs were observed. In conclusion, this is the first study to fully characterize systemic and regional changes in vascular resistance after food ingestion in humans. Our findings show that the postprandial drop in SVR is fully compensated for by increased CO and not by redistribution of blood from other organs. With the exception of a modest increase in renal blood flow, there was no evidence of altered blood flow to nondigestive organs. The proposed oral food challenge protocol can be applied safely in an MRI environment and may be useful for studying the involvement of the gut in systemic or cardiovascular disease.

Systemic Dissemination of H5N1 Influenza A Viruses in Ferrets and Hamsters after Direct Intragastric Inoculation

Although oral exposure to H5N1 highly pathogenic avian influenza viruses is a risk factor for infection in humans, it is unclear how oral exposure to these virus results in lethal respiratory infections. To address this issue, we inoculated ferrets and hamsters with two highly pathogenic H5N1 strains. These viruses, inoculated directly into the stomach, were isolated from the large intestine and the mesenteric lymph nodes within 1 day of inoculation and subsequently spread to multiple tissues, including lung, liver, and brain. Histopathologic analysis of ferrets infected with virus via direct intragastric inoculation revealed lymph folliculitis in the digestive tract and mesenteric lymph nodes and focal interstitial pneumonia. Comparable results were obtained with the hamster model. We conclude that, in mammals, ingested H5N1 influenza viruses can disseminate to nondigestive organs, possibly through the lymphatic system of the gastrointestinal tract.

RESIDUE LEVELS AND DISTRIBUTION FEATURES OF MICROCYSTINS IN FISH SAMPLES FROM LAKE DIANCHI

The occurrence of heavy water blooms of cyanobacteria (blue-green algae, BGA) in surface water is receiving increasing attention world wide as a potential health concern. This is a serious water quality problem because many of the cyanobacterial species or strains are able to produce potent toxins. The most frequently reported cyanobacterial toxins are cyclic heptapeptide hepatotoxins, microcystins, isolated from several species of the freshwater genera Micro-cystis, Planktothrix (Oscillatoria), Anabaena and Nostoc. They are potent and specific inhibitors of the serine threonine family of protein phosphatases, especially PP1 and PP2A. In order to minimize public exposure to MCs, the World Health Organization (WHO) has set a provisional guideline value of 1 μg/L for MC-LR in drinking water and estab-lished the tolerable daily intake (TDI) for consumption of cyanobacteria products contends MCs (0.04 μg/kg/day). Aquatic animals could bioaccumulate microcystins(cyanobacteria hepatotoxins) and so, beyond water, the ingestion of contaminated food represents a human health risk. In order to evaluate the potential risk of their ingestion, this study was mainly investigated the residue levels and distribution features of microcystins in fish from eutrophicated Lake Dianchi, a hypertropic lake in Yunnan Province containing toxic cyanobacteria blooms all the year round. Samples of silver carp (Hypophthalmichthys molitrix), bighead carp (Aristichthys nobilis) and grass carp (Ctenopharyngodon idellus) were collected in the biomanipulation test area in Lake Dianchi respectively in April and September, 2003. Microcystins in different tissues were all analyzed by enzyme-linked immunosorbent assay (ELISA) and the concentration was expressed as microcstin-LR equivalent. The results showed that microcystins presented in all samples, mainly distributing in liver, kidney and digestive tracts, and little in the muscle and the non-digestive tract organs. Different resi-due levels of microcystins were obviously in different fishes. Concentrations of microcystins in liver and kidney, the target organs of silver carp as well as bighead carp were significantly higher than that in grass carp. On the other hand, the residue levels of microcystins were also changeable along with seasons. Concentrations of microcystins in fish samples in April were lower than that in September. Finally, the safety assessment of the microcystin in fish muscle was also evaluated. According to the standard recommended by WHO, we calculated that the concentration of microcystins in fish muscle of all samples were not above the limit for human consumption. Then, we simply concluded that micro-cystins in fish muscle had not yet endangered to the human health only existed in the potential health risks.

Unique Methylation Pattern of Oncostatin M Receptor Gene in Cancers of Colorectum and Other Digestive Organs

Oncostatin M (OSM) is an interleukin-6 cytokine family member, which inhibits cell proliferation and induces cell differentiation and apoptosis in cancers. In melanoma cells, epigenetic silencing of OSM receptor (OSMR) by histone deacetylation contributes to escape of cell growth control by OSM. However, the silencing of OSMR by DNA methylation in any cancer has not been examined. Methylation status of OSMR was determined by sequencing or methylation-specific PCR in primary tumors and cell lines. Cell lines were treated with DNA methyltransferase inhibitors 5-aza-2-deoxycytidine or DNA methyltransferase 1 small interfering RNA or a histone deacetylase inhibitor trichostatin A. OSMR mRNA level was determined by reverse transcription-PCR. The acetylation of histone H3 was analyzed by chromatin immunoprecipitation assay. We observed methylation of OSMR in 88 of 98 (90%) colorectal cancers, 34 of 38 (89%) colorectal polyps, 17 of 31 (55%) normal-appearing mucosa adjacent to colorectal cancers, 13 of 40 (33%) gastric cancers, and 2 of 10 (20%) pancreatic cancers. OSMR methylation was absent or rarely detected in normal colonic mucosa from noncancer patients or in cancers of nondigestive organs, including breast, lung, liver, prostate, kidney, and melanoma. We observed a significant correlation between OSMR methylation and loss of mRNA expression in 39 cancer cell lines. Following the treatment of colorectal cancer cell lines with 5-aza-2-deoxycytidine, DNA methyltransferase 1 small interfering RNA, or trichostatin A, the induction of OSMR mRNA and the enrichment in the level of histone acetylation were observed. The epigenetic silencing and DNA methylation of OSMR occur frequently in colorectal cancers and rarely in cancers of nondigestive organs. OSMR methylation is an early event in the colorectal carcinogenesis.

Delayed effects of the terms of separation of rat pups from lactating females and low-protein diet on enzyme activity in digestive and non-digestive organs

Early and late separation of rat pups from lactating females and combined effects of the terms of separation and low-protein diet are essential for the formation of enzymes (maltase, alkaline phosphatase, aminopeptidase M, and glycyl-L-leucine dipeptidase) in the large and small intestine, liver and kidneys of adult animals. Similarities and differences in the enzyme reactions to early and late weaning and to a combination of untimely weaning and low-protein diet were detected.

Quality of nutrition during pregnancy or lactation programs functioning of enzyme systems of digestive and non-digestive organs in “Grandchildren” during their adult life

Quality of nutrition during pregnancy or lactation programs functioning of enzyme systems of digestive and non-digestive organs in “Grandchildren” during their adult life

Interstitial Cajal‐like cells in rat mesentery: an ultrastructural and immunohistochemical approach

Interstitial Cajal-like Cells (ICLC) were recently recognized in a plethora of non-digestive organs. Here, we describe a cell type of rat mesentery sharing ultrastructural and immunohistochemical features with ICLC. Mesenteric ICLC were demonstrated by transmission electron microscopy (TEM) and further tested by light microscope immunohistochemistry. The cell described here fulfils the TEM diagnostic criteria accepted for ICLC: location in the connective interstitium; close vicinity to nerves, capillaries and other interstitial cells; characteristic long, moniliform cell processes; specialized cell-to-cell junctions; caveolae; mitochondria at 5–10% of cytoplasmic volume; rough endoplasmic reticulum at about 1–2%; intermediate and thin filaments, microtubules; undetectable thick filaments. The processes of this mesenteric ICLC were particularly long, with a mean length of 24.91 μm (10.27–50.83 μm), and a convolution index of 2.32 (1.37–3.63) was calculated in order to measure their potential length. Mean distances versus main target cells of ICLC–nerve bundles, vessels, adipocytes and macrophages–were 110.69, 115.80, 205.07 and 34.65 nm, respectively. We also tested the expression of CD117/c-kit, CD34, vimentin, α-smooth muscle actin, nestin, NK-1, tryptase and chymase and the antigenic profile of the mesenteric ICLC was comparable if not identical with that recently observed in ICLC from other extra-digestive tissues. Due to the peculiar aspect of the mesenteric ICLC processes it can be hypothesized that these cells form a three-dimensional network within the mesentery that is at the same time resistant and deformable following stretches consequent to intestine movements, mainly avoiding blood vessels closure or controlling blood vessels rheology. It remains, however, to be established if and how such cells are connected with the archetypal enteric ICC.

Morfologia de órgãos digestivos e não digestivos de suínos de linhagens modernas durante as fases de crescimento, terminação e pós-terminação

The genetic market makes use of various modern swine genotypes that present high capacity for muscular mass development. These genetic lines have been used in swine production without existing scientific information about morphology, knowledge that can elucidate factors related to growth performance, such as weight gain and food conversion in lean meat yield. The aim of this experiment was to compare the morphology of digestive and non-digestive organs of modern genotypes. At the end of the phases: Growing I, Growing II, Finishing and Post-finishing, the pigs were slaughtered and the organs were weighed. The weight of the organs decreased (p < 0.01) with body development, in agreement with the biological growth of the animals. The morphology of the digestive organs were different (p < 0.06) among lineages, which showed that differences can exist, mainly regarding digestive capacity and, possibly, food intake and efficiency. The length of the small intestine was different (p < 0.06) among lines, which can be an indicative of increased body development due to an extended food exposition area to intestinal cells. The scientific knowledge of swine lines morphology is important because this information can contribute to animal growth performance.

Efeitos do incremento da fibra em detergente neutro na dieta de suínos sobre a morfologia dos órgãos digestivos e não digestivos

Objetivou-se avaliar os efeitos da inclusão na ração de 0 ou 8% de fibra em detergente neutro proveniente de feno de gramínea sobre a morfologia dos órgãos digestivos e não digestivos de suínos nas fases de creche e de crescimento-terminação. Foram utilizados suínos mestiços alimentados à vontade com rações isoprotéicas e isoenergéticas, em experimento inteiramente casualizado. Ao final de cada período, os animais foram abatidos e eviscerados. Observou-se que a ração fibrosa promoveu, na creche, aumento do peso do estômago vazio, do intestino grosso e do ceco cheio (expressos em percentual do peso vivo dos animais). Nos animais da fase de crescimento-terminação, registrou-se aumento do peso do trato gastrointestinal cheio e do estômago vazio. O aumento do peso de alguns órgãos digestivos sugere possível adaptação morfológica à presença de ração fibrosa.

Functioning of Enzyme Systems of Digestive and Non-Digestive Organs in Adult Rats Depends on Quality of Nutrition in Early Ontogenesis

It is revealed that restriction of protein in nutrition of rat pups in early ontogenesis, at the period of transition from the mixed to the definitive nutrition, produces change of structural parameters and functioning of digestive enzymes in various parts of small intestine (duodenum, jejunum, and ileum) and in large intestine as well as of these hydrolases in liver and kidney in adult life. The disturbance of quality of nutrition in early ontogenesis seems to affect negatively digestive functions of small intestine and trophic-barrier function of large intestine, liver, and kidney, which can promote development of diseases not only of the gastrointestinal tract, but also of other organs.

Research on potential radiation risks in areas with a nuclear power plant in Japan: analysis of cancer mortality between 1972-1997 from all lymphoid-hemopoietic tissues and non-digestive organs

Research on potential radiation risks in areas with a nuclear power plant in Japan: analysis of cancer mortality between 1972-1997 from all lymphoid-hemopoietic tissues and non-digestive organs

Female nutrition quality during lactation changes the functions of enzyme systems in digestive and nondigestive organs of the second-generation progeny

Female nutrition quality during lactation changes the functions of enzyme systems in digestive and nondigestive organs of the second-generation progeny

Relationship between Protein Deficiency in the Ration of Rats during Early Ontogeny and Function of Enzyme Systems of Digestive and Non-Digestive Organs in Adult Life

Low protein content in the ration of rat pups during transfer from mixed to definitive nutrition (days 21-30 of life) has a negative impact on digestive function of the small intestine and trophic and barrier functions of the large intestine, liver, and kidneys and increases (sucrase, glycyl-L-leucin dipeptidase) or decreases (alkaline phosphatase, aminopeptidase M, glycyl-L-leucine dipeptidase) enzyme activities in these organs in 6-month-old rats. Protein deficiency during the early ontogeny modulates functioning of the enzyme systems in digestive and non-digestive organs in adult life, which can lead to the development of not only gastrointestinal, but other visceral diseases.

Relationship between protein deficiency in the ration of rats during early ontogeny and function of enzyme systems of digestive and non-digestive organs in adult life

Relationship between protein deficiency in the ration of rats during early ontogeny and function of enzyme systems of digestive and non-digestive organs in adult life