5-Fluorouracil induces diarrhea with changes in the expression of inflammatory cytokines and aquaporins in mouse intestines

Peroxiporins and Oxidative Stress: Promising Targets to Tackle Inflammation and Cancer

Peroxiporins are a specialized subset of aquaporins, which are integral membrane proteins primarily known for facilitating water transport across cell membranes. In addition to the classical water transport function, peroxiporins have the unique capability to transport hydrogen peroxide (H2O2), a reactive oxygen species involved in various cellular signaling pathways and regulation of oxidative stress responses. The regulation of H2O2 levels is crucial for maintaining cellular homeostasis, and peroxiporins play a significant role in this process by modulating its intracellular and extracellular concentrations. This ability to facilitate the passage of H2O2 positions peroxiporins as key players in redox biology and cellular signaling, with implications for understanding and treating various diseases linked to oxidative stress and inflammation. This review provides updated information on the physiological roles of peroxiporins and their implications in disease, emphasizing their potential as novel biomarkers and drug targets in conditions where they are dysregulated, such as inflammation and cancer.

AQP1 Deficiency Drives Phthalate-Induced Epithelial Barrier Disruption through Intestinal Inflammation

Di-2-ethylhexyl phthalate (DEHP) is frequently used as a plasticizer to enhance the plasticity and durability of agricultural products, which pose adverse effects to human health and the environment. Aquaporin 1 (AQP1) is a main water transport channel protein and is involved in the maintenance of intestinal integrity. However, the impact of DEHP exposure on gut health and its potential mechanisms remain elusive. Here, we determined that DEHP exposure induced a compromised duodenum structure, which was concomitant with mitochondrial structural injury of epithelial cells. Importantly, DEHP exposure caused duodenum inflammatory epithelial cell damage and strong inflammatory response accompanied by activating the TLR4/MyD88/NF-κB signaling pathway. Mechanistically, DEHP exposure directly inhibits the expression of AQP1 and thus leads to an inflammatory response, ultimately disrupting duodenum integrity and barrier function. Collectively, our findings uncover the role of AQP1 in phthalate-induced intestinal disorders, and AQP1 could be a promising therapeutic approach for treating patients with intestinal disorders or inflammatory diseases.

Capecitabine-associated gastrointestinal ulceration, haemorrhage, and obstruction: a pharmacovigilance analysis based on the FAERS

Background

Capecitabine has been reported to be associated with severe gastrointestinal (GI) adverse drug reactions (gastrointestinal ulceration, haemorrhage, and obstruction). However, statistical correlations have not been demonstrated, and specific GI adverse drug reactions, such as GI obstruction, are not listed on its label.

Aim

We aimed to determine the associations between capecitabine and GI ulceration, haemorrhage, or obstruction among patients with breast cancer by examining data from the United States Food and Drug Administration Adverse Event Reporting System (FAERS).

Methods

We performed disproportionality analysis of GI ulceration, haemorrhage, and obstruction by evaluating the reporting odds ratio (ROR) and the information component (IC) with their 95% confidence intervals (CIs).

Results

We identified 279 patients with capecitabine-associated GI ulceration, haemorrhage, or obstruction reported between 1 January 2004 and 31 December 2020. One-fourth of the cases of GI ulceration, haemorrhage, or obstruction resulted in death. Capecitabine as a drug class had disproportionately high reporting rates for GI ulceration [ROR 1.94 (1.71-2.21); IC 0.80 (0.60-0.99)], haemorrhage [ROR 2.27 (1.86-2.76); IC 0.99 (0.69-1.28)], and obstruction [ROR 2.19 (1.63-2.95); IC 0.96 (0.51-1.40)].

Conclusion

Pharmacovigilance research on the FAERS has revealed a slight increase in reports of GI ulceration, haemorrhage, and obstruction in capecitabine users, which may cause serious or deadly consequences. In addition to the adverse reactions described in the package insert, close attention should be paid to GI obstruction to avoid discontinuation or life-threatening outcomes.

LTβR-RelB signaling in intestinal epithelial cells protects from chemotherapy-induced mucosal damage

The intricate immune mechanisms governing mucosal healing following intestinal damage induced by cytotoxic drugs remain poorly understood. The goal of this study was to investigate the role of lymphotoxin beta receptor (LTβR) signaling in chemotherapy-induced intestinal damage. LTβR deficient mice exhibited heightened body weight loss, exacerbated intestinal pathology, increased proinflammatory cytokine expression, reduced IL-22 expression, and proliferation of intestinal epithelial cells following methotrexate (MTX) treatment. Furthermore, LTβR-/-IL-22-/- mice succumbed to MTX treatment, suggesting that LTβR- and IL-22- dependent pathways jointly promote mucosal repair. Although both LTβR ligands LIGHT and LTβ were upregulated in the intestine early after MTX treatment, LIGHT-/- mice, but not LTβ-/- mice, displayed exacerbated disease. Further, we revealed the critical role of T cells in mucosal repair as T cell-deficient mice failed to upregulate intestinal LIGHT expression and exhibited increased body weight loss and intestinal pathology. Analysis of mice with conditional inactivation of LTβR revealed that LTβR signaling in intestinal epithelial cells, but not in Lgr5+ intestinal stem cells, macrophages or dendritic cells was critical for mucosal repair. Furthermore, inactivation of the non-canonical NF-kB pathway member RelB in intestinal epithelial cells promoted MTX-induced disease. Based on these results, we propose a model wherein LIGHT produced by T cells activates LTβR-RelB signaling in intestinal epithelial cells to facilitate mucosal repair following chemotherapy treatment.

Sodium Bicarbonate Decreases Alcohol Consumption in Mice

We previously reported that mice with low neuronal pH drink more alcohol, demonstrating the importance of pH for alcohol reward and motivation. In this study, we tested whether systemic pH affects alcohol consumption and if so, whether it occurs by changing the alcohol reward. C57BL/6J mice were given NaHCO3 to raise their blood pH, and the animals' alcohol consumption was measured in the drinking-in-the-dark and two-bottle free choice paradigms. Alcohol consumption was also assessed after suppressing the bitterness of NaHCO3 with sucrose. Alcohol reward was evaluated using a conditioned place preference. In addition, taste sensitivity was assessed by determining quinine and sucrose preference. The results revealed that a pH increase by NaHCO3 caused mice to decrease their alcohol consumption. The decrease in high alcohol contents (20%) was significant and observed at different ages, as well as in both males and females. Alcohol consumption was also decreased after suppressing NaHCO3 bitterness. Oral gavage of NaHCO3 did not alter quinine and sucrose preference. In the conditioned place preference, NaHCO3-treated mice spent less time in the alcohol-injected chamber. Conclusively, the results show that raising systemic pH with NaHCO3 decreases alcohol consumption, as it decreases the alcohol reward value.

TNF inhibits AQP2 expression via a miR137-dependent pathway

As miR-137 is a regulator of aquaporin (AQP)2 expression and tumor necrosis factor (TNF) inhibits the expression of several extrarenal AQPs, we tested the hypothesis that TNF inhibits AQP2 in the kidney via a miR-137-dependent mechanism. AQP2 mRNA and protein expression decreased ∼70% and 53%, respectively, in primary renal inner medullary collecting duct (IMCD) cells transfected with a miRNA mimic of mmu-miR-137, suggesting that miR-137 directly targets AQP2 mRNA in these cells. Exposure of IMCD cells for 2 h to 400 mosmol/kgH2O medium increased mmu-miR-137 mRNA expression about twofold, conditions that also increased TNF production approximately fourfold. To determine if the increase in mmu-miR-137 mRNA expression was related to the concomitant increase in TNF, IMCD cells were transfected with a lentivirus construct to silence TNF. This construct decreased mmu-miR-137 mRNA expression by ∼63%, suggesting that TNF upregulates the expression of miR-137. Levels of miR-137 also increased approximately twofold in IMCD tubules isolated from male mice given 1% NaCl in the drinking water for 3 days. Intrarenal lentivirus silencing of TNF increased AQP2 mRNA levels and protein expression concomitant with a decrease in miR-137 levels in tubules isolated from mice given NaCl. The changes in AQP2 expression levels affected the diluting ability of the kidney, which was assessed by measuring urine osmolality and urine volume, as the decrease in these parameters after renal silencing of TNF was prevented on intrarenal administration of miR-137. The study reveals a novel TNF function via a miR-137-dependent mechanism that regulates AQP2 expression and function.NEW & NOTEWORTHY An emerging intratubular tumor necrosis factor system, functioning during normotensive noninflammatory conditions, acts as a breaking mechanism that attenuates both the increases in Na+-K+-2Cl- cotransporter and aquaporin-2 induced by arginine vasopressin, thereby contributing to the regulation of electrolyte balance and blood pressure. A greater appreciation for the role of cytokines as mediators of immunophysiological responses may help reveal the relationship between the immune system and other physiological systems.

AQP1 in the Gastrointestinal Tract of Mice: Expression Pattern and Impact of AQP1 Knockout on Colonic Function

Aquaporin 1 (AQP1) is one of thirteen known mammalian aquaporins. Its main function is the transport of water across cell membranes. Lately, a role of AQP has been attributed to other physiological and pathological functions including cell migration and peripheral pain perception. AQP1 has been found in several parts of the enteric nervous system, e.g., in the rat ileum and in the ovine duodenum. Its function in the intestine appears to be multifaceted and is still not completely understood. The aim of the study was to analyze the distribution and localization of AQP1 in the entire intestinal tract of mice. AQP1 expression was correlated with the hypoxic expression profile of the various intestinal segments, intestinal wall thickness and edema, as well as other aspects of colon function including the ability of mice to concentrate stools and their microbiome composition. AQP1 was found in a specific pattern in the serosa, the mucosa, and the enteric nervous system throughout the gastrointestinal tract. The highest amount of AQP1 in the gastrointestinal tract was found in the small intestine. AQP1 expression correlated with the expression profiles of hypoxia-dependent proteins such as HIF-1α and PGK1. Loss of AQP1 through knockout of AQP1 in these mice led to a reduced amount of bacteroidetes and firmicutes but an increased amount of the rest of the phyla, especially deferribacteres, proteobacteria, and verrucomicrobia. Although AQP-KO mice retained gastrointestinal function, distinct changes regarding the anatomy of the intestinal wall including intestinal wall thickness and edema were observed. Loss of AQP1 might interfere with the ability of the mice to concentrate their stool and it is associated with a significantly different composition of the of the bacterial stool microbiome.

Growth differentiation factor 11 delivered by dairy Lactococcus lactis strains modulates inflammation and prevents mucosal damage in a mice model of intestinal mucositis

Mucositis is an inflammation of the gastrointestinal mucosa that debilitate the quality of life of patients undergoing chemotherapy treatments. In this context, antineoplastic drugs, such as 5-fluorouracil, provokes ulcerations in the intestinal mucosa that lead to the secretion of pro-inflammatory cytokines by activating the NF-κB pathway. Alternative approaches to treat the disease using probiotic strains show promising results, and thereafter, treatments that target the site of inflammation could be further explored. Recently, studies reported that the protein GDF11 has an anti-inflammatory role in several diseases, including in vitro and in vivo results in different experimental models. Hence, this study evaluated the anti-inflammatory effect of GDF11 delivered by Lactococcus lactis strains NCDO2118 and MG1363 in a murine model of intestinal mucositis induced by 5-FU. Our results showed that mice treated with the recombinant lactococci strains presented improved histopathological scores of intestinal damage and a reduction of goblet cell degeneration in the mucosa. It was also observed a significant reduction of neutrophil infiltration in the tissue in comparison to positive control group. Moreover, we observed immunomodulation of inflammatory markers Nfkb1, Nlrp3, Tnf, and upregulation of Il10 in mRNA expression levels in groups treated with recombinant strains that help to partially explain the ameliorative effect in the mucosa. Therefore, the results found in this study suggest that the use of recombinant L. lactis (pExu:gdf11) could offer a potential gene therapy for intestinal mucositis induced by 5-FU.

Non-Transport Functions of Aquaporins

Although it has been more than 20 years since the first aquaporin was discovered, the specific functions of many aquaporins are still under investigation, because various mice lacking aquaporins have no significant phenotypes. And in many studies, the function of aquaporin is not directly related to its transport function. Therefore, this chapter will focus on some unexpected functions of aquaporins, such the decreased tumor angiogenesis in AQP1 knockout mice, and AQP1 promotes cell migration, possibly by accelerating the water transport in lamellipodia of migrating cells. AQP transports glycerol, and water regulates glycerol content in epidermis and fat, thereby regulating skin hydration/biosynthesis and fat metabolism. AQPs may also be involved in neural signal transduction, cell volume regulation, and organelle physiology. AQP1, AQP3, and AQP5 are also involved in cell proliferation. In addition, AQPs have also been reported to play roles in inflammation in various tissues and organs. The functions of these AQPs may not depend on the permeability of small molecules such as water and glycerol, suggesting AQPs may play more roles in different biological processes in the body.

Amelioration of 5-Fluorouracil Induced Nephrotoxicity by Acacia catechu through Overcoming Oxidative Damage and Inflammation in Wistar Rats

AIM

The research intended to explore the possible nephroprotective potential of the ethyl acetate fraction derived from Acacia catechu leaves against nephrotoxicity brought about by 5-fluorouracil (5-FU) in Wistar rats.

BACKGROUND

While possessing strong anticancer properties, 5-FU is hindered in its therapeutic application due to significant organ toxicity linked to elevated oxidative stress and inflammation.

OBJECTIVE

The study is undertaken to conduct an analysis of the ethyl acetate fraction of A. catechu leaves both in terms of quality and quantity, examining its impact on different biochemical and histopathological parameters within the context of 5-FU-induced renal damage in rats and elucidation of the mechanism behind the observed outcomes.

METHODOLOGY

Intraperitoneal injection of 5-FU at a dosage of 20 mg/kg/day over 5 days was given to induce nephrotoxicity in rats. The evaluation of nephrotoxicity involved quantifying serum creatinine, urea, uric acid, and electrolyte concentrations. Furthermore, superoxide dismutase, catalase antioxidant enzymes, and TNF-α concentration in serum were also measured.

RESULTS

5-FU injection led to the initiation of oxidative stress within the kidneys, leading to modifications in renal biomarkers (including serum creatinine, urea, uric acid, and Na+, K+ levels), and a reduction in antioxidant enzymes namely superoxide dismutase and catalase. Notably, the presence of the inflammatory cytokine TNF-α was significantly elevated due to 5-FU. Microscopic examination of renal tissue revealed tubular degeneration and congestion. However, treatment involving the ethyl acetate fraction derived from A. catechu leaves effectively and dose-dependently reversed the changes observed in renal biomarkers, renal antioxidant enzymes, inflammatory mediators, and histopathological features, bringing them closer to normal conditions. The observed recuperative impact was mainly attributed to the antioxidant and antiinflammatory properties of the fraction.

CONCLUSION

The ethyl acetate fraction of A. catechu leaves exhibited a mitigating influence on the renal impairment caused by 5-FU, showcasing its potential as a nephroprotective agent capable of preventing and ameliorating 5-FU-induced nephrotoxicity.

Bacillus coagulans BACO-17 Alone or in Combination with Galacto-Oligosaccharide Ameliorates Salmonella-Induced Diarrhea and Intestinal Inflammation

In this study, a diarrhea model was established by exposing rats to appropriate antibiotics and Salmonella. After an in vitro screening of prebiotics, fructo-oligosaccharide and galacto-oligosaccharide (GOS) were selected; their synbiotic potential and ability to ameliorate diarrhea symptoms and intestinal inflammation with Bacillus coagulans BACO-17 were evaluated in vivo. After a 27-day feeding experiment including antibiotic intervention and Salmonella infection, it was found that using B. coagulans BACO-17 alone and in combination with GOS as a synbiotic could render a better recovery by lowering diarrhea indexes by 26.9% and 18.7%, respectively. Compared with the negative control, the administration of this synbiotic mixture resulted in the most significant increase in fecal concentrations of total short-chain fatty acids (about 2-fold higher), with a promising improvement in disrupted gut microbial balance. It was worth noting that the administration of B. coagulans BACO-17 alone or in combination with GOS effectively reduced intestinal inflammation (27–31%) and mucosal necrosis (82%) over the negative control. These results suggested that B. coagulans BACO-17 and GOS could be exploited as a promising synbiotic mixture to relieve intestinal inflammatory diseases and improve gut health.

Niacin Improves Intestinal Health through Up-Regulation of AQPs Expression Induced by GPR109A

(1) Background: Changes in the expression of aquaporins (AQPs) in the intestine are proved to be associated with the attenuation of diarrhea. Diarrhea is a severe problem for postweaning piglets. Therefore, this study aimed to investigate whether niacin could alleviate diarrhea in weaned piglets by regulating AQPs expression and the underlying mechanisms; (2) Methods: 72 weaned piglets (Duroc × (Landrace × Yorkshire), 21 d old, 6.60 ± 0.05 kg) were randomly allotted into 3 groups for a 14-day feeding trial. Each treatment group included 6 replicate pens and each pen included 4 barrows (n = 24/treatment). Piglets were fed a basal diet (CON), a basal diet supplemented with 20.4 mg niacin/kg diet (NA) or the basal diet administered an antagonist for the GPR109A receptor (MPN). Additionally, an established porcine intestinal epithelial cell line (IPEC-J2) was used to investigate the protective effects and underlying mechanism of niacin on AQPs expression after Escherichia coli K88 (ETEC K88) treatment; (3) Results: Piglets fed niacin-supplemented diet had significantly decreased diarrhea rate, and increased mRNA and protein level of ZO-1, AQP 1 and AQP 3 in the colon compared with those administered a fed diet supplemented with an antagonist (p < 0.05). In addition, ETEC K88 treatment significantly reduced the cell viability, cell migration, and mRNA and protein expression of AQP1, AQP3, AQP7, AQP9, AQP11, and GPR109A in IPEC-J2 cells (p < 0.05). However, supplementation with niacin significantly prevented the ETEC K88-induced decline in the cell viability, cell migration, and the expression level of AQPs mRNA and protein in IPEC-J2 cells (p < 0.05). Furthermore, siRNA GPR109A knockdown significantly abrogated the protective effect of niacin on ETEC K88-induced cell damage (p < 0.05); (4) Conclusions: Niacin supplementation increased AQPs and ZO-1 expression to reduce diarrhea and intestinal damage through GPR109A pathway in weaned piglets.

The Mechanism of Lung and Intestinal Injury in Acute Pancreatitis: A Review

Acute pancreatitis (AP), as a common cause of clinical acute abdomen, often leads to multi-organ damage. In the process of severe AP, the lungs and intestines are the most easily affected organs aside the pancreas. These organ damages occur in succession. Notably, lung and intestinal injuries are closely linked. Damage to ML, which transports immune cells, intestinal fluid, chyle, and toxic components (including toxins, trypsin, and activated cytokines to the systemic circulation in AP) may be connected to AP. This process can lead to the pathological changes of hyperosmotic edema of the lung, an increase in alveolar fluid level, destruction of the intestinal mucosal structure, and impairment of intestinal mucosal permeability. The underlying mechanisms of the correlation between lung and intestinal injuries are inflammatory response, oxidative stress, and endocrine hormone secretion disorders. The main signaling pathways of lung and intestinal injuries are TNF-α, HMGB1-mediated inflammation amplification effect of NF-κB signal pathway, Nrf2/ARE oxidative stress response signaling pathway, and IL-6-mediated JAK2/STAT3 signaling pathway. These pathways exert anti-inflammatory response and anti-oxidative stress, inhibit cell proliferation, and promote apoptosis. The interaction is consistent with the traditional Chinese medicine theory of the lung being connected with the large intestine (fei yu da chang xiang biao li in Chinese). This review sought to explore intersecting mechanisms of lung and intestinal injuries in AP to develop new treatment strategies.

Increased 20S Proteasome Expression and the Effect of Bortezomib during Cisplatin-Induced Muscle Atrophy

Cisplatin is a chemotherapy drug used to treat a variety of cancers. Muscle loss in cancer patients is associated with increased cancer-related mortality. Previously, we suggested that cisplatin administration increases the atrophic gene expressions of ubiquitin E3 ligases, such as atrogin-1 and muscle RING finger-1 (MuRF1), which may lead to muscle atrophy. In this study, C57BL/6J mice were treated with cisplatin (3 mg/kg, intraperitoneally) or saline for 4 consecutive days. Twenty-four hours after the final injection of cisplatin, quadriceps muscles were removed from the mice. The gene expression of Psma and Psmb, which comprise the 20S proteasome, was upregulated by cisplatin administration in the quadriceps muscle of mouse. Systemic administration of cisplatin significantly reduced not only the quadriceps muscle mass but also the diameter of the myofibers. In addition, bortezomib (0.125 mg/kg, intraperitoneally) was administered 30 min before each cisplatin treatment. The co-administration of bortezomib, a proteasome inhibitor, significantly recovered the reductions in the mass of quadriceps and myofiber diameter, although it did not recover the decline in the forelimb and forepaw strength induced by cisplatin. Increased 20S proteasome abundance may play a significant role in the development of cisplatin-induced muscle atrophy. During cisplatin-induced skeletal muscle atrophy, different mechanisms may be involved between loss of muscle mass and strength. In addition, it is suggested that bortezomib has essentially no effect on cisplatin-induced muscle atrophy.

Treatment of Gastrointestinal Disorders-Plants and Potential Mechanisms of Action of Their Constituents

The worldwide prevalence of gastrointestinal diseases is about 40%, with standard pharmacotherapy being long-lasting and economically challenging. Of the dozens of diseases listed by the Rome IV Foundation criteria, for five of them (heartburn, dyspepsia, nausea and vomiting disorder, constipation, and diarrhoea), treatment with herbals is an official alternative, legislatively supported by the European Medicines Agency (EMA). However, for most plants, the Directive does not require a description of the mechanisms of action, which should be related to the therapeutic effect of the European plant in question. This review article, therefore, summarizes the basic pharmacological knowledge of synthetic drugs used in selected functional gastrointestinal disorders (FGIDs) and correlates them with the constituents of medicinal plants. Therefore, the information presented here is intended as a starting point to support the claim that both empirical folk medicine and current and decades-old treatments with official herbal remedies have a rational basis in modern pharmacology.

Human Norovirus Induces Aquaporin 1 Production by Activating NF-κB Signaling Pathway

Human norovirus (HuNoV) is one of the major pathogens of acute nonbacterial gastroenteritis. Due to the lack of a robust and reproducible in vitro culture system and an appropriate animal model, the mechanism underlying HuNoV-caused diarrhea remains unknown. In the current study, we found that HuNoV transfection induced the expression of aquaporin 1 (AQP1), which was further confirmed in the context of virus infection, whereas the enterovirus EV71 (enterovirus 71) did not have such an effect. We further revealed that VP1, the major capsid protein of HuNoV, was crucial in promoting AQP1 expression. Mechanistically, HuNoV induces AQP1 production through the NF-κB signaling pathway via inducing the expression, phosphorylation and nuclear translocation of p65. By using a model of human intestinal epithelial barrier (IEB), we demonstrated that HuNoV and VP1-mediated enhancement of small molecule permeability is associated with the AQP1 channel. Collectively, we revealed that HuNoV induced the production of AQP1 by activating the NF-κB signaling pathway. The findings in this study provide a basis for further understanding the significance of HuNoV-induced AQP1 expression and the potential mechanism underlying HuNoV-caused diarrhea.

Diarrhea Induced by Small Molecule Tyrosine Kinase Inhibitors Compared With Chemotherapy: Potential Role of the Microbiome

Small molecule receptor tyrosine kinase inhibitors (SM-TKIs) are among a group of targeted cancer therapies, intended to be more specific to cancer cells compared with treatments, such as chemotherapy, hence reducing adverse events. Unfortunately, many patients report high levels of diarrhea, the pathogenesis of which remains under investigation. In this article, we compare the current state of knowledge of the pathogenesis of chemotherapy-induced diarrhea (CID) in comparison to SM-TKI–induced diarrhea, and investigate how a similar research approach in both areas may be beneficial. To this end, we review evidence that both treatment modalities may interact with the gut microbiome, and as such the microbiome should be investigated for its ability to reduce the risk of diarrhea.

The Superoxide Dismutase Mimetic M40403, Improves 5-Fluorouracil-induced Small Intestinal Mucositis in a Mouse Model

BACKGROUND/AIM

Intestinal mucositis with diarrhea is a dose-limiting toxicity of 5-fluorouracil (5-FU). M40403, a superoxide dismutase mimetic, was evaluated on whether it improves the mucositis with diarrhea.

MATERIALS AND METHODS

BALB/c mice were treated with daily intraperitoneal injections of 5-FU±M40403 for five consecutive days. Following treatment, light microscopy (apoptosis), electron microscopy (autophagy), and analyses for the expression of apoptosis/autophagy-related proteins were performed in analysing small intestinal samples. Body weight, diarrhea score, blood cytokine levels, complete blood count, and blood chemistries were measured. The in vivo anti-tumor activity of 5-FU±M40403 was also evaluated.

RESULTS

M40403 improved 5-FU-induced intestinal mucositis (apoptosis and autophagy) and attenuated 5-FU-induced changes in the expression of apoptosis/autophagy-related proteins, weight loss, diarrhea score, and serum TNF-α levels. M40403 neither added further adverse effects nor compromised the anti-tumor activity during 5-FU treatment.

CONCLUSION

M40403 can be useful in improving 5-FU-induced intestinal mucositis with diarrhea.

Zinc Finger Protein St18 Protects against Septic Death by Inhibiting VEGF-A from Macrophages

Zinc finger protein St18 was initially reported as candidate tumor suppressor gene, and also suggested that fibroblast St18 positively regulates NF-κB activation. Despite the pleiotropic functions of St18, little is known about its roles in macrophages. Here, we report that myeloid St18 is a potent inhibitor of VEGF-A. Mice lacking St18 in myeloid lineages exhibit increased retinal vasculature with enhanced serum VEGF-A concentrations. Despite the normal activation of NF-κB target genes, these mice are highly susceptible to LPS-induced shock, polymicrobial sepsis, and experimental colitis, accompanied by enhanced vascular and intestinal leakage. Pharmacological inhibition of VEGF signaling rescued the high mortality rate of myeloid-specific St18-deficient mice in response to inflammation. Mechanistically, St18 directly binds to Sp1 and attenuates its activity, leading to the suppression of Sp1 target gene VEGF-A. Using mouse genetic and pharmacological models, we reveal myeloid St18 as a critical septic death protector.

Capecitabine-Induced Terminal Ileitis: Case Report and Literature Review

Capecitabine is a well-established agent for adjuvant chemotherapy in breast and colorectal cancers. However, one of the limiting adverse events of this therapy is severe diarrhea, which is reported with increasing frequency as of late. Capecitabine-induced ileitis should be suspected in cases with severe, treatment-refractory diarrhea. We present a case of capecitabine-induced terminal ileitis in a patient who received the medication as adjuvant therapy for previously resected colon adenocarcinoma. Capecitabine-induced diarrhea secondary to ileitis is a severe adverse drug event, which occurs during adjuvant chemotherapy and does not respond to conservative treatment with antidiarrheals, often necessitating permanent drug withdrawal. A high index of suspicion is critical as the complications, such as dehydration and the associated electrolyte derangements, may be life-threatening if diagnosis and cause-specific treatment are delayed.

Aquaporin: targets for dietary nutrients to regulate intestinal health

Aquaporins (AQP) are a class of water channel membrane proteins that are widely expressed in the gut. The biological functions of aquaporins, which regulate the absorption and secretion of water molecules and small solutes, maintain the stable state of the intestine, regulate cell proliferation and migration, participate in the process of intestinal inflammation, and mediate tumorigenesis, demonstrate the physiological significance of these channels in intestinal health. The pathology of many intestinal diseases is associated with changes in the location and expression of aquaporins, such as intestinal infection, which can change the expression and distribution of AQPs in intestinal tissues/cells by affecting cytokines and chemokines. This can lead to various intestinal diseases such as diarrhoea, which also suggests the importance of aquaporins in the prevention and treatment of intestinal diseases. This review summarizes the relationship between aquaporins and intestinal physiology and diseases and focuses on drugs (such as plant extracts) or diets that can regulate intestinal health by regulating aquaporins. It provides a basis for establishing aquaporins as biomarkers and therapeutic targets for intestinal health.

Aquaporins in Immune Cells and Inflammation: New Targets for Drug Development

The mammalian immune system senses foreign antigens by mechanisms that involve the interplay of various kinds of immune cells, culminating in inflammation resolution and tissue clearance. The ability of the immune cells to communicate (via chemokines) and to shift shape for migration, phagocytosis or antigen uptake is mainly supported by critical proteins such as aquaporins (AQPs) that regulate water fluid homeostasis and volume changes. AQPs are protein channels that facilitate water and small uncharged molecules’ (such as glycerol or hydrogen peroxide) diffusion through membranes. A number of AQP isoforms were found upregulated in inflammatory conditions and are considered essential for the migration and survival of immune cells. The present review updates information on AQPs’ involvement in immunity and inflammatory processes, highlighting their role as crucial players and promising targets for drug discovery.

Aquaporins and diseases pathogenesis: From trivial to undeniable involvements, a disease-based point of view

Aquaporins (AQPs), as transmembrane proteins, were primarily identified as water channels with the ability of regulating the transmission of water, glycerol, urea, and other small-sized molecules. The classic view of AQPs involvement in therapeutic plan restricted them and their regulators into managing only a narrow spectrum of the diseases such as diabetes insipidus and the syndrome of inappropriate ADH secretion. However, further investigations performed, especially in the third millennium, has found that their cooperation in water transmission control can be manipulated to handle other burden-imposing diseases such as cirrhosis, heart failure, Meniere's disease, cancer, bullous pemphigoid, eczema, and Sjögren's syndrome.

The Gut Microbiota: A Potential Gateway to Improved Health Outcomes in Breast Cancer Treatment and Survivorship

Breast cancer is the most frequently diagnosed cancer in women worldwide. The disease and its treatments exert profound effects on an individual's physical and mental health. There are many factors that impact an individual's risk of developing breast cancer, their response to treatments, and their risk of recurrence. The community of microorganisms inhabiting the gastrointestinal tract, the gut microbiota, affects human health through metabolic, neural, and endocrine signaling, and immune activity. It is through these mechanisms that the gut microbiota appears to influence breast cancer risk, response to treatment, and recurrence. A disrupted gut microbiota or state of 'dysbiosis' can contribute to a biological environment associated with higher risk for cancer development as well as contribute to negative treatment side-effects. Many cancer treatments have been shown to shift the gut microbiota toward dysbiosis; however, the microbiota can also be positively manipulated through diet, prebiotic and probiotic supplementation, and exercise. The objective of this review is to provide an overview of the current understanding of the relationship between the gut microbiota and breast cancer and to highlight potential strategies for modulation of the gut microbiota that could lead to improved clinical outcomes and overall health in this population.

FengLiao affects gut microbiota and the expression levels of Na+/H+ exchangers, aquaporins and acute phase proteins in mice with castor oil-induced diarrhea

The severe side effects of chemosynthetic anti-diarrhea drugs have created an interest in low-toxic alternative plant-derived compounds. FengLiao consists of Polygonum hydropiper Linn. and Daphniphyllum calycinum Bench., and is widely used in China to treat diarrhea due to low levels of toxicity. In this study, the effects of FengLiao were analyzed in a castor oil-induced diarrhea model, using the anti-diarrhea drug, loperamide, as the positive control. The effects were evaluated using stool characteristics and the expression levels of various diarrhea-related factors in the jejunum and liver, as well as changes in the microbiota of the jejunum. The symptoms of diarrhea and stool consistency were improved through FengLiao and loperamide treatment. Furthermore, FengLiao down-regulated alpha 1-acid glycoprotein (AGP) and C-reactive protein (CRP) levels, and up-regulated transferrin (TRF) mRNA levels in the liver, and down-regulated Aquaporin 3 (AQP3) and Na+/H+ exchanger isoform 8 (NHE8) expression in the epithelial cells of the jejunum. It also increased the relative abundance of Bifidobacterium, Aerococcus, Corynebacterium_1 and Pseudomonas, and lowered the Firmicutes/Bacteroidetes (F/B) ratio, which maintained the balance between immunity and intestinal health. Taken together, FengLiao alleviated castor oil-induced diarrhea by altering gut microbiota, and levels of jejunum epithelial transport proteins and acute phase proteins.

The beneficial influence of rhubarb on 5-fluorouracil-induced ileal mucositis and the combined role of aquaporin-4, tumour necrosis factor-α, nuclear factor-kappa B & matrix metalloproteinase-9 in rat model: histological study

A 5-fluorouracil (5-FU) is used for cancer treatment despite its cytotoxic sequelae on healthy cells, especially the rapid proliferating ones. Intestinal mucositis is one of the most frequent chemotherapeutic debilitating sequelae. Rhubarb (Rh), an ancient herb, is known for its curing effect on gastrointestinal complications. This study aims to detect the role of aquaporin-4 (AQP-4), tumour necrosis factor-α (TNF-α), nuclear factor-kappa B (NF-κB), and matrix metalloproteinase-9 (MMP-9) in 5-FU-induced ileal histological and biochemical changes and the potential therapeutic effect of Rh water extract on these changes in rats. A 45 rats were divided into 3 groups; control, 5-FU (single intraperitoneal injection of 150 mg/kg/rat) and Rh-treated (oral 20 mg/kg/day/rat for 8 days). The change in animals’ weight, incidence of diarrhoea and AQP-4 and TNF-α values in ileal homogenates were measured. Ileal sections were subjected to hematoxylin and eosin stain, periodic acid Schiff (PAS)-reaction and MMP-9, NF-κB and AQP-4 immunohistochemical staining. A 5-FU group revealed marked ileal mucosal damage associated with a significant decrease in the mean body weight, AQP-4 level and area percent of PAS and AQP-4 positive reaction. Significant increase in the mean incidence of diarrhoea, TNF-α value and area percent of MMP-9 and NF-κB was detected. These changes were significantly corrected with Rh administration. A 5-FU resulted in severe ileal mucositis through TNF-α, NF-κB, MMP-9, and AQP-4 disturbances. Rh treatment was highly effective in preventing such mucositis.

Potential Probiotic or Trigger of Gut Inflammation - The Janus-Faced Nature of Cannabidiol-Rich Cannabis Extract

Cannabidiol (CBD) is the major non-psychotropic phytocannabinoid present in Cannabis sativa. In 2018, Congress designated certain C. sativa plant material as "hemp," thus removing it from the DEA's list of controlled substances. As a result, CBD-containing hemp extracts and other CBD products are now widely available and heavily marketed, yet their FDA regulatory status is still hotly debated. The goal of this study was to investigate the effects of a cannabidiol-rich cannabis extract (CRCE) on the gut microbiome and associated histomorphological and molecular changes in the mouse gut mucosa. Male C57BL6/J mice were gavaged with either 0, 61.5, 184.5, or 615 mg/kg/bw of CRCE in sesame oil for 2 weeks (Mon-Fri). Substantial CRCE-induced increases in the relative abundance of A. muciniphila, a bacterial species currently accepted as probiotic, was observed in fecal samples at all doses. This was paralleled by decreases in the relative abundance of other gut bacterial species. Coincident with the observed changes in gut ecology were multiple pro-inflammatory responses, including increased expression of cytokines and chemokines-Il1ß, Cxcl1, and Cxcl2 in the colon tissue. Furthermore, dramatic increases in the relative abundance of A. muciniphila significantly decreased expression of Muc2-a gene intimately associated with gut integrity. Taken together, these findings raise concerns about the safety of long-term CBD usage and underline the need for additional well-designed studies into its tolerability and efficacy.

Ancient Chinese Medicine Herbal Formula Huanglian Jiedu Decoction as a Neoadjuvant Treatment of Chemotherapy by Improving Diarrhea and Tumor Response

Background

Diarrhea is a major gastrointestinal complication in cancer patients receiving chemotherapy. Prognosis and treatment of chemotherapy-induced diarrhea (CID) remain unsatisfactory. This study aims to explore the potential of an ancient Chinese Medicine herbal formula Huanglian Jiedu Decoction (HLJDD) as an adjuvant treatment on CID.

Method

HLJDD extract was prepared by GMP manufacturing standard with quality and stability being checked. 5-fluorouracil (5-Fu) and irinotecan (CPT-11)-induced diarrhea model in mice was established and pre-, co- and post-treatment of HLJDD was implemented. Mechanism of action was explored by detecting related protein expression. In addition, the effect of HLJDD on diarrhea and tumor response induced by clinical regimens FOLFOX and FOLFIRI was measured in murine orthotopic colorectal cancer model.

Results

HLJDD exhibited consistency in quality and stability after 24-month storage. Pre-treatment of HLJDD, but not co-treatment or post-treatment, could significantly improve the diarrhea score, body weight loss and intestinal damage in 5-Fu- and CPT-11-treated mice. Pre-treatment of HLJDD reduced cell apoptosis in the intestine of chemotherapy-treated mice, and promoted renewal of intestinal cell wall. CD44 was predicted as the potential target of HLJDD-containing compounds in CID. HLJDD pre-treatment induced presentation of CD44-postive cells in the intestine of chemotherapy-treated mice, and initiated expression of stemness-associated genes. Transcriptional products of the downstream Wnt signaling of CD44 were elevated. Furthermore, pre-treatment of HLJDD could significantly improve the tumor response of clinical chemotherapy regimens FOLFOX and FOLFIRI in orthotopic colorectal cancer, and reduce diarrhea and intestinal damage. Conclusion: Our study suggests the potential of HLJDD as a neoadjuvant treatment of chemotherapy by reducing diarrhea and improving tumor response.

Excipient-free nanodispersion of 7-ethyl-10-hydroxycamptothecin exerts potent therapeutic effects against pancreatic cancer cell lines and patient-derived xenografts

Irinotecan (CPT-11) is an anti-tumor drug and formulated as nanomedicines to reduce side effects and improve efficacy. In vivo, CPT-11 must be hydrolyzed by carboxylesterase to its active form 7-ethyl-10-hydroxycamptothecin (SN-38) to exert anti-tumor activity, but the lack of this enzyme in humans causes inefficient generation of SN-38. Thus, direct delivery of SN-38, not relying on carboxylesterase, will potentially achieve higher efficacy. However, it is difficult to effectively formulate SN-38 using current excipients due to its hydrophobicity and tendency to crystallize. Herein, we report the nanodispersion of SN-38 with its amphiphilic prodrug, CPT-11, as an effective treatment for pancreatic cancer (PC). SN-38 and CPT-11 formed stable nanoparticles without any other excipients, and showed potent cytotoxicity against PC cells in vitro, slowed tumor growth in vivo, namely subcutaneously and orthotopically xenografted mice, with minimal adverse effects, and prolonged their overall survival. Even in clinically-relevant patient-derived xenograft (PDX) models, the nanodispersion showed greater anti-tumor efficacy than CPT-11. Importantly, the nanodispersion directly released SN-38, resulting in carboxylesterase-independent anti-tumor activity, in contrast to carboxylesterase-dependent CPT-11. These characteristics may enable the excipient-free nanodispersion to exert potent therapeutic effects in patients.

Alleviation of Intestinal Inflammation by Oral Supplementation With 2-Fucosyllactose in Mice

Milk oligosaccharides exert a prebiotic action that contributes to the development of the infant gut microbiota during lactation. Given that milk oligosaccharides remain intact after passage through stomach and small intestine, they can potentially influence the composition of the gut microbiota when ingested as dietary supplements after weaning. To address the regulatory effects of specific oligosaccharides in colitis linked to the microbiota composition, we have supplemented interleukin-10 null (Il10 ^-/-) mice with four fucosylated and sialylated oligosaccharides. We found that oral supplementation with 2-fucosyllactose significantly decreased the severity of colitis as displayed by reduced inflammatory marker expression, histological and diarrhea scores, an increased epithelial integrity and less pronounced colon shortening. Oral supplementation with 2-fucosyllactose led to a marked expansion of the commensal Ruminococcus gnavus, which was accompanied by an enhanced cecal concentration of propionate. Decreased activation of immune cells by R. gnavus was confirmed by reconstitution of antibiotic-treated Il10 ^-/- mice and by stimulation of dendritic cells in vitro. This study demonstrates that post-weaning administration of specific oligosaccharides can shift the composition of the gut microbiota to lessen chronic inflammation as observed in Il10 ^-/- mice. The expansion of R. gnavus sets a positive microbial environment at the cost of pro-inflammatory Gram-negative bacteria, thereby lowering intestinal inflammation.

Evaluation of the effects of chemotherapy-induced fatigue and pharmacological interventions in multiple mouse behavioral assays

Fatigue is a common symptom in many diseases and disorders and can reduce quality of life, yet lacks an adequate pharmacological intervention. To identify and develop such interventions, and to better understand fatigue, additional preclinical research is necessary. However, despite numerous mouse behavioral assays reportedly detecting fatigue-like behavior, the assumption that fatigue-like behavior is detected in many assays has not been validated through a cross-assay study. Thus, we modeled fatigue in mice by administering 5-fluorouracil, a chemotherapy drug known to cause fatigue in humans and fatigue-like behavior in mice, then evaluated its effects via voluntary wheel running activity (VWRA), locomotor activity in the open field test (OFT), immobility in the forced swim test (FST), and distance run in the treadmill fatigue test (TFT) and treadmill exercise capacity test. Additionally, taltirelin or methylphenidate was administered to alleviate fatigue-like behavior. As a result of 5-fluorouracil treatment, VWRA and the TFT were markedly reduced, indicating fatigue. The OFT, FST, and treadmill exercise capacity test, however, failed to detect fatigue-like behavior. Interestingly, both taltirelin and methylphenidate alleviated fatigue-like behavior in TFT. These data suggest that, of the current assays, only the TFT and VWRA should be expected to detect fatigue-like behavior. Moreover, this study provides additional evidence that taltirelin may provide a novel treatment for chemotherapy-induced fatigue and warrants further evaluation as an anti-fatigue therapeutic.

New Perspectives on the Potential Role of Aquaporins (AQPs) in the Physiology of Inflammation

Aquaporins (AQPs) are emerging, in the last few decades, as critical proteins regulating water fluid homeostasis in cells involved in inflammation. AQPs represent a family of ubiquitous membrane channels that regulate osmotically water flux in various tissues and sometimes the transport of small solutes, including glycerol. Extensive data indicate that AQPs, working as water channel proteins, regulate not only cell migration, but also common events essential for inflammatory response. The involvement of AQPs in several inflammatory processes, as demonstrated by their dysregulation both in human and animal diseases, identifies their new role in protection and response to different noxious stimuli, including bacterial infection. This contribution could represent a new key to clarify the dilemma of host-pathogen communications, and opens up new scenarios regarding the investigation of the modulation of specific AQPs, as target for new pharmacological therapies. This review provides updated information on the underlying mechanisms of AQPs in the regulation of inflammatory responses in mammals and discusses the broad spectrum of options that can be tailored for different diseases and their pharmacological treatment.

Aquaporin-4 Is Downregulated in the Basolateral Membrane of Ileum Epithelial Cells during Enterotoxigenic Escherichia coli-Induced Diarrhea in Mice

Enterotoxigenic Escherichia coli (ETEC) are opportunistic pathogens that colonize the small intestine, produce enterotoxins and induce diarrhea. Some aquaporins (AQPs), such as AQP3 and AQP8, have been reported to participate in diarrhea by decreasing cellular influx in the gastrointestinal (GI) tract. AQP4 is another important water channel in the GI tract, but its role in ETEC-induced diarrhea has not been reported. Here, we demonstrated the potential roles of AQP4 in ETEC-induced diarrhea. Reverse transcription-polymerase chain reaction (RT-PCR) and western blotting showed that AQP4 was expressed in the mouse ileum, but not in the duodenum or jejunum while immunohistochemical staining showed that AQP4 localized to the basolateral membrane of ileum epithelial cells. Using an ETEC-induced mice diarrhea model, we demonstrated that both AQP4 mRNA level and the AQP4 protein level in the ileum decreased gradually over a time course of 7 days. These results suggest that AQP4 plays a role in the pathogenesis of ETEC-induced diarrhea by mediating water transport.

Alteration of Gut Microbiota and Inflammatory Cytokine/Chemokine Profiles in 5-Fluorouracil Induced Intestinal Mucositis

Disturbed homeostasis of gut microbiota has been suggested to be closely associated with 5-fluorouracil (5-Fu) induced mucositis. However, current knowledge of the overall profiles of 5-Fu-disturbed gut microbiota is limited, and so far there is no direct convincing evidence proving the causality between 5-Fu-disturbed microbiota and colonic mucositis. In mice, in agreement with previous reports, 5-Fu resulted in severe colonic mucositis indicated by weight loss, diarrhea, bloody stool, shortened colon, and infiltration of inflammatory cells. It significantly changed the profiles of inflammatory cytokines/chemokines in serum and colon. Adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and VE-Cadherin were increased. While tight junction protein occludin was reduced, however, zonula occludens-1 (ZO-1) and junctional adhesion molecule-A (JAM-A) were increased in colonic tissues of 5-Fu treated mice. Meanwhile, inflammation related signaling pathways including NF-κB and mitogen activated protein kinase (MAPKs) in the colon were activated. Further study disclosed that 5-Fu diminished bacterial community richness and diversity, leading to the relative lower abundance of Firmicutes and decreased Firmicutes/Bacteroidetes (F/B) ratio in feces and cecum contents. 5-Fu also reduced the proportion of Proteobacteria, Tenericutes, Cyanobacteria, and Candidate division TM7, but increased that of Verrucomicrobia and Actinobacteria in feces and/or cecum contents. The fecal transplant from healthy mice prevented body weight loss and colon shortening of 5-Fu treated mice. In addition, the fecal transplant from 5-Fu treated mice reduced body weight and colon length of vancomycin-pretreated mice. Taken together, our study demonstrated that gut microbiota was actively involved in the pathological process of 5-Fu induced intestinal mucositis, suggesting potential attenuation of 5-Fu induced intestinal mucositis by manipulating gut microbiota homeostasis.

Aquaporin-1 expression as an indicator in evaluating the efficacy of meloxicam in the treatment of ankylosing spondylitis: A comparative study

OBJECTIVE

The key objective of the study was to investigate the correlation between the expression of aquaporin-1 (AQP1) and the efficacy of meloxicam and expressions of pro-inflammatory cytokines in ankylosing spondylitis (AS).

METHODS

40 AS patients whom had received meloxicam were recruited and subsequently placed into the experiment, while 40 healthy individuals were recruited as control group. Clinical indicators were detected before treatment (0 week), and at 2, 4, 6, 8, 10 and 12 week intervals after treatment, which included various assessments including Ankylosing Spondylitis 20% (ASAS20) response, Bath ankylosing spondylitis disease activity index (BASDAI), visual analog scale (VAS) for back pain, duration of morning stiffness, Bath ankylosing spondylitis functional index (BASFI), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) levels. Healthy volunteers were examined for ESR and CRP levels. The mRNA and protein expressions of AQP1 and pro-inflammatory cytokines, tumor necrosis factor-α (TNF-α) and interleukin-2 (IL-2), in peripheral blood mononuclear cells (PBMCs) were detected 6 and 12 weeks after treatment using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting. Correlation of expressions of AQP1, efficacy of meloxicam and expression of pro-inflammatory cytokines were determined via Pearson correlation analysis.

RESULTS

Following 12 weeks of meloxicam treatment, the ASAS20 response reached 93.7±3.61%. 6 weeks after treatment, BASDAI, VAS for back pain, duration of morning stiffness, BASFI, ESR, and CRP levels all exhibited considerably reduced levels compared to the initial levels observed prior to the commencement of treatment. Compared with before treatment, the expressions of TNF-α, IL-2 and AQP1 mRNA and protein all displayed decreases in the experiment group after both 6 and 12-week periods of treatment. Pre and post treatment levels of TNF-α, IL-2 and AQP1 mRNA and protein expressions were higher than those in the control group. The expressions of AQP1 mRNA and protein in the experiment group were positively correlated with clinical indicators and expressions of pro-inflammatory cytokines.

CONCLUSION

Our findings indicated that AQP1 was both highly expressed and positively correlated with the efficacy of meloxicam and expressions of pro-inflammatory cytokines in AS patients, thereby highlighting the promise of meloxicam as a potential indicator in predicting the efficacy in the treatment of AS.

Stability and efficacy of frozen and lyophilized fecal microbiota transplant (FMT) product in a mouse model of Clostridium difficile infection (CDI)

Freezing donor fecal microbiota has simplified fecal microbiota transplantation (FMT) in the treatment of recurrent C. difficile infection (CDI). However, the optimal storage time for the frozen FMT products remains unknown. Using an established murine model of CDI, stability and efficacy of frozen and lyophilized FMT product was studied at time points from 2 months to 15 months. DNA was extracted from fecal samples from the mice with identification of specific bacterial species by real-time quantitative PCR (qPCR). FMT product stability and efficacy were measured by occurrence of diarrhea in the challenged mice together with stability of the microbiota composition. The results were analyzed and compared by SAS statistical software. All mice treated with only C. difficile developed diarrhea within 72 h. Mice treated with frozen (n = 5/group), lyophilized (n = 5/group) products stored for ≤ 7-month or fresh FMT product (n = 22) were protected from post C. difficile challenge diarrhea. There was no difference between frozen and lyophilized products (n = 5/group) stored for ≤ 7 months 95% CI 1.00 (0.38-2.64) and 1.00 (0.38-2.64), respectively. Prevention if CDI by frozen and lyophilized product was not different for storage of 9-, 11- and 15-months. qPCR results demonstrated there were no significant quantitative change in Bacteroides and Clostridium species during any of the storage times (P > 0.05). In the present study, frozen and lyophilized FMT products were stored up to 7 months without losing microbiota composition and therapeutic efficacy. The animal model described may be useful to study stability of human microbiota designed for FMT.

Dai-Huang-Fu-Zi-Tang alleviates pulmonary and intestinal injury with severe acute pancreatitis via regulating aquaporins in rats

BACKGROUND

Dai-Huang-Fu-Zi-Tang (DHFZT) is a famous traditional Chinese prescription with intestinal obstruction, acute pancreatitis and cholecystalgia for thousands of years. Our previous work found that DHFZT could act against pulmonary and intestinal pathological injury in rats with severe acute pancreatitis (SAP). But the underlying mechanism has not been fully elucidated. The aim of present study was to investigate whether DHFZT could relieve pulmonary and intestinal injury by regulating aquaporins after SAP induced by sodium taurocholate in rats.

METHODS

Forty of SD rats were used for dose dependant experiments of DHFZT.Accurate-mass Time-of-flight liquid chromatography-mass spectrometry was used for qualitative screening of chemical compositions of DHFZT. Twenty-four rats were randomly divided into 3 groups: sham group (n = 8), model group (SAP, n = 8), DHFZT group (SAP with DHFZT treatment, n = 8). SAP models were established by retrograde injections of 5% sodium taurocholate solutions into rat pancreaticobiliary ducts. Blood samples were taken at 0, 12, 24, 48 h post-operation for detecting serum amylase, lipase, endotoxin, TNF-α, IL-6 and IL-10. Protein expression and location of aquaporin (AQP)1, 5, 8 and 9 were assessed by immunohistochemistry, western blot and immunofluorescence respectively.

RESULTS

The study showed that 27 kinds of chemical composition were identified, including 10 kinds in positive ion mode and 17 kinds in negative ion mode. The results showed that AQP1, AQP5 of lung, and AQP1, AQP5, AQP8 of intestine in model group were significantly lower than that of sham group (P < 0.05), and which were obviously reversed by treatment with DHFZT. In addition, protein levels of pro-inflammatory cytokines such as TNF-α, IL-6 and endotoxin in peripheral blood were significantly suppressed by DHFZT, and that anti-inflammatory cytokine like IL-10 was just opposite. Finally, we also noted that DHFZT reduced serum levels of amylase, lipase and endotoxin, and also improved edema and pathological scores of lung and intestine after SAP.

CONCLUSIONS

DHFZT ameliorated the pulmonary and intestinal edema and injury induced by SAP via the upregulation of different AQPs in lung and intestine, and suppressed TNF-α, IL-6 expression and enhanced IL-10 expression.

Aquaporin-3 is down-regulated in jejunum villi epithelial cells during enterotoxigenic Escherichia coli-induced diarrhea in mice

Enterotoxigenic Escherichia coli (ETEC)-induced diarrhea is a complex pathological process, involving ion channel regulation and water efflux. While the mechanism underlying water efflux in ETEC-induced diarrhea is still largely unknown, aquaporins (AQPs) play important roles in transcellular water movement, but their expression profile has not been demonstrated in the murine small intestine. We identified AQP3 expression in the jejunum, but not the duodenum or ileum, using reverse transcription PCR and western blotting. Immunohistochemistry showed that AQP3 localized to the jejunum villi epithelial cells. Using an ETEC-induced murine diarrhea model, we demonstrated that both AQP3 mRNA expression and protein concentration in the jejunum were gradually but significantly decreased over 7 d compared with controls. These results suggested impaired water influx also plays an important role in ETEC-induced diarrhea.

AMPK/α-Ketoglutarate Axis Regulates Intestinal Water and Ion Homeostasis in Young Pigs

Water and ion absorption via sensitive aquaporins (AQPs) and ion channels is of critical importance in intestinal health. However, whether α-ketoglutarate (AKG) could improve intestinal water and ion homeostasis in lipopolysaccharide (LPS)-challenged piglets and whether the AMP-activated protein kinase (AMPK) pathway is involved remains largely unknown. This study was conducted to investigate the effect of dietary AKG supplementation on the small intestinal water and ion homeostasis through modulating the AMPK pathway in a piglet diarrhea model. A total of 32 weaned piglets were used in a 2 × 2 factorial design; the major factors were diet (basal diet or 1% AKG diet) and challenge (Escherichia coli LPS or saline). The results showed that LPS challenge increased the diarrhea index and affected the concentrations of serum Na⁺, K⁺, Cl^-, glucose, and AKG and its metabolites in piglets fed the basal or AKG diet. However, the addition of AKG attenuated diarrhea incidence and reversed these serum parameter concentrations. Most AQPs (e.g., AQP1, AQP3, AQP4, AQP5, AQP8, AQP10, and AQP11) and ion transporters (NHE3, ENaC, and DRA/PAT1) were widely distributed in the duodenum and jejunum of piglets. We also found that AKG up-regulated the expression of intestinal epithelial AQPs while inhibiting the expression of ion transporters. LPS challenge decreased (P < 0.05) the gene and protein expression of the AMPK pathway (AMPKα1, AMPKα2, SIRT1, PGC-1α, ACC, and TORC2) in the jejunum and ileum. Notably, AKG supplementation enhanced the abundance of these proteins in the LPS-challenged piglets. Collectively, AKG plays an important role in increasing water and ion homeostasis through modulating the AMPK pathway. Our novel finding has important implications for the prevention and treatment of gut dysfunction in neonates.

Characterization of AQPs in Mouse, Rat, and Human Colon and Their Selective Regulation by Bile Acids

In normal individuals, the epithelium of the colon absorbs 1.5–2 l of water a day to generate dehydrated feces. However, in the condition of bile acid malabsorption (BAM), an excess of bile acids in the colon results in diarrhea. Several studies have attempted to address the mechanisms contributing to BAM induced by various bile acids. However, none have addressed a potential dysregulation of aquaporin (AQP) water channels, which are responsible for the majority of transcellular water transport in epithelial cells, as a contributing factor to the onset of diarrhea and the pathogenesis of BAM. In this study, we aimed to systematically analyze the expression of AQPs in colonic epithelia from rat, mouse, and human and determine whether their expression is altered in a rat model of BAM. Mass spectrometry-based proteomics, RT-PCR, and western blotting identified various AQPs in isolated colonic epithelial cells from rats (AQP1, 3, 4, 7, 8) and mice (AQP1, 4, 8). Several AQPs were also detected in human colon (AQP1, 3, 4, 7–9). Immunohistochemistry localized AQP1 to the apical plasma membrane of epithelial cells in the bottom of the crypts, whereas AQP3 (rat, human) and AQP4 (mice, human) were localized predominantly in the basolateral plasma membrane. AQP8 was localized intracellularly and at the apical plasma membrane of epithelial cells. Rats fed sodium cholate for 72 h had significantly increased fecal water content, suggesting development of BAM-associated diarrhea. Colonic epithelial cells isolated from this model had significantly altered levels of AQP3, 7, and 8, suggesting that these AQPs may be involved in the pathogenesis of bile acid-induced diarrhea.

Rhubarb extract partially improves mucosal integrity in chemotherapy-induced intestinal mucositis

AIM

To investigate the effects of orally gavaged aqueous rhubarb extract (RE) on 5-fluorouracil (5-FU)-induced intestinal mucositis in rats.

METHODS

Female Dark Agouti rats (n = 8/group) were gavaged daily (1 mL) with water, high-dose RE (HDR; 200 mg/kg) or low-dose RE (LDR; 20mg/kg) for eight days. Intestinal mucositis was induced (day 5) with 5-FU (150 mg/kg) via intraperitoneal injection. Intestinal tissue samples were collected for myeloperoxidase (MPO) activity and histological examination. Xenopus oocytes expressing aquaporin 4 water channels were prepared to examine the effect of aqueous RE on cell volume, indicating a potential mechanism responsible for modulating net fluid absorption and secretion in the gastrointestinal tract. Statistical significance was assumed at P < 0.05 by one-way ANOVA.

RESULTS

Bodyweight was significantly reduced in rats administered 5-FU compared to healthy controls (P < 0.01). Rats administered 5-FU significantly increased intestinal MPO levels (≥ 307%; P < 0.001), compared to healthy controls. However, LDR attenuated this effect in 5-FU treated rats, significantly decreasing ileal MPO activity (by 45%; P < 0.05), as compared to 5-FU controls. 5-FU significantly reduced intestinal mucosal thickness (by ≥ 29% P < 0.001) as compared to healthy controls. LDR significantly increased ileal mucosal thickness in 5-FU treated rats (19%; P < 0.05) relative to 5-FU controls. In xenopus oocytes expressing AQP4 water channels, RE selectively blocked water influx into the cell, induced by a decrease in external osmotic pressure. As water efflux was unaltered by the presence of extracellular RE, the directional flow of water across the epithelial barrier, in the presence of extracellular RE, indicated that RE may alleviate water loss across the epithelial barrier and promote intestinal health in chemotherapy-induced intestinal mucositis.

CONCLUSION

In summary, low dose RE improves selected parameters of mucosal integrity and reduces ileal inflammation, manifesting from 5-FU-induced intestinal mucositis.

EFFECT OF PYRROLE DERIVATIVE ON THE RAT COLONIC MUCOSA COMPARED TO 5-FLUOROURACIL

Prevention the development of malignant tumors and treatment of cancer patients remains an important problem today. In spite of substantive progress in the cancer diagnostics and treatment cancer occupies one of the main places in human morbidity and mortality in the World. Targeted therapy is an alternative to traditional one through targeted action on tumor cells and relatively low toxicity. Inhibitor of membrane tyrosine kinases dihydropyrrole derivative 5-amino-4-(1,3-benzothiazole-2-yl)-1-(3- methoxyphenyl)-1,2-dihydro-3Н-pyrrol-3-one (D-1) has significant antitumor activity on colorectal cancer and low toxicity acting in effective dose. However, to assess the D-1 therapeutic gap the investigation of its higher doses is necessary. The investigation was aimed at D-1 effects applied at different doses compared to 5-fluorouracil one on rats ascending colon mucosa. The research has found out that the dihydropyrrole derivative has no damaging effect on the colon of rats, whereas the administration of 5-fluorouracil causes marked mucosal lesion of the ascending colon. Hereby D-1 low toxicity to ascending colon mucosa compared to 5-FU and wide therapeutic gap of the first was concluded.

Expression, Distribution and Role of Aquaporin Water Channels in Human and Animal Stomach and Intestines

Stomach and intestines are involved in the secretion of gastrointestinal fluids and the absorption of nutrients and fluids, which ensure normal gut functions. Aquaporin water channels (AQPs) represent a major transcellular route for water transport in the gastrointestinal tract. Until now, at least 11 AQPs (AQP1–11) have been found to be present in the stomach, small and large intestines. These AQPs are distributed in different cell types in the stomach and intestines, including gastric epithelial cells, gastric glands cells, absorptive epithelial cells (enterocytes), goblet cells and Paneth cells. AQP1 is abundantly distributed in the endothelial cells of the gastrointestinal tract. AQP3 and AQP4 are mainly distributed in the basolateral membrane of epithelial cells in the stomach and intestines. AQP7, AQP8, AQP10 and AQP11 are distributed in the apical of enterocytes in the small and large intestines. Although AQP-null mice displayed almost no phenotypes in gastrointestinal tracts, the alterations of the expression and localization of these AQPs have been shown to be associated with the pathology of gastrointestinal disorders, which suggests that AQPs play important roles serving as potential therapeutic targets. Therefore, this review provides an overview of the expression, localization and distribution of AQPs in the stomach, small and large intestine of human and animals. Furthermore, this review emphasizes the potential roles of AQPs in the physiology and pathophysiology of stomach and intestines.

Curcumin Inhibits 5-Fluorouracil-induced Up-regulation of CXCL1 and CXCL2 of the Colon Associated with Attenuation of Diarrhoea Development

The compound 5-fluorouracil (5-FU) is used in cancer chemotherapy and is known to cause diarrhoea. We recently reported that chemokine (C-X-C motif) ligand 1 (CXCL1) and neutrophils in the colonic mucosa were markedly increased by the administration of 5-FU in mice. Curcumin has anti-inflammatory, antitumour and antioxidant properties. Therefore, we examined the effect of curcumin on 5-FU-induced diarrhoea development and CXCL1 and CXCL2 up-regulation in the colon. Mice were given 5-FU (50 mg/kg, i.p.) daily for 4 days. Curcumin (100 or 300 mg/kg, p.o.) was administered on the day before the first administration of 5-FU and administered 30 min. before the administration of 5-FU. Gene expression levels of CXCL1 and CXCL2 in the colon were examined by real-time RT-PCR. Curcumin reduced the 5-FU-induced diarrhoea development. Under this condition, the CXCL1 and CXCL2 gene up-regulated by 5-FU administration was inhibited by curcumin. The gene expression of CXCL1 and CXCL2 was also enhanced by 5-FU application in vitro. The 5-FU-induced up-regulated CXCL1 and CXCL2 gene expressions were inhibited by curcumin, Bay-117082 and bortezomib, nuclear factor kappa B (NF-κB) inhibitors, C646, a p300/cyclic adenosine monophosphate response element-binding protein-histone acetyltransferase (HAT) inhibitor. In conclusion, these findings suggested that curcumin prevented the development of diarrhoea by inhibiting NF-κB and HAT activation.

Characterization and differential expression analysis of Toxocara canis aquaporin-1 gene

Toxocara canis is an intestinal nematode of canids with a worldwide distribution, causing an important but neglected parasitic zoonosis in humans. Aquaporins (AQP) are a family of water channel proteins, which function as membrane channels to regulate water homeostasis. In this study, the coding sequence of aquaporin-1 gene of T. canis (Tc-aqp-1) was cloned and characterized. The obtained Tc-aqp-1 coding sequence was 933 bp in length, which predicted to encode 311 amino acids. Two conserved asparagine-proline-alanine (NPA) motifs were identified in the multiple sequence alignments. Phylogenetic analysis revealed the closest relationship between T. canis and Opisthorchis viverrini based on aquaporin-1 amino acid sequence. A structure was predicted with ligand binding sites predicted at H93, N95, N226, L94, I79, and I210 and with active sites predicted at I256 and G207. Gene Ontology (GO) annotations predicted its cellular component term of integral component of plasma membrane (GO: 0005887), molecular function term of channel activity (GO: 0015250), and biological process term of water transport (GO: 0006833). Tissue expression analysis revealed that the Tc-aqp-1 was highly expressed in the intestine of adult male. The findings of the present study provide the basis for further functional studies of T. canis aquaporin-1.