Methotrexate induces intestinal mucositis and alters gut protein metabolism independently of reduced food intake

Cynaroside ameliorates methotrexate-induced enteritis in rats through inhibiting NLRP3 inflammasome activation

Introduction

Cynaroside exhibits various biological properties, including anti-inflammatory, antiviral, antitumor, and cardioprotective effects. However, its involvement in methotrexate (MTX)-induced intestinal inflammation remains inadequately understood. Thus, we investigated the impact of cynaroside on MTX-induced intestinal inflammation and its potential mechanisms.

Methods

To assess the protective potential of cynaroside against intestinal inflammation, Sprague-Dawley rats were subjected to a regimen of 7 mg/kg MTX for 3 days, followed by treatment with cynaroside at varying doses (10, 20, or 40 mg/kg). Histopathological evaluations were conducted alongside measurements of inflammatory mediators to elucidate the involvement of the NLRP3 inflammasome in alleviating intestinal inflammation.

Results

Administration of 7 mg/kg MTX resulted in decreased daily food intake, increased weight loss, and elevated disease activity index in rats. Conversely, treatment with cynaroside at 20 or 40 mg/kg ameliorated the reductions in body weight and daily food intake and suppressed the MTX-induced elevation in the disease activity index. Notably, cynaroside administration at 20 or 40 mg/kg attenuated inflammatory cell infiltration, augmented goblet cell numbers and lowered serum levels of tumor necrosis factor-α, interleukin (IL)-1β, and IL-18, as well as the CD68-positive cell rate in the intestines of MTX-induced rats. Furthermore, cynaroside downregulated the expression levels of NLRP3, cleaved caspase 1, and cleaved IL-1β in MTX-induced rats.

Discussion

Collectively, our findings indicated that cymaroside alleviates intestinal inflammatory injury by inhibiting the activation of NLRP3 inflammasome in MTX-induced rats.

The Effect of Dextrose Hypotonic vs Saline Hydration on Methotrexate-Induced Nephrotoxicity in Male and Female Rats

Background

High-dose methotrexate (HDMTX) as a cytotoxic agent might cause various side effects. Hyperhydration has been implemented as the major strategy to decrease the potential risk of toxicities induced by HDMTX. This study aims to assess the renoprotective effect of hydration with dextrose water (DW) 5% versus normal saline (N/S) 0.9% against methotrexate (MTX) induced nephrotoxicity.

Materials and Methods

This experimental animal study has been conducted on 36 Wistar rats (200-250 g) categorized into six groups, including male (n = 6) and female (n = 6) rats receiving sodium chloride 0.9% saline plus MTX, DW 5% plus MTX, or MTX alone. By the fifth day after the MTX injection, biochemical indexes were measured. The rats were also sacrificed and renal specimens were evaluated microscopically to determine kidney tissue damage (KTD).

Results

The groups were not significantly different with regard to blood urea nitrogen (BUN) (P = 0.5), creatinine (Cr) (P = 0.24), kidney weight (P = 0.34), and urine flow (UF) (P = 0.5), while KTD score was remarkably less in the hydrated groups (P < 0.001). Weight loss in DW-treated rats was significantly more than N/S-treated ones, and creatinine clearance (CrCl) and urine load (UL) of Cr were statistically similar between males and females in the control group, but significantly lower among the DW5% treated males.

Conclusion

Based on the findings of this study, hydration with N/S was superior to DW5% for the prevention from HDMTX-induced nephrotoxicity. Besides, we found insignificant differences between male versus female rats in response to the hydration for HDMTX-induced renoprotection; however, females probably benefit more.

Whey protein concentrate ameliorates the methotrexate-induced liver and kidney damage

Methotrexate (MTX) is a cytotoxic immunosuppressant that is widely used in the treatment of tumours, rheumatoid arthritis and psoriasis. This study aims to evaluate the effects of whey proteins on MTX-induced liver and kidney damage by focusing on oxidant–antioxidant systems and eating habits. The study was conducted in four groups of thirty Sprague–Dawley rats (control, control + whey protein concentrate (WPC), MTX, MTX + WPC). A single dose of 20 mg/kg MTX was administered intraperitoneally to the MTX groups. Control and MTX groups were given 2 g/kg WPC by oral gavage every day for 10 d. At the end of day 10, blood samples were drawn and liver and kidney tissues were removed. MTX administration increased the lipid peroxidation level and decreased glutathione level, superoxide dismutase and glutathione-S-transferase activities in the liver and kidney. Administration of WPC significantly reduced the damage caused by MTX in the liver and kidney. While a decrease in serum urea level and an increase in serum creatinine level were detected in the MTX group, WPC administration reversed these results up to control group levels. Administration of WPC to the MTX group significantly reversed the histopathological damage scores of the liver and kidney. WPC administration ameliorated the MTX-induced oxidative damage in the liver and kidney tissues due to its antioxidant properties. Liver and kidney damage can be prevented by using whey proteins as a nutraceutical in MTX therapy. In conclusion, whey proteins demonstrated a protective effect against MTX-induced liver and kidney damage.

Colitis induced by PD-1 inhibitor combined with platinum-containing dual drug chemotherapy in Lewis mice and its mechanism

Aims

To explore the occurrence and possible mechanism of colitis in Lewis mice treated with PD-1 inhibitor combined with platinum-containing dual drug chemotherapy.

Subjects and Methods

A Lewis lung cancer model of C57BL/6 mice was established, randomly divided into the treatment group (group C, PD-1 inhibitor + Carboplatin (CARB) + Pemetrexed (PEM)) and model group (group B, normal saline), and a control group (group A, normal saline) was set up. Observe the changes in tumor-free weight, tumor volume, disease activity index (DAI), colon histopathology, identify serum interleukin (IL)-10, interferon (IFN)-γ, the expression of claudin-1, and occludin mRNA in the colon in each animals.

Results

Compared with group A, the tumor-free weight of mice in B decreased (P < 0.001), the content of IL-10 in serum increased (P < 0.01), the content of IFN-γ in serum decreased (P < 0.01). Compared with group B, the transplanted tumor volume in C was reduced (P < 0.05), DAI scores of D4 (P < 0.001), and D7 (P < 0.001) were increased, colonic histopathology analysis showed that colitis occurred, serum IL-10 content was decreased (P < 0.05), IFN-γ content was increased (P < 0.05), and the mRNA expression of claudin-1 (P < 0.05) and occludin (P < 0.05) was reduced.

Conclusions

This treatment can inhibit the growth of transplanted tumors but will cause colitis in Lewis mice. The impairment of intestinal barrier function following administration cause an imbalance in the expression of pro-inflammatory and anti-inflammatory factors in the colon, thus causing colitis.

Antineoplastic drugs in environmentally relevant concentrations cause endocrine disruption and testicular dysfunction in experimental conditions

5-fluorouracil (5-FU) and methotrexate (MTX) are among the most widely consumed antineoplastic drugs worldwide. These drugs are known as emerging pollutants, once after consumption are excreted by feces and/or urine in a mixture of compounds and metabolites, entering the aquatic environment due to low efficiency in drug removal by effluent treatment plants. Considering that these substances may interact with the DNA, causing metabolic and morphological changes, leading to cell death, the present study aimed to investigate the potential impact of a long-term exposure to these antineoplastic drugs in environmentally relevant concentrations, on testicular morphophysiology of rats. Male Wistar rats (70 days old) were distributed into 4 groups (n = 10 / group): control, received only vehicle; MTX, received methotrexate at 10ngL-1 in drinking water; 5-FU received 5-fluorouracil at 10ngL-1 in drinking water; and MTX+ 5FU, received the combination of MTX and 5-FU at 10ngL-1 each. The treatment period was from postnatal day (PND)70 to PND160, when the animals were euthanized for evaluation of testicular toxicity and changes in endocrine signaling. In these experimental conditions, both drugs acted as endocrine disruptors causing cytotoxic effects in the testes of exposed rats, altering the structural pattern of seminiferous tubules and leading to oxidative stress even at environmental concentrations.

Dihydromyricetin Modulates Nrf2 and NF-κB Crosstalk to Alleviate Methotrexate-Induced Lung Toxicity

BACKGROUND

Methotrexate (MTX) is an effective anticancer, anti-inflammatory, and immunomodulatory agent. However, it induces a serious pneumonitis that leads to irreversible fibrotic lung damage. This study addresses the protective role of the natural flavonoid dihydromyricetin (DHM) against MTX-induced pneumonitis via modulation of Nrf2/NF-κB signaling crosstalk.

METHODS

Male Wistar rats were divided into 4 groups: control, which received the vehicle; MTX, which received a single MTX (40 mg/kg, i.p) at day 9 of the experiment; (MTX + DHM), which received oral DHM (300 mg/kg) for 14 days and methotrexate (40 mg/kg, i.p) on the 9th day; and DHM, which received DHM (300 mg/kg, p.o) for 14 days.

RESULTS

Lung histopathological examination and scoring showed a decline in MTX-induced alveolar epithelial damage and decreased inflammatory cell infiltration by DHM treatment. Further, DHM significantly alleviated the oxidative stress by decreasing MDA while increasing GSH and SOD antioxidant levels. Additionally, DHM suppressed the pulmonary inflammation and fibrosis through decreasing levels of NF-κB, IL-1β, and TGF-β1 while promoting the expression of Nrf2, a positive regulator of antioxidant genes, and its downstream modulator, HO-1.

CONCLUSION

This study identified DHM as a promising therapeutic target against MTX-induced pneumonitis via activation of Nrf2 antioxidant signaling while suppressing the NF-κB mediated inflammatory pathways.

LENTINULA EDODES POLYSACCHARIDES SUPPRESSED PRO-INFLAMMATORY CYTOKINES EXPRESSION AND COLITIS IN MICE

BACKGROUND

Polysaccharides from edible mushrooms possess immunomodulatory, anti-inflammatory, and anti-tumor activities. Recent studies indicated that necroptosis plays a role in the pathogenesis of inflammatory diseases and mediates increased expression of inflammatory cytokines.

OBJECTIVE

Therefore, it is imperative to determine the impact of polysaccharide extract from Lentinula edodes (L. edodes) on inflammatory cytokines in experimental model of colitis in mice.

METHODS

Female C57BL/6 mice divided into three or four mice per group were used for this study. Polysaccharide sample was orally administered to mice prior to (7 days) and during colitis induction with 2.5% dextran sodium sulfate (7 days), followed by additional 3 days of administration. Changes in body weight and colon length were used as markers for colitis, and pro-inflammatory cytokines and tumor necrosis factor receptor 1 (TNFR1) expressions, as well as necroptosis were analyzed in the colon of colitis mice. Data obtained were analysed by Tukey-Kramer and two-tailed standard t tests.

RESULTS

The results indicated that the polysaccharide sample suppressed colitis in mice using effects on the body weight and colon length as markers. Also, it was demonstrated that necrostatin-1, a specific inhibitor of necroptosis, suppressed the expression of interleukin (IL)-8, a pro-inflammatory chemokine, in Caco-2 cells induced necroptosis induced by zVAD and TNF-α, an indication that necroptosis may be involved in the expression of pro-inflammatory cytokines. Moreover, the polysaccharide sample suppressed the expression of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, IL-6, IL-1β, and interferon (IFN)-γ in the colon of mice.

CONCLUSION

These results suggested that the suppressive effects of the polysaccharide sample on inflammatory cytokines expression may contribute to its anti-colitis effect, and so may serve as a potent therapeutic agent against inflammatory bowel disease.

Forsythiaside A alleviates methotrexate-induced intestinal mucositis in rats by modulating the NLRP3 signaling pathways

Most chemotherapeutic drugs can kill the tumor cells, but also cause a vast damage to body, such as intestinal mucositis (IM). The present study was design to find out the effect of Forsythiaside A (FTA) on chemotherapeutic-induced IM in rats. Briefly, for 3 consecutive days, male Sprague-Dawley rats were treated with 7 mg / kg methotrexate (MTX) to establish IM and simultaneously administered with 40 or 80 mg / kg FTA for 7 days. Our results showed that the final body weight and daily food intake were increased, and the disease activity index was reduced in the MTX group after FTA treatment. The MTX group showed the pathological alterations like the inflammatory cells infiltration, the mucosal layer destruction, glands expansion, intestinal villi structure disorder and goblet cells reduction, while we found that 80 mg / kg FTA treatment displayed evident reversal effects. ELISA further suggested that TNF-α, IL-1β and IL-18 levels in serum in MTX-induced rats were reduced after 80 mg / kg FTA treatment. Moreover, FTA decreased the number of leukocytes, neutrophils and lymphocytes in peripheral blood. Western blot and immunofluorescence results indicated that the expression levels of NLRP3, cleaved caspase 1, cleaved IL-1β and CD68 positive rate were down-regulated in MTX-induced rats after 80 mg / kg FTA intervention. The findings of the current study suggested that FTA effectively inhibited MTX-induced IM in rats by attenuating the activation of the NLRP3 signaling pathways.

Lactobacillus reuteri Alleviates Gastrointestinal Toxicity of Rituximab by Regulating the Proinflammatory T Cells in vivo

Rituximab (RTX) is a widely used anticancer drug with gastrointestinal side effects, such as nausea, vomiting, and diarrhea. The reason for these side effects is still poorly understood. Previous studies have reported that the intestinal microbiota is associated with the occurrence of disease and the therapeutic effect of drugs. In this study, we observed mucosal damage, inflammatory cell infiltration and increased intestinal inflammatory factor expression in RTX-treated mice. RTX also changed the diversity of the intestinal microbiota in mice, and decreased abundance of Lactobacillus reuteri was observed in RTX-treated mice. Further experiments revealed that intragastric administration of L. reuteri in RTX-treated mice attenuated the intestinal inflammatory response induced by RTX and regulated the proportion of helper T (Th) cells. In conclusion, our data characterize the effect of the intestinal microbiota on RTX-induced intestinal inflammation, suggesting that modifying the gut microbiota may represent a positive strategy for managing adverse reactions.

Antioxidant-rich fraction of Amomum subulatum fruits mitigates experimental methotrexate-induced oxidative stress by regulating TNF-α, IL-1β, and IL-6 proinflammatory cytokines

The culinary spice Amomum subulatum was assessed for its phytochemical composition, in vitro antioxidant potential, and in vivo ameliorating effect against methotrexate (MTX)-induced toxicities. Phytochemical analysis of methanolic extract of A. subulatum dry fruits (MEAS) confirmed the presence of different bioactive secondary metabolites. MEAS scavenged reactive free radicals and inhibited lipid peroxidation in vitro. To confirm the antioxidant efficiency of MEAS, in vivo experiment was carried out in which MTX was administered to induce oxidative stress. Co-administration of MEAS reduced MTX-induced hepatic, renal, and pulmonary toxicities via significantly (p < .01) enhancing antioxidant status and reducing oxidative stress. MTX treatment significantly (p < .01) increased liver and kidney toxicity markers and increased proinflammatory cytokine (TNF-α, IL-1β, and IL-6) levels. However, co-administration of MEAS significantly (p < .01) reduced their levels, and tissue histopathology confirmed the protective effect of MEAS in maintaining normal tissue architecture following MTX treatment. Protective effect of MEAS is accredited to the antioxidant and anti-inflammatory properties exhibited by bioactive compounds in MEAS. PRACTICAL APPLICATIONS: Amomum subulatum (Black cardamom) is a folkloric and culinary spice used for its organoleptic, nutritional, and medicinal properties. This study demonstrated the phytochemical composition and antioxidant potential of methanolic extract of A. subulatum dry fruits (MEAS). Toxicities associated with MTX therapy limit its clinical application. MEAS attenuated methotrexate-induced oxidative stress, inflammation, and associated organ damages, suggesting the possible therapeutic application of A. subulatum in reducing oxidative stress and associated diseases. Our results showed that A. subulatum is a potential functional food, which may be used for the betterment of health due to its richness in antioxidant and anti-inflammatory phytochemicals.

Dietary restriction increases protective gut bacteria to rescue lethal methotrexate-induced intestinal toxicity

Methotrexate (MTX) is a typical chemotherapeutic drug that is widely used in the treatment of various malignant diseases as well as autoimmune diseases, with gastrointestinal toxicity being its most prominent complication which could have a significant effect on the prognosis of patients. Yet effective ways to alleviate such complications remains to be explored. Here we show that 30% dietary restriction (DR) for 2 weeks dramatically increased the survival rate of 2-month-old female mice after lethal-dose MTX exposure. DR significantly reduced intestinal inflammation, preserved the number of basal crypt PCNA-positive cells, and protected the function of intestinal stem cells (ISCs) after MTX treatment. Furthermore, ablating intestinal microbiota by broad-spectrum antibiotics completely eliminated the protective effect achieved by DR. 16S rRNA gene deep-sequencing analysis revealed that short-term DR significantly increased the Lactobacillus genus, with Lactobacillus rhamnosus GG gavage partially mimicking the rescue effect of DR on the intestines of ad libitum fed mice exposed to lethal-dose MTX. Together, the current study reveals that DR could be a highly effective way to alleviate the lethal injury in the intestine after high-dose MTX treatment, which is functionally mediated by increasing the protective intestinal microbiota taxa in mice. Keywords: Dietary restriction, Methotrexate, Gut microbiota, Intestinal stem cells, intestinal toxicity.

Localised and sustained intradermal delivery of methotrexate using nanocrystal-loaded microneedle arrays: Potential for enhanced treatment of psoriasis

Methotrexate (MTX), typically used as its sodium salt (MTX Na), is a first-line treatments for moderate to severe psoriasis, showing good efficacy. However, its systemic administration is associated with many side effects. Intradermal delivery into psoriatic tissue could offer an alternative approach. However, successful intradermal administration of MTX Na is currently precluded by its physicochemical properties. Moreover, due to its hydrophilic nature, MTX Na is swiftly cleared from the target tissue, necessitating frequent dosing which may affect patient compliance. To address these limitations, we investigated the combination of nanocrystal (NC) and dissolving microneedle (MN) technologies as an alternative approach for localised and sustained intradermal delivery of MTX Na. Poorly water-soluble MTX nanocrystals (MTX NC) were produced by a bottom-up technique with a mean particle size of 678 ± 15 nm. Sustained in vitro drug release was observed over 72 h. The MTX NC were then incorporated into the shafts of dissolving MN arrays with a drug loading of 2.48 mg/array. The MTX NC-loaded MN arrays exhibited satisfactory mechanical strength and insertion capabilities in the skin-simulant Parafilm M® and their shafts dissolved entirely in less than 20 min after insertion into excised neonatal porcine skin. Importantly, in vivo studies in Sprague Dawley rats revealed that the MN arrays were able to deposit approximately 25.1% of the loaded MTX NC in the skin, which acted, in turn, as a drug depot and released the MTX in a sustained manner over 72 h, while minimising MTX systemic exposure. Indeed, 24 h from MN application, 312.70 ± 161.95 µg/g of MTX was retained in the skin at the application site. This was approximately 322-fold higher than the amount of MTX (0.942 ± 0.59 µg/g) retained in the skin after oral administration of MTX Na. Interestingly, even after 72 h after MN application, around 12.5% of the MTX NC deposited in the skin by the MN was retained. In contrast, the maximal blood concentration of MTX achieved following MN application, was only 40% of that measured after oral administration of MTX Na. Accordingly, MTX NC-loaded dissolving MN arrays could be a promising approach for effective localised and sustained intradermal delivery of MTX as a potential enhanced treatment for psoriasis.

Prevotella copri is associated with carboplatin-induced gut toxicity

As a widely used cancer drug, carboplatin often results in serious side effects, such as gut toxicity. In this study, we examined the effects of gut microbiota on mice with carboplatin-induced intestinal mucosal damage. Carboplatin resulted in intestinal mucositis, as indicated by weight loss, diarrhoea, and infiltration of inflammatory cells. It markedly increased the expression of inflammatory cytokines/chemokines in intestine. Carboplatin also altered the diversity and composition of the gut microbiota. A significantly higher abundance of Prevotella copri (P. copri) was observed in carboplatin-treated mice. Moreover, the content of P. copri was positively correlated with the severity of intestinal mucositis. Pretreatment with metronidazole reduced the content of P. copri and relieved the intestinal mucosal injury and inflammation that was induced by carboplatin. Further study revealed that supplementation with P. copri in carboplatin-treated mice resulted in more severe tissue damage, lower tight junction protein expression and higher cytokine expression, and it enhanced both local and systemic immune responses. These data demonstrated that P. copri was involved in the pathological process of carboplatin-induced intestinal mucositis, suggesting a potential attenuation of carboplatin-induced intestinal mucositis by targeting P. copri.

In vivo pharmacological evaluation and efficacy study of methotrexate-encapsulated polymer-coated layered double hydroxide nanoparticles for possible application in the treatment of osteosarcoma

Considering the existing drawbacks of methotrexate (MTX) with respect to its solubility and toxicity, we incorporated it in a nanoceramic matrix, Mg-Al-layered double hydroxide (LDH) to form LDH-MTX nanoparticles, and the same was in turn encapsulated in a nontoxic and biodegradable polymer, poly (D,L-lactide-co-glycolide) (PLGA), to arrest the initial burst release and dose-dumping-related toxicity, already reported by our group. Our present study was designed to evaluate the pharmacokinetics, tissue distribution, survival rate of the test animals, and antitumor efficacy of the PLGA-LDH-MTX nanoparticles and its counterpart without LDH, PLGA-MTX nanoparticles compared with bare MTX. The median lethal dose (LD₅₀) of the former was higher, compared with bare MTX, using Balb/c nude mice, indicating it to be completely safe for use. Also, a comparative pharmacokinetic and antitumour efficacy study using MTX, PLGA-MTX, and PLGA-LDH-MTX nanoparticles in osteosarcoma-induced Balb/c nude mice in vivo demonstrated superiority of PLGA-LDH-MTX as compared to PLGA-MTX and bare MTX. The results suggest that PLGA-LDH-MTX nanoparticles might exhibit potential advantages over the present-day chemotherapy over bare MTX, for the possibility of treatment of osteosarcoma.

Biomarkers and non-invasive tests for gastrointestinal mucositis

Gastrointestinal mucositis is a complex inflammatory reaction of the mucous membranes, a side effect of both chemotherapy and radiotherapy. Currently, assessment scales are used to diagnose mucositis. However, a biomarker which would determine whether there is mucositis and thereby establish the severity objectively would be very useful. This will give the opportunity to evaluate studies, to determine risk factors and incidence, and it will make it possible to compare studies. Moreover, this biomarker might improve clinical management for patients. In this paper, we reviewed studies concerning potential biomarkers in blood samples and fecal samples, and potential tests in breath samples and urine samples. We include biomarkers and tests studied in animal models and/or in clinical trials, and discuss the validity, diagnostic accuracy, and applicability.

Increased Ghrelin but Low Ghrelin-Reactive Immunoglobulins in a Rat Model of Methotrexate Chemotherapy-Induced Anorexia

Background and aims

Cancer chemotherapy is commonly accompanied by mucositis, anorexia, weight loss, and anxiety independently from cancer-induced anorexia–cachexia, further aggravating clinical outcome. Ghrelin is a peptide hormone produced in gastric mucosa that reaches the brain to stimulate appetite. In plasma, ghrelin is protected from degradation by ghrelin-reactive immunoglobulins (Ig). To analyze possible involvement of ghrelin in the chemotherapy-induced anorexia and anxiety, gastric ghrelin expression, plasma levels of ghrelin, and ghrelin-reactive IgG were studied in rats treated with methotrexate (MTX).

Methods

Rats received MTX (2.5 mg/kg, subcutaneously) for three consecutive days and were killed 3 days later, at the peak of anorexia and weight loss. Control rats received phosphate-buffered saline. Preproghrelin mRNA expression in the stomach was analyzed by in situ hybridization. Plasma levels of ghrelin and ghrelin-reactive IgG were measured by immunoenzymatic assays and IgG affinity kinetics by surface plasmon resonance. Anxiety- and depression-like behaviors in MTX-treated anorectic and in control rats were evaluated in the elevated plus-maze and the forced-swim test, respectively.

Results

In MTX-treated anorectic rats, the number of preproghrelin mRNA-producing cells was found increased (by 51.3%, p < 0.001) as well were plasma concentrations of both ghrelin and des-acyl-ghrelin (by 70.4%, p < 0.05 and 98.3%, p < 0.01, respectively). In contrast, plasma levels of total IgG reactive with ghrelin and des-acyl-ghrelin were drastically decreased (by 87.2 and 88.4%, respectively, both p < 0.001), and affinity kinetics of these IgG were characterized by increased small and big Kd, respectively. MTX-treated rats displayed increased anxiety- but not depression-like behavior.

Conclusion

MTX-induced anorexia, weight loss, and anxiety are accompanied by increased ghrelin production and by a decrease of ghrelin-reactive IgG levels and affinity binding properties. Such changes of ghrelin-reactive IgG may underlie their decreased ghrelin-transporting capacities compromising ghrelin orexigenic and anxiolytic effects and contributing to chemotherapy-induced loss of appetite.

Altered systemic bioavailability and organ distribution of azathioprine in methotrexate-induced intestinal mucositis in rats

OBJECTIVE

Intestinal mucositis is a significant problem haunting clinicians for decades. One of the major reasons for its occurrence is high-dose chemotherapy. The study is aimed at investigating effect of intestinal mucositis on pharmacokinetics, organ distribution, and bioavailability of azathioprine (AZA) (6-mercaptopurine).

MATERIALS AND METHODS

Intestinal mucositis was induced with methotrexate (MTX) (2.5 mg/kg). The oral absorption of AZA and 6-mercaptopurine (metabolite) levels were determined in control and MTX-treated rats: ex vivo (noneverted sac technique) and in vivo (pharmacokinetics and organ-distribution) using high-performance liquid chromatography. Immunohistochemistry was conducted to evaluate peptide transporter expression on luminal membrane of small intestine.

RESULTS

Intestinal permeation of AZA into systemic circulation of rats was lower after MTX administration, widely found in intestinal segments of mucositis-induced rats leading to decline in systemic bioavailability of AZA. Immunohistochemistry findings indicated diminution of peptide transporter expression representing hampered absorption of drugs absorbed via this transporter.

CONCLUSION

Study outcome has thrown light on altered fate of AZA when administered to individuals with mucositis which suggests modified drug therapy. These findings can further be investigated in different drug classes which might be administered concomitantly in mucositis and study outcome can be further confirmed in mucositis patients in clinical practice also.

The challenges of managing coexistent disorders with phenylketonuria: 30 cases

INTRODUCTION

The few published case reports of co-existent disease with phenylketonuria (PKU) are mainly genetic and familial conditions from consanguineous marriages. The clinical and demographic features of 30 subjects with PKU and co-existent conditions were described in this multi-centre, retrospective cohort study.

METHODS

Diagnostic age of PKU and co-existent condition, treatment regimen, and impact of co-existent condition on blood phenylalanine (Phe) control and PKU management were reported.

RESULTS

30 patients (11 males and 19 females), with PKU and a co-existent condition, current median age of 14 years (range 0.4 to 40 years) from 13 treatment centres from Europe and Turkey were described. There were 21 co-existent conditions with PKU; 9 were autoimmune; 6 gastrointestinal, 3 chromosomal abnormalities, and 3 inherited conditions. There were only 5 cases of parental consanguinity. Some patients required conflicting diet therapy (n=5), nutritional support (n=7) and 5 children had feeding problems. There was delayed diagnosis of co-existent conditions (n=3); delayed treatment of PKU (n=1) and amenorrhea associated with Grave's disease that masked a PKU pregnancy for 12 weeks. Co-existent conditions adversely affected blood Phe control in 47% (n=14) of patients. Some co-existent conditions increased the complexity of disease management and increased management burden for patients and caregivers.

CONCLUSIONS

Occurrence of co-existent disease is not uncommon in patients with PKU and so investigation for co-existent disorders when the clinical history is not completely consistent with PKU is essential. Integrating care of a second condition with PKU management is challenging.

Bovine Colostrum Modulates Myeloablative Chemotherapy-Induced Gut Toxicity in Piglets

BACKGROUND

Intensive chemotherapy frequently results in gut toxicity, indicated by oral and intestinal mucositis, resulting in poor treatment outcomes and increased mortality. There are no effective preventive strategies against gut toxicity and the role of diet is unknown.

OBJECTIVE

We hypothesized that the severity of chemotherapy-induced gut toxicity in early life is diet-dependent, and that intake of bovine colostrum (BC) provides better gut protection than an artificial milk replacer (MR).

METHODS

A total of 37 3-d-old pigs received for 6 d either intravenous saline control or myeloablative treatment with busulfan and cyclophosphamide, and were fed either BC or MR, resulting in the following 4 treatments (n = 8-10/group): bovine colostrum plus saline control (Ctr-BC), milk replacer plus saline control (Ctr-MR), bovine colostrum plus busulfan and cyclophosphamide chemotherapy (BUCY-BC), and milk replacer plus busulfan and cyclophosphamide chemotherapy (BUCY-MR). The gut was collected for analysis 11 d after the start of chemotherapy.

RESULTS

Relative to the control groups, both busulfan and cyclophosphamide chemotherapy (BUCY) groups showed signs of gut toxicity, with oral ulcers, reduced intestinal dimensions, and hematologic toxicity. Diet type did not affect mucosal structure on day 11, but BUCY-BC pigs had less vomiting than BUCY-MR pigs (1 of 10 vs. 10 of 10, P < 0.05). Markers of intestinal function were higher (up to 20-fold greater galactose absorption and 2-3-fold greater brush border enzyme activity, all P < 0.05), and tissue inflammatory cytokine concentrations and serum liver enzyme values were lower in BUCY-BC than in BUCY-MR pigs (30-50% reductions in interleukin 6 and 8, aminotransferase, and bilirubin concentrations, P < 0.05). Gut colonization was not significantly affected except that BUCY pigs had lower microbial diversity with a higher abundance of Lactobacilli.

CONCLUSION

BC may reduce gut toxicity during myeloablative chemotherapy in piglets by preserving intestinal function and reducing inflammation. Whether similar effects occur in children remains to be tested.

Herbal substance, acteoside, alleviates intestinal mucositis in mice

This study investigated the role of acteoside in the amelioration of mucositis. C57BL/6 mice were gavaged daily with acteoside 600 μg for 5 d prior to induction of mucositis and throughout the experimental period. Mucositis was induced by methotrexate (MTX; 12.5 mg/kg; s.c.). Mice were culled on d 5 and d 11 after MTX. The duodenum, jejunum, and ileum were collected for myeloperoxidase (MPO) activity, metallothionein (MT) levels, and histology. Acteoside reduced histological severity scores by 75, 78, and 88% in the duodenum, jejunum, and ileum, respectively, compared to MTX-controls on d 5. Acteoside reduced crypt depth by 49, 51, and 33% and increased villus height by 19, 38, and 10% in the duodenum, jejunum, and ileum, respectively, compared to MTX-controls on d 5. Acteoside decreased MT by 50% compared to MTX-control mice on d 5. Acteoside decreased MPO by 60% and 30% in the duodenum and jejunum, respectively, compared to MTX-controls on d 5. Acteoside alleviated MTX-induced small intestinal mucositis possibly by preventing inflammation.

Olmesartan decreased levels of IL-1β and TNF-α, down-regulated MMP-2, MMP-9, COX-2, RANK/RANKL and up-regulated SOCs-1 in an intestinal mucositis model

Methotrexate (MTX) is a pro-oxidant compound that depletes dihydrofolate pools and is widely used in the treatment of leukaemia and other malignancies. The efficacy of methotrexate is often limited by mucositis and intestinal injury, which are major causes of morbidity in children and adults. The aim of this study was to evaluate the effect of olmesartan (OLM), an angiotensin II receptor antagonist, on an Intestinal Mucositis Model (IMM) induced by MTX in Wistar rats. IMM was induced via intraperitoneal (i.p.) administration of MTX (7 mg/kg) for three consecutive days. The animals were pre-treated with oral OLM at 0.5, 1 or 5 mg/kg or with vehicle 30 min prior to exposure to MTX. Small intestinal homogenates were assayed for levels of the IL-1β, IL-10 and TNF-α cytokines, malondialdehyde and myeloperoxidase activity. Additionally, immunohistochemical analyses of MMP-2, MMP-9, COX-2, RANK/RANKL and SOCS-1 and confocal microscopy analysis of SOCS-1 expression were performed. Treatment with MTX + OLM (5 mg/kg) resulted in a reduction of mucosal inflammatory infiltration, ulcerations, vasodilatation and haemorrhagic areas (p<0.05) as well as reduced concentrations of MPO (p<0.001) and the pro-inflammatory cytokines IL-1β (p<0.001) and TNF-a (p<0.01), and increase anti-inflammatory cytocine IL-10 (p<0.05). Additionally, the combined treatment reduced expression of MMP-2, MMP-9, COX-2, RANK and RANKL(p<0.05) and increased cytoplasmic expression of SOCS-1 (p<0.05). Our findings confirm the involvement of OLM in reducing the inflammatory response through increased immunosuppressive signalling in an IMM. We also suggest that the beneficial effect of olmesartan treatment is specifically exerted during the damage through blocking inflammatory cytocines.

Risk analysis, diagnosis and management of gastrointestinal mucositis in pediatric cancer patients

Mucositis is a complex inflammatory reaction of the mucous membranes of the alimentary tract upon chemotherapy and radiotherapy treatment in oncology patients. Mucositis can be subdivided in oral and gastrointestinal mucositis (GI mucositis). The damage to the gastrointestinal tract compromises the intestinal function and thereby the nutritional status and the quality of life, and eventually affects survival. The literature on GI mucositis focuses mainly on adults. This review focuses on data available on GI mucositis in pediatric cancer patients. An evaluation of the clinical presentation and consequences of GI mucositis in children is outlined. The review summarizes key issues for clinicians with respect to risk analysis for developing mucositis and the diagnosis of this condition in children. Information on these issues is obtained from clinical trials in children and adults, and from animal models. Diagnostic tools and assessment of severity of GI mucositis in children is elaborated on. Furthermore, the clinical management of the symptoms and consequences of GI mucositis in children, with specific focus on nutritional support, are discussed.

Substantial decreases in the number and diversity of microbiota during chemotherapy-induced gastrointestinal mucositis in a rat model

PURPOSE

Earlier, we showed in acute myeloid leukemia (AML) patients that the microbiota changes dramatically during anticancer treatment, coinciding with gastrointestinal mucositis: The commensal anaerobic populations reduce in favor of potential pathogens. Therefore, interventions targeting the microbiota during mucositis might be interesting but can better be tested in animals than in vulnerable mucositis patients. Here, we aimed to study the potential microbial changes during methotrexate (MTX)-induced gastrointestinal mucositis in a well-established rat model and to study whether this model can be used for future microbial intervention studies.

METHODS

After injection with MTX or saline (day 0), rats were sacrificed between days 2 and 11. Plasma citrulline level, jejunal histology, and the number and diversity of intestinal bacteria in feces (using fluorescence in situ hybridization (FISH)) were determined.

RESULTS

Mucositis was most severe on day 4 when food intake, plasma citrulline, and villus length were the lowest, compared with controls (P < 0.0125). At the same time, MTX-treated rats showed an overall decrease (705-fold) in most bacteria (using a universal probe), compared with controls (P < 0.125). Reduced bacterial presence was related with the presence of diarrhea and a reduced villus length (rho = 0.38, P < 0.05). At day 4, there was an absolute and relative decrease of anaerobes (13-fold and -58 %, respectively) and streptococci (296-fold and -1 %, respectively) but a relative increase of Bacteroides (+49 %), compared with controls (P < 0.125).

CONCLUSIONS

In the mucositis rat model, we found substantial decreases in the number and diversity of microbiota, resembling earlier findings in humans. The model therefore seems well suited to study the effects of different microbial interventions on mucositis, prior to performing human studies.

Enteral glutamine infusion modulates ubiquitination of heat shock proteins, Grp-75 and Apg-2, in the human duodenal mucosa

Glutamine, the most abundant amino acid in the human body, plays several important roles in the intestine. Previous studies showed that glutamine may affect protein expression by regulating ubiquitin-proteasome system. We thus aimed to evaluate the effects of glutamine on ubiquitinated proteins in human duodenal mucosa. Five healthy male volunteers were included and received during 5 h, on two occasions and in a random order, either an enteral infusion of maltodextrins alone (0.25 g kg(-1) h(-1), control), mimicking carbohydrate-fed state, or maltodextrins with glutamine (0.117 g kg(-1) h(-1), glutamine). Endoscopic duodenal biopsies were then taken. Total cellular protein extracts were separated by 2D gel electrophoresis and analyzed by an immunodetection using anti-ubiquitin antibody. Differentially ubiquitinated proteins were then identified by liquid chromatography-electrospray ionization MS/MS. Five proteins were differentially ubiquitinated between control and glutamine conditions. Among these proteins, we identified two chaperone proteins, Grp75 and hsp74. Grp75 was less ubiquitinated after glutamine infusion compared with control. In contrast, hsp74, also called Apg-2, was more ubiquitinated after glutamine. In conclusion, we provide evidence that glutamine may regulate ubiquitination processes of specific proteins, i.e., Grp75 and Apg-2. Grp75 has protective and anti-inflammatory properties, while Apg-2 indirectly regulates stress-induced cell survival and proliferation through interaction with ZO-1. Further studies should confirm these results in stress conditions.

Disruption of ZO-1/claudin-4 interaction in relation to inflammatory responses in methotrexate-induced intestinal mucositis

PURPOSE

Methotrexate (MTX)-induced intestinal mucositis limits the use of the drug. We previously reported that MTX-dependent production of reactive oxygen species is an initiating signal leading to neutrophil migration and intestinal barrier dysfunction. Moreover, alterations of zonula occludens (ZO)-1, an integral component of tight junctions (TJs), contribute to its dysfunction. This study aimed to clarify the identity of inflammatory mediators in the intestine of MTX-treated rats and to evaluate MTX-stimulated alterations in the expression of TJ proteins other than ZO-1 (e.g., occludin and claudins).

METHODS

Male Wistar rats were administrated MTX (15 mg kg(-1)) orally once daily for 4 days. Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, macrophage inflammatory protein (MIP)-2, cytokine-induced neutrophil chemoattractant-2, Toll-like receptor 4 (TLR4), and occludin were determined by real-time RT-PCR. Expression, distribution, and interactions of TJ proteins were evaluated by Western blotting, immunohistochemistry, and immunoprecipitation.

RESULTS

MTX increased the mRNA levels of TNF-α, IL-1β, MIP-2, and TLR4 in the small intestine, as well as the protein expression of claudin-2. Increased claudin-2 and decreased claudin-4 immunostaining were also observed. Occludin mRNA levels were significantly diminished by MTX administration, whereas occludin protein levels and the interaction between ZO-1 and occludin were unaltered; however, the interaction between ZO-1 and claudin-4 was significantly compromised.

CONCLUSIONS

These results indicate that elevated levels of inflammatory cytokines and chemokines in the small intestine of MTX-treated rats may contribute to the inhibition of ZO-1/claudin-4 binding, and that inhibition of ZO-1/claudin-4 binding may in turn lead to a reduction in claudin-4 expression.

Enteral delivery of proteins stimulates protein synthesis in human duodenal mucosa in the fed state through a mammalian target of rapamycin-independent pathway

BACKGROUND

Glutamine modulates duodenal protein metabolism in fasted healthy humans, but its effects in a fed state remain unknown.

OBJECTIVE

We aimed to assess the effects of either glutamine or an isonitrogenous protein mixture on duodenal protein metabolism in humans in the fed state.

DESIGN

Twenty-four healthy volunteers were randomly included in 2 groups. Each volunteer was studied on 2 occasions in a random order and received, during 5 h, either an enteral infusion of maltodextrins alone (0.25 g · kg⁻¹ · h⁻¹; both groups) that mimicked a carbohydrate fed state or maltodextrins with glutamine (group 1) or an isonitrogenous (22.4 mg N · kg⁻¹ · h⁻¹) protein powder (group 2). Simultaneously, a continuous intravenous infusion of ¹³C-leucine and ²H₅-phenylalanine (both 9 μmol · kg⁻¹ · h⁻¹) was performed. Endoscopic duodenal biopsies were taken. Leucine and phenylalanine enrichments were assessed by using gas chromatography-mass spectrometry in duodenal proteins and the intracellular free amino acids pool to calculate the mucosal fractional synthesis rate (FSR). Proteasome proteolytic activities and phosphokinase expression were assessed by using specific fluorogenic substrates and macroarrays, respectively.

RESULTS

The FSR and proteasome activity were not different after the glutamine supply compared with after maltodextrins alone. In contrast, the FSR increased (1.7-fold increase; P < 0.05) after protein-powder delivery without modification of total proteasome activity. The protein powder increased insulinemia, PI3 kinase, and erk phosphorylation but did not affect the mammalian target of rapamycin (mTOR) pathway and mitogen-activated protein kinase signal-integrating kinase 1 phosphorylation. A trend for an increase of eukaryotic translation initiation factor 4E phosphorylation was observed (P = 0.07).

CONCLUSION

In the carbohydrate fed state, enteral proteins but not glutamine increased duodenal protein synthesis through an mTOR independent pathway in humans.

Reduced absorption of long-chain fatty acids during methotrexate-induced gastrointestinal mucositis in the rat

BACKGROUND & AIMS

Patients with chemotherapy-induced gastrointestinal mucositis suffer from weight loss and possibly malabsorption. Since long-chain fatty acids serve important functions in the body, we aimed to determine the intestinal capacity of fat absorption in rats with and without methotrexate-induced mucositis.

METHODS

Four days after intravenous injection with methotrexate (60 mg/kg) or saline, rats received saturated ([U-(13)C]palmitic acid) and unsaturated ([U-(13)C]linoleic acid) fatty acids dissolved in oil, either as a single bolus by oral gavage or by continuous intraduodenal infusion. We determined plasma and liver label concentrations at specific time points.

RESULTS

We confirmed methotrexate-induced mucositis by villus atrophy using microscopy. Methotrexate treatment severely reduced the appearance of [U-(13)C]palmitic- and [U-(13)C]linoleic acid in plasma and liver, compared to controls, either when administered as a bolus or continuously (all at least -63%, P < 0.05). Liver [U-(13)C]palmitic acid appearance was higher than [U-(13)C]linoleic acid appearance, either when administered as a bolus (2.8-fold, P < 0.01) or continuously (5.7-fold, P < 0.01).

CONCLUSIONS

The intestinal capacity to absorb long-chain fatty acids is severely reduced in rats with methotrexate-induced mucositis. Continuous administration does not overcome this impairment. The liver takes up and/or retains mainly saturated fatty acids during mucositis.

Continuous enteral administration can overcome the limited capacity to absorb glucose in rats with methotrexate-induced gastrointestinal mucositis

BACKGROUND

Patients with chemotherapy-induced gastrointestinal mucositis often suffer from weight loss. It is not well known how to enterally feed mucositis patients, potentially experiencing malabsorption. Recently, we showed in a rat model of methotrexate (MTX)-induced mucositis that intestinal absorption of glucose in trace amounts is still intact. We now determined the quantitative capacity to absorb glucose in rats with mucositis, relative to controls.

METHODS

We administered a physiologically relevant amount of [1-(13)C]glucose-enriched glucose (meal size) as a bolus by oral gavage (2 g/kg once) or continuously by intraduodenal infusion (±1.9 g/(kg·h) for 5 h) to rats with MTX-induced mucositis and controls. Blood [1-(13)C]glucose concentrations were determined during the experimental period. To calculate the quantitative absorptive capacity, Steele's one-compartment model, including simultaneous intravenous infusion of [6,6-(2)H(2)]glucose, was used. After the experiment, jejunal histology and plasma citrulline concentrations were assessed.

RESULTS

MTX-induced mucositis was confirmed by a reduction in villus length and plasma citrulline (both -57%, relative to controls, P < 0.01). When glucose was administered as a bolus, MTX-treated rats only absorbed 15% of administered glucose, compared with 85% in controls (medians, P < 0.01). Upon continuous intraduodenal glucose infusion, the median absorptive capacity for glucose in MTX-treated rats did not differ from controls (80 versus 93% of administered glucose respectively, P = 0.06). However, glucose absorption differed substantially between individual MTX-treated rats (range, 21-95%), which correlated poorly with villus length (rho = 0.54, P = 0.030) and plasma citrulline (rho = 0.56, P = 0.024).

CONCLUSION

Continuous enteral administration can almost completely overcome the reduced absorptive capacity for glucose in rats with mucositis.

Diarrhea in neutropenic children with cancer: An Egyptian center experience, with emphasis on neutropenic enterocolitis

Background:

Diarrhea is a frequent complication in children with cancer who received intensive chemotheraputic regimens. It may be caused by several factors, neutropenic enterocolitis (NE) being the most serious.

Aim:

To study diarrhea in neutropenic cancer patients in the pediatric age group, with its underlying etiologies and risk factors, especially the bacterial causes, with special concern on NE.

Materials and Methods:

This study was carried out at the Pediatric Hematology and Oncology Units, Zagazig University Hospitals, Egypt, from January 2009 to September 2010. All children with malignant diseases who are ≤12 years of age were included. Patients who were neutropenic (<500/ mm³) on admission or who became neutropenic during their stay in the hospital were monitored regularly (daily) for diarrhea. Neutropenic cancer patients with diarrhea were grouped into two groups: Group 1, with NE, and group 2, with neutropenic diarrhea rather than NE. On the first day of diarrhea, patients were subjected to complete blood count, blood cultures, stool microscopy and culture. Abdominal ultrasonography was carried out within 3 days of diarrhea.

Results:

A total of 200 children ≤12 years old, suffering from different malignancies, with a total of 180 neutropenic episodes were followed. Diarrhea was observed in 100 episodes (55.5%). NE constituted 16% of these diarrheal episodes. All patients with NE had significantly more severe neutropenia, and this was of longer duration than the other group. All patients with NE were febrile, with 100% positive blood culture. Stool analysis diagnosed giardiasis in 4.8% of the non-NE patients and in none of the NE patients, while stool culture was positive in 75% of the NE patients compared with 40.5% of the other group.

Conclusions:

Diarrhea is a common complication in neutropenic cancer children. Gram negative bacteria and Candida are the most incriminated pathogens. Duration and severity of neutropenia carry a great risk for the development of NE.

Methotrexate modulates tight junctions through NF-κB, MEK, and JNK pathways

OBJECTIVES

Chemotherapy often induces intestinal mucositis, which is associated with an increase in intestinal permeability; however, underlying mechanisms remain incompletely understood. Thus, we aimed to study the regulation of 3 tight junction (TJ) proteins, claudin-1, occludin, and zonula occludens-1, after anticancer treatment.

METHODS

Methotrexate (MTX) was subcutaneously injected for 3 consecutive days in Sprague-Dawley rats to induce intestinal mucositis and was applied on Caco-2 cell monolayers. TJ protein expression and cellular distribution were studied by Western blot and microscopy, respectively. In Caco-2 cells, the paracellular permeability was evaluated by both transepithelial electrical resistance and flux of fluorescein isothiocyanate-dextran marker. Cytokine production and signaling pathways were also assessed.

RESULTS

In MTX-treated rats, the cellular distribution of the 3 TJ proteins was altered and claudin-1 and occludin expression was reduced during the acute phase of mucositis compared with controls. During the recovery phase, these parameters were restored. In vitro, MTX treatment led to an increase in proinflammatory cytokine production at the apical side but did not affect Caco-2 cell apoptosis and necrosis. Increase in paracellular permeability was associated with altered occludin and zonula occludens-1 expression and cellular distribution. All of these alterations were prevented by MEK1 and 2, JNK, and NF-κB inhibitors.

CONCLUSIONS

MTX treatment induced an increase in intestinal permeability partially related to alteration of TJs protein expression and cellular distribution that may be mediated by MAPK and NF-κB pathways. These are potential targets to limit the adverse effects of chemotherapy.

Accelerated growth rate induced by neonatal high-protein milk formula is not supported by increased tissue protein synthesis in low-birth-weight piglets

Low-birth-weight neonates are routinely fed a high-protein formula to promote catch-up growth and antibiotics are usually associated to prevent infection. Yet the effects of such practices on tissue protein metabolism are unknown. Baby pigs were fed from age 2 to 7 or 28 d with high protein formula with or without amoxicillin supplementation, in parallel with normal protein formula, to determine tissue protein metabolism modifications. Feeding high protein formula increased growth rate between 2 and 28 days of age when antibiotic was administered early in the first week of life. This could be explained by the occurrence of diarrhea when piglets were fed the high protein formula alone. Higher growth rate was associated with higher feed conversion and reduced protein synthesis rate in the small intestine, muscle and carcass, whereas proteolytic enzyme activities measured in these tissues were unchanged. In conclusion, accelerated growth rate caused by high protein formula and antibiotics was not supported by increased protein synthesis in muscle and carcass.

Effect of vitamin supplementation on cisplatin-induced intestinal epithelial cell apoptosis in Wistar/NIN rats

OBJECTIVE

Chemotherapeutic agents induce small intestinal mucositis that is characterized structurally by crypt loss and villus atrophy and functionally by absorptive and barrier impairments. We studied the effect of selected individual vitamins and multiple-vitamin mixture supplementation in modulating cisplatin-induced intestinal damage and apoptosis.

METHODS

Thirty-six male Wistar/NIN rats 20 wk old and fed the control diet (AIN-93G) were randomly divided into six groups. Five groups were administered cisplatin (2.61 mg/kg of body weight) once a week for 3 wk and were concomitantly provided the control diet or riboflavin, folate, α- tocopherol, or a multiple-vitamin mixture supplemented diet. The sixth group served as a control for cisplatin and received saline as the vehicle. Intestinal epithelial cell apoptosis was monitored by morphometry, M30 staining, DNA fragmentation, and caspase-3 activity. Functional and structural integrities were determined by measuring activities of alkaline phosphatase and lysine ala-dipeptidyl aminopeptidase and the villus height/crypt depth ratio. Oxidative burden was assessed as the formation of thiobarbituric acid-reactive substances and protein carbonyls. Plasma levels of selected vitamins were also measured.

RESULTS

Cisplatin administration significantly increased intestinal apoptosis in the villus and crypt regions that correlated with increased oxidative damage, decreased Bcl-2/Bax, and compromised functional integrity. Riboflavin, folate, and the multiple-vitamin mixture supplementation attenuated the cisplatin-induced increase in apoptotic indices, with a decrease in oxidative burden, increased Bcl-2/Bax, and improved functional and structural integrities. The α-tocopherol supplementation, although effective in attenuating oxidative stress and improving functional integrity, failed to lower the apoptotic indices.

CONCLUSIONS

Riboflavin, folate, and the multiple-vitamin supplementation proved to be more efficacious in attenuating the cisplatin-induced intestinal damage and associated changes in apoptosis.

Biomarkers of regimen-related mucosal injury

Regimen-related mucosal toxicity is extremely common following cytotoxic chemotherapy and radiotherapy. The alimentary mucosa is particularly susceptible to injury and dysfunction, leading to a constellation of adverse side effects. Currently there is no "one fit" biomarker of such injury. A number of biomarkers have been investigated in the context of gastrointestinal diseases, which may prove useful in the oncology arena. Two of significant potential include citrulline and calprotectin, however more work is required to define the most appropriate settings for their use. Identification of a biomarker that is easily obtained, measured, and accurately indicates mucosal damage, would allow for improved patient diagnosis of toxicities and prompt appropriate intervention. In this review, we highlight the effectiveness of currently examined biomarkers and discuss future avenues for research in this exciting area.

Capturing changes in gene expression dynamics by gene set differential coordination analysis

Analyzing gene expression data at the gene set level greatly improves feature extraction and data interpretation. Currently most efforts in gene set analysis are focused on differential expression analysis--finding gene sets whose genes show first-order relationship with the clinical outcome. However the regulation of the biological system is complex, and much of the change in gene expression dynamics do not manifest in the form of differential expression. At the gene set level, capturing the change in expression dynamics is difficult due to the complexity and heterogeneity of the gene sets. Here we report a systematic approach to detect gene sets that show differential coordination patterns with the rest of the transcriptome, as well as pairs of gene sets that are differentially coordinated with each other. We demonstrate that the method can identify biologically relevant gene sets, many of which do not show first-order relationship with the clinical outcome.

Influence of leucine on protein metabolism, phosphokinase expression, and cell proliferation in human duodenum1,3

BACKGROUND

Although leucine increases protein anabolism through the mammalian target of rapamycin (mTOR) pathway in human muscles, its effects on intestinal mucosal proteins remain unknown.

OBJECTIVE

We aimed to assess the effects of leucine on duodenal protein metabolism in healthy humans and to elucidate the signaling pathways involved.

DESIGN

Eleven healthy volunteers received for 5 h, on 2 occasions and in random order, an enteral supply of maltodextrins (0.25 g . kg(-1) . h(-1)) or maltodextrins and leucine (0.035 g . kg(-1) . h(-1)) simultaneously with a continuous intravenous infusion of [(2)H(5)]phenylalanine (9 μmol . kg(-1) .h(-1)). Endoscopic duodenal biopsy samples were collected and frozen until analyzed. Phenylalanine enrichment was assessed by gas chromatography-mass spectrometry in duodenal protein and in free intracellular amino acid pools used as precursor to calculate the mucosal fractional synthesis rate (FSR). Proteasome proteolytic activities and phosphokinase expression were assessed by using specific fluorogenic substrates or macroarrays, respectively.

RESULTS

Leucine supplementation slightly reduced FSR (mean ± SEM: 81.3 ± 6.3%/d) compared with maltodextrins alone (91.7 ± 8.5%/d; P = 0.0537). In addition, total proteasome activity decreased significantly with leucine (236 ± 21 compared with 400 ± 58 relative fluorescence units/μg protein; P < 0.05), with no modification of chymotrypsin-like, trypsin-like, caspase-like, or peptidase activities. Leucine did not affect the mTOR pathway but did increase the phosphorylation states of PI3K, Akt, AMPK, p38 MAPK, JNK, GSK-3α/β, STAT3, and STAT5 and increased cyclin D1 mRNA concentrations, which suggested that leucine may enhance cell proliferation.

CONCLUSION

Enteral leucine supplementation decreased proteasome activity in duodenal mucosa and enhanced cell proliferation through the PI3K/Akt/GSK-3α/β-catenin pathway. This trial was registered at clinicaltrials.gov as NCT01254110.

Methotrexate toxicity in growing long bones of young rats: a model for studying cancer chemotherapy-induced bone growth defects in children

The advancement and intensive use of chemotherapy in treating childhood cancers has led to a growing population of young cancer survivors who face increased bone health risks. However, the underlying mechanisms for chemotherapy-induced skeletal defects remain largely unclear. Methotrexate (MTX), the most commonly used antimetabolite in paediatric cancer treatment, is known to cause bone growth defects in children undergoing chemotherapy. Animal studies not only have confirmed the clinical observations but also have increased our understanding of the mechanisms underlying chemotherapy-induced skeletal damage. These models revealed that high-dose MTX can cause growth plate dysfunction, damage osteoprogenitor cells, suppress bone formation, and increase bone resorption and marrow adipogenesis, resulting in overall bone loss. While recent rat studies have shown that antidote folinic acid can reduce MTX damage in the growth plate and bone, future studies should investigate potential adjuvant treatments to reduce chemotherapy-induced skeletal toxicities.

Clostridium difficile infection in cancer patients and hematopoietic stem cell transplant recipients

Clostridium difficile has become the most common bacterial cause of nosocomial diarrhea. High rates of C. difficile infection (CDI) coupled with increasing morbidity and mortality attributed to CDI have sparked a renewed interest in this disease. Emergence of hypervirulent strains, rising rates of severe and recurrent infection and associated infection control challenges, and diagnostic and therapeutic dilemmas are major issues in the non-oncology population. Scant data on CDI exist in the cancer/transplant population. The purpose of this article is to describe the epidemiology, pathogenesis and management of CDI in patients receiving cancer chemotherapeutic agents, and in hematopoietic stem cell transplant recipients.

Interleukin-10 and -12 predict chemotherapy-associated toxicity in esophageal adenocarcinoma

INTRODUCTION

Chemotherapy-associated mucositis often prevents completion of an entire chemotherapy cycle. The underlying pathophysiology of chemotherapy-associated mucositis has not been well established. The individual immunologic predisposition of patients seems to play an important role.

METHODS

One hundred fifty-six patients with locally advanced or metastatic esophageal adenocarcinoma received neoadjuvant chemotherapy with cisplatin, 5-fluorouracil, and leucovorin followed by resection. Before the neoadjuvant therapy, monocytes were isolated from blood samples and were stimulated with lipopolysaccharide and interferon. An enzyme-linked immunosorbent assay was used to measure interleukin (IL)-10 and -12 levels and correlated with patients' clinical course.

RESULTS

Twenty-two patients (14,1%) developed grade III to IV mucositis (according to the NCI-Common toxicity criteria scales) within the neoadjuvant chemotherapy. Pretherapeutic low IL-10 (<24.1 pg/ml) and high IL-12 (>5500 pg/ml) levels were significantly associated with mucositis causing a therapy interruption or even cessation. Patients with high IL-10 (>43.6 pg/ml) and low IL-12 (<4408.5 pg/ml) levels had an uneventful neoadjuvant chemotherapy.

CONCLUSIONS

Pretherapeutic individual monocyte function is correlated with the development and the grade of chemotherapy induced mucositis. This knowledge might help us in predicting the grade of mucositis and in understanding the genesis regarding the association to pro- and anti-inflammatory effects of monocyte cytokines.

Beneficial effects of cathepsin inhibition to prevent chemotherapy-induced intestinal mucositis

One of the main secondary toxic side effects of anti-mitotic agents used to treat cancer patients is intestinal mucositis. Previous data showed that cathepsin D activity, contributing to the proteolytic lysosomal pathway, is up-regulated during intestinal mucositis in rats. At the same time, cathepsin inhibition limits intestinal damage in animal models of inflammatory bowel diseases. The aim of this study was to evaluate the effects of cathepsin inhibition on methotrexate-induced mucositis in rats. Male Sprague-Dawley rats received saline solution subcutaneously as the control group or 2·5 mg/kg of methotrexate for 3 days (D0-D2). From D0 to D3 methotrexate-treated rats also received intraperitoneal injections of pepstatin A, a specific inhibitor of cathepsin D or E64, an inhibitor of cathepsins B, H and L, or vehicle. Rats were euthanized at D4 and jejunal samples were collected. Body weight and food intake were partially preserved in rats receiving E64 compared with rats receiving vehicle or pepstatin A. Cathepsin D activity, used as a marker of lysosomal pathway, was reduced both in E64 and pepstatin-treated rats. However, villus atrophy and intestinal damage observed in methotrexate-treated rats were restored in rats receiving E64 but not in rats receiving pepstatin A. The intramucosal concentration of proinflammatory cytokines, interleukin-1β and cytokine-induced neutrophil chemoattractant (CINC)-2, was markedly increased in methotrexate-treated rats receiving vehicle or pepstatin A but not after E64 treatment. In conclusion, a large broad inhibition of cathepsins could represent a new potential target to limit the severity of chemotherapy-induced mucositis as opposed to the inhibition of cathepsin D alone.

A diet containing whey protein, glutamine, and TGFbeta modulates gut protein metabolism during chemotherapy-induced mucositis in rats

BACKGROUND

Mucositis, a common side effect of chemotherapy, is characterized by compromised digestive function, barrier integrity and immune competence.

AIMS

Our aim was to evaluate the impact of a specifically designed diet Clinutren Protect (CP), which contains whey proteins, TGFbeta-rich casein, and free glutamine, on mucositis in rats.

METHODS

Mucositis was induced by three consecutive injections (day 0, day 1, day 2) of methotrexate (2.5 mg/kg). Rats had free access to CP or placebo diets from days -7 to 9. In the placebo diet, whey proteins and TGFbeta-rich casein were replaced by TGFbeta-free casein and glutamine by alanine. Intestinal parameters were assessed at day 3 and 9. Values, expressed as mean +/- SEM, were compared using two-way ANOVA.

RESULTS

At day 3, villus height was markedly decreased in the placebo (296 +/- 11 microm) and CP groups (360 +/- 10 microm) compared with controls (464 +/- 27 microm), but more markedly in the placebo as compared to CP group. The intestinal damage score was also reduced in the CP compared with the placebo group. Glutathione content increased in the CP compared with the placebo group (2.2 +/- 0.2 vs. 1.7 +/- 0.2 micromol/g tissue). Gut protein metabolism was more affected in the placebo than in the CP group. The fractional synthesis rate was decreased in the placebo group (93.8 +/- 4.9%/day) compared with controls (121.5 +/- 12.1, P < 0.05), but not in the CP group (106.0 +/- 13.1). In addition, at day 9, rats exhibited improved body weight and food intake recovery in the CP compared to the placebo group.

CONCLUSIONS

Clinutren Protect feeding reduces intestinal injury in the acute phase of methotrexate-induced mucositis in rats and improves recovery.

Increased proteasome-mediated degradation of occludin in irritable bowel syndrome

OBJECTIVES

Proteasome-mediated protein degradation may contribute to the regulation of intestinal inflammation. At the same time, low-grade inflammation and increased intestinal permeability seem to be involved in the pathophysiology of irritable bowel syndrome (IBS). Thus, we aimed to evaluate proteasome composition and activities in colonic mucosa of IBS patients and its putative pathogenic role.

METHODS

Proteasome activities and proteasome subunit expression were measured in colonic mucosa of IBS, Crohn's disease (CD), and control patients by fluorometric assays and western blot, respectively. Expression of inhibitor of kappa B factor (IkappaB alpha) and occludin, a tight junction protein, was also evaluated in colonic biopsies. The degradation of recombinant occludin incubated with protein extracts from colonic mucosa was evaluated in the presence or absence of proteasome inhibitor, MG132.

RESULTS

Proteasome trypsin-like activity was increased in IBS patients compared with CD and controls, whereas chymotrypsin-like activity was upregulated in CD patients only. Caspase-like activity was reduced both in IBS and CD patients. IkappaB alpha expression was similar between IBS and controls. In contrast, occludin expression was lower in IBS than in controls, but occludin mRNA level was similar. Protein extracts from IBS patients but not from controls degraded recombinant occludin (20% over 160 min), which was blocked by MG132. Although mast cell number was increased in IBS patients, no correlation was found between this number and proteasome alterations.

CONCLUSIONS

Our study shows that proteasome alterations are present in the colonic mucosa of IBS patients and may contribute to the pathophysiology of IBS by increasing occludin degradation.