Blood transcriptomic markers of necrotizing enterocolitis in preterm pigs.

BACKGROUND: Necrotizing enterocolitis (NEC), a severe gut disorder in preterm infants, is difficult to predict due to poor specificity and sensitivity of clinical signs and biomarkers. Using preterm piglets as a model, we hypothesized that early development of NEC affects blood gene expression, potentially related to early systemic immune responses. METHODS: A retrospective analysis of clinical, tissue, and blood data was performed on 129 formula-fed piglets with NEC diagnosis at necropsy on day 5. Subgroups of NEC (n = 20) and control piglets (CON, n = 19) were analyzed for whole-blood transcriptome. RESULTS: Preterm piglets had variable NEC lesions, especially in the colon region, without severe clinical signs (e.g. normal growth, activity, hematology, digestion, few piglets with bloody stools). Transcriptome analysis showed 344 differentially expressed genes (DEGs) between NEC and CON piglets. Validation experiment showed that AOAH, ARG2, FKBP5, PAK2, and STAT3 were among the genes affected by severe lesions on day 5, when analyzed in whole blood and in dried blood spots (DBS). CONCLUSION: Whole-blood gene expressions may be affected in preterm pigs before clinical signs of NEC get severe. Blood gene expression analysis, potentially using DBS samples, is a novel tool to help identify new early biomarkers of NEC. IMPACT: Preterm pig model was used to investigate if blood transcriptomics could be used to identify new early blood biomarkers of NEC progression. Whole-blood transcriptome revealed upregulation of target genes in NEC cases when clinical symptoms are subtle, and mainly colon regions were affected. Differential NEC-associated gene expressions could be detected also in dried blood spots, potentially allowing easy collection of small blood volumes in infants.

Milk diets influence doxorubicin-induced intestinal toxicity in piglets.

Chemotherapy-induced gastrointestinal (GI) toxicity is a common adverse effect of cancer treatment. We used preweaned piglets as models to test our hypothesis that the immunomodulatory and GI trophic effects of bovine colostrum would reduce the severity of GI complications associated with doxorubicin (DOX) treatment. Five-day-old pigs were administered DOX (1 × 100 mg/m(2)) or an equivalent volume of saline (SAL) and either fed formula (DOX-Form, n = 9, or SAL-Form, n = 7) or bovine colostrum (DOX-Colos, n = 9, or SAL-Colos, n = 7). Pigs were euthanized 5 days after initiation of chemotherapy to assess markers of small intestinal function and inflammation. All DOX-treated animals developed diarrhea, growth deficits, and leukopenia. However, the intestines of DOX-Colos pigs had lower intestinal permeability, longer intestinal villi with higher activities of brush border enzymes, and lower tissue IL-8 levels compared with DOX-Form (all P < 0.05). DOX-Form pigs, but not DOX-Colos pigs, had significantly higher plasma C-reactive protein, compared with SAL-Form. Plasma citrulline was not affected by DOX treatment or diet. Thus a single dose of DOX induces intestinal toxicity in preweaned pigs and may lead to a systemic inflammatory response. The toxicity is affected by type of enteral nutrition with more pronounced GI toxicity when formula is fed compared with bovine colostrum. The results indicate that bovine colostrum may be a beneficial supplementary diet for children subjected to chemotherapy and subsequent intestinal toxicity.

Doxorubicin-Induced Gut Toxicity in Piglets Fed Bovine Milk and Colostrum.

OBJECTIVE: Chemotherapy-induced intestinal toxicity is a common adverse effect of cancer treatment. We hypothesized that a milk diet containing bovine colostrum (BC) would reduce intestinal toxicity in doxorubicin-treated piglets. METHODS: "Study 1" investigated intestinal parameters 9 days after a single dose of doxorubicin (1 × 75 mg/m) in piglets fed bovine milk enriched with whey protein (BM). In "study 2," responses to doxorubicin treatment were investigated in piglets receiving either 7 BC feedings per day (Only-BC, n = 13), 4 BC feedings (High-BC, n = 13), 2 BC feedings (Low-BC, n = 14), or no BC (only BM, n = 13). RESULTS: Doxorubicin treatment induced clinical signs of intestinal toxicity with diarrhea and weight loss, relative to controls (P < 0.05). White blood cells, hexose absorptive function, plasma citrulline, weights of intestine, colon, and spleen were reduced, whereas gut permeability and plasma C-reactive protein levels were increased (all P < 0.05). Limited or no effects were observed for digestive enzymes, proinflammatory cytokines, or tight-junction proteins in the intestine. Increasing BC supplementation to doxorubicin-treated piglets (study 2) had no consistent effects on plasma C-reactive protein and citrulline levels, intestinal morphology, digestive enzymes, permeability, or proinflammatory cytokines. Only-BC pigs, however, had lower diarrhea severity toward the end of the experiment (P < 0.05 vs BM) and across the BC groups, intestinal toxicity was reduced (P < 0.01). CONCLUSIONS: Doxorubicin-treated piglets are relevant for studying chemotherapy-induced gut toxicity. Colostrum supplementation had limited effects on doxorubicin-induced toxicity in milk-fed piglets suggesting that colostrum and a bovine milk diet enriched with whey protein provided similar protection of the developing intestine from chemotherapy-induced toxicity.

Chemotherapy Modulates Intestinal Immune Gene Expression Including Surfactant Protein-D and Deleted in Malignant Brain Tumors 1 in Piglets.

BACKGROUND: Information about chemotherapy-induced intestinal gene expression may provide insight into the mechanisms underlying gut toxicity and help identify biomarkers and targets for intervention. METHODS: We analyzed jejunal tissue from piglets subjected to two different, clinically relevant chemotherapy regimens: (1) busulfan plus cyclophosphamide (BUCY) and (2) doxorubicin (DOX). RESULTS: Gene expression analysis identified 1,328 differentially expressed genes in the BUCY piglets and 594 in the DOX piglets, compared to controls. Similar changes in expression were found for 137 genes across the BUCY and DOX piglets. Selected genes of potential biological significance with a similar change in expression across the treatments were controlled by real-time polymerase chain reaction. Key innate defense molecules, including surfactant protein-D and deleted in malignant brain tumors 1, were among the upregulated genes for both treatments. CONCLUSION: In the developing intestine, chemotherapy increases the expression of genes related to innate immune functions involved in surveillance, protection, and homeostasis of mucosal surfaces.

Early gradual feeding with bovine colostrum improves gut function and NEC resistance relative to infant formula in preterm pigs.

It is unclear when and how to start enteral feeding for preterm infants when mother's milk is not available. We hypothesized that early and slow advancement with either formula or bovine colostrum stimulates gut maturation and prevents necrotizing enterocolitis (NEC) in preterm pigs, used as models for preterm infants. Pigs were given either total parenteral nutrition (TPN, n = 14) or slowly advancing volumes (16-64 ml·kg(-1)·day(-1)) of preterm infant formula (IF, n = 15) or bovine colostrum (BC, n = 13), both given as adjunct to parenteral nutrition. On day 5, both enteral diets increased intestinal mass (27 ± 1 vs. 22 ± 1 g/kg) and glucagon-like peptide 2 release, relative to TPN (P < 0.05). The incidence of mild NEC lesions was higher in IF than BC and TPN pigs (60 vs. 0 and 15%, respectively, P < 0.05). Only the IF pigs showed reduced gastric emptying and gastric inhibitory polypeptide release, and increased tissue proinflammatory cytokine levels (IL-1ß and IL-8, P < 0.05) and expression of immune-related genes (AOAH, LBP, CXCL10, TLR2), relative to TPN. The IF pigs also showed reduced intestinal villus-to-crypt ratio, lactose digestion, and some plasma amino acids (Arg, Cit, Gln, Tyr, Val), and higher intestinal permeability, compared with BC pigs (all P < 0.05). Colonic microbiota analyses showed limited differences among groups. Early feeding with formula induces intestinal dysfunction whereas bovine colostrum supports gut maturation when mother's milk is absent during the first week after preterm birth. A diet-dependent feeding guideline may be required for newborn preterm infants.

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.

Trophic factors in the treatment and prevention of alimentary tract mucositis.

PURPOSE OF REVIEW: Mucositis is a common adverse effect of cytotoxic anticancer treatment with serious implications for the quality of life, morbidity and mortality of cancers patients. Although, evidence supporting the use of certain treatments exists there is no gold standard for preventing or treating mucositis. Current management strategies are scarce with recommendations referring primarily to specific cytotoxic treatment regimens in certain clinical scenarios. RECENT FINDINGS: Trophic factors may contribute to preserve epithelial integrity, function, and accelerate regeneration after chemotherapeutic treatment. Accordingly, various growth factors have been evaluated in the prevention or treatment of alimentary tract mucositis. However, in spite of often showing promising results in preclinical testing currently perlifermin is the only trophic factor recommended for the prevention of mucositis. SUMMARY: More knowledge from representative preclinical models, and testing growth factor interventions across different models, may be the key to advance the field from basic science to clinical application of new growth factors. For promising new therapies, subsequent establishment of adequately powered clinical trials and uniform reporting of mucositis, are important elements to help establish new standard interventions that can be included into the continuously updated clinical recommendations for treatment of mucositis.

A Stepwise, Pilot Study of Bovine Colostrum to Supplement the First Enteral Feeding in Preterm Infants (Precolos): Study Protocol and Initial Results.

STUDY PROTOCOL: The optimal feeding for preterm infants during the first weeks is still debated, especially when mother's own milk is lacking or limited. Intact bovine colostrum (BC) contains high amounts of protein, growth factors, and immuno-regulatory components that may benefit protein intake and gut maturation. We designed a pilot study to investigate the feasibility and tolerability of BC as the first nutrition for preterm infants. The study was designed into three phases (A, B, and C) and recruited infants with birth weights of 1,000-1,800 g (China) or gestational ages (GAs) of 27 + 0 to 32 + 6 weeks (Denmark). In phase A, three infants were recruited consecutively to receive BC as a supplement to standard feeding. In phase B, seven infants were recruited in parallel. In phase C (not yet complete), 40 infants will be randomized to BC or standard feeding. Feeding intolerance, growth, time to full enteral feeding, serious infections/NEC, plasma amino acid profile, blood biochemistry, and intestinal functions are assessed. This paper presents the study protocol and results from phases A and B. RESULTS: Seven Danish and five Chinese infants received 22 ± 11 and 22 ± 6 ml·kg-1·day-1 BC for a mean of 7 ± 3 and 7 ± 1 days which provided 1.81 ± 0.89 and 1.83 ± 0.52 g·kg-1·day-1 protein, respectively. Growth rates until 37 weeks or discharge were in the normal range (11.8 ± 0.9 and 12.9 ± 2.7 g·kg-1·day-1 in Denmark and China, respectively). No clinical adverse effects were observed. Five infants showed a transient hypertyrosinemia on day 7 of life. DISCUSSION AND CONCLUSION: The three-phased study design was used to proceed with caution as this is the first trial to investigate intact BC as the first feed for preterm infants. BC supplementation appeared well tolerated and resulted in high enteral protein intake. Based on the safety evaluation of phases A and B, the randomized phase C has been initiated. When complete, the Precolos trial will document whether it is feasible to use BC as a novel, bioactive milk diet for preterm infants. Our trial paves the way for a larger randomized controlled trial on using BC as the first feed for preterm infants with insufficient access to mother's own milk.

Introducing enteral feeding induces intestinal subclinical inflammation and respective chromatin changes in preterm pigs.

AIM: To analyze how enteral food introduction affects intestinal gene regulation and chromatin structure in preterm pigs. MATERIALS & METHODS: Preterm pigs were fed parenteral nutrition plus/minus slowly increasing volumes of enteral nutrition. Intestinal gene-expression and chromatin structure were analyzed 5 days after birth. RESULTS: Enteral feeding led to differential upregulation of inflammatory and pattern recognition receptor genes, including IL8 (median: 5.8, 95% CI: 3.9-7.8 for formula; median: 2.2, 95% CI: 1.3-3.3 for colostrum) and TLR4 (median: 3.7, 95% CI: 2.6-4.8 for formula; no significant differences for colostrum) with corresponding decondensed chromatin configurations. On histology this correlated with mild mucosal lesions, particularly in formula-fed pigs. In CaCo-2 cells, histone hyperacetylation led to a marked increase in TLR4 mRNA and increased IL8 expression upon stimulation with lipopolysaccharide (median: 7.0; interquartile range: 5.63-8.85) compared with naive cells (median 4.2; interquartile range: 2.45-6.33; p = 0.03). CONCLUSION: Enteral feeding, particular with formula, induces subclinical inflammation in the premature intestine and more open chromatin structure in key inflammatory genes. This may increase the susceptibility for necrotizing enterocolitis.

Intestinal response to myeloablative chemotherapy in piglets.

Chemotherapy-induced myeloablation prior to allogeneic hematopoietic stem cell transplantation (HSCT) may be associated with severe toxicity. The current understanding of the pathophysiology of oral and gastrointestinal (GI) toxicity is largely derived from studies in rodents and very little is known from humans, especially children. We hypothesized that milk-fed piglets can be used as a clinically relevant model of GI-toxicity related to a standard conditioning chemotherapy (intravenous busulfan, Bu plus cyclophosphamide, Cy) used prior to HSCT. In study 1, dose-response relationships were investigated in three-day-old pigs (Landrace × Yorkshire × Duroc, n = 6). Pigs were given one of three different dose combinations of Bu and Cy (A: 4 days Bu, 2 × 1.6 mg/kg plus 2 days Cy, 60 mg/kg; B: 4 days Bu, 2 × 0.8 mg/kg plus 2 days Cy, 30 mg/kg; C: 2 days Bu at 2 × 1.6 mg/kg plus 1 day Cy, 60 mg/kg) and bone marrow was collected on day 11. Histology of bone marrow samples showed total aplasia after treatment A. Using this treatment in study 2, Bu-Cy pigs showed lowered spleen and intestinal weights and variable clinical signs of dehydration, sepsis, and pneumonia at tissue collection. Oral mucositis was evident as ulcers in the soft palate in 4/9 Bu-Cy pigs and villus height and brush-border enzyme activities were reduced, especially in the proximal intestine. There were no consistent effects on tissue cytokine levels (IL-8, IL-6, IL-1ß, TNF-α) or blood chemistry values (electrolytes, liver transaminases, bilirubin, alkaline phosphatase), except that blood iron levels were higher in Bu-Cy pigs. We conclude that a myeloablative Bu-Cy regimen to piglets results in clinical signs comparable to those seen in pediatric patients subjected to myeloablative treatment prior to HSCT. Piglets may be used as a model for investigating chemotherapy-induced toxicity and dietary and medical interventions.