The importance of pro-inflammatory signaling in neonatal necrotizing enterocolitis

NLRP1 restricts porcine deltacoronavirus infection via IL-11 inhibiting the phosphorylation of the ERK signaling pathway

Continuously emerging highly pathogenic coronaviruses remain a major threat to human and animal health. Porcine deltacoronavirus (PDCoV) is a newly emerging enterotropic swine coronavirus that causes large-scale outbreaks of severe diarrhea disease in piglets. Unlike other porcine coronaviruses, PDCoV has a wide range of species tissue tropism, including primary human cells, which poses a significant risk of cross-species transmission. Nucleotide-binding oligomerization domain-like receptor (NLR) family pyrin domain-containing 1 (NLRP1) has a key role in linking host innate immunity to microbes and the regulation of inflammatory pathways. We now report a role for NLRP1 in the control of PDCoV infection. Overexpression of NLRP1 remarkably suppressed PDCoV infection, whereas knockout of NLRP1 led to a significant increase in PDCoV replication. A mechanistic study revealed that NLRP1 suppressed PDCoV replication in cells by upregulating IL-11 expression, which in turn inhibited the phosphorylation of the ERK signaling pathway. Furthermore, the ERK phosphorylation inhibitor U0126 effectively hindered PDCoV replication in pigs. Together, our results demonstrated that NLRP1 exerted an anti-PDCoV effect by IL-11-mediated inhibition of the phosphorylation of the ERK signaling pathway, providing a novel antiviral signal axis of NLRP1-IL-11-ERK. This study expands our understanding of the regulatory network of NLRP1 in the host defense against virus infection and provides a new insight into the treatment of coronaviruses and the development of corresponding drugs.IMPORTANCECoronavirus, which mainly infects gastrointestinal and respiratory epithelial cells in vivo, poses a huge threat to both humans and animals. Although porcine deltacoronavirus (PDCoV) is known to primarily cause fatal diarrhea in piglets, reports detected in plasma samples from Haitian children emphasize the potential risk of animal-to-human spillover. Finding effective therapeutics against coronaviruses is crucial for controlling viral infection. Nucleotide-binding oligomerization-like receptor (NLR) family pyrin domain-containing 1 (NLRP1), a key regulatory factor in the innate immune system, is highly expressed in epithelial cells and associated with the pathogenesis of viruses. We demonstrate here that NLRP1 inhibits the infection of the intestinal coronavirus PDCoV through IL-11-mediated phosphorylation inhibition of the ERK signaling pathway. Furthermore, the ERK phosphorylation inhibitor can control the infection of PDCoV in pigs. Our study emphasizes the importance of NLRP1 as an immune regulatory factor and may open up new avenues for the treatment of coronavirus infection.

Despite Recovery from Necrotizing Enterocolitis Infants Retain a Hyperinflammatory Response to Injury

Background

Necrotizing enterocolitis (NEC) is the leading gastrointestinal cause of death of premature neonates. NEC is associated with prematurity, a hyperinflammatory response, and dysregulation of intestinal barrier function. We hypothesize that patients with NEC will have, and continue to have after recovery, an increased hyperinflammatory intestinal response compared to those patients without NEC.

Methods

Neonates with NEC, those that have recovered from NEC, and those without NEC undergoing intestinal resections had specimens collected and snap frozen or generated into enteroids. The enteroids were treated with 100ug/mL lipopolysaccharide (LPS) and subjected to 24 hr of hypoxia together, then compared with untreated controls. Expression of Tumor Necrosis Factor (TNF-α) and interleukin 8 (IL-8) were evaluated via RT-qPCR and ELISA to measure inflammatory response. ANOVA determined statistical significance (p<0.05).

Results

There was no difference in inflammatory markers in recovered NEC tissue compared to non-NEC tissue on RTqPCR (p=0.701 TNF-α and 0.861 IL-8). However, recovered NEC enteroids demonstrate elevated levels of inflammatory markers after treatment compared to non-NEC enteroids after treatment on RTqPCR (p=0.0485 TNF-α, p=0.0057 IL-8) and ELISA (p=0.0354 TNF-α, p=0.0011 IL-8). Recovered NEC enteroids that underwent treatment demonstrated increased inflammatory markers compared to recovered NEC enteroids without treatment on RTqPCR (p=0.0045 TNF-α, p=0.0002 IL-8) and ELISA (p=0.034 TNF-α, p=0.0002 IL-8) suggesting a heightened inflammatory response to a second hit.

Conclusion

Intestinal tissue resected from neonates with NEC has an elevated hyperinflammatory response compared to neonates recovered from NEC and neonates without NEC. Enteroids generated from patients that have recovered from NEC have a heightened inflammatory response in response to NEC inducing stimuli compared to controls. This tendency towards an increased hyperinflammatory state may be correlated with an infant's proclivity to develop NEC and demonstrates the significance of a second hit on this tissue creating a heightened inflammatory response. This could be correlated with the impact and trajectory of an illness post recovery from NEC.

Persistent Proclivity to a Proinflammatory State in a Human Enteroid Model of Necrotizing Enterocolitis

Background: Necrotizing enterocolitis (NEC) is a devastating disease of premature neonates with substantial morbidity and mortality. Necrotizing enterocolitis is associated with prematurity, a hyperinflammatory response, and dysregulation of intestinal barrier function. We hypothesize that patients with NEC will have an increased hyperinflammatory intestinal response compared with those without NEC. Patients and Methods: Enteroids were generated from intestinal tissue from neonates undergoing resection. They were treated with 100 mcg/mL lipopolysaccharide (LPS), subjected to 24 hours of hypoxia inducing experimental NEC, then compared with untreated controls. Expression of tumor necrosis factor (TNF-α) and interleukin 8 (IL-8) were evaluated via reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) to measure inflammatory response. Analysis of variance (ANOVA) determined statistical significance (p < 0.05). Results: Treated NEC-derived enteroids expressed significantly higher levels of IL-8 (RT-qPCR, p = 0.003; ELISA, p = 0.0002) compared with untreated NEC-derived enteroids with an increase in inflammatory marker concentration in those with a greater degree of prematurity (ELISA, p = 0.0015). A higher level of IL-8 was seen in NEC-derived enteroids compared with control after treatment (RT-qPCR, p = 0.024). Tumor necrosis factor-α levels were elevated in treated NEC-derived enteroids compared with untreated NEC-derived enteroids (RT-qPCR, p = 0.006; ELISA, p = 0.002) and compared with treated non-NEC-derived enteroids (RT-qPCR, p = 0.025; ELISA, p < 0.0001). Conclusions: Enteroids generated from neonates with NEC have an elevated hyperinflammatory response in response to NEC-inducing stimuli compared with controls. Enteroids generated from neonates with NEC with a greater degree of prematurity have a larger increase in inflammatory markers. This tendency toward a hyperinflammatory state may be correlated with an infant's proclivity to develop NEC and further demonstrates the hyperinflammatory state of prematurity.

Therapeutic Potential of Gut Microbiota and Its Metabolite Short-Chain Fatty Acids in Neonatal Necrotizing Enterocolitis

Short chain fatty acids (SCFAs), the principle end-products produced by the anaerobic gut microbial fermentation of complex carbohydrates (CHO) in the colon perform beneficial roles in metabolic health. Butyrate, acetate and propionate are the main SCFA metabolites, which maintain gut homeostasis and host immune responses, enhance gut barrier integrity and reduce gut inflammation via a range of epigenetic modifications in DNA/histone methylation underlying these effects. The infant gut microbiota composition is characterized by higher abundances of SCFA-producing bacteria. A large number of in vitro/vivo studies have demonstrated the therapeutic implications of SCFA-producing bacteria in infant inflammatory diseases, such as obesity and asthma, but the application of gut microbiota and its metabolite SCFAs to necrotizing enterocolitis (NEC), an acute inflammatory necrosis of the distal small intestine/colon affecting premature newborns, is scarce. Indeed, the beneficial health effects attributed to SCFAs and SCFA-producing bacteria in neonatal NEC are still to be understood. Thus, this literature review aims to summarize the available evidence on the therapeutic potential of gut microbiota and its metabolite SCFAs in neonatal NEC using the PubMed/MEDLINE database.

Neonatal intermittent hypoxia, fish oil, and/or antioxidant supplementation on gut microbiota in neonatal rats

BACKGROUND

Preterm infants frequently experience intermittent hypoxia (IH) episodes, rendering them susceptible to oxidative stress and gut dysbiosis. We tested the hypothesis that early supplementation with antioxidants and/or fish oil promotes gut biodiversity and mitigates IH-induced gut injury.

METHODS

Newborn rats were exposed to neonatal IH from birth (P0) to P14 during which they received daily oral supplementation with: (1) coenzyme Q10 (CoQ10) in olive oil, (2) fish oil, (3) glutathione nanoparticles (nGSH), (4) CoQ10 + fish oil, or (5) olive oil (placebo control). Pups were placed in room air (RA) from P14 to P21 with no further treatment. RA controls were similarly treated. Stool samples were assessed for microbiota and terminal ileum for histopathology and morphometry, total antioxidant capacity, lipid peroxidation, and biomarkers of gut injury.

RESULTS

Neonatal IH induced histopathologic changes consistent with necrotizing enterocolitis, which were associated with increased lipid peroxidation, toll-like receptor, transforming growth factor, and nuclear factor kappa B. Combination of CoQ10 + fish oil and nGSH were most effective for preserving gut integrity, reducing biomarkers of gut injury, and increasing commensal organisms.

CONCLUSIONS

Combination of antioxidants and fish oil may confer synergistic benefits to mitigate IH-induced injury in the terminal ileum.

IMPACT

Antioxidant and fish oil (PUFA) co-treatment was most beneficial for reducing neonatal IH-induced gut injury. The synergistic effects of antioxidant and fish oil is likely due to prevention of IH-induced ROS attack on lipids, thus preserving and augmenting its therapeutic benefits. Combination treatment was also effective for increasing the abundance of the non-pathogenic Firmicutes phylum, which is associated with a healthy gastrointestinal system of the newborn. Extremely low gestational age neonates who are at high risk for frequent, repetitive neonatal IH and oxidative stress-induced diseases may benefit from this combination therapy.

The benefits, limitations and opportunities of preclinical models for neonatal drug development

Increased research to improve preclinical models to inform the development of therapeutics for neonatal diseases is an area of great need. This article reviews five common neonatal diseases – bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, perinatal hypoxic–ischemic encephalopathy and neonatal sepsis – and the available in vivo, in vitro and in silico preclinical models for studying these diseases. Better understanding of the strengths and weaknesses of specialized neonatal disease models will help to improve their utility, may add to the understanding of the mode of action and efficacy of a therapeutic, and/or may improve the understanding of the disease pathology to aid in identification of new therapeutic targets. Although the diseases covered in this article are diverse and require specific approaches, several high-level, overarching key lessons can be learned by evaluating the strengths, weaknesses and gaps in the available models. This Review is intended to help guide current and future researchers toward successful development of therapeutics in these areas of high unmet medical need.

Summary: This article reviews and analyzes the available preclinical models for five common neonatal diseases to direct therapeutic development in these areas of high unmet medical need.

Enteric Nervous System in Neonatal Necrotizing Enterocolitis

BACKGROUND

The pathophysiology of necrotizing enterocolitis (NEC) is not clear, but increasing information suggests that the risk and severity of NEC may be influenced by abnormalities in the enteric nervous system (ENS).

OBJECTIVE

The purpose of this review was to scope and examine the research related to ENS-associated abnormalities that have either been identified in NEC or have been noted in other inflammatory bowel disorders (IBDs) with histopathological abnormalities similar to NEC. The aim was to summarize the research findings, identify research gaps in existing literature, and disseminate them to key knowledge end-users to collaborate and address the same in future studies.

METHODS

Articles that met the objectives of the study were identified through an extensive literature search in the databases PubMed, EMBASE, and Scopus.

RESULTS

The sources identified through the literature search revealed that: (1) ENS may be involved in NEC development and post-NEC complications, (2) NEC development is associated with changes in the ENS, and (3) NEC-associated changes could be modulated by the ENS.

CONCLUSION

The findings from this review identify the enteric nervous as a target in the development and progression of NEC. Thus, factors that can protect the ENS can potentially prevent and treat NEC and post-NEC complications. This review serves to summarize the existing literature and highlights a need for further research on the involvement of ENS in NEC.

The Role of Dietary Fats in the Development and Prevention of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a significant cause of mortality and morbidity in preterm infants. The pathogenesis of NEC is not completely understood; however, intestinal immaturity and excessive immunoreactivity of intestinal mucosa to intraluminal microbes and nutrients appear to have critical roles. Dietary fats are not only the main source of energy for preterm infants, but also exert potent effects on intestinal development, intestinal microbial colonization, immune function, and inflammatory response. Preterm infants have a relatively low capacity to digest and absorb triglyceride fat. Fat may thereby accumulate in the ileum and contribute to the development of NEC by inducing oxidative stress and inflammation. Some fat components, such as long-chain polyunsaturated fatty acids (LC-PUFAs), also exert immunomodulatory roles during the early postnatal period when the immune system is rapidly developing. LC-PUFAs may have the ability to modulate the inflammatory process of NEC, particularly when the balance between n3 and n6 LC-PUFAs derivatives is maintained. Supplementation with n3 LC-PUFAs alone may have limited effect on NEC prevention. In this review, we describe how various fatty acids play different roles in the pathogenesis of NEC in preterm infants.

Vagal Tone and Proinflammatory Cytokines Predict Feeding Intolerance and Necrotizing Enterocolitis Risk

BACKGROUND

Necrotizing enterocolitis (NEC) is the leading cause of death due to gastrointestinal disease in preterm neonates; yet, clinicians lack reliable and noninvasive predictive tools.

PURPOSE

We aimed to test that diminished high-frequency heart rate variability (HF-HRV) and elevated levels of proinflammatory cytokines would have utility in NEC prediction.

METHODS

In this multisite prospective study, we enrolled 250 preterm (26-34 weeks' postmenstrual age [PMA]) neonates with physiological stability at 72 hours of life. HRV was measured noninvasively using electrocardiograhic data from standardized cardiorespiratory monitors at postnatal week 1 of life and weekly thereafter until 35 weeks' PMA or discharge; blood was collected for cytokines at postnatal weeks 1 and 3. NEC was diagnosed via Modified Bell's Staging Criteria.

RESULTS

HF-HRV was decreased at weeks 1 and 2 in neonates (47% females) who developed feeding intolerance or stage 2+ NEC. In addition, these neonates displayed elevated levels of IL-8 at week 1 and increased levels of IL-1β, IL-6, TNF-α, and IL-8 at week 3 of life. Low HF-HRV was associated with elevated IL-6 or IL-8 levels at weeks 1 and 3 of life. Logistic regression indicated that only HF-HRV was a significant predictor of feeding intolerance or NEC development.

IMPLICATIONS FOR PRACTICE AND RESEARCH

HRV is a promising noninvasive modality for NEC risk detection. The association of low HF-HRV with elevated proinflammatory cytokines provides evidence for a putative role of the vagal cholinergic pathway in NEC pathogenesis. Future studies should focus on application of these techniques to test clinical therapeutics.Video Abstract available at https://journals.lww.com/advancesinneonatalcare/Pages/videogallery.aspx?autoPlay=false&videoId=54.

Multifunctional Benefits of Prevalent HMOs: Implications for Infant Health

Breastfeeding is the best source of nutrition during infancy and is associated with a broad range of health benefits. However, there remains a significant and persistent need for innovations in infant formula that will allow infants to access a wider spectrum of benefits available to breastfed infants. The addition of human milk oligosaccharides (HMOs) to infant formulas represents the most significant innovation in infant nutrition in recent years. Although not a direct source of calories in milk, HMOs serve as potent prebiotics, versatile anti-infective agents, and key support for neurocognitive development. Continuing improvements in food science will facilitate production of a wide range of HMO structures in the years to come. In this review, we evaluate the relationship between HMO structure and functional benefits. We propose that infant formula fortification strategies should aim to recapitulate a broad range of benefits to support digestive health, immunity, and cognitive development associated with HMOs in breastmilk. We conclude that acetylated, fucosylated, and sialylated HMOs likely confer important health benefits through multiple complementary mechanisms of action.

Necrotizing enterocolitis and its association with the neonatal abstinence syndrome

OBJECTIVE:

The purpose of this study was to describe an identified association between necrotizing enterocolitis (NEC) and prenatal opioid exposure with neonatal abstinence syndrome (NAS) in late preterm and full-term neonates.

STUDY DESIGN:

In this single-center retrospective cohort study, we analyzed inborn neonates with the diagnosis of NEC discharged from 2012 through 2017. We compared infants with NEC > 35 weeks’ gestation to those with NEC<35 weeks’ gestation. We compared gestational age, birth weight, age of onset of symptoms, and incidence of prenatal drug exposure between groups. Significance was determined using Mann-Whitney and Fisher’s exact tests.

RESULTS:

Over the study period, 23 infants were identified with NEC, 9 (39%) were babies > 35 weeks at birth and 14 (61%) < 35 weeks. Those > 35 weeks had a higher birth weight, earlier onset of symptoms, and a higher percentage of prenatal exposure to opioids compared to those < 35 weeks’ gestation. We further described seven infants with late gestational age onset NEC associated with prenatal opioid exposure.

CONCLUSIONS:

In this cohort of infants with NEC discharged over a 6 year period we found a higher than expected percentage of infants born at a later gestational age. We speculate that prenatal opioid exposure might be a risk factor for NEC in neonates born at > 35 weeks.

Interleukin 8 may predict surgical necrotizing enterocolitis in infants born less than 1500 g

Necrotizing enterocolitis (NEC) often leads to gastrointestinal emergency resulting high mortality in very low birth weight infants (VLBWIs) requiring surgery. To date, few studies have explored the role of serum cytokines in the development of feeding intolerance (FI) or NEC outcomes in VLBWIs. Infants born weighing <1500 g or of 32 weeks of gestational age were prospectively enrolled from May 2018 to Dec 2019. We measured several cytokines routinely within 72 h of life, even before NEC-like symptoms developed. NEC or FI group comprised 17 (27.4%) infants, and 6 (9.7%) infants had surgical NEC. The gestational age and birth weight were significantly lower in the NEC or FI group with more prematurity-related complications. The surgical NEC group also demonstrated significantly lower gestational age and birth weight along with more infants experiencing refractory hypotension within a 1 week of life, pulmonary hypertension, and patent ductus arteriosus. IL-10 levels were significantly higher in the NEC or FI group, whereas IL-8 levels were significantly higher in the infants with surgical NEC. Our findings indicated to IL-8 can predict surgical NEC while increased IL-10 can predict NEC development in VLBWIs.

Abnormal Splanchnic Regional Saturations in a Preterm Infant That Developed Necrotizing Enterocolitis Following a Red Blood Cell Transfusion

BACKGROUND

Necrotizing enterocolitis (NEC) has been associated with red blood cell (RBC) transfusions in preterm infants. Near-infrared spectroscopy (NIRS) can be used to noninvasively monitor regional oxygen saturations (rSO2).

CLINICAL FINDINGS

This former 28-week female premature infant, 29 days old, received an RBC transfusion due to increased apneic spells and a hematocrit of 27%. Within 24 hours she developed abdominal distension and passed a bloody stool (Bell's stage 2 NEC on abdominal x-ray). She completed 7 days of antibiotics and nothing-by-mouth status and was discharged home on room air and oral feedings on day of life 70.

PRIMARY DIAGNOSIS

We describe the presentation of NEC following a RBC transfusion in a preterm infant monitored with cerebral and splanchnic NIRS.

INTERVENTIONS

Mean rSO2 (cerebral and splanchnic) measurements were continuously recorded and calculated in 30-minute periods at baseline (prior to packed RBC transfusion), every hour during the RBC transfusion, and every 3 hours for the following 48 hours.

OUTCOMES

In this infant, average baseline splanchnic rSO2 was low at 46.5%, and increased during transfusion to 65%. However, following the RBC transfusion and an enteral feeding, splanchnic rSO2 dramatically decreased to 26%, and remained low until the time of NEC diagnosis.

PRACTICE RECOMMENDATIONS

To develop awareness of the increased risk for NEC in premature infants with significant anemia that receive packed RBC transfusions. With further studies and education, NIRS could be a valuable tool for the nurses and medical team to identify these at-risk neonates.

Potential role of endoplasmic reticulum stress is involved in the protection of fish oil on neonatal rats with necrotizing enterocolitis

Neonatal necrotizing enterocolitis (NEC) is a serious gastrointestinal disease with high death rate in premature infants. Fish oil (FO) and its constituents have been shown to ameliorate intestinal inflammation and mucosal damage. However, the underlying mechanism of action is not known. In the present study, we divided Sprague-Dawley rats into three groups: control group, NEC model group, and FO pre-feeding+NEC model group. Briefly, one week before NEC modeling, in addition to being fed with milk, the FO pre-feeding+NEC modeling group was fed with FO, the NEC group was fed with saline, and the control group was only inserted a gastric-tube for 7 days. Subsequently, histological assay, Western blot, and ELISA were performed. Pretreatment with FO attenuated the NEC symptoms, alleviated intestinal pathological injury, and decreased the expressions of pro-inflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Furthermore, pretreatment with FO reduced the expressions of endoplasmic reticulum stress (ERS) related proteins, caspase-12, and glucose-regulated protein 78 (GRP78). In addition, intestinal histopathological scores showed a significant positive correlation with intestinal expressions of IL-6, TNF-α, and caspase-12. Collectively, these results indicate that ERS pathway might be involved in the effect of FO in alleviating intestinal mucosal inflammation and injury in rats with NEC.

Hypoxic-ischemic enterocolitis: a proposal of a new terminology for early NEC or NEC-like disease in preterm infants, a single-center prospective observational study

We aimed to investigate the role of hypoxia-ischemia in the pathophysiology of early NEC/NEC like disease (ENEC) and classic NEC/NEC like disease (CNEC) in preterm infants. In this pilot study, preterm infants who developed the clinical symptoms and signs of NEC/NEC like disease were divided into two groups as early (≤ 7 days, ENEC) or late (> 7 days, CNEC) groups. Beside clinical variables, serum L-lactate, endothelin-1 (ET-1), platelet activating factor (PAF), and intestinal fatty acid binding protein (I-FABP) levels were measured from umbilical/peripheric venous blood in the first hour of life and during the clinical presentation in all groups. A total of 86 preterm infants were enrolled in the study. In the ENEC group, the incidences of fetal umbilical artery Doppler velocimetry abnormalities, IUGR, and delayed passage of first meconium were higher. In addition, mean levels of L-lactate, ET-1, PAF, and I-FABP were higher in the first hour of life.Conclusion: Our study firstly showed that the dominant pathophysiological factor of ENEC is prenatal hypoxic-ischemic event where intestinal injury and inflammation begin in-utero and become clinically apparent in the first week of life. Therefore, we propose a new term "Hypoxic-Ischemic Enterocolitis (HIEnt)" for the definition of ENEC in preterm infants with prenatal hemodynamic disturbances and IUGR. This new sight can provide individualized preventive and therapeutic strategies for preterm infants.What is Known:• The pathophysiology of early necrotizing enterocolitis (NEC) or NEC-like disease which is seen in the first week of life seems different than classic necrotizing enterocolitis (CNEC) which is always seen after the first week of life.What is New:• This study suggests that perinatal hypoxic-ischemic process with inflammation is the point of origin of fetal intestinal injury leading to ENEC.• We propose a new term "Hypoxic-Ischemic Enterocolitis (HIEnt)" for the definition and differentiation of this unique clinical entity.

Antiviral activity of interleukin-11 as a response to porcine epidemic diarrhea virus infection

Interleukin-11 (IL-11), a well-known anti-inflammatory factor, provides protection from intestinal epithelium damage caused by physical or chemical factors. However, little is known of the role of IL-11 during viral infections. In this study, IL-11 expression at mRNA and protein levels were found to be high in Vero cells and the jejunum of piglets during porcine epidemic diarrhea virus (PEDV) infection, while IL-11 expression was found to be positively correlated with the level of viral infection. Pretreatment with recombinant porcine IL-11 (pIL-11) was found to suppress PEDV replication in Vero E6 cells, while IL-11 knockdown promoted viral infection. Furthermore, pIL-11 was found to inhibit viral infection by preventing PEDV-mediated apoptosis of cells by activating the IL-11/STAT3 signaling pathway. Conversely, application of a STAT3 phosphorylation inhibitor significantly antagonized the anti-apoptosis function of pIL-11 and counteracted its inhibition of PEDV. Our data suggest that IL-11 is a newfound PEDV-inducible cytokine, and its production enhances the anti-apoptosis ability of epithelial cells against PEDV infection. The potential of IL-11 to be used as a novel therapeutic against devastating viral diarrhea in piglets deserves more attention and study.

Milk Fat Globule Membrane Ameliorates Necrotizing Enterocolitis in Neonatal Rats and Suppresses Lipopolysaccharide-Induced Inflammatory Response in IEC-6 Enterocytes

BACKGROUND

Evidence has provided support for the beneficial effects of milk fat globule membrane (MFGM) on inflammation in the intestinal tract. The objective of this study was to investigate the effects of MFGM on a rat model of necrotizing enterocolitis (NEC) and its potential mechanism of action.

METHODS

Sixty-two newborn Sprague Dawley rats were randomly divided into 4 experimental groups: Breast-fed normal, formula fed (FF), FF + 6 g/L MFGM, and FF + 12 g/L MFGM. The FF rats and the FF rats supplemented with MFGM were exposed to asphyxia/cold stress to induce NEC. Body weight, histological score, survival time, oxidative stress injury, enterocyte proliferation/apoptosis, and inflammatory response were assessed. Meanwhile, lipopolysaccharide (LPS)-stimulated IEC-6 enterocytes were used as a model to test the anti-inflammatory effects of MFGM.

RESULTS

Supplementation with 12 g/L MFGM alleviated body weight loss, reduced the incidence of NEC, increased the survival rate, and attenuated the severity of bowel damage in the NEC rat model. Furthermore, 12 g/L MFGM administration inhibited the protein expression of toll-like receptor 4 (TLR4) in the animal model. In IEC-6 enterocytes, the upregulation of TLR4, myeloid differentiation primary response gene 88 (MyD88), phosphorylated nuclear factor-κB (NF-κB) p65 subunit, and the nuclear translocation of NF-κBp65 induced by LPS was partially inhibited by MFGM pretreatment.

CONCLUSION

Our findings suggested that MFGM has beneficial effects on neonatal rats with NEC by suppressing inflammation via the TLR4/MyD88/NF-κB pathway.

Platelet transfusions and mortality in necrotizing enterocolitis

BACKGROUND

Prior studies have suggested an association between platelet transfusions (PTXs) and worse outcomes among infants with necrotizing enterocolitis (NEC), potentially mediated by proinflammatory factors released by platelets. However, the effects of storage on platelet proinflammatory factor release and the confounding role of illness severity on NEC outcomes have not been determined.

STUDY DESIGN AND METHODS

First, neuropeptide Y (a potent splanchnic vasoconstrictor released by platelets) was measured by enzyme-linked immunosorbent assay in fresh frozen plasma and in the supernatant of leukoreduced apheresis-derived platelets at different times during storage. Next, we evaluated the relationship between PTX rates and death in a multicenter cohort of very-low-birth-weight infants with NEC, adjusting for illness severity.

RESULTS

Neuropeptide Y levels increased over time in the supernatant of leukoreduced apheresis-derived platelets and were 4.4-fold and 8.9-fold higher than in fresh frozen plasma on Days 2 and 3 of storage, respectively (p < 0.001). Among 598 very-low-birth-weight infants, 44 developed NEC. In unadjusted analysis, PTX rate was 30.3 (95% confidence interval [CI], 11.5-80.1) per 100 infant-days among infants who died, compared to 6.0 (95% CI, 3.2-11.2) among survivors (incidence rate ratio, 5.1; 95% CI, 1.6-16.2; p = 0.006). In multivariable analysis, there was no association between PTX rate and mortality (incidence rate ratio, 3.0; 95% CI, 0.6-15.0; p = 0.18), although estimation was imprecise.

CONCLUSION

Proinflammatory mediators accumulate in platelet suspensions during storage. Although PTX rates were not associated with increased mortality among infants with NEC in our study, our estimates suggest the potential for such an association that needs evaluation in larger studies.

Berberine reduces the occurrence of neonatal necrotizing enterocolitis by reducing the inflammatory response

Necrotizing enterocolitis (NEC) is a life-threatening disease that occurs in premature infants. The aim of the present study was to investigate the effects of berberine, an isoquinoline alkaloid mainly used to treat digestive diseases, in a rat model of NEC. NEC models were established in newborn rats via inhalation of N₂ for 90 sec every 4 h and oral administration of 4 mg/kg/day lipopolysaccharides on days 0 and 1. Berberine was administered via oral gavage. In the NEC model group, Toll-like receptor (TLR)4, nuclear factor NF-κB (NF-κB), inducible nitric oxide synthase (iNOS), tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-10 were upregulated. Symptoms of NEC in the berberine intervention group were significantly relieved, with a clear reduction in the incidence of NEC compared with the NEC group. TLR4, NF-κB, iNOS, TNF-α, IL-6 and IL-10 expression was decreased following berberine intervention. Furthermore, the expression of mucin-2 (MUC2) and RNA polymerase σ factor SigA (SIgA) were decreased in the NEC model group and increased following berberine intervention, when compared with the untreated group. It was also demonstrated that the incidence of NEC was reduced following berberine administration, possibly owing to changes in the inflammatory responses. The results of the current study support a potential therapeutic role of berberine for the treatment of NEC.

FTY720 attenuates intestinal injury and suppresses inflammation in experimental necrotizing enterocolitis via modulating CXCL5/CXCR2 axis

Necrotizing enterocolitis (NEC) remains one of the leading causes of death in neonatal infants and new therapeutic strategies for NEC are urgently required. The immunomodulatory agent FTY720 has been shown to have protective effects in various inflammatory diseases. In this study, we hypothesized that treatment with FTY720 confers protection against experimental NEC. Experimental NEC was induced in five-day-old C57BL/6 neonatal mice by hyperosmolar formula feeding plus hypoxia and lipopolysaccharide (LPS) challenges. Induction of NEC resulted in substantial weight loss and high mortality compared to the control group, whereas FTY720 treatment significantly attenuated weight loss and improved survival in NEC-challenged neonatal mice. FTY720 treatment strongly ameliorated NEC-induced intestinal injury with reduced apoptosis and up-regulation of intestinal barrier proteins in the ileal tissues. Furthermore, FTY720 treatment abrogated NEC-initiated intestinal and systemic inflammation with markedly diminished inflammatory cytokines and chemokines. Moreover, FTY720 treatment suppressed NEC-activated CXCL5/CXCR2 axis with down-regulated expression of CXCL5 and CXCR2 at both mRNA and protein levels. Thus, we demonstrate that FTY720 protects neonatal mice against NEC-associated lethality by ameliorating intestinal injury and attenuating inflammation, possibly via its down-regulation of NEC-induced activation of intestinal CXCL5/CXCR2 axis.

CARMA3 Is a Critical Mediator of G Protein-Coupled Receptor and Receptor Tyrosine Kinase-Driven Solid Tumor Pathogenesis

The CARMA–Bcl10–MALT1 (CBM) signalosome is an intracellular protein complex composed of a CARMA scaffolding protein, the Bcl10 linker protein, and the MALT1 protease. This complex was first recognized because the genes encoding its components are targeted by mutation and chromosomal translocation in lymphoid malignancy. We now know that the CBM signalosome plays a critical role in normal lymphocyte function by mediating antigen receptor-dependent activation of the pro-inflammatory, pro-survival NF-κB transcription factor, and that deregulation of this signaling complex promotes B-cell lymphomagenesis. More recently, we and others have demonstrated that a CBM signalosome also operates in cells outside of the immune system, including in several solid tumors. While CARMA1 (also referred to as CARD11) is expressed primarily within lymphoid tissues, the related scaffolding protein, CARMA3 (CARD10), is more widely expressed and participates in a CARMA3-containing CBM complex in a variety of cell types. The CARMA3-containing CBM complex operates downstream of specific G protein-coupled receptors (GPCRs) and/or growth factor receptor tyrosine kinases (RTKs). Since inappropriate expression and activation of GPCRs and/or RTKs underlies the pathogenesis of several solid tumors, there is now great interest in elucidating the contribution of CARMA3-mediated cellular signaling in these malignancies. Here, we summarize the key discoveries leading to our current understanding of the role of CARMA3 in solid tumor biology and highlight the current gaps in our knowledge.

The novel preventive effect of Daikenchuto (TJ-100), a Japanese herbal drug, against neonatal necrotizing enterocolitis in rats

PURPOSE

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease of premature infants. Daikenchuto, a Japanese herbal drug, has several effects on the digestive system, so we investigated its preventive effects in a rat model of NEC.

METHODS

NEC was induced in newborn rats via asphyxia (100% N₂ for 90 s; every 4 h) + LPS (4 mg/kg/day [administered orally on days 0 and 1]). The effects of Daikenchuto were evaluated in four groups (control: 0 g/kg/day, I: 0.3 g/kg/day, II: 0.6 g/kg/day, and III: 1.0 g/kg/day). Daikenchuto was administered into the stomach through a microcatheter. The incidence and severity of NEC were pathologically assessed using the NEC grade in accordance with Dovorak's previous report. Cell positivity for inflammatory cytokine (IL-6) was also evaluated.

RESULTS

Daikenchuto reduced the incidence of NEC in control, Groups I, II, and III to 68.7, 30.0, 30.7, and 13.3%, respectively. High-dose Daikenchuto significantly improved the incidence of NEC, and the rate of IL-6 positive cells in group III was significantly lower than in the control group (p = 0.04).

CONCLUSION

We evaluated the effect of Daikenchuto against NEC and found that it reduced the incidence rate of NEC due to a decrease in the IL-6 production.

FLLL32, a curcumin analog, ameliorates intestinal injury in necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease that primarily affects premature infants. It is characterized by inflammation and leukocyte infiltration that can progress to intestinal necrosis, perforation, systemic inflammatory response, and death. In this study, we examined the effect of FLLL32, a curcumin analog, on an NEC-like neonatal intestinal injury model.

METHODS

NEC was induced in CD-1 mice pups using the Paneth cell ablation and Klebsiella infection model. Pups were divided into sham, NEC, and NEC + FLLL32 groups. At the end of the experiment, pups were euthanized; whole blood and small intestines were harvested. Intestinal inflammatory cytokine profile, in vivo intestinal permeability using serum fluorescein isothiocyanate-dextran, and histological injury scores were compared between the groups.

RESULTS AND CONCLUSION

FLLL32-treated pups had lower intestinal injury, improved intestinal permeability, and lower proinflammatory cytokine profiles compared to those in untreated pups with NEC. These results suggest that FLLL32 plays a protective role in NEC.

Glutamine Ameliorates Mucosal Damage Caused by Immune Responses to Duck Plague Virus

The immune-releasing effects of L-glutamine (Gln) supplementation in duck plague virus (DPV)-infected ducklings were evaluated in 120 seven-day-old ducklings that were divided into 8 groups. The ducklings in control and DPV, 0.5Gln and DPV + 0.5Gln, 1.0Gln and DPV + 1.0Gln, and 2.0Gln and DPV + 2.0Gln received 0, 0.5, 1.0, and 2.0 g of Gln/kg feed/d by gastric perfusion, respectively. Then, the ducklings in control to 2.0Gln were injected with 0.2 mL of phosphate-buffered saline, while those in DPV to DPV + 2.0Gln were injected with DPV at 0.2 mL of 2000 TCID₅₀ (50% tissue culture infection dose) 30 minutes after gavage with Gln, sampled at 12 hours and days 1, 2, 4, and 6. Glutamine supplementation under physiological conditions enhanced immune function and toll-like receptor 4 (TLR4) expressions in a dose-dependent manner. An increase in Gln supplementation under DPV-infected conditions enhanced growth performance, decreased immunoglobulin (Ig) release in plasma and secretory IgA in the duodenum, ameliorated plasma cytokine levels, and suppressed overexpressions of the TLR4 pathway in the duodenum. The positive effects of Gln on the humoral immunity- and intestinal inflammation-related damage should be considered a mechanism by which immunonutrition can assist in the recovery from DPV infection.

Pathogenesis of NEC: Role of the innate and adaptive immune response

Necrotizing enterocolitis (NEC) is a devastating disease in premature infants with high case fatality and significant morbidity among survivors. Immaturity of intestinal host defenses predisposes the premature infant gut to injury. An abnormal bacterial colonization pattern with a deficiency of commensal bacteria may lead to a further breakdown of these host defense mechanisms, predisposing the infant to NEC. Here, we review the role of the innate and adaptive immune system in the pathophysiology of NEC.

Bifidobacterium adolescentis protects against necrotizing enterocolitis and upregulates TOLLIP and SIGIRR in premature neonatal rats

Background

Necrotizing enterocolitis (NEC) is a serious gastrointestinal disorder that is often seen in premature infants. Probiotics decrease the risk of NEC; however, the mechanism by which probiotics work is not clear. The goal of this study was to evaluate the preventive effect of Bifidobacterium adolescentis in an NEC rat model.

Methods

Sprague-Dawley neonatal rats were obtained by caesarean section after 20-21 d gestation and randomly divided into the following 3 groups: dam fed (DF), formula fed (FF), and formula + B. adolescentis (FB). Those in the FF and FB groups developed NEC after exposure to asphyxia and cold stress. All rats were sacrificed 72 h after birth and intestinal injury and mRNA expression of TLR4, TOLLIP and SIGIRR were assessed.

Results

B. adolescentis significantly increased the 72-h survival rate from 56.3% in the FF group to 86.7% in the FB group. B. adolescentis significantly reduced the histological score from a median of 3.0 in the FF group to a median of 1.0 in the FB group,and significantly decreased the rate of NEC-like intestinal injury from 77.8% in the FF group to 23.1% in the FB group. The mRNA expression of TLR4 increased 3.6 fold in the FF group but decreased by 2 fold from B. adolescentis treatment. mRNA expression of TOLLIP and SIGIRR decreased 4.3 and 3.7 fold, respectively, in the FF group. B. adolescentis significantly increased mRNA expression of TOLLIP and SIGIRR by 3.7 fold and 2.6 fold, respectively.

Conclusions

This study demonstrated B. adolescentis prevents NEC in preterm neonatal rats and that the mechanism for this action might be associated with the alteration of TLR4, TOLLIP, and SIGIRR expression.

Astragaloside IV ameliorates necrotizing enterocolitis by attenuating oxidative stress and suppressing inflammation via the vitamin D3-upregulated protein 1/NF-κB signaling pathway

Astragaloside IV (AS-IV) is a flavonoid from the plant Astragalus membranaceus (Fisch) Bge that has a wide range of therapeutic effects. The aim of the present study was to examine the effect of AS-IV on rats with necrotizing enterocolitis (NEC) under oxidative stress and inflammation. Newborn Sprague-Dawley rats were induced with NEC by asphyxia and hypothermia applied on 3 consecutive days. The rats were orally administered AS-IV at 25, 50 and 75 mg/kg for 4 days. The results revealed that AS-IV administration prevented NEC-induced decrease in the concentration of malondialdehyde and myeloperoxidase, and increase in the activity of glutathione (GSH) and superoxide dismutase in murine models. AS-IV also inhibited NEC-induced elevation in the levels of interleukin (IL)-6, IL-1β, tumor necrosis factor-α and nuclear factor (NF)-κB. The effects of AS-IV were achieved under inflammation and oxidative stress. Western blotting demonstrated that AS-IV substantially inhibited the phosphorylated (p)-IκBα, NF-κBp65, p-NF-κBp65 protein levels and increased vitamin D3 upregulated protein 1 (VDUP1) and IκBα protein levels. These data indicate that AS-IV may be effective in the protection of NEC-induced ileum degeneration by inhibiting the levels of inflammatory markers and oxidative stress via the regulation of the VDUP1/NF-κB signaling pathway.

Plasma D-lactate Levels in Necrotizing Enterocolitis in Premature Infants

Background

D-Lactate is normally present in the blood of humans at nanomolar concentrations due to methylglyoxal metabolism; millimolar D-lactate concentrations can arise due to excess gastrointestinal microbial production.

Objectives

To examine the levels of plasma D-lactate in the necrotizing enterocolitis in premature infants.

Patients and Methods

128 premature infants were divided into control (group I, n = 69), feeding intolerance (group II, n = 42) and NEC (group III, n = 27) groups. Plasma D-lactate levels were measured at the onset of feeding intolerance or NEC and at weeks 2-3 in control infants (group I) by ELISA. Data were analyzed using descriptive statistics, non-parametric tests and Student’s t-test.

Results

In groups I, II, III, median birth weights were 1845.7 ± 267.5 g, 1913.1 ± 306.5 g, and 1898.4 ± 285.3 g, median gestational ages were 34.3 ± 1.7 weeks, 33.9 ± 2.2 weeks and 35.1 ± 2.6 weeks, ages of sampling were 12.3 ± 2.9 days, 14.6 ± 3.7 days and 15.1 ± 1.8 days, respectively. The differences of median birth weights, median gestational ages and ages of sampling were not statistically significant (P > 0.05). The plasma D-lactate levels in groups I, II, III were 3.6 ± 1.9 μg/mL, 12.7 ± 8.3 μg/mL, and 35.4 ± 29.1 μg/mL, respectively, group III had higher plasma D-lactate level than groups I, II, and the difference among these groups was significant (x² = 21.6, P < 0.01).

Conclusions

Plasma D-lactate significantly increased early in NEC. Plasma D-lactate levels were associated with extensive disease in NEC infants. Therefore, it could be used as a diagnosis indicator in the early stage of NEC.

The protective and anti-inflammatory effects of glucagon-like peptide-2 in an experimental rat model of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease, that affects premature infants. Glucagon-like peptide-2 (GLP-2) is an intestinotrophic hormone and reduces the inflammation. We suspected that GLP-2 would have protective and anti-inflammatory effects in an experimental rat model of NEC. NEC was induced in newborn rats by enteral feeding with hyperosmolar formula, asphyxial stress and enteral administration of lipopolysaccharide (LPS). Rats were randomly divided into the following four groups: dam-fed, NEC, NEC+GLP-2(L) given 80 μg/kg/day of GLP-2, and NEC+GLP-2(H) given 800 μg/kg/day of GLP-2. GLP-2 was administered subcutaneously every 6 h before stress. All animals surviving beyond 96 h or any that developed signs of distress were euthanized. The clinical sickness score in the NEC+GLP-2(H) group was significantly lower than that in the NEC group. The NEC score and the survival rate in the NEC+GLP-2(H) group was significantly improved compared with those in the NEC and the NEC+GLP-2(L) groups. Villous height and crypt depth in both the GLP-2 treatment groups were significantly increased compared with those in the NEC group. There were no significant differences in the crypt cell proliferation indices among the groups. Ileal interstitial TNF-α and IL-6 level in the NEC+GLP-2(H) group was decreased to the same levels in the dam-fed group. High dose GLP-2 administration improved the incidence and survival rate for NEC. It also decreased mucosal inflammatory cytokine production. These results support a potential therapeutic role for GLP-2 in the treatment of NEC.

Surfactant protein-D attenuates the lipopolysaccharide-induced inflammation in human intestinal cells overexpressing toll-like receptor 4

PURPOSE

Necrotizing enterocolitis (NEC) is a devastating inflammatory disease of preterm infants that may depend on overexpression of toll-like receptor-4 (TLR4) in the immature intestine. Surfactant protein (SP)-D is a member of the collectin family and plays an important role in innate immunity, particularly in the airways. Although SP-D also exists in the intestines, little is known about its function. This study investigated whether SP-D can attenuate the inflammatory response of TLR4-overexpressing embryonal intestinal cells.

METHODS

All experimental procedures were performed using the human intestinal cell line INT407 originally derived from human embryonal intestines. Platelet-activating factor (PAF), reported to be elevated in NEC patients, was used to induce TLR4 overexpression in the human embryonal intestinal cell line INT407. TLR4 expression was measured using quantitative real-time PCR. Inflammatory responses to PAF (5 µM), the TLR4 agonist lipopolysaccharide (LPS, 100 ng/ml), PAF + LPS, and PAF + LPS following SP-D pretreatment (20 µg/ml) were assessed by enzyme-linked immunosorbent assay (ELISA) of interleukin-8 (IL-8) release (in pg/ml).

RESULTS

Expression of TLR4 mRNA (mean ± SD) was upregulated by PAF (369 % ± 28 %, p < 0.001). Stimulation with PAF + LPS resulted in higher IL-8 release (1959.3 ± 52.3) than control (141.2 ± 12.4), LPS (167.3 ± 65.8), or PAF (1527.2 ± 129.4) treatment (p < 0.05). Release in response to PAF + LPS (1590.1 ± 319.3) was attenuated by SP-D pretreatment (1161.6 ± 131.6; p < 0.05).

CONCLUSION

SP-D attenuates LPS-induced IL-8 production in TLR4-overexpressing intestinal cells, suggesting that SP-D may have a protective effect in the development of NEC in preterm infants.

Oral administration of surfactant protein-a reduces pathology in an experimental model of necrotizing enterocolitis

OBJECTIVES

Necrotizing enterocolitis (NEC) frequently results in significant morbidity and mortality in premature infants. Others reported that mice deficient in pulmonary surfactant protein-A (SP-A) born and raised in a nonhygienic environment succumb to significant gastrointestinal tract pathology, and enteral administration of purified SP-A significantly reduced mortality. We hypothesized that oral administration of purified SP-A can ameliorate pathology in an experimental model of neonatal NEC.

METHODS

Experimental NEC was induced in newborn Sprague-Dawley rat pups by daily formula gavage and intermittent exposure to hypoxia. Purified human SP-A (5 μg/day) was administered by oral gavage. After 4 days, surviving pups were sacrificed, and intestinal pathology was assessed by histological examination of distal terminal ileal sections. Intestinal levels of inflammatory cytokines (IL-1β, IFN-γ, and TNF-α) were assessed by enzyme-linked immunosorbent assay and levels of Toll-like receptor 4 (TLR4) by Western analysis.

RESULTS

Sixty-one percent of the gavaged rat pups that survived to day 4 met the criteria for experimental NEC after hypoxia, whereas treatment with SP-A significantly reduced mortality and assessment of NEC. Intestinal levels of proinflammatory cytokines were significantly increased in pups exposed to hypoxia. Administration of SP-A to pups exposed to hypoxia significantly reduced IL-1β and TNF-α levels, but had little effect on elevated levels of IFN-γ. SP-A treatment of hypoxia-exposed pups significantly reduced expression of intestinal TLR4, key in NEC pathogenesis.

CONCLUSIONS

In a rat model of experimental neonatal NEC, oral administration of SP-A reduces intestinal levels of proinflammatory cytokines and TLR4 protein and ameliorates adverse outcomes associated with gastrointestinal pathologies.

Platelet-activating factor: a role in preterm delivery and an essential interaction with Toll-like receptor signaling in mice

Platelet-activating factor (PAF), a potent phospholipid activator of inflammation that signals through its cognate receptor (platelet-activating factor receptor, PTAFR), has been shown to induce preterm delivery in mice. Toll-like receptors (TLRs) are transmembrane receptors that mediate innate immunity. We have shown previously that Escherichia coli-induced preterm delivery in mice requires TLR signaling via the adaptor protein myeloid differentiation primary response gene 88 (MyD88), but not an alternative adaptor, Toll/IL-1 receptor domain-containing adapter protein-inducing interferon-beta (TRIF). In the present work, we analyzed the role of endogenously produced PAF in labor using mice lacking (knockout [KO]) PAF acetylhydrolase (PAF-AH; the key degrading enzyme for PAF). PAF-AH KO mice are more susceptible to E. coli-induced preterm delivery and inflammation than controls. In peritoneal macrophages, the PTAFR agonist carbamyl PAF induces production of inflammatory markers previously demonstrated to be upregulated during bacterially induced labor, including: inducible nitric oxide synthase (Nos2), the chemokine Ccl5 (RANTES), tumor necrosis factor (Tnf), and level of their end-products (NO, CCL5, TNF) in a process dependent upon both IkappaB kinase and calcium/calmodulin-dependent protein kinase II. Interestingly, this induced expression was completely eliminated not only in macrophages deficient in PTAFR, but also in those lacking either TLR4, MyD88, or TRIF. The dependence of PAF effects upon TLR pathways appears to be related to production of PTAFR itself: PAF-induced expression of Ptafr mRNA was eliminated completely in TLR4 KO and partially in MyD88 and TRIF KO macrophages. We conclude that PAF signaling plays an important role in bacterially induced preterm delivery. Furthermore, in addition to its cognate receptor, PAF signaling in peritoneal macrophages requires TLR4, MyD88, and TRIF.

Delayed initiation but not gradual advancement of enteral formula feeding reduces the incidence of necrotizing enterocolitis (NEC) in preterm pigs

Enteral formula feeding is a risk factor for necrotizing enterocolitis (NEC) in premature infants, yet studies are conflicting regarding the safest timing for introduction and advancement of feeds. Our aim was to test the effects of early vs. late initiation and abrupt vs. gradual advancement of enteral feeding of an intact vs. hydrolyzed protein formula on NEC incidence and severity in preterm pigs. In Experiment 1, preterm pigs received total parenteral nutrition (TPN) at birth with abrupt initiation of enteral formula feeds (50% full intake) on d of life (DOL) 2 (EA) or 5 (LA) while PN continued. Pigs were also fed formula containing either intact or hydrolyzed protein. In Experiment 2, preterm pigs received TPN at birth with enteral, hydrolyzed-protein formula feeds introduced on DOL 2 either abruptly (EA; 50% full feeds) or gradually (EG; 10-50% full feeds over 5 d) while PN continued. NEC incidence and severity were assessed based on macroscopic and histological scoring. In Experiment 1, NEC incidence (41% vs. 70%, P<0.05) and severity were reduced in LA vs. EA groups and LA was associated with a higher survival rate, daily weight gain and jejunum villus height. Piglets fed hydrolyzed vs. intact protein formula had lower stomach content weights and similar NEC incidence. In Experiment 2, NEC incidence and severity were not different between pigs the EG vs. EA group. Proinflammatory gene expression (IL-1β, IL-6 and S100A9) in the ileum was lower in both LA and EG vs. EA groups. In conclusion, delayed initiation but not gradual advancement of enteral feeding is protective against NEC in preterm pigs. Feeding hydrolyzed vs. intact protein formula improved gastric transit without affecting the NEC incidence.

Intestinal dysbiosis: novel mechanisms by which gut microbes trigger and prevent disease

New research has identified specific intestinal colonizing microbes that can have significant influence on health and disease. Evidence is reviewed supporting an association between Fusobacterium nucleatum and colon cancer and for a protective role of Faecalibacterium prausnitzii in inflammatory bowel disease, of Escherichia coli Nissle 1917 in acute intestinal inflammation, of Bifidobacterium infantis in neonatal necrotizing enterocolitis, and of Akkermansia muciniphila in obesity and diabetes. These novel bacteria are clinically relevant and present opportunities for more focused diagnosis of colon cancer and prevention of common diseases.

Glutamine downregulates TLR-2 and TLR-4 expression and protects intestinal tract in preterm neonatal rats with necrotizing enterocolitis

BACKGROUND/PURPOSE

Toll-like receptor (TLR)-4 and TLR-2 play an essential role in the pathogenesis of necrotizing enterocolitis (NEC). In this study, we investigated the protective effect of glutamine (Gln) in an NEC neonatal rat model, and the potential association with TLR-4 and TLR-2 expression in local intestinal tissues.

METHODS

Preterm neonatal rats were randomly divided into 3 groups: normal control; NEC model; and NEC plus Gln intervention. NEC was induced by feeding with artificial milk substitutes, plus exposure to hypoxia and cold stress. All preterm rats were sacrificed at 3 days after birth. The intestinal tissues were taken for pathological analysis. Protein and mRNA expression of TLR-2, TLR-4, and caspase-3 was examined by immunohistochemistry and real-time RT-PCR, respectively.

RESULTS

Compared with the normal control, the NEC neonatal rats showed mucosal injury and upregulated mRNA and protein expression of TLR-2, TLR-4, and caspase-3 in ileum and colon. Gln intervention significantly reduced the mucosal injury and suppressed the upregulated expression of TLR-2, TLR-4, and caspace-3 in the ileum and colon of NEC neonatal rats.

CONCLUSIONS

Gln protects the intestinal tract of NEC neonatal rats, which may be associated with the reduction of TLR-2 and TLR-4 expression in intestines.

Diminished vagal tone is a predictive biomarker of necrotizing enterocolitis-risk in preterm infants

BACKGROUND

Necrotizing enterocolitis (NEC) is an acute neonatal inflammatory disease which may lead to intestinal necrosis, multisystem failure, and death. Currently, NEC is diagnosed by a combination of laboratory and radiographic tests conducted a posteriori i.e., when NEC is already clinically significant. Given the acute onset and rapid progression of NEC, a non-invasive biomarker that allows early detection of patients at risk is required as a matter of urgency. We evaluated whether the high frequency (HF) component of heart rate variability (HRV), a measure of vagal efferent tonic cholinergic activity may be used as a predictive biomarker for NEC-risk before the onset of clinical disease.

METHODS

In this prospective study, stable preterm (gestational age 28-35 weeks) infants had HRV power spectra analyzed from surface electrocardiogram waveforms taken at rest on day 5-8 of life. We used regression modeling to determine the utility of HF-HRV in predicting NEC.

KEY RESULTS

HF-HRV power was 21.5 ± 2.7 and 3.9 ± 0.81 ms(2) in infants that remained healthy and those that later developed stage 2+ NEC, respectively (p < 0.001). Nine of 70 enrolled infants developed NEC. The ROC discriminated a HF-HRV value of 4.68 ms(2) predictive for developing NEC with a sensitivity and specificity of 89% and 87%, and positive and negative predictive value of 50% and 98%, respectively. With predictive regression modeling, the risk (odds ratio) of developing NEC was 10 per every one SD decrease in HF-HRV.

CONCLUSIONS & INFERENCES

Our preliminary data indicate that HF-HRV may serve as a potential, non-invasive predictive biomarker of NEC-risk in NICU infants.

Glutamine attenuates the inhibitory effect of methotrexate on TLR signaling during intestinal chemotherapy-induced mucositis in a rat

Toll-like receptor 4 (TLR-4) is crucial in maintaining intestinal epithelial homeostasis, participates in a vigorous signaling process and heightens inflammatory cytokine output. The objective of this study was to determine the effects of glutamine (GLN) on TLR-4 signaling in intestinal mucosa during methotrexate (MTX)-induced mucositis in a rat. Male Sprague-Dawley rats were randomly assigned to one of four experimental groups of 8 rats each: 1) control rats; 2) CONTR-GLN animals were treated with oral glutamine given in drinking water (2%) 48 hours before and 72 hours following vehicle injection; 3) MTX-rats were treated with a single IP injection of MTX (20 mg/kg); and 4) MTX-GLN rats were pre-treated with oral glutamine similar to group B, 48 hours before and 72 hours after MTX injection. Intestinal mucosal damage, mucosal structural changes, enterocyte proliferation and enterocyte apoptosis were determined 72 hours following MTX injection. The expression of TLR-4, MyD88 and TRAF6 in the intestinal mucosa was determined using real time PCR, Western blot and immunohistochemistry. MTX-GLN rats demonstrated a greater jejunal and ileal mucosal weight and mucosal DNA, greater villus height in ileum and crypt depth and index of proliferation in jejunum and ileum, compared to MTX animals. The expression of TLR-4 and MyD88 mRNA and protein in the mucosa was significantly lower in MTX rats versus controls animals. The administration of GLN increased significantly the expression of TLR-4 and MyD88 (vs the MTX group). In conclusion, treatment with glutamine was associated with up-regulation of TLR-4 and MyD88 expression and a concomitant decrease in intestinal mucosal injury caused by MTX-induced mucositis in a rat.

Dietary GD3 ganglioside reduces the incidence and severity of necrotizing enterocolitis by sustaining regulatory immune responses

OBJECTIVES

Gangliosides are glycosphingolipids, rich in colostrum and in membrane microdomains, which promote enterocyte growth and differentiation, and modulate TH1/TH2 responses. In an in vitro intestinal explant model of necrotizing enterocolitis (NEC), gangliosides have been shown to ameliorate intestinal injury; however, possible immunomodulatory mechanisms associated with this observation, as well as potential in vivo protective effects of gangliosides, remain unknown. The present study evaluates the effects of dietary GD3, the predominant ganglioside in neonatal rat intestine, both on the clinicopathologic expression of disease and on ileal Foxp3+ T regulatory cell immune responses in an experimental NEC model.

METHODS

Newborn rat pups were fed gavage formula (NEC) or formula supplemented with 15 μg/mL GD3 (GD3-NEC). Dam-fed (DF) littermates served as controls. NEC was induced by asphyxia and cold stress. At 96 hours, ileal gross and histologic changes were evaluated, and ileal cytokine profiles, Foxp3 expression, and Foxp3+ cell numbers were determined.

RESULTS

GD3 decreased the incidence and gross and histopathologic severity of NEC. Ileal Foxp3 expression and Foxp3+ cell numbers were significantly decreased in the NEC group compared with DF. GD3 increased ileal Foxp3 expression and Foxp3+ cell numbers, in association with upregulation of anti-inflammatory cytokine interleukin (IL)-10 and chemokines, tissue inhibitor of metalloproteinases 1, IL-1 receptor antagonist (IL-1ra), and suppressed proinflammatory mediators.

CONCLUSIONS

These data suggest that dietary GD3 protects newborn rats from NEC, in part, by augmenting mucosal Foxp3+ T regulatory immune responses.

Oral administration of transforming growth factor-β1 (TGF-β1) protects the immature gut from injury via Smad protein-dependent suppression of epithelial nuclear factor κB (NF-κB) signaling and proinflammatory cytokine production

Inflammatory immune responses play an important role in mucosal homeostasis and gut diseases. Nuclear factor κB (NF-κB), central to the proinflammatory cascade, is activated in necrotizing enterocolitis (NEC), a devastating condition of intestinal injury with extensive inflammation in premature infants. TGF-β is a strong immune suppressor and a factor in breast milk, which has been shown to be protective against NEC. In an NEC animal model, oral administration of the isoform TGF-β1 activated the downstream effector Smad2 in intestine and significantly reduced NEC incidence. In addition, TGF-β1 suppressed NF-κB activation, maintained levels of the NF-κB inhibitor IκBα in the intestinal epithelium, and systemically decreased serum levels of IL-6 and IFN-γ. The immature human fetal intestinal epithelial cell line H4 was used as a reductionistic model of the immature enterocyte to investigate mechanism. TGF-β1 pretreatment inhibited the TNF-α-induced IκBα phosphorylation that targets the IκBα protein for degradation and inhibited NF-κB activation. Chromatin immunoprecipitation (ChIP) assays demonstrated decreased NF-κB binding to the promoters of IL-6, IL-8, and IκBα in response to TNF-α with TGF-β1 pretreatment. These TGF-β1 effects appear to be mediated through the canonical Smad pathway as silencing of the TGF-β central mediator Smad4 resulted in loss of the TGF-β1 effects. Thus, TGF-β1 is capable of eliciting anti-inflammatory effects by inhibiting NF-κB specifically in the intestinal epithelium as well as by decreasing systemic IL-6 and IFN-γ levels. Oral administration of TGF-β1 therefore can potentially be used to protect against gastrointestinal diseases.

Lactobacillus acidophilus alleviates platelet-activating factor-induced inflammatory responses in human intestinal epithelial cells

Probiotics have been used as alternative prevention and therapy modalities in intestinal inflammatory disorders including inflammatory bowel diseases (IBD) and necrotizing enterocolitis (NEC). Pathophysiology of IBD and NEC includes the production of diverse lipid mediators, including platelet-activating factor (PAF) that mediate inflammatory responses in the disease. PAF is known to activate NF-κB, however, the mechanisms of PAF-induced inflammation are not fully defined. We have recently described a novel PAF-triggered pathway of NF-κB activation and IL-8 production in intestinal epithelial cells (IECs), requiring the pivotal role of the adaptor protein Bcl10 and its interactions with CARMA3 and MALT1. The current studies examined the potential role of the probiotic Lactobacillus acidophilus in reversing the PAF-induced, Bcl10-dependent NF-κB activation and IL-8 production in IECs. PAF treatment (5 µM×24 h) of NCM460 and Caco-2 cells significantly increased nuclear p65 NF-κB levels and IL-8 secretion (2-3-fold, P<0.05), compared to control, which were blocked by pretreatment of the cells for 6 h with L. acidophilus (LA) or its culture supernatant (CS), followed by continued treatments with PAF for 24 h. LA-CS also attenuated PAF-induced increase in Bcl10 mRNA and protein levels and Bcl10 promoter activity. LA-CS did not alter PAF-induced interaction of Bcl10 with CARMA3, but attenuated Bcl10 interaction with MALT1 and also PAF-induced ubiquitination of IKKγ. Efficacy of bacteria-free CS of LA in counteracting PAF-induced inflammatory cascade suggests that soluble factor(s) in the CS of LA mediate these effects. These results define a novel mechanism by which probiotics counteract PAF-induced inflammation in IECs.

Protective effects of hydrogen-rich saline on necrotizing enterocolitis in neonatal rats

PURPOSE

The aim of this study was to test the hypothesis that hydrogen-rich saline (HRS) might have protective effects on the development of necrotizing enterocolitis (NEC) in a neonatal rat model.

METHODS

NEC was induced in male newborn Sprague-Dawley rats by formula feeding, exposure to asphyxia and cold stress. Sixty-four rat pups were divided randomly into four groups: C+NS (n=11), C+H2 (n=11), NEC+NS (n=20), and NEC+H2 (n=22). Rats in the former two groups were mother-fed. Pups received intra-peritoneal injection of HRS (10 ml/kg, 10 min before asphyxia stress twice a day) or the same dose of normal saline. Rats were monitored until 96 h after birth. Body weight, histological NEC score, survival time, malondialdehyde, antioxidant capacity, inflammatory mediators, and mucosal integrity were assessed.

RESULTS

HRS treatment maintained the body weight, reduced the incidence of NEC from 85% (17/20) to 54.5% (12/22), increased the survival rate from 25% (5/20) to 68.2% (15/22), and attenuated the severity of NEC. In addition, HRS inhibited the mRNA expression of pro-inflammatory mediators (inducible nitric oxide synthase, tumor necrosis factor-α, and interleukin-6), down-regulated lipid peroxidation, enhanced total antioxidant capacity, and prevented the increase of diamine oxidase in serum. However, no significant influence of HRS on the interleukin-10 mRNA expression was observed.

CONCLUSIONS

HRS showed beneficial effects on neonatal rats with NEC via decreasing oxidative stress, increasing antioxidant capacity, suppressing inflammation, and preserving mucosal integrity.

The prevalence of platelet activating factor acetylhydrolase single nucleotide polymorphisms in relationship to necrotizing enterocolitis in Northwest Louisiana infants

PURPOSE

Studies documented that platelet activating factor (PAF) and the enzyme platelet activating factor acetylhydrolase (PAFAH) play a very important role in the pathogenesis of neonatal necrotizing enterocolitis (NEC). In this retrospective, case-controlled pilot study, the authors investigated the prevalence of single nucleotide polymorphisms (Ile198Thr and Ala379Val) of the PAFAH gene.

SUBJECTS AND METHODS

We screened 570 blood samples from both Caucasian and African-American preterm infants in the Northwest Louisiana population for the above mentioned PAFAH gene polymorphisms. Out of 570 infants, 36 had stage I or II NEC based on diagnostic coding, the International Classification of Diseases, 9th revision, Clinical Modification, 2009 (ICD-9-CM). The remaining infants without an ICD-9-CM diagnosis of NEC were recruited as control population. The DNA was isolated and restriction fragment length polymorphism microplate polymerase chain reaction assay was performed.

RESULTS

Variants of the PAFAH gene polymorphism (Ile198Thr and Ala379Val) frequencies were not significantly different between the infants with NEC and the control group (P value of 0.26 by either multiple logistic regression analysis or the Cochran-Mantel-Haenszel test).

CONCLUSIONS

This is the first study of its kind in exploring the relationship between NEC and single nucleotide polymorphisms in the coding genes of the enzyme PAFAH. Our preliminary data demonstrated that adjusted for the effect of race, PAFAH polymorphisms (Ile198Thr and Ala379Val) have no significant effect on NEC.

The macrophage migration inhibitory factor -173G/C polymorphism is not significantly associated with necrotizing enterocolitis in preterm infants

BACKGROUND AND PURPOSE

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality among premature infants. Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that has been implicated in the pathophysiology of inflammatory bowel diseases. The MIF promoter contains a functionally relevant single nucleotide polymorphism (SNP) G→C at position -173, with the MIF -173*C allele being associated with higher MIF expression in vitro and with higher MIF levels in vivo. The aim of this study was to investigate whether the G/C polymorphism at -173 of the MIF promoter is associated with the development of NEC.

METHODS

In this retrospective cohort study, 107 preterm infants (GA ≤ 32 weeks), of whom 41 had NEC (NEC Stage I n = 20, Stage II n = 3, Stage III n = 18) and 66 were not affected, were genotyped for the MIF -173 SNP. MIF genotyping was carried out by PCR and DHPLC.

RESULTS

We did not find significant differences in the prevalence of the -173G/C polymorphism and in the distribution of the -173 MIF genotype in infants with NEC compared to controls. Moreover, we did not observe an association between the polymorphism and mortality.

CONCLUSIONS

The polymorphism -173G/C of the MIF promoter does not appear to be of major importance in the pathophysiology of NEC in preterm infants.

Transfusion-related necrotizing enterocolitis: a conceptual framework

Necrotizing enterocolitis (NEC) is a disease primarily of prematurity characterized by partial or entire gut necrosis and is associated with significant mortality and morbidity. Recent studies report that approximately 25% to 35% of very low-birth-weight infants less than 1500 g receiving packed red blood cell transfusions develop temporally associated NEC, known as transfusion-related NEC (TR-NEC). Although there are many known risk factors for NEC, this article focuses on 3 contributing factors: packed red blood cell transfusions, enteral feedings, and gastrointestinal immaturity. Previous data suggest that these factors may interact to affect neonatal intestinal tissue oxygenation, which may lead to tissue ischemia, resulting in intestinal injury. This article presents a conceptual framework that combines current theoretical perspectives for TR-NEC, and reviews previous research examining related variables and how their interaction may increase the risk for TR-NEC development. In addition, incorporation of the proposed framework to guide future research and nursing care in this area is discussed.

Novel treatments for NEC: keeping IBD in mind

Necrotizing enterocolitis (NEC) is an inflammatory intestinal disease of premature newborns, thought to result in part from overactivity of the innate immune system. NEC has been well-studied from the perspective of prevention; however, after the disease onset, there are limited treatment options to control its progression. This review discusses four potential therapies that target the overactive immune response in NEC: pentoxifylline, platelet activating factor modulators, glucocorticoids, and vasoactive substances. In addition, given the similar pathogenesis of NEC and inflammatory bowel disease (IBD), we propose that IBD therapies could provide promising leads for novel strategies with which to treat NEC.

Smad7 inhibits autocrine expression of TGF-β2 in intestinal epithelial cells in baboon necrotizing enterocolitis

Preterm infants may be at risk of necrotizing enterocolitis (NEC) due to deficiency of transforming growth factor-β 2 (TGF-β(2)) in the developing intestine. We hypothesized that low epithelial TGF-β(2) expression in preterm intestine and during NEC results from diminished autocrine induction of TGF-β(2) in these cells. Premature baboons delivered at 67% gestation were treated per current norms for human preterm infants. NEC was diagnosed by clinical and radiological findings. Inflammatory cytokines, TGF-β(2), Smad7, Ski, and strawberry notch N (SnoN)/Ski-like oncoprotein (SKIL) was measured using quantitative reverse transcriptase-polymerase chain reaction, immunoblots, and immunohistochemistry. Smad7 effects were examined in transfected IEC6 intestinal epithelial cells in vitro. Findings were validated in archived human tissue samples of NEC. NEC was recorded in seven premature baboons. Consistent with existing human data, premature baboon intestine expressed less TGF-β(2) than term intestine. TGF-β(2) expression was regulated in epithelial cells in an autocrine fashion, which was interrupted in the premature intestine and during NEC due to increased expression of Smad7. LPS increased Smad7 binding to the TGF-β(2) promoter and was associated with dimethylation of the lysine H3K9, a marker of transcriptional silencing, on the nucleosome of TGF-β(2). Increased Smad7 expression in preterm intestine was correlated with the deficiency of SnoN/SKIL, a repressor of the Smad7 promoter. Smad7 inhibits autocrine expression of TGF-β(2) in intestinal epithelial cells in the normal premature intestine and during NEC. Increased Smad7 expression in the developing intestine may be due to a developmental deficiency of the SnoN/SKIL oncoprotein.

Necrotizing enterocolitis and cytomegalovirus infection in a premature infant

Necrotizing enterocolitis is the most common gastrointestinal emergency in neonates. The etiology is considered multifactorial. Risk factors include prematurity, enteral feeding, hypoxia, and bacterial colonization. The etiologic role of viruses is unclear. We present a case of necrotizing enterocolitis associated with cytomegalovirus and Proteobacteria in a 48-day-old, ex-premature infant and discuss the effects of potential viral-bacterial interactions on host susceptibility to this disease.

Lactobacillus rhamnosus (LGG) regulates IL-10 signaling in the developing murine colon through upregulation of the IL-10R2 receptor subunit

The intestinal microflora is critical for normal development, with aberrant colonization increasing the risk for necrotizing enterocolitis (NEC). In contrast, probiotic bacteria have been shown to decrease its incidence. Multiple pro- and anti-inflammatory cytokines have been identified as markers of intestinal inflammation, both in human patients with NEC and in models of immature intestine. Specifically, IL-10 signaling attenuates intestinal responses to gut dysbiosis, and disruption of this pathway exacerbates inflammation in murine models of NEC. However, the effects of probiotics on IL-10 and its signaling pathway, remain poorly defined. Real-time PCR profiling revealed developmental regulation of MIP-2, TNF-α, IL-12, IL-10 and the IL-10R2 subunit of the IL-10 receptor in immature murine colon, while the expression of IL-6 and IL-18 was independent of postnatal age. Enteral administration of the probiotic Lactobacillus rhamnosus GG (LGG) down-regulated the expression of TNF-α and MIP-2 and yet failed to alter IL-10 mRNA and protein expression. LGG did however induce mRNA expression of the IL-10R2 subunit of the IL-10 receptor. IL-10 receptor activation has been associated with signal transducer and activator of transcription (STAT) 3-dependent induction of members of the suppressors of cytokine signaling (SOCS) family. In 2 week-old mice, LGG also induced STAT3 phosphorylation, increased colonic expression of SOCS-3, and attenuated colonic production of MIP-2 and TNF-α. These LGG-dependent changes in phosphoSTAT3, SOCS3, MIP-2 and TNF-α were all inhibited by antibody-mediated blockade of the IL-10 receptor. Thus LGG decreased baseline proinflammatory cytokine expression in the developing colon through upregulation of IL-10 receptor-mediated signaling, most likely due to the combined induction of phospho-STAT3 and SOCS3. Furthermore, LGG-dependent increases in IL-10R2 were associated with reductions in TNF-α, MIP-2 and disease severity in a murine model of intestinal injury in the immature colon.

CDP-choline reduces severity of intestinal injury in a neonatal rat model of necrotizing enterocolitis

BACKGROUND

Cytidine 5'-diphosphocholine (CDP-choline) is an endogenous intermediate in the biosynthesis of phosphatidylcholine, a contributor to the mucosal defense of the intestine. The aim of this study was to evaluate the possible cytoprotective effect of CDP-choline treatment on intestinal cell damage, membrane phospholipid content, inflammation, and apoptosis in a neonatal rat model of necrotizing enterocolitis (NEC).

METHODS

We divided a total of 30 newborn pups into three groups: control, NEC, and NEC + CDP-choline. We induced NEC by enteral formula feeding, exposure to hypoxia-hyperoxia, and cold stress. We administered CDP-choline intraperitoneally at 300 mg/kg/d for 3 d starting from the first day of life. We evaluated apoptosis macroscopically and histopathologically in combination with proinflammatory cytokines in the gut samples. Moreover, we determined membrane phospholipid levels as well as activities of xanthine oxidase, superoxide dismutase, glutathione peroxidase, and myeloperoxidase enzymes and the malondialdehyde content of intestinal tissue.

RESULTS

Mean clinical sickness score, macroscopic gut assessment score, and intestinal injury score were significantly improved, whereas mean apoptosis score and caspase-3 levels were significantly reduced in pups in the NEC + CDP-choline group compared with the NEC group. Tissue proinflammatory cytokine (interleukin-1β, interleukin-6, and tumor necrosis factor-α) levels as well as tissue malondialdehyde content and myeloperoxidase activities were reduced, whereas glutathione peroxidase and superoxide dismutase activities were preserved in the NEC + CDP-choline group. In addition, NEC damage reduced intestinal tissue membrane phospholipids, whereas CDP-choline significantly enhanced total phospholipid and phosphatidylcholine levels. Long-term follow-up in additional experiments revealed increased body weight, decreased clinical sickness scores, and enhanced survival in CDP-choline-receiving versus saline-receiving pups with NEC lesions.

CONCLUSIONS

Our study reports, for the first time, beneficial effects of CDP-choline treatment on intestinal injury in a neonatal rat model of NEC. Our data suggest that CDP-choline may be used as an effective therapeutic agent to prevent NEC.