Anti-inflammatory effects of epidermal growth factor on the immature human intestine

Human milk extracellular vesicles modulate inflammation and cell survival in intestinal and immune cells

Human milk contains extracellular vesicles (EVs) that carry bioactive molecules such as microRNA, to the newborn intestine. The downstream effects of EV cargo on signaling and immune modulation may shield neonates against inflammatory diseases, including necrotizing enterocolitis. Premature infants are especially at risk, while human milk-feeding may offer protection. The effect of gestational-age specific term and preterm EVs from transitional human milk was characterized on human intestinal epithelial cells (HIECs and Caco-2), primary macrophages, and THP-1 monocytes. We hypothesized that term and preterm EVs differentially influence immune-related cytokines and cell death. We found that preterm EVs were enriched in CD14 surface marker, while both term and preterm EVs increased epidermal growth factor secretion. Following inflammatory stimuli, only term EVs inhibited secretion of IL-6 in HIECs, and reduced expression of pro-inflammatory cytokine IL-1β in macrophages. Term and preterm EVs inhibited secretion of IL-1β and reduced inflammasome related cell death. We proposed that human milk EVs regulate immune-related signaling via their conserved microRNA cargo, which could promote tolerance and a homeostatic immune response. These findings provide basis for further studies into potential therapeutic supplementation with EVs in vulnerable newborn populations by considering functional, gestational age-specific effects. IMPACT: This study reveals distinct functional differences between term and preterm transitional human milk extracellular vesicles (EVs) highlighting the importance of gestational age in their bioactivity. Term EVs uniquely inhibited IL-6 secretion, IL-1β expression, and apoptosis following inflammatory stimuli. Both term and preterm human milk EVs reduced IL-1β secretion and inflammasome-induced cell death. Conserved human milk extracellular vesicle microRNA cargo could be a mediator of the anti-inflammatory effects, particularly targeting cytokine production, the inflammasome, and programmed cell death. These findings underscore the importance of considering gestational age in future research exploring the therapeutic potential of human milk extracellular vesicles to prevent or treat intestinal inflammatory diseases in neonates.

Development and biological evaluation of smart powder bandage for wound healing and dressing applications

Cutaneous wounds are one of the pressing concerns for healthcare systems globally. With large amounts of water, conventional hydrogels encounter obstacles in effectively delivering small molecules and peptides for wound healing. The surplus water content challenges the stability and sustained release of small molecules and peptides, diminishing their therapeutic efficacy. Our pioneering smart powder bandage, fabricated through freeze-drying, ensures a water content of <1 % during storage. Upon contact with wound exudate, it forms hydrogel layers, thereby optimizing the delivery of peptides. Tailored for thermosensitive peptides such as EGF, this strategy surmounts the limitations of conventional hydrogels, providing a robust platform for efficacious therapeutic delivery in wound healing applications. Developing multifunctional wound dressings with antibacterial, anti-inflammatory, hemostatic, and healing properties is essential to promote wound healing. Therefore, the current investigation reports the development of multifunctional EGF@Silnanom SPB with the above-mentioned properties to promote wound healing using silver nanomix (Silnanom) and bioactive epidermal growth factors (EGF) as active therapeutics. The characterization of smart powder bandage (SPB) revealed that Silnanom were homogeneously dispersed in the entangled polymer network. The multifunctional smart powder bandage exhibited high bacterial inhibition rates against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), and rigorous hemocompatibility, cell compatibility, and in vivo studies also confirmed its biocompatibility. Furthermore, multifunctional EGF@Silnanom SPB effectively reduced pro-inflammatory markers, enhanced collagen deposition, promoted angiogenesis, and accelerated wound healing in a full-thickness mouse wound model through the sustained release of Silnanom and EGF. Additionally, the results of hemostasis analysis on the tail amputation mouse model confirmed the hemostasis properties of the EGF@Silnanom SPB. Overall, the multifunctional EGF@Silnanom SPB shows promising potential for skin wound repair, offering a potent and effective solution to the challenges posed by conventional wound dressings.

Gestational age at birth influences protein and RNA content in human milk extracellular vesicles

Human milk extracellular vesicles (HM EVs) are proposed to protect against disease development in infants. This protection could in part be facilitated by the bioactive EV cargo of proteins and RNA. Notably, mothers birth infants of different gestational ages with unique needs, wherein the EV cargo of HM may diverge. We collected HM from lactating mothers within two weeks of a term or preterm birth. Following purification of EVs, proteins and mRNA were extracted for proteomics and sequencing analyses, respectively. Over 2000 protein groups were identified, and over 8000 genes were quantified. The total number of proteins and mRNA did not differ significantly between the two conditions, while functional bioinformatics of differentially expressed cargo indicated enrichment in immunoregulatory cargo for preterm HM EVs. In term HM EVs, significantly upregulated cargo was enriched in metabolism-related functions. Based on gene expression signatures from HM-contained single cell sequencing data, we proposed that a larger portion of preterm HM EVs are secreted by immune cells, whereas term HM EVs contain more signatures of lactocyte epithelial cells. Proposed differences in EV cargo could indicate variation in mother's milk based on infants' gestational age and provide basis for further functional characterisation.

Lipocalin-2 and calprotectin as stool biomarkers for predicting necrotizing enterocolitis in premature neonates

BACKGROUND

Necrotizing enterocolitis (NEC) is a major challenge for premature infants in neonatal intensive care units and efforts toward the search for indicators that could be used to predict the development of the disease have given limited results until now.

METHODS

In this study, stools from 132 very low birth weight infants were collected daily in the context of a multi-center prospective study aimed at investigating the potential of fecal biomarkers for NEC prediction. Eight infants (~6%) received a stage 3 NEC diagnosis. Their stools collected up to 10 days before diagnosis were included and matched with 14 non-NEC controls and tested by ELISA for the quantitation of eight biomarkers.

RESULTS

Biomarkers were evaluated in all available stool samples leading to the identification of lipocalin-2 and calprotectin as the two most reliable predicting markers over the 10-day period prior to NEC development. Pooling the data for each infant confirmed the significance of lipocalin-2 and calprotectin, individually and in combination 1 week in advance of the NEC clinical diagnosis.

CONCLUSIONS

The lipocalin-2 and calprotectin tandem represents a significant biomarker signature for predicting NEC development. Although not yet fulfilling the "perfect biomarker" criteria, it represents a first step toward it.

IMPACT

Stool biomarkers can be used to predict NEC development in very low birth weight infants more than a week before the diagnosis. LCN2 was identified as a new robust biomarker for predicting NEC development, which used in conjunction with CALPRO, allows the identification of more than half of the cases that will develop NEC in very low birth weight infants. Combining more stool markers with the LCN2/CALPRO tandem such as PGE2 can further improve the algorithm for the prediction of NEC development.

Effect of Ketoprofen and ATB-352 on the Immature Human Intestine: Identification of Responders and Non-responders

BACKGROUND AND OBJECTIVE

The use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a broad spectrum of life-threatening adverse effects on the immature gastrointestinal tract. NSAID derivatives exploiting the beneficial effects of biologically active gases, such as hydrogen sulfide (H2S), have been developed. Herein, we determined the effects of ketoprofen and ATB-352, a H2S-releasing ketoprofen derivative, on selected metabolic pathways previously identified to be significantly altered by indomethacin in the human immature intestine.

METHODS

Ketoprofen and ATB-352 were tested on human mid-gestation small intestinal explants maintained in a serum-free organ culture system for 48 hours. The expression levels of the representative genes involved in selected metabolic pathways were measured by real-time PCR after a treatment of 48 hours.

RESULTS

Tested at a concentration that allows more than 80% inhibition of PGE2 production, ketoprofen was found to be less damaging than indomethacin at an equivalent dosage. However, based on the inducibility of cyclooxygenase-2 transcript expression, we were able to discriminate between responder individuals in which the deleterious effects observed with indomethacin were attenuated, and non-responder specimens in which the effects were similar to those observed with indomethacin. ATB-352 did not induce significant changes compared to ketoprofen on these metabolic pathways.

CONCLUSIONS

These results show less damaging effects of ketoprofen compared to indomethacin on the immature intestine and indicate that the intestinal response to this NSAID significantly varies between individuals. However, the results did not allow us to demonstrate a specific beneficial effect of H2S release in organ culture.

Neuroinflammation in Autism Spectrum Disorders: Role of High Mobility Group Box 1 Protein

The pathogenesis of autism spectrum disorder (ASD) likely involves genetic and environmental factors, impacting the complex neurodevelopmental and behavioral abnormalities of the disorder. Scientific research studies emerging within the past two decades suggest that immune dysfunction and inflammation have pathogenic influences through different mechanisms, all leading to both a chronic state of low grade inflammation, and alterations in the central nervous system and immune response, respectively. The high mobility group box-1 protein (HMGB1) is an inflammatory marker which has been shown to play a role in inducing and influencing neuroinflammation. Current evidences suggest a possible role in the multiple pathogenic mechanisms of ASD. The aim of this manuscript is to review the major hypothesis for ASD pathogenesis, with specific regards to the immunological ones, and to provide a comprehensive review of the current data about the association between HMGB1 and ASD. A systematic search has been carried out through Medline via Pubmed to identify all original articles published in English, on the basis of the following keywords: "HMGB1", "autism", "autism spectrum disorder", "neuroinflammation", and "child".

The nitric oxide synthase 2 pathway is targeted by both pro- and anti-inflammatory treatments in the immature human intestine

BACKGROUND AND AIM

NO synthase 2 (NOS2) was recently identified as one the most overexpressed genes in intestinal samples of premature infants with necrotizing enterocolitis (NEC). NOS2 is widely implicated in the processes of epithelial cell injury/apoptosis and host immune defense but its specific role in inflammation of the immature human intestinal mucosa remains unclear. Interestingly, factors that prevent NEC such as epidermal growth factor (EGF) attenuate the inflammatory response in the mid-gestation human small intestine using serum-free organ culture while drugs that are associated with NEC occurrence such as the non-steroidal anti-inflammatory drug, indomethacin (INDO), exert multiple detrimental effects on the immature human intestine. In this study we investigate the potential role of NOS2 in modulating the gut inflammatory response under protective and stressful conditions by determining the expression profile of NOS2 and its downstream pathways in the immature intestine.

METHODS

Gene expression profiles of cultured mid-gestation human intestinal explants were investigated in the absence or presence of a physiological concentration of EGF (50 ng/ml) or 1 μM INDO for 48 h using Illumina whole genome microarrays, Ingenuity Pathway Analysis software and quantitative PCR to investigate the expression of NOS2 and NOS2-pathway related genes.

RESULTS

In the immature intestine, NOS2 expression was found to be increased by EGF and repressed by INDO. Bioinformatic analysis identified differentially regulated pathways where NOS2 is known to play an important role including citrulline/arginine metabolism, epithelial cell junctions and oxidative stress. At the individual gene level, we identified many differentially expressed genes of the citrulline/arginine metabolism pathway such as ARG1, ARG2, GLS, OAT and OTC in response to EGF and INDO. Gene expression of tight junction components such as CLDN1, CLDN2, CLDN7 and OCN and of antioxidant markers such as DUOX2, GPX2, SOD2 were also found to be differentially modulated by EGF and INDO.

CONCLUSION

These results suggest that the protective effect of EGF and the deleterious influence of INDO on the immature intestine could be mediated via regulation of NOS2. Pathways downstream of NOS2 involved with these effects include metabolism linked to NO production, epithelial barrier permeability and antioxidant expression. These results suggest that NOS2 is a likely regulator of the inflammatory response in the immature human gut and may provide a mechanistic basis for the protective effect of EGF and the deleterious effects of INDO.

Late acute graft-versus-host disease: a prospective analysis of clinical outcomes and circulating angiogenic factors

Late acute (LA) graft-versus-host disease (GVHD) is persistent, recurrent, or new-onset acute GVHD symptoms occurring >100 days after allogeneic hematopoietic cell transplantation (HCT). The aim of this analysis is to describe the onset, course, morbidity, and mortality of and examine angiogenic factors associated with LA GVHD. A prospective cohort of patients (n = 909) was enrolled as part of an observational study within the Chronic GVHD Consortium. Eighty-three patients (11%) developed LA GVHD at a median of 160 (interquartile range, 128-204) days after HCT. Although 51 out of 83 (61%) achieved complete or partial response to initial therapy by 28 days, median failure-free survival was only 7.1 months (95% confidence interval, 3.4-19.1 months), and estimated overall survival (OS) at 2 years was 56%. Given recently described alterations of circulating angiogenic factors in classic acute GVHD, we examined whether alterations in such factors could be identified in LA GVHD. We first tested cases (n = 55) and controls (n = 50) from the Chronic GVHD Consortium and then validated the findings in 37 cases from Mount Sinai Acute GVHD International Consortium. Plasma amphiregulin (AREG; an epidermal growth factor [EGF] receptor ligand) was elevated, and an AREG/EGF ratio at or above the median was associated with inferior OS and increased nonrelapse mortality in both cohorts. Elevation of AREG was detected in classic acute GVHD, but not chronic GVHD. These prospective data characterize the clinical course of LA GVHD and demonstrate alterations in angiogenic factors that make LA GVHD biologically distinct from chronic GVHD.

Gene expression profiling in necrotizing enterocolitis reveals pathways common to those reported in Crohn's disease

BACKGROUND

Necrotizing enterocolitis (NEC) is the most frequent life-threatening gastrointestinal disease experienced by premature infants in neonatal intensive care units. The challenge for neonatologists is to detect early clinical manifestations of NEC. One strategy would be to identify specific markers that could be used as early diagnostic tools to identify preterm infants most at risk of developing NEC or in the event of a diagnostic dilemma of suspected disease. As a first step in this direction, we sought to determine the specific gene expression profile of NEC.

METHODS

Deep sequencing (RNA-Seq) was used to establish the gene expression profiles in ileal samples obtained from preterm infants diagnosed with NEC and non-NEC conditions. Data were analyzed with Ingenuity Pathway Analysis and ToppCluster softwares.

RESULTS

Data analysis indicated that the most significant functional pathways over-represented in NEC neonates were associated with immune functions, such as altered T and B cell signaling, B cell development, and the role of pattern recognition receptors for bacteria and viruses. Among the genes that were strongly modulated in neonates with NEC, we observed a significant degree of similarity when compared with those reported in Crohn's disease, a chronic inflammatory bowel disease.

CONCLUSIONS

Gene expression profile analysis revealed a predominantly altered immune response in the intestine of NEC neonates. Moreover, comparative analysis between NEC and Crohn's disease gene expression repertoires revealed a surprisingly high degree of similarity between these two conditions suggesting a new avenue for identifying NEC biomarkers.

Inflammation is increased with anxiety- and depression-like signs in a rat model of spinal cord injury

Spinal cord injury (SCI) leads to increased anxiety and depression in as many as 60% of patients. Yet, despite extensive clinical research focused on understanding the variables influencing psychological well-being following SCI, risk factors that decrease it remain unclear. We hypothesized that excitation of the immune system, inherent to SCI, may contribute to the decrease in psychological well-being. To test this hypothesis, we used a battery of established behavioral tests to assess depression and anxiety in spinally contused rats. The behavioral tests, and subsequent statistical analyses, revealed three cohorts of subjects that displayed behavioral characteristics of (1) depression, (2) depression and anxiety, or (3) no signs of decreased psychological well-being. Subsequent molecular analyses demonstrated that the psychological cohorts differed not only in behavioral symptoms, but also in peripheral (serum) and central (hippocampi and spinal cord) levels of pro-inflammatory cytokines. Subjects exhibiting a purely depression-like profile showed higher levels of pro-inflammatory cytokines peripherally, whereas subjects exhibiting a depression- and anxiety-like profile showed higher levels of pro-inflammatory cytokines centrally (hippocampi and spinal cord). These changes in inflammation were not associated with injury severity; suggesting that the association between inflammation and the expression of behaviors characteristic of decreased psychological well-being was not confounded by differential impairments in motor ability. These data support the hypothesis that inflammatory changes are associated with decreased psychological well-being following SCI.

Increased Epidermal Growth Factor Receptor (EGFR) Associated with Hepatocyte Growth Factor (HGF) and Symptom Severity in Children with Autism Spectrum Disorders (ASDs)

BACKGROUND

One in 88 children in the US is thought to have one of the autism spectrum disorders (ASDs). ASDs are characterized by social impairments and communication problems. Growth factors and their receptors may play a role in the etiology of ASDs. Research has shown that epidermal growth factor receptor (EGFR) activation is associated with nerve cell development and repair. This study was designed to measure plasma levels of EGFR in autistic children and correlate these levels with its ligand, epidermal growth factor, other related putative biomarkers such as hepatocyte growth factor (HGF), the ligand for MET (MNNG HOS transforming gene) receptor, as well as the symptom severity of 19 different behavioral symptoms.

SUBJECTS AND METHODS

Plasma EGFR concentration was measured in 33 autistic children and 34 age- and gender-similar neurotypical controls, using an enzyme-linked immunosorbent assay. Plasma EGFR levels were compared to putative biomarkers known to be associated with EGFR and MET and severity levels of 19 autism-related symptoms.

RESULTS

We found plasma EGFR levels significantly higher in autistic children, when compared to neurotypical controls. EGFR levels correlated with HGF and high-mobility group protein B1 (HMGB1) levels, but not other tested putative biomarkers, and EGFR levels correlated significantly with severity of expressive language, conversational language, focus/attention, hyperactivity, eye contact, and sound sensitivity deficiencies.

CONCLUSIONS

These results suggest a relationship between increased plasma EGFR levels and designated symptom severity in autistic children. A strong correlation between plasma EGFR and HGF and HMGB1 suggests that increased EGFR levels may be associated with the HGF/Met signaling pathway, as well as inflammation.

Chemokine network during adipogenesis in 3T3-L1 cells: Differential response between growth and proinflammatory factor in preadipocytes vs. adipocytes

Obesity is recognized as a low-grade chronic inflammatory state which involves a chemokine network contributing to a variety of diseases. As a first step toward understanding the roles of the obesity-driven chemokine network, we used a 3T3-L1 cell differentiation model to identify the chemokine profiles elicited during adipogenesis and how this profile is modified by epidermal growth factor (EGF) and tumor necrosis factor-α (TNF) as a growth and proinflammatory factor, respectively. The chemokine network was monitored using PCR arrays and qRT-PCR while main signaling pathways of EGF and TNF were measured using immunoblotting. The dominant chemokines in preadipocytes were CCL5, CCL8, CXCL1, and CXCL16, and in adipocytes CCL6 and CXCL13. The following chemokines were found in both preadipocytes and adipocytes: CCL2, CCL7, CCL25, CCL27, CXCL5, CXCL12, and CX3CL1. Among chemokine receptors, CXCR7 was specific for preadipocytes and CXCR2 for adipocytes. These findings indicate the development of a CXCL12–CXCR7 axis in preadipocytes and a CXCL5–CXCR2 axis in adipocytes. In addition to induction of CCL2 and CCL7 in both preadipocytes and adipocytes, EGF enhanced specifically CXCL1 and CXCL5 in adipocytes, indicating the potentiation of CXCR2-mediated pathway in adipocytes. TNF induced CCL2, CCL7, and CXCL1 in preadipocytes but had no response in adipocytes. EGFR downstream activation was dominant in adipocytes whereas NFκB activation was dominant in preadipocytes. Taken together, the adipocyte-driven chemokine network in the 3T3-L1 cell differentiation model involves CXCR2-mediated signaling which appears more potentiated to growth factors like EGF than proinflammatory factors like TNF.

Decreased Epidermal Growth Factor (EGF) Associated with HMGB1 and Increased Hyperactivity in Children with Autism

Background

Autism spectrum disorders (ASDs), characterized by impaired social interactions and deficits in verbal and nonverbal communication, are thought to affect 1 in 88 children in the United States. There is much support for the role of growth factors in the etiology of autism. Recent research has shown that epithelial growth factor (EGF) is decreased in young autistic children (2–4 years of age). This study was designed to determine plasma levels of EGF in an older group of autistic children (mean age 10.6 years) and to correlate these EGF levels with putative biomarkers HGF, uPA, uPAR, GAD2, MPO GABA, and HMGB1, as well as symptom severity of 19 different symptoms.

Subjects and methods

Plasma from 38 autistic children, 11 children with pervasive developmental disorder (PDD-NOS) and 40 neurotypical, age and gender similar controls was assessed for EGF concentration using ELISAs. Severity of 19 symptoms (awareness, expressive language, receptive language, (conversational) pragmatic language, focus/attention, hyperactivity, impulsivity, perseveration, fine motor skills, gross motor skills, hypotonia (low muscle tone), tiptoeing, rocking/pacing, stimming, obsessions/fixations, eye contact, sound sensitivity, light sensitivity, and tactile sensitivity) was assessed and then compared to EGF concentrations.

Results

In this study, we found EGF levels in autistic children and those with PDD-NOS to be significantly lower when compared with neurotypical controls. EGF levels correlated with HMGB1 levels but not the other tested putative biomarkers, and EGF correlated negatively with hyperactivity, gross motor skills, and tiptoeing but not other symptoms.

Conclusions

These results suggest an association between decreased plasma EGF levels and selected symptom severity. We also found a strong correlation between plasma EGF and HMGB1, suggesting inflammation is associated with decreased EGF.

Deleterious effects of indomethacin in the mid-gestation human intestine

The use of the anti-inflammatory drug indomethacin (INDO) in preterm infants has been associated with an increased risk of developing enteropathies. In this study, we have investigated the direct impact of INDO on the human mid-gestation intestinal transcriptome using serum-free organ culture. After determining the optimal dose of 1 μM of INDO (90% inhibition of intestinal prostaglandin E2 production and range of circulating levels in treated preterm babies), global gene expression profiles were determined using Illumina bead chip microarrays in both small and large intestines after 48 h of INDO treatment. Using Ingenuity Pathway Analysis software, we identified critical metabolic pathways that were significantly altered by INDO in both intestinal segments including inflammation and also glycolysis, oxidative phosphorylation and free radical scavenging/oxidoreductase activity, which were confirmed by qPCR at the level of individual genes. Taken together, these data revealed that INDO directly exerts multiple detrimental effects on the immature human intestine.