NOD2 and inflammation: current insights

The nucleotide-binding oligomerization domain (NOD) protein, NOD2, belonging to the intracellular NOD-like receptor family, detects conserved motifs in bacterial peptidoglycan and promotes their clearance through activation of a proinflammatory transcriptional program and other innate immune pathways, including autophagy and endoplasmic reticulum stress. An inactive form due to mutations or a constitutive high expression of NOD2 is associated with several inflammatory diseases, suggesting that balanced NOD2 signaling is critical for the maintenance of immune homeostasis. In this review, we discuss recent developments about the pathway and mechanisms of regulation of NOD2 and illustrate the principal functions of the gene, with particular emphasis on its central role in maintaining the equilibrium between intestinal microbiota and host immune responses to control inflammation. Furthermore, we survey recent studies illustrating the role of NOD2 in several inflammatory diseases, in particular, inflammatory bowel disease, of which it is the main susceptibility gene

Effect of Lactobacillus rhamnosus HN001 and Bifidobacterium longum BB536 on the healthy gut microbiota composition at phyla and species level: a preliminary study

AIM: To evaluate the ability of Lactobacillus rhamnosus HN001 and Bifidobacterium longum BB536 to colonize the intestinal environment of healthy subjects and modify the gut microbiota composition. METHODS: Twenty healthy Italian volunteers, eight males and twelve females, participated in the study. Ten subjects took a sachet containing 4 × 109 colony-forming units (CFU) of Bifidobacterium longum BB536 and 109 CFU of Lactobacillus rhamnosus HN001, 30 min before breakfast (pre-prandial administration), while ten subjects took a sachet of probiotic product 30 min after breakfast (post-prandial administration). The ability of Lactobacillus rhamnosus HN001 and Bifidobacterium longum BB536 to colonize human gut microbiota was assessed by means of quantitative real-time PCR, while changes in gut microbiota composition were detected by using Ion Torrent Personal Genome Machine. RESULTS: Immediately after 1-mo of probiotic administration, B. longum BB536 and L. rhamnosus HN001 load was increased in the majority of subjects in both pre-prandial and post-prandial groups. This increase was found also 1 mo after the end of probiotic oral intake in both groups, if compared to samples collected before probiotic consumption. At phyla level a significant decrease in Firmicutes abundance was detected immediately after 1-mo of B. longum BB536 and L. rhamnosus HN001 oral intake. This reduction persisted up to 1 mo after the end of probiotic oral intake together with a significant decrease of Proteobacteria abundance if compared to samples collected before probiotic administration. Whereas, at species level, a higher abundance of Blautia producta, Blautia wexlerae and Haemophilus ducrey was observed, together with a reduction of Holdemania filiformis, Escherichia vulneris, Gemmiger formicilis and Streptococcus sinensis abundance. In addition, during follow-up period we observed a further reduction in Escherichia vulneris and Gemmiger formicilis, together with a decrease in Roseburia faecis and Ruminococcus gnavus abundance. Conversely, the abundance of Akkermansia muciniphila was increased if compared to samples collected at the beginning of the experimental time course. CONCLUSION: B. longum BB536 and L. rhamnosus HN001 showed the ability to modulate the gut microbiota composition, leading to a significant reduction of potentially harmful bacteria and an increase of beneficial ones. Further studies are needed to better understand the specific mechanisms involved in gut microbiota modulation

Emerging roles of gut virome in pediatric diseases

In the last decade, the widespread application of shotgun metagenomics provided extensive characterization of the bacterial “dark matter” of the gut microbiome, propelling the development of dedicated, standardized bioinformatic pipelines and the systematic collection of metagenomic data into comprehensive databases. The advent of next-generation sequencing also unravels a previously underestimated viral population (virome) present in the human gut. Despite extensive efforts to characterize the human gut virome, to date, little is known about the childhood gut virome. However, alterations of the gut virome in children have been linked to pathological conditions such as inflammatory bowel disease, type 1 diabetes, malnutrition, diarrhea and celiac diseas

Statistical analysis of a weighting scheme for asteroid observation astrometric errors taking into consideration the classification of the observed asteroids

Observations of asteroids and other near-Earth objects are of great importance for planetary defence activities, the purpose of which is to determine their positions in space and the probabilities of Earth impacts, as well as developing strategies to mitigate this risk. In this framework, having precise observations is important to describe accurately the orbits of near-Earth asteroids. However, given a general absence of a-priori uncertainty information, the single observations are given proper weights that reflect the accuracy expected by the observers who perform the observations. The weights are calculated for each observer on the base of statistical analysis of systematic and random errors and providing them with an accurate definition is necessary if the magnitude of the error of a single observation is to be correctly estimated. In this paper a statistical analysis on the residuals of the astrometric data provided by the major surveys is presented introducing a dynamic classification of observed asteroids. The observations are thus subdivided between those relative to Near Earth and Main Belt Asteroids and the quality of the data for each station is studied focussing on this classification. The results show that most of the considered stations have the same quality regardless of the measured object, while four of them show a dependency on this factor

LPS-induced TNF-α factor mediates pro-inflammatory and pro-fibrogenic pattern in non-alcoholic fatty liver disease

Lipopolysaccharide (LPS) is currently considered one of the major players in non-alcoholic fatty liver disease (NAFLD) pathogenesis and progression. Here, we aim to investigate the possible role of LPS-induced TNF-α factor (LITAF) in inducing a pro-inflammatory and pro-fibrogenic phenotype of non-alcoholic steatohepatitis (NASH).We found that children with NAFLD displayed, in different liver-resident cells, an increased expression of LITAF which correlated with histological traits of hepatic inflammation and fibrosis. Total and nuclear LITAF expression increased in mouse and human hepatic stellate cells (HSCs). Moreover, LPS induced LITAF-dependent transcription of IL-1β, IL-6 and TNF-α in the clonal myofibroblastic HSC LX-2 cell line, and this effect was hampered by LITAF silencing. We showed, for the first time in HSCs, that LITAF recruitment to these cytokine promoters is LPS dependent. However, preventing LITAF nuclear translocation by p38MAPK inhibitor, the expression of IL-6 and TNF-α was significantly reduced with the aid of p65NF-ĸB, while IL-1β transcription exclusively required LITAF expression/activity. Finally, IL-1β levels in plasma mirrored those in the liver and correlated with LPS levels and LITAF-positive HSCs in children with NASH.In conclusion, a more severe histological profile in paediatric NAFLD is associated with LITAF over-expression in HSCs, which in turn correlates with hepatic and circulating IL-1β levels outlining a panel of potential biomarkers of NASH-related liver damage. The in vitro study highlights the role of LITAF as a key regulator of the LPS-induced pro-inflammatory pattern in HSCs and suggests p38MAPK inhibitors as a possible therapeutic approach against hepatic inflammation in NASH

Escherichia coli specific secretory IgA and cytokines in human milk from mothers of different ethnic groups resident in northern Italy.

Breast milk supplies many bioactive components. Neonates protection from pathogenic bacteria is mainly attributable to secretory IgA antibodies present in human milk in an amount depending on previous antigenic exposure. To bring new details into the field of immunological memory in secretory immunity, we evaluated the production of s-IgA specific for E. coli (E. coli s-IgA), and of proinflammatory (IL-6 and IL-8) or anti-inflammatory (IL-10) cytokines in the milk of mothers of different ethnic groups exposed in the past to poor conditions, but nowadays living in Italy in adequate conditions. Mothers from Italy, Africa, Asia and Eastern European Countries were included in the study. Anti- E. coli s-IgA, IL-6, IL-8 and IL-10 were determined by ELISA. Breast milk of all the foreign mothers presented higher levels of E. coli s-IgA than Italians, and for Asian and African mothers were significative (p=0.031 and p=0.015, respectively). Milk from women of Eastern European Countries revealed the highest IL-8 levels (p=0.026), while milk from Asian women presented the greatest concentration of IL-6 (p=0.04); however, the Africans reported the lowest concentrations of IL-10 (p=0.045). Since all the mothers had been living in Italy for some time, we believe that the presence of high levels of E. coli s-IgA, supported by high levels of pro-inflammatory cytokine, is part of a persisting immunological secretory memory

Fecal and mucosal microbiota profiling in pediatric inflammatory bowel diseases

An altered gut microbiota profile has been widely documented in inflammatory bowel diseases (IBD). The intestinal microbial community has been more frequently investigated in the stools than at the level of the mucosa, while most of the studies have been performed in adults. We aimed to define the gut microbiota profile either by assessing fecal and colonic mucosa samples (inflamed or not) from pediatric IBD patients

Role of HMGB1 as a suitable biomarker of subclinical intestinal inflammation and mucosal healing in patients with inflammatory bowel disease

BACKGROUND: Noninvasive biomarkers of high- and low-grade intestinal inflammation and of mucosal healing (MH) in patients with inflammatory bowel disease are currently lacking. We have recently shown that fecal high mobility group box 1 (HMGB1) protein is a novel biomarker of gut inflammation. We aimed at investigating in a mouse model if HMGB1 was able to foresee both a clinically evident and a subclinical gut inflammation and if its normalization indicated MH. We also aimed at confirming the results in patients with Crohn's disease (CD) and ulcerative colitis. METHODS: C57BL6/J mice were treated with increasing doses of dextran sodium sulphate to induce colitis of different severity degrees; 28 with CD, 23 with ulcerative colitis, and 17 controls were also enrolled. Fecal HMGB1 was analyzed by enzyme-linked immunosorbent assay and immunoblotting. RESULTS: Fecal HMGB1 increased by 5-, 11-, 18-, and 24-folds with dextran sodium sulphate doses of 0.25%, 0.50%, 1%, and 4%, respectively, showing that the protein detected a high-grade and a subclinical inflammation. After a recovery time of 4-week posttreatment, HMGB1 returned to control levels, paralleling MH. In patients, fecal HMGB1 significantly correlated with endoscopic indexes (Simple Endoscopic Score for Crohn's Disease [SES-CD], endoscopic Mayo subscore), but not with the disease activity indexes (Crohn's disease Activity Index, partial Mayo score). CONCLUSIONS: Fecal HMGB1 is a robust noninvasive biomarker of clinically overt and subclinical gut inflammation; it can also be a surrogate marker of MH. We suggest the use of fecal HMGB1 to monitor the disease course and assess therapy outcomes in inflammatory bowel diseaseBACKGROUND: Noninvasive biomarkers of high- and low-grade intestinal inflammation and of mucosal healing (MH) in patients with inflammatory bowel disease are currently lacking. We have recently shown that fecal high mobility group box 1 (HMGB1) protein is a novel biomarker of gut inflammation. We aimed at investigating in a mouse model if HMGB1 was able to foresee both a clinically evident and a subclinical gut inflammation and if its normalization indicated MH. We also aimed at confirming the results in patients with Crohn's disease (CD) and ulcerative colitis. METHODS: C57BL6/J mice were treated with increasing doses of dextran sodium sulphate to induce colitis of different severity degrees; 28 with CD, 23 with ulcerative colitis, and 17 controls were also enrolled. Fecal HMGB1 was analyzed by enzyme-linked immunosorbent assay and immunoblotting. RESULTS: Fecal HMGB1 increased by 5-, 11-, 18-, and 24-folds with dextran sodium sulphate doses of 0.25%, 0.50%, 1%, and 4%, respectively, showing that the protein detected a high-grade and a subclinical inflammation. After a recovery time of 4-week posttreatment, HMGB1 returned to control levels, paralleling MH. In patients, fecal HMGB1 significantly correlated with endoscopic indexes (Simple Endoscopic Score for Crohn's Disease [SES-CD], endoscopic Mayo subscore), but not with the disease activity indexes (Crohn's disease Activity Index, partial Mayo score). CONCLUSIONS: Fecal HMGB1 is a robust noninvasive biomarker of clinically overt and subclinical gut inflammation; it can also be a surrogate marker of MH. We suggest the use of fecal HMGB1 to monitor the disease course and assess therapy outcomes in inflammatory bowel diseas

The red cell distribution width (RDW): value and role in preterm, IUGR (intrauterine growth restricted), full-term infants.

To measure the red cell distribution width (RDW) ranges at birth and to evaluate potential association with typical neonatal diseases: patent of the ductus arteriousus (PDA), bronchopulmonary dysplasia (BPD), and late-onset sepsis (LOS) mortality.Forty-six full-term, 41 preterm, and 35 intrauterine growth restricted (IUGR) infants participated in this retrospective, observational study. RDW was measured before 3 days of life (T0) in all infants, and at first month of life (T1) in preterm/IURG patients.RDW% mean (standard deviation) at T0 was: 15.65 (1.18) in full-term newborns; 17.7 (2.06) in preterm; 17.45 (1.81) in IUGR. A negative correlation (r = -0.51; P0.001) between RDW and gestational age was found. RDW at T1 was: 17.25 (2.19) in the preterm group; 17.37 (2.56) in IUGR group. Fourteen preterm infants reported: 12 PDA, 5 LOS, 4 BPD, and 3 died; 10 IUGR infants had: 4 PDA, 6 LOS, 3 BPD, and 1 died. RDW of IUGR infants suffering from those pathologies was not statistically different compared with unaffected infants, while preterm newborns with pathologies reported higher RDW: PDA vs. PDA absent: P = 0.008 at T0; P0.002 at T1. BPD vs. BPD absent: P0.005 at T1. LOS vs. LOS absent: P0.005 at T0. RDW in preterm/IUGR population was associated with early mortality, T0: dead 21.2 (2.7) vs. alive 16.7 (1.7), P0.0001.RDW and gestational age at birth were negatively correlated. High RDW resulted to be an indication of risk for critical newborns. This parameter can be inexpensively and routinely verified and further studies are required to confirm its prognostic role in neonatal pathologies

Fecal High-Mobility Group Box 1 as a Marker of Early Stage of Necrotizing Enterocolitis in Preterm Neonates

Introduction: An early diagnosis of necrotizing enterocolitis (NEC), a major gastrointestinal emergency in preterm newborns, is crucial to improve diagnostic approach and prognosis. We evaluated whether fecal high-mobility group box protein 1 (HMGB1) may early identify preterms at risk of developing NEC.Materials and Methods: A case-control study including neonates admitted at the Neonatal Intensive Care Unit (NICU) of the Sapienza University Hospital “Umberto I” in Rome, from July 2015 to December 2016. Stool samples obtained from cases (preterm newborns with NEC) and controls (newborns without NEC) were collected at the enrolment (T0) and within 7–14 days after the first sample collection (T1). HMGB1, extracted and measured with western blot, was reported as densitometry units (DUS).Results: HMGB1 levels in 30 cases (n = 28—Bell stage 1, n = 2 Bell stage 2) were higher [T0: 21,462 DUS (95% CI, 16,370–26,553 DUS)—T1: 17,533 DUS (95% CI, 13,052–22,014 DUS)] than in 30 preterm controls [T0: 9,446 DUS (95% CI, 6,147–12,746 DUS)—T1: 9,261 DUS (95% CI, 5,126–13,396 DUS), p < 0.001). Preterm newborns showed significant higher levels of HMGB1 (15,690 DUS (95% CI, 11,929–19,451 DUS)] in comparison with 30 full-term neonates with birth weight >2,500 g [6,599 DUS (95% CI, 3,141–10,058 DUS), p = 0.003]. Multivariate analysis showed that the risk of NEC was significantly (p = 0.012) related to the HMGB1 fecal levels at T0.Conclusions: We suggest fecal HMGB1 as a reliable marker of early NEC in preterm neonates. This study supports further investigation on the role of fecal HMGB1 assessment in managing preterm newborns at risk of NEC. Further studies are advocated to evaluate diagnostic accuracy of this marker in more severe forms of the disease