Noninvasive Biomarkers of Gut Barrier Function in Patients Suffering from Diarrhea Predominant-IBS: An Update.

The intestinal barrier plays a crucial role in the absorption of nutrients and in preventing the entry of pathogenic microorganisms and toxic molecules. Several studies have shown a compromised intestinal barrier associated with low-grade inflammation in the small intestinal mucosa in celiac disease, inflammatory bowel disease, and irritable bowel syndrome (IBS), particularly in IBS with diarrhea (IBS-D). In light of these new data, IBS is no longer considered a functional disease but rather a heterogeneous syndrome that has yet to be carefully studied. Therefore, investigating the integrity and function of the intestinal barrier is now essential to improving knowledge of the pathophysiology of IBS-D and to improving the management of IBS-D patients. However, the study of the intestinal barrier must clarify some still unsolved methodological aspects and propose standardised assays before becoming a useful diagnostic tool. In this framework, this review will discuss data about the tests that noninvasively evaluate the integrity and functionality of the human intestinal barrier, paying particular attention to patients with IBS-D, in both clinical and research situations.

Improved Symptom Profiles and Minimal Inflammation in IBS-D Patients Undergoing a Long-Term Low-FODMAP Diet: A Lipidomic Perspective.

Given the link between the minimal inflammation underlying irritable bowel syndrome (IBS) and dietary treatments, considerable attention has focused on diets low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs). In this context, inflammatory patterns and lipidomic investigations may shed light on the pathophysiological mechanisms whereby a low-FODMAP diet (LFD) improves the IBS diarrhoea (IBS-D) variant. Thus, we investigated whether a long-term LFD induced changes in symptom profiles, anthropometric characteristics, inflammatory markers (C-reactive protein, cyclooxygenase-2, and prostaglandin E2) and erythrocyte-membrane fatty acid (FA) composition in IBS-D patients. Twenty IBS-D patients underwent a 90 day personalised LFD programme, and were regularly evaluated at scheduled visits. At the diet's end, both IBS symptoms and anthropometric parameters were significantly improved. A significant decrease in prostaglandin E2 also accompanied these reductions. As for FAs, the putative inflammatory indicators, arachidonic acid (AA) levels and the AA/eicosapentaenoic acid ratio were significantly decreased. In conclusion, IBS-D patients following a controlled long-term LFD experienced improved symptom profiles and decreased inflammatory markers linked to FAs. Lipidomic data may be insightful for unravelling the molecular mechanisms associated with IBS-D pathophysiology.

Noninvasive biomarkers of gut barrier function identify two subtypes of patients suffering from diarrhoea predominant-IBS: a case-control study.

BACKGROUND: Alterations of the small-intestinal permeability (s-IP) might play an essential role in both diarrhoea-predominant IBS (D-IBS) and celiac disease (CD) patients. Our aims were to analyse in D-IBS patients the symptom profile along with the levels of urinary sucrose (Su), lactulose (La), mannitol (Ma), and circulating biomarkers (zonulin, intestinal fatty acid binding protein - I-FABP, and diamine oxidase - DAO) of the gastrointestinal (GI) barrier function. The pro-inflammatory interleukins 6 and 8 (IL-6 and IL-8), the plasma values of lipopolysaccharide (LPS), and Toll-like receptor 4 (TLR-4) were also investigated. Besides, these biomarkers were compared with those in CD and healthy controls (HC). Finally, comparisons were performed between D-IBS patients with [D-IBS(+)] and without [D-IBS(-)] increased s-IP according to normal or altered La/Ma ratio. METHODS: The study included 39 D-IBS patients, 32 CD patients, and 20 HC. GI permeability was assayed by high-performance liquid chromatography determination in the urine of Su and La/Ma ratio. ELISA kits assayed circulating concentrations of zonulin, I-FABP, DAO, IL-6, IL-8, LPS, and TLR-4. The Mann-Whitney or the Kruskal-Wallis with Dunn's post-test was used to assess differences among the groups. RESULTS: As for the La/Ma ratio, %Su, and I-FABP levels, D-IBS patients were significantly different from CD, but not HC. IL-6 levels were significantly higher in CD than HC, whereas IL-8 levels were significantly higher in both D-IBS and CD patients than HC. By opposite, LPS, and TLR-4 concentrations did not differ significantly among the groups. When D-IBS patients were categorised according to normal or altered s-IP, D-IBS(+) patients had %La, %Su, I-FABP, and DAO levels significantly higher than D-IBS(-) ones. The inflammatory parameters and markers of bacterial translocation (namely, IL-6 and LPS) were significantly higher in D-IBS(+) patients than D-IBS(-) ones. CONCLUSIONS: The present study suggests that two distinct D-IBS subtypes could be identified. The investigation of possible s-IP alterations (i.e., considering the La/Ma ratio) might be useful to assess better and categorise this heterogeneous D-IBS population. TRIAL REGISTRATION: NCT01574209 . Registered March 2012. First recruitment started in April 2012.

Adipose Tissue-Derived Biomarkers of Intestinal Barrier Functions for the Characterization of Diarrhoea-Predominant IBS.

BACKGROUND: Alterations of the small-intestinal permeability (s-IP) might play an essential role in a subgroup of diarrhoea-predominant IBS (D-IBS) patients. GOALS: (a) To analyse in D-IBS patients the symptom profile in relation to the altered (+) or not (-) s-IP using the Gastrointestinal Symptom Rating Scale (GSRS). (b) To assess the circulating levels of the adipokines IL-6, IL-8, TNF-α, leptin, and adiponectin, along with LPS, TLR-4, neurotensin, and brain-derived neurotrophic factor (BDNF). The frequency distribution of SNPs at the loci for the investigated molecules and leptin receptor was evaluated. STUDY: The study included 34 D-IBS patients and 17 healthy controls (HC). s-IP permeability was assayed by high-performance liquid chromatography determination in the urine of the lactulose to mannitol ratio. Concentrations of IL-6, IL-8, TNF-α, LPS, TLR-4, leptin, adiponectin, neurotensin, and BDNF were assayed by ELISA. Screening of genetic variants was done employing the restriction fragment length polymorphism-polymerase chain reaction method. RESULTS: D-IBS(-) patients had a significantly higher GSRS cluster pain and diarrhoea profile than D-IBS(+) ones. Significant correlations were found between the symptoms clusters and immune activation and inflammation markers. The levels of adipo(cyto)kines in D-IBS(+) patients were higher than those of controls, and IL-6 levels correlated with those of LPS. Leptin and BDNF were significantly higher, and neurotensin levels were significantly lower in D-IBS(+) than in controls. No differences were found in the frequency distribution of genotypes among the study groups. CONCLUSIONS: Results from this study could be of some help in the characterization of the D-IBS and highlight the contribution of an altered intestinal barrier in the pathogenesis of this syndrome. Besides, a role could be ascribed to molecules secreted by the visceral adipose tissue that can impact on barrier functions.

Mitochondria and redox balance in coeliac disease: A case-control study.

BACKGROUND: Coeliac disease (CD) is a gluten-sensitive autoimmune disorder. Gluten toxicity encompasses a wide spectrum of target organ functions and pathologies, including the activation of the immune response and triggering of oxidative stress. The aim of this study was to investigate inflammation and the redox balance in patients with active CD, and to evaluate whether alteration of mitochondrial function is involved in the disease status. DESIGN: In this prospective case-control study, blood samples from sixteen adult CD patients and sixteen healthy controls (HC) were investigated for IL-1ß, IL-6 and IL-8 plasma concentrations, for serum PON1 arylesterase, total and MnSOD antioxidant enzyme activities, induced TBARs levels, and for lymphocyte mtDNA content. RESULTS: Patients showed IL-8 and IL-1ß concentrations significantly higher than HC counterparts. Patients had a significantly higher content of induced TBARS compared to HC value, indicating a shift in their serum redox balance towards pro-oxidant species. The assay of antioxidant enzyme activities showed a significant 25% increase in PON1, a higher total SOD, and a significant 21% higher MnSOD in patients compared to HC. Lymphocyte mtDNA content in patients was significantly twofold higher than in HC, supporting the induction of mitochondrial biogenesis. The patients' mitochondrial compensatory response may explain the correlation between MnSOD activity and mtDNA content. The patients' mitochondrial oxidative stress, cooperating to cytokines secretion, may justify the correlation between IL-1ß concentration and mtDNA content. CONCLUSIONS: These results highlight the mitochondrial involvement in CD and suggest the evaluation of the mtDNA content as a potential diagnostic and follow-up parameter.

Colonic Transit Time and Gut Peptides in Adult Patients with Slow and Normal Colonic Transit Constipation.

PURPOSE: To investigate whether pathophysiological differences exist among healthy controls (HC) and patients with slow and normal transit constipation (STC and NTC), we evaluated (1) gastrointestinal (GI) symptoms using validated questionnaires; (2) circulating concentrations of neurotensin, motilin, corticotrophin-releasing factor (CRF), and somatostatin; and (3) possible differences in frequency distribution of the neurotensin rs1800832 A/G and Neurotensin Receptor 1 rs6090453 C/G SNPs. METHODS: Fifty-one patients with severe functional constipation and 20 HC completed the study. Symptoms were evaluated by GSRS and Constipaq scoring system. Plasma concentrations of GI peptides were evaluated by ELISA on fasting and six sequential blood samples after a standard meal. Genotyping was performed by PCR and endonuclease digestion. RESULTS: Symptom profiles largely overlapped between NTC and STC patients. As for peptide profiles, neurotensin showed lower concentrations at 60 and 90 min in STC versus HC, and motilin showed throughout the curve 85% and 82% lower levels in STC than HC and NTC, respectively. Finally, neurotensin polymorphism resulted in being associated with the peptide levels. CONCLUSIONS: Symptom profile is not a reliable tool to discriminate STC, whilst the GI peptide profiles might help in identifying it.

A possible role for ghrelin, leptin, brain-derived neurotrophic factor and docosahexaenoic acid in reducing the quality of life of coeliac disease patients following a gluten-free diet.

PURPOSE: A gluten-free diet (GFD) has been reported to negatively impact the quality of life (QoL) of coeliac disease (CD) patients. The gut-brain axis hormones ghrelin and leptin, with the brain-derived neurotrophic factor (BDNF), may affect QoL of CD patients undergoing GFD. Our aims were to evaluate whether: (a) the circulating concentrations of leptin, ghrelin and BDNF in CD patients were different from those in healthy subjects; (b) GFD might induce changes in their levels; (c) BDNF Val66Met polymorphism variability might affect BDNF levels; and (d) serum BDNF levels were related to dietary docosahexaenoic acid (DHA) as a neurotrophin modulator. METHODS: Nineteen adult coeliac patients and 21 healthy controls were included. A QoL questionnaire was administered, and serum concentrations of ghrelin, leptin, BDNF and red blood cell membrane DHA levels were determined at the enrolment and after 1 year of GFD. BDNF Val66Met polymorphism was analysed. RESULTS: Results from the questionnaire indicated a decline in QoL after GFD. Ghrelin and leptin levels were not significantly different between groups. BDNF levels were significantly (p = 0.0213) lower in patients after GFD (22.0 ± 2.4 ng/ml) compared to controls (31.2 ± 2.2 ng/ml) and patients at diagnosis (25.0 ± 2.5 ng/ml). BDNF levels correlated with DHA levels (p = 0.008, r = 0.341) and the questionnaire total score (p = 0.041, r = 0.334). CONCLUSIONS: Ghrelin and leptin seem to not be associated with changes in QoL of patients undergoing dietetic treatment. In contrast, a link between BDNF reduction and the vulnerability of CD patients to psychological distress could be proposed, with DHA representing a possible intermediate.

Gastric Activity and Gut Peptides in Patients With Functional Dyspepsia: Postprandial Distress Syndrome Versus Epigastric Pain Syndrome.

GOALS: The goals of the study were to investigate in both postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS) the gastric electrical activity and the gastric emptying (GE) time together with the circulating concentrations of motilin, somatostatin, corticotrophin-releasing factor, and neurotensin, and to establish whether the genetic variability in the neurotensin system genes differs between these 2 categories of functional dyspepsia (FD). BACKGROUND: The current FD classification is based on symptoms and it has been proven not to be completely satisfying because of a high degree of symptom overlap between subgroups. STUDY: Gastric electrical activity was evaluated by cutaneous electrogastrography: the GE time by C-octanoic acid breast test. Circulating concentrations of gut peptides were measured by a radioimmunoassay. NTS 479 A/G and NTSR1 rs6090453 SNPs were evaluated by PCR and endonuclease digestion. RESULTS: Fifty-four FD patients (50 female/4 male) were studied. Using a symptom questionnaire, 42 patients were classified as PDS and 12 as EPS, although an overlap between the symptom profiles of the 2 subgroups was recorded. The electrogastrographic parameters (the postprandial instability coefficient of dominant frequency, the dominant power, and the power ratio) were significantly different between the subgroups, whereas the GE time did not differ significantly. In addition, EPS was characterized by a different gut peptide profile compared with PDS. Finally, neurotensin polymorphism was shown to be associated with neurotensin levels. This evidence deserves further studies in consideration of an analgesic role of neurotensin. CONCLUSIONS: Analysis of gut peptide profiles could represent an interesting tool to enhance FD diagnosis and overcome limitations due to a distinction based solely on symptoms.

The obestatin/ghrelin ratio and ghrelin genetics in adult celiac patients before and after a gluten-free diet, in irritable bowel syndrome patients and healthy individuals.

BACKGROUND: Ghrelin levels and obestatin/ghrelin ratio have been proposed as activity markers in ulcerative colitis, but no data are available in celiac disease (CD) and irritable bowel syndrome (IBS). Our aims were as follows: (a) to assess obestatin and ghrelin concentrations in adult active CD patients, diarrhea-predominant IBS (IBS-d), and healthy controls (HC) in relation to intestinal permeability; (b) to evaluate the ghrelin-obestatin profile in CD patients after a 1-year gluten-free diet (GFD); and (c) to establish the impact of ghrelin genetics. METHODS: The study included 31 CD patients, 28 IBS-d patients, and 19 HC. Intestinal permeability, assayed by high-performance liquid chromatography determination of urinary lactulose (La)/mannitol (Ma), and circulating concentrations of obestatin, ghrelin, and their ratio were evaluated at enrollment and after GFD. The ghrelin single nucleotide polymorphisms Arg51Gln (rs34911341), Leu72Met (rs696217), and Gln90Leu (rs4684677) were analyzed. RESULTS: Intestinal permeability was impaired in CD patients and ameliorated after GFD. Ghrelin was significantly (P=0.048) higher and the obestatin/ghrelin ratio was significantly (P=0.034) lower in CD patients compared with both IBS-d and HC, and GFD reduced the peptide levels, but without reaching the concentrations in HC. Significant differences (P<0.05) were found in the Leu72Met polymorphism among groups, with the reduction of the GT genotype and the T allele in both CD and IBS-d patients compared with HC. CONCLUSION: Intestinal permeability is altered in CD, but not in IBS-d patients, and ghrelin levels increase in CD patients as observed in other inflammatory conditions. Moreover, a role for ghrelin genetics is hypothesized in sustaining the many pathogenetic components of these different pathologies, but with a similar symptom profile.

Corticotropin releasing hormone and Urocortin 2 activate inflammatory pathways in cultured trophoblast cell lines.

OBJECTIVE: Embryo implantation and parturition are recognized as inflammatory events involving endocrine and immune system. NF-kB and MAPK are two transcription factor families involved in inflammation. A possible role of neuroendocrine mechanism in early pregnancy and delivery was proposed for the neuropeptides related to corticotropin releasing hormones (CRH), named Urocortins (Ucns). Experimental and clinical studies support a role for CRH, Ucn, Ucn2 and Ucn3 in the endocrine/immune modulation of inflammation in human trophoblast; however the intracellular mechanisms are not yet recognized. The aim of the present study was to evaluate which of these neuropeptides modulate NF-kB or MAPKs pathways. STUDY DESIGN: In Jeg-3 placental cell line the effect of CRH, Ucn, Ucn2 or Ucn3 on NF-kB and MAPKs pathways were evaluated using Western blot analysis. RESULTS: CRH induced the phosphorylation of MAPK subunits; Ucn2 was able to induce the phosphorylation of both NF-kB and MAPK subunits. Ucn and Ucn3 had no effects on these pathways. CONCLUSIONS: These data provide novel information on inflammatory process in trophoblast cells: Ucn2 is a potent pro-inflammatory neuropeptide via NF-kB and MAPK pathways and CRH via MAPK, and CRH and Ucn2 network participates in the inflammatory mechanisms of pregnancy and parturition.

The labyrinth of autoinflammatory disorders: a snapshot on the activity of a third-level center in Italy.

Autoinflammatory disorders (AIDs) are a novel class of diseases elicited by mutations in genes regulating the homeostasis of innate immune complexes, named inflammasomes, which lead to uncontrolled oversecretion of the proinflammatory cytokine interleukin-1ß. Protean inflammatory symptoms are variably associated with periodic fever, depicting multiple specific conditions. Childhood is usually the lifetime in which most hereditary AIDs start, though still a relevant number of patients may experience a delayed disease onset and receive a definite diagnosis during adulthood. As a major referral laboratory for patients with recurrent fevers, we have tested samples from 787 patients in the period September 2007-March 2014, with a total of 1,328 AID-related genes evaluated and a gene/patient ratio of 1.69. In this report, we describe our experience in the clinical approach to AIDs, highlight the most striking differences between child and adult-onset AIDs, and shed an eye-opening insight into their diagnostic process.

Snai1 promotes ESC exit from the pluripotency by direct repression of self-renewal genes.

Although much is known about the pluripotency self-renewal circuitry, the molecular events that lead embryonic stem cells (ESCs) exit from pluripotency and begin differentiation are largely unknown. We found that the zinc finger transcription factor Snai1, involved in gastrulation and epithelial-mesenchymal transition, is already expressed in the inner cell mass of the preimplantation blastocysts. In ESCs, Snai1 does not respond to TGFß or BMP4 signaling but it is induced by retinoic acid treatment, which induces the binding, on the Snai1 promoter, of the retinoid receptors RARγ and RXRα, the dissociation of the Polycomb repressor complex 2 which results in the decrease of H3K27me3, and the increase of histone H3K4me3. Snai1 mediates the repression of pluripotency genes by binding directly to the promoters of Nanog, Nr5a2, Tcl1, c-Kit, and Tcfcp2l1. The transient activation of Snai1 in embryoid bodies induces the expression of the markers of all three germ layers. These results suggest that Snai1 is a key factor that triggers ESCs exit from the pluripotency state and initiate their differentiation processes.

Untangling the web of systemic autoinflammatory diseases.

The innate immune system is involved in the pathophysiology of systemic autoinflammatory diseases (SAIDs), an enlarging group of disorders caused by dysregulated production of proinflammatory cytokines, such as interleukin-1ß and tumor necrosis factor-α, in which autoreactive T-lymphocytes and autoantibodies are indeed absent. A widely deranged innate immunity leads to overactivity of proinflammatory cytokines and subsequent multisite inflammatory symptoms depicting various conditions, such as hereditary periodic fevers, granulomatous disorders, and pyogenic diseases, collectively described in this review. Further research should enhance our understanding of the genetics behind SAIDs, unearth triggers of inflammatory attacks, and result in improvement for their diagnosis and treatment.

Key facts and hot spots on tumor necrosis factor receptor-associated periodic syndrome.

Tumor necrosis factor receptor-associated periodic syndrome (TRAPS), formerly known as familial Hibernian fever, is the most common autosomal dominant autoinflammatory disease, resulting from mutations in the TNFRSF1A gene, encoding the 55-kD tumor necrosis factor receptor. The pathophysiologic mechanism of TRAPS remains ambiguous and only partially explained. The onset age of the syndrome is variable and the clinical scenery is characterized by recurrent episodes of high-grade fever that typically lasts 1-3 weeks, associated with migrating myalgia, pseudocellulitis, diffuse abdominal pain, appendicitis-like findings, ocular inflammatory signs, and risk of long-term amyloidosis. Fever episodes are responsive to high-dose corticosteroids, but different classes of drugs have been reported to be ineffective. The use of etanercept is unable to control systemic inflammation, while interleukin-1 blockade has been shown as effective in the control of disease activity in many patients reported so far.

Gut peptide profile and chemotherapy-associated dyspepsia syndrome in patients with breast cancer undergoing FEC60 chemotherapy.

AIM: The association of motilin, ghrelin, leptin, gastrin, pepsinogen (PG) I and II with cancer chemotherapy-associated dyspepsia syndrome (CADS) was investigated in 35 patients with breast cancer receiving first cycle of 5-fluorouracil, cyclophosphamide, epirubicin (FEC60) chemotherapy. PATIENTS AND METHODS: The onset of dyspeptic symptoms on days 3 and 10 after chemotherapy identified patients with and without CADS. Gastrointestinal symptoms were scored with the Gastrointestinal Symptom Scoring Rate (GSRS) questionnaire. Gastrointestinal peptides were evaluated by enzyme-linked immunosorbent assay. RESULTS: Twenty-one patients (60%) had CADS. The area under the curve (AUC) of ghrelin was higher, whereas that of PGI, PGII and motilin were lower in patients with CADS compared to those without. In patients with CADS, the AUC of PGI and PGII negatively correlated with the GSRS indigestion cluster. CONCLUSION: Impairment of gastrointestinal motility suggested by low motilin concentrations and mucosal damage mirrored by an increase of ghrelin seem to be involved in the onset of CADS in patients during chemotherapy for breast cancer.

Adipokine profile in celiac patients: differences in comparison with patients suffering from diarrhea-predominant IBS and healthy subjects.

OBJECTIVE. The role of adipokines such as resistin, leptin, and adiponectin could be pivotal in the molecular crosstalk between the inflamed intestine and the surrounding mesenteric adipose tissue. Our aims were to a) evaluate their circulating concentrations in patients with active celiac disease (ACD) and compare them to those in patients with diarrhea-predominant irritable bowel syndrome (IBS-d) and healthy subjects; b) establish the impact of genetic variability in resistin; and c) evaluate whether a 1-year gluten-free diet (GFD) modifies circulating concentrations of resistin, leptin, and adiponectin in celiac patients. MATERIAL AND METHODS. The study included 34 ACD patients, 29 IBS-d patients, and 27 healthy controls. Circulating concentrations of resistin, leptin, adiponectin, IL-6, and IL-8 were evaluated at the time of enrollment. Resistin +299 G/A polymorphism was also analysed. In CD patients, biochemical measurements were repeated after a 1-year GFD. RESULTS. Along with higher IL-6 and IL-8 plasma levels, higher resistin and adiponectin concentrations were found in ACD and IBS-d patients compared with controls (p: 0.0351 and p: 0.0020, respectively). Resistin values proved to be predictable from a linear combination of IL-8 and +299 polymorphism. GFD affected resistin (p: 0.0009), but not leptin and adiponectin concentrations. CONCLUSIONS. Our data suggest that these adipokines are involved in modulating inflammatory processes in both CD and IBS-d patients. Alterations in the adipokine profile as well as the higher prevalence of the resistin +299 G/A SNP A allele compared to controls support the hypothesis that, at least in well-defined cases of IBS, a genetic component may also be supposed.

The effects of fluorouracil, epirubicin, and cyclophosphamide (FEC60) on the intestinal barrier function and gut peptides in breast cancer patients: an observational study.

BACKGROUND: Several GI peptides linked to intestinal barrier function could be involved in the modification of intestinal permeability and the onset of diarrhea during adjuvant chemotherapy. The aim of the study was to evaluate the circulating levels of zonulin, glucagon-like peptide-2 (GLP-2), epidermal growth factor (EGF) and ghrelin and their relationship with intestinal permeability and chemotherapy induced diarrhea (CTD). METHODS: Sixty breast cancer patients undergoing an FEC60 regimen were enrolled, 37 patients completed the study. CTD(+) patients were discriminated by appropriate questionnaire and criteria. During chemotherapy, intestinal permeability was assessed by lactulose/mannitol urinary test on day 0 and day 14. Zonulin, GLP-2, EGF and ghrelin circulating levels were evaluated by ELISA tests at five time-points (days 0, 3, 10, 14, and 21). RESULTS: During FEC60 administration, the lactulose/mannitol ratio was significantly higher on day 14 than at baseline. Zonulin levels were not affected by chemotherapy, whereas GLP-2 and EGF levels decreased significantly. GLP-2 levels on day 14 were significantly lower than those on day 0 and day 3, while EGF values were significantly lower on day 10 than at the baseline. In contrast, the total concentrations of ghrelin increased significantly at day 3 compared to days 0 and 21, respectively. Ten patients (27%) suffered from diarrhea. On day 14 of chemotherapy, a significant increase of the La/Ma ratio occurred in CTD(+) patients compared to CTD(-) patients. With regards to circulating gut peptides, the AUCg of GLP-2 and ghrelin were significantly lower and higher in CTD(+) patients than CTD(-) ones, respectively. Finally in CTD(+) patients a significant and inverse correlation between GLP-2 and La/Ma ratio was found on day 14. CONCLUSIONS: Breast cancer patients undergoing FEC60 showed alterations in the intestinal permeability, which was associated with modifications in the levels of GLP-2, ghrelin and EGF. In CTD(+) patients, a different GI peptide profile and increased intestinal permeability was found in comparison to CTD(-) patients. This evidence deserves further studies for investigating the potentially different intestinal luminal and microbiota conditions. TRIAL REGISTRATION: Clinical trial NCT01382667.

Inulin-enriched pasta improves intestinal permeability and modifies the circulating levels of zonulin and glucagon-like peptide 2 in healthy young volunteers.

Apart from the intestinal environment, inulin induces physiological effects, which includes a reduction in glucose and lipid concentrations and modulation of gastrointestinal motility through the release of different peptides. We hypothesized that inulin-enriched pasta may also improve small intestine permeability in relation to zonulin and glucagon-like peptide 2 (GLP-2) levels in healthy young subjects. Twenty healthy, young male volunteers completed a randomized, double-blind crossover study consisting of a 2-week run-in period and two 5-week study periods (11% inulin-enriched or control pasta), with an 8-week washout period in between. The intestinal barrier function was assessed by lactulose-mannitol excretion in urine. Zonulin values and GLP-2 release were evaluated by enzyme-linked immunosorbent assay. In the inulin group, the urinary lactulose recovery was significantly lower than the other 2 groups. There were no significant differences in urinary mannitol levels between groups. Accordingly, the lactulose-mannitol excretion ratio was significantly decreased in the inulin-enriched pasta group compared with the other 2 groups. The inulin-enriched pasta group had significantly lower zonulin serum values and significantly higher GLP-2 basal values when compared with the baseline and control pasta groups. The dietary use of inulin-enriched pasta preserves intestinal mucosal barrier functioning and modulates circulating levels of zonulin and GLP-2, suggesting that prebiotics could be used in the prevention of gastrointestinal diseases and metabolic disorders.

c-ABL modulates MAP kinases activation downstream of VEGFR-2 signaling by direct phosphorylation of the adaptor proteins GRB2 and NCK1.

Vascular Endothelial Growth Factor-A (VEGF-A) is a key molecule in normal and tumor angiogenesis. This study addresses the role of c-ABL as a novel downstream target of VEGF-A in primary Human Umbilical Vein Endothelial Cells (HUVEC). On the basis of immunoprecipitation experiments, in vitro kinase assay and RNA interference, we demonstrate that VEGF-A induces the c-ABL kinase activity through the VEGF Receptor-2/Phosphatidylinositol-3-Kinase pathway. By treating HUVEC with the specific tyrosine kinase inhibitor STI571 and over-expressing a dominant negative c-ABL mutant, we show that the VEGF-A-activated c-ABL reduces the amplitude of Mitogen-Activated Protein Kinases (ERK1/2, JNKs and p38) activation in a dose-dependent manner by a negative feedback mechanism. By analysis of the adaptor proteins NCK1 and GRB2 mutants we further show that the negative loop on p38 is mediated by c-ABL phosphorylation at tyrosine 105 of the adaptor protein NCK1, while the phosphorylation at tyrosine 209 of GRB2 down-modulates ERK1/2 and JNKs signaling. These findings suggest that c-ABL function is to establish a correct and tightly controlled response of endothelial cells to VEGF-A during the angiogenic process.

Effects of a diet with inulin-enriched pasta on gut peptides and gastric emptying rates in healthy young volunteers.

AIM: Our group has previously shown that the administration of pasta enriched along with the prebiotic inulin induces a significant reduction in triglyceride and glucose levels with a significant delay in gastric emptying (GE) rates. This protective effect may occur by affecting the release of a number of gut peptides involved in the control of gastrointestinal motility. The aim of the present study was to evaluate the effects of inulin-enriched pasta on the circulating levels of neurotensin (NT), somatostatin (SS), and corticotropin-releasing factor (CRF) in relation to the GE time in young healthy subjects. METHODS: Twenty healthy young male volunteers completed a randomized double-blind crossover study consisting of a 2-week run-in period and two 5-week study periods (11% inulin-enriched/control pasta), with an 8-week wash-out period in between. Gut peptide concentrations were evaluated by radioimmunoassay. GE time was evaluated by ultrasonography. RESULTS: The prebiotic treatment significantly increased the area under the curve (AUC) values of both NT and SS (p < 0.05 Dunn's post-test). With regard to gastric motility, along with a significant delay in both the final time and T (1/2) gastric emptying time, a positive correlation was found between T (1/2) and SS AUC values (r = 0.57, p = 0.009) in the inulin-enriched pasta group. CONCLUSION: These results support the hypothesis that inulin plays an active role in mechanisms affecting the release of these gut peptides, which may modulate the gastric emptying of digesta.