Emilie Duchalais

Modulation of lipopolysaccharide-induced neuronal response by activation of the enteric nervous system

BackgroundEvidence continues to mount concerning the importance of the enteric nervous system (ENS) in controlling numerous intestinal functions in addition to motility and epithelial functions. Nevertheless, little is known concerning the direct participation of the ENS in the inflammatory response of the gut during infectious or inflammatory insults. In the present study we analyzed the ENS response to bacterial lipopolysaccharide, in particular the production of a major proinflammatory cytokine, tumor necrosis factor-alpha (TNF-α).MethodsTNF-α expression (measured by qPCR, quantitative Polymerase Chain Reaction) and production (measured by ELISA) were measured in human longitudinal muscle-myenteric plexus (LMMP) and rat ENS primary cultures (rENSpc). They were either treated or not treated with lipopolysaccharide (LPS) in the presence or not of electrical field stimulation (EFS). Activation of extracellular signal-regulated kinase (ERK) and 5’-adenosine monophosphate-activated protein kinase (AMPK) pathways was analyzed by immunocytochemistry and Western blot analysis. Their implications were studied using specific inhibitors (U0126, mitogen-activated protein kinase kinase, MEK, inhibitor and C compound, AMPK inhibitor). We also analyzed toll-like receptor 2 (TLR2) expression and interleukin-6 (IL-6) production after LPS treatment simultaneously with EFS or TNF-α-neutralizing antibody.ResultsTreatment of human LMMP or rENSpc with LPS induced an increase in TNF-α production. Activation of the ENS by EFS significantly inhibited TNF-α production. This regulation occurred at the transcriptional level. Signaling analyses showed that LPS induced activation of ERK but not AMPK, which was constitutively activated in rENSpc neurons. Both U0126 and C compound almost completely prevented LPS-induced TNF-α production. In the presence of LPS, EFS inhibited the ERK and AMPK pathways. In addition, we demonstrated using TNF-α-neutralizing antibody that LPS-induced TNF-α production increased TLR2 expression and reduced IL-6 production.ConclusionsOur results show that LPS induced TNF-α production by enteric neurons through activation of the canonical ERK pathway and also in an AMPK-dependent manner. ENS activation through the inhibition of these pathways decreased TNF-α production, thereby modulating the inflammatory response induced by endotoxin.

The arachidonic acid metabolite 11β-ProstaglandinF2α controls intestinal epithelial healing: deficiency in patients with Crohn's disease.

In healthy gut enteric glial cells (EGC) are essential to intestinal epithelial barrier (IEB) functions. In Crohn’s Disease (CD), both EGC phenotype and IEB functions are altered, but putative involvement of EGC in CD pathogenesis remains unknown and study of human EGC are lacking. EGC isolated from CD and control patients showed similar expression of glial markers and EGC-derived soluble factors (IL6, TGF-β, proEGF, GSH) but CD EGC failed to increase IEB resistance and healing. Lipid profiling showed that CD EGC produced decreased amounts of 15-HETE, 18-HEPE, 15dPGJ2 and 11βPGF2α as compared to healthy EGC. They also had reduced expression of the L-PGDS and AKR1C3 enzymes. Produced by healthy EGC, the 11βPGF2 activated PPARγ receptor of intestinal epithelial cells to induce cell spreading and IEB wound repair. In addition to this novel healing mechanism our data show that CD EGC presented impaired ability to promote IEB functions through defect in L-PGDS-AKR1C3-11βPGF2α dependent pathway.

Is the Failure of Laparoscopic Peritoneal Lavage Predictable in Hinchey III Diverticulitis Management

BACKGROUND: Laparoscopic peritoneal lavage is an alternative to sigmoid resection in Hinchey III diverticulitis (generalized purulent peritonitis). The main limitation of laparoscopic peritoneal lavage is the higher rate of reoperation for persistent sepsis in comparison with sigmoid resection. OBJECTIVE: The purpose of the current study was to identify risk factors for laparoscopic peritoneal lavage failure in patients who have Hinchey III diverticulitis. DESIGN: This was a retrospective multicenter study. SETTINGS: The study was conducted in 3 clinical sites in France. PATIENTS: From 2006 to 2015, all consecutive patients undergoing emergent surgery for diverticulitis were reviewed. All patients operated on with laparoscopic peritoneal lavage for laparoscopically confirmed Hinchey III diverticulitis were included. MAIN OUTCOME MEASURES: The main outcome was laparoscopic peritoneal lavage failure, defined as reoperation or death at 30 postoperative days. RESULTS: A series of 71 patients (43 men, mean age 58 ± 15 years) were operated on with laparoscopic peritoneal lavage for Hinchey III diverticulitis. Laparoscopic peritoneal lavage failed in 14 (20%) of them: 1 died and 13 underwent reoperations. No major complication (Dindo-Clavien score ≥3) occurred after reoperation. Immunosuppressive drugs (p = 0.01) and ASA grade ≥3 (p = 0.02) were associated with laparoscopic peritoneal lavage failure after univariate analysis. Multivariate analysis identified only immunosuppressive drug intake (steroids or chemotherapy for cancer) as an independent predictive factor. Mean length of stay was 14.9 days (5–67). At the end of the 30 first postoperative days, 12 (17%) patients had a stoma. LIMITATIONS: The study was limited by its retrospective nature and the small size of the cohort. CONCLUSION: Our results highlight immunosuppressive drug intake as a major risk factor for laparoscopic peritoneal lavage failure in patients who have Hinchey III diverticulitis. Immunosuppression and severe comorbidities (ASA ≥3) should be considered when selecting a surgical option in patients with Hinchey III diverticulitis. See Video Abstract at http://links.lww.com/DCR/A423.

Uncommon perineal tumours: caution with aggressive surgical management

An asymptomatic 66-year-old woman showed a large perineal mass extending close to pelvic organs on MRI. CT-guided needle biopsies revealed a desmoid tumour (DT). The patient refused radical surgery. Four years later, the tumour had marginally increased in size and was still asymptomatic. The revision of earlier biopsies then revealed typical aspects of aggressive angiomyxoma (AA). AA and DT are rare mesenchymal tumours of low-grade malignancy, usually of large size, that occurs in female pelvi-perineal region. Radical resection with wide margins is classically advocated in such tumours in order to prevent the high risk of recurrences. However, due to a slow growth, rare infiltration of adjacent organs and a very low metastatic potential, a watchful waiting policy can be proposed when high postoperative morbidity is expected. In order to propose the accurate treatment, frontline biopsies of the tumour are essential.

Long-Term Outcome Following Implanted Pulse Generator Change in Patients Treated With Sacral Nerve Modulation for Fecal Incontinence: Outcome after SNM IPG replacement

Long‐term outcome of sacral nerve modulation (SNM) patients after implanted pulse generator (IPG) change for fecal incontinence (FI) is unknown. This study reported the outcome and long‐term satisfaction after a change of an exhausted IPG, questioning the need to concurrently change the electrode and looking for factors involved in the maintenance of treatment efficiency.

Colorectal Cancer Cells Adhere to and Migrate Along the Neurons of the Enteric Nervous System

Background & Aims In several types of cancers, tumor cells invade adjacent tissues by migrating along the resident nerves of the tumor microenvironment. This process, called perineural invasion, typically occurs along extrinsic nerves, with Schwann cells providing physical guidance for the tumor cells. However, in the colorectal cancer microenvironment, the most abundant nervous structures belong to the nonmyelinated intrinsic enteric nervous system (ENS). In this study, we investigated whether colon cancer cells interact with the ENS. Methods Tumor epithelial cells (TECs) from human primary colon adenocarcinomas and cell lines were cocultured with primary cultures of ENS and cultures of human ENS plexus explants. By combining confocal and atomic force microscopy, as well as video microscopy, we assessed tumor cell adhesion and migration on the ENS. We identified the adhesion proteins involved using a proteomics approach based on biotin/streptavidin interaction, and their implication was confirmed further using selective blocking antibodies. Results TEC adhered preferentially and with stronger adhesion forces to enteric nervous structures than to mesenchymal cells. TEC adhesion to ENS involved direct interactions with enteric neurons. Enteric neuron removal from ENS cultures led to a significant decrease in tumor cell adhesion. TECs migrated significantly longer and further when adherent on ENS compared with on mesenchymal cells, and their trajectory faithfully followed ENS structures. Blocking N-cadherin and L1CAM decreased TEC migration along ENS structures. Conclusions Our data show that the enteric neuronal network guides tumor cell migration, partly via L1CAM and N-cadherin. These results open a new avenue of research on the underlying mechanisms and consequences of perineural invasion in colorectal cancer.

Characterisation of tau in the human and rodent enteric nervous system under physiological conditions and in tauopathy

Tau is normally a highly soluble phosphoprotein found predominantly in neurons. Six different isoforms of tau are expressed in the adult human CNS. Under pathological conditions, phosphorylated tau aggregates are a defining feature of neurodegenerative disorders called tauopathies. Recent findings have suggested a potential role of the gut-brain axis in CNS homeostasis, and therefore we set out to examine the isoform profile and phosphorylation state of tau in the enteric nervous system (ENS) under physiological conditions and in tauopathies. Surgical specimens of human colon from controls, Parkinson’s disease (PD) and progressive supranuclear palsy (PSP) patients were analyzed by Western Blot and immunohistochemistry using a panel of anti-tau antibodies. We found that adult human ENS primarily expresses two tau isoforms, localized in the cell bodies and neuronal processes. We did not observe any difference in the enteric tau isoform profile and phosphorylation state between PSP, PD and control subjects. The htau mouse model of tauopathy also expressed two main isoforms of human tau in the ENS, and there were no apparent differences in ENS tau localization or phosphorylation between wild-type and htau mice. Tau in both human and mouse ENS was found to be phosphorylated but poorly susceptible to dephosphorylation with lambda phosphatase. To investigate ENS tau phosphorylation further, primary cultures from rat enteric neurons, which express four isoforms of tau, were pharmacologically manipulated to show that ENS tau phosphorylation state can be regulated, at least in vitro. Our study is the first to characterize tau in the rodent and human ENS. As a whole, our findings provide a basis to unravel the functions of tau in the ENS and to further investigate the possibility of pathological changes in enteric neuropathies and tauopathies.

Recommandations pour le traitement de la constipation : une aide efficace de plus à la décision thérapeutique ! (1 ère partie)

Les recommandations de pratique professionnelle sont habituellement destinees au plus grand nombre. Classiquement, le texte court est accessible a tous avec une volonte de dissemination aupres des praticiens de medecine generale et du personnel soignant : il est disponible sur les sites des trois societes savantes partenaires. Le texte long developpe un argumentaire detaille qui releve souvent du domaine de l’expertise et de la specialite.La communication des grades de recommandations a l’occasion de journees de formation medicale continue ou d’une publication reste malheureusement une etape souvent insuffisante a leur dissemination. Le texte est de lecture laborieuse et il n’est pas souvent d’un grand secours dans la pratique quotidienne (document trop synthetique, lecture non adaptee pendant la consultation). Ce constat a conduit plusieurs societes savantes et tutelles a abandonner ces grands travaux a l’impact limite.Le choix qui a ete fait cette fois concerne l’elaboration d’algorithmes argumentes, representant une aide a la decision therapeutique dans les situations les plus courantes. Ces algorithmes ont ete elabores de facon independante de la redaction du texte court des recommandations mais ils reposent sur la meme methodologie. Les differentes etapes de chaque algorithme sont documentees par un texte court, des grades de recommandations et les references essentielles. Leur objectif principal est celui d’une meilleure penetration, en pratique de soins, des donnees scientifiques disponibles.

Clinical, histological, and molecular risk factors for cancer recurrence in patients with stage II colon cancer

Introduction The assessment of risk factors of cancer recurrence in patients with stage II colon cancer (CC) is crucial. Our aim was to study the clinical, histological, and molecular features associated with 3-year disease-free survival in a series of consecutive patients with stage II CC treated in three regional digestive oncology centers. Methods Clinical and histological data of all patients after curative surgery for stage II CC, treated from 2001 until 2009, were collected retrospectively. Histological samples were obtained and tested prospectively for microsatellite instability using fluorescent PCR amplification. Cox proportional hazards regression models were used to calculate P values, hazard ratios (HRs), and 95% confidence intervals (CIs). Results Among 195 patients studied, 22 (11%) had disease recurrence during the 3-year period following diagnosis. On multivariate analysis, only low number of lymph nodes (HR=3.81, 95% CI: 1.19–12.19, P=0.02) and T4 status (HR=5.49, 95% CI: 1.06–28.43, P=0.04) were associated significantly with an increased risk of relapse. Conclusion In this series of stage II CC patients, only T4 status and low number of lymph nodes were independent risk factors for poor 3-year disease-free survival, suggesting that patients with these features should be considered for adjuvant chemotherapy.