A60 THE NEURAL SIGNAL, CALCITONIN GENE-RELATED PEPTIDE (CGRG) ENHANCES A REGULATORY PHENOTYPE IN THE HUMAN IL-4 TREATED HUMAN MACROPHAGE

Background

Recent studies in pre-clinical models of disease have revealed the ability of murine and human IL-4-treated macrophages (M(IL4)) to promote wound recovery and reduce the severity of colitis. An unbiased RNA-sequence analysis of human blood-derived macrophages revealed increased expression of the RAMP1 chain of the CGRP receptor in IL-4 treated cells, raising the intriguing possibility of neural control of regulatory macrophages in the context of neuroimmune interaction in colitis. Thus, we sought to address if this mRNA signal translated into increased RAMP1 protein, if/how CGPR affected M(IL4) function, and if this applied to macrophages from patients with IBD as well as those from healthy donors.

Aims

To determine if CRGP-RAMP1 signalling in human IL-4 treated macrophages enhances a regulatory phenotype.

Methods

Peripheral blood mononuclear cells from healthy volunteers and individuals with IBD were cultured on plastic (2h, 37°C) and non-adherent cells removed. The adherent cells were cultured with recombinant hM-CSF (10 ng/ml) for 7 days. The resultant macrophages (2.5×105) were differentiated with IL-4 (48h 20 ng/mL) and assessed by qPCR and immunocytochemistry. In other cells, CGRP (10 nM) was added 24h after IL-4 and (1) cAMP (2) cytokines and (3) phagocytosis of inert FITC-beads measured, and (4) the capacity of supernatant from the cells to promote healing in wounded Caco2 epithelial monolayers tested.

Results

Compared to non-treated macrophages (M(0)), M(IL4)s from healthy individuals had increased mRNA for both chains of the CGRP-receptor (i.e. RAMP1 and CLR), and increased surface expression of the receptor as shown by immunostaining and CGRP-evoked cAMP. The IL-4 evoked RAMP1 mRNA was only detected in macrophages from 50% of the patients with active IBD. M(IL4)s treated with CGRP showed enhanced expression of the mannose receptor (CD206, allows detection of bacteria), increase phagocytosis of inert beads/macrophages. Moreover, CGRP increases VEGF and CCL18 expression in M(IL4), and soluble mediators from these cells promoted in vitro epithelial wound repair.

Conclusions

Reduced expression of CGRP and its receptor has been shown in IBD. The findings herein, demonstrating how CGRP-RAMP1 signalling can reinforce and enhance a regulatory, reparatory phenotype in human macrophages reveals another aspect of IBD pathophysiology. We speculate that loss of this neuroimmune axis (i.e. CGRP/Nerve-M(IL4) interaction) has the potential to significantly impair mucosal healing in IBD.

Funding Agencies

CCCAlberta Innovates in Health Innovation

A49 BUTYRATE PRESERVES THE EPITHELIAL MITOCHONDRIAL NETWORK DISRUPTED BY THE CROHN’S DISEASE PATHOBIONT ADHERENT-INVASIVE E. COLI

Background

Mitochondria exist in a dynamic network that undergoes continuous cycles of fission and fusion that is tightly controlled. Mitochondrial dysfunction is implicated in several autoimmune and inflammatory diseases. Adherent-invasive E. coli (AIEC) is a pathogenic strain of bacteria associated with Crohn’s disease (CD), that can evoke pro-inflammatory responses. Data from our lab showed that AIEC (strain LF82) infection in gut epithelial cells (T84 human cell line) caused dramatic mitochondrial network fragmentation and loss of mitochondrial membrane potential. Short chain fatty acids (SCFA) produced by commensal bacteria in the gut have a wide range of benefits including enhancing mitochondrial biogenesis.

Aims

To determine (1) if sodium butyrate (NaB) treatment can protect against mitochondrial dysfunction induced by AIEC (strain LF82) infection in T84 epithelial cells and then (2) to identify the mechanism by which NaB restores mitochondrial functions.

Methods

We assessed changes in mitochondrial network morphology through confocal microscopy live cell imaging of mitotracker-stained T84 epithelial cells based on unbiased Hoechst-stained nuclei to select the field of view. The effect of NaB on the proliferation of bacteria and their invasion of T84-epithelia was assessed by growth curve analysis and bacterial internalisation assays. Finally, mRNA and protein expression of peroxisome proliferating activator receptor gamma co-activator 1 alpha (PGC1α), a regulator of mitochondrial biogenesis, were assessed by qPCR and Western Blot.

Results

We confirmed that AIEC infection (strain LF82, 108cfu, 4h) induces massive mitochondrial fragmentation in T84 cells (2x105). We also found that cotreatment of T84 cells with NaB (10mM) and LF82 showed increased percentage of fused mitochondrial networks compared to LF82-treated cells. This result was also seen in cells treated with mitochondrial uncoupler dinitrophenol (DNP; 0.1 mM, 2h) and NaB. Moreover, the protective effect of NaB was not related to inhibition of proliferation of the bacteria as we demonstrated that LF82 growth and its invasive phenotype was not compromised by NaB (3-20mM; 0-24hr). In agreement with the effect of LF82 on mitochondrial functions, LF82 significantly reduced PGC1α mRNA expression in T84 cells, that was prevented by co-treatment with NaB.

Conclusions

These data suggest the pathogen disruption of the epithelial mitochondrial network is a component of IBD; thus, identifying mitochondrial fission and fusion pathways as novel therapeutic targets to control enteric inflammation. The data underscore the complex interplay between bacteria and the epithelium, such that commensal organisms may preserve the mitochondrial network in the face of challenge from pathogens that seek to disrupt mitochondrial form and function

Funding Agencies

CIHR

Crohn's Disease Pathobiont Adherent-Invasive E coli Disrupts Epithelial Mitochondrial Networks With Implications for Gut Permeability

BACKGROUND & AIMS

Adherent-invasive Escherichia coli are implicated in inflammatory bowel disease, and mitochondrial dysfunction has been observed in biopsy specimens from patients with inflammatory bowel disease. As a novel aspect of adherent-invasive E coli-epithelial interaction, we hypothesized that E coli (strain LF82) would elicit substantial disruption of epithelial mitochondrial form and function.

METHODS

Monolayers of human colon-derived epithelial cell lines were exposed to E coli-LF82 or commensal E coli and RNA sequence analysis, mitochondrial function (adenosine triphosphate synthesis) and dynamics (mitochondrial network imaging, immunoblotting for fission and fusion proteins), and epithelial permeability (transepithelial resistance, flux of fluorescein isothiocyanate-dextran and bacteria) were assessed.

RESULTS

E coli-LF82 significantly affected epithelial expression of ∼8600 genes, many relating to mitochondrial function. E coli-LF82-infected epithelia showed swollen mitochondria, reduced mitochondrial membrane potential and adenosine triphosphate, and fragmentation of the mitochondrial network: events not observed with dead E coli-LF82, medium from bacterial cultures, or control E coli. Treatment with Mitochondrial Division Inhibitor 1 (Mdivi1, inhibits dynamin-related peptide 1, guanosine triphosphatase principally responsible for mitochondrial fission) or P110 (prevents dynamin-related peptide 1 binding to mitochondrial fission 1 protein) partially reduced E coli-LF82-induced mitochondrial fragmentation in the short term. E coli-LF82-infected epithelia showed loss of the long isoform of optic atrophy factor 1, which mediates mitochondrial fusion. Mitochondrial Division Inhibitor 1 reduced the magnitude of E coli-LF82-induced increased transepithelial flux of fluorescein isothiocyanate dextran. By 8 hours after infection, increased cytosolic cytochrome C and DNA fragmentation were apparent without evidence of caspase-3 or apoptosis inducing factor activation.

CONCLUSIONS

Epithelial mitochondrial fragmentation caused by E coli-LF82 could be targeted to maintain cellular homeostasis and mitigate infection-induced loss of epithelial barrier function. Data have been deposited in NCBI's Gene Expression Omnibus and are accessible through GEO series accession numbers GSE154121 and GSE154122 (https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE154121).

The objective assessment of the effects on cognition functioning among military personnel exposed to hypobaric-hypoxia: A pilot fMRI study

OBJECTIVE

To identify regions of the brain affected during cognitive working memory during tasks to assess attention, planning and decision making among military aviation personnel who have chronic intermittent exposure to high altitude environment.

METHOD

A case-control study was conducted in the Universiti Putra Malaysia among eight military personnel, four of whom had chronic intermittent exposure to high altitude training. They were divided into two groups, chronic intermittent exposure group (CE) (n=4) and a control group (n=4). They underwent a task-based functional magnetic resonance imaging (fMRI) that utilised spatial working memory task to objectively evaluate the neural activation in response to the Tower of London paradigm. Each correct answer was given a score of one and the maximum achievable score was 100%.

RESULTS

A consecutive dichotomised group of CE (4/8) and control (4/8) of age-matched military aviation personnel with a mean age of 37.23±5.52 years; showed significant activation in the right middle frontal gyrus (MFG). This in turn was positively correlated with response accuracy. A significant difference in the response accuracy was noted among both the groups at p<0.05.

CONCLUSION

At the minimum results of power analysis of this preliminary fMRI study, our group of aviation personnel who had chronic intermittent exposure to hypobaric hypoxic environment, did not have any significant decrease in cognitive function namely attention, decision-making and problem solving compared to controls during a working memory task.

Analysis of needs, expectations and capacities of health and social care professionals in order to provide culturally adapted care

The Mig-HealthCare consortium conducted a qualitative study of the health care needs of vulnerable migrants/refugees in Europe. The research was conducted between Fall 2017 and Spring 2018. In total, 20 focus group discussions or, where necessary individual interviews (19), were organised with health care professionals and service providers; policymakers; and representatives from Non-Governmental Organisations - NGOs. Thematic qualitative analysis was employed. The main results of the analysis show that:

Health care provision for migrants is uneven throughout the EU and variations exist even within the same country. Health care providers and NGOs agree that health care for migrants is inadequate and biased in favour of particular conditions and cases (minors, pregnant women and acute conditions). Challenges faced by different countries vary; while in some countries the main issue is legal access, in other basic needs such as sanitation and basic infrastructure were emphasised. Austerity measures following the 2008 financial crisis have negatively affected the health care system in general, which in turn has negatively affected the provision of health care for migrants/refugees. Discrimination linked to socio-economic and ethnic conditions is reported as a barrier to equal health care access. Knowledge, language and communication on both the demand and the supply side of health care provision emerge as crucial to ensure equal access for migrants/refugees. Gender may act as a barrier with women tending to be more marginalised in the host country, in terms of language proficiency and health literacy, lowering health care access. One of the main challenges for providing equal health care access for migrants has to do with the ability to balance a universal right to health with the particular means of achieving it. The evidence collected here shows how this tension between end and means is at work in different moments of the provision of health care for migrants/refugees.

The sexual and reproductive health in men with generalized epilepsy: a multidisciplinary evaluation

This study was specifically aimed to evaluate the sexual and reproductive health in a group of men with generalized epilepsy. In total, 44 men with generalized epilepsy were included in this study, their ages between 18 and 48 years (29.2+/-9.9) and duration of illness between 2 and 35 years (11.2+/-7.4); 34 patients were treated with conventional antiepileptic drugs (AEDs). Sexological and psychological interviews together with serum total testosterone, E(2), FSH, LH and prolactin were determined. Hyposexuality was diagnosed in 61.4%. Erectile dysfunction (ED) and premature ejaculation represented 70.4 and 66.7%, respectively. Variables such as hyposexuality, seizure duration and its poor control on AEDs were significantly associated with depressive symptoms. Compared to the normal control group, all patients reported elevated E(2) levels (P<0.001), 10 had FSH (n=4) and LH (n=6) levels exceeding that of the normal range for controls and two had hyperprolactinemia. Although the patients' mean value of total testosterone remained within the normal range, but it was significantly lower in hyposexual men compared to nonhyposexual (P<0.002), only two epileptic patients had markedly reduced level of total testosterone beyond normal control levels. This study strongly supports that: (1) The risk of hyposexuality and reproductive disturbances is high in epileptic patients with GTC convulsions despite the AEDs utilized. The risk for SD is further increased by poor seizure control and the frequently accompanied depressive manifestations. (2) It is possible that elevated E2 could increase the risk of SD by reducing active testosterone through negative feedback and the reduction of active testosterone could increase seizure intractability to antiepileptic medications.

Effect of colchicine on schistosoma-induced renal amyloidosis in Syrian golden hamsters

Seventy Syrian golden hamsters were infected with Schistosoma haematobium, and 10 uninfected hamsters served as negative controls. Of the schistosome-infected hamsters, 10 served as positive controls (infected but untreated) and the rest (60 hamsters) received treatment. In 30 hamsters treatment was given 9 weeks after infection (before the appearance of renal amyloidosis) and in the other 30 it was given after the appearance of amyloid deposits, 15 weeks after infection. Each treatment group was subdivided into 3 groups (10 hamsters each) in which treatment was either anti-schistosomal alone, combined anti-schistosomal and colchicine, or colchicine alone. Eighteen weeks after infection half of the animals in each group were sacrificed, while the rest were sacrificed 24 weeks after infection. Kidney specimens were evaluated semiquantitatively for renal amyloid deposits. Significant reductions in renal amyloid deposits and proteinuria were observed when combined treatment was given. This was nearly complete with early treatment and only partial when treatment was given late. When colchicine was given alone, a partial but significant reduction in proteinuria with no recognizable effect on renal amyloid deposits was observed. We conclude that colchicine is effective for the prevention and cure of schistosome-related renal amyloidosis in golden hamsters.