A165 FCGBP IN THE COLON IS SPATIALLY DEPENDENT ON MUC2 EXPRESSION AND IS DEGRADED IN DEXTRAN SULFATE SODIUM-INDUCED COLITIS

Background

The colonic mucus bilayer is an integral innate host defense mechanism that provides a physical barrier separating the lumen and its contents from the underlying epithelium. This essential barrier is produced by specialized secretory goblet cells of which Muc2 mucin is its primary product. IgG-Fc-binding protein (Fcgbp) is the second most abundant protein produced by goblet cells, which has a suggested function of crosslinking with Muc2 to stabilize the structural integrity of mucus. FCGBP is observed to decrease preceding the onset of inflammation in ulcerative colitis patients, leading to spatially distinct structural mucus weakening to contribute to the pathogenesis of the disease.

Purpose

Fcgbp is altered regionally in the gut and plays a role in the pathogenesis of dextran sulfate sodium (DSS)-induced colitis. The specific aims are:

To characterize the spatial expression of Muc2 and Fcgbp basally in goblet cells

To quantify alterations in Muc2 and Fcgbp in response to DSS-induced colitis and at restitution of disease

Method

mRNA and protein expression in Muc2^+/+ and Muc2^-/- C57BL/6 littermates were analyzed by RT-qPCR and Western blotting, respectively. Mucin granules were isolated from colonic goblet cells and the proteome quantified by liquid chromatography and tandem mass spectrometry (LC-MS/MS). Colitis was induced in Muc2^+/+ mice with 3.5% (w/v) DSS in tap water for five days, whereas Muc2^-/- littermates were given 1.5% (w/v) DSS in tap water for three days, ad libitum. Mice were given regular tap water for the remainder of the experiment to allow restitution of inflammation. Disease activity index (DAI) was scored based on weight loss. Mice were sacrificed at various time points up to 10 days, and colons excised and sectioned for histopathology analysis.

Result(s)

LC-MS/MS of mucin granules run under reducing and non-reducing conditions confirmed that Muc2 and Fcgbp were the most abundant proteins in mucin granules and were non-covalently bound to each other. mRNA and protein expression of Muc2 and Fcgbp were highly expressed in the mid colon, and regulation of Fcgbp was unaffected in Muc2^-/- littermates. In response to DSS-induced colitis in Muc2^+/+ mice, Muc2 transcription rapidly increased in all regions of the colon with highest expression in the mid colon. In contrast, Fcgbp transcription increased in the mid and distal colons and peaked during highest disease activity. Interestingly, Fcgbp protein expression was abrogated in the mid colon even at restitution. In Muc2^-/- mice, Fcgbp transcription decreased during disease onset but returned to normal levels following removal of DSS.

Image

Conclusion(s)

This study demonstrates that in response to DSS, Fcgbp expression was spatially degraded at the onset of disease and remained low at restitution. The disappearance of Fcgbp in the mid colon of Muc2^+/+ littermates, despite Muc2 restoration, suggests that the mucus barrier remains structurally altered and functionally impaired at restitution. Supported by CIHR

Disclosure of Interest

None Declared

A230 A MISSENSE MUTATION IN GOBLET CELL PROTEIN FCGBP ALTERS THE GLYCOMIC PROFILE AND FUNCTION OF THE COLONIC MUCUS BARRIER

Background

MUC2 mucin, produced by colonic goblet cells, forms a mucus bilayer that provides a physical barrier between potential pathogens in the lumen and the underlying epithelial cells. Mucus is thus the first line of innate host defense in the gastrointestinal (GI) tract. Many GI diseases including inflammatory bowel disease and colon cancer affect the glycosylation of mucus. Goblet cells produce a variety of proteins that are associated with the mucus layer. Of these proteins, FCGBP is of significant interest due to its structural similarities to MUC2 mucin with unknown functions. In this study, we investigated how a missense mutation in FCGBP altered the glycosylation of goblet cell MUC2 and affected its barrier functions.

Purpose

Hypothesis: A missense mutation in FCGBP results an impaired mucus layer by the altering glycomic profiles of goblet cell mucins. Specific aims:

1) To determine mechanistically how FCGBP impeded the structural integrity of the mucus layer

2) To quantify MUC2 glycoprotein modifications in the altered mucus layer

Method

To investigate whether FCGBP impaired mucus barrier functions, two cell types were investigated: wildtype LS174T (WT) MUC2 mucus-producing goblet cells and LS174T cells with a missense mutation in FCGBP (FCGBP MS). To determine if FCGBP MS led to loss in barrier function in the mucus layer, the penetration of 0.2, 1, and 2 μm fluorescent beads (to mimic bacteria) through the mucus layer were quantified. To determine if the differences in penetrability were caused by differences in MUC2 glycosylation in the goblet cell lines, sensitive glycomic analyses were performed by high-performance liquid chromatography-mass spectrometry (HPLC-MS) and capillary electrophoresis with laser-induced fluorescence detection (CE-LIF). Both intact cells and isolated MUC2 mucin granules were analyzed. To determine if differences in the glycomic profiles was caused by differences in glycotransferases, RT-PCR was performed on over 30 human glycosyltransferases.

Result(s)

FCGBP MS cells exhibited significant loss in MUC2 mucus barrier function as quantified by fluorescent beads penetration through the mucus layer in a temporal manner. FCGBP MS cells exhibited an altered glycomic profile with a notable increase in sialylated glycans as quantified by HPLC-MS. The increase in sialylated glycans was associated with a significant increase in sialyl-transferase expression in FCGBP MS cells.

Conclusion(s)

These data demonstrate that a single missense mutation in FCGBP altered the penetrability of the mucus layer associated with an increase in sialylated proteins, a signature hallmark of numerous colonic diseases. FCGBP was critical in providing structural integrity of the mucus layer and maintenance of goblet cell glycosylation profiles.

Please acknowledge all funding agencies by checking the applicable boxes below

CIHR

Disclosure of Interest

None Declared

A187 DIETARY FIBERS ELICIT GUT IMMUNE AND EPITHELIAL BARRIER MODIFYING EFFECTS IN INFLAMMATORY BOWEL DISEASES BASED ON FOOD SOURCE AND FIBER CHEMICAL FEATURES

Background

Dietary fibers are not digested in the bowel; they are fermented by microbes, typically promoting gut health. However, IBD patients experience sensitivity to consumption of fibers. Our previous findings offered the first mechanistic evidence demonstrating that unfermented dietary β-fructans (inulin and oligofructose) can induce pro-inflammatory cytokines and altered epithelial barrier integrity in a subset of pediatric IBD colonic biopsies cultured ex vivo, and in the SYNERGY-1 (β-fructan) clinical study of adult remission UC patients. Fermentation of β-fructan by whole-microbiota intestinal washes from non-IBD or remission IBD patients (but not non-IBD microbes) reduced pro-inflammatory responses.

Purpose

Here we aimed to expand our findings to uncover the physiologically relevant gut immune and epithelial responses to over 50 unfermented and partially fermented dietary fibers (arabinoxylans, β-glucans, β-mannans, galatooligosaccharides, inulins, oligofructoses, pectins, raffinooligosaccharides, xyloglucans) sourced from commonly consumed fruits, grains, and vegetables to better understand which foods are safe for IBD patients, and in which disease state settings.

Method

Colonic biopsies cultured ex vivo, peripheral blood mononuclear cells (PBMCs), colonic organoids, and cell lines were incubated with individual dietary fibers or mixture of fibers extracted from commonly consumed fruits, grains, and vegetables. Epithelial barrier integrity (TEER, microscopy, FITC-dextran) and immune responses (cytokine secretion [ELISA/MSD] and expression [qPCR]) were assessed. Structural features of the different fibers (e.g., degree of polymerization, phenolic/phytic content, branching, sugar content) were measured by HPLC and gas chromatography and correlated to host cell responses.

Result(s)

Most significantly unfermented inulin, oligofructose, and arabinoxylan induced pro-inflammatory responses, particularly in myeloid cells. Pectin and galatooligosaccharides were either non-inflammatory or anti-inflammatory depending on the food source. The epithelial barrier response to select dietary fibers correlated more significantly with the chemical properties of the fibers; longer fibers (greater degree of polymerization; e.g., inulin) displayed improved barrier integrity while shorter dietary fibers with higher phenolic content displayed reduced barrier integrity. Fiber structural properties varied significantly between different fiber subtypes along with the same fiber subtype sourced from different foods.

Conclusion(s)

Our findings suggest that intolerance and avoidance of fibers in select IBD patients occurs in patients whose gut microbiota do not support fermentation of fibers resulting in increased presence of unfermented dietary fibers in the gut. Here we show which specific dietary fibers from specific food items can elicit gut barrier damage and inflammation in the gut dependent on fiber structural features, suggesting mechanisms underlying IBD patient avoidance of specific high-fiber foods.

Please acknowledge all funding agencies by checking the applicable boxes below

Other

Please indicate your source of funding;

Weston Family Foundation, MMSF, NSERC, CRC

Disclosure of Interest

None Declared

Use of levodopa-carbidopa intestinal gel to treat patients with multiple system atrophy

BACKGROUND

Levodopa-carbidopa intestinal gel (LCIG) is an effective treatment for late-stage Parkinson's disease (PD) but had not been evaluated in levodopa-responsive patients with the parkinsonian variant of multiple system atrophy (MSA-P) and motor fluctuations. We aimed to assess the safety of LCIG in MSA-P patients.

METHODS

In a retrospective, single-center study, we analyzed clinical and treatment-related data for all patients with MSA-P or PD treated with LCIG between December 2004 and November 2017. Adverse events (AEs) were classified into three classes: AEs related to gastrointestinal effects or to the PEG-J procedure, AEs related to the device, and AEs related to the pharmacological effect of LCIG.

RESULTS

7 MSA-P and 63 PD patients had been treated with LCIG for a median [interquartile range] period of 31 [16;43] and 19 [8;45] months, respectively. There were no significant intergroup differences in safety. Enteral nutrition was introduced at the same time as LCIG treatment in 4 (57%) MSA-P patients. In the MSA-P and PD groups, LCIG was associated with a better Global Clinical Impression score and discontinuation of oral anti-parkinsonian drugs (in 43% and 27% of cases, respectively).

CONCLUSIONS

LCIG treatment is feasible in MSA-P patients with severe motor complications. The safety profile is similar to that seen in PD.

AB0444 ENPATORAN: PRECLINICAL EVIDENCE SUPPORTING GLUCOCORTICOID DOSE REDUCTION AND PHASE II STUDY DESIGN IN PATIENTS WITH SLE AND/OR CLE (WILLOW)

Background

Enpatoran is a potent selective dual inhibitor of toll-like receptor (TLR) 7 and TLR8, aberrant activation of which may be involved in systemic lupus erythematosus (SLE) pathogenesis and glucocorticoid resistance.1,2,3 Enpatoran suppressed disease development in lupus mouse models, improving survival and reducing proteinuria, autoantibodies, and the interferon (IFN) gene signature.1 In healthy participants and patients hospitalized with COVID-19 pneumonia, enpatoran was well tolerated and demonstrated effective TLR7/8 engagement.4 Enpatoran is potentially glucocorticoid sparing and may help avoid the detrimental effects of long-term corticosteroid use in SLE management.5,6

Objectives

To evaluate the glucocorticoid-sparing effect of enpatoran and design a basket trial to assess its efficacy and safety in patients with SLE and/or cutaneous lupus erythematosus (CLE).

Methods

Cytokine concentrations and gene expression changes were measured in stimulated human peripheral blood mononuclear cells (PBMCs) from healthy donors after treatment with dexamethasone, TLR7/8 inhibitor, or both. A Phase II, basket design proof-of-concept, dose-finding study in patients with SLE and/or CLE (WILLOW) was designed.

Results

In healthy donor PBMCs, synergy was observed between TLR7/8 inhibitor and dexamethasone. Combination treatment inhibited cytokine release (IL-6) with greater potency than either treatment alone and reduced the expression of nuclear factor-kappa B and IFN-regulated genes. WILLOW is a Phase II, basket proof-of-concept, dose-finding, randomized, double-blind, placebo (PBO)-controlled 24-week study with two cohorts (NCT05162586, Figure 1). The primary objectives of WILLOW are to evaluate the dose–response relationship of enpatoran in reducing disease activity based on Cutaneous Lupus Erythematosus Disease Area and Severity Index-A (CLASI-A) or BILAG-Based Composite Lupus Assessment (BICLA) response rate. The secondary objectives are to investigate effects on both BICLA response and clinically meaningful corticosteroid reduction and evaluate disease control (including clinically meaningful corticosteroid reduction) in patients with predominantly active CLE or SLE. Cohort A will enroll patients with CLE (active subacute CLE and/or discoid LE) or SLE with predominantly active lupus rash. Cohort B, in two parts, will enroll SLE patients with moderate to severe systemic disease activity. Part 1 will assess clinical signal and Part 2 may be adapted to improve dose finding. Glucocorticoid-sparing will be evaluated by mandatory tapering to a prednisone-equivalent dose of ≤5 mg/day.

Figure 1.

WILLOW study design.

Cohort A and Cohort B Part 1 will start in parallel.

*Part 2 will be initiated after a pre-specified number of patients are enrolled in Part 1; enpatoran doses in Part 2 may be adapted to improve dose finding (dashed boxes).

BILAG, British Isles Lupus Assessment Group; CLASI-A, Cutaneous Lupus Erythematosus Disease Area and Severity Index-A; CLE, cutaneous lupus erythematosus; CS, corticosteroid; DBPC, double-blind placebo-controlled; DLE, discoid lupus erythematosus; PBO, placebo; SCLE, Subacute cutaneous lupus erythematosus; SLE, systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index.

Conclusion

Enpatoran is a novel TLR7/8 inhibitor and may enable glucocorticoid dose reduction in patients with SLE and CLE. The WILLOW study incorporates multiple novel elements including a basket design and evaluation of glucocorticoid-sparing.

References

[1]Vlach, et al. J Pharmacol Exp Ther. 2021;376:397–409;

[2]Northcott, et al. Lancet Rheumatol. 2021;5:e357–e370;

[3]Guiducci, et al. Nature. 2010;465:937–941;

[4]Port, et al. Pharmacol Res Perspect. 2021;9:e00842;

[5]Thamer, et al. J Rheumatol. 2009;36:560–564;

[6]Ruiz-Irastorza, et al. Rheumatology. 2012;51:1145–1153.

Acknowledgements

This study was sponsored by the healthcare business of Merck KGaA, Darmstadt, Germany (CrossRef Funder ID: 10.13039/100009945), who funded medical writing support by Bioscript Stirling Ltd.

Disclosure of Interests

Eric F. Morand: None declared, Andrew Bender Shareholder of: Shares in Merck KGaA, Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Aditee Deshpande Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Bharat Vaidyanathan Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), cristina vazquez mateo Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Melinda Przetak Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Flavie Moreau Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Mukhy Khursheed Employee of: Merck Serono Ltd (an affiliate of Merck KGaA), Sanjeev Roy Employee of: Ares Trading SA (an affiliate of Merck KGaA), David Pearson Consultant of: Biogen Inc.

POS1268 PHASE II TRIAL OF ENPATORAN IN PATIENTS HOSPITALIZED WITH COVID-19 PNEUMONIA

Background

Enpatoran is a selective and potent dual toll-like receptor (TLR) 7/8 inhibitor in development for the treatment of cutaneous and systemic lupus erythematosus (CLE/SLE). Enpatoran inhibits TLR7/8 activation in vitro and suppresses disease activity in lupus mouse models.1 Enpatoran was well tolerated and had linear pharmacokinetic (PK) parameters in healthy volunteers.2 As TLR7/8 mediate immune responses to single-stranded RNA viruses, including SARS-CoV-2, it was postulated that enpatoran may prevent hyperinflammation and cytokine storm in COVID-19.

Objectives

In response to the COVID-19 pandemic, we conducted an exploratory Phase II trial to assess safety and determine whether enpatoran prevents clinical deterioration in patients (pts) hospitalized with COVID-19 pneumonia. PK and pharmacodynamics (PD) of enpatoran were also evaluated.

Methods

ANEMONE was a randomized, double-blind, placebo (PBO)-controlled study conducted in Brazil, the Philippines, and the USA (NCT04448756). Pts aged 18–75 years, hospitalized with COVID-19 pneumonia (WHO 9-point scale score =4) but not mechanically ventilated, with SpO2 <94% and PaO2/FiO2 ≥150 (FiO2 maximum 0.4) were eligible. Those with a history of uncontrolled illness, active/unstable cardiovascular disease and SARS-CoV-2 vaccination were excluded. Pts received PBO or enpatoran (50 or 100 mg twice daily [BID]) for 14 days, with monitoring to Day 28 and safety follow-up to Day 60. Primary outcomes were safety and time to recovery (WHO 9-point scale ≤3). Clinical deterioration (time to clinical status >4, WHO 9-point scale) was a secondary outcome. Exploratory endpoints were enpatoran and biomarker concentrations (cytokines, C-reactive protein [CRP], D-dimer and interferon gene signature [IFN-GS] scores) assessed over time.

Results

149 pts received either PBO (n=49), or enpatoran 50 mg (n=54) or 100 mg (n=46) BID; 88% completed treatment and 86% received concomitant steroids. Median age was 50 years (77% <60 years old), 66% were male, and 50% had ≥1 comorbidity (40% hypertension, 24% diabetes). Overall, 59% pts reported a treatment-emergent adverse event (TEAE) with three non-treatment-related deaths; 11% reported a treatment-related TEAE. The proportion of pts in the enpatoran group reporting serious TEAEs was low (50 mg BID 9%; 100 mg BID 2%) vs PBO (18%). Gastrointestinal disorders were most common (PBO 8%; 50 mg BID 28%; 100 mg BID 9%). The primary outcome of time to recovery with enpatoran vs PBO was not met; medians were 3.4–3.9 days. A positive signal in time to clinical deterioration from Day 1 through Day 28 was observed; hazard ratios [95% CI] for enpatoran vs PBO were 0.39 [0.13, 1.15] (50 mg BID) and 0.30 [0.08, 1.08] (100 mg BID). Mean enpatoran exposure was dose-proportional, and PK properties were within expectations. The median (quartile [Q]1– Q3) interleukin 6 (IL-6), CRP and D-dimer baseline concentration across the groups were 5.7 (4.0–13.5) pg/mL, 30.04 (11.40–98.02) and 0.62 (0.39–1.01) mg/L, respectively. Baseline IFN-GS scores were similar across groups.

Conclusion

The ANEMONE trial was the first to evaluate the safety and efficacy of a TLR7/8 inhibitor in an infectious disease for preventing cytokine storm. Enpatoran up to 100 mg BID for 14 days was well tolerated by patients acutely ill with COVID-19 pneumonia. Time to recovery was not improved with enpatoran, perhaps due to the younger age of patients who had fewer comorbidities compared to those in similar COVID-19 trials. However, there was less likelihood for clinical deterioration with enpatoran than placebo. This trial provides important safety, tolerability, PK and PD data supporting continued development of enpatoran in SLE and CLE (NCT04647708, NCT05162586).

References

[1]Vlach, et al. J Pharmacol Exp Ther 2021;376:397–409;

[2]Port, et al. Pharmacol Res Perspect 2021;9:e00842.

Acknowledgements

We would like to thank those who took part in the the ANEMONE trial. This study was sponsored by the healthcare business of Merck KGaA, Darmstadt, Germany (CrossRef Funder ID: 10.13039/100009945), who funded medical writing support by Bioscript Stirling Ltd.

Disclosure of Interests

John E. McKinnon Consultant of: EMD Serono Research & Development Institute, Inc., Billerica, MA, USA, an affiliate of Merck KGaA, Joel Santiaguel Speakers bureau: Merck Healthcare KGaA, Claudia Murta Speakers bureau: Pfizer/Wyeth, Dongzi Yu Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Mukhy Khursheed Employee of: Merck Serono Ltd (an affiliate of Merck KGaA), Flavie Moreau Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Lena Klopp-Schulze Employee of: Merck Healthcare KGaA, Jamie Shaw Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Sanjeev Roy Employee of: Ares Trading SA (an affiliate of Merck KGaA), Amy Kao Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA)

Prevalence of Intracranial Atherosclerotic Disease in Patients with Low-Risk Transient or Persistent Neurologic Events

BACKGROUND AND PURPOSE

There are limited data on the prevalence and outcome of intracranial atherosclerotic disease in patients with low-risk transient or persistent minor neurologic events. We sought to determine the prevalence and risk factors associated with intracranial atherosclerotic disease in patients with low-risk transient or persistent neurologic events.

MATERIALS AND METHODS

Participants with available intracranial vascular imaging from the Diagnosis of Uncertain-Origin Benign Transient Neurologic Symptoms (DOUBT) study, a large prospective multicenter cohort study, were included in this post hoc analysis. The prevalence of intracranial atherosclerotic disease of ≥50% was determined, and the association with baseline characteristics and DWI lesions was evaluated using logistic regression.

RESULTS

We included 661 patients with a median age of 62 years (interquartile range, 53-70 years), of whom 53% were women. Intracranial atherosclerotic disease was found in 81 (12.3%) patients; asymptomatic intracranial atherosclerotic disease alone, in 65 (9.8%); and symptomatic intracranial atherosclerotic disease, in 16 (2.4%). The most frequent location was in the posterior cerebral artery (29%). Age was the only factor associated with any intracranial atherosclerotic disease (adjusted OR, 1.9 for 10 years increase; 95% CI, 1.6-2.5). Multivariable logistic regression showed a strong association between intracranial atherosclerotic disease and the presence of acute infarct on MR imaging (adjusted OR, 3.47; 95% CI, 1.91-6.25).

CONCLUSIONS

Intracranial atherosclerotic disease is not rare in patients with transient or persistent minor neurologic events and is independently associated with the presence of MR imaging-proved ischemia in this context. Evaluation of the intracranial arteries could be valuable in establishing the etiology of such low-risk events.

A63 THE COLONIC PATHOGEN, ENTAMOEBA HISTOLYTICA ACTIVATES CASPASE-4 IN HUMAN MACROPHAGES THAT CLEAVES GASDERMIN D TO FACILITATE IL-1β SECRETION IN THE ABSENCE OF CELL DEATH

Background

A hallmark of Entamoeba histolytica ( Eh) invasion in the gut is acute intestinal inflammation dominated by the secretion of pro-inflammatory cytokines. Live Eh in contact with macrophages activates caspase-1 by the recruitment of the NLRP3 inflammasome in a Gal-lectin and Eh cysteine proteases 5 ( EhCP-A5)-dependent manner, resulting in the maturation and secretion of IL-1β. Eh in contact with macrophages also activates caspase-4 by outside-in signaling but it is unclear how Eh-induced caspase-1/4 regulates gasdermin D (GSDMD) cleavage to drive both pore formation and IL-1β secretion without causing cell death. In this study, we interrogated the requirements and mechanism of Eh-induced caspase-4 activation in cleaving GSDMD to mediate bioactive IL-1β release.

Aims

Hypothesis: Eh-induced activation of caspase-4 regulates GSDMD mediated pro-inflammatory responses.

Specific aim: To quantify caspase-1/4 cleavage of GSDMD in Eh-induced pro-inflammatory responses.

Methods

Human PMA-differentiated THP-1 macrophages were used for Eh-macrophage studies. Caspase-1/4 activation and GSDMD cleavage were detected by immunoblot analysis. Bioactive IL-1β secretion was quantified by HEK-Blue^TM IL-1β reporter cells via the measurement of secreted embryonic alkaline phosphatase (SEAP) and cell pyroptosis (inflammatory cell death) was determined by LDH assay. Immunoprecipitation was performed in HEK 293T cells transfected with human GSDMD plasmid followed by in vitro caspase cleavage assay.

Results

Unlike caspase-1, Eh-induced caspase-4 activation and IL-1β secretion was independent of the NLRP3 inflammasome as revealed with the use of CRISPR-Cas9 gene edited caspase-1, 4, ASC and NLRP3 macrophages. In the absence of caspase-1, caspase-4 activation was significantly upregulated that promoted the cleavage of GSDMD to induce robust IL-1β secretion. Eh-induced caspase-4 played a major role in triggering IL-1β release and GSDMD pore formation as quantified by SEAP assay and immunoprecipitation of overexpressed GSDMD in HEK 293T cells followed by in vitro caspase cleavage assay. Pharmacological inhibition of GSDMD pore formation and in CRISPR-Cas9 gene edited GSDMD macrophages, Eh-induced IL-1β secretion was highly dependent on GSDMD pore formation and independent of pyroptosis. This was in marked contrast to the positive control, LPS + Nigericin that induced high expression of caspase-1 but not caspase-4 that enhanced GSDMD cleavage and IL-1β secretion and induced massive pyroptosis.

Conclusions

These results suggest that Eh induced a state of “hyperactivated macrophages” that led to caspase-4 dependent GSDMD cleavage and IL-1β secretion in the absence of pyroptosis important in disease pathogenesis.

Funding Agencies

NSERC

A43 HIGH MUC2 MUCIN BIOSYNTHESIS BY GOBLET CELLS UNDER METABOLIC STRESS PRODUCE ELEVATED LEVELS OF PRO-INFLAMMATORY CYTOKINES

Background

The colonic mucus bilayer is an integral innate host defense mechanism that houses the commensal gut microbiota whilst protecting the underlying mucosa against harmful pathogens. This essential barrier is generated via a highly ER stressful mechanism by goblet cells that produce MUC2 mucin. Goblet cells also produce a variety of proteins and peptides as well as pro-inflammatory cytokines that interact with and activate other arms of the innate immune system. In ulcerative and infectious colitis, goblet cells hyper secrete mucus and become depleted of their mucin stores. However, it is not known if other proteins or pro-inflammatory responses are altered in mucin-depleted goblet cells. Here, we elucidated the molecular mechanisms that regulate pro-inflammatory responses in WT and CRISPR/Cas9 MUC2 KO human goblet cells.

Aims

Hypothesis: MUC2 biosynthesis and production augment pro-inflammatory responses in goblet cells. The specific aims are:

1. To determine the pro-inflammatory responses in WT and MUC2KO goblet cells

2. To determine if the MAPK signaling pathway is altered in WT and MUC2KO goblet cells

Methods

mRNA and protein expression of various pro-inflammatory chemokines/cytokines in WT and CRISPR/Cas9 MUC2KO LS174T goblet cells were analyzed by RT-qPCR and 15-plex Luminex array. IL-22 was used to alleviate ER stress, as quantified by the expression of stress proteins by Western blotting. To determine differences in pro-inflammatory cytokine release, cells were stimulated with phorbol myristate acetate (PMA, positive control), live Entamoeba histolytica (Eh), and lysed soluble amebic proteins (SAP). MAPK signaling was enumerated by specific pharmacological inhibitors and analyzed by Western blotting.

Results

Basally and in response to live Eh, WT goblet cells expressed high levels of the metabolic stress proteins, ATF4, GRP78, and CHOP as compared to MUC2KO cells. In response to PMA, live Eh, and SAP, WT cells expressed high levels of mRNA transcripts and secreted significant amounts of the pro-inflammatory chemokines, monocyte chemoattractant protein-1 (MCP-1), interleukin-8 (IL-8), and interleukin-13 (IL-13) as compared to MUC2KO cells. Reducing ER stress with IL-22 significantly augmented IL-8 protein release in both WT and MUC2KO cells. Signaling via the ERK MAPK pathway was elevated in WT whereas in MUC2KO goblet the response was delayed.

Conclusions

This study demonstrates that high MUC2 mucin biosynthesis regulates the expression and secretion of the pro-inflammatory cytokines MCP-1, IL-8, and IL-13. Mechanistically, MUC2 induced metabolic stress regulated MAPK activity for high output pro-inflammatory responses as compared to MUC2KO goblet cells.

Funding Agencies

CIHR

A198 COLONIC MUC2 MUCIN IS STABILIZED BY FCGBP TO RESIST SALMONELLA TYPHIMURIUM INVASION IN GOBLET CELLS

Background

The colonic mucus bilayer is the first line of innate defense against pathogen invasion in the gut by forming a physical barrier between the lumen and the underlying single layer of mucosal epithelial cells. While MUC2 mucin is the primary component of the mucus layer, it also contains several mucus associated proteins of which FCGBP is of significant interest due to its structural similarities to MUC2 with unknown functions. Here we elucidated the functions of FCGBP in MUC2 mucin in response to S. typhimurium ( St) adherence and invasion in human colonic goblet cells.

Aims

Hypothesis: FCGBP is coordinately produced with MUC2 mucin and plays an important role in innate host defense. The specific aims are:

1. To determine if FCGBP alters the structural integrity of the mucus layer

2. To determine the role of FCGBP in St adherence and invasion of goblet cells

Methods

To investigate whether FCGBP impaired mucus barrier functions, wildtype LS174T (WT) MUC2 mucus-producing goblet cells and LS174T cells with a missense mutation in FCGBP (FCGBP MS) were used. To determine if FCGBP MS led to loss in barrier function, St adherence and invasion, and 0.2, 1, and 2 μM fluorescent bead penetration through the mucus monolayers were quantified. MUC2 and FCGBP mRNA and protein expression induced by St were analysed by RT-PCR and Western blotting. St-induced pro-inflammatory cytokines responses were analyzed by RT-PCR and human focus 15-plex cytokine and chemokine array. Cell killing was enumerated by LDH assay.

Results

FCGBP MS cells exhibited significant loss in MUC2 mucus barrier function as quantified by fluorescent beads penetration closer towards the epithelial cell surface temporally as compared to WT cells independent of bead size. Adherence of St was significantly increased in FCGBP MS cells and induced robust MUC2 mRNA and protein expressions in a time-dependent manner. Similarly, St elicited robust expression of pro-inflammatory cytokine mRNA and protein release in FCGBP MS as compared to WT cells. FCGBP MS were readily invaded by St that resulted in increased cell death as compared to WT cells.

Conclusions

Loss of function by FCGBP MS, but not in WT cells, showed increased penetration of fluorescent beads through the mucus layer that resulted in increased St adherence, invasion, and cell death. In WT cells, FCGBP and MUC2 were coordinately upregulated in response to St. The concurrent increase in pro-inflammatory cytokine expression in FCGBP MS cells in response to St suggests that bacteria directly interacted with the cell surface indicative of an impaired mucus layer. The overall trend for increased bacterial invasion, pro-inflammatory response and cell death in FCGBP MS demonstrates that FCGBP was critical in providing structural integrity and protective functions of the mucus layer.

Funding Agencies

CIHR

Triple Leidenfrost Effect: Preventing Coalescence of Drops on a Hot Plate

We report on the collision-coalescence dynamics of drops in Leidenfrost state using liquids with different physicochemical properties. Drops of the same liquid deposited on a hot concave surface coalesce practically at contact, but when drops of different liquids collide, they can bounce several times before finally coalescing when the one that evaporates faster reaches a size similar to its capillary length. The bouncing dynamics is produced because the drops are not only in Leidenfrost state with the substrate, they also experience Leidenfrost effect between them at the moment of collision. This happens due to their different boiling temperatures, and therefore, the hotter drop works as a hot surface for the drop with lower boiling point, producing three contact zones of Leidenfrost state simultaneously. We called this scenario the triple Leidenfrost effect.

Faux Pas Recognition and Executive Processes in Patients with Alcohol Use Disorder: Toward an Investigation of Interindividual Heterogeneity

OBJECTIVE

Impairment of executive functions (EF) has been documented for decades in patients with alcohol use disorders (AUD), while more recent studies have also reported impaired theory of mind. Both have been associated with negative outcomes, particularly a high risk of relapse. However, the interrelatedness of EF and theory of mind impairments remains subject to debate.

METHOD

About 19 AUD outpatients and 20 healthy controls (HC) were asked to complete measures of motor inhibition, mental flexibility, and updating to assess EF, and the faux pas test to assess theory of mind.

RESULTS

As expected, patients' mean performances on EF and faux pas measures were poorer than those of HC. Correlational analyses revealed that executive processes were differentially related to faux pas subscores. Additional single-case analyses corroborated the strong association between EF and faux pas interpretation, as patients with AUD mostly had congruent performances (i.e., both EF and faux pas impaired or both EF and faux pas preserved).

CONCLUSIONS

This study highlights the interrelatedness of EF and faux pas performances in AUD, but also emphasizes the incomplete overlap of the cognitive processes involved in these tasks, with heterogeneous patterns of association. Based on these findings, tailored cognitive rehabilitation programs that simultaneously target EF and faux pas recognition could be developed to favor patients' social inclusion and reduce the risk of relapse. Results also argue in favor of systematic screening for EF and theory of mind impairments among AUD patients.

A24 FCGBP MAINTAINS MUC2 MUCUS STRUCTURAL INTEGRITY BY STABILIZING THE MUCUS LAYER IN RESPONSE TO THE COLONIC PATHOGEN, ENTAMOEBA HISTOLYTICA

Background

MUC2 mucin is the major component of the colonic mucus bilayer that serves as the first line of innate host defense against pathogens while supporting a healthy microbiota and regulating epithelial barrier function. Proteomic studies of colonic mucus have identified various mucus-associated proteins. One of the most abundant is FCGBP, similar to MUC2 mucin, but its interaction with MUC2 or function is not known. Here, we elucidated FCGBP functional role in stabilizing MUC2 mucus and in innate host defence against Entamoeba histolytica (Eh).

Aims

Hypothesis: MUC2 mucin and FCGBP are coordinately produced and play an important role in innate host defense. The specific aims are:

1. To determine if FCGBP alters the structural integrity of the mucus layer

2. To determine the role of FCGBP in Eh infection

Methods

FCGBP mRNA and protein expression induced by Eh, in WT and FCGBP CRISPR/Cas9 LS174T goblet cells were analysed by RT-PCR and Western blotting. To compare integrity of the mucus layer, fluorescent Eh and 1μM fluorescent beads were inoculated on WT and KO monolayers and adherent Eh and bead penetrability analyzed. To quantify MUC2 and FCGBP degradation by Eh, purified MUC2 and recombinant FCGBP were incubated with Eh proteases (SPs) and Western blotted using highly specific antibodies against various regions of the proteins.

Results

In response to live Eh, FCGBP and MUC2 mRNA and protein expressions were significantly increased in a time-dependent manner. Surprisingly, FCGBP KO cells elicited robust expression of pro-inflammatory cytokine mRNA and protein as compared to WT cells. More fluorescent Eh were attached to the mucus layer of FCGBP KO cells as compared to WT or MUC2 KO cells. Fluorescent beads penetrated further towards the epithelial cell surface in KO as compared to WT cells. Interestingly, while both MUC2 and FCGBP from purified polymeric mucins were degraded by Eh SPs, FCGBP cleavage occurred at a faster rate than MUC2. Degradation of FCGBP and MUC2 was mediated by EhCP-A5 cysteine proteinase using purified MUC2 and recombinant FCGBP.

Conclusions

In WT goblet cells, FCGBP and MUC2 were upregulated temporally in response to Eh. The increase in pro-inflammatory cytokine expression in FCGBP KO cells in response to Eh suggests that Eh directly interacted with the cell surface suggesting an impaired protective mucus layer. In support of this, fluorescent beads penetrated the mucus layer close to the cell surface and more Eh were attached to FCGBP KO mucus demonstrating that FCGBP was critical in providing structural integrity of the mucus layer. In response to Eh, FCGBP degradation was a prerequisite for MUC2 cleavage, providing direct evidence that FCGBP and MUC2 interactions conferred biophysical properties of the protective functions of the mucus gel.

Funding Agencies

CIHR

A31 COMPLEX ROLE OF DIETARY FIBERS IN IBD: MICROBES MEDIATE FIBER-INDUCED INFLAMMATION

Background

Dietary fibers pass through the bowel undigested and are fermented within the intestine by microbes, typically promoting gut health. However, many IBD patients describe experiencing sensitivity to fibers. β-glucan, found on the surface of fungal cells during fungal infection, has been shown to bind to fiber receptors, such as Dectin-1, on host immune cells, resulting in a pro-inflammatory response. These fungal fibres share properties with dietary fibers.

Aims

As an altered gut microbial composition has been associated with IBD, we hypothesized that the loss of fiber-fermenting microbes populating the gut in IBD could lead to dietary fibers not being efficiently broken down into their beneficial biproducts (e.g. short chain fatty acids; SCFA), resulting in binding of intact fibers to pro-inflammatory host cell receptors.

Methods

Immune and epithelial cell lines and colonic biopsies cultured ex vivo were incubated with oligofructose or inulin (5g/L), or pre-fermented fibers (24hr anaerobic fermentation). Immune responses were measured by cytokine secretion (ELISA), and expression (qPCR). Barrier integrity was measured by transepithelial resistance (TEER). Food frequency questionnaire (FFQ) data of patient fiber consumption were correlated with gut microbes (shotgun sequencing) and immune responses to fiber in patient biopsies.

Results

Unfermented oligofructose induced IL-1β secretion in leukocytes (macrophage, T cell, neutrophil) and in colon biopsies from pediatric Crohn disease (CD; n=38) and ulcerative colitis (UC; n=20) patients cultured ex vivo, but not in non-IBD patients (n=21). IL-1β secretion was greater in patients with more severe disease. Pre-fermentation of oligofructose by whole-microbe intestinal washes from non-IBD patients or remission patients reduced secretion of IL-1β, while whole microbe intestinal washes from severe IBD patients were unable to ferment oligofructose or reduce cytokine secretion. Fiber effects on IL-1β secretion in biopsies positively correlated with effects on barrier integrity in T84 cells. Fiber-associated immune responses in patient biopsies cultured ex vivo (ELISA) correlated with fiber avoidance (FFQ) and gut microbiome (sequencing) in matching patient samples.

Conclusions

Our findings demonstrate that intolerance and avoidance of prebiotic fibers in select IBD patients is associated with the inability to ferment these fibers, leading to pro-inflammatory immune responses and intestinal barrier disruption. This highlights select disease state scenarios, in which administration of fermentable fibers should be avoided and tailored dietary interventions should be considered in IBD patients.

Funding Agencies

CIHRWeston Foundation

Automated MRI assessment confirms cartilage thickness modification in patients with knee osteoarthritis: post-hoc analysis from a phase II sprifermin study

BACKGROUND

Sprifermin is under investigation as a potential disease-modifying osteoarthritis drug. Previously, 2-year results from the FORWARD study showed significant dose-dependent modification of cartilage thickness in the total femorotibial joint (TFTJ), medial and lateral femorotibial compartments (MFTC, LFTC), and central medial and lateral TFTJ subregions, by quantitative magnetic resonance imaging (qMRI) using manual segmentation.

OBJECTIVE

To determine whether qMRI findings from FORWARD could be reproduced by an independent method of automated segmentation using an identical dataset and similar anatomical regions in a post-hoc analysis.

METHOD

Cartilage thickness was assessed at baseline and 6, 12, 18 and 24 months, using automated cartilage segmentation with active appearance models, a supervised machine learning method. Images were blinded for treatment and timepoint. Treatment effect was assessed by observed and adjusted changes using a linear mixed model for repeated measures.

RESULTS

Based on automated segmentation, statistically significant, dose-dependent structural modification of cartilage thickness was observed over 2 years with sprifermin vs placebo for TFTJ (overall treatment effect and dose response, both P < 0.001), MFTC (P = 0.004 and P = 0.044), and LFTC (both P < 0.001) regions. For highest dose, in the central medial tibial (P = 0.008), central lateral tibial (P < 0.001) and central lateral femoral (P < 0.001) regions.

CONCLUSIONS

Cartilage thickness assessed by automated segmentation provided a consistent dose response in structural modification compared with manual segmentation. This is the first time that two independent quantification methods of image analysis have reached the same conclusions in an interventional trial, strengthening the conclusions that sprifermin modifies structural progression in knee osteoarthritis.

Caractéristiques des infections à SARS-CoV-2 chez 10 patients infectés par le VIH

Introduction

Peu de cas de COVID-19 chez des patients infectés par le VIH ont été rapportés dans la littérature. Nous décrivons les caractéristiques clinicobiologiques et l’évolution de la COVID-19 chez 10 patients infectés par le VIH.

Matériels et méthodes

10 patients (1,8 %) de notre file active de 560 patients ont eu la COVID-19 entre le 9 mars et le 30 avril 2020. Le diagnostic d’infection à Coronavirus SARS-CoV-2 a été fait par amplification par PCR en temps réel du gène E du betacoronavirus sur écouvillon nasopharyngé.

Résultats

Dix patients infectés par le VIH-1, 6 hommes et 4 femmes, d’âge moyen 56 ans ont présenté la COVID-19. L’infection par le VIH avait été diagnostiquée depuis 19 ans environ (min : 6 mois, max : 32 ans). Sept patients sur 10 étaient classés stade C. Tous les patients avaient un traitement antirétroviral : trithérapie (9/10) ou bithérapie (1/10), une charge virale VIH indétectable et des LT CD4 > 200/mm³ (min : 295, max : 1350/mm³). Quatre patients ont été hospitalisés pour une pneumonie, 1 patiente avec antécédent de cancer du poumon a présenté une pneumonie nosocomiale à SARS-CoV-2. Quatre patients ambulatoires avaient une infection respiratoire haute et 1 un tableau digestif isolé. Les patients hospitalisés pour pneumonie communautaire avaient des comorbidités : hypertension artérielle (4/4), diabète de type 2 (4/4), obésité (2/4), maladie respiratoire chronique (1/4). La présentation clinique comprenait : fièvre (7/10), toux (7/10), anosmie et agueusie (3 des 5 patients ambulatoires) et troubles digestifs (3/10). La guérison survenait en 7 à 14 jours sous traitement symptomatique (formes ambulatoires). L’hospitalisation survenait entre 7 et 12 jours après le début des symptômes avec une durée d’hospitalisation de 8 à plus de 45 jours. Deux patients ont présenté un SDRA : une décédée à 12 jours en médecine ; l’autre admis en réanimation avec ventilation mécanique pendant 2 mois. La patiente décédée a eu du ritonavir/lopinavir, une corticothérapie et un antagoniste du récepteur IL1. Les autres patients hospitalisés ont reçu : antibiotiques (4/5), hydroxychloroquine (2/5), antagoniste du récepteur C5 (1/5).

Conclusion

Les patients infectés par le VIH ont les mêmes présentations cliniques que ceux non infectés par le VIH avec des formes sévères de COVID-19 survenant chez des patients ayant les facteurs de risque décrits dans la littérature (âge, comorbidités tels l’hypertension artérielle, le diabète, l’obésité ou une pathologie respiratoire chronique). Une infection par le VIH bien contrôlée sur le plan immunovirologique ne semble pas être un facteur de risque de COVID-19. Par ailleurs, le traitement antirétroviral en cours ne semble pas être un facteur protecteur contre l’infection à SARS-CoV-2. Une étude étiologique est nécessaire pour confirmer ces hypothèses.

[Nasopharyngeal carriage of SARS-CoV-2 among health personnel with symptoms suggestive of COVID-19 in a University Hospital in the Paris suburbs]

Introduction

Une consultation dédiée aux professionnels de santé symptomatiques a été ouverte au début de l'épidémie de COVID-19, afin de répondre aux besoins spécifiques de cette population. L'objectif de ce travail était d'estimer la fréquence du portage nasopharyngé du SARS-Cov-2 chez les personnels de santé symptomatiques suspects de COVID-19, et de déterminer les facteurs associés à ce portage.

Méthodes

Étude descriptive des caractéristiques cliniques et épidémiologiques des consultants, conduite du 5 mars au 17 avril 2020. Le recueil des données cliniques et des résultats du test RT-PCR a été conduit à l'aide de formulaires standardisés.

Résultats

Des 522 consultants, 308 exerçaient à l'Hôpital et 214 à l'extérieur. Ils avaient des formes bénignes de COVID-19 et des signes cliniques non spécifiques à l'exception de l'agueusie/anosmie, significativement plus fréquente chez ceux avec RT-PCR positive. Le taux de positivité de la RT-PCR était globalement de 38 %, sans différence significative selon la profession, supérieur chez les consultants extérieurs (47 % versus 31 %). À l'hôpital, ce taux était significativement moindre pour les personnels symptomatiques des secteurs de soins, comparé aux personnels des plateaux techniques et laboratoires (24 %, versus 45 %, p = 0,006 et 54 %, p < 0,001, respectivement), mais ne différait pas entre personnels des unités COVID et des autres secteurs de soins (30 % versus 28 %). Parmi les consultants extérieurs, les taux de positivité des personnels des EHPAD et des libéraux (53 % et 55 % respectivement) étaient plus du double de celui du personnel soignant hospitalier (24 %, p < 0,001).

Conclusions

Ces données confirment l'impact fort du COVID-19 sur les professionnels de santé. Les taux de positivité plus élevés chez les professionnels symptomatiques exerçant en dehors de l'hôpital, comparativement à ceux exerçant à l'hôpital, pourraient s'expliquer en partie par une pénurie en équipements de protection et par des difficultés d'accès au diagnostic virologique, qui étaient plus importants en dehors de l'hôpital quand l'épidémie a commencé.

FRI0404 SEPERATION OF HIGH AND LOW RESPONSE GROUPS IN OSTEOARTHRITIS USING SERUM CARTILAGE DEGRADATION AND FORMATION MARKERS – A 3 YEAR FOLLOW-UP ON THE FORWARD STUDY TESTING THE EFFICACY OF SPRIFERMIN

Background:

In osteoarthritis (OA), response to different interventions could be more pronounced in different endotypes of cartilage turnover. Data from UK biobank suggest that an endotype of low cartilage repair is associated with structural progression in osteoarthritis (OA)[1]. Sprifermin a truncated and recombinant FGF18 have been shown to induce chondrocyte proliferation and cartilage formation in in vitro settings[2–4]. Efficacy on cartilage thickness in OA was recently demonstrated in the FORWARD study[5].

Objectives:

We investigated markers of cartilage formation (serum PRO-C2) and degradation (urine CTX-II), to assess profiles indicative of chondrocyte metabolic activity would be associated with both structural and symptomatic responses to sprifermin.

Methods:

Serum and urine from participants of the FORWARD study, a phase II clinical trial testing the efficacy of intra-articular (IA) sprifermin, were collected throughout the study. Clinical data recorded at baseline, year 2 and year 3 follow-up were used, including cartilage thickness and WOMAC. All available baseline samples of the placebo and treatment arms were assessed for serum PRO-C2 and urinary CTX-II. Patients were separated into dichotomized groups based on 33, 50 or 66 percentiles cut-points and two-year treatment responses were compared in a prospective-retrospective statistical design manner.

Results:

Patients with low baseline PRO-C2 (<66%), in the 100ug/4x treatment arm, had greater difference to placebo in cartilage thickness as compared to the high PRO-C2 and all-comers groups (0.06 vs 0.03 and 0.05 mm, respectively) at two and three years (Fig.). Similar effect was seen for low CTX-II (<50%) (0.07 vs -0.03 and 0.05 mm, respectively). In addition, the WOMAC placebo effect was reduced in the low PRO-C2 and the low CTX-II groups, resulting in a difference compared to placebo of -0.81vs. 1.35 (low vs high proC2 and -2.35 vs 1.47 (low vs high CTX-II).

Conclusion:

We noticed that low baseline PRO-C2 and CTX-II indicative for low metabolic activity of chondrocytes were associated with improved symptomatic outcome and slightly increased cartilage thickness compared to high metabolic activity. The parallelism between PRO-C2 and CTX-II point towards the existence of a low cartilage repair endotype and might reflect a subgroup of patients with higher sensitivity towards interventions - an effect that was maintained over three years.

References:

[1]Tachmazidou I, et al. ”Identification of new therapeutic targets for osteoarthritis through genome-wide analyses of UK Biobank data.” Nat Genet 2019;51:230–6.

[2]Gigout A, et al. ”Sprifermin (rhFGF18) enables proliferation of chondrocytes producing a hyaline cartilage matrix”. Osteoarthr Cartil. 2017;25.

[3]Reker D et al. “Sprifermin (rhFGF18) modulates extracellular matrix turnover in cartilage explants ex vivo”. J Transl Med. 2017;15.

[4]Luo Y et al. ”A Novel High Sensitivity Type II Collagen Blood-Based Biomarker, PRO-C2, for Assessment of Cartilage Formation”. Int J Mol Sci 2018;19:3485.

[5]Hochberg MC et al. “Effect of Intra-Articular Sprifermin vs Placebo on Femorotibial Joint Cartilage Thickness in Patients With Osteoarthritis”. JAMA. 2019; Oct 8;322(14).

Disclosure of Interests:

Hans Gühring Employee of: Merck KGaA, Anne-Christine Bay-Jensen Shareholder of: Nordic Bioscience A/S, Employee of: Full time employee at Nordic Bioscience A/S., Flavie Moreau Employee of: Merck KGaA, Jeppe Ragnar Andersen Shareholder of: Nordic Bioscience A/S., Employee of: Full time employee of Nordic Bioscience., Asger Reinstrup Bihlet Shareholder of: Nordic Bioscience A/S., Morten Karsdal Shareholder of: Nordic Bioscience A/S., Employee of: Full time employee at Nordic Bioscience A/S.

OP0189 ASSESSMENT OF CARTILAGE DEGRADATION AND PROTECTIVE MARKERS IN SYNOVIAL FLUID FROM OSTEOARTHRITIS PATIENTS BEFORE AND AFTER CYCLES OF INTRA-ARTICULAR INJECTIONS WITH SPRIFERMIN

Background:

It is challenging to monitor treatment effects after intra-articular (IA) injection with tissue modifying drugs. Assessment of biomarker levels in synovial fluid may be one solution to the challenge. Sprifermin is a truncated form of fibroblast growth factor (FGF) 18 known to induce chondrocyte proliferation and type II collagen formation [1,2]. Data from preclinical investigations show that cartilage formation happens in different phases after therapy with sprifermin, starting with a phase of cartilage degradation during the induction of proliferation of chondrocytes followed by a phase of cartilage formation/production of extracellular matrix.

Objectives:

The aim was to investigate the effect of IA administrated sprifermin on cartilage turnover activity as compared to placebo in the injected joint by measurement of markers using longitudinal synovial fluid samples of patients participating in the FORWARD study.

Methods:

Each included patient had baseline and at least one FU sample available. Synovial fluid (SF) from participants receiving injections at three consecutive weeks in six month intervals through to week (wk) 80 (fig.A) available from the phase II clinical trial evaluating the efficacy and safety of intraarticularly delivered sprifermin [3] were selected for the investigations. Biochemical markers were measured in available SF samples of the placebo (containing saline IA, n=38) and the highest sprifermin dose group (100 mcg/IAx4, n=59). Samples were pretreated with ultrasound and centrifugation to decrease viscosity. Markers measured were PRO-C2 (type II collagen formation), huARGS (aggrecan degradation), and FBN-C (fibronectin). Markers are technically validated for synovial fluid measurement. Data were individually normalized to baseline to investigate the median proportional change over time.

Results:

Baseline mean (SD) levels of the markers in SF at BL were: PRO-C2, 21.4 (13.6) ng/mL, huARGS, 1117 (516) pM and FBN-C, 2556 (1959) ng/mL. PRO-C2 was initially decreased (from BL to wk 2) after injection with sprifermin; however, the level was increased at the beginning of each new injection cycle followed by a decrease after injection of sprifermin (Fig.B). Overall synovial PRO-C2 levels increased over time in therapy with sprifermin, while no change was observed for the placebo arm. huARGS showed a similar pattern as PRO-C2 – there was an overall increase in ARGS over time in the sprifermin group (fig.C). Interestingly ARGS continuously decreased over time in the placebo group. FBN-C is continuously increased after injection’s cycles, whereas no effect was seen in the placebo group (fig.D).

Conclusion:

Confirmatory of the preclinical investigations a biphasic response on cartilage turnover after injection with sprifermin was observed. Biochemical indications of cartilage formation and chondrocyte proliferation was only modulated in the sprifermin group, and cartilage degradation (ARGS) was temporal induced and reduced by sprifermin and placebo injections, respectively.

References:

[1]Gigout A, et al. “Sprifermin (rhFGF18) enables proliferation of chondrocytes producing a hyaline cartilage matrix”. Osteoarthr Cartil. 2017;25.

[2]Reker D, et al. “Sprifermin (rhFGF18) modulates extracellular matrix turnover in cartilage explants ex vivo”. J Transl Med. 2017;15.

[3]Hochberg MC, et al. “Effect of Intra-Articular Sprifermin vs Placebo on Femorotibial Joint Cartilage Thickness in Patients With Osteoarthritis”. JAMA. 2019; Oct 8;322(14).

Disclosure of Interests:

Anne-Christine Bay-Jensen Shareholder of: Nordic Bioscience A/S, Employee of: Full time employee at Nordic Bioscience A/S., Angela Manginelli Employee of: Merck KGaA, Flavie Moreau Employee of: Merck KGaA, Yi He Employee of: YH is a full time employee of Nordic Bioscience A/S, Yunyun Luo Employee of: Nordic Bioscience A/S, Jeppe Ragnar Andersen Shareholder of: Nordic Bioscience A/S., Employee of: Full time employee of Nordic Bioscience., Asger Reinstrup Bihlet Shareholder of: Nordic Bioscience A/S., Morten Karsdal Shareholder of: Nordic Bioscience A/S., Employee of: Full time employee at Nordic Bioscience A/S., Hans Gühring Employee of: Merck KGaA, Christoph Ladel Employee of: Merck KGaA

Review shows that using surfactant a number of times or as a vehicle for budesonide may reduce the risk of bronchopulmonary dysplasia

AIM

Bronchopulmonary dysplasia (BPD) remains the most common respiratory morbidity in immature infants. This review describes the diagnosis of BPD has evolved and summarises the therapeutic approaches that have made it possible to limit the incidence of BPD.

METHOD

We reviewed the literature from the first definition of BPD by Northway in 1967 to the surfactant treatment policies that are currently in use, drawing on more than 50 papers up to 2017.

RESULTS

Our review showed that improvements in neonatal survival have been associated with an increased risk of severe BPD, significant levels of long-term morbidity and the increased use of healthcare resources. These issues have encouraged researchers to explore potential new treatments that limit the incidence of BPD. Repeated surfactant instillation and the use of surfactant as a vehicle for budesonide are promising strategies for alleviating the burden of chronic lung disease. Ongoing research on surfactant or stem cell therapy may further improve the respiratory prognosis for prematurely born children.

CONCLUSION

Considerable research has been carried out into the increase in BPD, which has resulted from improvements in neonatal survival. Key areas of research include repeated surfactant administration, using surfactant as a vehicle for budesonide and stem cell therapy.

Roux-en-Y gastric bypass reduces plasma cholesterol in diet-induced obese mice by affecting trans-intestinal cholesterol excretion and intestinal cholesterol absorption

OBJECTIVE

Bariatric surgery appears as the most efficient therapeutic alternative in morbidly obese patients. In addition to its efficiency to decrease body weight, it also improves metabolic complications associated to morbid obesity, including dyslipidemia. Although the cholesterol-lowering effect varies with the bariatric procedures, the underlying molecular mechanisms remain poorly defined. This study aims to assess the consequence of both restrictive (sleeve gastrectomy; SG) and malabsorptive (Roux-en-Y gastric bypass; RYGB) procedures on cholesterol metabolism in mice.

SUBJECTS

Ten-week-old C57BL6/J males were fed with a high-fat diet for 8-14 weeks before sleeve or RYGB surgery.

RESULTS

SG has a modest and transient effect on plasma cholesterol levels, linked to a reduction in food intake. In contrast, modified RYGB led to a sustained ≈35% reduction in plasma cholesterol concentrations with a drastic increase in fecal cholesterol output. Mechanistically, RYGB exerts a synergystic effect on cholesterol metabolism by inducing the trans-intestinal cholesterol efflux and reducing the intestinal cholesterol absorption.

CONCLUSIONS

In mice, RYGB, but not sleeve, strongly favors plasma cholesterol elimination by concomitantly increasing trans-intestinal cholesterol excretion and by decreasing intestinal cholesterol absorption. Our models open new perspective for deciphering the hypocholesterolemic effects of bariatric procedures.

[Teledermatology between two French hospitals: Two years of experience]

BACKGROUND

Teledermatology is currently booming. Due to the shortage of dermatologists in hospitals access to dermatological consultations is very limited in some hospitals. We present our experience of collaboration between an expert center, the dermatology department of the Victor-Dupouy Hospital Centre in Argenteuil, and all medical structures under the André-Mignot Hospital in Versailles (CHV), including 2 prison medical centers (UCSA), traditional departments and emergency department.

PATIENTS AND METHODS

Teledermatology, developed in the form of tele-expertise, began at the UCSA in November 2013. This expertise was then extended in June 2014 to the Internal Medicine department of CHV, and in December 2014 to all departments, including the emergency department. The rules and ethics of teledermatology were strictly adhered to. While UCSA could file all expertise dossiers, only urgent or difficult cases could be filed by other CHV departments.

RESULTS

In 26 months, 347 expertise requests were filed: 231 by prisons and 116 by the other departments of the CHV. No patients refused teledermatology. The quality of information and photographs was considered good or excellent in over 95% of cases. A response was given within 3hours in more than 50% of cases and in all cases within 24hours (on working days). Analysis of diseases diagnosed illustrates the wide variety of conditions encountered in dermatology, with different structures having their own specific features.

CONCLUSION

Our example illustrates the possibility of developing such an inter-hospital platform. However, it does not yet cater for requests made by patients to dermatologists, by dermatologists to dermatologists, or by dermatologists to the hospital teledermatology department. Acceptability was considered excellent by patients (with no refusals), physicians at the CHV, and the expert center.

Substitution of insulin by exenatide in bad controlled type 2 diabetic patients: efficacy and predictive factors

AIM

Exenatide therapy is indicated in type 2 diabetes after failure of oral antidiabetic agents (OAD). The aim of this observational prospective study was to assess efficacy of exenatide, in improving HbA1c of at least of 1% (responders) in type 2 diabetic patients treated previously with insulin.

METHODS

Thirty-six patients (HbA1c >7.5%), with chronic bad glycemic control, were hospitalized to improve glycemia using transient continuous insulin infusion followed by administration of exenatide and OAD agents. In these patients, insulin had been introduced previously because of OAD failure without any sign of severe insulin deficiency.

RESULTS

On the 27 patients analyzed at 3 months, 19 patients were responders (HbA1c: M0: 9.9±1.7%; M3: 7.6±1.2%). Among the 8 non-responders, only 4 deteriorated their HbA1c. After 9 months, 10 patients remained Responders (HbA1c: 7±0.9%). Predictive factors for an improvement of glycemic control were: diabetes duration shorter than 12 years, ratio fasting glycemia/C-peptide less than 1, fasting C-peptide higher than 2.0 µg/L and mean capillary blood glucose after 3 days of exenatide lower than 200 mg/dL. These criteria remained valid in case of a high HbA1c at baseline.

CONCLUSION

In patients with no signs of insulin dependence and in case of insulin failure, exenatide associated to OAD may be tried in order to improve glycemic control, this objective was reached by 70% of our patients. Predictive factors for good response, easily available in clinical practice, may help therapeutic choices.

Obstructive sleep apnoea in people with Type 1 diabetes: prevalence and association with micro- and macrovascular complications

AIMS

Few reports have assessed the relationship between Type 1 diabetes and sleep disorders. The purposes of our study were to determine the prevalence of obstructive sleep apnoea in Type 1 diabetes and to compare the clinical profile of people with Type 1 diabetes with or without obstructive sleep apnoea.

METHODS

In this cross sectional study of 67 consecutive people with Type 1 diabetes, we performed polysomnography as part of their yearly check-ups.

RESULTS

In our cohort, with a mean BMI of 25.8 ± 4.7 kg/m(2), the prevalence of obstructive sleep apnoea [apnoea-hypopnoea index (AHI) > 10/h] was 46%. Severe obstructive sleep apnoea (AHI ≥ 30/h) was present in 19% of the patients. We found no significant differences in age, sex, body mass index, HbA1c or Epworth sleepiness scale score between people with or without obstructive sleep apnoea. People with obstructive sleep apnoea had a longer course of diabetes mellitus (P < 0.01) and a higher prevalence of retinopathy (P < 0.01), neuropathy (P = 0.05), cardiovascular disease (P < 0.01) and hypertension (P < 0.01). The occurrence of macrovascular complications was independently associated with the presence of OSA [odds ratio (OR) 8.28; 95% confidence interval (CI), 1.56-43.97; P = 0.013] and the duration of diabetes (OR 1.08; 95% CI, 1.02-1.15; P = 0.01). Moreover, retinopathy was independently associated with OSA (OR 4.54; 95% CI, 1.09-18.82; P = 0.04) and the duration of diabetes (OR 1.09; 95% CI, 1.04-1.15; P = 0.001).

CONCLUSIONS

The prevalence of obstructive sleep apnoea was high in people with Type 1 diabetes. Obstructive sleep apnoea was independently associated with macrovascular complications and retinopathy. Obesity and excessive daytime sleepiness were uncommon in this population.

Early effects of liver regeneration on endocrine pancreas: in vivo change in islet morphology and in vitro assessment of systemic effects on β-cell function and viability in the rat model of two-thirds hepatectomy

Liver and pancreas share key roles in glucose homeostasis. Liver regeneration is associated with systemic modifications and depends especially on pancreatic hormones. The aim of the study was to investigate the role of systemic factors released after two-thirds hepatectomy (2/3H) on early possible consequences of liver regeneration on endocrine pancreas structure and function. The pancreas and serum were harvested 1, 2, or 3 days after 2/3H or sham operation in Lewis rats. The HGF and VEGF serum concentrations and plasma microparticles levels were measured. The fate of endocrine pancreas was examined through islets histomorphometry and function in sham and 2/3H rats. β-Cell line RIN-m5F viability was assessed after 24 h of growth in media supplemented with 10% serum from 2/3H or sham rats instead of FCS. Three days after surgery, the pancreas was heavier in 2/3H compared to sham rats (0.56 vs. 0.40% of body weight, p < 0.05) and the proportion of islets of intermediate size was lower in 2/3H rats (5 vs. 15%, p < 0.05). Compared to Sham, sera obtained 3 days after hepatectomy were more efficient to maintain the viability of RIN-m5F cells (99 vs. 67%, p < 0.01). Three days after surgery, no significant differences in serum HGF, a trend to significant increase in VEGF concentration and a significant increase in microparticles levels, were observed in 2/3H vs. sham rats (9.8 vs. 6.5 nM Phtd Ser Eq., p < 0.05). Liver regeneration is associated with early effects on islets and could influence β-cell viability and function by systemic effect.

Gal-lectin-dependent contact activates the inflammasome by invasive Entamoeba histolytica

Entamoeba histolytica (Eh) is an extracellular protozoan parasite of the human colon, which occasionally breaches the intestinal barrier. Eradicating ameba that invades is essential for host survival. A defining but uncharacterized feature of amebic invasion is direct contact between ameba and host cells. This event corresponds with a massive pro-inflammatory response. To date, pathogen recognition receptors (PRRs) that are activated by contact with viable Eh are unknown. Here we show that the innate immune system responds in a qualitatively different way to contact with viable Eh vs. soluble ligands produced by viable or dead ameba. This unique Eh Gal-lectin contact-dependent response in macrophages was mediated by activation of the inflammasome. Soluble native Gal-lectin did not induce inflammasome activation, but was sufficient for transcriptional priming of the inflammasome and non-inflammasome-dependent pro-inflammatory cytokine release. We conclude the inflammasome is a pathogenicity sensor for invasive Eh and identify for the first time a PRR that specifically responds to contact with intact parasites in a manner that accords with scale immune response to parasite invasion.

Osteoinduction of biphasic calcium phosphate scaffolds in a nude mouse model

Bioceramics combined with isolated stem cells, or with total bone marrow, constitute the main strategies under consideration in the field of bone tissue engineering. In the present preclinical study, two biphasic calcium phosphate scaffolds currently on the market, MBCP® and MBCP+®, with different hydroxyapatite/β-tricalcium phosphate ratio, were implanted ectopically in a nude mouse model. These scaffolds were supplemented either with human mesenchymal stromal cells, or with human total bone marrow, or rat total bone marrow. Biomaterials alone were found to have potentially low, but non-zero, osteoinductive properties, while biomaterials associated with total bone marrow consistently improved osteoinduction in comparison with high concentrations of isolated human stromal cells.

Treatment de-escalation in HPV-positive oropharyngeal carcinoma: ongoing trials, critical issues and perspectives

Due to the generally poor prognosis of head and neck squamous cell carcinoma (HNSCC), treatment has been intensified, these last decades, leading to an increase of serious side effects. High-risk human papillomavirus (HR-HPV) infection has been recently etiologically linked to a subset of oropharyngeal squamous cell carcinoma (OPSCC), which is on the increase. These tumors are different, at the clinical and molecular level, when compared to tumors caused by traditional risk factors. Additionally, their prognosis is much more favorable which has led the medical community to consider new treatment strategies. Indeed, it is possible that less intensive treatment regimens could achieve similar efficacy with less toxicity and improved quality of life. Several clinical trials, investigating different ways to de-escalate treatment, are currently ongoing. In this article, we review these main approaches, discuss the rationale behind them and the issues raised by treatment de-escalation in HPV-positive OPSCC.