Parallel neurodegenerative phenotypes in sporadic Parkinson's disease fibroblasts and midbrain dopamine neurons

Understanding the mechanisms causing Parkinson's disease (PD) is vital to the development of much needed early diagnostics and therapeutics for this debilitating condition. Here, we report cellular and molecular alterations in skin fibroblasts of late-onset sporadic PD subjects, that were recapitulated in matched induced pluripotent stem cell (iPSC)-derived midbrain dopamine (DA) neurons, reprogrammed from the same fibroblasts. Specific changes in growth, morphology, reactive oxygen species levels, mitochondrial function, and autophagy, were seen in both the PD fibroblasts and DA neurons, as compared to their respective controls. Additionally, significant alterations in alpha synuclein expression and electrical activity were also noted in the PD DA neurons. Interestingly, although the fibroblast and neuronal phenotypes were similar to each other, they differed in their nature and scale. Furthermore, statistical analysis revealed potential novel associations between various clinical measures of the PD subjects and the different fibroblast and neuronal data. In essence, these findings encapsulate spontaneous, in-tandem, disease-related phenotypes in both sporadic PD fibroblasts and iPSC-based DA neurons, from the same patient, and generates an innovative model to investigate PD mechanisms with a view towards rational disease stratification and precision treatments.

Evaluation of S201086/GLPG1972, an ADAMTS-5 inhibitor, for the treatment of knee osteoarthritis in ROCCELLA: a phase 2 randomized clinical trial

OBJECTIVE

To evaluate the efficacy and safety of the anti-catabolic ADAMTS-5 inhibitor S201086/GLPG1972 for the treatment of symptomatic knee osteoarthritis.

DESIGN

ROCCELLA (NCT03595618) was a randomized, double-blind, placebo-controlled, dose-ranging, phase 2 trial in adults (aged 40-75 years) with knee osteoarthritis. Participants had moderate-to-severe pain in the target knee, Kellgren-Lawrence grade 2 or 3 and Osteoarthritis Research Society International joint space narrowing (grade 1 or 2). Participants were randomized 1:1:1:1 to once-daily oral S201086/GLPG1972 75, 150 or 300 mg, or placebo for 52 weeks. The primary endpoint was change from baseline to week 52 in central medial femorotibial compartment cartilage thickness (cMFTC) assessed quantitatively by magnetic resonance imaging. Secondary endpoints included change from baseline to week 52 in radiographic joint space width, Western Ontario and McMaster Universities Osteoarthritis Index total and subscores, and pain (visual analogue scale). Treatment-emergent adverse events (TEAEs) were also recorded.

RESULTS

Overall, 932 participants were enrolled. No significant differences in cMFTC cartilage loss were observed between placebo and S201086/GLPG1972 therapeutic groups: placebo vs 75 mg, P = 0.165; vs 150 mg, P = 0.939; vs 300 mg, P = 0.682. No significant differences in any of the secondary endpoints were observed between placebo and treatment groups. Similar proportions of participants across treatment groups experienced TEAEs.

CONCLUSIONS

Despite enrolment of participants who experienced substantial cartilage loss over 52 weeks, during the same time period, S201086/GLPG1972 did not significantly reduce rates of cartilage loss or modify symptoms in adults with symptomatic knee osteoarthritis.

Parallel Neurodegenerative Phenotypes in Sporadic Parkinson's Disease Fibroblasts and Midbrain Dopamine Neurons

Understanding the mechanisms causing Parkinson's disease (PD) is vital to the development of much needed early diagnostics and therapeutics for this debilitating condition. Here, we report cellular and molecular alterations in skin fibroblasts of late-onset sporadic PD subjects, that were recapitulated in matched induced pluripotent stem cell (iPSC)-derived midbrain dopamine (DA) neurons, reprogrammed from the same fibroblasts. Specific changes in growth, morphology, reactive oxygen species levels, mitochondrial function, and autophagy, were seen in both the PD fibroblasts and DA neurons, as compared to their respective controls. Additionally, significant alterations in alpha synuclein expression and electrical activity were also noted in the PD DA neurons. Interestingly, although the fibroblast and neuronal phenotypes were similar to each other, they also differed in their nature and scale. Furthermore, statistical analysis revealed novel associations between various clinical measures of the PD subjects and the different fibroblast and neuronal data. In essence, these findings encapsulate spontaneous, in-tandem, disease-related phenotypes in both sporadic PD fibroblasts and iPSC-based DA neurons, from the same patient, and generates an innovative model to investigate PD mechanisms with a view towards rational disease stratification and precision treatments.

Epigenetic regulation of IPF fibroblast phenotype by glutaminolysis

OBJECTIVE

Excessive extra-cellular-matrix production and uncontrolled proliferation of the fibroblasts are characteristics of many fibrotic diseases, including idiopathic pulmonary fibrosis (IPF). The fibroblasts have enhanced glutaminolysis with up-regulated glutaminase, GLS1, which converts glutamine to glutamate. Here, we investigated the role of glutaminolysis and glutaminolysis-derived metabolite α-ketoglutarate (α-KG) on IPF fibroblast phenotype and gene expression.

METHODS

Reduced glutamine conditions were carried out either using glutamine-free culture medium or silencing the expression of GLS1 with siRNA, with or without α-KG compensation. Cell phenotype has been characterized under these different conditions, and gene expression profile was examined by RNA-Seq. Specific profibrotic genes (Col3A1 and PLK1) expression were examined by real-time PCR and western blots. The levels of repressive histone H3K27me3, which demethylase activity is affected by glutaminolysis, were examined and H3K27me3 association with promoter region of Col3A1 and PLK1 were checked by ChIP assays. Effects of reduced glutaminolysis on fibrosis markers were checked in an animal model of lung fibrosis.

RESULTS

The lack of glutamine in the culture medium alters the profibrotic phenotype of activated fibroblasts. The addition of exogenous and glutaminolysis-derived metabolite α-KG to glutamine-free media barely restores the pro-fibrotic phenotype of activated fibroblasts. Many genes are down-regulated in glutamine-free medium, α-KG supplementation only rescues a limited number of genes. As α-KG is a cofactor for histone demethylases of H3K27me3, the reduced glutaminolysis alters H3K27me3 levels, and enriches H3K27me3 association with Col3A1 and PLK1 promoter region. Adding α-KG in glutamine-free medium depleted H3K27me3 association with Col3A1 promoter region but not that of PLK1. In a murine model of lung fibrosis, mice with reduced glutaminolysis showed markedly reduced fibrotic markers.

CONCLUSIONS

This study indicates that glutamine is critical for supporting pro-fibrotic fibroblast phenotype in lung fibrosis, partially through α-KG-dependent and -independent mechanisms, and supports targeting fibroblast metabolism as a therapeutic method for fibrotic diseases.

Mesenchymal stromal cell aging impairs the self-organizing capacity of lung alveolar epithelial stem cells

Multicellular organisms maintain structure and function of tissues/organs through emergent, self-organizing behavior. In this report, we demonstrate a critical role for lung mesenchymal stromal cell (L-MSC) aging in determining the capacity to form three-dimensional organoids or 'alveolospheres' with type 2 alveolar epithelial cells (AEC2s). In contrast to L-MSCs from aged mice, young L-MSCs support the efficient formation of alveolospheres when co-cultured with young or aged AEC2s. Aged L-MSCs demonstrated features of cellular senescence, altered bioenergetics, and a senescence-associated secretory profile (SASP). The reactive oxygen species generating enzyme, NADPH oxidase 4 (Nox4), was highly activated in aged L-MSCs and Nox4 downregulation was sufficient to, at least partially, reverse this age-related energy deficit, while restoring the self-organizing capacity of alveolospheres. Together, these data indicate a critical role for cellular bioenergetics and redox homeostasis in an organoid model of self-organization and support the concept of thermodynamic entropy in aging biology.

Restoration of SIRT3 gene expression by airway delivery resolves age-associated persistent lung fibrosis in mice

Aging is a risk factor for progressive fibrotic disorders involving diverse organ systems, including the lung. Idiopathic pulmonary fibrosis, an age-associated degenerative lung disorder, is characterized by persistence of apoptosis-resistant myofibroblasts. In this report, we demonstrate that sirtuin-3 (SIRT3), a mitochondrial deacetylase, is downregulated in lungs of IPF human subjects and in mice subjected to lung injury. Over-expression of the SIRT3 cDNA via airway delivery restored capacity for fibrosis resolution in aged mice, in association with activation of the forkhead box transcription factor, FoxO3a, in fibroblasts, upregulation of pro-apoptotic members of the Bcl-2 family, and recovery of apoptosis susceptibility. While transforming growth factor-β1 reduced levels of SIRT3 and FoxO3a in lung fibroblasts, cell non-autonomous effects involving macrophage secreted products were necessary for SIRT3-mediated activation of FoxO3a. Together, these findings reveal a novel role of SIRT3 in pro-resolution macrophage functions that restore susceptibility to apoptosis in fibroblasts via a FoxO3a-dependent mechanism.

NADPH Oxidase Inhibition in Fibrotic Pathologies

Significance: Fibrosis is a stereotypic, multicellular tissue response to diverse types of injuries that fundamentally result from a failure of cell/tissue regeneration. This complex tissue remodeling response disrupts cellular/matrix composition and homeostatic cell-cell interactions, leading to loss of normal tissue architecture and progressive loss of organ structure/function. Fibrosis is a common feature of chronic diseases that may affect the lung, kidney, liver, and heart. Recent Advances: There is emerging evidence to support a combination of genetic, environmental, and age-related risk factors contributing to susceptibility and/or progression of fibrosis in different organ systems. A core pathway in fibrogenesis involving these organs is the induction and activation of nicotinamide adenine dinucleotide phosphate oxidase (NOX) family enzymes. Critical Issues: We explore current pharmaceutical approaches to targeting NOX enzymes, including repurposing of currently U.S. Food and Drug Administration (FDA)-approved drugs. Specific inhibitors of various NOX homologs will aid establishing roles of NOXs in the various organ fibroses and potential efficacy to impede/halt disease progression. Future Directions: The discovery of novel and highly specific NOX inhibitors will provide opportunities to develop NOX inhibitors for treatment of fibrotic pathologies.

Oxidative cross-linking of fibronectin confers protease resistance and inhibits cellular migration

The oxidation of tyrosine residues to generate o,o'-dityrosine cross-links in extracellular proteins is necessary for the proper function of the extracellular matrix (ECM) in various contexts in invertebrates. Tyrosine oxidation is also required for the biosynthesis of thyroid hormone in vertebrates, and there is evidence for oxidative cross-linking reactions occurring in extracellular proteins secreted by myofibroblasts. The ECM protein fibronectin circulates in the blood as a globular protein that dimerizes through disulfide bridges generated by cysteine oxidation. We found that cellular (fibrillar) fibronectin on the surface of transforming growth factor-β1 (TGF-β1)-activated human myofibroblasts underwent multimerization by o,o'-dityrosine cross-linking under reducing conditions that disrupt disulfide bridges, but soluble fibronectin did not. This reaction on tyrosine residues required both the TGF-β1-dependent production of hydrogen peroxide and the presence of myeloperoxidase (MPO) derived from inflammatory cells, which are active participants in wound healing and fibrogenic processes. Oxidative cross-linking of matrix fibronectin attenuated both epithelial and fibroblast migration and conferred resistance to proteolysis by multiple proteases. The abundance of circulating o,o'-dityrosine-modified fibronectin was increased in a murine model of lung fibrosis and in human subjects with interstitial lung disease compared to that in control healthy subjects. These studies indicate that tyrosine can undergo stable, covalent linkages in fibrillar fibronectin under inflammatory conditions and that this modification affects the migratory behavior of cells on such modified matrices, suggesting that this modification may play a role in both physiologic and pathophysiologic tissue repair.

Mapping a nosocomial outbreak of measles, coinciding with a period of sustained transmission in South London in 2018

A measles outbreak in London is described, involving 34 cases across two hospitals and a local community across two countries. After a single introduction to hospital, spread propagated via unvaccinated retail shop workers to healthcare staff, highlighting the importance of expanding occupational health policies to non-clinical hospital staff. Further spread into an under-vaccinated Traveller community is a reminder that measles can spread in the absence of herd immunity. Subsequently endemic measles transmission has been re-established in the UK.

AB0860 STUDY DESIGN OF ROCCELLA: A PHASE 2 CLINICAL TRIAL WITH A DISEASE-MODIFYING OSTEOARTHRITIS DRUG CANDIDATE GLPG1972/S201086

Background:

Loss of articular cartilage is one of the major signs of osteoarthritis (OA). Aggrecan, the main proteoglycan component of the extracellular matrix of articular cartilage is cleaved by ADAMTS-5 (A Disintegrin And Metalloproteinase with ThromboSpondin-motif-5).1GLPG1972/S201086, a potent and highly selective inhibitor of ADAMTS-5, is an oral Disease-Modifying OsteoArthritis Drug (DMOAD) candidate. In a pooled Phase 1 safety analysis involving 171 participants GLPG1972/S201086 was shown to be well tolerated.

Objectives:

To present the study design of ROCCELLA, a large Phase 2 clinical trial in knee OA (KOA) patients, evaluating the efficacy and safety of GLPG1972/S201086 in reducing cartilage loss in OA.

Methods:

ROCCELLA is a multinational 52-week, multicentre randomized double-blind placebo-controlled dose-ranging phase 2 trial for the treatment of OA (NCT03595618). Eligible patients were aged 40–75 years with a diagnosis of primary femorotibial KOA, a pain score of 40–90mm on a 100 mm Visual Analogue Scale (VAS), predominant medial disease and a combined Kellgren/Lawrence (KL) 2 or 3 and Osteoarthritis Research Society International (OARSI) medial joint space narrowing (JSN) 1 or 2 severity grading range upon central reading of the X-ray. If both knees were eligible, the target knee was selected based first on the highest KL grade, then on the highest JSN grade and finally on the highest pain VAS score at baseline. Patients were randomized 1:1:1:1 to take placebo or three dose levels of GLPG1972/S201086 orally once daily for 52 weeks. The target knee was evaluated by quantitative Magnetic Resonance Imaging (qMRI) at baseline visit, week 28 and week 52, or at early withdrawal.

The primary endpoint of the study is change from baseline to week 52 in cartilage thickness of the central medial tibio-femoral compartment (cMTFC) of the target knee. Secondary objectives are safety and tolerability including treatment emergent serious adverse events. Additional secondary structural and clinical efficacy objectives are based on changes from baseline in the target knee: cartilage thickness and bone area on qMRI, KOA “progressor” rates, Joint Space Width on X-ray, pain VAS, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total and sub scores, Patient Global Assessment VAS and the proportion of Outcome Measures in Rheumatology (OMERACT)-OARSI responders. Blood will be collected to assess the pharmacokinetics of GLPG1972/S201086. Planned, exploratory analyses include biochemical biomarkers of cartilage and bone turn-over. The study is designed to maintain the experiment wise type I error at 5%. A Mixed-effects Model for Repeated Measures will be used for the primary analysis. The randomisation was stratified by geographic region.

Results:

The study started in August 2018 and was fully recruited (N=938) by June 2019. Large numbers of patients with KOA had to be screened to meet the stringent pre-specified selection criteria. The study completion is expected by end of 2020.

Conclusion:

This is the first large Phase 2 study where patients with primary KOA are treated for 52 weeks with GLPG1972/S201086, an orally administered DMOAD candidate. This clinical trial was designed with a combination of two radiological selection criteria to ensure sufficient structural progression (cartilage loss) in the study population.

References:

[1]Durigova Met al.Osteoarthritis Cartilage2008;16:1245–52.

Acknowledgments:

This study was funded by Galapagos NV. Editorial support was provided by Oxford PharmaGenesis and funded by Galapagos NV.

Disclosure of Interests:

Henri Deckx Employee of: Galapagos, Ellen van der Aar Employee of: Galapagos, Marjolijne van der Stoep Employee of: Galapagos, Marianne Wooning Employee of: Galapagos NV, Katy Bernard Employee of: Institut de Recherches Internationales Servier, Sergey GRANKOV Employee of: Institut de Recherches Internationales Servier, Olivier Imbert Employee of: Institut de Recherches Internationales Servier, Maria Pueyo Employee of: Institut de Recherches Internationales Servier, Felix Eckstein Grant/research support from: Merck, Orthotrphix, Servier, Galapagos, Kolon Tissuegene, Samumed, Novartis, Consultant of: Merck, Bioclinica, Servier, Samumed, Roche, Kolon Tissuegene, Galapagos and Novartis, Employee of: co-owner and employment with Chondrometrics

FRI0393 BASELINE CHARACTERISTICS OF THE STUDY POPULATION IN ROCCELLA, A PHASE 2 CLINICAL TRIAL EVALUATING THE EFFICACY AND THE SAFETY OF S201086/GLPG1972 IN PATIENTS WITH KNEE OSTEOARTHRITIS

Background:

Osteoarthritis (OA) is a degenerative joint disease involving structural pathology of all joint tissues, and most commonly affecting the knee, hip and hand. Degradation of the cartilage extracellular matrix represents a central feature of OA and is widely thought to be mediated by proteinases that degrade primarily aggrecan and collagen. ADAMTS-5, a Disintegrin And Metalloproteinase with ThromboSpondin-motif-5, is a key aggrecan-cleaving enzyme involved in cartilage degradation. S201086/GLPG1972, a potent and highly selective inhibitor of ADAMTS-5, is an oral Disease-Modifying OsteoArthritis Drug (DMOAD) candidate.

Objectives:

The primary objective of the ROCCELLA phase 2 clinical trial (NCT03595618) is to evaluate the effect of S201086/GLPG1972 over 52 weeks of treatment (3 dose groups compared to placebo) in reducing cartilage loss. Cartilage thickness of the knee is being measured quantitatively by Magnetic Resonance Imaging. Here, we describe the baseline characteristics of patients included in the ROCCELLA clinical trial.

Methods:

The main inclusion criteria were: male or female, aged 40 to 75, with a diagnosis of knee OA according to the clinical and radiological criteria of the American College of Rheumatology. The target knee had to meet a pain score between 40 and 90 mm on a 100 mm Visual Analog Scale (VAS), and the following radiographic feature upon central radiographic readings: Kellgren/Lawrence (KL) 2 or 3 and OARSI medial joint space narrowing (JSN) 1 or 2 (for more details see Deckxet al. OARSI 2020). The rationale for these specific radiographic inclusion criteria was to ensure sufficient cartilage loss over 12 months to assess the efficacy of S201086/GLPG1972.

Results:

Across 12 countries, 3319 patients were screened and 932 were finally included in the study. The screen failure of 72% is mainly due to the radiological criteria. The age of the patients was 62.9 ± 7.3 years (mean ± SD) with a majority of women (69.3%). The BMI was 30.5 ± 4.7 kg/m2. The duration of knee OA was 7.2 ± 6.9 years. Five hundred and one (53.8%) patients reported a medical history of musculoskeletal and connective tissue disorders, mainly osteoarthritis in other sites (20.2%), back pain (13.6%), and arthralgia (9.8%). At inclusion, 97.2% of the patients were taking different types of drug treatments, mainly anti-inflammatory and anti-rheumatic products (69.4%) and analgesics (42%). At baseline, 11% of the target knees were KL2 and 89% were KL3; 32% were OARSI medial JSN grade 1 and 68% grade 2. Target knees at inclusion had a pain score on the VAS of 63.5 ± 11.4 mm (range 0-100, with 0 for no and 100 for extreme pain) and a total WOMAC (Likert 3.1) score of 48.0 ± 15.0 (range 0-96). The WOMAC subscores for pain, stiffness and physical function were 10.0 ± 3.2 (range 0-20), 4.2 ± 1.6 (range 0-8) and 33.8 ± 11.2 (range 0-68, indicating functional limitation), respectively.

Conclusion:

For this clinical trial, patients were selected to present radiological criteria (i.e.OARSI JSN 1 and 2) to ensure sufficient structural progression (cartilage loss) over 12 months, as well as clinical symptoms. These stringent selection criteria were the main cause for the high screen failure rate. These baseline characteristics should warrant the ability to evaluate the efficacy of S201086/GLPG1972 as a DMOAD candidate. The search for an effective pharmacological treatment that can prevent or cure OA remains a major challenge and unmet medical need.

Disclosure of Interests:

Katy Bernard Employee of: Institut de Recherches Internationales Servier, Sergey GRANKOV Employee of: Institut de Recherches Internationales Servier, Marjolijne van der Stoep Employee of: Galapagos, Agnès Lalande Employee of: Institut de Recherches Internationales Servier, Olivier Imbert Employee of: Institut de Recherches Internationales Servier, De Phung Employee of: Galapagos, Damien Chimits Employee of: Institut de Recherches Internationales Servier, Karine Muller Employee of: Galapagos, Ellen van der Aar Employee of: Galapagos, Henri Deckx Employee of: Galapagos, Maria Pueyo Employee of: Institut de Recherches Internationales Servier, Felix Eckstein Grant/research support from: Merck, Orthotrphix, Servier, Galapagos, Kolon Tissuegene, Samumed, Novartis, Consultant of: Merck, Bioclinica, Servier, Samumed, Roche, Kolon Tissuegene, Galapagos and Novartis, Employee of: co-owner and employment with Chondrometrics

FRI0411 SAFETY, TOLERABILITY, PHARMACOKINETICS AND PHARMACODYNAMICS IN HEALTHY MALE JAPANESE SUBJECTS OF THE ADAMTS-5 INHIBITOR S201086/GLPG1972, A POTENTIAL NEW TREATMENT IN OA

Background:

The disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS-5) is a key enzyme in OA (Verma P,et al.J Cell Biochem 2011;112:3507-14). In preclinical models of OA, S201086, a potent and selective ADAMTS-5 inhibitor, protects from cartilage degradation (Clement-Lacroix,et al.Osteoarthritis Cartilage 2017;25:S58). Therefore, S201086 is co-developed by Servier and Galapagos (GLPG1972) as a potential new treatment in OA.

Objectives:

This phase I study was to assess and compare the safety, tolerability, pharmacokinetics and pharmacodynamics of S201086 in healthy male Japanese and Caucasian subjects.

Methods:

Six ascending single doses of S201086 (50 to 1500 mg) were administered orally as tablets in fasting conditions in 6 groups of 8 Japanese subjects (aged 20-45 years) and 3 ascending multiple doses (300, 600 or 1050 mg/day for 14 days) were administered orally as tablets in fed conditions in 3 groups of 8 Japanese subjects. Additionally, 2 cohorts of 8 Caucasian subjects received either a single oral dose of 300 mg or repeated oral dose of 300 mg once daily for 14 days. In each group, 6 subjects received S201086 and 2 placebo. Plasma was collected at several time points for the quantification of S201086 by LC-MS/MS. Plasma pharmacokinetic parameters were calculated via non-compartmental analysis using Phoenix® WinNonlin® software. Pharmacodynamics was assessed by measurement of the aggrecan ARGS neoepitope levels in serum by ELISA.

Results:

No serious adverse drug reactions were observed after administration of single and multiple ascending doses of S201086 in either Japanese or Caucasian subjects. Most adverse events were of mild to moderate intensity and were resolved by the end of the study. Following single administration to Japanese subjects, Cmax and AUC increased proportionally with doses from 50 to 600 mg and slightly less than dose-proportionally from 600 to 1500 mg, consistent with what was previously observed in the first in-human study in healthy Caucasian subjects (van der Aar E,et al.Osteoarthritis Cartilage 2018;26:S310). In Japanese subjects, after 14-days administration, a limited 1.2- to 1.4-fold accumulation was observed on both Cmax and AUC at Day14 as compared to Day1, and the steady-state exposure increased dose-proportionally within the 300-1050 mg dose range. Taking the inter-subject variability into account, no difference was observed in Cmax and AUC between Caucasian and Japanese subjects after single administrations of 300 mg and repeated administrations of 300 mg once daily for 14 days. The serum ARGS neoepitope levels decreased between baseline and last day of treatment for S201086-treated subjects but not for subjects receiving placebo. This decrease was similar for the 3 tested doses in Japanese subjects and was significant as compared to the placebo-treated subjects.

Table.

Comparison of ARGS concentration relative change from baseline to last day of treatment according to dose in Japanese participants

S 201086 300 mg (N = 6)S 201086 600 mg (N = 6)S 201086 1050 mg (N = 6)Placebo (N = 6)Descriptive Statistics(D14 pre-dose – Baseline) / Baselinen6646Mean ± SD-42.67 ± 8.81-53.70 ± 6.50-54.11 ± 5.2013.35 ± 16.53Statistical analysisE (SE)56.01 (6.156)67.04 (6.156)67.45 (6.883)95% CI43.08; 68.9554.11; 79.9752.99; 81.91p-value< 0.0001< 0.0001< 0.0001

Conclusion:

S201086 was shown to be safe and well-tolerated in Japanese and Caucasian healthy male subjects with a suitable PK profile and a significant decrease of the ARGS neoepitope, indicating target engagement. A global Phase 2 study to evaluate the efficacy of S201086 in patients with knee OA is ongoing (NCT03595618).

Disclosure of Interests:

Agnès Lalande Employee of: Institut de Recherches Internationales Servier, Nadya KUZNIATSOVA-MOUCHETTE Employee of: Institut de Recherches Internationales Servier, Florian CHASSEREAU Employee of: Institut de Recherches Internationales Servier, Julia GERONIMI Employee of: Institut de Recherches Internationales Servier, Katy Bernard Employee of: Institut de Recherches Internationales Servier, Staffan Larsson: None declared, André Struglics: None declared, Stefan Lohmander: None declared, Maria Pueyo Employee of: Institut de Recherches Internationales Servier

NADPH Oxidases and Aging Models of Lung Fibrosis

There is a growing recognition that aging is a risk factor for fibrosis that affects a number of organ systems, including the lung. Despite this understanding, most studies of experimental fibrosis have been conducted in young mice that typically resolve injury-induced lung fibrosis over the course of several months. Our studies demonstrate that aged mouse models may recapitulate human disease by generating a more persistent fibrotic response to injury. This is, in part, due to an imbalance in the expression and activity of NADPH oxidase (NOX) enzymes, in particular the NOX4 isoform, and a related deficiency in antioxidant responses in pathogenic myofibroblasts. These pathogenic myofibroblasts acquire features of cellular senescence and become resistant to apoptosis. In this chapter, we present methods and procedures to apply the aging model of lung fibrosis in mice that will allow interrogation of myofibroblast functions and the expression and activity of NOX4 in cells. We provide recommendations for best laboratory practices to assess the severity and resolution of fibrosis in murine models of aging.

Fibronectin on the Surface of Extracellular Vesicles Mediates Fibroblast Invasion

Extracellular vesicles (EVs) are endosome and plasma membrane-derived nano-sized vesicles that participate in intercellular signaling. Although EV cargo may signal via multiple mechanisms, how signaling components on the surface of EVs mediate cellular signaling is less well understood. In this study, we show that fibroblast-derived EVs carry fibronectin on the vesicular surface, as evidenced by mass spectrometry-based proteomics (Sequential Window Acquisition of all Theoretical Mass Spectra) and flow-cytometric analyses. Fibroblasts undergoing replicative senescence or transforming growth factor β1-induced senescence and fibroblasts isolated from human subjects with an age-related lung disorder, idiopathic pulmonary fibrosis, secreted higher numbers of EVs than their respective controls. Fibroblast-derived EVs induced an invasive phenotype in recipient fibroblasts. This invasive fibroblast phenotype was dependent on EV surface localization of fibronectin, interaction with the fibronectin receptor α5β1 integrin, and activation of invasion-associated signaling pathways involving focal adhesion kinase and Src family kinases. EVs in the cellular supernatant, unbound to the extracellular matrix, were capable of mediating invasion signaling on recipient fibroblasts, supporting a direct interaction of EV surface fibronectin with the plasma membrane of recipient cells. Together, these studies uncover a novel mechanism of EV signaling of fibroblast invasion that may be relevant in the pathogenesis of fibrotic diseases and cancer.

Glutaminolysis Epigenetically Regulates Antiapoptotic Gene Expression in Idiopathic Pulmonary Fibrosis Fibroblasts

Fibrotic responses involve multiple cellular processes, including epigenetic changes. Epigenetic changes are sensitive to alterations in the tissue microenvironment such as the flux of tricarboxylic acid (TCA) cycle metabolites. TCA metabolites directly regulate epigenetic states, in part by regulating histone modification-related enzymes. Glutaminolysis is a critical metabolic process by which glutamine is converted to glutamate by glutaminase and then to α-ketoglutarate (α-KG), a TCA cycle metabolite. Idiopathic pulmonary fibrosis (IPF) is a disease characterized by aberrant metabolism, including enhanced glutaminolysis. IPF fibroblasts are apoptosis resistant. In this study, we explored the relationship between glutaminolysis and the resistance to apoptosis of IPF fibroblasts. Inhibition of glutaminolysis decreased expression of XIAP and survivin, members of the inhibitor of apoptosis protein (IAP) family. α-KG is a cofactor for JMJD3 histone demethylase, which targets H3K27me3. In the absence of glutamine, JMJD3 activity in fibroblasts is significantly decreased, whereas H3K27me3 levels are increased. Chromatin immunoprecipitation assays confirmed that JMJD3 directly interacts with XIAP and survivin promoter regions in a glutamine-dependent manner. Exogenous α-KG partially restores JMJD3 function and its interaction with the XIAP and survivin promoter regions under glutamine-deficient conditions. Interestingly, α-KG upregulates XIAP, but not survivin, suggesting differential α-KG-dependent and -independent mechanisms by which glutamine regulates these IAPs. Our data demonstrate a novel mechanism of metabolic regulation in which glutaminolysis promotes apoptosis resistance of IPF fibroblasts through epigenetic regulation of XIAP and survivin.

Metformin reverses established lung fibrosis in a bleomycin model

Fibrosis is a pathological result of a dysfunctional repair response to tissue injury and occurs in a number of organs, including the lungs1. Cellular metabolism regulates tissue repair and remodelling responses to injury2-4. AMPK is a critical sensor of cellular bioenergetics and controls the switch from anabolic to catabolic metabolism5. However, the role of AMPK in fibrosis is not well understood. Here, we demonstrate that in humans with idiopathic pulmonary fibrosis (IPF) and in an experimental mouse model of lung fibrosis, AMPK activity is lower in fibrotic regions associated with metabolically active and apoptosis-resistant myofibroblasts. Pharmacological activation of AMPK in myofibroblasts from lungs of humans with IPF display lower fibrotic activity, along with enhanced mitochondrial biogenesis and normalization of sensitivity to apoptosis. In a bleomycin model of lung fibrosis in mice, metformin therapeutically accelerates the resolution of well-established fibrosis in an AMPK-dependent manner. These studies implicate deficient AMPK activation in non-resolving, pathologic fibrotic processes, and support a role for metformin (or other AMPK activators) to reverse established fibrosis by facilitating deactivation and apoptosis of myofibroblasts.

Glutaminolysis is required for transforming growth factor-β1-induced myofibroblast differentiation and activation

Myofibroblasts participate in physiological wound healing and pathological fibrosis. Myofibroblast differentiation is characterized by the expression of α-smooth muscle actin and extracellular matrix proteins and is dependent on metabolic reprogramming. In this study, we explored the role of glutaminolysis and metabolites of TCA in supporting myofibroblast differentiation. Glutaminolysis converts Gln into α-ketoglutarate (α-KG), a critical intermediate in the TCA cycle. Increases in the steady-state concentrations of TCA cycle metabolites including α-KG, succinate, fumarate, malate, and citrate were observed in TGF-β1-differentiated myofibroblasts. The concentration of glutamate was also increased in TGF-β1-differentiated myofibroblasts compared with controls, whereas glutamine levels were decreased, suggesting enhanced glutaminolysis. This was associated with TGF-β1-induced expression of the glutaminase (GLS) isoform, GLS1, which converts Gln into glutamate, at both the mRNA and protein levels. The stimulation of GLS1 expression by TGF-β1 was dependent on both SMAD3 and p38 mitogen-activated protein kinase activation. Depletion of extracellular Gln prevented TGF-β1-induced myofibroblast differentiation. The removal of extracellular Gln postmyofibroblast differentiation decreased the expression of the profibrotic markers fibronectin and hypoxia-inducible factor-1α and reversed TGF-β1-induced metabolic reprogramming. Silencing of GLS1 expression, in the presence of Gln, abrogated TGF-β1-induced expression of profibrotic markers. Treatment of GLS1-deficient myofibroblasts with exogenous glutamate or α-KG restored TGF-β1-induced expression of profibrotic markers in GLS1-deficient myofibroblasts. Together, these data demonstrate that glutaminolysis is a critical component of myofibroblast metabolic reprogramming that regulates myofibroblast differentiation.

NADPH Oxidase 4 (Nox4) Suppresses Mitochondrial Biogenesis and Bioenergetics in Lung Fibroblasts via a Nuclear Factor Erythroid-derived 2-like 2 (Nrf2)-dependent Pathway

Mitochondrial bioenergetics are critical for cellular homeostasis and stress responses. The reactive oxygen species-generating enzyme, NADPH oxidase 4 (Nox4), regulates a number of physiological and pathological processes, including cellular differentiation, host defense, and tissue fibrosis. In this study we explored the role of constitutive Nox4 activity in regulating mitochondrial function. An increase in mitochondrial oxygen consumption and reserve capacity was observed in murine and human lung fibroblasts with genetic deficiency (or silencing) of Nox4. Inhibition of Nox4 expression/activity by genetic or pharmacological approaches resulted in stimulation of mitochondrial biogenesis, as evidenced by elevated mitochondrial-to-nuclear DNA ratio and increased expression of the mitochondrial markers transcription factor A (TFAM), citrate synthase, voltage-dependent anion channel (VDAC), and cytochrome c oxidase subunit 4 (COX IV). Induction of mitochondrial biogenesis was dependent on TFAM up-regulation but was independent of the activation of the peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α). The enhancement of mitochondrial bioenergetics as well as the increase in mitochondrial proteins in Nox4-deficient lung fibroblasts is inhibited by silencing of nuclear factor erythroid-derived 2-like 2 (Nrf2), supporting a key role for Nrf2 in control of mitochondrial biogenesis. Together, these results indicate a critical role for both Nox4 and Nrf2 in counter-regulation of mitochondrial biogenesis and metabolism.

Developmental Reprogramming in Mesenchymal Stromal Cells of Human Subjects with Idiopathic Pulmonary Fibrosis

Cellular plasticity and de-differentiation are hallmarks of tissue/organ regenerative capacity in diverse species. Despite a more restricted capacity for regeneration, humans with age-related chronic diseases, such as cancer and fibrosis, show evidence of a recapitulation of developmental gene programs. We have previously identified a resident population of mesenchymal stromal cells (MSCs) in the terminal airways-alveoli by bronchoalveolar lavage (BAL) of human adult lungs. In this study, we characterized MSCs from BAL of patients with stable and progressive idiopathic pulmonary fibrosis (IPF), defined as <5% and ≥10% decline, respectively, in forced vital capacity over the preceding 6-month period. Gene expression profiles of MSCs from IPF subjects with progressive disease were enriched for genes regulating lung development. Most notably, genes regulating early tissue patterning and branching morphogenesis were differentially regulated. Network interactive modeling of a set of these genes indicated central roles for TGF-β and SHH signaling. Importantly, fibroblast growth factor-10 (FGF-10) was markedly suppressed in IPF subjects with progressive disease, and both TGF-β1 and SHH signaling were identified as critical mediators of this effect in MSCs. These findings support the concept of developmental gene re-activation in IPF, and FGF-10 deficiency as a potentially critical factor in disease progression.

Novel Mechanisms for the Antifibrotic Action of Nintedanib

Idiopathic pulmonary fibrosis (IPF) is a disease with relentless course and limited therapeutic options. Nintedanib (BIBF-1120) is a multiple tyrosine kinase inhibitor recently approved by the U.S. Food and Drug Administration for the treatment of IPF. The precise antifibrotic mechanism(s) of action of nintedanib, however, is not known. Therefore, we studied the effects of nintedanib on fibroblasts isolated from the lungs of patients with IPF. Protein and gene expression of profibrotic markers were assessed by Western immunoblotting and real-time PCR. Autophagy markers and signaling events were monitored by biochemical assays, Western immunoblotting, microscopy, and immunofluorescence staining. Silencing of autophagy effector proteins was achieved with small interfering RNAs. Nintedanib down-regulated protein and mRNA expression of extracellular matrix (ECM) proteins, fibronectin, and collagen 1a1 while inhibiting transforming growth factor (TGF)-β1-induced myofibroblast differentiation. Nintedanib also induced beclin-1-dependent, ATG7-independent autophagy. Nintedanib's ECM-suppressive actions were not mediated by canonical autophagy. Nintedanib inhibited early events in TGF-β signaling, specifically tyrosine phosphorylation of the type II TGF-β receptor, activation of SMAD3, and p38 mitogen-activated protein kinase. Nintedanib down-regulates ECM production and induces noncanonical autophagy in IPF fibroblasts while inhibiting TGF-β signaling. These mechanisms appear to be uncoupled and function independently to mediate its putative antifibrotic effects.

Glycolytic Reprogramming in Myofibroblast Differentiation and Lung Fibrosis

RATIONALE

Dysregulation of cellular metabolism has been shown to participate in several pathologic processes. However, the role of metabolic reprogramming is not well appreciated in the pathogenesis of organ fibrosis.

OBJECTIVES

To determine if glycolytic reprogramming participates in the pathogenesis of lung fibrosis and assess the therapeutic potential of glycolytic inhibition in treating lung fibrosis.

METHODS

A cell metabolism assay was performed to determine glycolytic flux and mitochondrial respiration. Lactate levels were measured to assess glycolysis in fibroblasts and lungs. Glycolytic inhibition by genetic and pharmacologic approaches was used to demonstrate the critical role of glycolysis in lung fibrosis.

MEASUREMENTS AND MAIN RESULTS

Augmentation of glycolysis is an early and sustained event during myofibroblast differentiation, which is dependent on the increased expression of critical glycolytic enzymes, in particular, 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3). Augmented glycolysis contributes to the stabilization of hypoxia-inducible factor 1-α, a master regulator of glycolytic enzymes implicated in organ fibrosis, by increasing cellular levels of tricarboxylic acid cycle intermediate succinate in lung myofibroblasts. Inhibition of glycolysis by the PFKFB3 inhibitor 3PO or genomic disruption of the PFKFB3 gene blunted the differentiation of lung fibroblasts into myofibroblasts, and attenuated profibrotic phenotypes in myofibroblasts isolated from the lungs of patients with idiopathic pulmonary fibrosis. Inhibition of glycolysis by 3PO demonstrates therapeutic benefit in bleomycin-induced and transforming growth factor-β1-induced lung fibrosis in mice.

CONCLUSIONS

Our data support the novel concept of glycolytic reprogramming in the pathogenesis of lung fibrosis and provide proof-of-concept that targeting this pathway may be efficacious in treating fibrotic disorders, such as idiopathic pulmonary fibrosis.

Metabolic Reprogramming Is Required for Myofibroblast Contractility and Differentiation

Contraction is crucial in maintaining the differentiated phenotype of myofibroblasts. Contraction is an energy-dependent mechanism that relies on the production of ATP by mitochondria and/or glycolysis. Although the role of mitochondrial biogenesis in the adaptive responses of skeletal muscle to exercise is well appreciated, mechanisms governing energetic adaptation of myofibroblasts are not well understood. Our study demonstrates induction of mitochondrial biogenesis and aerobic glycolysis in response to the differentiation-inducing factor transforming growth factor β1 (TGF-β1). This metabolic reprogramming is linked to the activation of the p38 mitogen-activated protein kinase (MAPK) pathway. Inhibition of p38 MAPK decreased accumulation of active peroxisome proliferator-activated receptor γ coactivator 1α in the nucleus and altered the translocation of mitochondrial transcription factor A to the mitochondria. Genetic or pharmacologic approaches that block mitochondrial biogenesis or glycolysis resulted in decreased contraction and reduced expression of TGF-β1-induced α-smooth muscle actin and collagen α-2(I) but not of fibronectin or collagen α-1(I). These data indicate a critical role for TGF-β1-induced metabolic reprogramming in regulating myofibroblast-specific contractile signaling and support the concept of integrating bioenergetics with cellular differentiation.

Extended characterization of Corynebacterium pyruviciproducens based on clinical strains from Canada and Switzerland

The species Corynebacterium pyruviciproducens was described in 2010 based on the features of a single strain. In this report, we describe the chemotaxonomic and phenotypic characteristics of 11 C. pyruviciproducens clinical strains isolated in Switzerland and Canada in comparison to the strain 06-17730(T). Heterogeneities within the type strain were found in the 16S rRNA gene and in biochemical markers. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) identification of this species could not be achieved since currently this bacterial species is not included in the corresponding database. Reliable identification is obtained only with sequence-based identification tools. Results of antimicrobial susceptibility testing of this species with an extended panel of antimicrobials are presented here for the first time.

NADPH oxidases in lung health and disease

SIGNIFICANCE

The evolution of the lungs and circulatory systems in vertebrates ensured the availability of molecular oxygen (O2; dioxygen) for aerobic cellular metabolism of internal organs in large animals. O2 serves as the physiologic terminal acceptor of mitochondrial electron transfer and of the NADPH oxidase (Nox) family of oxidoreductases to generate primarily water and reactive oxygen species (ROS), respectively.

RECENT ADVANCES

The purposeful generation of ROS by Nox family enzymes suggests important roles in normal physiology and adaptation, most notably in host defense against invading pathogens and in cellular signaling.

CRITICAL ISSUES

However, there is emerging evidence that, in the context of chronic stress and/or aging, Nox enzymes contribute to the pathogenesis of a number of lung diseases.

FUTURE DIRECTIONS

Here, we review evolving functions of Nox enzymes in normal lung physiology and emerging pathophysiologic roles in lung disease.

Reversal of persistent fibrosis in aging by targeting Nox4-Nrf2 redox imbalance

The incidence and prevalence of pathological fibrosis increase with advancing age, although mechanisms for this association are unclear. We assessed the capacity for repair of lung injury in young (2 months) and aged (18 months) mice. Whereas the severity of fibrosis was not different between these groups, aged mice demonstrated an impaired capacity for fibrosis resolution. Persistent fibrosis in lungs of aged mice was characterized by the accumulation of senescent and apoptosis-resistant myofibroblasts. These cellular phenotypes were sustained by alterations in cellular redox homeostasis resulting from elevated expression of the reactive oxygen species-generating enzyme Nox4 [NADPH (reduced form of nicotinamide adenine dinucleotide phosphate) oxidase-4] and an impaired capacity to induce the Nrf2 (NFE2-related factor 2) antioxidant response. Lung tissues from human subjects with idiopathic pulmonary fibrosis (IPF), a progressive and fatal lung disease, also demonstrated this Nox4-Nrf2 imbalance. Nox4 mediated senescence and apoptosis resistance in IPF fibroblasts. Genetic and pharmacological targeting of Nox4 in aged mice with established fibrosis attenuated the senescent, antiapoptotic myofibroblast phenotype and led to a reversal of persistent fibrosis. These studies suggest that loss of cellular redox homeostasis promotes profibrotic myofibroblast phenotypes that result in persistent fibrosis associated with aging. Our studies suggest that restoration of Nox4-Nrf2 redox balance in myofibroblasts may be a therapeutic strategy in age-associated fibrotic disorders, potentially able to resolve persistent fibrosis or even reverse its progression.

Inhibition of mechanosensitive signaling in myofibroblasts ameliorates experimental pulmonary fibrosis

Matrix stiffening and myofibroblast resistance to apoptosis are cardinal features of chronic fibrotic diseases involving diverse organ systems. The interactions between altered tissue biomechanics and cellular signaling that sustain progressive fibrosis are not well defined. In this study, we used ex vivo and in vivo approaches to define a mechanotransduction pathway involving Rho/Rho kinase (Rho/ROCK), actin cytoskeletal remodeling, and a mechanosensitive transcription factor, megakaryoblastic leukemia 1 (MKL1), that coordinately regulate myofibroblast differentiation and survival. Both in an experimental mouse model of lung fibrosis and in human subjects with idiopathic pulmonary fibrosis (IPF), we observed activation of the Rho/ROCK pathway, enhanced actin cytoskeletal polymerization, and MKL1 cytoplasmic-nuclear shuttling. Pharmacologic disruption of this mechanotransduction pathway with the ROCK inhibitor fasudil induced myofibroblast apoptosis through a mechanism involving downregulation of BCL-2 and activation of the intrinsic mitochondrial apoptotic pathway. Treatment with fasudil during the postinflammatory fibrotic phase of lung injury or genetic ablation of Mkl1 protected mice from experimental lung fibrosis. These studies indicate that targeting mechanosensitive signaling in myofibroblasts to trigger the intrinsic apoptosis pathway may be an effective approach for treatment of fibrotic disorders.

Histone modifications in senescence-associated resistance to apoptosis by oxidative stress

Aging and age-related diseases are associated with cellular senescence that results in variable apoptosis susceptibility to oxidative stress. Although fibroblast senescence has been associated with apoptosis resistance, mechanisms for this have not been well defined. In this report, we studied epigenetic mechanisms involving histone modifications that confer apoptosis resistance to senescent human diploid fibroblasts (HDFs). HDFs that undergo replicative senescence display typical morphological features, express senescence-associated β-galactosidase, and increased levels of the tumor suppressor genes, p16, p21, and caveolin-1. Senescent HDFs are more resistant to oxidative stress (exogenous H₂O₂)-induced apoptosis in comparison to non-senescent (control) HDFs; this is associated with constitutively high levels of the anti-apoptotic gene, Bcl-2, and low expression of the pro-apoptotic gene, Bax. Cellular senescence is characterized by global increases in H4K20 trimethylation and decreases in H4K16 acetylation in association with increased activity of Suv420h2 histone methyltransferase (which targets H4K20), decreased activity of the histone acetyltransferase, Mof (which targets H4K16), as well as decreased total histone acetyltransferase activity. In contrast to Bax gene, chromatin immunoprecipitation studies demonstrate marked enrichment of the Bcl-2 gene with H4K16Ac, and depletion with H4K20Me3, predicting active transcription of this gene in senescent HDFs. These data indicate that both global and locus-specific histone modifications of chromatin regulate altered Bcl-2:Bax gene expression in senescent fibroblasts, contributing to its apoptosis-resistant phenotype.

Severe Legionnaire's disease caused by Legionella longbeachae in a long-term renal transplant patient: the importance of safe living strategies after transplantation

Legionella species are intracellular gram-negative bacilli that require specific culture media for growth. Transplant recipients with impaired cellular immunity are at particular risk for infection with this pathogen. Most human disease is caused by Legionella pneumophila; disease caused by non-L. pneumophila species is reported mainly in immunosuppressed patients with the exception of Legionella longbeachae. L. longbeachae is a common cause of Legionnaires' disease in Australia and New Zealand, and is associated with exposure to potting soil. We report the case of a patient, 26 years post kidney transplant, who presented with severe and rapidly progressive respiratory illness. L. longbeachae serogroup 1 was isolated from respiratory cultures. Further investigation revealed that she had significant soil exposure before the onset of illness. We highlight the importance of following safe living strategies to prevent exposure-related illness even in long-term transplant recipients.

Cross-linking of ΔF508-CFTR promotes its trafficking to the plasma membrane

CFTR is a cAMP-activated chloride channel responsible for agonist stimulated chloride and fluid transport across epithelial surfaces.(1) Mutations in the CFTR gene lead to cystic fibrosis (CF) which affects the function of secretory organs like the intestine, the pancreas, the airways and the sweat glands. Most of the morbidity and mortality in CF has been linked to a decrease in airway function.(2) The ΔF508 mutation is the most common CF-related mutation in the Caucasian population and represents 90% of CF alleles. Homozygote carriers of this mutation present with a severe CF phenotype.(3) The ΔF508 mutation causes misfolding of the nascent CFTR polypeptide, which leads to inefficient export from the endoplasmic reticulum (ER) and rapid degradation by the proteasome.

Curcumin cross-links cystic fibrosis transmembrane conductance regulator (CFTR) polypeptides and potentiates CFTR channel activity by distinct mechanisms

Cystic fibrosis (CF) is caused by loss-of-function mutations in the CFTR chloride channel. Wild type and mutant CFTR channels can be activated by curcumin, a well tolerated dietary compound with some appeal as a prospective CF therapeutic. However, we show here that curcumin has the unexpected effect of cross-linking CFTR polypeptides into SDS-resistant oligomers. This effect occurred for CFTR channels in microsomes as well as in intact cells and at the same concentrations that are effective for promoting CFTR channel activity (5-50 mum). Both mature CFTR polypeptides at the cell surface and immature CFTR protein in the endoplasmic reticulum were cross-linked by curcumin, although the latter pool was more susceptible to this modification. Curcumin cross-linked two CF mutant channels (Delta F508 and G551D) as well as a variety of deletion constructs that lack the major cytoplasmic domains. In vitro cross-linking could be prevented by high concentrations of oxidant scavengers (i.e. reduced glutathione and sodium azide) indicating a possible oxidation reaction with the CFTR polypeptide. Importantly, cyclic derivatives of curcumin that lack the reactive beta diketone moiety had no cross-linking activity. One of these cyclic derivatives stimulated the activities of wild type CFTR channels, Delta 1198-CFTR channels, and G551D-CFTR channels in excised membrane patches. Like the parent compound, the cyclic derivative irreversibly activated CFTR channels in excised patches during prolonged exposure (>5 min). Our results raise a note of caution about secondary biochemical effects of reactive compounds like curcumin in the treatment of CF. Cyclic curcumin derivatives may have better therapeutic potential in this regard.

Effects of the AMPA receptor modulator S 18986 on measures of cognition and oxidative stress in aged rats

RATIONALE

Development of cognitive-enhancing drugs that delay or halt mild cognitive impairment progression to Alzheimer's disease would be of great benefit.

OBJECTIVES

The aim of this study was to examine the ability of (S)-2,3-dihydro-[3,4]-cyclopentano-1,2,4-benzothiadiazine-1,1-dioxide (S 18986), a positive allosteric modulator of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, to improve behavioral performance and alleviate age-related deficits in oxidative stress status in the prelimbic cortex and hippocampus.

MATERIALS AND METHODS

Daily administration of S 18986 (0.1, 0.3, and 1.0 mg/kg) or vehicle was given to separate groups of male rats starting at 12 months of age. Additionally, daily vehicle administration was given to a group of rats starting at 3 months of age. Four months after initiation of drug administration, rats were trained and tested in an operant-delayed alternation task and a reinforcer devaluation task. Upon completion of testing, oxidative stress status was assessed in the prelimbic cortex and hippocampus.

RESULTS

S 18986 dose-dependently altered responses in the reinforcer devaluation task such that aged rats came to resemble young rats. There were no age or drug effects in the operant-delayed alternation task. Levels of the lipid peroxidation product 4-hydroxy-nonenal (HNE) were increased, and Cu/Zn-superoxide dismutase (SOD) levels were decreased in prelimbic cortex in aged rats, changes that were reversed by S 18986. Similarly, age-related increases in hippocampal HNE levels were prevented by S 18986.

CONCLUSIONS

Positive modulation of AMPA receptor activity may be a therapeutic approach to halt or slow progression of mild cognitive impairment via improvement in oxidative stress status in the hippocampus and prelimbic cortex.

A culture filtrate of Phytophthora infestans primes defense reaction in potato cell suspensions

Priming of defense reactions by an elicitor results in an enhanced ability of the plant to respond to subsequent pathogen challenges. We previously showed that application of lipopolysaccharides (LPS) to potato cell suspensions causes apoplastic acidification, but does not stimulate lipoxygenase (LOX) activity. Here, we tested the ability of various elicitors to prime and elicit defense reactions in potato cell suspensions. Adding 20 microg ml(1) LPS, laminarin, harpin N, or a concentrated culture filtrate (CCF) of Phytophthora infestans to cell cultures 18 h before a second elicitation with LPS did not alter the intensity of apoplastic acidification compared with a single LPS application. Conversely, high concentrations (200 or 400 microg ml(1)) of LPS, laminarin, and harpin N activated LOX in cells pretreated with 1 microg ml(1) CCF, but not in cells pretreated with LPS, laminarin, or harpin N. LOX response was maximal in pretreated cells of potato cv. Bintje when the second elicitation occurred 18 to 24 h after CCF application. These results showed that LOX activation is primed in potato cells by CCF, but not by LPS, harpin N, or laminarin. Finally, bioassays showed a slightly greater reduction of rot weight in half tubers treated with CCF followed by LPS before inoculation with Pectobacterium atrosepticum than in half tubers treated with either preparation alone, indicating a priming effect of CCF on both LOX induction and disease suppression.

Comparison of single vs. multiple administrations of the AMPA receptors modulator S 18986 in the object recognition task in rats

The present study aimed at defining the best scheme of administration of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor-positive modulator (S)-2,3-dihydro-[3,4]-cyclopentano-1,2,4-benzothiadiazine-1,1-dioxide (S 18986) [once daily (o.d.) administration of 1 mg/kg for 3 days vs. three times daily (t.i.d.) administration of 0.3 mg/kg for 3 days] to get an optimal procognitive activity in the object recognition task in rats. Memory performance [Recognition Index (RI)] of rats was significantly improved 1 h (RI = 41%, P < 0.01) and 3 h (RI = 46%, P < 0.001) following oral administration of S 18986 (1 mg/kg, o.d.) when compared with animals receiving the vehicle (RI = 6%). When the interval between administration and testing was increased to 6 h and 9 h, no statistically significant improvement in memory performance was observed (RI = 42% for 6 h and RI = 18% for 9 h vs. 20% for the vehicle group). When S 18986 was administered at 0.3 mg/kg t.i.d., no statistically significant improvement in memory performance was observed (RI = 36%). These findings show a long-lasting efficacy of the AMPA receptor allosteric modulator in the object recognition task despite a short half-life in plasma and in brain (approximately 1 h). Accordingly, multiple administrations of S 18986 are not required to obtain a maximal efficacy in this paradigm, because a o.d. schedule of administration leads to a powerful procognitive activity.

Enhancement of P2Y6-induced Cl- secretion by IL-13 and modulation of SK4 channels activity in human bronchial cells

Expression of functional P2Y(6) receptors was demonstrated in primary cultures of human bronchial cells (NHBE cells). P2Y(6) receptors were located only on the apical membranes of NHBE cells. Their stimulation by UDP induced a chloride secretion (short-circuit current) reflected by the development of two I(sc) components (I(fast) and I(late)). A pharmacological characterization of those two I(sc) components showed the involvement of CaCC and CFTR channel activity in I(fast) and I(late) respectively. I(fast) was also found to be under control of basolateral SK4 channels. Indeed, inhibition of SK4 channels opening by clotrimazole dramatically reduced I(fast) amplitude. The epithelial ion transporting phenotype depends on the cellular state of differentiation. As previously reported, we observed that Ultroser G increased the epithelial tightness and Na(+)-transport capacity while IL-13 switch the epithelial ion transport phenotype from a Na(+)-absorbing to a Cl(-)-secreting one. In our study, we report for the first time a change in the K(+) cell permeability associated to IL-13-induced cell differentiation. IL-13 treatment increased the-resting K(+) permeability as well as the Ca(2+)-dependent K(+) permeability stimulated by UDP or ionomycin. SK4 channels activity, underlying the Ca(2+)-dependent K(+) permeability was in particular increased by IL-13. The on/off effect of IL-13 on P2Y(6)-induced Cl-secretion may help to identify the molecular determinants responsible for the CaCC channel activity.

[Comparison of quality of life in morbidly obese patients and healthy volunteers. A prospective study using the GIQLI questionnaire]

BACKGROUND

Morbid obesity decreases the quality of life. The aims of surgical and medical treatment are weight loss, reduction of co-morbidity, and improved quality of life.

AIMS

To compare the quality of life between obese patients (BMI: 40 or>35+comorbidity) and healthy volunteers using the GIQLI (Gastrointestinal Quality of Life) questionnaire.

PATIENTS

Between January 2001 and December 2002, 127 morbidly obese patients (109 female, 18 male) with a mean age of 40.1 years were surgically treated with laparoscopic gastric banding. Quality of life, as measured by the GIQLI questionnaire, was systematically evaluated pre-operatively. During the same period, a control group of 125 healthy volunteers of comparable age, gender, and prior surgical history were evaluated using the same questionnaire.

RESULT

The two groups, while comparable in age and gender, were significantly different in terms of weight (123 vs. 66 kg), BMI (44.3 vs. 22.2) (p<0.001), co-morbidity factors (p=0.001), and professional activity (p=0.02). The mean global GICLI score was 122 for healthy individuals and 95 for morbidly obese patients. (p=0.001), and the differences were most marked in the super obese. These differences particularly involved social dysfunction, physical status, and emotional symptoms but were not significantly different for gastrointestinal symptoms.

CONCLUSION

The quality of life in morbidly obese and super obese patients is significantly diminished from that of a control population. There was good correlation between the degree of obesity (BMI) and the alteration of the GIQLI global and subscales scores. Quality of life should be systematically evaluated before and after both medical and surgical therapy.

Improvement of episodic contextual memory by S 18986 in middle-aged mice: comparison with donepezil

INTRODUCTION

This study compared the effects of S 18986, a positive allosteric modulator of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptors, to those of donepezil a cholinesterase inhibitor on memory impairments induced by ageing in a contextual serial discrimination (CSD) task in middle-aged mice.

MATERIALS AND METHODS

The CSD task involved the learning of two consecutive discriminations in a four-hole board, each performed on two different floors. This model has been developed to study simultaneously different forms of memory in mice (i.e., episodic-like vs semantic-like forms of memory). We showed that placebo-middle-aged mice (14-15 months old) and placebo-aged subjects (19-20 months old) exhibited a severe memory deficit for the first but not the second discrimination, which was due to an increase in interference, as compared with placebo-treated young mice (5 months old). Middle-aged mice were given (9 days) per os administration of either donepezil, S 18986, or placebo.

RESULTS AND DISCUSSION

Both 0.3 mg/kg donepezil and 0.1 mg/kg S 18986 reversed the deficit of middle-aged mice through a significant increase in contextually correct responses and in parallel a tendency to reduce interfering responses.

CONCLUSION

Overall, S 18986 emerges as having a beneficial impact on contextual memory processes in middle-aged mice.

Curcumin opens cystic fibrosis transmembrane conductance regulator channels by a novel mechanism that requires neither ATP binding nor dimerization of the nucleotide-binding domains

Cystic fibrosis transmembrane conductance regulator (CFTR) chloride channels are essential mediators of salt transport across epithelia. Channel opening normally requires ATP binding to both nucleotide-binding domains (NBDs), probable dimerization of the two NBDs, and phosphorylation of the R domain. How phosphorylation controls channel gating is unknown. Loss-of-function mutations in the CFTR gene cause cystic fibrosis; thus, there is considerable interest in compounds that improve mutant CFTR function. Here we investigated the mechanism by which CFTR is activated by curcumin, a natural compound found in turmeric. Curcumin opened CFTR channels by a novel mechanism that required neither ATP nor the second nucleotide-binding domain (NBD2). Consequently, this compound potently activated CF mutant channels that are defective for the normal ATP-dependent mode of gating (e.g. G551D and W1282X), including channels that lack NBD2. The stimulation of NBD2 deletion mutants by curcumin was strongly inhibited by ATP binding to NBD1, which implicates NBD1 as a plausible activation site. Curcumin activation became irreversible during prolonged exposure to this compound following which persistently activated channels gated dynamically in the absence of any agonist. Although CFTR activation by curcumin required neither ATP binding nor heterodimerization of the two NBDs, it was strongly dependent on prior channel phosphorylation by protein kinase A. Curcumin is a useful functional probe of CFTR gating that opens mutant channels by circumventing the normal requirements for ATP binding and NBD heterodimerization. The phosphorylation dependence of curcumin activation indicates that the R domain can modulate channel opening without affecting ATP binding to the NBDs or their heterodimerization.

Impact of peritoneal tears on the outcome and late results (4 years) of endoscopic totally extra-peritoneal inguinal hernioplasty

BACKGROUND

The reported rate of intra-operative peritoneal laceration during endoscopic extra-peritoneal hernioplasty (TEP) ranges from 10 to 64%.

AIMS

To evaluate in a prospective study the predictive factors of peritoneal tears, their consequences in terms of outcome and late results.

PATIENTS AND METHODS

Between July 1994 and December 2000, we performed 467 endoscopic extra-peritoneal hernia repairs (TEP). In 14.8% of the cases, single or multiples recurrences after conventional open herniotomy were treated. One hundred and forty-nine patients (38%) had had previous surgery (appendectomy); 277 procedures (70.8%) were performed by experienced surgeons and 114 (29.2%) by surgical trainees. We used a diathermic hook in 26.3% of the procedures. The mean follow-up period was 68 months (48-100).

RESULTS

Peritoneal tears occurred in 43 patients (10.9%). Six of them (13%) required operative closure, and six a conversion (four Lichtenstein, one Shouldice, and one TAPP). In 37 cases (86%), the tears were not closed. Peritoneal tears were significantly correlated with surgical experience, Nyhus classification, scar adhesion from previous surgery and the use of sharp instruments. Peritoneal tears interfere significantly (P=0.001) with the operating time (82 vs. 63 min) and conversion rate (13.9 vs. 1.7%). It does not affect the outcome and late results in terms of recurrences, pain, or small bowel obstruction.

CONCLUSION

Our data suggest that peritoneal tears in the vast majority of cases may be safely managed without peritoneal closure. In case of peritoneal laceration, the operative time was significantly longer, and the conversion rate was increased. These situations do not affect the outcome and late complications compared with the procedures without peritoneal tears.

Emergence of an invasive clone of nontoxigenic Corynebacterium diphtheriae in the urban poor population of Vancouver, Canada

Invasive disease due to Corynebacterium diphtheriae is rare in North America. Here we describe the emergence of a predominant clone of a nontoxigenic strain of C. diphtheriae in the impoverished population of Vancouver's downtown core. This clone has caused significant morbidity and contributed to at least two deaths. Over a 5-year period, seven cases of bacteremia due to C. diphtheriae were detected in patients admitted to Vancouver hospitals. Injection drug use, diabetes mellitus, skin colonization/infection with C. diphtheriae, and homelessness all appeared to be related to the development of bacteremia with the organism. Ribotyping of isolates recovered from blood culture revealed a predominant ribotype pattern that has not previously been reported in North America.

Vasotocin and vasopressin stimulation of the chloride secretion in the human bronchial epithelial cell line, 16HBE14o-

1. Effects of neuropeptides of the vasopressin family on Cl(-) secretion have not yet been reported in lung. Using the 16HBE14o- bronchial epithelial cell line, we investigated their action on Cl(-) secretion. 2. In symmetrical Cl(-) solutions, basolateral application of arginine vasotocin (AVT), oxytocin or isotocin induced a transient I(sc) stimulation (I(peak)), whereas arginine vasopressin (AVP) did not. The effects of different Cl(-) channel blockers and of a protein kinase C (PKC) inhibitor suggest that CFTR is involved in I(peak). The calcium-activated K(+) channel (SK4) and the Cl(-)/HCO(-)(3) exchanger favor the driving force for AVT-mediated Cl(-) secretion. The antagonists of V1a (SR49059)- and V1b (SSR149415)-receptors blocked I(peak), while SR121463B, a V2 receptor antagonist, did not. These results point to the stimulation of a V1-like receptor mediating I(peak) and presenting an efficacy order, AVT>oxytocin>isotocin>>AVP. 3. When a serosal to mucosal Cl(-) gradient was applied, AVT and AVP both stimulated I(sc) according to a biphasic profile, I(peak) being followed by a plateau phase (I(plateau)). The pharmacology of I(plateau) suggests that CFTR channels are involved and that Na(+)/K(+)/2Cl(-) is the only transporter associated with I(plateau). dDAVP, a V2 receptor agonist-induced I(plateau) with the same potency as AVP, suggesting the involvement of V2 receptors in the AVP-induced I(plateau). V2 receptors are present on both opposite membranes, while V1-like receptors are mainly expressed on the basolateral membranes. RT-PCR experiments show the expression of V1a, V1b, V2 and vasopressin-activated calcium-mobilizing (VACM) receptors mRNAs.