Liraglutide, a glucagon-like peptide 1 receptor agonist, exerts analgesic, anti-inflammatory and anti-degradative actions in osteoarthritis

Osteoarthritis (OA) is a common disabling disease worldwide, with no effective and safe disease-modifying drugs (DMOAD) in the market. However, studies suggest that drugs, such as liraglutide, which possess strong potential in decreasing low-grade systemic inflammation may be effective in treating OA. Therefore, the aim of this study was to examine the anti-inflammatory, analgesic, and anti-degradative effects in OA using in vitro and in vivo experiments. The results showed that intra-articular injection of liraglutide alleviated pain-related behavior in in vivo sodium monoiodoacetate OA mouse model, which was probably driven by the GLP-1R-mediated anti-inflammatory activity of liraglutide. Moreover, liraglutide treatment significantly decreased IL-6, PGE₂ and nitric oxide secretion, and the expression of inflammatory genes in vitro in chondrocytes and macrophages in a dose-dependent manner. Additionally, liraglutide shifted polarized macrophage phenotype in vitro from the pro-inflammatory M1 phenotype to the M2 anti-inflammatory phenotype. Furthermore, liraglutide exerted anti-catabolic activity by significantly decreasing the activities of metalloproteinases and aggrecanases, a family of catabolic enzymes involved in cartilage breakdown in vitro. Overall, the findings of this study showed that liraglutide ameliorated OA-associated pain, possess anti-inflammatory and analgesic properties, and could constitute a novel therapeutic candidate for OA treatment.

Targeting the GLP-1/GLP-1R axis to treat osteoarthritis: A new opportunity?

Osteoarthritis (OA) is a degenerative joint disease affecting millions of people worldwide. In OA, chondrocytes, synovial cells and other joint cells become activated when exposed to an abnormal environment, including mechanical stress, inflammatory cytokines or disorganization of matrix proteins. Several analogues of the hormones called incretins have been developed and are used notably for treating type 2 diabetes mellitus. Data has accumulated to suggest that incretinomimetics, which bind to the glucagon-like peptide-1 receptor (GLP-1R), have beneficial pleiotropic effects such as immunomodulation, anti-inflammation and neuronal protection. Thus, because of their anti-inflammatory properties, GLP-1-based therapies could benefit OA patients. This review focuses on the GLP-1R pathway, molecular mechanisms and phenotypes related to OA pathogenesis.

The translational potential of this article

The search for new therapeutic targets to treat people suffering from OA remains urgent as there is currently no disease-modifyingtherapy available for this disease. This review discusses how GLP-1 analogues could be potential DMOADs for treating OA thanks to their anti-inflammatory, immunoregulatory and differentiation properties.

POS0373 LIRAGLUTIDE HAS POTENT ANTI-INFLAMMATORY AND ANTI-CATABOLIC IN VITRO ACTIVITIES IN OSTEOARTHRITIS

Background:

Osteoarthritis (OA) is an age-related joint disease which provokes chronic pain and limits mobility. The disease progression is associated with inflammatory responses and cartilage degradation. Both chondrocytes, the only cell type present in cartilage, and macrophages from the synovium, play a major role in OA pathophysiology. Liraglutide is a Glucagon-Like Peptide-1 Receptor (GLP-1R) agonist widely prescribed for the treatment of type 2 diabetes. Interestingly, anti-inflammatory properties of the GLP-1 pathway have been reported in various diseases outside diabetes.

Objectives:

We evaluated the anti-inflammatory and anti-catabolic effects of Liraglutide in two in vitro models relevant to OA by evaluating surrogate markers of inflammation, cartilage matrix proteolysis and differentiation.

Methods:

Lipopolysaccharide (LPS)-stimulated murine Raw 264.7 macrophages were treated with 10 concentrations (6.6nM-3.4µM) of Liraglutide for 24h. Anti-inflammatory activity was evaluated by the production of nitric oxide (NO) and prostaglandin E2 (PGE2) using Griess reaction and ELISA, respectively. Interleukin 1β (IL-1β)-stimulated mouse articular chondrocytes were treated with Liraglutide (6.6nM-3.4µM) for 24h. Production of IL-6, matrix metalloproteinase-3 (MMP-3) and glycosaminoglycans (GAG) was measured by ELISA and GAG assay, respectively. RTqPCR analyses were performed with three selected concentrations of Liraglutide (13.3nM, 53.1nM and 1.7µM) on both cell types to assess the expression of a panel of genes related to inflammation (IL-6, TNF, iNOS), M1/M2 macrophage phenotype (MCP-1, CD38, ERG-2), catabolism (MMP-13, ADAMTS-5) and differentiation (Sox9, Col2a1, Acan).

Results:

Liraglutide induced a dose-dependent inhibition of the LPS-induced production of NO (IC50=45nM) and PGE2 (IC50=54nM) in macrophages. Moreover, IL-6 and TNF gene expressions were significantly and dose-dependently decreased in Raw 264.7 cells treated with Liraglutide compared to LPS alone. Interestingly, there was a significant dose-dependent reduction of MCP-1 and CD38 (M1 marker) gene expression in cells treated with the 3 doses of Liraglutide compared to LPS alone while we observed a dose-dependent increase of ERG-2 (M2 marker) gene expression induced by Liraglutide. Liraglutide significantly dose-dependently reduced the IL-1β-induced release of IL-6 (IC50=38nM), MMP-3 (IC50=56nM) and GAG (IC50=47nM) in chondrocytes. Additionally, Liraglutide treatment dose-dependently decreased the IL-1β-induced gene expression of iNOS, MMP-13 and ADAMTS-5. Finally, IL-1β decreased gene expression of Sox9, Col2a1 and Acan differentiation markers, which was rescued in a dose-dependent manner by Liraglutide (Table 1).

Table 1.

Gene expression results (fold change) in Raw 264.7 murine macrophages or mouse primary articular chondrocytes

Cell typeMarkersVehicleVehicleLiraglutide (nM)13.353.11700Macrophages- LPS+ LPSIL61.0±0.2*63.6±7.158.8±6.536.3±8.4*30.8±2.6*TNFα1.0±0.2*26.8±4.917.5±2.6*9.5±1.8*4.1±2.1*MCP11.1±0.6*91.7±11.267.8±4.3*47.3±6.1*25.1±5.5*CD381.1±0.6*103.5±22.373.2±12.3*44.6±8.9*17.4±3.3*ERG21.0±0.3*0.3±0.11.1±0.5*2.1±0.6*3.1±0.2*Chondrocytes- IL1β+ IL1βiNOS1.0±0.2*47.8±17.634.2±15.518.9±8.2*11.8±2.9*MMP131.0±0.2*9.8±2.07.6±1.04.6±0.7*2.5±0.4*ADAMTS51.2±0.82.7±0.62.0±0.61.6±0.31.1±0.2Sox91.0±0.1*0.4±0.20.4±0.20.6±0.00.7±0.2Col2a11.0±0.2*0.3±0.10.3±0.10.5±0.30.8±0.3*Acan1.2±0.8*0.2±0.10.1±0.00.5±0.1*0.7±0.2*

* p<0.05 vs LPS or IL1β alone, n=4

Conclusion:

A shift in M1/M2 macrophage phenotype and the inhibition of chondrocyte expression of several mediators involved in inflammation and cartilage degradation explain, at least in part, our previous results from rodent osteoarthritis models that showed an analgesic, anti-inflammatory and anti-degradative effect of Liraglutide. The fact that Liraglutide is already safely prescribed in another indication allows us to foresee a first trial in humans in the short term.

Acknowledgements:

All the people who contributed to the InOsteo project: the members of 4P-Pharma, INSERM UMRS_938 research team, SATT Lutech and Sorbonne University

Disclosure of Interests:

Francis Berenbaum Consultant of: Boehringer, Bone Therapeutics, CellProthera, Expanscience, Galapagos, Gilead, GSK, Merck Sereno, MSD, Nordic, Novartis, Pfizer, Regulaxis, Roche, Sandoz, Sanofi, Servier, UCB, Peptinov, 4P Pharma, 4Moving Biotech, Grant/research support from: TRB Chemedica, Coralie Meurot Employee of: 4P-Pharma, Laure Sudre Employee of: 4P-Pharma, Keren Bismuth Employee of: 4P-Pharma, Revital Rattenbach Shareholder of: 4P-Pharma, Employee of: 4P-Pharma, Patrice Denefle Speakers bureau: 4P-Pharma, Consultant of: 4P-Pharma, Pierre Fabre, Mimetas, Employee of: 4P-Pharma, Celine Martin Employee of: 4P-Pharma, Claire Jacques: None declared

THU0055 ANTI-DEGRADATIVE AND PRO-CHONDROGENIC PROPERTIES OF LIRAGLUTIDE, A GLUCAGON-LIKE-PEPTIDE 1 RECEPTOR AGONIST: EVIDENCE FROM PRECLINICAL STUDIES AND IMPLICATION FOR OSTEOARTHRITIS

Background:

Osteoarthritis (OA) is a degenerative joint disease affecting millions of individuals worldwide. Its development has been reported to be associated with cartilage degradation and inflammatory responses leading to pain, swelling and reduced function. Although OA is a disorder of the whole joint, the progressive destruction of cartilage extracellular matrix is considered as its hallmark. To date, approved OA treatments are only symptomatic. Therefore, there is an urgent need to explore disease-modifying OA drugs (DMOADs) that can mitigate, stop, or even reverse the development of OA.

Objectives:

In this context, the objective of this study was to assess the effect of liraglutide, a Glucagon-Like-Peptide 1 Receptor (GLP-1R) agonist approved for type 2 diabetes, on chondrogenesis, catabolism/inflammation and cartilage protection inin vitroandin vivopreclinical models of OA.

Methods:

The capacity of liraglutide to induce chondrogenesis was evaluated using primary human mesenchymal stem cells (hMSCs). Alcian blue staining was used to assess differentiation of hMSC into chondrocyte spheroids. IL-1β-stimulated mouse articular chondrocytes were treated with different concentrations of liraglutide for 24h. Production of matrix metalloproteinase MMP-13, prostaglandin E2 (PGE2) and nitrite was measured by ELISA and Griess reaction, respectively. Exendin 9-39, a GLP-1R antagonist, was used to confirm target engagement in thein vitroexperiments. Intra-articular (IA) injections of liraglutide or vehicle were performed in the type II collagenase rat model. Histopathological analyses (OARSI scores1) were conducted blindly by one investigator.

Results:

Liraglutide induced the differentiation of hMSCs into chondrocytes. Indeed, 21 days after differentiation initiation, 5/6 and 4/6 alcian-blue positive spheroids were observed for 10 and 100nM liraglutide, respectively, versus 0/6 for vehicle. Liraglutide significantly reduced dose-dependently the IL-1β-induced production of PGE2 (5808±178 for vehicle vs 4560±140, 2933±171 and 2365±85 pg/ml for liraglutide 10, 100 and 500nM, respectively, p≤0.001), nitrite (24.9±0.4 for vehicle vs 20.9±1.5, 19.1±0.9 and 16.5±0.5 µM for liraglutide 10, 100 and 500nM, respectively, p≤0.001) and MMP-13 (686±9 for vehicle vs 553±3, 402±5 and 297±8 pg/ml for liraglutide 10, 100 and 500nM, respectively, p≤0.001) in murine chondrocytes. Effects of liraglutide were GLP-1R dependent since exendin 9-39 significantly counteracted both chondrogenesis and inflammation/catabolism markers expression. Histological assessment of rat collagenase-injected knee joint revealed a significant (p≤0.05) decrease of the total joint score in the IA Liraglutide treated group (8±4) compared to vehicle (11±4).

Conclusion:

Liraglutide induced chondrogenesis, decreased metalloproteinase and inflammatory mediators production by chondrocytes and protected cartilage inin vitroandin vivopreclinical OA models, opening the way for repositioning this drug as a potential DMOAD.

References:

[1]Osteoarthritis Cartilage. 2010 Oct;18 Suppl 3:S24-34

Acknowledgments:

All the people who contributed to the InOsteo project: the members of 4P-Pharma, INSERM UMR S938 research team, SATT Lutech and Sorbonne University

Disclosure of Interests:

Francis Berenbaum Grant/research support from: TRB Chemedica (through institution), MSD (through institution), Pfizer (through institution), Consultant of: Novartis, MSD, Pfizer, Lilly, UCB, Abbvie, Roche, Servier, Sanofi-Aventis, Flexion Therapeutics, Expanscience, GSK, Biogen, Nordic, Sandoz, Regeneron, Gilead, Bone Therapeutics, Regulaxis, Peptinov, 4P Pharma, Paid instructor for: Sandoz, Speakers bureau: Novartis, MSD, Pfizer, Lilly, UCB, Abbvie, Roche, Servier, Sanofi-Aventis, Flexion Therapeutics, Expanscience, GSK, Biogen, Nordic, Sandoz, Regeneron, Gilead, Sandoz, Coralie Meurot Employee of: 4P-Pharma, Jerome Breton Employee of: 4P-Pharma, Laure Sudre: None declared, Carole Bougault: None declared, Revital Rattenbach Shareholder of: 4P-Pharma, Employee of: 4P-Pharma, Celine Martin Employee of: 4P-Pharma, Claire Jacques: None declared

Activation of innate immunity by 14-3-3 ε, a new potential alarmin in osteoarthritis

OBJECTIVE

The innate immune system plays a central role in osteoarthritis (OA). We identified 14-3-3ε as a novel mediator that guides chondrocytes toward an inflammatory phenotype. 14-3-3ε shares common characteristics with alarmins. These endogenous molecules, released into extracellular media, are increasingly incriminated in sustaining OA inflammation. Alarmins bind mainly to toll-like receptor 2 (TLR2) and TLR4 receptors and polarize macrophages in the synovium. We investigated the effects of 14-3-3ε in joint cells and tissues and its interactions with TLRs to define it as a new alarmin involved in OA.

DESIGN

Chondrocyte, synoviocyte and macrophage cultures from murine or OA human samples were treated with 14-3-3ε. To inhibit TLR2/4 in chondrocytes, blocking antibodies were used. Moreover, chondrocytes and bone marrow macrophage (BMM) cultures from knockout (KO) TLRs mice were stimulated with 14-3-3ε. Gene expression and release of inflammatory mediators [interleukin 6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor alpha (TNFα)] were evaluated via reverse transcription quantitative polymerase chain reaction (RT-qPCR) and ELISA.

RESULTS

In vitro, 14-3-3ε induced gene expression and release of IL6 and MCP1 in the treated cells. The inflammatory effects of 14-3-3ε were significantly reduced following TLRs inhibition or in TLRs KO chondrocytes and BMM.

CONCLUSIONS

14-3-3ε is able to induce an inflammatory phenotype in synoviocytes, macrophages and chondrocytes in addition to polarizing macrophages. These effects seem to involve TLR2 or TLR4 to trigger innate immunity. Our results designate 14-3-3ε as a novel alarmin in OA and as a new target either for therapeutic and/or prognostic purposes.

Human mesenchymal stem cell responses to hydrostatic pressure and shear stress

The effects of mechanical stimuli to which cells are exposed in vivo are, at best, incompletely understood; in this respect, gene-level information regarding cell functions which are pertinent to new tissue formation is of special interest and importance in applications such as tissue engineering and tissue regeneration. Motivated by this need, the present study investigated the early responses of human mesenchymal stem cells (hMSCs) to intermittent shear stress (ISS) and to cyclic hydrostatic pressure (CHP) simulating some aspects of the biological milieu in which these cells exist in vivo. Production of nitric oxide (NO) and mRNA expression of several known mechanosensitive genes as well as ERK1/2 activation in the hMSC response to the two mechanical stimuli tested were monitored and compared. NO production depended on the type of the mechanical stimulus to which the hMSCs were exposed and was significantly higher after exposure to ISS than to CHP. At the conditions of NO peak release (i.e., at 0.7 Pa for ISS and 50,000 Pa for CHP), ISS was more effective than CHP in up-regulating mechanosensitive genes. ERK1/2 was activated by ISS but not by CHP. The present study is the first to report that PGTS2, IER3, EGR1, IGF1, IGFBP1, ITGB1, VEGFA and FGF2 are involved in the response of hMSCs to ISS. These findings establish that, of the two mechanical stimuli tested, ISS is more effective than CHP in triggering expression of genes from hMSCs which are bioactive and pertinent to several cell functions (such as cell differentiation and release of specific growth factors and cytokines) and also to tissue-related processes such as wound healing.

Coordinated expression of matrix Gla protein is required during endochondral ossification for chondrocyte survival

Matrix Gla protein (MGP) is a 14-kD extracellular matrix protein of the mineral-binding Gla protein family. Studies of MGP-deficient mice suggest that MGP is an inhibitor of extracellular matrix calcification in arteries and the epiphyseal growth plate. In the mammalian growth plate, MGP is expressed by proliferative and late hypertrophic chondrocytes, but not by the intervening chondrocytes. To investigate the functional significance of this biphasic expression pattern, we used the ATDC5 mouse chondrogenic cell line. We found that after induction of the cell line with insulin, the differentiating chondrocytes express MGP in a stage-specific biphasic manner as in vivo. Treatment of the ATDC5 cultures with MGP antiserum during the proliferative phase leads to their apoptosis before maturation, whereas treatment during the hypertrophic phase has no effect on chondrocyte viability or mineralization. After stable transfection of ATDC5 cells with inducible sense or antisense MGP cDNA constructs, we found that overexpression of MGP in maturing chondrocytes and underexpression of MGP in proliferative and hypertrophic chondrocytes induced apoptosis. However, overexpression of MGP during the hypertrophic phase has no effect on chondrocyte viability, but it does reduce mineralization. This work suggests that coordinated levels of MGP are required for chondrocyte differentiation and matrix mineralization.