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

Neuregulin signaling regulates neural precursor growth and the generation of oligodendrocytes in vitro

Neuregulin 1 (Nrg-1) isoforms have been shown to influence the emergence and growth of oligodendrocytes, the CNS myelin-forming cells. We have investigated how Nrg-1 signaling of ErbB receptors specifically controls the early stages of oligodendrocyte generation from multipotential neural precursors (NPs). We show here that embryonic striatal NPs express multiple Nrg-1 transcripts and proteins as well as their specific receptors, ErbB2 and ErbB4, but not ErbB3. The major isoform synthesized by striatal NPs is a transmembrane type III isoform called cysteine-rich domain Nrg-1. To examine the biological effect of Nrg-1, we added soluble ErbB3 (sErbB3) to growing neurospheres. This inhibitor of Nrg-1 bioactivity decreased mitosis of NPs and increased their apoptosis, resulting in a significant reduction in neurosphere size and number. When NPs were induced to migrate and differentiate by adhesion of neurospheres to the substratum, the level of type III isoforms detected by RT-PCR and Western blot decreased in parallel with a reduction in Nrg-1 fluorescence intensity in differentiating astrocytes, neurons, and oligodendrocytes. Pretreatment of growing neurospheres with sErbB3 induced a threefold increase in the proportion of oligodendrocytes generated from NPs migrating out of the neurosphere. This effect was not observed with an unrelated soluble receptor. Addition of sErbB3 during NP growth and differentiation enhanced oligodendrocyte maturation as shown by expression of galactocerebroside and myelin basic protein. We propose that both type III Nrg-1 signaling and soluble ErbB receptors modulate oligodendrocyte development from NPs.