Similar effect of co-administration of methotrexate and folic acid for the treatment of arthritis compared to separate administration.

OBJECTIVES: MTX is the recommended first-line treatment for RA associated with folic acid (FA) to reduce side effects related to MTX. Here, we proposed to test a co-administration of MTX with FA in the rat adjuvant-induced arthritis (AIA) on efficacy. MATERIAL AND METHODS: AIA was induced in female Lewis rats and treated with MTX in three groups. The first group of rats received only MTX (n = 13), whereas the second received MTX and FA on the same day (n = 14). The third group received FA one day after MTX (n = 14). Arthritic index (AI), ankle circumference (AC), ankle microcomputed tomography, and blood tests assessed arthritis severity and MTX tolerance. RESULTS: AI and AC were similar in MTX groups at various time points. Bone erosion and bone loss parameters were similar in all groups. MTX-PG1 was found at similar levels in various MTX groups and correlated negatively with arthritis severity. Finally, haematology and metabolic parameters were found at a similar level in MTX groups. CONCLUSION: Co-administration of MTX with FA on the same day did not reduce efficacy compared with FA application one day after MTX. Thus, co-administration of MTX and FA could be more convenient and improve compliance in patients.

YAP promotes cell-autonomous immune responses to tackle intracellular Staphylococcus aureus in vitro.

Transcriptional cofactors YAP/TAZ have recently been found to support autophagy and inflammation, which are part of cell-autonomous immunity and are critical in antibacterial defense. Here, we studied the role of YAP against Staphylococcus aureus using CRISPR/Cas9-mutated HEK293 cells and a primary cell-based organoid model. We found that S. aureus infection increases YAP transcriptional activity, which is required to reduce intracellular S. aureus replication. A 770-gene targeted transcriptomic analysis revealed that YAP upregulates genes involved in autophagy/lysosome and inflammation pathways in both infected and uninfected conditions. The YAP-TEAD transcriptional activity promotes autophagic flux and lysosomal acidification, which are then important for defense against intracellular S. aureus. Furthermore, the staphylococcal toxin C3 exoenzyme EDIN-B was found effective in preventing YAP-mediated cell-autonomous immune response. This study provides key insights on the anti-S. aureus activity of YAP, which could be conserved for defense against other intracellular bacteria.

Polarization of Femtosecond Laser for Titanium Alloy Nanopatterning Influences Osteoblastic Differentiation.

Ultrashort pulse lasers have significant advantages over conventional continuous wave and long pulse lasers for the texturing of metallic surfaces, especially for nanoscale surface structure patterning. Furthermore, ultrafast laser beam polarization allows for the precise control of the spatial alignment of nanotextures imprinted on titanium-based implant surfaces. In this article, we report the biological effect of beam polarization on human mesenchymal stem cell differentiation. We created, on polished titanium-6aluminum-4vanadium (Ti-6Al-4V) plates, a laser-induced periodic surface structure (LIPSS) using linear or azimuthal polarization of infrared beams to generate linear or radial LIPSS, respectively. The main difference between the two surfaces was the microstructural anisotropy of the linear LIPSS and the isotropy of the radial LIPSS. At 7 d post seeding, cells on the radial LIPSS surface showed the highest extracellular fibronectin production. At 14 days, qRT-PCR showed on the same surface an increase in osteogenesis-related genes, such as alkaline phosphatase and osterix. At 21 d, mineralization clusters indicative of final osteoinduction were more abundant on the radial LIPSS. Taken together, we identified that creating more isotropic than linear surfaces enhances cell differentiation, resulting in an improved osseointegration. Thus, the fine tuning of ultrashort pulse lasers may be a promising new route for the functionalization of medical implants.

Improvement of Pain Management by Nefopam in a Rat Adjuvant-Induced Arthritis Model.

Introduction: The adjuvant-induced arthritis (AIA) model is widely used in research to investigate arthritis pathogenesis. Hind paw inflammation is the main outcome in this model with high loss of mobility function partly related to pain. However, analgesics such as non-steroidal anti-inflammatory drugs or opioid drugs interfere with the inflammation process related to arthritis, thus reducing their beneficial use in this model. Therefore, we investigated the effect of nefopam on arthritis development in order to improve pain management in the AIA model. Methods: Female Lewis rats were randomly divided into two groups, and each group received an injection of Mycobacterium butyricum on defining day (D) 0. At D6, rats (n = 10) received nefopam (intraperitoneally or orally) or NaCl 0.9% IP or 1% sucrose in water (n = 5 for each). Rats were monitored with the arthritic index (AI) and ankle circumference. Pain was assessed by scoring based on behavioral indicators. Histology, RT-qPCR, and microcomputed tomography were performed. Results: The clinical parameter AI and ankle circumference were not different in both groups at various time points. However, pain score was significantly lower in the nefopam group at the early stage of the disease. At a later stage of the disease, inflammation was mildly lower whereas bone erosion and bone loss parameters increased in the nefopam group. Conclusion: Nefopam provided a slight reduction in the level of pain at the arthritis onset without reducing arthritis severity and bone loss in the rat AIA model. However, it should be administrated orally for a shorter period to avoid inflammation reduction in the long run.

YAP Transcriptional Activity Dictates Cell Response to TNF In Vitro.

YAP/TAZ are transcription co-factors recently described responsive to pro-inflammatory cytokines and involved in inflammatory-related disorders. However, the role of tumor necrosis factor (TNF), a major pro-inflammatory cytokine, on YAP signaling is not well understood and controversial. Here, we observe in vitro, using wild type and YAP knockout HEK293 cells, that TNF triggers YAP nuclear translocation and transcriptional activity, thus being dependent on Rho family of GTPases. In response to TNF, YAP transcriptional activity orientates cell fate toward survival. Transcriptional analysis with Nanostring technology reveals that YAP modulates TNF-induced increase in fibro-inflammatory pathways such as NF-κB, inflammasomes, cytokines or chemokines signaling and pro-fibrotic pathways involving TGF-ß and extracellular matrix remodeling. Therefore, in response to TNF, YAP acts as a sustainer of the inflammatory response and as a molecular link between inflammation and fibrotic processes. This work identifies that YAP is critical to drive several biological effects of TNF which are involved in cancer and inflammatory disorders.

YAP/TAZ: Key Players for Rheumatoid Arthritis Severity by Driving Fibroblast Like Synoviocytes Phenotype and Fibro-Inflammatory Response.

Objective: The role of YAP/TAZ, two transcriptional co-activators involved in several cancers, was investigated in rheumatoid arthritis (RA). Methods: Fibroblast like synoviocytes (FLS) from patients with RA or osteoarthritis were cultured in 2D or into 3D synovial organoids. Arthritis rat model (n=28) and colitis mouse model (n=21) were used. YAP/TAZ transcriptional activity was inhibited by verteporfin (VP). Multiple techniques were used to assess gene and/or protein expression and/or localization, cell phenotype (invasion, proliferation, apoptosis), bone erosion, and synovial stiffness. Results: YAP/TAZ were transcriptionally active in arthritis (19-fold increase for CTGF expression, a YAP target gene, in RA vs. OA organoids; p<0.05). Stiff support of culture or pro-inflammatory cytokines further enhanced YAP/TAZ transcriptional activity in RA FLS. Inhibiting YAP/TAZ transcriptional activity with VP restored a common phenotype in RA FLS with a decrease in apoptosis resistance, proliferation, invasion, and inflammatory response. Consequently, VP blunted hyperplasic lining layer formation in RA synovial organoids. In vivo, VP treatment strongly reduced arthritis severity (mean arthritic index at 3.1 in arthritic group vs. 2.0 in VP treated group; p<0.01) by restoring synovial homeostasis and decreasing systemic inflammation. YAP/TAZ transcriptional activity also enhanced synovial membrane stiffening in vivo, thus creating a vicious loop with the maintenance of YAP/TAZ activation over time in FLS. YAP/TAZ inhibition was also effective in another inflammatory model of mouse colitis. Conclusion: Our work reveals that YAP/TAZ were critical factors during arthritis. Thus, their transcriptional inhibition could be relevant to treat inflammatory related diseases.