Background: The health benefits of plant polyphenols have stimulated a growing interest in the scientific community. Their ability to influence various pathological processes has been demonstrated in several in vitro and in vivo disease models [1]. We have recently shown that polydatin, a stilbenoid and precursor of resveratrol, is capable of preventing calcium pyrophosphate (CPP) crystal-induced arthritis in mice [2]. Objectives: The aim of this study was to investigate some potential mechanisms of action associated with this anti-inflammatory effect. Methods: Acute arthritis was induced by injection of a suspension of sterile CPP crystals into the ankle joint of Balb/c mice. Animals were randomised to receive polydatin or colchicine (the control drug) according to a prophylactic protocol. Ankle swelling (primary outcome) was measured at different time points before and after CPP injection. Both joints and muscles were harvested at sacrifice. Histological parameters were assessed by H&E, safranin and Masson's trichrome staining. Muscle damage was evaluated by H&E staining, while Kondziela's inverted test was used to assess muscle strength. A cytokine antibody array (Ray-Biotech) was performed on the joint tissue. Results: Injection of CPP crystals into the ankle resulted in oedema with evident swelling (primary outcome), moderate areas of leukocyte infiltration, loss of homogeneity of synovial membrane structure, moderate to severe loss of proteoglycan in the superficial hyaline layer of cartilage with damage extending into the underlying region. Mice pretreated with polydatin showed reduced ankle swelling 48 hours after crystal injection, similar to that seen after colchicine pretreatment. This was associated with very limited inflammatory damage, with moderate and focal zones of proteoglycan loss and significant preservation of cartilage and bone structures. Intact cartilage and bone surfaces were observed in untreated joints. Regarding the effect on gastrocnemius muscle, CPP crystals induced leukocyte infiltration, loss of muscle fibres and eosinophilic degenerative fibres with enlarged interstitial areas due to increased muscle oedema. In PD- and colchicine-treated mice, muscle damage was limited and the musculoskeletal structure was generally preserved. The cytokine array showed the activation of different inflammatory pathways after CPP injection. PD showed to strongly influence leukocyte migration (MIP-1G, L-selectin, CXCL16, BLC), angiogenesis (VEGF, VEGF-R2, VEGF-R3, MMP-3) and resolution of inflammation (sTNF-RI, sTNF-RII). Conclusion: PD effectively prevents the acute inflammatory response to CPP crystals in mice, preserving both articular and muscular structures. The most affected pathways involve leukocyte migration and the angiogenic process. REFERENCES: [1] Oliviero F, Scanu A, Zamudio-Cuevas Y, Punzi L, Spinella P. Anti-inflammatory effects of polyphenols in arthritis. J Sci Food Agric. 2018;98:1653-1659. doi: 10.1002/jsfa.8664. [2] Oliviero F, Galozzi P, Scanu A, et al. Polydatin Prevents Calcium Pyrophosphate Crystal-Induced Arthritis in Mice. Nutrients. 2021;13:929. doi: 10.3390/nu13030929. Acknowledgements: NIL. Disclosure of Interests: None declared.

Purpose: Intra-articular injections of hyaluronic acid (HA) are widely used to treat osteoarthritis (OA). HYADD®4 (HS), a hexadecylamide derivative of HA, has demonstrated in preclinical studies greater beneficial effects to those of unmodified hyaluronans. Recently, in vivo experiments have demonstrated that bisphosphonates may have a therapeutic potential to attenuate the progression of OA. Among these, alendronate (ALN) has been shown to decrease MMP-13 and ADAMTS-5 expression and increase COL2A1 mRNA levels in in vitro OA models.

BACKGROUND:Polydatin is a stilbenoid with important antioxidant, anti-inflammatory, and immunomodulating properties. The aim of this study was to assess the anti-inflammatory preventive effect of polydatin in the mouse model of acute arthritis induced by calcium pyrophosphate (CPP) crystals.METHODS:Acute arthritis was induced by the injection of a suspension of sterile CPP crystals into the ankle joint of Balb/c mice. Animals were randomized to receive polydatin or colchicine (the control drug) according to a prophylactic and a therapeutic protocol. The primary outcome was the variation of ankle swelling obtained after crystal injection and treatment, while histological parameters such as leukocyte infiltration, IL-1ß and CXCL1 levels and tissue expression were considered as secondary outcomes.RESULTS:Prophylactic treatment with PD significantly diminished ankle swelling after 48 h from crystal injection. Secondary outcomes such as leukocyte infiltration, necrosis, edema, and synovitis were also decreased. PD caused a reduction in circulating levels of IL-1ß and CXCL1, as well as their tissue expression. By contrast, the therapeutic administration of PD did not have any beneficial effect.CONCLUSIONS:PD can effectively prevent acute inflammatory response to crystals in the mouse model of CPP crystal-induced arthritis. These results suggest that this bioactive compound might be used in the prevention of crystal-induced acute attacks in humans.

Francesca Galuppini Matteo Fassan Loris Bertazza Susi Barollo Luciano Cascione Sara WatutantrigeFernando Vanni Lazzarin Paolo Simonato Federica Vianello Massimo Rugge Caterina Mian Gianmaria Pennelli 1Pathology Unit, Department of Medicine (DIMED), University of Padova, Padova 35121, Italy; 2Endocrinology Unit, Department of Medicine (DIMED), University of Padova, Padova 35121, Italy; 3Università Della Svizzera Italiana, Institute of Oncology Research and Swiss Institute of Bioinformatics, Bellinzona 6500, Switzerland; 4Department of Radiotherapy, Istituto Oncologico del Veneto, Padova 35128, Italy Background: The primary goal of papillary thyroid cancer (PTC) management was to stratify patients at preand post-surgical level to identify the small proportion of cases with potentially aggressive disease. Purpose: The aim of our study is to evaluate the possible role of programmed cell death 4 (PDCD4) and BRAF status as prognostic markers in PTC. Patients and methods: We investigate programmed cell death 4 (PDCD4) immunohistochemical expression in 125 consecutive PTCs with median follow-up of 75.3 months (range, 15–98 months) to verify the possible correlation between BRAF status and correlate the classical clinicopathological prognostic factors and PTC outcome with PDCD4 expression. To further support the data, miR-21 expression was tested (by quantitative real-time PCR and in situ hybridization) in a different series of 30 cases (15 PTCs BRAFwt and 15 PTCs BRAFV600E). Moreover, we validated our results using TGCA thyroid carcinoma dataset. Results: We found that 59.8% of the patients showed low-grade PDCD4 nuclear expression and low-grade expression correlated with BRAF V600E. Compared with BRAF 15 wild-type tissue samples, a significant miR-21 up-regulation was associated with BRAF V600E mutations. Lowgrade PDCD4 resulted, and was associated with aggressive histological variants, higher cancer size, extra-thyroidal extension, multifocality, lymph-node metastasis and lymph nodal ratio at the diagnosis. Concerning the outcome, the low-grade PDCD4 expression correlated at univariate and multivariate analysis, with lower levels of recurrence-free survival rate (RFS) and with poor outcome. Moreover, there was significant association between BRAF V600E patients with PDCD4 nuclear loss and lower RFS, whilet here was significant association between BRAF wild-type patients with PDCD4 nuclear expression and better outcome. Conclusion: These results showed that PDCD4 could predict PTC outcome and that the sum of PDCD4 and BRAF alterations increases the prognostic power of BRAF mutation alone.

Background Although in vivo studies have demonstrated that periodontitis aggravates experimental arthritis, there are no animal models that mimic the co-occurrence of these diseases. Objectives To investigate the arthritogenic effect of lipopolysaccharide (LPS) in a mouse model of periodontal disease. Methods Periodontitis was induced in CD1 mice by injection of 0.01 or 0.05 µg of LPS in 5 µl of PBS every 48 hour into the vestibular gingiva of the second molar on the left maxilla. Untreated mice or injected with LPS at the tail were used as controls. Mice (n=10 per condition) were monitored daily and arthritis was estimated by conventional visual scoring method (scale 0–5) and recording the paw swelling with a calliper. 2 weeks after the 9th injection mice were sacrificed to collect blood, maxilla and paw samples. The left maxilla was analysed by microCT and the alveolar bone loss was assessed measuring the distance between the cementum-enamel junction (CEJ) and the alveolar bone crest (ABC) of each molar. Ultrasound (US) was performed to measure the ankle joint space. Periodontal and paw tissues were processed for histological analysis. Inflammation, vascular proliferation and bone resorption were scored (0–3) in maxilla. Inflammation, pannus formation, cartilage and bone destruction were scored (0–5) in ankle joints. CXCL1, IL-1β, IL-6 and TNF serum levels were determined by ELISA. Results Ankle swelling and inflammation were noted after the 5th periodontal injection of 0.05 µg of LPS, picked at day 18 and continued for the next 15 days with paw swelling and score higher than those of untreated mice (at the sacrifice p<0.001). 0.01 µg of LPS did not induce paw changes. Therefore, the subsequent assessments were conducted only in mice injected with 0.05 µg of LPS. The CEJ-ABC distance was greater in the inoculated (0.29±0.08 mm) than in the control (0.17±0.05 mm) mice (p<0.001). Histological analysis showed that LPS induced a mild vascular proliferation (score 0.8±0.42) in periodontal tissue and a substantial alveolar bone resorption (score 1.8±0.42), but not inflammation. US revealed the presence of effusion and a 1.5-fold higher joint space in the ankle of mice with periodontitis than in controls (p<0.05). Leukocyte infiltration (score 2.36±1.56) and synovial proliferation (score 2.09±1.54) were observed after histology in ankle joints of mice injected orally. The same sections had slight cartilage (score 1.32±1.21) and bone destruction (score 0.68±0.72). Animals that received LPS tail injection did not show any clinical and histological signs of arthritis. CXCL1 and TNF were higher in arthritic mice (CXCL1:2226.87±264.38 pg/ml; TNF:24.55±7.0 pg/ml), than in controls (CXCL1:445.97±92.09 pg/ml; TNF:3.22±1.04 pg/ml). Although there was no statistical difference, IL-1β and IL-6 were highest in LPS-mice (IL-1β:79.49±11.99 pg/ml; IL-6:196.02±40.62 pg/ml). Conclusions This study shows that experimental arthritis and periodontal disease can co-occur after LPS oral injection in mice. Our model may be useful to improve the understanding of the mechanisms underlying the link between periodontitis and arthritis. Disclosure of Interest None declared