The role of NOX2-derived reactive oxygen species in collagenase-induced osteoarthritis.

OBJECTIVE: Synovitis in collagenase-induced osteoarthritis (CiOA) is driven by locally released S100A8/A9 proteins and enhances joint destruction. S100A8/A9 can induce reactive oxygen species (ROS) release by phagocytes in OA synovium via neutrophil cytosolic factor-1 (Ncf1)-regulated NOX2 activation. In the present study we investigated whether NOX2-derived ROS affect joint pathology during CiOA. METHODS: CiOA was induced in knee joints of wild type (WT) and Ncf1-deficient (Ncf1**) mice. Synovial gene expression of NOX2-subunits was measured with quantitative real-time polymerase chain reaction (qRT-PCR). Joint pathology was assessed using histology and immunohistochemistry for aggrecan neo-epitope VDIPEN. Levels of inflammatory proteins were measured with Luminex or ELISA. Phagocytes in synovium, blood, bone marrow (BM) and spleen were analyzed with flow cytometry. ROS release by phagocytes was measured with a ROS detection kit. RESULTS: CiOA induction in knee joints of WT mice caused significantly increased synovial gene expression of NOX2 subunits. On day 7 of CiOA, cartilage damage and MMP activity, as measured by VDIPEN, were comparable between WT and Ncf1** mice. Synovial thickening, synovial S100A8/A9 levels and percentages of synovial macrophages, polymorphonuclear cells (PMNs), and monocytes were not different, as were levels of inflammatory mediators in serum and phagocyte percentages in blood, BM and spleen. On day 42 of CiOA, synovitis, cartilage damage, and osteophyte formation in Ncf1** mice were unaltered when compared to WT mice. ROS detection confirmed that Ncf1** PMNs lack functional NOX2, but in vitro macrophages showed ROS production, suggesting activation of compensatory mechanisms. CONCLUSIONS: Absence of Ncf1-mediated ROS production does not alter joint pathology in CiOA.

Medical-Grade Honey Is a Versatile Wound Care Product for the Elderly.

Introduction: Ageing of the global population has led to an increase in the demand for the treatment of wounds, especially considering the challenges of managing wounds in the elderly. Therefore, more effective treatment strategies need to be explored. In this article, we aimed to compare medical-grade honey (MGH) products with other wound care products and to provide guidelines on using MGH in wounds commonly found in the elderly. Methods: Based on literature research and expert opinion, an overview of commonly used wound care products and their wound healing characteristics is provided. In addition, literature-based classification of wounds in the elderly and the recommendations for treatments are provided. Results: Frequently used wound care products include povidone-iodine, enzymatic products, absorbing dressings, larvae, silver dressings, and MGH dressings. Supported by systematic reviews and meta-analyses, MGH dressings were identified as the most potent and all-round wound care product compared to the others. Next, we provided basic guidelines for managing the most common wounds in the elderly, both acute and chronic, and specified how and which MGH products can be used in these wounds. Conclusion: MGH is a widely applicable, safe, easy-to-use, and cost-effective product to manage wounds in the elderly. In case of doubt, refer to a trained wound care specialist who can support the treatment of difficult-to-heal wounds.