The Chondropaties: study of antagonism between growth factors and reactive oxygen species; clinical applications in the early stage of chondral lesions

Oxidative stress is one of the risk factors for chondropathies. Deterioration of the cell functions due to oxidative stress has been found to be the initial stage changes involving disruption of the cartilage homeostasis. Eventually these changes progress to the final stage of osteoarthritis involving series of catabolic damage mediated by pro-inflammatory cytokines, MMPs, aggrecanases and cell death. Our study investigated the role of fluid, isolated from post operation knee drainage (emartri), of patients who underwent prosthesis replacement surgery, against hydrogen peroxide (H2O2) - induced oxidative stress on normal human articular chondrocytes (HCa). HCa were pre-treated with emartri and then exposed to H2O2 to mimic oxidative stress. Intracellular reactive oxygen species (ROS) levels were measured by using the molecular probe H2DCFDA; intracellular oxidative status in both the cytoplasm and mitochondrial compartment was measured by using HCa infected with lentiviral particle harbouring the redox sensing green fluorescent protein (roGFP); cell proliferation was determined by measuring the rate of DNA synthesis with BrdU incorporation. Moreover, superoxide dismutase (SOD), catalase and glutathione levels from the cell lysates were measured. Haematic sera from the same patient, obtained post-operation, were included in our study to compare and evaluate the response given by the two types of sera.Our study showed that emartri is able to overcome the H2O2 - elicited oxidative stress by decreasing the intracellular ROS levels, maintaining both cytoplasm and mitochondria in a reduced status, inhibiting the cell death due to oxidative stress and up-regulating the antioxidant defence system in chondrocytes. Emartri is assumed to be an important source of growth factors and anti-inflammatory substances that are attracted to the site of surgery. Our results support and propose an important effect of emartri-contained substances in maintaining HCa functions by mediating the up-regulation of the anti-oxidative system and protect cells from oxidative stress. We hypothesized that emartri could be used as an autologous treatment for patients in the early stage undergoing an operation of positioning of the prosthesis, with chondropathies and/or arthrosis or a developing osteoarthritis in the initial stage in the same or other locations in the body.