Use of Reticulated Hyaluronic Acid Alone or Associated With Ozone Gas in the Treatment of Osteoarthritis Due to Hip Dysplasia in Dogs

Mechanical osteoarthritis of the hip in a one medicine concept: a narrative review

Human and veterinary medicine have historically presented many medical areas of potential synergy and convergence. Mechanical osteoarthritis (MOA) is characterized by a gradual complex imbalance between cartilage production, loss, and derangement. Any joint instability that results in an abnormal overload of the joint surface can trigger MOA. As MOA has a prevailing mechanical aetiology, treatment effectiveness can only be accomplished if altered joint mechanics and mechanosensitive pathways are normalized and restored. Otherwise, the inflammatory cascade of osteoarthritis will be initiated, and the changes may become irreversible. The management of the disease using non-steroidal anti-inflammatory drugs, analgesics, physical therapy, diet changes, or nutraceuticals is conservative and less effective. MOA is a determinant factor for the development of hip dysplasia in both humans and dogs. Hip dysplasia is a hereditary disease with a high incidence and, therefore, of great clinical importance due to the associated discomfort and significant functional limitations. Furthermore, on account of analogous human and canine hip dysplasia disease and under the One Medicine concept, unifying veterinary and human research could improve the well-being and health of both species, increasing the acknowledgement of shared diseases. Great success has been accomplished in humans regarding preventive conservative management of hip dysplasia and following One Medicine concept, similar measures would benefit dogs. Moreover, animal models have long been used to better understand the different diseases' mechanisms. Current research in animal models was addressed and the role of rabbit models in pathophysiologic studies and of the dog as a spontaneous animal model were highlighted, denoting the inexistence of rabbit functional models to investigate therapeutic approaches in hip MOA.

Canine Mesenchymal Cell Lyosecretome Production and Safety Evaluation after Allogenic Intraarticular Injection in Osteoarthritic Dogs

In recent years, mesenchymal stromal cells (MSCs) have shown promise as a therapy in treating musculoskeletal diseases, and it is currently believed that their therapeutic effect is mainly related to the release of proteins and extracellular vesicles (EVs), known as secretome. In this work, three batches of canine MSC-secretome were prepared by standardized processes according to the current standard ISO9001 and formulated as a freeze-dried powder named Lyosecretome. The final products were characterized in protein and lipid content, EV size distribution and tested to ensure the microbiological safety required for intraarticular injection. Lyosecretome induced the proliferation of adipose tissue-derived canine MSCs, tenocytes, and chondrocytes in a dose-dependent manner and showed anti-elastase activity, reaching 85% of inhibitory activity at a 20 mg/mL concentration. Finally, to evaluate the safety of the preparation, three patients affected by bilateral knee or elbow osteoarthritis were treated with two intra-articular injections (t = 0 and t = 40 days) of the allogeneic Lyosecretome (20 mg corresponding 2 × 10⁶ cell equivalents) resuspended in hyaluronic acid in one joint and placebo (mannitol resuspended in hyaluronic acid) in the other joint. To establish the safety of the treatment, the follow-up included a questionnaire addressed to the owner and orthopaedic examinations to assess lameness grade, pain score, functional disability score and range of motion up to day 80 post-treatment. Overall, the collected data suggest that intra-articular injection of allogeneic Lyosecretome is safe and does not induce a clinically significant local or systemic adverse response.

Upregulation of antioxidant and autophagy pathways via NRF2 activation protects spinal cord neurons from ozone damage

Ozone therapy can relieve multiple types of pain but exhibits potential neurotoxicity, the mechanism of which is unclear. The present study aimed to identify the role of nuclear factor (erythroid-derived-2)-related 2 (NRF2) in preventing spinal cord injury caused by ozone overdose. Primary neuronal cells were extracted from newborn Wistar rats and authenticated by immunofluorescence using anti-microtubule-associated protein 2 as a cell type-specific marker. Cell viability assay with different ozone concentrations (0, 10, 20, 30 and 40 µg/ml) was used to determine the concentration that caused primary neuron injury; 30 min of 40 µg/ml ozone therapy notably decreased cell viability to 71%. In order to test the effects of ozone, the cells were divided into five treatment groups [0-, 30- and 40 µg/ml ozone, tert-butylhydroquinone (tBHQ) + 40 µg/ml ozone (T40) and tBHQ (T0)]. Cells in the T40 and T0 groups received 40 µmol/l tBHQ on the fifth day of SCN cultivation. Reverse transcription-quantitative PCR and western blotting showed that protein expression levels of heme oxygenase-1 (HO-1) and mRNA expression levels of HO-1 and NRF2 were decreased. NRF2, ubiquitin-binding protein p62 and microtubule-associated proteins 1A/1B light chain 3B expression levels were decreased following treatment with 40 µg/ml ozone. Immunofluorescence showed that NRF2 nuclear expression levels also decreased following 40 µg/ml ozone treatment. However, cells in the T40 group did not display decreased NRF2 nuclear expression levels. Normal/Apoptotic/Necrotic Cell Detection kit revealed that necrosis rate increased following treatment with 40 µg/ml ozone; however, the T40 group did not exhibit this increased necrosis. At 40 µg/ml, ozone increased spinal cord neuron (SCN) death in vitro. Moreover, treatment with 40 µg/ml ozone damaged SCNs. The p62/NRF2/antioxidant response element pathway prevented such injury. tBHQ activated this pathway, upregulated autophagy and increased local nuclear NRF2 concentration, thus enhancing the antioxidant system to protect SCNs from injury caused by high concentrations of ozone.

A Regenerative Approach to Canine Osteoarthritis Using Allogeneic, Adipose-Derived Mesenchymal Stem Cells. Safety Results of a Long-Term Follow-Up

Mesenchymal stem cells (MSC) are emerging as an effective therapeutic tool in treating canine osteoarthritis (OA). In this report, we focused on the questions of whether MSC transplantation has long-term beneficial effects for the improvement in motion and also evaluated the safety of MSC injection. Visceral adipose tissue, a surgical waste obtained during routine ovariectomy served as a source of allogeneic MSCs and used to treat OA. Altogether, fifty-eight dogs were transplanted in the study suffering from OA in the elbow (42 animals), hip (5), knee (8), ankle (2), and hock (1). The effect of MSC transplantation was evaluated by the degree of lameness at a 4-5-years follow-up period based on the owners' subjective observations. The results showed that 83% of the OA patients improved or retained improvement in lameness. Clinical safety of the treatment was assessed by evaluating the coincidence of tumors or other diseases and other adverse reactions (such as local inflammation) after MSC cell therapy. Two incidences of local inflammation for <1 week at the site of injection were reported. No other adverse reactions were detected post-treatment. Sixteen dogs died during the study, 4 due to cancer and 12 due to other diseases, diagnosed by veterinarians. Overall, our survey suggests that MSC transplantation has long-term beneficial effects in reducing lameness. Moreover, no enrichment in a specific cause of death was observed in the transplanted animals, compared to reported literature. Our data suggest that MSC treatment could be an effective and safe long-term therapy for canine OA.