Regulación de la plasticidad celular y senescencia en condrocitos articulares: conexina 43 como diana terapéutica para el tratamiento de la artrosis

Abstract

Introduction: Osteoarthritis (OA) is a degenerative musculoskeletal disease, which affects approximately the 13% of western population. Nowadays, there is no effective treatment for OA to avoid disease progression or to promote cartilage regeneration. Connexin43 (Cx43) is a transmembrane protein increased in cartilage and synovium from OA patients. Cx43 forms membrane channels that allow the exchange of molecules and ions between two adjacent cells through gap junctions (GJs), or between a cell and its environment through hemichannels. In this study we investigated the involvement of Cx43 and GJ intercellular communication in the degradation of articular cartilage in chondrocytes from patients with OA. Material and methods: Primary chondrocytes were obtained from cartilage from OA and healthy donors. Protein levels were evaluated by western-blot, immunofluorescence and flow cytometry. RNA expression was evaluated by RT-qPCR. A scrape loading/dye transfer assay was used to evaluate cell communication. Cell senescence was analysed by flow cytometry or by light microscopy using β-galactosidase assay. Results: Cx43 and GJs overactivities were correlated with the progression of OA, by promoting chronic cell dedifferentiation and senescence in vitro assays. We found that Cx43 overexpression activates factors involved in epithelial-to-mesenchymal transition, such as Twist-1. Increased levels of dedifferentiated cells, with high rates of cell proliferation, led to cell senescence via p53/p16 INK4a , activating the senescence-associated secretory phenotype (SASP) and promoting the synthesis and liberation of inflammatory factors, including the interleukin-6 (IL-6). Cx43 downregulation by using small molecules, such as oleuropein, or by genetic edition with CRISPR technology, led to the chondrocyte redifferentiation and an improved phenotype, with increased synthesis of extracellular matrix proteins such as Col2A1 and downregulating the synthesis of MMPs, inflammation and senescence. Conclusions: Downregulation of Cx43 in OA chondrocytes restores regeneration by activating chondrocyte re-differentiation and decreasing cellular senescence. These results corroborate the use of Cx43 as an effective therapeutic target in order to restore cartilage regeneration and avoid OA progression.

Signo de digito-presión en pacientes con osteoartritis de rodilla

“…La osteoartritis (OA) de rodilla se define como una enfermedad articular crónica de tipo degenerativo caracterizada por un componente inflamatorio, elongación de la cápsula articular con cambios en los tejidos blandos periarticulares, aumento de la remodelación ósea, pérdida progresiva de cartílago hialino y del hueso subcondral hasta la aparición de lesiones condrales, así como daño en el tejido sinovial, formación de osteofitos y envejecimiento de la matriz por causa de la senescencia de los condrocitos, secundario a productos de glicación avanzada. 1,2,3,4,5 Se estima que 302 millones de personas en el mundo son afectadas por la osteoartritis, de las cuales entre 6 y 60% corresponden a osteoartritis de rodilla; en Estados Unidos la cifra llega a los 14 millones y en México destaca una prevalencia de 10.5%. La Encuesta Nacional de Salud 2021 refiere que 1.4% de la población mexicana utiliza los servicios de salud pública por problemas articulares.…”