Matrilin‐3 codelivery with adipose‐derived mesenchymal stem cells promotes articular cartilage regeneration in a rat osteochondral defect model. (2nd October 2017) - Muttigi, Manjunatha S.
Abstract: Matrilin‐3 is an essential extracellular matrix component present only in cartilaginous tissues. Matrilin‐3 exerts chondroprotective effects by regulating an anti‐inflammatory function and extracellular matrix components. We hypothesized that the codelivery of matrilin‐3 with infrapatellar adipose‐tissue‐derived mesenchymal stem cells (Ad‐MSCs) may enhance articular cartilage regeneration. Matrilin‐3 treatment of Ad‐MSCs in serum‐free media induced collagen II and aggrecan expression, and matrilin‐3 in chondrogenic media also enhanced in vitro chondrogenic differentiation. Next, the in vivo effect of matrilin‐3 codelivery with Ad‐MSCs on cartilage regeneration was assessed in an osteochondral defect model in Sprague Dawley rats: Ad‐MSCs and hyaluronic acid were implanted at the defect site with or without matrilin‐3 (140, 280, and 700 ng). Safranin O staining revealed that matrilin‐3 (140 and 280 ng) treatment significantly improved cartilage regeneration and glycosaminoglycan accumulation. In the animals treated with 140‐ng matrilin‐3, in particular, the defect site exhibited complete integration with surrounding tissue and a smooth glistening surface. The International Cartilage Repair Society macroscopic and O'Driscoll microscopic scores for regenerated cartilage were furthermore shown to be considerably higher for this group (matrilin‐3; 140 ng) compared with the other groups. Furthermore, the defects treated with 140‐ng matrilin‐3 revealed significant hyaline‐like cartilage regeneration in the osteochondral defect model; in contrast, the defects treated with 700‐ng matrilin‐3 exhibited drastically reduced cartilage regeneration with mixed hyaline–fibrocartilage morphology. Codelivery of matrilin‐3 with Ad‐MSCs significantly influenced articular cartilage regeneration, supporting the potential use of this tissue‐specific protein for a cartilage‐targeted stem cell therapy.