Extracellular Matrix Protection Factor Increases Sulfated Proteoglycan Production in Serum‐free, Primary Cultures of Human Osteoarthritic Chondrocytes

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Osteoarthritis (OA) is a common chronic condition which involves the loss of articular cartilage, the cushion between joints that provides a smooth surface for the bones to glide. Three compounds that make up most of the articular cartilage are type II collagen, proteoglycans, and water. In OA there is an increase in collagenase activity that degrades collagens and proteoglycans necessary for healthy cartilage. The composition of the extracellular matrix changes in OA as evidenced by production of type I collagen. Previous studies in our lab have shown that primary cultures of human osteoarthritic chondrocytes (HOACs) can be reared in serum‐free alginate culture but measurable extracellular matrix endpoints of the OA profile are dampened when chondrocytes isolated from sides of greater and least pathology in the joint are pooled together in culture. In this study, we obtained HOACs from patients undergoing total knee arthroplasty. Femoral condyles and the tibial plateau were labeled greater or least pathology, determined by gross anatomical observation, the cells were isolated and plated separately in three‐dimensional, twelve‐well, alginate cultures at a density of 1.8 × 106 cells per 0.5 mL. Samples were treated for 48 hours from day of plating with either 250nM Extracellular Matrix Protective Factor‐1 (ECPF‐1) or hyaluronic acid conjugated ECPF‐1 (HA‐ECPF‐1). Collagen I degradation and sulfated proteoglycan synthesis were measured in alginate‐associated matrix of the treated cultures. HOACs isolated from the side of greatest pathology responded to treatment by reducing collagen type I degradation (8.42ng/culture Control, 7.25ng/culture ECPF‐1 and 4.25ng/culture HA‐ECPF‐1) and increasing retention of sulfated proteoglycans in the extracellular matrix (0.36ug/culture Control versus 0.56ug/culture ECPF‐1 treated). These data confirm that 48 hour treatment in serum free HOAC culture is sufficient to measure the therapeutic efficacy of an OA drug intervention and that both formulations of ECPF‐1 can slow the progression of OA by altering production of sulfated proteoglycan and collagen type I.Support or Funding InformationThis work was supported in part by a grant from the New Jersey Health Foundation and Philadelphia College of Osteopathic Medicine's Center for Chronic Disorders of Aging and the Division of Research.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.