AGC

Interleukin-ip (IL1P), Tumor Necrosis Factor alpha (TNF-a) and Interleukin-6 (IL6) are pro-inflammatory cytokines involved in the pathophysiology of OA, inducing overexpression of metalloproteinases (MMPs) and decrease synthesis of macromolecules, including aggrecan (POREE et al., 2008; KAPOOR et al., 2011).

Specifically, Parkinson and colleagues found increased levels of proteoglycans such as aggrecan in the tendon samples from patients that were used in this study (Parkinson et al., 2011).

Cartilage consists of a relatively small amount of chondrocytes embedded in abundant ECM, which contains numerous macromolecules, especially collagen fibrils and the large aggregating proteoglycan aggrecan (18).

Using these assays, we identified a donor, whose SFMSCs were similar to the BMMSCs in their proliferation and expression of CD29, CD44, and CD90 but exhibited a significantly higher chondrogenic potential based on the increased expression of aggrecan and type II collagen proteins [16].

With the advent of more sophisticated chromosomal testing techniques, including whole exome sequencing (WES), additional etiologies of ISS are being identified, most notably mutations in aggrecan (ACAN) and NPR2 genes [2, 3].

Chondroitin sulfate proteoglycans (CSPGs), including the lecticans aggrecan, versican, neurocan, and brevican, are joined to the hyaluronic acid polymer through "link" proteins including cartilage link protein (Crtl1).

It is also known for influencing fibril formation for collagens type I and II, accelerating fibrillogenesis and binding to aggrecan, mediating the organization of cartilage matrix for its load bearing function.

The density of aggrecan molecules is decreased with a resultant increase in cartilage water content.

(7) In trigger finger tendons, collagen type 1A1 and 3A1, aggrecan, and biglycan are up-regulated, while metalloproteinase inhibitor 3 (TIMP-3) and matrix metallopeptidase (3) (MMP-3) are down-regulated, a situation also described in Achilles tendinosis.

(20) The most abundant PG in articular cartilage and the ECM is aggrecan which is composed of a core protein, hyaluronan (HA), and several side chains of GAGs.