Tendon stem/progenitor cells regulate inflammation in tendon healing via JNK and STAT3 signaling [Research]

Tendon stem/progenitor cells (TSCs) have been found in different anatomic locations and showed a promising regenerative potential. We identified a role of TSCs in the regulation of inflammation during healing of acute tendon injuries. Delivery of connective tissue growth factor (CTGF) into full-transected rat patellar tendons significantly increased the number of CD146+ TSCs, leading to enhanced healing. In parallel, CTGF delivery significantly reduced the number of iNOS+ M1 macrophages and increased the expression of anti-inflammatory IL-10 at 2 d after surgery, with over 85% CD146+ TSCs expressing IL-10. By 1 wk, the elevated IL-10 expression remained, and IL-6 expression was significantly attenuated in CTGF-delivered tendon healing. Matrix metalloproteinase (MMP)-3 expression in CTGF-delivered tendon was organized along with the reorienting collagen fibers by 1 wk after surgery, in comparison with the control group showing the abundant MMP-3 expression localized at healing junction. Tissue inhibitor of metalloprotease (TIMP)-3 was expressed in CD146+ TSCs at 1 wk with CTGF, in contrast to control with no TIMP-3 expression. In vitro, IL-10 expression was detected only when tendon cells were stimulated with IL-1β, and CTGF and significantly higher in CD146+ TSCs than CD146– tendon cells. Similarly, TIMP-3 expression was detected only when treated with CTGF or CTGF and IL-1β that is significantly higher in CD146+ TSCs compared to CD146– tendon cells. Sig...

Source: FASEB Journal - August 31, 2017 Category: Biology Authors: Tarafder, S., Chen, E., Jun, Y., Kao, K., Sim, K. H., Back, J., Lee, F. Y., Lee, C. H. Tags: Research Source Type: research