Pathological alterations in the expression status of rotator cuff tendon matrix components in hyperlipidemia

Hyperlipidemia is an important risk factor in the development and progression of tendon pathology, however its role in aggravating rotator cuff tendon injury (RCTI) is largely unknown. We aimed to assess the expression status of key extracellular matrix (ECM) components in the tendon tissues and tenocytes under hyperlipidemia. Shoulder rotator cuff (RC) tendon tissues harvested from the swine model of hyperlipidemia displayed alterations in histomorphometry and the expression status of major ECM component proteins including COL-I, COL-III, COL-IV, COL-V, COL-VI, MMP2, and MMP9. Similarly, the LDL- and oxLDL-challenged tenocytes displayed altered expression of the same proteins at both transcriptional and translational levels. In addition, the lipid uptake and cellular reactive oxygen radicals predominated in the lipid-challenged tenocytes compared to the control. Overall, the LDL-treated cells displayed predominant pathological alterations compared to the ox-LDL-treated cells. Further understanding regarding the underlying molecular mechanisms driving the tendon matrisome alteration and subsequent aggravated RCTI pathology in hyperlipidemia could open novel translational avenues in the management of RCTI.