Hyperlipidemia in tendon injury: chronicles of low-density lipoproteins

Hyperlipidemia impacts millions of people globally and has been the major risk factor for developing atherosclerosis and cardiovascular disease. Interestingly, hyperlipidemic subjects exhibit increased incidence of rotator cuff tendon injury (RCTI) and disorganization of tendon matrix. Low-density lipoproteins (LDL) and its oxidized form (ox-LDL) play a crucial role in hyperlipidemia-driven pro-inflammatory responses in multiple tissues including the tendon. The signaling of oxLDL upregulates the inflammatory cytokines, chemokines, adhesion molecules, and the activation of monocytes/macrophages/resident tendon cells and matrix metalloproteinases impairing the tendon homeostasis resulting in the alteration of extracellular matrix. In addition, the hyperlipidemia-driven immune response and subsequent oxidative stress promote degenerative responses in the tendon tissue. However, the pathological mechanisms underlying the occurrence of RCTI in hyperlipidemia and the effect of ox-LDL in tendon matrix are currently unknown. The present review focuses on the implications and perspectives of LDL/oxLDL on the increased incidence of RCTI.

Automated summary

Hyperlipidemia is a major risk factor for developing atherosclerosis and cardiovascular disease, and it also contributes to an increased incidence of rotator cuff tendon injury (RCTI). Low-density lipoproteins (LDL) and its oxidized form (ox-LDL) play a crucial role in promoting pro-inflammatory responses in the tendon, leading to tendon matrix disorganization. The exact mechanisms underlying RCTI in hyperlipidemia and the effects of ox-LDL on tendon matrix are currently unknown. This review focuses on the implications and future perspectives of LDL/oxLDL in the increased incidence of RCTI.