Probing potential mechanisms of collagen crimp formation during embryonic tendon development.

摘要

Tendons are dense connective tissues that are responsible for transmitting muscle mechanical forces to bone. The primary component of the tendon ECM is collagen type I, which gives the tendon its strength and elasticity. The collagen is made up of fibers that run parallel to the long axis of the tendon and exhibit a crimped (wavy) morphology. This crimped morphology is responsible for the non-linear portion of the tendon's stress-strain curve. Intrinsic factors such as age and site location and extrinsic factors like exercise and injury can cause changes to the collagen fiber crimp morphology, in turn leading to disrupted function and increased risk of rupture. Tendon tissue engineering and regeneration strategies do not reliably create the distinctive collagen crimp critical for tendon function, likely due to a lack of knowledge about the mechanisms of its formation during normal tissue development. This motivated our current study to understand how collagen fiber crimp forms during embryonic tendon development. This work first focuses on trying to characterize changes in the collagen fiber crimp morphology during early stages of embryonic chick tendon. Next, the work shifts to observing how the cell contractile machinery through the actin cytoskeletal network may play a role in collagen fiber crimp formation.