The mTOR pathway is involved in the process of platelet-rich plasma improving intervertebral disc degeneration

Platelet-rich plasma (PRP) contains multiple growth hormones that may stimulate tissue repair. We aimed to assess PRP’s efficacy and explore possible mechanisms using the intervertebral disc degeneration (IDD) model. 

A total of 48 male Sprague-Dawley (SD) rats were randomly divided into three groups: sham, IDD+PBS, and IDD+PRP (n=16, respectively). IL-1β (10 ng/ml) was used to establish a humanized IDD model in human lumbar nucleus pulposus (NP) tissues from 36 patients with degenerative disc disease. These NP cells were randomly divided into three groups: sham, IDD+PBS, and IDD+PRP (n=12, respectively). RT-PCR and western blot were used to detect the expression of aggrecan, collagen II, IL-1β, IL-6, TNF-α, Bcl-2, cleaved-Caspase 3, Bax and Akt/mTOR/p70S6K signaling pathway. A related assay kit was used to detect MDA, SOD, and GSH.

PRP affected the expression of aggrecan, collagen II, IL-1β, IL-6, TNF-α, MDA, SOD, GSH, Bcl-2, cleaved-Caspase 3, and Bax in IDD rats. Compared with the IDD+PBS group, the expression of p-mTOR, p-p70/S6K, and p-Akt was much lower in the rat IDD+PRP group (P<0.05). Similarly, with PRP treatment in the humanized IDD model, the expression of p-mTOR, p-p70/S6K, and p-Akt was also inhibited.

PRP may be a potential therapy for IDD via the mTOR signaling pathway in regulating and affecting extracellular matrix degradation, inflammatory factors, oxidative stress, and apoptosis.