Detrimental effects of discectomy on intervertebral disc biology can be decelerated by growth factor treatment during surgery: a large animal organ culture model

Abstract

BACKGROUND CONTEXT Lumbar discectomies are common surgical interventions that treat radiculopathy by removing herniated and loose intervertebral disc (IVD) tissues. However, remaining IVD tissue can continue to degenerate resulting in long-term clinical problems. Little information is available on the effects of discectomy on IVD biology. Currently no treatments exist that can suspend or reverse the degeneration of the remaining IVD. PURPOSE To improve knowledge how discectomy procedures influence IVD physiology and to assess the potential of growth-factor treatment as an augmentation during surgery STUDY DESIGN To determine effects of discectomy on IVDs with and without TGFβ3 augmentation using bovine IVD organ culture. METHODS This study determined effects of discectomy with and without TGFβ3 injection using 1, 6, and 19 days organ culture experiments. Treated IVDs were injected with 0.2μg TGFβ3 in 20μl PBS+BSA into several locations of the discectomy site. Cell viability, gene expression, nitric-oxide release, IVD height, aggrecan degradation, and proteoglycan content were determined. RESULTS Discectomy significantly increased cell death, aggrecan degradation and nitric-oxide release in healthy IVDs. TGFβ3 injection treatment prevented or mitigated those effects for the 19 days culture period. CONCLUSIONS Discectomy procedures induced cell death, catabolism and nitric-oxide production in healthy IVDs, and we conclude that post-discectomy degeneration is likely to be associated with cell death and matrix degradation. TGFβ3 injection augmented discectomy procedures by acting to protect IVD tissues by maintaining cell viability, limiting matrix degradation and suppressing nitric-oxide. We conclude that discectomy procedures can be improved with injectable therapies at the time of surgery although further in vivo and human studies are required.

Changes and significance of inflammatory cytokines in a rat model of cervical spondylosis

“…TGF-β has been reported to increase proteoglycan production to adjust the proliferation of type II collagen intervertebral disk cells and reduce matrix degradation to thereby regulate the metabolism of intervertebral disc cells (33,34). While certain studies found that proteoglycan production in nucleus pulposus cells was increased through gene therapy with TGF-β, it is inferred that TGF-β is a protective cytokine in the intervertebral disc (35)(36)(37). In the present study, an increasing trend of TGF-β1 at 1 month post-operation was identified, while it had significantly decreased at 3 months.…”

Mast Cell/Proteinase Activated Receptor 2 (PAR2) Mediated Interactions in the Pathogenesis of Discogenic Back Pain

“…As a preliminary proof of concept study to assess the potential therapeutic effects of a PAR2 antagonist on MC-induced IVD degeneration, we chose to use a bovine ex vivo organ model which has been utilized previously as a model of IVD degeneration and to screen therapeutics (Purmessur et al, 2013b; Illien-Jünger et al, 2014; Grant et al, 2016). Treatment of IVD organ culture samples with PAR2A had no detectable impact on viability for AF as demonstrated by MTT staining co-localized with DNA stain Hoechst (Figure 5B).…”

“…Isolated samples were washed in 70% EtOH and PBS before being treated with isolation (Prime Growth 319-511-EL) and neutralizing solution (Prime Growth 319-512-CL) and then culture in Wisent Prime Growth Media (Prime Growth 319-510-CL) + 1% P/S for 24 h at 37°C 5% CO 2 20% O 2 according to Wisent protocol as outlined prior (Grant et al, 2016). Injury was induced for relevant samples via an “X” cut through the AF region and partial NP removal (Illien-Jünger et al, 2014). After 10 days, samples were split into the following groups: (1) control with no injury or treatment, (2) injury+MCCM, or (3) injury+MCCM+100 nM PAR2A.…”

“…After 10 days, samples were split into the following groups: (1) control with no injury or treatment, (2) injury+MCCM, or (3) injury+MCCM+100 nM PAR2A. 10 μL of 100 nM PAR2A (FSLLRY-NH 2 ) in PBS was injected with a high-precision 25G syringe (Hamilton; Reno, NV, United States) into the relevant bovine IVDs (Illien-Jünger et al, 2014). IVDs were cultured for 96 h and then tissue isolated for histology, cell viability and qRT-PCR.…”

TGF-β signaling in intervertebral disc health and disease

“…It has been reported that TGF-b1 can upregulate the AFCs proliferation, and have synergic effects with some growth factors on cell proliferation, including insulin-like growth factor-I (IGF-I) and fibroblast growth factor-2 (FGF-2) 80,81 . In rat NPCs, exogenous administration of TGF- Apart from the promotion of cell proliferation, TGF-b signaling can delay IVD degeneration by mitigating cell death in the IVD 76,84 . Apoptosis and autophagy have been confirmed to play a key role in the progression of IVD degeneration 85 .…”