Correlation of Early Outcomes and Intradiscal Interleukin-6 Expression in Lumbar Fusion Patients.

OBJECTIVE: To determine if there is correlation between intradiscal levels of interleukin-6 (IL-6) and early outcome measures in patients undergoing lumbar fusion for painful disc degeneration. METHODS: Intervertebral disc tissue was separated into annulus fibrosus/nucleus pulposus and cultured separately in vitro in serum-free medium (Opti-MEM). Conditioned media was collected after 48 hours. The concentration of IL-6 was quantified using enzyme-linked immunosorbent assay. Pearson correlation coefficients quantified relationships between IL-6 levels and pre- and postoperative visual analogue scale (VAS) back pain and Oswestry Disability Index (ODI), as well as change in VAS/ODI. RESULTS: Sixteen discs were harvested from 9 patients undergoing anterior lumbar interbody fusion (mean age, 47.4 years; range, 21-70 years). Mean preoperative and 6-month postoperative VAS were 8.1 and 3.7, respectively. Mean preoperative and postoperative ODI were 56.2 and 25.6, respectively. There were significant positive correlations between IL-6 expression and postoperative VAS (ρ = 0.38, p = 0.048) and ODI (ρ = 0.44, p = 0.02). No significant correlations were found between intradiscal IL-6 expression and preoperative VAS (ρ = -0.12, p = 0.54). Trends were seen associating IL-6 expression and change in VAS/ODI (ρ = -0.35 p = 0.067; ρ = -0.34, p = 0.08, respectively). A trend associated IL-6 and preoperative ODI (ρ = 0.36, p = 0.063). CONCLUSION: The direct association between IL-6 expression and VAS/ODI suggests patients with elevated intradiscal cytokine expression may have worse early outcomes than those with lower expression of IL-6 after surgery for symptomatic disc degeneration

An organ culture system to model early degenerative changes of the intervertebral disc

ABSTRACT: INTRODUCTION: Back pain, a significant source of morbidity in our society, is related to the degenerative changes of the intervertebral disc. At present, the treatment of disc disease consists of therapies that are aimed at symptomatic relief. This shortcoming stems in large part from our lack of understanding of the biochemical and molecular events that drive the disease process. The goal of this study is to develop a model of early disc degeneration using an organ culture. This approach is based on our previous studies that indicate that organ culture closely models molecular events that occur in vivo in an ex vivo setting. METHODS: To mimic a degenerative insult, discs were cultured under low oxygen tension in the presence of TNF-α, IL-1β and serum limiting conditions. RESULTS: Treatment resulted in compromised cell survival and changes in cellular morphology reminiscent of degeneration. There was strong suppression in the expression of matrix proteins including collagen types 1, 2, 6 and 9, proteoglycans, aggrecan and fibromodulin. Moreover, a strong induction in expression of catabolic matrix metalloproteinases (MMP) 3, 9 and 13 with a concomitant increase in aggrecan degradation was seen. An inductive effect on NGF expression was also noticed. Although similar, nucleus pulposus and annulus fibrosus tissues showed some differences in their response to the treatment. CONCLUSIONS: Results of this study show that perturbations in microenvironmental factors result in anatomical and gene expression change within the intervertebral disc that may ultimately compromise cell function and induce pathological deficits. This system would be a valuable screening tool to investigate interventional strategies aimed at restoring disc cell function

Inhibition of Neurogenic Inflammatory Pathways Associated with the Reduction in Discogenic Back Pain

Study Design Retrospective cohort study. Purpose This study aimed to determine whether the initiation of anti-calcitonin gene-related peptide (CGRP inhibitor) medication therapy for migraines was also associated with improvements in back/neck pain, mobility, and function in a patient population with comorbid degenerative spinal disease and migraine. Overview of Literature CGRP upregulates pro-inflammatory cytokines such as tumor necrosis factor-α, interleukin-6, brain-derived neurotrophic factor, and nerve growth factor in spinal spondylotic disease, which results in disc degeneration and sensitization of nociceptive neurons. Although CGRP inhibitors can quell neurogenic inflammation in migraines, their off-site efficacy as a therapeutic target for discogenic back/neck pain conditions remains unknown. Methods All adult patients diagnosed with spinal spondylosis and migraine treated with CGRP inhibitors at a single academic institution between 2017 and 2020 were retrospectively identified. Patient demographic and medical data, follow-up duration, migraine severity and frequency, spinal pain, functional status, and mobility before and after the administration of CGRP inhibitors were collected. Paired univariate analysis was conducted to determine significant changes in spinal pain, headache severity, and headache frequency before and after the administration of CGRP inhibitors. The correlation between changes in the spinal pain score and functional or mobility improvement was assessed with Spearman’s rho. Results In total, 56 patients were included. The mean follow-up time after the administration of CGRP inhibitors was 123 days for spinal pain visits and 129 days for migraine visits. Back/neck pain decreased significantly (p<0.001) from 6.30 to 4.36 after starting CGRP inhibitor therapy for migraine control. As recorded in the spine follow-up notes, 25% of patients experienced a functional improvement in the activities of daily living, and 17.5% experienced mobility improvement while taking CGRP inhibitors. Change in back/neck pain moderately correlated (ρ=−0.430) with functional improvement but was not correlated with mobility improvement (ρ=−0.052). Conclusions Patients taking CGRP inhibitors for chronic migraines with comorbid degenerative spinal conditions experienced significant off-target reduction of back/neck pain

Does Riluzole Influence Bone Formation? : An In Vitro Study of Human Mesenchymal Stromal Cells and Osteoblast

STUDY DESIGN: A post-test design biological experiment. OBJECTIVE: The aim of this study was to evaluate the osteogenic effects of riluzole on human mesenchymal stromal cells and osteoblasts. SUMMARY OF BACKGROUND DATA: Riluzole may benefit patients with spinal cord injury (SCI) from a neurologic perspective, but little is known about riluzole's effect on bone formation, fracture healing, or osteogenesis. METHODS: Human mesenchymal stromal cells (hMSCs) and human osteoblasts (hOB) were obtained and isolated from healthy donors and cultured. The cells were treated with riluzole of different concentrations (50, 150, 450 ng/mL) for 1, 2, 3, and 4 weeks. Cytotoxicity was evaluated as was the induction of osteogenic differentiation of hMSCs. Differentiation was evaluated by measuring alkaline phosphatase (ALP) activity and with Alizarin red staining. Osteogenic gene expression of type I collagen (Col1), ALP, osteocalcin (Ocn), Runx2, Sox9, Runx2/Sox9 ratio were measured by qRT-PCR. RESULTS: No cytotoxicity or increased proliferation was observed in bone marrow derived hMSCs and primary hOBs cultured with riluzole over 7 days. ALP activity was slightly increased in hMSCs after treatment for 2 weeks with riluzole 150 ng/mL and slightly upregulated by 150% (150 ng/mL) and 90% (450 ng/mL) in hMSCs at 3 weeks. In hOBs, ALP activity almost doubled after 2 weeks of culture with riluzole 150 ng/mL (P < 0.05). More pronounced 2.6-fold upregulation was noticed after 3 weeks of culture with riluzole at both 150 ng/mL (P = 0.05) and 450 ng/mL (P = 0.05). No significant influence of riluzole on the mRNA expression of osteocalcin (OCN) was observed. CONCLUSION: The effect of riluzole on bone formation is mixed; low-dose riluzole has no effect on the viability or function of either hMSCs or hOBs. The activity of ALP in both cell types is upregulated by high-dose riluzole, which may indicate that high-dose riluzole can increase osteogenic metabolism and subsequently accelerate bone healing process. However, at high concentrations, riluzole leads to a decrease in osteogenic gene expression, including Runx2 and type 1 collagen. LEVEL OF EVIDENCE: N/A

Does Riluzole Influence Bone Formation? : An In Vitro Study of Human Mesenchymal Stromal Cells and Osteoblast

STUDY DESIGN: A post-test design biological experiment. OBJECTIVE: The aim of this study was to evaluate the osteogenic effects of riluzole on human mesenchymal stromal cells and osteoblasts. SUMMARY OF BACKGROUND DATA: Riluzole may benefit patients with spinal cord injury (SCI) from a neurologic perspective, but little is known about riluzole's effect on bone formation, fracture healing, or osteogenesis. METHODS: Human mesenchymal stromal cells (hMSCs) and human osteoblasts (hOB) were obtained and isolated from healthy donors and cultured. The cells were treated with riluzole of different concentrations (50, 150, 450 ng/mL) for 1, 2, 3, and 4 weeks. Cytotoxicity was evaluated as was the induction of osteogenic differentiation of hMSCs. Differentiation was evaluated by measuring alkaline phosphatase (ALP) activity and with Alizarin red staining. Osteogenic gene expression of type I collagen (Col1), ALP, osteocalcin (Ocn), Runx2, Sox9, Runx2/Sox9 ratio were measured by qRT-PCR. RESULTS: No cytotoxicity or increased proliferation was observed in bone marrow derived hMSCs and primary hOBs cultured with riluzole over 7 days. ALP activity was slightly increased in hMSCs after treatment for 2 weeks with riluzole 150 ng/mL and slightly upregulated by 150% (150 ng/mL) and 90% (450 ng/mL) in hMSCs at 3 weeks. In hOBs, ALP activity almost doubled after 2 weeks of culture with riluzole 150 ng/mL (P < 0.05). More pronounced 2.6-fold upregulation was noticed after 3 weeks of culture with riluzole at both 150 ng/mL (P = 0.05) and 450 ng/mL (P = 0.05). No significant influence of riluzole on the mRNA expression of osteocalcin (OCN) was observed. CONCLUSION: The effect of riluzole on bone formation is mixed; low-dose riluzole has no effect on the viability or function of either hMSCs or hOBs. The activity of ALP in both cell types is upregulated by high-dose riluzole, which may indicate that high-dose riluzole can increase osteogenic metabolism and subsequently accelerate bone healing process. However, at high concentrations, riluzole leads to a decrease in osteogenic gene expression, including Runx2 and type 1 collagen. LEVEL OF EVIDENCE: N/A

Does Riluzole Influence Bone Formation? An in vitro Study of Human Mesenchymal Stromal Cells and Osteoblast.

STUDY DESIGN: A post-test design biological experiment. OBJECTIVE: To evaluate the osteogenic effects of riluzole on human mesenchymal stromal cells and osteoblasts. SUMMARY OF BACKGROUND DATA: Riluzole may benefit patients with SCI from a neurologic perspective but little is known about riluzole\u27s effect on bone formation, fracture healing, or osteogenesis. METHODS: Human mesenchymal stromal cells (hMSCs)and osteoblasts (hOB) were obtained and isolated from healthy donors and cultured. The cells were treated with riluzole of different concentrations (50,150,450 ng/ml) for 1,2,3, and 4 weeks. Cytotoxicity was evaluated as was the induction of osteogenic differentiation of hMSCs. Differentiation was evaluated by measuring alkaline phosphatase (ALP) activity and with Alizarin red staining. Osteogenic gene expression of type I collagen(Col1), ALP, osteocalcin (Ocn), Runx2, Sox9, Runx2/Sox9 ratio were measured by qRT-PCR. RESULTS: No cytotoxicity or increased proliferation were observed in bone marrow derived hMSCs and primary hOBs cultured with riluzole over 7 days. ALP activity was slightly increased in hMSCs after treatment for 2 weeks with riluzole 150 ng/ml; and slightly up-regulated by 150% (150 ng/ml) and 90% (450 ng/ml) in hMSCs at 3 weeks. In hOBs, ALP activity almost doubled after 2 weeks of culture with riluzole 150 ng/ml (p \u3c 0.05). More pronounced 2.6-fold upregulation was noticed after 3 weeks of culture with riluzole at both 150 ng/ml (p = 0.05) and 450 ng/ml (p = 0.05). No significant influence of riluzole on the mRNA expression of osteocalcin (OCN) was observed. CONCLUSIONS: The effect of riluzole on bone formation is mixed; low dose riluzole has no effect on the viability or function of either hMSCs or hOBs. The activity of ALP in both cell types is upregulated by high dose riluzole, which may indicate that high dose riluzole can increase osteogenic metabolism and subsequently accelerate bone healing process. However, at high concentrations, riluzole leads to a decrease in osteogenic gene expression including Runx2 and type 1 collagen. LEVEL OF EVIDENCE: N/A