Increased Expression of Inflammatory Cytokines and Discogenic Neck Pain

TIGAR attenuates intervertebral disc degeneration via autophagy-mediated Keap1 degradation and Nrf2 nuclear translocation to suppress nucleus pulposus pyroptosis

Pyroptosis plays a pivotal role in intervertebral disc degeneration (IVDD) driven by oxidative-inflammatory cascades, inducing nucleus pulposus (NP) cell lysis through gasdermin-mediated pore formation and subsequent release of proinflammatory cytokines, including IL-1β and IL-18. TP53-induced glycolysis and apoptosis regulator (TIGAR) alleviates oxidative stress by scavenging reactive oxygen species (ROS); however, its involvement in the autophagy-pyroptosis axis mediating IVDD remains unclear. In this study, we aimed to investigate how TIGAR delays IVDD progression via the autophagy-pyroptosis axis. First, we discovered from the NP tissues collected from patients undergoing lumbar spine surgeries and mice with needle puncture-induced models that the expression of TIGAR was reduced in severely degenerated tissues. In the IL-1β-induced human NP cell, TIGAR knockdown exacerbated the degradation of the extracellular matrix and pyroptosis, whereas TIGAR overexpression reversed this phenomenon. Ultrastructural analysis via transmission electron microscopy (TEM) and autophagic flux quantification revealed TIGAR-mediated autophagy in NP cells under inflammatory conditions. Co-immunoprecipitation assays validated the formation of a Keap1-p62-ubiquitin ternary complex, which directed Keap1 toward lysosome-dependent degradation and enhanced Nrf2 nuclear translocation. Therapeutic intradiscal delivery of AAV-TIGAR attenuated IVDD progression in mouse models, evidenced by preserved disc height index and reduced histopathological scores. Collectively, this work identified TIGAR as a redox-sensitive molecular switch that mitigated oxidative stress and inflammasome-driven pyroptosis through Keap1 autophagic clearance, offering a novel therapeutic paradigm for precision-targeted IVDD intervention.

Risk factors for poor neurological recovery after anterior cervical discectomy and fusion: imaging characteristics

BACKGROUND

Poor neurological recovery in patients after anterior cervical discectomy and fusion has been frequently reported; however, no study has analyzed the preoperative imaging characteristics of patients to investigate the factors affecting surgical prognosis. The purpose of this study was to investigate the factors that affect the preoperative imaging characteristics of patients and their influence on poor neurologic recovery after anterior cervical discectomy and fusion.

METHODS

We retrospectively analyzed the clinical data of 89 patients who met the criteria for anterior cervical discectomy and fusion for the treatment of single-level cervical spondylotic myelopathy and evaluated the patients' neurological recovery based on the recovery rate of the Japanese Orthopaedic Association (JOA) scores at the time of the final follow-up visit. Patients were categorized into the "good" and "poor" groups based on the JOA recovery rates of ≥ 50% and < 50%, respectively. Clinical information (age, gender, body mass index, duration of symptoms, preoperative JOA score, and JOA score at the final follow-up) and imaging characteristics (cervical kyphosis, cervical instability, ossification of the posterior longitudinal ligament (OPLL), calcification of herniated intervertebral discs, increased signal intensity (ISI) of the spinal cord on T2-weighted imaging (T2WI), and degree of degeneration of the discs adjacent to the fused levels (cranial and caudal) were collected from the patients. Univariate and binary logistic regression analyses were performed to identify risk factors for poor neurologic recovery.

RESULTS

The mean age of the patients was 52.56 ± 11.18 years, and the mean follow-up was 26.89 ± 11.14 months. Twenty patients (22.5%) had poor neurological recovery. Univariate analysis showed that significant predictors of poor neurological recovery were age (p = 0.019), concomitant OPLL (p = 0.019), concomitant calcification of herniated intervertebral discs (p = 0.019), ISI of the spinal cord on T2WI (p <0.05), a high grade of degeneration of the discs of the cranial neighboring levels (p <0.05), and a high grade of discs of the caudal neighboring levels (p <0.05). Binary logistic regression analysis showed that ISI of the spinal cord on T2WI (p = 0.001 OR = 24.947) and high degree of degeneration of adjacent discs on the cranial side (p = 0.040 OR = 6.260) were independent risk factors for poor neurological prognosis.

CONCLUSION

ISI of the spinal cord on T2WI and high degree of cranial adjacent disc degeneration are independent risk factors for poor neurological recovery after anterior cervical discectomy and fusion. A comprehensive analysis of the patients' preoperative imaging characteristics can help in the development of surgical protocols and the management of patients' surgical expectations.

Clinical and Radiological Outcomes of Cervical Disc Arthroplasty in Patients with Modic Change

OBJECTIVE

Modic change (MC) is defined as abnormalities observed in the intervertebral disc subchondral and adjacent vertebral endplate subchondral bone changes. Most studies on MC were reported in the lumbar spine and associated with lower back pain. However, MC has been rarely reported in the cervical spine, let alone in those who underwent cervical disc replacement (CDR). This study aimed to focus on MC in the cervical spine and reveal clinical and radiological parameters, especially heterotopic ossification (HO), for patients who underwent CDR. Furthermore, we illustrated the association between MC and HO.

METHODS

We retrospectively reviewed patients who underwent CDA from January 2008 to December 2019. The Japanese Orthopaedic Association (JOA), Neck Disability Index (NDI), and Visual Analog Scale (VAS) scores were used to evaluate the clinical outcomes. Radiological evaluations were used to conclude the cervical alignment (CL) and range of motion (ROM) of C2-7, functional spinal unit angle (FSUA), shell angle (SA), FSU height, and HO. Univariate and multivariate logistic regressions were performed to identify the risk factors for HO. The Kaplan-Meier (K-M) method was used to analyze potential risk factors, and multivariate Cox regression was used to identify independent risk factors.

RESULTS

A total of 139 patients were evaluated, with a mean follow-up time of 46.53 ± 26.60 months. Forty-nine patients were assigned to the MC group and 90 to the non-MC group. The incidence of MC was 35.3%, with type 2 being the most common. Clinical outcomes (JOA, NDI, VAS) showed no significant difference between the two groups. The differences in C2-7 ROM between the two groups were not significant, while the differences in SA ROM and FSUA ROM were significantly higher in the non-MC than in the MC group (p < 0.05). Besides, FSU height in MC group was significantly lower than that in non-MC group. Parameters concerning CL, including C2-7, FSUA, SA, were not significantly different between the two groups. The incidence of HO and high-grade HO, respectively, in the MC group was 83.7% and 30.6%, while that in the non-MC group was 53.3% and 2.2%, and such differences were significant (p < 0.05). Multivariate logistic regression analyses and Cox regression showed that MC and involved level were significantly associated with HO occurrence (p < 0.05). No implant migration and secondary surgery were observed.

CONCLUSION

MC mainly affected the incidence of HO. Preoperative MC was significantly associated with HO formation after CDR and should be identified as a potential risk factor for HO. Rigorous criteria for MC should be taken into consideration when selecting appropriate candidates for CDR.

Short-Term Effects of Two COX-2 Selective Non-Steroidal Anti-Inflammatory Drugs on the Release of Growth Factors and Cytokines from Canine Platelet-Rich Gel Supernatants

(1) Background: There is a lack of knowledge about how a single dose of COX-2 selective non-steroidal anti-inflammatory drugs (NSAIDs) might affect the release of growth factors (GFs) and cytokines from canine platelet-rich gels (PRGs) and other hemocomponents. (2) Methods: A crossover study was conducted in six adult mongrel dogs. Animals were randomized to receive a single dose of either carprofen or firocoxib. PRG, temperature-induced platelet lysate (TIPL), chemically induced PL (CIPL), and plasma hemocomponents were obtained from each dog before (1 h) and after (6 h) the treatments. Platelet and leukocyte counts and determination of the concentrations of platelet-derived growth factor-BB, (PDGF-BB), transforming growth factor beta-1 (TGF-β1), interleukin 1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α) and IL-10 concentrations were assayed by ELISA in all hemocomponents. (3) Results: Both platelet and leukocyte counts and PDGF-BB concentrations were not affected by NSAIDs and time. Total TGF-β1 concentrations were not affected by NSAIDs; however, the release of this GF was increased in PRG supernatants (PRGS) at 6 h. IL-1β and TNF-α concentrations were significantly (p < 0.001) lower in both firocoxib PRGS and plasma at 6 h, respectively. IL-10 concentrations were significantly (p < 0.001) lower at 6 h in all hemocomponents treated with both NSAIDs. (4) Conclusions: The clinical implications of our findings could indicate that these drugs should be withdrawn from patients to allow their clearance before the clinical use of PRP/PRG. On the other hand, the prophylactic use of NSAIDs to avoid the inflammatory reactions that some patients might have after PRP/PRG treatment should be performed only in those animals with severe reactive inflammation to the treatment.

The Sanbi Decoction alleviates intervertebral disc degeneration in rats through intestinal flora and serum metabolic homeostasis modulation

BACKGROUND

Intervertebral disc degeneration (IVDD) is an essential cause of low back pain (LBP), the incidence of which has risen in recent years and is progressively younger, but treatment options are limited, placing a serious economic burden on society. Sanbi decoction (SBD) is an important classical formula for the treatment of IVDD, which can significantly improve patients' symptoms and is a promising alternative therapy.

PURPOSE

The aim of this study is to investigate the safety and efficacy of SBD in the treatment of IVDD and to explore the underlying mechanisms by using an integrated analytical approach of microbiomics and serum metabolomics, as well as by using molecular biology.

METHODS

A rat IVDD puncture model was established and treated by gavage with different concentrations of SBD, and clean faeces, serum, liver, kidney, and intervertebral disc (IVD) were collected after 4 weeks. We assessed the safety by liver and kidney weighing, functional tests and tissue staining, the expression of tumor necrosis factor-alpha (TNF-ɑ), interleukin 1β (IL-1β) and interleukin 6 (IL-6) inflammatory factors in serum was detected by ELISA kits, and X-ray test, magnetic resonance imaging (MRI) examination, immunohistochemistry (IHC), western blotting (WB), hematoxylin-eosin (HE) staining and safranin O-fast green (SO/FG) staining were used to assess the efficacy. Finally, we performed 16S rRNA sequencing analysis on the faeces of different groups and untargeted metabolomics on serum and analyzed the association between them.

RESULTS

SBD can effectively reduce the inflammatory response, regulate the metabolic balance of extracellular matrix (ECM), improve symptoms, and restore IVD function. In addition, SBD can significantly improve the diversity of intestinal flora and maintain the balance. At the phylum level, SBD greatly increased the relative abundance of Patescibacteria and Actinobacteriota and decreased the relative abundance of Bacteroidota. At the genus level, SBD significantly increased the relative abundance of Clostridia_UCG-014, Enterorhabdus, and Adlercreutzia, and decreased the relative abundance of Ruminococcaceae_UCG-005 (p < 0.05). Untargeted metabolomics indicated that SBD significantly improved serum metabolites and altered serum expression of 4alpha-phorbol 12,13-didecanoate (4alphaPDD), euscaphic acid (EA), alpha-muricholic acid (α-MCA), 5-hydroxyindoleacetic acid (5-HIAA), and kynurenine (Kyn) (p < 0.05), and the metabolic pathways were mainly lipid metabolism and amino acid metabolism.

CONCLUSIONS

This study demonstrated that SBD can extensively regulate intestinal flora and serum metabolic homeostasis to reduce inflammatory response, inhibit the degradation of ECM, restore IVD height and water content to achieve apparent therapeutic effect for IVDD.

Sagittal Full-Spine vs. Sectional Cervical Lateral Radiographs: Are the Measurements of Cervical Alignment Interchangeable?

(1) Background: This study assessed the relationship between cervical spine parameters taken on standing full-spine lateral radiographic images compared to sectional lateral cervical radiographs. (2) Methods: Full-spine (FS) and sectional lateral cervical (LC) radiographs from four spine treatment facilities across the USA retrospectively provided data collected on 220 persons to assess the comparison of three sagittal cervical radiographic measurements between the two views. The measures included cervical lordosis using the absolute rotation angle from C2-C7, sagittal cervical translation of C2-C7, and atlas plane angle to horizontal. Linear correlation and R2 models were used for statistical comparison of the measures for the two views. (3) Results: The mean values of the three measurements were statistically different from each other: C2-C7 translation (FS = 19.84 ± 11.98 vs. LC = 21.18 ± 11.8), C2-C7 lordosis (FS = -15.3 ± 14.63 vs. LC = -18.32 ± 13.16), and atlas plane (FS = -19.99 ± 8.88 vs. LC = -22.56 ± 8.93), where all values were p < 0.001. Weak-to-moderate-to-strong correlations existed between the full-spine and sectional lateral cervical radiographic variables. The R2 values varied based on the measurement were R2 = 0.768 (p < 0.001) for sagittal cervical translation of C2-C7 (strong), R2 = 0.613 (p < 0.001) for the absolute rotation angle C2-C7 (moderate), and R2 = 0.406 (p < 0.001) for the atlas plane line (weak). Though a linear correlation was identified, there were consistent intra-person differences between the measurements on the full spine versus sectional lateral cervical radiographic views, where the full-spine view consistently underestimated the magnitude of the variables. (4) Conclusion: Key sagittal cervical radiographic measurements on the full spine versus sectional lateral cervical radiographic views show striking intra-person differences. The findings of this study confirm that full spine versus sectional lateral cervical radiographic views provide different biomechanical magnitudes of cervical sagittal alignment, and caution should be exercised by health care providers as these are not interchangeable. We recommend the LC view for measurement of cervical sagittal alignment variables.