Upregulated expression of chemokines in herniated nucleus pulposus resorption

The progression of neurovascular features and chemokine signatures of the intervertebral disc with degeneration

Inflammatory cytokine production and de novo neurovascularization have been identified in painful, degenerated intervertebral discs (IVDs). However, the temporal trajectories of these key pathoanatomical features, including the cascade of inflammatory chemokines and neo- vessel and neurite infiltration, and their associations with IVD degeneration, remain relatively unknown. Investigating this process in the caudal mouse IVD enables the opportunity to study the tissue-specific response without confounding inflammatory signaling from neighboring structures. Thus this study aims to define the progression of chemokine production and neurovascular invasion during the IVD degeneration initiated by injury in the caudal spine 3-month-old C57BL6/J mice. Forty-nine IVD-secreted chemokines and matrix metalloproteinases (MMPs) was measured using multiplex ELISA, and the intradiscal infiltrating vessels (endomucin) and nerves (protein-gene-product 9.5) was quantified in the tissue volume using immunohistochemistry. Injury provoked the increase secretion of IL6, CCL2, CCL12, CCL17, CCL20, CCL21, CCL22, CXCL2 and MMP2 proteins. The centrality and structure of inflammatory networks in IVDs evolved over the 12 post-injury weeks, highlighting distinct responses between the acute and chronic phases. Neurites propagated rapidly within 2-weeks post-injury and remained relatively constant until 12-weeks. Vascular vessel length was observed to peak at 4-weeks post-injury and it regressed by 12-weeks. These findings identified the temporal flux of inflammatory chemokines and pain-associated pathoanatomy in a model of IVD degeneration using the mouse caudal spine.

Complete resolution of lumbar disc sequestration with Ayurveda management: A case report

Lumbar disc herniation (LDH) is the most common spinal disorder among which disc sequestration is a severe type where the herniated disc fragment migrates and is completely separated from the parent disc. A 46-year-old female patient with severe lower back pain radiating to right lower limb, disability, and numbness in the affected extremity came to Panchakarma O.P.D of our hospital. She was a chronic case of disc sequestration where her symptoms were severely aggravated after a sudden jolt felt on her lower back while traveling on a motorcycle. The patient's Oswestry disability index (ODI) score was 90 % which indicates a bed-bound condition and even Schobar's test indicated a severe reduction in lumbar flexion capability. MRI showed postero-central herniation with disc sequestration at L5-S1 caused compression on the subarachnoid space and traversing S1 nerve roots. She was treated according to Ayurveda treatment principles and underwent Panchakarma like medicated enema (Basti) and fomentation of a lumbosacral region with oil (Kati Basti). She also received different oral medications on successive follow-ups. After 6 months of Ayurveda treatment, the patient showed remission in lower back pain (LBP), radiculopathy, and numbness. Her ODI score was reduced to 6 %. The MRI repeated post-treatment showed complete interval resolution of disc sequestration and no neurological compression was observed.

The importance of inflammatory biomarkers in non-specific acute and chronic low back pain: a systematic review

OBJECTIVE

The purpose of this study was to systematically review the evidence on inflammatory biomarkers as analytic predictors of non-specific low back pain (NsLBP). Low back pain (LBP) is the number one cause of disability globally, posing a major health problem that causes an enormous social and economic burden, and there is an increasing interest on the importance of biomarkers in quantifying and even emerge as potential therapeutic tools to LBP.

METHODS

A systematic search was conducted on July 2022 in Cochrane Library, MEDLINE and Web of Science for all the available literature. Cross-sectional, longitudinal cohort or case-control studies that evaluated the relationship between inflammatory biomarkers collected from blood samples and low back pain in humans were considered eligible for inclusion, as well as prospective and retrospective studies.

RESULTS

The systematic database search resulted in a total of 4016 records, of which 15 articles were included for synthesis. Sample size comprised a total of 14,555 patients with LBP (acute LBP (n = 2073); chronic LBP (n = 12482)) and 494 controls. Most studies found a positive correlation between classic pro-inflammatory biomarkers and NsLBP, namely C-reactive protein (CRP), interleukin 1 (IL-1) and IL-1β, interleukin 6 (IL-6) and tumour necrosis factor α (TNF-α). On the other hand, anti-inflammatory biomarker interleukin 10 (IL-10) demonstrated a negative association with NsLBP. Four studies have made direct comparisons between ALBP and CLBP groups regarding their inflammatory biomarkers profile.

CONCLUSIONS

This systematic review found evidence of increased levels of pro-inflammatory biomarkers CRP, IL-6 and TNF-α and decreased levels of anti-inflammatory biomarker IL-10 in patients with LBP. Hs-CRP was not correlated with LBP. There is insufficient evidence to associate these findings with the degree of pain severity or the activity status of the lumbar pain over time.

Biomaterials delivery strategies to repair degenerated intervertebral discs by regulating the inflammatory microenvironment

Intervertebral disc degeneration (IVDD) is one of the leading causes of lower back pain. Although IVDD cannot directly cause death, it can cause pain, psychological burdens, and economic burdens to patients. Current conservative treatments for IVDD can relieve pain but cannot reverse the disease. Patients who cannot tolerate pain usually resort to a strategy of surgical resection of the degenerated disc. However, the surgical removal of IVDD can affect the stability of adjacent discs. Furthermore, the probability of the reherniation of the intervertebral disc (IVD) after surgery is as high as 21.2%. Strategies based on tissue engineering to deliver stem cells for the regeneration of nucleus purposes (NP) and annulus fibrosus (AF) have been extensively studied. The developed biomaterials not only locally withstand the pressure of the IVD but also lay the foundation for the survival of stem cells. However, the structure of IVDs does not provide sufficient nutrients for delivered stem cells. The role of immune mechanisms in IVDD has recently become clear. In IVDD, the IVD that was originally in immune privilege prevents the attack of immune cells (mainly effector T cells and macrophages) and aggravates the disease. Immune regulatory and inflammatory factors released by effector T cells, macrophages, and the IVD further aggravate IVDD. Reversing IVDD by regulating the inflammatory microenvironment is a potential approach for the treatment of the disease. However, the biological factors modulating the inflammatory microenvironment easily degrade in vivo. It makes it possible for different biomaterials to modulate the inflammatory microenvironment to repair IVDD. In this review, we have discussed the structures of IVDs and the immune mechanisms underlying IVDD. We have described the immune mechanisms elicited by different biological factors, including tumor necrosis factors, interleukins, transforming growth factors, hypoxia-inducible factors, and reactive oxygen species in IVDs. Finally, we have discussed the biomaterials used to modulate the inflammatory microenvironment to repair IVDD and their development.

[Research progress of resorption of lumbar disc herniation]

Objective

To summarize the research progress of resorption of lumbar disc herniation (RLDH).

Methods

The literature on RLDH at home and abroad in recent years was reviewed to summarize its influencing factors, pathogenesis, imaging findings, and predictive effect, as well as its influence on the treatment selection of lumbar disc herniation (LDH).

Results

The main mechanism of RLDH is the combined effect of inflammatory response and neovascularization. Age, smoking, body mass index, and clinical manifestations are the influencing factors. Studies have shown that the annular enhancement around the nucleus pulposus on enhanced MRI images is the characteristic imaging manifestation of RLDH, which is a predictor of whether RLDH occurs. In the treatment of LDH, cyclooxygenase 2 inhibitors may have a negative impact on RLDH.

Conclusion

The occurrence of RLDH suggests that strict conservative treatment is the first choice for LDH treatment, but surgery is still an important treatment method when the patient's symptoms and imaging symptoms don't significantly improved after conservative treatment.

Characteristics and mechanisms of resorption in lumbar disc herniation

Lumbar disc herniation (LDH) can be spontaneously absorbed without surgical treatment. However, the pathogenesis and physiological indications for predicting protrusion reabsorption are still unclear, which prevents clinicians from preferentially choosing conservative treatment options for LDH patients with reabsorption effects. The purpose of this review was to summarize previous reports on LDH reabsorption and to discuss the clinical and imaging features that favor natural absorption. We highlighted the biological mechanisms involved in the phenomenon of LDH reabsorption, including macrophage infiltration, inflammatory responses, matrix remodeling, and neovascularization. In addition, we summarized and discussed potential clinical treatments for promoting reabsorption. Current evidence suggests that macrophage regulation of inflammatory mediators, matrix metalloproteinases, and specific cytokines in intervertebral disc is essential for the spontaneous reabsorption of LDH.

Network Pharmacological Dissection of the Mechanisms of Eucommiae Cortex-Achyranthis Radix Combination for Intervertebral Disc Herniation Treatment

Eucommiae cortex (EC) and Achyranthis radix (AR) are herbal medicines widely used in combination for the treatment of intervertebral disc herniation (IDH). The mechanisms of action of the herbal combination have not been understood from integrative and comprehensive points of view. By adopting network pharmacological methodology, we aimed to investigate the pharmacological properties of the EC-AR combination as a therapeutic agent for IDH at a systematic molecular level. Using the pharmacokinetic information for the chemical ingredients of the EC-AR combination obtained from the comprehensive herbal drug-associated databases, we determined its 31 bioactive ingredients and 68 IDH-related therapeutic targets. By analyzing their enrichment for biological functions, we observed that the targets of the EC-AR combination were associated with the regulation of angiogenesis; cytokine and chemokine activity; oxidative and inflammatory stress responses; extracellular matrix organization; immune response; and cellular processes such as proliferation, apoptosis, autophagy, differentiation, migration, and activation. Pathway enrichment investigation revealed that the EC-AR combination may target IDH-pathology-associated signaling pathways, such as those of cellular senescence and chemokine, neurotrophin, TNF, MAPK, toll-like receptor, and VEGF signaling, to exhibit its therapeutic effects. Collectively, these data provide mechanistic insights into the pharmacological activity of herbal medicines for the treatment of musculoskeletal diseases such as IDH.

Does paravertebral ozone injection have efficacy as an additional treatment for acute lumbar disc herniation? A randomized, double-blind, placebo-controlled study

OBJECTIVE

In this study we investigate the effects of paravertebral ozone injections (POI), which have been used as a new treatment approach for lower back pain in recent years, on pain and physical activity in patients with acute lumbar disc herniation (LDH) as an additional treatment.

METHODS

Thirty-eight patients were assigned into the ozone therapy (OT) group (n= 20) and placebo control (PC) group (n= 18). Both groups received two sessions per week, a total of 8 sessions of lumbar POI. The ozone concentrations of 20-25 μg/ml (30 ml) and 0.1 μg/ml (30 ml) were administered to the OT and PC groups, respectively. The patients were assessed with the visual analog scale (VAS) and Oswestry Disability Index (ODI) before the treatment (V1), 15 (V2) and 30 (V3) days after the treatment started, and one month (V4) after the treatment ended.

RESULTS

A significant improvement was seen in the VAS and ODI scores in the final follow-up (V4) as compared with the baselines scores (V1) in both groups (P< 0.05). The patients in the OT group had lower mean VAS and ODI scores in V2, V3, and V4 follow-ups compared with the patients in the PC group. This significant difference reached its peak in the final follow-up (V4) (P< 0.05).

CONCLUSION

As an additional treatment combined with conservative treatment, lumbar POI can lessen pain and disability in patients with acute LDH.

Lumbar spine abnormalities in patients with obstructive sleep apnoea

Previous studies suggested cervical spondylosis as a risk factor for development of obstructive sleep apnoea (OSA). We aimed to assess lumbar disc degeneration in patients with OSA and correlate the findings with symptoms and disease severity. Twenty-seven patients with OSA and 29 non-OSA controls underwent sleep studies and lumbar magnetic resonance imaging (MRI), and completed the Epworth Sleepiness Scale and the 24-item Roland-Morris Disability Questionnaire (RMDQ) questionnaires. Plasma klotho was determined with enzyme-linked immunosorbent assay. Patients with OSA had higher number of disc bulges (4.6 ± 3.7 vs. 1.7 ± 2.5, p < 0.01) and anterior spondylophytes (2.7 ± 4.2 vs. 0.8 ± 2.1, p < 0.01), increased disc degeneration (total Pfirrmann score 16.7 ± 4.7 vs. 13.2 ± 4.1, p < 0.01) and vertebral fatty degeneration (7.8 ± 4.7 vs. 3.8 ± 3.7, p < 0.01). There was no difference in the RMDQ score (0/0-3.5/ vs. 0/0-1/, p > 0.05). Markers of OSA severity, including the oxygen desaturation index and percentage of total sleep time spent with saturation < 90% as well as plasma levels of klotho were correlated with the number of disc bulges and anterior spondylophytes (all p < 0.05). OSA is associated with lumbar spondylosis. Our study highlights the importance of lumbar imaging in patients with OSA reporting lower back pain.

Sequential CCL2 Expression Profile After Disc Injury in Mice

Macrophages produce proinflammatory cytokines in injured intervertebral discs (IVDs). We recently showed that macrophage-derived inflammatory cytokines contribute to the production of pain-related factors. However, the mechanism by which macrophages are recruited to injured IVDs has not been fully clarified. Here, we examined the expression dynamics of the chemokine CCL2 in a mouse IVD injury model and the mechanisms of its regulation. The percentage of macrophages increased from day 1 after injury and persisted up until day 28. At 1 and 3 days after injury, the expression of both Ccl2 messenger RNA (mRNA) and CCL2 protein was elevated in the IVD injury group, after which expression decreased to basal levels. Consistent with the increase in CCL2 expression, Ccr2 and Tnfa expression and various types of macrophages were also immediately elevated following disc injury. Further, tumor necrosis factor-α (TNF-α) stimulated Ccl2 mRNA and CCL2 protein expression in IVD cells in vitro. The expressions of M1 (Cd86 and Nos2) and M2a (Ym1) macrophage markers were all significantly elevated from  day 1 following injury in injured compared with control mice. Meanwhile, the expression of Cd206 (M2a and M2c marker) was significantly elevated on days 3, 7, 14, and 28 following injury. These results suggest that in IVD injury, TNF-α stimulates CCL2, which, in turn, mediates the recruitment of macrophages with the recruited macrophages subsequently differentiating into M1 and M2 subtypes. CCL2 signaling may, therefore, play an important role in IVD pathology via macrophage recruitment. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:895-901, 2020.

Effect of the CCL5-Releasing Fibrin Gel for Intervertebral Disc Regeneration

OBJECTIVE

To explore if chemokine (C-C motif) ligand 5 (CCL5) delivery could recruit annulus fibrosus (AF) cells to the injury sites and facilitate the repair of ruptured AF.

DESIGN

The effects of CCL5 on bovine AF cells in vitro were tested by transwell assay and quantitative real-time polymerase chain reaction. Fibrin gel containing CCL5 was used to treat annulotomized bovine caudal discs cultured under dynamic loading conditions. After 14 days of loading, the samples were collected for histological examination. A pilot animal study was performed using sheep cervical discs to investigate the effect of fibrin gel encapsulated with CCL5 for the treatment of ruptured AF. After 14 weeks, the animals were sacrificed, and the discs were scanned with magnetic resonance imaging before histopathological examination.

RESULTS

CCL5 showed a chemotactic effect on AF cells in a dose-dependent manner. AF cells cultured with CCL5 in vitro did not show any change of the gene expression of CCL5 receptors, catabolic and proinflammatory markers. In vitro release study showed that CCL5 exhibited sustained release from the fibrin gel into the culture media; however, in the organ culture study CCL5 did not stimulate homing of AF cells toward the defect sites. The pilot animal study did not show any repair effect of CCL5.

CONCLUSIONS

CCL5 has a chemotactic effect on AF cells in vitro, but no ex vivo or in vivo regenerative effect when delivered within fibrin gel. Further study with a stronger chemotactic agent and/or an alternate biomaterial that is more conductive of cell migration is warranted.

Polarization of Macrophages in Epidural Inflammation Induced by Canine Intervertebral Disc Herniation

Introduction: Canine interverterbral disc (IVD), although physiologically acellular, displays an inflammatory cell population consisting almost exclusively of macrophages (Mϕ) when acutely herniated. Mϕ encompass a heterogenous cell population, roughly divided into classically (M1) or alternatively activated (M2)Mϕ. Polarization into M1 Mϕ leads to strong antimicrobial activity and pro-inflammatory response. In contrast, M2Mϕ exibit anti-inflammatory function and regulate wound healing. The purpose of this study was to characterize the phenotype of the Mϕ population present in naturally occurring IVD herniation.

Materials and Methods: IVD material of dogs with IVD disease was collected during standard decompressive surgery. A negative control consisting of IVD material of dogs without IVD degeneration and a positive control consisting of canine liver and lymph node samples were also included. All samples were embedded in OCT and shock frozen. Eight micrometer cryostat sections were prepared, air dried and immunostained without prefixation or permeabilization. CD14 was used as marker Mϕ, MHCII for M1Mϕ and CD206 for M2Mϕ.

Results: Fifteen samples of dogs with IVD herniation, 10 negative, and 5 positive control samples were obtained. No positive cell was found in the negative control group. The positive control group displayed several MHCII and CD206 positive cells, all of them being simultaneously positive to CD14. All herniated samples displayed a mixed population of M1Mϕ and M2Mϕ, and some sparse Mϕ displaying markers for both M1 and M2Mϕ simultaneously.

Conclusion: The mixed phenotype encountered shows the plasticity and dynamism of Mϕ and evidences the chronic component of IVD disease despite its acute clinical presentation.

Up-regulation of circulating microRNA-17 is associated with lumbar radicular pain following disc herniation

Background

Previous studies suggest that regulatory microRNAs (miRs) may modulate neuro-inflammatory processes. The purpose of the present study was to examine the role of miR-17 following intervertebral disc herniation.

Methods

In a cohort of 97 patients with leg pain and disc herniation verified on MRI, we investigated the association between circulating miR-17 and leg pain intensity. A rat model was used to examine possible changes in miR-17 expression in nucleus pulposus (NP) associated with leak of NP tissue out of the herniated disc. The functional role of miR-17 was addressed by transfection of miR-17 into THP-1 cells (human monocyte cell line).

Results

An association between the level of miR-17 in serum and the intensity of lumbar radicular pain was shown. Up-regulation of miR-17 in the rat NP tissue when applied onto spinal nerve roots and increased release of TNF following transfection of miR-17 into THP-1 cells were also observed. Hence, our data suggest that miR-17 may be involved in the pathophysiology underlying lumbar radicular pain after disc herniation.

Conclusions

We conclude that miR-17 may be associated with the intensity of lumbar radicular pain after disc herniation, possibly through a TNF-driven pro-inflammatory mechanism.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1967-y) contains supplementary material, which is available to authorized users.

Spontaneous regression of extruded lumbar disc herniation: Correlation with clinical outcome

Objective:

To evaluate the natural history of lumbar extruded disc with conservative treatment on MRI and to assess relation between the radiologic changes and clinical outcome.

Methods:

This prospective observational study was conducted at University of Health Sciences, Diskapi Yildirim Beyazit Training and Research Hospital between May 2015-June 2018. It included consecutive patients who were diagnosed as having lumbar symptomatic extruded disc as shown in MRI. After an average period of 17.0±7.2 months, repeat MRI was taken in 40 patients who received only conservative care during follow-up. Changes in the volume of herniated disc was measured. The patients were assigned into 3 groups as follow: (1) non-regression, (2) partial-regression, and (3) complete resolution. Numeric Rating Scale (NRS) pain score, the Oswestry Low Back Pain Disability Index (ODI) and muscle weakness were evaluated.

Results:

Based on disc volume of the T2-weighted MR images; four patients (10%) did not show any regression, six patients (15%) had a partial regression, and 30 patients (75%) had a complete resolution. Patients with complete resolution showed a significant improvement in the NRS pain score and the ODI score (p<0,001) over time. In patients with partial regression, only the ODI score improved significantly (p=0,043). Non-regression group did not show any improvement in any clinical outcome measure (p>0,05). Changes in the NRS scores over time were significantly higher in complete resolution group compared to non-regression group (p=0.016).

Conclusion:

The majority of the patients with extruded lumbar disc herniation might have reduction in size of herniated disc in the long run along with improvement in symptoms and function with conservative care.

Spontaneous regression of cervical discs: Retrospective analysis of 14 cases

Cervical disc herniation is a condition which arises from compression of cervical spinal nerve root by the degenerated disc and vast majority of the patients are aged between 30 and 40 years. Spontaneous regression of cervical disc was first reported by Kriegerand Maniker in 1992. Our study is the second large series in literature. Besides, 4 patients are the first who were shown to have resorption in C 4-5.The records of patients diagnosed with cervical disc herniation who applied to the Spine Polyclinic between 2014 and 2018 were reviewed retrospectively. The files of the patients who were recommended surgery with the diagnosis of cervical disc herniation were examined. Patients who did not accept surgery on their own initiative, but who attended our outpatient clinic for a check-up were included in the study.Of a total of 14 patients, 28.57% (n = 4) were male and 71.43% (n = 10) were female. Mean age of the patients was 40.79 (range 25-60).The results of the study indicate that likelihood of spontaneous regression is higher in para-central or foraminal disc compared to central disc hernias. Although there are a limited number of case reports in the literature, conservative treatment seems to be a good option in patients without neurological deficits, with foraminal disc hernias and not requiring emergency surgery.

Spontaneous regression of herniated nucleus pulposus: The clinical findings of 76 patients

Lumbar disc hernia is common disease, affecting about 5% of the population. Many studies to date reported regression of disc herniation without surgical intervention.Medical records of the patients who applied to the spine clinic in an outpatient setting were retrospectively reviewed. Age, sex, radiological findings, neurological examinations, and medical treatments of the patients were evaluated.Male patients constituted 52.6% of the cases (n = 40) and 47.4% (n = 36) were female. The ages of the patients ranged from 25 to 82 years, with a mean of 48.5 ± 12.1 years. Visual analog scale (VAS) measurements ranged from 0 to 8 and the mean was determined as 2.65 ± 1.98. The VAS score of pain severity of 12 (15.78%) cases was 0, VAS score of 39 (51.31%) cases was 1 to 3, VAS score of 20 (26.31%) cases was 4 to 6, VAS score of 5 (6.57%) cases was 7 to 10. Eighteen (23.68%) of the cases underwent neuropathic pain treatment for more than 6 months. Fifteen (19.7%) patients also developed permanent motor deficits.Findings of our study show that there was no direct association between radiological improvement and clinical improvement. Indication for surgery still existed in a high number of patients, substantial of which developed permanent motor deficits. Current results suggest that we need to advise our patients in favor of early surgery as soon as indication for surgery is established upon neurological and radiological examination.

The inflammatory response in the regression of lumbar disc herniation

Lumbar disc herniation (LDH) is highly associated with inflammation in the context of low back pain. Currently, inflammation is associated with adverse symptoms related to the stimulation of nerve fibers that may lead to pain. However, inflammation has also been indicated as the main factor responsible for LDH regression. This apparent controversy places inflammation as a good prognostic indicator of spontaneous regression of LDH. This review addresses the molecular and cellular mechanisms involved in LDH regression, including matrix remodeling and neovascularization, in the scope of the clinical decision on conservative versus surgical intervention. Based on the evidence, a special focus on the inflammatory response in the LDH context is given, particularly in the monocyte/macrophage role. The phenomenon of spontaneous regression of LDH, extensively reported in the literature, is therefore analyzed here under the perspective of the modulatory role of inflammation.

Stand-alone Lateral Recess Decompression Without Discectomy in Patients Presenting With Claudicant Radicular Pain and MRI Evidence of Lumbar Disc Herniation: A Prospective Study

STUDY DESIGN

A prospective study.

OBJECTIVE

The aim of this study was to analyze the outcomes of stand-alone lateral recess decompression without discectomy in patients with claudicant radicular pain and magnetic resonance imaging (MRI) showing LRS (lateral recess stenosis) with lumbar disc herniation.

SUMMARY OF BACKGROUND DATA

Discectomy is the gold standard treatment for symptomatic lumbar disc herniations refractory to conservative care. Typically, patients with positive SLR (Straight leg raising test) and flexion dominant leg pain are the ideal candidates who can be benefited from discectomy. There is a subset of patients with morphological features of lumbar disc herniation with LRS on MRI and presenting with diametrically opposite symptoms such as claudicant leg pain, extension dominant leg pain, relief on flexion, and a negative SLR. Until now, no focused prospective study in the literature highlights stand-alone lateral recess decompression in this group of patients.

METHODS

From January 2007 to June 2013, 55 patients having unilateral claudicant radicular pain were selected to undergo stand-alone lateral recess decompression with tubular retractors. Intraoperatively, disc consistency and presence of sequestrated fragments were analyzed. Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) score, and Macnab criteria were used to measure outcomes.

RESULTS

Out of 55 patients, stand-alone lateral recess decompression was successfully executed in 51 patients and remaining four patients had sequestrated discs that required removal. Mean age at presentation was 54.5 years (41-67 years), male:female ratio was 1.12:1, and mean follow-up was 3.8 years (3-5.8 years). Significant improvement (P < 0.0001) was noticed between preoperative and postoperative VAS score (8.39 ± 0.84 vs. 2.5 ± 0.48) and ODI score (46.79 ± 1.85 vs. 18.71 ± 2.41). As per Macnab criteria, 94% patients were satisfied with surgery.

CONCLUSION

Stand-alone lateral recess decompression without discectomy is clinically effective for a large majority of patients with claudicant radicular pain and MRI evidence of LRS with associated lumbar disc herniation. The ability to perform it with minimal invasive techniques makes it focused and targeted with minimal morbidity.

LEVEL OF EVIDENCE

4.

Trattamento della lombosciatalgia acuta e cronica con infiltrazione perigangliare di steroide

Scopo del nostro lavoro è stato quello di valutare l'efficacia di un'infiltrazione perigangliare di steroide in pazienti affetti da lombosciatalgia acuta o cronica.

56 pazienti affetti da lombosciatalgia dipendente da patologia degenerativa discale o vertebrale, con pregressa valutazione TC e/o RM del rachide lombare, sono stati sottoposti ad una infiltrazione TC guidata perigangliare, con 2 cc (80 mgr) di Depomedrol® usando un ago di Chiba spinale centimetrato da 22 g, senza effettuazione di alcuna preparazione, anestesia o somministrazione di mezzo di contrasto. La lombosciatalgia, e la sua evoluzione a 1 e 12 mesi dal trattamento, è stata valutata mediante scala “Owestry low back pain disability scale”.

Il 71% dei pazienti dimostrava un significativo miglioramento della sintomatologia, con scomparsa o riduzione della sintomatologia. In conclusione, il trattamento periradicolare TC guidato con iniezione di steroide sembra costituire una valida alternativa minimamente invasiva per il trattamento della patologia radicolare lombare.

Interleukin-17 upregulates vascular endothelial growth factor by activating the JAK/STAT pathway in nucleus pulposus cells

OBJECTIVES

Intervertebral disc (IVD) related diseases and age-related IVD degeneration are responsible for significant morbidity. Inflammatory mediators and pro-inflammatory cytokines, including interleukin (IL)-17, show elevated expression in degenerated disc tissue. IL-17 is reported to transduce signals across the cell membrane predominantly via the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signal transduction pathway, leading to transcriptional activation of target genes.

METHODS

In this study, we investigated whether the JAK/STAT pathway plays a role in IL-17-mediated signaling in the nucleus pulposus (NP) cells of IVDs. Vascular endothelial growth factor (VEGF) and IL-17 were found to be highly expressed in human degenerated NP tissue. In isolated rat NP cells, IL-17-induced VEGF expression in a time- and dose-dependent manner. Rat NP cells were co-transfected with VEGF promoter plasmid along with constitutively active STAT1, STAT3 or JAK2 plasmid. VEGF promoter activity was found to be increased by STAT1, STAT3 and JAK2 in IL-17-treated cells. Transfection of cultured rat NP cells with STAT1 or STAT3 lentiviral short hairpin RNAs or treatment with the JAK2 inhibitor AG490 significantly reduced IL-17-stimulated VEGF expression.

CONCLUSIONS

IL-17 upregulated VEGF expression in rat NP cells mediated by the JAK/STAT pathway, and elevated levels of IL-17 and VEGF are present in human degenerated NP tissue. These findings provide new insight into the pathology of IVD degeneration.

Inflammatory Serum Protein Profiling of Patients with Lumbar Radicular Pain One Year after Disc Herniation

Earlier studies suggest that lumbar radicular pain following disc herniation may be associated with a local or systemic inflammatory process. In the present study, we investigated the serum inflammatory protein profile of such patients. All 45 patients were recruited from Oslo University Hospital, Ullevål, Norway, during the period 2007–2009. The new multiplex proximity extension assay (PEA) technology was used to analyze the levels of 92 proteins. Interestingly, the present data showed that patients with radicular pain 12 months after disc herniation may be different from other patients with regard to many measurable serum cytokines. Given a false discovery rate (FDR) of 0.10 and 0.05, we identified 41 and 13 proteins, respectively, which were significantly upregulated in the patients with severe pain one year after disc herniation. On the top of the list ranked by estimated increase we found C-X-C motif chemokine 5 (CXCM5; 217% increase), epidermal growth factor (EGF; 142% increase), and monocyte chemotactic protein 4 (MCP-4; 70% increase). Moreover, a clear overall difference in the serum cytokine profile between the chronic and the recovered patients was demonstrated. Thus, the present results may be important for future protein serum profiling of lumbar radicular pain patients with regard to prognosis and choice of treatment. We conclude that serum proteins may be measurable molecular markers of persistent pain after disc herniation.

Reduced tonicity stimulates an inflammatory response in nucleus pulposus tissue that can be limited by a COX-2-specific inhibitor

In intervertebral disc herniation with nucleus pulposus (NP) extrusion, the elicited inflammatory response is considered a key pain mechanism. However, inflammatory cytokines are reported in extruded herniated tissue, even before monocyte infiltration, suggesting that the tissue itself initiates the inflammation. Since herniated tissue swells, we investigated whether this simple mechanobiological stimulus alone could provoke an inflammatory response that could cause pain. Furthermore, we investigated whether sustained-release cyclooxygenase-2 (COX2) inhibitor would be beneficial in such conditions. Healthy bovine NP explants were allowed to swell freely or confined. The swelling explants were treated with Celecoxib, applied either as a bolus or in sustained-release. Swelling explants produced elevated levels of interleukin-6 (IL-6) and prostaglandin E2 (PGE2 ) for 28 days, while confined explants did not. Both a high concentration bolus and 10 times lower concentration in sustained release completely inhibited PGE2 production, but did not affect IL-6 production. Swelling of NP tissue, without the inflammatory system response, can trigger cytokine production and Celecoxib, even in bolus form, may be useful for pain control in extruded disc herniation.

Spontaneous regression of posterior epidural migrated lumbar disc fragments: case series

BACKGROUND CONTEXT

Posterior epidural migrated lumbar disc fragments is an extremely rare disorder. Surgical treatment was performed in all reported cases. To the best of our knowledge, there are no reported cases of the use of conservative treatment for posterior epidural migrated lumbar disc fragments.

PURPOSE

To report the possibility of a spontaneous regression of posterior epidural migrated lumbar disc fragments.

STUDY DESIGN

Case series.

METHODS

Four patients with posterior epidural migrated lumbar disc fragments were treated at Karatsu Red Cross Hospital between April 2008 and August 2010. Spontaneous regression of the posterior epidural migrated lumbar disc fragments with relief of symptoms was observed on magnetic resonance imaging (MRI) in three cases. Another patient underwent surgical treatment. The present and previously reported cases of posterior epidural migrated lumbar disc fragments were analyzed with respect to patient age, imaging features on MRI, the level of the lesion, clinical symptoms, treatment, and outcomes.

RESULTS

Conservative treatment was successful, and spontaneous lesion regression was seen on MRI with symptom relief in three cases.

CONCLUSIONS

Although posterior epidural migrated lumbar disc fragment cases are generally treated surgically, the condition can regress spontaneously over time, as do sequestrated disc fragments. Spontaneous regression of lumbar disc herniations is a widely accepted observation at present. Posterior epidural migrated lumbar disc fragments fall under the sequestrated type of disc herniation. In fact, the course of treatment for posterior epidural migrated lumbar disc fragments should be determined based on the symptoms and examination findings, as in cases of ordinary herniation. However, providing early surgical treatment is important if the patient has acute cauda equina syndrome or the neurologic symptoms worsen over time.

Fractalkine receptor chemokine (CX3CR1) influences on cervical and lumbar disc herniation

BACKGROUND

Herniation of nuclear or disc material along with, inflammatory chemokines such as prostaglandin E2, interleukin-6, matrix metalloproteinase and nitric oxide has definite correlation, possibly they are over produced. CX3CL1 and its receptor (CX3CR1) are part of chemokine system involved in leukocyte recruitment and adhesion in chronic inflammatory disease, but its role in spinal herniated nucleus pulposus (HNP) is unknown. We evaluated the expression of CX3CL1 and CX3CR1 in patients with disc herniation to clarify the role of CX3CL1 and CX3CR1 in the disc degeneration and to compare between cervical and lumbar HNP.

MATERIALS AND METHODS

The mRNA concentrations of CX3CL1/CX3CR1 chemokine were analyzed in the surgically obtained disc specimens from C-HNP (n = 13) and L-HNP (n = 13) by real-time polymerase chain reaction (PCR). The localization of CX3CL1/CX3CR1 chemokine in the disc of C-HNP and L-HNP patients was determined using immunohistochemical study. Blood samples from patients with C-HNP and L-HNP patients were stained for CX3CR1 with flow cytometric analysis.

RESULTS

The CX3CL1 positive cell ratio in the discs was observed in both groups by immunohistochemical study. CX3CR1 was strongly expressed on endothelial cells in C-spine disc, but sparely expressed in L-spine disc. There was greater CX3CR1 mRNA expression in C-HNP patients than in L-HNP patients as quantified by reversal transcription-PCR (P = 0.010). CX3CR1 positive cell frequencies and CX3CR1 expression levels were increased in CD4 (+) T-cells and natural killer (NK) cells from patients with C-HNP (P = 0.210 and P = 0.040).

CONCLUSIONS

This study identified that increases in CX3CL1 and CX3CR1-expressing cells are significantly related to pathomechanism of HNP for the first time. Especially, CD4 (+) T-cells and NK cells expressing CX3CR1 may play an important role in developing C-HNP.

The probability of spontaneous regression of lumbar herniated disc: a systematic review

OBJECTIVE

To determine the probability of spontaneous disc regression among each type of lumbar herniated disc, using a systematic review.

DATA SOURCES

Medline, Cochrane Library, CINAHL, and Web of Science were searched using key words for relevant original articles published before March 2014. Articles were limited to those published in English and human studies.

REVIEW METHODS

Articles had to: (1) include patients with lumbar disc herniation treated conservatively; (2) have at least two imaging evaluations of the lumbar spine; and (3) exclude patients with prior lumbar surgery, spinal infections, tumors, spondylolisthesis, or spinal stenosis. Two reviewers independently extracted study details and findings. Thirty-one studies met the inclusion criteria. Furthermore, if the classification of herniation matched the recommended classification of the combined Task Forces, the data were used for combined analysis of the probability of disc regression of each type. Nine studies were applicable for probability calculation.

RESULTS

The rate of spontaneous regression was found to be 96% for disc sequestration, 70% for disc extrusion, 41% for disc protrusion, and 13% for disc bulging. The rate of complete resolution of disc herniation was 43% for sequestrated discs and 15% for extruded discs.

CONCLUSIONS

Spontaneous regression of herniated disc tissue can occur, and can completely resolve after conservative treatment. Patients with disc extrusion and sequestration had a significantly higher possibility of having spontaneous regression than did those with bulging or protruding discs. Disc sequestration had a significantly higher rate of complete regression than did disc extrusion.

Contribution of chemokine CCL2/CCR2 signaling in the dorsal root ganglion and spinal cord to the maintenance of neuropathic pain in a rat model of lumbar disc herniation

Lumbar disc herniation (LDH) is a major cause of sciatica, but the underlying mechanisms are not well understood. Chemokine CCL2 has been implicated to play a vital role in the neuroinflammation and central sensitization after spinal nerve ligation. Here we investigated the expression and the role of CCL2 and its receptor CCR2 in LDH-induced pain. Implantation of autologous nucleus pulposus induced persistent pain hypersensitivity, associated with increased mRNA expression of CCL2 and CCR2 in the dorsal root ganglion and spinal cord. Interestingly, CCL2 was increased in neurons and CCR2 was mainly increased in macrophages in the dorsal root ganglion, whereas CCL2 and CCR2 were increased in astrocytes and neurons, respectively, in the spinal cord. Intrathecal injection of CCR2 antagonist RS504393 at 3 days or 10 days significantly attenuated nucleus pulposus-induced mechanical allodynia. The results suggest that CCL2/CCR2 in the dorsal root ganglion and spinal cord is involved in the maintenance of LDH-induced pain. Targeting CCL2/CCR2 signaling may be a potential treatment for chronic radicular neuropathic pain.

PERSPECTIVE

These results suggest that CCL2/CCR2 signaling in the dorsal root ganglion and spinal cord is involved in LDH-induced pain via distinct mechanisms. These findings provide evidence of the antinociceptive effect of CCR2 antagonist on radicular neuropathic pain.

Endogenous TGF-β activity limits TSLP expression in the intervertebral disc tissue by suppressing NF-κB activation

Thymic stromal lymphopoietin (TSLP), an IL-7-like cytokine, is highly expressed in herniated disc (HD) tissue and may act as a key molecule for the initiation of macrophage recruitment into the tissue and natural resorption of HD. However, it remains unclear how TSLP expression is regulated in the intervertebral discs. This study showed that expression of TSLP and phosphorylated NF-κB in HD tissue samples was inversely correlated with expression of phosphorylated Smad2/3 (an indicator of active TGF-β signaling) and vice versa in posterior lumbar spinal fusion samples. The pharmacological blockades of endogenous TGF-β activity induced TSLP expression in mouse intervertebral disc tissue culture, which was inhibited by NF-κB inhibitors. Additionally, phosphorylation of Smad2/3 was constitutively detected in mouse intervertebral disc tissue in the steady states. Collectively, these results suggest that endogenous TGF-β activity limits TSLP expression in intervertebral disc tissue in the steady states by suppressing NF-κB activation. The findings reveal a regulatory mechanism how TSLP expression is induced in the intervertebral disc tissue and suggest a novel role of TGF-β in maintaining the homeostasis of intervertebral disc tissue.

CCL20 Secretion from the Nucleus Pulposus Improves the Recruitment of CCR6-Expressing Th17 Cells to Degenerated IVD Tissues

BACKGROUND

Studies elucidated that Th17 cells are important contributors to the pathogenesis of many immune-mediated diseases, and IL-17A is present in pathologic intervertebral disc (IVD) tissues. However, the mechanisms, how these cells traffic into the degenerate discs are not clear.

MATERIALS AND METHODS

The samples collected from 53 patients had been divided into 3 groups: Group P (annulus fibrosus was intact), Group E (annulus fibrosus was reptured) and normal control. Immunohistochemistry was used to detect the expression of CCL20, CCR6, IL-17A, TNF-α and CD4 in IVD tissues. Moreover, nucleus pulposus (NP) cells had been cultured in the presence and absence of Th17 associated cytokines. The supernatants were detected for CCL20 concentrations by ELISA, and the NP cells for the expression of CCL20 mRNA. Additionally, peripheral blood (PB) samples had undergone detection for the expression of CCR6 mRNA and the proportion of IL-17-producing cells, including the surface expression of CCR6.

RESULTS

Immunohistochemistry revealed that CCL20 and TNF-α were expressed in degenerated NP cells. Double-labeled immunofluorescence elaborated, IL-17-producing cells (CD4(+)IL-17A(+) and CD4(+)CCR6(+)) appeared in the Group E samples, but no traces or expression in Group P and normal control. IL-17A and TNF-α, alone or combined, could enhance CCL20 secretion in a dose-dependent manner, which was obtained through RT-PCR results. There was a notable difference of CCR6 mRNA expression between patients and normal controls. In comparison to controls, flow cytometry data indicated that the proportion of IL-17-producing cells and the CCR6 expression in PB were significantly increased.

CONCLUSION

Our results provide a potential explanation for involvement of the CCL20-CCR6 system in the trafficking of IL-17-producing cells to degenerated IVD tissues. Additionally, our results explain the contribution of Th17 associated cytokines to the development of degenerated discs via the up-regulation of CCL20 secretion from NP cells, which forms a positive chemotactic feedback loop.

Relationship between neovascularization and degenerative changes in herniated lumbar intervertebral discs

PURPOSE

Lumbar disc degeneration may be associated with intensity of neovascularization in disc herniations. Our study was designed to evaluate how much the severity of histodegeneration is related to the development of neovascularization and to the level of pleiotrophin in the herniated lumbar discs.

METHODS

Surgically excised lumbar disc specimens were obtained from 29 patients with noncontained (i.e., extruding through the posterior longitudinal ligament) and 21 patients with contained disc herniations. The histodegeneration scores and levels of neovascularization were estimated according to semiquantitative analysis in lumbar disc and endplate samples. Immunohistochemical staining were performed to identify the newly formed blood vessels and to detect the presence of pleiotrophin in the specimens.

RESULTS

Higher levels of disc and endplate neovascularity were registered in noncontained herniations. The level of neovascularization was significantly related to the score of histodegeneration in the herniated disc tissues but not in the endplate specimens. Both contained and noncontained herniations had the highest values of histodegeneration in conjunction with the highest level of neovascularization but the relations between neovascularity and degenerative changes remained to be significant only in the group of noncontained herniations. Registration or frequency of pleiotrophin positive cells did not correlate significantly with histodegeneration or level of neovascularization in the disc samples.

CONCLUSION

Severe histodegeneration of the lumbar disc herniations is associated with enhanced neovascularization and potentially also spontaneous regression of the herniated tissue.

Clinical and pathological analysis of epidural inflammation in intervertebral disk extrusion in dogs

BACKGROUND

Little is known about the pathologic changes in the epidural space after intervertebral disk (IVD) extrusion in the dog.

OBJECTIVES

To analyze the pathology of the epidural inflammatory response, and to search for correlations between this process and clinical findings.

METHODS

Clinical data from 105 chondrodystrophic (CD) and nonchondrodystrophic (NCD) dogs with IVD extrusion were recorded. Epidural material from these dogs was examined histopathologically and immunohistochemically. Using statistical analysis, we searched for correlations between severity of epidural inflammation and various clinical and pathologic variables.

RESULTS

Most dogs exhibited an epidural inflammatory response, ranging from acute invasion of neutrophils to formation of chronic granulation tissue. The mononuclear inflammatory infiltrates consisted mostly of monocytes and macrophages and only few T and B cells. Surprisingly, chronic inflammatory patterns also were found in animals with an acute clinical history. Severity of the epidural inflammation correlated with degree of the epidural hemorrhage and nucleus pulposus calcification (P = .003 and .040), but not with age, chondrodystrophic phenotype, neurologic grade, back pain, pretreatment, or duration. The degree of inflammation was statistically (P = .021) inversely correlated with the ability to regain ambulation.

CONCLUSION AND CLINICAL IMPORTANCE

Epidural inflammation occurs in the majority of dogs with IVD extrusion and may develop long before the onset of clinical signs. Presence of calcified IVD material and hemorrhage in the epidural space may be the triggers of this lesion rather than an adaptive immune response to the nucleus pulposus as suggested in previous studies. Because epidural inflammation may affect outcome, further research is warranted.

IκB kinase β inhibitor downregulates pain-related neuropeptide production in the sensory neurons innervating injured lumbar intervertebral discs in the dorsal root ganglia of rats

BACKGROUND CONTEXT

Nuclear factor-κB (NF-κB) is an essential gene transcriptional regulator of inflammatory cytokines, and it plays important roles in numerous conditions, including inflammatory and neuropathic pain, especially when discogenic pain is involved. Phosphorylation of IκB protein through IκB kinase (IKK) is the first step in the activation of NF-κB activation and the upregulation of NF-κB-responsive genes.

PURPOSE

To investigate whether IKK inhibition alters the properties of pain-related neuropeptides in the rat lumbar degenerative intervertebral disc (IVD) model.

STUDY DESIGN

Retrograde neurotracing and immunofluorescent investigation of pain-related neuropeptide (calcitonin gene-related peptide [CGRP]) in the sensory innervation of injured lumbar IVD in rat dorsal root ganglia (DRGs).

METHODS

Forty female Sprague-Dawley rats were equally divided into four groups: naive, sham, and two agent-treated groups (vehicle [saline] group and anti-IKKβ [IMD-0560, IKKβ inhibitor] group). The L5-L6 IVDs of the agent-treated rats were exposed and injured by repeated punctures. The retrograde neurotracer Fluoro-Gold (FG) and corresponding treatment agents were intradiscally applied. In the sham group, FG alone was applied onto uninjured IVDs. One week later, L1-L3 DRGs were harvested and immunolabeled for CGRP as a pain marker. The proportions of FG-labeled CGRP-immunoreactive (-ir) DRG neurons were assessed.

RESULTS

Fluoro-Gold-labeled DRG neurons were almost equally prevalent at each DRG level. The proportions of FG-labeled CGRP-ir DRG neurons in the two agent-treated groups were significantly increased in comparison with those in the naive and the sham groups (p<.05) and were significantly decreased in the anti-IKKβ group in comparison with that in the vehicle group (p<.05).

CONCLUSIONS

The neuropeptide CGRP as a pain marker was upregulated in DRG neurons innervating the injured IVDs, and intradiscal inhibition of IKKβ significantly suppressed CGRP production in the DRG neurons innervating the rat IVD, suggesting the possible analgesic effect of IKKβ inhibition in discogenic pain.

Evaluation of the association between runt-related transcription factor 2 expression and intervertebral disk aging in dogs

OBJECTIVE

To investigate the relationship between runt-related transcription factor 2 (RUNX2) expression in canine nucleus pulposus (NP) cells and intervertebral disk aging in chondrodystrophoid dogs.

ANIMALS

7 healthy Beagles (mean age, 35.6 months) and 11 Dachshunds with herniated disks (mean age, 61 months).

PROCEDURES

All dogs underwent MRI examination of the thoracic and lumbar vertebral column immediately before sample collection under general anesthesia. The disk center-to-CSF T2-weighted signal intensity ratio was determined for healthy Beagles. Samples of NP were obtained from nonherniated disks in healthy Beagles and from herniated disks during surgical treatment of hospitalized Dachshunds. Samples were evaluated for RUNX2 and matrix metalloproteinase 13 transcript expression via reverse transcriptase PCR assay; RUNX2 protein expression was evaluated via immunohistochemical analysis, and correlation between these variables and age of dogs was evaluated. A 3' and 5' rapid amplification of cDNA ends method was used to identify the RUNX2 coding region.

RESULTS

RUNX2 cDNA had > 97% conservation with the human cDNA sequence and approximately 95% conservation with the mouse cDNA sequence; RUNX2 and matrix metalloproteinase 13 mRNA expression and RUNX2 protein expression in NP cells were positively correlated with age. The disk center-to-CSF T2-weighted signal intensity ratio was negatively correlated with RUNX2 protein expression in the NP of healthy dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that RUNX2 mRNA and protein expression in the NP are enhanced in aging intervertebral disks in dogs.

[Spontaneous resorption of thoracic calcified disc herniation: Report of two cases and review of the literature]

We report on two cases of spontaneous resorption of a calcified thoracic hernia. This phenomenom is widely recognised in lumbar and cervical hernia, but is exceptional at the thoracic level. The potential mechanisms underlying this resorption are discussed trough a review of the literature. We think this could be another argument for a "wait and watch" period before a surgical decision in the patients who have few symptoms.

A kind of specific osteolytic destruction of the vertebral bodies

This report describes two young patients with osteolytic destruction in two adjacent vertebral bodies along with the intervertebral disc, and reveals its possible mechanism. A lateral radiograph and CT scan displayed a giant osteolytic cavity in the L4 vertebral body. An MRI or CT scan with a two-dimensional reconstruction displayed the same changes in the L4 vertebral body and lower endplate erosion in the L3 vertebral body. A comprehensive preoperative evaluation did not identify a specific cause of vertebral destruction. Both patients underwent anterior lumbar fusion surgery. The lesions were removed for histological and immunohistochemical examination. Histopathological study of the destructed vertebral bodies in the two patients revealed the disruption or atrophy of bone trabeculae with infiltration of a large amount of B-lymphocytes and macrophages into the marrow cavities. Studies of its pathogenesis reveal that it is likely to be a B-lymphocyte-mediated local immune inflammatory reaction in the lumbar spine.

Age-related expression of MCP-1 and MMP-3 in mouse intervertebral disc in relation to TWEAK and TNF-α stimulation

This study was undertaken to investigate the age-related differences of monocyte chemotactic protein-1 (MCP-1) and matrix metalloproteinase-3 (MMP-3) expression in mouse intervertebral disc (IVD) and to determine whether MMP-3 plays a role in disc degeneration. Expression of MCP-1 and MMP-3 mRNA in mouse IVD was assessed by quantitative PCR. The ability of MCP-1 and MMP-3 expression in IVD to respond to TNF-α or TWEAK stimulation was examined by quantitative PCR, WB, ELISA, and immunohistochemistry. IVD derived from MMP-3-deficient and wild-type mice were compared using Safranin-O staining and immunohistochemistry. mRNA levels of MCP-1 and MMP-3 in IVD significantly diminished and the ability of MCP-1 or MMP-3 expression to respond to TNF-α or TWEAK stimulation was significantly reduced as age increased. IVD derived from 64-week-old wild-type mice showed clearly diffuse proteoglycan loss by Safranin-O staining and immunohistochemistry compared with younger mice. However, no loss of proteoglycan and typeII collagen were observed in IVD derived from 64-week-old MMP-3-deficient mice. MCP-1 and MMP-3 expression in mouse IVD showed age-related decreases. The response to inflammation in IVD also displayed age-related changes. Therefore, disc degeneration may vary with the patients' age and targeting MMP-3 may be a possible future therapeutic strategy for disc degeneration.

Effect of atorvastatin on angiogenesis in degenerated intervertebral disc in rat

STUDY DESIGN

An experimental study to measure the depth of penetration of new vessels in degenerated intervertebral disc in rat.

OBJECTIVE

To evaluate the effects of atorvastatin on angiogenesis in experimental disc degeneration in rat.

SUMMARY OF BACKGROUND DATA

Back pain is strongly associated with degenerated intervertebral disc and management of this condition is still empirical. Decrease of nucleus nutrition due to loss of vascularity with aging may aggravate the process of disc degeneration. So, angiogenesis may be useful in the healing process of degenerated disc. In this study, we wanted to evaluate the effect of atorvastatin, whose stimulating effect on angiogenesis on other tissues was shown in several studies, on degenerated intervertebral disc in rat.

METHODS

Atorvastatin was administered intraperitoneally for 6 weeks in doses of 1, 4, and 8 mg/kg in rats after experimental disc degeneration. The rats intervertebral disc sections were stained immunohistochemically for von Willebrand Factor to evaluate the depth of vessels penetration and degree of vascularity.

RESULTS

In the nonoperated control group, the intervertebral discs were avascular. But experimental disc degeneration promoted angiogenesis. In this group, the mean of penetration was 49.25 μ (standard deviation = 19.905). Atorvastatin stimulated angiogenesis after experimental disc degeneration in the rats and the angiogenesis was more significant in the high and medium dose groups than operated control group. High-dose atorvastatin could not inhibit angiogenesis in experimental degenerated disc. There was no any significant difference in degree of vascularity among the groups.

CONCLUSION

Atorvastatin stimulates angiogenesis in experimental disc degeneration in rats. But, it does not show a biphasic effect.

Attenuation of inflammatory events in human intervertebral disc cells with a tumor necrosis factor antagonist

STUDY DESIGN

The inflammatory responses of primary human intervertebral disc (IVD) cells to tumor necrosis factor α (TNF-α) and an antagonist were evaluated in vitro.

OBJECTIVE

To investigate an ability for soluble TNF receptor type II (sTNFRII) to antagonize TNF-α-induced inflammatory events in primary human IVD cells in vitro.

SUMMARY OF BACKGROUND DATA

TNF-α is a known mediator of inflammation and pain associated with radiculopathy and IVD degeneration. sTNFRs and their analogues are of interest for the clinical treatment of these IVD pathologies, although information on the effects of sTNFR on human IVD cells remains unknown.

METHODS

IVD cells were isolated from surgical tissues procured from 15 patients and cultured with or without 1.4 nmol/L TNF-α (25 ng/mL). Treatment groups were coincubated with varying doses of sTNFRII (12.5-100 nmol/L). Nitric oxide (NO), prostaglandin E₂ (PGE₂), and interleukin-6 (IL6) levels in media were quantified to characterize the inflammatory phenotype of the IVD cells.

RESULTS

Across all patients, TNF-α induced large, statistically significant increases in NO, PGE₂, and IL6 secretion from IVD cells compared with controls (60-, 112-, and 4-fold increases, respectively; P < 0.0001). Coincubation of TNF-α with nanomolar doses of sTNFRII significantly attenuated the secretion of NO and PGE₂ in a dose-dependent manner, whereas IL6 levels were unchanged. Mean IC₅₀ values for NO and PGE₂ were found to be 35.1 and 20.5 nmol/L, respectively.

CONCLUSION

Nanomolar concentrations of sTNFRII were able to significantly attenuate the effects of TNF-α on primary human IVD cells in vitro. These results suggest this sTNFR to be a potent TNF antagonist with potential to attenuate inflammation in IVD pathology.

Local application of interleukin-6 to the dorsal root ganglion induces tumor necrosis factor-α in the dorsal root ganglion and results in apoptosis of the dorsal root ganglion cells

STUDY DESIGN

The mechanisms of apoptosis behind the formation of tissue reactions at the surface of the dorsal root ganglion (DRG) exposed to the nucleus pulposus were studied with special reference to the role of interleukin-6 (IL-6), using electron microscopy and immunohistochemistry in rats.

OBJECTIVE

To study the role of IL-6 on the DRG.

SUMMARY OF BACKGROUND DATA

It has been reported that nucleus pulposus cells are capable to produce proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-α) and IL-6. Recently, it was observed that local application of nucleus pulposus induced a characteristic tissue reaction at the surface of the DRG. This change was due to apoptosis of DRG neurons. However, the role of IL-6 is not known regarding the apoptosis of the DRG neurons.

METHODS

Recombinant IL-6 was applied between the L4 DRG and the dura to mimic a disc herniation of the L4-L5 disc in rats. The L4 DRGs were resected 24 hours after surgery. The sections were processed for immunohistochemistry using antisera to TNF-α. Furthermore, the sections of the specimens were observed using light and electron microscopy to confirm the induced apoptosis of the DRG neurons. The sections were also processed for immunohistochemistry, using antisera to single-stranded DNA (ssDNA) and Caspase 3.

RESULTS

TNF-α immunoreactivity was observed in the peripheral area of DRG at the site of the application of IL-6. Typical changes of the cell nuclei were observed in the DRG by light and electron microscopy, indicating the presence of apoptosis. The presence of ssDNA and Caspase 3 further enhanced the impression that there was apoptosis of the DRG neurons.

CONCLUSION

IL-6 seemed to induce TNF-α at the surface of DRG exposed to IL-6 and to induce a characteristic reaction at the surface of the DRG. IL-6 may thus play an important role in nucleus pulposus-induced apoptosis of the DRG neurons as well as TNF-α.

Frequency of lumbar intervertebral disc calcification and angiogenesis, and their correlation with clinical, surgical, and magnetic resonance imaging findings

STUDY DESIGN

This study measured the frequency of lumbar intervertebral disc nucleus pulposus microscopic calcification and angiogenesis in adult patients undergoing discectomy compared to normal cadavers.

OBJECTIVE

The results were compared to determine the relationship between disc microscopic calcification with disc degeneration type, histopathological angiogenesis, patients' age, gender, and duration of symptoms.

SUMMARY OF BACKGROUND DATA

True frequency of microscopic calcification in normal or degenerated lumbar discs have not been fully defined nor linked to disc degeneration type and angiogenesis. Some studies demonstrated that angiogenesis and calcification are related to each other in several another tissues.

METHODS

The frequency of microscopic calcification in specimens of disc nucleus pulpous obtained from 2 groups were measured: specimens were obtained during surgery from 90 consecutive patients of 15 to 50 years old suffering from disc herniation in single level of L4-L5 or L5-S1 between 2005 and 2006, 60 additional specimens of lumbar disc nucleus pulposus were obtained from normal cadavers of the same ages. Calcification was determined microscopically by Von Kossa staining and angiogenesis by H/E, and type of degeneration radiologically by Modic classification.

RESULTS

Frequency of microscopic calcification was significantly higher in degenerated disc than normal cadaveric (54.4% vs. 6.7%) and was higher in Modic type III than type I (III: 95.0%, II: 57.4%, I: 13.0%), also prevalence of angiogenesis was significantly higher in patients than cadaveric discs (41.0% vs. 6.7%) and in calcified than noncalcified discs (59.2% vs. 19.5%) (P < 0.001). There was no relationship between disc calcification and patients' gender and level of discectomy.

CONCLUSION

Disc nucleus pulposus microscopic calcification is a common event occurring in adult patients suffering from lumbar disc herniation. Mechanisms that link disc degeneration, angiogenesis, and calcification remain a focus for further researches that may be useful in future medical treatments before surgical treatment of lumbar disc herniation.

Intramuscular oxygen-ozone therapy in the treatment of acute back pain with lumbar disc herniation: a multicenter, randomized, double-blind, clinical trial of active and simulated lumbar paravertebral injection

STUDY DESIGN

Multicenter randomized, double-blind, simulated therapy-controlled trial in a cohort of patients with acute low back pain (LBP) due to lumbar disc herniation (LDH).

OBJECTIVE

To assess the benefit of intramuscular-paravertebral injections of an oxygen-ozone (O2O3) mixture.

SUMMARY OF BACKGROUND DATA

Recent findings have shown that O2O3 therapy can be used to treat LDH that fails to respond to conservative management. However, these findings are based on intradiscal/intraforaminal O2O3 injection, whereas intramuscular-paravertebral injection is the technique used most in clinical practice in Italy and other Western countries.

METHODS

Sixty patients suffering from acute LBP caused by LDH was randomized to an intramuscular O2O3 or control group. Patients were observed up to assess pain intensity, LBP-related disability, and drug intake (15 [V2] and 30 [V3] days after treatment started, and 2 weeks [V4], and 3 [V5] and 6 [V6] months after treatment ended).

RESULTS

A significant difference between the 2 groups in the percentage of cases who had become pain-free (61% vs. 33%, P < 0.05) was observed at V6. Patients who received O2O3 had a lower mean pain score than patients who received simulated therapy throughout the observation period. A significant improvement was observed in LBP-related disability in the study group patients when compared with the control group patients. Active O2O3 therapy was followed by a significantly lower number of days on nonsteroidal anti-inflammatory drugs at V2 and V3 and by a lower number of days at V4. No adverse events were reported.

CONCLUSION

Treatment of LBP and sciatica is a major concern. Although the natural history of acute LBP is often self-limiting, conservative therapies are not always effective; in such cases, O2O3 intramuscular lumbar paravertebral injections, which are minimally invasive, seem to safely and effectively relieve pain, as well as reduce both disability and the intake of analgesic drugs.

TNF-alpha-induced NF-kappaB signaling reverses age-related declines in VEGF induction and angiogenic activity in intervertebral disc tissues

We previously demonstrated that VEGF and its receptors were expressed in human herniated discs (HD). TNF-alpha induced VEGF, resulting in neovascularization of disc tissues in a model of HD. The goal of the current research was to investigate the precise role of TNF-alpha-induced VEGF and the mechanism of angiogenesis in disc tissues. We performed ELISAs, Western blots, and immunohistological examinations to assess the role of TNF-alpha-induced VEGF using organ disc cultures with wild type, TNF receptor 1-null (TNF-RI(null)), or TNF receptor 2-null (TNF-RII(null)) mice. VEGF induction was inhibited when we used TNF-RI(null)-derived disc tissues. NF-kappaB pathway inhibitors also strongly suppressed VEGF induction. Thus, TNF-alpha induced VEGF expression in disc cells primarily through the NF-kappaB pathway. In addition, VEGF immunoreactivity was detected predominantly in annulus fibrosus cells and increased after TNF-alpha stimulation. TNF-alpha treatment also resulted in CD31 expression on endothelial cells and formation of an anastomosing network. In contrast, angiogenic activity was strongly inhibited in the presence of NF-kappaB inhibitors or anti-VEGF antibody. Our data show angiogenesis activity in disc tissues is regulated by VEGF and the NF-kappaB pathway, both of which are induced by TNF-alpha. The level of angiogenic activity in disc tissues was closely related to aging. Because neovascularization of HD is indispensable for HD resorption, the prognosis of HD and the rate of the resorption process in patients may vary as a function of the patient's age.

Mechanism of signal transduction in tumor necrosis factor-like weak inducer of apoptosis-induced matrix degradation by MMP-3 upregulation in disc tissues

STUDY DESIGN

Molecular biologic and immuno-histologic analyses using in vitro murine intervertebral disc tissue culture.

OBJECTIVE

To investigate the role of tumor necrosis factor-like weak inducer of apoptosis (TWEAK) in matrix metalloproteinase 3 (MMP-3) pathway induction, and the effect of TWEAK to induce other cytokines or angiogenesis factors in disc tissues.

SUMMARY OF BACKGROUND DATA

We previously demonstrated that TWEAK and its receptor Fn14 were expressed in murine disc tissues. TWEAK induced MMP-3 upregulation and aggrecan downregulation in disc tissues.

METHODS

Enzyme-Linked ImmunoSorbent Assay (ELISA), western blot, and immuno-histologic analyses were used to assess the role of TWEAK-induced MMP-3, using murine disc tissue culture.

RESULTS

TWEAK induced disc cells to generate MMP-3 as did TNF-alpha and IL-1beta. MMP-3 activity was detectable in murine disc cells. MMP-3 induction was markedly inhibited with a c-Jun N-terminal kinase (JNK) inhibitor. Phosphorylation of JNK was also confirmed. Introduction of TWEAK resulted in the degradation of disc matrix in organ disc culture, whereas proteoglycan degradation was markedly abrogated in the presence of an MMP-3 specific inhibitor or a JNK inhibitor. In addition, TWEAK also induced monocyte chemotactic protein (MCP)-1 via the NF-kappaB pathway, as phosphorylation of NF-kappaB was confirmed by western blotting.

CONCLUSION

TWEAK plays an important role in MMP-3 induction in murine disc cells via JNK that results in degradation of disc matrix. TWEAK also induces MCP-1, which belongs to the chemokine family that recruits inflammatory cells via the NF-kappaB pathway.

Effect of a nonprotein bioactive agent on the reduction of cyclooxygenase-2 and tumor necrosis factor–α in human intervertebral disc cells in vitro

Object

Neurotropin is a nonprotein extract from the inflamed skin of rabbits inoculated with vaccinia virus. In the present study the authors sought to clarify the focal antiinflammatory effects of Neurotropin in intervertebral disc cells, and these effects were compared with those induced by the selective cyclooxygenase (COX)–2 inhibitor 6-methoxy-2-naphthylacetic acid (nabumetone).

Methods

Six human intervertebral disc specimens were harvested during spinal surgery for lumbar disc herniation. Cells were stimulated with 500 pg/ml of interleukin (IL)–1β in the presence of various concentrations of Neurotropin (0, 10−5, 10−4, and 10−3Neurotropin Units/ml) or 50 μg/ml of nabumetone for 3 hours. The mRNA was extracted for polymerase chain reaction (PCR), and real-time PCR was used to quantify the mRNA levels of COX- 2, tumor necrosis factor (TNF)–α, and phospholipase A2. Cyclooxygenase-2, TNFα, and prostaglandin E2 (PGE2) protein concentrations were each determined by enzyme-linked immunosorbent assay.

Results

Neurotropin was found to significantly suppress the expression of COX-2 and TNFα at mRNA levels as well as the concentration of COX-2 at protein levels in a dose-dependent manner. Nabumetone was found to significantly increase COX-2 at mRNA levels but directly suppress the concentration of PGE2 in culture medium.

Conclusions

Results in this study suggest that Neurotropin has an analgesic effect through the suppression of COX-2 and TNFα in a focal area, and nabumetone shows this same effect through the suppression of PGE2 production. Thus, Neurotropin could decrease pain by blocking the central pain pathway or increasing focal antiinflammatory effects.

Postdiskogram CT features of lidocaine-sensitive and lidocaine-insensitive severely painful disks at provocation lumbar diskography

BACKGROUND AND PURPOSE

At lumbar diskography, intradiskal lidocaine can eliminate or reduce provoked diskogenic pain. The purpose of this study was to evaluate the postdiskogram CT features of lidocaine-sensitive and lidocaine-insensitive severely painful disks.

MATERIALS AND METHODS

Intradiskal lidocaine was injected at 182 severely painful levels in 111 patients. Clinical records/imaging studies were reviewed for response to intradiskal lidocaine (complete/substantial, partial, and no pain improvement), evidence of diskographic contrast leakage (fluoroscopic/CT images), and the overall postdiskogram CT appearance in these severely painful disks. The assessed traditional Dallas grade (degeneration/radial tear [RT]) was supplemented by identified postdiskogram CT features of annular derangement (annular gap [AG], RT into peripheral annular tear [PAT], isolated PAT, lamellar annular tear, free/attached annular fragments, bucket-handle tear, and peripheral annular pocket).

RESULTS

Isolated degenerative changes (40%) and radial defects with or without degeneration (60%) subsets were noted. Dallas grade 3 degeneration was most commonly observed (69%) with increased features of annular derangement in disks with a worsening Dallas grade. Complete/substantial versus no pain improvement was significantly associated with disk state (diskographic leakage, contained), radial defect (none, RT, or AG), and "RT-into-PAT" and were statistically significant in univariate models (P < .001). The associations remained significant in multivariate models. Higher Dallas degenerative grade and presence of free annular fragments were associated with a greater chance of no pain relief.

CONCLUSION

Severely painful disks demonstrated complex annular derangement with both radial defects (RTs and AGs) or degenerative changes present, alone or in combination. Complete/substantial pain improvement after lidocaine administration is associated with disk state, radial defect (RT and AG), and RT-into-PAT.