DYRK1-mediated phosphorylation of endocytic components is required for extracellular lumen expansion in ascidian notochord

BACKGROUND: The biological tube is a basal biology structure distributed in all multicellular animals, from worms to humans, and has diverse biological functions. Formation of tubular system is crucial for embryogenesis and adult metabolism. Ascidian Ciona notochord lumen is an excellent in vivo model for tubulogenesis. Exocytosis has been known to be essential for tubular lumen formation and expansion. The roles of endocytosis in tubular lumen expansion remain largely unclear. RESULTS: In this study, we first identified a dual specificity tyrosine-phosphorylation-regulated kinase 1 (DYRK1), the protein kinase, which was upregulated and required for ascidian notochord extracellular lumen expansion. We demonstrated that DYRK1 interacted with and phosphorylated one of the endocytic components endophilin at Ser263 that was essential for notochord lumen expansion. Moreover, through phosphoproteomic sequencing, we revealed that in addition to endophilin, the phosphorylation of other endocytic components was also regulated by DYRK1. The loss of function of DYRK1 disturbed endocytosis. Then, we demonstrated that clathrin-mediated endocytosis existed and was required for notochord lumen expansion. In the meantime, the results showed that the secretion of noto-chord cells is vigorous in the apical membrane. CONCLUSIONS: We found the co-existence of endocytosis and exocytosis activities in apical membrane during lumen formation and expansion in Ciona notochord. A novel signaling pathway is revealed that DYRK1 regulates the endocytosis by phosphorylation that is required for lumen expansion. Our finding thus indicates a dynamic balance between endocytosis and exocytosis is crucial to maintain apical membrane homeostasis that is essential for lumen growth and expansion in tubular organogenesis.

Metastatic poorly differentiated chordoma: the eyes do not see what the mind does not know

Chordoma is a rare tumor. It has unique clinical, pathological and immunohistochemical characteristics. Accurate diagnosis is essential as the tumor shows an aggressive clinical course and requires a multimodal therapeutic approach. A case with wide spread distant metastatic disease that was initially thought to represent metastatic thyroid carcinoma is presented. Appropriate clincopathologic correlation and the histologic findings raised the possibility of poorly differentiated chordoma. The diagnosis was confirmed by immunohistochemistry for INI-1 and Brachyury. The approach to the diagnosis emphasizing the clinical and pathologic findings of this case is discussed and reviewed in the context of the published literature.

Incidentally-Discovered Extraosseous Cystic Nasopharyngeal Chordoma in a Papillary Thyroid Cancer Patient

Skull base chordomas are rare, malignant tumors arising from primitive notochord remnants of the axial skeleton and comprise approximately 25–35% of all chordoma cases. Nasal endoscopy in previous case reports has characterized nasopharyngeal chordomas as firm, semi-translucent masses protruding from the posterior nasopharyngeal wall with a pink, “meaty” appearance. However, the nasopharyngeal chordoma in the present case had a soft, cystic appearance, unlike the tumors previously described. Herein, an unusual case of an incidentally discovered nasopharyngeal chordoma is reported in a patient with papillary thyroid cancer; the discovered chordoma had a benign cystic appearance with no abnormal positron emission tomography-computed tomography (PET-CT) uptake.

Chordomas: Histopathological Study in View of Anatomical Location

BACKGROUND: Chordomas are aggressive bone tumors that have a predilection for the axial skeleton including the skull base and spinal/sacral bones. However, the histopathological and clinical differences between skull base chordoma (SBC) and sacral/spinal chordoma (SC) are unclear as previous studies have been focused on patient prognosis and treatment outcome. This study aimed to evaluate the clinicopathologic features and prognosis of chordoma according to its location. METHODS: Patients with chordomas were enrolled, and the histopathologic features were compared according to the tumor location. RESULTS: A total of 52 patients were enrolled. SBCs had more abundant chondroid matrix and diffuse growth pattern, while SCs had non-chondroid, myxoid matrix and a lobulating pattern, typical of chordoma. Old age and residual tumors were risk factors for shorter overall survival in SBCs. The chondroid matrix was an independent risk factor for shorter disease-free survival in the overall population. CONCLUSION: Chordomas have different histopathologic features depending on the anatomical location.

Segmental Spinal Dysgenesis–“Redefined”

STUDY DESIGN: Retrospective single institutional observational study. PURPOSE: Segmental spinal dysgenesis (SSD), a complex spinal dysraphic state caused by notochord malformation disorders, is named after its morphological presentation where a spine segment is dysgenetic, malformed or absent. This study’s objective was to examine and reassess SSD imaging findings and correlate them with an embryological explanation. OVERVIEW OF LITERATURE: Scott and his colleagues defined SSD as segmental agenesis or dysgenesis of the lumbar or thoracolumbar vertebrae and underlying spinal cord. Tortori-Donati and his colleagues defined it as a morphologic continuum ranging from hypoplasia to an absent spinal cord segment. METHODS: Fifteen children, whose imaging findings and clinical features were consistent with SSD, were included in the study. Magnetic resonance imaging (MRI) was performed per institutional spine protocol. RESULTS: Five children (33.3%) presented with a high-ending bulbous cord with no caudal segment, six (40%) presented with a dorsal or lumbar segmental dysgenetic cord with a low-lying, bulky caudal cord but without significant spinal canal narrowing, and four (26.6%) presented with segmental caudal dysgenesis with severe kyphoscoliosis, gibbus deformity, and spinal canal narrowing with a normal distal segment (normal or low-lying). CONCLUSIONS: SSD is a complex spinal anomaly in children requiring clinical-radiological assessment followed by multidisciplinary management based on the extent and severity of the dysgenetic cord and the type of SSD. MRI plays a crucial role in both diagnosing and classifying SSD prior to surgical treatment to prevent further impairment.

Reto neuroquirúrgico actual del cordoma cervical / Current neurosurgical challenge of the cervical chordoma

El cordoma es un tumor osteocartilaginoso raro, de lento crecimiento, con una tasa de incidencia global de 8,4 casos por cada 10 millones de habitantes. Comúnmente aparece en la quinta y sexta década de la vida, predomina en el sexo masculino. Se presenta un paciente masculino de 47 años de edad, con cervicobraquialgia, cuadriparesia y masa tumoral palpable en región anterolateral del cuello. El estudio de resonancia magnética demostró la presencia de una lesión retrofraríngea con destrucción vertebral y compresión extradural. Se decidió resección quirúrgica de la lesión. El diagnóstico histopatológico por inmunohistoquímica arrojó como resultado, un cordoma(AU)

Chordoma is a rare, slow-growing osteocartilaginous tumor with an overall incidence rate of 8.4 cases per 10 million inhabitants. Commonly appears in the fifth and sixth decade of life, predominates in the male sex. We present a 47-year-old male patient with cervicobrachialgia, quadriparesis and palpable tumor mass in the anterolateral region of the neck. The magnetic resonance study showed the presence of a retropharyngeal lesion with vertebral destruction and extradural compression. Surgical resection of the lesion was decided. The histopathological diagnosis by immunohistochemistry resulted in a chordoma(AU)

Ontogenetic development of tetra Astyanax lacustris (Characiformes: Characidae)

Ontogenetic development of the tetra Astyanax lacustris was studied under laboratory conditions. Larvae obtained by induced reproduction were maintained individually in tissue-culture plates, at 25°C. Daily observations and morphometric measurements were performed. Larvae hatched with a total length (TL) of 3.02 ± 0.34 mm (average ± standard deviation) without pigmentation and 0.06 ± 0.02 mm³ of yolk reserves. The yolk-sac larval period lasted 26 h post-hatching (hph). During this period, eye pigmentation started, the digestive tract emerged, the anus opened, and the animals began to show steady movements. Inflation of the swimming bladder initiates the preflexion stage, which extended until 230 hph. During this stage, the transition from endogenous to exogenous feeding was observed, with the yolk reserve being completely absorbed after 74 hph (TL: 4.17 ± 0.36 mm). Up to 86 hph it was possible to observe the first food ingested within the digestive tract. This period was followed by the flexion stage, with the folding of the notochord tip and development of the caudal fin (11-13 days post-hatching). Finally, during the last larval developmental stage (postflexion), the segmentation of the fin rays was completed, and the emergence of scales was observed (TL: 5.97 ± 0.65 mm). The larval ontogenetic development of A. lacustris was completed after 22 post-hatching days (dph).(AU)

O desenvolvimento ontogenético do lambari Astyanax lacustris (Pisces, Characidae) foi estudado em condições ambientais controladas. Larvas obtidas através de reprodução induzida, foram mantidas individualmente em placas de cultivo celular, a 25°C. Diariamente foram realizadas observações e medições morfométricas. As larvas eclodiram com 3,02 ± 0,34 mm (média ± desvio padrão) de comprimento total (CT); sem pigmentação e com 0,06 ± 0,02 mm³ de reserva vitelínica. O período larval vitelino estendeu-se durante as primeiras 26 horas pós-eclosão (hpe) e durante este período teve início o processo de pigmentação dos olhos, o surgimento do tubo digestório, abertura anal e os animais passaram a apresentar movimentação constante. Com o inflamento da bexiga natatória tem início o estágio de pré-flexão, que se estendeu por até 230 hpe. Durante este estágio, foi observada a transição entre a alimentação endógena e a exógena, sendo a reserva vitelínica totalmente absorvida após 74 hpe (com os animais atingindo 4,17 ± 0,36 mm de CT) e em até 86 hpe foi possível observar a primeira alimentação no trato digestório. Após esse período, teve início o estágio de flexão da parte final da notocorda e da estruturação da nadadeira caudal (11 e 13 dias após a eclosão). Por fim, no último estágio de desenvolvimento larval (pós-flexão), foi observada a segmentação completa dos raios das nadadeiras e o início do aparecimento das escamas (CT: 5,97 ± 0,65 mm). O desenvolvimento ontogenético larval de A. lacustris foi concluído após 22 dias pós-eclosão (dpe).(AU)

Effect of RNA Interference-Mediated Suppression of p75 on the Viability of Rat Notochordal Cells

STUDY DESIGN: In vitro cell culture model. PURPOSE: To investigate the effects of RNA interference (RNAi) on p75 expression and viability of rat notochordal cells treated with serum deprivation. OVERVIEW OF LITERATURE: RNAi enables the inhibition of specific genes by sequence-specific gene silencing using a double-stranded RNA. METHODS: Notochordal cells were isolated, cultured, and placed in 10% (control) or 0% (apoptosis-promoting) fetal bovine serum (FBS) for 48 hours. The expression of p75, apoptosis, and cell proliferation were determined. To suppress p75 expression, a small interfering RNA (siRNA) was synthesized against p75 (p75 siRNA) and transfected into cells. The suppression of p75 mRNA expression was investigated using the reverse transcription-polymerase chain reaction. The degree of p75 suppression was semiquantitatively analyzed using densitometry. The effect of p75 siRNA on apoptosis and proliferation of cells was determined. Solutions of an unrelated siRNA and transfection agent alone served as controls. RESULTS: Serum deprivation significantly increased apoptosis by 40.3%, decreased proliferation of notochordal cells by 45.3% (both, p<0.001), and upregulated p75 expression. The p75 siRNA suppressed p75 expression in cells cultured in 0% FBS. The rate of suppression by p75 siRNA of p75 mRNA was 72.9% (p<0.001). Suppression of p75 expression by p75 siRNA inhibited apoptosis by 7% and increased proliferation by 14% in cells cultured in 0% FBS (both, p<0.05). CONCLUSIONS: siRNA-mediated suppression of p75 inhibited apoptosis and increased proliferation of notochordal cells under conditions of serum deprivation, suggesting that RNAi might serve as a novel therapeutic approach for disc degeneration caused by insufficient viability of disc cells through the suppression of the expression of harmful genes.

Rat Notochordal Cells Undergo Premature Stress-Induced Senescence by High Glucose

STUDY DESIGN: In vitro cell culture. PURPOSE: The purpose of the study was to investigate the effect of high glucose on premature stress-induced senescence of rat notochordal cells. OVERVIEW OF LITERATURE: Glucose-mediated increase of oxidative stress is a major causative factor for the development of diseases associated with diabetes mellitus such as senescence. However, no information is available for the effect of high glucose on premature stress-induced senescence of rat notochordal cells. METHODS: Notochordal cells were isolated from 4-week-old rats, cultured and placed in either 10% fetal bovine serum (FBS, normal control) or 10% FBS plus two high glucose concentrations (0.1 M and 0.2 M, experimental conditions) for 1 and 3 days. We identified and quantified the mitochondrial damage (mitochondrial transmembrane potential), reactive oxygen species (ROS) and antioxidants, such as manganese superoxide dismutase (MnSOD) and catalase, for each condition. We also identified and quantified senescence and telomerase activity. Finally, we determined the expression of proteins related to replicative senescence (p53-p21-pRB) and stress-induced senescence (p16-pRB) pathways. RESULTS: Two high glucose concentrations enhanced the disruption of mitochondrial transmembrane potential and excessive generation of ROS in notochordal cells for 1 and 3 days, respectively. The expressions of MnSOD and catalase were increased in notochordal cells treated with both high glucose concentrations at 1 and 3 days. The telomerase activity declined at 1 and 3 days. Two high glucose concentrations increased the occurrence of stress-induced senescence of notochordal cells by p16-pRB pathways at 1 and 3 days. CONCLUSIONS: Despite compensatory expression of antioxidants, high glucose-induced oxidative stress accelerates stress-induced senescence in rat notochordal cells. This may result in dysfunction of notochordal cells, leading to accelerated premature disc degeneration. The prevention of excessive generation of oxidative stress by strict blood glucose control is important to prevent or to delay premature disc degeneration in young patients with diabetes mellitus.

Benign notochordal cell tumor of cervical vertebrae: a clinicopathologic analysis / 中华病理学杂志

<p><b>OBJECTIVE</b>To report 2 rare cases of benign notochordal cell tumor (BNCT), according to WHO classification of tumors of soft tissue and bone (4th edition). Their radiologic and clincopathologic features and differential diagnosis were investigated.</p><p><b>METHODS</b>Two cases of BNCT were studied by retrospective review of the clinical, radiologic, pathologic and immunophenotypical findings. Related literatures were reviewed at the same time.</p><p><b>RESULTS</b>Case 1 was a 53-year-old man, and case 2 was a 61-year-old woman. Radiographically, both patients presented with abnormal imaging findings in the fifth cervical vertebral body with the lesions located within the bone but without extra osseous mass. Histopathologically, the lesions lacked lobular architecture and extracellular myxoid matrix. The tumor cells were vacuolated and had centrally or peripherally placed round or oval nuclei with small nucleoli, mimicking mature adipocytes. No cytological atypia or mitotic figures were seen. The affected bone trabeculae were sclerotic and islands of bone marrow were often entrapped within the tumor.</p><p><b>CONCLUSIONS</b>Although sharing similar anatomic distribution and immunophenotype to those of chordoma, BNCT has distinct radiologic and pathologic features and different treatment and prognosis. The differential diagnosis between BNCT and chordoma requires detailed clinical, radiologic and histopathologic evaluations.</p>

A Case of Endoscopic Removal of Clival Chordoma through Extended Transclival Approach / 대한이비인후과학회지

Clival chordoma is a rare malignant tumor which arises from the remnants of notochord. Although it is a slow-growing tumor that rarely metastasize to other organs, it is regarded as clinically malignant because of local invasiveness and high recurrence rate. Furthermore, because its location is critical and surgical resection is difficult, it has poor prognosis. Neurosurgeons have traditionally taken the lead in managing tumor, however, with the development of endoscopic techniques and wide spread of usage in skull base surgery, the role of ENT surgeon has become bigger recently. We report a recent case of recurrent clival chordoma successfully removed by endoscopic extended transclival approach.

Matrix Degradative Enzymes and Their Inhibitors during Annular Inflammation: Initial Step of Symptomatic Intervertebral Disc Degeneration

OBJECTIVE: Symptomatic disc degeneration develops from inflammatory reactions in the annulus fibrosus (AF). Although inflammatory mediators during annular inflammation have been studied, the roles of matrix metalloproteinases (MMPs) and their inhibitors have not been fully elucidated. In this study, we evaluated the production of MMPs and tissue inhibitors of metalloproteinase (TIMPs) during annular inflammation using an in vitro co-culture system. We also examined the effect of notochordal cells on annular inflammation. METHODS: Human AF (hAF) pellet was co-cultured for 48 hours with phorbol myristate acetate-stimulated macrophage-like THP-1 cells. hAF pellet and conditioned media (CM) from co-cultured cells were assayed for MMPs, TIMPs, and insulin-like growth factor (IGF)-1 levels using real-time reverse-transcriptase polymerase chain reaction and enzyem-linked immunosorbent assay. To evaluate whether notochordal cells affected MMPs or TIMPs production on annular inflammation, hAF co-cultured with notochordal cells from adult New Zealand White rabbits, were assayed. RESULTS: MMP-1, -3, -9; and TIMP-1 levels were significantly increased in CM of hAF co-cultured with macrophage-like cells compared with hAF alone, whereas TIMP-2 and IGF-1 levels were significantly decreased (p<0.05). After macrophage exposure, hAF produced significantly more MMP-1 and -3 and less TIMP-1 and -2. Interleukin-1beta stimulation enhanced MMP-1 and -3 levels, and significantly diminished TIMP-2 levels. Co-culturing with rabbit notochordal cells did not significantly influence MMPs and TIMPs production or COL1A2 gene expression. CONCLUSION: Our results indicate that macrophage-like cells evoke annular degeneration through the regulation of major degradative enzymes and their inhibitors, produced by hAF, suggesting that the selective regulation of these enzymes provides future targets for symptomatic disc degeneration therapy.

The Unresolved Case of Sacral Chordoma: From Misdiagnosis to Challenging Surgery and Medical Therapy Resistance

PURPOSE: A sacral chordoma is a rare, slow-growing, primary bone tumor, arising from embryonic notochordal remnants. Radical surgery is the only hope for cure. The aim of our present study is to analyse our experience with the challenging treatment of this rare tumor, to review current treatment modalities and to assess the outcome based on R status. METHODS: Eight patients were treated in our institution between 2001 and 2011. All patients were discussed by a multidisciplinary tumor board, and an en bloc surgical resection by posterior perineal access only or by combined anterior/posterior accesses was planned based on tumor extension. RESULTS: Seven patients underwent radical surgery, and one was treated by using local cryotherapy alone due to low performance status. Three misdiagnosed patients had primary surgery at another hospital with R1 margins. Reresection margins in our institution were R1 in two and R0 in one, and all three recurred. Four patients were primarily operated on at our institution and had en bloc surgery with R0 resection margins. One had local recurrence after 18 months. The overall morbidity rate was 86% (6/7 patients) and was mostly related to the perineal wound. Overall, 3 out of 7 resected patients were disease-free at a median follow-up of 2.9 years (range, 1.6-8.0 years). CONCLUSION: Our experience confirms the importance of early correct diagnosis and of an R0 resection for a sacral chordoma invading pelvic structures. It is a rare disease that requires a challenging multidisciplinary treatment, which should ideally be performed in a tertiary referral center.

Temporal and Spatial Expression Patterns of miR-302 and miR-367 During Early Embryonic Chick Development

The microRNAs (miRNAs) are small, non-coding RNAs that modulate protein expression by interfering with target mRNA translation or stability. miRNAs play crucial roles in various functions such as cellular, developmental, and physiological processes. The spatial expression patterns of miRNAs are very essential for identifying their functions. The expressions of miR-302 and miR-367 are critical in maintaining stemness of pluripotent stem cells, including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) but their functions in early development are not fully elucidated. So, we used Locked Nucleic Acid (LNA) probes to perform in situ hybridization and confirmed the temporal and spatial distribution patterns during early chick development. As a result, we found that miR-302 and miR-367 were expressed in various tissues such as primitive steak, neural ectoderm, neural plate, neural fold, neural tube, notochord, and oral cavity. Specially, we confirmed that miR-302 and miR-367 were strongly expressed in neural folds in HH8 to HH10. miR-302 was expressed on dorsal part of the neural tube but miR-367 was expressed on lateral and ventral parts of the neural tube. And also we performed quantitative stem-loop real-time PCR to analyze global expression level of miR-302 and miR-367. miR-302 and miR-367 expression was sustained before Hamburger and Hamilton stage (HH) 14. Thus, the temporal and spatial expression patterns of miR-302 and miR-367 may provide us information of the role of these miRNAs on tissue formation during early chick development.

Giant Chordoma of the Upper Thoracic Spine with Mediastinal Involvement: A Surgical Challenge

Thoracic chordomas are very rare malignant tumours originating from notochordal remnants. These tumours develop within a vertebral body and enlarge involving the mediastinal compartment. Because of their slow-growing attitude, they become symptomatic only when they invade or compress the spinal cord and/or mediastinal organs. We present a rare case of a thoracic spine chordoma presenting with increasing paraparesis with a huge mediastinal component which was surgically debulked to decompress the spinal cord and medistinal organs.

Acesso endoscópico endonasal para cordomas do clivus: relato de caso e revisão da literatura / Endoscopic endonasal approach for clival chordomas – case report and review of literature

Cordomas do clivo são lesões agressivas que se originam de remanescentes da notocorda primitiva, apresentando diagnostico e conduta desafiadoras. A ressecção radical da lesão tem sido recomendada para melhor prognóstico e o tratamento cirúrgico constitui desafio ao neurocirurgião. Vias de acesso transbasal, orbitozigomática, subtemporal, transcondilar, transmaxilar, e transesfenoidal extendida tem sido opções no tratamento cirúrgico. Relatamos caso de cordoma de clivus tratado por via endoscópica endonasal transesfenoidal.

Chordoma in the Tail of a Ferret / 한국실험동물학회지

A chordoma is an uncommon tumor that originates from the remnants of the notochord and most commonly involves the cranial and caudal regions of the axial skeleton. Chordoma has been described in laboratory animals such as dogs, rats, minks, and ferrets. This report describes a case of a chordoma in the tail of a ferret. Grossly, a grayish-white, expansile, subcutaneous soft-tissue mass was observed in the tail. Histopathologically, the mass was a loosely placed, nodular, unencapsulated neoplasm within the dermis. In the mass, tumor lobules were intermingled with fibrous tissues. Fibrous tissues contained abundant extracellular basophilic material that was consistent with mucin. The tumor was composed of a close pack of adipocyte-like vacuolated cells (physaliferous cells). The cells were centrally or eccentrically located round nuclei and eosinophilic cytoplasm with large vacuoles. Immunohistologically, neoplastic cells were positive for vimentin and S-100 protein. Based on histopathologic findings and special staining characteristics, this case was diagnosed as chordoma.

A Case of Giant Sacral Chordoma

PURPOSE: Chordoma is a rare primary osseous tumor arising from the remnants of the primitive notochord. It occurs once in 2,000,000. It is characterized by its slow growth, high frequency to invade destroy bone by direct extension. We experienced giant sacral chordoma and reconstructed with gluteal advancement flap. METHODS: A 52-year-old woman presented with a 2-years history of gluteal pain. In the biopsy study revealed sacral chordoma. MRI study showed 13 x 12 x 10 cm sized m0cs. We approached anterior and posterior resection and reconstructed with bilateral gluteus maximus advancement flap. RESULTS: After the operation, blader and anal function were slightly decreased. But, 4 months later those were almost fully recovered. There was no significant complication and recurrence after 2-years follow-up. CONCLUSION: Chordoma is characterized by its slow growth, high frequency to invade and destroy bone by direct extension. Wide surgical resection is the only curative procedure. We report a ase of giant sacral chordoma which was successfully treated by anterior and posterior approach and reconstructed with bilateral gluteal advancement flap.

A Case of Giant Sacral Chordoma

PURPOSE: Chordoma is a rare primary osseous tumor arising from the remnants of the primitive notochord. It occurs once in 2,000,000. It is characterized by its slow growth, high frequency to invade destroy bone by direct extension. We experienced giant sacral chordoma and reconstructed with gluteal advancement flap. METHODS: A 52-year-old woman presented with a 2-years history of gluteal pain. In the biopsy study revealed sacral chordoma. MRI study showed 13 x 12 x 10 cm sized m0cs. We approached anterior and posterior resection and reconstructed with bilateral gluteus maximus advancement flap. RESULTS: After the operation, blader and anal function were slightly decreased. But, 4 months later those were almost fully recovered. There was no significant complication and recurrence after 2-years follow-up. CONCLUSION: Chordoma is characterized by its slow growth, high frequency to invade and destroy bone by direct extension. Wide surgical resection is the only curative procedure. We report a ase of giant sacral chordoma which was successfully treated by anterior and posterior approach and reconstructed with bilateral gluteal advancement flap.

Notochordal Cells Influence Gene Expression of Inflammatory Mediators of Annulus Fibrosus Cells in Proinflammatory Cytokines Stimulation

OBJECTIVE: Notochordal cells in the intervertebral disc interact with nucleus pulposus (NP) cells and support the maintenance of disc homeostasis by regulation of matrix production. However, the influence of notochordal cells has not been evaluated in the annulus fibrosus (AF), which is the primary pain generator in the disc. We hypothesized that the notochordal cell has the capacity to modulate inflammatory mediators secreted by AF cells secondary to stimulation. METHODS: Notochordal and AF cells were isolated from adult New Zealand white rabbits. AF pellets were cultured with notochordal cell clusters or in notochordal cell-conditioned media (NCCM) for 24 or 48 hours with proinflammatory cytokines at varying concentrations. Gene expression in AF pellets were assayed for nitric oxide synthase (iNOS), cyclo-oxygenase (COX)-2, and interleukin (IL)-6 by real time reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: AF pellet in NCCM significantly decreased the iNOS and COX-2 messenger ribonucleic acid (mRNA) levels compared to AF pellets alone and AF pellets with notochordal cells (p < 0.05). AF pellet resulted in dose-dependent iNOS and COX-2 expression in response to IL-1beta, stimulation, demonstrating that 1 ng/ml for 24 hours yielded a maximal response. AF pellet in NCCM significantly decreased the expression of iNOS and COX-2 in response to 1ng/ml IL-1beta, stimulation at 24 hours (p < 0.05). There was no difference in IL-6 expression compared to AF pellets alone or AF pellets with notochordal cell clusters. CONCLUSION: We conclude that soluble factors from notochordal cells mitigate the gene expression of inflammatory mediators in stimulated AF, as expected after annular injury, suggesting that notochordal cells could serve as a novel therapeutic approach in symptomatic disc development.