Joji Mochida

Tokai University, Hiratuka, Kanagawa, Japan

Are you Joji Mochida?

Claim your profile

Publications (154)376.07 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: IntroductionAngiogenesis is an important factor in the development of osteoarthritis (OA). We investigated the efficacy of bevacizumab, an antibody against vascular endothelial growth factor and an inhibitor of angiogenesis, in the treatment of OA using a rabbit model of anterior cruciate ligament transection.Methods First, we evaluated the response of gene expression and histology of the normal joint to bevacizumab treatment. Next, in a rabbit model of OA induced by anterior cruciate ligament transection, we used macroscopic and histological evaluations and real-time polymerase chain reaction (PCR) to examine the responses to intravenous (systemic) administration of bevacizumab (OAB IV group). We also investigated the efficacy of intra-articular (local) administration of bevacizumab in OA-induced rabbits (OAB IA group).ResultsHistologically, bevacizumab had no negative effect in normal joints. Bevacizumab did not increase the expression of genes for catabolic factors in the synovium, subchondral bone, or articular cartilage, but it increased the expression of collagen type 2 in the articular cartilage. Macroscopically and histologically, the OAB IV group exhibited a reduction in articular cartilage degeneration and less osteophyte formation and synovitis compared with the control group (no bevacizumab; OA group). Real-time PCR showed significantly lower expression of catabolic factors in the synovium in the OAB IV group compared with the OA group. In articular cartilage, expression levels of aggrecan, collagen type 2, and chondromodulin-1 were higher in the OAB IV group than in the OA group. Histological evaluation and assessment of pain behaviour showed a superior effect in the OAB IA group compared with the OAB IV group 12 weeks after administration of bevacizumab, even though the total dosage given to the OAB IA group was half that received by the OAB IV group.Conclusions Considering the dosage and potential adverse effects of bevacizumab, the local administration of bevacizumab is a more advantageous approach than systemic administration. Our results suggest that intra-articular bevacizumab may offer a new therapeutic approach for patients with post-traumatic OA.
    Arthritis research & therapy. 09/2014; 16(5):427.
  • [Show abstract] [Hide abstract]
    ABSTRACT: In anatomic anterior cruciate ligament (ACL) reconstruction, several pitfalls in creating the femoral bone tunnels at the correct position are of great concern. Our new method, the tibia rotational (TR) technique, may contribute to resolving these. The purpose of this study is to describe further details about the TR technique in anatomic double-bundle ACL reconstruction. Both anteromedial and posterolateral femoral bone tunnels were drilled through a posterolateral tibial bone tunnel using tibial rotation without deep knee flexion. When it is difficult to reach the mark with the rigid guide pin, the narrow curved TR technique guide and the flexible drill system allow drilling femoral bone tunnels in the correct position. The TR technique offers the technical ease required for widespread acceptance while prioritizing the fundamental goals of an anatomic double-bundle ACL reconstruction.
    Arthroscopy techniques. 08/2014; 3(4).
  • [Show abstract] [Hide abstract]
    ABSTRACT: After traumatic spinal cord injury (SCI), endoplasmic reticulum (ER) stress exacerbates secondary injury, leading to expansion of demyelination and reduced remyelination due to oligodendrocyte precursor cell (OPC) apoptosis. Although recent studies have revealed that amiloride controls ER stress and leads to improvement in several neurological disorders including SCI, its mechanism is not completely understood. Here, we used a rat SCI model to assess the effects of amiloride on functional recovery, secondary damage expansion, ER stress-induced cell death and OPC survival. Hindlimb function in rats with spinal cord contusion significantly improved after amiloride administration. Amiloride significantly decreased the expression of the pro-apoptotic transcription factor CHOP in the injured spinal cord and significantly increased the expression of the ER chaperone GRP78, which protects cells against ER stress. In addition, amiloride treatment led to a significant decrease in ER stress-induced apoptosis and a significant increase of NG2-positive OPCs in the injured spinal cord. Furthermore, in vitro experiments performed to investigate the direct effect of amiloride on OPCs revealed that amiloride reduced CHOP expression in OPCs cultured under ER stress. These results suggest that amiloride controls ER stress in SCI and inhibits cellular apoptosis, contributing to OPC survival. The present study suggests that amiloride may be an effective treatment to reduce ER stress-induced cell death in the acute phase of SCI.
    European Journal of Neuroscience 06/2014; · 3.75 Impact Factor
  • Yoshiyasu Uchiyama, Joji Mochida
    [Show abstract] [Hide abstract]
    ABSTRACT: It is difficult to target low-intensity pulsed ultrasound (LIPUS) to the thick portion of soft tissue at the femoral shaft, proximal humerus, spine, and hip joint. A femoral targeting method using ultrasonography (US) was therefore employed to examine the clinical effect of treatment.
    Journal of orthopaedic trauma. 06/2014; 28(6):S5.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Oxidative stress, caused by the over production of reactive oxygen species (ROS), has been shown to contribute to cell damage associated with neurotrauma and neurodegenerative diseases. ROS mediates cell damage either through direct oxidation of lipids, proteins and DNA or by acting as signaling molecules to trigger cellular apoptotic pathways. The 78 kDa glucose-regulated protein (GRP78) is an ER chaperone that has been suggested to protect cells against ROS-induced damage. However, the protective mechanism of GRP78 remains unclear. In this study, we used C6 glioma cells transiently overexpressing GRP78 to investigate the protective effect of GRP78 against oxidative stress (hydrogen peroxide)-induced injury. Our results showed that the overexpression of GRP78 significantly protected cells from ROS-induced cell damage when compared to non-GRP78 overexpressing cells, which was most likely due to GRP78-overexpressing cells having higher levels of glutathione (GSH) and quinone oxidoreductase 1 (NQO1), two antioxidants that protect cells against oxidative stress. Although hydrogen peroxide treatment increased lipid peroxidation in non-GRP78 overexpressing cells, this increase was significantly reduced in GRP78-overexpressing cells. Overall, these results indicate that GRP78 plays an important role in protecting glial cells against oxidative stress via regulating the expression of GSH and NQO1.
    PLoS ONE 01/2014; 9(1):e86951. · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Loss of vital functions in the somatic motor and sensory nervous systems can be induced by severe peripheral nerve transection with a long gap following trauma. In such cases, autologous nerve grafts have been used as the gold standard, with the expectation of activation and proliferation of graft-concomitant Schwann cells associated with their paracrine effects. However, there are a limited number of suitable sites available for harvesting of nerve autografts due to the unavoidable sacrifice of other healthy functions. To overcome this problem, the potential of skeletal muscle-derived multipotent stem cells (Sk-MSCs) was examined as a novel alternative cell source for peripheral nerve regeneration. Cultured/expanded Sk-MSCs were injected into severely crushed sciatic nerve corresponding to serious neurotmesis. After 4 weeks, engrafted Sk-MSCs preferentially differentiated into not only Schwann cells, but also perineurial/endoneurial cells, and formed myelin sheath and perineurium/endoneurium, encircling the regenerated axons. Increased vascular formation was also observed, leading to a favorable blood supply and waste product excretion. In addition, engrafted cells expressed key neurotrophic and nerve/vascular growth factor mRNAs; thus, endocrine/paracrine effects for the donor/recipient cells were also expected. Interestingly, skeletal myogenic capacity of expanded Sk-MSCs was clearly diminished in peripheral nerve niche. The same differentiation and tissue reconstitution capacity of Sk-MSCs was sufficiently exerted in the long nerve gap bridging the acellular conduit, which facilitated nerve regeneration/reconnection. These effects represent favorable functional recovery in Sk-MSC-treated mice, as demonstrated by good corduroy walking. We also demonstrated that these differentiation characteristics of the Sk-MSCs were comparable to native peripheral nerve-derived cells, whereas the therapeutic capacities were largely superior in Sk-MSCs. Therefore, Sk-MSCs can be a novel/suitable alternative cell source for healthy nerve autografts.
    PLoS ONE 01/2014; 9(3):e91257. · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Release of chemotactic factors in response to tissue damage has been described for different musculoskeletal tissues, including the intervertebral disc (IVD). This study investigated the chemoattractants that are released by induced degenerative IVDs and may be involved in recruiting mesenchymal stem cells (MSCs). Bovine caudal discs were cultured within a bioreactor and loaded under conditions that mimicked physiological or degenerative settings. Between days 4-6, medium was replaced by PBS, which was subsequently used for proteomic, ELISA and immunoprecipitation analyses of secreted chemokines and cytokines. A Boyden chamber assay was used to observe human MSC migration towards native and chemokine depleted media. Gene expression levels of chemokine receptors in human MSCs were analysed, and CCL5 was localised in bovine and human IVD by immunohistochemistry. Proteomic analysis revealed the presence of CCL5 and CXCL6 within conditioned media. Higher concentrations of CCL5 were found in the degenerative media, and a relationship was found between interleukin-1β and CCL5 concentration. Chemokine immunoprecipitation showed that MSCs had a significantly reduced chemotactic migration towards CCL5-immunoprecipitated and CCL5/CXCL6 co-immunoprecipitated media, whilst CXCL6 depletion did not change MSC chemotaxis. MSCs showed a significant increase in mRNA expression of the CCL5 receptors, CCR1 and CCR4, upon culture in degenerative media. Furthermore, CCL5 was identified in bovine and human disc tissue by immunohistochemistry. Hence, CCL5 may be a key chemoattractant that is produced and released by the intervertebral disc cells. Therefore, these factors could be used to enhance stem/progenitor cell mobilisation in regenerative therapies for early stages of disc degeneration.
    European cells & materials 01/2014; 27:124-36. · 4.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In our previous studies, we have demonstrated effective regeneration of cartilage through the creation and application of layered cell sheets that combine both chondrocytes and synovial cells. In this study, we were able to demonstrate that cells derived from cell sheets can survive for long periods after transplantation into rat knee joints having osteochondral defects. We established a method for generating cell sheets from firefly luciferase-expressing chondrocytes obtained from transgenic Lewis rats, and carried out allogenic transplantation of these cell sheets into wild-type Lewis rats. We then administered luciferin and monitored the survival of the transplanted cells by using bioluminescence imaging (BLI). Our data showed that the transplanted cells survived and could be detected for more than 21 months, which was longer than expected. Furthermore, the BLI data showed that the transplanted cells remained in the knee joint and did not migrate to other parts of the body, thus confirming the safety of the cell sheets. In this study, we monitored the duration of survival of cell sheets composed of only chondrocytes, only synovial cells, or both chondrocytes and synovial cells, and found that all three types of cell sheets survived for an extended period of time.
    Biomaterials 12/2013; · 8.31 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cartilage damage is typically treated by chondrocyte transplantation, mosaicplasty, or microfracture. Recent advances in tissue engineering have prompted research on techniques to repair articular cartilage damage using a variety of transplanted cells. We studied the repair and regeneration of cartilage damage using layered chondrocyte sheets prepared in a temperature-responsive culture dish. We previously reported achieving robust tissue repair when covering only the surface layer of partial-thickness defects with layered chondrocyte sheets in domestic rabbits. We also reported good Safranin O staining and integration with surrounding tissue in a minipig model of full-thickness cartilaginous defects in the knee joint. We have continued our studies using human chondrocytes obtained from patients under IRB approval, and have confirmed the safety and efficacy of chondrocyte sheets, and have submitted a report to the Ministry of Health, Labour, and Welfare in Japan. In 2011, the Ministry gave us approval to perform a clinical study of joint repair using cell sheets. We have just started implanting cell sheets in patients at Tokai University Hospital. Anat Rec, 2013. © 2013 Wiley Periodicals, Inc.
    The Anatomical Record Advances in Integrative Anatomy and Evolutionary Biology 12/2013; · 1.34 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Study design:Focus group studyObjective:To investigate cell-specific endoplasmic reticulum (ER) stress reactions in contusive spinal cord by evaluating the expression of the glucose-regulated protein 78 (GRP78) and C/EBP homologous transcription factor protein (CHOP) using immunohistochemical staining.Setting:Data were analysed at Tokai University School of Medicine in Japan.Methods:The authors generated rat spinal cord injury (SCI) models using an IH-Impactor (100 kdyne(LI), 200 kdyne (HI)). Rats were killed at 1, 3, 5, 7 and 14 days post operation (dpo). Spinal cord sections were prepared and the expression ratio of GRP78 and CHOP was evaluated in oligodendrocyte precursor cells (OPCs) (NG2+), oligodendrocytes (OLs) (APC+), neurons (NeuN+) and astrocytes (GFAP+) using double immunohistochemical staining. We examined an area 8 mm distal from SCI-epicenter.Results:Compared with the sham group, both injured groups had higher GRP78 expression ratio in contused spinal cord at 1 dpo. GRP78 expression ratio was highest in GFAP+ cells of both groups, and lowest in NG2+ cells. Although GRP78 was expressed strongly immediately after SCI in the both groups, increased CHOP expression was observed only in the HI group. The CHOP expression in NG2+ cells was significantly higher than that observed in GFAP+ cells at 5 dpo.Conclusion:Although the ER stress response contributes to cell survival in the low-stress SCI conditions, the ER stress response induces an apoptotic cascade in high-stress SCI conditions. The ER response varies according to cell type, with the highest observed in astrocytes, and the lowest observed in oligodendrocyte precursor cells.Spinal Cord advance online publication, 22 October 2013; doi:10.1038/sc.2013.118.
    Spinal Cord 10/2013; · 1.90 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Development of tissue-engineered materials to treat anterior cruciate ligament (ACL) injury has been limited by the lack of phenotypic markers. We investigated the feasibility of inducing ACL regeneration using cell sheet technology based on the expression of tenomodulin (TNMD) as an early phenotypic marker of ligaments. ACL remnants, the synovium surrounding cruciate ligaments (SCL), the synovium surrounding the infrapatellar fat pads (SIF), and subcutaneous fat tissue (SCF) were obtained from patients undergoing ACL reconstruction or total knee arthroplasty. ACL cell sheets and SCL-derived cell sheets were fabricated successfully A three-dimensional bioengineered ACL was generated by combining triple-layered ACL cell sheets with a bioabsorbable mesh composite. Immunohistochemical examination showed that TNMD was expressed in human ACL fibers, triple-layered ACL cell sheets, ACL remnants, SCL, and SIF, but not in SCF. Real-time PCR showed that TNMD mRNA was expressed at substantially higher levels in the ACL, SCL, and SIF than in the SCF. These results suggest that TNMD is a specific marker of the human ACL and that ACL sheets have a phenotype similar to that of the ACL. The greater expression of TNMD in the SCL- and SIF- suggests that the synovium is a potential cell source for ACL regeneration. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
    Journal of Biomedical Materials Research Part A 09/2013; · 2.83 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Type II odontoid fracture is the most frequent individual fracture in elderly people. An older person usually sustains a Type II odontoid fracture in a fall from standing or a seated height. A relationship between osteoarthritis in the upper cervical spine and Type II odontoid fracture has been reported. However, to our knowledge, few reports have investigated statistically whether disproportionate degeneration between joints influences the susceptibility to fracture. The purpose of this study was to assess predisposition to Type II odontoid fracture in the elderly. Retrospective review of elderly patients sustained Type II odontoid fracture and other axis fractures. Thirty-eight patients aged 65 years and older with axis fractures. Evaluation of computed tomography findings by focusing on osteoporosis and the disproportion in degeneration between each of the upper cervical joints (atlantooccipital, atlantoodontoid, and lateral atlantoaxial joints). Seventeen patients had a Type II odontoid fracture, and 21 patients had other axis fractures. Using the computed tomography findings, we classified osteoporosis at the dens-body junction and the severity of degenerative changes in the atlantoodontoid, atlantooccipital, and lateral atlantoaxial joints as none, mild, moderate, or severe. The proportion of patients with moderate or severe osteoporosis and degenerative changes in each joint and that of patients with disproportionate degenerative changes between joints (difference in grade of ≥2 levels between joints) were compared statistically. The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this article. Patients with osteoporosis and with disproportionate degenerative changes between the atlantoodontoid and lateral atlantoaxial joints were significantly more likely to have a Type II odontoid fracture than other axis fractures. These two factors were also assessed in multivariate logistic analysis. The disproportionate degenerative change between the atlantoodontoid and lateral atlantoaxial joint remained significant, even after adjusting for osteoporosis. Older patients with the dens fixed to the atlas because of degeneration of the atlantoodontoid joint and a smooth lateral atlantoaxial joint seem to sustain Type II odontoid fractures because, during a simple fall, the rotation of the head produces torque force on the osteoporotic dens-body junction, which acts as the rotatory center. The presence of the disproportionate osteoarthritic degeneration between the atlantoodontoid and lateral atlantoaxial joints predisposes older people to a Type II odontoid fracture.
    The spine journal: official journal of the North American Spine Society 09/2013; · 2.90 Impact Factor
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: It has been shown that coculture of bone marrow-derived stromal cells (BMSCs) with intervertebral disc (IVD) nucleus pulposus (NP) cells significantly activates the biological characteristics of NP cells in animal models and in humans. We therefore predicted that activated NP cells would be a useful graft source for cellular transplantation therapy in the treatment of degenerative IVDs. However, the activation protocol is based on fresh isolation and activation of NP cells, which limits the timing of clinical application. Cell transplantation therapy could be offered to more patients than is now possible if activated NP cells could be transplanted as and when required by the condition of the patient. No study has investigated the effect of cryopreservation on NP cells after enzymatic isolation. We investigated the effects of cryopreservation of canine and human NP cells in both cell and tissue form before coculture with autologous BMSCs. Cell viability, proliferation, glycosaminoglycan production, aggrecan transcriptional activity, colony generation, and gene expression profile of the cells after cryopreservation and subsequent coculture were analyzed. The influence of cryopreservation on cell chromosomal abnormalities and tumorigenesis was also studied. The results showed that there were no clear differences between the noncryopreserved and cryopreserved cells in terms of cell viability, proliferation capacity, and capacity to synthesize extracellular matrix. Furthermore, the cells showed no apparent chromosomal abnormalities or tumorigenic ability and exhibited similar patterns of gene expression. These findings suggest that by using cryopreservation, it may be possible to transplant activated NP cells upon request for patients' needs.
    BioResearch open access. 08/2013; 2(4):273-82.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: There is considerable interest in using cell sheets for the treatment of various lesions as part of regenerative medicine therapy. Cell sheets can be prepared in temperature-responsive culture dishes and applied to injured tissue. For example, cartilage-derived cell sheets are currently under preclinical testing for use in treatment of knee cartilage injuries. The additional use of cryopreservation technology could increase the range and practicality of cell sheet therapies. To date, however, cryopreservation of cell sheets has proved impractical. Here we have developed a novel and effective method for cryopreserving fragile chondrocyte sheets. We modified the vitrification method previously developed for cryopreservation of mammalian embryos to vitrify a cell sheet through use of a minimum volume of vitrification solution containing 20% dimethyl sulfoxide, 20% ethylene glycol, 0.5 M sucrose, and 10% carboxylated poly-L-lysine. The principal feature of our method is the coating of the cell sheet with a viscous vitrification solution containing permeable and non-permeable cryoprotectants prior to vitrification in liquid nitrogen vapor. This method prevented fracturing of the fragile cell sheet even after vitrification and rewarming. Both the macro- and microstructures of the vitrified cell sheets were maintained without damage or loss of major components. Cell survival in the vitrified sheets was comparable to that in non-vitrified samples. We have shown here that it is feasible to vitrify chondrocyte cell sheets and that these sheets retain their normal characteristics upon thawing. The availability of a practical cryopreservation method should make a significant contribution to the effectiveness and range of applications of cell sheet therapy.
    BMC Biotechnology 07/2013; 13(1):58. · 2.17 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Conventional culture methods using temperature-responsive culture dishes require 4-5 weeks to prepare layered chondrocyte sheets that can be used in articular cartilage repair and regeneration. This study investigated whether the use of synovial tissue obtained from the same joint as the chondrocyte nutritive supply source could more quickly facilitate the preparation of chondrocyte sheets. After culturing derived synoviocytes and chondrocytes together (i.e. combined culture or co-culture) on temperature-responsive inserts, chondrocyte growth was assessed and a molecular analysis of the chondrocyte sheets was performed. Transplantable tissue could be obtained more quickly using this method (average 10.5 days). Real-time polymerase chain reaction and immunostaining of the three-layer chondrocyte sheets confirmed the significant expression of genes critical to cartilage maintenance, including type II collagen (COL2), aggrecan-1 and tissue metallopeptidase inhibitor 1. However, the expression of COL1, matrix metalloproteinase 3 (MMP3), MMP13 and A-disintegrin and metalloproteinase with thrombospondin motifs 5 was suppressed. The adhesive factor fibronectin-1 (FN1) was observed in all sheet layers, whereas in sheets generated using conventional preparation methods positive FN1 immunostaining was observed only on the surface of the sheets. The results indicate that synoviocyte co-cultures provide an optimal environment for the preparation of chondrocyte sheets for tissue transplantation and are particularly beneficial for shortening the required culture period. Copyright © 2013 John Wiley & Sons, Ltd.
    Journal of Tissue Engineering and Regenerative Medicine 07/2013; · 4.43 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Aim: To cover the large tissue deficits associated with significant loss of function following surgery, a 3D gel-patch-like nerve-vascular reconstitution system was developed using the skeletal muscle-derived multipotent stem cell (Sk-MSC) sheet pellet. Materials & methods: The Sk-MSC sheet pellet was prepared from GFP transgenic mice by the collagenase extraction and 7 days expansion cell culture, and transplanted into a severe muscle damage model with large disruptions to muscle fibers, blood vessels and peripheral nerves. Results: At 4 weeks after transplantation, engrafted cells contributed to nerve-vascular regeneration associated with cellular differentiation into Schwann cells, perineurial/endoneurial cells, vascular endothelial cells and pericytes. However, skeletal myogenic differentiation was scarcely observed. Paracrine effects regarding donor cells/tissues could also be expected, because of the active expression of neurogenic and vasculogenic factor mRNAs in the sheet pellet. Conclusion: These results indicate that the vigorous skeletal myogenic potential of Sk-MSCs was clearly reduced in the sheet pellet preparation and this method may be a useful adjuvant for nerve-vascular regeneration in various tissue engineering applications.
    Regenerative Medicine 07/2013; 8(4):437-51. · 3.87 Impact Factor
  • Source
    Akihiko Hiyama, Daisuke Sakai, Joji Mochida
    [Show abstract] [Hide abstract]
    ABSTRACT: Many of the causes of low back pain are still unknown; sufficient evidence indicates that both degenerative and mechanical change within the intervertebral disk (IVD) is a relevant factor. This article reviews intracellular signaling pathways related to pain receptors in the degenerated IVD. Several reports have demonstrated the number of nerve fibers in the IVD was increased in degenerated disks. In recent years, some groups have reported that an increase in nerve fibers is associated with the presence of inflammatory mediators and/or neurotrophins in the IVD. Cell signaling events, which are regulated by inflammatory mediators and neurotrophins, must be identified to clarify the mechanism underlying low back pain. Major intracellular signaling pathways (nuclear factor kappa β, mitogen-activated protein kinases, and Wnts) potentially play vital roles in mediating the molecular events responsible for the initiation and progression of IVD degeneration. These signaling pathways may represent therapeutic targets for the treatment of IVD degeneration and its associated back pain.
    Global spine journal. 06/2013; 3(3):165-174.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Increased expression of the proinflammatory cytokine TNF-α in intervertebral discs (IVDs) leads to inflammation, which results in progressive IVD degeneration. We have previously reported that activation of Wnt-β-catenin (hereafter called Wnt) signaling suppresses the proliferation of nucleus pulposus cells and induces cell senescence, suggesting that Wnt signaling triggers the process of degeneration of the IVD. However, it is not known whether cross talk between TNF-α and Wnt signaling plays a role in the regulation of nucleus pulposus cells. The goal of the present study was to examine the effect of the interaction between Wnt signaling and the proinflammatory cytokine TNF-α in nucleus pulposus cells. Cells isolated from rat nucleus pulposus regions of IVDs were cultured in monolayers, and the expression and promoter activity of Wnt signaling and TNF-α were evaluated. We also examined whether the inhibition of Wnt signaling using cotransfection with Dickkopf (DKK) isoforms and Sclerostin (SOST) could block the effects of pathological TNF-α expression in nucleus pulposus cells. TNF-α stimulated the expression and promoter activity of Wnt signaling in nucleus pulposus cells. In addition, the activation of Wnt signaling by 6-bromoindirubin-3'-oxime (BIO), which is a selective inhibitor of glycogen synthase kinase 3 (GSK-3) activity that activates Wnt signaling, increased TNF-α expression and promoter activity. Conversely, the suppression of TNF-α promoter activity using a β-catenin small interfering RNA was evident. Moreover, transfection with DKK-3, DKK-4, or SOST, which are inhibitors of Wnt signaling, blocked Wnt signaling-mediated TNF-α activation; these effects were not observed for DKK-1 or DKK-2. Here, we have demonstrated that Wnt signaling regulates TNF-α and that Wnt signaling and TNF-α form a positive-feedback loop in nucleus pulposus cells. The results of the present study provide in vitro evidence that activation of Wnt signaling upregulates the TNF-α expression and might cause the degeneration of nucleus pulposus cells. We speculate that blocking this pathway might protect nucleus pulposus cells against degeneration.
    Arthritis research & therapy 01/2013; 15(6):R189. · 4.27 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The gene encoding c-fos is an important factor in the pathogenesis of joint disease in patients with osteoarthritis. However, it is unknown whether the signal mechanism of c-fos acts in intervertebral disc (IVD) cells. We investigated whether c-fos is activated in relation to mitogen-activated protein kinases (MAPKs) and the protein kinase C (PKC) pathway in nucleus pulposus (NP) cells. Reverse transcription-polymerase chain reaction and western blotting analyses were used to measure the expression of c-fos in rat IVD cells. Transfections were performed to determine the effects of c-fos on target gene activity. The effect of c-fos protein expression was examined in transfection experiments and in a 3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide cell viability assay. Phorbol 12-myristate 13-acetate (PMA), the most commonly used phorbol ester, binds to and activates protein kinase C (PKC), causing a wide range of effects in cells and tissues. PMA induced the expression of c-fos gene transcription and protein expression, and led to activation of the MAPK pathways in NP cells. The c-fos promoter was suppressed completely in the presence of the MAPK inhibitor PD98059, an inhibitor of the MEK/ERK kinase cascade, but not in the presence of SKF86002, SB202190, or SP600125. The effects of the PKC pathway on the transcriptional activity of the c-fos were evaluated. PKCγ and PKCδ suppressed the promoter activity of c-fos. Treatment with c-fos inhibited aggrecan and Col2 promoter activities and the expression of these genes in NP cells. This study demonstrated, for the first time, that the MAPK and PKC pathways had opposing effects on the regulation of c-fos in NP cells. Thus, the expression of c-fos can be suppressed in the extracellular matrix of NP cells.
    PLoS ONE 01/2013; 8(9):e73210. · 3.53 Impact Factor

Publication Stats

2k Citations
376.07 Total Impact Points

Institutions

  • 1993–2014
    • Tokai University
      • Department of Orthopaedic Surgery
      Hiratuka, Kanagawa, Japan
  • 2011
    • Konkuk University
      • Department of Laboratory Medicine
      Sŏul, Seoul, South Korea
  • 2008–2011
    • Thomas Jefferson University
      • Department of Orthopaedic Surgery
      Philadelphia, PA, United States
  • 2010
    • Jichi Medical University
      • Department of Anesthesiology and Critical Care Medicine
      Totigi, Tochigi, Japan
  • 2007–2009
    • Numazu City Hospital
      Sizuoka, Shizuoka, Japan
  • 2005–2006
    • National Defense Medical College
      Tokorozawa, Saitama, Japan