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ABSTRACT: TNFα-converting enzyme (TACE/ADAM17) is a membrane-bound proteolytic enzyme with a diverse set of target molecules. Most importantly, TACE is indispensable for the release and activation of pro-TNFα and the ligands for epidermal growth factor receptor in vivo. Previous studies suggested that the overproduction of TACE is causally related to the pathogenesis of inflammatory diseases and cancers. To test this hypothesis, we generated a transgenic line in which the transcription of exogenous Tace is driven by a CAG promoter. The Tace-transgenic mice were viable and exhibited no overt defects, and the quantitative RT-PCR and Western blot analyses confirmed that the transgenically introduced Tace gene was highly expressed in all of the tissues examined. The Tace-transgenic mice were further crossed with Tace(-/+) mice to abrogate the endogenous TACE expression, and the Tace-transgenic mice lacking endogenous Tace gene were also viable without any apparent defects. Furthermore, there was no difference in the serum TNFα levels after lipopolysaccharide injection between the transgenic mice and control littermates. These observations indicate that TACE activity is not necessarily dependent on transcriptional regulation and that excess TACE does not necessarily result in aberrant proteolytic activity in vivo.
PLoS ONE 01/2013; 8(1):e54412. · 4.09 Impact Factor
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Kenta Saito,
Keisuke Horiuchi, Tokuhiro Kimura,
Sakiko Mizuno,
Masaki Yoda,
Hideo Morioka,
Haruhiko Akiyama,
David Threadgill,
Yasunori Okada,
Yoshiaki Toyama,
Kazuki Sato
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ABSTRACT: TNFα-converting enzyme (TACE) is a membrane-bound proteolytic enzyme with essential roles in the functional regulation of TNFα and epidermal growth factor receptor (EGFR) ligands. Previous studies have demonstrated critical roles for TACE in vivo, including epidermal development, immune response, and pathological neoangiogenesis, among others. However, the potential contribution of TACE to skeletal development is still unclear. In the present study, we generated a Tace mutant mouse in which Tace is conditionally disrupted in chondrocytes under the control of the Col2a1 promoter. These mutant mice were fertile and viable but all exhibited long bones that were approximately 10% shorter compared to those of wild-type animals. Histological analyses revealed that Tace mutant mice exhibited a longer hypertrophic zone in the growth plate, and there were fewer osteoclasts at the chondro-osseous junction in the Tace mutant mice than in their wild-type littermates. Of note, we found an increase in osteoprotegerin transcripts and a reduction in Rankl and Mmp-13 transcripts in the TACE-deficient cartilage, indicating that dysregulation of these genes is causally related to the skeletal defects in the Tace mutant mice. Furthermore, we also found that phosphorylation of EGFR was significantly reduced in the cartilage tissue lacking TACE, and that suppression of EGFR signaling increases osteoprotegerin transcripts and reduces Rankl and Mmp-13 transcripts in primary chondrocytes. In accordance, chondrocyte-specific abrogation of Egfr in vivo resulted in skeletal defects nearly identical to those observed in the Tace mutant mice. Taken together, these data suggest that TACE-EGFR signaling in chondrocytes is involved in the turnover of the growth plate during postnatal development via the transcriptional regulation of osteoprotegerin, Rankl, and Mmp-13.
PLoS ONE 01/2013; 8(1):e54853. · 4.09 Impact Factor
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Masaki Yoda, Tokuhiro Kimura,
Takahide Tohmonda,
Shinichi Uchikawa,
Takeshi Koba,
Jiro Takito,
Hideo Morioka,
Morio Matsumoto,
Daniel C Link,
Kazuhiro Chiba,
Yasunori Okada,
Yoshiaki Toyama,
Keisuke Horiuchi
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ABSTRACT: Previous studies have revealed various extrinsic stimuli and factors involved in the regulation of hematopoiesis. Among these, Notch-mediated signaling has been suggested to be critically involved in this process. Herein, we show that conditional inactivation of ADAM10, a membrane-bound protease with a crucial role in Notch signaling (S2 cleavage), results in myeloproliferative disorder (MPD) highlighted by severe splenomegaly and increased populations of myeloid cells and hematopoietic stem cells. Reciprocal transfer of bone marrow cells between wild-type and ADAM10 mutant mice revealed that ADAM10 activity in both hematopoietic and nonhematopoietic cells is involved in the development of MPD. Notably, we found that MPD caused by lack of ADAM10 in nonhematopoietic cells was mediated by G-CSF, whereas MPD caused by ADAM10-deficient hematopoietic cells was not. Taken together, the present findings reveal previously undescribed nonredundant roles of cell-autonomous and non-cell-autonomous ADAM10 activity in the maintenance of hematopoiesis.
Blood 12/2011; 118(26):6939-42. · 9.90 Impact Factor
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Kana Miyamoto,
Shigeyuki Yoshida,
Miyuri Kawasumi,
Kazuaki Hashimoto, Tokuhiro Kimura,
Yuiko Sato,
Tami Kobayashi,
Yoshiteru Miyauchi,
Hiroko Hoshi,
Ryotaro Iwasaki,
Hiroya Miyamoto,
Wu Hao,
Hideo Morioka,
Kazuhiro Chiba,
Takashi Kobayashi,
Hisataka Yasuda,
Josef M Penninger,
Yoshiaki Toyama,
Toshio Suda,
Takeshi Miyamoto
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ABSTRACT: Hematopoietic stem cells (HSCs) are maintained in a specific bone marrow (BM) niche in cavities formed by osteoclasts. Osteoclast-deficient mice are osteopetrotic and exhibit closed BM cavities. Osteoclast activity is inversely correlated with hematopoietic activity; however, how osteoclasts and the BM cavity potentially regulate hematopoiesis is not well understood. To investigate this question, we evaluated hematopoietic activity in three osteopetrotic mouse models: op/op, c-Fos-deficient, and RANKL (receptor activator of nuclear factor kappa B ligand)-deficient mice. We show that, although osteoclasts and, by consequence, BM cavities are absent in these animals, hematopoietic stem and progenitor cell (HSPC) mobilization after granulocyte colony-stimulating factor injection was comparable or even higher in all three lines compared with wild-type mice. In contrast, osteoprotegerin-deficient mice, which have increased numbers of osteoclasts, showed reduced HSPC mobilization. BM-deficient patients and mice reportedly maintain hematopoiesis in extramedullary spaces, such as spleen; however, splenectomized op/op mice did not show reduced HSPC mobilization. Interestingly, we detected an HSC population in osteopetrotic bone of op/op mice, and pharmacological ablation of osteoclasts in wild-type mice did not inhibit, and even increased, HSPC mobilization. These results suggest that osteoclasts are dispensable for HSC mobilization and may function as negative regulators in the hematopoietic system.
Journal of Experimental Medicine 10/2011; 208(11):2175-81. · 13.85 Impact Factor
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ABSTRACT: Pilocytic astrocytoma (PA) is a low-grade astrocytic tumor arising predominantly during the first two decades of life. Hemorrhagic onset of PAs is uncommon, and the etiology of hemorrhage remains unclear. Here we report a case of hemorrhagic onset of cerebellar PA in a 29-year-old man who presented with a week-long history of headache and gait instability. Computed tomography and magnetic resonance imaging revealed a hemorrhagic tumor located in the right cerebellar hemisphere, and total resection was performed. Histological examination showed bipolar glial cell proliferation in a biphasic pattern in a compact area and a loose microcystic area with Rosenthal fibers and eosinophilic granular bodies, indicating PA. Prominent changes in tumor vasculature, including aggregation of sclerotic thick-walled and ectatic thin-walled vessels, was observed, and nodules of thrombi containing complex vascular proliferation suggesting recanalized thrombi formed in partially ruptured vessels were also found. Thus, rupture of these abnormal vessels appeared to be the cause of hemorrhage. Review of the literature revealed that age distribution of patients with hemorrhagic PAs tends to be older than that of patients with general PAs. These findings imply a possibility that degenerative changes in blood vessels in long-standing PAs might be related to the mechanisms of spontaneous intratumoral hemorrhage.
Brain Tumor Pathology 10/2011; 29(2):96-102. · 1.19 Impact Factor
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ABSTRACT: Vascular endothelial growth factor 165 (VEGF165) and its receptors, including neuropilin 1 (NRP-1), are overexpressed in human osteoarthritic (OA) articular cartilage, although their functional roles in the cartilage are not fully understood. An axon-guidance molecule, semaphorin 3A (Sema3A), which binds to NRP-1, acts as an antagonist of VEGF signaling in endothelial cells. The aim of this study was to examine the expression of Sema3A and the functions of the VEGF165/Sema3A/NRP-1 axis in OA cartilage.
The expression of Sema3A in OA and normal cartilage samples was examined by real-time polymerase chain reaction and immunohistochemical analyses. Functional analyses of VEGF165 and Sema3A were carried out using OA chondrocytes in culture. The migration activity of chondrocytes was examined in a monolayer wound assay. The effects of Sema3A on VEGF165-induced up-regulation of matrix metalloproteinases (MMPs) and intracellular signaling were also studied in cultured chondrocytes.
Sema3A expression was significantly elevated in OA cartilage as compared to normal cartilage. Sema3A immunoreactivity directly correlated with the Mankin score and with chondrocyte cloning. VEGF165 promoted the migration of chondrocytes, and this activity was suppressed by VEGF receptor 2 tyrosine kinase inhibitors. Sema3A antagonized the chondrocyte migration promoted by VEGF165, and the activity was blocked by a selective inhibitor of, or small interfering RNA for, Sema3A. VEGF165-induced overexpression of MMPs and phosphorylation of ERK and focal adhesion kinase in chondrocytes were inhibited by Sema3A.
Our findings provide the first evidence that Sema3A is overexpressed, with a direct correlation with cloning, in OA cartilage and that it suppresses the VEGF165-promoted migration of chondrocytes. Our findings also suggest that Sema3A plays a role in chondrocyte cloning through inhibition of cell migration in OA cartilage.
Arthritis & Rheumatism 10/2011; 63(10):3000-9. · 7.87 Impact Factor
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ABSTRACT: Giant cell arteritis involving intramural coronary artery branches is rare, and its clinical features remain poorly understood. We report a 56-year-old hemodialysed patient with a history of mitral valve replacement, who presented with "fever of unknown origin" and intractable hypotension. The antemortem diagnosis was very difficult and the autopsy revealed giant-cell-rich vasculitis in arteries in multiple organs. The heart was most severely involved, in which almost all of the intramural coronary artery branches were infiltrated by many multinucleated giant cells, macrophages, and lymphocytes with luminal narrowing, but the epicardial segments of the coronary arteries were spared. Superimposed on the preexisting valvular heart disease, the vasculitic lesions were thought to play a central role in severe cardiac dysfunction resulting in dialysis-related hypotension, which led to fatal non-occlusive mesenteric ischemia. This case highlights the possibility that giant cell arteritis of intramural coronary arteries could be an uncommon underlying cause of refractory dialysis-related hypotension.
Heart and Vessels 06/2011; 27(2):216-20. · 2.05 Impact Factor
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ABSTRACT: Extraventricular neurocytoma is an uncommon neuronal tumor, located outside the cerebral ventricles, which shows histological features similar to those of central neurocytoma. Most extraventricular neurocytomas are situated in the intraaxial regions of the central nervous system. We report a rare case of an extraaxial neurocytoma in the sphenocavernous-petroclival region that was successfully treated by radiation therapy following partial removal and pathological evaluation of the tumor.
Brain Tumor Pathology 05/2011; 28(3):273-7. · 1.19 Impact Factor
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Shizuko Kagawa,
Koichi Fukunaga,
Tsuyoshi Oguma,
Yusuke Suzuki,
Tetsuya Shiomi,
Koichi Sayama, Tokuhiro Kimura,
Hiroyuki Hirai,
Kinya Nagata,
Masataka Nakamura,
Koichiro Asano
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ABSTRACT: The prostaglandin D(2) (PGD(2))/CRTH2 pathway is important for eosinophil trafficking in vitro; however, genetic deficiency of CRTH2 does not suppress in vivo eosinophilic airway inflammation in acute models of asthma, and the role of CRTH2 in the pathogenesis of asthma is still ambiguous. Therefore, in the present study we explored whether the PGD(2)/CRTH2 pathway could affect the phenotypes of chronic asthma. Either CRTH2-deficient (CRTH2-/-) or wild-type mice were sensitized and exposed to ovalbumin (OVA) for 3 days (acute model) or 6 weeks (chronic model). While the magnitude of the acute eosinophilic inflammation was equivalent between CRTH2-/- and wild-type mice, the number of inflammatory cells and eosinophils in bronchoalveolar lavage fluid after chronic OVA exposure was significantly reduced in CRTH2-/- mice (18.0 ± 2.6 × 10(4) cells and 2.0 ± 0.5 × 10(4) cells) compared to wild-type mice (27.9 ± 2.5 × 10(4) cells and 6.8 ± 1.1 × 10(4) cells, p < 0.001). On the contrary, no difference was observed between CRTH2-/- and wild-type mice in terms of airway hyperresponsiveness or remodeling (goblet cell hyperplasia) in the chronic model of asthma. In conclusion, CRTH2 that mediates PGD(2) activity is essential for sustained eosinophilic inflammation in the airways, and its antagonists could exert an anti-inflammatory effect in chronic asthma.
International Archives of Allergy and Immunology 01/2011; 155 Suppl 1:6-11. · 2.40 Impact Factor
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ABSTRACT: Intracranial clear cell meningioma is very rare. We present 3 cases of intracranial clear cell meningiomas genetically characterized by comparative genomic hybridization with a review of the literature.
Patient 1 is a 38-year-old woman with a petroclival tumor. Patient 2 is a 60-year-old man with a tumor at the foramen magnum. Patient 3 is a 60-year-old man with a tumor at the posterior clinoid process. Gross total resection was performed in patients 1 and 2. Patient 1 has been free from recurrence for 10 years. Patient 2 had a tumor recurrence at 14 months after the operation. After partial resection, conventional radiotherapy was given, and there was no tumor regrowth at 2 years after radiotherapy. Subtotal resection was performed in patient 3, and no regrowth was detected for 3 months. Histologically, all tumors were composed of cells with clear cytoplasm reactive for periodic acid-Schiff and diagnosed as clear cell meningioma. The MIB-1 and p53 staining indexes were 1.8, 1.7, and 5.6 and 1.1, 1.0, and 5.5, respectively. Comparative genomic hybridization revealed no chromosomal number aberrations in patient 1, numerous losses and gains including loss of chromosome 1 in patient 2, and loss of only 22q in patient 3. Because staining indexes of MIB-1 and p53 were equivalent in 2 patient (patients 1 and 2) with a long follow-up period, the contrary clinical courses are likely associated with genetic characteristics.
To the best of our knowledge, this is the first report that suggests association between tumor behavior and genetic characteristics in clear cell meningiomas.
Neurosurgery 09/2010; 67(3):E870-1; discussion E871. · 2.79 Impact Factor
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Daihiko Hakuno,
Naritaka Kimura,
Masatoyo Yoshioka,
Makio Mukai, Tokuhiro Kimura,
Yasunori Okada,
Ryohei Yozu,
Chisa Shukunami,
Yuji Hiraki,
Akira Kudo,
Satoshi Ogawa,
Keiichi Fukuda
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ABSTRACT: Valvular heart disease (VHD) is the term given to any disease process involving one or more of the heart valves. The condition can be congenital or acquired, for example as a result of atherosclerosis or rheumatic fever. Despite its clinical importance, the molecular mechanisms underlying VHD remain unknown. We investigated the pathophysiologic role and molecular mechanism of periostin, a protein that plays critical roles in cardiac valve development, in degenerative VHD. Unexpectedly, we found that periostin levels were drastically increased in infiltrated inflammatory cells and myofibroblasts in areas of angiogenesis in human atherosclerotic and rheumatic VHD, whereas periostin was localized to the subendothelial layer in normal valves. The expression patterns of periostin and chondromodulin I, an angioinhibitory factor that maintains cardiac valvular function, were mutually exclusive. In WT mice, a high-fat diet markedly increased aortic valve thickening, annular fibrosis, and MMP-2 and MMP-13 expression levels, concomitant with increased periostin expression; these changes were attenuated in periostin-knockout mice. In vitro and ex vivo studies revealed that periostin promoted tube formation and mobilization of ECs. Furthermore, periostin prominently increased MMP secretion from cultured valvular interstitial cells, ECs, and macrophages in a cell type-specific manner. These findings indicate that, in contrast to chondromodulin I, periostin plays an essential role in the progression of cardiac valve complex degeneration by inducing angiogenesis and MMP production.
The Journal of clinical investigation 07/2010; 120(7):2292-306. · 15.39 Impact Factor
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Kosuke Tajima,
Hironari Takaishi,
Jiro Takito,
Takahide Tohmonda,
Masaki Yoda,
Norikazu Ota,
Naoto Kosaki,
Morio Matsumoto,
Hiroyasu Ikegami,
Toshiyasu Nakamura, Tokuhiro Kimura,
Yasunori Okada,
Keisuke Horiuchi,
Kazuhiro Chiba,
Yoshiaki Toyama
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ABSTRACT: Skeletal fracture healing involves a variety of cellular and molecular events; however, the mechanisms behind these processes are not fully understood. In the current study, we investigated the potential involvement of the signal transducer and activator of transcription 1 (STAT1), a critical regulator for both osteoclastogenesis and osteoblast differentiation, in skeletal fracture healing. We used a fracture model and a cortical defect model in mice, and found that fracture callus remodeling and membranous ossification are highly accelerated in STAT1-deficient mice. Additionally, we found that STAT1 suppresses Osterix transcript levels and Osterix promoter activity in vitro, indicating the suppression of Osterix transcription as one of the mechanisms behind the inhibitory effect of STAT1 on osteoblast differentiation. Furthermore, we found that fludarabine, a potent STAT1 inhibitor, significantly increases bone formation in a heterotopic ossification model. These results reveal previously unknown functions of STAT1 in skeletal homeostasis and may have important clinical implications for the treatment of skeletal bone fracture.
Journal of Orthopaedic Research 07/2010; 28(7):937-41. · 2.81 Impact Factor
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ABSTRACT: Reversion-inducing cysteine-rich protein with Kazal motifs (RECK) is a membrane-anchored matrix metalloproteinase regulator, but its functions in cartilage are not fully understood. The aim of the present study was to examine the expression and functions of RECK in human osteoarthritic (OA) cartilage. Quantitative RT-PCR indicated that the expression level of RECK is significantly higher in OA cartilage than in normal cartilage. By immunohistochemical analysis, RECK was localized to chondrocytes in OA cartilage, and the immunoreactivity directly correlated with the Mankin score and degree of chondrocyte cloning and proliferation. In cultured OA chondrocytes, RECK was expressed on the cell surface by glycosylphosphatidylinositol anchoring. The expression was stimulated by insulin-like growth factor-1 and suppressed by interleukin-1 and tumor necrosis factor-alpha. Down-regulation of RECK by small interfering RNA showed reduced spreading and smaller focal adhesions in the chondrocytes. Chondrocyte migration in a monolayer wounding assay was increased by down-regulation of RECK and inhibited by RECK overexpression in an matrix metalloproteinase activity-dependent manner. On the other hand, chondrocyte proliferation was suppressed by RECK silencing, and this was associated with reduced phosphorylation of focal adhesion kinase and extracellular signal-regulated kinase, whereas the proliferation was enhanced by RECK overexpression. These data are the first to demonstrate that RECK is up-regulated in human OA cartilage and suggest that RECK plays a role in chondrocyte cloning probably through suppression and promotion of chondrocyte migration and proliferation, respectively.
American Journal Of Pathology 06/2010; 176(6):2858-67. · 4.89 Impact Factor
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ABSTRACT: Compensatory lung growth has been well described as a phenomenon in many animal models, but still little is known about the nature, extent, and modulation of such growth. We hypothesized that compensatory lung growth may at least in part recapitulate developmental lung growth, and factors known to be important during normal lung development, such as thyroid transcription factor 1 (TTF-1), may be reactivated during compensatory lung growth.
To investigate the role of TTF-1 in correlation with the morphological changes during compensatory lung growth.
Sequential changes in TTF-1 expression and morphology were examined in the residual right lung after left pneumonectomy in 9-week-old mice. The effect of temporary knockdown of TTF-1 on compensatory lung growth was also evaluated.
TTF-1 was transiently but significantly elevated at an early stage in compensatory lung growth. Morphologically, a process resembling septation in lung development may have been initiated during this period in the vicinity of the alveolar duct. furthermore, temporary knockdown of ttf-1 transiently but significantly delayed the early phase of compensatory lung growth.
These results indicate the influential role of TTF-1 in modulating, and possibly initiating, the early phase of compensatory lung growth. Morphologically, compensatory lung growth may at least in part resemble developmental growth.
American Journal of Respiratory and Critical Care Medicine 03/2010; 181(12):1397-406. · 11.08 Impact Factor
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M Kato,
H Takaishi,
M Yoda,
T Tohmonda,
J Takito,
N Fujita,
N Hosogane,
K Horiuchi, T Kimura,
Y Okada,
T Saito,
H Kawaguchi,
T Kikuchi,
M Matsumoto,
Y Toyama,
K Chiba
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ABSTRACT: The role of postmenopause on the pathogenesis of cartilage degeneration has been an open question. We assessed cartilage degeneration in estrogen receptor (ER)alpha null mice and examined the role of glucocorticoid receptor-interacting protein 1 (GRIP1) in the ERalpha-dependent transcription of a type II collagen gene (col2a1) with special reference to a crosstalk with the transforming growth factor (TGF)-beta signaling pathway.
The vertebral cartilaginous endplate from female ERalpha null mice was subjected to histological analyses. Col2a1 expression of primary chondrocytes (PCs) obtained from ERalpha null mice after 17beta-estradiol (E(2)) and TGF-beta1 stimulation was examined by reverse transcription polymerase chain reaction (RT-PCR). Estrogen response element (ERE) or col2a1 promoter-enhancer luciferase reporter system was used to investigate the crosstalk among ERalpha, GRIP1, and MKK6. Col2a1 expression and glycosaminoglycan (GAG) content were measured in ATDC5 cells treated with GRIP1 small interfering RNA (siRNA).
ERalpha deficiency clearly accelerated impairment of the vertebral cartilaginous endplate. E(2) and TGF-beta1 stimulation increased col2a1 expression in PC from wild-type mice, but not that from ERalpha null mice. The same stimulation increased the col2a1 promoter-enhancer reporter activity, and the elevated activity was decreased by dominant-negative ERalpha and p38 mitogen-activated protein kinase (MAPK) inhibitor. GRIP1 increased the E(2)-dependent ERE activation in the presence of ERalpha and constitutive-active MKK6. GRIP1 siRNA repressed col2a1 expression and GAG production in ATDC5 cells.
Crosstalks between ERalpha/GRIP1 and TGF-beta/MKK6/p38 MAPK pathway have protective roles on cartilage metabolism via regulating the extracellular matrices expression. The finding may lead to the development of a novel therapeutic approach for cartilage degeneration.
Osteoarthritis and Cartilage 03/2010; 18(7):934-41. · 3.90 Impact Factor
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Hideaki Kanazawa,
Masaki Ieda,
Kensuke Kimura,
Takahide Arai,
Haruko Kawaguchi-Manabe,
Tomohiro Matsuhashi,
Jin Endo,
Motoaki Sano,
Takashi Kawakami, Tokuhiro Kimura,
Toshiaki Monkawa,
Matsuhiko Hayashi,
Akio Iwanami,
Hideyuki Okano,
Yasunori Okada,
Hatsue Ishibashi-Ueda,
Satoshi Ogawa,
Keiichi Fukuda
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ABSTRACT: Although several cytokines and neurotrophic factors induce sympathetic neurons to transdifferentiate into cholinergic neurons in vitro, the physiological and pathophysiological roles of this remain unknown. During congestive heart failure (CHF), sympathetic neural tone is upregulated, but there is a paradoxical reduction in norepinephrine synthesis and reuptake in the cardiac sympathetic nervous system (SNS). Here we examined whether cholinergic transdifferentiation can occur in the cardiac SNS in rodent models of CHF and investigated the underlying molecular mechanism(s) using genetically modified mice. We used Dahl salt-sensitive rats to model CHF and found that, upon CHF induction, the cardiac SNS clearly acquired cholinergic characteristics. Of the various cholinergic differentiation factors, leukemia inhibitory factor (LIF) and cardiotrophin-1 were strongly upregulated in the ventricles of rats with CHF. Further, LIF and cardiotrophin-1 secreted from cultured failing rat cardiomyocytes induced cholinergic transdifferentiation in cultured sympathetic neurons, and this process was reversed by siRNAs targeting Lif and cardiotrophin-1. Consistent with the data in rats, heart-specific overexpression of LIF in mice caused cholinergic transdifferentiation in the cardiac SNS. Further, SNS-specific targeting of the gene encoding the gp130 subunit of the receptor for LIF and cardiotrophin-1 in mice prevented CHF-induced cholinergic transdifferentiation. Cholinergic transdifferentiation was also observed in the cardiac SNS of autopsied patients with CHF. Thus, CHF causes target-dependent cholinergic transdifferentiation of the cardiac SNS via gp130-signaling cytokines secreted from the failing myocardium.
The Journal of clinical investigation 02/2010; 120(2):408-21. · 15.39 Impact Factor
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Norikazu Ota,
Hironari Takaishi,
Naoto Kosaki,
Jiro Takito,
Masaki Yoda,
Takahide Tohmonda, Tokuhiro Kimura,
Yasunori Okada,
Hisataka Yasuda,
Hiroshi Kawaguchi,
Morio Matsumoto,
Kazuhiro Chiba,
Hiroyasu Ikegami,
Yoshiaki Toyama
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ABSTRACT: Receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG), a decoy receptor of RANKL, maintain bone mass by regulating the differentiation of osteoclasts, which are bone-resorbing cells. Endochondral bone ossification and bone fracture healing involve cartilage resorption, a less well-understood process that is needed for replacement of cartilage by bone. Here we describe the role of OPG produced by chondrocytes in chondroclastogenesis. Fracture healing in OPG(-/-) mice showed faster union of the fractured bone, faster resorption of the cartilaginous callus, and an increased number of chondroclasts at the chondroosseous junctions compared with that in wild-type littermates. When a cultured pellet of OPG(-/-) chondrocytes was transplanted beneath the kidney capsule, the pellet recruited many chondroclasts. The pellet showed the ability to induce tartrate-resistant acid phosphatase-positive multinucleated cells from RAW 264.7 cells in vitro. Finally, OPG(-/-) chondrocytes (but not wild-type chondrocytes) cultured with spleen cells induced many tartrate-resistant acid phosphatase-positive multinucleated cells. The expression of RANKL and OPG in chondrocytes was regulated by several osteotropic factors including 1,25-dihydroxyvitamin D(3), PTHrP, IL-1alpha, and TNF-alpha. Thus, local OPG produced by chondrocytes probably controls cartilage resorption as a negative regulator for chondrocyte-dependent chondroclastogenesis.
Endocrinology 10/2009; 150(11):4823-34. · 4.46 Impact Factor
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Mitsuru Furukawa,
Hironari Takaishi,
Jiro Takito,
Masaki Yoda,
Sadaoki Sakai,
Tomohiro Hikata,
Akihiro Hakozaki,
Shinichi Uchikawa,
Morio Matsumoto,
Kazuhiro Chiba, Tokuhiro Kimura,
Yasunori Okada,
Koichi Matsuo,
Hiroki Yoshida,
Yoshiaki Toyama
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ABSTRACT: IL-27 was first discovered as a factor supporting initial Th1 immune responses. Subsequent studies revealed that this cytokine has pleiotropic effects, including inhibition of certain immune cells, a regulatory role in hemopoietic stem cell differentiation, and antitumor activities. However, the role of human IL (hIL)-27 in human osteoclast precursors and inflammatory bone disease is unclear. Here, we examined the direct effect of hIL-27 on human osteoclastogenesis. Human bone marrow cells cultured in MethoCult medium containing human (h) GM-CSF, human stem cell factor, and hIL-3 expressed Mac-1, c-kit, and c-Fms. These cells, called hCFU-GMs, also expressed the IL-27 receptor, an IL-27Ralpha (WSX-1)/gp130 heterodimer. Cultivation in hM-CSF and human receptor activator of NF-kappaB ligand induced the differentiation of tartrate-resistant acid phosphatase-positive multinucleated cells (osteoclasts) from hCFU-GMs, and hIL-27 inhibited this osteoclastogenesis in a dose-dependent manner. hIL-27 also repressed bone resorption by osteoclasts on a dentine slice. hIL-27 caused a remarkable increase in STAT1 phosphorylation and enhanced the STAT1 protein level. It also inhibited the expression of receptor activator of NF-kappaB ligand-induced c-Fos and cytoplasmic, calcineurin-dependent 1 NFAT (NFATc1), which are indispensable transcription factors for osteoclastogenesis. Fludarabine, a STAT1 inhibitor, and STAT1 small interfering RNA partially rescued the inhibition of osteoclastogenesis by IL-27. A WSX-1 deficiency caused severe inflammatory bone destruction primed by Escherichia coli cell wall lysate in vivo. Therefore, hIL-27 may act as an anti-inflammatory cytokine in human bone destruction, by inhibiting osteoclastogenesis from hCFU-GMs via STAT1-dependent down-regulation of the transcription factor c-Fos. Our results suggest that hIL-27 may prove useful as a therapeutic target for inflammatory bone destruction.
The Journal of Immunology 09/2009; 183(4):2397-406. · 5.79 Impact Factor
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ABSTRACT: Intrabronchial involvement by metastatic tumors from extrapulmonary primary sites is referred to as "endobronchial metastasis", which is an uncommon mode of metastasis. Although various primary sites (for example, breast, colon, and kidney) have been reported previously, endobronchial metastasis of hepatocellular carcinoma (HCC) is rare. Here, we report a case of a 71-year-old woman with hepatitis C-related HCC, in whom respiratory failure due to bilateral endobronchial metastasis occurred. Notably, long tree-like tumor shadows reminiscent of the structure of the bronchial tree were observed in the bilateral lungs on computed tomography scan, and postmortem analysis clearly revealed metastatic HCC growing and spreading extensively in the lumina of the bronchi. This growth pattern is in sharp contrast to the ordinary endobronchial metastasis, which involves a relatively short segment of the unilateral bronchus. This is the first case report of bilateral and extensive spreading of endobronchial metastatic HCC, and this phenomenon should be considered as a cause of dyspnea in advanced HCC patients.
Pathology - Research and Practice 05/2009; 206(2):116-20. · 1.21 Impact Factor
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ABSTRACT: VATER association represents a cluster of Vertebral, Anal, Tracheo-Esophageal, Radial and Renal malformations, and caudal regression syndrome is an entity consisting of a spectrum of congenital anomalies of lower spine and hips associated with genitourinary and lower limb defects. The concurrence of various malformations may be explained by a common defect in blastogenesis, but direct evidence is yet to be accumulated. Here, by the use of autofluorescence and the teratogenic effect of adriamycin, we demonstrated that adriamycin administered to eggs of White Leghorns distributes to the caudal portion of the embryo and foregut epithelium and induces caudal regression and tracheal and pulmonary agenesis. The induction of caudal regression syndrome-like anomaly was developmental stage and dose dependent. Embryos with caudal regression demonstrated tracheoesophageal anomalies, one of the defects included in VATER association. The stages at which anomalies were produced corresponded to that of human embryos between days 22 and 26 (Carnegie stages 10-11). In view of the antitumor activity of adriamycin by intercalating to double-stranded DNA of undifferentiated cells undergoing rapid cell division, it is possible that adriamycin had preferentially attacked cells in the caudal end where pronounced proliferation takes place during this narrow period of greatest susceptibility.
Pediatric Research 03/2009; 65(6):607-12. · 2.70 Impact Factor
