Hideki Mizutani

Bio: Hideki Mizutani is an academic researcher from Fujita Health University. The author has contributed to research in topics: Temporomandibular joint & Collagen, type I, alpha 1. The author has an hindex of 12, co-authored 74 publications receiving 517 citations. Previous affiliations of Hideki Mizutani include Nagoya University.

Ganglioside GD3 promotes cell growth and invasion through p130Cas and paxillin in malignant melanoma cells

Abstract: Although ganglioside GD3 levels are highly elevated in malignant melanomas, the role of GD3 in melanomas' malignant properties has not been clearly shown. To investigate this problem, we genetically generated GD3-positive (GD3+) transfectant cells from a GD3-negative (GD3-) mutant line SK-MEL-28-N1 and analyzed the phenotypic changes in the transfected cells. GD3+ cells showed markedly increased cell growth and invasive characteristics. Two bands that underwent stronger tyrosine phosphorylation in GD3+ cell lines than in controls after treatment with FCS were found with molecular masses of 130 and 68 kDa. They were identified as p130Cas and paxillin by sequential immunoprecipitation. Their roles in cell growth and invasion were analyzed with a small interfering RNA (siRNA) approach. Cell growth, as analyzed by BrdUrd uptake, was strongly suppressed in GD3+ cells to near the levels of GD3- cells when treated with siRNA for p130Cas but not when treated with siRNA for paxillin. However, treatment with siRNAs of either p130Cas or paxillin resulted in the marked suppression of the invasive activity of GD3+ cells almost to the levels of control cells. These results suggested that these two molecules function as effectors of GD3-mediated signaling, leading to such malignant properties as rapid cell growth and invasion.

Immunohistochemical study of vascular endothelial growth factor (VEGF) and bone morphogenetic protein-2, -4 (BMP-2, -4) on lengthened rat femurs

Abstract: Summary Background With a hypothesis that “angiogenesis occurs before osteogenesis,” an experimental study using a rat model was carried out. Histological and immunohistochemical examinations of vascular endothelial growth factor (VEGF) and bone morphogenetic protein-2, -4 (BMP-2, -4) were performed at the margins of bone formation after femoral bone lengthening. Material and methods Thirty-five Wistar rats weighing 380–400 g (11-week-old males) were used. An external fixator was applied on the femur, and an osteotomy performed under general anaesthesia. Five days after the operation, femoral lengthening was initiated at a rate of 0.8 mm/day for 8 days. The rats were sacrificed just after distraction was completed, and at 1, 3, 5, 7, 9 and 14 days after distraction. The specimens from these rats were stained with haematoxylin–eosin, VEGF, and BMP-2, -4 immunohistochemical staining, and were investigated. Results Expression of VEGF was observed in the woven bone at the osteogenetic front and near to osteoblasts around the newly formed bone. On the other hand, expressions of BMP-2, -4 were seen in the hypertrophic chondrocytes. In the same specimen, the VEGF area was further away from the bone stump than the BMP-2, -4 areas. Conclusion These results confirm the hypothesis that angiogenesis is induced before osteogenesis.

Type VI collagen in mouse masseter tendon, from osseous attachment to myotendinous junction

Abstract: Background and Methods: The association of masseter tendon type VI collagen with other extracellular matrix (ECM) components was examined from osseous attachment to myotendinous junction by immunohistochemistry and transmission electron microscopy with ATP treatment and enzyme digestion. Results: In the tendon proper, fibrocytes extended their processes among bundles of striated collagen fibrils and associated with adjacent cells through amorphous materials, thus forming a three-dimensional network. The amorphous or filamentous material was observed around the fibrocyte cell body and along the cell processes, where the localization of type VI collagen was confirmed by immunohistochemistry using anti-type VI collagen antibody. After treatment with 20 mM adenosine 5′-triphosphate (ATP), 100 nm periodic fibrils, an aggregated form of type VI collagen, were formed in the place where amorphous or filamentous material was present before the treatment. In myotendinous junction, the ATP-aggregated periodic fibrils were observed to associate with the external lamina of the muscle cells as well as among junctional tendon collagen fibrils. In the tendonbone boundary, ATP-aggregated periodic fibrils were observed around fibrocartilage-like cells in the uncalcifying area but not in the calcification front. Prolonged ATP treatment or hyaluronidase predigestion caused the formation of type VI collagen periodic fibrils in the area near the calcified matrix. Conclusions: The distribution of type VI collagen in mouse masseter tendon is different in different anatomical position. This may reflect the different functional demand for this collagen. © 1995 Wiley-Liss, Inc.

Influence of food consistency and dental extractions on the rat mandibular condyle: a morphological, histological and immunohistochemical study

Abstract: The purpose of this study was to investigate the relationship between food consistency and the growth of the mandibular condyle in rats. Secondly, the effect of dental extractions on cartilage of the mandibular condyle was examined in young adult rats fed foods of varying consistency. Thirty-six male Wistar rats were divided into four groups: (A) Solid diet--non-Extraction (non-Ext.) group; (B) Solid diet--Extraction (Ext.) group; (C) Powder diet--non-Ext. group; and (D) Powder diet--Ext. group. Extractions were performed at 12 weeks of age. The mandibular condyles were removed at 1, 4, and 8 weeks after the extractions. The shape of the mandibular condyles in the powder diet groups (C and D) was significantly narrower. In the Ext. groups (B and D), the thickness of the hypertrophic zone was reduced one week after the extractions. In the powder diet groups (C and D), the intensity of the staining of fibronectin decreased in the proliferative zone regardless of the extractions. In group B, a decreased intensity of this reaction was observed one week after the extractions. From these results, it appeared that food consistency and/or dental extractions affected the morphology of the mandibular condyle and the histological characteristics of the mandibular condylar cartilage.

Osteogenesis and angiogenesis: the potential for engineering bone.

Abstract: The repair of large bone defects remains a major clinical orthopaedic challenge. Bone is a highly vascularised tissue reliant on the close spatial and temporal connection between blood vessels and bone cells to maintain skeletal integrity. Angiogenesis thus plays a pivotal role in skeletal development and bone fracture repair. Current procedures to repair bone defects and to provide structural and mechanical support include the use of grafts (autologous, allogeneic) or implants (polymeric or metallic). These approaches face significant limitations due to insufficient supply, potential disease transmission, rejection, cost and the inability to integrate with the surrounding host tissue. The engineering of bone tissue offers new therapeutic strategies to aid musculoskeletal healing. Various scaffold constructs have been employed in the development of tissue-engineered bone; however, an active blood vessel network is an essential pre-requisite for these to survive and integrate with existing host tissue. Combination therapies of stem cells and polymeric growth factor release scaffolds tailored to promote angiogenesis and osteogenesis are under evaluation and development actively to stimulate bone regeneration. An understanding of the cellular and molecular interactions of blood vessels and bone cells will enhance and aid the successful development of future vascularised bone scaffold constructs, enabling survival and integration of bioengineered bone with the host tissue. The role of angiogenic and osteogenic factors in the adaptive response and interaction of osteoblasts and endothelial cells during the multi step process of bone development and repair will be highlighted in this review, with consideration of how some of these key mechanisms can be combined with new developments in tissue engineering to enable repair and growth of skeletal fractures. Elucidation of the processes of angiogenesis, osteogenesis and tissue engineering strategies offer exciting future therapeutic opportunities for skeletal repair and regeneration in orthopaedics.

Neurotrophins: Mediators and Modulators of Pain

Abstract: The neurotrophin family of neurotrophic factors are well-known for their effects on neuronal survival and growth. Over the past decade, considerable evidence has accumulated from both humans and animals that one neurotrophin, nerve growth factor (NGF), is a peripheral pain mediator, particularly in inflammatory pain states. NGF is upregulated in a wide variety of inflammatory conditions, and NGFneutralizing molecules are effective analgesic agents in many models of persistent pain. Such molecules are now being evaluated in clinical trials. NGF regulates the expression of a second neurotrophin, brain-derived neurotrophic factor (BDNF), in nociceptors. BDNF is released when nociceptors are activated, and it acts as a central modulator of pain. The chapter reviews the evidence for these roles (and briefly the effects of other neurotrophins), the range of conditions under which they act, and their mechanism of action.

The anatomical basis for disease localisation in seronegative spondyloarthropathy at entheses and related sites.

Abstract: The 2 major categories of idiopathic inflammatory arthritis are rheumatoid arthritis and the seronegative spondyloarthropathies. Whilst the synovium is the primary site of joint disease in the former, the primary site in the latter is less well defined. However, it has recently been proposed that enthesitis-associated changes in the spondyloarthropathies are primary and that all other joint manifestations are secondary. Nevertheless, some of the sites of disease localisation have not been adequately explained in terms of enthesitis. This article summarises current knowledge of the structure, function, blood supply, innervation, molecular composition and histopathology of the classic enthesis (i.e. the bony attachment of a tendon or ligament) and introduces the concept of ‘functional’ and articular ‘fibrocartilaginous’ entheses. The former are regions where tendons or ligaments wrap-around bony pulleys, but are not attached to them, and the latter are synovial joints that are lined by fibrocartilage rather than hyaline cartilage. We describe how these 3 types of entheses relate to other, and how all are prone to pathological changes in spondyloarthropathy. We propose that the inflammatory responses characteristic of spondyloarthropathies are triggered at these seemingly diverse sites, in genetically susceptible individuals, by a combination of anatomical factors which lead to higher levels of tissue microtrauma, and the deposition of microbes.

Different approaches for interpretation and reporting of immunohistochemistry analysis results in the bone tissue – a review

Abstract: Immunohistochemistry (IHC) is a well-established, widely accepted method in both clinical and experimental parts of medical science. It allows receiving valuable information about any process in any tissue, and especially in bone. Each year the amount of data, received by IHC, grows in geometric progression. But the lack of standardization, especially on the post-analytical stage (interpreting and reporting of results), makes the comparison of the results of different studies impossible. Comprehensive PubMED literature search with a combination of search words “immunohistochemistry” and “scoring system” was performed and 773 articles describing IHC results were identified. After further manual analysis 120 articles were selected for detailed evaluation of used approaches. Six major approaches to the interpretation and presentation of IHC analysis results were identified, analyzed and described. The overview of the existing approaches in evaluation and interpretation of IHC data, which are provided in the article, can be used in bone tissue research and for either better understanding of existing scoring systems or developing a new one. Standard multiparametric, semiquantitative IHC scoring systems should simplify and clarify the process of interpretation and reporting of received data. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_221