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Ken-ichi Matsumoto - One of the best experts on this subject based on the ideXlab platform.
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impairment of corneal epithelial wound healing is association with increased neutrophil infiltration and reactive oXygen species activation in Tenascin X deficient mice
Laboratory Investigation, 2021Co-Authors: Takayoshi Sumioka, Ken-ichi Matsumoto, Yuka Okada, Hiroki Iwanishi, Masayasu Miyajima, Kana Ichikawa, Peter S Reinach, Shizuya SaikaAbstract:The purpose of the study was to uncover the role of Tenascin X in modulation of healing in mouse corneas subjected to epithelium debridement. Healing in corneas with an epithelial defect was evaluated at the levels of gene and protein eXpression. Wound healing-related mediators and inflammatory cell infiltration were detected by histology, immunohistochemistry and real-time RT-PCR. Tenascin X protein was upregulated in the wounded wild-type (WT) corneal epithelium. The lack of Tenascin X impaired closure of an epithelial defect and accelerated infiltration of neutrophils into the wound periphery as compared to the response in WT tissue. EXpression of wound healing-related proinflammatory and reparative components, i.e., interleukin-6, transforming growth factor β, matriX metalloproteinases, were unaffected by the loss of Tenascin X eXpression. Marked accumulation of malondialdehyde (a lipid peroXidation-derived product) was observed in KO healing epithelia as compared with its WT counterpart. Neutropenia induced by systemic administration of a specific antibody rescued the impairment of epithelial healing in KO corneas, with reduction of malondialdehyde levels in the epithelial cells. Finally, we showed that a chemical scavenging reactive oXygen species reversed the impairment of attenuation of epithelial repair with a reduction of tissue levels of malondialdehyde. In conclusion, loss of Tenascin X prolonged corneal epithelial wound healing and increased neutrophilic inflammatory response to debridement in mice. Tenascin X contributes to the control of neutrophil infiltration needed to support the regenerative response to injury and prevent the oXidative stress mediators from rising to cytotoXic levels.
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measurement of serum Tenascin X in joint hypermobility syndrome patients
Biological & Pharmaceutical Bulletin, 2019Co-Authors: Kazuo Yamada, Atsushi Watanabe, Haruo Takeshita, Atsushi Fujita, Noriko Miyake, Naomichi Matsumoto, Ken-ichi MatsumotoAbstract:Joint hypermobility syndrome (JHS) (also termed hypermobility type Ehlers-Danlos syndrome, hEDS) is a heritable connective tissue disorder that is characterized by generalized joint hypermobility, chronic pain, fatigue, and minor skin changes. Initially, it was reported that there is a small subset of patients with JHS/hEDS who have haploinsufficiency of Tenascin-X (TNX). However, the relationship between TNXB and JHS/hEDS has not been reported at all afterwards. EDS was reclassified into thirteen types in 2017, and the causative gene of JHS/hEDS remained to be identified. Therefore, in this study in order to determine whether JHS/hEDS can be diagnosed by the concentrations of serum form of TNX (sTNX), we measured the concentrations of sTNX in 17 JHS/hEDS patients. The sTNX concentrations in half of the JHS/hEDS patients were significantly lower than those in healthy individuals. No mutations, insertions or deletions were detected in the TNX eXon sequence of the JHS/hEDS patients eXcept for one in patient. That patient has a heterozygous mutation. A correlation between sTNX concentration and mutation of the TNXB genomic sequence was not found in the JHS/hEDS patients. These results indicate that the decrease in sTNX concentration could be used as a risk factor for JHS/hEDS.
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Wound healing-related properties detected in an eXperimental model with a collagen gel contraction assay are affected in the absence of Tenascin-X.
Experimental cell research, 2017Co-Authors: Kei Hashimoto, Naoyo Kajitani, Yasunori Miyamoto, Ken-ichi MatsumotoAbstract:Abstract Patients with Tenascin-X (TNX)-deficient type Ehlers-Danlos syndrome (EDS) do not eXhibit delayed wound healing, unlike classic type EDS patients, who eXhibit mutations in collagen genes. Similarly, in TNX-knockout (KO) mice, wound closure of the skin is normal even though these mice eXhibit a reduced breaking strength. Therefore, we speculated that the wound healing process may be affected in the absence of TNX. In this study, to investigate the effects of TNX absence on wound healing-related properties, we performed collagen gel contraction assays with wild-type (WT) and TNX-KO mouse embryonic fibroblasts (MEFs). Collagen gels with embedded TNX-KO MEFs showed significantly greater contraction than those containing WT MEFs. Subsequently, we assessed collagen gel contraction-related properties, such as the activities of matriX metalloproteinase (MMP)-2 and MMP-9 and the protein and mRNA eXpression levels of transforming growth factor β1 (TGF-β1) in the collagen gels. The activities of MMP-2 and MMP-9 and the eXpression level of TGF-β1 were elevated in the absence of TNX. Furthermore, filopodia-like protrusion formation, cell proliferation, migration, and collagen eXpression in MEFs were promoted in the absence of TNX. These results indicate that these wound healing-related properties are affected in a TNX-deficient eXtracellular environment.
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loss of Tenascin X gene function impairs injury induced stromal angiogenesis in mouse corneas
Journal of Cellular and Molecular Medicine, 2017Co-Authors: Takayoshi Sumioka, Ken-ichi Matsumoto, Yuka Okada, Hiroki Iwanishi, Masayasu Miyajima, Yuka Nidegawa, Shizuya SaikaAbstract:To determine the contribution by Tenascin X (TnX) gene eXpression to corneal stromal angiogenesis, the effects were determined of its loss on this response in TNX knockout (KO) mice. In parallel, the effects of such a loss were evaluated on vascular endothelial growth factor (VEGF) and transforming growth factor β1 (TGFβ1) gene and protein eXpression in fibroblasts and macrophages in cell culture. Histological, immunohistochemical and quantitative RT-PCR changes determined if TnX gene ablation on angiogenic gene eXpression, inflammatory cell infiltration and neovascularization induced by central corneal stromal cauterization. The role was determined of TnX function in controlling VEGF-A or TGFβ1 gene eXpression by comparing their eXpression levels in ocular fibroblasts and macrophages obtained from wild-type (WT) and body-wide TnX KO mice. TnX was up-regulated in cauterized cornea. In TnX KO, macrophage invasion was attenuated, VEGF-A and its cognate receptor mRNA eXpression along with neovascularization were lessened in TnX KOs relative to the changes occurring in their WT counterpart. Loss of TnX instead up-regulated in vivo mRNA eXpression of anti-angiogenic VEGF-B but not VEGF-A. On the other hand, TGFβ1 mRNA eXpression declined in TnX KO cultured ocular fibroblasts. Loss of TnX gene eXpression caused VEGF-A eXpression to decline in macrophages. TnX gene eXpression contributes to promoting TGFβ1 mRNA eXpression in ocular fibroblasts and VEGF-A in macrophages, macrophage invasion, up-regulation of VEGF-A eXpression and neovascularization in an injured corneal stroma. On the other hand, it suppresses anti-angiogenic VEGF-B mRNA eXpression in vivo.
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a potential contribution of Tenascin X to blood vessel formation in peripheral nerves
Neuroscience Research, 2017Co-Authors: Hiromichi Sakai, Naoyo Kajitani, Shigefumi Yokota, Tsunao Yoneyama, Kohei Kawakami, Yukihiko Yasui, Ken-ichi MatsumotoAbstract:Tenascin-X (TNX), an eXtracellular matriX protein, is abundantly eXpressed in peripheral nerves. However, the physiological role of TNX in peripheral nerves remains unknown. In this study, we found that actin levels in sciatic nerves of TNX-deficient mice were markedly decreased. Since actin was highly eXpressed in endothelial cells in wild-type sciatic nerves, we assessed morphological alterations of blood vessels in TNX-null sciatic nerves. The density of blood vessels was significantly decreased and the size of blood vessels was larger than those in wild-type sciatic nerves. Immunofluorescence showed that TNX was eXpressed by Schwann cells and fibroblasts in sciatic nerves. The results suggest that TNX secreted from Schwann cells and/or fibroblasts is involved in blood vessel formation in peripheral nerves.
Hiroyoshi Ariga - One of the best experts on this subject based on the ideXlab platform.
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Tenascin X induces cell detachment through p38 mitogen activated protein kinase activation
Biological & Pharmaceutical Bulletin, 2009Co-Authors: Shinpei Fujie, Ken-ichi Matsumoto, Hiroyoshi Ariga, Hiroshi MaitaAbstract:EXtracellular matriX glycoprotein Tenascin-X (TNX) is the largest member of the Tenascin family. In this study, we investigated the adhesive properties of TNX and the signaling pathway to be induced to mouse fibroblast L cells on TNX substrate. ApproXimately 45% of evaluable cells used in the cell adhesion assay were attached to purified TNX but did not spread and were rounded on TNX. The remaining 55% of cells were detached from the TNX substrate and were floating in the conditioned medium. In rounded cells on TNX, phosphorylation of focal adhesion kinase (FAK) was diminished compared with that in cells on control phosphate buffered saline (PBS). To better understand the pathways that lead to the detachment of cells on the TNX substrate, we eXamined phosphorylation of p38 mitogen-activated protein (MAP) kinase. Phosphorylation of p38 MAP kinase was observed in the rounded cells on TNX in a dose-dependent manner, and the maXimum effect was observed at 30 min on TNX. Inhibition of p38 MAP kinase α eXpression by RNA interference partially suppressed the TNX-induced cell detachment. These results suggest that the p38 MAP kinase is a major mediator of TNX-induced cell detachment.
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serum Tenascin X strongly binds to vascular endothelial growth factor
Biological & Pharmaceutical Bulletin, 2009Co-Authors: Taichi Ishitsuka, Ken-ichi Matsumoto, Tomoki Ikuta, Hiroyoshi ArigaAbstract:Interstitial eXtracellular matriX Tenascin-X (iTNX) with about 450 kDa is prominently present in various tissues. Previously, we identified the serum form of TNX (sTNX) with 200 kDa in the mouse. In the present study, in order to investigate distinctive features and functions of sTNX, a plasmid encoding the recombinant mouse sTNX was constructed. As a control, we also constructed a plasmid encoding mouse 450-kDa iTNX and a plasmid encoding 250-kDa iTNX, which lacks the region of 200-kDa sTNX from 450-kDa iTNX. In cells stably eXpressing each recombinant TNX, a more than 7-fold larger amount of 200-kDa sTNX was released into conditioned medium than the amounts of 250-kDa iTNX and 450-kDa iTNX released into the medium. We previously reported that a splice isoform of iTNX (340-kDa iTNX) binds to vascular endothelial growth factor B (VEGF-B) as well as to VEGF-A. Therefore, the ability of VEGF-A and VEGF-B to bind to 200-kDa sTNX was eXamined by a co-immunoprecipitation assay in comparison with the binding abilities to 250-kDa iTNX and 450-kDa iTNX. It was found that sTNX strongly bound to VEGF-A and VEGF-B, compared with the binding abilities of other iTNX proteins. Based on the results of assays of incorporation of 5-ethynyl-2′-deoXyuridine (EdU), we found that purified recombinant 200-kDa sTNX both alone and in combination with VEGF-A or basic fibroblast growth factor (bFGF) can weakly promote DNA synthesis in proliferating vascular endothelial cells (UV♀2 cells). These results suggest that sTNX possesses weak activity for proliferation of endothelial cells.
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truncated form of Tenascin X Xb s interacts with mitotic motor kinesin eg5
Molecular and Cellular Biochemistry, 2009Co-Authors: Toshiya Endo, Hiroyoshi Ariga, Ken-ichi MatsumotoAbstract:XB-S is a protein with an amino-terminal-truncated form of Tenascin-X (TNXB). However, the precise roles of XB-S in vivo are unknown. In this study, to determine the role of XB-S in vivo, we screened XB-S-binding proteins. FLAG-tagged XB-S was transiently introduced into 293T cells. Then its associated proteins were purified by immunoprecipitation using an anti-FLAG antibody and its components were identified by mass spectrometric analyses. Mitotic motor kinesin Eg5 was identified in the immunoprecipitates. XB-S and Eg5 proteins were co-localized in the cytoplasm in interphase and mitosis, but XB-S did not localize on mitotic spindle microtubules, on which Eg5 prominently localized in mitosis. As for Eg5 binding to XB-S, glutathione S-transferase-fused XB-S eXpressed in vitro directly bound to full-length Eg5 translated in reticulocyte lysate, and the XB-S-binding region was located in the motor domain of Eg5. Furthermore, during cell cycle progression XB-S showed a similar eXpression profile to that of Eg5. These results suggest possible involvement of XB-S in the function of Eg5.
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Induction of truncated form of Tenascin-X (XB-S) through dissociation of HDAC1 from SP-1/HDAC1 compleX in response to hypoXic conditions
Experimental Cell Research, 2008Co-Authors: Akari Kato, Toshiya Endo, Hiroyoshi Ariga, Shun Abiko, Ken-ichi MatsumotoAbstract:ABSTRACT XB-S is an amino-terminal truncated protein of Tenascin-X (TNX) in humans. The levels of the XB-S transcript, but not those of TNX transcripts, were increased upon hypoXia. We identified a critical hypoXia-responsive element (HRE) localized to a GT-rich element positioned from − 1410 to − 1368 in the XB-S promoter. Using an electrophoretic mobility shift assay (EMSA), we found that the HRE forms a DNA–protein compleX with Sp1 and that GG positioned in − 1379 and − 1378 is essential for the binding of the nuclear compleX. Transfection eXperiments in SL2 cells, an Sp1-deficient model system, with an Sp1 eXpression vector demonstrated that the region from − 1380 to − 1371, an HRE, is sufficient for efficient activation of the XB-S promoter upon hypoXia. The EMSA and a chromatin immunoprecipitation (ChIP) assay showed that Sp1 together with the transcriptional repressor histone deacetylase 1 (HDAC1) binds to the HRE of the XB-S promoter under normoXia and that hypoXia causes dissociation of HDAC1 from the Sp1/HDAC1 compleX. The HRE promoter activity was induced in the presence of a histone deacetylase inhibitor, trichostatin A, even under normoXia. Our results indicate that the hypoXia-induced activation of the XB-S promoter is regulated through dissociation of HDAC1 from an Sp1-binding HRE site.
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distinct glycosylation in interstitial and serum Tenascin X
Biological & Pharmaceutical Bulletin, 2007Co-Authors: Takeshi Kinoshita, Hiroyoshi Ariga, Ken-ichi MatsumotoAbstract:We developed an easy and fast method to isolate eXtracellular matriX Tenascin-X (TNX) from various tissues in mice based on TNX antibody affinity purification. We purified approXimately 350-kDa cellular interstitial TNX (iTNX) from the spleen, liver and kidney as well as 200-kDa serum TNX (sTNX). Since the nature and significance of glycosylation in TNX remains to be elucidated, glycobiochemical properties of purified TNX were characterized by lectin blot analysis. Lectin blots by Con A, LCA, PHA-E4, RCA120 or WGA revealed the presence of N-glycan in the cellular TNX and especially compleX-type N-glycan in the serum TNX. In addition, the iTNX from liver and kidney also possessed O-glycan based on the reaction to PNA. The binding to AAL indicated that iTNX from the three tissues possesses fucose linked α1,6 to a pentasaccharide core, whereas sTNX does not. The reaction to SSA but not to MAM suggested the presence of sialic acid linked α2,6 to galactose in both cellular and serum TNX. Lectin blots of trypsin-treated iTNX from the spleen also demonstrated that WGA alone reacts to the t300 product derived from the amino-terminal 300-kDa portion.
Joost Schalkwijk - One of the best experts on this subject based on the ideXlab platform.
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loss of Tenascin X eXpression during tumor progression a new pan cancer marker
Matrix Biology Plus, 2020Co-Authors: Sophie Liot, Joost Schalkwijk, Ulrich Valcourt, Alexandre Aubert, Valerie Hervieu, Naima El Kholti, Bernard Verrier, Elise LambertAbstract:Cancer is a systemic disease involving multiple components produced from both tumor cells themselves and surrounding stromal cells. The pro- or anti-tumoral role of the stroma is still under debate. Indeed, it has long been considered the main physical barrier to the diffusion of chemotherapy by its dense and fibrous nature and its poor vascularization. However, in murine models, the depletion of fibroblasts, the main EXtraCellular MatriX (ECM)-producing cells, led to more aggressive tumors even though they were more susceptible to anti-angiogenic and immuno-modulators. Tenascin-C (TNC) is a multifunctional matricellular glycoprotein (i.e. an ECM protein also able to induce signaling pathway) and is considered as a marker of tumor eXpansion and metastasis. However, the status of other Tenascin (TN) family members and particularly Tenascin-X (TNX) has been far less studied during this pathological process and is still controversial. Herein, through (1) in silico analyses of the Gene EXpression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases and (2) immunohistochemistry staining of Tissue MicroArrays (TMA), we performed a large and eXtensive study of TNX eXpression at both mRNA and protein levels (1) in the 6 cancers with the highest incidence and mortality in the world (i.e. lung, breast, colorectal, prostate, stomach and liver) and (2) in the cancers for which sparse data regarding TNX eXpression already eXist in the literature. We thus demonstrated that, in most cancers, TNX eXpression is significantly downregulated during cancer progression and we also highlighted, when data were available, that high TNXB mRNA eXpression in cancer is correlated with a good survival prognosis.
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well defined clinical presentation of ehlers danlos syndrome in patients with Tenascin X deficiency a report of four cases
Clinical Dysmorphology, 2012Co-Authors: A G M Hendriks, Joost Schalkwijk, Nicol C Voermans, Ben C J Hamel, Michelle M Van RossumAbstract:The Ehlers-Danlos syndrome (EDS) is a clinically and genetically heterogeneous group of inherited connective tissue disorders. The siX major, well-defined, subtypes are classified according to diagnostic criteria, formalized in the Villefranche revised nosology. Shortly after the publication of these criteria in 1998, a further distinct type of EDS, the Tenascin-X (TNX)-deficient type EDS, was reported. The phenotype of this largely unknown type of EDS resembles the phenotype of the classical type of EDS, but its inheritance is autosomal recessive and wound healing is normal; hence, no atrophic scars are present. The clinical diagnosis can be confirmed by the absence of TNX in the serum and by mutation analysis of the TNXB gene. Because the TNX-deficient type EDS is rare and not included in the current diagnostic criteria, this diagnosis is often delayed or even overlooked. Here, we describe four cases which improve the clinical recognition of this type of EDS.
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mild muscular features in Tenascin X knockout mice a model of ehlers danlos syndrome
Connective Tissue Research, 2011Co-Authors: Nicol C Voermans, Joost Schalkwijk, D F Egging, Kiek Verrijp, L Eshuis, M C M Balemans, Ellen Sterrenburg, I A L M Van Rooij, J A W M Van Der Laak, S M Van Der MaarelAbstract:Introduction: Tenascin-X (TNX) is an eXtracellular matriX (ECM) glycoprotein, the absence of which in humans leads to a recessive form of Ehlers–Danlos syndrome (EDS), a group of inherited connective tissue disorders characterized by joint hypermobility, skin hypereXtensibility, and tissue fragility. A mouse model of TNX-deficient type EDS has been used to characterize the dermatological, orthopedic, and obstetrical features. The growing insight in the clinical overlap between myopathies and inherited connective tissue disorders asks for a study of the muscular characteristics of inherited connective tissue diseases. Therefore, this study aims to define the muscular phenotype of TNX knockout (KO) mice. Materials and methods: We performed a comprehensive study on the muscular phenotype of these TNX KO mice, consisting of standardized clinical assessment, muscle histology, and gene eXpression profiling of muscle tissue. Furthermore, peripheral nerve composition was studied by histology and electron microsco...
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Tenascin X deficiency and ehlers danlos syndrome a case report and review of the literature
British Journal of Dermatology, 2010Co-Authors: M Oconnell, N P Burrows, I M J J Van Vlijmenwillems, S M Clark, Joost SchalkwijkAbstract:Tenascin-X is a large eXtracellular matriX glycoprotein that is widely distributed within connective tissues and is associated with an autosomal recessive type of Ehlers-Danlos syndrome (EDS). Tenascin-X represents the first EDS susceptibility gene that does not code for a fibrillar collagen or collagen-processing enzyme. We describe a paediatric case of Tenascin-X deficiency and review the literature.
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analysis of obstetric complications and uterine connective tissue in Tenascin X deficient humans and mice
Cell and Tissue Research, 2008Co-Authors: D F Egging, Anita C.t.m. Peeters, Guido Veit, Manuel Koch, Ivonne M J J Van Vlijmenwillems, Jiwon Choi, Desiree Van Rens, Elaine C Davis, Joost SchalkwijkAbstract:Tenascin-X (TNX) is a large, multi-domain, eXtracellular matriX glycoprotein. Complete deficiency of TNX in humans leads to a recessive form of Ehlers-Danlos syndrome (EDS), and TNX haploinsufficiency is a cause of hypermobility type EDS. EDS patients appear to have a higher risk of several complications during pregnancy, such as pelvic instability, premature rupture of membranes, and postpartum hemorrhage. Here, we present a study of genitourinary and obstetric complications in TNX-deficient women of reproductive age. We have found complications, such as uterus prolapses, that are in agreement with previous findings in other EDS types. In TNX knockout (KO) mice, we have observed mild pregnancy-related abnormalities. Morphological and immunohistological analysis of uterine tissues has not revealed obvious quantitative or spatial differences between TNX KO and wildtype mice with respect to collagen types I, III, V, and XII or elastic fibers. We conclude that TNX-deficient women are at risk of obstetric complications, but that TNX KO mice show only a mild phenotype. Furthermore, we show that TNX is involved in the stability of elastic fibers rather than in their initial deposition.
Claire Lethias - One of the best experts on this subject based on the ideXlab platform.
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New insight of some eXtracellular matriX molecules in beef muscles. Relationships with sensory qualities
animal, 2016Co-Authors: Annabelle Dubost, Claire Lethias, Didier Micol, Anne ListratAbstract:The aim of this study was to highlight the relationships between decorin, Tenascin-X and type XIV collagen, three minor molecules of eXtracellular matriX (ECM), with some structural parameters of connective tissue and its content in total collagen, its cross-links (CLs) and its proteoglycans (PGs). In addition, we have evaluated impact of these minor molecules on beef quality traits. The relative abundance of these molecules was evaluated by western blot analysis in Longissimus thoracis (LT) and Biceps femoris (BF) muscles from Aberdeen Angus and Blond d'Aquitaine beef breeds. Decorin and Tenascin-X were more abundant in BF than in LT (1.8 v. 0.5 arbitrary units (AU), respectively, P
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Tenascin-X: beyond the architectural function
Cell Adhesion & Migration, 2015Co-Authors: Ulrich Valcourt, Jean-yves Exposito, Claire Lethias, Lindsay B Alcaraz, Laurent BartholinAbstract:Tenascin-X is the largest member of the Tenascin (TN) family of evolutionary conserved eXtracellular matriX glycoproteins, which also comprises TN-C, TN-R and TN-W. Among this family, TN-X is the only member described so far to eXert a crucial architectural function as evidenced by a connective tissue disorder (a recessive form of Ehlers-Danlos syndrome) resulting from a loss-of-function of this glycoprotein in humans and mice. However, TN-X is more than an architectural protein, as it displays features of a matricellular protein by modulating cell adhesion. However, the cellular functions associated with the anti-adhesive properties of TN-X have not yet been revealed. Recent findings indicate that TN-X is also an eXtracellular regulator of signaling pathways. Indeed, TN-X has been shown to regulate the bioavailability of the Transforming Growth Factor (TGF)-β and to modulate epithelial cell plasticity. The neXt challenges will be to unravel whether the signaling functions of TN-X are functionally linked to its matricellular properties.
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Tenascin-X increases the stiffness of collagen gels without affecting fibrillogenesis
Biophysical Chemistry, 2010Co-Authors: Yoran Margaron, Jean-yves Exposito, Luciana Bostan, Maryline Malbouyres, Ana-maria Trunfio-sfarghiu, Yves Berthier, Claire LethiasAbstract:Tenascin-X is an eXtracellular matriX protein whose absence leads to an Ehlers-Danlos Syndrome in humans, mainly characterised by connective tissue defects including the disorganisation of fibrillar networks, a reduced collagen deposition, and modifications in the mechanical properties of dense tissues. Here we tested the effect of Tenascin-X on collagen fibril formation. We observed that the main parameters of fibrillogenesis were unchanged, and that the diameter of fibrils was not significantly different when they were formed in the presence of Tenascin-X. Interestingly, mechanical analysis of collagen gels showed an increased compressive resistance of the gels containing Tenascin-X, indicating that this protein might be directly involved in determinating the mechanical properties of collagen-rich tissues .
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nanomechanical properties of Tenascin X revealed by single molecule force spectroscopy
Journal of Molecular Biology, 2009Co-Authors: Ashlee Jollymore, Claire Lethias, Qing Peng, Yi CaoAbstract:Tenascin-X is an eXtracellular matriX protein and binds a variety of molecules in eXtracellular matriX and on cell membrane. Tenascin-X plays important roles in regulating the structure and mechanical properties of connective tissues. Using single-molecule atomic force microscopy, we have investigated the mechanical properties of bovine Tenascin-X in detail. Our results indicated that Tenascin-X is an elastic protein and the fibronectin type III (FnIII) domains can unfold under a stretching force and refold to regain their mechanical stability upon the removal of the stretching force. All the 30 FnIII domains of Tenascin-X show similar mechanical stability, mechanical unfolding kinetics, and contour length increment upon domain unfolding, despite their large sequence diversity. In contrast to the homogeneity in their mechanical unfolding behaviors, FnIII domains fold at different rates. Using the 10th FnIII domain of Tenascin-X (TNXfn10) as a model system, we constructed a polyprotein chimera composed of alternating TNXfn10 and GB1 domains and used atomic force microscopy to confirm that the mechanical properties of TNXfn10 are consistent with those of the FnIII domains of Tenascin-X. These results lay the foundation to further study the mechanical properties of individual FnIII domains and establish the relationship between point mutations and mechanical phenotypic effect on Tenascin-X. Moreover, our results provided the opportunity to compare the mechanical properties and design of different forms of Tenascins. The comparison between Tenascin-X and Tenascin-C revealed interesting common as well as distinguishing features for mechanical unfolding and folding of Tenascin-C and Tenascin-X and will open up new avenues to investigate the mechanical functions and architectural design of different forms of Tenascins.
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a model of Tenascin X integration within the collagenous network
FEBS Letters, 2006Co-Authors: Claire Lethias, Caroline Cluzel, Alexandre F Carisey, Jane Comte, Jean-yves ExpositoAbstract:Tenascin-X is an eXtracellular matriX protein whose absence leads to an Ehlers-Danlos syndrome in humans, characterized mainly by disorganisation of collagen and elastic fibril networks. After producing recombinant full-length Tenascin-X in mammalian cells, we find that this protein assembled into disulfide-linked oligomers. Trimers were the predominant form observed using rotary shadowing. By solid phase interaction studies, we demonstrate that Tenascin-X interacts with types I, III and V fibrillar collagen molecules when they are in native conformation. The use of Tenascin-X variants with large regions deleted indicated that both epidermal growth factor repeats and the fibrinogen-like domain are involved in this interaction. Moreover, we demonstrate that Tenascin-X binds to the fibril-associated types XII and XIV collagens. We thus suggest that Tenascin-X, via trimerization and multiple interactions with components of collagenous fibrils, plays a crucial role in the organisation of eXtracellular matrices.
James Bristow - One of the best experts on this subject based on the ideXlab platform.
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Tenascin X collagen elastin and the ehlers danlos syndrome
American Journal of Medical Genetics Part C-seminars in Medical Genetics, 2005Co-Authors: James Bristow, David Egging, William A Carey, Joost SchalkwijkAbstract:Tenascin-X is an eXtracellular matriX protein initially identified because of its overlap with the human CYP21B gene. Because studies of gene and protein function of other Tenascins had been poorly predictive of essential functions in vivo, we used a genetic approach that critically relied on an understanding of the genomic locus to uncover an association between inactivating Tenascin-X mutations and novel recessive and dominant forms of Ehlers-Danlos syndrome. Tenascin-X provides the first eXample of a gene outside of the fibrillar collagens and their processing enzymes that causes Ehlers-Danlos syndrome. Tenascin-X null mice recapitulate the skin findings of the human disease, confirming a causative role for this gene in Ehlers-Danlos syndrome. Further evaluation of these mice showed that Tenascin-X is an important regulator of collagen deposition in vivo, suggesting a novel mechanism of disease in this form of Ehlers-Danlos syndrome. Further studies suggest that Tenascin-X may do this through both direct and indirect interactions with the collagen fibril. Recent studies show that TNX effects on matriX eXtend beyond the collagen to the elastogenic pathway and matriX remodeling enzymes. Tenascin-X serves as a compelling eXample of how human eXperiments of nature can guide us to an understanding of genes whose function may not be evident from their sequence or in vitro studies of their encoded proteins.
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Tenascin X deficiency in autosomal recessive ehlers danlos syndrome
American Journal of Medical Genetics Part A, 2005Co-Authors: Noralane M Lindor, James BristowAbstract:We present two unrelated individuals with complete deficiency of Tenascin-X, resulting in an autosomal recessive form of Ehlers-Danlos syndrome (EDS). Consistent with the original description of Tenascin-X deficiency, these individuals had marked skin hypereXtensibility, easy bruising, and joint laXity. Unlike classical EDS they did not have atrophic scarring or poor wound healing. Significant medical problems occurring in these individuals included severe diverticular intestinal disease, mitral valve prolapse requiring valve replacement, and obstructive airway disease.
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elastic fiber abnormalities in hypermobility type ehlers danlos syndrome patients with Tenascin X mutations
Clinical Genetics, 2005Co-Authors: Manon C. Zweers, James Bristow, Willow B Dean, A H M S M Van Kuppevelt, Joost SchalkwijkAbstract:Ehlers-Danlos syndrome (EDS) is a heterogeneous group of connective tissue disorders with characteristic skin and joint involvement. The concept that EDS is a disease of fibrillar collagen was challenged by the identification of a clinically distinct, recessive type of EDS caused by deficiency of the eXtracellular matriX protein Tenascin-X (TNX). Interestingly, haploinsufficiency of TNX is associated with the dominantly inherited hypermobility type of EDS. In this study, we eXamined whether missense mutations in the TNX gene can account for some of the cases of hypermobility type EDS. Furthermore, we studied whether missense mutations or heterozygosity for truncating mutations in the TNX gene lead to alterations in the dermal connective tissue. Sequence analysis revealed three missense mutations in TNX in hypermobility type EDS patients, which were not present in 192 control alleles. Morphometric analysis of skin biopsies of these patients showed altered elastic fibers in one of them, suggesting that this missense mutation is disease causing. Light microscopic and ultrastructural changes of the elastic fibers were observed in TNX-haploinsufficient hypermobility type EDS patients, which were not found in hypermobility type EDS patients in whom TNX mutations were eXcluded. Our results indicate that the observed alterations in elastic fibers are specific for hypermobility type EDS patients with mutations of TNX.
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deficiency of Tenascin X causes abnormalities in dermal elastic fiber morphology
Journal of Investigative Dermatology, 2004Co-Authors: Manon C. Zweers, James Bristow, Peter M Steijlen, Toine H Van Kuppevelt, Ivonne M J J Van Vlijmenwillems, Robert P Mecham, Joost SchalkwijkAbstract:Deficiency of the eXtracellular matriX protein Tenascin-X (TNX) was recently described as the molecular basis of a new, recessive type of Ehlers-Danlos syndrome. Here we report gross abnormalities of the elastic fibers and microfibrils in the dermis of these patients, and reduced dermal collagen content, as determined by quantitative image analysis. The ascending, fine elastic fibers in the papillary dermis were absent or inconspicuous and had few branches. The coarse elastic fibers of the reticular dermis were fragmented and clumped. At the ultrastructural level, irregular and immature elastin fibers and fibers devoid of microfibrils were observed. In TNX-deficient patients the dermal collagen density was reduced, but no structural abnormalities in the collagen fibrils were found. These findings suggest that both elastic fiber abnormalities and reduced collagen content contribute to the observed phenotype in TNX-deficient patients.
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localization and analysis of the principal promoter for human Tenascin X
Genomics, 2002Co-Authors: Sujeewa D Wijesuriya, James Bristow, Walter L. MillerAbstract:Tenascin-X is a large eXtracellular matriX protein eXpressed in connective tissues. Mutations in TNXB are a cause of Ehlers-Danlos syndrome. Comparison of 25 kb of human and mouse DNA near the TNXB untranslated eXon identified eight regions of >80% identity. Of 17 cell types and lines screened, TNXB eXpression was abundant only in fibroblasts and HT1080 human skin fibrosarcoma cells. EXpression of TNXB promoter/reporter constructs in HT1080 cells showed that region E, near the untranslated eXon, had the greatest activity, and the two regions of greatest identity, 5.0 and 3.3 kb upstream, had no activity. Mobility shift assays identified siX protein-binding regions. Regions I, II, and IV bound Sp1 and Sp3, but only I and IV were functional in HT1080 cells. Regions III and V bound unknown proteins and eXerted strong enhancer-like activity. Mutation of regions III and V in promoter/reporter constructs decreased TNXB transcription and identified functionally important Sp1 and Sp3 sites. These eXperiments provide an essential foundation for understanding the regulation of this vital protein.
