Novel Human Tenascin-C Function-Blocking Camel Single Domain Nanobodies.

The extracellular matrix (ECM) molecule Tenascin-C (TNC) is well-known to promote tumor progression by multiple mechanisms. However, reliable TNC detection in tissues of tumor banks remains limited. Therefore, we generated dromedary single-domain nanobodies Nb3 and Nb4 highly specific for human TNC (hTNC) and characterized the interaction with TNC by several approaches including ELISA, western blot, isothermal fluorescence titration and negative electron microscopic imaging.

Tenascin-W Is a Novel Stromal Marker in Biliary Tract Cancers.

Extrahepatic cancers of the biliary system are typically asymptomatic until after metastasis, which contributes to their poor prognosis. Here we examined intrahepatic cholangiocarcinomas (n = 8), carcinomas of perihilar bile ducts (n = 7), carcinomas of the gallbladder (n = 11) and hepatic metastasis from carcinomas of the gallbladder (n = 4) for the expression of the extracellular matrix glycoproteins tenascin-C and tenascin-W. Anti-tenascin-C and anti-tenascin-W immunoreactivity was found in all biliary tract tumors examined.

Pivotal Role of Tenascin-W (-N) in Postnatal Incisor Growth and Periodontal Ligament Remodeling.

The continuously growing mouse incisor provides a fascinating model for studying stem cell regulation and organ renewal. In the incisor, epithelial and mesenchymal stem cells assure lifelong tooth growth. The epithelial stem cells reside in a niche known as the cervical loop.

Generation and characterization of dromedary Tenascin-C and Tenascin-W specific antibodies.

Tenascin-C (TNC) and tenascin-W (TNW), large hexameric glycoproteins overexpressed in the tumor microenvironment, are useful tumor biomarkers for theranostic applications. For now, polyclonal and monoclonal antibodies, as well as aptamers targeting TNC and TNW have been developed. However, the immunostaining sensitivity of antibodies is very heterogenous.

Preparation and Application of a Decellularized Extracellular Matrix for Identification of ADAMTS Substrates.

Here we describe the use of a decellularized ECM produced in vitro by BALB/c 3T3 fibroblasts for the identification of ADAMTS substrates. Seeding of ADAMTS protease-producing HEK cells on top of the cell-free ECM followed by analysis of the conditioned medium by liquid chromatography tandem mass spectrometry (LC-MS/MS), allows for screening of ADAMTS substrates without prior purification of full-length protease.

A Selective Extracellular Matrix Proteomics Approach Identifies Fibronectin Proteolysis by A Disintegrin-like and Metalloprotease Domain with Thrombospondin Type 1 Motifs (ADAMTS16) and Its Impact on Spheroid Morphogenesis.

Secreted and cell-surface proteases are major mediators of extracellular matrix (ECM) turnover, but their mechanisms and regulatory impact are poorly understood. We developed a mass spectrometry approach using a cell-free ECM produced to identify fibronectin (FN) as a novel substrate of the secreted metalloprotease ADAMTS16. ADAMTS16 cleaves FN between its (I) and (I) modules, releasing the N-terminal 30 kDa heparin-binding domain essential for FN self-assembly.

The teneurin C-terminal domain possesses nuclease activity and is apoptogenic.

Teneurins are type 2 transmembrane proteins expressed by developing neurons during periods of synaptogenesis and apoptosis. Neurons expressing teneurin-1 synapse with other teneurin-1-expressing neurons, and neurons expressing teneurin-2 synapse with other teneurin-2-expressing neurons. Knockdowns and mutations of teneurins lead to abnormal neuronal connections, but the mechanisms underlying teneurin action remain unknown.

Comprehensive list of SUMO targets in Caenorhabditis elegans and its implication for evolutionary conservation of SUMO signaling.

Post-translational modification by small ubiquitin-related modifier (SUMO) is a key regulator of cell physiology, modulating protein-protein and protein-DNA interactions. Recently, SUMO modifications were postulated to be involved in response to various stress stimuli. We aimed to identify the near complete set of proteins modified by SUMO and the dynamics of the modification in stress conditions in the higher eukaryote, Caenorhabditis elegans.

KLF4α stimulates breast cancer cell proliferation by acting as a KLF4 antagonist.

Krüppel-like factor 4 (KLF4), a transcription factor involved in both tumor suppression and oncogenesis in various human tumors, is subject to alternative splicing that produces KLF4α. KLF4α is primarily expressed in the cytoplasm because it lacks exon 3 of KLF4, which contains the nuclear localization signal. The role of KLF4 in breast cancer remains unclear and nothing is known yet about the expression and function of the isoform KLF4α.

The expression of tenascin-C and tenascin-W in human ossicles.

The ossicles of the middle ear (the malleus, incus and stapes) transmit forces resulting from vibrations of the tympanic membrane to the cochlea where they are coded as sound. Hearing loss can result from diseases such as rheumatoid arthritis (RA) that affect the joints between the ossicles or degenerative processes like otosclerosis that lead to ankylosis of the footplate of the stapes in the oval window of the cochlea. In this study, immunohistochemistry was used to determine if the extracellular matrix glycoproteins tenascin-C or tenascin-W are expressed in the incudomalleolar and incudostapedial joints of ossicles dissected from human cadavers.

Missense mutations in TENM4, a regulator of axon guidance and central myelination, cause essential tremor.

Essential tremor (ET) is a common movement disorder with an estimated prevalence of 5% of the population aged over 65 years. In spite of intensive efforts, the genetic architecture of ET remains unknown. We used a combination of whole-exome sequencing and targeted resequencing in three ET families.

Tenascin-C: Its functions as an integrin ligand.

This review summarizes the experimental evidence of tenascin-C/integrin interactions, emphasizing the identification of integrin binding sites and the effects of specific interactions on cell behavior. At least four integrins appear to bind to the third fibronectin-type 3 domain of tenascin-C: α9β1, αVβ3, α8β1 and αVβ6. The α9β1 integrin recognizes a highly conserved IDG motif in this domain, while the others recognize an RGD motif.

Mechanism of irradiation-induced mammary cancer metastasis: A role for SAP-dependent Mkl1 signaling.

Radiotherapy is a standard treatment after conservative breast cancer surgery. However, cancers relapsing within a previously irradiated area have an increased probability to metastasize. The mechanisms responsible for this aggressiveness remain unclear.

Transcriptional regulation of tenascin-W by TGF-beta signaling in the bone metastatic niche of breast cancer cells.

Tenascin-W is a matricellular protein with a dynamically changing expression pattern in development and disease. In adults, tenascin-W is mostly restricted to stem cell niches, and is also expressed in the stroma of solid cancers. Here, we analyzed its expression in the bone microenvironment of breast cancer metastasis.

CCN4/WISP1 (WNT1 inducible signaling pathway protein 1): a focus on its role in cancer.

The matricellular protein WISP1 is a member of the CCN protein family. It is induced by WNT1 and is a downstream target of β-catenin. WISP1 is expressed during embryonic development, wound healing and tissue repair.

Transcriptional regulation of tenascin genes.

Extracellular matrix proteins of the tenascin family resemble each other in their domain structure, and also share functions in modulating cell adhesion and cellular responses to growth factors. Despite these common features, the 4 vertebrate tenascins exhibit vastly different expression patterns. Tenascin-R is specific to the central nervous system.

The intracellular domain of teneurin-1 induces the activity of microphthalmia-associated transcription factor (MITF) by binding to transcriptional repressor HINT1.

Teneurins are large type II transmembrane proteins that are necessary for the normal development of the CNS. Although many studies highlight the significance of teneurins, especially during development, there is only limited information known about the molecular mechanisms of function. Previous studies have shown that the N-terminal intracellular domain (ICD) of teneurins can be cleaved at the membrane and subsequently translocates to the nucleus, where it can influence gene transcription.

The evolution of tenascins and fibronectin.

Tenascins are extracellular matrix glycoproteins that act both as integrin ligands and as modifiers of fibronectin-integrin interactions to regulate cell adhesion, migration, proliferation and differentiation. In tetrapods, both tenascins and fibronectin bind to integrins via RGD and LDV-type tripeptide motifs found in exposed loops in their fibronectin-type III domains. We previously showed that tenascins appeared early in the chordate lineage and are represented by single genes in extant cephalochordates and tunicates.

Tenascin-C is required for normal Wnt/β-catenin signaling in the whisker follicle stem cell niche.

Whisker follicles have multiple stem cell niches, including epidermal stem cells in the bulge as well as neural crest-derived stem cells and mast cell progenitors in the trabecular region. The neural crest-derived stem cells are a pool of melanocyte precursors. Previously, we found that the extracellular matrix glycoproteins tenascin-C and tenascin-W are expressed near CD34-positive cells in the trabecular stem cell niche of mouse whisker follicles.

SAP domain-dependent Mkl1 signaling stimulates proliferation and cell migration by induction of a distinct gene set indicative of poor prognosis in breast cancer patients.

Background: The main cause of death of breast cancer patients is not the primary tumor itself but the metastatic disease. Identifying breast cancer-specific signatures for metastasis and learning more about the nature of the genes involved in the metastatic process would 1) improve our understanding of the mechanisms of cancer progression and 2) reveal new therapeutic targets. Previous studies showed that the transcriptional regulator megakaryoblastic leukemia-1 (Mkl1) induces tenascin-C expression in normal and transformed mammary epithelial cells.

Tenascins in stem cell niches.

Tenascins are extracellular matrix proteins with distinct spatial and temporal expression during development, tissue homeostasis and disease. Based on their expression patterns and knockout phenotypes an important role of tenascins in tissue formation, cell adhesion modulation, regulation of proliferation and differentiation has been demonstrated. All of these features are of importance in stem cell niches where a precise regulation of growth versus differentiation has to be guaranteed.

TGF-β-induced differentiation into myofibroblasts involves specific regulation of two MKL1 isoforms.

Cellular transformation into myofibroblasts is a central physiological process enabling tissue repair. Its deregulation promotes fibrosis and carcinogenesis. TGF-β is the main inducer of the contractile gene program that drives myofibroblast differentiation from various precursor cell types.

The LIM-only protein FHL2 attenuates lung inflammation during bleomycin-induced fibrosis.

Fibrogenesis is usually initiated when regenerative processes have failed and/or chronic inflammation occurs. It is characterised by the activation of tissue fibroblasts and dysregulated synthesis of extracellular matrix proteins. FHL2 (four-and-a-half LIM domain protein 2) is a scaffolding protein that interacts with numerous cellular proteins, regulating signalling cascades and gene transcription.

Tenascin-C and tenascin-W in whisker follicle stem cell niches: possible roles in regulating stem cell proliferation and migration.

The whisker follicle has CD34-positive stem cells that migrate from their niche near the bulge along the glassy membrane to the whisker bulb, where they participate in the formation of the whisker shaft. Using immunohistochemistry, we found the glycoprotein tenascin-C in the fibrous capsule of mouse whisker follicles, along the glassy membrane and in the trabecular region surrounding keratin-15-negative, CD34-positive stem cells. The related glycoprotein tenascin-W is found in the CD34-positive stem cell niche, in nearby trabeculae and along the glassy membrane.

Deciphering teneurin domains that facilitate cellular recognition, cell-cell adhesion, and neurite outgrowth using atomic force microscopy-based single-cell force spectroscopy.

Teneurins are evolutionarily conserved transmembrane receptors that function as axon guidance and target selection molecules in the developing nervous system. How teneurins recognize each other, whether they establish neuronal adhesion, and which teneurin specific interactions guide neurons remains to be determined. To reveal insight into these pertinent questions we combine atomic force microscopy-based single-cell force spectroscopy with genetic engineering and quantify the interactions teneurins establish between animal cells.