tenascin-C Research Articles

Tenascin-C expressing touch dome keratinocytes exhibit characteristics of all epidermal lineages.

The touch dome (TD) keratinocytes are specialized epidermal cells that intimately associate with the light touch sensing Merkel cells (MCs). The TD keratinocytes function as a niche for the MCs and can induce de novo hair follicles upon stimulation; however, how the TD keratinocytes are maintained during homeostasis remains unclear. scRNA-seq identified a specific TD keratinocyte marker, Tenascin-C (TNC). Lineage tracing of Tnc-expressing TD keratinocytes revealed that these cells maintain themselves as an autonomous epidermal compartment and give rise to MCs upon injury. Molecular characterization uncovered that, while the transcriptional and chromatin landscape of the TD keratinocytes is remarkably similar to that of the interfollicular epidermal keratinocytes, it also shares certain molecular signatures with the hair follicle keratinocytes. Our study highlights that the TD keratinocytes in the adult skin have molecular characteristics of keratinocytes of diverse epidermal lineages.

Extracellular Matrix-Trapped Bioinspired Lipoprotein Prolongs Tumor Retention to Potentiate Antitumor Immunity.

The immunomodulatory effects of many therapeutic agents are significantly challenged by their insufficient delivery efficiency and short retention time in tumors. Regarding the distinctively upregulated fibronectin (FN1) and tenascin C (TNC) in tumor stroma, herein a protease-activated FN1 and/or TNC binding peptide (FTF) is designed and an extracellular matrix (ECM)-trapped bioinspired lipoprotein (BL) (FTF-BL-CP) is proposed that can be preferentially captured by the TNC and/or FN1 for tumor retention, and then be responsively dissociated from the matrix to potentiate the antitumor immunity. The FTF-BL-CP treatment produces a 6.96-, 9.24-, 6.72-, 7.32-, and 6.73-fold increase of CD3+CD8+ T cells and their interferon-γ-, granzyme B-, perforin-, and Ki67-expressing subtypes versus the negative control, thereby profoundly eliciting the antitumor immunity. In orthotopic and lung metastatic breast cancer models, FTF-BL-CP produces notable therapeutic benefits of retarding tumor growth, extending survivals, and inhibiting lung metastasis. Therefore, this ECM-trapping strategy provides an encouraging possibility of prolonging tumor retention to potentiate the antitumor immunity for anticancer immunotherapy.

Role of integrin β1 and tenascin C mediate TGF-SMAD2/3 signaling in chondrogenic differentiation of BMSCs induced by type I collagen hydrogel.

Cartilage defects may lead to severe degenerative joint diseases. Tissue engineering based on type I collagen hydrogel that has chondrogenic potential is ideal for cartilage repair. However, the underlying mechanisms of chondrogenic differentiation driven by type I collagen hydrogel have not been fully clarified. Herein, we explored potential collagen receptors and chondrogenic signaling pathways through bioinformatical analysis to investigate the mechanism of collagen-induced chondrogenesis. Results showed that the super enhancer-related genes induced by collagen hydrogel were significantly enriched in the TGF-β signaling pathway, and integrin-β1 (ITGB1), a receptor of collagen, was highly expressed in bone marrow mesenchymal stem cells (BMSCs). Further analysis showed genes such as COL2A1 and Tenascin C (TNC) that interacted with ITGB1 were significantly enriched in extracellular matrix (ECM) structural constituents in the chondrogenic induction group. Knockdown of ITGB1 led to the downregulation of cartilage-specific genes (SOX9, ACAN, COL2A1), SMAD2 and TNC, as well as the downregulation of phosphorylation of SMAD2/3. Knockdown of TNC also resulted in the decrease of cartilage markers, ITGB1 and the SMAD2/3 phosphorylation but overexpression of TNC showed the opposite trend. Finally, in vitro and in vivo experiments confirmed the involvement of ITGB1 and TNC in collagen-mediated chondrogenic differentiation and cartilage regeneration. In summary, we demonstrated that ITGB1 was a crucial receptor for chondrogenic differentiation of BMSCs induced by collagen hydrogel. It can activate TGF-SMAD2/3 signaling, followed by impacting TNC expression, which in turn promotes the interaction of ITGB1 and TGF-SMAD2/3 signaling to enhance chondrogenesis. These may provide concernful support for cartilage tissue engineering and biomaterials development.

The Role of Tenascin-C in Hypertrophic Scar Formation: Insights from Cell and Animal Experiments.

Hypertrophic scars (HS) are dermal diseases characterized by excessive fibroblast proliferation and collagen deposition following burns or trauma. While Tenascin-C (TNC)'s role in promoting visceral fibrosis has been established, its impact on skin tissue fibrosis remains unclear. This study aims to investigate the effects of TNC on HS. RNA sequence and IHC techniques were used to examine the upregulation of TNC gene in human hypertrophic scar tissue compared to normal tissues. Knockdown of TNC in Human skin fibroblasts (HFF-1) cells was achieved, and expression of Col1 and Col3 was evaluated using qPCR. Sirius red collagen staining assessed impact on total collagen content and ECM deposition. Effects on cell proliferation and migration were investigated through cck-8 and cell scratch experiments. Lentivirus infection was used to knock out TNC, and resulting samples were injected into ear wound of rabbits. Effects of TNC knockout on ear scar formation were measured using digital morphology, ultrasound, SEI, H&E, and Masson trichrome methods. Cell experiments: downregulation of TNC decreased Col1 and Col3 expression, leading to reduced collagen production and extracellular matrix deposition. It did not affect HFF-1 cell proliferation and migration. Animal experiments: TNC knockdown promoted wound healing and reduced collagen deposition in rabbit ears. This study suggests that knocking down TNC inhibits collagen formation and extracellular matrix deposition, thereby inhibiting hypertrophic scar formation. Therefore, TNC can be considered a potential biomarker for HS formation and may offer promising treatment strategies for clinical management of hypertrophic scars.

Assessment of Tenascin C levels in the serum of patients with bronchial asthma

Asthma is a heterogeneous disease that affects a large proportion of the global population and is distinguished by airway hyperresponsiveness to direct and indirect stimulations. It is a multifactorial disease that is triggered by heredity and environmental causes. Tenascin C (TNC) is an extracellular matrix glycoprotein that promotes inflammatory cell migration from the interstitium to the airways. Stimulation of TNC is through cytokines from T helper 2 (Th2) cells, in addition, it proliferates within basement membranes of the airways in asthmatic patients. This study aimed to determine whether serum TNC can be used as a novel biomarker for asthma diagnosis and to evaluate the association between serum TNC measurement and asthma severity. This case-control study included 64 patients with mild to severe bronchial asthma, diagnosed according to GINA 2022, referred to the Allergy and Clinical Immunology outpatient clinic at Ain Shams University Hospital, and 64 normal subjects as controls. Serum TNC levels were measured by ELISA. Serum TNC levels were significantly higher among bronchial asthma patients than controls (p ˂0.001). The sensitivity of serum TNC measurement in the diagnosis of bronchial asthma was 93.75%, the specificity 60.94%, and the negative predictive value 90.7%. Besides, a significant relation was found between serum TNC levels and the severity of bronchial asthma (p=0.004), as elevated serum TNC levels were the highest among severe asthmatic patients. In conclusion, the results gained in this study revealed that serum TNC level could be proposed as a potential biomarker for the diagnosis of bronchial asthma and a potential predictor of disease severity.

Small extracellular vesicle-based human melanocyte and melanoma signature.

Intercellular communication is a cell-type and stimulus-dependent event driven not only by soluble factors but also by extracellular vesicles (EVs). EVs include vesicles of different size and origin that contain a myriad of molecules. Among them, small EVs (sEV; <200 nm) have been shown to modulate not just regional cell responses but also distant organ behavior. In cancer, distant organ modulation by sEVs has been associated to disease dissemination, which is one of the main concerns in melanoma. Description of broadly conserved alterations in sEV-contained molecules represents a strategy to identify key modifications in cellular communication as well as new disease biomarkers. Here, we characterize proteomes of cutaneous melanocyte and melanoma-derived sEVs to deepen on the landscape of normal and disease-related cell communication. Results reveal the presence of unique protein signatures for melanocytes and melanoma cells that reflect cellular transformation-related profound modifications. Melanocyte-derived sEVs are enriched in oxidative metabolism (e.g., aconitase 2, ACO2) or pigmentation (e.g., tyrosinase, TYR) related proteins while melanoma-derived sEVs reflect a generalized decrease in mature melanocytic markers (e.g., melanoma antigen recognized by T-cells 1, MART-1, also known as MLANA) and an increase in epithelial to mesenchymal transition (EMT)-related adhesion molecules such as tenascin C (TNC).

Single-cell Transcriptomic Analysis Reveals an Immunosuppressive Network Between POSTN CAFs and ACKR1 ECs in TKI-resistant Lung Cancer.

Tyrosine kinase inhibitor (TKI) therapy, a principal treatment for advanced non-small cell lung cancer (NSCLC), frequently encounters the development of drug resistance. The tumor microenvironment (TME) plays a critical role in the progression of NSCLC, yet the relationship between endothelial cells (ECs) and cancer-associated fibroblasts (CAFs) subpopulations in TKI treatment resistance remains largely unexplored. The BioProject database PRJNA591860 project was used to analyze scRNA-seq data including 49 advanced-stage NSCLC samples across three different time points: pre-targeted therapy (naïve), post-partial response (PR) to targeted therapy, and post-progressive disease (PD) stage. The data involved clustering stromal cells into multiple CAFs and ECs subpopulations. The abundance changes and functions of each cluster during TKI treatment were investigated by KEGG and GO analysis. Additionally, we identified specific transcription factors and metabolic pathways via DoRothEA and scMetabolism. Moreover, cell-cell communications between PD and PR stages were compared by CellChat. ECs and CAFs were clustered and annotated using 49 scRNA-seq samples. We identified seven ECs subpopulations, with OIT3 ECs showing enrichment in the PR phase with a drug-resistance phenotype, and ACKR1 ECs being prevalent in the PD phase with enhanced cell adhesion. Similarly, CAFs were clustered into 7 subpopulations. PLA2G2A CAFs were predominant in PR, whereas POSTN CAFs were prevalent in PD, characterized by an immunomodulatory phenotype and increased collagen secretion. CellChat analysis showed that ACKR1 ECs strongly interacted with macrophage through the CD39 pathway and POSTN CAFs secreted Tenascin-C (TNC) to promote the progression of epithelial cells, primarily malignant ones, in PD. This study reveals that POSTN CAFs and ACKR1 ECs are associated with resistance to TKI treatment, based on single-cell sequencing.

Engrailed 2 serves as a master regulator of the super-enhancer in the TNC gene locus in non-small cell lung cancer.

Engrailed 2 (EN2) is a homeodomain-containing protein that is dysregulated in many types of cancer. However, the role of EN2 in non-small cell lung cancer (NSCLC) and the mechanism underlying its biological function are largely unclear. Here, we showed that EN2 played an oncogenic function in NSCLC and greatly enhanced the malignant phenotype of NSCLC cells. Meanwhile, EN2 was able to boost the expression of a well-studied oncogenic Tenascin-C (TNC) gene, which in turn activated the AKT signaling pathway. Interestingly, we found that EN2 directly bound to the super-enhancer (SE) region in the TNC locus. The histone marker H3K27ac was also enriched in the region, indicating the activation of the SE. Treatment of the cells with JQ1, an inhibitor of SE activity, abrogated the effect of EN2 on the expression of TNC and phosphorylation of AKT-Ser473. Collectively, our work unveils a novel mode of EN2 function, in which EN2 governs the SE in the TNC locus, consequently activating the oncogenic TNC-AKT axis in NSCLC.

Characteristics of n6-methyladenosine (m6A) regulators and role of FTO/TNC in scleroderma

Backgroundm6A regulators have important roles in a variety of autoimmune diseases, but their potential function in scleroderma, a refractory connective tissue disease, remains unclear. Tenascin C (TNC) is known to be a factor promoting collagen deposition in the development of scleroderma, but the regulatory relationship between TNC and m6A regulators is unknown. MethodsWe extracted GSE33463 data consisting of forty-one healthy controls and sixty-one patients with scleroderma, and we analyzed the expression levels of twenty-one m6A regulators as well as the associations between them. In addition, we obtained random forest (RF) and nomogram models to predict the likehood of scleroderma. Next, we categorized the m6Aclusters and geneclusters by consensus clustering, and we performed an immune cell infiltration analysis for each cluster. Finally, we injected adenoviruses into a bleomycin (BLM)-induced mouse model of scleroderma, which was used to overexpress FTO and TNC. We assess the extent of skin fibrosis in the mice samples using pathology stains and measuring their hydroxyproline content and collagen mRNA. ResultsWe initially identified fourteen differentially expressed m6A regulators (WTAP, RBM15, CBLL1, FTO, ALKBH5, YTHDC1, YTHDC2, YTHDF1, YTHDF2, YTHDF3, RBMX, HNRNPC, IGFBP1 and IGFBP2). We found ALKBH5 to be positively associated with CBLL1 and RBM15, and FTO to be negatively associated with WTAP. In addition, we identified four m6A regulators (CBLL1, IGFBP1, YTHDF2 and IGFBP2) using a RF model, and we designed a nomogram model with those variables that proved reliable according to the calibration curve and clinical impact curve. We found that the m6Acluster A was correlated with Type 1 T helper cell infiltration and the genecluster A was correlated with regulatory T cell infiltration. Finally, we showed that FTO overexpression downregulated the m6A and mRNA levels of TNC, and alleviated skin fibrosis in the mouse model of scleroderma. Thus, our overexpression experiments provide preliminary evidence suggesting that TNC is an adverse factor in scleroderma. ConclusionOur approach might be useful as a new and accurate scleroderma diagnosis method. Moreover, our results suggested that FTO/TNC might be a novel scleroderma therapeutic target.

Schnurri-3 drives tumor growth and invasion in cancer cells expressing interleukin-13 receptor alpha 2

Interleukin 13 receptor alpha 2 (IL13Rα2) is a relevant therapeutic target in glioblastoma (GBM) and other tumors associated with tumor growth and invasion. In a previous study, we demonstrated that protein tyrosine phosphatase 1B (PTP1B) is a key mediator of the IL-13/IL13Rα2 signaling pathway. PTP1B regulates cancer cell invasion through Src activation. However, PTP1B/Src downstream signaling mechanisms that modulate the invasion process remain unclear. In the present research, we have characterized the PTP1B interactome and the PTP1B-associated phosphoproteome after IL-13 treatment, in different cellular contexts, using proteomic strategies. PTP1B was associated with proteins involved in signal transduction, vesicle transport, and with multiple proteins from the NF-κB signaling pathway, including Tenascin-C (TNC). PTP1B participated with NF-κB in TNC-mediated proliferation and invasion. Analysis of the phosphorylation patterns obtained after PTP1B activation with IL-13 showed increased phosphorylation of the transcription factor Schnurri-3 (SHN3), a reported competitor of NF-κB. SHN3 silencing caused a potent inhibition in cell invasion and proliferation, associated with a down-regulation of the Wnt/β-catenin pathway, an extensive decline of MMP9 expression and the subsequent inhibition of tumor growth and metastasis in mouse models. Regarding clinical value, high expression of SHN3 was associated with poor survival in GBM, showing a significant correlation with the classical and mesenchymal subtypes. In CRC, SHN3 expression showed a preferential association with the mesenchymal subtypes CMS4 and CRIS-B. Moreover, SHN3 expression strongly correlated with IL13Rα2 and MMP9-associated poor prognosis in different cancers. In conclusion, we have uncovered the participation of SNH3 in the IL-13/IL13Rα2/PTP1B pathway to promote tumor growth and invasion. These findings support a potential therapeutic value for SHN3.

BIOM-32. EVS CARRYING TENASCIN-C ENABLE TUMOR-SPECIFIC MUTATION ANALYSIS IN GLIOBLASTOMA PATIENTS

Abstract Extracellular vesicles (EVs) transport biological and specific information from tumors into the bloodstream, enabling non-invasive detection of tumor material and disease monitoring. Based on a proteomics screen, we performed immunophenotyping of eight glioma-related antigens (tenascin-C (TNC), integrin-beta 1 (ITGB1), profilin-1 (PFN1), CD44, CD133, GPNMB, HLA-II, SPARC) and tetraspanins (CD9, CD63 and CD81) in plasma EVs from GBM patients (before and after surgery (n = 38)), from matched GBM relapse patients (n = 11), and from healthy donors (HD, n = 12) using imaging flow cytometry. Double-positive TNC+/CD9+ EVs showed the strongest differences per mL of plasma in primary (FC = 7.6, p&amp;lt; .0001, ROC analysis AUC = 81%) and relapsed GBM (FC = 16.5, p&amp;lt; .0001; AUC = 90%) compared to HD subjects. High TNC signals were also observed in GBM-EVs by immunogold electron microscopy compared to HD-EVs. In paired analysis, TNC+/CD9+ EVs showed a 3.9-fold decrease after tumor removal (p&amp;lt; .001) and re-increased at GBM recurrence in these patients (FC = 8.4, p&amp;lt; .05; AUC = 84%). In tissue samples, TNC levels were 5.4-fold higher in GBM patients than in non-neoplastic cortex controls (p&amp;lt; .01) measured by immunohistochemistry and correlated positively with plasma TNC+/CD9+ EV levels in RTK-I/II GBM patients (r = 0.42, p&amp;lt; .05). Accordingly, spatial transcriptomics of GBM tissue sections revealed that TNC is specifically overexpressed in GBM cells. Furthermore, magnetic sorting of TNC in plasma EVs allowed detection of GBM-specific TERT*C228T mutations by digital droplet PCR. Mutated TERT DNA was enriched in TNC+ EVs (n = 13) compared to TNC- EVs (FC = 110, p&amp;lt; 0.0001), total EV DNA (FC = 36.7, p&amp;lt; 0.01), and cfDNA (FC = 7.2, p &amp;lt; 0.05). In conclusion, we identified TNC as a biomarker in circulating EVs from GBM patients that can be isolated and used for tumor-specific mutation analysis.

Estimation of Tenascin-C Levels in Iraqi Patients with Diabetic Nephropathy

Background: Diabetic nephropathy (DN) is a highly malignant chronic microvascular complication of diabetes that is the principal cause of end-stage renal disease (ESRD). Objective: The purpose of this study is to ascertain the correlation between diabetic nephropathy and Tenascin-C (TNC), in addition to quantifying TNC levels at different phases of this pathogenesis. Methods: Thirty healthy subjects and ninety T2DM patients participated in this cross-sectional study. Patients were divided into three groups according to the albumin-creatinine ratio (ACR): normal albuminuria, microalbuminuria, and macroalbuminuria. By employing an ELISA reagent, the serum TNC concentration was ascertained. Results: Significant disparities were observed in the concentrations of TNC and FBG, TC, TGs, HDL, LDL, and VLDL between individuals with diabetic nephropathy and those who were in good health. There were also substantial differences between the levels of TNC and kidney function in patients with various disease stages. Furthermore, a noteworthy positive correlation was identified between TNC and blood concentrations of ACR, urea, and creatinine. Conclusions: Based on the available evidence, it can be deduced that TNC may serve as the most precise predictor of diabetic nephropathy and may be associated with its progression.

A systematic investigation of the effects of TGF-β3 and mechanical stimulation on tenogenic differentiation of mesenchymal stromal cells in a poly(ethylene glycol)/gelatin-based hydrogel

BackgroundHigh post-surgical failure rates following tendon injury generate high medical costs and poor patient recovery. Cell-based tendon tissue engineering has the potential to produce fully functional replacement tissue and provide new strategies to restore tendon function and healing. In this endeavour, the application of mesenchymal stromal cells (MSCs) encapsulated in biomaterial scaffolds has shown great promise. However, a consensus on optimal promotion of tenogenic differentiation of MSCs has yet to be reached, although growth factors and mechanical cues are generally acknowledged as important factors. MethodsIn this study, we prepared a hydrogel cell culture system consisting of methacrylated poly(d,l-lactic acid-ethylene glycol-d,l-lactic acid) (P(LA-EG-LA)) and gelatin methacrylate (GelMA) to encapsulate human bone marrow-derived MSCs (hBMSCs). We further systematically investigated the influence of static and intermittent cyclic uniaxial strain mechanical stimulation, in combination with transforming growth factor-β3 (TGF-β3) supplementation, on tenogenic differentiation of hBMSCs. ResultsIncreased TGF-β3 concentration upregulated the tenogenic genes Scleraxis (SCX) and collagen type I (COL1A1) but showed no effects on tenascin-c (TNC) and collagen type III (COL3A1) expression. Mechanical stimulation had no observable effect on gene expression, but intermittent cyclic uniaxial strain stimulation improved matrix deposition. Together, these data provide new insights into how TGF-β3 and mechanical stimulation regulate MSC tenogenesis, with TGF-β3 promoting the expression of key tenogenic genes whilst mechanical stimulation aided matrix deposition in the engineered tissue. Furthermore, intermittent cyclic uniaxial strain at 3% elongation and 0.33 ​Hz for 1 ​h/day showed improved matrix effects compared to static strain. ConclusionTogether, the most promising result for tenogenic differentiation of hBMSCs was identified as treatment with 5 ​ng/ml TGF-β3 under intermittent cyclic uniaxial strain (3% strain; 0.33 ​Hz; 1 ​h/day). This knowledge is of importance for the development of an improved protocol for tenogenic differentiation of MSCs and thereby for tendon tissue engineering. The translational potential of this articleTissue-engineered strategies for tendon repair require a consensus on the differentiation of mesenchymal stromal cells to tenocytes, which is currently lacking. This article provides a systematic investigation of two main tenogenic differentiation conditions to further development of a tenogenic differentiation protocol.

Caveolin-1-dependent tenascin C inclusion in extracellular vesicles is required to promote breast cancer cell malignancy.

Background: Elevated expression of CAV1in breast cancer increases tumor progression. Extracellular vesicles (EVs) from CAV1-expressing MDA-MB-231 breast cancer cells contain Tenascin C (TNC), but the relevance of TNC remained to be defined. Methods: EVs were characterized by nanotracking analysis, microscopy and western blotting. The uptake of EVs by cells was studied using flow cytometry. The effects of EVs on breast cancer cells were tested in migration, invasion, colony formation and in vivo assays. Results: EVs were taken up by cells; however, only those containing TNC promoted invasiveness. In vivo, EVs lacking TNC ceased to promote tumor growth. Conclusion: CAV1 and TNC contained in breast cancer cell-derived EVs were identified as proteins that favor progression of breast cancer.

Tenascin-C-enriched regeneration-specific extracellular matrix guarantees superior muscle regeneration in Ambystoma mexicanum

Severe muscle injury causes distress and difficulty in humans. Studying the high regenerative ability of the axolotls may provide hints for the development of an effective treatment for severe injuries to muscle tissue. Here, we examined the regenerative process in response to a muscle injury in axolotls. We found that axolotls are capable of complete regeneration in response to a partial muscle resection called volumetric muscle loss (VML), which mammals cannot perfectly regenerate. We investigated the mechanisms underlying this high regenerative capacity in response to VML, focusing on the migration of muscle satellite cells and the extracellular matrix (ECM) formed during VML injury. Axolotls form tenascin-C (TN-C)-enriched ECM after VML injury. This TN-C-enriched ECM promotes the satellite cell migration. We confirmed the importance of TN-C in successful axolotl muscle regeneration by creating TN-C mutant animals. Our results suggest that the maintenance of a TN-C-enriched ECM environment after muscle injury promotes the release of muscle satellite cells and supports eventually high muscle regenerative capacity. In the future, better muscle regeneration may be achieved in mammals through the maintenance of TN-C expression.

Chemokine Binding to Tenascin-C Influences Chemokine-Induced Immune Cell Migration.

Tenascin-C (TNC) is a complex glycoprotein of the extracellular matrix (ECM) involved in a plethora of (patho-)physiological processes, such as oncogenesis and inflammation. Since chemokines play an essential role in both disease processes, we have investigated here the binding of TNC to some of the key chemokines, namely CCL2, CCL26, CXCL8, CXCL10, and CXCL12. Thereby, a differential chemokine-TNC binding pattern was observed, with CCL26 exhibiting the highest and CCL2 the lowest affinity for TNC. Heparan sulfate (HS), another member of the ECM, proved to be a similarly high-affinity ligand of TNC, with a Kd value of 730 nM. Chemokines use glycosa-minoglycans such as HS as co-receptors to induce immune cell migration. Therefore, we assumed an influence of TNC on immune cell chemotaxis due to co-localization within the ECM. CCL26- and CCL2-induced mobilization experiments of eosinophils and monocytes, respectively, were thus performed in the presence and the absence of TNC. Pre-incubation of the immune cells with TNC resulted in a 3.5-fold increase of CCL26-induced eosinophil chemotaxis, whereas a 1.3-fold de-crease in chemotaxis was observed when monocytes were pre-incubated with CCL2. As both chemokines have similar HS binding but different TNC binding affinities, we speculate that TNC acts as an attenuator in monocyte and as an amplifier in eosinophil mobilization by impeding CCL2 from binding to HS on the one hand, and by reinforcing CCL26 to bind to HS on the other hand.

DNA methyltransferase 3A induces the occurrence of oral submucous fibrosis by promoting the methylation of the von Hippel-Lindau.

Oral submucous fibrosis (OSF) is associated with malignant disorders. DNA methyltransferase 3A (DNMT3A) is a DNA methylesterase reported to be upregulated in multiple organs and shown to inhibit fibrosis. However, the detailed effect of DNMT3A on OSF remains unclear. To mimic OSF in vitro, oral fibroblasts were exposed to arecoline and molecular biological experiments were performed to detect the function of DNMT3A in OSF. We found that von Hippel-Lindau (VHL) was downregulated and highly methylated in OSF. Arecoline remarkably increased the viability, invasiveness, and migration of oral fibroblasts, but upregulation of VHL partially reversed these effects. DNMT3A induces DNA hypermethylation in the VHL promoter, and VHL markedly inhibits the level of tenascin-C (TNC) by inducing the ubiquitination of TNC. TNC reversed the inhibitory effect of VHL upregulation on the differentiation of oral fibroblasts into myofibroblasts. DNMT3A induces OSF by promoting methylation of the VHL promoter. Hence, our study provides novel insights into the discovery of novel strategies that can be employed against OSF.

Abstract P3016: Pathologic Matrix Markers Are Differentially Modulated By VSMC-Specific SGK-1 Activity In Hypertension And Abdominal Aortic Aneurysm

Introduction: The VSMC switch to synthetic phenotype promotes aortic pathology such as hypertension (HTN) and abdominal aortic aneurysm (AAA). Mechanical activation of serum and glucocorticoid inducible kinase-1 (SGK-1) alters the VSMC synthetic profile to promote remodeling. Plasma biomarkers may represent opportunities to assess VSMC function in aortic disease, and we hypothesize that analysis of a panel of plasma pathologic matrix markers (PMM) representing synthetic VSMC phenotype can reflect SGK-1-dependent activity. Methods: HTN was induced in wild-type C57Bl/6 (WT) and smooth muscle cell specific SGK-1 knockout (SMC-SGK-1KO +/- ) mice with AngiotensinII infusion (1.46mg/kg/day, n=4-6). Separate mice underwent AAA induction by peri-adventitial CaCl 2 application (n=4-6). Terminal procedure included collecting systolic blood pressure (SBP), aortic diameter (AoD), and plasma. ELISA for PMMs included Interleukin-6 (IL-6), Matrix Metalloproteinase-9 (MMP-9), Cathepsin S (CtsS), and Cystatin C (CysC), Osteoprotegerin (OPG), and Tenascin C (TNC). Impact of the panel was evaluated by a composite T-score. Statistics included T-test and ANOVA. Results: WT+HTN had &gt;30% increased SBP and elevation of IL-6, CtsS, CysC, and TNC (p&lt;0.05). SMC-SGK-1KO +/- +HTN had equally elevated SBP, but no change in PMMs, suggesting that SGK-1 contributed to HTN-induced VSMC synthetic activity. WT+AAA had &gt;65% increased AoD and elevation of all PMMs (p&lt;0.05). Alternatively, SMC-SGK-1KO +/- +AAA had abrogated growth (29.4 + 3.6%, p&lt;0.05 vs WT and WT+AAA) with IL-6, CtsS, CysC, and TNC returning to baseline, suggesting that SGK-1-dependent production of these PMMS was necessary for true AAA growth. Composite T-scores differed between Control, HTN, and AAA in WT mice (0.78 + 0.08 vs 2.91 + 0.29 vs 7.11 + 0.71 respectively, p&lt;0.05). In SMC-SGK-1KO +/- mice, T-score normalized in HTN but remained elevated in AAA (2.19 + 0.21, p&lt;0.05 vs Control and WT+AAA), attributable to the elevations in MMP-9 and OPG, peptides produced by inflammatory infiltrate. Conclusion: A panel of PMMs can be scored to reflect synthetic activity of VSMCs in aortic pathology, as well as response to inhibition, and warrants further investigation for the clinical care of patients with vascular disease.

Intravitreal CendR peptides target laser-induced choroidal neovascularization sites in mice

Choroidal neovascularization (CNV) is a common ocular pathology that may be associated in a variety of eye diseases. Although intravitreal injection treatment of anti-vascular endothelial growth factor (anti-VEGF) drugs shows significant clinical benefits in CNV treatment, the limitations of the current therapy need to be addressed. The aim of our study was to investigate the potential utility of three C-end Rule (CendR) peptides (RPARPAR, PL3, iRGD) for CNV targeting and to evaluate the efficacy of peptides for treating experimental CNV in mice. We observed that the CendR peptides localize to the CNV lesion sites after intravitreal injection and were mainly found in the outer nuclear cell layer (ONL) of the mouse retina. Interestingly, experimental therapy with tenascin-C (TNC-C) and neuropilin-1 (NRP-1)-targeting PL3 peptide, reduced angiogenesis and decreased vascular leakage. The results suggest that PL3 and potentially other CendR peptides could serve as affinity targeting ligands and therapeutics for ocular diseases that involve pathological CNV.

Tenascin-C in Tissue Repair after Myocardial Infarction in Humans.

Adverse ventricular remodeling after myocardial infarction (MI) is progressive ventricular dilatation associated with heart failure for weeks or months and is currently regarded as the most critical sequela of MI. It is explained by inadequate tissue repair due to dysregulated inflammation during the acute stage; however, its pathophysiology remains unclear. Tenascin-C (TNC), an original member of the matricellular protein family, is highly up-regulated in the acute stage after MI, and a high peak in its serum level predicts an increased risk of adverse ventricular remodeling in the chronic stage. Experimental TNC-deficient or -overexpressing mouse models have suggested the diverse functions of TNC, particularly its pro-inflammatory effects on macrophages. The present study investigated the roles of TNC during human myocardial repair. We initially categorized the healing process into four phases: inflammatory, granulation, fibrogenic, and scar phases. We then immunohistochemically examined human autopsy samples at the different stages after MI and performed detailed mapping of TNC in human myocardial repair with a focus on lymphangiogenesis, the role of which has recently been attracting increasing attention as a mechanism to resolve inflammation. The direct effects of TNC on human lymphatic endothelial cells were also assessed by RNA sequencing. The results obtained support the potential roles of TNC in the regulation of macrophages, sprouting angiogenesis, the recruitment of myofibroblasts, and the early formation of collagen fibrils during the inflammatory phase to the early granulation phase of human MI. Lymphangiogenesis was observed after the expression of TNC was down-regulated. In vitro results revealed that TNC modestly down-regulated genes related to nuclear division, cell division, and cell migration in lymphatic endothelial cells, suggesting its inhibitory effects on lymphatic endothelial cells. The present results indicate that TNC induces prolonged over-inflammation by suppressing lymphangiogenesis, which may be one of the mechanisms underlying adverse post-infarct remodeling.