tenascin-C Research Articles

Endoplasmic reticulum stress-related super enhancer promotes epithelial-mesenchymal transformation in hepatocellular carcinoma through CREB5 mediated activation of TNC

Super-enhancers (SEs) are associated with key genes that control cellular state and cell identity. Endoplasmic reticulum stress (ERS) regulates epithelial-mesenchymal transformation (EMT). However, whether SEs are involved in ERS-related activation of EMT in hepatocellular carcinoma (HCC) is unknown. In this study, we identified 17 ERS-related SEs by comparing ERS-HCC cells with untreated control cells using ChIP-seq and RNA-seq. CRISPR-Cas9 and RT-qPCR identified CAMP responsive element binding protein 5 (CREB5) as a key target of ERS-related SE. Analyses of TCGA datasets and tissue arrays showed that CREB5 mRNA and protein expression levels were higher in liver cancer tissues than in paired normal tissues. In addition, overexpression of CREB5 was associated with poor prognosis and an aggressive phenotype in patients with HCC. We also found that activation of ERS enhanced the expression of CREB5, and upregulation of CREB5 significantly increased cell proliferation, migration, and invasion, and promoted EMT, but inhibited apoptosis. More importantly, ERS activation increased the expression of several EMT markers by modulating the expression of CREB5. Mechanistically, CREB5 upregulates the transcription of tenascin-C (TNC) by directly binding to its promoter region, thereby promoting EMT in liver cancer cells. In summary, our findings suggest that ERS activation promotes EMT in liver cancer cells via SE-mediated upregulation of the CREB5/TNC pathway. This result provides a new direction for uncovering how ERS regulates EMT and a foundation for preventing the progression of EMT in HCC.

Tenascin-C promotes bone regeneration via inflammatory macrophages.

During the early stage of tissue injury, macrophages play important roles in the activation of stem cells for further regeneration. However, the regulation of macrophages during bone regeneration remains unclear. Here, the extracellular matrix (ECM) tenascin-C (TNC) is found to express in the periosteum and recruit inflammatory macrophages. TNC-deficiency in the periosteum delays bone repair. Transplantation of macrophages derived from injured periosteum is able to rescue the decreased skeletal stem cells and impaired bone regeneration caused by TNC deficiency. The cell communication analysis identifies ITGA7 as a TNC receptor contributing to the recruitment of inflammatory macrophages. TNC expression declines in aged mice and the exogenous delivery of TNC significantly promotes bone regeneration after aging through the recruitment of macrophages. Taken together, this study reveals the regulation of macrophage recruitment and its function in the activation of skeletal stem cells after bone injury, providing a strategy to accelerate bone regeneration by TNC delivery.

Tenascin C-Guided Nanosystem for Precision Delivery of Obeticholic Acid in Liver Fibrosis Therapy.

Objective: Liver fibrosis, a hallmark of chronic liver diseases, is characterized by excessive extracellular matrix (ECM) deposition and scar tissue formation. Current antifibrotic nanomedicines face significant limitations, including poor penetration into fibrotic tissue, rapid clearance, and suboptimal therapeutic efficacy. The dense fibrotic ECM acts as a major physiological barrier, necessitating the development of a targeted delivery strategy to achieve effective therapeutic outcomes. Methods: We designed a liposomal delivery system functionalized with the GBI-10 aptamer and encapsulating obeticholic acid (OCA lips@Apt) to enhance selective delivery to fibrotic liver tissue while minimizing systemic toxicity. Results: Both in vitro and in vivo studies demonstrated that the aptamer-modified OCA liposomes effectively treated hepatic fibrosis through dual mechanisms: modulation of abnormal bile acid metabolism and attenuation of inflammation. The targeted delivery system leveraged the overexpression of Tenascin-C (TnC), a key ECM component in fibrotic tissues, for precise localization and enhanced endocytosis via the exposed cationic liposome surface. Conclusions: The OCA lips@Apt nanodrug demonstrated superior therapeutic efficacy with minimal off-target effects, offering a promising strategy to overcome critical barriers in liver fibrosis treatment. By precisely targeting the fibrotic ECM and modulating key pathological pathways, this TnC-guided liposomal delivery system provides a significant advancement in antifibrotic nanomedicine.

Engrailed 2 facilitates progression of triple-negative and HER2-enriched breast cancer by binding to enhancer region of Tenascin-C

Engrailed 2 (EN2) is a homeodomain-containing protein whose aberrant expression is observed in various cancer types, yet its role in breast cancer remains unclear. This study investigates the roles and mechanisms of EN2 in breast cancer progression. Using online dataset analysis, we assessed the correlation between EN2 expression and breast cancer progression and chemotherapeutic sensitivity. Functional assays, including RT-qPCR, Western blot, cell viability, transwell migration and invasion, spheroid formation, and flow cytometry, were conducted to explore EN2's role. Mechanistic insights were obtained through luciferase reporter assays, ChIP, and Caspase 3 activity detection. Our results showed that EN2 is highly expressed in breast cancer patients, negatively correlating with survival rates and positively with disease progression and reduced chemotherapy sensitivity. Functional experiments confirmed EN2's oncogenic role, and it was found to promote the expression of the oncogenic Tenascin-C (TNC) gene. Notably, EN2 directly interacts with the super-enhancer region within the TNC locus. Elevated TNC expression mitigated the effects of EN2 knockdown on breast cancer cell progression. Our study unveils a novel mechanism by which EN2 regulates the TNC locus super-enhancer, thereby activating oncogenic pathways in breast cancer.

IL-18R supported CAR T cells targeting oncofetal tenascin C for the immunotherapy of pediatric sarcoma and brain tumors

BackgroundOncofetal splice variants of extracellular matrix (ECM) proteins present a unique group of target antigens for the immunotherapy of pediatric cancers. However, limited data is available if these splice variants...

Abstract C050: Leveraging ECM deposition by CAF-like Ewing sarcoma tumor cells to target micrometastases with matrix-binding VHHs

Abstract Ewing sarcoma (EwS) is an aggressive bone and soft tissue tumor and EwS patients often succumb to their disease years after initial treatment due to relapses at metastatic sites. Novel therapeutic strategies are needed that can successfully eliminate microscopic residual disease foci that persist at the end of primary therapy. Extracellular matrix (ECM) proteins in the tumor microenvironment (TME) provide critical pro-survival and pro-invasion signals to tumor cells. Our published and unpublished data show that the glycoprotein tenascin-C (TNC) is enriched in EwS metastases and that TNC and other pro-tumorigenic ECM proteins are deposited by subpopulations of CAF-like tumor cells that are activated in response to tumor and TME-derived TGF-beta ligands. TNC is abundantly produced by multiple human tumors of epithelial and non-epithelial lineage but is otherwise rarely expressed outside of development and wound healing. Importantly, TNC is specifically enriched in metastatic lesions where it has been implicated as a mediator of metastatic competence and treatment resistance. In the current work we have tested whether the TNC-rich TME of disseminated EwS tumor foci could be leveraged to direct therapies to sites of residual micrometastatic disease. To achieve this, we generated monovalent and bivalent anti-human TNC VHHs (hTNC-VHH) using a mammalian expression platform. Camelid-derived hTNC-VHH sequences were sourced from published literature. VHHs are single domain heavy chain only antibody fragments with higher stability and tissue penetration than conventional monoclonal antibodies. Using EwS tumor spheroids in collagen-rich 3D culture, hTNC-VHH penetrated dense ECM matrices and bound through multiple cell layers in under 10 minutes. hTNC-VHH accumulated in TNC-positive but not TNC-knockout EwS spheroids and were retained beyond 96 hours. To assess their potential to drive protein and immune therapies to TNC-rich TMEs, we fused hTNC-VHH to immune modulating CD3- and CD28-activating VHHs. These hTNC-VHH-CD3/CD28-conjugates promoted immune cell activation and tumor cell death in PBMC-tumor co-culture assays as determined by CD25 flow cytometry and fluorescence microscopy, respectively. To assess in vivo localization, fluorescently-tagged hTNC-VHH were intravenously injected into mice that had been xenografted with EwS cells. Tissue microscopy confirmed selective binding of hTNC-VHH to small lung and liver EwS micrometastases in less than 4 hours. VHHs were not retained in non-tumor bearing organs including the brain and heart or in tumor-free lung and liver regions. Experiments are ongoing to assess anti-tumor efficacy and pharmacodynamics of hTNC-VHH conjugates in EwS xenografts. Together these findings suggest that the ECM-remodeling properties of CAF-like EwS cells can be exploited to recruit novel ECM-targeting protein therapeutics to micrometastases. If successful, this innovative approach could eradicate microscopic residual disease and prevent metastatic EwS recurrence. Citation Format: Emma D. Wrenn, Jason P. Price, Raymond O. Ruff, Nicolas M. Garcia, James M. Olson, Elizabeth R. Lawlor. Leveraging ECM deposition by CAF-like Ewing sarcoma tumor cells to target micrometastases with matrix-binding VHHs [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C050.

Abstract 4136627: Development of a biomarker to predict refractory cases in Kawasaki disease patients -towards the development of diagnostic kit-

Introduction: Kawasaki disease (KD), which is the most common multisystem vasculitis with unknown causes in childhood, causes coronary artery lesions (CALs). Treatment with a high dose of intravenous immunoglobulin (IVIG) is the most effective therapy for the acute phase of KD. However, some very severe cases need several additional treatments and are at risk for CALs. Several scoring systems that have tried to predict IVIG-resistant patients failed in multiethnic populations. Aims: To develop the most effective biomarker for predicting refractory cases and determine the cut-off value for the development of the diagnostic kit. Methods: Multicenter, prospective, observational study was conducted at 49 hospitals in Japan between September 2017 and December 2023. The subjects consisted of 1310 KD patients, including Group 1 (n=50); treatment-resistant cases that required additional treatment of 3rd line or more (defined as refractory cases), and Group 2 (n=1260); cases that completed the treatment with 1st or 2nd line. Tenascin C (TN-C), Pentraxin 3 (PTX3), and Procalcitonin (PCT) values, which were selected by systematic review and a pilot study, were measured before initial treatment in each group. The cut-off value of the biomarker, which had the highest area under the curve (AUC), was determined. Results: All three biomarker values were significantly higher in Group 1 than Group 2 (p<0.01). Median [Interquartile range] in Group 1 vs Group 2 and AUC were PTX3; 44.6 [32.3-67.9] vs 12.2 [6.9-26.9]ng/ml, AUC=0.83, PCT; 4.3 [1.9-7.8] vs 0.6 [0.2-1.9]ng/ml, AUC=0.81, TN-C; 182 [122-222] vs 123 [94-163]ng/ml, AUC=0.71. PTX3 showed the highest AUC with the cut-off value of 31.7ng/ml [95% confidence interval; 31.7-34.9]. Group 1 could be predicted by PTX3 with the sensitivity of 80%, the specificity of 82%, the positive predictive value of 13% and the negative predictive value of 99%. Conclusions: It may be possible to predict refractory KD cases with high sensitivity and specificity by PTX3 value before initial treatment, and possibly develop a diagnostic kit using PTX3 value for prediction of refractory cases.

Tenascin-C potentiates Wnt signaling in thyroid cancer.

Tenascin-C (TNC) is a secreted extracellular matrix protein that is highly expressed during embryonic development and re-expressed during wound healing, inflammation, and neoplasia. Studies in developmental models suggest that TNC may regulate the Wnt signaling pathway. Our lab has shown high levels of Wnt signaling and TNC expression in anaplastic thyroid cancer (ATC), a highly lethal cancer with an abysmal ~3-5 month median survival. Here, we investigated the role of TNC in facilitating ligand-dependent Wnt signaling in thyroid cancer. We utilized bulk RNA-sequencing from three independent multi-institutional thyroid cancer patient cohorts. TNC expression was spatially localized in patient tumors with RNA in situ hybridization. The role of TNC was investigated in vitro using Wnt reporter assays and in vivo with a NOD.PrkdcscidIl2rg-/- mouse ATC xenograft tumor model. TNC expression was associated with aggressive thyroid cancer behavior, including anaplastic histology, extrathyroidal extension, and metastasis. Spatial localization of TNC in patient tissue demonstrated a dramatic increase in expression within cancer cells along the invasive edge, adjacent to Wnt ligand-producing fibroblasts. TNC expression was also increased in areas of intravascular invasion. In vitro, TNC bound Wnt ligands and potentiated Wnt signaling. Finally, in an ATC mouse model, TNC increased Wnt signaling, tumor burden, invasion, and metastasis. Altogether, TNC potentiated ligand driven Wnt signaling and promotes cancer cell invasion and metastasis in a mouse model of thyroid cancer. Understanding the role of TNC and its interaction with Wnt ligands could lead to the development of novel biomarkers and targeted therapeutics for thyroid cancer.

Tenascin-C-Matrix Metalloproteinase-3 Phenotype and the Risk of Tendinopathy in High-Performance Athletes: A Case-Control Study.

Background/Objectives: Tendon structure is predominantly composed of the extracellular matrix (ECM), and genetic variants in non-collagenous ECM components may influence susceptibility to tendinopathy. We investigated the potential influence of single nucleotide polymorphisms (SNPs) in fibrillin-2 (FBN2), tenascin-C (TNC), and matrix metalloproteinase-3 (MMP3) on the tendon regeneration failure phenotype and impact on the susceptibility to tendinopathy in Brazilian high-performance athletes. Methods: This case-control study was conducted with 397 high-performance athletes from different sports modalities (197 tendinopathy cases and 200 controls), and they were analyzed by validated TaqManTM SNP genotyping assays of the SNPs FBN2 (rs331079), TNC (rs2104772), and MMP3 (rs591058). Results: Out of the 197 tendinopathy cases, 63% suffered from chronic tendon pain and 22% experienced more than three episodes of disease manifestation. The TNC-rs2104772-A allele was significantly associated with tendinopathy (OR: 1.4; 95% CI: 1.1-1.8), while athletes carrying the MMP3-rs591058-T allele were linked to an increased risk of more episodes of disease manifestation (OR: 1.7; 95% CI: 1.1-2.8). The TNC-MMP3 tendon regeneration failure phenotype (TNC-A/MMP3-T) was associated with an increased risk of tendinopathy (OR: 1.4; 95% CI: 1.1-2.0) and episodes of disease manifestation (OR: 2.0; 95% CI: 1.2-3.5). Athletes with tendinopathy who had the TNC-A/MMP3-T interaction were more prone to experiencing more than three disease exacerbations (OR: 4.3; 95% CI: 1.8-10.5) compared to TNC-A/TNC-C. Conclusions: This study suggests that rs2104772 and rs591058 SNPs could be involved in the tendon regeneration failure phenotype and may influence the molecular mechanism related to the regulation of the tendon ECM during training workload.

Tenascin-C from the tissue microenvironment promotes muscle stem cell self-renewal through Annexin A2.

Skeletal muscle tissue self-repair occurs through the finely timed activation of resident muscle stem cells (MuSC). Following perturbation, MuSC exit quiescence, undergo myogenic commitment, and differentiate to regenerate the injured muscle. This process is coordinated by signals present in the tissue microenvironment, however the precise mechanisms by which the microenvironment regulates MuSC activation are still poorly understood. Here, we identified Tenascin-C (TnC), an extracellular matrix (ECM) glycoprotein, as a key player in promoting of MuSC self-renewal and function. We show that fibro-adipogenic progenitors (FAPs) are the primary cellular source of TnC during muscle repair, and that MuSC sense TnC signaling through cell the surface receptor Annexin A2. We provide in vivo evidence that TnC is required for efficient muscle repair, as mice lacking TnC exhibit a regeneration phenotype of premature aging. We propose that the decline of TnC in physiological aging contributes to inefficient muscle regeneration in aged muscle. Taken together, our results highlight the pivotal role of TnC signaling during muscle repair in healthy and aging skeletal muscle.

Reduced Na current in dystrophin-deficient ventricular cardiomyocytes is rescued by tenascin-C inhibition

Abstract Background Duchenne muscular dystrophy (DMD) is an X-linked hereditary disease triggered by the deficiency of the structural protein dystrophin, which leads to muscular degeneration mainly affecting young males. Major contributors to early death in DMD patients are cardiac arrhythmias and dystrophic cardiomyopathy. One cause for arrhythmias is impaired ventricular impulse conduction, which leads to ventricular asynchrony and reentrant mechanisms. We recently showed that the disruption of dystrophin results in a significant reduction of Na current in ventricular cardiomyocytes (vCMs) of the dystrophin-deficient mdx mouse model for human DMD. Na current reduction provides a mechanistic explanation for the impaired ventricular conduction and accompanying arrhythmias in the dystrophic heart. The extracellular matrix protein tenascin-C (TN-C) is a significant remodeling factor in the injured and diseased heart and is strongly upregulated in dystrophic cardiomyopathy. To this date, it is unknown how the upregulation of TN-C in DMD patients affects dystrophic cardiomyopathy. Purpose In this study, we examined the effect of TN-C inhibition on diminished Na currents in dystrophin-deficient vCMs. Methods We compared four different mouse genotypes with each other, namely wild-type, dystrophin-deficient mdx, TN-C-deficient and dystrophin- plus TN-C-deficient mice. Furthermore, a cohort of mdx mice was injected with TN-C siRNA twice a week for 9 weeks to investigate the effect of TN-C knockdown. Hearts from adult male mice were enzymatically digested using a Langendorff system to isolate single vCMs. Na currents were then measured with the whole cell patch clamp technique. Results Na current densities were increased in TN-C deficient vCMs compared to wild-type vCMs. Accordingly, 24-hour incubation of wild-type vCMs with human recombinant TN-C resulted in a significant decrease in Na current. Na currents of vCMs from mdx mice were reduced, but restored to the wild-type level in vCMs from TN-C-deficient mdx mice. Moreover, vCMs of TN-C siRNA-treated mdx mice had significantly increased Na currents compared to control mdx vCMs. Conclusion Upregulation of TN-C in dystrophin-deficient vCMs reduces Na currents, whereas inhibition of TN-C prevents this reduction. Therefore, inhibition of TN-C in DMD patients may be considered as a potential new therapeutic strategy to improve ventricular conduction and reduce arrhythmia vulnerability.

Granzyme B cleaves tenascin-C to release its C-terminal domain in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a common autoimmune disorder characterized by exacerbated joint inflammation. Despite the well-documented accumulation of the serine protease granzyme B (GzmB) in RA patient biospecimens, little is understood pertaining to its role in pathobiology. In the present study, tenascin-C (TNC) - a large, pro-inflammatory extracellular matrix glycoprotein - was identified as a substrate for GzmB in RA. GzmB cleaves TNC to generate 3 fragments in vitro: a 130 kDa fragment that remains anchored to the matrix and 2 solubilized fragments of 70 and 30 kDa. Mass spectrometry results suggested that the 30 kDa fragment contained the pro-inflammatory TNC C-terminal fibrinogen-like domain. In the synovial fluids of patients with RA, soluble levels of GzmB and TNC were significantly elevated compared with healthy controls. Further, immunoblotting revealed soluble 70 and 30 kDa TNC fragments in the synovial fluids of patients with RA, matching TNC fragment sizes generated by GzmB cleavage in vitro. Granzyme K (GzmK), another serine protease of the granzyme family, also cleaves TNC in vitro; however, the molecular weights of GzmK-generated TNC fragments did not correspond to TNC fragment sizes detected in patients. Our data support that GzmB, but not GzmK, contributes to RA through the cleavage of TNC.

Immunohistochemical Expression of Tenascin-C in Canine Meningiomas.

In humans, tenascin-C (TN-C) expression has been detected in more aggressive neoplasms of the central nervous system, such as gliomas and meningiomas. No study has analyzed the immune expression of TN-C in canine meningioma. The current study aimed to investigate the immunohistochemical distribution of TN-C in different grades of canine meningiomas. Twenty-one cases of canine meningioma (12 grade I, 6 grade II, and 3 grade III) were analyzed. All samples were examined by immunohistochemistry with the following antibodies: TN-C, epithelial membrane antigen (EMA), Ki-67, pan-cytokeratin (Pan CK), and vimentin. The histopathological diagnosis of meningioma was reinforced with the positive labeling of vimentin (moderate to strong) and EMA (mild to moderate) in neoplastic cells in most cases, independently of its grade or subtype. The immunoreactivity of TN-C was irregular: mild in grade I, moderate in grade II, and moderate to severe in grade III neoplasms. Usually, immune positivity was observed in the stroma and perivascular space in all subtypes. In addition, the concentric whorls of neoplastic cells were labeled positive in some psammomatous and transitional meningiomas. The reaction to TN-C was more significant in grade II and III tumors. The immunohistochemical findings of the current study suggest that TN-C can act as a stromal marker, mainly in grade II or III meningiomas.

Pingchuan formula improve airway remodeling via regulation of the nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3/interleukin-1β and C-Jun N-terminal kinase pathways.

Asthma is a prevalent chronic inflammatory airway disease that affects both adults and children. Inflammation-induced airway remodeling can lead to irreversible damage to the airways. Traditional Chinese medicine (TCM) plays a significant role in healthcare, offering potential improvements for chronic airway inflammation associated with asthma. The objective of this study is to investigate the efficacy of Pingchuan formula (PCF) in treating asthma and explore its underlying mechanisms. The asthmatic model mice were sensitized on days 1 and 7, followed by aerosolized OVA challenge for a total of 21 times starting from day 14, spanning weeks 3 to 9. PCF was administered daily after the first challenge. The mice were orally dosed daily based on their individual body weights for a continuous period of 47 days. The examined items encompassed proteomic analysis of the target proteins impacted by PCF. The levels of interleukins IL-1β, IL-18, and transforming growth factor-β (TGF-β) in bronchoalveolar lavage fluid (BALF) were measured using ELISA. Immunohistochemistry was employed to assess the expression levels of nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3), caspase-1, and TGF-β in the airways. Western blotting and real-time quantitative PCR analysis were conducted to determine NLRP3 and caspase-1 expression levels. Additionally, Western blotting was performed to evaluate C-Jun N-terminal kinase (JNK), phosphorylated JNK (p-JNK), matrix metalloproteinase-9 (MMP-9), N-cadherin, E-cadherin, and tenascin C (T-NC) expression. Compared to the asthma model group, histological analysis using hematoxylin and eosin (HE) staining and Masson staining revealed that PCF exhibited a significant reduction in airway inflammation exudation and collagen fiber production in asthmatic mice. The proteomics analysis revealed that there were 174 proteins exhibiting differential expression in the PCF group compared to the asthma model group, indicating a strong association with negative regulation of the cell cycle and inflammation in the airways of asthmatic individuals. The PCF also exhibited a significant reduction in the protein and mRNA expressions of NLRP3 and caspase-1 in lung tissue (P<0.05). Additionally, it decreased the protein expressions of ASC, p-JNK, MMP-9, E-cadherin, and T-NC while increasing N-cadherin levels (P<0.05). The inflammatory factors IL-1β, IL-18 and TGF-β were reduced (P<0.05). This study revealed that Pingchuan Decoction can inhibit airway remodeling by inhibiting NLRP/IL-1β and JNK pathway activation, and effectively improve airway histological inflammation and remodeling in mice.

Discovery of Biomarkers of a Recombinant Human Erythropoietin Administration to Thoroughbred Geldings by Label‐Free Proteomics

ABSTRACTErythropoiesis‐stimulating agents (ESAs) continue to be a significant threat to the integrity of human and equine sports. Besides conventional direct testing, monitoring the biomarkers associated with the effects of ESAs may provide a complementary approach via indirect detection to enhance doping control. In this study, we applied label‐free proteomics to discover plasma protein biomarkers in Thoroughbred geldings after administration with a long‐acting form of recombinant human erythropoietin (rhEPO), methoxy polyethylene glycol epoetin beta, Mircera. Increased haematocrit, haemoglobin and red blood cell (RBC) levels were evidenced as early as 4 days post‐administration in all three horses to varying extents. Tryptic peptides were obtained from plasma samples and analysed by nanoflow ultra‐high‐performance liquid chromatography–high‐resolution tandem mass spectrometry (nano‐UHPLC‐HRMSMS) using data‐independent acquisition. Differential protein abundance analysis has shortlisted seven protein biomarker candidates that showed significant changes specifically after Mircera administration in the treated but not in the control geldings, which comprised downregulation of two proteins, haptoglobin (HP) and haemopexin (HPX), and upregulation of five proteins, transferrin receptor 1 (TFR1), phospholipid transfer protein (PLTP), tenascin C (TNC), vascular cell adhesion molecule 1 (VCAM1) and galectin 3 binding protein (LGALS3BP). Multivariate analysis of plasma proteome has allowed the classification of control and treated samples. This is the first report on the discovery of plasma protein biomarkers of rhEPO administration to geldings. The results lay a foundation for applications of protein biomarkers for controlling the misuse of ESAs.

Tenascin-C in the early lung cancer tumor microenvironment promotes progression through integrin αvβ1 and FAK.

Pre-cancerous lung lesions are commonly initiated by activating mutations in the RAS pathway, but do not transition to lung adenocarcinomas (LUAD) without additional oncogenic signals. Here, we show that expression of the extracellular matrix protein Tenascin-C (TNC) is increased in and promotes the earliest stages of LUAD development in oncogenic KRAS-driven lung cancer mouse models and in human LUAD. TNC is initially expressed by fibroblasts and its expression extends to tumor cells as the tumor becomes invasive. Genetic deletion of TNC in the mouse models reduces early tumor burden and high-grade pathology and diminishes tumor cell proliferation, invasion, and focal adhesion kinase (FAK) activity. TNC stimulates cultured LUAD tumor cell proliferation and migration through engagement of αv-containing integrins and subsequent FAK activation. Intringuingly, lung injury causes sustained TNC accumulation in mouse lungs, suggesting injury can induce additional TNC signaling for early tumor cell transition to invasive LUAD. Biospecimens from patients with stage I/II LUAD show TNC in regions of FAK activation and an association of TNC with tumor recurrence after primary tumor resection. These results suggest that exogenous insults that elevate TNC in the lung parenchyma interact with tumor-initiating mutations to drive early LUAD progression and local recurrence.

Tenascin C Deletion Impairs Tendon Healing and Functional Recovery After Rotator Cuff Repair.

The biological factors that affect healing after rotator cuff repair (RCR) are not well understood. Genetic variants in the extracellular matrix protein Tenascin C (TNC) are associated with impaired tendon healing and it is expressed in rotator cuff tendon tissue after injury, suggesting it may have a role in the repair process. The purpose of the current study was to determine the role of TNC on tendon healing after RCR in a murine model. The supraspinatus tendon was transected and repaired on the left shoulder of Wild-Type (WT-RCR), Tenascin C null (Tnc --RCR) and Tnc heterozygous (Tnc +/--RCR) mice. Controls included the unoperated, contralateral shoulder of WT-RCR, Tnc - RCR, Tnc +/--RCR mice and unoperated shoulders from age and genotype matched controls. We performed histologic, activity testing, RNA-seq, and biomechanical analyses. At 8-weeks post-RCR, Tnc - and Tnc +/- mice had severe bone and tendon defects following rotator cuff repair. Tnc --RCR mice had reduced activity after rotator cuff repair including reduced wheel rotations, wheel duration, and wheel episode average velocity compared with WT-RCR. Loss of Tnc following RCR altered gene expression in the shoulder, including upregulation of sex hormone and WNT pathways and a downregulation of inflammation and cell cycle pathways. Tnc - mice had similar biomechanical properties after repair as WT. Further research is required to evaluate tissue specific alterations of Tnc, the interactions of Tnc and sex hormone and inflammation pathways as well as possible adjuvants to improve enthesis healing in the setting of reduced TNC function.

Decreased plasma gelsolin fosters a fibrotic tumor microenvironment and promotes chemoradiotherapy resistance in esophageal squamous cell carcinoma

BackgroundStromal fibrosis is highly associated with therapeutic resistance and poor survival in esophageal squamous cell carcinoma (ESCC) patients. Low expression of plasma gelsolin (pGSN), a serum abundant protein, has been found to correlate with inflammation and fibrosis. Here, we evaluated pGSN expression in patients with different stages of cancer and therapeutic responses, and delineated the molecular mechanisms involved to gain insight into therapeutic strategies for ESCC.MethodsCirculating pGSN level in ESCC patients was determined by enzyme-linked immunosorbent assay analysis, and the tissue microarray of tumors was analyzed by immunohistochemistry staining. Cell-based studies were performed to investigate cancer behaviors and molecular mechanisms, and mouse models were used to examine the pGSN-induced tumor suppressive effects in vivo.ResultsCirculating pGSN expression is distinctively decreased during ESCC progression, and low pGSN expression correlates with poor therapeutic responses and poor survival. Methylation-specific PCR analysis confirmed that decreased pGSN expression is partly attributed to the hypermethylation of the GSN promoter, the gene encoding pGSN. Importantly, cell-based immunoprecipitation and protein stability assays demonstrated that pGSN competes with oncogenic tenascin-C (TNC) for the binding and degradation of integrin αvβ3, revealing that decreased pGSN expression leads to the promotion of oncogenic signaling transduction in cancer cells and fibroblasts. Furthermore, overexpression of pGSN caused the attenuation of TNC expression and inactivation of cancer-associated fibroblast (CAF), thereby leading to tumor growth inhibition in mice.ConclusionsOur results demonstrated that GSN methylation causes decreased secretion of pGSN, leading to integrin dysregulation, oncogenic TNC activation, and CAF formation. These findings highlight the role of pGSN in therapeutic resistance and the fibrotic tumor microenvironment of ESCC.

Expression of Tenascin-C Is Upregulated in the Early Stages of Radiation Pneumonitis/Fibrosis in a Novel Mouse Model.

The lung is a major dose-limiting organ for radiation therapy (RT) for cancer in the thoracic region, and the clarification of radiation-induced lung damage (RILD) is important. However, there have been few reports containing a detailed comparison of radiographic images with the pathological findings of radiation pneumonitis (RP)/radiation fibrosis (RF). We recently reported the upregulated expression of tenascin-C (TNC), an inflammation-associated extracellular matrix molecule, in surgically resected lung tissue, and elevated serum levels were elevated in a RILD patient. Therefore, we have developed a novel mouse model of partial lung irradiation and studied it with special attention paid to the computed tomography (CT) images and immunohistological findings. The right lungs of mice (BALB/c) were irradiated locally at 30 Gy/1fr, and the following two groups were created. In Group 1, sequential CT was performed to confirm the time-dependent changes in RILD. In Group 2, the CT images and histopathological findings of the lung were compared. RP findings were detected histologically at 16 weeks after irradiation; they were also observed on the CT images from 20 weeks. The immunostaining of TNC was observed before the appearance of RP on the CT images. The findings suggest that TNC could be an inflammatory marker preceding lung fibrosis.

CSF1-dependent macrophage support matrisome and epithelial stress-induced keratin remodeling in Eosinophilic esophagitis

Atopic diseases such as Eosinophilic Esophagitis (EoE) often progress into fibrosis (FS-EoE), compromising organ function with limited targeted treatment options. Mechanistic understanding of FS-EoE progression is confounded by the lack of preclinical models and the heavy focus of research on eosinophils themselves. We found that macrophage accumulation precedes esophageal fibrosis in FS-EoE patients. We developed a FS-EoE model via chronic administration of oxazalone allergen, in a transgenic mouse over-expressing esophageal epithelial hIL-5 (L2-IL5OXA). These mice display striking histopathologic features congruent with that found in FS-EoE patients. Unbiased proteomic analysis, using a unique extracellular-matrix (ECM) focused technique, identified an inflammation-reactive provisional basal lamina membrane signature and this was validated in two independent EoE patient RNA-sequencing/proteomic cohorts, supporting model significance. A wound healing signature was also observed involving hemostasis-associated molecules previously unnoted in EoE. We further identified the ECM glycoprotein, Tenascin-C (TNC), and the stress-responsive keratin-16 (KRT16) as IL-4 and IL-13 responsive mediators, acting as biomarkers of FS-EoE. To mechanistically address how the immune infiltrate shapes FS-EoE progression, we phenotyped the major immune cell subsets that coalesce with fibrosis in both the L2-IL5OXA mice and in FS-EoE patients. We found that macrophage are required for matrisome and cytoskeletal remodeling. Importantly, we show that macrophage accumulation precedes esophageal fibrosis and provide a novel therapeutic target in FS-EoE as their depletion with anti-CSF1 attenuated reactive matrisome and cytoskeletal changes. Thus, macrophage-based treatments and the exploration of TNC and KRT16 as biomarkers may provide novel therapeutic options for patients with fibrostenosis.