Tenascin-c renders a proangiogenic phenotype in macrophage via annexin II

The role of TNC in atherosclerosis and drug development opportunities

Tenascin C (TNC), a rich glycoprotein of the extracellular matrix, exhibits a pro-atherosclerosis or anti-atherosclerosis effect depending on its location. TNC, especially its C domain/isoform (TNC-C), is strongly overexpressed in atherosclerotic plaque active areas but virtually undetectable in most normal adult tissues, suggesting that TNC is a promising delivery vector target for atherosclerosis-targeted drugs. Many delivery vectors were investigated by recognizing TNC-C, including G11, G11-iRGD, TN11, PL1, and PL3. F16 and FNLM were also investigated by recognizing TNC-A1 and TNC, respectively. Notably, iRGD was undergoing clinical trials. PL1 not only recognizes TNC-C but also the extra domain-B (EDB) of fibronectin (FN), which is also a promising delivery vector for atherosclerosis-targeted drugs, and several conjugate agents are undergoing clinical trials. The F16-conjugate agent F16IL2 is undergoing clinical trials. Therefore, G11-iRGD, PL1, and F16 have great development value. Furthermore, ATN-RNA and IMA950 were investigated in clinical trials as therapeutic drugs and vaccines by targeting TNC, respectively. Therefore, targeting TNC could greatly improve the success rate of atherosclerosis-targeted drugs and/or specific drug development. This review discussed the role of TNC in atherosclerosis, atherosclerosis-targeted drug delivery vectors, and agent development to provide knowledge for drug development targeting TNC.

Biology of Tenascin C and its Role in Physiology and Pathology

Tenascin-C (TNC) is a multimodular extracellular matrix (ECM) protein hexameric with several molecular forms (180-250 kDa) produced by alternative splicing at the pre-mRNA level and protein modifications. The molecular phylogeny indicates that the amino acid sequence of TNC is a well-conserved protein among vertebrates. TNC has binding partners, including fibronectin, collagen, fibrillin-2, periostin, proteoglycans, and pathogens. Various transcription factors and intracellular regulators tightly regulate TNC expression. TNC plays an essential role in cell proliferation and migration. Unlike embryonic tissues, TNC protein is distributed over a few tissues in adults. However, higher TNC expression is observed in inflammation, wound healing, cancer, and other pathological conditions. It is widely expressed in a variety of human malignancies and is recognized as a pivotal factor in cancer progression and metastasis. Moreover, TNC increases both pro-and anti-inflammatory signaling pathways. It has been identified as an essential factor in tissue injuries such as damaged skeletal muscle, heart disease, and kidney fibrosis. This multimodular hexameric glycoprotein modulates both innate and adaptive immune responses regulating the expression of numerous cytokines. Moreover, TNC is an important regulatory molecule that affects the onset and progression of neuronal disorders through many signaling pathways. We provide a comprehensive overview of the structural and expression properties of TNC and its potential functions in physiological and pathological conditions.

Mechanisms of Endothelial Cell Membrane Repair: Progress and Perspectives

Endothelial cells are the crucial inner lining of blood vessels, which are pivotal in vascular homeostasis and integrity. However, these cells are perpetually subjected to a myriad of mechanical, chemical, and biological stresses that can compromise their plasma membranes. A sophisticated repair system involving key molecules, such as calcium, annexins, dysferlin, and MG53, is essential for maintaining endothelial viability. These components orchestrate complex mechanisms, including exocytosis and endocytosis, to repair membrane disruptions. Dysfunctions in this repair machinery, often exacerbated by aging, are linked to endothelial cell death, subsequently contributing to the onset of atherosclerosis and the progression of cardiovascular diseases (CVD) and stroke, major causes of mortality in the United States. Thus, identifying the core machinery for endothelial cell membrane repair is critically important for understanding the pathogenesis of CVD and stroke and developing novel therapeutic strategies for combating CVD and stroke. This review summarizes the recent advances in understanding the mechanisms of endothelial cell membrane repair. The future directions of this research area are also highlighted.

Tenascins and osteopontin in biological response in cornea

The structural composition, integrity and regular curvature of the cornea contribute to the maintenance of its transparency and vision. Disruption of its integrity caused by injury results in scarring, inflammation and neovascularization followed by losses in transparency. These sight compromising effects is caused by dysfunctional corneal resident cell responses induced by the wound healing process. Upregulation of growth factors/cytokines and neuropeptides affect development of aberrant behavior. These factors trigger keratocytes to first transform into activated fibroblasts and then to myofibroblasts. Myofibroblasts express extracellular matrix components for tissue repair and contract the tissue to facilitate wound closure. Proper remodeling following primary repair is critical for restoration of transparency and visual function. Extracellular matrix components contributing to the healing process are divided into two groups; a group of classical tissue structural components and matrix macromolecules that modulate cell behaviors/activities besides being integrated into the matrix structure. The latter components are designated as matricellular proteins. Their functionality is elicited through mechanisms which modulate the scaffold integrity, cell behaviors, activation/inactivation of either growth factors or cytoplasmic signaling regulation. We discuss here the functional roles of matricellular proteins in mediating injury-induced corneal tissue repair. The roles are described of major matricellular proteins, which include tenascin C, tenascin X and osteopontin. Focus is directed towards dealing with their roles in modulating individual activities of wound healing-related growth factors, e. g., transforming growth factor β (TGF β). Modulation of matricellular protein functions could encompass a potential novel strategy to improve the outcome of injury-induced corneal wound healing.

Matricellular proteins in atherosclerosis development

The extracellular matrix (ECM) is an intricate network composed of various multi-domain macromolecules like collagen, proteoglycans, and fibronectin, etc., that form a structurally stable composite, contributing to the mechanical properties of tissue. However, matricellular proteins are non-structural, secretory extracellular matrix proteins, which modulate various cellular functions via interacting with cell surface receptors, proteases, hormones, and cell-matrix. They play essential roles in maintaining tissue homeostasis by regulating cell differentiation, proliferation, adhesion, migration, and several signal transduction pathways. Matricellular proteins display a broad functionality regulated by their multiple structural domains and their ability to interact with different extracellular substrates and/or cell surface receptors. The expression of these proteins is low in adults, however, gets upregulated following injuries, inflammation, and during tumor growth. The marked elevation in the expression of these proteins during atherosclerosis suggests a positive association between their expression and atherosclerotic lesion formation. The role of matricellular proteins in atherosclerosis development has remained an area of research interest in the last two decades and studies revealed these proteins as important players in governing vascular function, remodeling, and plaque formation. Despite extensive research, many aspects of the matrix protein biology in atherosclerosis are still unknown and future studies are required to investigate whether targeting pathways stimulated by these proteins represent viable therapeutic approaches for patients with atherosclerotic vascular diseases. This review summarizes the characteristics of distinct matricellular proteins, discusses the available literature on the involvement of matrix proteins in the pathogenesis of atherosclerosis and suggests new avenues for future research.

Proline/serine-rich coiled-coil protein 1 inhibits macrophage inflammation and delays atherosclerotic progression by binding to Annexin A2

BACKGROUND

Atherosclerosis (AS), the main pathological basis of life-threatening cardiovascular disease, is essentially caused by chronic macrophage inflammation. Overexpression of proline/serine-rich coiled-coil protein 1 (PSRC1) reduces macrophage inflammatory responses and delays AS development. However, the exact mechanism of PSRC1 is unclear.

METHODS

Proteins interacting with PSRC1 were screened by proteomics in RAW264.7 cells, followed by RT-qPCR, immunoprecipitation and immunofluorescence to explore the specific mechanistic pathways affecting inflammation. CRISPR-Cas9 constructs for PSRC1^-/- ApoE^-/- (DKO) mice and high-fat diet-fed ApoE^-/- and DKO mice were used for AS models for in vivo experiments. Upstream transcription factors of PSRC1 were predicted by ATAC-seq, ChIP-seq and UCSC, and the regulatory mechanism was verified by ChIP-qPCR and dual luciferase assays. Peripheral blood serum and monocytes were collected from coronary artery disease (CAD) patients and non-CAD patients.

RESULTS

Increased binding of ANXA2 to PSRC1 in macrophages under oxidized low-density lipoprotein stimulation and decreased release of ANXA2 to the extracellular compartment were observed. Knockdown of ANXA2 in AS model mice delayed AS progression. Knockdown of ANXA2 in DKO mice reversed the AS-promoting effect of PSRC1 knockdown. Mechanistically, ANXA2 promotes STAT3 phosphorylation, which in turn promotes inflammatory responses. In addition, SP1 is a PSRC1 upstream repressive transcription factor, and the SP1 inhibitor mithramycin (Mith) elevated PSRC1 expression and exerted anti-AS effects in AS model mice. Patients with CAD had considerably greater serum levels of ANXA2 than those without CAD, and Mith reduced the secretion of ANXA2 in peripheral blood monocytes of CAD patients.

CONCLUSION

In macrophages, PSRC1 can interact with ANXA2 to inhibit its extracellular release and delay AS development. SP1 is an upstream transcription factor of PSRC1 and inhibits the transcription of PSRC1. The SP1 inhibitor Mith can elevate PSRC1 levels and slow AS progression while reducing ANXA2 release from monocytes in CAD patients. Mith is expected to be a new agent for AS treatment.

MiR-495-3p depletion contributes to myocardial ischemia/reperfusion injury in cardiomyocytes by targeting TNC

Background

Tenascin-C (TNC) has been found to abnormally express in myocardial ischemia/reperfusion injury (MI/RI), but its effect on cardiomyocytes apoptosis is unknown and is worthy of investigation.

Methods

H9C2 cells were given hypoxia/reoxygenation (H/R) treatment to obtain the replica of MI/RI in vitro. The effect of H/R on viability, apoptosis and inflammation was studied by CCK-8 assay, flow cytometry, mitochondrial membrane potential (MMP) and Ca²⁺ measurements as well as enzyme linked immunosorbent assay. We applied bioinformatics analysis and luciferase reporter assay to screened and validated TNC-targeting miR-495-3p which was then mechanistically investigated by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. With the assistance of cell transfection, rescue assays were conducted.

Results

H9C2 cells showed diminished viability, accelerated apoptosis, elevated tumour necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β), and TNC overexpression in response to H/R induction, while silencing of TNC partially reversed the effect of H/R treatment on the H9C2 cells. TNC silencing reduced Ca²⁺ level and enhanced MMP level in the H/R-stimulated cells. MiR-495-3p targeted TNC and showed a low expression in the H/R-stimulated cells. The expression of TNC was negatively regulated by miR-495-3p. Inhibition of miR-495-3p repressed viability and MMP level, and facilitated apoptosis and levels of Ca²⁺, TNF-α and IL-1β in the H/R-stimulated cells. The effect of TNC silencing and miR-495-3p depletion on H/R-induced cardiomyocyte injury was mutually reversed in vitro.

Conclusion

MiR-495-3p targeted TNC to regulate the apoptosis and inflammation of cardiomyocytes in H/R induction, which was associated with Ca²⁺ overload.

Tenascin-C: A Key Regulator in Angiogenesis during Wound Healing

(1) Background: Injury repair is a complex physiological process in which multiple cells and molecules are involved. Tenascin-C (TNC), an extracellular matrix (ECM) glycoprotein, is essential for angiogenesis during wound healing. This study aims to provide a comprehensive review of the dynamic changes and functions of TNC throughout tissue regeneration and to present an up-to-date synthesis of the body of knowledge pointing to multiple mechanisms of TNC at different restoration stages. (2) Methods: A review of the PubMed database was performed to include all studies describing the pathological processes of damage restoration and the role, structure, expression, and function of TNC in post-injury treatment; (3) Results: In this review, we first introduced the construction and expression signature of TNC. Then, the role of TNC during the process of damage restoration was introduced. We highlight the temporal heterogeneity of TNC levels at different restoration stages. Furthermore, we are surprised to find that post-injury angiogenesis is dynamically consistent with changes in TNC. Finally, we discuss the strategies for TNC in post-injury treatment. (4) Conclusions: The dynamic expression of TNC has a significant impact on angiogenesis and healing wounds and counters many negative aspects of poorly healing wounds, such as excessive inflammation, ischemia, scarring, and wound infection.

Annexins and cardiovascular diseases: Beyond membrane trafficking and repair

Cardiovascular diseases (CVD) remain the leading cause of mortality worldwide. The main cause underlying CVD is associated with the pathological remodeling of the vascular wall, involving several cell types, including endothelial cells, vascular smooth muscle cells, and leukocytes. Vascular remodeling is often related with the development of atherosclerotic plaques leading to narrowing of the arteries and reduced blood flow. Atherosclerosis is known to be triggered by high blood cholesterol levels, which in the presence of a dysfunctional endothelium, results in the retention of lipoproteins in the artery wall, leading to an immune-inflammatory response. Continued hypercholesterolemia and inflammation aggravate the progression of atherosclerotic plaque over time, which is often complicated by thrombus development, leading to the possibility of CV events such as myocardial infarction or stroke. Annexins are a family of proteins with high structural homology that bind phospholipids in a calcium-dependent manner. These proteins are involved in several biological functions, from cell structural organization to growth regulation and vesicle trafficking. In vitro gain- or loss-of-function experiments have demonstrated the implication of annexins with a wide variety of cellular processes independent of calcium signaling such as immune-inflammatory response, cell proliferation, migration, differentiation, apoptosis, and membrane repair. In the last years, the use of mice deficient for different annexins has provided insight into additional functions of these proteins in vivo, and their involvement in different pathologies. This review will focus in the role of annexins in CVD, highlighting the mechanisms involved and the potential therapeutic effects of these proteins.

Charcot-Marie-Tooth-1A and sciatic nerve crush rat models: insights from proteomics

The sensorimotor and histological aspects of peripheral neuropathies were already studied by our team in two rat models: the sciatic nerve crush and the Charcot-Marie-Tooth-1A disease. In this study, we sought to highlight and compare the protein signature of these two pathological situations. Indeed, the identification of protein profiles in diseases can play an important role in the development of pharmacological targets. In fact, Charcot-Marie-Tooth-1A rats develop motor impairments that are more severe in the hind limbs. Therefore, for the first time, protein expression in sciatic nerve of Charcot-Marie-Tooth-1A rats was examined. First, distal sciatic nerves were collected from Charcot-Marie-Tooth-1A and uninjured wild-type rats aged 3 months. After protein extraction, sequential window acquisition of all theoretical fragment ion spectra liquid chromatography and mass spectrometry was employed. 445 proteins mapped to Swiss-Prot or trEMBL Uniprot databases were identified and quantified. Of these, 153 proteins showed statistically significant differences between Charcot-Marie-Tooth-1A and wild-type groups. The majority of these proteins were overexpressed in Charcot-Marie-Tooth-1A. Hierarchical clustering and functional enrichment using Gene Ontology were used to group these proteins based on their biological effects concerning Charcot-Marie-Tooth-1A pathophysiology. Second, proteomic characterization of wild-type rats subjected to sciatic nerve crush was performed sequential window acquisition of all theoretical fragment ion spectra liquid chromatography and mass spectrometry. One month after injury, distal sciatic nerves were collected and analyzed as described above. Out of 459 identified proteins, 92 showed significant differences between sciatic nerve crush and the uninjured wild-type rats used in the first study. The results suggest that young adult Charcot-Marie-Tooth-1A rats (3 months old) develop compensatory mechanisms at the level of redox balance, protein folding, myelination, and axonogenesis. These mechanisms seem insufficient to hurdle the progress of the disease. Notably, response to oxidative stress appears to be a significant feature of Charcot-Marie-Tooth-1A, potentially playing a role in the pathological process. In contrast to the first experiment, the majority of the proteins that differed from wild-type were downregulated in the sciatic nerve crush group. Functional enrichment suggested that neurogenesis, response to axon injury, and oxidative stress were important biological processes. Protein analysis revealed an imperfect repair at this time point after injury and identified several distinguishable proteins. In conclusion, we suggest that peripheral neuropathies, whether of a genetic or traumatic cause, share some common pathological pathways. This study may provide directions for better characterization of these models and/or identifying new specific therapeutic targets.

Targeting Wnt/tenascin C-mediated cross talk between pancreatic cancer cells and stellate cells via activation of the metastasis suppressor NDRG1

A major barrier to successful pancreatic cancer (PC) treatment is the surrounding stroma, which secretes growth factors/cytokines that promote PC progression. Wnt and tenascin C (TnC) are key ligands secreted by stromal pancreatic stellate cells (PSCs) that then act on PC cells in a paracrine manner to activate the oncogenic β-catenin and YAP/TAZ signaling pathways. Therefore, therapies targeting oncogenic Wnt/TnC cross talk between PC cells and PSCs constitute a promising new therapeutic approach for PC treatment. The metastasis suppressor N-myc downstream-regulated gene-1 (NDRG1) inhibits tumor progression and metastasis in numerous cancers, including PC. We demonstrate herein that targeting NDRG1 using the clinically trialed anticancer agent di-2-pyridylketone-4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC) inhibited Wnt/TnC-mediated interactions between PC cells and the surrounding PSCs. Mechanistically, NDRG1 and DpC markedly inhibit secretion of Wnt3a and TnC by PSCs, while also attenuating Wnt/β-catenin and YAP/TAZ activation and downstream signaling in PC cells. This antioncogenic activity was mediated by direct inhibition of β-catenin and YAP/TAZ nuclear localization and by increasing the Wnt inhibitor, DKK1. Expression of NDRG1 also inhibited transforming growth factor (TGF)-β secretion by PC cells, a key mechanism by which PC cells activate PSCs. Using an in vivo orthotopic PC mouse model, we show DpC downregulated β-catenin, TnC, and YAP/TAZ, while potently increasing NDRG1 expression in PC tumors. We conclude that NDRG1 and DpC inhibit Wnt/TnC-mediated interactions between PC cells and PSCs. These results further illuminate the antioncogenic mechanism of NDRG1 and the potential of targeting this metastasis suppressor to overcome the oncogenic effects of the PC-PSC interaction.

Tenascin-C induction exacerbates post-stroke brain damage

The role of tenascin-C (TNC) in ischemic stroke pathology is not known despite its prognostic association with cerebrovascular diseases. Here, we investigated the effect of TNC knockdown on post-stroke brain damage and its putative mechanism of action in adult mice of both sexes. Male and female C57BL/6 mice were subjected to transient middle cerebral artery occlusion and injected (i.v.) with either TNC siRNA or a negative (non-targeting) siRNA at 5 min after reperfusion. Motor function (beam walk and rotarod tests) was assessed between days 1 and 14 of reperfusion. Infarct volume (T2-MRI), BBB damage (T1-MRI with contrast), and inflammatory markers were measured at 3 days of reperfusion. The TNC siRNA treated cohort showed significantly curtailed post-stroke TNC protein expression, motor dysfunction, infarction, BBB damage, and inflammation compared to the sex-matched negative siRNA treated cohort. These results demonstrate that the induction of TNC during the acute period after stroke might be a mediator of post-ischemic inflammation and secondary brain damage independent of sex.

Transcriptomic and Lipidomic Mapping of Macrophages in the Hub of Chronic Beta-Adrenergic-Stimulation Unravels Hypertrophy-, Proliferation-, and Lipid Metabolism-Related Genes as Novel Potential Markers of Early Hypertrophy or Heart Failure

Sympathetic nervous system overdrive with chronic release of catecholamines is the most important neurohormonal mechanism activated to maintain cardiac output in response to heart stress. Beta-adrenergic signaling behaves first as a compensatory pathway improving cardiac contractility and maladaptive remodeling but becomes dysfunctional leading to pathological hypertrophy and heart failure (HF). Cardiac remodeling is a complex inflammatory syndrome where macrophages play a determinant role. This study aimed at characterizing the temporal transcriptomic evolution of cardiac macrophages in mice subjected to beta-adrenergic-stimulation using RNA sequencing. Owing to a comprehensive bibliographic analysis and complementary lipidomic experiments, this study deciphers typical gene profiles in early compensated hypertrophy (ECH) versus late dilated remodeling related to HF. We uncover cardiac hypertrophy- and proliferation-related transcription programs typical of ECH or HF macrophages and identify lipid metabolism-associated and Na⁺ or K⁺ channel-related genes as markers of ECH and HF macrophages, respectively. In addition, our results substantiate the key time-dependent role of inflammatory, metabolic, and functional gene regulation in macrophages during beta-adrenergic dependent remodeling. This study provides important and novel knowledge to better understand the prevalent key role of resident macrophages in response to chronically activated beta-adrenergic signaling, an effective diagnostic and therapeutic target in failing hearts.

Tenascin-C: Friend or Foe in Lung Aging?

Lung aging is characterized by lung function impairment, ECM remodeling and airspace enlargement. Tenascin-C (TNC) is a large extracellular matrix (ECM) protein with paracrine and autocrine regulatory functions on cell migration, proliferation and differentiation. This matricellular protein is highly expressed during organogenesis and morphogenetic events like injury repair, inflammation or cancer. We previously showed that TNC deficiency affected lung development and pulmonary function, but little is known about its role during pulmonary aging. In order to answer this question, we characterized lung structure and physiology in 18 months old TNC-deficient and wild-type (WT) mice. Mice were mechanically ventilated with a basal and high tidal volume (HTV) ventilation protocol for functional analyses. Additional animals were used for histological, stereological and molecular biological analyses. We observed that old TNC-deficient mice exhibited larger lung volume, parenchymal volume, total airspace volume and septal surface area than WT, but similar mean linear intercept. This was accompanied by an increase in proliferation, but not apoptosis or autophagy markers expression throughout the lung parenchyma. Senescent cells were observed in epithelial cells of the conducting airways and in alveolar macrophages, but equally in both genotypes. Total collagen content was doubled in TNC KO lungs. However, basal and HTV ventilation revealed similar respiratory physiological parameters in both genotypes. Smooth muscle actin (α-SMA) analysis showed a faint increase in α-SMA positive cells in TNC-deficient lungs, but a marked increase in non-proliferative α-SMA + desmin + cells. Major TNC-related molecular pathways were not up- or down-regulated in TNC-deficient lungs as compared to WT; only minor changes in TLR4 and TGFβR3 mRNA expression were observed. In conclusion, TNC-deficient lungs at 18 months of age showed exaggerated features of the normal structural lung aging described to occur in mice between 12 and 18 months of age. Correlated to the increased pulmonary function parameters previously observed in young adult TNC-deficient lungs and described to occur in normal lung aging between 3 and 6 months of age, TNC might be an advantage in lung aging.

lncRNA RP11-531A24.3 inhibits the migration and proliferation of vascular smooth muscle cells by downregulating ANXA2 expression

A complete understanding of the behavioral influence and phenotypic transition of vascular smooth muscle cells, as well as the effects of the characteristics of these cells on the physiological and pathological processes of atherosclerosis, is crucial if new therapeutic targets for atherosclerosis are to be identified. In the present study, the long non-coding RNA RP11-531A24.3 was identified to be expressed at low levels in plaque tissues through screening a microarray for differentially expressed genes. The functional experimental results suggested that RP11-531A24.3 reduced the viability and inhibited the migration of human aortic vascular smooth muscle cells (HA-VSMCs). RNA antisense purification-mass spectrometry was used to identify the RNA-binding proteins (RBPs) for RP11-531A24.3. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis indicated that the pathway with the highest degree of association with RP11-531A24.3 RBPs was related to cell migration. The reduced migration and viability mediated by RP11-531A24.3 overexpression was more significantly suppressed after annexin 2 (ANXA2) depletion in RP11-531A24.3-overexpressing HA-VSMCs. Culture of HA-VSMCs under hypoxic conditions (1% O₂) reduced the expression of RP11-531A24.3, and enhanced the protein expression of ANXA2 and HIF-1α, while knockdown of ANXA2 downregulated the protein expression of HIF-1α. These results suggested that RP11-531A24.3 regulated the proliferation and migration of HA-VSMCs through ANXA2 expression, and hypoxia may be an external factor in the regulation of RP11-531A24.3 and its downstream targets.

Identification of Adrenomedullin-Induced S-Nitrosylated Proteins in JEG-3 Placental Cells

Extravillous cytotrophoblast (EVCT) is responsible for trophoblast invasion, which is important during placentation. Dysregulation of the process leads to pregnancy complications. S-nitrosylation of proteins is associated with cell invasion in many cell types. Adrenomedullin (ADM), a polypeptide expressed abundantly in the first-trimester placentas, induces EVCT invasion by upregulation of protein S-nitrosylation. This study aimed to identify the S-nitrosylated proteins induced by ADM in the JEG-3 placental cells. By using affinity chromatography followed by mass spectrometric analysis, tubulin, enolase, eukaryotic translation initiation factor 4A1, actin, annexin II (ANX II), and glyceraldehyde 3-phosphate dehydrogenaseprotein-1 were found to be S-nitrosylated by ADM. In vitro treatment with ADM or S-Nitrosoglutathione (GSNO) significantly increased the ANX II surface expression, but not its total expression in the JEG-3 cells. Translocation of ANX II to cell surface has been reported to act as a cell surface receptor to plasmin, plasminogen, and tissue plasminogen activator (tPA), thereby stimulating cell invasion and migration. However, in this study, ADM-induced surface expression of ANX II in the JEG-3 cells was not associated with changes in the secretory and membrane-bound tPA activities. Future studies are required to understand the roles of surface expression of S-nitrosylated ANX II on trophoblast functions. To conclude, this study provided evidences that ADM regulated the nitric oxide signaling pathway and modulated trophoblast invasion.

Associations Between Tenascin-C and Testosterone Deficiency in Men with Major Depressive Disorder: A Cross-Sectional Retrospective Study

Background

Elevated levels of tenascin-C are linked to increased risk and severity of major depressive disorder (MDD), while testosterone shows a protective effect. The present study explored associations between serum levels of tenascin-C and testosterone in Chinese men with MDD.

Methods

Testosterone and tenascin-C levels were measured in sera of 412 men with MDD and 237 age- and sex-matched controls. Serum levels of thyroid hormone, lipids, and high-sensitivity C-reactive protein (hs-CRP) were also quantified. Potential associations were examined using covariance, subgroup analysis, and multivariate linear regression analyses.

Results

Significantly higher concentrations of tenascin-C were detected in sera of subjects with MDD than in controls. Among subjects with MDD, testosterone concentrations inversely correlated with tenascin-C levels. This relationship was observed when patients were stratified by age at onset; duration or severity of depression; or concentration of thyroid hormones, low- or high-density lipoprotein, or hs-CRP. The negative association remained even when the statistical model was adjusted for age, smoking status, alcohol use, and body mass index. Linear regression with bootstrap resampling confirmed that high tenascin-C levels inversely correlated with testosterone levels.

Conclusion

In men with MDD, high tenascin-C concentrations correlate with testosterone deficiency. The combination of elevated tenascin-C and testosterone deficiency may be associated with MDD progression.

Annexins: Involvement in cholesterol homeostasis, inflammatory response and atherosclerosis

The annexin superfamily consists of 12 proteins with a highly structural homology that binds to phospholipids depending on the availability of Ca²⁺-dependent. Different studies of overexpression, inhibition, or using recombinant proteins have linked the main function of these proteins to their dynamic and reversible binding to membranes. Annexins are found in multiple cellular compartments, regulating different functions, such as membrane trafficking, anchoring to the cell cytoskeleton, ion channel regulation, as well as pro- or anti-inflammatory and anticoagulant activities. The use of animals deficient in any of these annexins has established their possible functions in vivo, demonstrating that annexins can participate in relevant functions independent of Ca²⁺ signalling. This review will focus mainly on the role of different annexins in the pathological vascular remodelling that underlies the formation of the atherosclerotic lesion, as well as in the control of cholesterol homeostasis.

Characterization of an Aggregated Three-Dimensional Cell Culture Model by Multimodal Mass Spectrometry Imaging

Mass spectrometry imaging (MSI) is an established analytical tool capable of defining and understanding complex tissues by determining the spatial distribution of biological molecules. Three-dimensional (3D) cell culture models mimic the pathophysiological environment of in vivo tumors and are rapidly emerging as a valuable research tool. Here, multimodal MSI techniques were employed to characterize a novel aggregated 3D lung adenocarcinoma model, developed by the group to mimic the in vivo tissue. Regions of tumor heterogeneity and the hypoxic microenvironment were observed based on the spatial distribution of a variety of endogenous molecules. Desorption electrospray ionization (DESI)-MSI defined regions of a hypoxic core and a proliferative outer layer from metabolite distribution. Targeted metabolites (e.g., lactate, glutamine, and citrate) were mapped to pathways of glycolysis and the TCA cycle demonstrating tumor metabolic behavior. The first application of imaging mass cytometry (IMC) with 3D cell culture enabled single-cell phenotyping at 1 μm spatial resolution. Protein markers of proliferation (K_i-67) and hypoxia (glucose transporter 1) defined metabolic signaling in the aggregoid model, which complemented the metabolite data. Laser ablation inductively coupled plasma (LA-ICP)-MSI analysis localized endogenous elements including magnesium and copper, further differentiating the hypoxia gradient and validating the protein expression. Obtaining a large amount of molecular information on a complementary nature enabled an in-depth understanding of the biological processes within the novel tumor model. Combining powerful imaging techniques to characterize the aggregated 3D culture highlighted a future methodology with potential applications in cancer research and drug development.

Clinicopathological value and underlying molecular mechanism of annexin A2 in 992 cases of thyroid carcinoma

BACKGROUND

Thyroid carcinoma (THCA) is one of the most frequent endocrine cancers and has increasing morbidity. Annexin A2 (ANXA2) has been found to be highly expressed in various cancers; however, its expression level and potential mechanism in THCA remain unknown. This study investigated the clinicopathological value and primary molecular machinery of ANXA2 in THCA.

MATERIAL AND METHODS

Public RNA-sequencing and microarray data were obtained and analyzed with ANXA2 expression in THCA and corresponding non-cancerous thyroid tissue. A Pearson correlation coefficient calculation was used for the acquisition of ANXA2 coexpressed genes, while edgR, limma, and Robust Rank Aggregation were employed for differentially expressed gene (DEG) in THCA. The probable mechanism of ANXA2 in THCA was predicted by gene ontology and pathway enrichment. A dual-luciferase reporter assay was employed to confirm the targeting relationships between ANXA2 and its predicted microRNA (miRNA).

RESULTS

Expression of ANXA2 was significantly upregulated in THCA tissues with a summarized standardized mean difference of 1.09 (P < 0.0001) based on 992 THCA cases and 589 cases of normal thyroid tissue. Expression of ANXA2 was related to pathologic stage. Subsequently, 1442 genes were obtained when overlapping 4542 ANXA2 coexpressed genes with 2248 DEGs in THCA; these genes were mostly enriched in pathways of extracellular matrix-receptor interaction, cell adhesion molecules, and complement and coagulation cascades. MiR-23b-3p was confirmed to target ANXA2 by dual-luciferase reporter assay.

CONCLUSIONS

Upregulated expression of ANXA2 may promote the malignant biological behavior of THCA by affecting the involving pathways or being targeted by miR-23b-3p.

[Serum annexin A2 level is significantly elevated in patients with coronary heart disease]

OBJECTIVE

To analyze the correlation of annexin A2 with coronary atherosclerotic heart disease (CAD) and the severity of CAD.

METHODS

We collected data from a total of 200 inpatients admitted in our department between August, 2017 and August, 2019. According to the.

RESULTS

of coronary angiography, the patients were divided into CAD group (n=150) and non-CAD (n=50), and the CAD patients was further divided, according to their clinical stability, into stable angina (SAP) group and acute coronary syndrome (ACS) group. Serum levels of annexin A2, MPO and PON1 were detected in all these patients, and their correlations with CAD, disease severity, and degree of coronary artery stenosis were analyzed.ResultsThe levels of annexin A2 and MPO were significantly higher in CAD patients than in non-CAD patients (P < 0.05). Among the CAD patients, those with ACS had significantly higher levels of annexin A2 (P < 0.05) and lower levels of PON-1 (P < 0.05) than those with SAP, but annexin A2 level was not significantly correlated with coronary lesion count, Gensini score, or the co-morbidity of diabetes.

CONCLUSIONS

Annexin A2 is significantly elevated in patients with CAD, especially in those with ACS, and can be used as a predictor of clinical instability.

Tenascin-C accelerates adverse ventricular remodelling after myocardial infarction by modulating macrophage polarization

AIMS

Tenascin-C (TN-C) is an extracellular matrix protein undetected in the normal adult heart, but expressed in several heart diseases associated with inflammation. We previously reported that serum TN-C levels of myocardial infarction (MI) patients were elevated during the acute stage, and that patients with high peak TN-C levels were at high risk of left ventricular (LV) remodelling and poor outcome, suggesting that TN-C could play a significant role in the progression of ventricular remodelling. However, the detailed molecular mechanisms associated with this process remain unknown. We aimed to elucidate the role and underlying mechanisms associated with TN-C in adverse remodelling after MI.

METHODS AND RESULTS

MI was induced by permanent ligation of the coronary artery of TN-C knockout (TN-C-KO) and wild type (WT) mice. In WT mice, TN-C was expressed at the borders between intact and necrotic areas, with a peak at 3 days post-MI and observed in the immediate vicinity of infiltrating macrophages. TN-C-KO mice were protected from ventricular adverse remodelling as evidenced by a higher LV ejection fraction as compared with WT mice (19.0 ± 6.3% vs. 10.6 ± 4.4%; P < 0.001) at 3 months post-MI. During the acute phase, flow-cytometric analyses showed a decrease in F4/80+CD206lowCD45+ M1 macrophages and an increase in F4/80+CD206highCD45+ M2 macrophages in the TN-C-KO heart. To clarify the role of TN-C on macrophage polarization, we examined the direct effect of TN-C on bone marrow-derived macrophages in culture, observing that TN-C promoted macrophage shifting into an M1 phenotype via Toll-like receptor 4 (TLR4). Under M2-skewing conditions, TN-C suppressed the expression of interferon regulatory factor 4, a key transcription factor that controls M2-macrophage polarization, via TLR4, thereby inhibiting M2 polarization.

CONCLUSION

These results suggested that TN-C accelerates LV remodelling after MI, at least in part, by modulating M1/M2-macrophage polarization.

Immunomodulatory role of the extracellular matrix protein tenascin-C in neuroinflammation

The extracellular matrix (ECM) consists of a dynamic network of various macromolecules that are synthesized and released by surrounding cells into the intercellular space. Glycoproteins, proteoglycans and fibrillar proteins are main components of the ECM. In addition to general functions such as structure and stability, the ECM controls several cellular signaling pathways. In this context, ECM molecules have a profound influence on intracellular signaling as receptor-, adhesion- and adaptor-proteins. Due to its various functions, the ECM is essential in the healthy organism, but also under pathological conditions. ECM constituents are part of the glial scar, which is formed in several neurodegenerative diseases that are accompanied by the activation and infiltration of glia as well as immune cells. Remodeling of the ECM modulates the release of pro- and anti-inflammatory cytokines affecting the fate of immune, glial and neuronal cells. Tenascin-C is an ECM glycoprotein that is expressed during embryonic central nervous system (CNS) development. In adults it is present at lower levels but reappears under pathological conditions such as in brain tumors, following injury and in neurodegenerative disorders and is highly associated with glial reactivity as well as scar formation. As a key modulator of the immune response during neurodegeneration in the CNS, tenascin-C is highlighted in this mini-review.

Matrix-Targeting Immunotherapy Controls Tumor Growth and Spread by Switching Macrophage Phenotype

The interplay between cancer cells and immune cells is a key determinant of tumor survival. Here, we uncovered how tumors exploit the immunomodulatory properties of the extracellular matrix to create a microenvironment that enables their escape from immune surveillance. Using orthotopic grafting of mammary tumor cells in immunocompetent mice and autochthonous models of breast cancer, we discovered how tenascin-C, a matrix molecule absent from most healthy adult tissues but expressed at high levels and associated with poor patient prognosis in many solid cancers, controls the immune status of the tumor microenvironment. We found that, although host-derived tenascin-C promoted immunity via recruitment of proinflammatory, antitumoral macrophages, tumor-derived tenascin-C subverted host defense by polarizing tumor-associated macrophages toward a pathogenic, immune-suppressive phenotype. Therapeutic monoclonal antibodies that blocked tenascin-C activation of Toll-like receptor 4 reversed this phenotypic switch in vitro and reduced tumor growth and lung metastasis in vivo, providing enhanced benefit in combination with anti-PD-L1 over either treatment alone. Combined tenascin-C:macrophage gene-expression signatures delineated a significant survival benefit in people with breast cancer. These data revealed a new approach to targeting tumor-specific macrophage polarization that may be effective in controlling the growth and spread of breast tumors.