Annexin A2 is a soluble mediator of macrophage activation

Impact of Annexin A2 on virus life cycles

Due to the limited size of viral genomes, hijacking host machinery by the viruses taking place throughout the virus life cycle is inevitable for the survival and proliferation of the virus in the infected hosts. Recent reports indicated that Annexin A2 (AnxA2), a calcium- and lipid-binding cellular protein, plays an important role as a critical regulator in various steps of the virus life cycle. The multifarious AnxA2 functions in cells, such as adhesion, adsorption, endocytosis, exocytosis, cell proliferation and division, inflammation, cancer metastasis, angiogenesis, etc., are intimately related to the various clinical courses of viral infection. Ubiquitous expression of AnxA2 across multiple cell types indicates the broad range of susceptibility of diverse species of the virus to induce disparate viral disease in various tissues, and intracellular expression of AnxA2 in the cytoplasmic membrane, cytosol, and nucleus suggests the involvement of AnxA2 in the regulation of the different stages of various virus life cycles within host cells. However, it is yet unclear as to the molecular processes on how AnxA2 and the infected virus interplay to regulate virus life cycles and thereby the virus-associated disease courses, and hence elucidation of the molecular mechanisms on AnxA2-mediated virus life cycle will provide essential clues to develop therapeutics deterring viral disease.

Single cell atlas of human gastric muscle immune cells and macrophage-driven changes in idiopathic gastroparesis

Gastrointestinal immune cells, particularly muscularis macrophages (MM) interact with the enteric nervous system and influence gastrointestinal motility. Here we determine the human gastric muscle immunome and its changes in patients with idiopathic gastroparesis (IG). Single cell sequencing was performed on 26,000 CD45+ cells obtained from the gastric tissue of 20 subjects. We demonstrate 11 immune cell clusters with T cells being most abundant followed by myeloid cells. The proportions of cells belonging to the 11 clusters were similar between IG and controls. However, 9/11 clusters showed 578-11,429 differentially expressed genes. In IG, MM had decreased expression of tissue-protective and microglial genes and increased the expression of monocyte trafficking and stromal activating genes. Furthermore, in IG, IL12 mediated JAK-STAT signaling involved in the activation of tissue-resident macrophages and Eph-ephrin signaling involved in monocyte chemotaxis were upregulated. Patients with IG had a greater abundance of monocyte-like cells. These data further link immune dysregulation to the pathophysiology of gastroparesis.

The flavagline FL3 interferes with the association of Annexin A2 with the eIF4F initiation complex and transiently stimulates the translation of annexin A2 mRNA

Introduction: Annexin A2 (AnxA2) plays a critical role in cell transformation, immune response, and resistance to cancer therapy. Besides functioning as a calcium- and lipidbinding protein, AnxA2 also acts as an mRNA-binding protein, for instance, by interacting with regulatory regions of specific cytoskeleton-associated mRNAs. Methods and Results: Nanomolar concentrations of FL3, an inhibitor of the translation factor eIF4A, transiently increases the expression of AnxA2 in PC12 cells and stimulates shortterm transcription/translation of anxA2 mRNA in the rabbit reticulocyte lysate. AnxA2 regulates the translation of its cognate mRNA by a feed-back mechanism, which can partly be relieved by FL3. Results obtained using the holdup chromatographic retention assay results suggest that AnxA2 interacts transiently with eIF4E (possibly eIF4G) and PABP in an RNA-independent manner while cap pulldown experiments indicate a more stable RNA-dependent interaction. Short-term (2 h) treatment of PC12 cells with FL3 increases the amount of eIF4A in cap pulldown complexes of total lysates, but not of the cytoskeletal fraction. AnxA2 is only present in cap analogue-purified initiation complexes from the cytoskeletal fraction and not total lysates confirming that AnxA2 binds to a specific subpopulation of mRNAs. Discussion: Thus, AnxA2 interacts with PABP1 and subunits of the initiation complex eIF4F, explaining its inhibitory effect on translation by preventing the formation of the full eIF4F complex. This interaction appears to be modulated by FL3. These novel findings shed light on the regulation of translation by AnxA2 and contribute to a better understanding of the mechanism of action of eIF4A inhibitors.

Deciphering crucial genes in multiple sclerosis pathogenesis and drug repurposing: A systems biology approach

This study employed systems biology and high-throughput technologies to analyze complex molecular components of MS pathophysiology, combining data from multiple omics sources to identify potential biomarkers and propose therapeutic targets and repurposed drugs for MS treatment. This study analyzed GEO microarray datasets and MS proteomics data using geWorkbench, CTD, and COREMINE to identify differentially expressed genes associated with MS disease. Protein-protein interaction networks were constructed using Cytoscape and its plugins, and functional enrichment analysis was performed to identify crucial molecules. A drug-gene interaction network was also created using DGIdb to propose medications. This study identified 592 differentially expressed genes (DEGs) associated with MS disease using GEO, proteomics, and text-mining datasets. 37 DEGs were found to be important by topographical network studies, and 6 were identified as the most significant for MS pathophysiology. Additionally, we proposed six drugs that target these key genes. Crucial molecules identified in this study were dysregulated in MS and likely play a key role in the disease mechanism, warranting further research. Additionally, we proposed repurposing certain FDA-approved drugs for MS treatment. Our in silico results were supported by previous experimental research on some of the target genes and drugs. SIGNIFICANCE: As the long-lasting investigations continue to discover new pathological territories in neurodegeneration, here we apply a systems biology approach to determine multiple sclerosis's molecular and pathophysiological origin and identify multiple sclerosis crucial genes that contribute to candidating new biomarkers and proposing new medications.

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.

Inflammatory serum factors from aortic valve stenosis patients modulate sex differences in valvular myofibroblast activation and osteoblast-like differentiation

Aortic valve stenosis (AVS) is a sexually dimorphic cardiovascular disease that is driven by fibrosis and calcification of the aortic valve leaflets. Circulating inflammatory factors present in serum from AVS patients contribute to sex differences in valve fibro-calcification by driving the activation of valvular interstitial cells (VICs) to myofibroblasts and/or osteoblast-like cells. However, the molecular mechanisms by which inflammatory factors contribute to sex-specific valve fibro-calcification remain largely unknown. In this study, we identified inflammatory factors present in serum samples from AVS patients that regulate sex-specific myofibroblast activation and osteoblast-like differentiation. After correlating serum proteomic datasets with clinical and in vitro myofibroblast datasets, we identified annexin A2 and cystatin C as candidate inflammatory factors that correlate with both AVS patient severity and myofibroblast activation measurements in vitro. Validation experiments utilizing hydrogel biomaterials as cell culture platforms that mimic the valve extracellular matrix confirmed that annexin A2 and cystatin C promote sex-specific VIC activation to myofibroblasts via p38 MAPK signaling. Additionally, annexin A2 and cystatin C increase osteoblast-like differentiation primarily in male VICs. Our results implicate serum inflammatory factors as potential AVS biomarkers that also contribute to sexually dimorphic AVS progression by driving VIC myofibroblast activation and/or osteoblast-like differentiation. Collectively, the results herein further our overall understanding as to how biological sex may impact inflammation-driven AVS and may lead to the development of sex-specific drug treatment strategies.

The Annexin A2-Notch regulatory loop in hepatocytes promotes liver fibrosis in NAFLD by increasing osteopontin expression

BACKGROUND

The mechanisms underlying the progression of liver disease from simple hepatic steatosis to advanced nonalcoholic steatohepatitis (NASH) and liver fibrosis warrant further investigation. Increased mRNA levels of Annexin A2 protein (Anxa2) have been observed in patients with NASH. However, the role of Anxa2 in NASH remains unclear.

METHODS

The protein levels of Anxa2 were analyzed in the livers of mice and patients with NASH. Anxa2-knockout and -knockdown mice were generated, and NASH was induced through a high fructose, palmitate, and cholesterol (FPC) diet or methionine- and choline-deficient (MCD) diet.

FINDINGS

We found elevated expression of Anxa2 in the livers of patients and mice with NASH. Anxa2 knockdown but not knockout ameliorated liver fibrosis in both FPC and MCD diet-fed mice. Liver-specific Anxa2 overexpression increased collagen deposition in mice fed a normal diet. Mechanistically, Anxa2 overexpression in hepatocytes promoted hepatic stellate cell activation in a paracrine manner by increasing osteopontin expression. Notch inhibition suppressed the exogenous overexpression of Anxa2-induced osteopontin and endogenous Anxa2 expression. Additionally, Anxa2 overexpression accelerated the progression of nonalcoholic fatty liver disease (NAFLD) in mice fed a high-fat diet. Moreover, Anxa2 levels were higher in NAFLD patients with advanced liver fibrosis than in those with mild liver fibrosis, as determined using the Gene Expression Omnibus database.

INTERPRETATION

In conclusion, we found increased Anxa2 expression in hepatocytes promoted liver fibrosis in NASH mice by increasing osteopontin expression. The Anxa2-Notch positive regulatory loop contributes to this process and represents a novel target for the treatment of NASH-related liver fibrosis.

Dental pulp stem cell-derived extracellular matrix: autologous tool boosting bone regeneration

BACKGROUND AIMS

To facilitate artificial bone construct integration into a patient's body, scaffolds are enriched with different biologically active molecules. Among various scaffold decoration techniques, coating surfaces with cell-derived extracellular matrix (ECM) is a rapidly growing field of research. In this study, for the first time, this technology was applied using primary dental pulp stem cells (DPSCs) and tested for use in artificial bone tissue construction.

METHODS

Rat DPSCs were grown on three-dimensional-printed porous polylactic acid scaffolds for 7 days. After the predetermined time, samples were decellularized, and the remaining ECM detailed proteomic analysis was performed. Further, DPSC-secreated ECM impact to mesenchymal stromal cells (MSC) behaviour as well as its role in osteoregeneration induction were analysed.

RESULTS

It was identified that DPSC-specific ECM protein network ornamenting surface-enhanced MSC attachment, migration and proliferation and even promoted spontaneous stem cell osteogenesis. This protein network also demonstrated angiogenic properties and did not stimulate MSCs to secrete molecules associated with scaffold rejection. With regard to bone defects, DPSC-derived ECM recruited endogenous stem cells, initiating the bone self-healing process. Thus, the DPSC-secreted ECM network was able to significantly enhance artificial bone construct integration and induce successful tissue regeneration.

CONCLUSIONS

DPSC-derived ECM can be a perfect tool for decoration of various biomaterials in the context of bone tissue engineering.

Molecular Insights on the Possible Role of Annexin A2 in COVID-19 Pathogenesis and Post-Infection Complications

Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) has infected >235 million people and killed over 4.8 million individuals worldwide. Although vaccines have been developed for prophylactic management, there are no clinically proven antivirals to treat the viral infection. Continuous efforts are being made all over the world to develop effective drugs but these are being delayed by periodic outbreak of mutated SARS-CoV-2 and a lack of knowledge of molecular mechanisms underlying viral pathogenesis and post-infection complications. In this regard, the involvement of Annexin A2 (AnxA2), a lipid-raft related phospholipid-binding protein, in SARS-CoV-2 attachment, internalization, and replication has been discussed. In addition to the evidence from published literature, we have performed in silico docking of viral spike glycoprotein and RNA-dependent RNA polymerase with human AnxA2 to find the molecular interactions. Overall, this review provides the molecular insights into a potential role of AnxA2 in the SARS-CoV-2 pathogenesis and post-infection complications, especially thrombosis, cytokine storm, and insulin resistance.

In vivo N-Terminomics Highlights Novel Functions of ADAMTS2 and ADAMTS14 in Skin Collagen Matrix Building

A disintegrin and metalloproteinase with thrombospondin type I motif (ADAMTS)2 and ADAMTS14 were originally known for their ability to cleave the aminopropeptides of fibrillar collagens. Previous work using N-terminomic approach (N-TAILS) in vitro led to the identification of new substrates, including some molecules involved in TGF-β signaling. Here, N-TAILS was used to investigate the substrates of these two enzymes in vivo, by comparing the N-terminomes of the skin of wild type mice, mice deficient in ADAMTS2, in ADAMTS14 and in both ADAMTS2 and ADAMTS14. This study identified 68 potential extracellular and cell surface proteins, with the majority of them being cleaved by both enzymes. These analyses comfort their role in collagen matrix organization and suggest their implication in inflammatory processes. Regarding fibrillar collagen, this study demonstrates that both ADAMTS2 and ADAMTS14 are involved in the processing of the aminopropeptide of alpha1 and alpha2 type V collagen. It also revealed the existence of several cleavage sites in the Col1 domain and in the C-propeptide of type I collagens. In addition to collagens and other extracellular proteins, two major components of the cell cytoskeleton, actin and vimentin, were also identified as potential substrates. The latter data were confirmed in vitro using purified enzymes and could potentially indicate other functions for ADAMTS2 and 14. This original investigation of mouse skin degradomes by N-terminomic highlights the essential role of ADAMTS2 and ADAMTS14 in collagen matrix synthesis and turnover, and gives clues to better understand their functions in skin pathophysiology. Data are available via ProteomeXchange with identifier PXD022179.

Annexin A2 promotion of hepatocellular carcinoma tumorigenesis via the immune microenvironment

Hepatocellular carcinoma (HCC) is the most common primary liver cancer with a dismal prognosis, especially when diagnosed at advanced stages. Annexin A2 (ANXA2), is found to promote cancer progression and therapeutic resistance. However, the underlining mechanisms of ANXA2 in immune escape of HCC remain poorly understood up to now. Herein, we summarized the molecular function of ANXA2 in HCC and its relationship with prognosis. Furthermore, we tentatively elucidated the underlying mechanism of ANXA2 immune escape of HCC by upregulating the proportion of regulatory T cells and the expression of several inhibitory molecules, and by downregulating the proportion of natural killer cells and dendritic cells and the expression of several inhibitory molecules or effector molecules. We expect a lot of in-depth studies to further reveal the underlying mechanism of ANXA2 in immune escape of HCC in the future.

Regulation of macrophage activation in the liver after acute injury: Role of the fibrinolytic system

The liver functions, in part, to prevent exposure of the body to potentially harmful substances ingested in the diet. While it is highly efficient at accomplishing this, it is frequently prone to liver injury due to the biotransformation of xenobiotics into toxic metabolites. To counter this injury, the liver has evolved a unique capacity to rapidly and efficiently repair itself. Successful resolution of acute liver injury relies on hepatic macrophage populations that orchestrate the reparative response. After injury, Kupffer cells, the resident macrophages of the liver, become activated and secrete proinflammatory cytokines. These cytokines recruit other immune cells, including monocyte-derived macrophages, to the liver where they contribute to the repair process. Monocyte-derived macrophages traffic into the necrotic foci where they rapidly phagocytose dead cell debris. Simultaneous with this process, these cells change phenotype from a proinflammatory macrophage to a pro-restorative macrophage that produce pro-mitogenic growth factors and anti-inflammatory cytokines. Ultimately this process triggers resolution of inflammation, and along with proliferation of other hepatic cells, restores the liver architecture and function. While the mechanisms regulating specific macrophage functions during repair remain to be elucidated, recent studies indicate a key role for the fibrinolytic system in coordinating macrophage function during repair. In this review, we will highlight the function and role of hepatic macrophages in repair after acute liver injury, and will discuss the role of the fibrinolytic enzyme, plasmin, in regulation of these various processes.

[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.

Cell-surface translocation of annexin A2 contributes to bleomycin-induced pulmonary fibrosis by mediating inflammatory response in mice

Bleomycin, a widely used anti-cancer drug, may give rise to pulmonary fibrosis, a serious side effect which is associated with significant morbidity and mortality. Despite the intensive efforts, the precise pathogenic mechanisms of pulmonary fibrosis still remain to be clarified. Our previous study showed that bleomycin bound directly to annexin A2 (ANXA2, or p36), leading to development of pulmonary fibrosis by impeding transcription factor EB (TFEB)-induced autophagic flux. Here, we demonstrated that ANXA2 also played a critical role in bleomycin-induced inflammation, which represents another major cause of bleomycin-induced pulmonary fibrosis. We found that bleomycin could induce the cell surface translocation of ANXA2 in lung epithelial cells through exosomal secretion, associated with enhanced interaction between ANXA2 and p11. Knockdown of ANXA2 or blocking membrane ANXA2 mitigated bleomycin-induced activation of nuclear factor (NF)-κB pathway and production of pro-inflammatory cytokine IL-6 in lung epithelial cells. ANXA2-deficient (ANXA2-/-) mice treated with bleomycin exhibit reduced pulmonary fibrosis along with decreased cytokine production compared with bleomycin-challenged wild-type mice. Further, the surface ANXA2 inhibitor TM601 could ameliorate fibrotic and inflammatory response in bleomycin-treated mice. Taken together, our results indicated that, in addition to disturbing autophagic flux, ANXA2 can contribute to bleomycin-induced pulmonary fibrosis by mediating inflammatory response.

Critical role and its underlying molecular events of the plasminogen receptor, S100A10 in malignant tumor and non-tumor diseases

S100A10 is a small molecular weight protein expressed in the cytoplasm of many cells and one of the members of the S100 protein family that binds calcium and forms the largest subgroup of EF-hand proteins. The regulatory processes of S100A10 are complicated. S100A10 participates in the regulation of a variety of tumor and non-tumor diseases through cascade reactions with multitudinous signaling molecules. In malignant tumors, such as acute promyelocytic leukemia (APL) and lung cancer, S100A10 is likely involved in their progression, including invasion and metastasis through the regulation of plasmin production and subsequent plasmin-dependent stimulation of other proteases, such as matrix metalloproteinase (MMP)-2 and -9. Both the plasmin and MMPs are capable of inducing degradation of the extracellular matrix (ECM) and basement membrane, which is a critical step for tumor progression. In non-tumor diseases, the distribution of S100A10 in the brain and its interaction with 5-hydroxytryptamine 1B (5-HT1B) receptor, an important mediator in the central nervous system that maintains a dynamic balance of the neurotransmitters, correlates with depression-like behavior. S100A10 also participates in inflammatory responses through the regulation of peripheral macrophage migration to the inflammatory sites, which depends on the generation of plasmin and other proteinases at the surface of macrophages. Considerable attention should be paid to understand the significant role of S100A10 in the modulation of malignant tumor and non-tumor diseases.

Reciprocal regulation of pro-inflammatory Annexin A2 and anti-inflammatory Annexin A1 in the pathogenesis of rheumatoid arthritis

Annexin A2 has been implicated in several immune modulated diseases including Rheumatoid arthritis (RA) pannus formation. The most relied treatment option for RA pathogenesis is glucocorticoids. Glucocorticoids regulate the synthesis, phosphorylation and cellular deposition of Annexin A1. This annexin mediates the anti-inflammatory actions of glucocorticoids. These two first characterized members of annexin superfamily proteins acts reciprocally, one as an anti-inflammatory and the other proinflammatory in nature. The possibility of these molecules as soluble biomarkers and as an upstream regulator of major cytokine devastation at RA microenvironment has not been previously explored. Current study elucidates the reciprocal regulation of these two annexins in RA pathogenesis. These Annexin A2/A1 and downstream cytokines in RA serum were analysed by ELISA. Western blot, Immunocytochemistry, immunoprecipitation and Immunohistochemistry were adapted to analyse these molecules in tissue and synovial fibroblasts and also in different experimental conditions. Significant increase in the level of Annexin A2 was noticed in naïve RA patients compared to controls (14.582 ± 1.766 ng/ml vs. 7.37 ± 1.450 ng/ml; p ≤ 0.001). In remission cases significant low levels was detected. On the contrary, significant decrease in the level of Annexin A1 was noticed in naïve RA patients compared to healthy controls (12.322 ± 2.91 vs. 16.998 ± 4.298 ng/ml; p ≤ 0.001), wherein remission cases serum Annexin A1 was significantly high. The knockdown of proinflammatory Annexin A2 by siRNA/antibody treatment could mimic the glucocorticoid treatment as which induced cellular Annexin A1 and membrane translocation resulting in the terminal action. Current data elucidating the regulatory interplay between Annexin A2 and Annexin A1 in RA pathogenesis.

Annexins in Translational Research: Hidden Treasures to Be Found

The vertebrate annexin superfamily (AnxA) consists of 12 members of a calcium (Ca²⁺) and phospholipid binding protein family which share a high structural homology. In keeping with this hallmark feature, annexins have been implicated in the Ca²⁺-controlled regulation of a broad range of membrane events. In this review, we identify and discuss several themes of annexin actions that hold a potential therapeutic value, namely, the regulation of the immune response and the control of tissue homeostasis, and that repeatedly surface in the annexin activity profile. Our aim is to identify and discuss those annexin properties which might be exploited from a translational science and specifically, a clinical point of view.

Circular RNA profiling reveals that circular RNAs from ANXA2 can be used as new biomarkers for multiple sclerosis

Multiple sclerosis is an autoimmune disease, with higher prevalence in women, in whom the immune system is dysregulated. This dysregulation has been shown to correlate with changes in transcriptome expression as well as in gene-expression regulators, such as non-coding RNAs (e.g. microRNAs). Indeed, some of these have been suggested as biomarkers for multiple sclerosis even though few biomarkers have reached the clinical practice. Recently, a novel family of non-coding RNAs, circular RNAs, has emerged as a new player in the complex network of gene-expression regulation. MicroRNA regulation function through a 'sponge system' and a RNA splicing regulation function have been proposed for the circular RNAs. This regulating role together with their high stability in biofluids makes them seemingly good candidates as biomarkers. Given the dysregulation of both protein-coding and non-coding transcriptome that have been reported in multiple sclerosis patients, we hypothesised that circular RNA expression may also be altered. Therefore, we carried out expression profiling of 13.617 circular RNAs in peripheral blood leucocytes from multiple sclerosis patients and healthy controls finding 406 differentially expressed (P-value < 0.05, Fold change > 1.5) and demonstrate after validation that, circ_0005402 and circ_0035560 are underexpressed in multiple sclerosis patients and could be used as biomarkers of the disease.

Calcium channel α2δ1 subunit as a novel biomarker for diagnosis of hepatocellular carcinoma

Objective:

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide. The identification of new simple, inexpensive and highly accurate markers for HCC diagnosis and screening is needed. This case-control study evaluates the role of annexin A2 and voltage-gated calcium channels α2δ1 subunit as serum biomarkers for HCC diagnosis.

Methods:

The study comprised three groups: group 1, 50 patients with an initial diagnosis of HCC associated with chronic hepatitis C virus infection; group 2, 25 patients diagnosed with chronic hepatitis C virus infection and cirrhosis without any evidence of HCC; and group 3, 15 healthy controls. All participants were subjected to clinical and laboratory investigations, and radiological scanning. The serum levels of alpha-fetoprotein (AFP), annexin A2, and the α2δ1 subunit were evaluated by using ELISA technique.

Results:

The serum levels of annexin A2 significantly increased in patients with HCC (10.4±2.5 ng/mL; P<0.001) or with cirrhosis (9.31±1.8 ng/mL;P<0.001) comparing to that of healthy controls (0.296±0.09 ng/mL). However, there was no significant difference in serum annexin A2 levels in patients with HCC comparing to those with cirrhosis. Serum α2δ1 subunit significantly increased in patients with HCC (20.12±3.7 ng/mL) comparing to that in patients with cirrhosis (10.41±3.4 ng/mL,P<0.001) and healthy controls (10.2±2.9 ng/mL,P<0.001).

Conclusions:

The serum α2δ1 subunit may function as a new biomarker for HCC diagnosis. Conversely, serum annexin A2 has low diagnostic value as an HCC marker, especially in patients with underlying cirrhosis.

Characterization of interactions between hepatitis C virus NS5B polymerase, annexin A2 and RNA - effects on NS5B catalysis and allosteric inhibition

Background

Direct acting antivirals (DAAs) provide efficient hepatitis C virus (HCV) therapy and clearance for a majority of patients, but are not available or effective for all patients. They risk developing HCV-induced hepatocellular carcinoma (HCC), for which the mechanism remains obscure and therapy is missing. Annexin A2 (AnxA2) has been reported to co-precipitate with the non-structural (NS) HCV proteins NS5B and NS3/NS4A, indicating a role in HCC tumorigenesis and effect on DAA therapy.

Methods

Surface plasmon resonance biosensor technology was used to characterize direct interactions between AnxA2 and HCV NS5B, NS3/NS4 and RNA, and the subsequent effects on catalysis and inhibition.

Results

No direct interaction between AnxA2 and NS3/NS4A was detected, while AnxA2 formed a slowly dissociating, high affinity (K_D = 30 nM), complex with NS5B, decreasing its catalytic activity and affinity for the allosteric inhibitor filibuvir. The RNA binding of the two proteins was independent and AnxA2 and NS5B interacted with different RNAs in ternary complexes of AnxA2:NS5B:RNA, indicating specific preferences.

Conclusions

The complex interplay revealed between NS5B, AnxA2, RNA and filibuvir, suggests that AnxA2 may have an important role for the progression and treatment of HCV infections and the development of HCC, which should be considered also when designing new allosteric inhibitors.

Electronic supplementary material

The online version of this article (10.1186/s12985-017-0904-4) contains supplementary material, which is available to authorized users.

Annexin A2 links poor myofiber repair with inflammation and adipogenic replacement of the injured muscle

Repair of skeletal muscle after sarcolemmal damage involves dysferlin and dysferlin-interacting proteins such as annexins. Mice and patient lacking dysferlin exhibit chronic muscle inflammation and adipogenic replacement of the myofibers. Here, we show that similar to dysferlin, lack of annexin A2 (AnxA2) also results in poor myofiber repair and progressive muscle weakening with age. By longitudinal analysis of AnxA2-deficient muscle we find that poor myofiber repair due to the lack of AnxA2 does not result in chronic inflammation or adipogenic replacement of the myofibers. Further, deletion of AnxA2 in dysferlin deficient mice reduced muscle inflammation, adipogenic replacement of myofibers, and improved muscle function. These results identify multiple roles of AnxA2 in muscle repair, which includes facilitating myofiber repair, chronic muscle inflammation and adipogenic replacement of dysferlinopathic muscle. It also identifies inhibition of AnxA2-mediated inflammation as a novel therapeutic avenue for treating muscle loss in dysferlinopathy.

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

Tenascin-c is an extracellular matrix glycoprotein, the expression of which relates to the progression of atherosclerosis, myocardial infarction and heart failure. Annexin II acts as a cell surface receptor of tenascin-c. This study aimed to delineate the role of tenascin-c and annexin II in macrophages presented in atherosclerotic plaque. Animal models with atherosclerotic lesions were established using ApoE-KO mice fed with high-cholesterol diet. The expression of tenascin-c and annexin II in atherosclerotic lesions was determined by qRT-PCR, Western blot and immunohistochemistry analysis. Raw 264.7 macrophages and human primary macrophages were exposed to 5, 10 and 15 μg/ml tenascin-c for 12 hrs. Cell migration as well as the proangiogenic ability of macrophages was examined. Additionally, annexin II expression was delineated in raw 264.7 macrophages under normal condition (20% O₂ ) for 12 hrs or hypoxic condition (1% O₂ ) for 6-12 hrs. The expression of tenascin-c and annexin II was markedly augmented in lesion aorta. Tenascin-c positively regulated macrophage migration, which was dependent on the expression of annexin II in macrophages. VEGF release from macrophages and endothelial tube induction by macrophage were boosted by tenascin-c and attenuated by annexin II blocking. Furthermore, tenascin-c activated Akt/NF-κB and ERK signalling through annexin II. Lastly, hypoxia conditioning remarkably facilitates annexin II expression in macrophages through hypoxia-inducible factor (HIF)-1α but not HIF-2α. In conclusion, tenascin-c promoted macrophage migration and VEGF expression through annexin II, the expression of which was modulated by HIF-1α.

Cross Talk Pathways Between Coagulation and Inflammation

Anatomic pathology studies performed over 150 years ago revealed that excessive activation of coagulation occurs in the setting of inflammation. However, it has taken over a century since these seminal observations were made to delineate the molecular mechanisms by which these systems interact and the extent to which they participate in the pathogenesis of multiple diseases. There is, in fact, extensive cross talk between coagulation and inflammation, whereby activation of one system may amplify activation of the other, a situation that, if unopposed, may result in tissue damage or even multiorgan failure. Characterizing the common triggers and pathways are key for the strategic design of effective therapeutic interventions. In this review, we highlight some of the key molecular interactions, some of which are already showing promise as therapeutic targets for inflammatory and thrombotic disorders.

Biomarkers of systemic lupus erythematosus identified using mass spectrometry-based proteomics: a systematic review

Advances in mass spectrometry technologies have created new opportunities for discovering novel protein biomarkers in systemic lupus erythematosus (SLE). We performed a systematic review of published reports on proteomic biomarkers identified in SLE patients using mass spectrometry‐based proteomics and highlight their potential disease association and clinical utility. Two electronic databases, MEDLINE and EMBASE, were systematically searched up to July 2015. The methodological quality of studies included in the review was performed according to Preferred Reporting Items for Systematic Reviews and Meta‐analyses guidelines. Twenty‐five studies were included in the review, identifying 241 SLE candidate proteomic biomarkers related to various aspects of the disease including disease diagnosis and activity or pinpointing specific organ involvement. Furthermore, 13 of the 25 studies validated their results for a selected number of biomarkers in an independent cohort, resulting in the validation of 28 candidate biomarkers. It is noteworthy that 11 candidate biomarkers were identified in more than one study. A significant number of potential proteomic biomarkers that are related to a number of aspects of SLE have been identified using mass spectrometry proteomic approaches. However, further studies are required to assess the utility of these biomarkers in routine clinical practice.

Exosomal Annexin II Promotes Angiogenesis and Breast Cancer Metastasis

Tumor-derived exosomes are emerging mediators of tumorigenesis and tissue-specific metastasis. Proteomic profiling has identified Annexin II as one of the most highly expressed proteins in exosomes; however, studies focused on the biological role of exosomal Annexin II (exo-Anx II) are still lacking. In this study, mechanistic insight was sought regarding exo-Anx II and its function in angiogenesis and breast cancer metastasis. Multiple in vitro and in vivo techniques were used to study the role of exo-Anx II in angiogenesis. Using atomic force microscopy and Western blotting, exo-Anx II expression was characterized in normal and breast cancer cells. In addition, organ-specific metastatic breast cancer cells and animal models were used to define the role exo-Anx II in breast cancer metastasis. Results revealed that exo-Anx II expression is significantly higher in malignant cells than normal and premetastatic breast cancer cells. In vitro and in vivo studies demonstrated that exo-Anx II promotes tPA-dependent angiogenesis. Furthermore, in vivo analysis indicated that metastatic exosomes create a favorable microenvironment for metastasis, and exo-Anx II plays an important role in this process, as priming with Anx II-depleted exosomes reduces brain (∼4-fold) and lung (∼2-fold) metastasis. Upon delineating the mechanism, it was discovered that exo-Anx II causes macrophage-mediated activation of the p38MAPK, NF-κB, and STAT3 pathways and increased secretion of IL6 and TNFα. These data demonstrate an important role for exo-Anx II in breast cancer pathogenesis.

IMPLICATIONS

Exosome-associated Annexin II plays an important role in angiogenesis and breast cancer metastasis, which can be exploited as a potential biomarker as well as a therapeutic target for diagnosis and treatment of metastatic breast cancer. Mol Cancer Res; 15(1); 93-105. ©2016 AACR.

Heterogeneous Porphyromonas gingivalis LPS modulates immuno-inflammatory response, antioxidant defense and cytoskeletal dynamics in human gingival fibroblasts

Periodontal (gum) disease is a highly prevalent infection and inflammation accounting for the majority of tooth loss in adult population worldwide. Porphyromonas gingivalis is a keystone periodontal pathogen and its lipopolysaccharide (PgLPS) acts as a major virulence attribute to the disease. Herein, we deciphered the overall host response of human gingival fibroblasts (HGFs) to two featured isoforms of tetra-acylated PgLPS_1435/1449 and penta-acylated PgLPS₁₆₉₀ with reference to E. coli LPS through quantitative proteomics. This study unraveled differentially expressed novel biomarkers of immuno-inflammatory response, antioxidant defense and cytoskeletal dynamics in HGFs. PgLPS₁₆₉₀ greatly upregulated inflammatory proteins (e.g. cyclophilin, inducible nitric oxide synthase, annexins, galectin, cathepsins and heat shock proteins), whereas the anti-inflammatory proteins (e.g. Annexin A2 and Annexin A6) were significantly upregulated by PgLPS_1435/1449. Interestingly, the antioxidants proteins such as mitochondrial manganese-containing superoxide dismutase and peroxiredoxin 5 were only upregulated by PgLPS_1690. The cytoskeletal rearrangement-related proteins like myosin were differentially regulated by these PgLPS isoforms. The present study gives new insight into the biological properties of P. gingivalis LPS lipid A moiety that could critically modulate immuno-inflammatory response, antioxidant defense and cytoskeletal dynamics in HGFs, and thereby enhances our understanding of periodontal pathogenesis.

Microdialysis Sampling from Wound Fluids Enables Quantitative Assessment of Cytokines, Proteins, and Metabolites Reveals Bone Defect-Specific Molecular Profiles

Bone healing involves a variety of different cell types and biological processes. Although certain key molecules have been identified, the molecular interactions of the healing progress are not completely understood. Moreover, a clinical routine for predicting the quality of bone healing after a fracture in an early phase is missing. This is mainly due to a lack of techniques to comprehensively screen for cytokines, growth factors and metabolites at their local site of action. Since all soluble molecules of interest are present in the fracture hematoma, its in-depth assessment could reveal potential markers for the monitoring of bone healing. Here, we describe an approach for sampling and quantification of cytokines and metabolites by using microdialysis, combined with solid phase extractions of proteins from wound fluids. By using a control group with an isolated soft tissue wound, we could reveal several bone defect-specific molecular features. In bone defect dialysates the neutrophil chemoattractants CXCL1, CXCL2 and CXCL3 were quantified with either a higher or earlier response compared to dialysate from soft tissue wound. Moreover, by analyzing downstream adaptions of the cells on protein level and focusing on early immune response, several proteins involved in the immune cell migration and activity could be identified to be specific for the bone defect group, e.g. immune modulators, proteases and their corresponding inhibitors. Additionally, the metabolite screening revealed different profiles between the bone defect group and the control group. In summary, we identified potential biomarkers to indicate imbalanced healing progress on all levels of analysis.

Salivary pellets induce a pro-inflammatory response involving the TLR4-NF-kB pathway in gingival fibroblasts

Background

Whole saliva provokes a substantial pro-inflammatory response in gingival fibroblasts. This raises the question whether the salivary pellet, which is used for diagnostic purposes, also has a pro-inflammatory capacity and, if yes, what the underlying mechanisms at the molecular level are.

Methods

We examined the ability of extensively washed salivary pellets to provoke the expression of chemokines in gingival fibroblasts by real-time polymerase chain reaction and immunoassays. Protein composition was determined with proteomic analysis. Endotoxins were analyzed by a Limulus assay and removed by affinity chromatography. The inhibitors TAK-242 and BAY11-7082 were used to determine the involvement of the TLR4 and NF-kB signaling, respectively. Western blot was performed to detect phosphorylated p65.

Results

The experiments show that salivary pellets and the corresponding washing solution contain pro-inflammatory activity without impairing cell viability. Proteomic analysis revealed proteins with a binding capacity for lipopolysaccharides, and the Limulus assay indicated the presence of endotoxin in the salivary pellets. Blocking TLR4 with TAK-242 and depletion of endotoxins both lowered the capacity of salivary pellets to increase chemokine expression and phosphorylation of p65. BAY11-7082 suppressed chemokine expression in response to the salivary pellets. Autoclaving salivary pellets also reduced their pro-inflammatory activity.

Conclusions

The data support the molecular mechanism of a TLR4-NF-kB-dependent pro-inflammatory response of the gingival fibroblasts exposed to preparations of washed salivary pellets. Together, the data indicate that the salivary pellet is rich in endotoxin but it is mainly a heat labile fraction that accounts for the chemokine expression in the bioassay.

Electronic supplementary material

The online version of this article (doi:10.1186/s12903-016-0229-5) contains supplementary material, which is available to authorized users.

Proteome analysis of human amniotic mesenchymal stem cells (hA-MSCs) reveals impaired antioxidant ability, cytoskeleton and metabolic functionality in maternal obesity

Maternal obesity increases the risk of obesity and/or obesity-related diseases in the offspring of animal models. The aim of this study was to identify metabolic dysfunctions that could represent an enhanced risk for human obesity or obesity-related diseases in newborn or in adult life, similar to what occurs in animal models. To this aim, we studied the proteome of 12 obese (Ob-) and 6 non-obese (Co-) human amniotic mesenchymal stem cells (hA-MSCs) obtained from women at delivery by cesarean section (pre-pregnancy body mass index [mean ± SD]: 42.7 ± 7.7 and 21.3 ± 3.3 kg/m², respectively). The proteome, investigated by two-dimensional fluorescence difference gel electrophoresis/mass spectrometry, revealed 62 differently expressed proteins in Ob- vs Co-hA-MSCs (P < 0.05), nine of which were confirmed by western blotting. Bioinformatics analysis showed that these 62 proteins are involved in several statistically significant pathways (P < 0.05), including the stress response, cytoskeleton and metabolic pathways. Oxidative stress was shown to be an early triggering factor of tissue fat accumulation and obesity-related disorders in the offspring of obese animal models. Our finding of a reduced stress response in Ob-hA-MSCs suggests that a similar mechanism could occur also in humans. Long-term follow-up studies of newborns of obese mothers are required to verify this hypothesis.

The Annexin a2 Promotes Development in Arthritis through Neovascularization by Amplification Hedgehog Pathway

The neovascularization network of pannus formation plays a crucial role in the development of rheumatoid arthritis (RA). Annexin a2 (Axna2) is an important mediating agent that induces angiogenesis in vascular diseases. The correlation between Axna2 and pannus formation has not been studied. Here, we provided evidence that compared to osteoarthritis (OA) patients and healthy people, the expression of Axna2 and Axna2 receptor (Axna2R) were up-regulated in patients with RA. Joint swelling, inflammation and neovascularization were increased significantly in mice with collagen-induced arthritis (CIA) that were exogenously added Axna2. Cell experiments showed that Axna2 promoted HUVEC proliferation by binding Axna2R, and could activate Hedgehog (HH) signaling and up-regulate the expression of Ihh and Gli. Besides, expression of Ihh, Patched (Ptc), Smoothened (Smo) and Gli and matrix metalloproteinase-2 (MMP-2), vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2), angiogenic growth factor of HH signaling downstream, were down-regulated after inhibition of expression Axna2R on HUVEC. Together, our research definitely observed that over-expression of Axna2 could promote the development of CIA, especially during the process of pannus formation for the first time. Meanwhile, Axna2 depended on combining Axna2R to activate and enlarge HH signaling and the expression of its downstream VEGF, Ang-2 and MMP-2 to promote HUVEC proliferation, and eventually caused to angiogenesis. Therefore, the role of Axna2 is instructive for understanding the development of RA, suppress the effect of Axna2 might provide a new potential measure for treatment of RA.

Annexin A2 binds to endosomes and negatively regulates TLR4-triggered inflammatory responses via the TRAM-TRIF pathway

Lipopolysaccharide (LPS) derived from Gram-negative bacteria activates plasma membrane signaling via Toll-like receptor 4 (TLR4) on host cells and triggers innate inflammatory responses, but the underlying mechanisms remain to be fully elucidated. Here we reveal a role for annexin A2 (AnxA2) in host defense against infection as anxa2^−/− mice were highly susceptible to Gram-negative bacteria-induced sepsis with enhanced inflammatory responses. Computing analysis and biochemical experiments identified that constitutive AnxA2 expression facilitated TLR4 internalization and its subsequent translocation into early endosomal membranes. It activated the TRAM-dependent endosomal signaling, leading to the release of anti-inflammatory cytokines. Importantly, AnxA2 deficiency prolonged TLR4-mediated signaling from the plasma membrane, which was attributable to pro-inflammatory cytokine production (IL-6, TNFα and IL-1β). Thus, AnxA2 directly exerted negative regulation of inflammatory responses through TLR4-initiated TRAM-TRIF pathway occurring on endosomes. This study reveals AnxA2 as a critical regulator in infection-initiated inflammation, which protects the host from excessive inflammatory damage.

DAMPs and influenza virus infection in ageing

Influenza A virus (IAV) is a serious global health problem worldwide due to frequent and severe outbreaks. IAV causes significant morbidity and mortality in the elderly population, due to the ineffectiveness of the vaccine and the alteration of T cell immunity with ageing. The cellular and molecular link between ageing and virus infection is unclear and it is possible that damage associated molecular patterns (DAMPs) may play a role in the raised severity and susceptibility of virus infections in the elderly. DAMPs which are released from damaged cells following activation, injury or cell death can activate the immune response through the stimulation of the inflammasome through several types of receptors found on the plasma membrane, inside endosomes after endocytosis as well as in the cytosol. In this review, the detriment in the immune system during ageing and the links between influenza virus infection and ageing will be discussed. In addition, the role of DAMPs such as HMGB1 and S100/Annexin in ageing, and the enhanced morbidity and mortality to severe influenza infection in ageing will be highlighted.

A clinically based protein discovery strategy to identify potential biomarkers of response to anti-TNF-α treatment of psoriatic arthritis

PURPOSE

Psoriatic arthritis (PsA) can be treated using biologic therapies targeting biomolecules such as tumor necrosis factor alpha, interleukins (IL)-17 and IL-23. Although 70% PsA patients respond well to therapy, 30% patients show no or limited clinical improvement. Biomarkers that predict response to therapy would help to avoid unnecessary use of expensive biologics in nonresponding patients and enable alternative treatments to be explored.

EXPERIMENTAL DESIGN

Patient synovial tissue samples from two clinical studies were analysed using difference in-gel electrophoresis-based proteomics to identify protein expression differences in response to anti-TNF-α treatment. Subsequent multiplexed MRM measurements were used to verify potential biomarkers.

RESULTS

A total of 119 proteins were differentially expressed (p<0.05) in response to anti-TNF-α treatment and 25 proteins were differentially expressed (p<0.05) between "good responders" and "poor responders". From these differentially expressed proteins, MRM assays were developed for four proteins to explore their potential as treatment predictive biomarkers.

CONCLUSION AND CLINICAL RELEVANCE

Gel-based proteomics strategy has demonstrated differential protein expression in synovial tissue of PsA patients, in response to anti-TNF-α treatment. Development of multiplex MRM assays to these differentially expressed proteins has the potential to predict response to therapy and allow alternative, more effective treatments to be explored sooner.

Annexin A2 Regulates Autophagy in Pseudomonas aeruginosa Infection through the Akt1-mTOR-ULK1/2 Signaling Pathway

Earlier studies reported that a cell membrane protein, Annexin A2 (AnxA2), plays multiple roles in the development, invasion, and metastasis of cancer. Recent studies demonstrated that AnxA2 also functions in immunity against infection, but the underlying mechanism remains largely elusive. Using a mouse infection model, we reveal a crucial role for AnxA2 in host defense against Pseudomonas aeruginosa, as anxa2(-/-) mice manifested severe lung injury, systemic dissemination, and increased mortality compared with wild-type littermates. In addition, anxa2(-/-) mice exhibited elevated inflammatory cytokines (TNF-α, IL-6, IL-1β, and IFN-γ), decreased bacterial clearance by macrophages, and increased superoxide release in the lung. We further identified an unexpected molecular interaction between AnxA2 and Fam13A, which activated Rho GTPase. P. aeruginosa infection induced autophagosome formation by inhibiting Akt1 and mTOR. Our results indicate that AnxA2 regulates autophagy, thereby contributing to host immunity against bacteria through the Akt1-mTOR-ULK1/2 signaling pathway.

New Insight on the Role of Plasminogen Receptor in Cancer Progression

OBJECTIVE

Plasminogen system plays a crucial role in physiological and pathological events related to tissue regeneration, wound healing, immune response, angiogenesis, invasion and metastasis. It gets activated when plasminogen associates with its cell surface receptors. Latest information on some of the well-explored plasminogen receptors such as annexin II–S100A10, cytokeratin 8, α-enolase, plasminogen receptor (KT) (Plg-R(KT)) and histone H2B has been discussed in the present review. These receptors can pave the way for effective new therapeutic and diagnostic strategies to counteract malignant diseases.

CONCLUSION

The present review concludes the key role of plasminogen receptors in extracellular matrix degradation, infiltration into surrounding tissues, neovascularization, invasion, metastasis and drug resistance. This review also discusses the possible effect of blocking these plasminogen receptors with monoclonal antibodies and DNA-based vaccination or silencing plasminogen receptor gene using small interfering RNA or short hairpin RNA to counteract cancer invasion and metastasis.

Proteome from patients with metabolic syndrome is regulated by quantity and quality of dietary lipids

Background

Metabolic syndrome is a multi-component disorder associated to a high risk of cardiovascular disease. Its etiology is the result of a complex interaction between genetic and environmental factors, including dietary habits. We aimed to identify the target proteins modulated by the long-term consumption of four diets differing in the quality and quantity of lipids in the whole proteome of peripheral blood mononuclear cells (PBMC).

Results

A randomized, controlled trial conducted within the LIPGENE study assigned 24 MetS patients for 12 weeks each to 1 of 4 diets: a) high-saturated fatty acid (HSFA), b) high-monounsaturated fatty acid (HMUFA), c) low-fat, high-complex carbohydrate diets supplemented with placebo (LFHCC) and d) low-fat, high-complex carbohydrate diets supplemented with long chain (LC) n-3 polyunsaturated fatty acids (PUFA) (LFHCC n-3). We analyzed the changes induced in the proteome of both nuclear and cytoplasmic fractions of PBMC using 2-D proteomic analysis. Sixty-seven proteins were differentially expressed after the long-term consumption of the four diets. The HSFA diet induced the expression of proteins responding to oxidative stress, degradation of ubiquitinated proteins and DNA repair. However, HMUFA, LFHCC and LFHCC n-3 diets down-regulated pro-inflammatory and oxidative stress-related proteins and DNA repairing proteins.

Conclusion

The long-term consumption of HSFA, compared to HMUFA, LFHCC and LFHCC n-3, seems to increase the cardiovascular disease (CVD) risk factors associated with metabolic syndrome, such as inflammation and oxidative stress, and seem lead to DNA damage as a consequence of high oxidative stress.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1725-8) contains supplementary material, which is available to authorized users.

Expression and significance of annexin A2 in patients with gastric adenocarcinoma and the association with E-cadherin

Annexin A2 is a calcium-dependent phospholipid-binding protein, involved in invasion, angiogenesis and migration in cancer cells. The aims of the present study were to evaluate the expression levels of annexin A2 and E-cadherin in gastric adenocarcinoma (GAC), and to investigate the association between the expression of annexin A2 and that of E-cadherin and Ki67, in addition to various clinicopathological factors. This study included 126 patients that were histopathologically diagnosed with GAC. Tissue samples were acquired by surgical resection, and annexin A2 mRNA expression levels were determined using reverse transcription-quantitative polymerase chain reaction. Annexin A2, E-cadherin and Ki67 protein expression levels were detected using western blot analysis and/or immunohistochemical staining. The expression of annexin A2 mRNA and protein was significantly upregulated in the GAC tissues. Annexin A2 expression was detected in 52/126 cases (41.3%) of gastric cancer (GC), and correlations were identified between annexin A2 expression and Tumor, Node, Metastasis (TNM) stage (P=0.002), lymph node metastasis (P=0.016) and distal metastasis (P=0.005). The positive expression rates of E-cadherin and Ki67 in the tumor tissue of patients with GAC were 27.8% (35/126) and 56.2% (71/126), respectively. A negative correlation was observed between the expression of annexin A2 and E-cadherin (P<0.001). No significant association was detected between the expression levels of annexin A2 and Ki67 (P=0.801). In conclusion, upregulated annexin A2 expression was associated with lymph node metastasis, distal metastasis, advanced TNM stage and E-cadherin expression in patients with GAC. The association between the expression of annexin A2 and that of E-cadherin may indicate an underlying mechanism by which annexin A2 contributes to the metastasis in GC, and thus annexin A2 may represent a potential target for the treatment of GAC.

Proteomic analysis of pure human airway gland mucus reveals a large component of protective proteins

Airway submucosal glands contribute to innate immunity and protect the lungs by secreting mucus, which is required for mucociliary clearance and which also contains antimicrobial, anti-inflammatory, anti-proteolytic and anti-oxidant proteins. We stimulated glands in tracheal trimmings from three lung donors and collected droplets of uncontaminated mucus as they formed at the gland orifices under an oil layer. We analyzed the mucus using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Analysis identified 5486 peptides and 441 proteins from across the 3 samples (269-319 proteins per subject). We focused on 269 proteins common to at least 2 0f 3 subjects, of which 102 (38%) had protective or innate immunity functions. While many of these have long been known to play such roles, for many others their cellular protective functions have only recently been appreciated in addition to their well-studied biologic functions (e.g. annexins, apolipoproteins, gelsolin, hemoglobin, histones, keratins, and lumican). A minority of the identified proteins are known to be secreted via conventional exocytosis, suggesting that glandular secretion occurs via multiple mechanisms. Two of the observed protective proteins, major vault protein and prohibitin, have not been observed in fluid from human epithelial cultures or in fluid from nasal or bronchoalveolar lavage. Further proteomic analysis of pure gland mucus may help clarify how healthy airways maintain a sterile environment.

Localization of annexins A1 and A2 in the respiratory tract of healthy calves and those experimentally infected with Mannheimia haemolytica

Annexins A1 and A2 are proteins known to function in the stress response, dampening inflammatory responses and mediating fibrinolysis. We found, in healthy cattle recently arrived to a feedlot, that lower levels of these proteins correlated with later development of pneumonia. Here we determine the localization of annexin A1 and A2 proteins in the respiratory tract and in leukocytes, in healthy calves and those with Mannheimia haemolytica pneumonia. In healthy calves, immunohistochemistry revealed cytoplasmic expression of annexin A1 in the surface epithelium of large airways, tracheobronchial glands and goblet cells, to a lesser degree in small airways, but not in alveolar epithelium. Immunocytochemistry labeled annexin A1 in the cytoplasm of neutrophils from blood and bronchoalveolar lavage fluid, while minimal surface expression was detected by flow cytometry in monocytes, macrophages and lymphocytes. Annexin A2 expression was detected in surface epithelium of small airways, some mucosal lymphocytes, and endothelium, with weak expression in large airways, tracheobronchial glands and alveolar septa. For both proteins, the level of expression was similar in tissues collected five days after intrabronchial challenge with M. haemolytica compared to that from sham-inoculated calves. Annexins A1 and A2 were both detected in leukocytes around foci of coagulative necrosis, and in necrotic cells in the center of these foci, as well as in areas outlined above. Thus, annexins A1 and A2 are proteins produced by airway epithelial cells that may prevent inflammation in the healthy lung and be relevant to development of pneumonia in stressed cattle.

Annexin A2 as a target endothelial cell membrane autoantigen in Behçet's disease

Cell membrane proteins are believed to play a critical role in the pathogenesis of autoimmune diseases. However, few membrane autoantigens have been linked with Behçet's disease. Here, a cell-chip was performed to identify autoantibody target cells, and the suspected autoantigens were detected using immunoblotting. The amino acid sequences of the detected proteins were determined using LC-MALDI-TOF/TOF. Putative proteins were recombinantly expressed and purified, and a corresponding ELISA was developed and clinically validated using real clinical samples. It was found that a 36-kDa membrane protein--annexin A2--was detected in approximately one-third of the patients' blood circulation. The immunohistochemistry results showed that annexin A2 was highly expressed in vascular endothelial cells. Moreover, vascular involvement was significantly higher in the anti-annexin A2 antibody-positive group versus the anti-annexin A2 antibody-negative group among all the clinical samples analyzed, indicating that annexin A2 is a novel endothelial cell membrane antigen involved in Behçet's disease.

Annexin A2 autoantibodies in thrombosis and autoimmune diseases

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by arterial, venous or small-vessel thrombotic events, and recurrent miscarriages or fetal loss. APS diagnosis is based on the repeated detection of anti-phospholipid (PL) antibodies (Ab), typically associated with anti-β2 glycoprotein I (β2GPI)-Ab. Recent studies suggest that anti-β2GPI Ab activity involves a protein complex including β2GPI and annexin A2 (ANXA2). Anti-ANXA2 Ab recognizes this complex, and these Ab can effectively promote thrombosis by inhibiting plasmin generation, and by activating endothelial cells. Therefore, anti-ANXA2 Ab represent a new biomarker, which can be detected in up to 25% of APS patients. Moreover, anti-ANXA2 Ab have been detected, in thrombotic associated diseases including pre-eclampsia, in other autoimmune diseases, and in cancer.

Post-traumatic immunosuppression is reversed by anti-coagulated salvaged blood transfusion: deductions from studying immune status after knee arthroplasty

Major trauma increases vulnerability to systemic infections due to poorly defined immunosuppressive mechanisms. It confers no evolutionary advantage. Our objective was to develop better biomarkers of post-traumatic immunosuppression (PTI) and to extend our observation that PTI was reversed by anti-coagulated salvaged blood transfusion, in the knowledge that others have shown that non-anti-coagulated (fibrinolysed) salvaged blood was immunosuppressive. A prospective non-randomized cohort study of patients undergoing primary total knee arthroplasty included 25 who received salvaged blood transfusions collected post-operatively into acid-citrate-dextrose anti-coagulant (ASBT cohort), and 18 non-transfused patients (NSBT cohort). Biomarkers of sterile trauma included haematological values, damage-associated molecular patterns (DAMPs), cytokines and chemokines. Salvaged blood was analysed within 1 and 6 h after commencing collection. Biomarkers were expressed as fold-changes over preoperative values. Certain biomarkers of sterile trauma were common to all 43 patients, including supranormal levels of: interleukin (IL)-6, IL-1-receptor-antagonist, IL-8, heat shock protein-70 and calgranulin-S100-A8/9. Other proinflammatory biomarkers which were subnormal in NSBT became supranormal in ASBT patients, including IL-1β, IL-2, IL-17A, interferon (IFN)-γ, tumour necrosis factor (TNF)-α and annexin-A2. Furthermore, ASBT exhibited subnormal levels of anti-inflammatory biomarkers: IL-4, IL-5, IL-10 and IL-13. Salvaged blood analyses revealed sustained high levels of IL-9, IL-10 and certain DAMPs, including calgranulin-S100-A8/9, alpha-defensin and heat shock proteins 27, 60 and 70. Active synthesis during salvaged blood collection yielded increasingly elevated levels of annexin-A2, IL-1β, Il-1-receptor-antagonist, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-17A, IFN-γ, TNF-α, transforming growth factor (TGF)-β1, monocyte chemotactic protein-1 and macrophage inflammatory protein-1α. Elevated levels of high-mobility group-box protein-1 decreased. In conclusion, we demonstrated that anti-coagulated salvaged blood reversed PTI, and was attributed to immune stimulants generated during salvaged blood collection.

Proteomic white adipose tissue analysis of obese mice fed with a high-fat diet and treated with oral angiotensin-(1-7)

Angiotensin-(1-7) has been described as a new potential therapeutic tool for the treatment and prevention of metabolic disorders by regulating several pathways in visceral white adipose tissue (vWAT). The aim of this study was to access the proteins differentially regulated by Ang-(1-7) using proteomic analysis of visceral adipose tissue. Male mice were divided into three groups and fed for 60 days, with each group receiving one of the following diets: standard diet+HPβCD (ST), high fat diet+HPβCD (HFD) and high fat diet+Ang-(1-7)/HPβCD (HFD+Ang-(1-7)). Body weight, fat weight and food intake were measured. At the end of treatment, Ang-(1-7) induced a decrease in body and fat weight. Differential proteomic analysis using two-dimensional electrophoresis (2-DE) combined with mass spectrometry were performed. Results of protein mapping of mesenteric adipose tissue using 2-DE revealed the presence of about 450 spots in each gel (n=3/treatment) with great reproducibility (>70%). Image analysis and further statistical analysis allowed the detection and identification of eight proteins whose expression was modulated in response to HFD when compared to ST. Among these, two proteins showed a sensitive response to Ang-(1-7) treatment (eno1 and aldehyde dehydrogenase). In addition, three proteins were expressed statistically different between HFD+Ang-(1-7) and HFD groups, and four proteins were modulated compared to standard diet. In conclusion, comparative proteomic analysis of a mice model of diet-induced obesity allowed us to outline possible pathways involved in the response to Ang-(1-7), suggesting that Ang-(1-7) may be a useful tool for the treatment of metabolic disorders.

Aberrant expression of interleukin-1β and inflammasome activation in human malignant gliomas

Objective

Glioblastoma is the most frequent and malignant form of primary brain tumor with grave prognosis. Mounting evidence supports that chronic inflammation (such as chronic overactivation of IL-1 system) is a crucial event in carcinogenesis and tumor progression. IL-1 also is an important cytokine with species-dependent regulations and roles in CNS cell activation. While much attention is paid to specific anti-tumor immunity, little is known about the role of chronic inflammation/innate immunity in glioma pathogenesis. In this study, we examined whether human astrocytic cells (including malignant gliomas) can produce IL-1 and its role in glioma progression.

Methods

We used a combination of cell culture, real-time PCR, ELISA, western blot, immunocytochemistry, siRNA and plasmid transfection, micro-RNA analysis, angiogenesis (tube formation) assay, and neurotoxicity assay.

Results

Glioblastoma cells produced large quantities of IL-1 when activated, resembling macrophages/microglia. The activation signal was provided by IL-1 but not the pathogenic components LPS or poly IC. Glioblastoma cells were highly sensitive to IL-1 stimulation, suggesting its relevance in vivo. In human astrocytes, IL-1β mRNA was not translated to protein. Plasmid transfection also failed to produce IL-1 protein, suggesting active repression. Suppression of microRNAs that can target IL-1α/β did not induce IL-1 protein. Glioblastoma IL-1β processing occurred by the NLRP3 inflammasome, and ATP and nigericin increased IL-1β processing by upregulating NLRP3 expression, similar to macrophages. RNAi of annexin A2, a protein strongly implicated in glioma progression, prevented IL-1 induction, demonstrating its new role in innate immune activation. IL-1 also activated Stat3, a transcription factor crucial in glioma progression. IL-1 activated glioblastoma-conditioned media enhanced angiogenesis and neurotoxicity.

Conclusions

Our results demonstrate unique, species-dependent immune activation mechanisms involving human astrocytes and astrogliomas. Specifically, the ability to produce IL-1 by glioblastoma cells may confer them a mesenchymal phenotype including increased migratory capacity, unique gene signature and proinflammatory signaling.

Age-dependent transcriptome and proteome following transection of neonatal spinal cord of Monodelphis domestica (South American grey short-tailed opossum)

This study describes a combined transcriptome and proteome analysis of Monodelphis domestica response to spinal cord injury at two different postnatal ages. Previously we showed that complete transection at postnatal day 7 (P7) is followed by profuse axon growth across the lesion with near-normal locomotion and swimming when adult. In contrast, at P28 there is no axon growth across the lesion, the animals exhibit weight-bearing locomotion, but cannot use hind limbs when swimming. Here we examined changes in gene and protein expression in the segment of spinal cord rostral to the lesion at 24 h after transection at P7 and at P28. Following injury at P7 only forty genes changed (all increased expression); most were immune/inflammatory genes. Following injury at P28 many more genes changed their expression and the magnitude of change for some genes was strikingly greater. Again many were associated with the immune/inflammation response. In functional groups known to be inhibitory to regeneration in adult cords the expression changes were generally muted, in some cases opposite to that required to account for neurite inhibition. For example myelin basic protein expression was reduced following injury at P28 both at the gene and protein levels. Only four genes from families with extracellular matrix functions thought to influence neurite outgrowth in adult injured cords showed substantial changes in expression following injury at P28: Olfactomedin 4 (Olfm4, 480 fold compared to controls), matrix metallopeptidase (Mmp1, 104 fold), papilin (Papln, 152 fold) and integrin α4 (Itga4, 57 fold). These data provide a resource for investigation of a priori hypotheses in future studies of mechanisms of spinal cord regeneration in immature animals compared to lack of regeneration at more mature stages.

Annexin A2: its molecular regulation and cellular expression in cancer development

Annexin A2 (ANXA2) orchestrates multiple biologic processes and clinical associations, especially in cancer progression. The structure of ANXA2 affects its cellular localization and function. However, posttranslational modification and protease-mediated N-terminal cleavage also play critical roles in regulating ANXA2. ANXA2 expression levels vary among different types of cancers. With some cancers, ANXA2 can be used for the detection and diagnosis of cancer and for monitoring cancer progression. ANXA2 is also required for drug-resistance. This review discusses the feasibility of ANXA2 which is active in cancer development and can be a therapeutic target in cancer management.

Urine annexin A1 as an index for glomerular injury in patients

BACKGROUND

We recently demonstrated high urine levels of annexin A1 (ANXA1) protein in a mouse Adriamycin-induced glomerulopathy (ADG) model.

OBJECTIVE

To establish ANXA1 as a potential biomarker for glomerular injury in patients.

METHODS

A time-course study in the mouse ADG model, followed by renal tissues and urine samples from patients with various types of glomerular disorders for ANXA1.

RESULTS

Urinary ANXA1 protein was (1) detectable in both the ADG model and in patients except those with minimal change disease (MCD); (2) positively correlated with renal lesions in patients; and (3) early detectable in diabetes patients with normoalbuminuria.

CONCLUSIONS

ANXA1 is a universal biomarker that is helpful in the early diagnosis, prognostic prediction, and outcome monitoring of glomerular injury. Measurement of urinary ANXA1 protein levels can help in differentiating MCD from other types of glomerular disorders.