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The objective of this study is to perform proteomic analysis of pleomorphic adenoma (PA) in the human parotid gland (PG) with comparison of normal PG. This is an individual prospective randomized controlled trial. This study was performed in a tertiary referral center. Tissue samples of PG and PA were taken after surgical excision of PG from 13 patients. Protein extracts were prepared and protein pools created from the soluble extracts were subjected to 2D-DIGE analysis. Proteins displaying regulation in their abundance were determined and identified using MALDIT-OF/TOF analysis. The identified proteins were subjected to STRING analysis for classification of the proteins based on their biological roles in metabolic pathways. Fifteen proteins, carbonic anhydrase 1, carbonic anhydrase 2, fibrinogen beta chain, alpha-amylase 1, heats hock protein hsp 90-alpha, clusterin, 78 kDa glucose-regulated protein, endoplasmin, alpha-amylase 2b, ATP synthase subunit alpha (mitochondrial), elongation factor 1-gamma, malate dehydrogenase, cytoplasmic, triosephosphate isomerase, receptor of activated protein c kinase 1, and aconitate hydratase, mitochondrial were down-regulated, whereas 11 proteins including ig kappa chain c region, serotransferrin, vimentin, annexin a5, glial fibrillary acidic protein, calreticulin, cartilage oligomeric matrix protein, microfibril-associated glycoprotein 4, 14-3-3 protein epsilon, fibulin-5, and f-box only protein 2 were up-regulated in PA samples in comparison to healthy parotid tissue. This study described the differences observed in protein expression patterns of the PA and normal PG. The results may provide new insights into the pathogenesis and diagnosis of PA in human PG. Level of evidence: 1b.

Cystic fibrosis (CF), the most common autosomal recessive disease in Caucasians, is due to mutations in the CFTR gene. F508del, the most frequent mutation in patients, impairs CFTR protein folding and biosynthesis. The F508del-CFTR protein is retained in the endoplasmic reticulum (ER) and its traffic to the plasma membrane is altered. Nevertheless, if it reaches the cell surface, it exhibits a Cl(-) channel function despite a short half-life. Pharmacological treatments may target the F508del-CFTR defect directly by binding to the mutant protein or indirectly by altering cellular proteostasis, and promote its plasma membrane targeting and stability. We previously showed that annexine A5 (AnxA5) directly binds to F508del-CFTR and, when overexpressed, promotes its membrane stability, leading to the restoration of some Cl(-) channel function in cells. Because Gonadotropin-Releasing Hormone (GnRH) increases AnxA5 expression in some cells, we tested it in CF cells. We showed that human epithelial cells express GnRH-receptors (GnRH-R) and that GnRH induces an AnxA5 overexpression and an increased Cl(-) channel function in F508del-CFTR cells, due to an increased stability of the protein in the membranes. Beside the numerous physiological implications of the GnRH-R expression in epithelial cells, we propose that a topical use of GnRH is a potential treatment in CF.

The interaction between immune cells and phosphatidylserine (PS) molecules exposed on the surface of apoptotic-tumor bodies, such as those induced by chemotherapies, contributes to the formation of an immunosuppressive tumor microenvironment (TME). Annexin A5 (AnxA5) binds with high affinity to PS externalized by apoptotic cells, thereby hindering their interaction with immune cells. Here, we show that AnxA5 administration rescue the immunosuppressive state of the TME induced by chemotherapy. Due to the preferential homing of AnxA5 to the TME enriched with PS+ tumor cells, we demonstrate in vivo that fusing tumor-antigen peptide to AnxA5 significantly enhances its immunogenicity and antitumor efficacy when administered after chemotherapy. Also, the therapeutic antitumor effect of an AnxA5-peptide fusion can be further enhanced by administration of other immune checkpoint inhibitors. Our findings support the administration of AnxA5 following chemotherapy as a promising immune checkpoint inhibitor for cancer treatment. AnnexinV has been shown to bind phosphatidylserine expressed by chemotherapy-induced apoptotic cells increasing their immunogeneicity. Here, the authors demonstrate in a preclinical tumor model that fusing tumor-antigen peptide to Annexin V enhances its efficacy when administered after chemotherapy and with other immune checkpoint inhibitors.

Neutrophil extracellular traps (NETs) play a critical role in acute myocardial infarction (AMI) and the externalization of S100 family members. Here, we show the effects of S100A12 on NETs formation and myocardial injury following AMI. S100A12 expression increases rapidly in neutrophils and peaks on day 1 after AMI, promoting NETs production and exacerbating myocardial injury. DNase I, an inhibitor of NETs, reduces apoptosis of cardiomyocytes induced by S100A12. Mechanistically, the interaction of S100A12 and Annexin A5 (ANXA5) enhances calcium influx and promotes NETs formation. Blockage of ANXA5 effectively attenuates heart function impairment after AMI. Finally, we show that plasma S100A12 levels correlate with dsDNA concentration, and this correlation is associated with an increased risk of all-cause mortality during the 1-year follow-up of AMI patients. These findings, derived from male mice, reveal the S100A12-ANXA5-calcium influx axis as a potential therapeutic target and biomarker for AMI. Neutrophil extracellular traps (NETs) contribute to heart damage after acute myocardial infarction (AMI). Here, the authors show that S100A12 promotes NETs formation and worsens injury, whereas blocking its interaction with ANXA5 reduces damage, suggesting a new therapeutic target for AMI.

Eukaryotic cells possess a universal repair machinery that ensures rapid resealing of plasma membrane disruptions. Before resealing, the torn membrane is submitted to considerable tension, which functions to expand the disruption. Here we show that annexin-A5 (AnxA5), a protein that self-assembles into two-dimensional (2D) arrays on membranes upon Ca 2+ activation, promotes membrane repair. Compared with wild-type mouse perivascular cells, AnxA5-null cells exhibit a severe membrane repair defect. Membrane repair in AnxA5-null cells is rescued by addition of AnxA5, which binds exclusively to disrupted membrane areas. In contrast, an AnxA5 mutant that lacks the ability of forming 2D arrays is unable to promote membrane repair. We propose that AnxA5 participates in a previously unrecognized step of the membrane repair process: triggered by the local influx of Ca 2+ , AnxA5 proteins bind to torn membrane edges and form a 2D array, which prevents wound expansion and promotes membrane resealing. Eukaryotic cell plasma membranes possess a mechanism to repair tears caused by stimuli such as mechanical stress. The authors demonstrate that annexin-A5, when assembled into two-dimensional arrays in the presence of calcium, is required for membrane repair.

BackgroundCervical cancer is a common malignant gynecological disease that threatens the health of women all over the world. The abnormal expression of Annexin A5 (ANXA5) is closely related to the biological behavior of various malignant tumors, however, the relationship between ANXA5 and cervical cancer is still unclear. Therefore, the effects of low expression of ANXA5 on the proliferation, apoptosis, migration and invasion of cervical cancer cells (HeLa) and its related mechanism were explored.MethodsThe cells were divided into three groups: ANXA5-si group, negative control group and blank group. RNA interference was used to suppress ANXA5 expression. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, colony formation assay, flow cytometry and propidium iodide (PI) staining, wound healing assay and transwell assay were employed to detect cell proliferation, apoptosis, migration and invasion respectively. Meanwhile, gene expression was detected by qPCR and Western blotting.ResultsANXA5 suppression lead to the increase of proliferation, migration, invasion and the decrease of apoptosis of cervical cancer HeLa cells. Furthermore, the expression of both pPI3K and pAkt increased.ConclusionANXA5 might inhibit Hela cells proliferation and metastasis by regulating PI3K/Akt signal pathway.

Background Daunorubicin is used clinically in the treatment of myeloma, acute lymphatic and myelocytic leukaemia. The toxic lesions caused by daunorubicin induce various modes of cell death, including apoptosis. Apoptosis is highly regulated programmed cell death that can be initiated mainly via two pathways, through death receptors (extrinsic) or involvement of the mitochondria (intrinsic). Induction of apoptosis via these pathways has been alluded following treatment with daunorubicin, but never compared in acute lymphoblastic leukaemia over a time course. Methods This study investigated the mechanisms of daunorubicin induced apoptosis in the treatment of CCRF-CEM, MOLT-4 (acute T-lymphoblastic leukaemia) and SUP-B15 (acute B-lymphoblastic leukaemia) cells. Cells were treated with daunorubicin for 4 h, and then placed in recovery medium (without daunorubicin) for 4 h, 12 h and 24 h. Apoptotic response was analysing using annexin-V expression, caspase activity, mitochondrial membrane potential change and an array to detect 43 apoptotic proteins. Results Daunorubicin induced apoptosis in all leukemic cell lines, but with different levels and duration of response. Both apoptosis levels and caspase activity increased after four hours recovery then declined in CCRF-CEM and MOLT-4 cells. However, SUP-B15 cells displayed initially comparable levels but remained elevated over the 24 h assessment period. Changes in mitochondrial membrane potential occurred in both MOLT-4 and CCRF-CEM cells but not in SUP-B15 cells. Expression of apoptotic proteins, including Bcl-2, Bax, caspase 3 and FADD, indicated that daunorubicin potentially induced both extrinsic and intrinsic apoptosis in both CCRF-CEM and MOLT-4 cells, but only extrinsic apoptosis in SUP-B15 cells. Conclusions This study describes variations in sensitivities and timing of apoptotic responses in different leukaemia cell lines. These differences could be attributed to the lack of functional p53 in coordinating the cells response following cytotoxic treatment with daunorubicin, which appears to delay apoptosis and utilises alternative signalling mechanisms that need to be further explored.

The development of neutralizing antibodies (inhibitors) against coagulation factor VIII (FVIII) remains the most serious complication in the treatment of hemophilia A. While immune tolerance induction (ITI) is the standard strategy to eliminate these antibodies, it fails in approximately 30% of patients with severe hemophilia A, underscoring the need for innovative approaches to promote FVIII-specific tolerance. To address this challenge, we generated fusion proteins composed of A2, A3-C1-C2 (light chain, LCh), and C2 domains of FVIII linked to Annexin A5 (AnxA5), a protein that binds phosphatidylserine (PS), a hallmark of apoptotic cells. ELISA confirmed high-affinity binding of all fusion proteins to immobilized PS. To model PS exposure , red blood cells (RBCs) were treated with phorbol 12-myristate 13-acetate (PMA), leading to the release of PS-exposing microvesicles. Flow cytometry showed that FVIII-AnxA5 fusion proteins selectively bound to PS-exposing microvesicles but not to intact RBCs. Using mass spectrometry-based immunopeptidomics, we demonstrated that macrophages pulsed with FVIII-AnxA5 fusion proteins efficiently processed and presented FVIII-derived peptides on HLA-DR molecules. These findings suggest that FVIII-AnxA5 fusion proteins can engage apoptotic cell clearance pathways to facilitate antigen presentation in a potentially tolerogenic context. This strategy may offer a novel means of inducing immune tolerance to FVIII in hemophilia A.

Irisin is a recently identified myokine which brings increases in energy expenditure and contributes to the beneficial effects of exercise through the browning of white adipose tissues. However, its effects in the heart remains unknown. This study sought to determine the effects of irisin on hypoxia/reoxygenation injury and its relationship with HDAC4. Wild type and stable HDAC4-overexpression cells were generated from H9c2 cardiomyoblasts. HDAC4 overexpression cells and wild type H9c2 cells were exposed to 24 hours of hypoxia followed by one hour of reoxygenation in vitro in the presence or absence of irisin (5 ng/ml). Cell cytotoxicity, apoptosis, mitochondrial respiration, and mitochondrial permeability transition pore (mPTP) were determined. Western blotting was employed to determine active-caspase 3, annexin V, and HDAC4 expression. As compared to wild type H9c2 group, HDAC4 overexpression remarkably led to a great increase in cell death as evident by the increased lactate dehydrogenase (LDH) leakage, ratio of caspase-3-positive cells as well as the upregulated levels of active-caspase 3 and annexin V shown by western blot analysis. In addition, HDAC4 overexpression also induced much severe mitochondrial dysfunction, as indicated by apoptotic mitochondria and increased mPTP. However, irisin treatment significantly attenuated all of these effects. Though irisin treatment did not influence the expression of HDAC4 at the transcriptional level, western blot analysis showed that HDAC4 protein levels decreased in a time-dependent way after administration of irisin, which is associated with the degradation of HDAC4 mediated by small ubiquitin-like modification (SUMO). Our results are the first to demonstrate that the protective effects of irisin in cardiomyoblasts exposed to hypoxia/reoxygenation might be associated with HDAC4 degradation.

Annexin A5 has been found to act as an oncogenic protein in a variety of cancers. However, its specific biological role and mechanism in renal cell cancer (RCC) remains unknown. Quantitative Real-time PCR and western blotting were used to evaluate the mRNA and protein expression level of Annexin A5 in human RCC cell lines and tissues. Immunohistochemistry was adopted to measure the Annexin A5 expression in 123 cases of RCC tissues. Survival analysis was performed to explore the association between Annexin A5 expression and the prognosis of RCC. The effect of Annexin A5 on RCC growth and metastasis was studied in vitro and in vivo. Annexin A5 was frequently highly expressed in both human RCC cells and tissues. High Annexin A5 expression was associated with higher clinical stage and histological grade. In addition, Annexin A5 might be used as a predictive factor for the prognosis of RCC. Further research suggested that upregulated Annexin A5 in RCC cells could significantly promote tumor cell proliferation, migration and invasion in vitro. Subcutaneous xenograft tumor model displayed that knockdown of Annexin A5 could impede tumorigenesis in vivo. Moreover, mechanism study exhibited that Annexin A5 could activate PI3K/Akt/mTOR signaling pathway, promote epithelial-mesenchymal transition (EMT) and the expression of MMP2 and MMP9. Annexin A5 may be a potential prognostic biomarker in RCC and promotes proliferation, migration and invasion of RCC cells via activating PI3K/Akt/mTOR signaling pathway and regulating EMT process and MMP expression.