Annexin A1 N-terminal derived peptide Ac2-26 stimulates fibroblast migration in high glucose conditions

The time-dependent expression of FPR2 and ANXA1 in murine deep vein thrombosis model and its relation to thrombus age

Thrombus age determination in fatal venous thromboembolism cases is an important task for forensic pathologists. In this study, we investigated the time-dependent expressions of formyl peptide receptor 2 (FPR2) and Annexin A1 (ANXA1) in a stasis-induced deep vein thrombosis (DVT) murine model, with the aim of obtaining useful information for thrombus age timing. A total of 75 ICR mice were randomly classified into thrombosis group and control group. In thrombosis group, a DVT model was established by ligating the inferior vena cava (IVC) of mice, and thrombosed IVCs were harvested at 1, 3, 5, 7, 10, 14, and 21 days after modeling. In control group, IVCs without thrombosis were taken as control samples. The expressions of FPR2 and ANXA1 during thrombosis were detected using immunohistochemistry and double immunofluorescence staining. Their protein and mRNA levels in the samples were determined by Western blotting and quantitative real-time PCR. The results reveal that FPR2 was predominantly expressed by intrathrombotic neutrophils and macrophages. ANXA1 expression in the thrombi was mainly distributed in neutrophils, endothelial cells of neovessels, and fibroblastic cells. After thrombosis, the expressions of FPR2 and ANXA1 were time-dependently up-regulated. The percentage of FPR2-positive cells and the level of FPR2 protein significantly elevated at 1, 3, 5 and 7 days after IVC ligation as compared to those at 10, 14 and 21 days after ligation (p < 0.05). Moreover, the mRNA level of FPR2 were significantly higher at 5 days than that at the other post-ligation intervals (p < 0.05). Besides, the levels of ANXA1 mRNA and protein peaked at 10 and 14 days after ligation, respectively. A significant increase in the mRNA level of ANXA1 was found at 10 and 14 days as compared with that at the other post-ligation intervals (p < 0.01). Our findings suggest that FPR2 and ANXA1 are promising as useful markers for age estimation of venous thrombi.

The role of ANXA1 in the tumor microenvironment

Annexin A1 (ANXA1) is widely expressed in a variety of body tissues and cells and is also involved in tumor development through multiple pathways. The invasion, metastasis, and immune escape of tumor cells depend on the interaction between tumor cells and their surrounding environment. Research shows that ANXA1 can act on a variety of cells in the tumor microenvironment (TME), and subsequently affect the proliferation, invasion and metastasis of tumors. This article describes the role of ANXA1 in the various components of the tumor microenvironment and its mechanism of action, as well as the existing clinical treatment measures related to ANXA1. These findings provide insight for the further design of strategies targeting ANXA1 for the diagnosis and treatment of malignant tumors.

Magnetic Shape-Memory Heuslers Turn to Bio: Cytocompatibility of Ni-Mn-Ga Films and Biomedical Perspective

Magnetic shape-memory (MSM) Heuslers have attracted great attention in recent years for both caloric and magnetomechanical applications. Thanks to their multifunctional properties, they are also promising for a vast variety of biomedical applications. However, this topic has been rarely investigated so far. In this communication, we present the first report on the absence of cytotoxicity of MSM Heuslers in Ni-Mn-Ga epitaxial thin films and the perspective toward bioapplications. Qualitative and quantitative biological characterizations reveal that Ni-Mn-Ga films can promote the adhesion and proliferation of human fibroblasts without eliciting any cytotoxic effect. Additionally, our findings show that the morphology, composition, microstructure, phase transformation, and magnetic characteristics of the films are well preserved after the biological treatments, making the material a promising candidate for further investigations.

E2F1-initiated transcription of PRSS22 promotes breast cancer metastasis by cleaving ANXA1 and activating FPR2/ERK signaling pathway

Breast cancer (BC) is the most common malignant tumor in women worldwide. Metastasis is the main cause of BC-related death. The specific mechanism underlying BC metastasis remains obscure. Recently, PRSS22 was discovered to be involved in tumor development, however, its detailed biological function and regulatory mechanism in BC are unclear. Here, we characterized that PRSS22 expression is upregulated in BC tissues compared with non-tumorous breast tissues. Dual luciferase assays, bioinformatics analyses and chromatin immunoprecipitation (ChIP) assays indicated that transcription factor E2F1 directly binds to the PRSS22 promoter region and activates its transcription. Functionally, upregulation of PRSS22 promoted invasion and metastasis of BC cells in vitro and in vivo, whereas knockdown of PRSS22 inhibited its function. Mechanistically, the combination of PRSS22 and ANXA1 protein in BC cells was first screened by protein mass spectrometry analysis, and then confirmed by co-immunoprecipitation (Co-IP) and western blot assays. Co-overexpression of PRSS22 and ANXA1 could promote BC cell migration and invasion. We further demonstrated that PRSS22 promotes the cleavage of ANXA1 and in turn generates an N-terminal peptide, which initiates the FPR2/ERK signaling axis to increase BC aggressiveness.

Efferocytosis of vascular cells in cardiovascular disease

Cell death and the clearance of apoptotic cells are tightly regulated by various signaling molecules in order to maintain physiological tissue function and homeostasis. The phagocytic removal of apoptotic cells is known as the process of efferocytosis, and abnormal efferocytosis is linked to various health complications and diseases, such as cardiovascular disease, inflammatory diseases, and autoimmune diseases. During efferocytosis, phagocytic cells and/or apoptotic cells release signals, such as "find me" and "eat me" signals, to stimulate the phagocytic engulfment of apoptotic cells. Primary phagocytic cells are macrophages and dendritic cells; however, more recently, other neighboring cell types have also been shown to exhibit phagocytic character, including endothelial cells and fibroblasts, although they are comparatively slower in clearing dead cells. In this review, we focus on macrophage efferocytosis of vascular cells, such as endothelial cells, smooth muscle cells, fibroblasts, and pericytes, and its relation to the progression and development of cardiovascular disease. We also highlight the role of efferocytosis-related molecules and their contribution to the maintenance of vascular homeostasis.

The Pyrazolyl-Urea Gege3 Inhibits the Activity of ANXA1 in the Angiogenesis Induced by the Pancreatic Cancer Derived EVs

The pyrazolyl-urea Gege3 molecule has shown interesting antiangiogenic effects in the tumor contest. Here, we have studied the role of this compound as interfering with endothelial cells activation in response to the paracrine effects of annexin A1 (ANXA1), known to be involved in promoting tumor progression. ANXA1 has been analyzed in the extracellular environment once secreted through microvesicles (EVs) by pancreatic cancer (PC) cells. Particularly, Gege3 has been able to notably prevent the effects of Ac2-26, the ANXA1 mimetic peptide, and of PC-derived EVs on endothelial cells motility, angiogenesis, and calcium release. Furthermore, this compound also inhibited the translocation of ANXA1 to the plasma membrane, otherwise induced by the same ANXA1-dependent extracellular stimuli. Moreover, these effects have been mediated by the indirect inhibition of protein kinase Cα (PKCα), which generally promotes the phosphorylation of ANXA1 on serine 27. Indeed, by the subtraction of intracellular calcium levels, the pathway triggered by PKCα underwent a strong inhibition leading to the following impediment to the ANXA1 localization at the plasma membrane, as revealed by confocal and cytofluorimetry analysis. Thus, Gege3 appeared an attractive molecule able to prevent the paracrine effects of PC cells deriving ANXA1 in the tumor microenvironment.

ANXA1 Contained in EVs Regulates Macrophage Polarization in Tumor Microenvironment and Promotes Pancreatic Cancer Progression and Metastasis

The tumor microenvironment (TME) is a dynamic system where nontumor and cancer cells intercommunicate through soluble factors and extracellular vesicles (EVs). The TME in pancreatic cancer (PC) is critical for its aggressiveness and the annexin A1 (ANXA1) has been identified as one of the oncogenic elements. Previously, we demonstrated that the autocrine/paracrine activities of extracellular ANXA1 depend on its presence in EVs. Here, we show that the complex ANXA1/EVs modulates the macrophage polarization further contributing to cancer progression. The EVs isolated from wild type (WT) and ANXA1 knock-out MIA PaCa-2 cells have been administrated to THP-1 macrophages finding that ANXA1 is crucial for the acquisition of a protumor M2 phenotype. The M2 macrophages activate endothelial cells and fibroblasts to induce angiogenesis and matrix degradation, respectively. We have also found a significantly increased presence of M2 macrophage in mice tumor and liver metastasis sections previously obtained by orthotopic xenografts with WT cells. Taken together, our data interestingly suggest the relevance of ANXA1 as potential diagnostic/prognostic and/or therapeutic PC marker.

The Procoagulant Activity of Emoxilane®: A New Appealing Therapeutic Use in Epistaxis of the Combination of Sodium Hyaluronate, Silver Salt, α-tocopherol and D-panthenol

Epistaxis is one of the most frequent hemorrhages resulting from local or systemic factors. Its management without hospitalization has prompted an interest in locally applied hemostatic agents. Generally, the therapy approaches involve sprays or creams acting as a physical barrier, even used as tampons or gauze. In this study, we have investigated the activity of Emoxilane^®, a combination of sodium hyaluronate, silver salt, α-tocopherol acetate and D-panthenol, which is known to be able to separately act in a different biological manner. Our in vitro results, obtained on endothelial and nasal epithelial cells, have shown that the association of these molecules presented a notable antioxidant activity mainly due to the α-tocopherol and D-panthenol and a significant antimicrobial role thanks to the silver compound. Moreover, remarkable hemostatic activity was found by evaluating plasmin inhibition attributable to the sodium hyaluronate. Interestingly, on human plasma, we have confirmed that Emoxilane^® strongly induced the increase of thrombin levels. These data suggest that the use of this association could represent an appealing pharmacological approach to actively induce hemostasis during epistaxis. Our future perspective will aim to the creation of a formulation for an easy topical application in the nose which is able to contrast the bleeding.

Counteracting the Ramifications of UVB Irradiation and Photoaging with Swietenia macrophylla King Seed

In this day and age, the expectation of cosmetic products to effectively slow down skin photoaging is constantly increasing. However, the detrimental effects of UVB on the skin are not easy to tackle as UVB dysregulates a wide range of molecular changes on the cellular level. In our research, irradiated keratinocyte cells not only experienced a compromise in their redox system, but processes from RNA translation to protein synthesis and folding were also affected. Aside from this, proteins involved in various other processes like DNA repair and maintenance, glycolysis, cell growth, proliferation, and migration were affected while the cells approached imminent cell death. Additionally, the collagen degradation pathway was also activated by UVB irradiation through the upregulation of inflammatory and collagen degrading markers. Nevertheless, with the treatment of Swietenia macrophylla (S. macrophylla) seed extract and fractions, the dysregulation of many genes and proteins by UVB was reversed. The reversal effects were particularly promising with the S. macrophylla hexane fraction (SMHF) and S. macrophylla ethyl acetate fraction (SMEAF). SMHF was able to oppose the detrimental effects of UVB in several different processes such as the redox system, DNA repair and maintenance, RNA transcription to translation, protein maintenance and synthesis, cell growth, migration and proliferation, and cell glycolysis, while SMEAF successfully suppressed markers related to skin inflammation, collagen degradation, and cell apoptosis. Thus, in summary, our research not only provided a deeper insight into the molecular changes within irradiated keratinocytes, but also serves as a model platform for future cosmetic research to build upon. Subsequently, both SMHF and SMEAF also displayed potential photoprotective properties that warrant further fractionation and in vivo clinical trials to investigate and obtain potential novel bioactive compounds against photoaging.

Annexin A1 Released in Extracellular Vesicles by Pancreatic Cancer Cells Activates Components of the Tumor Microenvironment, through Interaction with the Formyl-Peptide Receptors

Pancreatic cancer (PC) is one of the most aggressive cancers in the world. Several extracellular factors are involved in its development and metastasis to distant organs. In PC, the protein Annexin A1 (ANXA1) appears to be overexpressed and may be identified as an oncogenic factor, also because it is a component in tumor-deriving extracellular vesicles (EVs). Indeed, these microvesicles are known to nourish the tumor microenvironment. Once we evaluated the autocrine role of ANXA1-containing EVs on PC MIA PaCa-2 cells and their pro-angiogenic action, we investigated the ANXA1 paracrine effect on stromal cells like fibroblasts and endothelial ones. Concerning the analysis of fibroblasts, cell migration/invasion, cytoskeleton remodeling, and the different expression of specific protein markers, all features of the cell switching into myofibroblasts, were assessed after administration of wild type more than ANXA1 Knock-Out EVs. Interestingly, we demonstrated a mechanism by which the ANXA1-EVs complex can stimulate the activation of formyl peptide receptors (FPRs), triggering mesenchymal switches and cell motility on both fibroblasts and endothelial cells. Therefore, we highlighted the importance of ANXA1/EVs-FPR axes in PC progression as a vehicle of intercommunication tumor cells-stroma, suggesting a specific potential prognostic/diagnostic role of ANXA1, whether in soluble form or even if EVs are captured in PC.

Biological and physical approaches on the role of piplartine (piperlongumine) in cancer

Chronic inflammation provides a favorable microenvironment for tumorigenesis, which opens opportunities for targeting cancer development and progression. Piplartine (PL) is a biologically active alkaloid from long peppers that exhibits anti-inflammatory and antitumor activity. In the present study, we investigated the physical and chemical interactions of PL with anti-inflammatory compounds and their effects on cell proliferation and migration and on the gene expression of inflammatory mediators. Molecular docking data and physicochemical analysis suggested that PL shows potential interactions with a peptide of annexin A1 (ANXA1), an endogenous anti-inflammatory mediator with therapeutic potential in cancer. Treatment of neoplastic cells with PL alone or with annexin A1 mimic peptide reduced cell proliferation and viability and modulated the expression of MCP-1 chemokine, IL-8 cytokine and genes involved in inflammatory processes. The results also suggested an inhibitory effect of PL on tubulin expression. In addition, PL apparently had no influence on cell migration and invasion at the concentration tested. Considering the role of inflammation in the context of promoting tumor initiation, the present study shows the potential of piplartine as a therapeutic immunomodulator for cancer prevention and progression.

Annexin A1-derived peptide Ac2-26 facilitates wound healing in diabetic mice

Impaired wound healing is a common complication of diabetes. In diabetic wounds, macrophages present dysfunctional efferocytosis and abnormal phenotypes, which could result in excessive neutrophil accumulation and prolonged inflammation, thereby eventually hindering wound repair. ANXA1 N-terminal peptide Ac2-26 exhibits a high potential in mitigating inflammation and improving repair; however, its efficacy in diabetic wound repair remains unclear. In this study, a cutaneous excisional wound model was built in genetically diabetic mice. Ac2-26 or a vehicle solution was employed locally in wound sites. Subsequently, wound zones were measured and sampled at different time intervals post-wounding. Using hematoxylin-eosin and Masson's trichrome staining, we observed the histopathological variations and collagen deposition in wound samples. Based on immunohistochemistry and immunofluorescence, the numbers of neutrophils, macrophages, and CD206-positive macrophages in the wound samples were determined. Cytokine expression in wound samples was studied by immunoblot assay. Results showed that Ac2-26 treatment could facilitate diabetic wound closure, down-regulate the number of neutrophils, and improve angiogenesis and collagen deposition. In addition, Ac2-26 application expedited macrophage recruitment and up-regulated the percentage of macrophages expressing CD206, which is a marker for M2 macrophages. Moreover, Ac2-26 inhibited the expressions of TNF-α and IL-6 and up-regulated the expressions of IL-10, TGF-β, and VEGFA during diabetic wound healing. Hence, based on the aforementioned findings, Ac2-26 application in diabetic wounds could exert anti-inflammatory and pro-repair effects by reducing neutrophil accumulation and facilitating M2 macrophage development.

Annexin A1 Contained in Extracellular Vesicles Promotes the Activation of Keratinocytes by Mesoglycan Effects: An Autocrine Loop Through FPRs

We have recently demonstrated that mesoglycan, a fibrinolytic compound, may be a promising pro-healing drug for skin wound repair. We showed that mesoglycan induces migration, invasion, early differentiation, and translocation to the membrane of keratinocytes, as well as the secretion of annexin A1 (ANXA1), further involved in keratinocytes activation. These events are triggered by the syndecan-4 (SDC4)/PKCα pathway. SDC4 also participates to the formation and secretion of microvesicles (EVs) which may contribute to wound healing. EVs were isolated from HaCaT cells, as human immortalized keratinocytes, and then characterised by Western blotting, Field Emission-Scanning Electron Microscopy, and Dynamic Light Scattering. Their autocrine effects were investigated by Wound-Healing/invasion assays and confocal microscopy to analyse cell motility and differentiation, respectively. Here, we found that the mesoglycan increased the release of EVs which amplify its same effects. ANXA1 contained in the microvesicles is able to promote keratinocytes motility and differentiation by acting on Formyl Peptide Receptors (FPRs). Thus, the extracellular form of ANXA1 may be considered as a link to intensify the effects of mesoglycan. In this study, for the first time, we have identified an interesting autocrine loop ANXA1/EVs/FPRs in human keratinocytes, induced by mesoglycan.

Annexin A12-26 Treatment Improves Skin Heterologous Transplantation by Modulating Inflammation and Angiogenesis Processes

Skin graft successful depends on reduction of local inflammation evoked by the surgical lesion and efficient neovascularization to nutrition the graft. It has been shown that N-terminal portion of the Annexin A1 protein (AnxA1) with its anti-inflammatory properties induces epithelial mucosa repair and presents potential therapeutic approaches. The role of AnxA1 on wound healing has not been explored and we investigated in this study the effect of the peptide Ac2-26 (N-terminal AnxA1 peptide Ac2-26; AnxA1_2-26) on heterologous skin scaffolds transplantation in BALB/c mice, focusing on inflammation and angiogenesis. Treatment with AnxA1_2-26, once a day, from day 3-60 after scaffold implantation improved the take of the implant, induced vessels formation, enhanced gene and protein levels of the vascular growth factor-A (VEGF-A) and fibroblast influx into allograft tissue. It also decreased pro- while increasing anti-inflammatory cytokines. The pro-angiogenic activity of AnxA1_2-26 was corroborated by topical application of AnxA1_2-26 on the subcutaneous tissue of mice. Moreover, treatment of human umbilical endothelial cells (HUVECs) with AnxA1_2-26 improved proliferation, shortened cycle, increased migration and actin polymerization similarly to those evoked by VEGF-A. The peptide treatment instead only potentiated the tube formation induced by VEGF-A. Collectively, our data showed that AnxA1_2-26 treatment favors the tissue regeneration after skin grafting by avoiding exacerbated inflammation and improving the angiogenesis process.

Annexin A1 in plasma from patients with bronchial asthma: its association with lung function

BACKGROUND

Annexin-A1 (ANXA1) is a glucocorticoid-induced protein with multiple actions in the regulation of inflammatory cell activation. The anti-inflammatory protein ANXA1 and its N-formyl peptide receptor 2 (FPR2) have protective effects on organ fibrosis. However, the exact role of ANXA1 in asthma remains to be determined. The aim of this study was to identify the role of ANXA1 in bronchial asthma.

METHODS

In mice sensitized and challenged with ovalbumin (OVA-OVA mice) and mice sensitized with saline and challenged with air (control mice), we investigated the potential links between ANXA1 levels and bronchial asthma using ELISA, immunoblotting, and immunohistochemical staining. Moreover, we also determined ANXA1 levels in blood from 50 asthmatic patients (stable and exacerbated states).

RESULTS

ANXA1 protein levels in lung tissue and bronchoalveolar lavage fluid were significantly higher in OVA-OVA mice compared with control mice. FPR2 protein levels in lung tissue were significantly higher in OVA-OVA mice compared with control mice. Plasma ANXA1 levels were increased in asthmatic patients compared with healthy controls. Plasma ANXA1 levels were significantly lower in exacerbated patients compared with stable patients with bronchial asthma (p < 0.05). The plasma ANXA1 levels in controlled asthmatic patients were correlated with forced expiratory volume in 1 s (FEV₁) (r = - 0.191, p = 0.033) and FEV₁/forced vital capacity (FVC) (r = -0.202, p = 0.024).

CONCLUSION

These results suggest that ANXA1 may be a potential marker and therapeutic target for asthma.

HMGB1 induces lung fibroblast to myofibroblast differentiation through NF‑κB‑mediated TGF‑β1 release

The proinflammatory factor high-mobility group box protein 1 (HMGB1) has been implicated in the pathogenesis of lung fibrosis; however, the role of HMGB1 in lung fibrosis remains unclear. It has previously been reported that nuclear factor (NF)-κB and transforming growth factor (TGF)-β1 may be involved in lung fibrosis. Therefore, the present study aimed to examine the potential molecular mechanisms that underlie HMGB1-induced lung fibrosis via the regulation of NF-κB and TGF-β1. The results demonstrated that HMGB1 stimulation increased the activation of NF-κB and the release of TGF-β1, as well as the expression of α-smooth muscle actin (α-SMA) and collagen I in human lung fibroblasts in vitro. In addition, inhibition of NF-κB activation blocked HMGB1-induced TGF-β1 release, as well as α-SMA and collagen I expression in lung fibroblasts. Preventing the release of TGF-β1 inhibited HMGB1-induced α-SMA and collagen I expression; however, it had no effect on NF-κB activation. Collectively, these findings indicate that HMGB1 induces fibroblast to myofibroblast differentiation of lung fibroblasts via NF-κB-mediated TGF-β1 release.

Heterogeneity of mast cells and expression of Annexin A1 protein in a second degree burn model with silver sulfadiazine treatment

Mast cells (MCs) participate in all stages of skin healing and one of their mediators is the Annexin A1 protein (AnxA1), linked to inflammation, proliferation, migration and apoptosis processes, but not studied in thermal burns yet. Therefore, our objectives were to evaluate the behavior of MCs and AnxA1 in a second degree burn model, treated or not with silver sulfadiazine 1% (SDP 1%) and associated to macrophages quantification and cytokines dosages. MCs counts showed few cells in the early stages of repair but increased MCs in the final phases in the untreated group. The normal skin presented numerous tryptase-positive MCs that were reduced after burning in all analyzed periods. Differently, few chymase-positive MCs were observed in the early stages of healing, however, increased chymase-positive MCs were found at the final phase in the untreated group. MCs also showed high immunoreactivity for AnxA1 on day 3 in both groups. In the tissue there was a strong protein expression in the early stages of healing, but in the final phases only in the SDP treated animals. TNF-α, IL-1β, IL-6, IL-10 and MCP-1 levels and macrophages quantification were increased in inflammation and reepithelialization phases. Reduced IL-1β, IL-6 and IL-10 levels and numerous macrophages occurred in the treated animals during tissue repair. Our results indicate modulation in the profile of MCs and AnxA1expression during healing by the treatment with SDP 1%, pointing them as targets for therapeutic interventions on skin burns.

Annexin A1 influences in breast cancer: Controversies on contributions to tumour, host and immunoediting processes

Annexin A1 is a multifunctional protein characterised by its actions in modulating the innate and adaptive immune response. Accumulating evidence of altered annexin A1 expression in many human tumours raises interest in its functional role in cancer biology. In breast cancer, altered annexin A1 expression levels suggest a potential influence on tumorigenic and metastatic processes. However, reports of conflicting results reveal a relationship that is much more complex than first conceptualised. In this review, we explore the diverse actions of annexin A1 on breast tumour cells and various host cell types, including stromal immune and structural cells, particularly in the context of cancer immunoediting.

Hypoxia regulates ANXA1 expression to support prostate cancer cell invasion and aggressiveness

Annexin A1 (ANXA1) is a Ca²⁺-binding protein overexpressed in the invasive stages of prostate cancer (PCa) development; however, its role in this tumor metastatization is largely unknown. Moreover, hypoxic conditions in solid tumors have been related to poor prognosis in PCa patients. We have previously demonstrated that ANXA1 is implicated in the acquisition of chemo-resistant features in DU145 PCa cells conferring them a mesenchymal/metastatic phenotype. In this study, we have investigated the mechanisms by which ANXA1 regulates metastatic behavior in LNCaP, DU145 and PC3 cells exposed to hypoxia. ANXA1 was differentially expressed by PCa cell lines in normoxia whereas hypoxic stimuli resulted in a significant increase of protein expression. Additionally, in low oxygen conditions ANXA1 was extensively secreted out-side the cells where its binding to formyl peptide receptors (FPRs) induced cell invasion. Loss and gain of function experiments performed by using the RNA interfering siANXA1 and an ANXA1 over-expressing plasmid (MF-ANXA1), also confirmed the leading role of the protein in modulating LNCaP, DU145 and PC3 cell invasiveness. Finally, ANXA1 played a crucial role in the regulation of cytoskeletal dynamics underlying metastatization process, such as the loss of adhesion molecules and the occurrence of the epithelial to mesenchymal transition (EMT). ANXA1 expression increased inversely to epithelial markers such as E-cadherin and cytokeratins 8 and 18 (CKs) and proportionally to mesenchymal ones such as vimentin, ezrin and moesin. Our results indicated that ANXA1 may be a key mediator of hypoxia-related metastasis-associated processes in PCa.

Annexin A1 is involved in the acquisition and maintenance of a stem cell-like/aggressive phenotype in prostate cancer cells with acquired resistance to zoledronic acid

In this study, we have characterized the role of annexin A1 (ANXA1) in the acquisition and maintenance of stem-like/aggressive features in prostate cancer (PCa) cells comparing zoledronic acid (ZA)-resistant DU145R80 with their parental DU145 cells. ANXA1 is over-expressed in DU145R80 cells and its down-regulation abolishes their resistance to ZA. Moreover, ANXA1 induces DU145 and DU145R80 invasiveness acting through formyl peptide receptors (FPRs). Also, ANXA1 knockdown is able to inhibit epithelial to mesenchymal transition (EMT) and to reduce focal adhesion kinase (FAK) and metalloproteases (MMP)-2/9 expression in PCa cells. DU145R80 show a cancer stem cell (CSC)-like signature with a high expression of CSC markers including CD44, CD133, NANOG, Snail, Oct4 and ALDH7A1 and CSC-related genes as STAT3. Interestingly, ANXA1 knockdown induces these cells to revert from a putative prostate CSC to a more differentiated phenotype resembling DU145 PCa cell signature. Similar results are obtained concerning some drug resistance-related genes such as ATP Binding Cassette G2 (ABCG2) and Lung Resistant Protein (LRP). Our study provides new insights on the role of ANXA1 protein in PCa onset and progression.

Annexin A1 contributes to pancreatic cancer cell phenotype, behaviour and metastatic potential independently of Formyl Peptide Receptor pathway

Annexin A1 (ANXA1) is a Ca(2+)-binding protein over-expressed in pancreatic cancer (PC). We recently reported that extracellular ANXA1 mediates PC cell motility acting on Formyl Peptide Receptors (FPRs). Here, we describe other mechanisms by which intracellular ANXA1 could mediate PC progression. We obtained ANXA1 Knock-Out (KO) MIA PaCa-2 cells using the CRISPR/Cas9 genome editing technology. LC-MS/MS analysis showed altered expression of several proteins involved in cytoskeletal organization. As a result, ANXA1 KO MIA PaCa-2 partially lost their migratory and invasive capabilities with a mechanism that appeared independent of FPRs. The acquisition of a less aggressive phenotype has been further investigated in vivo. Wild type (WT), PGS (scrambled) and ANXA1 KO MIA PaCa-2 cells were engrafted orthotopically in SCID mice. No differences were found about PC primary mass, conversely liver metastatization appeared particularly reduced in ANXA1 KO MIA PaCa-2 engrafted mice. In summary, we show that intracellular ANXA1 is able to preserve the cytoskeleton integrity and to maintain a malignant phenotype in vitro. The protein has a relevant role in the metastatization process in vivo, as such it appears attractive and suitable as prognostic and therapeutic marker in PC progression.

Formylpeptide Receptors Promote the Migration and Differentiation of Rat Neural Stem Cells

Neural stem cells (NSCs) bear characteristics for proliferation, migration and differentiation into three main neural cell type(s): neurons, astrocytes and/or oligodendrocytes. Formylpeptide receptors (Fprs), belonging to the family of G protein-coupled chemoattractant receptors, have been detected on neurons in the central nervous system (CNS). Here, we report that Fpr1 and Fpr2 are expressed on NSCs as detected with immunohistochemistry, RT-PCR and WB assays. In addition, Fpr1 and Fpr2 promoted NSC migration through F-actin polymerization and skewed NSC differentiation to neurons. Our study demonstrates a unique role of Fpr1 and Fpr2 in NSCs and opens a novel window for cell replacement therapies for brain and spinal cord injury.

Differential Expression of Proteins Associated with the Hair Follicle Cycle - Proteomics and Bioinformatics Analyses

Hair follicle cycling can be divided into the following three stages: anagen, catagen, and telogen. The molecular signals that orchestrate the follicular transition between phases are still unknown. To better understand the detailed protein networks controlling this process, proteomics and bioinformatics analyses were performed to construct comparative protein profiles of mouse skin at specific time points (0, 8, and 20 days). Ninety-five differentially expressed protein spots were identified by MALDI-TOF/TOF as 44 proteins, which were found to change during hair follicle cycle transition. Proteomics analysis revealed that these changes in protein expression are involved in Ca2+-regulated biological processes, migration, and regulation of signal transduction, among other processes. Subsequently, three proteins were selected to validate the reliability of expression patterns using western blotting. Cluster analysis revealed three expression patterns, and each pattern correlated with specific cell processes that occur during the hair cycle. Furthermore, bioinformatics analysis indicated that the differentially expressed proteins impacted multiple biological networks, after which detailed functional analyses were performed. Taken together, the above data may provide insight into the three stages of mouse hair follicle morphogenesis and provide a solid basis for potential therapeutic molecular targets for this hair disease.

Activation of annexin A1 signalling in renal fibroblasts exerts antifibrotic effects

AIM

The anti-inflammatory protein annexin A1 (AnxA1) and its formyl peptide receptor 2 (FPR2) have protective effects in organ fibrosis. Their role in chronic kidney disease (CKD) has not yet been elucidated. Our aim was to characterize the AnxA1/FPR2 system in models of renal fibrosis.

METHODS

Rats were treated with angiotensin receptor antagonist during the nephrogenic period (ARAnp) to induce late-onset hypertensive nephropathy and fibrosis. Localization and regulation of AnxA1 and FPR2 were studied by quantitative real-time PCR and double labelling immunofluorescence. Biological effects of AnxA1 were studied in cultured renal fibroblasts from AnxA1(-/-) and wild-type mice.

RESULTS

Angiotensin receptor antagonist during the nephrogenic period kidneys displayed matrix foci containing CD73(+) fibroblasts, alpha-smooth muscle actin (a-SMA)(+) myofibroblasts and CD68(+) macrophages. TGF-β and AnxA1 mRNAs were ~threefold higher than in controls. AnxA1 was localized to macrophages and fibroblasts; myofibroblasts were negative. FPR2 was localized to fibroblasts, myofibroblasts, macrophages and endothelial cells. AnxA1 and FPR2 immunoreactive signals were increased in the foci, with fibroblasts and macrophages expressing both proteins. AnxA1(-/-) fibroblasts revealed higher α-SMA (sevenfold) and collagen 1A1 (Col1A1; 144-fold) mRNA levels than controls. Treatment of murine WT fibroblasts with TGF-β (22.5 ng mL 24 h(-1)) increased mRNA levels of α-SMA (9.3-fold) and Col1A1 (fourfold). These increases were greatly attenuated upon overexpression of AnxA1 (1.5- and 1.7-fold, respectively; P < 0.05). Human fibroblasts reacted similarly when receiving the FPR2 inhibitor WRW4.

CONCLUSION

Our results demonstrate that AnxA1 and FPR2 are abundantly expressed in the renal interstitium and modulate fibroblast phenotype and extracellular matrix synthesis activity.

Role of intracellular and extracellular annexin A1 in migration and invasion of human pancreatic carcinoma cells

BACKGROUND

Annexin A1 (ANXA1), a 37 kDa multifunctional protein, is over-expressed in tissues from patients of pancreatic carcinoma (PC) where the protein seems to be associated with malignant transformation and poor prognosis.

METHODS

The expression and localization of ANXA1 in MIA PaCa-2, PANC-1, BxPC-3 and CAPAN-2 cells were detected by Western Blotting and Immunofluorescence assay. Expression and activation of Formyl Peptide Receptors (FPRs) were shown through flow cytometry/PCR and FURA assay, respectively. To investigate the role of ANXA1 in PC cell migration and invasion, we performed in vitro wound-healing and matrigel invasion assays.

RESULTS

In all the analyzed PC cell lines, a huge expression and a variable localization of ANXA1 in sub-cellular compartments were observed. We confirmed the less aggressive phenotype of BxPC-3 and CAPAN-2 compared with PANC-1 and MIA PaCa-2 cells, through the evaluation of Epithelial-Mesenchymal Transition (EMT) markers. Then, we tested MIA PaCa-2 and PANC-1 cell migration and invasiveness rate which was inhibited by specific ANXA1 siRNAs. Both the cell lines expressed FPR-1 and -2. Ac2-26, an ANXA1 mimetic peptide, induced intracellular calcium release, consistent with FPR activation, and significantly increased cell migration/invasion rate. Interestingly, in MIA PaCa-2 cells we found a cleaved form of ANXA1 (33 kDa) that localizes at cellular membranes and is secreted outside the cells, as confirmed by MS analysis. The importance of the secreted form of ANXA1 in cellular motility was confirmed by the administration of ANXA1 blocking antibody that inhibited migration and invasion rate in MIA PaCa-2 but not in PANC-1 cells that lack the 33 kDa ANXA1 form and show a lower degree of invasiveness. Finally, the treatment of PANC-1 cells with MIA PaCa-2 supernatants significantly increased the migration rate of these cells.

CONCLUSION

This study provides new insights on the role of ANXA1 protein in PC progression. Our findings suggest that ANXA1 protein could regulate metastasis by favouring cell migration/invasion intracellularly, as cytoskeleton remodelling factor, and extracellularly like FPR ligand.

Inflammation and cancer: role of annexin A1 and FPR2/ALX in proliferation and metastasis in human laryngeal squamous cell carcinoma

The anti-inflammatory protein annexin A1 (ANXA1) has been associated with cancer progression and metastasis, suggesting its role in regulating tumor cell proliferation. We investigated the mechanism of ANXA1 interaction with formylated peptide receptor 2 (FPR2/ALX) in control, peritumoral and tumor larynx tissue samples from 20 patients, to quantitate the neutrophils and mast cells, and to evaluate the protein expression and co-localization of ANXA1/FPR2 in these inflammatory cells and laryngeal squamous cells by immunocytochemistry. In addition, we performed in vitro experiments to further investigate the functional role of ANXA1/FPR2 in the proliferation and metastasis of Hep-2 cells, a cell line from larynx epidermoid carcinoma, after treatment with ANXA1_2–26 (annexin A1 N-terminal-derived peptide), Boc2 (antagonist of FPR) and/or dexamethasone. Under these treatments, the level of Hep-2 cell proliferation, pro-inflammatory cytokines, ANXA1/FPR2 co-localization, and the prostaglandin signalling were analyzed using ELISA, immunocytochemistry and real-time PCR. An influx of neutrophils and degranulated mast cells was detected in tumor samples. In these inflammatory cells of peritumoral and tumor samples, ANXA1/FPR2 expression was markedly exacerbated, however, in laryngeal carcinoma cells, this expression was down-regulated. ANXA1_2–26 treatment reduced the proliferation of the Hep-2 cells, an effect that was blocked by Boc2, and up-regulated ANXA1/FPR2 expression. ANXA1_2–26 treatment also reduced the levels of pro-inflammatory cytokines and affected the expression of metalloproteinases and EP receptors, which are involved in the prostaglandin signalling. Overall, this study identified potential roles for the molecular mechanism of the ANXA1/FPR2 interaction in laryngeal cancer, including its relationship with the prostaglandin pathway, providing promising starting points for future research. ANXA1 may contribute to the regulation of tumor growth and metastasis through paracrine mechanisms that are mediated by FPR2/ALX. These data may lead to new biological targets for therapeutic intervention in human laryngeal cancer.