Apelin-13 Increases Functional Connexin-43 through Autophagy Inhibition via AKT/mTOR Pathway in the Non-Myocytic Cell Population of the Heart

Studies have shown a link between the downregulation of connexin 43 (Cx43), the predominant isoform in cardiac gap junctions, and high susceptibility to cardiac arrhythmias and cardiomyocyte death. Non-myocytic cells (NMCs), the most abundant component of the heart, exert multiple cardiac functions and represent an important therapeutic target for diseased cardiac tissue. A few studies have investigated the effect of Apelin-13, an endogenous peptide with a key role in various cardiovascular functions, on Cx43 expression in cardiomyocytes. However, it remained unknown whether Apelin-13 influences Cx43 expression in NMCs. Here, we found that in NMCs, Cx43 protein expression increased after Apelin-13 treatment (100 nM for 48 h). Furthermore, dye transfer assays proved that Apelin-13-treated NMCs had a greater ability to communicate with surrounding cardiomyocytes, and this effect was abrogated by carbenoxolone, a gap junction inhibitor. Interestingly, we showed that Apelin-13 increased Cx43 through autophagy inhibition, as proved by the upregulation of p62 and LC3I, acting as 3-MA, a well-known autophagy inhibitor. In addition, Apelin-13-induced AKT and mTOR phosphorylation was abolished by LY294002 and rapamycin inhibitors resulting in Cx43 increased suppression. These results open the possibility of targeting gap junctions in NMCs with Apelin-13 as an exciting therapeutic approach with great potential

Targeting cancer cells overexpressing folate receptors with new terpolymer-based nanocapsules: Toward a novel targeted dna delivery system for cancer therapy

Chemotherapeutics represent the standard treatment for a wide range of cancers. However, these agents also affect healthy cells, thus leading to severe off-target effects. Given the non-selectivity of the commonly used drugs, any increase in the selective tumor tissue uptake would represent a significant improvement in cancer therapy. Recently, the use of gene therapy to completely remove the lesion and avoid the toxicity of chemotherapeutics has become a tendency in oncotherapy. Ideally, the genetic material must be safely transferred from the site of administration to the target cells, without involving healthy tissues. This can be achieved by encapsulating genes into non-viral carriers and modifying their surface with ligands with high selectivity and affinity for a relevant receptor on the target cells. Hence, in this work we evaluate the use of terpolymer-based nanocapsules for the targeted delivery of DNA toward cancer cells. The surface of the nanocapsules is decorated with folic acid to actively target the folate receptors overexpressed on a variety of cancer cells. The nanocapsules demonstrate a good ability of encapsulating and releasing DNA. Moreover, the presence of the targeting moieties on the surface of the nanocapsules favors cell uptake, opening up the possibility of more effective therapies

Bioactive materials: In vitro investigation of different mechanisms of hydroxyapatite precipitation

Abstract Bioactive materials, able to induce hydroxyapatite precipitation in contact with body fluids, are of great interest for their bone bonding capacity. . The aim of this paper is to compare bioactive materials with different surface features to verify the mechanisms of action and the relationship with kinetics and type of precipitated hydroxyapatite over time. Four different surface treatments for Ti/Ti6Al4V alloy and a bioactive glass were selected and a different mechanism of bioactivity is supposed for each of them. Apart from the conventional techniques (FESEM, XPS and EDX), less common characterizations (zeta potential measurements on solid surfaces and FTIR chemical imaging) were applied. The results suggest that the OH groups on the surface have several effects: the total number of the OH groups mainly affects hydrophilicity of surfaces, while the isoelectric points, surface charge and ions attraction mainly depend on OH acidic/basic strength. Kinetics of hydroxyapatite precipitation is faster when it involves a mechanism of ion exchange while it is slower when it is due to electrostatic effects . The electrostatic effect cooperates with ion exchange and it speeds up kinetics of hydroxyapatite precipitation. Different bioactive surfaces are able to differently induce precipitation of type A and B of hydroxyapatite, as well as different degrees of crystallinity and carbonation. Statement of significance The bone is made of a ceramic phase (a specific type of hydroxyapatite), a network of collagen fibers and the biological tissue. A strong bond of an orthopedic or dental implant with the bone is achieved by bioactive materials where precipitation and growth of hydroxyapatite occurs on the implant surface starting from the ions in the physiological fluids. Several bioactive materials are already known and used, but their mechanism of action is not completely known and the type of precipitated hydroxyapatite not fully investigated. In this work, bioactive titanium and bioglass surfaces are compared through conventional and innovative methodologies. Different mechanisms of bioactivity are identified, with different kinetics and the materials are able to induce precipitation of different types of hydroxyapatite, with different degree of crystallinity and carbonation

The mechanical and chemical stability of the interfaces in bioactive materials: The substrate-bioactive surface layer and hydroxyapatite-bioactive surface layer interfaces

Abstract Bioactive materials should maintain their properties during implantation and for long time in contact with physiological fluids and tissues. In the present research, five different bioactive materials (a bioactive glass and four different chemically treated bioactive titanium surfaces) have been studied and compared in terms of mechanical stability of the surface bioactive layer-substrate interface, their long term bioactivity, the type of hydroxyapatite matured and the stability of the hydroxyapatite-surface bioactive layer interface. Numerous physical and chemical analyses (such as Raman spectroscopy, macro and micro scratch tests, soaking in SBF, Field Emission Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy (SEM-EDS), zeta potential measurements and Fourier Transformed Infra-Red spectroscopy (FTIR) with chemical imaging) were used. Scratch measurements evidenced differences among the metallic surfaces concerning the mechanical stability of the surface bioactive layer-substrate interface. All the surfaces, despite of different kinetics of bioactivity, are covered by a bone like carbonate-hydroxyapatite with B-type substitution after 28 days of soaking in SBF. However, the stability of the apatite layer is not the same for all the materials: dissolution occurs at pH around 4 (close to inflammation condition) in a more pronounced way for the surfaces with faster bioactivity together with detachment of the surface bioactive layer. A protocol of characterization is here suggested to predict the implant-bone interface stability

Crustal wedging triggering recent deformation in the Andean thrust front between 31°S and 33°S: Sierras Pampeanas-Precordillera interaction

We document a new model of crustal structure of the Andean front in Argentina where numerous historic earthquakes destroyed the cities of Mendoza in 1861 (M[subscript s] = ~7) and San Juan in 1944 (M[subscript w] = 7.0). The Cerro Salinas anticline is formed above the west directed Cerro Salinas thrust. An east facing monocline with an amplitude of about 2 km folds the Cerro Salinas thrust and overlying Neogene succession. This monocline is formed above a blind crustal thrust in the basement. Its dip of 14° west is inferred from fold geometry. This thick-skinned east directed blind thrust and the thin-skinned west directed Cerro Salinas thrust define a tectonic wedge; the wedge tip occurs at a depth of 5.4 km. Growth of the monocline after ~8.5 Ma is revealed on multichannel seismic (MSC) profile 31017 (Repsol-YPF). Rates of Cerro Salinas thrust displacement are of the order of 1 mm/yr, whereas vertical uplift of ~0.45 mm/yr results from the combined displacement on the Cerro Salinas thrust and growth of east facing monocline. The lateral extent of the east directed crustal blind ramp corresponds with the along-strike extent of the Eastern Precordillera. When combined with the low displacement rate, a long earthquake recurrence interval is implied. Smaller magnitude earthquakes, however, indicate that segments of the blind thrust ramps ruptured in historic events. If all the segments of the blind thrust ruptured together the fault area is ~7000 km² and could produce a M[subscript w] ~ 7.7 earthquake. The crustal wedge model provides new constraints on the origin and potential size of earthquakes that threaten the densely populated region.Keywords: tectonic structure, seismogenic implications, growth strata, AndesKeywords: tectonic structure, seismogenic implications, growth strata, Ande

Cretaceous intraplate contraction in Southern Patagonia: A far-field response to changing subduction dynamics?

The origin, extent, and timing of intraplate contraction in Patagonia are among the least understood geological processes of southern South America. Particularly, the intraplate Deseado fold-thrust belt (FTB), located in the Patagonian broken foreland (47°–48°300 S), is one of the most enigmatic areas. In this belt, time constraints on tectonic events are limited and synorogenic deposits have not been documented so far. Furthermore, the driving mechanism for intraplate contraction remains unknown. In this study, we carried out a structural and sedimentological analysis. We report the first syntectonic deposits in this area in the Baqueró (Aptian) and Chubut (Cenomanian/Campanian) groups and a newly found unit referred to as the Albian beds (109.9 ± 1.5 Ma). Thus, several contractional stages in late Aptian, Albian, and Cenomanian-Campanian are then inferred. We suggest that the Deseado FTB constituted the southernmost expression of the early Patagonian broken foreland in Cretaceous times. Additionally, we analyzed the spatiotemporal magmatic arc behavior as a proxy of dynamic changes in the Andean subduction during determined stages of intraplate contraction. We observe a significant arc broadening from ~121 to 82 Myr and magmatic quiescence after ~67 Ma. This is interpreted as a slab shallowing to flattening process. Far-field tectonic forces would have been produced by increased plate coupling linked to the slab flattening as indirectly indicated by the correlation between Cretaceous arc expansion and intraplate contraction. Finally, the tectonic evolution of the Deseado FTB favors studies supporting inception of Andean shortening since Cretaceous times.Fil: Gianni, Guido Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Geofísico Sismológico Volponi; ArgentinaFil: Navarrete Granzotto, César Rodrigo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Liendo, Ingrid Florencia. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Díaz, Marianela Ximena Yasmin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Geología; ArgentinaFil: Gimenez, Mario Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto Geofísico Sismológico Volponi; ArgentinaFil: Encinas, Alfonso. Universidad de Concepción; ChileFil: Folguera Telichevsky, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas; Argentin

Role of image-guided fine-needle aspiration biopsy in the management of patients with splenic metastasis

BACKGROUND: Splenic metastases are very rare and are mostly diagnosed at the terminal phase of the disease or at the time of autopsy. The cytohistological diagnosis, when done, is made prevalently by splenectomy. Reports on splenic percutaneous biopsies in the diagnosis of splenic metastasis are fragmentary and very poor. The aims of this study are to analyse retrospectively the accuracy, safety and the clinical impact of ultrasound (US)-guided fine-needle aspiration biopsy (UG-FNAB) in patients with suspected splenic metastasis. METHODS: A retrospective analysis of 1800 percutaneous abdominal biopsies performed at our institute during the period from 1993 to 2003 was done and 160 patients that underwent splenic biopsy were found. Among these 160 patients, 12 cases with the final diagnosis of solitary splenic metastases were encountered and they form the basis of this report. The biopsies were performed under US guidance using a 22-gauge Chiba needle. All the patients underwent laboratory tests, CT examination of the abdomen and chest, US examination of abdomen and pelvis. RESULTS: There were 5 women and 7 men, median age 65 years (range 48–80). Eight patients had a known primary cancer at the time of the diagnosis of splenic metastasis: 3 had breast adenocarcinoma, 2 colon adenocarcinoma, 2 melanoma and 1 lung adenocarcinoma. Four patients were undiagnosed at the time of the appearance of splenic metastasis and subsequent investigations showed adenocarcinoma of the lung in 2 patients and colon adenocarcinoma in the remaining 2. There was a complete correspondence between the US and Computed Tomography (CT) in detecting focal lesions of the spleen. The splenic biopsies allowed a cytological diagnosis of splenic metastasis in all the 12 patients and changed clinical management in all cases. Reviewing the 160 patients that underwent UG-FNAB of the spleen we found no complications related to the biopsies. CONCLUSION: These results indicate that UG-FNAB is a successful technique for diagnosis of splenic metastasis allowing an adequate treatment of the affected patients