61 research outputs found
Crucial role of phospholamban phosphorylation and S-nitrosylation in the negative lusitropism induced by 17β-estradiol in the male rat heart.
Background/Aims: 17β-estradiol (17βE2) plays an important cardiovascular role by activating estrogen receptors (ER) α and ERβ. Previous studies demonstrated that the novel estrogen G protein-coupled receptor (GPR30/GPER) mediates estrogen action in different tissues. We have recently shown in the rat heart that 17βE2 elicits negative inotropism through ERα, ERβ and GPR30, by triggering activation of ERK1/2, phosphatidylinositol 3-kinase (PI3K), protein kinase A (PKA) and endothelial Nitric Oxide synthase (eNOS) signaling. Methods: In the present study, using the isolated and Langendorff-perfused rat heart as a model system we analyzed: i) whether and to which extent 17βE2 modifies mammalian ventricular myocardial relaxation (lusitropism); ii) the type of ERs and the signaling pathways involved in this effect. Results: We found that 17βE2 negatively modulated the ventricular lusitropic performance. This effect, which partially involved the vascular endothelium, recruited ERβ and occurred via PI3K, eNOS-NO-cGMP-protein kinase G (PKG) transduction cascade. Of note, 17βE2-mediated negative lusitropism associated with a modification of phospholamban (PLN) phosphorylation and S-nitrosylation (SNO) both in isolated Langendorff rat heart and in isolated cardiomyocytes. Conclusion: Taken together, our results allow including 17βE2 to the family of substances that control ventricular relaxation. This is of relevance in relation not only to the normal endocrine control of cardiac function, but also to physio-pathologic conditions characterized by an altered ventricular diastolic performance
Self-Assembling Peptide-Based Magnetogels for the Removal of Heavy Metals from Water
In this study, we present the synthesis of a novel peptide-based magnetogel obtained through the encapsulation of ?-Fe2O3-polyacrylic acid (PAA) nanoparticles (?-Fe(2)O(3)NPs) into a hydrogel matrix, used for enhancing the ability of the hydrogel to remove Cr(III), Co(II), and Ni(II) pollutants from water. Fmoc-Phe (Fluorenylmethoxycarbonyl-Phenylalanine) and diphenylalanine (Phe(2)) were used as starting reagents for the hydrogelator (Fmoc-Phe(3)) synthesis via an enzymatic method. The PAA-coated magnetic nanoparticles were synthesized in a separate step, using the co-precipitation method, and encapsulated into the peptide-based hydrogel. The resulting organic/inorganic hybrid system (?-Fe(2)O(3)NPs-peptide) was characterized with different techniques, including FT-IR, Raman, UV-Vis, DLS, ?-potential, XPS, FESEM-EDS, swelling ability tests, and rheology. Regarding the application in heavy metals removal from aqueous solutions, the behavior of the obtained magnetogel was compared to its precursors and the effect of the magnetic field was assessed. Four different systems were studied for the separation of heavy metal ions from aqueous solutions, including (1) ?-Fe(2)O(3)NPs stabilized with PAA, (?-Fe(2)O(3)NPs); (2) Fmoc-Phe(3) hydrogel (HG); (3) ?-Fe(2)O(3)NPs embedded in peptide magnetogel (?-Fe(2)O(3)NPs@HG); and (4) ?-Fe(2)O(3)NPs@HG in the presence of an external magnetic field. To quantify the removal efficiency of these four model systems, the UV-Vis technique was employed as a fast, cheap, and versatile method. The results demonstrate that both Fmoc-Phe(3) hydrogel and ?-Fe(2)O(3)NPs peptide magnetogel can efficiently remove all the tested pollutants from water. Interestingly, due to the presence of magnetic ?-Fe(2)O(3)NPs inside the hydrogel, the removal efficiency can be enhanced by applying an external magnetic field. The proposed magnetogel represents a smart multifunctional nanosystem with improved absorption efficiency and synergic effect upon applying an external magnetic field. These results are promising for potential environmental applications of ?-Fe(2)O(3)NPs-peptide magnetogels to the removal of pollutants from aqueous media
Chronic pain and spinal cord stimulation.
Chronic pain can have a devastating impact and lead to patient isolation. Many people with chronic pain are predisposed to anxiety-depressant symptoms, due to a lower quality life. The aim of the study is to demonstrate how neuromodulation methods, can encourage the reduction of chronic pain and an improvement in the quality of life, therefore advancing the restoration of psychological well-being.We involved 50 patients with a diagnosis of pain that not respond to traditional pharmacological therapies. Interventions: All subject had depression and anxiety symptoms and a low-quality life. We used the spinal cord stimulation treatment and a psychological evaluation for assessment of depression-anxiety symptomatology and the level of quality life.We observed a significant difference in physical functioning, role limitations due to physical health, general health perceptions, vitality, social functioning, role limitations due to emotional problems and mental health.Our study affirms that the perception of chronic pain has a great impact on the perception of psychological well-being, quality of life, and the performance of normal daily social and professional activities
Quercetin derivatives as novel antihypertensive agents: Synthesis and physiological characterization
The antihypertensive flavonol quercetin (Q1) is endowedwith a cardioprotective effect againstmyocardial ischemic
damage. Q1 inhibits angiotensin converting enzymeactivity, improves vascular relaxation, and decreases oxidative
stress and gene expression. However, the clinical application of this flavonol is limited by its poor
bioavailability and low stability in aqueous medium.
In the aimto overcome these drawbacks and preserve the cardioprotective effects of quercetin, the present study
reports on the preparation of five different Q1 analogs, in which all OH groups were replaced by hydrophobic
functional moieties.
Q1 derivatives have been synthesized by optimizing previously reported procedures and analyzed by spectroscopic
analysis. The cardiovascular properties of the obtained compounds were also investigated in order to evaluate
whether chemical modification affects their biological efficacy. The interaction with β-adrenergic receptors
was evaluated by molecular docking and the cardiovascular efficacy was investigated on the ex vivo Langendorff
perfused rat heart. Furthermore, the bioavailability and the antihypertensive properties of the most active derivative
were evaluated by in vitro studies and in vivo administration (1month) on spontaneously hypertensive rats
(SHRs), respectively.
Among all studied Q1 derivatives, only the ethyl derivative reduced left ventricular pressure (at
10−8M÷10−6Mdoses) and improved relaxation and coronary dilation. NOSs inhibition by L-NAME abolished
inotropism, lusitropism and coronary effects. Chronic administration of high doses of this compound on SHR reduced
systolic and diastolic pressure. Differently, the acetyl derivative induced negative inotropism and
lusitropism (at 10−10M and 10−8 ÷ 10−6 M doses), without affecting coronary pressure. Accordingly, docking
studies suggested that these compounds bind both β1/β2-adrenergic receptors.
Taking into consideration all the obtained results, the replacement of OHwith ethyl groups seems to improve Q1
bioavailability and stability; therefore, the ethyl derivative could represent a good candidate for clinical use in
hypertension
HSP90 and eNOS partially co-localize and change cellular localization in relation to different ECM components in 2D and 3D cultures of adult rat cardiomyocytes.
Background information. Cultivation techniques promoting three-dimensional organization of mammalian cells are of increasing interest, since they confer key functionalities of the native ECM (extracellular matrix) with a power for regenerative medicine applications. Since ECM compliance influences a number of cell functions, Matrigel-based gels have become attractive tools, because of the ease with which their mechanical properties can be controlled. In the present study, we took advantage of the chemical and mechanical tunability of commonly used cell culture substrates, and co-cultures to evaluate, on both two- and three-dimensional cultivated adult rat cardiomyocytes, the impact of ECM chemistry and mechanics on the cellular localization of two interacting signalling proteins: HSP90 (heat-shock protein of 90 kDa) and eNOS (endothelial nitric oxide synthase). Results. Freshly isolated rat cardiomyocytes were cultured on fibronectin, Matrigel gel or laminin, or in co-culture with cardiac fibroblasts, and tested for both integrity and viability. As validation criteria, integrity of both plasma membrane and mitochondria was evaluated by transmission electron microscopy. Cell sensitivity to microenvironmental stimuli was monitored by immunofluorescence and confocal microscopy. We found that HSP90 and eNOS expression and localization are affected by changes in ECM composition. Elaboration of the images revealed, on Matrigel-cultured cardiomyocytes, areas of high co-localization between HSP90 and eNOS and co-localization coefficients, which indicated the highest correlation with respect to the other substrates. Conclusions. Our three-dimensional adult cardiomyocyte cultures are suitable for both analysing cell–ECM interactions at electron and confocal microscopy levels and monitoring micro-environment impact on cardiomyocyte phenotype
The Cholesterol Metabolite 25-Hydroxycholesterol Activates Estrogen Receptor α-Mediated Signaling in Cancer Cells and in Cardiomyocytes
The hydroxylated derivatives of cholesterol, such as the oxysterols, play important roles in lipid metabolism. In particular, 25-hydroxycholesterol (25 HC) has been implicated in a variety of metabolic events including cholesterol homeostasis and atherosclerosis. 25 HC is detectable in human plasma after ingestion of a meal rich in oxysterols and following a dietary cholesterol challenge. In addition, the levels of oxysterols, including 25 HC, have been found to be elevated in hypercholesterolemic serum.Here, we demonstrate that the estrogen receptor (ER) α mediates gene expression changes and growth responses induced by 25 HC in breast and ovarian cancer cells. Moreover, 25 HC exhibits the ERα-dependent ability like 17 β-estradiol (E2) to inhibit the up-regulation of HIF-1α and connective tissue growth factor by hypoxic conditions in cardiomyocytes and rat heart preparations and to prevent the hypoxia-induced apoptosis.The estrogen action exerted by 25 HC may be considered as an additional factor involved in the progression of breast and ovarian tumors. Moreover, the estrogen-like activity of 25 HC elicited in the cardiovascular system may play a role against hypoxic environments
Risk of hospitalization for heart failure in patients with type 2 diabetes newly treated with DPP-4 inhibitors or other oral glucose-lowering medications: A retrospective registry study on 127,555 patients from the Nationwide OsMed Health-DB Database
Aims Oral glucose-lowering medications are associated with excess risk of heart failure (HF). Given the absence of comparative data among drug classes, we performed a retrospective study in 32 Health Services of 16 Italian regions accounting for a population of 18 million individuals, to assess the association between HF risk and use of sulphonylureas, DPP-4i, and glitazones. Methods and results We extracted data on patients with type 2 diabetes who initiated treatment with DPP-4i, thiazolidinediones, or sulphonylureas alone or in combination with metformin during an accrual time of 2 years. The endpoint was hospitalization for HF (HHF) occurring after the first 6 months of therapy, and the observation was extended for up to 4 years. A total of 127 555 patients were included, of whom 14.3% were on DPP-4i, 72.5% on sulphonylurea, 13.2% on thiazolidinediones, with average 70.7% being on metformin as combination therapy. Patients in the three groups differed significantly for baseline characteristics: age, sex, Charlson index, concurrent medications, and previous cardiovascular events. During an average 2.6-year follow-up, after adjusting for measured confounders, use of DPP-4i was associated with a reduced risk of HHF compared with sulphonylureas [hazard ratio (HR) 0.78; 95% confidence interval (CI) 0.62-0.97; P = 0.026]. After propensity matching, the analysis was restricted to 39 465 patients, and the use of DPP-4i was still associated with a lower risk of HHF (HR 0.70; 95% CI 0.52-0.94; P = 0.018). Conclusion In a very large observational study, the use of DPP-4i was associated with a reduced risk of HHF when compared with sulphonylureas
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