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Antihypertensive effects of novel Quercetin derivatives
58
Abstracts
Nitric oxide mediated cytoprotection against simulated ischemia/reperfusion caused injury in induced pluripotent stem cell-derived cardiac myocytes A. Görbea,e,, J. Pálóczia, E. Ruivoa, Á. Szántaia, R. Gáspára, J. Koboláka, A. Dinnyésb,c, P. Ferdinandyd,e a Cardiovascular Research Group, Department of Biochemistry, University of Szeged, Hungary b Biotalentum Ltd., Gödöllő, Hungary c Molecular Animal Biotechnology Laboratory, Szent István University, Gödöllő, Hungary d Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary e Pharmahungary Group, Szeged, Hungary Objectives: Induced pluripotent stem cell (iPSC)-derived cardiac myocytes are potential cell sources for the study of cardioprotective mechanisms and therapy. Here we aimed to test the ischemic sensitivity of iPSCs after simulated ischemia/reperfusion (SI/R) and possible way of direct cytoprotection. Materials and methods: Mouse embryonic bodies (EBs) were seeded onto gelatin coated surface and were harvested in growth medium under normoxic conditions (at 37 °C, 5% CO2) or 8– 16 days. EBs were dissociated with 4 different digestion procedures (trypsin, collagenase IV, collagenase II, EDTA buffer). Cells were then labeled with cTnI and VCAM-1 antibodies and immunopositive cells were detected by flow cytometry for identification of cardiac myocytes. In separate experiments, mouse EBs (stem cell derived HM1 and iPS 3.4, iPS 4.1) were subjected to 150 min SI in the presence of the NO-donor SNAP (10–6 M) or vehicle, followed by 120 min R. After SI/R, viability of cells was assayed by propidium iodine staining. After staining, one set of full EBs was measured with plate reader, while another set of EBs was digested and cells were immunolabeled (cTnI and VCAM) and analyzed by FACS. Results: The intracellular antigen cTnI was remarkably expressed in both day-8 and day-16 with all types of digestions. The highest cTnI expression was registered on day-8 (75% of total cells) with application of trypsin. The cell surface antigen VCAM-1 was not detectable after trypsin digestion. However, the application of collagenase type IV on day-16 resulted in the highest ratio of VCAM-1 positive cells (41%). IPS (line 3.4) EBs and VCAM positive cells were more sensitive for SI/R injury than IPS 4.1 cell line. Interestingly, SNAP protected full EBs of HM1 cell line from SI/R, but not immunopositive cardiac myocytes isolated from the EBs. Conclusions: We conclude that the cardiocytoprotective NO donor protects full EBs against SI/R injury, but not the cardiac myocytes in the EBs, suggesting that iPS-derived cardiac myocytes at the current development stage are not suitable for testing cardiocytoprotective mechanisms.
doi:10.1016/j.vph.2015.11.078
Antihypertensive effects of novel Quercetin derivatives F. Grandea,c,, R.A. Mordoccoa,c, F. Puocia,c, O.I. Parisia,c, L. Scrivanoa,c, A.M. Quintierib,c, C. Roccab,c, P. Cantafiob,c, S. Ferlac,d, A. Brancalec,d, M.C. Cerrab,c, M.S. Sinicropia,c, T. Angeloneb,c a Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, CS, Italy b Department of Biology, Ecology and E.S., University of Calabria, Rende, CS, Italy c Department of Informatics, Modeling, Electronics and Systems Engineering, University of Calabria, Rende, CS, Italy d School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
Objectives: Quercetin is a flavonol able to elicit cardiovascular protection. It induces antihypertensive effect by decreasing oxidative stress, inhibiting angiotensin converting enzyme activity, improving vascular endothelial relaxation, and by modulating cell signaling and gene expression. However, clinical application of Quercetin is limited by its poor bioavailability and low stability in aqueous medium. During the last years, several studies were carried out to enhance the pharmacokinetic properties and chemical stability of Quercetin. Here we describe the preparation of five Quercetin derivatives in which all the OH groups were substituted by hydrophobic functional groups. The biological effects of these derivatives were analyzed to evaluate whether chemical modification affects the cardiovascular properties of Quercetin. Materials and methods: Quercetin derivatives were synthesized by optimizing procedures already reported. All of them were analyzed by routine spectroscopic analysis and subjected to Molecular Docking studies to analyze the mode of interaction with β-adrenergic receptors. The cardiovascular efficacy of the synthesized derivatives was evaluated on the rat heart ex vivo perfused according to Langendorff. The antihypertensive properties of the most active compound were evaluated by its in vivo administration (1 month) on spontaneously hypertensive rats (SHR). Results: Among all tested compounds, only the ethyl derivative determined a reduction of the left ventricular pressure (LVP), significantly from 10–8 M to 10–6 M. This compound also improves relaxation and coronary dilation. Inotropism, lusitropism and coronary effects were abolished by NOS inhibition by L-NAME. Chronic administration of higher doses of this compound on SHR rats determined a significant reduction of both systolic and diastolic pressure. Differently, the acetyl derivative induced a negative inotropism and lusitropism significant at 10–10 M and from 10–8 to 10–6 M, without affecting coronary pressure. Conclusions: These results suggest that the substitution of OH with ethyl groups improves Quercetin bioavailability and stability. Taking into account the antihypertensive properties of Quercetin, the ethyl derivative could represent a good candidate for clinical use in the presence of hypertension.
doi:10.1016/j.vph.2015.11.079
Myocardial actions of the chromogranin A-derived pyroglutaminated serpinin in the goldfish (Carassius auratus) and in the frog (Rana esculenta) S. Imbrognoa,, R. Mazzaa, C. Pugliesea, M. Filicea, T. Angelonea, Y.P. Lohb, B. Totaa, M.C. Cerraa a Dept. of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy b National Institutes of Health, Bethesda, MD, USA Objectives: Chromogranin A (CgA) is an acidic protein stored in secretory granules of endocrine cells and neurons together with hormones and neuropeptides. Proteolytic cleavage in the highly conserved C terminus of CgA generates a 2.9 kDa peptide named serpinin (Ala26Leu) that can be modified at its N terminus to form a pyroglutamate residue (pGlu23Leu). Ala26Leu and pGlu23Leu have been recently proposed as novel cardiac modulators. On the Langendorff perfused rat heart, Ala26Leu and pGlu23Leu increased contractility and relaxation. Both peptides act through a β1-adrenergic receptor (β1AR)/adenylate cyclase/cAMP/protein kinase A (PKA) pathway, indicating a β-adrenergic-like action (Tota et al., FASEB J. 26: 2888-98, 2012). In a comparative perspective, we explored whether Ala26Leu and pGlu23Leu could also affect myocardial contractility in two poikilotherm vertebrate species, such as the goldfish (Carassius auratus) and the frog (Rana esculenta).
Abstracts
Nitric oxide mediated cytoprotection against simulated ischemia/reperfusion caused injury in induced pluripotent stem cell-derived cardiac myocytes A. Görbea,e,, J. Pálóczia, E. Ruivoa, Á. Szántaia, R. Gáspára, J. Koboláka, A. Dinnyésb,c, P. Ferdinandyd,e a Cardiovascular Research Group, Department of Biochemistry, University of Szeged, Hungary b Biotalentum Ltd., Gödöllő, Hungary c Molecular Animal Biotechnology Laboratory, Szent István University, Gödöllő, Hungary d Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary e Pharmahungary Group, Szeged, Hungary Objectives: Induced pluripotent stem cell (iPSC)-derived cardiac myocytes are potential cell sources for the study of cardioprotective mechanisms and therapy. Here we aimed to test the ischemic sensitivity of iPSCs after simulated ischemia/reperfusion (SI/R) and possible way of direct cytoprotection. Materials and methods: Mouse embryonic bodies (EBs) were seeded onto gelatin coated surface and were harvested in growth medium under normoxic conditions (at 37 °C, 5% CO2) or 8– 16 days. EBs were dissociated with 4 different digestion procedures (trypsin, collagenase IV, collagenase II, EDTA buffer). Cells were then labeled with cTnI and VCAM-1 antibodies and immunopositive cells were detected by flow cytometry for identification of cardiac myocytes. In separate experiments, mouse EBs (stem cell derived HM1 and iPS 3.4, iPS 4.1) were subjected to 150 min SI in the presence of the NO-donor SNAP (10–6 M) or vehicle, followed by 120 min R. After SI/R, viability of cells was assayed by propidium iodine staining. After staining, one set of full EBs was measured with plate reader, while another set of EBs was digested and cells were immunolabeled (cTnI and VCAM) and analyzed by FACS. Results: The intracellular antigen cTnI was remarkably expressed in both day-8 and day-16 with all types of digestions. The highest cTnI expression was registered on day-8 (75% of total cells) with application of trypsin. The cell surface antigen VCAM-1 was not detectable after trypsin digestion. However, the application of collagenase type IV on day-16 resulted in the highest ratio of VCAM-1 positive cells (41%). IPS (line 3.4) EBs and VCAM positive cells were more sensitive for SI/R injury than IPS 4.1 cell line. Interestingly, SNAP protected full EBs of HM1 cell line from SI/R, but not immunopositive cardiac myocytes isolated from the EBs. Conclusions: We conclude that the cardiocytoprotective NO donor protects full EBs against SI/R injury, but not the cardiac myocytes in the EBs, suggesting that iPS-derived cardiac myocytes at the current development stage are not suitable for testing cardiocytoprotective mechanisms.
doi:10.1016/j.vph.2015.11.078
Antihypertensive effects of novel Quercetin derivatives F. Grandea,c,, R.A. Mordoccoa,c, F. Puocia,c, O.I. Parisia,c, L. Scrivanoa,c, A.M. Quintierib,c, C. Roccab,c, P. Cantafiob,c, S. Ferlac,d, A. Brancalec,d, M.C. Cerrab,c, M.S. Sinicropia,c, T. Angeloneb,c a Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, CS, Italy b Department of Biology, Ecology and E.S., University of Calabria, Rende, CS, Italy c Department of Informatics, Modeling, Electronics and Systems Engineering, University of Calabria, Rende, CS, Italy d School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK
Objectives: Quercetin is a flavonol able to elicit cardiovascular protection. It induces antihypertensive effect by decreasing oxidative stress, inhibiting angiotensin converting enzyme activity, improving vascular endothelial relaxation, and by modulating cell signaling and gene expression. However, clinical application of Quercetin is limited by its poor bioavailability and low stability in aqueous medium. During the last years, several studies were carried out to enhance the pharmacokinetic properties and chemical stability of Quercetin. Here we describe the preparation of five Quercetin derivatives in which all the OH groups were substituted by hydrophobic functional groups. The biological effects of these derivatives were analyzed to evaluate whether chemical modification affects the cardiovascular properties of Quercetin. Materials and methods: Quercetin derivatives were synthesized by optimizing procedures already reported. All of them were analyzed by routine spectroscopic analysis and subjected to Molecular Docking studies to analyze the mode of interaction with β-adrenergic receptors. The cardiovascular efficacy of the synthesized derivatives was evaluated on the rat heart ex vivo perfused according to Langendorff. The antihypertensive properties of the most active compound were evaluated by its in vivo administration (1 month) on spontaneously hypertensive rats (SHR). Results: Among all tested compounds, only the ethyl derivative determined a reduction of the left ventricular pressure (LVP), significantly from 10–8 M to 10–6 M. This compound also improves relaxation and coronary dilation. Inotropism, lusitropism and coronary effects were abolished by NOS inhibition by L-NAME. Chronic administration of higher doses of this compound on SHR rats determined a significant reduction of both systolic and diastolic pressure. Differently, the acetyl derivative induced a negative inotropism and lusitropism significant at 10–10 M and from 10–8 to 10–6 M, without affecting coronary pressure. Conclusions: These results suggest that the substitution of OH with ethyl groups improves Quercetin bioavailability and stability. Taking into account the antihypertensive properties of Quercetin, the ethyl derivative could represent a good candidate for clinical use in the presence of hypertension.
doi:10.1016/j.vph.2015.11.079
Myocardial actions of the chromogranin A-derived pyroglutaminated serpinin in the goldfish (Carassius auratus) and in the frog (Rana esculenta) S. Imbrognoa,, R. Mazzaa, C. Pugliesea, M. Filicea, T. Angelonea, Y.P. Lohb, B. Totaa, M.C. Cerraa a Dept. of Biology, Ecology and Earth Sciences, University of Calabria, Rende, CS, Italy b National Institutes of Health, Bethesda, MD, USA Objectives: Chromogranin A (CgA) is an acidic protein stored in secretory granules of endocrine cells and neurons together with hormones and neuropeptides. Proteolytic cleavage in the highly conserved C terminus of CgA generates a 2.9 kDa peptide named serpinin (Ala26Leu) that can be modified at its N terminus to form a pyroglutamate residue (pGlu23Leu). Ala26Leu and pGlu23Leu have been recently proposed as novel cardiac modulators. On the Langendorff perfused rat heart, Ala26Leu and pGlu23Leu increased contractility and relaxation. Both peptides act through a β1-adrenergic receptor (β1AR)/adenylate cyclase/cAMP/protein kinase A (PKA) pathway, indicating a β-adrenergic-like action (Tota et al., FASEB J. 26: 2888-98, 2012). In a comparative perspective, we explored whether Ala26Leu and pGlu23Leu could also affect myocardial contractility in two poikilotherm vertebrate species, such as the goldfish (Carassius auratus) and the frog (Rana esculenta).