Biography:

In the past Ryszard T. Smolenski has collaborated on articles with Hitoshi Ogino and Mariola Olkowicz. One of their most recent publications is Original article: CardiovascularInfluence of preconditioning on rat heart subjected to prolonged cardioplegic arrest. Which was published in journal The Annals of Thoracic Surgery.

More information about Ryszard T. Smolenski research including statistics on their citations can be found on their Copernicus Academic profile page.

Ryszard T. Smolenski's Articles: (14)

Original article: CardiovascularInfluence of preconditioning on rat heart subjected to prolonged cardioplegic arrest

Background.Ischemic preconditioning (IP) can reduce lethal injury to the myocardium induced by prolonged ischemia. However, little is known about the effect of preconditioning on the heart subjected to cardioplegic arrest and hypothermic preservation. We evaluated the effect of IP on myocardial metabolism, mechanical performance, and coronary endothelial function after cardioplegic arrest and prolonged hypothermic preservation.Methods.An isovolumic Langendorff perfused rat heart model was used, and hearts were divided into two groups. The first group (IP, n = 14) was preconditioned by 5 minutes of global normothermic (37°C) ischemia followed by 10 minutes of normothermic reperfusion before 6 hours of cold (4°C) preservation, followed by 60 minutes of reperfusion. The second group (control, n = 15) was subjected to 6 hours of cold preservation followed by 60 minutes of reperfusion without preconditioning. Mechanical function was assessed using left ventricular balloon by constructing pressure-volume curves in two ways: at defined left ventricular volumes or at defined left ventricular end-diastolic pressures. Initially, the volume of the balloon was increased incrementally from 0 to 150 /gmL in 25-μL steps. Measurements were then repeated with loading balloon to achieve left ventricular end-diastolic pressure of 5, 10, 15, or 20 mm Hg. Myocardial function was assessed before ischemia and at 15 or 60 minutes of reperfusion. Metabolic status of the heart was evaluated by measuring the release of purine catabolites during the initial 15 minutes of reperfusion and concentrations of myocardial nucleotides at the end of reperfusion. Endothelium-mediated vasodilatation was evaluated using 10 μmol/L 5-hydroxytryptamine before and after ischemia.Results.Left ventricular end-diastolic pressure values were significantly lower in the IP group, by 20% to 40%, during the reperfusion phase at each volume of the balloon compared with the control group. The rate-pressure product was more favorable during reperfusion in the IP than in the control group because of a 15% increased heart rate in the IP group. The release of purine catabolites from the heart during the reperfusion phase was reduced (p < 0.01) in the IP group (0.66 ± 0.04 μmol) relative to the control group (0.92 ± 0.06 μmol). No difference in the recovery of systolic function, myocardial adenosine triphosphate concentration, or endothelial function was observed between the groups.Conclusions.Under conditions of cardioplegic arrest and hypothermic preservation, IP can offer additional protection for the heart by preventing an increase in diastolic stiffness. However, metabolic improvement or better preservation of the systolic or endothelial function was not observed in this model.

A novel route of ATP synthesis

AbstractIncorporation of the adenine moiety of 2'-deoxyadenosine (dAdo) into ATP, consistently observed in human erythrocytes, is a phenomenon which cannot be explained by the operation of any known pathway. We reported previously that this effect was not observed in adenine phosphoribosyltransferase-deficient erythrocytes showing that adenine must be an obligatory intermediate. However, generation of adenine from dAdo was difficult to reconcile with the operation of any known process in human cells, and involvement of S-adenosylhomocysteine hydrolase (SAH-hydrolase) was postulated. The present studies with intact human erythrocytes demonstrate that nucleoside analogues which inhibit SAH-hydrolase caused substantial attenuation of adenine transfer from dAdo into ATP. It was confirmed that dAdo is not a substrate of 5'deoxy-5'methylthioadenosine (5'MT-adenosine) phosphorylase. Inhibition of the transfer of the adenine moiety of dAdo into ATP did not correlate with inhibition of 5'MT-adenosine phosphorylase by nucleoside analogues. This report provides further evidence that the pathway involving nucleoside (adenosine) analogue binding to SAH-hydrolase, release of base and subsequent phosphoribosylation can operate in intact cells. The metabolic significance of this process relates to the possible generation of free bases (adenine) in the human body, ATP synthesis and nucleoside drug interconversions.

Original article: CardiovascularInfluence of preconditioning on rat heart subjected to prolonged cardioplegic arrest

Background.Ischemic preconditioning (IP) can reduce lethal injury to the myocardium induced by prolonged ischemia. However, little is known about the effect of preconditioning on the heart subjected to cardioplegic arrest and hypothermic preservation. We evaluated the effect of IP on myocardial metabolism, mechanical performance, and coronary endothelial function after cardioplegic arrest and prolonged hypothermic preservation.Methods.An isovolumic Langendorff perfused rat heart model was used, and hearts were divided into two groups. The first group (IP, n = 14) was preconditioned by 5 minutes of global normothermic (37°C) ischemia followed by 10 minutes of normothermic reperfusion before 6 hours of cold (4°C) preservation, followed by 60 minutes of reperfusion. The second group (control, n = 15) was subjected to 6 hours of cold preservation followed by 60 minutes of reperfusion without preconditioning. Mechanical function was assessed using left ventricular balloon by constructing pressure-volume curves in two ways: at defined left ventricular volumes or at defined left ventricular end-diastolic pressures. Initially, the volume of the balloon was increased incrementally from 0 to 150 /gmL in 25-μL steps. Measurements were then repeated with loading balloon to achieve left ventricular end-diastolic pressure of 5, 10, 15, or 20 mm Hg. Myocardial function was assessed before ischemia and at 15 or 60 minutes of reperfusion. Metabolic status of the heart was evaluated by measuring the release of purine catabolites during the initial 15 minutes of reperfusion and concentrations of myocardial nucleotides at the end of reperfusion. Endothelium-mediated vasodilatation was evaluated using 10 μmol/L 5-hydroxytryptamine before and after ischemia.Results.Left ventricular end-diastolic pressure values were significantly lower in the IP group, by 20% to 40%, during the reperfusion phase at each volume of the balloon compared with the control group. The rate-pressure product was more favorable during reperfusion in the IP than in the control group because of a 15% increased heart rate in the IP group. The release of purine catabolites from the heart during the reperfusion phase was reduced (p < 0.01) in the IP group (0.66 ± 0.04 μmol) relative to the control group (0.92 ± 0.06 μmol). No difference in the recovery of systolic function, myocardial adenosine triphosphate concentration, or endothelial function was observed between the groups.Conclusions.Under conditions of cardioplegic arrest and hypothermic preservation, IP can offer additional protection for the heart by preventing an increase in diastolic stiffness. However, metabolic improvement or better preservation of the systolic or endothelial function was not observed in this model.

Original article: CardiovascularInfluence of preconditioning on rat heart subjected to prolonged cardioplegic arrest

Background.Ischemic preconditioning (IP) can reduce lethal injury to the myocardium induced by prolonged ischemia. However, little is known about the effect of preconditioning on the heart subjected to cardioplegic arrest and hypothermic preservation. We evaluated the effect of IP on myocardial metabolism, mechanical performance, and coronary endothelial function after cardioplegic arrest and prolonged hypothermic preservation.Methods.An isovolumic Langendorff perfused rat heart model was used, and hearts were divided into two groups. The first group (IP, n = 14) was preconditioned by 5 minutes of global normothermic (37°C) ischemia followed by 10 minutes of normothermic reperfusion before 6 hours of cold (4°C) preservation, followed by 60 minutes of reperfusion. The second group (control, n = 15) was subjected to 6 hours of cold preservation followed by 60 minutes of reperfusion without preconditioning. Mechanical function was assessed using left ventricular balloon by constructing pressure-volume curves in two ways: at defined left ventricular volumes or at defined left ventricular end-diastolic pressures. Initially, the volume of the balloon was increased incrementally from 0 to 150 /gmL in 25-μL steps. Measurements were then repeated with loading balloon to achieve left ventricular end-diastolic pressure of 5, 10, 15, or 20 mm Hg. Myocardial function was assessed before ischemia and at 15 or 60 minutes of reperfusion. Metabolic status of the heart was evaluated by measuring the release of purine catabolites during the initial 15 minutes of reperfusion and concentrations of myocardial nucleotides at the end of reperfusion. Endothelium-mediated vasodilatation was evaluated using 10 μmol/L 5-hydroxytryptamine before and after ischemia.Results.Left ventricular end-diastolic pressure values were significantly lower in the IP group, by 20% to 40%, during the reperfusion phase at each volume of the balloon compared with the control group. The rate-pressure product was more favorable during reperfusion in the IP than in the control group because of a 15% increased heart rate in the IP group. The release of purine catabolites from the heart during the reperfusion phase was reduced (p < 0.01) in the IP group (0.66 ± 0.04 μmol) relative to the control group (0.92 ± 0.06 μmol). No difference in the recovery of systolic function, myocardial adenosine triphosphate concentration, or endothelial function was observed between the groups.Conclusions.Under conditions of cardioplegic arrest and hypothermic preservation, IP can offer additional protection for the heart by preventing an increase in diastolic stiffness. However, metabolic improvement or better preservation of the systolic or endothelial function was not observed in this model.

Original article: CardiovascularInfluence of preconditioning on rat heart subjected to prolonged cardioplegic arrest

Background.Ischemic preconditioning (IP) can reduce lethal injury to the myocardium induced by prolonged ischemia. However, little is known about the effect of preconditioning on the heart subjected to cardioplegic arrest and hypothermic preservation. We evaluated the effect of IP on myocardial metabolism, mechanical performance, and coronary endothelial function after cardioplegic arrest and prolonged hypothermic preservation.Methods.An isovolumic Langendorff perfused rat heart model was used, and hearts were divided into two groups. The first group (IP, n = 14) was preconditioned by 5 minutes of global normothermic (37°C) ischemia followed by 10 minutes of normothermic reperfusion before 6 hours of cold (4°C) preservation, followed by 60 minutes of reperfusion. The second group (control, n = 15) was subjected to 6 hours of cold preservation followed by 60 minutes of reperfusion without preconditioning. Mechanical function was assessed using left ventricular balloon by constructing pressure-volume curves in two ways: at defined left ventricular volumes or at defined left ventricular end-diastolic pressures. Initially, the volume of the balloon was increased incrementally from 0 to 150 /gmL in 25-μL steps. Measurements were then repeated with loading balloon to achieve left ventricular end-diastolic pressure of 5, 10, 15, or 20 mm Hg. Myocardial function was assessed before ischemia and at 15 or 60 minutes of reperfusion. Metabolic status of the heart was evaluated by measuring the release of purine catabolites during the initial 15 minutes of reperfusion and concentrations of myocardial nucleotides at the end of reperfusion. Endothelium-mediated vasodilatation was evaluated using 10 μmol/L 5-hydroxytryptamine before and after ischemia.Results.Left ventricular end-diastolic pressure values were significantly lower in the IP group, by 20% to 40%, during the reperfusion phase at each volume of the balloon compared with the control group. The rate-pressure product was more favorable during reperfusion in the IP than in the control group because of a 15% increased heart rate in the IP group. The release of purine catabolites from the heart during the reperfusion phase was reduced (p < 0.01) in the IP group (0.66 ± 0.04 μmol) relative to the control group (0.92 ± 0.06 μmol). No difference in the recovery of systolic function, myocardial adenosine triphosphate concentration, or endothelial function was observed between the groups.Conclusions.Under conditions of cardioplegic arrest and hypothermic preservation, IP can offer additional protection for the heart by preventing an increase in diastolic stiffness. However, metabolic improvement or better preservation of the systolic or endothelial function was not observed in this model.

A novel route of ATP synthesis

AbstractIncorporation of the adenine moiety of 2'-deoxyadenosine (dAdo) into ATP, consistently observed in human erythrocytes, is a phenomenon which cannot be explained by the operation of any known pathway. We reported previously that this effect was not observed in adenine phosphoribosyltransferase-deficient erythrocytes showing that adenine must be an obligatory intermediate. However, generation of adenine from dAdo was difficult to reconcile with the operation of any known process in human cells, and involvement of S-adenosylhomocysteine hydrolase (SAH-hydrolase) was postulated. The present studies with intact human erythrocytes demonstrate that nucleoside analogues which inhibit SAH-hydrolase caused substantial attenuation of adenine transfer from dAdo into ATP. It was confirmed that dAdo is not a substrate of 5'deoxy-5'methylthioadenosine (5'MT-adenosine) phosphorylase. Inhibition of the transfer of the adenine moiety of dAdo into ATP did not correlate with inhibition of 5'MT-adenosine phosphorylase by nucleoside analogues. This report provides further evidence that the pathway involving nucleoside (adenosine) analogue binding to SAH-hydrolase, release of base and subsequent phosphoribosylation can operate in intact cells. The metabolic significance of this process relates to the possible generation of free bases (adenine) in the human body, ATP synthesis and nucleoside drug interconversions.

Simultaneous accurate quantification of HO-1, CD39, and CD73 in human calcified aortic valves using multiple enzyme digestion – filter aided sample pretreatment (MED-FASP) method and targeted proteomics

Highlights•A novel LC-MRM/MS method for quantification of HO-1, CD39 and CD73 was developed.•The method was applied for analysis in normal and pathological human valves.•Up-regulation of HO-1 and down-regulation of CD39, CD73 were found in CAS.•The quantification results well correlated with immunoassays.•The assay may be used for species specific protein analysis in other biomedical research.

Uremic ToxicityN-methyl-2-pyridone-5-carboxamide: A novel uremic toxin?

N-methyl-2-pyridone-5-carboxamide: A novel uremic toxin?BackgroundN-methyl-2-pyridone-5-carboxamide (2PY) is one of the end products of nicotinamide-adenine dinucleotide (NAD) degradation. We recently found that serum 2PY concentrations in chronic renal failure (CRF) patients were enhanced to the values, which are potentially toxic. The aim of this study was to determine whether 2PY is an inhibitor of poly(ADP-ribose) polymerase, the nuclear enzyme that is highly involved in variety of physiologic events, including regulation of DNA replication and DNA repair.MethodsHigh-performance liquid chromatography (HPLC) was used to determine 2PY and other NAD catabolite concentrations in serum of: nondialyzed patients; patients chronically hemodialyzed; patients after kidney transplantation; and healthy individuals (control group). Moreover, the effect of nicotinamide and 2PY on poly(ADP-ribose) polymerase (PARP-1) in vitro was studied.ResultsThe serum nicotinamide, 2PY, and 4PY (N-methyl-4-pyridone-3-carboxamide) concentrations are many times elevated in nondialyzed CRF patients when compared with controls. The direct correlations were found between serum 2PY (as well as 4PY and nicotinamide) concentrations and serum creatinine concentration, and negative correlations between serum concentrations of these compounds and creatinine clearance. The concentration of 2PY decreases considerably after hemodialysis (HD) session, but elevates back 48 hours later. It permanently declines after kidney transplantation. Nicotinamide and 2PY significantly inhibit PARP-1 activity in vitro.ConclusionsIncreased serum 2PY concentration, along with a deterioration of kidney function and its toxic properties (significant inhibition of PARP-1 by 2PY), suggest that it could be a novel uremic toxin.

Extracellular matrix production by adipose-derived stem cells: Implications for heart valve tissue engineering

AbstractA key challenge in tissue engineering a heart valve is to reproduce the major tissue structures responsible for native valve function. Here we evaluated human adipose-derived stem cells (ADSCs) as a source of cells for heart valve tissue engineering investigating their ability to synthesize and process collagen and elastin. ADSCs were compared with human bone marrow mesenchymal stem cells (BmMSCs) and human aortic valve interstitial cells (hVICs). ADSCs and BmMSCs were stretched at 14% for 3 days and collagen synthesis determined by [3H]-proline incorporation. Collagen and elastin crosslinking was assessed by measuring pyridinoline and desmosine respectively, using liquid chromatography/mass spectrometry. Three-dimensional culture was obtained by seeding cells onto bovine collagen type I scaffolds for 2–20 days. Expression of matrix proteins and processing enzymes was assessed by Real Time-PCR, immunofluorescence and transmission electron microscopy. Stretch increased the incorporation of [3H]-proline in ADSCs and BmMSCs, however only ADSCs and hVICs upregulated COL3A1 gene. ADSCs produced collagen and elastin crosslinks. ADSCs uniformly populated collagen scaffolds after 2 days, and fibrillar-like collagen was detected after 20 days. ADSCs sense mechanical stimulation and produce and process collagen and elastin. These novel findings have important implications for the use of these cells in tissue engineering.

Disturbances of purine nucleotide metabolism in uremia

The increased concentration of adenosine triphosphate (ATP) in erythrocytes from patients with chronic renal failure (CRF) has been observed in many studies but the mechanism leading to these abnormalities still is controversial. It is believed that hyperphosphatemia and metabolic acidosis triggering enhanced reutilization of purine bases are the factors responsible for changes in erythrocyte nucleotide concentration. During the past decade we have performed several studies. A summary of the obtained results is presented. A high-performance liquid chromatography technique was used for the determination of plasma and intraerythrocyte nucleotide concentrations. Labeled adenine and adenosine were used for measuring adenine incorporation. In CRF patients treated conservatively increased concentrations of ATP levels and other nucleotides such as adenosine diphosphate were found. Adenosine monophosphate and hypoxanthine levels were lower than in controls. In hemodialyzed patients both ATP and adenosine monophosphate intraerythrocyte concentrations were higher than in controls. At the same time, adenosine monophosphate and hypoxantine level were comparable with levels in healthy people. The main pattern of nucleotides during hemodialysis remained unchanged, independent from the mode of therapy. The only exception was a decreased level of hypoxantine. Results of a consecutive study have suggested that the increased rate of adenine incorporation into the adenine nucleotide pool could be partially responsible for the increased ATP concentration in uremic erythrocytes. Last but not least, trying to elucidate the pathomechanism of adenine nucleotide disturbances in uremia, we have found that the concentration of N-methyl-2-pyridone-5-carboxamide (2PY), one of the end products of nicotinamide-adenine dinucleotide degradation, were enhanced in CRF patients to values that are potentially toxic. Our findings suggest that 2PY could be a novel uremic toxin. Disturbances of nucleotide metabolism are one of the important components of uremic syndrome.

Down-regulation of Zac1 gene expression in rat white adipose tissue by androgens

Highlights•Zac1 is highly expressed in rat white adipose tissue, mainly in adipocytes.•ZAC1 mRNA level is higher in abdominal than inguinal white adipose tissue.•Female white adipose tissue ZAC1 mRNA level was 2-fold higher than in male rats.•Androgens decrease ZAC1 mRNA level in adipose tissue.•ZAC1 mRNA level in adipose tissue is positively associated with PPARγ mRNA level.

Review articleEndothelial toxicity of unusual nucleotide metabolites

AbstractEndothelium plays a pivotal role in the vascular tone regulation, platelet aggregation, regulation of immune response, inflammation and angiogenesis and its dysfunction is an earliest event in the development of cardiovascular disease. All these processes are affected by endothelial dysfunction. Endothelial toxicity induced by metabolites present in blood is a common scenario in pathology. This involves physiological metabolites such as asymmetric dimethylarginine or homocysteine that are normally excreted by kidneys, but accumulate in pathological conditions, adversely affecting function of endothelium. Our group identified new molecule with potential endothelial toxicity: 4-pirydone-3-carboxamide-1-β-d-ribonucleoside (4PYR). This nucleoside is most likely produced by oxidation of nicotinamide containing precursor by aldehyde oxidase. 4PYR easy crosses cell membrane and become phosphorylated inside the cell giving rise to mono-, di- and triphospates (4PYMP, 4PYDP and 4PYTP). There is considerable evidence that 4PYR is toxic in endothelium and other cell types by disrupting cell energetics evident as ATP depletion. Endothelial dysfunction in the in vitro and in vivo experiments is, however, evident only after prolonged exposure to 4PYR while acute cardiovascular effects are minor. 4PYR endothelial toxicity could be particularly important in patients with chronic renal disease where accumulation of 4PYR and its metabolites is particularly prominent. 4PYR metabolism and toxicity could be blocked by application of nucleoside transport inhibitors and we have proven efficiency of such intervention. We believe that blocking metabolism of endothelial nucleoside toxins such as 4PYR could become important strategy for endothelial targeted therapy.

Review articleThe role of ecto-5′-nucleotidase in endothelial dysfunction and vascular pathologies

AbstractEcto-5′-nucleotidase (e5NT, CD73) is an enzyme that is highly expressed in endothelium and is involved in the extracellular nucleotide catabolism. CD73 converts AMP to adenosine that via specific subtypes of P1 receptor mediates cytoprotection involving diverse mechanisms such as vasodilatation, suppression of inflammation, inhibition of thrombosis and anti-adrenergic effect. Physiological intravascular concentration of adenosine is in nanomolar range, but could become micromolar in response to various forms of stress. Endothelium is a major site for both CD73 mediated production of adenosine and its cytoprotective effect. Nucleotides (predominantly ATP or ADP) that could be released from different cells via controlled specific of unspecific mechanisms constitute a major source of substrate for adenosine production via CD73. Direct effects of extracellular nucleotides (mediated by P2 receptors) are typically opposite to adenosine P1 mediated activities. Retention of nucleotides and decreased adenosine production due to loss of CD73 function may have negative implications and could be important cause of various pathologies. Protective role of CD73 was indicated in ectopic calcification, atherosclerosis, rejection after xenotransplantation and thrombosis. Reduced activity of CD73 due to lymphocyte contact with endothelium increases its permeability that leads to enhanced leukocyte transmigration. Upregulation of endothelial CD73 may therefore be protective in a number of cardiovascular pathologies. Such effect has been confirmed for some common drugs such as statins and it could be part of its pleiotropic portfolio. Activation of CD73 could be a new target for specific treatment strategy that in particular will enhance endothelial protection.

Original articleCardioprotective effect of N-methylnicotinamide salt of pyruvate in experimental model of cardiac hypoxia

AbstractBackgroundPyruvate improves contractility of normal, hypoxic, and post-ischemic myocardium. However, sodium overload is a major problem with its therapeutic application if sodium pyruvate is used. Development of alternative forms such as N-1-methylnicotinamide (MNA) pyruvate may help to overcome this problem. The aim of the study was to investigate the effect of MNA pyruvate in a murine model of cardiac ischemia.MethodsSeven month old male ApoE−/−LDLr−/− mice that develop myocardial infarction when exposed to hypoxic stress, were used in this study. Hypoxia (8% O2 in inspired air) was maintained for 8 min and was followed by reoxygenation (21% O2 in inspired air). Four groups of mice were treated 10 min before the hypoxic event by intravenous injection of MNA, MNA pyruvate, sodium pyruvate, and saline as control. The myocardial ischemia and damage was recorded by ECG. Four hours following the hypoxic episode serum troponin T and creatine kinase activity were measured.ResultsSignificant hypernatremia was found in the sodium pyruvate group. During hypoxia, control and MNA group developed profound STU depressions on ECG while no changes were observed in MNA pyruvate and sodium pyruvate group. Creatine kinase activity and troponin T content in the mice plasma were significantly higher in the control and MNA group as compared to the MNA pyruvate and sodium pyruvate group.ConclusionsThis study demonstrated that administration of MNA pyruvate prior to a hypoxia-induced cardiac event was cardioprotective. This intervention did not cause hypernatremia in contrast to sodium pyruvate.

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