Nicoleta Alexandru - Academia.edu (original) (raw)

Papers by Nicoleta Alexandru

Frontiers in Pharmacology

Cardiac pathological hypertrophy is the major risk factor that usually progresses to heart failur... more Cardiac pathological hypertrophy is the major risk factor that usually progresses to heart failure. We hypothesized that extracellular vesicles (EVs), known to act as important mediators in regulating physiological and pathological functions, could have the potential to reduce the cardiac hypertrophy and the ensuing cardiovascular diseases. Herein, the effects of mesenchymal stem cell-derived extracellular vesicles (EV-MSCs) on cardiac hypertrophy were investigated. EVs were isolated from the secretome of human adipose tissue-derived stem cells (EV-ADSCs) or bone marrow-derived stem cells (EV-BMMSCs). Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were stimulated with AngII and TGF-β1, in absence or presence of EVs. The results showed that exposure of hiPSC-CMs to AngII and TGF-β1 generated in vitro model of hypertrophic cardiomyocytes characterized by increases in surface area, reactive oxygen species production, protein expression of cardiac-specific biomar...

Pharmaceutics, May 17, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Cell Transplantation, 2020

Diabetes reduces the number and induces dysfunction in circulating endothelial progenitor cells (... more Diabetes reduces the number and induces dysfunction in circulating endothelial progenitor cells (EPCs) by mechanisms that are still uncovered. This study aims to evaluate the number, viability, phenotype, and function of EPCs in dyslipidemic mice with early diabetes mellitus and EPC infiltration in the aortic valve in order to identify possible therapeutic targets in diabetes-associated cardiovascular disease. A streptozotocin-induced diabetic apolipoprotein E knock-out (ApoE−/−) mouse model was used to identify the early and progressive changes, at 4 or 7 days on atherogenic diet after the last streptozotocin or citrate buffer injection. Blood and aortic valves from diabetic or nondiabetic ApoE−/−animals were collected.EPCs were identified as CD34 and vascular endothelial growth factor receptor 2 positive monocytes, and the expression levels of α4β1, αVβ3, αVβ5, β1, αLβ2, α5integrins, and C-X-C chemokine receptor type 4 chemokine receptor on EPC surface were assessed by flow cytome...

Cells, 2020

Atherosclerosis and cardiovascular disease development is the outcome of intermediate processes w... more Atherosclerosis and cardiovascular disease development is the outcome of intermediate processes where endothelial dysfunction and vascular inflammation are main protagonists. Cell-derived microvesicles (MVs), endothelial progenitor cells (EPCs), and circulating microRNAs (miRNAs) are known as biomarkers and potential regulators for atherosclerotic vascular disease, but their role in the complexity of the inflammatory process and in the mechanism of vascular restoration is far from clear. We aimed to evaluate the biological activity and functional role of MVs, in particular of the EPCs-derived MVs (MVEs), of healthy origins in reducing atherosclerotic vascular disease development. The experiments were performed on hamsters divided into the following groups: simultaneously hypertensive–hyperlipidemic (HH group) by combining two feeding conditions for 4 months; HH with retro-orbital sinus injection containing 1 × 105 MVs or MVEs from control hamsters, one dose per month for 4 months of...

Frontiers in Medicine, 2019

Alexandru et al. MicroRNA Profile and EPC Therapy in Atherosclerosis Conclusions: The present stu... more Alexandru et al. MicroRNA Profile and EPC Therapy in Atherosclerosis Conclusions: The present study revealed that miRNAs have differential expression profiles in plasma, platelets, and PMVs under hypertension associated with hyperlipidemia conditions. The different miRNA profile in PMVs compared with platelets indicated an active mechanism of selective packing of miRNAs into PMVs from maternal cells; various miRNAs such as miR-19a,-21,-126,-26b,-92a,-155,-204,-210,-221,-222, and−34a delivered by PMVs may contribute to enrichment of circulating plasma miRNA expression. In addition, our study showed that the EPC-based therapy can regulate the expressions of investigated miRNAs into the three sources. These results provide novel information that could help in finding potential targets for the development of new therapeutic strategies in the cardiovascular disease.

Diabetes and Vascular Disease Research, 2019

Diabetes contributes directly to the development of cardiovascular aortic valve disease. There is... more Diabetes contributes directly to the development of cardiovascular aortic valve disease. There is currently no drug therapy available for a dysfunctional valve and this urges the need for additional research to identify distinctive mechanisms of cardiovascular aortic valve disease evolution. The aim of this study was to evaluate changes of valvular aortic lesions induced in a hyperlipemic ApoE−/− mouse model by early type 1 diabetes onset (at 4 and 7 days after streptozotocin induction). The haemodynamic valve parameters were evaluated by echography and blood samples and aortic valves were collected. Plasma parameters were measured, and inflammatory, remodelling and osteogenic markers were evaluated in the aortic valves. Next, correlations between all parameters were determined. The results showed early aortic valve dysfunction detected by echography after 1 week of diabetes; lesions were found in the aortic root. Moreover, increased expression of cell adhesion molecules, extracellu...

Extracellular Vesicles and Their Importance in Human Health, 2019

Extracellular vesicles (EVs) are particles released in the extracellular space from all cell type... more Extracellular vesicles (EVs) are particles released in the extracellular space from all cell types in physiological and pathological conditions and emerge as a new way of cell-cell communication by transferring their biological contents into target cells. The levels and composition of circulating EVs differ from a normal condition to a pathological one, making them real circulating biomarkers. EVs have a very complex contribution in both health and disease, most likely in relationship between diabetes and cardiovascular disease. The involvement of EVs to the development of cardiovascular complications in diabetes remains an open discussion for therapists. Circulating EVs may offer a continuous access path to circulating information on the disease state and a new perspective in finding a correct diagnosis, in estimating a prognosis and also in applying an effective therapy. Besides their role as biomarkers and targets for therapy, EVs can be exploited as biological tools in influencing the different processes affected in diabetic cardiovascular diseases. This chapter will summarize the current knowledge about EVs as biological vectors modulating diabetic cardiovascular diseases, including atherosclerosis, coronary artery disease, and peripheral arterial disease. Finally, we will point out EVs' considerable value as clinical biomarkers, therapeutic targets, and potential biomedical tools for the discovery of effective therapy in diabetic cardiovascular diseases.

Frontiers in Pharmacology, 2019

The purpose was to evaluate the effect of platelets on functional properties of late endothelial ... more The purpose was to evaluate the effect of platelets on functional properties of late endothelial progenitor cells (EPCs), in the direct co-culture conditions, and to investigate the involved mediators, in experimental induced atherosclerosis. The late EPCs obtained from two animal groups, hypertensive-hyperlipidemic (HH) and control (C) hamsters, named late EPCs-HH and late EPCs-C, were co-incubated with or without platelets isolated from both groups. Our results have showed that exposure to platelets from control animals: (i) promoted the late EPCs-C capacity to form colonies and capillarylike structures, and also to proliferate and migrate; (ii) improved the functional properties of late EPCs-HH; (iii) strengthened the direct binding EPCs-platelets; (iv) increased SDF-1α,VEGF, PDGF, and reduced CD40L, IL-1β,-6,-8 levels; and (v) enhanced miR-223 and IGF-1R expressions. Platelets from HH group diminished functional abilities for both EPC types and had opposite effects on these pro-angiogenic and pro-inflammatory molecules. Furthermore, testing the direct effect of miR-223 and IGF-1R on late EPCs disclosed that these molecular factors improve late EPC functional properties in atherosclerosis in terms of stimulation of the proliferation and migration abilities. In conclusion, in vitro exposure to platelets of healthy origins had a positive effect on functional properties of atherosclerotic late EPCs. The most likely candidates mediating EPC-platelet interaction can be SDF-1α, VEGF, CD40L, PDGF, IL-1β,-6,-8, miR-223, and IGF-1R. The current study brings evidences that the presence of healthy origin platelets is of utmost importance on functional improvement of EPCs in atherosclerosis.

Frontiers in Pharmacology, 2019

In this study, we aimed to identify the mechanisms underlying the different effects of palmitic a... more In this study, we aimed to identify the mechanisms underlying the different effects of palmitic acid and oleic acid on human pancreatic beta cell function. To address this problem, the oxidative stress, endoplasmic reticulum stress, inflammation, apoptosis and their mediator molecules have been investigated in the insulin releasing beta cells exposed to palmitic and/or oleic acid. Herein, we have demonstrated that in cultured 1.1B4 beta cells oleic acid promotes neutral lipid accumulation and insulin secretion, whereas palmitic acid is poorly incorporated into triglyceride and it does not stimulate insulin secretion from human pancreatic islets at physiologically glucose concentrations. In addition, palmitic acid caused: (1) oxidative stress through a mechanism involving increases in ROS production and MMP-2 protein expression/gelatinolytic activity associated with down-regulation of SOD2 protein; (2) endoplasmic reticulum stress by up-regulation of chaperone BiP protein and unfolded protein response (UPR) transcription factors (eIF2α, ATF6, XBP1u proteins) and by PTP-1B down-regulation in both mRNA and protein levels; (3) inflammation through enhanced synthesis of proinflammatory cytokines (IL6, IL8 proteins); and (4) apoptosis by enforced proteic expression of CHOP multifunctional transcription factor. Oleic acid alone had opposite effects due to its different capacity of controlling these metabolic pathways, in particular by reduction of the ROS levels and MMP-2 activity, down-regulation of BiP, eIF2α, ATF6, XBP1u, CHOP, IL6, IL8 and by SOD2 and PTP-1B overexpression. The supplementation of saturated palmitic acid with the monounsaturated oleic acid reversed the negative effects of palmitic acid alone regulating insulin secretion from pancreatic beta cells through ROS, MMP-2, ATF6, XBP1u, IL8 reduction and SOD2, PTP-1B activation. Our findings have shown the protective action of oleic acid against palmitic acid on beta cell lipotoxicity through promotion of triglyceride accumulation and insulin secretion and regulation of some effector molecules involved in oxidative stress, endoplasmic reticulum stress, inflammation and apoptosis.

Current Hypertension Reports, 2016

Purpose of Review Hypertension is either a cause or a consequence of the endothelial dysfunction ... more Purpose of Review Hypertension is either a cause or a consequence of the endothelial dysfunction and a major risk factor for cardiovascular disease (CVD). In vitro and in vivo studies established that microRNAs (miRNAs) are decisive for endothelial cell gene expression and function in various pathological conditions associated with CVD. This review provides an overview of the miRNA role in controlling the key connections between endothelial dysfunction and hypertension. Recent Findings Herein we summarize the present understanding of mechanisms underlying hypertension and its associated endothelial dysfunction as well as the miRNA role in endothelial cells with accent on the modulation of renin-angiotensin-aldosterone-system, nitric oxide, oxidative stress and on the control of vascular inflammation and angiogenesis in relation to endothelial dysfunction in hypertension. In particular, latest insights in the identification of endothelialspecific microRNAs and their targets are added to the understanding of miRNA significance in hypertension. Summary This comprehensive knowledge of the role of miRNAs in endothelial dysfunction and hypertension and of molecular mechanisms proposed for miRNA actions may offer novel diagnostic biomarkers and therapeutic targets for controlling hypertension-associated endothelial dysfunction and other cardiovascular complications.

Biochemical and biophysical research communications, Jan 25, 2016

The recognition of the importance of diabetes in vascular disease has greatly increased lately. C... more The recognition of the importance of diabetes in vascular disease has greatly increased lately. Common risk factors for diabetes-related vascular disease include hyperglycemia, insulin resistance, dyslipidemia, inflammation, hypercoagulability, hypertension, and atherosclerosis. All of these factors contribute to the endothelial dysfunction which generates the diabetic complications, both macro and microvascular. Knowledge of diabetes-related vascular complications and of associated mechanisms it is becoming increasingly important for therapists. The discovery of microparticles (MPs) and their associated microRNAs (miRNAs) have opened new perspectives capturing the attention of basic and clinical scientists for their potential to become new therapeutic targets and clinical biomarkers. MPs known as submicron vesicles generated from membranes of apoptotic or activated cells into circulation have the ability to act as autocrine and paracrine effectors in cell-to-cell communication. The...

Biology of the Cell, 2016

Background InformationAtherosclerosis is an inflammatory disease, in which risk factors such as h... more Background InformationAtherosclerosis is an inflammatory disease, in which risk factors such as hyperlipidemia and hypertension affect the arterial endothelium, resulting in dysfunction, cell damage or both. The number of circulating endothelial progenitor cells and microparticles provides invaluable outcome prediction for atherosclerosis disease. However, evidence for the therapeutic potential of endothelial progenitor cells and microparticles in atherosclerosis development is limited. Our study was designed to investigate the possible protective role of a cell therapy‐based approach, using endothelial progenitor cells and the dual behaviour of circulating platelet microparticles, on atherosclerosis development in hypertensive‐hypercholesterolemic hamster model. Consequently, control hamsters received four intravenous inoculations of: (1) 1×105 endothelial progenitor cells of healthy origins in one dose per month, during four months of diet‐induced atherosclerosis, and after hypert...

Farmacia

Endothelial progenitor cells (EPCs) and circulating microparticles (MPs) have been proposed as ma... more Endothelial progenitor cells (EPCs) and circulating microparticles (MPs) have been proposed as markers of endothelial function. In turn, the protective role of irbesartan, an angiotensin receptor blocker, on the endothelium has been demonstrated in the recent years but the mechanism has not been yet fully elucidated. In this context, we investigated whether irbesartan can influence these two new biomarkers in patients with cardiovascular (CV) risk factors. We compared the levels of EPCs and MPs in patients with hypertension and dyslipidemia which received irbesartan with the levels in patients with the same CV risk factors but receiving other antihypertensive drugs and in healthy individuals. Using this methodology we showed the positive effect of angiotensin receptor blockade on the two proposed markers of endothelial function, reflecting both endothelial injury and repair, MPs and EPC respectively, in the same subjects with cardiovascular risk factors. Moreover, we found that patients with hypertension and dyslipidemia display an altered balance between the levels of endothelial regenerative cells like EPCs and markers of endothelial injury like circulating MPs. Rezumat Celulele endoteliale progenitoare (EPC) si microparticulele circulante (MP) au fost propuse ca markeri ai funcţiei endoteliale. Pe de altă parte, in ultimii ani a fost demonstrat rolul protector al irbesartanului, un blocant al receptorilor de angiotensină, asupra endoteliului, dar mecanismul implicat nu a fost complet elucidat. In acest context am studiat potenţialul irbesartanului de a influenţa acesti noi biomarkeri la pacienţii cu factori de risc cardiovasculari (CV). Am comparat nivelurile circulante de EPC si MP la pacienţi cu hipertensiune arterială si dislipidemie ce au primit tratament cu irbesartan, cu cele măsurate la pacienţi cu aceiasi factori de risc CV, dar trataţi cu altă clasă de medicamente antihipertensive si la indivizi sănătosi. Cu ajutorul aceastei metodologii am demonstrat efectul benefic al blocadei receptorilor de angiotensină asupra markerilor de disfuncţie endotelială ce reflectă atât afectarea cât si procesul reparator endotelial, MP si EPC

Biology of the Cell, 2015

Background informationRecent studies suggest that endothelial progenitor cells (EPCs) and platele... more Background informationRecent studies suggest that endothelial progenitor cells (EPCs) and platelets have an important role in repair following vascular injury. Although evidence suggest that platelets are essential in EPC attracting, homing and differentiation to the injury site; however, the platelet effects on EPC function in atherosclerosis have received less attention. In this context, we followed the consequences of circulating EPCs and platelet microparticles (PMPs) administration on platelet–EPC interaction in atherosclerosis and the involved mechanisms. The experiments were performed on Golden Syrian hamsters divided in five equal groups: control (C), hypertensive–hypercholesterolemic (HH), HH treated with EPCs (HH–EPCs) or PMPs (HH–PMPs) and HH treated with EPCs and PMPs (HH–EPCs–PMPs).ResultsCompared with C group, EPCs isolated from HH and HH–PMPs groups presented a reduction of endothelial nitric oxide synthase and vascular endothelial growth factor expressions and an inc...

Clinical laboratory, 2011

Chronic venous insufficiency (CVI) is a common medical problem that may result in significant mor... more Chronic venous insufficiency (CVI) is a common medical problem that may result in significant morbidity and mortality. Platelets are key players in haemostasis and thrombosis, but their role in the development of venous thrombosis is more controversial. The purpose of this study was to investigate platelet properties in CVI and their interaction with the venular endothelium. Human peripheral venules were explanted during leg surgery of patients with CVI and of healthy subjects (C); concurrently, the platelets were isolated from blood samples collected. The techniques used were: fluorescence and electron microscopy and Western-blotting. Compared with the C group, the platelets of patients with CVI are activated, as demonstrated by: (i) cellular modifications, such as alteration of the discoidal shape by the development of extended cytoplasmic filopodia and changes of the cells normal ultrastructure, (ii) biochemical modifications, such as the enhanced protein levels of FAK, p85 PI3K,...

PLoS ONE, 2013

Aim: The purpose of this project was to evaluate the influence of circulating endothelial progeni... more Aim: The purpose of this project was to evaluate the influence of circulating endothelial progenitor cells (EPCs) and platelet microparticles (PMPs) on blood platelet function in experimental hypertension associated with hypercholesterolemia. Methods: Golden Syrian hamsters were divided in six groups: (i) control, C; (ii) hypertensive-hypercholesterolemic, HH; (iii) 'prevention', HHin-EPCs, HH animals fed a HH diet and treated with EPCs; (iv) 'regression', HHfin-EPCs, HH treated with EPCs after HH feeding; (v) HH treated with PMPs, HH-PMPs, and (vi) HH treated with EPCs and PMPs, HH-EPCs-PMPs. Results: Compared to HH group, the platelets from HHin-EPCs and HHfin-EPCs groups showed a reduction of: (i) activation, reflected by decreased integrin 3b, FAK, PI3K, src protein expression; (ii) secreted molecules as: SDF-1, MCP-1, RANTES, VEGF, PF4, PDGF and (iii) expression of pro-inflammatory molecules as: SDF-1, MCP-1, RANTES, IL-6, IL-1b; TFPI secretion was increased. Compared to HH group, platelets of HH-PMPs group showed increased activation, molecules release and proteins expression. Compared to HH-PMPs group the combination EPCs with PMPs treatment induced a decrease of all investigated platelet molecules, however not comparable with that recorded when EPC individual treatment was applied. Conclusion: EPCs have the ability to reduce platelet activation and to modulate their pro-inflammatory and antithrombogenic properties in hypertension associated with hypercholesterolemia. Although, PMPs have several beneficial effects in combination with EPCs, these did not improve the EPC effects. These findings reveal a new biological role of circulating EPCs in platelet function regulation, and may contribute to understand their cross talk, and the mechanisms of atherosclerosis.

Trends in Cardiovascular Medicine, 2010

This article provides an overview of the current knowledge on intraplatelet oxidative/nitrative s... more This article provides an overview of the current knowledge on intraplatelet oxidative/nitrative stress, an abnormality associated with platelet activation and hyper-reactivity. The first issue discussed is related to induction of platelet endogenous stress by the molecules present within the circulating (extracellular) milieu that bathes these cells. The second issue concerns the intraplatelet oxidative/nitrative stress associated with specific pathologies or clinical procedures and action of particular molecules and platelet agonists as well as of the specialized intraplatelet milieu and its redox system; the biomarkers of endogenous oxidative/nitrative stress are also briefly outlined. Next, the association between intraplatelet oxidative/nitrative stress and the risk factors of the metabolic syndrome is presented. Then, the most recent strategies aimed at the control/regulation of platelet endogenous oxidative/nitrative stress, such as exploitation of circulating extracellular reactive oxygen species scavengers, manipulation of platelet molecules, and the use of antioxidants, are discussed. Finally, the results of studies on platelet-dependent redox mechanisms, which deserve immediate attention for potential clinical exploitation, are illustrated.

Journal of Thrombosis and Haemostasis, 2011

The aim of this study was to determine the effect of simultaneous hypertension and hypercholester... more The aim of this study was to determine the effect of simultaneous hypertension and hypercholesterolemia on platelet activation, nitric oxide (NO) production and oxidative stress, and to evaluate the role of irbesartan, an angiotensin II type 1 receptor antagonist. Methods: Golden Syrian hamsters were divided into three groups: controls, C (fed a standard diet); hypertensive-hypercholesterolemic, HH (fed a diet enriched in 3% cholesterol, 15% butter and 8% NaCl, for 4 months); and hypertensive-hypercholesterolemic treated with irbesartan, HHI (fed as HH group, plus irbesartan 10 mg kg)1 per day, for 4 months). Results: Compared with the C group, platelets isolated from the HH group showed: morphological modifications; increased integrin b3 exposure and protein expression of P-selectin, FAK, PI3K, Akt and Src; reduced eNOS protein expression and NO production; higher generation of ROS, mostly produced by NADPH-oxidase, cyclooxygenase-1 (COX-1) and 12lipoxygenase; and enhanced NAD(P)H oxidase activity and protein expression of gp91phox and p22phox subunits, 12lipoxygenase, COX-1, cPLA 2 and PKC. Compared with the HH group, the treatment with irbesartan (HHI group) significantly attenuates the changes in all the molecules tested, reduces platelet aggregation, and improves intraplatelet redox balance. Conclusions: Experimental hypertension associated with hypercholesterolemia produces major changes in morphology, signaling mechanisms and oxidative stress in blood platelets. These changes were significantly diminished by irbesartan administration, which functions as an antioxidant on platelets.

Frontiers in Pharmacology

Cardiac pathological hypertrophy is the major risk factor that usually progresses to heart failur... more Cardiac pathological hypertrophy is the major risk factor that usually progresses to heart failure. We hypothesized that extracellular vesicles (EVs), known to act as important mediators in regulating physiological and pathological functions, could have the potential to reduce the cardiac hypertrophy and the ensuing cardiovascular diseases. Herein, the effects of mesenchymal stem cell-derived extracellular vesicles (EV-MSCs) on cardiac hypertrophy were investigated. EVs were isolated from the secretome of human adipose tissue-derived stem cells (EV-ADSCs) or bone marrow-derived stem cells (EV-BMMSCs). Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were stimulated with AngII and TGF-β1, in absence or presence of EVs. The results showed that exposure of hiPSC-CMs to AngII and TGF-β1 generated in vitro model of hypertrophic cardiomyocytes characterized by increases in surface area, reactive oxygen species production, protein expression of cardiac-specific biomar...

Pharmaceutics, May 17, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Cell Transplantation, 2020

Diabetes reduces the number and induces dysfunction in circulating endothelial progenitor cells (... more Diabetes reduces the number and induces dysfunction in circulating endothelial progenitor cells (EPCs) by mechanisms that are still uncovered. This study aims to evaluate the number, viability, phenotype, and function of EPCs in dyslipidemic mice with early diabetes mellitus and EPC infiltration in the aortic valve in order to identify possible therapeutic targets in diabetes-associated cardiovascular disease. A streptozotocin-induced diabetic apolipoprotein E knock-out (ApoE−/−) mouse model was used to identify the early and progressive changes, at 4 or 7 days on atherogenic diet after the last streptozotocin or citrate buffer injection. Blood and aortic valves from diabetic or nondiabetic ApoE−/−animals were collected.EPCs were identified as CD34 and vascular endothelial growth factor receptor 2 positive monocytes, and the expression levels of α4β1, αVβ3, αVβ5, β1, αLβ2, α5integrins, and C-X-C chemokine receptor type 4 chemokine receptor on EPC surface were assessed by flow cytome...

Cells, 2020

Atherosclerosis and cardiovascular disease development is the outcome of intermediate processes w... more Atherosclerosis and cardiovascular disease development is the outcome of intermediate processes where endothelial dysfunction and vascular inflammation are main protagonists. Cell-derived microvesicles (MVs), endothelial progenitor cells (EPCs), and circulating microRNAs (miRNAs) are known as biomarkers and potential regulators for atherosclerotic vascular disease, but their role in the complexity of the inflammatory process and in the mechanism of vascular restoration is far from clear. We aimed to evaluate the biological activity and functional role of MVs, in particular of the EPCs-derived MVs (MVEs), of healthy origins in reducing atherosclerotic vascular disease development. The experiments were performed on hamsters divided into the following groups: simultaneously hypertensive–hyperlipidemic (HH group) by combining two feeding conditions for 4 months; HH with retro-orbital sinus injection containing 1 × 105 MVs or MVEs from control hamsters, one dose per month for 4 months of...

Frontiers in Medicine, 2019

Alexandru et al. MicroRNA Profile and EPC Therapy in Atherosclerosis Conclusions: The present stu... more Alexandru et al. MicroRNA Profile and EPC Therapy in Atherosclerosis Conclusions: The present study revealed that miRNAs have differential expression profiles in plasma, platelets, and PMVs under hypertension associated with hyperlipidemia conditions. The different miRNA profile in PMVs compared with platelets indicated an active mechanism of selective packing of miRNAs into PMVs from maternal cells; various miRNAs such as miR-19a,-21,-126,-26b,-92a,-155,-204,-210,-221,-222, and−34a delivered by PMVs may contribute to enrichment of circulating plasma miRNA expression. In addition, our study showed that the EPC-based therapy can regulate the expressions of investigated miRNAs into the three sources. These results provide novel information that could help in finding potential targets for the development of new therapeutic strategies in the cardiovascular disease.

Diabetes and Vascular Disease Research, 2019

Diabetes contributes directly to the development of cardiovascular aortic valve disease. There is... more Diabetes contributes directly to the development of cardiovascular aortic valve disease. There is currently no drug therapy available for a dysfunctional valve and this urges the need for additional research to identify distinctive mechanisms of cardiovascular aortic valve disease evolution. The aim of this study was to evaluate changes of valvular aortic lesions induced in a hyperlipemic ApoE−/− mouse model by early type 1 diabetes onset (at 4 and 7 days after streptozotocin induction). The haemodynamic valve parameters were evaluated by echography and blood samples and aortic valves were collected. Plasma parameters were measured, and inflammatory, remodelling and osteogenic markers were evaluated in the aortic valves. Next, correlations between all parameters were determined. The results showed early aortic valve dysfunction detected by echography after 1 week of diabetes; lesions were found in the aortic root. Moreover, increased expression of cell adhesion molecules, extracellu...

Extracellular Vesicles and Their Importance in Human Health, 2019

Extracellular vesicles (EVs) are particles released in the extracellular space from all cell type... more Extracellular vesicles (EVs) are particles released in the extracellular space from all cell types in physiological and pathological conditions and emerge as a new way of cell-cell communication by transferring their biological contents into target cells. The levels and composition of circulating EVs differ from a normal condition to a pathological one, making them real circulating biomarkers. EVs have a very complex contribution in both health and disease, most likely in relationship between diabetes and cardiovascular disease. The involvement of EVs to the development of cardiovascular complications in diabetes remains an open discussion for therapists. Circulating EVs may offer a continuous access path to circulating information on the disease state and a new perspective in finding a correct diagnosis, in estimating a prognosis and also in applying an effective therapy. Besides their role as biomarkers and targets for therapy, EVs can be exploited as biological tools in influencing the different processes affected in diabetic cardiovascular diseases. This chapter will summarize the current knowledge about EVs as biological vectors modulating diabetic cardiovascular diseases, including atherosclerosis, coronary artery disease, and peripheral arterial disease. Finally, we will point out EVs' considerable value as clinical biomarkers, therapeutic targets, and potential biomedical tools for the discovery of effective therapy in diabetic cardiovascular diseases.

Frontiers in Pharmacology, 2019

The purpose was to evaluate the effect of platelets on functional properties of late endothelial ... more The purpose was to evaluate the effect of platelets on functional properties of late endothelial progenitor cells (EPCs), in the direct co-culture conditions, and to investigate the involved mediators, in experimental induced atherosclerosis. The late EPCs obtained from two animal groups, hypertensive-hyperlipidemic (HH) and control (C) hamsters, named late EPCs-HH and late EPCs-C, were co-incubated with or without platelets isolated from both groups. Our results have showed that exposure to platelets from control animals: (i) promoted the late EPCs-C capacity to form colonies and capillarylike structures, and also to proliferate and migrate; (ii) improved the functional properties of late EPCs-HH; (iii) strengthened the direct binding EPCs-platelets; (iv) increased SDF-1α,VEGF, PDGF, and reduced CD40L, IL-1β,-6,-8 levels; and (v) enhanced miR-223 and IGF-1R expressions. Platelets from HH group diminished functional abilities for both EPC types and had opposite effects on these pro-angiogenic and pro-inflammatory molecules. Furthermore, testing the direct effect of miR-223 and IGF-1R on late EPCs disclosed that these molecular factors improve late EPC functional properties in atherosclerosis in terms of stimulation of the proliferation and migration abilities. In conclusion, in vitro exposure to platelets of healthy origins had a positive effect on functional properties of atherosclerotic late EPCs. The most likely candidates mediating EPC-platelet interaction can be SDF-1α, VEGF, CD40L, PDGF, IL-1β,-6,-8, miR-223, and IGF-1R. The current study brings evidences that the presence of healthy origin platelets is of utmost importance on functional improvement of EPCs in atherosclerosis.

Frontiers in Pharmacology, 2019

In this study, we aimed to identify the mechanisms underlying the different effects of palmitic a... more In this study, we aimed to identify the mechanisms underlying the different effects of palmitic acid and oleic acid on human pancreatic beta cell function. To address this problem, the oxidative stress, endoplasmic reticulum stress, inflammation, apoptosis and their mediator molecules have been investigated in the insulin releasing beta cells exposed to palmitic and/or oleic acid. Herein, we have demonstrated that in cultured 1.1B4 beta cells oleic acid promotes neutral lipid accumulation and insulin secretion, whereas palmitic acid is poorly incorporated into triglyceride and it does not stimulate insulin secretion from human pancreatic islets at physiologically glucose concentrations. In addition, palmitic acid caused: (1) oxidative stress through a mechanism involving increases in ROS production and MMP-2 protein expression/gelatinolytic activity associated with down-regulation of SOD2 protein; (2) endoplasmic reticulum stress by up-regulation of chaperone BiP protein and unfolded protein response (UPR) transcription factors (eIF2α, ATF6, XBP1u proteins) and by PTP-1B down-regulation in both mRNA and protein levels; (3) inflammation through enhanced synthesis of proinflammatory cytokines (IL6, IL8 proteins); and (4) apoptosis by enforced proteic expression of CHOP multifunctional transcription factor. Oleic acid alone had opposite effects due to its different capacity of controlling these metabolic pathways, in particular by reduction of the ROS levels and MMP-2 activity, down-regulation of BiP, eIF2α, ATF6, XBP1u, CHOP, IL6, IL8 and by SOD2 and PTP-1B overexpression. The supplementation of saturated palmitic acid with the monounsaturated oleic acid reversed the negative effects of palmitic acid alone regulating insulin secretion from pancreatic beta cells through ROS, MMP-2, ATF6, XBP1u, IL8 reduction and SOD2, PTP-1B activation. Our findings have shown the protective action of oleic acid against palmitic acid on beta cell lipotoxicity through promotion of triglyceride accumulation and insulin secretion and regulation of some effector molecules involved in oxidative stress, endoplasmic reticulum stress, inflammation and apoptosis.

Current Hypertension Reports, 2016

Purpose of Review Hypertension is either a cause or a consequence of the endothelial dysfunction ... more Purpose of Review Hypertension is either a cause or a consequence of the endothelial dysfunction and a major risk factor for cardiovascular disease (CVD). In vitro and in vivo studies established that microRNAs (miRNAs) are decisive for endothelial cell gene expression and function in various pathological conditions associated with CVD. This review provides an overview of the miRNA role in controlling the key connections between endothelial dysfunction and hypertension. Recent Findings Herein we summarize the present understanding of mechanisms underlying hypertension and its associated endothelial dysfunction as well as the miRNA role in endothelial cells with accent on the modulation of renin-angiotensin-aldosterone-system, nitric oxide, oxidative stress and on the control of vascular inflammation and angiogenesis in relation to endothelial dysfunction in hypertension. In particular, latest insights in the identification of endothelialspecific microRNAs and their targets are added to the understanding of miRNA significance in hypertension. Summary This comprehensive knowledge of the role of miRNAs in endothelial dysfunction and hypertension and of molecular mechanisms proposed for miRNA actions may offer novel diagnostic biomarkers and therapeutic targets for controlling hypertension-associated endothelial dysfunction and other cardiovascular complications.

Biochemical and biophysical research communications, Jan 25, 2016

The recognition of the importance of diabetes in vascular disease has greatly increased lately. C... more The recognition of the importance of diabetes in vascular disease has greatly increased lately. Common risk factors for diabetes-related vascular disease include hyperglycemia, insulin resistance, dyslipidemia, inflammation, hypercoagulability, hypertension, and atherosclerosis. All of these factors contribute to the endothelial dysfunction which generates the diabetic complications, both macro and microvascular. Knowledge of diabetes-related vascular complications and of associated mechanisms it is becoming increasingly important for therapists. The discovery of microparticles (MPs) and their associated microRNAs (miRNAs) have opened new perspectives capturing the attention of basic and clinical scientists for their potential to become new therapeutic targets and clinical biomarkers. MPs known as submicron vesicles generated from membranes of apoptotic or activated cells into circulation have the ability to act as autocrine and paracrine effectors in cell-to-cell communication. The...

Biology of the Cell, 2016

Background InformationAtherosclerosis is an inflammatory disease, in which risk factors such as h... more Background InformationAtherosclerosis is an inflammatory disease, in which risk factors such as hyperlipidemia and hypertension affect the arterial endothelium, resulting in dysfunction, cell damage or both. The number of circulating endothelial progenitor cells and microparticles provides invaluable outcome prediction for atherosclerosis disease. However, evidence for the therapeutic potential of endothelial progenitor cells and microparticles in atherosclerosis development is limited. Our study was designed to investigate the possible protective role of a cell therapy‐based approach, using endothelial progenitor cells and the dual behaviour of circulating platelet microparticles, on atherosclerosis development in hypertensive‐hypercholesterolemic hamster model. Consequently, control hamsters received four intravenous inoculations of: (1) 1×105 endothelial progenitor cells of healthy origins in one dose per month, during four months of diet‐induced atherosclerosis, and after hypert...

Farmacia

Endothelial progenitor cells (EPCs) and circulating microparticles (MPs) have been proposed as ma... more Endothelial progenitor cells (EPCs) and circulating microparticles (MPs) have been proposed as markers of endothelial function. In turn, the protective role of irbesartan, an angiotensin receptor blocker, on the endothelium has been demonstrated in the recent years but the mechanism has not been yet fully elucidated. In this context, we investigated whether irbesartan can influence these two new biomarkers in patients with cardiovascular (CV) risk factors. We compared the levels of EPCs and MPs in patients with hypertension and dyslipidemia which received irbesartan with the levels in patients with the same CV risk factors but receiving other antihypertensive drugs and in healthy individuals. Using this methodology we showed the positive effect of angiotensin receptor blockade on the two proposed markers of endothelial function, reflecting both endothelial injury and repair, MPs and EPC respectively, in the same subjects with cardiovascular risk factors. Moreover, we found that patients with hypertension and dyslipidemia display an altered balance between the levels of endothelial regenerative cells like EPCs and markers of endothelial injury like circulating MPs. Rezumat Celulele endoteliale progenitoare (EPC) si microparticulele circulante (MP) au fost propuse ca markeri ai funcţiei endoteliale. Pe de altă parte, in ultimii ani a fost demonstrat rolul protector al irbesartanului, un blocant al receptorilor de angiotensină, asupra endoteliului, dar mecanismul implicat nu a fost complet elucidat. In acest context am studiat potenţialul irbesartanului de a influenţa acesti noi biomarkeri la pacienţii cu factori de risc cardiovasculari (CV). Am comparat nivelurile circulante de EPC si MP la pacienţi cu hipertensiune arterială si dislipidemie ce au primit tratament cu irbesartan, cu cele măsurate la pacienţi cu aceiasi factori de risc CV, dar trataţi cu altă clasă de medicamente antihipertensive si la indivizi sănătosi. Cu ajutorul aceastei metodologii am demonstrat efectul benefic al blocadei receptorilor de angiotensină asupra markerilor de disfuncţie endotelială ce reflectă atât afectarea cât si procesul reparator endotelial, MP si EPC

Biology of the Cell, 2015

Background informationRecent studies suggest that endothelial progenitor cells (EPCs) and platele... more Background informationRecent studies suggest that endothelial progenitor cells (EPCs) and platelets have an important role in repair following vascular injury. Although evidence suggest that platelets are essential in EPC attracting, homing and differentiation to the injury site; however, the platelet effects on EPC function in atherosclerosis have received less attention. In this context, we followed the consequences of circulating EPCs and platelet microparticles (PMPs) administration on platelet–EPC interaction in atherosclerosis and the involved mechanisms. The experiments were performed on Golden Syrian hamsters divided in five equal groups: control (C), hypertensive–hypercholesterolemic (HH), HH treated with EPCs (HH–EPCs) or PMPs (HH–PMPs) and HH treated with EPCs and PMPs (HH–EPCs–PMPs).ResultsCompared with C group, EPCs isolated from HH and HH–PMPs groups presented a reduction of endothelial nitric oxide synthase and vascular endothelial growth factor expressions and an inc...

Clinical laboratory, 2011

Chronic venous insufficiency (CVI) is a common medical problem that may result in significant mor... more Chronic venous insufficiency (CVI) is a common medical problem that may result in significant morbidity and mortality. Platelets are key players in haemostasis and thrombosis, but their role in the development of venous thrombosis is more controversial. The purpose of this study was to investigate platelet properties in CVI and their interaction with the venular endothelium. Human peripheral venules were explanted during leg surgery of patients with CVI and of healthy subjects (C); concurrently, the platelets were isolated from blood samples collected. The techniques used were: fluorescence and electron microscopy and Western-blotting. Compared with the C group, the platelets of patients with CVI are activated, as demonstrated by: (i) cellular modifications, such as alteration of the discoidal shape by the development of extended cytoplasmic filopodia and changes of the cells normal ultrastructure, (ii) biochemical modifications, such as the enhanced protein levels of FAK, p85 PI3K,...

PLoS ONE, 2013

Aim: The purpose of this project was to evaluate the influence of circulating endothelial progeni... more Aim: The purpose of this project was to evaluate the influence of circulating endothelial progenitor cells (EPCs) and platelet microparticles (PMPs) on blood platelet function in experimental hypertension associated with hypercholesterolemia. Methods: Golden Syrian hamsters were divided in six groups: (i) control, C; (ii) hypertensive-hypercholesterolemic, HH; (iii) 'prevention', HHin-EPCs, HH animals fed a HH diet and treated with EPCs; (iv) 'regression', HHfin-EPCs, HH treated with EPCs after HH feeding; (v) HH treated with PMPs, HH-PMPs, and (vi) HH treated with EPCs and PMPs, HH-EPCs-PMPs. Results: Compared to HH group, the platelets from HHin-EPCs and HHfin-EPCs groups showed a reduction of: (i) activation, reflected by decreased integrin 3b, FAK, PI3K, src protein expression; (ii) secreted molecules as: SDF-1, MCP-1, RANTES, VEGF, PF4, PDGF and (iii) expression of pro-inflammatory molecules as: SDF-1, MCP-1, RANTES, IL-6, IL-1b; TFPI secretion was increased. Compared to HH group, platelets of HH-PMPs group showed increased activation, molecules release and proteins expression. Compared to HH-PMPs group the combination EPCs with PMPs treatment induced a decrease of all investigated platelet molecules, however not comparable with that recorded when EPC individual treatment was applied. Conclusion: EPCs have the ability to reduce platelet activation and to modulate their pro-inflammatory and antithrombogenic properties in hypertension associated with hypercholesterolemia. Although, PMPs have several beneficial effects in combination with EPCs, these did not improve the EPC effects. These findings reveal a new biological role of circulating EPCs in platelet function regulation, and may contribute to understand their cross talk, and the mechanisms of atherosclerosis.

Trends in Cardiovascular Medicine, 2010

This article provides an overview of the current knowledge on intraplatelet oxidative/nitrative s... more This article provides an overview of the current knowledge on intraplatelet oxidative/nitrative stress, an abnormality associated with platelet activation and hyper-reactivity. The first issue discussed is related to induction of platelet endogenous stress by the molecules present within the circulating (extracellular) milieu that bathes these cells. The second issue concerns the intraplatelet oxidative/nitrative stress associated with specific pathologies or clinical procedures and action of particular molecules and platelet agonists as well as of the specialized intraplatelet milieu and its redox system; the biomarkers of endogenous oxidative/nitrative stress are also briefly outlined. Next, the association between intraplatelet oxidative/nitrative stress and the risk factors of the metabolic syndrome is presented. Then, the most recent strategies aimed at the control/regulation of platelet endogenous oxidative/nitrative stress, such as exploitation of circulating extracellular reactive oxygen species scavengers, manipulation of platelet molecules, and the use of antioxidants, are discussed. Finally, the results of studies on platelet-dependent redox mechanisms, which deserve immediate attention for potential clinical exploitation, are illustrated.

Journal of Thrombosis and Haemostasis, 2011

The aim of this study was to determine the effect of simultaneous hypertension and hypercholester... more The aim of this study was to determine the effect of simultaneous hypertension and hypercholesterolemia on platelet activation, nitric oxide (NO) production and oxidative stress, and to evaluate the role of irbesartan, an angiotensin II type 1 receptor antagonist. Methods: Golden Syrian hamsters were divided into three groups: controls, C (fed a standard diet); hypertensive-hypercholesterolemic, HH (fed a diet enriched in 3% cholesterol, 15% butter and 8% NaCl, for 4 months); and hypertensive-hypercholesterolemic treated with irbesartan, HHI (fed as HH group, plus irbesartan 10 mg kg)1 per day, for 4 months). Results: Compared with the C group, platelets isolated from the HH group showed: morphological modifications; increased integrin b3 exposure and protein expression of P-selectin, FAK, PI3K, Akt and Src; reduced eNOS protein expression and NO production; higher generation of ROS, mostly produced by NADPH-oxidase, cyclooxygenase-1 (COX-1) and 12lipoxygenase; and enhanced NAD(P)H oxidase activity and protein expression of gp91phox and p22phox subunits, 12lipoxygenase, COX-1, cPLA 2 and PKC. Compared with the HH group, the treatment with irbesartan (HHI group) significantly attenuates the changes in all the molecules tested, reduces platelet aggregation, and improves intraplatelet redox balance. Conclusions: Experimental hypertension associated with hypercholesterolemia produces major changes in morphology, signaling mechanisms and oxidative stress in blood platelets. These changes were significantly diminished by irbesartan administration, which functions as an antioxidant on platelets.