Effects of aspirin on number, activity and inducible nitric oxide synthase of endothelial progenitor cells from peripheral blood

Chemical composition, biological activities, and quality standards of hawthorn leaves used in traditional Chinese medicine: a comprehensive review

Hawthorn leaves also known as crataegi foilum, are a combination of botanical drugs used commonly in Traditional Chinese Medicine. Hawthorn, the plant from which hawthorn leaves are prepared, is distributed in Northeast China, North China, and other regions in China. Hawthorn leaves are known to activate blood circulation and eliminate stasis, invigorating Qi, eliminating turbidity, and reducing the levels of lipids. So far, over a hundred compounds have been isolated from hawthorn leaves, including flavonoids, terpenoids, lignans, organic acids, and nitrogenous compounds. Hawthorn leaves are used for the treatment of hypertension, protecting against ischemic injury, angina, hyperglycemia, hyperlipidemia, and certain other conditions. Several of the currently available clinical preparations also use hawthorn leaves as raw materials, such as Yixintong capsules, Xinan capsules, etc. The present report systematically reviews the chemical composition, biological activities, and quality standards of hawthorn leaves, to provide a scientific basis and reference for detailed research on hawthorn leaves.

Fetal endothelial colony-forming cell impairment after maternal kidney transplantation

BACKGROUND

Successful pregnancies are nowadays possible after kidney transplantation but are associated with a higher incidence of maternal and fetal complications. Immunosuppressive therapy causes cardiovascular side effects but must be maintained during pregnancy. Little is known about the consequences of maternal kidney transplantation on offspring's endothelial health. Endothelial colony forming cells (ECFCs) represent a highly proliferative subtype of endothelial progenitor cells and are crucial for vascular homeostasis, repair and neovascularization. Therefore, we investigated whether maternal kidney transplantation affects fetal ECFCs' characteristics.

METHODS

ECFCs were isolated from umbilical cord blood of uncomplicated and post-kidney-transplant pregnancies and analyzed for their functional abilities with proliferation, cell migration, centrosome orientation and angiogenesis assays. Further, ECFCs from uncomplicated pregnancies were exposed to either umbilical cord serum from uncomplicated or post-kidney-transplant pregnancies.

RESULTS

Post-kidney-transplant ECFCs showed significantly less proliferation, less migration and less angiogenesis compared to control ECFCs. The presence of post-kidney-transplant umbilical cord serum led to similar functional aberrations of ECFCs from uncomplicated pregnancies.

CONCLUSIONS

These pilot data demonstrate differences in ECFCs' biological characteristics in offspring of women after kidney transplantation. Further studies are needed to monitor offspring's long-term cardiovascular development and to assess possible causal relationships with immunosuppressants, uremia and maternal cardiovascular alterations.

IMPACT

Pregnancy after kidney transplantation has become more common in the past years but is associated with higher complications for mother and offspring. Little is known of the impact of maternal kidney transplantation and the mandatory immunosuppressive therapy on offspring vascular development. In this study we are the first to address and detect an impairment of endothelial progenitor cell function in offspring of kidney-transplanted mothers. Serum from post-transplant pregnancies also causes negative effects on ECFCs' function. Clinical studies should focus on long-term monitoring of offspring's cardiovascular health.

Effects and safety of aspirin use in patients after cerebrovascular bypass procedures

Object

Superficial temporal artery to middle cerebral artery (STA-MCA) bypass is the most effective treatment for Moyamoya disease (MMD). In this study, we aimed to assess whether aspirin improves STA-MCA bypass patency and is safe in patients with MMD.

Methods

We performed a retrospective medical record review of patients with ischaemic-onset MMD who had undergone STA-MCA bypass at two hospitals between January 2011 and August 2018, to clarify the effects and safety of aspirin following STA-MCA bypass. The neurological status at the last follow-up (FU) was compared between patients with FU bypass patency and occlusion.

Results

Among 217 identified patients (238 hemispheres), the mean age was 41.4±10.2 years, and 51.8% were male; the indications for STA-MCA bypass were stroke (48.2%), followed by a transient ischaemic attack (44.0%). Immediate bypass patency was confirmed in all cases. During the FU period (1.5±1.5 y), 15 cases were occluded at FU imaging, resulting in an overall cumulative patency rate of 94%. The patency rates were 93% and 94% in the short-term FU group (n=131, mean FU time 0.5±0.2 years) and long-term FU group (n=107, mean FU time 4.1±3.5 years), respectively. The STA-MCA bypass patency rate in the aspirin group was higher than that in the non-aspirin group (98.7% vs 89.7%; HR 1.57; 95% CI 1.106 to 2.235; p=0.012). No significant difference in the FU haemorrhagic events was observed between the aspirin and non-aspirin groups.

Conclusions

Among adult patients with ischaemic-onset MMD undergoing STA-MCA bypass procedures, aspirin might increase the bypass patency rate, without increasing the bleeding risk. FU bypass patency may be associated with a better outcome. Additional studies, especially carefully designed prospective studies, are needed to address the role of aspirin after bypass procedures.

Nonsteroidal Anti-Inflammatory Drugs: A Potential Pharmacological Treatment for Intracranial Aneurysm

Background

Saccular intracranial aneurysms (IAs) are outpouchings of the vessel wall of intracranial arteries. Rupture of IAs results in subarachnoid hemorrhage which is associated with high morbidity and mortality. Surgical interventions, such as clipping and coiling, have associated risks. Currently, there are no proven pharmacological treatments to prevent the growth or rupture of IAs. Infiltration of proinflammatory cytokines in response to increased wall sheer stress is a hallmark of IA. Nonsteroidal anti-inflammatory drugs (NSAIDs) are being investigated as potential therapeutic agents for reduction in growth and/or prevention of IA through inhibition of inflammatory pathways.

Summary

This review will discuss the role of NSAIDs in attenuating the inflammation that drives IA progression and rupture. There are two main subtypes of NSAIDs, nonselective COX and selective COX-2 inhibitors, both of which have merit in treating IA. Evidence will be presented which shows that NSAIDs inhibit several key inflammatory mediators involved in IA progression including nuclear factor-κB, tumor necrosis factor-α, and matrix metalloproteinases. In addition, the role of NSAIDs in limiting inflammatory cell adhesion to endothelial cells and attenuating endothelial cell senescence will be discussed.

Key Messages

There is an abundance of basic science and preclinical data that support NSAIDs as a promising treatment for IA. Additionally, a combination treatment strategy of low-dose aspirin given concomitantly with a selective COX-2 inhibitor may result in a reduced side effect profile compared to aspirin or selective COX-2 inhibitor use alone. Several large clinical trials are currently planned to further investigate the efficacy of NSAIDs as an effective nonsurgical treatment for IAs.

A new method to optimize root order classification based on the diameter interval of fine root

Plant roots are a highly heterogeneous and hierarchical system. Although the root-order method is superior to the root diameter method for revealing differences in the morphology and physiology of fine roots, its complex partitioning limits its application. Whether root order can be determined by partitioning the main root based on its diameter remains uncertain. Four methods were employed for studying the morphological characteristics of seedling roots of two Pinus species in a natural and nitrogen-enriched environment. The intrinsic relationships among categories of roots by root order and diameter were systematically compared to explore the possibility of using the latter to describe root morphology. The normal transformation method proved superior to the other three in that the diameter intervals corresponded most closely (at least 68.3%) to the morphological characteristics. The applied methods clearly distinguished the results from the natural and nitrogen-rich environments. Considering both root diameter and order simplified the classification of fine roots, and improved the estimation of root lifespan and the data integrity of field collection, but failed to partition all roots into uniform diameter intervals.

Co-administration of aspirin and allogeneic adipose-derived stromal cells attenuates bone loss in ovariectomized rats through the anti-inflammatory and chemotactic abilities of aspirin

Introduction

Osteoporosis is a syndrome of excessive skeletal fragility characterized by the loss of mass and deterioration of microarchitecture in bone. Single use of aspirin or adipose-derived stromal cells (ASCs) has been recognized recently to be effective against osteoporosis. The goal of the study was to evaluate the osteogenic effects of the co-administration of aspirin and allogeneic rat adipose-derived stromal cells (rASCs) on ovariectomized (OVX)-induced bone loss in rats. The underlying mechanisms were investigated in vitro and in vivo.

Methods

Firstly, allogeneic rASCs were isolated and cultured, and the conditioned medium (CM) from the maintenance of rASCs was collected. Secondly, the OVX rats were administrated CM, rASCs, aspirin (ASP) or rASCs + ASP, respectively. Twelve weeks later, the anti-inflammatory and osteogenic effects were assessed by micro-CT, undecalcified histological sections, dynamic histomorphometric analyses and serologic assays for biochemical markers. Finally, a Transwell migration assay in vitro and cell-trafficking analyses in vivo were used to explore the effects of aspirin on rASC migration.

Results

Systemic administration of aspirin and rASCs attenuated OVX-induced bone loss better than single use of aspirin or ASCs (p < 0.05, respectively). Next, we analyzed the underlying mechanisms of the anti-inflammatory and chemotactic abilities of aspirin. Aspirin suppressed serum levels of the pro-inflammatory cytokines on tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), and the anti-inflammatory ability was positively associated with bone morphometry. Also, aspirin exhibited excellent chemotactic effects in vitro and accelerated the homing of allogeneic rASCs into bone marrow during early in vivo stages.

Conclusions

Co-administered aspirin and allogeneic ASCs can partially reverse OVX-induced bone loss in rats. This effect appears to be mediated by the anti-inflammatory and chemotactic abilities of aspirin.

Impact of lysophosphatidylcholine on survival and function of UEA-1(+)acLDL (+) endothelial progenitor cells in patients with coronary artery disease

Lysophosphatidylcholine (LPC) generated from oxidized low-density lipoprotein by lipoprotein-associated phospholipase A2 plays a key role in plaque inflammation and vulnerability. Endothelial progenitor cells (EPCs) can repair injured endothelium and exert anti-inflammatory effects of vulnerable plaque. We study the impact and mechanisms of LPC on UEA-1 and acLDL binding EPCs (UEA-1(+)acLDL(+) EPCs). UEA-1(+)acLDL(+) EPCs from coronary artery disease (CAD) patients were cultured and exposed to LPC at different concentrations and different timepoints. We determined the significant concentration (40 μM). UEA-1(+)acLDL(+) EPCs were preincubated for 30 min with pravastatin (20 μM) with LY249002, a specific inhibitor of the Akt signaling pathway, and exposed for 24 h to LPC 40 μM. The survival, migration, adhesion, and proliferation of UEA-1(+)acLDL(+) EPCs were assessed. To examine the mechanisms of LPC toxicity and pravastatin effects, phosphorylated Akt and endothelial nitric oxide synthase (eNOS) levels and the ratio of Bcl-2/Bax protein expression were assessed. LPC induced apoptosis and impaired migration and adhesion of UEA-1(+)acLDL(+) EPCs significantly. The detrimental effects of LPC were attenuated by pravastatin. However, when UEA-1(+)acLDL(+) EPCs were pretreated with pravastatin and LY249002, a specific inhibitor of the Akt signaling pathway, simultaneously, the beneficial effects of pravastatin were abolished. Furthermore, LPC suppressed Akt and eNOS phosphorylation and increased Bcl-2/Bax expression. The effects of LPC on Akt/eNOS and Bcl-2/Bax activity were reversed by pravastatin. In conclusion, LPC inhibited UEA-1(+)acLDL(+) EPCs survival and impaired its functions, and these were attributable to inhibition of the Akt/eNOS and Bcl-2/Bax pathway. Pravastatin reversed the detrimental action of LPC. These findings suggest that LPC inhibition can be a possible strategy for CAD through EPC revitalization.

Death in the substantia nigra: a motor tragedy

It is well known that the death of dopaminergic neurons of the substantia nigra pars compacta (SNc) is the pathological hallmark of Parkinson's disease (PD), the second most common and disabling condition in the expanding elderly population. Nevertheless, the intracellular cascade of events leading to dopamine cell death is still unknown and, consequently, treatment is largely symptomatic rather than preventive. Moreover, the mechanisms whereby nigral dopaminergic neurons may degenerate still remain controversial. Hitherto, several data have shown that the earlier cellular disturbances occurring in dopaminergic neurons include oxidative stress, excitotoxicity, inflammation, mitochondrial dysfunction and altered proteolysis. These alterations, rather than killing neurons, trigger subsequent death-related molecular pathways, including elements of apoptosis. In rare incidences, PD may be inherited; this evidence has opened a new and exciting area of research, attempting to shed light on the nature of the more common idiopathic PD form. In this review, the characteristics of the SNc dopaminergic neurons and their lifecycle from birth to death are reviewed. In addition, of the mechanisms by which the aforementioned alterations cause neuronal dopaminergic death, particular emphasis will be given to the role played by inflammation, and the relevance of the possible use of anti-inflammatory drugs in the treatment of PD. Finally, new evidence of a possible de novo neurogenesis in the SNc of adult animals and in PD patients will also be examined.

Does drug therapy reverse endothelial progenitor cell dysfunction in diabetes?

Endothelial progenitor cells (EPCs) are vital for the maintenance and repair of the endothelium. Decreased EPC number and function have been associated with increased cardiovascular (CVD) risk. Patients with diabetes have decreased number of circulating EPCs and decreased EPC function. This may account for some of the increased CVD risk seen in patients with diabetes that is not explained by traditional risk factors such as glycemic control, dyslipidemia and hypertension. Recent studies seem to indicate that drugs commonly used in diabetes patients such as metformin, thiazolidinediones, GLP-1 agonists, DPP-4 inhibitors, insulin, statins and ACE inhibitors may increase EPC number and improve EPC function. The mechanisms by which these drugs modulate EPC function may involve reduction in inflammation, oxidative stress and insulin resistance as well as an increase in nitric oxide (NO) bioavailability. This review will discuss the evidence in the literature regarding the above mentioned topics.

Pinocembrin, a major flavonoid in propolis, improves the biological functions of EPCs derived from rat bone marrow through the PI3K-eNOS-NO signaling pathway

The number and quality of endothelial progenitor cells (EPCs) are damaged to varying degrees in patients at risk for developing atherosclerosis. The improvement of the quantity and functions of EPCs can enhance repair of injured endothelial monolayer resulting in inhibiting atherosclerosis. The purpose of this study was to investigate the effect of pinocembrin (PIN), a major flavonoid in propolis on the differentiation and biological functions of EPCs and the potential mechanisms of these effects. Flow cytometry analysis revealed that PIN treatment increased the number of CD34(+), CD133(+), FLK-1(+), CD133(+)/FLK-1(+) and CD34(+)/FLK-1(+) mononuclear cells (MNCs) in the peripheral blood of apoE(-/-) mice compared to untreated control mice. In vitro PIN treatment significantly increased the number of CD34(+), CD133(+), FLK-1(+) and CD133(+)/FLK-1(+) MNCs derived from SD bone marrow compared to untreated controls by 42.1, 84.6, 165.9 and 23.1 %, respectively. Additionally, PIN can improve biological functions of EPCs, such as proliferation, migration, adhesion, and in vitro tube formation and NO release. All of these improvements were inhibited by LY294002, while L-NAME only inhibited the PIN-induced increase in EPC proliferation and adhesion. We conclude that PIN can both promote the differentiation of EPCs in vitro and ex vivo and improve the biological functions of EPCs. The PI3K-eNOS-NO signaling pathway may be involved in the PIN-induced increase in the proliferation and adhesion of EPCs.

Effects of tumour necrosis factor-alpha on activity and nitric oxide synthase of endothelial progenitor cells from peripheral blood

The aim of this investigation was to determine whether tumour necrosis factor-alpha (TNF-α) has any effect on endothelial progenitor cells (EPCs). Total mononuclear cells were isolated from peripheral blood by Ficoll density gradient centrifugation, and then the cells were plated on fibronectin-coated culture dishes. After 7 days culture, attached cells were stimulated with tumour necrosis factor-α (final concentrations: 0, 10, 20, 50 and 100 mg/l) for 0, 6, 12, 24 and 48 h. EPCs were characterized as adherent cells double positive for DiLDL-uptake and lectin binding, by direct fluorescence staining. EPC proliferation and migration were assayed using the MTT assay and modified Boyden chamber assay, respectively. EPC adhesion assay was performed by re-plating those cells on fibronectin-coated dishes, and adherent cells were counted. Tube formation activity was assayed using a tube formation kit. Levels of apoptosis were revealed using an annexin V apoptosis detection kit. Vascular endothelial growth factor Receptor-1 (VEGF-R1) and stromal derived factor-1 (SDF-1) mRNA, assessed by real-time RT-PCR inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) were assayed by western blot analysis. Incubation of EPCs with tumour necrosis factor-α reduced EPC proliferation, migration, adhesion, tube formation capacity, iNOS and eNOS in concentration- and time-dependent manners. Tumour necrosis factor-α reduced proliferation, migration, adhesion and tube formation capacity of EPCs. TNF-α increased EPC apoptosis level, reduced VEGF-R1 and SDF-1 mRNA expression; tumour necrosis factor-α also reduced iNOS and eNOS in the EPCs.

The effect of aspirin on endothelial progenitor cell biology: preliminary investigation of novel properties

Atherosclerosis develops in an environment of endothelial injury and inflammation. Circulating endothelial progenitor cells (EPCs) are required for vascular repair and restoration of normal endothelial function. We tested the hypothesis that the nonselective cyclooxygenase (COX) inhibitor aspirin (ASA) exerts an effect on circulating EPCs.

METHODS

As part of a larger study evaluating the effect of aspirin dose in primary and secondary prevention, subjects (n=32) were assigned randomly to either 81 mg or 325 mg aspirin daily for two months, and circulating mononuclear cells were enumerated at the beginning of the study and after 2 months using fluorescent antibodies against CD34 and CD133 as well as based on aldehyde dehydrogenase (ALDH) activity. Brachial artery endothelial function via flow-mediated dilation (BAFMD) and light transmittance platelet aggregometry in response to physiologic agonists was also determined.

RESULTS

Subjects taking aspirin at the time of study entry had a lower numbers of CD133+/34+ cells compared to those not previously exposed (0.01% vs. 0.05% of MNCs, P<0.03). After 2 months, subjects randomized to 81 vs. 325 mg of ASA had no significant differences in the median numbers of EPCs, although mean numbers trended lower in the high dose group. Patients on chronic ASA therapy continued to have lower numbers of EPCs. Similar effects were observed in CD34 and CD 133 single-positive cells, as well as ALDH(br) cells. BAFMD did not differ nor change significantly over time between aspirin dose groups. All patients had decreased ex vivo platelet aggregation in response to arachidonic acid and ADP stimulation.

CONCLUSIONS

Our preliminary studies suggest that aspirin exerts a time-dependent effect on circulating EPCs. Short-term exposure to differing doses of ASA had indeterminate effects on EPCs levels, suggesting that time of ASA exposure may play a more important role than dose. Determining the responsible mechanism(s) and the overall clinical relevance of these findings will require further investigation.

Current perspective of pathophysiological and interventional effects on endothelial progenitor cell biology: focus on PI3K/AKT/eNOS pathway

For more than a decade, endothelial progenitor cells (EPCs) have been implicated in cardiovascular homeostasis. EPCs are believed to reside within the bone marrow in close contact with surrounding stromal cells, and, under stimulation of pro-inflammatory cytokines, EPCs are mobilized out of the bone marrow. Hereafter circulating EPCs home to peripheral tissues, undergoing further proliferation and differentiation. Under certain pathophysiologic conditions this process seems to be blunted, resulting in a reduced capacity of EPCs to engage in vasculogenesis at sites of endothelial injury or tissue ischemia. In this review, we focus on the effects of traditional cardiovascular risk factors on EPC biology and we explore whether pharmacological, dietary and lifestyle interventions can favorably restore EPC mobilization, differentiation, homing and angiogenic properties. Because the PI3K/Akt/eNOS pathway plays a pivotal role in the process of EPC mobilization, migration and homing, we specifically emphasize the involvement of PI3K, Akt and eNOS in EPC biology under these different (patho)physiologic conditions. (Pre)clinically used drugs or lifestyle interventions that have been shown to ameliorate EPC biology are reviewed. These treatment strategies remain attractive targets to restore the regenerative capacity of EPCs in cardiovascular diseases.

Stimulation of endothelial progenitor cells: a new putative effect of several cardiovascular drugs

The role of vascular endothelium in cardiovascular disorders is well recognized. Mature endothelial cells contribute to the repair of endothelial injury, but they only have a limited capacity to do so. This has led to growing interest and further investigation into circulating endothelial progenitor cells (EPCs) and their role in vascular healing, repair, and postnatal neovascularization. The current perception of vascular health is that of a balance between ongoing injury and resultant vascular repair, mediated at least in part by circulating EPCs. Circulating EPCs play an important role in accelerating endothelialization at areas of vascular damage, and EPC enumeration is a viable strategy for assessing reparative capacity. Recent studies have shown that EPCs are affected both in number and function by several cardiovascular risk factors as well as various cardiovascular disease states, such as hypertension, hypercholesterolemia, and coronary artery disease. The present review summarizes the most relevant studies on the effects of cardiovascular drugs on vascular function and EPCs, focusing on their mechanisms of action.

Emerging hematological targets and therapy for cardiovascular disease: From bench to bedside

Atherosclerotic cardiovascular disease is the leading cause of death and a major part of its pathophysiology remains obscure. Some hematological targets have been related to the development and clinical outcome of this disease, especially soluble cytokines, leukocytes, red blood cells, hemostatic factors and platelets, and bone-marrow vascular progenitors. These emerging factors may be modulated by current antiatherosclerotic pharmacotherapy, target-designed novel drugs or progenitor cell therapy. The aim of current review article is to comprehensively review the role of these antiatherosclerotic targets and therapy.

Endothelial progenitor cells and arterial functions in the late convalescence period of Kawasaki disease

AIM

The relationship was investigated between endothelial progenitor cells (EPCs) level and arterial functions in the convalescence of Kawasaki disease (KD).

METHODS

Sixty-three children were divided into coronary artery lesion (CAL) group (group 1, n = 21), non-CAL group (group 2, n = 20) and control group (group 3, n = 22). EPCs were examined by flow cytometry and arterial functions (flow-mediated dilation [FMD], carotid artery stiffness index [SI]) were measured by ultrasound.

RESULTS

From group 1 to group 3, FMD was 4.5%+/- 1.5%, 9.5%+/- 2.8% and 12.1%+/- 2.3% (p < 0.01 between any two groups); carotid artery SI was 4.10 +/- 0.44, 3.81 +/- 0.50 and 3.59 +/- 0.46 (group 1 vs. group 2, p < 0.05; group 1 vs. group 3, p < 0.01; group 2 vs. group 3, p = 0.142) and the number of EPCs was 2.0 +/- 0.6/microL, 4.2 +/- 0.8/microL, 4.5 +/- 0.7/microL (p < 0.01 for group 1 vs. group 2 and group 1 vs. group 3; group 2 vs. group 3, p = 0.292). Multiple linear regressions analysis and correlation analysis identified that FMD and carotid artery SI were significant determinants of EPCs level and were all independently correlated with EPCs level.

CONCLUSIONS

Our results indicate decreased EPCs are associated with arterial dysfunction in patients with CAL in the convalescence of KD. Our findings suggest EPCs may have a role in alteration of arterial functions.