Pathophysiology of coronary vascular remodeling: relationship with traditional risk factors for coronary artery disease

TGF-β/Smads signaling pathway, Hippo-YAP/TAZ signaling pathway, and VEGF: Their mechanisms and roles in vascular remodeling related diseases

Vascular remodeling is a basic pathological process in various diseases characterized by abnormal changes in the morphology, structure, and function of vascular cells, such as migration, proliferation, hypertrophy, and apoptosis. Various growth factors and pathways are involved in the process of vascular remodeling. The transforming growth factor-β (TGF-β) signaling pathway, which is mainly mediated by TGF-β1, is an important factor in vascular wall enhancement during vascular development and regulates the vascular response to injury by promoting the accumulation of intimal tissue. Vascular endothelial growth factor (VEGF) has an important effect on initiating the formation of blood vessels. The Hippo-YAP/TAZ signaling pathway also plays an important role in angiogenesis. In addition, studies have shown that there is a certain interaction between the TGF-β/Smads signaling pathway, Hippo-YAP/TAZ signaling pathway, and VEGF. Many studies have shown that in the development of atherosclerosis, hypertension, aneurysm, vertebrobasilar dolichoectasia, pulmonary hypertension, restenosis after percutaneous transluminal angioplasty, and other diseases, various inflammatory reactions lead to changes in vascular structure and vascular microenvironment, which leads to vascular remodeling. The occurrence of vascular remodeling changes the morphology of blood vessels and thus changes the hemodynamics, which is the cause of further development of the disease process. Vascular remodeling can cause vascular smooth muscle cell dysfunction and vascular homeostasis regulation. This review aims to explore the mechanisms of the TGF-β/Smads signaling pathway, Hippo-YAP/TAZ signaling pathway, and vascular endothelial growth factor in vascular remodeling and related diseases. This paper is expected to provide new ideas for research on the occurrence and development of related diseases and provide a new direction for research on the treatment of related diseases.

Mechanobiology of Microvascular Function and Structure in Health and Disease: Focus on the Coronary Circulation

The coronary microvasculature plays a key role in regulating the tight coupling between myocardial perfusion and myocardial oxygen demand across a wide range of cardiac activity. Short-term regulation of coronary blood flow in response to metabolic stimuli is achieved via adjustment of vascular diameter in different segments of the microvasculature in conjunction with mechanical forces eliciting myogenic and flow-mediated vasodilation. In contrast, chronic adjustments in flow regulation also involve microvascular structural modifications, termed remodeling. Vascular remodeling encompasses changes in microvascular diameter and/or density being largely modulated by mechanical forces acting on the endothelium and vascular smooth muscle cells. Whereas in recent years, substantial knowledge has been gathered regarding the molecular mechanisms controlling microvascular tone and how these are altered in various diseases, the structural adaptations in response to pathologic situations are less well understood. In this article, we review the factors involved in coronary microvascular functional and structural alterations in obstructive and non-obstructive coronary artery disease and the molecular mechanisms involved therein with a focus on mechanobiology. Cardiovascular risk factors including metabolic dysregulation, hypercholesterolemia, hypertension and aging have been shown to induce microvascular (endothelial) dysfunction and vascular remodeling. Additionally, alterations in biomechanical forces produced by a coronary artery stenosis are associated with microvascular functional and structural alterations. Future studies should be directed at further unraveling the mechanisms underlying the coronary microvascular functional and structural alterations in disease; a deeper understanding of these mechanisms is critical for the identification of potential new targets for the treatment of ischemic heart disease.

Impact of Arterial Remodeling of Intermediate Coronary Lesions on Long-Term Clinical Outcomes in Patients with Stable Coronary Artery Disease: An Intravascular Ultrasound Study

Background

Treatment of coronary intermediate lesions remains a controversy, and the role of arterial remodeling patterns determined by intravascular ultrasound in intermediate lesion is still not well known. The aim of this study was to investigate the impact of arterial remodeling of intermediate coronary lesions on long-term clinical outcomes.

Methods

Arterial remodeling patterns were assessed in 212 deferred intermediate lesions from 162 patients after IVUS examination. Negative, intermediate, and positive remodeling was defined as a remodeling index of <0.88, 0.88∼1.0, and >1.0, respectively. The primary endpoint was the composite vessel-oriented clinical events, defined as the composition of target vessel-related cardiac death, target vessel-related myocardial infarction, and target vessel revascularization. Quantitative flow ratio was assessed for evaluating the functional significance of intermediate lesions.

Results

72 intermediate remodeling lesions were present in 66 patients, whereas 77 negative remodeling lesions were present in 71 patients, and 63 positive remodeling lesions were present in 55 patients. Negative remodeling lesions had the smallest minimum lumen area (4.16 ± 1.03 mm² vs. 5.05 ± 1.39 mm² vs. 4.85 ± 1.76 mm²; P < 0.01), smallest plaque burden (63.45 ± 6.13% vs. 66.12 ± 6.82% vs. 71.17 ± 6.45%; P < 0.01), and highest area stenosis rate (59.32% ± 10.15% vs. 54.61% ± 9.09% vs. 51.67% ± 12.96%; P < 0.01). No significant difference was found in terms of quantitative flow ratio among three groups. At 5 years follow-up, negative remodeling lesions had a higher rate of composite vessel-oriented clinical event (14.3%), compared to intermediate (1.4%, P=0.004) or positive remodeling lesions (4.8%, P=0.06). After adjusting for multiple covariates, negative remodeling remained an independent determinant for vessel-oriented clinical event (HR: 4.849, 95% CI 1.542-15.251, P=0.007).

Conclusion

IVUS-derived negative remodeling is associated with adverse long-term clinical outcome in stable patients with intermediate coronary artery stenosis.

Diabetes, its duration, and the long-term risk of abdominal aortic aneurysm: The Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND AND AIMS

We aimed at comprehensively evaluate the independent association of diabetes and its duration with incident abdominal aortic aneurysm (AAA) and aortic diameter.

METHODS AND RESULTS

We prospectively studied incident AAA according to baseline glycemic status (diabetes, prediabetes, normal glycemia) in 13,116 ARIC participants (1990-1992) and the time-varying exposure of duration post incident diabetes in 11,675 participants (1987-1989) using Cox models. Additionally, we cross-sectionally explored ultrasound-based abdominal aortic diameter by glycemic status and cumulative duration of diabetes in 4710 participants (2011-2013) using linear regression models. Over ~20 years of follow-up, diabetes (vs. normal glycemia) at baseline was independently associated with lower AAA risk (489 cases) (hazard ratio: 0.71 [95%CI 0.51-0.99]), especially after 10 years (hazard ratio: 0.58 [0.38-0.87]). Prediabetes did not demonstrate an independent association. The inverse association was more evident with longer duration of diabetes (p for trend = 0.045), with 30-50% lower risk in eight years after diabetes diagnosis. The cross-sectional analysis demonstrated smaller aortic diameters with longer duration of diabetes (e.g., -0.76 mm [-1.24, -0.28] in diabetes with 8-12 years) compared to non-diabetes, whereas prediabetes consistently showed nominally greater diameter.

CONCLUSIONS

Diabetes, especially with longer duration, but not prediabetes, was independently associated with lower risk of AAA and smaller aortic diameter. Our findings suggest that long lasting clinical hyperglycemia plays an important role in the reduced AAA risk, and the reduced aortic diameter may be a structural mechanism behind this paradoxical association.

Different risk factors in identical features of intracranial atherosclerosis plaques in the posterior and anterior circulation in high-resolution MRI

Background:

We constructed a high-volume registry to identify whether risk factors of intracranial atherosclerotic plaque (ICAP) features differ in the posterior and anterior circulation in patients with symptomatic intracranial atherosclerotic stenosis (ICAS) investigated by high-resolution magnetic resonance imaging (HRMRI).

Methods:

The registry was constructed for patients with symptomatic ICAS who underwent HRMRI for culprit plaques. ICAP-vulnerable features included positive remodelling, diffuse distribution, intraplaque haemorrhage and strong enhancement.

Results:

We analysed risk factors for the same ICAP features between the posterior and anterior circulation in data of 97 patients in the posterior circulation and 105 patients in the anterior circulation ICAPs. In patients with diffuse distribution, the probability of being female were lower [odds ratio (OR):0.08; 95% confidence interval (CI):0.02–0.34; p = 0.001] and having diabetes mellitus was higher (OR: 7.75; 95% CI:1.75–34.39; p = 0.007) in posterior circulation patients. In patients with strong enhancement, the probability of having diabetes was higher in posterior circulation patients (OR:6.71; 95% CI:1.37–32.81; p = 0.019).

Conclusions:

Our results demonstrate more risk factors in the posterior than in the anterior circulation in patients with the same ICAP-vulnerable features, highlighting the need for stratification of risk factors in symptomatic ICAPs.

Trial Registration:

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02705599.

Chloroquine differentially modulates coronary vasodilation in control and diabetic mice

BACKGROUND AND PURPOSE

Chloroquine is a traditional medicine to treat malaria. There is increasing evidence that chloroquine not only induces phagocytosis but regulates vascular tone. Few reports investigating the effect of chloroquine on vascular responsiveness of coronary arteries have been made. In this study, we examined how chloroquine affected endothelium-dependent relaxation in coronary arteries under normal and diabetic conditions.

EXPERIMENTAL APPROACH

We isolated coronary arteries from mice and examined endothelium-dependent relaxation (EDR). Human coronary endothelial cells and mouse coronary endothelial cells isolated from control and diabetic mouse (TALLYHO/Jng [TH] mice, a spontaneous type 2 diabetic mouse model) were used for the molecular biological or cytosolic NO and Ca²⁺ measurements.

KEY RESULTS

Chloroquine inhibited endothelium-derived NO-dependent relaxation but had negligible effect on endothelium-derived hyperpolarization (EDH)-dependent relaxation in coronary arteries of control mice. Chloroquine significantly decreased NO production in control human coronary endothelial cells partly by phosphorylating eNOS^Thr495 (an inhibitory phosphorylation site of eNOS) and attenuating the rise of cytosolic Ca²⁺ concentration after stimulation. EDR was significantly inhibited in diabetic mice in comparison to control mice. Interestingly, chloroquine enhanced EDR in diabetic coronary arteries by, specifically, increasing EDH-dependent relaxation due partly to its augmenting effect on gap junction activity in diabetic mouse coronary endothelial cells.

CONCLUSIONS AND IMPLICATIONS

These data indicate that chloroquine affects vascular relaxation differently under normal and diabetic conditions. Therefore, the patients' health condition such as coronary macrovascular or microvascular disease, with or without diabetes, must be taken account into the consideration when selecting chloroquine for the treatment of malaria.

MicroRNA-24 attenuates vascular remodeling in diabetic rats through PI3K/Akt signaling pathway

BACKGROUND AND AIMS

The vascular remodeling plays a crucial role in pathogenesis of diabetic cardiovascular complications. In this study, we intended to explore the effects and potential mechanisms of microRNA-24 (miR-24) on vascular remodeling under diabetic conditions.

METHODS AND RESULTS

MiR-24 recombinant adenovirus (Ad-miR-24-GFP) was used to induce miR-24 overexpression either in carotid arteries or high glucose (HG)-induced vascular smooth muscle cells (VSMCs). Cell proliferation was analyzed using CCK-8 method. Cell migration was examined using wound-healing and transwell assay. mRNA and protein expressions of critical factors were, respectively, measured by real-time PCR and western blot as follows: qRT-PCR for the levels of miR-24, PIK3R1; western blot for the protein levels of PI3K (p85α), Akt, p-Akt, mTOR, p-mTOR, 4E-BP1, p-4E-BP1, p70s6k, p-p70s6k, MMP 2, MMP 9, collagen Ⅰ, as well as collagen Ⅲ. Carotid arteries in diabetic rats suffered balloon injury were harvested and examined by HE, immunohistochemical and Masson trichrome staining. The expression of miR-24 was decreased in HG-stimulated VSMCs and balloon-injured carotid arteries of diabetic rats, accompanied by increased mRNA expression of PIK3R1. The up-regulation of miR-24 suppressed VSMCs proliferation, migration, collagen deposition not only induced by HG in vitro, but also in balloon-injured diabetic rats, which were related to inactivation of PI3K/Akt signaling pathway.

CONCLUSION

The up-regulation of miR-24 significantly attenuated vascular remodeling both in balloon-injured diabetic rats and HG-stimulated VSMCs via suppression of proliferation, migration and collagen deposition by acting on PIK3R1 gene that modulated the PI3K/Akt/mTOR axes.

Resveratrol attenuates hydrogen peroxide-induced aging through upregulation of autophagy in human umbilical vein endothelial cells

Purpose

Resveratrol (RESV; trans-3,5,4′-trihydroxystilbene) has emerged as a potential new therapeutic for age-related atherosclerotic diseases. However, the effect of RESV on cellular aging and its underlying mechanisms remain unknown. Therefore, the aim of this study was to examine whether RESV can delay cellular aging through upregulation of autophagy.

Materials and methods

Human umbilical endothelial vein cells (HUVECs) were divided into four groups: the control group, and the hydrogen peroxide (H₂O₂) alone, H₂O₂ + RESV pretreatment, and H₂O₂ + 3-methyladenine (3-MA) + RESV pretreatment intervention groups. The cell viability was evaluated by a cell counting kit-8 assay. Superoxide dismutase (SOD) activity and intracellular reactive oxygen species (ROS) levels were tested using commercial kits. Senescence-related β-galactosidase activities were detected by immunohistochemical staining. The expression levels of aging-related and autophagy-related markers, including phosphorylated Rb (p-Rb), LC3, and p62, with or without RESV were measured by Western blotting.

Results

Pretreatment with 10 µM RESV increased the cell viability and SOD levels. The remarkably higher positive rate of senescence-associated β-galactosidase and increased intracellular ROS levels in the H₂O₂ treatment group were reversed by treatment with 10 µM RESV. As compared to the H₂O₂ treatment group, 10 µM RESV could upregulate autophagy through the regulation of p-Rb, LC3, and p62 levels. The anti-aging effect of RESV via an autophagy regulation mechanism was further confirmed by the suppression of these effects with 3-MA treatment.

Conclusion

RESV may reverse and delay the aging process of HUVECs via upregulation of autophagy and could be a candidate therapeutic for age-related atherosclerotic diseases.

Recent Advances in Understanding the Pathogenesis of Cardiovascular Diseases and Development of Treatment Modalities

Cardiovascular Diseases (CVDs) are a leading cause of morbidity and mortality worldwide. The underlying pathology for cardiovascular disease is largely atherosclerotic in nature and the steps include fatty streak formation, plaque progression and plaque rupture. While there is optimal drug therapy available for patients with CVD, there are also underlying drug delivery obstacles that must be addressed. Challenges in drug delivery warrant further studies for the development of novel and more efficacious medical therapies. An extensive understanding of the molecular mechanisms of disease in combination with current challenges in drug delivery serves as a platform for the development of novel drug therapeutic targets for CVD. The objective of this article is to review the pathogenesis of atherosclerosis, first-line medical treatment for CVD, and key obstacles in an efficient drug delivery.

Endothelial to mesenchymal transition in atherosclerotic vascular remodeling

Endothelial cells are the main components of the heart, blood vessels, and lymphatic vessels, which play an important role in regulating the physiological functions of the cardiovascular system. Endothelial dysfunction is involved in a variety of acute and chronic cardiovascular diseases. As a special type of epithelial-mesenchymal transition (EMT), endothelium to mesenchymal transition (EndMT) regulates the transformation of endothelial cells into mesenchymal cells accompanied by changes in the expression of various transcription factors and cytokines, which is closely related to vascular endothelial injury, vascular remodeling, myocardial fibrosis and valvar disease. Endothelial cells undergoing EndMT lose their endothelial characteristics and undergo a transition toward a more mesenchymal-like phenotype. However, the molecular mechanism of EndMT remains unclear. EndMT, as a type of endothelial dysfunction, can cause vascular remodeling which is a major determinant of atherosclerotic luminal area. Therefore, exploring the important signaling pathways in the process of EndMT may provide novel therapeutic strategies for treating atherosclerotic diseases.

Greater Coronary Heart Disease Risk With Lower Intensity and Longer Duration Smoking Compared With Higher Intensity and Shorter Duration Smoking: Congruent Results Across Diverse Cohorts

INTRODUCTION

Relative risks (RRs) for coronary heart disease (CHD) by cigarettes/day exhibit a concave pattern, implying the RR increase with each additional cigarette/day consumed decreases with greater intensity. Interpreting this pattern faces limitations, since cigarettes/day alone does not fully characterize smoking-related exposure. A more complete understanding of smoking and CHD risk requires a more comprehensive representation of smoking.

METHODS

Using Poisson regression, we applied a RR model in pack-years and cigarettes/day to analyze two diverse cohorts, the US Agricultural Health Study, with 4396 CHD events and 1 425 976 person-years of follow-up, and the Finnish Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, with 5979 CHD events and 486 643 person-years.

RESULTS

In both cohorts, the concave RR pattern with cigarettes/day was consistent with cigarettes/day modifying a linear RR association for CHD by pack-years within categories of cigarettes/day, indicating that strength of the pack-years association depended on cigarettes/day (p < .01). For example, at 50 pack-years (365 000 total cigarettes), estimated RRs of CHD were 2.1 for accrual at 20 cigarettes/day and 1.5 for accrual at 50 cigarettes/day.

CONCLUSIONS

RRs for CHD increased with pack-years with smoking intensities affecting the strength of association. For equal pack-years, smoking fewer cigarettes/day for longer duration was more deleterious than smoking more cigarettes/day for shorter duration. We have now observed inverse smoking intensity effects in multiple cohorts with differing smoking patterns and other characteristics, suggesting a common underlying phenomenon.

IMPLICATIONS

Risk of CHD increases with pack-years of smoking, but accrual intensity strongly influences the strength of the association, such that smoking fewer cigarettes/day for longer duration is more deleterious than smoking more cigarettes/day for shorter duration. This observation offers clues to better understanding biological mechanisms, and reinforces the importance of cessation rather than smoking less to reduce CHD risk.

Risk of Cardiovascular Disease from Cumulative Cigarette Use and the Impact of Smoking Intensity

BACKGROUND

Relative risks (RRs) for cardiovascular disease (CVD) by smoking rate exhibit a concave pattern, with RRs in low rate smokers exceeding a linear extrapolation from higher rate smokers. However, cigarettes/day does not by itself fully characterize smoking-related risks. A reexamination of the concave pattern using a comprehensive representation of smoking may enhance insights.

METHODS

Data were from the Atherosclerosis Risk in Communities (ARIC) Study, a prospective cohort enrolled in four areas of the US in 1987-1989. Follow-up was through 2008. Analyses included 14,233 participants, 245,915 person-years, and 3,411 CVD events.

RESULTS

The concave RRs with cigarettes/day were consistent with cigarettes/day modifying a linear RR association of pack-years with CVD (i.e., strength of the pack-years association depended on cigarettes/day, indicating that the manner of pack-years accrual impacted risk). Smoking fewer cigarettes/day for longer duration was more deleterious than smoking more cigarettes/day for shorter duration (P < 0.01). For 50 pack-years (365,000 cigarettes), estimated RRs of CVD were 2.1 for accrual at 20 cigarettes/day and 1.6 for accrual at 50 cigarettes/day. Years since smoking cessation did not alter the diminishing strength of association with increasing cigarettes/day. Analyses that accounted for competing risks did not affect findings.

CONCLUSION

Pack-years remained the primary determinant of smoking-related CVD risk; however, accrual influenced RRs. For equal pack-years, smoking fewer cigarettes/day for longer duration was more deleterious than smoking more cigarettes/day for shorter duration. This observation provides clues to better understanding the biological mechanisms, and reinforces the importance of cessation rather than smoking less to reduce CVD risk.

Bakuchiol attenuates myocardial ischemia reperfusion injury by maintaining mitochondrial function: the role of silent information regulator 1

Ischemia reperfusion (IR) injury (IRI) is associated with poor prognoses in the settings of both cardiac surgery and ischemic heart disease and causes mitochondrial oxidative stress and cell death. Silent information regulator 1 (SIRT1), a member of the histone deacetylase family, exerts anti-IRI effects. Bakuchiol (BAK), an analog of resveratrol and a monoterpene phenol isolated from the seeds of Psoralea corylifolia (Leguminosae), protects tissues from injury. This study was designed to investigate the protective effects of BAK treatment in the setting of myocardial IRI and to elucidate the potential mechanism of those effects. Prior to induction of IR, isolated rat hearts or cardiomyocytes were exposed to BAK in either the absence or presence of the SIRT1 inhibitors Sirtinol and SIRT1 siRNA. BAK exerted cardioprotective effects, as evidenced by the improvements noted in cardiac function following ischemia, attenuated myocardial apoptosis, and changes in several biochemical parameters (including increases in the level of the anti-apoptotic protein Bcl2, decreases in the level of the pro-apoptotic protein Bax, and decreases in the cleaved Caspase 3 level). However, Sirtinol and SIRT1 siRNA each blocked BAK-induced cardioprotection by inhibiting SIRT1 signaling. Additionally, BAK significantly increased the activities of mitochondrial succinate dehydrogenase, cytochrome c oxidase, and mitochondrial superoxide dismutase and decreased the production of malondialdehyde. These findings suggested that BAK significantly attenuated IR-induced mitochondrial oxidative damage. However, Sirtinol and SIRT1 siRNA abolished BAK-dependent mitochondrial function. In summary, our results demonstrate that BAK treatment attenuates IRI by attenuating IR-induced mitochondrial oxidative damage via the activation of SIRT1/PGC-1α signaling.

NOR-1/NR4A3 regulates the cellular inhibitor of apoptosis 2 (cIAP2) in vascular cells: role in the survival response to hypoxic stress

Vascular cell survival is compromised under pathological conditions such as abdominal aortic aneurysm (AAA). We have previously shown that the nuclear receptor NOR-1 is involved in the survival response of vascular cells to hypoxia. Here, we identify the anti-apoptotic protein cIAP2 as a downstream effector of NOR-1. NOR-1 and cIAP2 were up-regulated in human AAA samples, colocalizing in vascular smooth muscle cells (VSMC). While NOR-1 silencing reduced cIAP2 expression in vascular cells, lentiviral over-expression of this receptor increased cIAP2 mRNA and protein levels. The transcriptional regulation of the human cIAP2 promoter was analyzed in cells over-expressing NOR-1 by luciferase reporter assays, electrophoretic mobility shift analysis and chromatin immunoprecipitation, identifying a NGFI-B site (NBRE-358/-351) essential for NOR-1 responsiveness. NOR-1 and cIAP2 were up-regulated by hypoxia and by a hypoxia mimetic showing a similar time-dependent pattern. Deletion and site-directed mutagenesis studies show that NOR-1 mediates the hypoxia-induced cIAP2 expression. While NOR-1 over-expression up-regulated cIAP2 and limited VSMC apoptosis induced by hypoxic stress, cIAP2 silencing partially prevented this NOR-1 pro-survival effect. These results indicate that cIAP2 is a target of NOR-1, and suggest that this anti-apoptotic protein is involved in the survival response to hypoxic stress mediated by NOR-1 in vascular cells.

Impact of renal function on mean platelet volume and its relationship with coronary artery disease: A single-centre cohort study

BACKGROUND

Mean platelet volume (MPV) has been proposed as a marker of platelet reactivity and cardiovascular disease. Chronic kidney disease (CKD) significantly favors the occurrence of cardiovascular events, by increasing the circulating levels of a wide spectrum of pro-oxidant and pro-thrombotic mediators. However, opposite alterations of platelet function, both enhanced aggregability and increased bleeding diathesis have been reported in these patients, with contrasting results on the effects of renal function on MPV and coronary artery disease, that were assessed in present study.

METHODS

In patients undergoing coronary angiography, MPV and renal function (serum creatinine and estimated Glomerular Filtration Rate, eGFR, by MDRD formula) were assessed at admission. Coronary artery disease (CAD) was defined as a stenosis >50% in at least 1 coronary vessel, while severe CAD as left main or trivessel disease.

RESULTS

Among 3712 patients, 1044 (28.1%) had chronic kidney disease. CKD was related with age, female gender, diabetes and glycemic control, history of myocardial infarction, cerebrovascular accidents, coronary artery bypass grafting and left ventricular dysfunction or arrhythmias as indication to angiography, therapy with angiotensin-receptor blockers, nitrates, diuretics and calcium-antagonists, but lower rate of smoking, lower fibrinogen levels, haemoglobin, total and HDL cholesterol (p<0.001, respectively). CKD patients displayed increased severity and complexity of CAD (p<0.001) and significantly larger platelet volume (p<0.001), with CKD resulting as independent predictor of MPV above the median (≥10.85fl; Adjusted OR[95%CI]=1.56[1.23,1.99], p=0.002). Moreover, in the 1044 patients with renal failure, higher platelet volume (above the median value; ≥10.85fl) was associated with age (p=0.05), haemoglobin levels and platelet count (p<0.001), but not to a higher prevalence or extent of coronary artery disease (CAD: adjusted OR[95%CI]=0.80[0.58-1.09], p=0.16; severe CAD, adjusted OR[95%CI]=1.07[0.81-1.41], p=0.65).

CONCLUSIONS

Higher values of MPV are observed among patients with chronic kidney disease, inversely relating to eGFR. However, larger platelet size does not contribute to explain the increased severity of coronary artery disease observed among these patients.

Accelerated Vascular Aging as a Paradigm for Hypertensive Vascular Disease: Prevention and Therapy

Aging is considered the most important nonmodifiable risk factor for cardiovascular disease and death after age 28 years. Because of demographic changes the world population is expected to increase to 9 billion by the year 2050 and up to 12 billion by 2100, with several-fold increases among those 65 years of age and older. Healthy aging and prevention of aging-related diseases and associated health costs have become part of political agendas of governments around the world. Atherosclerotic vascular burden increases with age; accordingly, patients with progeria (premature aging) syndromes die from myocardial infarctions or stroke as teenagers or young adults. The incidence and prevalence of arterial hypertension also increases with age. Arterial hypertension-like diabetes and chronic renal failure-shares numerous pathologies and underlying mechanisms with the vascular aging process. In this article, we review how arterial hypertension resembles premature vascular aging, including the mechanisms by which arterial hypertension (as well as other risk factors such as diabetes mellitus, dyslipidemia, or chronic renal failure) accelerates the vascular aging process. We will also address the importance of cardiovascular risk factor control-including antihypertensive therapy-as a powerful intervention to interfere with premature vascular aging to reduce the age-associated prevalence of diseases such as myocardial infarction, heart failure, hypertensive nephropathy, and vascular dementia due to cerebrovascular disease. Finally, we will discuss the implementation of endothelial therapy, which aims at active patient participation to improve primary and secondary prevention of cardiovascular disease.

Association of insulin resistance and coronary artery remodeling: an intravascular ultrasound study

Background

There are few studies that investigated the correlation between insulin resistance (IR) and the coronary artery remodeling. The aim of the study is to investigate the association of IR measured by homeostasis model assessment of insulin resistance (HOMA-IR) and coronary artery remodeling evaluated by intravascular ultrasound (IVUS).

Methods

A total of 298 consecutive patients who received percutaneous coronary interventions under IVUS guidance were retrospectively enrolled. The value of HOMA-IR more than 2.5 was considered as IR positive. Metabolic syndrome was classified according to NCEP ATP III guidelines. The remodeling index was defined as the ratio of the external elastic membrane (EEM) area at the lesion site to the EEM area at the proximal reference site.

Results

A total of 369 lesions were analyzed (161 lesions in HOMA-IR positive and 208 lesions in HOMA-IR negative). Remodeling index was significantly higher in the HOMA-IR positive group compared with the negative group (HOMA-IR positive vs. negative: 1.074 ± 0.109 vs. 1.042 ± 0.131, p = 0.013). There was a significant positive correlation between remodeling index and HOMA-IR (p = 0.010). Analysis of HOMA-IR according to remodeling groups showed increasing tendency of HOMA-IR, and it was statistically significant (p = 0.045). Multivariate analysis revealed that only HOMA-IR was an independent predictor of remodeling index (r = 0.166, p = 0.018).

Conclusion

Increased IR estimated by HOMA-IR was significantly associated with a higher remodeling index and positive coronary artery remodeling.

A computational and functional study elicits the ameliorating effect of the Chinese herbal formula Huo Luo Xiao Ling Dan on experimental ischemia-induced myocardial injury in rats via inhibition of apoptosis

Ischemic heart disease (IHD) is the leading cause of death worldwide and remains a major life-threatening factor in humans. Apoptosis has been implicated in the pathogenesis of IHD. The Chinese herbal formula Huo Luo Xiao Ling Dan (HLXLD), one of the commonly used Chinese herbal formulas, consists of Salviae miltiorrhizae, Angelica sinensis, Gummi olibanum, and Commiphora myrrha, with a wide spectrum of pharmacological activity. However, the mechanism of action and molecular targets of HLXLD in the treatment of IHD are unclear. This study aimed to computationally predict the molecular interactions between the major active components of HLXLD and key regulators of apoptosis and then examine the effect of HLXLD on coronary artery ligation-induced acute myocardial ischemia in rats. The molecular interactions between the major active components of HLXLD, including ferulic acid, ligustilide, succinic acid, vanillic acid, tanshinone IIA, tanshinone IIB, danshensu, salvianolic acid A, salvianolic acid C, protocatechuic aldehyde, and β-boswellic acid and human protein molecules including B cell lymphoma-extra large (Bcl-xl), B cell lymphoma 2 antagonist/killer 1 (Bak1), B cell lymphoma 2 (Bcl-2), procaspase 3, and caspase 9 with regard to hydrogen bond formation, charge interaction, and π-π stacking using Discovery Studio(®) program 3.1. The 12 HLXLD components were predicted by ADMET (absorption, distribution, metabolism, excretion and toxicity) Predictor to have favorable pharmacokinetic and low hepatotoxicity profiles. The acute myocardial ischemia was established by surgical ligation of the left anterior descending coronary artery. The rats were divided into a sham operative group, a model group, a positive control group treated with 0.2 mg/kg isosorbide mononitrate, and groups treated with 2.7, 5.4, or 10.8 g/kg HLXLD. The results showed that administration of HLXLD increased mean arterial pressure, left ventricular systolic pressure, heart rate, and maximal rate of rise/descent of left ventricular pressure levels. Administration of HLXLD significantly ameliorated coronary artery ligation-induced tissue damage in the left ventricle, with restored arrangement of myocardial fibers and recovered myoplasm in rats. Furthermore, HLXLD markedly increased the expression level of Bcl-2 but decreased the level of cleaved caspase 3. Taken together, administration of HLXLD attenuated acute myocardial ischemia-induced damage in cardiomyocytes and inhibited apoptotic death of cardiomyocytes, thereby exerting a cardioprotective effect in rats with IHD. These findings suggest that HLXLD may represent a promising herbal formula for the treatment of cardiovascular disease by counteracting apoptotic cell death via multiple active compounds. More studies are warranted to fully elucidate the mechanisms of action, identify the therapeutic targets, and validate the efficacy and safety of HLXLD in the treatment of IHD.

Glucose attenuates hypoxia-induced changes in endothelial cell growth by inhibiting HIF-1α expression

Hyperglycaemia and hypoxia play essential pathophysiological roles in diabetes. We determined whether hyperglycaemia influences endothelial cell growth under hypoxic conditions in vitro. Using a Ruskinn Invivo₂ 400 Hypoxia Workstation, bovine aortic endothelial cells (BAEC) were exposed to high glucose concentrations (25 mM glucose) under normoxic or hypoxic conditions before cell growth (balance of proliferation and apoptosis) was assessed by fluorescence-activated cell sorting (FACS) analysis, proliferating cell nuclear antigen (pCNA), Bcl-x_L and caspase-3 protein expression and activity. Hypoxia increased hypoxia response element (HRE) transactivation and induced hypoxia-inducible factor-1α (HIF-1α) expression when compared to normoxic controls concomitant with a significant decrease in cell growth. High glucose (25 mM) concentrations attenuated HRE transactivation and HIF-1α protein expression while concurrently reducing hypoxia-induced changes in BAEC growth. Knockdown of HIF-1α expression significantly decreased hypoxia-induced changes in growth and attenuated the modulatory effects of glucose. These results provide evidence that hypoxia-induced control of BAEC growth can be altered by the presence of glucose via inhibition of HIF-1α expression and activation.

Biomarkers in diabetic retinopathy and the therapeutic implications

The main problem both in type 1 (T1DM) and type 2 (T2DM) diabetes is the development of chronic vascular complications encompassing micro- as well as macrocirculation. Chronic complications lower the quality of life, lead to disability, and are the cause of premature death in DM patients. One of the chronic vascular complications is a diabetic retinopathy (DR) which leads to a complete loss of sight in DM patients. Recent trials show that the primary cause of diabetic retinopathy is retinal neovascularization caused by disequilibrium between pro- and antiangiogenic factors. Gaining knowledge of the mechanisms of action of factors influencing retinal neovascularization as well as the search for new, effective treatment methods, especially in advanced stages of DR, puts special importance on research concentrating on the implementation of biological drugs in DR therapy. At present, it is antivascular endothelial growth factor and antitumor necrosis factor that gain particular significance.