Rho-Associated Protein Kinase Contributes to Early Atherosclerotic Lesion Formation in Mice

Ischemic cardiac stromal fibroblast-derived protein mediators in the infarcted myocardium and transcriptomic profiling at single cell resolution

This article focuses on screening the major secreted proteins by the ischemia-challenged cardiac stromal fibroblasts (CF), the assessment of their expression status and functional role in the post-ischemic left ventricle (LV) and in the ischemia-challenged CF culture and to phenotype CF at single cell resolution based on the positivity of the identified mediators. The expression level of CRSP2, HSP27, IL-8, Cofilin-1, and HSP90 in the LV tissues following coronary artery bypass graft (CABG) and myocardial infarction (MI) and CF cells followed the screening profile derived from the MS/MS findings. The histology data unveiled ECM disorganization, inflammation and fibrosis reflecting the ischemic pathology. CRSP2, HSP27, and HSP90 were significantly upregulated in the LV-CABG tissues with a concomitant reduction ion LV-MI whereas Cofilin-1, IL8, Nrf2, and Troponin I were downregulated in LV-CABG and increased in LV-MI. Similar trends were exhibited by ischemic CF. Single cell transcriptomics revealed multiple sub-phenotypes of CF based on their respective upregulation of CRSP2, HSP27, IL-8, Cofilin-1, HSP90, Troponin I and Nrf2 unveiling pathological and pro-healing phenotypes. Further investigations regarding the underlying signaling mechanisms and validation of sub-populations would offer novel translational avenues for the management of cardiac diseases.

Phosphorylation of USP20 on Ser334 by IRAK1 promotes IL-1β-evoked signaling in vascular smooth muscle cells and vascular inflammation

Reversible lysine-63 (K63) polyubiquitination regulates proinflammatory signaling in vascular smooth muscle cells (SMCs) and plays an integral role in atherosclerosis. Ubiquitin-specific peptidase 20 (USP20) reduces NFκB activation triggered by proinflammatory stimuli, and USP20 activity attenuates atherosclerosis in mice. The association of USP20 with its substrates triggers deubiquitinase activity; this association is regulated by phosphorylation of USP20 on Ser334 (mouse) or Ser333 (human). USP20 Ser333 phosphorylation was greater in SMCs of atherosclerotic segments of human arteries as compared with nonatherosclerotic segments. To determine whether USP20 Ser334 phosphorylation regulates proinflammatory signaling, we created USP20-S334A mice using CRISPR/Cas9-mediated gene editing. USP20-S334A mice developed ∼50% less neointimal hyperplasia than congenic WT mice after carotid endothelial denudation. WT carotid SMCs showed substantial phosphorylation of USP20 Ser334, and WT carotids demonstrated greater NFκB activation, VCAM-1 expression, and SMC proliferation than USP20-S334A carotids. Concordantly, USP20-S334A primary SMCs in vitro proliferated and migrated less than WT SMCs in response to IL-1β. An active site ubiquitin probe bound to USP20-S334A and USP20-WT equivalently, but USP20-S334A associated more avidly with TRAF6 than USP20-WT. IL-1β induced less K63-linked polyubiquitination of TRAF6 and less downstream NFκB activity in USP20-S334A than in WT SMCs. Using in vitro phosphorylation with purified IRAK1 and siRNA-mediated gene silencing of IRAK1 in SMCs, we identified IRAK1 as a novel kinase for IL-1β-induced USP20 Ser334 phosphorylation. Our findings reveal novel mechanisms regulating IL-1β-induced proinflammatory signaling: by phosphorylating USP20 Ser334, IRAK1 diminishes the association of USP20 with TRAF6 and thus augments NFκB activation, SMC inflammation, and neointimal hyperplasia.

Where the Action Is-Leukocyte Recruitment in Atherosclerosis

Atherosclerosis is the leading cause of death worldwide and leukocyte recruitment is a key element of this phenomenon, thus allowing immune cells to enter the arterial wall. There, in concert with accumulating lipids, the invading leukocytes trigger a plethora of inflammatory responses which promote the influx of additional leukocytes and lead to the continued growth of atherosclerotic plaques. The recruitment process follows a precise scheme of tethering, rolling, firm arrest, crawling and transmigration and involves multiple cellular and subcellular players. This review aims to provide a comprehensive up-to-date insight into the process of leukocyte recruitment relevant to atherosclerosis, each from the perspective of endothelial cells, monocytes and macrophages, neutrophils, T lymphocytes and platelets. In addition, therapeutic options targeting leukocyte recruitment into atherosclerotic lesions-or potentially arising from the growing body of insights into its precise mechanisms-are highlighted.

The Outcomes of Small-Molecule Kinase Inhibitors and the Role of ROCK2 as a Molecular Target for the Treatment of Alzheimer's Disease

BACKGROUND

Alzheimer's disease is rapidly becoming a major threat to public health, with an increasing number of individuals affected as the world's population ages. In this sense, studies have been carried out aiming at the identification of new small-molecule kinase inhibitors useful for the treatment of Alzheimer's disease.

OBJECTIVE

In the present study, we investigated the compounds developed as inhibitors of different protein kinases associated with the pathogenesis of Alzheimer's disease.

METHODS

The applied methodology was the use of the Clarivate Analytics Integrity and ClinicalTrials. com databases. Moreover, we highlight ROCK2 as a promising target despite being little studied for this purpose. A careful structure-activity relationship analysis of the ROCK2 inhibitors was performed to identify important structural features and fragments for the interaction with the kinase active site, aiming to rationally design novel potent and selective inhibitors.

RESULTS

We were able to notice some structural characteristics that could serve as the basis to better guide the rational design of new ROCK2 inhibitors as well as some more in-depth characteristics regarding the topology of the active site of both isoforms of these enzymes, thereby identifying differences that could lead to planning more selective compounds.

CONCLUSION

We hope that this work can be useful to update researchers working in this area, enabling the emergence of new ideas and a greater direction of efforts for designing new ROCK2 inhibitors to identify new therapeutic alternatives for Alzheimer's disease.

Insight Into Rho Kinase Isoforms in Obesity and Energy Homeostasis

Obesity and associated complications increasingly jeopardize global health and contribute to the rapidly rising prevalence of type 2 diabetes mellitus and obesity-related diseases. Developing novel methods for the prevention and treatment of excess body adipose tissue expansion can make a significant contribution to public health. Rho kinase is a Rho-associated coiled-coil-containing protein kinase (Rho kinase or ROCK). The ROCK family including ROCK1 and ROCK2 has recently emerged as a potential therapeutic target for the treatment of metabolic disorders. Up-regulated ROCK activity has been involved in the pathogenesis of all aspects of metabolic syndrome including obesity, insulin resistance, dyslipidemia and hypertension. The RhoA/ROCK-mediated actin cytoskeleton dynamics have been implicated in both white and beige adipogenesis. Studies using ROCK pan-inhibitors in animal models of obesity, diabetes, and associated complications have demonstrated beneficial outcomes. Studies via genetically modified animal models further established isoform-specific roles of ROCK in the pathogenesis of metabolic disorders including obesity. However, most reported studies have been focused on ROCK1 activity during the past decade. Due to the progress in developing ROCK2-selective inhibitors in recent years, a growing body of evidence indicates more attention should be devoted towards understanding ROCK2 isoform function in metabolism. Hence, studying individual ROCK isoforms to reveal their specific roles and principal mechanisms in white and beige adipogenesis, insulin sensitivity, energy balancing regulation, and obesity development will facilitate significant breakthroughs for systemic treatment with isoform-selective inhibitors. In this review, we give an overview of ROCK functions in the pathogenesis of obesity and insulin resistance with a particular focus on the current understanding of ROCK isoform signaling in white and beige adipogenesis, obesity and thermogenesis in adipose tissue and other major metabolic organs involved in energy homeostasis regulation.

ROCK Inhibition as Potential Target for Treatment of Pulmonary Hypertension

Pulmonary hypertension (PH) is a cardiovascular disease caused by extensive vascular remodeling in the lungs, which ultimately leads to death in consequence of right ventricle (RV) failure. While current drugs for PH therapy address the sustained vasoconstriction, no agent effectively targets vascular cell proliferation and tissue inflammation. Rho-associated protein kinases (ROCKs) emerged in the last few decades as promising targets for PH therapy, since ROCK inhibitors demonstrated significant anti-remodeling and anti-inflammatory effects. In this review, current aspects of ROCK inhibition therapy are discussed in relation to the treatment of PH and RV dysfunction, from cell biology to preclinical and clinical studies.

Role of Macrophages and RhoA Pathway in Atherosclerosis

The development, progression, or stabilization of the atherosclerotic plaque depends on the pro-inflammatory and anti-inflammatory macrophages. The influx of the macrophages and the regulation of macrophage phenotype, inflammatory or anti-inflammatory, are controlled by the small GTPase RhoA and its downstream effectors. Therefore, macrophages and the components of the RhoA pathway are attractive targets for anti-atherosclerotic therapies, which would inhibit macrophage influx and inflammatory phenotype, maintain an anti-inflammatory environment, and promote tissue remodeling and repair. Here, we discuss the recent findings on the role of macrophages and RhoA pathway in the atherosclerotic plaque formation and resolution and the novel therapeutic approaches.

Integrated transcriptome and phosphoproteome analyses reveal that fads2 is critical for maintaining body LC-PUFA homeostasis

Fatty acid desaturate 2 (Fads2) is associated with many chronic diseases. Nevertheless, comprehensive researches on its role have not been performed. We here conducted an integrated analysis of long-chain polyunsaturated fatty acid (LC-PUFA) metabolism of fads2-deletion zebrafish (fads2^-/-) by transcriptomics, proteomics and phosphoproteomics. Compared with wild type zebrafish (WT), fads2^-/- showed significantly higher contents of hepatic linoleic acid (all-cis-9,12-C18:2), α-linolenic acid (all-cis-9,12,15-C18:3) and docosapetaenoic acid (all-cis-7,10,13,16,19-C22:5), and lower contents of γ-linolenic acid (all-cis-6,9,12-C18:3), stearidonic acid (all-cis-6,9,12,15-C18:4) and docosahexaenoic acid (all-cis-4,7,10,13,16,19-C22:6), accompanied by an increased n-6/n-3 PUFA level. In total, we identified 1608 differentially expressed genes (DEGs), 209 differentially expressed proteins (DEPs) and 153 differentially expressed phosphorylated proteins (DEPPs) with 190 sites between fads2^-/- and WT. Transcriptome and proteome analysis simultaneously aggregated these DEGs and DEPs into LC-PUFA synthesis and PPAR signaling pathways. Further interaction network analysis of the DEPPs showed that spliceosome and protein processing in endoplasmic reticulum pathway were critical groups. Additionally, we determined seven highly phosphorylated kinases and a highly expressed phosphatase in fads2^-/- zebrafish. These results give insights into the mechanism by which fads2 affects metabolic disease occurrence, and provide datasets for target selections for human disease treatment. SIGNIFICANCE: Balanced LC-PUFA composition was deeply associated with body health, while changes of LC-PUFAs usually induced serious diseases such as cardiovascular disease, type 2 diabetes and inflammatory disease. Fatty acid desaturase 2 (Fads2), subordinating to the fatty acid desaturase protein family, catalyzes the first desaturation reaction in LC-PUFA synthesis. Although Fads2 is associated with many chronic diseases including metabolic abnormalities, type 2 diabetes and obesity, comprehensive researches on its role have not been performed. On the basis of the integrated transcriptome, proteome and phosphoproteome analysis, we identified that fads2 was critical for maintaining body LC-PUFA homeostasis. Moreover, the crucial pathways including PPAR signaling pathway, spliceosome and protein processing in endoplasmic reticulum pathway, and candidate kinase targets associated with LC-PUFA metabolism were determined. These findings will contribute to the revealing of the mechanism and supply possible datasets for target selection for human disease treatment.

Atherosclerosis and Nanomedicine Potential: Current Advances and Future Opportunities

Atherosclerosis is the leading inducement of cardiovascular diseases, which ranks the first cause of global deaths. It is an arterial disease associated with dyslipidemia and changes in the composition of the vascular wall. Besides invasive surgical strategy, the current conservative clinical treatment for atherosclerosis falls into two categories, lipid regulating-based therapy and antiinflammatory therapy. However, the existing strategies based on conventional drug delivery systems have shown limited efficacy against disease development and plenty of side effects. Nanomedicine has great potential in the development of targeted therapy, controlled drug delivery and release, the design of novel specific drugs and diagnostic modalities, and biocompatible scaffolds with multifunctional characteristics, which has led to an evolution in the diagnosis and treatment of atherosclerosis. This paper will focus on the latest nanomedicine strategies for atherosclerosis diagnosis and treatment as well as discussing the potential therapeutic targets during atherosclerosis progress, which could form the basis of development of novel nanoplatform against atherosclerosis.

Regulation of efferocytosis by caspase-dependent apoptotic cell death in atherosclerosis

During the growing process of the atherosclerotic lesions, lipid-filled macrophage foam cells form, accumulate, and ultimately undergo apoptotic death. If the apoptotic foam cells are not timely removed, they may undergo secondary necrosis, and form a necrotic lipid core which renders the plaque unstable and susceptible to rupture. Therefore, the non-lipid-filled fellow macrophages, as the main phagocytic cells in atherosclerotic lesions, need to effectively remove the apoptotic foam cells. In general, in apoptotic macrophages, caspases are the central regulators of several key processes required for their efficient efferocytosis. The processes include the generation of "Find-Me" signals (such as adenosine triphosphate/uridine triphosphate, fractalkine, lysophosphatidylcholine, and sphingosine-1-phosphate) for the recruitment of viable macrophages, generation of the "Eat-Me" signals (for example, phosphatidylserine) for the engulfment process, and, finally, release of anti-inflammatory mediators (including transforming factor β and interleukin-10) as a tolerance-enhancing and an anti-inflammatory response, and for the motile behavior of the apoptotic cell. The caspase-dependent mechanisms are operative also in apoptotic macrophages driving the atherogenesis. In this review, we explore the role of the molecular pathways related to the caspase-dependent events in efferocytosis in the context of atherosclerosis. Understanding of the molecular mechanisms of apoptotic cell death in atherosclerotic lesions is essential when searching for new leads to treat atherosclerosis.

The role of extracellular matrix in biomechanics and its impact on bioengineering of cells and 3D tissues

The cells and tissues of the human body are constantly exposed to exogenous and endogenous forces that are referred to as biomechanical cues. They guide and impact cellular processes and cell fate decisions on the nano-, micro- and macro-scale, and are therefore critical for normal tissue development and maintaining tissue homeostasis. Alterations in the extracellular matrix composition of a tissue combined with abnormal mechanosensing and mechanotransduction can aberrantly activate signaling pathways that promote disease development. Such processes are therefore highly relevant for disease modelling or when aiming for the development of novel therapies. In this mini review, we describe the main biomechanical cues that impact cellular fates. We highlight their role during development, homeostasis and in disease. We also discuss current techniques and tools that allow us to study the impact of biomechanical cues on cell and tissue development under physiological conditions, and we point out directions, in which in vitro biomechanics can be of use in the future.

Protective Effect of Buyang Huanwu Decoction on Neurovascular Unit in Alzheimer's Disease Cell Model via Inflammation and RAGE/LRP1 Pathway

Background

The aim of this study was to investigate the protective mechanism of neurovascular unit of Buyang Huanwu decoction (BYHWD) in an Alzheimer’s disease (AD) cell model via RAGE/LRP1 pathway and find a reliable target for Alzheimer’s disease treatment.

Material/Methods

Rat brain microvessel endothelial cells (BMECs) were cultured in 10% FBS and 1% penicillin/streptomycin. The AD model was established by administration of 24 μmol/L amyloid-β peptides 25~35. Different concentrations of BYHWD (0.1 mg/mL, 1 mg/mL, and 10 mg/mL) were added as the drug intervention. The morphology of the cells was observed by light microscopy and the ultrastructure of the cells was observed by microscopy. The inflammatory factors IL-1β, IL-6, TNF-α, and Aβ_25–35 were detected by ELISA. Flow cytometry was used to assess the apoptosis rate. The expressions of RAGE, LRP1, ICAM-1, VCAM-1, Apo J, Apo E, and NF-κBp65 were detected by Western blotting.

Results

The structure of cells in BYHWDM and BYHWDH gradually recovered with increasing dose. BYHWD decreased the apoptotic rate of BMECs induced by Aβ_25–35. The cells treated with different concentrations of BYHWD had significant difference in terms of anti-apoptotic effect. The therapeutic effect of BYHWD on AD was via the RAGE/LRP1 and NF-κBp65 pathways.

Conclusions

BYHWD regulates Aβ metabolism via the RAGE/LRP1 pathway, inhibits vascular endothelial inflammation induced by ICAM-1 and VCAM-1 via the NF-κBP65 pathway, and promotes morphological changes induced by Aβ-induced brain microvascular endothelial cell damage.

Pharmacological inhibition of LIM kinase pathway impairs platelets functionality and facilitates thrombolysis

Actin is highly abundant in platelets, and its function is dependent on its structure. Actin filaments (F-actin) are dynamic structures involved in many cellular processes including platelet shape changes and adhesion. The actin cytoskeleton is tightly regulated by actin-binding proteins, which include members of the actin depolymerising factor (ADF)/cofilin family. LIM kinase (LIMK) and its phosphatase slingshot (SSH-1L) regulate actin dynamics by controlling the binding affinity of ADF/cofilin towards actin. We hypothesised that the inhibition of LIMK activity may prevent the changes in platelet shape and their function during activation by controlling the dynamics of F-actin. Our results demonstrate that in platelet, inhibition of LIMK by small LIMK inhibitors controls the level of filamentous actin leading to decreased platelet adhesion and aggregation. These findings encourage further studies on controlling platelet function via the cytoskeleton.

Cellular Mechanotransduction: From Tension to Function

Living cells are constantly exposed to mechanical stimuli arising from the surrounding extracellular matrix (ECM) or from neighboring cells. The intracellular molecular processes through which such physical cues are transformed into a biological response are collectively dubbed as mechanotransduction and are of fundamental importance to help the cell timely adapt to the continuous dynamic modifications of the microenvironment. Local changes in ECM composition and mechanics are driven by a feed forward interplay between the cell and the matrix itself, with the first depositing ECM proteins that in turn will impact on the surrounding cells. As such, these changes occur regularly during tissue development and are a hallmark of the pathologies of aging. Only lately, though, the importance of mechanical cues in controlling cell function (e.g., proliferation, differentiation, migration) has been acknowledged. Here we provide a critical review of the recent insights into the molecular basis of cellular mechanotransduction, by analyzing how mechanical stimuli get transformed into a given biological response through the activation of a peculiar genetic program. Specifically, by recapitulating the processes involved in the interpretation of ECM remodeling by Focal Adhesions at cell-matrix interphase, we revise the role of cytoskeleton tension as the second messenger of the mechanotransduction process and the action of mechano-responsive shuttling proteins converging on stage and cell-specific transcription factors. Finally, we give few paradigmatic examples highlighting the emerging role of malfunctions in cell mechanosensing apparatus in the onset and progression of pathologies.

Decreased thromboembolic stroke but not atherosclerosis or vascular remodelling in mice with ROCK2-deficient platelets

Aims

Rho-associated coiled-coil containing kinase (ROCK)-2 is an important mediator of the actin cytoskeleton. Because changes in the actin cytoskeleton are critical for platelet function, we hypothesized that ROCK2 in platelets will play important role in thrombosis and can be potentially a target for therapeutic intervention in thromboembolic stroke.

Methods and results

We generated platelet-specific ROCK2-deficient mice (ROCK2Plt-/-) from conditional ROCK2fl°x/fl°x and platelet factor (PF)-4-Cre transgenic mice. Platelets from ROCK2Plt-/- mice were less responsive to thrombin stimulation in terms of pseudopodia formation, collagen adhesion, and in the formation of homotypic and heterotypic aggregates. This corresponded to prolonged bleeding time and delayed vascular occlusion following vessel injury. To determine whether these changes in platelet function could affect thrombotic disease, we utilized a clot-embolic model of ischaemic stroke. When pre-formed clots from ROCK2Plt-/- mice were injected into the middle cerebral artery of control mice, cerebral blood flow recovery occurred more rapidly, leading to decreased cerebral injury and neurological deficits, compared to pre-formed clots from control mice. Interestingly, pre-formed clots from control mice produced similar degree of cerebral injury when injected into control or ROCK2Plt-/- mice, suggesting that platelet ROCK2 deficiency affects clot formation but not propagation. Indeed, in a non-thrombotic intra-filament MCA occlusion model of stroke, platelet ROCK2 deletion was not protective. Furthermore, ROCK2Plt-/- mice exhibit similar atherosclerosis severity and vascular remodeling as control mice.

Conclusion

These findings indicate that platelet ROCK2 plays important role in platelet function and thrombosis, but does not contribute to the pathogenesis of atherosclerosis and vascular remodeling.

Genetic Depletion or Hyperresponsiveness of Natural Killer Cells Do Not Affect Atherosclerosis Development

Rationale:

Chronic inflammation is central in the development of atherosclerosis. Both innate and adaptive immunities are involved. Although several studies have evaluated the functions of natural killer (NK) cells in experimental animal models of atherosclerosis, it is not yet clear whether NK cells behave as protective or proatherogenic effectors. One of the main caveats of previous studies was the lack of specificity in targeting loss or gain of function of NK cells.

Objectives:

We used 2 selective genetic approaches to investigate the role of NK cells in atherosclerosis: (1) Ncr1 iCre/+ R26 lsl− DTA/+ mice in which NK cells were depleted and (2) Noé mice in which NK cells are hyperresponsive.

Methods and Results:

No difference in atherosclerotic lesion size was found in Ldlr −/− (low-density lipoprotein receptor null) mice transplanted with bone marrow (BM) cells from Ncr1 iCre R26R lsl− DTA , Noé , or wild-type mice. Also, no difference was observed in plaque composition in terms of collagen content, macrophage infiltration, or the immune profile, although Noé chimera had more IFN (interferon)-γ–producing NK cells, compared with wild-type mice. Then, we investigated the NK-cell selectivity of anti–asialoganglioside M1 antiserum, which was previously used to conclude the proatherogenicity of NK cells. Anti–asialoganglioside M1 treatment decreased atherosclerosis in both Ldlr −/− mice transplanted with Ncr1 iCre R26R lsl− DTA or wild-type bone marrow, indicating that its antiatherogenic effects are unrelated to NK-cell depletion, but to CD8 + T and NKT cells. Finally, to determine whether NK cells could contribute to the disease in conditions of pathological NK-cell overactivation, we treated irradiated Ldlr −/− mice reconstituted with either wild-type or Ncr1 iCre R26R lsl− DTA bone marrow with the viral mimic polyinosinic:polycytidylic acid and found a significant reduction of plaque size in NK-cell–deficient chimeric mice.

Conclusions:

Our findings, using state-of-the-art mouse models, demonstrate that NK cells have no direct effect on the natural development of hypercholesterolemia-induced atherosclerosis, but may play a role when an additional systemic NK-cell overactivation occurs.

Common variants of ROCKs and the risk of hypertension, and stroke: Two case-control studies and a follow-up study in Chinese Han population

The Rho kinases (ROCKs) are recognized as a critical regulator of vascular functions in cardiovascular disorders. It is crucial to illustrate the association of ROCKs genetic variation and hypertension and/or stroke events. Herein we aimed at investigating the association of ROCK1 and ROCK2 with hypertension and stroke in Chinese Han population. Seven tagSNPs at ROCK1 and ROCK2 were genotyped in a community-based case-control study consisting of 2012 hypertension cases and 2210 normotensive controls and 4128 subjects were further followed up. In stroke case-control study, 1471 ischemic stroke (IS) inpatients and 607 hemorrhagic stroke (HS) inpatients were collected, and 2443 age-matched controls were selected from the follow-up population. Risks were estimated as odds ratio (OR) and hazard ratio (HR) by logistic and Cox regression. The community-based case-control study didn't identify any significant tagSNPs associated with hypertension even after adjustment for covariates. The follow-up analysis showed that rs1481280 of ROCK1 significantly associated with incident hypertension (HR=1.130, P=0.048) after adjusting for covariates. rs7589629 and rs978906 of ROCK2 were significantly associated with incident IS (HR=1.373, P=0.004; HR=1.284, P=0.026) respectively. In stroke case-control study, rs288980, rs1481280 and rs7237677 were significantly associated with IS and the adjusted ORs (P values) of additive model were 0.879 (0.010), 0.895 (0.036) and 0.857 (0.002) respectively. Furthermore, rs288980, rs7237677 and rs978906 were significantly associated with HS and the adjusted ORs (P values) of additive model were 0.857 (0.025), 0.848 (0.018) and 0.856 (0.027) respectively. Our findings suggest that ROCK1 and ROCK2 contribute to the genetic susceptibility of hypertension and stroke.

Vascular Smooth Muscle Cells and Arterial Stiffening: Relevance in Development, Aging, and Disease

The cushioning function of large arteries encompasses distension during systole and recoil during diastole which transforms pulsatile flow into a steady flow in the microcirculation. Arterial stiffness, the inverse of distensibility, has been implicated in various etiologies of chronic common and monogenic cardiovascular diseases and is a major cause of morbidity and mortality globally. The first components that contribute to arterial stiffening are extracellular matrix (ECM) proteins that support the mechanical load, while the second important components are vascular smooth muscle cells (VSMCs), which not only regulate actomyosin interactions for contraction but mediate also mechanotransduction in cell-ECM homeostasis. Eventually, VSMC plasticity and signaling in both conductance and resistance arteries are highly relevant to the physiology of normal and early vascular aging. This review summarizes current concepts of central pressure and tensile pulsatile circumferential stress as key mechanical determinants of arterial wall remodeling, cell-ECM interactions depending mainly on the architecture of cytoskeletal proteins and focal adhesion, the large/small arteries cross-talk that gives rise to target organ damage, and inflammatory pathways leading to calcification or atherosclerosis. We further speculate on the contribution of cellular stiffness along the arterial tree to vascular wall stiffness. In addition, this review provides the latest advances in the identification of gene variants affecting arterial stiffening. Now that important hemodynamic and molecular mechanisms of arterial stiffness have been elucidated, and the complex interplay between ECM, cells, and sensors identified, further research should study their potential to halt or to reverse the development of arterial stiffness.

Carbon black aggregates cause endothelial dysfunction by activating ROCK

Carbon black nanoparticles (CBNs) have been associated with the progression of atherosclerosis. CBNs normally enter the bloodstream and crosslink together to form agglomerates. However, most studies have used nano-sized CB particles to clarify the involvement of CBN exposure in CBN-induced endothelial dysfunction. Herein, we studied endothelial toxicity of CBN aggregates (CBA) to human EA.hy926 vascular cells. Cell viability, lactate dehydrogenase leakage, and oxidative stress were affected by the highest concentration of CBA. Moreover, transmission electron microscopic results showed that CBA entered cells through membrane enclosed vesicles. Rho-associated kinase (ROCK) is involved in regulating vascular diseases. Thus, we co-treated with the of ROCK inhibitor Y-27632 to study whether other adverse effects caused by CBA are related to activating ROCK. As expected, co-treatment with Y-27632 attenuated CBA-induced cytoskeletal damage, dysfunction of the endothelial barrier, and expression of inflammatory factors. Taken together, these results demonstrate that aggregated CBNs can cause endothelial dysfunction possibly by activating ROCK.

Interdisciplinary approach to compensation of hypoglycemia in diabetic patients with chronic heart failure

Diabetes mellitus is a chronic disease requiring lifelong control with hypoglycemic agents that must demonstrate excellent efficacy and safety profiles. In patients taking glucose-lowering drugs, hypoglycemia is a common cause of death associated with arrhythmias, increased thrombus formation, and specific effects of catecholamines due to sympathoadrenal activation. Focus is now shifting from merely glycemic control to multifactorial approach. In the context of individual drugs and classes, this article reviews interdisciplinary strategies evaluating metabolic effects of drugs for treatment of chronic heart failure (CHF) which can mask characteristic hypoglycemia symptoms. Hypoglycemia unawareness and cardiac autonomic neuropathy are discussed. Data suggesting that hypoglycemia modulates immune response are reviewed. The potential role of gut microbiota in improving health of patients with diabetes and CHF is emphasized. Reports stating that nondiabetic CHF patients can have life-threatening hypoglycemia associated with imbalance of thyroid hormones are discussed. Regular glycemic control based on HbA1c measurements and adequate pharmacotherapy remain the priorities in diabetes management. New antihyperglycemic drugs with safer profiles should be preferred in vulnerable CHF patients. Multidrug interactions must be considered. Emerging therapies with reduced hypoglycemia risk, telemedicine, sensor technologies, and genetic testing predicting hypoglycemia risk may help solving the challenges of hypoglycemia in CHF patients with diabetes. Interdisciplinary work may involve cardiologists, diabetologists/endocrinologists, immunologists, gastroenterologists, microbiologists, nutritionists, imaging specialists, geneticists, telemedicine experts, and other relevant specialists. This review emphasizes that systematic knowledge on pathophysiology of hypoglycemia in diabetic patients with CHF is largely lacking and the gaps in our understanding require further discoveries.

Redox regulation of the actin cytoskeleton and its role in the vascular system

The actin cytoskeleton is critical for form and function of vascular cells, serving mechanical, organizational and signaling roles. Because many cytoskeletal proteins are sensitive to reactive oxygen species, redox regulation has emerged as a pivotal modulator of the actin cytoskeleton and its associated proteins. Here, we summarize work implicating oxidants in altering actin cytoskeletal proteins and focus on how these alterations affect cell migration, proliferation and contraction of vascular cells. Finally, we discuss the role of oxidative modification of the actin cytoskeleton in vivo and highlight its importance for vascular diseases.

Targeting endothelial metaflammation to counteract diabesity cardiovascular risk: Current and perspective therapeutic options

The association of obesity and diabetes, termed "diabesity", defines a combination of primarily metabolic disorders with insulin resistance as the underlying common pathophysiology. Cardiovascular disorders associated with diabesity represent the leading cause of morbidity and mortality in the Western world. This makes diabesity, with its rising impacts on both health and economics, one of the most challenging biomedical and social threats of present century. The emerging comprehension of the genes whose alteration confers inter-individual differences on risk factors for diabetes or obesity, together with the potential role of genetically determined variants on mechanisms controlling responsiveness, effectiveness and safety of anti-diabetic therapy underlines the need of additional knowledge on molecular mechanisms involved in the pathophysiology of diabesity. Endothelial cell dysfunction, resulting from the unbalanced production of endothelial-derived vascular mediators, is known to be present at the earliest stages of insulin resistance and obesity, and may precede the clinical diagnosis of diabetes by several years. Once considered as a mere consequence of metabolic abnormalities, it is now clear that endothelial dysfunctional activity may play a pivotal role in the progression of diabesity. In the vicious circle where vascular defects and metabolic disturbances worsen and reinforce each other, a low-grade, chronic, and 'cold' inflammation (metaflammation) has been suggested to serve as the pathophysiological link that binds endothelial and metabolic dysfunctions. In this paradigm, it is important to consider how traditional antidiabetic treatments (specifically addressing metabolic dysregulation) may directly impact on inflammatory processes or cardiovascular function. Indeed, not all drugs currently available to treat diabetes possess the same anti-inflammatory potential, or target endothelial cell function equally. Perspective strategies pointing at reducing metaflammation or directly addressing endothelial dysfunction may disclose beneficial consequences on metabolic regulation. This review focuses on existing and potential new approaches ameliorating endothelial dysfunction and vascular inflammation in the context of diabesity.

Lower urinary tract symptoms/benign prostatic hypertrophy and vascular function: Role of the nitric oxide-phosphodiesterase type 5-cyclic guanosine 3',5'-monophosphate pathway

It is well known that there is an association of lower urinary tract symptoms/benign prostatic hypertrophy with cardiovascular disease, suggesting that lower urinary tract symptoms/benign prostatic hypertrophy is a risk factor for cardiovascular events. Vascular function, including endothelial function and vascular smooth muscle function, is involved in the pathogenesis, maintenance and development of atherosclerosis, leading to cardiovascular events. Vascular dysfunction per se should also contribute to lower urinary tract symptoms/benign prostatic hypertrophy. Both lower urinary tract symptoms/benign prostatic hypertrophy and vascular dysfunction have cardiovascular risk factors, such as hypertension, dyslipidemia, diabetes mellitus, aging, obesity and smoking. Inactivation of the phosphodiesterase type 5-cyclic guanosine 3',5'-monophosphate-nitric oxide pathway causes lower urinary tract symptoms/benign prostatic hypertrophy through an enhancement of sympathetic nervous activity, endothelial dysfunction, increase in Rho-associated kinase activity and vasoconstriction, and decrease in blood flow of pelvic viscera. Both endogenous nitric oxide and exogenous nitric oxide act as vasodilators on vascular smooth muscle cells through an increase in the content of cyclic guanosine 3',5'-monophosphate, which is inactivated by phosphodiesterase type 5. In a clinical setting, phosphodiesterase type 5 inhibitors are widely used in patients with lower urinary tract symptoms/benign prostatic hypertrophy. Phosphodiesterase type 5 inhibitors might have beneficial effects on vascular function through not only inhibition of cyclic guanosine 3',5'-monophosphate degradation, but also increases in testosterone levels and nitric oxide bioavailability, increase in the number and improvement of the function of endothelial progenitor cells, and decrease in insulin resistance. In the present review, the relationships between lower urinary tract symptoms/benign prostatic hypertrophy, the phosphodiesterase type 5-nitric oxide-cyclic guanosine 3',5'-monophosphate pathway, vascular function and cardiovascular outcomes are examined.

Endothelial dysfunction and abnormal vascular structure are simultaneously present in patients with heart failure with preserved ejection fraction

BACKGROUND

Endothelial dysfunction and abnormal vascular structure may be involved in the pathogenesis of chronic heart failure (HF). The purpose of this study was to evaluate simultaneously vascular function and vascular structure in patients with heart failure with preserved ejection fraction (HFpEF).

METHODS

We measured flow-mediated vasodilatation (FMD) and nitroglycerine-induced vasodilation as indices of vascular function and intima-media thickness (IMT) as an index of vascular structure of the brachial artery in 41 patients with HFpEF (23 men and 18 women; mean age, 66±12yr) and 165 patients without HF (95 men and 70 women; mean age, 54±16yr).

RESULTS

FMD was significantly smaller in patients with HFpEF than in patients without HF (2.9±2.1% versus 4.6±2.7%, P=0.0002). Nitroglycerine-induced vasodilation was significantly smaller in patients with HFpEF than in patients without HF (9.3±4.1% versus 12.9±4.9%, P<0.0001). Brachial artery IMT was significantly larger in patients with HFpEF than in patients without HF (0.35±0.06mm versus 0.31±0.07mm, P=0.0002). After adjustment for age, sex, hypertension, dyslipidemia, and diabetes mellitus, the associations remained significant between HFpEF and FMD (odds ratio, 0.79; 95% confidence interval, 0.66-0.92; P=0.0032), nitroglycerine-induced vasodilation (odds ratio, 0.88; 95% confidence interval, 0.80-0.96; P=0.0039), and brachial artery IMT (odds ratio, 1.08; 95% confidence interval, 1.01-1.17; P=0.033).

CONCLUSIONS

These findings suggest that both endothelial dysfunction and abnormal vascular structure may contribute to the pathogenesis and maintenance of HFpEF. Endothelial function and vascular structure may be potential therapeutic targets for HFpEF.

Rho Kinases in Health and Disease: From Basic Science to Translational Research

Rho-associated kinases ROCK1 and ROCK2 are key regulators of actin cytoskeleton dynamics downstream of Rho GTPases that participate in the control of important physiologic functions, S including cell contraction, migration, proliferation, adhesion, and inflammation. Several excellent review articles dealing with ROCK function and regulation have been published over the past few years. Although a brief overview of general molecular, biochemical, and functional properties of ROCKs is included, an effort has been made to produce an original work by collecting and synthesizing recent studies aimed at translating basic discoveries from cell and experimental models into knowledge of human physiology, pathophysiological mechanisms, and medical therapeutics. This review points out the specificity and distinct roles of ROCK1 and ROCK2 isoforms highlighted in the last few years. Results obtained from genetically modified mice and genetic analysis in humans are discussed. This review also addresses the involvement of ROCKs in human diseases and the potential use of ROCK activity as a biomarker or a pharmacological target for specific inhibitors.

Rho-associated kinase activity is an independent predictor of cardiovascular events in acute coronary syndrome

Rho-associated kinases play an important role in a variety of cellular functions. Although Rho-associated kinase activity has been shown to be an independent predictor for future cardiovascular events in a general population, there is no information on Rho-associated kinase activity in patients with acute coronary syndrome. We evaluated leukocyte Rho-associated kinase activity by Western blot analysis in 73 patients with acute coronary syndrome and 73 age- and gender-matched control subjects. Rho-associated kinase activity within 2 hours of acute coronary syndrome onset was higher in patients with acute coronary syndrome than in the control subjects (0.95±0.55 versus 0.69±0.31; P<0.001). Rho-associated kinase activity promptly increased from 0.95±0.55 to 1.11±0.81 after 3 hours and reached a peak of 1.21±0.76 after 1 day (P=0.03 and P=0.03, respectively) and then gradually decreased to 0.83±0.52 after 7 days, 0.78±0.42 after 14 days, and 0.72±0.30 after 6 months (P=0.22, P=0.29, and P=0.12, respectively). During a median follow-up period of 50.8 months, 31 first major cardiovascular events (death from cardiovascular causes, myocardial infarction, ischemic stroke, and coronary revascularization) occurred. After adjustment for age, sex, cardiovascular risk factors, and concomitant treatment with statins, increased Rho-associated kinase activity was associated with increasing risk of first major cardiovascular events (hazard ratio, 4.56; 95% confidence interval, 1.98–11.34; P<0.001). These findings suggest that Rho-associated kinase activity is dramatically changed after acute coronary syndrome and that Rho-associated kinase activity could be a useful biomarker to predict cardiovascular events in Japanese patients with acute coronary syndrome.

Sympathetic control of reflex cutaneous vasoconstriction in human aging

This Synthesis highlights a series of recent studies that has systematically interrogated age-related deficits in cold-induced skin vasoconstriction. In response to cold stress, a reflex increase in sympathetic nervous system activity mediates reductions in skin blood flow. Reflex vasoconstriction during cold exposure is markedly impaired in aged skin, contributing to the relative inability of healthy older adults to maintain core temperature during mild cold stress in the absence of appropriate behavioral thermoregulation. This compromised reflex cutaneous vasoconstriction in healthy aging can occur as a result of functional deficits at multiple points along the efferent sympathetic reflex axis, including blunted sympathetic outflow directed to the skin vasculature, reduced presynaptic neurotransmitter synthesis and/or release, and altered end-organ responsiveness at several loci, in addition to potential alterations in afferent thermoreceptor function. Arguments have been made that the relative inability of aged skin to appropriately constrict is due to the aging cutaneous arterioles themselves, whereas other data point to the neural circuitry controlling those vessels. The argument presented herein provides strong evidence for impaired efferent sympathetic control of the peripheral cutaneous vasculature during whole body cold exposure as the primary mechanism responsible for attenuated vasoconstriction.

Angiotensin II type I receptor blockade attenuates reflex cutaneous vasoconstriction in aged but not young skin

Stimulation of angiotensin II type I receptors (AT1R) elicits vasoconstriction (VC) that may be occurring through the activation of a pathogenic vascular pathway such as Rho kinase (ROCK). We hypothesize that reflex cutaneous VC to whole body cooling (mean skin temperature = 30.5°C) in older humans relies in part on AT1R activation, which may explain greater ROCK activity attendant with aging. Two microdialysis (MD) fibers were placed in the forearm skin of 10 young (Y; 24 ± 1 yr) and 10 older (O; 70 ± 2 yr) individuals for infusion of 1) lactated Ringer's solution (switched to fasudil, a ROCK antagonist, after cooling); and 2) AT1R blockade with losartan. Laser Doppler flux (LDF) was measured over each MD site and cutaneous vascular conductance (CVC) was calculated (CVC = LDF/mean arterial pressure) and expressed as percent change from baseline (%ΔCVCBASELINE). In older individuals the VC response to whole body cooling was blunted (Y = −34 ± 2, O = −17 ± 3%ΔCVC) and was further attenuated at the losartan site (Y = −34 ± 3, O = −9 ± 3%ΔCVC; P < 0.05). The VC response to an exogenous 10-μM dose of angiotensin II (Y = −27 ± 3, O = −42 ± 5%ΔCVC) was completely blocked in sites pretreated with losartan or with fasudil. These data suggest that AT1R activation contributes to the reflex VC response in aged but not young skin. Furthermore, the angiotensin II component of the VC response appears to occur primarily through a ROCK-mediated mechanism.

Effects of statin on circulating microRNAome and predicted function regulatory network in patients with unstable angina

BACKGROUND

Statin therapy plays a pivotal role in stabilizing the plaque for unstable angina (UA) patients although its mechanism(s) remains largely unexplored. Here we aim to identify microRNAs (miRNAs) mediating the protective effect of statins in UA patients.

METHODS

MiRNAs Array was carried out to compare the circulating whole blood miRNA profile of UA patients treated with (n = 10) and without statin (n = 10) and plasma miRNA profile UA patients treated with (n = 5) and without statin (n = 5). 22 whole blood miRNAs and 19 plasma miRNAs were found significantly upregulated in statin group. Targets of these miRNAs were predicted by algoritms: Targetscan, Miranda and Diana microT, then clustered according to functions and cell types by using the Database for Annotation, Visualization and Integrated Discovery (DAVID). To reveal the enriched function pathways in human atherosclerotic plaque, we analyzed microarray data from GEO database, Coronary atherosclerotic plaque (n = 80); macrophages in ruptured plaque (n = 11); carotid atheroma plaque (n = 64); advanced carotid atherosclerotic plaque (n = 29) using Reactome database. Integrated analysis indicated that statin induced miRNAs mainly regulate the signaling pathways of Rho GTPase and hemostasis in human atherosclerotic lesion. In vulnerable plaque, additional immune system signaling was also targeted.

RESULTS

The data showed target genes regulated by these statin induced miRNAs majorly expressed in i) plaque macrophage and platelet, where they were involved in hemostasis process; ii) in monocyte to regulate NGF apoptosis; iii) and in endothelial cell function in Rho GTPase pathway. Integrate analysis indicated that statin induced miRNAs mainly regulate the signaling pathways of Rho GTPase and hemostasis in human atherosclerotic lesion.

CONCLUSIONS

Our study suggest that statin induces the expression of multiple miRNAs in the circulation of UA patient, which play important roles by regulating signal pathways critical for the pathogenesis of UA.

Exogenous nitric oxide inhibits Rho-associated kinase activity in patients with angina pectoris: a randomized controlled trial

The RhoA/Rho-associated kinase (ROCK) pathway has a key physiological role in the pathogenesis of atherosclerosis. Increased ROCK activity is associated with cardiovascular diseases. Endogenous nitric oxide (NO) has an anti-atherosclerotic effect, whereas the exogenous NO-mediated cardiovascular effect still remains controversial. The purpose of this study was to evaluate the effect of exogenous NO on ROCK activity in patients with angina pectoris. This is a prospective, open-label, randomized, controlled study. A total of 30 patients with angina pectoris were randomly assigned to receive 40 mg day(-1) of isosorbide mononitrate (n=15, 12 men and 3 women, mean age of 63±12 years, isosorbide mononitrate group) or conventional treatment (n=15, 13 men and 2 women, mean age of 64±13 years, control group) for 12 weeks. ROCK activity in peripheral leukocytes was measured by western blot analysis. ROCK activities at 4 and 12 weeks after treatment were decreased in the isosorbide mononitrate group (0.82±0.33 at 0 week, 0.62±0.20 at 4 weeks, 0.61±0.19 at 12 weeks, n=15 in each group, P<0.05, respectively) but not altered in the control group. ROCK1 and ROCK2 expression levels were similar in all treatment periods in the two groups. These findings suggest that the administration of exogenous NO can inhibit ROCK activity, indicating that the usage of exogenous NO could have a protective effect in patients with angina pectoris.

Critical role of exogenous nitric oxide in ROCK activity in vascular smooth muscle cells

Objective

Rho-associated kinase (ROCK) signaling pathway has been shown to mediate various cellular functions including cell proliferation, migration, adhesion, apoptosis, and contraction, all of which may be involved in pathogenesis of atherosclerosis. Endogenous nitric oxide (NO) is well known to have an anti-atherosclerotic effect, whereas the exogenous NO-mediated cardiovascular effect still remains controversial. The purpose of this study was to evaluate the effect of exogenous NO on ROCK activity in vascular smooth muscle cells (VSMCs) in vitro and in vivo.

Methods

VSMCs migration was evaluated using a modified Boyden chamber assay. ROCK activities were measured by Western blot analysis in murine and human VSMCs and aorta of mice treated with or without angiotensin II (Ang II) and/or sodium nitroprusside (SNP), an NO donor.

Results

Co-treatment with SNP inhibited the Ang II-induced cell migration and increases in ROCK activity in murine and human VSMCs. Similarly, the increased ROCK activity 2 weeks after Ang II infusion in the mouse aorta was substantially inhibited by subcutaneous injection of SNP.

Conclusions

These findings suggest that administration of exogenous NO can inhibit ROCK activity in VSMCs in vitro and in vivo.

Vasodilator-stimulated phosphoprotein protects against vascular inflammation and insulin resistance

Among the pleotropic effects of endothelial nitric oxide (NO) is protection against vascular inflammation during high-fat diet (HFD) feeding. The current work investigated the role of the enzyme vasodilatory-stimulated phosphoprotein (VASP) as a downstream mediator of the anti-inflammatory effect of NO signaling in vascular tissue. Relative to mice fed a low-fat diet (LFD), levels of VASP Ser(239) phosphorylation, a marker of VASP activation, were dramatically reduced in aortic tissue of mice with obesity induced by consuming a HFD. As reported previously, the effect of the HFD was associated with increased aortic inflammation, as measured by increased NF-κB-dependent gene expression, and reduced vascular insulin sensitivity (including insulin-stimulated phosphorylation of eNOS and Akt). These effects of the HFD were recapitulated by VASP knockout, implying a physiological role for VASP to constrain inflammatory signaling and thereby maintain vascular insulin sensitivity. Conversely, overexpression of VASP in endothelial cells blocked inflammation and insulin resistance induced by palmitate. The finding that transplantation of bone marrow from VASP-deficient donors into normal recipients does not recapitulate the vascular effects of whole body VASP deficiency suggests that the protective effects of this enzyme are not mediated in immune or other bone marrow-derived cells. These studies implicate VASP as a downstream mediator of the NO/cGMP pathway that is both necessary and sufficient to protect against vascular inflammation and insulin resistance. As such, this work identifies VASP as a potential therapeutic target in the treatment of obesity-related vascular dysfunction.

Rho-kinase as a therapeutic target in vascular diseases: striking nitric oxide signaling

Rho GTPases are a globular, monomeric group of small signaling G-protein molecules. Rho-associated protein kinase/Rho-kinase (ROCK) is a downstream effector protein of the Rho GTPase. Rho-kinases are the potential therapeutic targets in the treatment of cardiovascular diseases. Here, we have primarily discussed the intriguing roles of ROCK in cardiovascular health in relation to nitric oxide signaling. Further, we highlighted the biphasic effects of Y-27632, a ROCK inhibitor under shear stress, which acts as an agonist of nitric oxide production in endothelial cells. The biphasic effects of this inhibitor raised the question of safety of the drug usage in treating cardiovascular diseases.

Anti-inflammation effect of Exercise and Korean red ginseng in aging model rats with diet-induced atherosclerosis

BACKGROUND/OBJECTIVES

The aim of this study was to investigate the effects of exercise (EX) and Korean red ginseng (KRG) on inflammation mechanism in aging model rats with diet-induced atherosclerosis.

MATERIALS/METHODS

Forty-eight male Sprague-Dawley rats were divided into 6 groups: Young control (Y-C), Aging control (A-C), A-C with HFD (AHF), AHF with EX (AHF-EX), AHF-EX with KRG (AHF-EX+RG), and AHF with KRG (AHF-RG). Aging was induced by D-gal (100mg/kg) and atherosclerosis was induced by HFD (60% fat) for 9 weeks. The experimental rats were performed swimming (60 min/day, 5 days/week) and supplied KRG orally (dose of 200 mg/kg) for 8 weeks. All rat aorta samples were harvested for biochemical and immunohistochemical analyses.

REULTS

The EX and KRG supplementation significantly inhibited body weight and levels of TC, TG, LDL-C, and enhance of HDL-C compared with untreated AHF groups. AHF-EX, AHF-EX+RG, and AHF-RG group showed a decreased plasma CRP and increase plasma NO activities compared to AHF group. In addition, these groups revealed reduced 4-HNE, NF-kB, TNF-α, IL-6, COX-2, ICAM-1, VCAM-1 and enhanced eNOS expression in the aorta.

CONCLUSION

These results suggest that EX alone, KRG alone, and combined treatment of EX and KRG may be an effective anti-inflammatory therapeutic for the atherosclerosis, possibly acting via the decreased of CRP and pro-inflammation proteins and the increased NO and eNOS.

Gene variations of ROCKs and risk of ischaemic stroke: the Women's Genome Health Study

Recent animal and human studies have demonstrated the importance of the ROCK (RhoA/Rho-associated kinase) pathway in IsST (ischaemic stroke). Whether the genetic variation within ROCK-associated genes modulates the risk of IsST remains elusive. The association between 66 tSNPs [tagging SNPs (single nucleotide polymorphisms)] of three ROCK-associated genes [ROCK1, ROCK2 and ARHGEF10 (Rho guanine-nucleotide-exchange factor 10)] and the incidence of IsST was investigated in 23294 Caucasian female participants of the prospective WGHS (Women's Genome Health Study). All were free of known cancer and cardiovascular disease at baseline. During a 15-year follow-up period, 323 participants developed their first ever IsST. Multivariable Cox regression analysis was performed to investigate the relationship between genotypes and risk of IsST assuming an additive genetic model. Haplotype-block analysis was also performed. A total of ten tSNPs were associated with the risk of IsST (three in ARHGEF10 and seven in ROCK1; P<0.050). Further investigation using the haplotype-block analysis revealed a similar significant association of pre-specified haplotypes of ROCK1 with the risk of IsST (P=0.005). If corroborated in other large prospective studies, the findings of the present study suggest that genetic variation within the ROCK-associated pathway gene loci examined, and in particular ROCK1 gene variation, may influence the risk of IsST.

Rho/Rho-associated coiled-coil forming kinase pathway as therapeutic targets for statins in atherosclerosis

SIGNIFICANCE

The 3-hydroxy-methylglutaryl coenzyme A reductase inhibitors or statins are important therapeutic agents for lowering serum cholesterol levels. However, recent studies suggest that statins may exert atheroprotective effects beyond cholesterol lowering. These so-called "pleiotropic effects" include effects of statins on vascular and inflammatory cells. Thus, it is important to understand whether other signaling pathways that are involved in atherosclerosis could be targets of statins, and if so, whether individuals with "overactivity" of these pathways could benefit from statin therapy, regardless of serum cholesterol level.

RECENT ADVANCES

Statins inhibit the synthesis of isoprenoids, which are important for the function of the Rho/Rho-associated coiled-coil containing kinase (ROCK) pathway. Indeed, recent studies suggest that inhibition of the Rho/ROCK pathway by statins could lead to improved endothelial function and decreased vascular inflammation and atherosclerosis. Thus, the Rho/ROCK pathway has emerged as an important target of statin therapy for reducing atherosclerosis and possibly cardiovascular disease.

CRITICAL ISSUES

Because atherosclerosis is both a lipid and an inflammatory disease, it is important to understand how inhibition of Rho/ROCK pathway could contribute to statins' antiatherosclerotic effects.

FUTURE DIRECTIONS

The role of ROCKs (ROCK1 and ROCK2) in endothelial, smooth muscle, and inflammatory cells needs to be determined in the context of atherogenesis. This could lead to the development of specific ROCK1 or ROCK2 inhibitors, which could have greater therapeutic benefits with less toxicity. Also, clinical trials will need to be performed to determine whether inhibition of ROCKs, with and without statins, could lead to further reduction in atherosclerosis and cardiovascular disease.

Rho-associated kinase activity is a predictor of cardiovascular outcomes

Cardiovascular diseases are associated with chronic activation of Rho-associated kinase. Rho-associated kinase activity is significantly correlated with endothelial function and Framingham risk score. However, there is no information on the prognostic value of Rho-associated kinase activity. We evaluated Rho-associated kinase activity in peripheral leukocytes by Western blot analysis in 633 subjects who underwent health-screening examination at Hiroshima University Hospital. We assessed the associations between Rho-associated kinase activity and first major cardiovascular events (death from cardiovascular causes, myocardial infarction, and stroke), death from cardiovascular causes, acute myocardial infarction, stroke, revascularization (percutaneous coronary intervention, coronary artery bypass grafting), and hospitalization for heart failure. During a median period of 42.0 months (interquartile range, 24.4-56.6 months) of follow-up, 29 subjects died (10 from cardiovascular causes), 2 myocardial infarction, 20 revascularization, 15 stroke, and 17 hospitalization for heart failure. After adjustment for age, sex, cardiovascular risk factors, and other relevant variables, Rho-associated kinase activity remained a strong independent indicator of first major cardiovascular events (hazard ratio, 2.19; 95% confidence interval, 1.35-3.70; P=0.002), death from cardiovascular disease (hazard ratio, 2.57; 95% confidence interval, 1.18-6.60; P=0.002), stroke (hazard ratio, 2.14; 95% confidence interval, 1.24-3.86; P=0.006), and revascularization (hazard ratio, 2.68; 95% confidence interval, 1.60-4.66; P<0.001). Leukocyte Rho-associated kinase activity may be a new biomarker of cardiovascular events. These findings suggest that inhibition of Rho-associated kinase activity may be a therapeutic target for prevention of cardiovascular events.

Molecular biology of atherosclerosis

At least 468 individual genes have been manipulated by molecular methods to study their effects on the initiation, promotion, and progression of atherosclerosis. Most clinicians and many investigators, even in related disciplines, find many of these genes and the related pathways entirely foreign. Medical schools generally do not attempt to incorporate the relevant molecular biology into their curriculum. A number of key signaling pathways are highly relevant to atherogenesis and are presented to provide a context for the gene manipulations summarized herein. The pathways include the following: the insulin receptor (and other receptor tyrosine kinases); Ras and MAPK activation; TNF-α and related family members leading to activation of NF-κB; effects of reactive oxygen species (ROS) on signaling; endothelial adaptations to flow including G protein-coupled receptor (GPCR) and integrin-related signaling; activation of endothelial and other cells by modified lipoproteins; purinergic signaling; control of leukocyte adhesion to endothelium, migration, and further activation; foam cell formation; and macrophage and vascular smooth muscle cell signaling related to proliferation, efferocytosis, and apoptosis. This review is intended primarily as an introduction to these key signaling pathways. They have become the focus of modern atherosclerosis research and will undoubtedly provide a rich resource for future innovation toward intervention and prevention of the number one cause of death in the modern world.

Small G Proteins in the Cardiovascular System: Physiological and Pathological Aspects

Small G proteins exist in eukaryotes from yeast to human and constitute the Ras superfamily comprising more than 100 members. This superfamily is structurally classified into five families: the Ras, Rho, Rab, Arf, and Ran families that control a wide variety of cell and biological functions through highly coordinated regulation processes. Increasing evidence has accumulated to identify small G proteins and their regulators as key players of the cardiovascular physiology that control a large panel of cardiac (heart rhythm, contraction, hypertrophy) and vascular functions (angiogenesis, vascular permeability, vasoconstriction). Indeed, basal Ras protein activity is required for homeostatic functions in physiological conditions, but sustained overactivation of Ras proteins or spatiotemporal dysregulation of Ras signaling pathways has pathological consequences in the cardiovascular system. The primary object of this review is to provide a comprehensive overview of the current progress in our understanding of the role of small G proteins and their regulators in cardiovascular physiology and pathologies.

Mechanosensitive microRNAs-role in endothelial responses to shear stress and redox state

Endothelial functions are highly regulated by imposed shear stress in vivo. The characteristics of shear stress determine mechanotransduction events that regulate phenotypic outcomes including redox and inflammatory states. Recent data indicate that microRNAs (miRs) in vascular endothelial cells play an essential role in shear stress-regulated endothelial responses. More specifically, atheroprotective pulsatile flow (PS) induces miRs that inhibit mediators of oxidative stress and inflammation while promoting those involved in maintaining vascular homeostasis. Conversely, oscillatory flow (OS) elicits the opposing networks. This is exemplified by the PS-responsive transcription factor Krüppel-like factor 2 (KLF2), which regulates miR expression but is also regulated by OS-sensitive miRs to ultimately regulate the oxidative and inflammatory state of the endothelium. In this review, we outline important findings demonstrating the multifaceted roles of shear stress-regulated miRs in endothelial redox and inflammatory balance. Furthermore, we discuss the use of algorithms in deciphering signaling networks differentially regulated by PS and OS.

Increased leukocyte Rho-kinase activity in a population with acute coronary syndrome

Accumulating evidence suggests that Rho-associated kinase (ROCK) may be important in the pathogenesis of atherosclerosis and coronary vasospasm. In the present study, we investigated whether ROCK activity is increased in acute coronary syndrome (ACS) patients. Twenty-one patients with ACS (12 males, mean age 58.0±8.0 years) and 20 control subjects (10 males, mean age 55.0±6.0 years) were enrolled. Blood samples were obtained and demographics were recorded. Peripheral leukocyte ROCK activity was determined by the ratio of phospho-myosin‑binding subunit (P-MBS) on myosin light-chain phosphatase to total MBS. Compared with the control subjects, ROCK activity was significantly increased in ACS patients (0.69±0.07 vs. 0.45±0.04, P<0.001). There was no apparent correlation between the lipid levels (total cholesterol and low-density lipoprotein) and ROCK activity (r=0.17, P>0.05; r=0.08, P>0.05; respectively). However, ROCK activity correlated with mean arterial pressure (r=0.58; P<0.01). ROCK activity is increased in ACS patients indicating that this may be a novel serological marker of ACS.

Dominant negative PPARγ promotes atherosclerosis, vascular dysfunction, and hypertension through distinct effects in endothelium and vascular muscle

Agonists of the nuclear hormone receptor peroxisome proliferator-activated receptor γ (PPARγ) have potent insulin-sensitizing effects and inhibit atherosclerosis progression in patients with Type II diabetes. Conversely, missense mutations in the ligand-binding domain of PPARγ that render the transcription factor dominant negative (DN) cause early-onset hypertension and Type II diabetes. We tested the hypothesis that DN PPARγ-mediated interference of endogenous wild-type PPARγ in the endothelium and vascular smooth muscle exacerbates atherosclerosis in apolipoprotein E-deficient (ApoE(-/-)) mice. Endothelium-specific expression of DN PPARγ on the ApoE(-/-) background unmasked significant impairment of endothelium-dependent relaxation in aortic rings, increased systolic blood pressure, altered expression of atherogenic markers (e.g., Cd36, Mcp1, Catalase), and enhanced diet-induced atherosclerotic lesion formation in aorta. Smooth muscle-specific expression of DN PPARγ, which induces aortic dysfunction and increased systolic blood pressure at baseline, also resulted in enhanced diet-induced atherosclerotic lesion formation in aorta on the ApoE(-/-) background that was associated with altered expression of a shared, yet distinct, set of atherogenic markers (e.g., Cd36, Mcp1, Osteopontin, Vcam1). In particular, induction of Osteopontin expression by smooth muscle-specific DN PPARγ correlated with increased plaque calcification. These data demonstrate that inhibition of PPARγ function specifically in the vascular endothelium or smooth muscle may contribute to cardiovascular disease.

Association analysis of polymorphisms in ROCK2 with cardiovascular disease in a Chinese population

Background

Rho-kinase (ROCK) has been shown to play an important role in cardiovascular disease such as coronary artery disease (CAD) and hypertension. Recently, common variants of ROCK2 have been reported to influence blood pressure, but the relationship between common ROCK2 variants and cardiovascular disease has not been extensively studied in the Chinese population.

Methods

To derive a more precise estimation of their relationship, we screened for the common variants by direct sequencing of all exons of ROCK2, and then we performed genetic association analyses in a CAD case–control study, including a total of 1344 cases and 1267 ethnically and geographically matched controls.

Results

Unconditional logistic regression showed that no significant association between common variants in the coding region of ROCK2 and CAD was observed in our study (for rs978906, OR = 0.92, 95% CI 0.72–1.20 and P = 0.63; for rs2230774, OR = 0.90, 95% CI 0.70–1.16 and P = 0.47; for rs56304104, OR = 0.97, 95% CI 0.70–1.31 and P = 0.83; respectively).

Conclusions

The relationship between the ROCK2 polymorphisms and cardiovascular disease risk cannot be entirely discounted and warrants further evaluation in a large population.

Effects of rosuvastatin vs. simvastatin/ezetimibe on arterial wall stiffness in patients with coronary artery disease

OBJECTIVE

Statins prevent cardiovascular events in patients with coronary artery disease (CAD). However, there is little information regarding the vascular effects of statins on arterial wall stiffness in CAD patients.

METHODS

A total of 36 patients were randomly assigned to receive rosuvastatin (10 mg per day) or simvastatin/ezetimibe (10/10 mg per day) for eight weeks. The aim of the present study was to determine the effects of rosuvastatin or simvastatin/ezetimibe on arterial wall stiffness measured according to the brachial and ankle pulse wave velocity (baPWV) in CAD patients.

RESULTS

Both treatments significantly improved the levels of total cholesterol (TC), triglycerides (TGs), low-density lipoprotein cholesterol (LDL-C) and high-sensitivity C-reactive protein (hs-CRP) (p<0.05). The ROCK activity and baPWV were significantly improved in the rosuvastatin group compared with that observed in the simvastatin/ezetimibe group (p<0.05). The changes in baPWV were significantly correlated with the changes in the ROCK activity (r=0.488, p<0.01), but not with the changes in the lipid profile or the hs-CRP level.

CONCLUSION

Compared with simvastatin/ezetimibe (10/10 mg), rosuvastatin (10 mg) appears to more effectively improve arterial wall stiffness that may be mediated by modulation of the ROCK activity.