Hypertension is one of the major risk factors for cardiovascular and cerebrovascular disease and mortality. Patients who receive insufficient doses of antihypertensive agents or who are poorly adherent to multidrug treatment regimens often fail to achieve adequate blood pressure (BP) control. The aim of this study was to determine the efficacy of an angiotensin II receptor blocker (ARB) and calcium channel blocker (CCB) combination tablet containing a regular dose of irbesartan (100 mg) and a high dose of amlodipine (10 mg) with regard to lowering BP and other risk factors for cardiovascular disease.
We retrospectively evaluated data from 68 patients with essential hypertension whose treatment regimen was changed either from combination treatment with an independent ARB and a low-dose or regular-dose CCB or from a combination tablet of ARB and a low-dose or regular-dose CCB to a combination tablet containing amlodipine 10 mg and irbesartan 100 mg, because of incomplete BP control. Previous treatments did not include irbesartan as the ARB.
The combination tablet decreased systolic and diastolic BP. In addition, it significantly decreased serum uric acid, low-density lipoprotein cholesterol, and increased high-density lipoprotein cholesterol levels, independent of the BP-lowering effect. Treatment with the combination tablet did not affect serum triglycerides, plasma glucose, glycated hemoglobin, serum potassium or creatinine levels, or the urinary albumin excretion rate.
The combination tablet containing amlodipine 10 mg and irbesartan 100 mg had a greater BP-lowering effect than an ARB and a low-dose or regular-dose CCB. In addition, the combination tablet had more favorable effects on serum uric acid, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol levels in patients with hypertension.
blood pressure; combination tablet; uric acid; low-density lipoprotein cholesterol; high-density lipoprotein cholesterol
Mechanisms regulating adiponectin expression have not been fully clarified. MicroRNAs (miRNAs), small non-coding RNAs that regulate gene expression, are involved in biological processes, including obesity and insulin resistance. We evaluated whether the miRNA-378 pathway is involved in regulating adiponectin expression.
Methods and Results
First, we determined a putative target site for miRNA-378 in the 3 prime untranslated region (3'UTR) of the adiponectin gene by in silico analysis. The levels of adiponectin mRNA and protein were decreased in 3T3-L1 cells overexpressing the mimic of miRNA-378. Luminescence activity in HEK293T cells expressing a renilla-luciferase-adiponectin-3'UTR sequence was inhibited by overexpressing the mimic of miRNA-378, and the decrease was reversed by adding the inhibitor of miRNA-378. Moreover, we confirmed the inhibitory effects of the mimic were cancelled in a deleted mutant of the miR-378 3′-UTR binding site. Addition of tumor necrosis factor-α (TNFα) led a upregulation of miR-378 and downregulation of adiponectin at mRNA and protein levels in 3T3-L1 cells. Level of miR-378 was higher and mRNA level of adiponectin was lower in diabetic ob/ob mice than those of normal C57BL/6 mice and levels of miR378 and adiponectin were negatively well correlated (r = −0.624, p = 0.004).
We found that levels of miRNA-378 could modulate adiponectin expression via the 3'UTR sequence-binding site. Our findings warrant further investigations into the role of miRNAs in regulating the adiponectin expression.
The effectiveness of angioplasty and stenting in intracranial atherosclerotic diseases is controversial due to high rates of delayed restenosis and hemorrhage compared with extracranial arteries. However, the mechanisms underlying these differences are still unclear, because their pathophysiology is yet to be examined. To address this issue, we established a novel vascular injury model in the intracranial internal carotid arteries (IICAs) in mice, and analyzed the remodeling process in comparison to that of the femoral arteries (FAs). In IICAs, neointimal hyperplasia was observed from day 14 and grew until day 56. Although smooth muscle cells (SMCs) emerged in the neointima from day 28, SMCs in the injured media were continuously lost with eventual extinction of the media. Re-endothelialization was started from day 7 and completed on day 28. Accumulation of macrophages was continued in the adventitia until day 56. Compared with FAs, the following points are unique in IICAs: (1) delayed continuous formation of neointima; (2) accumulation of macrophages in the media on day 14; (3) continuous loss of SMCs in the media followed by extinction of the media itself; and (4) continuously growing adventitia. These pathophysiologic differences might be associated with unfavorable outcomes in percutaneous transluminal angioplasty and stenting in intracranial arteries.
atherosclerosis; endothelium; inflammation; smooth muscle; vascular biology
A high-calorie diet and physical inactivity, an imbalance between caloric intake and energy consumption, are major causes of metabolic syndrome (MetS), which manifests as accumulation of visceral fat and insulin resistance. However, the lifestyle-related factors associated with visceral fat mass in healthy men are not fully understood.
We evaluated visceral fat area (VFA), skeletal muscle mass, caloric intake, and energy expenditure in 67 healthy male participants (mean age, 36.9 ± 8.8 years; body mass index 23.4 ± 2.5 kg/m2).
Multiple regression analysis showed that the total skeletal muscle mass (P < 0.001) were negatively and age (P < 0.001) were positively associated with VFA. Lower limb muscle mass (P < 0.001) was strongly associated with VFA. However, total caloric intake, total energy expenditure, and energy expenditure during exercise were not associated with VFA.
Skeletal muscle mass especially lower limb muscle mass negatively contributes to visceral fat mass in healthy men. Therefore, maintaining lower limb muscular fitness through daily activity may be a useful strategy for controlling visceral obesity and metabolic syndrome.
Exercise; Skeletal muscle; Metabolic syndrome; Prevention
Hypoandrogenemia is associated with an increased risk of ischemic diseases. Since actions of androgens are exerted through androgen receptor (AR) activation, we studied hind limb ischemia in AR knockout (KO) mice to elucidate the role of AR in response to ischemia.
Methods and Results
Both male and female ARKO mice exhibited impaired blood flow recovery, more cellular apoptosis and a higher incidence of autoamputation after ischemia. In ex vivo and in vivo angiogenesis studies, AR-deficient vascular endothelial cells showed reduced angiogenic capability. In ischemic limbs of ARKO mice, reductions in the phosphorylation of the Akt protein kinase and endothelial nitric oxide synthase (eNOS) were observed despite a robust increase in hypoxia-inducible factor 1α and vascular endothelial cell growth factor (VEGF) gene expression. In in vitro studies, siRNA-mediated ablation of AR in vascular endothelial cells blunted VEGF-stimulated phosphorylation of Akt and eNOS. Immunoprecipitation experiments documented an association between AR and kinase insert domain protein receptor (KDR) that promoted the recruitment of downstream signaling components.
These results document a physiological role of AR in gender-independent angiogenic potency and provide evidence for a novel cross-talk between androgen/AR signaling and VEGF/KDR signaling pathways.
androgen receptor; angiogenesis; KDR; Akt; eNOS
Azilsartan, an angiotensin II type 1 (AT1) receptor blocker (ARB), has a higher affinity for and slower dissociation from AT1 receptors and shows stronger inverse agonism compared to other ARBs. Possible benefits of azilsartan in diabetic vascular dysfunction have not been established.
We measured vascular reactivity of aortic rings in male KKAy diabetic mice treated with vehicle, 0.005% azilsartan, or 0.005% candesartan cilexetil for 3 weeks. Expression of markers of inflammation and oxidative stress was measured using semiquantitative RT-PCR in the vascular wall, perivascular fat, and skeletal muscle. Phosphorylation of endothelial nitric oxide synthase (eNOS) at Ser1177 and Thr495 was measured using Western blotting, and the ratio of phosphorylation at Ser1177 to phosphorylation at Thr495 was used as a putative indicator of vascular eNOS activity.
(1) Vascular endothelium–dependent relaxation with acetylcholine in KKAy mice was improved by azilsartan treatment compared to candesartan cilexetil; (2) the ratio of Ser1177/Thr495 phosphorylation of eNOS was impaired in KKAy and was effectively restored by azilsartan; (3) anomalies in the expression levels of monocyte chemotactic protein 1 (MCP1), F4/80, NAD(P)H oxidase (Nox) 2, and Nox4 of the aortic wall and in the expression of TNFα in the perivascular fat were strongly attenuated by azilsartan compared to candesartan cilexetil.
These results provide evidence that azilsartan prevents endothelial dysfunction in diabetic mice, more potently than does candesartan cilexetil. Azilsartan’s higher affinity for and slower dissociation from AT1 receptors may underlie its efficacy in diabetic vascular dysfunction via a dual effect on uncoupled eNOS and on Nox.
Bone marrow-derived cells (BMCs) are considered to be a major source of mesenchymal stem cells (MSCs) in adults and are known to be effective in periodontal tissue regeneration. However, whether endogenous BMCs are involved in periodontal tissue repair process is uncertain. We therefore created periodontal tissue defects in the buccal alveolar bone of mandibular first molars in bone marrow chimeric mice, and immunohistochemically examined the expression of stromal cell derived factor-1 (SDF-1) and the mobilization of BMCs. We found that SDF-1 expression was increased around the defects at as early as 1 week after injury and that BMCs were mobilized to the defects, while GFP+/CD45+ were rarely observed. Fluorescence-activated cell sorting (FACS) analysis demonstrated that the number of platelet-derived growth factor receptor (pdgfr) α+/Sca-1+ (PαS) cells in the bone marrow decreased after injury. Taken together, these results suggest that BMCs are mobilized to the periodontal tissue defects. Recruitment of BMCs, including a subset of MSCs could be a new target of periodontal treatment.
bone marrow chimeric mice; periodontal defects; mesenchymal stem cells; recruitment; SDF-1
Inflammation is induced in the heart during the development of cardiac hypertrophy. The initiating mechanisms and the role of inflammation in cardiac hypertrophy, however, remain unclear. Toll‐like receptor‐2 (TLR2) recognizes endogenous molecules that induce noninfectious inflammation. Here, we examined the role of TLR2‐mediated inflammation in cardiac hypertrophy.
Methods and Results
At 2 weeks after transverse aortic constriction, Tlr2−/− mice showed reduced cardiac hypertrophy and fibrosis with greater left ventricular dilatation and impaired systolic function compared with wild‐type mice, which indicated impaired cardiac adaptation in Tlr2−/− mice. Bone marrow transplantation experiment revealed that TLR2 expressed in the heart, but not in bone marrow–derived cells, is important for cardiac adaptive response to pressure overload. In vitro experiments demonstrated that TLR2 signaling can induce cardiomyocyte hypertrophy and fibroblast and vascular endothelial cell proliferation through nuclear factor–κB activation and interleukin‐1β upregulation. Systemic administration of a nuclear factor–κB inhibitor or anti–interleukin‐1β antibodies to wild‐type mice resulted in impaired adaptive cardiac hypertrophy after transverse aortic constriction. We also found that heat shock protein 70, which was increased in murine plasma after transverse aortic constriction, can activate TLR2 signaling in vitro and in vivo. Systemic administration of anti–heat shock protein 70 antibodies to wild‐type mice impaired adaptive cardiac hypertrophy after transverse aortic constriction.
Our results demonstrate that TLR2‐mediated inflammation induced by extracellularly released heat shock protein 70 is essential for adaptive cardiac hypertrophy in response to pressure overload. Thus, modulation of TLR2 signaling in the heart may provide a novel strategy for treating heart failure due to inadequate adaptation to hemodynamic stress.
heart failure; hypertrophy; inflammation; interleukins; signal transduction
Recent accumulating evidence suggests that innate immunity is associated with obesity-induced chronic inflammation and metabolic disorders. Here, we show that a Toll-like receptor (TLR) protein, radioprotective 105 (RP105)/myeloid differentiation protein (MD)-1 complex, contributes to high-fat diet (HFD)-induced obesity, adipose tissue inflammation, and insulin resistance. An HFD dramatically increased RP105 mRNA and protein expression in stromal vascular fraction of epididymal white adipose tissue (eWAT) in wild-type (WT) mice. RP105 mRNA expression also was significantly increased in the visceral adipose tissue of obese human subjects relative to nonobese subjects. The RP105/MD-1 complex was expressed by most adipose tissue macrophages (ATMs). An HFD increased RP105/MD-1 expression on the M1 subset of ATMs that accumulate in eWAT. Macrophages also acquired this characteristic in coculture with 3T3-L1 adipocytes. RP105 knockout (KO) and MD-1 KO mice had less HFD-induced adipose tissue inflammation, hepatic steatosis, and insulin resistance compared with wild-type (WT) and TLR4 KO mice. Finally, the saturated fatty acids, palmitic and stearic acids, are endogenous ligands for TLR4, but they did not activate RP105/MD-1. Thus, the RP105/MD-1 complex is a major mediator of adipose tissue inflammation independent of TLR4 signaling and may represent a novel therapeutic target for obesity-associated metabolic disorders.
We investigated the effects of purified eicosapentaenoic acid (EPA) on vascular endothelial function and free fatty acid composition in Japanese hyperlipidemic subjects. In subjects with hyperlipidemia (total cholesterol ≥220 mg/dL and/or triglycerides ≥150 mg/dL), lipid profile and forearm blood flow (FBF) during reactive hyperemia were determined before and 3 months after supplementation with 1800 mg/day EPA. Peak FBF during reactive hyperemia was lower in the hyperlipidemic group than the normolipidemic group. EPA supplementation did not change serum levels of total, HDL, or LDL cholesterol, apolipoproteins, remnant-like particle (RLP) cholesterol, RLP triglycerides, or malondialdehyde-modified LDL cholesterol. EPA supplementation did not change total free fatty acid levels in serum, but changed the fatty acid composition, with increased EPA and decreased linoleic acid, γ-linolenic acid, and dihomo-γ-linolenic acid. EPA supplementation recovered peak FBF after 3 months. Peak FBF recovery was correlated positively with EPA and EPA/arachidonic acid levels and correlated inversely with dihomo-γ-linolenic acid. EPA supplementation restores endothelium-dependent vasodilatation in hyperlipidemic patients despite having no effect on serum cholesterol and triglyceride patterns. These results suggest that EPA supplementation may improve vascular function at least partly via changes in fatty acid composition.
Telmisartan is a well-established angiotensin II type 1 receptor blocker that improves insulin sensitivity in animal models of obesity and insulin resistance, as well as in humans. Telmisartan has been reported to function as a partial agonist of the peroxisome proliferator-activated receptor (PPAR) γ, which is also targeted by the nicotinamide adenine dinucleotide (NAD)-dependent deacetylase (SIRT1). Here, we investigated the pathways through which telmisartan acts on skeletal muscle, in vitro as well as in vivo.
Nine-week-old male db/db mice were fed a 60% high-fat diet, with orally administrated either vehicle (carboxymethyl-cellulose, CMC), 5 mg/kg telmisartan, or 5 mg/kg telmisartan and 1 mg/kg GW9662, a selective irreversible antagonist of PPARγ, for 5 weeks. Effects of telmisartan on Sirt1 mRNA, AMPK phosphorylation, and NAD+/NADH ratio were determined in C2C12 cultured myocytes.
Results and discussion
Telmisartan treatment improved insulin sensitivity in obese db/db mice fed a high-fat diet and led to reduction in the size of hypertrophic pancreatic islets in these mice. Moreover, in vitro treatment with telmisartan led to increased expression of Sirt1 mRNA in C2C12 skeletal muscle cells; the increase in Sirt1 mRNA in telmisartan-treated C2C12 myoblasts occurred concomitantly with an increase in AMPK phosphorylation, an increase in NAD+/NADH ratio, and increases in the mRNA levels of PGC1α, FATP1, ACO, and GLUT4.
Our results indicate that telmisartan acts through a PPARγ-independent pathway, but at least partially exerts its effects by acting directly on skeletal muscle AMPK/SIRT1 pathways.
Adiponectin; AMP-activated protein kinase; Obesity; Peroxisome proliferator-activated receptor-γ; SIRT1
Growing evidence suggests that epicardial adipose tissue (EAT) may contribute to the development of coronary artery disease (CAD). In this study, we explored gender disparities in EAT volume (EATV) and its impact on coronary atherosclerosis.
The study population consisted of 90 consecutive subjects (age: 63 ± 12 years; men: 47, women: 43) who underwent 256-slice multi-detector computed tomography (MDCT) coronary angiography. EATV was measured as the sum of cross-sectional epicardial fat area on CT images, from the lower surface of the left pulmonary artery origin to the apex. Subjects were segregated into the CAD group (coronary luminal narrowing > 50%) and non-CAD group.
EATV/body surface area (BSA) was higher among men in the CAD group than in the non-CAD group (62 ± 13 vs. 33 ± 10 cm3/m2, p < 0.0001), but did not differ significantly among women in the 2 groups (49 ± 18 vs. 42 ± 9 cm3/m2, not significant). Multivariate logistic analysis showed that EATV/BSA was the single predictor for >50% coronary luminal narrowing in men (p < 0.0001). Predictors excluded were age, body mass index, hypertension, diabetes mellitus, and hyperlipidemia.
Increased EATV is strongly associated with coronary atherosclerosis in men.
Atherosclerosis; Gender difference; Epicardial adipose tissue; Obesity
Cardiovascular disease and renal disease have a close relationship that forms a vicious cycle as a cardiorenal syndrome (CRS). Oxidative stress, endothelial dysfunction, and vascular inflammation could be therapeutic targets when the renin-angiotensin-aldosterone system is activated by accumulation of conventional cardiovascular risk factors; however, a strategy for management of CRS has not been established yet. Statins, HMG-CoA reductase inhibitors, have not only cholesterol-lowering effects but also pleiotropic effects on cardiovascular systems, including anti-inflammatory and antioxidant effects and improvement of nitric oxide bioavailability. Since recent studies have indicated that statins have beneficial effects on chronic kidney disease and heart failure as well as coronary artery disease in cholesterol-lowering-dependent/independent manners, treatment with statins might be a successful strategy for preventing deterioration of CRS.
An antianginal KATP channel opener nicorandil has various beneficial effects on cardiovascular systems; however, its effects on pulmonary vasculature under pulmonary arterial hypertension (PAH) have not yet been elucidated. Therefore, we attempted to determine whether nicorandil can attenuate monocrotaline (MCT)-induced PAH in rats.
Materials and Methods
Sprague-Dawley rats injected intraperitoneally with 60 mg/kg MCT were randomized to receive either vehicle; nicorandil (5.0 mg·kg−1·day−1) alone; or nicorandil as well as either a KATP channel blocker glibenclamide or a nitric oxide synthase (NOS) inhibitor Nω-nitro-l-arginine methyl ester (l-NAME), from immediately or 21 days after MCT injection. Four or five weeks later, right ventricular systolic pressure (RVSP) was measured, and lung tissue was harvested. Also, we evaluated the nicorandil-induced anti-apoptotic effects and activation status of several molecules in cell survival signaling pathway in vitro using human umbilical vein endothelial cells (HUVECs).
Four weeks after MCT injection, RVSP was significantly increased in the vehicle-treated group (51.0±4.7 mm Hg), whereas it was attenuated by nicorandil treatment (33.2±3.9 mm Hg; P<0.01). Nicorandil protected pulmonary endothelium from the MCT-induced thromboemboli formation and induction of apoptosis, accompanied with both upregulation of endothelial NOS (eNOS) expression and downregulation of cleaved caspase-3 expression. Late treatment with nicorandil for the established PAH was also effective in suppressing the additional progression of PAH. These beneficial effects of nicorandil were blocked similarly by glibenclamide and l-NAME. Next, HUVECs were incubated in serum-free medium and then exhibited apoptotic morphology, while these changes were significantly attenuated by nicorandil administration. Nicorandil activated the phosphatidylinositol 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK) pathways in HUVECs, accompanied with the upregulation of both eNOS and Bcl-2 expression.
Nicorandil attenuated MCT-induced vascular endothelial damage and PAH through production of eNOS and anti-apoptotic factors, suggesting that nicorandil might have a promising therapeutic potential for PAH.
We have provided evidence that saturated fatty acids, which are released from adipocytes via macrophage-induced adipocyte lipolysis, serve as a naturally occurring ligand for the Toll-like receptor (TLR) 4 complex in macrophages, thereby aggravating obesity-induced adipose tissue inflammation. The aim of this study was to identify the molecule(s) activated in adipose tissue macrophages in obesity.
RESEARCH DESIGN AND METHODS
We performed a cDNA microarray analysis of coculture of 3T3-L1 adipocytes and RAW264 macrophages. Cultured adipocytes and macrophages and the adipose tissue of obese mice and humans were used to examine mRNA and protein expression.
We found that macrophage-inducible C-type lectin (Mincle; also called Clec4e and Clecsf9), a type II transmembrane C-type lectin, is induced selectively in macrophages during the interaction between adipocytes and macrophages. Treatment with palmitate, a major saturated fatty acid released from 3T3-L1 adipocytes, induced Mincle mRNA expression in macrophages at least partly through the TLR4/nuclear factor (NF)-κB pathway. Mincle mRNA expression was increased in parallel with macrophage markers in the adipose tissue of obese mice and humans. The obesity-induced increase in Mincle mRNA expression was markedly attenuated in C3H/HeJ mice with defective TLR4 signaling relative to control C3H/HeN mice. Notably, Mincle mRNA was expressed in bone-marrow cell (BMC)-derived proinflammatory M1 macrophages rather than in BMC-derived anti-inflammatory M2 macrophages in vitro.
Our data suggest that Mincle is induced in adipose tissue macrophages in obesity at least partly through the saturated fatty acid/TLR4/NF-κB pathway, thereby suggesting its pathophysiologic role in obesity-induced adipose tissue inflammation.
Purpose: Efficient and secure collection of CD34+ cells are
crucial for the angiogenic therapies. We have developed autologous peripheral
blood-mononuclear cell (MNC) transplantation induced by erythropoietin (rhEPO) for
critical ischemic limbs.
Methods: Seven patients, including five with
arteriosclerosis obliterans, one with Buerger’s disease and one with progressive systemic
sclerosis, underwent ten cell therapies. The first administration of rhEPO was performed
two weeks before apheresis, and the second administration and blood donation were
performed one week before apheresis to activate bone marrow. MNCs including CD34+ cells,
isolated from peripheral blood by apheresis, were immediately injected intramuscularly
into ischemic limbs.
Results: The number of peripheral blood-CD34 + cells had
significantly increased from 1.32 ± 0.83/microL, before the rhEPO induction, to 1.86 ±
0.94/microL, before the apheresis. The number of transplanted MNCs ranged between 0.5 ×
109 and 16.5 × 109, and that of CD34+ cells, between 0.1 ×
106 and 12.7 × 106, accounting for 0.02%–0.1% of MNCs. There were
no serious complications. Finger ulcers with Buerger’s disease were significantly improved
one month after the transplantations, but the same or other ulcer(s) appeared 2–6 months
later. Three patients had an improvement in rest pain, and one patient extended maximum
pain-free walking distance.
Conclusions: Erythropoietin-induced autologous peripheral
blood-MNC transplantation is a useful and safe alternative for ischemic limbs.
Keywordserythropoietin; angiogenesis; autologous peripheral blood-derived mononuclear cell transplantation; critical ischemic limbs
Although higher serum phosphate level is a risk factor for cardiovascular diseases in general population as well as chronic kidney disease patients, it has not been clarified whether higher phosphate can affect atherosclerotic plaque formation. In this study, we investigated the effect of prolonged-intake of different concentrations of phosphate on atherosclerosis formation using apolipoprotein E-deficient mice. Apolipoprotein E-deficient mice were fed with high fat diet including 0.6%, 1.2% or 1.8% phosphate. After 20-week treatment, atherosclerotic plaque formation in aorta in 1.8% phosphate diet group was unexpectedly less than that in the other groups. To elucidate mechanisms of suppression of plaque formation by high phosphate diet, we hypothesized that high phosphate diet may modify a profile of monocytes/macrophages suppressing plaque formation. We confirmed that elevated peripheral monocytes (CD11b+, F4/80+ cell numbers) in apolipoprotein E-deficient mice were decreased by feeding with 1.8% P diet. In addition, ex vivo study indicated that high dose of phosphate induced macrophage apoptosis. These observations suggest that excess phosphate intake decreased atherosclerosis formation, at least in part, by changing the profile of peripheral monocytes or inducing apoptosis of macrophages in apolipoprotein E-deficient mice.
hyperphosphatemia; atherosclerogenesis; apoptosis; macrophage; chronic kidney disease
It is generally believed that the vascular endothelium serves as an inflammatory barrier by providing a nonadherent surface to leukocytes. Here, we report that Fas ligand (FasL) is expressed on vascular endothelial cells (ECs) and that it may function to actively inhibit leukocyte extravasation. TNFα downregulates FasL expression with an accompanying decrease in EC cytotoxicity toward co-cultured Fas-bearing cells. Local administration of TNFα to arteries downregulates endothelial FasL expression and induces mononuclear cell infiltration. Constitutive FasL expression markedly attenuates TNFα-induced cell infiltration and adherent mononuclear cells undergo apoptosis under these conditions. These findings suggest that endothelial FasL expression can negatively regulate leukocyte extravasation.
It has been established that patients with chronic kidney disease (CKD) suffer from frequent cardiovascular events. On the other hand, recent studies suggest that renal damage tends to worsen in patients with cardiovascular diseases (CVD). Although the mechanisms for the cardiorenal association are unclear, the presence of arteriosclerotic risk factors common to both CVD and CKD is important. In arteriosclerosis, vascular derangement progresses not only in the heart but also in the kidney. In addition, heart failure, cardiac catheterization and hesitation of medical treatments due to renal dysfunction may explain the progression of renal damage. Therefore, the goal of treatments is a total control of arteriosclerotic risk factors. Medication should be selected among agents with protective effects on both heart and kidney. It is important to always consider the presence of CKD for the treatment of the cardiovascular disease and strictly control the risk factors.
CKD; angiotensin II; aldosterone; ARB; hypertension.
Acute myocardial infarction (AMI) is a common and lethal heart disease, and the recruitment of fibroblastic cells to the infarct region is essential for the cardiac healing process. Although stiffness of the extracellular matrix in the infarct myocardium is associated with cardiac healing, the molecular mechanism of cardiac healing is not fully understood. We show that periostin, which is a matricellular protein, is important for the cardiac healing process after AMI. The expression of periostin protein was abundant in the infarct border of human and mouse hearts with AMI. We generated periostin−/− mice and found no morphologically abnormal cardiomyocyte phenotypes; however, after AMI, cardiac healing was impaired in these mice, resulting in cardiac rupture as a consequence of reduced myocardial stiffness caused by a reduced number of α smooth muscle actin–positive cells, impaired collagen fibril formation, and decreased phosphorylation of FAK. These phenotypes were rescued by gene transfer of a spliced form of periostin. Moreover, the inhibition of FAK or αv-integrin, which blocked the periostin-promoted cell migration, revealed that αv-integrin, FAK, and Akt are involved in periostin signaling. Our novel findings show the effects of periostin on recruitment of activated fibroblasts through FAK-integrin signaling and on their collagen fibril formation specific to healing after AMI.
Heparin cofactor II (HCII) specifically inhibits thrombin action at sites of injured arterial wall, and patients with HCII deficiency exhibit advanced atherosclerosis. However, the in vivo effects and the molecular mechanism underlying the action of HCII during vascular remodeling remain elusive. To clarify the role of HCII in vascular remodeling, we generated HCII-deficient mice by gene targeting. In contrast to a previous report, HCII–/– mice were embryonically lethal. In HCII+/– mice, prominent intimal hyperplasia with increased cellular proliferation was observed after tube cuff and wire vascular injury. The number of protease-activated receptor–1–positive (PAR-1–positive) cells was increased in the thickened vascular wall of HCII+/– mice, suggesting enhanced thrombin action in this region. Cuff injury also increased the expression levels of inflammatory cytokines and chemokines in the vascular wall of HCII+/– mice. The intimal hyperplasia in HCII+/– mice with vascular injury was abrogated by human HCII supplementation. Furthermore, HCII deficiency caused acceleration of aortic plaque formation with increased PAR-1 expression and oxidative stress in apoE-KO mice. These results demonstrate that HCII protects against thrombin-induced remodeling of an injured vascular wall by inhibiting thrombin action and suggest that HCII is potentially therapeutic against atherosclerosis without causing coagulatory disturbance.