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Pressure-overload-induced cardiac hypertrophy represents one cause of the development of heart failure. The aim of this study is to characterize the influence of the TIR-domain-containing adapter-inducing interferon-β (TRIF) during afterload-induced myocardial remodeling. After trans-aortic constriction (TAC), cardiac pressure overload leads to an early increase in MyD88- (Myeloid differentiation primary response gene 88) and TRIF-dependent cytokines. The maximum cytokine expression appeared within the first week and decreased to its control level within five weeks. While cardiomyocyte hypertrophy was comparable, the myocardial accumulation of the inflammatory cells was lower in TRIF−/−mice. At d7, TRIF deficiency reduced transcription factors and TRIF-dependent cytokines. Through the modulation of the TGF-β-signaling pathway and anti-fibrotic microRNAs, TRIF was involved in the development of interstitial fibrosis. The absence of TRIF was associated with a decreased expression of proapoptotic proteins. In echocardiography and working heart analyses, TRIF deficiency slowed left-ventricular wall thickening, myocardial hypertrophy, and reduces the ejection fraction. In summary, TRIF is an important adapter protein for the release of inflammatory cytokines and the accumulation of inflammatory cells in the early stage of maladaptive cardiac remodeling. TRIF is involved in the development of cardiac fibrosis by modulating inflammatory and fibrotic signal transduction pathways. [ABSTRACT FROM AUTHOR]

Copyright of Herz is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background Since kidney transplant recipients (KTRs) have a high cardiovascular disease burden, adequate risk prediction is of importance. Whether echocardiographic parameters and plasma biomarkers, natriuretic peptides [N-terminal pro-B-type natriuretic peptide (NT-proBNP)] and troponin T provide complementary or overlapping prognostic information on cardiovascular events remains uncertain. Methods The prospective Heterogeneity of Monocytes and Echocardiography Among Allograft Recipients in Nephrology (HOME ALONE) study followed 177 KTRs for 5.4 ± 1.7 years. Predefined endpoints were hospitalization for acute decompensated heart failure or all-cause death (HF/D) and major atherosclerotic cardiovascular events or all-cause death (MACE/D). At baseline, plasma NT-proBNP, plasma troponin T and echocardiographic parameters [left atrial volume index, left ventricular (LV) mass index, LV ejection fraction, and LV filling pressure] were assessed. Results Among all echocardiographic and plasma biomarkers measured, only NT-proBNP was consistently associated with HF/D in univariate and multivariate {third versus first tertile: hazard ratio [HR] 4.20 [95% confidence interval (CI) 1.02–17.27]} analysis, and only troponin T was consistently associated with MACE/D in univariate and multivariate [third versus first tertile: HR 8.15 (95% CI 2.75–24.18)] analysis. Conclusion Our data suggest that plasma biomarkers are robust and independent predictors of heart failure and atherosclerotic cardiovascular events after kidney transplantation, whereas standard echocardiographic follow-up does not add to risk prediction. [ABSTRACT FROM AUTHOR]

Some studies have indicated that successful catheter ablation of atrial fibrillation with durable sinus rhythm may lead to improvement of tricuspid valve function in case of lesser tethering height (< 6 mm) [[5]]. A retrospective analysis on > 400 patients undergoing surgical AF ablation during mitral valve surgery confirmed AF recurrence to be associated with progression of TR and right remodeling TR [[5]]. This comment refers to the article available at https://doi.org/10.1007/s10840-022-01410-x Atrial fibrillation (AF) is the most common rhythm disorder worldwide, with increasing prevalence. [Extracted from the article]

Background: We aimed to explore whether interventional closure of patent foramen ovale (PFO) results in reduction of composite outcome [stroke/transitory ischemic attack (TIA), death, and thrombolysis in myocardial infarction—TIMI bleeding], stroke and stroke/TIA compared to medical treatment in patients with cryptogenic stroke.Methods and results: Searching the PUBMED and Cochrane library database, we performed meta-analysis from all randomized controlled studies that compared effects of interventional PFO closure with medical treatment on stroke prevention. 3560 patients from six randomized trials were included. Interventional PFO closure reduced composite outcome (RR of 0.47, 0.26-0.85, p = 0.01), stroke (RR of 0.38, 0.18-0.82, p = 0.01) and stroke/TIA (RR of 0.56, 0.43-0.74, p < 0.0001). Analysis had 70.5% power to detect observed reduction of RR for the primary outcome, 70.6% for stroke and 98.7% for stroke/TIA. Bleeding rates were comparable (RR of 0.91, 0.60-1.38, p = 0.66), while there was higher burden of new AF (RR of 5.54, 3-10.2, p < 0.0001) after interventional closure. Subgroup analysis revealed that patients with large shunts had substantial less recurrent strokes over patients with small shunts (p for interaction = 0.02). Use of Amplatzer PFO device was associated with substantial less AF (RR of 2.36, p = 0.06) compared with other devices (RR of 8.93, p < 0.0001) (p for interaction = 0.04), with comparable benefit for stroke prevention (p for interaction = 0.73).Conclusions: Interventional closure of PFO resulted in significant reduction of stroke and stroke/TIA compared with antiplatelets/anticoagulants with comparable bleeding rates between the groups, whereas AF occurred more frequently in the intervention group. Patients with large shunts had more benefit from interventional closure. [ABSTRACT FROM AUTHOR]

Aims Unicuspid aortic valve (UAV) is a rare congenital malformation associated with severe aortic stenosis or regurgitation. This study aimed to systematically determine echocardiographic criteria to identify UAV. Methods and results All patients underwent a preoperative baseline examination, including echocardiography. A total of 69 patients with intraoperatively confirmed UAV underwent an aortic valve repair procedure between August 2001 and May 2011. To compare the findings of UAV cases with those of other valve morphologies, we examined 99 consecutive patients with a bicuspid aortic valve (BAV) and 103 consecutive patients with a tricuspid aortic valve (TAV) undergoing isolated aortic valve surgery before May 2016. The mean age of the 271 patients was 44.2 ± 12.8 years; 85% were male, with a mean body mass index of 26.2 ± 4.0 kg/m2. Patients with UAV were younger and had fewer co-morbidities than patients with BAV or TAV, respectively. The major criteria for the echocardiographic diagnosis of UAV were defined based on our preoperative examination as follows: (i) single commissural attachment zone, (ii) rounded, leaflet-free edge on the opposite side of the commissural attachment zone, (iii) eccentric valvular orifice during systole, and (iv) patient age <20 years and mean transvalvular gradient >15 mmHg. The minor criteria were defined as an associated thoracic aortopathy and age <40 years. Three out of the four major criteria or two out of the four major criteria and one minor criterion were met in all patients with UAV and in none of the patients with BAV or TAV. Associated 95% confidence intervals were calculated for each estimate of sensitivity (94.7–100%) and specificity (98.1–100%), indicating that an adequate number of patients were included in each of the three groups. Conclusion The proposed echocardiographic score appears to be a specific and sensitive method to distinguish UAV from BAV and TAV. [ABSTRACT FROM AUTHOR]

Abstract: Secondary mitral regurgitation (MR) results from left ventricular dilatation and dysfunction. Quantification of secondary MR is challenging because of the underlying myocardial disease. Clinical and echocardiographic evaluation requires a multi‐parametric approach. Severe secondary MR occurs in up to one‐fourth of patients with heart failure with reduced ejection fraction, which is associated with a mortality rate of 40% to 50% in 3 years. Percutaneous edge‐to‐edge mitral valve repair (MitraClip) has emerged as an alternative to surgical valve repair to improve symptoms, functional capacity, heart failure hospitalizations, and cardiac haemodynamics. Further new transcatheter strategies addressing MR are evolving. The Carillion, Cardioband, and Mitralign devices were designed to reduce the annulus dilatation, which is a frequent and important determinant of secondary MR. Several transcatheter mitral valve replacement systems (Tendyne, CardiAQ‐Edwards, Neovasc, Tiara, Intrepid, Caisson, HighLife, MValve System, and NCSI NaviGate Mitral) are emerging because valve replacement might be more durable compared with valve repair. In small studies, these interventional therapies demonstrated feasibility and efficiency to reduce MR and to improve heart failure symptoms. However, neither transcatheter nor surgical mitral valve repair or replacement has been proven to impact on the prognosis of heart failure patients with severe MR, which remains high with a mortality rate of 14–20% at 1 year. To date, the primary indication for treatment of secondary severe MR is the amelioration of symptoms, reinforcing the value of a Heart Team discussion. Randomized studies to investigate the treatment effect and long‐term outcome for any transcatheter or surgical mitral valve intervention compared with optimized medical treatment are urgently needed and underway. [ABSTRACT FROM AUTHOR]

Background: Cardiological societies recommend, in their guidelines, that patients with atrial fibrillation and an intermediate (or higher) risk of stroke and systemic embolization should be treated with oral anticoagulant drugs. For patients who do not have mitral valve stenosis or a mechanical valve prosthesis, non-vitamin-K dependent oral anticoagulants (NOAC) are preferred over vitamin K antagonists (VKA) for this purpose. It is unclear, however, whether patients with chronic kidney disease and atrial fibrillation benefit from oral anticoagulation to the same extent as those with normal kidney function. It is also unclear which of the two types of anti - coagulant drug is preferable for patients with chronic kidney disease; NOAC are, in part, renally eliminated. Methods: This review is based on pertinent publications retrieved by a selective literature search, and on international guidelines. Results: Current evidence suggests that patients with atrial fibrillation who have chronic kidney disease with a glomerular filtration rate (GFR) above 15 mL/ min/1.73 m² should be treated with an oral anticoagulant drug if they have an at least intermediate risk of embolization, as assessed with the CHA2DS2-VASc score. For patients with advanced chronic kidney disease (GFR from 15 to 29 mL/ min/1.73 m²), however, this recommendation is based only on registry studies. For dialysis patients with atrial fibrillation, decisions whether to give oral anticoagulant drugs should be taken on an individual basis, in view of the elevated risk of hemorrhage and the unclear efficacy of such drugs in these patients. The subgroup analyses of the NOAC approval studies show that, for patients with atrial fibrillation and chronic kidney disease with a creatinine clearance of >25-30 mL/min, NOAC should be given in preference to VKA, as long as the patient does not have mitral valve stenosis or a mechanical valve prosthesis. For those whose creatinine clearance is less than 25 mL/min, the relative merits of NOAC versus VKA are still debated. Conclusion: The cardiological societies' recommendation that patients with atrial fibrillation should be given oral anticoagulant drugs applies to the majority of such patients who also have chronic kidney disease. [ABSTRACT FROM AUTHOR]

Background: Apolipoprotein E-deficient (ApoE(-/-)) rodents spontaneously develop severe hypercholesterolemia and increased aortic stiffness, both accepted risk factors for cardiovascular morbidity and mortality in humans. In patients with resistant hypertension renal denervation (RDN) may improve arterial stiffness, however the underlying mechanisms are incompletely understood. This study investigates the impact of RDN on aortic compliance in a novel atherosclerosis prone ApoE(-/-)-rat model.Methods: Normotensive, 8 weeks old ApoE(-/-) and Sprague-Dawley (SD) rats were subjected to bilateral surgical RDN (n = 6 per group) or sham operation (n = 5 per group) and fed with normal chow for 8 weeks. Compliance of the ascending aorta was assessed by magnetic resonance imaging. Vasomotor function was measured by aortic ring tension recordings. Aortic collagen content was quantified histologically and plasma aldosterone levels were measured by enzyme-linked immunosorbent assay (ELISA).Results: After 8 weeks, ApoE(-/-)-sham demonstrated a 58 % decrease in aortic distensibility when compared with SD-sham (0.0051 ± 0.0011 vs. 0.0126 ± 0.0023 1/mmHg; p = 0.02). This was accompanied by an impaired endothelium-dependent relaxation of aortic rings and an increase in aortic medial fibrosis (17.87 ± 1.4 vs. 12.27 ± 1.1 %; p = 0.006). In ApoE(-/-)-rats, RDN prevented the reduction of aortic distensibility (0.0128 ± 0.002 vs. 0.0051 ± 0.0011 1/mmHg; p = 0.01), attenuated endothelial dysfunction, and decreased aortic medial collagen content (12.71 ± 1.3 vs. 17.87 ± 1.4 %; p = 0.01) as well as plasma aldosterone levels (136.33 ± 6.6 vs. 75.52 ± 8.4 pg/ml; p = 0.0003). Cardiac function and metabolic parameters such as hypercholesterolemia were not influenced by RDN.Conclusion: ApoE(-/-)-rats spontaneously develop impaired vascular compliance. RDN improves aortic distensibility and attenuated endothelial dysfunction in ApoE(-/-)-rats. This was associated with a reduction in aortic fibrosis formation, and plasma aldosterone levels. [ABSTRACT FROM AUTHOR]

Background: Coronary collateral arteries function as natural bypasses in the event of coronary obstruction. The degree of collateral network development significantly impacts the outcome of patients after an acute myocardial infarction (AMI). MicroRNAs (miRNAs, miRs) have arisen as biomarkers to identify heterogeneous patients, as well as new therapeutic targets in cardiovascular disease. We sought to identify miRNAs that are differentially expressed in chronic total occlusion (CTO) patients with well or poorly developed collateral arteries. Methods and Results: Forty-one CTO patients undergoing coronary angiography and invasive assessment of their coronary collateralization were dichotomized based on their collateral flow index (CFI). After miRNA profiling was conducted on aortic plasma, four miRNAs were selected for validation by real-time quantitative reverse transcription polymerase chain reaction in patients with low (CFI<0.39) and high (CFI>0.39) collateral artery capacity. We confirmed significantly elevated levels of miR423-5p (p<0.05), miR10b (p<0.05), miR30d (p<0.05) and miR126 (p<0.001) in patients with insufficient collateral network development. We further demonstrated that each of these miRNAs could serve as circulating biomarkers to discriminate patients with low collateral capacity (p<0.01 for each miRNA). We also determined significantly greater expression of miR30d (p<0.05) and miR126 (p<0.001) in CTO patients relative to healthy controls. Conclusion: The present study identifies differentially expressed miRNAs in patients with high versus low coronary collateral capacity. We have shown that these miRNAs can function as circulating biomarkers to discriminate between patients with insufficient or sufficient collateralization. This is the first study to identify miRNAs linked to coronary collateral vessel function in humans. [ABSTRACT FROM AUTHOR]

The article discusses renal nerve ablation for resistant hypertension. Topics discussed include cardiovascular mortality and morbidity due to hypertension, role of renal denervation in decreasing blood pressure (BP) in resistant hypertension and BP responses for physical activities and use of radiofrequency (RF) energy in electrophysiology.

BACKGROUND Obstructive sleep apnea (OSA) is associated with hypertension and the progression of chronic kidney disease (CKD). Renal sympathetic innervation contributes to either condition. METHODS We investigated the effect of renal sympathetic denervation (RDN) on blood pressure (BP), renal perfusion, and neurohumoral responses during and after repetitive obstructive apneas in a pig model for OSA. BP, femoral artery, and renal artery flow were measured in 29 spontaneously breathing urethane-chloralose–anesthetized pigs. The effect of RDN (n = 14) and irbesartan (n = 3) was investigated. Repetitive tracheal occlusions for 2 minutes with applied negative tracheal pressure at −80 mbar were performed over 4 hours. RESULTS Spontaneous breathing attempts during tracheal occlusion caused an intra-apneic breathing synchronous oscillating pattern of renal flow. Renal flow oscillations were >2-fold higher compared with femoral flow that almost showed changes proportional to the BP alterations (2.9%/mm Hg vs. 1.3%/mm Hg; P < 0.0001). A marked postapneic BP rise from 102±3 to 172±8 mm Hg (P < 0.00001) was associated with renal hypoperfusion (from 190±24 to 70±20ml/min; P < 0.00001) occurring after application of obstructive respiratory events. RDN, but not irbesartan, inhibited postapneic BP rises and renal hypoperfusion and attenuated increased plasma renin activity and aldosterone concentration induced by repetitive tracheal occlusions. Additionally, increased urinary protein/creatinine ratio was significantly reduced by RDN, whereas intra-apneic hemodynamic changes or blood gases were not modified by RDN. CONCLUSIONS Repetitive obstructive respiratory events result in postapneic BP rises and renal hypoperfusion, as well as neurohumoral responses and increased protein/creatinine ratio. These changes are mainly sympathetically driven because they could be attenuated by RDN. [ABSTRACT FROM AUTHOR]

Inflammation and fibrosis play an important pathophysiological role in chronic kidney disease (CKD), with pro-inflammatory mediators and leukocytes promoting organ damage with subsequent fibrosis. Since chemokines are the main regulators of leukocyte chemotaxis and tissue inflammation, we performed systemic chemokine profiling in early CKD in mice. This revealed (C-C motif) ligands 6 and 9 (CCL6 and CCL9) as the most upregulated chemokines, with significantly higher levels of both chemokines in blood (CCL6: 3–4 fold; CCL9: 3–5 fold) as well as kidney as confirmed by Enzyme-linked Immunosorbent Assay (ELISA) in two additional CKD models. Chemokine treatment in a mouse model of early adenine-induced CKD almost completely abolished the CKD-induced infiltration of macrophages and myeloid cells in the kidney without impact on circulating leukocyte numbers. The other way around, especially CCL9-blockade aggravated monocyte and macrophage accumulation in kidney during CKD development, without impact on the ratio of M1-to-M2 macrophages. In parallel, CCL9-blockade raised serum creatinine and urea levels as readouts of kidney dysfunction. It also exacerbated CKD-induced expression of collagen (3.2-fold) and the pro-inflammatory chemokines CCL2 (1.8-fold) and CCL3 (2.1-fold) in kidney. Altogether, this study reveals for the first time that chemokines CCL6 and CCL9 are upregulated early in experimental CKD, with CCL9-blockade during CKD initiation enhancing kidney inflammation and fibrosis. [ABSTRACT FROM AUTHOR]

The coronary arteries have been regarded as end arteries for decades. However, there are functionally relevant anastomotic vessels, known as collateral arteries, which interconnect epicardial coronary arteries. These vessels provide an alternative source of blood supply to the myocardium in cases of occlusive coronary artery disease. The relevance of these collateral arteries is a matter of ongoing debate, but increasing evidence indicates a relevant protective role in patients with coronary artery disease. The collateral circulation can be assessed by different methods; the gold standard involves intracoronary pressure measurements. While the first clinical trials to therapeutically induce growth of collateral arteries have been unavailing, recent pilot studies using external counterpulsation or growth factors such as granulocyte colony stimulating factor (G-CSF) have shown promising results. [ABSTRACT FROM AUTHOR]

Aims Peripartum cardiomyopathy (PPCM) is associated with high mortality and morbidity. Endothelial damage involving cathepsin-D to form a 16 kDa prolactin (PRL) peptide is pathogenetically relevant. Inhibiting PRL peptide with bromocriptine has yielded promising results. We investigated whether microparticles (MPs) can be quantified in serum as markers for diagnosis and treatment effects in PPCM. Methods and results Patients with PPCM were compared with age-matched healthy post-partum women (PPCTR), healthy pregnant women (PCTR), healthy non-pregnant women (NPCTR), patients with ischaemic cardiomyopathy (ICM), patients with stable coronary artery disease (CAD) and healthy controls (HCTR). Peripartum cardiomyopathy treated with bromocriptine (PPCM-BR) and with PPCM without bromocriptine-treatment as control (PPCM-BRCTR) were compared. Microparticles were determined by flow cytometry. Endothelial MPs (EMPs) were elevated in PPCM compared with PPCTR, PCTR, and NPCTR, each P< 0.001. They were significantly elevated compared with ICM, CAD, and HCTR (P< 0.001). Pregnancy (PCTR) exhibited only slight increases vs. ICM, CAD, NPCTR, and HCTR. The increase in PPCM was due to an increase of activated but not apoptotic EMPs. Platelet-derived microparticles were highly increased in PPCM compared with ICM (P< 0.001) but 9.3 ± 4.4-fold compared with CAD (P< 0.001). In NPCTR (P< 0.001) compared with NPCTR, the increase was 5.9 ± 1.7-fold (P< 0.001). Microparticles generated from monocytes (MMPs) were increased 2.4 ± 1.8-fold in PPCM compared with PCTR (P< 0.001) and 4.8 ± 3.6-fold compared with CAD (P< 0.001), whereas leucocyte MPs (LMPs) were not significantly elevated. Endothelial microparticles were significantly reduced in PPCM treated additionally with bromocriptine compared with PPCM treated only with heart failure therapy (P< 0.001). Conclusion Microparticle profiles may in long-term distinguish PPCM from normal pregnancy, heart failure, and vascular diseases and might be a diagnostic marker related to the pathomechanism of PPCM. [ABSTRACT FROM PUBLISHER]

Aims Collateral arteries protect tissue from ischaemia. Heart rate correlates with vascular events in patients with arterial obstructive disease. Here, we tested the effect of heart-rate reduction (HRR) on collateral artery growth. Methods and results The If-channel inhibitor ivabradine reduced heart rate by 11% in wild-type and 15% in apolipoprotein E (ApoE)−/− mice and restored endothelium-dependent relaxation in aortic rings of ApoE−/− mice. Microsphere perfusion and angiographies demonstrated that ivabradine did not change hindlimb perfusion in wild-type mice but improved perfusion in ApoE−/− mice from 40.5 ± 15.8–60.2 ± 18.5% ligated/unligated hindlimb. Heart rate reduction (13%) with metoprolol failed to improve endothelial function and perfusion. Protein expression of endothelial nitric oxide synthase (eNOS), phosphorylated eNOS, and eNOS activity were increased in collateral tissue following ivabradine treatment of ApoE−/− mice. Co-treatment with nitric oxide-inhibitor N (G)-nitro-L- arginine methyl ester abolished the effects of ivabradine on arteriogenesis. Following ivabradine, classical inflammatory cytokine expression was lowered in ApoE−/− circulating mononuclear cells and in plasma, but unaltered in collateral-containing hindlimb tissue, where numbers of perivascular macrophages also remained unchanged. However, ivabradine reduced expression of anti-arteriogenic cytokines CXCL10and CXCL11 and of smooth muscle cell markers smoothelin and desmin in ApoE−/− hindlimb tissue. Endothelial nitric oxide synthase and inflammatory cytokine expression were unchanged in wild-type mice. Ivabradine did not affect cytokine production in HUVECs and THP1 mononuclear cells and had no effect on the membrane potential of HUVECs in patch-clamp experiments. Conclusion Ivabradine-induced HRR stimulates adaptive collateral artery growth. Important contributing mechanisms include improved endothelial function, eNOS activity, and modulation of inflammatory cytokine gene expression. [ABSTRACT FROM PUBLISHER]

Aims In patients with obstructive coronary artery disease (CAD), the growth of collateral arteries, i.e. arteriogenesis, can preserve myocardial tissue perfusion and function. Monocytes modulate this process, supplying locally the necessary growth factors and degrading enzymes. Knowledge on factors involved in human arteriogenesis is scarce. Thus, the aim of the present study is to identify targets in monocytes that are critical for arteriogenesis in patients with CAD. Methods and results A total of 50 patients with a chronic total coronary occlusion were dichotomized according to their collateral flow index. From each patient, RNA was isolated from unstimulated peripheral blood monocytes, monocytes stimulated by lipopolysaccharide (LPS) or interleukin (IL)-4, and from macrophages. Increased mRNA expression of galectin-2 was found in three out of four monocytic cell types of patients with a low capacity of the collateral circulation (P= 0.03 for unstimulated monocytes; P= 0.02 for LPS-stimulated monocytes; P= 0.20 for IL-4-stimulated monocytes; P= 0.02 for macrophages). Additionally, galectin-2 mRNA expression was significantly associated with the rs7291467 polymorphism in LGALS2 encoding galectin-2 in all four monocytic cell types. Patient with the rs7291467 CC genotype displayed highest galectin-2 expression, and also tended to have a lower arteriogenic response. To evaluate the effect of galectin-2 on arteriogenesis in vivo, we used a murine hindlimb model. Treatment with galectin-2 markedly impaired the perfusion restoration at Day 7. Conclusion Collectively, these results identify galectin-2 as a novel inhibitor of arteriogenesis. Modulation of galectin-2 may constitute a new therapeutic strategy for the stimulation of arteriogenesis in patients with CAD. [ABSTRACT FROM PUBLISHER]

Aims ‘Functional foods’ supplemented with plant sterol esters (PSE) and plant stanol esters (PSA) are therapeutic options for the management of hypercholesterolaemia. However, their effects on blood monocytes, endothelial function, atherogenesis, and sterol tissue concentrations are poorly understood. Methods and results Male apoE−/− mice (n= 30) were randomized to three different diets for 6 weeks (n= 10 per group): high-cholesterol (1.25%) western-type diet (WTD), WTD + 2% PSE, and WTD + 2% PSA. Both supplements reduced serum cholesterol. WTD + PSE resulted in increased plant sterol serum concentrations and increased inflammatory Ly-6C(high) monocyte numbers. WTD + PSA increased plant stanol serum concentrations and Ly-6C-monocyte numbers, but decreased vascular superoxide release, lipid hydroperoxides, and inflammatory cytokines in aortic tissue, in plasma, and in circulating monocytes. Despite reduced serum cholesterol concentrations, both supplements impaired endothelial vasodilation compared with WTD. WTD + PSA reduced the development of atherosclerotic lesions compared with WTD alone (12.7 ± 3.7 vs. 28.3 ± 3.5%), and WTD + PSE was less effective (17.5 ± 3.7%). WTD + PSE and WTD + PSA reduced the cholesterol content in the liver, but not in the brain. However, WTD + PSE and WTD + PSA increased plant sterol and plant stanol concentrations in the liver as well as in the brain. Conclusion PSE and PSA supplementation reduced serum cholesterol, but increased plant sterol and plant stanol concentrations. Elevated levels of PSE and PSA were associated with endothelial dysfunction and increased central nervous system depositions. Atherosclerotic lesion retardation was more pronounced in WTD + PSA, coinciding with higher regenerative monocyte numbers, decreased oxidative stress, and decreased inflammatory cytokines compared with WTD + PSE. [ABSTRACT FROM AUTHOR]

The adipocytokine leptin has distinct functions regulating vascular tone, inflammation, and collateral artery growth. Arteriogenesis is an inflammatory process and provides a mechanism to overcome the effects of vascular obstruction. We, therefore, tested the effects of leptin in hypoperfused rat brain (three-vessel occlusion). Systemic leptin administration for 1 week after occlusion surgery increased cerebral hemodynamic reserve similar to granulocyte-macrophage colony-stimulating factor (GM-CSF), as indicated by improved CO2 reactivity (vehicle 0.53%±0.26% versus leptin 1.05%±0.6% per mm Hg arterial pCO2, P<0.05). Infusion of microspheres under maximal vasodilation failed to show a positive effect of leptin on cerebral perfusion (vehicle 64.9%±4.5% versus leptin 66.3%±7.0%, occluded/nonoccluded hemisphere). Acute treatment with GM-CSF led to a significant increased CO2 reactivity and cerebral perfusion (79.2%±8.1% versus 64.9%±4.5%, P<0.05). Vasoconstrictive response of isolated rat carotid artery rings, after phenylephrine was attenuated at 24 hours following preincubation with leptin, was unaffected by removal of endothelium but abrogated by coculture with N-(omega)-nitro-L-arginine methylester, pointing toward an inducible nitric oxide synthase-mediated mechanism. In chronic cerebral hypoperfusion, acute leptin treatment restored the hemodynamic reserve of the cerebral vasculature through its effects on vascular tone, while leaving vascular outward remodeling unaffected. Our results, for the first time, reveal a protective role of leptin on vascular function in hemodynamically compromised brain tissue. [ABSTRACT FROM AUTHOR]

Background: Circulating CD34+ progenitor cells have the potential to differentiate into a variety of cells, including endothelial cells. Knowledge is still scarce about the transcriptional programs used by CD34+ cells from peripheral blood, and how these are affected in coronary artery disease (CAD) patients. Results: We performed a whole genome transcriptome analysis of CD34+ cells, CD4+ T cells, CD14+ monocytes, and macrophages from 12 patients with CAD and 11 matched controls. CD34+ cells, compared to other mononuclear cells from the same individuals, showed high levels of KRAB box transcription factors, known to be involved in gene silencing. This correlated with high expression levels in CD34+ cells for the progenitor markers HOXA5 and HOXA9, which are known to control expression of KRAB factor genes. The comparison of expression profiles of CD34+ cells from CAD patients and controls revealed a less naïve phenotype in patients' CD34+ cells, with increased expression of genes from the Mitogen Activated Kinase network and a lowered expression of a panel of histone genes, reaching levels comparable to that in more differentiated circulating cells. Furthermore, we observed a reduced expression of several genes involved in CXCR4-signaling and migration to SDF1/CXCL12. Conclusions: The altered gene expression profile of CD34+ cells in CAD patients was related to activation/ differentiation by a retinoic acid-induced differentiation program. These results suggest that circulating CD34+ cells in CAD patients are programmed by retinoic acid, leading to a reduced capacity to migrate to ischemic tissues. [ABSTRACT FROM AUTHOR]

During collateral artery growth, monocytes adhere to the endothelium and secrete cytokines from the perivascular space promoting arteriogenesis. Recently, the endothelial glycocalyx has been shown to modulate leucocyte infiltration in atherogenic regions. The role of this endothelial surface coating in arteriogenesis, however, has not been investigated so far. We now report that local plasma levels of hyaluronic acid are specifically increased in collateral arterial blood of coronary artery disease patients and hypothesized that components of the endothelial glycocalyx are shed during arteriogenesis, resulting in decreased glycocalyx dimensions and an increased leucocyte extravasation. In a rabbit model of femoral artery ligation, electron microscopy revealed a decrease in glycocalyx dimensions in collateral arteries compared with quiescent anastomoses (67.5 ± 47.2 nm versus 101.0 ± 11.3 nm; P < 0.001). This decrease was correlated with a higher number of perivascular macrophages around collateral arteries. The additional glycocalyx perturbation by local hyaluronidase infusion almost completely removed the endothelial surface layer and temporarily stimulated leucocyte accumulation in the perivascular space. However, complete perturbation of the glycocalyx by hyaluronidase infusion resulted in a significant attenuation of collateral artery growth assessed by microsphere-based perfusion measurements (ml/min/100 mmHg: hyaluronidase: 27.5 ± 3.5; Controls: 47.1 ± 3.83; P < 0.001) and a lower percentage of actively proliferating vascular smooth muscle cells. A decreased expression of the shear-stress regulated pro-arteriogenic genes eNOS and TGF-β1 suggests an impaired mechanotransduction as the underlying mechanisms. For the first time, we describe the role of the endothelial glycocalyx in collateral artery growth. Although complete abrogation led to attenuated arteriogenesis, shedding of glycocalyx components is observed during collateral artery growth. [ABSTRACT FROM AUTHOR]

The specific antagonists of tumor necrosis factor-α (TNF-α), infliximab and etanercept, are established therapeutic agents for inflammatory diseases such as rheumatoid arthritis and Crohn's disease. Although the importance of TNF-α in chronic inflammatory diseases is well established, little is known about its implications in the cardiovascular system. Because proliferation of arteriolar connections toward functional collateral arteries (arteriogenesis) is an inflammatory-like process, we tested in vivo the hypothesis that infliximab and etanercept have antiarteriogenic actions. Sixty-three New Zealand White rabbits underwent femoral artery occlusion and received infliximab, etanercept, or vehicle according to clinical dosage regimes. After 1 wk, collateral conductance, assessed with fluorescent microspheres, revealed significant inhibition of arteriogenesis (collateral conductance): 52.4 (SD 8.1), 35.2 (SD 7.7), and 33.3 (SD 10.1) ml·min-1100 mmHg-1 with PBS, infliximab, and etanercept, respectively (P < 0.001). High-resolution angiography showed no significant differences in number of collateral arteries, but immunohistochemical analysis demonstrated a decrease in mean collateral diameter, proliferation of vascular smooth muscle cells, and reduction of leukocyte accumulation around collateral arteries in treated groups. Infliximab and etanercept bound to infiltrating leukocytes, which are important mediators of arteriogenesis. Infliximab induced monocyte apoptosis, and neither substance affected monocyte expression of the adhesion molecule Mac-1. We demonstrated that TNF-α serves as a pivotal modulator of arteriogenesis, which is attenuated by treatment with TNF-α inhibitors. Reduction of collateral conductance is most likely due to inhibition of perivascular leukocyte infiltration and subsequent lower vascular smooth muscle cell proliferation. This is the first report showing a negative influence of TNF-α inhibitors on collateral artery growth. [ABSTRACT FROM AUTHOR]

Strategies to therapeutically stimulate collateral artery growth in experimental models have been studied intensively in the last decades. However, the experimental methods to detect collateral artery growth are discussed controversially and vary significantly. We compared different methods in a model of arteriogenesis in the rabbit hind limb and determined the effects on collateral flow of a known pro-arteriogenic factor, monocyte chemoattractant protein-1 (MCP-1), and a cytokine not previously evaluated for its arteriogenic efficacy, the adipocytokine leptin.Forty-two New Zealand White rabbits received either MCP-1, leptin or PBS after ligation of the right femoral artery. The pro-arteriogenic effect of MCP-1 was confirmed by flow measurements during reactive hyperemia, as demonstrated by increased flow ratio (PBS 0.56±0.07 vs. MCP-1 0.77±0.06, no unit, p<0.0001), ankle-brachial index and microsphere-based conductance measurements (PBS 50.8±2.1 vs. MCP-1 225.8±8.8 ml/min/100 mm Hg, p<0.001). Biological activity of leptin on rabbit monocytes was shown by a dose dependent increase in Mac-1 expression. In-vivo administration of leptin also led to an increase in hyperemic flow and flow ratio (leptin 0.69±0.03, p<0.05 vs. PBS), but not to an increase in collateral conductance (leptin 54.7±4.1 ml/min/100 mm Hg, p=ns vs. PBS) or proliferation of vascular smooth muscle cells (Ki-67 staining: PBS 24.7±3.9%, leptin 22.7%±0.8% (p=ns), MCP-1 32.0±1.9% (p<0.01)). Ki-67 mRNA measured by real-time polymerase chain reaction increased (8.8±3.1-fold, p<0.01) during natural arteriogenesis, and was further enhanced (25.5±8.1-fold, p<0.005) after stimulation with MCP-1.MCP-1 and leptin increase collateral flow in the rabbit hind limb model. In contrast to MCP-1, leptin does not enhance direct markers of vascular proliferation such as collateral conductance under maximal vasodilation and proliferation indices. The observed increase in hyperemic collateral flow thus most probably can be attributed to the well-documented vasodilatory effects of leptin. These data stress the necessity of the use of proliferation markers and microsphere-based conductance measurements under maximal vasodilation in order to separate effects of substances on vascular proliferation from effects on vasodilation. [Copyright &y& Elsevier]

Peripheral arterial disease (PAD) affects a large percentage of the elderly population. Standard invasive treatment, apart from risk factor modulation, consists of bypass surgery or percutaneous transluminal angioplasty. However, symptomatic recurrence rates are high for both procedures and a substantial part of the patient population with PAD is not a candidate for invasive revascularization due to complexity of the lesion and/or co-morbidity. Therapeutic arteriogenesis has been proposed as an alternative treatment option. The present paper describes the design of the START-trial. This trial aims to determine the potential of the proarteriogenic substance granulocyte/macrophage colony stimulating factor (GM-CSF) to increase maximal walking distance in patients with intermittent claudication. A double-blinded, randomized, placebo-controlled study will be performed in 40 patients with peripheral obstructive arterial disease Rutherford grade I, category 2 or 3, that are candidates for bypass surgery or percutaneous transluminal angioplasty. Based on pharmacokinetic and toxicologic studies, a dose of 10 μg/kg will be used. Patients will be treated for a period of 14 days on each consecutive day, with the last injection applied on day 12. The primary endpoint will be the change in walking distance from day 0 to day 14 as assessed by an exercise treadmill test. Secondary endpoints will be the ankle–brachial index at rest and after exercise, the pain-free walking distance and cutaneous microcirculatory alterations as assessed by laser Doppler fluxmetry. Iliac flow reserve and conductance will be measured by magnetic resonance imaging. [ABSTRACT FROM AUTHOR]

The coronary arteries have been regarded as end arteries for decades. However, there are functionally relevant anastomotic vessels, known as collateral arteries, which interconnect epicardial coronary arteries. These vessels provide an alternative source of blood supply to the myocardium in cases of occlusive coronary artery disease. The relevance of these collateral arteries is a matter of ongoing debate, but increasing evidence indicates a relevant protective role in patients with coronary artery disease. The collateral circulation can be assessed by different methods; the gold standard involves intracoronary pressure measurements. While the first clinical trials to therapeutically induce growth of collateral arteries have been unavailing, recent pilot studies using external counterpulsation or growth factors such as granulocyte colony stimulating factor (G-CSF) have shown promising results. [ABSTRACT FROM AUTHOR]