Structure and localization of mRNA encoding a pigment dispersing hormone (PDH) in the eyestalk of the crayfish Orconectes limosus

AbstractThe pigment-dispersing hormone (PDH) is produced in the eyestalks of Crustacea where it induces light-adapting movements of pigment in the compound eye and regulates the pigment dispersion in the chromatophores. To study this hormone at the mRNA level, we cloned and sequenced cDNA encoding PDH in the crayfish Orconectes limosus. The structure of the PDH preprohormone consists of a signal peptide, a PDH precursor-related peptide (PPRP) and the highly conserved PDH peptide at the carboxy-terminal end. In situ hybridization in combination with immunocytochemistry revealed four cell clusters expressing PDH in the optic ganglia of the eyestalk. Three clusters stained both with the PDH cRNA probe and the PDH antiserum, however, the perikarya in the lamina ganglionaris (LG) only stained with the PDH antiserum, suggesting the presence of a PDH-like peptide in the LG

Atherosclerotic Plaque Biomarkers: Beyond the Horizon of the Vulnerable Plaque

Cardiovascular disease (CVD) is the number one cause of death globally, and the majority of CVD is caused by atherosclerosis. Atherosclerosis is a systemic inflammatory disease that leads to myocardial infarction, stroke and lower limb ischemia. Pathological studies have given insight to development of atherosclerosis and the importance of local plaque vulnerability, leading to thrombus formation and cardiovascular events. Due to the burden of cardiovascular disease, identification of patients at risk for cardiovascular events and treatment stratification is needed. The predictive power of classical risk factors is limited, especially in patients with manifest atherosclerosis. Imaging modalities have focused on the characteristics of the vulnerable plaque. However, it has become evident that not all so-called vulnerable plaques lead to rupture and subsequent thrombosis. The latter obviously limits the positive predictive value for imaging assessment of plaques and patients at risk. Serum biomarkers have also been studied extensively, but have very limited application in a clinical setting for risk stratification. In line with the important relation between vulnerable plaques and cardiovascular events, plaque biomarker studies have been initiated. These longitudinal studies are based on the concept, that a vulnerable plaque contains predictive information for future cardiovascular events, also in other territories of the vascular tree. Results look promising and plaque markers can be used to develop imaging modalities to identify patients at risk, or to monitor treatment effect. Plaque biomarker studies do not challenge the definition of the vulnerable plaque, but use its concept in favor of prediction improvement for vascular patients

Intraobserver and interobserver variability and spatial differences in histologic examination of carotid endarterectomy specimens

IntroductionStudies using histologic examination and protein analysis of atherosclerotic plaques are increasingly being performed, but reproducibility of plaque histology and variation of plaque composition among different parts of the plaque, which are key to reliability of these studies, are relatively unexplored. Therefore, this study investigated the intraobserver and interobserver variability of plaque histology and spatial variability in plaque composition.MethodsAtherosclerotic plaques (n = 100) obtained during carotid endarterectomy were divided into 0.5-cm segments. Paraffin sections were stained and semiquantitatively analyzed (four categories: no, minor, moderate, and heavy) for fat, macrophages, smooth muscle cells, collagen, calcification, thrombus, and overall phenotype. First, to determine the intraobserver and interobserver reproducibility, two independent observers independently analyzed the plaques. Second, to investigate spatial variability in plaque composition, histologic appearances of the culprit lesions (0-segment) were compared with the histologic appearances of adjacent (+5 mm) and more distant (+10 mm) plaque segments of 30 specimens.ResultsThe κ values for intraobserver variability of fat, macrophages, smooth muscle cells, collagen, calcifications, thrombus, and overall phenotype were 0.83, 0.85, 0.71, 0.63, 0.81, 0.80, and 0.86, respectively, and κ values for interobserver variability were 0.68, 0.74, 0.54, 0.59, 0.82, 0.75, and 0.71, respectively. Comparison of the histologic scorings of adjacent segments revealed a mean κ of 0.40 (range, 0.33 to 0.60). When the culprit segment was compared with the more distant segment, the mean κ was 0.24; however, in 91% of cases, the difference between the culprit segment and the distal segment was one category or less.ConclusionSemiquantitative analysis of carotid atherosclerotic plaque histology was well reproducible, both intraobserver and interobserver. Although variation between different plaque segments in histologic appearance was observed, differences were small in almost all cases. Variability in histologic examination needs to be taken into account in studies comparing plaque imaging with histopathology and plaque research studies

Preoperative hypertension is associated with atherosclerotic intraplaque hemorrhage in patients undergoing carotid endarterectomy

BACKGROUND AND AIMS: Both hypertension and atherosclerotic plaque characteristics such as intraplaque hemorrhage (IPH) are associated with cardiovascular events (CVE). It is unknown if hypertension is associated with IPH. Therefore, we studied if hypertension is associated with unstable atherosclerotic plaque characteristics in patients undergoing carotid endarterectomy (CEA). METHODS: Prospectively collected data of CEA-patients (2002-2014) were retrospectively analyzed. Blood pressure (BP) was the mean of 3 preoperative measurements. Preoperative hypertension was defined as systolic BP ≥ 160 mmHg. Post-CEA, carotid atherosclerotic plaques were analyzed for the presence of calcifications, collagen, smooth muscle cells, macrophages, lipid core, IPH and microvessel density. Associations between BP (systolic and diastolic), patient characteristics and carotid plaque characteristics were assessed with univariate and multivariate analyses with correction for potential confounders. Results were replicated in a cohort of patients that underwent iliofemoral endarterectomy. RESULTS: Within CEA-patients (n = 1684), 708 (42%) had preoperative hypertension. Increased systolic BP was associated with the presence of plaque calcifications (adjusted OR1.11 [95% CI 1.01-1.22], p = 0.03), macrophages (adjusted OR1.12 [1.04-1.21], p 10% of plaque area (adjusted OR1.15 [1.05-1.25], p < 0.01), IPH (adjusted OR1.12 [1.03-1.21], p = 0.01) and microvessels (adjusted beta 0.04 [0.00-0.08], p = 0.03). Increased diastolic BP was associated with macrophages (adjusted OR1.36 [1.17-1.58], p < 0.01), lipid core (adjusted OR1.29 [1.10-1.53], p < 0.01) and IPH (adjusted OR1.25 [1.07-1.46], p < 0.01) but not with microvessels nor plaque calcifications. Replication in an iliofemoral-cohort (n = 657) showed that increased diastolic BP was associated with the presence of macrophages (adjusted OR1.78 [1.13-2.91], p = 0.01), lipid core (adjusted OR1.45 [1.06-1.98], p = 0.02) and IPH (adjusted OR1.48 [1.14-1.93], p < 0.01). CONCLUSIONS: Preoperative hypertension in severely atherosclerotic patients is associated with the presence of carotid plaque macrophages, lipid core and IPH. IPH, as a plaque marker for CVE, is associated with increased systolic and diastolic BP in both the CEA and iliofemoral population

Magnetic Resonance Imaging Identified Brain Ischaemia in Symptomatic Patients Undergoing Carotid Endarterectomy Is Related to Histologically Apparent Intraplaque Haemorrhage

Objective: Intraplaque haemorrhage (IPH) has been independently associated with a higher risk of future ipsilateral stroke in patients with carotid artery stenosis. Evaluation of plaque characteristics may contribute to risk assessment of recurrent (silent) cerebrovascular events in order to prioritise patients for timing of treatment. It is unknown if patients showing histologically apparent IPH also have increased risk of silent ischaemic brain lesions in the waiting period between index event and revascularisation. Methods: A retrospective analysis was performed based on prospectively collected data of patients included simultaneously in the magnetic resonance imaging (MRI) substudy of the International Carotid Stenting Study and Athero-Express biobank. Patients randomised for carotid endarterectomy (CEA) underwent surgery between 2003 and 2008. Brain MRI was performed one to seven days prior to CEA. Plaques were histologically examined for presence of IPH. The primary outcome parameter was presence of silent ipsilateral brain ischaemia on magnetic resonance diffusion weighted imaging (MR-DWI) appearing hypo or isointense on apparent diffusion coefficient. Results: Fifty-three patients with symptomatic carotid stenosis meeting the study criteria were identified, of which 13 showed one or more recent ipsilateral DWI lesion on pre-operative scan. The median time between latest ipsilateral neurological event and revascularisation was 45 days (range 6–200) in DWI negative patients vs. 34 days (range 6–74, p = .16) in DWI positive patients. IPH was present in 24/40 (60.0%) DWI negative patients vs. 12/13 (92.3%) DWI positive patients (OR 8.00; 95% CI 0.95–67.7, p = .06). Multivariable logistic regression analysis correcting for age and type of index event revealed that IPH was independently associated with DWI lesions in the waiting period till surgery (OR 10.8; 95% CI 1.17–99.9, p = .04). Conclusion: Symptomatic patients with ipsilateral carotid stenosis and silent brain ischaemia on pre-operative MR-DWI, more often showed pathological evidence of IPH compared with those without ischaemic lesions. This identifies carotid IPH as a marker for patients at risk of silent brain ischaemia and possibly for future stroke and other arterial disease complications. Such patients may be more likely to benefit from CEA than those without evidence of ipsilateral carotid IPH

Vascular extracellular vesicles in comorbidities of heart failure with preserved ejection fraction in men and women : The hidden players. A mini review

Left ventricular diastolic dysfunction, the main feature of heart failure with preserved ejection fraction (HFpEF), is thought to be primarily caused by comorbidities affecting the endothelial function of the coronary microvasculature. Circulating extracellular vesicles, released by the endothelium have been postulated to reflect endothelial damage. Therefore, we reviewed the role of extracellular vesicles, in particularly endothelium microparticles, in these comorbidities, including obesity and hypertension, to identify if they may be potential markers of the endothelial dysfunction underlying left ventricular diastolic dysfunction and HFpEF

Vascular extracellular vesicles in comorbidities of heart failure with preserved ejection fraction in men and women : The hidden players. A mini review

Left ventricular diastolic dysfunction, the main feature of heart failure with preserved ejection fraction (HFpEF), is thought to be primarily caused by comorbidities affecting the endothelial function of the coronary microvasculature. Circulating extracellular vesicles, released by the endothelium have been postulated to reflect endothelial damage. Therefore, we reviewed the role of extracellular vesicles, in particularly endothelium microparticles, in these comorbidities, including obesity and hypertension, to identify if they may be potential markers of the endothelial dysfunction underlying left ventricular diastolic dysfunction and HFpEF

Polygenic Susceptibility of Aortic Aneurysms Associates to the Diameter of the Aneurysm Sac : the Aneurysm-Express Biobank Cohort

Recent genome-wide association studies (GWAS) have discovered ten genetic risk variants for abdominal aortic aneurysms (AAA). To what extent these genetic variants contribute to the pathology of aneurysms is yet unknown. The present study aims to investigate whether genetic risk variants are associated with three clinical features: diameter of aneurysm sac, type of artery and aneurysm related-symptoms in aortic and peripheral aneurysm patients. Aneurysm tissue of 415 patients included in the Aneurysm-Express biobank was used. A best-fit polygenic risk score (PRS) based on previous GWAS effect estimates was modeled for each clinical phenotype. The best-fit PRS (including 272 variants at PT = 0.01015) showed a significant correlation with aneurysm diameter (R2 = 0.019, p = 0.001). No polygenic association was found with clinical symptoms or artery type. In addition, the ten genome-wide significant risk variants for AAA were tested individually, but no associations were observed with any of the clinical phenotypes. All models were corrected for confounders and data was normalized. In conclusion, a weighted PRS of AAA susceptibility explained 1.9% of the phenotypic variation (p = 0.001) in diameter in aneurysm patients. Given our limited sample size, future biobank collaborations need to confirm a potential causal role of susceptibility variants on aneurysmal disease initiation and progression

Local overexpression of C-type natriuretic peptide ameliorates vascular adaptation of porcine hemodialysis grafts

Local overexpression of C-type natriuretic peptide ameliorates vascular adaptation of porcine hemodialysis grafts.BackgroundOutflow obstruction at the outflow tract of arteriovenous grafts contributes significantly to the poor patency rates of dialysis grafts in vivo. We addressed the potential of local periadventitial gene therapy at the outflow tract for improving access patency in a validated porcine model of arteriovenous grafts using an adenoviral vector encoding murine C-type natriuretic peptide (Ad.CNP).MethodsGene transfer efficiency and optimal virus concentration were determined using Ad.LacZ on porcine jugular veins in vivo (N = 2). Next, in 14 pigs, arteriovenous grafts were implanted bilaterally between the carotid artery and the jugular vein, followed local venous transduction with Ad.CNP (right) and Ad.mock (left). Transduction efficiency of Ad.CNP was evaluated by reverse transcription-polymerase chain reaction (RT-PCR) and cyclic guanosine monophosphate (cGMP) measurements (N = 2). Fourteen days after gene transfer, arteriovenous grafts were excised for histologic analysis (N = 12).ResultsAd.LacZ transduction (1 × 10E10 IU) of porcine veins resulted in evident expression of β-galactosidase, mainly in the adventitia. At termination, intima/media ratio was decreased by 37% in CNP-treated veins, predominantly due to medial thickening (Ad.CNP 3.1 ± 0.6mm2 vs. Ad.mock 1.70 ± 0.3mm2; P < 0.01) rather than decreased intimal hyperplasia (NS). Adventitial delivery of CNP resulted in increased external elastic lamina (EEL) (Ad.CNP 11.8 ± 1.4mm vs. Ad.mock 9.4 ± 1.0mm; P = 0.04) and luminal area (Ad.CNP 10.7 ± 1.4mm2 vs. Ad.mock 8.8 ± 1.7mm2; P = 0.05) at the venous anastomosis.ConclusionOverexpression of CNP enhances venous medial thickening and increases outward remodeling in the outflow tract of porcine arteriovenous grafts. These findings underscore the potential of local gene-therapeutic interventions in preventing luminal narrowing at the outflow tract of hemodialysis grafts