Misfolded alpha-synuclein (AS) and other neurodegenerative disorder proteins display prion-like transmission of protein aggregation. Factors responsible for the initiation of AS aggregation are unknown. To evaluate the role of amyloid proteins made by the microbiota we exposed aged rats and transgenic C. elegans to E. coli producing the extracellular bacterial amyloid protein curli. Rats exposed to curli-producing bacteria displayed increased neuronal AS deposition in both gut and brain and enhanced microgliosis and astrogliosis compared to rats exposed to either mutant bacteria unable to synthesize curli, or to vehicle alone. Animals exposed to curli producing bacteria also had more expression of TLR2, IL-6 and TNF in the brain than the other two groups. There were no differences among the rat groups in survival, body weight, inflammation in the mouth, retina, kidneys or gut epithelia, and circulating cytokine levels. AS-expressing C. elegans fed on curli-producing bacteria also had enhanced AS aggregation. These results suggest that bacterial amyloid functions as a trigger to initiate AS aggregation through cross-seeding and also primes responses of the innate immune system.

Individuals who inherit one faulty von Hippel-Lindau gene (VHL) allele are predisposed to VHL disease, which is characterized by the development of cerebellar, spinal, and retinal hemangioblastoma, pheochromocytoma, and clear-cell renal cell carcinoma (CC-RCC) (29). The tumor develops upon the somatic loss of the remaining wild-type VHL allele in a susceptible cell. Importantly, biallelic loss of VHL is associated with the vast majority of sporadic CC-RCCs, establishing VHL as a critical suppressor of renal oncogenesis (29). CC-RCC is resistant to conventional radiation and chemotherapies, and approximately one-quarter of renal cancer patients present with advanced disease, including locally invasive or metastatic CC-RCC (12). Unfortunately, one-third of patients who undergo surgical removal of localized tumors have recurrence of the disease, and the median survival for patients harboring metastatic CC-RCC is 13 months (12). Moreover, the principal cause of morbidity and death of VHL patients is CC-RCC (29). Despite the need to better understand the aggressive nature of CC-RCC, the molecular pathways governing its malignant phenotype remain unresolved.The most well-characterized function of VHL is as a substrate-recognition component of the SCF (Skp1/Cdc53/F-box protein)-like E3 ubiquitin ligase complex called ECV (elongins/Cul2/VHL) that selectively ubiquitylates oxygen-dependent prolyl-hydroxylated ␣ subunits of hypoxia-inducible factor

Many cardiovascular and cerebrovascular disorders are accompanied by an increased blood content of fibrinogen (Fg), a high molecular weight plasma adhesion protein. Fg is a biomarker of inflammation and its degradation products have been associated with microvascular leakage. We tested the hypothesis that at pathologically high levels, Fg increases endothelial cell (EC) permeability through extracellular signal regulated kinase (ERK) signaling and by inducing F-actin formation. In cultured ECs, Fg binding to intercellular adhesion molecule-1 and to α 5 β 1 integrin, caused phosphorylation of ERK. Subsequently, F-actin formation increased and coincided with formation of gaps between ECs, which corresponded with increased permeability of ECs to albumin. Our data suggest that formation of F-actin and gaps may be the mechanism for increased albumin leakage through the EC monolayer. The present study indicates that elevated un-degraded Fg may be a factor causing microvascular permeability that typically accompanies cardiovascular and cerebrovascular disorders.

The current study assesses the antihypertensive efficacy and safety of the investigational angiotensin receptor blocker (ARB), azilsartan medoxomil (AZL-M), compared with placebo and the ARB olmesartan medoxomil (OLM-M). This randomized, double-blind, placebocontrolled, multicenter study assessed change from baseline in mean 24-hour ambulatory systolic blood pressure (SBP) following 6 weeks of treatment. Patients with primary hypertension (n=1275) and baseline 24-hour mean ambulatory systolic pressure !130 mm Hg and 170 mm Hg were studied; 142 received placebo and the remainder received 20 mg, 40 mg, or 80 mg AZL-M or 40 mg OLM-M. Mean age of participants was 58AE11 years, baseline mean 24-hour SBP was 146 mm Hg. Dose-dependent reductions in 24-hour mean SBP at study end occurred in all AZL-M groups. Reduction in 24-hour mean SBP was greater with AZL-M 80 mg than OLM-M 40 mg by 2.1 mm Hg (95% confidence interval, )4.0 to )0.1; P=.038), while AZL-M 40 mg was noninferior to OLM-M 40 mg. The side effect profiles of both ARBs were similar to placebo. AZL-M is well tolerated and more efficacious at its maximal dose than the highest dose of OLM-M. J Clin Hypertens (Greenwich). 2011;13:81-88. 1 Despite the availability of antihypertensive treatments, hypertension remains inadequately controlled, with slightly less than half of patients who receive treatment successfully achieving blood pressure (BP) goals.2 While there are many drug classes available to reduce BP, drugs that modulate the renin-angiotensin-aldosterone system (RAAS) are more commonly used because of their efficacy, coupled with one of the lowest side effect profiles.3 Moreover, within the RAAS classes, those that inhibit the action of angiotensin II by binding directly to the angiotensin type 1 (AT 1 ) receptor (ie, angiotensin receptor blockers [ARBs]) are the best tolerated of all antihypertensive drug classes.3 Some ARBs have shown efficacy in reducing mortality in patients with heart failure and post-myocardial infarction as well as slowing progression of diabetic nephropathy.

Fibrinogen (Fg) is a high molecular weight plasma adhesion protein and a biomarker of inflammation. Many cardiovascular and cerebrovascular disorders are accompanied by increased blood content of Fg. Increased levels of Fg result in changes in blood rheological properties such as increases in plasma viscosity, erythrocyte aggregation, platelet thrombogenesis, alterations in vascular reactivity and compromises in endothelial layer integrity. These alterations exacerbate the complications in peripheral blood circulation during cardiovascular diseases such as hypertension, diabetes and stroke. In addition to affecting blood viscosity by altering plasma viscosity and erythrocyte aggregation, growing experimental evidence suggests that Fg alters vascular reactivity and impairs endothelial cell layer integrity by binding to its endothelial cell membrane receptors and activating signalling mechanisms. The purpose of this review is to discuss experimental data, which demonstrate the effects of Fg causing vascular dysfunction and to offer possible mechanisms for these effects, which could exacerbate microcirculatory complications during cardiovascular diseases accompanied by increased Fg content.

Elevated plasma homocysteine (Hcy) is associated with cerebrovascular disease and activates matrix metalloproteinases (MMPs), which lead to vascular remodeling that could disrupt the blood-brain barrier. To determine whether Hcy administration can increase brain microvascular leakage secondary to activation of MMPs, we examined pial venules by intravital video microscopy through a craniotomy in anesthetized mice. Bovine serum albumin labeled with fluorescein isothiocyanate (BSA-FITC) was injected into a carotid artery to measure extravenular leakage. Hcy (30 μM/total blood volume) was injected 10 min after FITC-BSA injection. Four groups of mice were examined: 1) wild type (WT) given vehicle; 2) WT given Hcy (WT + Hcy); 3) MMP-9 gene knockout given Hcy (MMP-9−/− + Hcy); and 4) MMP-9−/− with topical application of histamine (10 −4 M) (MMP-9 −/− + histamine). In the WT + Hcy mice, leakage of FITC-BSA from pial venules was significantly (P < 0.05) greater than in the other groups. There was no significant leakage of pial microvessels in MMP-9−/− + Hcy mice. Increased cerebrovascular leakage in the MMP-9−/− + histamine group showed that microvascular permeability could still increase by a mechanism independent of MMP-9. Treatment of cultured mouse microvascular endothelial cells with 30 μM Hcy resulted in significantly greater F-actin formation than in control cells without Hcy. Treatment with a broad-range MMP inhibitor (GM-6001; 1 μM) ameliorated Hcy-induced F-actin formation. These data suggest that Hcy increases microvascular permeability, in part, through MMP-9 activation.

Abstract-Azilsartan medoxomil, an effective, long-acting angiotensin II receptor blocker, is a new treatment for hypertension that is also being developed in fixed-dose combinations with chlorthalidone, a potent, long-acting thiazide-like diuretic. We compared once-daily fixed-dose combinations of azilsartan medoxomil/chlorthalidone force titrated to a high dose of either 40/25 mg or 80/25 mg with a fixed-dose combination of the angiotensin II receptor blocker olmesartan medoxomil plus the thiazide diuretic hydrochlorothiazide force titrated to 40/25 mg. The design was a randomized, 3-arm, double-blind, 12-week study of 1071 participants with baseline clinic systolic blood pressure 160 to 190 mm Hg and diastolic blood pressure Յ119 mm Hg. Patients had a mean age of 57 years; 59% were men, 73% were white, and 22% were black. At baseline, mean clinic blood pressure was 165/96 mm Hg and 24-hour mean blood pressure was 150/88 mm Hg. Changes in clinic (primary end point) and ambulatory systolic blood pressures at week 12 were significantly greater in both azilsartan medoxomil/chlorthalidone arms than in the olmesartan/hydrochlorothiazide arm (PϽ0.001). Changes in clinic systolic blood pressure (meanϮSE) were Ϫ42.5Ϯ0. 1 Therefore, there is a need for more effective antihypertensive regimens that include simple single-pill fixed-dose combination (FDC) products.Azilsartan medoxomil is a newly approved, effective, long-acting angiotensin II receptor blocker (ARB). It is a prodrug that is quickly hydrolyzed to the active moiety azilsartan, a potent and selective ARB with estimated bioavailability of 60% and elimination half-life of 12 hours.2 At its maximal dose, azilsartan medoxomil has superior efficacy compared with both olmesartan and valsartan at their maximum, approved doses, without increasing adverse events. [3][4][5] Chlorthalidone is a potent, long-acting thiazide-like diuretic that has a strong evidence base supporting cardiovascular benefit from randomized, controlled clinical trials. [6][7][8][9][10][11][12] It is also more effective in lowering BP than the more commonly used thiazide diuretic, hydrochlorothiazide.13 Therefore, combinations of azilsartan medoxomil and chlorthalidone are being developed as an effective 2-drug FDC.The present multicenter study is a large, forced-titration, active-comparator study of an ARB-chlorthalidone combination. We compared the antihypertensive efficacy, safety, and tolerability of azilsartan medoxomil plus chlorthalidone with

We previously showed that an elevated content of fibrinogen (Fg) increased formation of filamentous actin and enhanced endothelial layer permeability. In the present work we tested the hypothesis that Fg binding to endothelial cells (ECs) alters expression of actin-associated endothelial tight junction proteins (TJP). Rat cardiac microvascular ECs were grown in gold plated chambers of an electrical cell-substrate impedance system, 8-well chambered, or in 12-well plates. Confluent ECs were treated with Fg (2 or 4 mg/ml), Fg (4 mg/ml) with mitogen-activated protein kinase (MEK) kinase inhibitors (PD98059 or U0126), Fg (4 mg/ml) with anti-ICAM-1 antibody or BQ788 (endothelin type B receptor blocker), endothelin-1, endothelin-1 with BQ788, or medium alone for 24 h. Fg induced a dose-dependent decrease in EC junction integrity as determined by transendothelial electrical resistance (TEER). Western blot analysis and RT-PCR data showed that the higher dose of Fg decreased the contents of TJPs, occludin, zona occluden-1 (ZO-1), and zona occluden-2 (ZO-2) in ECs. Fg-induced decreases in contents of the TJPs were blocked by PD98059, U0126, or anti-ICAM-1 antibody. While BQ788 inhibited endothelin-1-induced decrease in TEER, it did not affect Fg-induced decrease in TEER. These data suggest that Fg increases EC layer permeability via the MEK kinase signaling pathway by affecting occludin, ZO-1, and ZO-2, TJPs, which are bound to actin filaments. Therefore, increased binding of Fg to its major EC receptor, ICAM-1, during cardiovascular diseases may increase microvascular permeability by altering the content and possibly subcellular localization of endothelial TJPs.