Atorvastatin protects against liver and vascular damage in a model of diet induced steatohepatitis by resetting FXR and GPBAR1 signaling.

Farnesoid-x-receptor (FXR) agonists, currently trialed in patients with non-alcoholic steatosis (NAFLD), worsen the pro-atherogenic lipid profile and might require a comedication with statin. Here we report that mice feed a high fat/high cholesterol diet (HFD) are protected from developing a pro-atherogenic lipid profile because their ability to dispose cholesterol through bile acids. This protective mechanism is mediated by suppression of FXR signaling in the liver by muricholic acids (MCAs) generated in mice from chenodeoxycholic acid (CDCA). In contrast to CDCA, MCAs are FXR antagonists and promote a CYP7A1-dependent increase of bile acids synthesis. In mice feed a HFD, the treatment with obeticholic acid, a clinical stage FXR agonist, failed to improve the liver histopathology while reduced Cyp7a1 and Cyp8b1 genes expression and bile acids synthesis and excretion. In contrast, treating mice with atorvastatin mitigated liver and vascular injury caused by the HFD while increased the bile acids synthesis and excretion. Atorvastatin increased the percentage of 7α-dehydroxylase expressing bacteria in the intestine promoting the formation of deoxycholic acid and litocholic acid, two GPBAR1 agonists, along with the expression of GPBAR1-regulated genes in the white adipose tissue and colon. In conclusion, present results highlight the central role of bile acids in regulating lipid and cholesterol metabolism in response to atorvastatin and provide explanations for limited efficacy of FXR agonists in the treatment of NAFLD.

Far-infrared radiation alleviates cisplatin-induced vascular damage and impaired circulation via activation of HIF-1α.

Severe vascular damage and complications are often observed in cancer patients during treatment with chemotherapeutic drugs such as cisplatin. Thus, development of potential options to ameliorate the vascular side effects is urgently needed. In this study, the effects and the underlying mechanisms of far-infrared radiation (FIR) on cisplatin-induced vascular injury and endothelial cytotoxicity/dysfunction in mice and human umbilical vein endothelial cells (HUVECs) were investigated. An important finding is that the severe vascular stenosis and poor blood flow seen in cisplatin-treated mice were greatly mitigated by FIR irradiation (30 minutes/day) for 1-3 days. Moreover, FIR markedly increased the levels of phosphorylation of PI3K and Akt, and VEGF secretion, as well as the expression and the activity of hypoxia-inducible factor 1α (HIF-1α) in cisplatin-treated HUVECs in a promyelocytic leukemia zinc finger protein (PLZF)-dependent manner. However, FIR-stimulated endothelial angiogenesis and VEGF release were significantly diminished by transfection with HIF-1α siRNA. We also confirmed that HIF-1α, PI3K, and PLZF contribute to the inhibitory effect of FIR on cisplatin-induced apoptosis in HUVECs. Notably, FIR did not affect the anticancer activity and the HIF-1α/VEGF cascade in cisplatin-treated cancer cells under normoxic or hypoxic condition, indicating that the actions of FIR may specifically target endothelial cells. It is the first study to demonstrate that FIR effectively attenuates cisplatin-induced vascular damage and impaired angiogenesis through activation of HIF-1α-dependent processes via regulation of PLZF and PI3K/Akt. Taken together, cotreatment with the noninvasive and easily performed FIR has a therapeutic potential to prevent the pathogenesis of vascular complications in cancer patients during cisplatin treatment.

Aspirin Resistance in Vascular Disease: A Review Highlighting the Critical Need for Improved Point-of-Care Testing and Personalized Therapy.

Aspirin resistance describes a phenomenon where patients receiving aspirin therapy do not respond favorably to treatment, and is categorized by continued incidence of adverse cardiovascular events and/or the lack of reduced platelet reactivity. Studies demonstrate that one in four patients with vascular disease are resistant to aspirin therapy, placing them at an almost four-fold increased risk of major adverse limb and adverse cardiovascular events. Despite the increased cardiovascular risk incurred by aspirin resistant patients, strategies to diagnose or overcome this resistance are yet to be clinically validated and integrated. Currently, five unique laboratory assays have shown promise for aspirin resistance testing: Light transmission aggregometry, Platelet Function Analyzer-100, Thromboelastography, Verify Now, and Platelet Works. Newer antiplatelet therapies such as Plavix and Ticagrelor have been tested as an alternative to overcome aspirin resistance (used both in combination with aspirin and alone) but have not proven to be superior to aspirin alone. A recent breakthrough discovery has demonstrated that rivaroxaban, an anticoagulant which functions by inhibiting active Factor X when taken in combination with aspirin, improves outcomes in patients with vascular disease. Current studies are determining how this new regime may benefit those who are considered aspirin resistant.

Soluble Endoglin Stimulates Inflammatory and Angiogenic Responses in Microglia That Are Associated with Endothelial Dysfunction.

Increased soluble endoglin (sENG) has been observed in human brain arteriovenous malformations (bAVMs). In addition, the overexpression of sENG in concurrence with vascular endothelial growth factor (VEGF)-A has been shown to induce dysplastic vessel formation in mouse brains. However, the underlying mechanism of sENG-induced vascular malformations is not clear. The evidence suggests the role of sENG as a pro-inflammatory modulator, and increased microglial accumulation and inflammation have been observed in bAVMs. Therefore, we hypothesized that microglia mediate sENG-induced inflammation and endothelial cell (EC) dysfunction in bAVMs. In this study, we confirmed that the presence of sENG along with VEGF-A overexpression induced dysplastic vessel formation. Remarkably, we observed increased microglial activation around dysplastic vessels with the expression of NLRP3, an inflammasome marker. We found that sENG increased the gene expression of VEGF-A, pro-inflammatory cytokines/inflammasome mediators (TNF-α, IL-6, NLRP3, ASC, Caspase-1, and IL-1ß), and proteolytic enzyme (MMP-9) in BV2 microglia. The conditioned media from sENG-treated BV2 (BV2-sENG-CM) significantly increased levels of angiogenic factors (Notch-1 and TGFß) and pERK1/2 in ECs but it decreased the level of IL-17RD, an anti-angiogenic mediator. Finally, the BV2-sENG-CM significantly increased EC migration and tube formation. Together, our study demonstrates that sENG provokes microglia to express angiogenic/inflammatory molecules which may be involved in EC dysfunction. Our study corroborates the contribution of microglia to the pathology of sENG-associated vascular malformations.

Pulmonary and vascular effects of acute ozone exposure in diabetic rats fed an atherogenic diet.

Air pollutants may increase risk for cardiopulmonary disease, particularly in susceptible populations with metabolic stressors such as diabetes and unhealthy diet. We investigated effects of inhaled ozone exposure and high-cholesterol diet (HCD) in healthy Wistar and Wistar-derived Goto-Kakizaki (GK) rats, a non-obese model of type 2 diabetes. Male rats (4-week old) were fed normal diet (ND) or HCD for 12 weeks and then exposed to filtered air or 1.0 ppm ozone (6 h/day) for 1 or 2 days. We examined pulmonary, vascular, hematology, and inflammatory responses after each exposure plus an 18-h recovery period. In both strains, ozone induced acute bronchiolar epithelial necrosis and inflammation on histopathology and pulmonary protein leakage and neutrophilia; the protein leakage was more rapid and persistent in GK compared to Wistar rats. Ozone also decreased lymphocytes after day 1 in both strains consuming ND (~50%), while HCD increased circulating leukocytes. Ozone increased plasma thrombin/antithrombin complexes and platelet disaggregation in Wistar rats on HCD and exacerbated diet effects on serum IFN-γ, IL-6, KC-GRO, IL-13, and TNF-α, which were higher with HCD (Wistar>GK). Ex vivo aortic contractility to phenylephrine was lower in GK versus Wistar rats at baseline(~30%); ozone enhanced this effect in Wistar rats on ND. GK rats on HCD had higher aortic e-NOS and tPA expression compared to Wistar rats. Ozone increased e-NOS in GK rats on ND (~3-fold) and Wistar rats on HCD (~2-fold). These findings demonstrate ways in which underlying diabetes and HCD may exacerbate pulmonary, systemic, and vascular effects of inhaled pollutants.

Regulation of the parental gene GRM4 by circGrm4 RNA transcript and glutamate-mediated neurovascular toxicity in eyes.

Epigenetic memory plays crucial roles in gene regulation. It not only modulates the expression of specific genes but also has ripple effects on transcription as well as translation of other genes. Very often an alteration in expression occurs either via methylation or demethylation. In this context, "1-carbon metabolism" assumes a special significance since its dysregulation by higher levels of homocysteine; Hcy (known as hyperhomocysteinemia; HHcy), a byproduct of "1-Carbon Metabolism" during methionine biosynthesis leads to serious implications in cardiovascular, renal, cerebrovascular systems, and a host of other conditions. Currently, the circular RNAs (circRNAs) generated via non-canonical back-splicing events from the pre-mRNA molecules are at the center stage for their essential roles in diseases via their epigenetic manifestations. We recently identified a circular RNA transcript (circGRM4) that is significantly upregulated in the eye of cystathionine ß-synthase-deficient mice. We also discovered a concurrent over-expression of the mGLUR4 receptor in the eyes of these mice. In brief, circGRM4 is selectively transcribed from its parental mGLUR4 receptor gene (GRM4) functions as a "molecular-sponge" for the miRNAs and results into excessive turnover of the mGLUR4 receptor in the eye in response to extremely high circulating glutamate concentration. We opine that this epigenetic manifestation potentially predisposes HHcy people to retinovascular malfunctioning.

The vascular endothelial growth factor trap aflibercept induces vascular dysfunction and hypertension via attenuation of eNOS/NO signaling in mice.

Aflibercept, as a soluble decoy vascular endothelial growth factor receptor, Which has been used as a first-line monotherapy for cancers. Aflibercept often causes cardiovascular toxicities including hypertension, but the mechanisms underlying aflibercept-induced hypertension remain unknown. In this study we investigated the effect of short-term and long-term administration of aflibercept on blood pressure (BP), vascular function, NO bioavailability, oxidative stress and endothelin 1 (ET-1) in mice and cultured endothelial cells. We showed that injection of a single-dose of aflibercept (18.2, 36.4 mg/kg, iv) rapidly and dose-dependently elevated BP in mice. Aflibercept treatment markedly impaired endothelial-dependent relaxation (EDR) and resulted in NADPH oxidases 1 (NOX1)- and NADPH oxidases 4 (NOX4)-mediated generation of ROS, decreased the activation of protein kinase B (Akt) and endothelial nitric oxide synthase (eNOS) concurrently with a reduction in nitric oxide (NO) production and elevation of ET-1 levels in mouse aortas; these effects were greatly attenuated by supplementation of L-arginine (L-arg, 0.5 or 1.0 g/kg, bid, ig) before aflibercept injection. Similar results were observed in L-arg-pretreated cultured endothelial cells, showing markedly decreased ROS accumulation and AKT/eNOS/NO signaling impairment induced by aflibercept. In order to assess the effects of long-term aflibercept on hypertension and to evaluate the beneficial effects of L-arg supplementation, we administered these two drugs to WT mice for up to 14 days (at an interval of two days). Long-term administration of aflibercept resulted in a sustained increase in BP and a severely impaired EDR, which are associated with NOX1/NOX4-mediated production of ROS, increase in ET-1, inhibition of AKT/eNOS/NO signaling and a decreased expression of cationic amino acid transporter (CAT-1). The effects caused by long-term administration were greatly attenuated by L-arg supplementation in a dose-dependent manner. We conclude that aflibercept leads to vascular dysfunction and hypertension by inhibiting CAT-1/AKT/eNOS/NO signaling, increasing ET-1, and activating NOX1/NOX4-mediated oxidative stress, which can be suppressed by supplementation of L-arg. Therefore, L-arg could be a potential therapeutic agent for aflibercept-induced hypertension.

Associations between peripheral perfusion disorders, mean arterial pressure and dose of norepinephrine administrated in the early phase of septic shock.

The aim of the study was to explore the correlations between peripheral perfusion, mean arterial pressure and the dose-rate of norepinephrine (NE) infused for the treatment of septic shock. The study is retrospective analysis of data acquired prospectively on 57 patients during the first 24 hours after the occurrence of the shock. Clinical and haemodynamic characteristics, skin perfusion parameters (capillary refill time [CRT], mottling score and temperature gradients) and the dose rate of NE infusion were collected. Negative correlations between mean arterial pressure (MAP) and temperature gradients (core-to-toe: P = .03, core-to-index: P = .04) were found and abnormal CRT was associated with lower MAP (P = .02). The dose rate of NE was negatively correlated with temperature gradients (core-to-toe: P = .02, core-to-index: P = .01, forearm-to-index: P = .008) in the overall population. In patients receiving NE for at least 12 hours, the NE dose rate positively was correlated with the mottling score (P = .006), temperature gradients (core-to-toe: P = .04, forearm-to-index: P = .02, core-to-index: P = .005) and CRT (P = .001). The dose of NE administrated was associated with 14-days mortality (odds ration [OR] = 1.21 [1.06-1.38], P = .006) and with 28-days mortality (OR = 1.17 [1.01-1.36], P = 0.04). In conclusion, the study described the presence of correlations between peripheral perfusion and MAP and between peripheral perfusion and the dose rate of NE infusion.

Aldosterone Negatively Regulates Nrf2 Activity: An Additional Mechanism Contributing to Oxidative Stress and Vascular Dysfunction by Aldosterone.

High levels of aldosterone (Aldo) trigger oxidative stress and vascular dysfunction independent of effects on blood pressure. We sought to determine whether Aldo disrupts Nrf2 signaling, the main transcriptional factor involved in antioxidant responses that aggravate cell injury. Thoracic aorta from male C57Bl/6J mice and cultured human endothelial cells (EA.hy926) were stimulated with Aldo (100 nM) in the presence of tiron [reactive oxygen species (ROS) scavenger, eplerenone [mineralocorticoid receptor (MR) antagonist], and L-sulforaphane (SFN; Nrf2 activator). Thoracic aortas were also isolated from mice infused with Aldo (600 µg/kg per day) for 14 days. Aldo decreased endothelium-dependent vasorelaxation and increased ROS generation, effects prevented by tiron and MR blockade. Pharmacological activation of Nrf2 with SFN abrogated Aldo-induced vascular dysfunction and ROS generation. In EA.hy926 cells, Aldo increased ROS generation, which was prevented by eplerenone, tiron, and SFN. At short times, Aldo-induced ROS generation was linked to increased Nrf2 activation. However, after three hours, Aldo decreased the nuclear accumulation of Nrf2. Increased Keap1 protein expression, but not activation of p38 MAPK, was linked to Aldo-induced reduced Nrf2 activity. Arteries from Aldo-infused mice also exhibited decreased nuclear Nrf2 and increased Keap1 expression. Our findings suggest that Aldo reduces vascular Nrf2 transcriptional activity by Keap1-dependent mechanisms, contributing to mineralocorticoid-induced vascular dysfunction.

Vascular effects of cancer treatments.

Chemotherapy, alone or in association with radiation therapy, has represented the cornerstone of cancer treatment for decades. However, in the last several years, an unprecedented progress in the understanding of cancer biology and the discovery of novel therapeutic targets have led to a paradigm shift in the management of patients with neoplastic diseases. The introduction of tyrosine kinase inhibitors, vascular endothelial growth factor pathway inhibitors, immunomodulatory agents, proteasome inhibitors, immune checkpoint inhibitors, and chimeric antigen receptor T cells, among others, has been associated with prolonged survival in many forms of cancer. A common feature of both chemotherapy and novel cancer treatments is the frequent occurrence of vascular toxicity, mainly mediated by injury to the endothelium. While the mechanisms may vary between agents, the clinical manifestations may overlap and range from hypertension, vasospastic and thrombotic arterial events (myocardial ischemia and infarction, peripheral ischemia, and limb gangrene), venous thromboembolism (deep vein thrombosis and pulmonary embolism) to capillary leak syndrome. Therefore, the effective management of patients with cancer requires a multidisciplinary team approach in which oncologist and cardiovascular medicine specialists work together to prevent, detect, and minimize acute vascular toxicity and long-term consequences of cancer therapy.

Abdominal Imaging Manifestations of Recreational Drug Use.

Recreational drug use is a burgeoning health issue worldwide, with a variety of presenting symptoms and complications. These complications can be secondary to the toxic effects of the drug itself, drug impurities, and nonsterile injection. The abdominal radiologist is likely to encounter patients who use drugs recreationally and may be responsible for recognizing and reporting these acute conditions, which in some cases can be life threatening. Because these patients often present with an altered mental state and may deny or withhold information on drug use, the underlying cause may be difficult to determine. The most commonly used drugs worldwide include cocaine, cannabinoids, opioids, and amphetamines and their derivatives. Complications of use of these drugs that can be seen at abdominopelvic CT can involve multiple organ systems, including the soft tissue and gastrointestinal, genitourinary, vascular, and musculoskeletal systems. A diverse range of abdominal complications associated with these drugs can be seen at imaging, including disseminated infections, gastrointestinal ischemia, and visceral infarction. Radiologists should be familiar with the imaging findings of these complications to accurately diagnose these entities and help guide workup and patient treatment. ©RSNA, 2020.

Occupational exposure to carbon black nanoparticles increases inflammatory vascular disease risk: an implication of an ex vivo biosensor assay.

BACKGROUND: Among manufactured or engineered nanoparticles, carbon black (CB) has largest production worldwide and is also an occupational respiratory hazard commonly seen in rubber industry. Few studies have assessed the risk for cardiovascular disease in carbon black exposed populations. An endothelial biosensor assay was used to quantify the capacity of sera from 82 carbon black packers (CBP) and 106 non-CBPs to induce endothelial cell activation ex vivo. The mediation effect of circulatory proinflammatory factors on the association between carbon black exposure and endothelial cell activation was assessed and further validated using in vitro intervention experiments. RESULTS: The average elemental carbon level inside carbon black bagging facilities was 657.0 µg/m3, which was 164-fold higher than that seen in reference areas (4.0 µg/m3). A global index was extracted from mRNA expression of seven candidate biosensor genes using principal component analysis and used to quantify the magnitude of endothelial cell activation. This global index was found to be significantly altered in CBPs compared to non-CBPs (P < 0.0001), however this difference did not vary by smoking status (P = 0.74). Individual gene analyses identified that de novo expression of key adhesion molecules (e.g., ICAM and VCAM) and chemotactic factors (e.g., CCL2, CCL5, and CXCL8) responsible for the recruitment of leukocytes was dramatically induced in CBPs with CXCL8 showing the highest fold of induction (relative quantification = 9.1, P < 0.0001). The combination of mediation analyses and in vitro functional validation confirmed TNF-α, IL-1ß, and IL-6 as important circulatory factors mediating the effects of carbon black exposure on endothelial cell activation responses. CONCLUSIONS: Inflammatory mediators in sera from CBPs may bridge carbon black exposure and endothelial cell activation response assessed ex vivo. CBPs may have elevated risk for cardiovascular diseases when comorbidity exists. Our study may serve as a benchmark for understanding health effects of engineered carbon based nanoparticles with environmental and occupational health relevance.

Central hemodynamics in relation to low-level environmental lead exposure.

Purpose: Arterial stiffness predicts cardiovascular complications. The association between arterial stiffness and blood lead (BL) remains poorly documented. We aimed to assess the association of central hemodynamic measurements, including pulse wave velocity (aPWV), with blood lead in a Flemish population.Materials and Methods: In this Flemish population study (mean age, 37.0 years; 48.3% women), 267 participants had their whole BL and 24-h urinary cadmium (UCd) measured by electrothermal atomic absorption spectrometry in 1985-2005. After 9.4 years (median), they underwent applanation tonometry to estimate central pulse pressure (cPP), the augmentation index (AI), pressure amplification (PA), and aPWV. The amplitudes of the forward (Pf) and backward (Pb) pulse waves and reflection index (RI) were derived by a pressure-based wave separation algorithm.Results: BL averaged 2.93 µg/dL (interquartile range, 1.80-4.70) and UCd 4.79 µg (2.91-7.85). Mean values were 45.0 ± 15.2 mm Hg for cPP, 24.4 ± 12.4% for AI, 1.34 ± 0.21 for PA, 7.65 ± 1.74 m/s for aPWV, 32.7 ± 9.9 mm Hg for Pf, 21.8 ± 8.4 mm Hg for Pb, and 66.9 ± 18.4% for RI. The multivariable-adjusted association sizes for a 2-fold higher BL were: +3.03% (95% confidence interval, 1.56, 4.50) for AI; -0.06 (-0.08, -0.04) for PA; 1.02 mm Hg (0.02, 2.02) for Pb; and 3.98% (1.71, 6.24) for RI (p ≤ .045). In 206 participants never on antihypertensive drug treatment, association sizes were +2.59 mm Hg (0.39, 4.79) for cPP and +0.26 m/s (0.03, 0.50) for aPWV. Analyses adjusted for co-exposure to cadmium were consistent.Conclusion: In conclusion, low-level environmental lead exposure possibly contributes to arterial stiffening and wave reflection from peripheral sites.

Perinatal iron deficiency combined with a high salt diet in adulthood causes sex-dependent vascular dysfunction in rats.

KEY POINTS: Perinatal iron deficiency causes changes in offspring mesenteric artery function in adulthood, particularly in males, which can be exacerbated by chronic intake of a high salt diet. Perinatal iron deficient male offspring exhibit enhanced conversion of big endothelin-1 to active endothelin-1, coinciding with decreased nitric oxide levels. Perinatal iron deficient male offspring have reduced nitric oxide-mediated endothelial-dependent vasodilatation coincident with increased vascular superoxide levels following consumption of a high salt diet. Perinatal iron deficiency has no apparent effects on vascular function in female offspring, even when fed a high salt diet. These results help us better understand underlying vascular mechanisms contributing to increased cardiovascular risk from perinatal stressors such as iron deficiency. ABSTRACT: Pre- and immediate postnatal stressors, such as iron deficiency, can alter developmental trajectories and predispose offspring to long-term cardiovascular dysfunction. Here, we investigated the impact of perinatal iron deficiency on vascular function in the adult offspring, and whether these long-term effects were exacerbated by prolonged consumption of a high salt diet in adulthood. Female Sprague Dawley rats were fed either an iron-restricted or -replete diet prior to and throughout pregnancy. Six weeks prior to experimentation at 6 months of age, adult offspring were fed either a normal or high salt diet. Mesenteric artery responses to vasodilators and vasoconstrictors were assessed ex vivo by wire myography. Male perinatal iron deficient offspring exhibited decreased reliance on nitric oxide with methacholine-induced vasodilatation (interaction P = 0.03), coincident with increased superoxide levels when fed the high salt diet (P = 0.01). Male perinatal iron deficient offspring exhibit enhanced big endothelin-1 conversion to active endothelin-1 (P = 0.02) concomitant with decreased nitric oxide levels (P = 0.005). Female offspring vascular function was unaffected by perinatal iron deficiency, albeit the high salt diet was associated with impaired vasodilation and decreased nitric oxide production (P = 0.02), particularly in the perinatal iron deficient offspring. These findings implicate vascular dysfunction in the sex-specific programming of cardiovascular dysfunction in the offspring by perinatal iron deficiency.

NRF2 activation with Protandim attenuates salt-induced vascular dysfunction and microvascular rarefaction.

HYPOTHESIS: This study tested the hypothesis that dietary activation of the master antioxidant and cell protective transcription factor nuclear factor, erythroid -2-like 2 (NRF2), protects against salt-induced vascular dysfunction by restoring redox homeostasis in the vasculature. METHODS: Male Sprague-Dawley rats and Syrian hamsters were fed a HS (4.0% NaCl) diet containing ~60 mg/kg/day Protandim supplement for 2 weeks and compared to controls fed HS diet alone. RESULTS: Protandim supplementation restoredendothelium-dependent vasodilation in response to acetylcholine (ACh) in middle cerebral arteries (MCA)of HS-fed rats and hamster cheek pouch arterioles, and increased microvessel density in the cremastermuscle of HS-fed rats. The restored dilation to ACh in MCA of Protandim-treated rats was prevented by inhibiting nitric oxide synthase (NOS) with L-NAME [100 µM] and was absent in MCA from Nrf2(-/-) knockout rats fed HS diet. Basilar arteries from HS-fed rats treated with Protandim exhibited significantly lower staining for mitochondrial oxidizing species than untreated animals fed HS diet alone; and Protandim treatment increased MnSOD (SOD2) protein expression in mesenteric arteries of HS-fed rats. CONCLUSIONS: These results suggest that dietary activation of NRF2 protects against salt-induced vascular dysfunction, vascular oxidative stress, and microvascular rarefaction by upregulating antioxidant defenses and reducing mitochondrial ROS levels.

Ginkgolide B ameliorates oxidized low-density lipoprotein-induced endothelial dysfunction via modulating Lectin-like ox-LDL-receptor-1 and NADPH oxidase 4 expression and inflammatory cascades.

The current study was undertaken to delineate the protective effect of Ginkgolide B, a phyto-constituent from Ginkgo biloba, on oxidized (ox)-LDL-induced endothelial dysfunction via targeting Lectin-like ox-LDL-receptor-1 (LOX-1), NADPH oxidase 4 (NOX-4), and other inflammatory proteins. Our results have shown that Ginkgolide B downregulated the expression of LOX-1 in ox-LDL-treated human umbilical vein endothelial cells (HUVECs) and RAW246.7 murine macrophages which ultimately resulted in decreased cholesterol deposits in HUVECs and RAW264.7. Moreover, Ginkgolide B suppressed the enhanced NOX4 expression, which was associated with attenuation of ROS generation in ox-LDL-stimulated HUVECs and RAW264.7 cells. Ginkgolide B also ameliorated the endothelial dysfunction by inhibiting the augmented expression of monocyte chemotactic protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in ox-LDL-activated HUVECs. Furthermore, the enhanced expression of many inflammatory cytokines in ox-LDL-induced RAW264.7 macrophages, both at transcription and protein level, was significantly down-regulated after Ginkgolide B treatment. Ginkgolide B also illustrated atheroprotective property via suppressing the augmented expression of matrix metalloproteinase-1 and cyclooxygenase-2 in ox-LDL-stimulated RAW264.7 macrophages. In summary, our study has established that Ginkgolide B ameliorates endothelial dysfunction via targeting LOX-1, NOX-4, MCP-1, ICAM-1, and VCAM-1 along with the markers associated with inflammatory cascades and thus could be promoted as a valuable therapeutic agent in prevention and management of atherosclerosis.

Treatment of Arsenite Intoxication-Induced Peripheral Vasculopathy with Mesenchymal Stem Cells.

Arsenite (As), a notorious toxic metal, is ubiquitously distributed in the earth and poses a serious threat to human health. Histopathological lesions of As intoxication are known as thromboangiitis obliterans, which are resistant to current treatment and often lead to lower limb amputation. In this study, we attempt to find that treatment with mesenchymal stem cells (MSCs) may be effective for As-induced vasculopathy. We first conducted an in vitro study with a co-culture system containing human MSCs and human umbilical vein endothelial cells (HUVECs) and treated individual and co-cultured cells with various concentrations of arsenite. We also designed an in vivo study in which Sprague Dawley (SD) rats received periodic intraperitoneal (IP) injections of 16 ppm arsenite for 12 weeks. MSCs were harvested from BALB/c mice that were transplanted via tail vein injection. We found that there was significantly higher cellular viability in human mesenchymal stem cells (hMSCs) than in HUVECs under concentrations of arsenite between 15 and 25 µM. The Annexin V apoptosis assay further confirmed this finding. Cytokine array assay for As-conditioned media revealed an elevated vascular endothelial growth factor (VEGF) level secreted by MSCs, which is crucial for HUVEC survival and was evaluated by an siRNA VEGF knockdown test. In the in vivo study, we demonstrated early apoptotic changes in the anterior tibial vessels of As-injected SD rats with a Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, but these apoptotic changes were less frequently observed upon MSCs transplantation, indicating that the cytoprotective effect of MSCs successfully protected against As-induced peripheral vasculopathy. The feasibility of MSCs to treat and /or prevent the progression of As-induced vasculopathy is justified. Further clinical studies are required to demonstrate the therapeutic efficacy of MSCs in patients suffering from As intoxication with vasculopathy.

NLRP3 Inflammasome Mediates Aldosterone-Induced Vascular Damage.

BACKGROUND: Inflammation is a key feature of aldosterone-induced vascular damage and dysfunction, but molecular mechanisms by which aldosterone triggers inflammation remain unclear. The NLRP3 inflammasome is a pivotal immune sensor that recognizes endogenous danger signals triggering sterile inflammation. METHODS: We analyzed vascular function and inflammatory profile of wild-type (WT), NLRP3 knockout (NLRP3-/-), caspase-1 knockout (Casp-1-/-), and interleukin-1 receptor knockout (IL-1R-/-) mice treated with vehicle or aldosterone (600 µg·kg-1·d-1 for 14 days through osmotic mini-pump) while receiving 1% saline to drink. RESULTS: Here, we show that NLRP3 inflammasome plays a central role in aldosterone-induced vascular dysfunction. Long-term infusion of aldosterone in mice resulted in elevation of plasma interleukin-1ß levels and vascular abnormalities. Mice lacking the IL-1R or the inflammasome components NLRP3 and caspase-1 were protected from aldosterone-induced vascular damage. In vitro, aldosterone stimulated NLRP3-dependent interleukin-1ß secretion by bone marrow-derived macrophages by activating nuclear factor-κB signaling and reactive oxygen species generation. Moreover, chimeric mice reconstituted with NLRP3-deficient hematopoietic cells showed that NLRP3 in immune cells mediates aldosterone-induced vascular damage. In addition, aldosterone increased the expression of NLRP3, active caspase-1, and mature interleukin-1ß in human peripheral blood mononuclear cells. Hypertensive patients with hyperaldosteronism or normal levels of aldosterone exhibited increased activity of NLRP3 inflammasome, suggesting that the effect of hyperaldosteronism on the inflammasome may be mediated through high blood pressure. CONCLUSIONS: Together, these data demonstrate that NLRP3 inflammasome, through activation of IL-1R, is critically involved in the deleterious vascular effects of aldosterone, placing NLRP3 as a potential target for therapeutic interventions in conditions with high aldosterone levels.

Normal saline is associated with increased sickle red cell stiffness and prolonged transit times in a microfluidic model of the capillary system.

OBJECTIVE: Vaso-occlusive crisis (VOC) is a complex process that occurs in patients with sickle cell disease (SCD) and is often associated with pain and urgent hospitalization. A major instigator of VOC is microvascular obstruction by pathologically stiffened sickle red blood cells (RBCs), and thus, therapy relies heavily on optimizing intravenous fluid (IVF) hydration to increase RBC deformability. However, no evidence-based guidelines regarding the choice of IVF currently exist. We therefore analyzed alterations in biomechanical properties of sickle RBCs isolated from patients with homozygous SCD (hemoglobin SS) after exposure to different osmolarities of clinical IVF formulations. METHODS: Atomic force microscopy (AFM) was used to assess stiffness of RBCs after exposure to different IVFs. A microfluidic model of the human capillary system was used to assess transit time (TT) and propensity to occlusion after exposure to the different IVF formulations. RESULTS: Sickle RBCs exposed to normal saline (NS) had increased stiffness, TTs, and propensity to microchannel occlusion compared to other osmolarities. CONCLUSION: NS, an IVF formulation often used to treat patients with SCD during VOC, may induce localized microvascular obstruction due to alterations of sickle RBC biomechanical properties.

Effect of long-term hydroxychloroquine on vascular events in patients with systemic lupus erythematosus: a database prospective cohort study.

Objectives: The incidence of thromboembolism in patients with SLE is higher than that in the general population. HCQ, widely used to treat lupus, may have vascular protective effects. The aim of this study was to determine whether long-term HCQ exposure is associated with decreased thromboembolism risk in SLE. Methods: We designed a prospective cohort study within an SLE population based on the National Health Insurance Research Database in Taiwan. We divided participants into HCQ and control groups according to HCQ prescription during the first year. These groups were defined by medication possession ratio (MPR) ⩾80% and MPR = 0%, respectively. Patients with an MPR between 0 and 80% were excluded. The primary outcome was a composite vascular event, including acute coronary syndrome, ischaemic stroke, pulmonary embolism, deep vein thrombosis and peripheral arterial disease 1 year after inclusion. We excluded patients from the cohort if they had outcomes within the first year. Results: A total of 8397 patients were eligible for analysis. After propensity-score matching, we included 1946 patients in each group. During a mean follow-up of 7.4 years, the number of events was 139 in the HCQ group (7.1%) and 149 in the control group (7.7%). The risk of vascular events in the HCQ group was similar to that in the control group (hazard ratio = 0.91; 95% CI: 0.72, 1.15). Further subgroup analyses confirmed no statistically significant differences between the groups. Conclusion: Long-term HCQ appears to have no vascular protective effect in patients with SLE.