Brd4 participates in epigenetic regulation of the extinction of remote auditory fear memory.

BACKGROUND: Inaccurate fear memories can be maladaptive and potentially portrait a core symptomatic dimension of fear adaptive disorders such as post-traumatic stress disorder (PTSD), which is generally characterized by an intense and enduring memory for the traumatic events. Evidence exists in support of epigenetic regulation of fear behavior. Brd4, a member of the bromodomain and extra-terminal domain (BET) protein family, serves as a chromatin "reader" by binding to histones in acetylated lysine residues, and hence promotes transcriptional activities. However, less is known whether Brd4 participates in modulating cognitive activities especially memory formation and extinction. Here we provide evidence for a role of Brd4 in modulation of auditory fear memory. Auditory fear conditioning resulted in a biphasic Brd4 activation in the anterior cingulate cortex (ACC) and hippocampus of adult mice. Thus, Brd4 phosphorylation occurred 6 h and 3-14 days, respectively, after auditory fear conditioning. Systemic inhibition of Brd4 with a BET inhibitor, JQ1, impaired the extinction of remote (i.e., 14 days after conditioning) fear memory. Further, conditional Brd4 knockout in excitatory neurons of the forebrain impaired remote fear extinction as observed in the JQ1-treated mice. Herein, we identified that Brd4 is essential for extinction of remote fear in rodents. These results thus indicate that Brd4 potentially plays a role in the pathogenesis of PTSD.

MicroRNA-126 alleviates endothelial cells injury in atherosclerosis by restoring autophagic flux via inhibiting of PI3K/Akt/mTOR pathway.

MicroRNAs (miRNAs) have emerged as critical modulators of ECs function and play a vital role in the development of cardiovascular disease. Among them, miR-126 is a crucial regulator of atherosclerosis. Endothelial cells (ECs) death and autophagy have been described in cells to cope with the progression of atherosclerosis. Hence, the aim of this study is to investigate the effects of miR-126 on atherosclerosis in oxidized low-density lipoprotein (ox-LDL)-stimulated human umbilical vein endothelial cells (HUVECs) and the potential roles of autophagy flux in these processes. Our results showed that miR-126 level was significantly reduced in ox-LDL-treated HUVECs and miR-126 overexpression induced by miR-126 mimics remarkably blocked ox-LDL-induced HUVECs injury as evidenced by the reduced cell viability, and the increased LDH release, caspase-3 activity and apoptosis ratio. In addition, ox-LDL increased LC3-II, Beclin 1, and p62 expressions in HUVECs, while these changes were nullified in the presence of treatment with bafilomycin A1 (BafA1, an inhibit autophagic flux inhibitor). However, we found that ox-LDL-induced impaired autophagy flux was recused by miR-126 mimics. Subsequently, we found that Bafi A1 pretreatment reversed the protection of miR-126 mimics against ox-LDL-induced HUVECs injury. Finally, our results showed that miR-126 mimics rescued ox-LDL-induced impaired autophagy flux through inhibiting PI3K/Akt/mTOR signaling. Taken together, our findings suggested that miR-126 alleviates ox-LDL-induced HUVECs injury through restoring autophagy flux via repressing PI3K/Akt/mTOR pathway, and further implicate the potential therapeutic targets to reverse atherosclerosis.

MicroRNA-21 suppresses ox-LDL-induced human aortic endothelial cells injuries in atherosclerosis through enhancement of autophagic flux: Involvement in promotion of lysosomal function.

Atherosclerosis is a common pathological basis of cardiovascular disease and remains the leading cause of mortality. Endothelial cell (EC) injury and autophagy dysfunction have been proved to contribute to the development of atherosclerosis. Recently, accumulating evidence confirms that microRNAs (miRNAs) have emerged as vital regulators and fine-tuners of various pathophysiological cellular impacts and molecular signaling pathways involved in atherosclerosis. Herein, the objective of the present study was to explore the biological function of miR-21 in oxidized low-density lipoprotein (ox-LDL)-induced human aortic endothelial cells (HAECs) injury and the underlying molecular mechanism. The results showed that ox-LDL treatment significantly decreased HAECs viability, increased caspase-3 activity, apoptosis ratio and Bax protein expression, and reduced Bcl-2 protein expression resulting in EC injuries. Simultaneously, ox-LDL treatment obviously reduced miR-21 level in a time-and dose-dependent manner. Notably, ox-LDL-induced EC injuries were abolished by miR-21 mimics transfection. In addition, miR-21 mimics alleviated ox-LDL-induced impaired autophagic flux as illustrated by the increases in LC3-II/LC3-I ratio and Beclin-1 protein expression, and the decrease in p62 protein expression in HAECs. Moreover, ox-LDL suppressed the expressions of lysosomal membrane protein (LAMP1) and cathepsin D proteins, and attenuated cathepsin D activity in HAECs, leading to lysosomal dysfunction, while these effects were also blocked by miR-21 mimics. These findings indicated that miR-21 restored impaired autophagic flux and lysosomal dysfunction, thereby attenuating ox-LDL-induced HAECs injuries.

[An improved method of electrode placement for ECG monitoring in children].

OBJECTIVE: This study examines the impacts of an improved electrode placement on the electrocardiogram (ECG) results in order to determine a better electrode placement for ECG monitoring in children. METHODS: ECG was recorded using the traditional electrode placement and the modified electrode placement (with shortened electrode distance) respectively in 50 pediatric patients. The amplitudes of P wave and QRS wave on ECG by the two measurements were compared. Furthermore, the impacts of different body positions on the amplitudes of P wave and QRS wave were studied after applying the modified electrode placement. RESULTS: There were no significant differences in the amplitudes of P wave and QRS wave on ECG by the traditional electrode placement and the modified electrode placement (P>0.05). When modified electrode placement was utilized, the body position change did not lead to significant changes in the amplitudes of P wave and QRS wave (P>0.05). CONCLUSIONS: A satisfactory ECG can be obtained with the modified electrode placement independent of patient's body position, suggesting that the modified electrode placement can be used instead of the traditional placement in children.

Involvement of anandamide transporter in calcitonin gene-related peptide expression stimulated by nitroglycerin and influence of ALDH2 Glu504Lys polymorphism.

The aim of this study was to investigate whether N-arachidonic acid ethanolamine (anandamide, AEA) transporter contributed to calcitonin gene-related peptide (CGRP) expression mediated by nitroglycerin (GTN) in peripheral blood mononuclear cells (PBMCs) of healthy volunteers and its association with the mitochondrial aldehyde dehydrogenase-2 (ALDH2) Glu504Lys (ALDH2*2) polymorphism. In 10 ALDH2*2-genotyped Chinese volunteers, we assessed the activity of AEA transporter and expression of CGRP messenger ribonucleic acid (mRNA) in cultured PBMCs treated with different concentration of GTN with or without pretreatment with AM404 (the AEA transporter blocker). In this study, the activity of AEA transporter and expression of CGRP mRNA elevated with the increase in the concentration of GTN. Pretreatment of the cells with AM404 (1 µM) 2 hours before GTN reduced the GTN-induced increase in both AEA transporter activity and CGRP mRNA expression significantly, and cells with the ALDH2*1/*1 homozygote genotype showed significantly higher activity of AEA transporter and CGRP mRNA expression than carriers of the ALDH2*2 allele. Therefore, we strongly suggested that GTN can stimulate CGRP expression by elevating the AEA transporter activity, which is affected by ALDH2 Glu504Lys polymorphism.

Influence of ALDH2 Glu504Lys polymorphism on nitroglycerin response in chronic heart failure and involvement of Calcitonin Gene Related Peptide (CGRP).

OBJECTIVE: The aim of this study was to investigate whether the neuropeptide calcitonin gene related peptide (CGRP) contributes to nitroglycerin (GTN) response in patients with chronic heart failure (CHF) and the association with the mitochondrial aldehyde dehydrogenase-2 (ALDH2) Glu504Lys (ALDH2*2) polymorphism. METHODS: This is a 2-period, placebo-controlled clinical study. An intravenous infusion of saline followed by GTN (20 µg/min), each for 2 hours, respectively, was given to 49 stable CHF patients. Blood pressure (BP), heart rate (HR) and respiratory rate (RR) were measured at baseline, at 10 min, 30 min, 1.0 h, 1.5 h, and 2.0 h after initiation of saline infusion and initiation of GTN therapy. Blood samples were drawn for the determination of plasma CGRP for 49 patients at baseline, and at 2.0 h after initiation of saline and GTN infusion, respectively. Global clinical status of the patients was evaluated. Left ventricular ejection (LVEF), left ventricular end-diastolic volume (LVEDV), stroke volume (SV) and cardiac output (CO) were measured with 2D echocardiography with Simpson's biplane method (Pillip HP sonos 5500) by the same investigator at baseline and at 2.0 h after initiation of saline and GTN infusion. RESULTS: Systolic blood pressure (SBP), diastolic blood pressure (DBP), and left ventricular end-diastolic volume (LVEDV) were decreased, while left ventricular ejection fraction (LVEF) was increased at the end of GTN infusion (p < 0.001, respectively). Saline infusion showed no hemodynamic effects. At the end of GTN infusion, ALDH2*1/*1 homozygous patients showed higher degrees of both the absolute decrease in SBP (DSBP) (p < 0.001) and increase in LVEF (p < 0.001) than carriers of the ALDH2*2 allele. Mean plasma concentration of CGRP was increased after GTN infusion (p < 0.001), but not changed after saline infusion (p > 0.05). Changes in plasma concentration of CGRP correlated positively with the improvement in LVEF (r = 0.400, p = 0.004), while correlated negatively with changes in SBP (r = -0.300, p = 0.036) and LVEDV (r = -0.290, p = 0.043). CONCLUSIONS: ALDH2*2 polymorphism is associated with contributions of CGRP to GTN response in CHF patients.

Effect of profilin-1 on the asymmetric dimethylarginine-induced vascular lesion-associated hypertension.

Previous studies have demonstrated that the levels of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide (NO) synthesis, are strongly associated with hypertension, diabetes, and cardiovascular diseases. Profilin-1, an actin-binding protein, has been documented to be involved in endothelial injury and in the proliferation of vascular smooth muscle cells resulting from hypertension. However, the role of profilin-1 in ADMA-induced vascular injury in hypertension remains largely unknown. Forty healthy subjects and forty-two matched patients with essential hypertension were enrolled, and the related indexes of vascular injury in plasma were detected. Rat aortic smooth muscle cells (RASMCs) were treated with different concentrations of ADMA for different periods of time and transfected with profilin-1 small hairpin RNA to interrupt the expression of profilin-1. To determine the role of the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway, RASMCs were pretreated with AG490 or rapamycin. The expression of profilin-1 was tested using real-time polymerase chain reaction (PCR) and western blot analysis. Cell proliferation was measured by flow cytometry and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazoliumbromide assays. Compared with healthy subjects, the levels of ADMA and profilin-1 were markedly elevated in hypertensive individuals, while the levels of NO were significantly decreased (p < 0.05). In vitro, studies showed ADMA-induced profilin-1 expression in a concentration- and time-dependent manner in RASMCs (p < 0.05), concomitantly with promoting the proliferation of RASMCs. Furthermore, ADMA-mediated proliferation of RASMCs and upregulation expression of profilin-1 were inhibited by blockade of the JAK2/STAT3 pathway or knockdown of profilin-1. Profilin-1 implicated in the ADMA-mediated vascular lesions in hypertension.

Soluble epoxide hydrolase: a promising therapeutic target for cardiovascular diseases.

Epoxyeicosatrienoic acids (EETs) are cytochrome P450 (CYP450) products of arachidonic acid and EETs are endogenous lipid mediators synthesized by the vascular endothelium which perform important biological functions, including vasodilation, anti-inflammation, antimigratory, and cellular signaling regulations. However, EETs are rapidly degraded by soluble epoxide hydrolase (sEH) to the corresponding diols: dihydroxyeicosatrienoic acids (DHETs), which have little active in causing vasorelaxation. A number of studies have supported that the inhibition of sEH (sEHIs) had cardiovascular protective effects in hypertension, cardiac hypertrophy, atherosclerosis, ischemia-reperfusion injury, and ischemic stroke. Moreover, sEHIs could slow the progression of inflammation, protect end-organ damage and prevent ischemic events, also, attenuate endothelial dysfunction, suggesting that the pharmacological blockade of sEH might provide a broad and novel avenue for the treatment of many cardiovascular diseases.

BET proteins inhibitor JQ-1 impaired the extinction of remote auditory fear memory: An effect mediated by insulin like growth factor 2.

Fear extinction is an important preclinical model for behavior therapy in human anxiety disorders, such as post-traumatic stress disorder (PTSD). Histone acetylation is involved in the extinction of fear memory. As the "readers" of histone acetylation markers, the role of the bromodomain and extraterminal domain (BET) proteins in fear extinction is still unclear. In the present study, we found that suppression of BET proteins using small molecule JQ-1 had no effects on the acquisition of auditory fear or on the extinction of recent auditory fear, but it impaired the extinction of remote auditory fear. We found that insulin like growth factor 2 (IGF-2) mRNA and protein were up-regulated in the anterior cingulate cortex (ACC) after the extinction training of remote fear memory, and that this effect was inhibited by JQ-1 administration. Further, the local delivery of IGF-2 protein to the ACC region rescued the impaired extinction of remote memory caused by JQ-1 administration, which suggesting IGF-2 mediates the effects of JQ-1 on remote memory extinction. Gene expression profiling analysis demonstrated that JQ-1 treatment inhibited the up-regulated expression of a key set of neuroplasticity-related genes following remote memory extinction. Together, these findings establish BET proteins as epigenetic mediator for the extinction of remote fear memory. In particular, the findings of this study imply that as a prospective preclinical cancer drug, JQ-1 (or other BET bromodomain inhibitors) should be modified to prevent it from crossing the blood brain barrier and causing neurological side effects.

Role of insulin-like growth factor-1 (IGF-1) in regulating cell cycle progression.

AIMS: Insulin-like growth factor-1 (IGF-1) is a polypeptide protein hormone, similar in molecular structure to insulin, which plays an important role in cell migration, cell cycle progression, cell survival and proliferation. In this study, we investigated the possible mechanisms of IGF-1 mediated cell cycle redistribution and apoptosis of vascular endothelial cells. METHOD: Human umbilical vein endothelial cells (HUVECs) were pretreated with 0.1, 0.5, or 2.5 microg/mL of IGF-1 for 30 min before the addition of Ang II. Cell cycle redistribution and apoptosis were examined by flow cytometry. Expression of Ang II type 1 (AT(1)) mRNA and cyclin E protein were determined by RT-PCR and Western blot, respectively. RESULTS: Ang II (1 micromol/L) induced HUVECs arrested at G(0)/G(1), enhanced the expression level of AT(1) mRNA in a time-dependent manner, reduced the enzymatic activity of nitric oxide synthase (NOS) and nitric oxide (NO) content as well as the expression level of cyclin E protein. However, IGF-1 enhanced NOS activity, NO content, and the expression level of cyclin E protein, and reduced the expression level of AT(1) mRNA. L-NAME significantly counteracted these effects of IGF-1. CONCLUSIONS: Our data suggests that IGF-1 can reverse vascular endothelial cells arrested at G(0)/G(1) and apoptosis induced by Ang II, which might be mediated via a NOS-NO signaling pathway and is likely associated with the expression levels of AT1 mRNA and cyclin E proteins.

Losartan inhibits monocytic adhesion induced by ADMA via downregulation of chemokine receptors in monocytes.

OBJECTIVE: Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase (NOS) inhibitor, can induce the adhesiveness of monocytes to vascular endothelium, and chemokines play an important role in this process. The present study was carried out to test whether the inhibitory effect of losartan on ADMA-induced monocytic adhesion is mediated by chemokine receptors. METHODS: Human monocytoid cells (THP-1) were incubated with exogenous ADMA (30 microM) for 4 or 24 h in the absence or presence of losartan. The monocytic adhesion, the levels of chemokines, and the expression of chemokine receptors were determined. The possible signal pathway was also explored. RESULTS: In cultured monocytes, ADMA (30 microM) markedly increased monocytic adhesion to endothelial cells, elevated the levels of monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8), and upregulated the mRNA expression of chemokine receptors CCR2 and CXCR2. Exposure to ADMA (30 microM) significantly induced the generation of intracellular reactive oxygen species (ROS) and activation of nuclear factor (NF)-kappaB. Pretreatment with AT1 receptor blocker (ARB) losartan (1, 3, 10 microM) attenuated monocytic adhesiveness elicited by ADMA and downregulated the expression of CCR2 and CXCR2 mRNA, accompanied by a significant decrease in ROS generation and NF-kappaB activity and expression. CONCLUSION: The present study suggests that the inhibitory effect of losartan on ADMA-induced monocytic adhesion may be related to downregulation of chemokine receptors by inhibiting the ROS/NF-kappaB pathway.

Involvement of the MiR-181b-5p/HMGB1 Pathway in Ang II-induced Phenotypic Transformation of Smooth Muscle Cells in Hypertension.

Phenotypic transformation of vascular smooth muscle cells (VSMCs) contributes to vascular remodeling in hypertension. High mobility group box-1 (HMGB1) has been reported to be involved in several pathogenic processes including VSMC proliferation and migration. The present study was designed to determine the role of HMGB1 in VSMC phenotypic transformation in hypertension. First, we demonstrated that HMGB1 was elevated in a model of Ang II-induced VSMC phenotypic transformation, which showed down-regulation of contractile proteins and up-regulation of synthetic proteins. Knockdown of HMGB1 and losartan could block the phenotypic transformation. Next, we identified three potential miRNAs for upstream regulation of HMGB1 by bioinformatic analysis; only miR-181b-5p was significantly down-regulated in Ang II-treated cells. Co-treating the cells with miR-181b-5p mimics suppressed HMGB1 expression as well as the phenotypic transformation, migration, and proliferation. Furthermore, the luciferase reporter gene assay confirmed the direct interaction between miR-181b-5p and HMGB1. Finally, to extend these cell-based studies to clinical patients, we demonstrated that plasma miR-181b-5p levels were decreased, while Ang II and HMGB1 levels, as well as the intima-media thickness (IMT) were increased in hypertensive patients; these effects were reversed following the administration of angiotensin receptor blockers. Based on these observations, we conclude that the down-regulation of miR-181b-5p leads to the elevation of HMGB1 levels in hypertensive patients, which accounts, at least partially, for VSMCs phenotypic transformation and vascular remodeling. Our findings also highlight that the plasma levels of miR-181b-5p and HMGB1 may serve as novel biomarkers for vascular remodeling in the hypertensive patients.

Association of CALCA genetic polymorphism with essential hypertension.

BACKGROUND: Calcitonin gene-related peptide (CGRP) is the predominant neurotransmitter in capsaicin-sensitive sensory nerves. Participation of CGRP in hypertension is one of the most extensively studied topics in the field. There is growing evidence to the effect that CGRP is associated with essential hypertension (EH). The aims of this study were to pinpoint whether single nucleotide polymorphisms (SNPs) in the genes coding for CALCA were associated with EH susceptibility in a Hunan Han population. METHODS: A total of 293 subjects with EH and 208 controls were enrolled in the study. Genomic DNA was extracted from peripheral blood leucocytes by a phenol-chloroform method. The CALCA T-692C was genotyped using a restriction fragment length polymorphism method. RESULTS: A statistically significant difference in CALCA T-692C genotypic distribution was observed between cases and controls (P=0.001). Moreover, the frequencies of the C allele were 14.85% in the EH group and 7.45% in the control group, prevalence of C alleles in EH subjects and controls was significantly incomparable (P<0.001). Furthermore, the results of Logistic regression analysis showed that the carriers of C allele (TC+CC genotypes) were associated with increased EH risk (OR=2.093, 95% CI: 1.317-3.326, P<0.01). CONCLUSIONS: CALCA genetic polymorphism is associated with EH susceptibility. Carriers of at least one C allele at the polymorphic site CALCA T-692C showed increased risk for EH.

[Transthoracic echocardiography in transcatheter closure of atrial septal aneurysm combined with secoundum-type atrial septal defect].

OBJECTIVE: To explore the value of transthoracic echocardiography (TTE) in transcatheter closure of atrial septal aneurysm (ASA) combined with secoundum-type atrial septal defect (ASD). METHODS: Fourteen patients (3 males and 11 females) who had ASA combined with secoundum-type ASD were diagnosed by TTE or transesophageal echocardiography. The ASA projected to the right atrium in all patients. The width of basilar part was 13 approximately 24 (18.5+/-3.9) mm, and the vertical extent was 7 approximately 11(9.7+/-1.8) mm. Ten patients combined with single hole ASD and 4 patients with multiple hole ASD. Blood shifting from the left atrium to the right atrium was displayed in color Doppler in all patients. All patients were treated by transcatheter closure under the guiding of X fluoroscopy and TTE, and examined with TTE during the follow-up. RESULTS: Transcatheter closure was successfully performed by 14 occluders in all patients. No residual shunt was detected immediately by TTE after the procedure in all patients. During the 6 approximately 12 month follow-up, no residual shunt or occluder shifting was found, the dimensions of the heart became normal in 11 patients (79%) and were significantly decreased in 4. CONCLUSION: Transcatheter closure is feasible in patients with ASA combined with secoundum-type ASD, and extra attention must be paid to the specialty. TTE is very important in case selection before transcatheter closure, and it may be used to monitor and guide the procedure during transcatheter closure.

Isorhamnetin protects against hypoxia/reoxygenation-induced injure by attenuating apoptosis and oxidative stress in H9c2 cardiomyocytes.

To unveil the possible protective role of isorhamnetin, an immediate 3'-O-methylated metabolite of quercetin, in cardiomyocyte under hypoxia/reoxygenation (H/R) condition and the underlying mechanisms involved, H9c2 cardiomyocytes were exposed to the vehicle or H/R for 6 h (2 h of hypoxia following by 4 h of reoxygenation) with isorhamnetin (0, 3, 6, 12, 25, 50 µM for 4 h prior to H/R exposure). Apoptosis was evaluated by TUNEL staining, flow cytometry analysis and western blot assay for cleaved caspase-3. Myocardial injure in vivo was determined by infarct size using TTC staining, histological damage using H&E staining and myocardial apoptosis. Here, we found that isorhamnetin dose-dependently protected H9c2 cardiomyocytes against H/R-induced injure, as evidenced by the reduction in lactate dehydrogenase (LDH) levels, increases in cell viability, superoxide dismutase (SOD) and catalase (CAT) activity, with the maximal effects at 25 µΜ. In addition, isorhamnetin treatment significantly inhibited apoptosis in H/R-induced H9c2 cardiomyocytes and ameliorated H/R-induced myocardial injure in vivo, concomitant with the upregulation of sirtuin 1 (SIRT1) expression. Mechanism studies demonstrated that isorhamnetin pretreatment remarkably abolished H/R-induced downregulation of Nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expressions and upregulation of NADPH oxidase-2/4 (NOX-2/4) expressions in cardiomyocytes. However, SIRT1 inhibition (Sirtinol) not only inhibited isorhamnetin-induced Nrf2/HO-1 upregulation and NOX-2/4 downregulation, but also alleviated its anti-apoptotic effects. Taken together, these data indicate that isorhamnetin can exhibit positive effect on H/R-induced injure by attenuating apoptosis and oxidative stress in H9c2 cardiomyocytes, which is partly attributable to the upregulation of SIRT1 and Nrf2/HO-1-mediated antioxidant signaling pathway.

Role of asymmetric dimethylarginine in inflammatory reactions by angiotensin II.

Previous investigations have demonstrated that angiotensin (Ang) II induces inflammatory reactions and asymmetric dimethylarginine (ADMA), an endogenous NOS inhibitor, might be a novel inflammatory factor. Endothelial cell activation was induced by incubation with Ang II or ADMA. Incubation with Ang II (10(-6) M) for 24 h elevated the levels of ADMA and decreased the levels of nitrite/nitrate concomitantly with a significant increase in the expression of protein arginine methyltransferase and a decrease in the activity of dimethylarginine dimethylaminohydrolase (DDAH). Exposure to Ang II (10(-6) M for 24 h) also enhanced intracellular ROS elaboration and the levels of tumor necrosis factor (TNF)-alpha and interleukin (IL)-8, upregulated chemokine receptor CXCR2 mRNA expression, increased adhesion of endothelial cells to monocytes and induced a significant increase in the activity of nuclear factor (NF)-kappaB, which was attenuated by pretreatment with the Ang II receptor blocker losartan (1, 3 and 10 muM). Exogenous ADMA (30 microM) also increased ROS generation and the levels of TNF-alpha and IL-8, decreased the levels of nitrite/nitrate, upregulated CXCR2 gene expression, increased endothelial cell binding with monocytes and activated the NF-kappaB pathway, which was inhibited by pretreatment with losartan or L-arginine. These data suggest that ADMA is a potential proinflammatory factor and may be involved in the inflammatory reaction induced by Ang II.

[Effects of Tongxinluo on cell viability and tissue factor in AngII induced vascular endothelial cells].

OBJECTIVE: To determine the effects of Tongxinluo on cell viability and tissue factor (TF) in AngII induced vascular endothelial cells and to investigate its mechanism. METHODS: AngII(10(-6)mol/L) was added to human vascular endothelial cells (HUVECs) culture media alone or with various concentration of Tongxinluo drug containing plasma (5%,10%, and 20%) added 30 minutes before AngII. Cell viability was evaluated after 24-hour incubation with AngII in a dose manner. TF, AngII type 1 receptor (AT(1)) mRNA, NO synthase (NOS) and NO were observed after 24-hour incubation with AngII. In addition, NOS inhibitor nomega-nitro-larginine (L-NAME) was added 30 minutes before Tongxinluo and AngII. Cell viability, TF, AT(1)mRNA, the level of NOS and NO were evaluated after 24-hour incubation with Tongxinluo and AngII. RESULTS: Tongxinluo significantly improved AngII induced endothelial cell viability and the effect was the most obvious at 10%. Tongxinluo (10%) decreased the TF and AT(1) mRNA while increased the NOS and NO levels. L-NAME obviously inhibited the effects of Tongxinluo on cell viability, TF, AT(1) mRNA, and NOS and NO levels. CONCLUSION: Up-regulating NOS-NO signaling may be the mechanism of Tongxinluo on cell viability and TF in AngII induced vacular endothelial cells.