The Correlation Between Whole Blood Copper (Cu), Zinc (Zn) Levels and Cu/Zn Ratio and Sepsis-Induced Left Ventricular Systolic Dysfunction (SILVSD) in Patients with Septic Shock: A Single-Center Prospective Observational Study.

PURPOSE: This study aimed to explore relationships between whole blood copper (Cu), zinc (Zn) and Cu/Zn ratio and cardiac dysfunction in patients with septic shock. SUBJECTS AND METHODS: Between April 2018 and March 2020, septic shock patients with sepsis-induced left ventricular systolic dysfunction (SILVSD, left ventricular ejection fraction, LVEF<50%) and with no sepsis-induced myocardial dysfunction (non-SIMD, septic shock alone and LVEF>50%) and controls were prospectively enrolled. Whole blood Cu and Zn levels were measured using flame atomic absorption spectrophotometry. RESULTS: Eighty-six patients with septic shock including both 41 SILVSD and 45 non-SIMD and 25 controls were studied. Whole blood Cu levels and Cu/Zn ratio were significantly higher and Zn levels were lower in SILVSD compared with non-SIMD and controls (Cu, p=0.009, <0.001; Zn, p=0.029, <0.001; Cu/Zn ratio, p=0.003, <0.001). Both increased whole blood Cu and Cu/Zn ratio and reduced Zn were associated with lower LVEF (all p<0.001) and higher amino-terminal pro-B-type natriuretic peptide (NT-proBNP) (Cu, p=0.002; Zn, p<0.001; Cu/Zn ratio, p<0.001) and had predictive values for SILVSD (Cu, AUC=0.666, p=0.005; Zn, AUC=0.625, p=0.039; Cu/Zn ratio, AUC=0.674, p=0.029). Whole blood Cu levels and Cu/Zn ratio were increased but Zn levels were reduced in non-survivors compared with survivors (Cu, p<0.001; Zn, p<0.001; Cu/Zn ratio, p<0.001). Whole blood Cu and Zn displayed the value of predicting 28-day mortality (Cu, AUC = 0.802, p<0.001; Zn, AUC=0.869, p<0.001; Cu/Zn ratio, AUC=0.902, p<0.001). CONCLUSION: Findings of the study suggest that whole blood Cu levels and Cu/Zn ratio are increased in SILVSD patients and positively correlated with cardiac dysfunction, while whole blood Zn levels are reduced and negatively associated with cardiac dysfunction. Moreover, both whole blood Cu, Zn and Cu/Zn ratio might distinguish between SILVSD and non-SIMD in septic shock patients and predict 28-day mortality. TRIAL REGISTRATION: Registered at http://www.chictr.org.cn/ChiCTR1800015709.

Identification and Functional Prediction of Long Non-Coding RNAs in Dilated Cardiomyopathy by Bioinformatics Analysis.

Dilated cardiomyopathy (DCM) is a relatively common cause of heart failure and the leading cause of heart transplantation. Aberrant changes in long non-coding RNAs (lncRNAs) are involved in DCM disorder; however, the detailed mechanisms underlying DCM initiation and progression require further investigation, and new molecular targets are needed. Here, we obtained lncRNA-expression profiles associated with DCM and non-failing hearts through microarray probe-sequence re-annotation. Weighted gene co-expression network analysis revealed a module highly associated with DCM status. Then eight hub lncRNAs in this module (FGD5-AS1, AC009113.1, WDFY3-AS2, NIFK-AS1, ZNF571-AS1, MIR100HG, AC079089.1, and EIF3J-AS1) were identified. All hub lncRNAs except ZNF571-AS1 were predicted as localizing to the cytoplasm. As a possible mechanism of DCM pathogenesis, we predicted that these hub lncRNAs might exert functions by acting as competing endogenous RNAs (ceRNAs). Furthermore, we found that the above results can be essentially reproduced in an independent external dataset. We observed the localization of hub lncRNAs by RNA-FISH in human aortic smooth muscle cells and confirmed the upregulation of the hub lncRNAs in DCM patients through quantitative RT-PCR. In conclusion, these findings identified eight candidate lncRNAs associated with DCM disease and revealed their potential involvement in DCM partly through ceRNA crosstalk. Our results facilitate the discovery of therapeutic targets and enhance the understanding of DCM pathogenesis.

A Variant in the Nicotinic Acetylcholine Receptor Alpha 3 Subunit Gene Is Associated With Hypertension Risks in Hypogonadic Patients.

Ephb6 gene knockout causes hypertension in castrated mice. EPHB6 controls catecholamine secretion by adrenal gland chromaffin cells (AGCCs) in a testosterone-dependent way. Nicotinic acetylcholine receptor (nAChR) is a ligand-gated Ca2+/Na+ channel, and its opening is the first signaling event leading to catecholamine secretion by AGCCs. There is a possibility that nAChR might be involved in EPHB6 signaling, and thus sequence variants of its subunit genes are associated with hypertension risks. CHRNA3 is the major subunit of nAChR used in human and mouse AGCCs. We conducted a human genetic study to assess the association of CHRNA3 variants with hypertension risks in hypogonadic males. The study cohort included 1,500 hypogonadic Chinese males with (750 patients) or without (750 patients) hypertension. The result revealed that SNV rs3743076 in the fourth intron of CHRNA3 was significantly associated with hypertension risks in the hypogonadic males. We further showed that EPHB6 physically interacted with CHRNA3 in AGCCs, providing a molecular basis for nAChR being in the EPHB6 signaling pathway.

MicroRNA­125a­mediated regulation of the mevalonate signaling pathway contributes to high glucose­induced proliferation and migration of vascular smooth muscle cells.

Hyperglycemia contributes to the excessive proliferation and migration of vascular smooth muscle cells (VSMC), which are closely associated with atherosclerosis. MicroRNAs (miRNAs/miRs) constitute a novel class of gene regulators, which have important roles in various pathological conditions. The aim of the present study was to identify miRNAs involved in the high glucose (HG)­induced VSMC phenotype switch, and to investigate the underlying mechanism. miRNA sequencing and reverse transcription­quantitative PCR results indicated that inhibition of miR­125a expression increased the migration and proliferation of VSMCs following HG exposure, whereas the overexpression of miR­125a abrogated this effect. Furthermore, dual­luciferase reporter assay results identified that 3­hydroxy­3-methyglutaryl­coA reductase (HMGCR), one of the key enzymes in the mevalonate signaling pathway, is a target of miR­125a. Moreover, HMGCR knockdown, similarly to miR­125a overexpression, suppressed HG­induced VSMC proliferation and migration. These results were consistent with those from the miRNA target prediction programs. Using a rat model of streptozotocin­induced diabetes mellitus, it was demonstrated that miR­125a expression was gradually downregulated, and that the expressions of key enzymes in the mevalonate signaling pathway in the aortic media were dysregulated after several weeks. In addition, it was found that HG­induced excessive activation of the mevalonate signaling pathway in VSMCs was suppressed following transfection with a miR­125a mimic. Therefore, the present results suggest that decreased miR­125a expression contributed to HG­induced VSMC proliferation and migration via the upregulation of HMGCR expression. Thus, miR­125a­mediated regulation of the mevalonate signaling pathway may be associated with atherosclerosis.

Comparison of transesophageal echocardiography findings after different anticoagulation strategies in patients with atrial fibrillation: a systematic review and meta-analysis.

BACKGROUND: High risk of embolic events exists in both patients with chronic atrial fibrillation (AF) and patients in the perioperative period of ablation (effective treatment for AF). Therefore, anticoagulant therapy is important. Oral anticoagulants can be divided into two major categories: vitamin K antagonists (VKAs) and non-vitamin K antagonist oral anticoagulants (NOACs). VKAs, represented by warfarin, have been widely used as traditional anticoagulants, whereas NOACs have been used in clinical practice, but their anticoagulant effects and side effects are still the focus of research. We used a meta-analysis to compare the incidence of left atrial thrombi (LAT) between different anticoagulants. METHODS: We searched PubMed, EMBASE, Web of Science, and the Cochrane Library databases for observational studies that compared the transesophageal echocardiography (TEE) findings for patients treated with NOACs and VKAs. The incidence of LAT and dense spontaneous echocardiographic contrast (dense SEC) were extracted as the basis of the meta-analysis. RESULTS: Fifteen studies were included in the meta-analysis. We found that patients anticoagulated with NOACs and VKAs had similar incidence of LAT (OR = 0.74, 95%CI: 0.55-1.00). After excluding the heterogeneous article by sensitivity analysis, we found the incidence of LAT in patients anticoagulated with NOACs is lower than VKAs (OR = 0.59, 95%CI: 0.42-0.84). The results of subgroup analysis showed that the incidence of LAT among three types of NOACs have no significant difference (dabigatran vs. rivaroxaban, OR = 1.16 [0.75, 1.81]; rivaroxaban vs. apixaban, OR = 0.97 [0.54, 1.74]; dabigatran vs. apixaban, OR = 1.09 [0.55, 2.16]). CONCLUSION: Patients anticoagulated with NOACs may have lower incidence of LAT than VKAs. The incidence of LAT among different type of NOACs are similar.

Analysis of the association of EPHB6, EFNB1 and EFNB3 variants with hypertension risks in males with hypogonadism.

Several members of the EPH kinase family and their ligands are involved in blood pressure regulation, and such regulation is often sex- or sex hormone-dependent, based on animal and human genetic studies. EPHB6 gene knockout (KO) in mice leads to hypertension in castrated males but not in un-manipulated KO males or females. To assess whether this finding in mice is relevant to human hypertension, we conducted a human genetic study for the association of EPHB6 and its two ligands, EFNB1 and EFNB3, with hypertension in hypogonadic patients. Seven hundred and fifty hypertensive and 750 normotensive Han Chinese patients, all of whom were hypogonadic, were genotyped for single nucleotide polymorphisms (SNPs) within the regions of the genes, plus an additional 50 kb 5' of the genes for EPHB6, EFNB1 and EFNB3. An imputed insertion/deletion polymorphism, rs35530071, was found to be associated with hypertension at p-values below the Bonferroni-corrected significance level of 0.0024. This marker is located 5' upstream of the EFNB3 gene start site. Previous animal studies showed that while male EFNB3 gene knockout mice were normotensive, castration of these mice resulted in hypertension, corroborating the results of the human genetic study. Considering the significant associations of EFNB3 SNPs with hypertension in hypogonadic males and supporting evidence from castrated EFNB3 KO mice, we conclude that loss-of-function variants of molecules in the EPHB6 signaling pathway in the presence of testosterone are protective against hypertension in humans.

The Role of RhoA in Neovascular-Related Functions of Endothelial Progenitor Cells Induced by Angiotensinâ ¡.

BACKGROUND/AIMS: Interference with endothelial progenitor cell (EPC) neovascularization is a novel therapeutic target for neovascular-related diseases. Angiotensin Ⅱ (Ang Ⅱ) was found to enhance new vessel formation and aggravated neovascular-related diseases. In this study, we investigated the effects of Ang Ⅱ on EPC neovascular-related functions and explored the underlying mechanisms. METHODS: EPCs were cultured from bone marrow derived mononuclear cells. The effects of Ang Ⅱ on EPC proliferation, adhesion, migration, and in vitro tube formation were investigated using the MTT assay, adhesion assay, transwell chamber assay, and in vitro tube formation assay respectively. The underlying mechanisms were explored using Western blotting assay. RESULTS: EPC adhesion, migration and in vitro tube formation were promoted by Ang Ⅱ, and the effects were reversed by RhoA/Rho-associated kinases (ROCK) signaling pathway inhibitors including C3 exoenzyme, GGTI-286 and Y-27632. The active form of RhoA was up-regulated by Ang Ⅱ and this effect was abolished by C3 exoenzyme. Moreover, RhoA silencing resulted in a notable inhibition of EPC adhesion, migration and in vitro tube formation, suggesting that RhoA activation played a pivotal role in Ang Ⅱ angiogenic effect. The results also demonstrated that phosphorylation of p38 mitogen-activated protein kinase (MAPK) and c-Jun-NH2 kinase was elevated by Ang Ⅱ and attenuated by C3 exoenzyme, GGTI-286 and Y-27632. The enhancing effects of Ang Ⅱ on EPC adhesion, migration and in vitro vasculogenesis were reversed by p38 inhibitor SB202190 and JNK inhibitor SP600125. CONCLUSION: Ang Ⅱ may enhance EPC neovascular-related functions through activating RhoA/ ROCK and MAPK signaling pathway.

Risk analysis of new oral anticoagulants for gastrointestinal bleeding and intracranial hemorrhage in atrial fibrillation patients: a systematic review and network meta-analysis.

BACKGROUND: Antithrombotic therapy using new oral anticoagulants (NOACs) in patients with atrial fibrillation (AF) has been generally shown to have a favorable risk-benefit profile. Since there has been dispute about the risks of gastrointestinal bleeding (GIB) and intracranial hemorrhage (ICH), we sought to conduct a systematic review and network meta-analysis using Bayesian inference to analyze the risks of GIB and ICH in AF patients taking NOACs. METHODS: We analyzed data from 20 randomized controlled trials of 91 671 AF patients receiving anticoagulants, antiplatelet drugs, or placebo. Bayesian network meta-analysis of two different evidence networks was performed using a binomial likelihood model, based on a network in which different agents (and doses) were treated as separate nodes. Odds ratios (ORs) and 95% confidence intervals (CIs) were modeled using Markov chain Monte Carlo methods. RESULTS: Indirect comparisons with the Bayesian model confirmed that aspirin+clopidogrel significantly increased the risk of GIB in AF patients compared to the placebo (OR 0.33, 95% CI 0.01-0.92). Warfarin was identified as greatly increasing the risk of ICH compared to edoxaban 30 mg (OR 3.42, 95% CI 1.22-7.24) and dabigatran 110 mg (OR 3.56, 95% CI 1.10-8.45). We further ranked the NOACs for the lowest risk of GIB (apixaban 5 mg) and ICH (apixaban 5 mg, dabigatran 110 mg, and edoxaban 30 mg). CONCLUSIONS: Bayesian network meta-analysis of treatment of non-valvular AF patients with anticoagulants suggested that NOACs do not increase risks of GIB and/or ICH, compared to each other.

Abnormal expression of long non-coding RNAs in myocardial infarction.

Myocardial infarction (MI) is the leading cause of fatality worldwide. Our study aimed to investigate the dysregulated long non-coding RNA (lncRNA) in MI and elucidate the mechanism of it in MI. The lncRNA and mRNA expression profiling of the whole left ventricular tissue of MI mice model (8 mice) and Sham group (8 mice) was obtained based on microarray analysis. Differentially expressed lnRNAs/mRNA (DELs/DEMs) were identified in MI. DELs/DEMs co-expression network construction, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were conducted to predict the biological functions of DEMs. Quantitative real-time polymerase chain reaction (qRT-PCR) was subjected to validate the abnormally expressed DELs in left ventricular tissues of MI mice model. Total of 168 DELs (37 up- and 131 down-regulated) and 126 DEMs (87 up- and 39 down-regulated) were identified in MI compared with Sham group. The co-expression network of candidate DELs and DEMs was constructed, which covered 219 nodes and 1775 edges. The qRT-PCR validation results indicated that ENSMUST00000124047 was significantly down-regulated in MI group and AK166279 was significantly up-regulated in MI group. ENSMUST00000121611 and NR_015515 had the up-regulated tendency in MI group compared with Sham group. The DEMs in MI were significantly enriched in 41 signaling pathways including complement and coagulation cascades, cytokine-cytokine receptor interaction and chemokine signaling pathway. The expression profiling of dysregulated DELs in MI was identified. Our results might provide useful information for exploring the pathogenesis mechanism of MI.

Congenital giant left atrial appendage aneurysm: a case report.

BACKGROUND: Congenital left atrial appendage aneurysm (LAAA) is a rare cardiac anomaly with potentially serious complications, including life-threatening systemic thromboembolism, atrial tachyarrhythmia, and cardiac dysfunction. Currently, early surgical intervention is generally recommended to prevent these complications. CASE PRESENTATION: We present a case of congenital giant LAAA in a female patient who successfully completed pregnancy and underwent caesarean section with no obvious complications. Surgical resection of the LAAA was performed 3 years later, at the onset of chest pain resulting from compression of adjacent cardiac structures by the LAAA. CONCLUSION: Surgical resection is recommended for the majority of patients with LAAA because of potential LAAA-related severe outcomes. However, clinical monitoring may be an optional strategy for asymptomatic patients without intra-atrial thrombus or other complications. Precise evaluation with echocardiography and brain magnetic resonance imaging is valuable for the subsequent management of LAAA.

Inhibition of farnesyl pyrophosphate synthase improves pressure overload induced chronic cardiac remodeling.

Farnesyl pyrophosphate synthase (FPPS) is a key enzyme in the mevalonate pathway. In our previous studies, we find that inhibition of FPPS attenuates angiotensin II-induced cardiac hypertrophy and fibrosis by suppressing RhoA while FPPS and Ras are up-regulated in pressure overload rats. In this study, we evaluate the effects and mechanisms of FPPS inhibition in pressure overload mice. Male FPPS-small interfering RNA (SiRNA) transgenic (Tg) mice and non-transgenic littermate control (NLC) were randomly divided into suprarenal abdominal aortic constriction (AAC) group and sham operation group. 12 weeks following AAC, mice were sacrificed by cervical dislocation. Histological and echocardiographic assessments showed that inhibition of FPPS improved chronic cardiac remodeling which was induced by AAC. The reductions of Ras farnesylation and GTP-Ras, as well as their downstream extracellular signal-related kinases 1/2 (ERK1/2) expression were observed in the heart of Tg-AAC mice compared with NLC-AAC mice, along with the reduction of fetal gene expression. We provide here important experimental evidence that inhibition of FPPS improves AAC induced chronic cardiac remodeling and fibrosis by the reduction of farnesylated Ras and the downregulation of Ras-ERK1/2 pathway.

Farnesyl pyrophosphate synthase inhibitor, ibandronate, improves endothelial function in spontaneously hypertensive rats.

Reactive oxygen species (ROS), originating predominantly from vascular smooth muscle cells (VSMCs), lead to vascular damage and endothelial dysfunction in rats with hypertension. The downstream signaling pathways of farnesyl pyrophosphate (FPP) synthase, Ras-related C3 botulinum toxin substrate 1 (Rac1) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, mediate the generation of ROS. The present study investigated the effect of the FPP synthase inhibitor, ibandronate, on ROS production, the possible beneficial effect on endothelial dysfunction and the underlying mechanisms in spontaneously hypertensive rats (SHRs). The SHRs were treated with ibandronate for 30 days. Endothelium­dependent and independent vasorelaxation were measured in isolated aortic rings. Additionally, VSMCs from the SHRs and Wistar­Kyoto (WKY) rats were cultured. The production of ROS and activation of NADPH oxidase were determined using fluorescence and chemiluminescence, respectively, in vivo and in vitro. Angiotensin II (Ang II) increased ROS production in the cultured VSMCs from the WKY rats and SHRs, in a concentration­dependent manner. The Ang II­induced responses were more marked in the SHR VSMCs, compare with those in the WKY VSMCs, however, the response decreased significantly following ibandronate pretreatment. Treatment with ibandronate significantly decreased the production of ROS, translocation of NADPH oxidase subunit p47phox, and activities of NADPH oxidase and Rac1 in the aorta and VSMCs, and improved the impaired endothelium­dependent vasodilation in the SHRs. Adding geranylgeraniol, but not farnesol or mevalonate, reversed the inhibitory effects of ibandronate. In addition, inhibiting geranylgeranyl-transferase mimicked the effect of ibandronate on the excess oxidative response. Ibandronate exerted cellular antioxidant effects through the Rac1/NADPH oxidase pathway. These effects may have contributed to the vasoprotective effects on the impaired endothelium in SHRs.

Heart failure: advanced development in genetics and epigenetics.

Heart failure (HF) is a complex pathophysiological syndrome that arises from a primary defect in the ability of the heart to take in and/or eject sufficient blood. Genetic mutations associated with familial dilated cardiomyopathy, hypertrophic cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy can contribute to the various pathologies of HF. Therefore, genetic screening could be an approach for guiding individualized therapies and surveillance. In addition, epigenetic regulation occurs via key mechanisms, including ATP-dependent chromatin remodeling, DNA methylation, histone modification, and RNA-based mechanisms. MicroRNA is also a hot spot in HF research. This review gives an overview of genetic mutations associated with cardiomyopathy and the roles of some epigenetic mechanisms in HF.

Lentiviral-mediated silencing of farnesyl pyrophosphate synthase through RNA interference in mice.

Farnesyl pyrophosphate synthase (FPPS) plays a vital role in the mevalonate pathway and has been shown to be involved in hypertrophy and cardiovascular diseases. Lentivirus-mediated RNA interference (RNAi) to knock down a gene of interest has become a promising new tool for the establishment of transgenic animals. The interfering fragment, named pLVT202, was chosen from cardiomyocytes tested in vitro and was microinjected into the perivitelline space of zygotes from C57BL/6J mice via a lentivirus vehicle; 20 were identified as carrying copies of the transgene using the polymerase chain reaction (PCR). Real-time PCR and western blotting analysis showed that FPPS was downregulated in multiple tissues in the transgenic mice. The transgenic mouse model provides a novel means of studying the gene function of FPPS.

Lycopene protects against apoptosis in hypoxia/reoxygenation­induced H9C2 myocardioblast cells through increased autophagy.

Lycopene (Ly), the most common type of antioxidant in the majority of diet types, provides tolerance to ischemia/reperfusion injury. However, the underlying mechanism of the protective effects observed following Ly administration remains poorly investigated. The aim of the current study was to investigate whether Ly prevents damage to hypoxia/reoxygenation (HR)­induced H9C2 myocardioblasts in an autophagy­dependent manner. The levels of autophagic markers were detected using western blotting, the level of apoptosis was detected using western blotting and flow cytometry. The activation of autophagy was impaired via knockdown of the expression of 'microtubule­associated protein 1­light chain 3ß (MAP1LC3B)' and 'Beclin 1'. After 16 h hypoxia, followed by 2 h reoxygenation, the expression levels of the microtubule­associated protein 1A/1B­light chain 3 (LC3) and Βeclin 1 autophagic biomarkers, and cell viability were reduced, whereas the percentage of apoptotic cells, and the expression levels of the Bax/B­cell lymphoma 2 (Bcl­2) and active caspase­3 apoptotic biomarkers were increased. Pre­incubation of the cells with different Ly concentrations reversed the HR­induced inhibition of autophagy and cell viability, and the HR­induced elevation in apoptotic levels. The induction of autophagy was accompanied by reduced apoptosis, and decreased expression levels of Bax/Bcl­2 and active caspase­3. In addition, the impairment of autophagy by silencing the expression of MAP1LC3B and Beclin 1 accelerated HR­induced H9C2 cell apoptosis and the Ly­mediated protective effects disappeared. Furthermore, Bax/Bcl­2 and active caspase­3 expression levels were increased. Moreover, Ly­induced autophagy was associated with increased adenosine monophosphate kinase (AMPK) phosphorylation. Suppressed AMPK phosphorylation using compound C terminates Ly­mediated cytoprotective effects. Ly treatment improves cell viability and reduces apoptosis as a result of the activation of the adaptive autophagic response on HR­induced H9C2 myocardioblasts. AMPK phosphorylation may be involved in the progression.

Chronic treatment with qiliqiangxin ameliorates aortic endothelial cell dysfunction in diabetic rats.

Qiliqiangxin (QL), a traditional Chinese medicine, has been shown to be beneficial for chronic heart failure. However, whether QL can also improve endothelial cell function in diabetic rats remains unknown. Here, we investigated the effect of QL treatment on endothelial dysfunction by comparing the effect of QL to that of benazepril (Ben) in diabetic Sprague-Dawley rats for 8 weeks. Cardiac function was evaluated by echocardiography and catheterization. Assays for acetylcholine-induced, endothelium-dependent relaxation (EDR), sodium nitroprusside-induced endothelium-independent relaxation, serum nitric oxide (NO), and nitric oxide synthase (NOS) as well as histological analyses were performed to assess endothelial function. Diabetic rats showed significantly inhibited cardiac function and EDR, decreased expression of serum NO and phosphorylation at Ser(1177) on endothelial NOS (eNOS), and impaired endothelial integrity after 8 weeks. Chronic treatment for 8 weeks with either QL or Ben prevented the inhibition of cardiac function and EDR and the decrease in serum NO and eNOS phosphorylation caused by diabetes. Moreover, either QL or Ben suppressed inducible NOS (iNOS) protein levels as well as endothelial necrosis compared with the diabetic rats. Additionally, QL prevented the increase in angiotensin-converting enzyme 1 and angiotensin II receptor type 1 in diabetes. Thus, chronic administration of QL improved serum NO production, EDR, and endothelial integrity in diabetic rat aortas, possibly through balancing eNOS and iNOS activity and decreasing renin-angiotensin system expression.

Autophagy protects against senescence and apoptosis via the RAS-mitochondria in high-glucose-induced endothelial cells.

BACKGROUNDS: Autophagy is an important process in the pathogenesis of diabetes and plays a critical role in maintaining cellular homeostasis. However, the autophagic response and its mechanism in diabetic vascular endothelium remain unclear. METHODS AND RESULTS: We studied high-glucose-induced renin-angiotensin system (RAS)-mitochondrial damage and its effect on endothelial cells. With regard to therapeutics, we investigated the beneficial effect of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II type 1 receptor blockers (ARBs) against high-glucose-induced endothelial responses. High glucose activated RAS, enhanced mitochondrial damage and increased senescence, apoptosis and autophagic-responses in endothelial cells, and these effects were mimicked by using angiotensin II (Ang). The use of an ACEI or ARB, however, inhibited the negative effects of high glucose. Direct mitochondrial injury caused by carbonyl cyanide 3-chlorophenylhydrazone (CCCP) resulted in similar negative effects of high glucose or Ang and abrogated the protective effects of an ACEI or ARB. Additionally, by impairing autophagy, high-glucose-induced senescence and apoptosis were accelerated and the ACEI- or ARB-mediated beneficial effects were abolished. Furthermore, increases in FragEL™ DNA Fragmentation (TUNEL)-positive cells, ß-galactosidase activation and the expression of autophagic biomarkers were revealed in diabetic patients and rats, and the treatment with an ACEI or ARB decreased these responses. CONCLUSIONS: These data suggest that autophagy protects against senescence and apoptosis via RAS-mitochondria in high-glucose-induced endothelial cells.

Inhibition of farnesyl pyrophosphate synthase prevents norepinephrine-induced fibrotic responses in vascular smooth muscle cells from spontaneously hypertensive rats.

Both norepinephrine (NE) and connective tissue growth factor (CTGF) contribute to vascular fibrosis during hypertension. Recent studies indicate that farnesyl pyrophosphate synthase (FPPS) plays an important role in cardiac remodeling in hypertension. However, the role of FPPS in NE-induced fibrotic responses and related molecular mechanisms is unknown. Vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) were stimulated with NE. The fibrotic responses were assessed by measuring CTGF, hydroxyproline (hyp), and α-1 procollagen I levels using Western blot, a hydroxyproline test kit, and real-time quantitative PCR assays, respectively. Ras activity was determined by a pull-down assay using a Ras activation assay kit and detected by Western blot. NE dose-dependently increased fibrosis in SHR-VSMCs, and this increase was significantly reduced by ibandronate, an inhibitor of FPPS. The addition of farnesol, but not geranylgeraniol, partially reversed the inhibitory effects of ibandronate. Furthermore, the anti-fibrotic effects of ibandronate could be mimicked by FTI-276 but not by GGTI-286. A pull-down assay showed that ibandronate reduced the NE-induced Ras activation. Moreover, ibandronate inhibited the NE-induced activation of p38, JNK, and ERK1/2. Only SB203580 (specific inhibitor of p38) diminished the NE-induced CTGF production. These results demonstrated that inhibiting FPPS prevents NE-induced fibrotic responses in SHR-VSMCs and that the Ras kinase and p38 pathways were the underlying mechanisms involved in this process.

Alteration of mevalonate pathway related enzyme expressions in pressure overload-induced cardiac hypertrophy and associated heart failure with preserved ejection fraction.

BACKGROUND: Abnormalities of the mevalonate pathway, an important cellular metabolic pathway, are common in many diseases including cardiovascular disease. The mevalonate pathway related enzyme expressions in pressure overload-induced cardiac hypertrophy and associated diastolic dysfunction remains largely unknown. This study aims to investigate whether the expression of mevalonate pathway related enzyme is altered during the progression of cardiac hypertrophy and associated diastolic dysfunction induced by pressure overload. METHODS: Male Sprague-Dawley (SD) rats were randomly divided into two groups: the suprarenal abdominal aortic coarctation (AAC) group and the sham group. RESULTS: Histological and echocardiographic assessments showed that there was a significant cardiovascular remodeling in the AAC group compared with the sham group after 3 weeks post-operatively, and the left ventricular (LV) diastolic function was reduced at 8 and 14 weeks post-operatively in the AAC group, without any change in systolic function during the study. The tissue of the heart and the abdominal aorta proximal to the coarctation showed over-expression of several enzymes, including 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), farnesyl diphosphate synthase (FDPS), farnesyltransferase-α (FNTA), farnesyltransferase-ß (FNTB), geranylgeranyltransferase type I (GGTase-I) and the activation of their downstream proteins was enhanced. CONCLUSIONS: AAC induced compensatory LV hypertrophy to decompensatory diastolic dysfunction, accompanied by altered expression of several key enzymes in the mevalonate pathway.

Phospholamban antisense RNA improves SR Ca2+-ATPase activity and left ventricular function in STZ-induced diabetic rats.

OBJECTIVE: To study the effect of phospholamban antisense RNA (asPLB) on sarcoplasmic reticulum Ca2+-ATPase activity and cardiac function in rats with diabetes mellitus (DM) mediated by recombinant adeno-associated virus (rAAV) vector. METHODS: Six weeks after the induction of DM by streptozotocin injected intraperitoneally, the rats were divided into three groups, namely: DM-rAAV-asPLB group, DM-saline group and DM group (control group). The rats in the DM-rAAV-asPLB group were intramyocardially injected with rAAV-asPLB, the rats in the DM-saline group were injected with saline, and those in the control group did not receive any treatment. Six weeks after gene transfer, the expressions of PLB protein and PLB phosphorylation were detected by Western-blot, while the activity of sarcoplasmic reticulum (SR) Ca2+-ATPase and left ventricular function were measured. RESULTS: The PLB protein expression level was significantly higher whereas the PLB phosphorylation, SR Ca2+-ATPase activity and left ventricular function were significantly lower in the DM-saline group than in the control group. No significant difference was found in PLB protein expression level, PLB phosphorylation or SR Ca2+-ATPase activity between the DM-rAAV-asPLB group and the control group. The left ventricular function in the DM-rAAV-asPLB group was poorer than in the control group and was better than in the DM-saline group. CONCLUSION: rAAV-asPLB can down-regulate PLB protein expression and up-regulate PLB phosphorylation and SR Ca2+-ATPase activity, thus contributing to the improvement of in vivo left ventricular function.