Long noncoding RNA MALAT1 promotes high glucose-induced human endothelial cells pyroptosis by affecting NLRP3 expression through competitively binding miR-22.

Cell death and inflammation play critical roles in atherosclerosis. Pyroptosis, a novel proinflammatory programmed cell death process, participates in atherosclerosis pathogenesis. Recently, MALAT1 was identified as a pyroptosis-related long noncoding RNA (lncRNA). Here, we investigated the potential role and underlying mechanism of lncRNA MALAT1 in endothelial cells pyroptosis. We first established an endothelial cell pyroptosis model by stimulating EA.hy926 human endothelial cells (EA.hy926 cells) with high glucose. Then, we investigated lncRNA MALAT1 expression and found that it was upregulated in high glucose-treated EA.hy926 cells. Furthermore, lncRNA MALAT1 knockdown significantly inhibited high glucose-induced pyroptosis in EA.hy926 cells, which may critically influence atherosclerosis. Moreover, miR-22 was a target of lncRNA MALAT1 and was negatively correlated with lncRNA MALAT1. NLRP3 expression was significantly suppressed by transfection with a MALAT1-targeting antisense oligonucleotide (ASO). Ultimately, miR-22 overexpression abrogated the effect of MALAT1 on high glucose-induced EA.hy926 cells pyroptosis. Together, our results suggest that lncRNA MALAT1 promotes high glucose-induced pyroptosis of endothelial cells partly by affecting NLRP3 expression through competitively binding miR-22. Our findings indicate a new regulatory mechanism for endothelial cells pyroptosis under high-glucose stress, providing a novel therapeutic target for atherosclerosis.

Uncertainty evaluation in clinical chemistry, immunoassay, hematology and coagulation analytes using only external quality assessment data.

BACKGROUND: Measurement uncertainty (MU) is a parameter associated with the result of a measurement that characterizes its dispersion. We report results for estimating MU following the application of a top-down procedure using only proficiency test data to establish uncertainty levels for various analytes. METHODS: Data were obtained from 142 laboratories participating in the Beijing Center for Clinical Laboratory (BCCL) proficiency testing/external quality assessment (PT/EQA) schemes. The 24-month study included six selected PT shipments to obtain estimates for 50th percentile (median) and 90th percentile MUs and to compare those estimates to usual analytic goals. The number of laboratory participants varied for each trial. The expanded uncertainty (U) was calculated using a cover factor of k=2 for a confidence interval of 95%. All reproducibility, method and laboratory biases came from the PT/EQA data. RESULTS: The median U (k=2) ranged from 3.2% (plasma sodium, indirect ion selective electrode) to 32.8% (triglycerides, free glycerol blanking) for clinical chemistry analyte means from participants in the same method group. Immunoassay analyte median U results ranged from 11.3% (CA125 tumor marker, Roche) to 33.8% (prostate-specific antigen [PSA], Abbott). The range for median U was 3.5% (red blood cell [RBC], Abx) to 30.3% (fibrinogen [FBG], other) for hematology and coagulation analytes. The MUs for most analytes satisfied quality requirements. CONCLUSIONS: The use of PT/EQA data, when available, provides an effective means for estimating uncertainties associated with quantitative measurements. Thus, medical laboratories can calculate their own MUs. Proficiency testing organizers can provide participants with an additional MU estimate using only EQA data, which may be updated at the end of each survey.

Ox-LDL-Induced MicroRNA-155 Promotes Autophagy in Human Endothelial Cells via Repressing the Rheb/ mTOR Pathway.

BACKGROUND/AIMS: Autophagy, an evolutionary conserved biological process, is activated in cells to cope with various types of stress. MicroRNAs control several activities related to autophagy. However, the role of autophagy-related microRNAs during atherosclerosis is far from known. MicroRNA-155 was identified to be a crucial regulator of atherosclerosis. The objectives of the study were to analyze the effect of microRNA-155 on autophagic signaling and explore its mechanism in human endothelial cells under ox-LDL stress. METHODS: The study included human endothelial cells surrogate EA.hy926 lines (EA.hy926 cells). The expression of microRNA-155 was analyzed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The effect of microRNA-155 on endothelial autophagy was observed along with the expression levels of Rheb, LC3B, Beclin1, and P62/SQSTM1 by western blotting (WB) and immunofluorescence through microRNA-155 overexpression or inhibition. Bioinformatics analysis and Luciferase reporter assay were used to explore the target gene of microRNA-155. Cell viability and apoptosis were examined by 3-[4,5-dimethylthiazol-2-yl]-5- [3-carboxy-methoxyphenyl]-2-[4-sulfophenyl]-2H-tetrazolium inner salt (MTS) assay and TdT-mediated dUTP Nick-End Labeling (TUNEL) apoptosis assay. RESULTS: MicroRNA-155 expression was significantly increased under ox-LDL stress. MicroRNA-155 increased autophagic activity, while inhibition of it alleviated ox-LDL-induced autophagy in EA.hy926 endothelial cells. In addition, dual-luciferase reporter assays showed that microRNA-155 suppressed Rheb transcription. MicroRNA-155 increased autophagic activity in EA.hy926 cells via inhibition of Rheb-mediated mTOR/P70S6kinase/4EBP signaling pathway. Furthermore, we demonstrated that microRNA-155 could regulate not only autophagy but also apoptosis in EA.hy926 cells. CONCLUSIONS: MicroRNA-155 works as a regulator of endothelial function under ox-LDL stress, making it a potential candidate for the novel therapeutic strategies against atherosclerotic diseases.

miR-155 Regulated Inflammation Response by the SOCS1-STAT3-PDCD4 Axis in Atherogenesis.

Inflammation response plays a critical role in all phases of atherosclerosis (AS). Increased evidence has demonstrated that miR-155 mediates inflammatory mediators in macrophages to promote plaque formation and rupture. However, the precise mechanism of miR-155 remains unclear in AS. Here, we also found that miR-155 and PDCD4 were elevated in the aortic tissue of atherosclerotic mice and ox-LDL treated RAW264.7 cells. Further studies showed that miR-155 not only directly inhibited SOCS1 expression, but also increased the expression of p-STAT and PDCD4, as well as the production of proinflammation mediators IL-6 and TNF-α. Downregulation of miR-155 and PDCD4 and upregulation of SOCS1 obviously decreased the IL-6 and TNF-α expression. In addition, inhibition of miR-155 levels in atherosclerotic mice could notably reduce the IL-6 and TNF-α level in plasma and aortic tissue, accompanied with increased p-STAT3 and PDCD4 and decreased SOCS1. Thus, miR-155 might mediate the inflammation in AS via the SOCS1-STAT3-PDCD4 axis. These results provide a rationale for intervention of intracellular miR-155 as possible antiatherosclerotic targets.

Integrated analysis of differentially expressed genes and miRNA expression profiles in dilated cardiomyopathy.

Background: Although dilated cardiomyopathy (DCM) is a prevalent form of cardiomyopathy, the molecular mechanisms underlying its pathogenesis and progression remain poorly understood. It is possible to identify and validate DCM-associated genes, pathways, and miRNAs using bioinformatics analysis coupled with clinical validation methods. Methods: Our analysis was performed using 3 mRNA datasets and 1 miRNA database. We employed several approaches, including gene ontology (GO) analysis, KEGG pathway enrichment analysis, protein-protein interaction networks analysis, and analysis of hub genes to identify critical genes and pathways linked to DCM. We constructed a regulatory network for DCM that involves interactions between miRNAs and mRNAs. We also validated the differently expressed miRNAs in clinical samples (87 DCM ，83 Normal) using qRT-PCR.The miRNAs' clinical value was evaluated by receiver operating characteristic curves (ROCs). Results: 78 differentially expressed genes (DEGs) and 170 differentially expressed miRNAs (DEMs) were associated with DCM. The top five GO annotations were collagen-containing extracellular matrix, cell substrate adhesion, negative regulation of cell differentiation, and inflammatory response. The most enriched KEGG pathways were the Neurotrophin signaling pathway, Thyroid hormone signaling pathway, Wnt signaling pathway, and Axon guidance. In the PPI network, we identified 10 hub genes, and in the miRNA-mRNA regulatory network, we identified 8 hub genes and 15 miRNAs. In the clinical validation, we found 13 miRNAs with an AUC value greater than 0.9. Conclusion: Our research offers novel insights into the underlying mechanisms of DCM and has implications for identifying potential targets for diagnosis and treatment of this condition.

Integrating genomic profiling to clinical data: assessing the impact of CD147 expression on plaque stability.

Background: Acute Coronary Syndrome (ACS) continues to be a leading cause of death and illness worldwide. Differentiating stable from unstable coronary plaques is essential for enhancing patient outcomes. This research investigates the role of CD147 as a biomarker for plaque stability among coronary artery disease patients. Methods: The study began with high-throughput sequencing of blood samples from six patients, divided equally between those with Stable Angina (SA) and Unstable Angina (UA), followed by bioinformatics analysis. Expanding upon these findings, the study included 31 SA patients and 30 patients with ACS, using flow cytometry to examine CD147 expression on platelets and monocytes. Additionally, logistic regression was utilized to integrate traditional risk factors and evaluate the predictive value of CD147 expression for plaque stability. Results: Initial sequencing displayed a notable difference in CD147 expression between SA and UA groups, with a significant increase in UA patients. Further analysis confirmed that elevated platelet CD147 expression was strongly associated with unstable plaques (OR = 277.81, P < .001), after adjusting for conventional risk factors, whereas monocyte CD147 levels did not show a significant difference. Conclusion: Elevated CD147 expression on platelets is a crucial biomarker for identifying unstable coronary artery plaques, offering insights into patient risk stratification and the development of targeted treatment strategies. This underscores the pivotal role of molecular research in understanding and managing coronary artery disease, paving the way for improved clinical outcomes.

Machine learning-based prediction model for myocardial ischemia under high altitude exposure: a cohort study.

High altitude exposure increases the risk of myocardial ischemia (MI) and subsequent cardiovascular death. Machine learning techniques have been used to develop cardiovascular disease prediction models, but no reports exist for high altitude induced myocardial ischemia. Our objective was to establish a machine learning-based MI prediction model and identify key risk factors. Using a prospective cohort study, a predictive model was developed and validated for high-altitude MI. We consolidated the health examination and self-reported electronic questionnaire data (collected between January and June 2022 in 920th Joint Logistic Support Force Hospital of china) of soldiers undergoing high-altitude training, along with the health examination and second self-reported electronic questionnaire data (collected between December 2022 and January 2023) subsequent to their completion on the plateau, into a unified dataset. Participants were subsequently allocated to either the training or test dataset in a 3:1 ratio using random assignment. A predictive model based on clinical features, physical examination, and laboratory results was designed using the training dataset, and the model's performance was evaluated using the area under the receiver operating characteristic curve score (AUC) in the test dataset. Using the training dataset (n = 2141), we developed a myocardial ischemia prediction model with high accuracy (AUC = 0.86) when validated on the test dataset (n = 714). The model was based on five laboratory results: Eosinophils percentage (Eos.Per), Globulin (G), Ca, Glucose (GLU), and Aspartate aminotransferase (AST). Our concise and accurate high-altitude myocardial ischemia incidence prediction model, based on five laboratory results, may be used to identify risks in advance and help individuals and groups prepare before entering high-altitude areas. Further external validation, including female and different age groups, is necessary.

miR-155 inhibits oxidized low-density lipoprotein-induced apoptosis of RAW264.7 cells.

Macrophage apoptosis is a prominent feature of advanced atherosclerotic plaques. Here, we examined the hypothesis that the apoptotic machinery is regulated by microRNA-155 (miR-155). Constitutive expression of miR-155 was detected in RAW264.7 cells, which was increased following stimulation with oxidized low-density lipoprotein (OxLDL) in a dose- and time-dependent manner. OxLDL-treated RAW264.7 cells showed a marked time- and dose-dependent increase in apoptosis, which was suppressed in the presence of mimics and increased with antagonists of miR-155. Bioinformatics analysis revealed Fas-associated death domain-containing protein (FADD) as a putative target of miR-155. Luciferase reporter assay and Western blot further disclosed that miR-155 inhibits FADD expression by directly targeting the 3'-UTR region. We propose that miR-155 attenuates the macrophage apoptosis, at least in part, through FADD regulation, since forced expression of FADD blocked the ability of miR-155 to inhibit apoptosis. Our results collectively suggest that miR-155 attenuates apoptosis of OxLDL-mediated RAW264.7 cells by targeting FADD, supporting a possible therapeutic role in atherosclerosis.

Silencing stromal interaction molecule 1 by RNA interference inhibits the proliferation and migration of endothelial progenitor cells.

Knockdown of stromal interaction molecule 1 (STIM1) significantly suppresses neointima hyperplasia after vascular injury. Endothelial progenitor cells (EPCs) are the major source of cells that respond to endothelium repair and contribute to re-endothelialization by reducing neointima formation after vascular injury. We hypothesized that the effect of STIM1 on neointima hyperplasia inhibition is mediated through its effect on the biological properties of EPCs. In this study, we investigated the effects of STIM1 on the proliferation and migration of EPCs and examined the effect of STIM1 knockdown using cultured rat bone marrow-derived EPCs. STIM1 was expressed in EPCs, and knockdown of STIM1 by adenoviral delivery of small interfering RNA (siRNA) significantly suppressed the proliferation and migration of EPCs. Furthermore, STIM1 knockdown decreased store-operated channel entry 48h after transfection. Replenishment with recombinant human STIM1 reversed the effects of STIM1 knockdown. Our data suggest that the store-operated transient receptor potential canonical 1 channel is involved in regulating the biological properties of EPCs through STIM1. STIM1 is a potent regulator of cell proliferation and migration in rat EPCs and may play an important role in the biological properties of EPCs.

Inhibitor of DNA binding-1 promotes the migration and proliferation of endothelial progenitor cells in vitro.

Migration and proliferation of endothelial progenitor cells (EPCs) are the key mechanisms in re-endothelialization after vascular injury. Inhibitor of DNA binding-1 (Id1) function has been linked to the proliferation, migration, and senescence of cells, and studies have shed light on the relationship between Id1 and the biological functions of EPCs. On the basis of the available data concerning Id1 and the behavior of EPCs, we hypothesized that Id1 was an important regulator in modulating the migration and proliferation of EPCs. Culture of spleen-derived EPCs was done as previously described. Id1 was presented at low levels in EPCs. Id1 was localized predominantly in the cytoplasm, and was rapidly upregulated by stimulation with serum and vascular endothelial growth factor. The migration and proliferation of EPCs were extensively improved by overexpression of adenovirus-mediated exogenous Id1 and inhibited by silencing of endogenous Id1 in EPCs. These results suggest that Id1 has a direct role in regulation of the migration and proliferation in EPCs.

Automatic Corneal Ulcer Segmentation Combining Gaussian Mixture Modeling and Otsu Method.

In this paper, we proposed and validated a novel and accurate pipeline for automatically segmenting flaky corneal ulcer areas from fluorescein staining images. The ulcer area was segmented within the cornea by employing a joint method of Otsu and Gaussian Mixture Modeling (GMM). In the GMM based segmentation, the total number of Gaussians was determined intelligently using an information theory based algorithm. And the fluorescein staining images were processed in the HSV color model rather than the original RGB color model, aiming to improve the segmentation results' robustness and accuracy. In the Otsu based segmentation, the images were processed in the grayscale space with Gamma correction being conducted before the Otsu binarization. Afterwards, morphological operations and median filtering were employed to further improve the Otsu segmentation result. The GMM and Otsu segmentation results were then intersected, for which post-processing was conducted by identifying and filling holes through a fast algorithm using priority queues of pixels. The proposed pipeline has been validated on a total of 150 clinical images. Accurate ulcer segmentation results have been obtained, with the mean Dice Similarity Coefficient (DSC) being 0.88 when comparing the automatic segmentation result with the manually-delineated gold standard. For images in the RGB color space, the mean DSC was 0.83, being much lower than that of the images in the HSV color space.

[The role of activator protein-1 in unstable coronary atherosclerotic changes].

OBJECTIVE: To investigate the relation between activator protein-1 (AP-1) and coronary atherosclerotic changes and the potential role of AP-1 in the stabilization of atherosclerotic plaques in patients with coronary heart disease (CHD). METHOD: 142 patients were included in this study and divided into CHD group (107) and control group (35) according to coronary angiography (CAG). The CHD group was further divided into a stable angina pectoris (SAP) group (32) and an acute coronary syndrome (ACS) group (75) according to the clinical manifestations. In addition, the CHD group was divided into A type group, B type group and C type group according to the standard of ACC/AHA coronary change in 1988. Meanwhile, the CHD group was further divided into light stenosis group, moderate stenosis group and severe stenosis group according to the degree of coronary lesion. The lysate of cells was obtained through lysis of the leucocytes from peripheral blood with cell lysis buffer. The amount of Phospho-c-Jun in lysate was measured with enzyme-linked immunosorbent assay (ELISA). The results were demonstrated with absorbance, which reflects the amount of AP-1. RESULTS: The main coronary changes in the SAP group were A type (68.7%) and the changes were mainly of light degree (53.1%); the main coronary changes in the ACS group were B type (52.0%) or C type (37.3%) and the changes were mainly of heavy degree (66.7%). The absorbance of Phospho-c-Jun in CHD group was significantly higher than that in the control subjects (1.43 +/- 0.33 vs 0.71 +/- 0.13, P < 0.001). The absorbance of Phospho-c-Jun in the ACS group was significantly higher than that in the SAP group (1.56 +/- 0.28 vs 1.14 +/- 0.25, P < 0.001). The absorbance of Phospho-c-Jun increased gradually from A type group to C type group (1.18 +/- 0.27 vs 1.42 +/- 0.26 vs 1.71 +/- 0.27, P < 0.001) and from light stenosis group to severe stenosis group (1.09 +/- 0.20 vs 1.37 +/- 0. 26 vs 1.60 +/- 0.29, P < 0.001). CONCLUSION: There is a significant relationship between AP-1 and coronary atherosclerotic changes. AP-1 may be a factor that can predict coronary arteriosclerotic progression and stability of the plaque.

[Association between plasma macrophage migration inhibitory factor concentration and coronary artery lesion severity.].

OBJECTIVE: To investigate the relationship between the plasma macrophage migration inhibitory factor (MIF), activator protein-1 (AP-1) and MMP-9 concentrations and the severity of coronary artery lesions in coronary heart disease (CHD) patients. METHODS: Patients were divided into normal controls (n = 35), stable angina pectoris (SAP, n = 32) and acute coronary syndrome (ACS, n = 75) according to the coronary angiography (CAG), clinical and laboratory examinations. The CAG severity and extent of coronary lesions were analyzed by means of Gensini coronary score system. Enzyme linked immunosorent assay was used to measure the plasma MIF, AP-1 and MMP-9 concentrations. RESULTS: Plasma MIF, AP-1 and MMP-9 concentrations were significant increased in CHD patients [MIF: (14.97 +/- 2.11) microg/L, AP-1: 1.43 +/- 0.33, MMP-9: (1.48 +/- 0.14) microg/L] compared to those in control group [MIF: (9.07 +/- 1.28) microg/L, AP-1: 0.71 +/- 0.13, MMP-9: (1.01 +/- 0.07) microg/L, all P < 0.05]. The MIF, AP-1 and MMP-9 concentrations in ACS group [MIF: (16.66 +/- 2.56) microg/L, AP-1: 1.56 +/- 0.22, MMP-9: (1.58 +/- 0.14) microg/L] were also significant higher than those in SAP group [MIF: (11.01 +/- 2.12) microg/L, AP-1: 1.04 +/- 0.25, MMP-9: (1.25 +/- 0.07) microg/L, all P < 0.05] and there was significant positive correlation between MIF, AP-1 and MMP-9 concentrations and the Gensini score of coronary artery lesions (all P < 0.05). AP-1 was positively correlated with MMP-9 in CHD patients (P < 0.05). CONCLUSIONS: Plasma MIF, AP-1 and MMP-9 concentrations were positively correlated to the severity of coronary lesions in CHD patients. Higher MIF, AP-1 and MMP-9 concentrations in ACS patients than in SAP patients might suggest higher plaque instability in ACS patients.

Yunnanterpene G, a spiro-triterpene from the roots of Cimicifuga foetida, downregulates the expression of CD147 and MMPs in PMA differentiated THP-1 cells.

A new cycloartane triterpene, yunnanterpene G (1), containing an oxaspiro[5.4]decane moiety, was purified from the roots of Cimicifuga foetida. The new structure was determined from spectroscopic data and the X-ray diffraction method. Biological evaluations revealed that compound 1 significantly inhibited the mRNA expression of the atherosclerosis-related adhesion molecule CD147 (extracellular matrix metalloproteinase inducer, EMMPRIN), and proteolytic enzymes matrix metalloproteinase 2 (MMP-2), MMP-9 and MMP-14, in a dose-dependent manner in phorbol-12-myristate-13-acetate-induced human monocytic THP-1 cells by quantitative real-time PCR method. At the same time, the migration ability of the induced THP-1 cells was potently inhibited. Furthermore, western blot experiments showed that compound 1 at 25 µM strongly suppressed phosphorylation of NF-κB p65 and p38 MAPK in the differentiated THP-1 cells.

[Association between murine double minute 2 expression and AngII and ceramide induced endothelial cells apoptosis].

OBJECTIVE: To observe the relationship between murine double minute 2 (mdm2) expression and AngII and ceramide induced human umbilical endothelial cells apoptosis. METHOD: Human umbilical endothelial cells (ECs) were cultured in vitro and treated with angiotensin II alone or in combination with losartan (an inhibitor of AT1), PD123319 (an inhibitor of AT2) and FB1 (an inhibitor of ceramidase) respectively. ECs were also treated with different doses of C2-ceramide. The apoptosis of ECs was detected with Tunel, the mdm2 mRNA and protein expressions were measured with reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. RESULTS: PD123319 and FB1 but not losartan inhibited AngII induced ECs apoptosis and down-regulated the AngII induced increased mdm2 expressions. C2-ceramide also induces ECs apoptosis and down-regulated mdm2 expressions at protein and mRNA levels in a dose-dependent manner. CONCLUSIONS: AngII binding with AT2 induces ECs apoptosis via ceramide. AngII and ceramide induce EC apoptosis by inhibiting mdm2.

Atorvastatin attenuates plaque vulnerability by downregulation of EMMPRIN expression via COX-2/PGE2 pathway.

Extracellular matrix metalloproteinase inducer (EMMPRIN) reportedly has a key regulatory role in matrix metalloproteinase (MMP) activities and the progression of atherosclerosis. Statins, which are anti-atherosclerotic pharmacological agents, are widely applied in clinical settings. The aim of the present study was to investigate the pharmaceutical effect of atorvastatin on EMMPRIN expression in atherosclerotic plaques. An atherosclerotic mouse model was established using apoliprotein E-deficient (ApoE-/-) mice raised on a high-fat diet. Additionally, a low (5 mg/kg/day) or high dosage (10 mg/kg/day) of atorvastatin suspension was administered orally for eight weeks, beginning on week 7 or 11 respectively. The effects of atorvastatin on atherosclerotic plaque formation and EMMPRIN expression were subsequently determined. The THP-1 cell line was used to investigate the effect of atorvastatin on EMMPRIN expression in vitro. The results demonstrated that the high-fat diet led to vulnerable plaques (VPs) and increased EMMPRIN expression in VPs in ApoE-/- mice. Atorvastatin treatment decreased EMMPRIN expression in the aortas and plaques of ApoE-/- mice. In vitro, oxidized low-density lipoprotein (ox-LDL) induced the expression of cyclooxygenase-2 (COX-2) and EMMPRIN in THP-1 macrophages, and atorvastatin inhibited ox-LDL-induced expression of PGE2, EMMPRIN and COX-2 in THP-1 macrophages. Therefore, the present data indicated that atorvastatin treatment reduces the vulnerability of atherosclerotic plaques and expression of EMMPRIN, and that the inhibitory effect of atorvastatin on EMMPRIN may occur via the COX-2/PGE2 signaling pathway in macrophages.

[Angiotensin II up-regulates expression of inducible nitric oxide synthase in human umbilical endothelial cells: roles of AT1 and AT2].

OBJECTIVE: Angiotensin II is an important pro inflammation factor in the cardiovascular system. This experiment is aimed to study the effects of angiotensin II on inducible nitric oxide synthase expression in human umbilical endothelial cells. METHODS: Human umbilical endothelial cells were cultured in vitro and treated with angiotensin II alone or in combination with AT1, AT2 and NF-kappaB inhibitors respectively. The inducible nitric oxide synthase expressions at protein and mRNA levels were measured with Western blot and reverse transcription-polymerase chain reaction (RT-PCR), and the activity of NF-kappaB was analyzed with EMSA. RESULTS: Angiotensin II up-regulated inducible nitric oxide synthase expressions at the protein and mRNA levels at 5 h (P < 0.05), the activity of NF-kappaB was enhanced at 2 h (P < 0.05). These effects could be blocked by AT1 and NF-kappaB inhibitors but not by AT2 inhibitor. CONCLUSION: Angiotensin II can upregulate the expression of inducible nitric oxide synthase through NF-kappaB pathway in human umbilical endothelial cells. AT1, other than AT2, play a key role in this process.

[Gene expression of Ang II receptors in myocardium in congestive heart failure].

OBJECTIVE: To explore the relation among myocardial AT(1)-/AT(2)- receptor expression, myocardial remodeling and cardiac function in patients with congestive heart failure. METHODS: Pathologic and morphologic studies on myocardial tissue of 31 patients with CHF due to valvular heart disease and 5 control subjects were carried out with optical and electronic microscopy. Message RNA expression of and AT(1)-/AT(2)-receptors in myocardial tissue were analyzed using the reverse transcriptase-polymerase chain reaction. RESULTS: Pathological changes of myocardial tissue in CHF due to valvular heart disease showed typical myocardial remodeling. AT(1)-receptor mRNA expression was slightly increased in the patients with mild CHF than in the control subjects, but decreased in the moderate and severe CHF patients. No difference was observed in AT(2)-receptor mRNA expression among all the groups. CONCLUSIONS: The expression of AT(1)-receptor was up-regulated in mild CHF. Cardiomyocyte hypertrophy may be mediated by AT(1)-receptor. The expression of AT(1)-receptor was down-regulated in moderate and severe CHF. The do minant receptor subtype was transformed to AT(2). The significance of these alterations may be a local protective mechanism of myocardium. Cardiomyocyte apoptosis may be induced via AT(2)-receptor, leading to deterioration of cardiac function.

[Tumor necrosis factor alpha and myocardial matrix metalloproteinases in left ventricular remodeling].

OBJECTIVE: The cytokine tumor necrosis factor (TNF) alpha has been causally linked to left ventricular (LV) remodeling, but the molecular basis for this effect is unknown. It is essential to study the changes of plasma levels of TNF alpha and matrix metalloproteinase-2,3,9 (MMP-2,3,9) expressions in myocardium during congestive heart failure (CHF). METHODS: Plasma levels of TNF alpha were measured with enzyme-linked immunoassay in CHF patients of various degrees and in healthy controls. Using Western blotting assay, we detected the protein expressions of MMP-2,3,9 on myocardial tissue in CHF patients and in healthy controls. Cardiac function parameters were measured with echocardiographic studies. RESULTS: Plasma levels of TNF alpha increased significantly in patients with CHF (P < 0.05 or < 0.01). The protein expressions of MMP-2,3,9 were significantly higher in patients with CHF than in controls (P < 0.05 or < 0.01). The higher the degree of CHF, the greater the numbers of expressions. No changes of MMP-2 could be found between the controls and CHF patients of NYHA II. There was a positive correlation between plasma levels of TNF alpha and the protein expressions of MMP-2,3,9 (P < 0.01 or < 0.001). CONCLUSIONS: It is suggested that alterations of TNF alpha may stimulate the expressions of MMPs, contribute to myocardial remodeling and lead to the development and progression of congestive heart failure. These changes may induce a direct effect on the progression and deterioration of heart failure.

microRNA-155 is inversely associated with severity of coronary stenotic lesions calculated by the Gensini score.

OBJECTIVES: This study aimed to investigate the association between microRNA-155 (miR-155) and the severity and extent of coronary stenotic lesions. PATIENTS AND METHODS: We measured the miR-155 expression by real-time PCR in 110 consecutive patients undergoing coronary angiography for suspected coronary artery disease. The severity and extent of coronary stenotic lesions were evaluated on the basis of coronary angiography findings by the Gensini score. RESULTS: The miR-155 expression was significantly lower in 56 patients with coronary heart disease than those in 54 controls (P<0.01). The level of miR-155 in peripheral blood mononuclear cells or plasma was lower in patients with unstable angina pectoris and acute myocardial infarction than in patients with chest pain syndrome, whereas no statistically significant differences were observed between patients with stable angina pectoris and chest pain syndrome. Spearman's correlation analysis showed that the expression of miR-155 in plasma correlated positively with the expression in peripheral blood mononuclear cells. The levels of miR-155 in the patients with diseased vessels of two and three or more were significantly lower than in those with diseased vessel of zero and one. The levels of miR-155 were not significantly different among groups with diseased vessels of zero and one. miR-155 were associated negatively with Gensini scores (r = -0.663, P<0.001). The miR-155 expression was correlated significantly to age (r = -0.227), hypertension (r = -0.440), total cholesterol (r = 0.239), high-density lipoprotein cholesterol (r = 0.280), low-density lipoprotein cholesterol (r = -0.315), tobacco use (r = -0.363), angiotensin-converting enzyme inhibitor (r = -0.250), statins (r = -0.368), and high-sensitivity C-reactive protein (r = -0.515). CONCLUSION: miR-155 expression is associated inversely with complicated proatherogenic metabolic risk factors, and the severity of coronary stenotic lesions calculated by Gensini scores.