Effects of cigarette smoking on HDL quantity and function: implications for atherosclerosis.

Cigarette smoking has been identified as an independent and preventable risk factor for atherosclerosis and cardiovascular disease. Population studies have shown that plasma high density lipoprotein (HDL) cholesterol levels are inversely related to the risk of developing cardiovascular disease. Cigarette smoking is associated with reduced HDL cholesterol levels. Cigarette smoking can alter the critical enzymes of lipid transport, lowering lecithin: cholesterol acyltransferase (LCAT) activity and altering cholesterol ester transfer protein (CETP) and hepatic lipase activity, which attributes to its impact on HDL metabolism and HDL subfractions distribution. In addition, HDL is susceptible to oxidative modifications by cigarette smoking, which makes HDL become dysfunctional and lose its atheroprotective properties in smokers. Therefore, cigarette smoking has a negative impact on both HDL quantity and function, which can explain, in part, the increased risk of cardiovascular disease in smokers.

Protective effect of HDL on endothelial NO production: the role of DDAH/ADMA pathway.

Accumulating studies have demonstrated that the dimethylarginine dimethylaminohydrolase/asymmetric dimethylarginine (DDAH/ADMA) system is a novel pathway for modulating nitric oxide (NO) production. The aim of this study was to investigate whether the protective effect of high density lipoprotein (HDL) on endothelial NO production was related to its effect on DDAH/ADMA pathway. Human umbilical vein endothelial cells (HUVECs) were prior exposed to HDL (10, 50, or 100 µg/ml) for 1 h, and then incubated with oxidized low density lipoprotein (ox-LDL) (100 µg/ml) for 24 h. The cultured medium was collected for measuring the concentration of NO and ADMA. The cells were collected for measuring the mRNA and protein expression of DDAH-II as well as DDAH activity. HUVECs treated with ox-LDL (100 µg/ml) for 24 h significantly decreased the concentration of NO, the mRNA and protein expression of DDAH-II as well as DDAH activity and increased the level of ADMA. Pretreatment with HDL (10, 50, or 100 µg/ml) could counteract these changes induced by ox-LDL (100 µg/ml). HDL significantly increased the attenuated endothelial cell NO production induced by ox-LDL, which was attributed to its effect on DDAH/ADMA pathway.

Protective effect of neferine on endothelial cell nitric oxide production induced by lysophosphatidylcholine: the role of the DDAH-ADMA pathway.

Neferine, extracted from the seed embryo of Nelumbo nucifera Gaertn., has multiple cardiovascular pharmacological effects. The dimethylarginine dimethylaminohydrolase (DDAH) - asymmetric dimethylarginine (ADMA) system is a novel pathway for modulating nitric oxide (NO) production. The aim of this study was to investigate whether the protective effect of neferine on endothelial NO production was related to the DDAH-ADMA pathway. Human umbilical vein endothelial cells (HUVECs) were first exposed to neferine (0.1, 1.0, or 10.0 µmol/L) for 1 h, and then incubated with lysophosphatidylcholine (LPC; 10 µg/mL) in the presence of neferine for 24 h. The medium was collected for measuring the levels of NO, maleic dialdehyde (MDA), as well as ADMA. The endothelial cells were collected for measuring DDAH activity and the level of reactive oxygen species (ROS). LPC significantly decreased NO concentration and DDAH activity and increased the levels of ADMA, ROS, and MDA. Neferine could partially counteract the changes induced by LPC. These findings suggested that neferine could modulate the DDAH-ADMA pathway via its antioxidant properties, which was involved in its beneficial effect on endothelial NO production.

[Endoplasmic reticulum stress and related apoptosis in the lungs of a chronic obstructive pulmonary disease rat model].

OBJECTIVE: To study the endoplasmic reticulum stress (ERS) and the apoptosis of alveolar epithelial cells in a COPD rat model. METHODS: Twenty-four Wistar rats were divided into a control group and a COPD group at random. The COPD rat model was established by intratracheal instillation of lipopolysaccharide (LPS) twice and exposure to cigarette smoke daily. The spirometry was conducted and the pathological changes were observed after the model was established. The levels of glucose regulated protein 78 (GRP78) and CCAAT/enhancer binding protein homologous protein (CHOP) mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR). The protein expression of GRP78, CHOP and caspase-12 was detected by Western blot. TdT-mediated dUTP nick end labeling (TUNEL) was used to analyze alveolar epithelial cell apoptosis. Comparisons between the two groups were performed by t-test. RESULTS: Significant decrease of FEV(0.3)/FVC [(60 ± 6)%] and dynamic compliance of lung (CLdyn) [(0.17 ± 0.02) cm H2O×ml(-1)×s(-1)], and increase of airway resistance [(0.64 ± 0.07) ml/cm H2O] were found in the COPD group compared with the control group [(83 ± 7)%, (0.31 ± 0.03) cm H2O×ml(-1)×s(-1), (0.32 ± 0.03) ml/cm H2O] (t = -14.532 - 11.619, P < 0.05). GRP78 mRNA and CHOP mRNA densitometry [(0.65 ± 0.07), (0.79 ± 0.06)] were significantly increased in the COPD group compared with the control group [(0.21 ± 0.04), (0.07 ± 0.04), respectively] (t = -19.102 and -32.573, P < 0.05). GRP78, CHOP, and active caspase-12 protein densitometry (0.83 ± 0.06, 0.82 ± 0.06 and 0.81 ± 0.07) were significantly increased in the COPD group compared with the control group [(0.33 ± 0.05, 0.05 ± 0.03 and 0.24 ± 0.06), respectively] (t = -40.866 - -22.070, P < 0.05). More apoptotic alveolar epithelial cells were found in the COPD group [(32.4 ± 3.7)%] than in the control group [(6.2 ± 0.9)%] (t = -23.852, P < 0.05). CONCLUSIONS: ERS was triggered in the lung tissues of COPD rats, especially in the alveolar epithelial cells. Alveolar epithelial cell apoptosis was increased in the COPD group. The ERS mediated apoptosis pathway may participate in the alveolar epithelial cell apoptosis in COPD.

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.

Melatonin protects against sepsis-induced cardiac dysfunction by regulating apoptosis and autophagy via activation of SIRT1 in mice.

AIMS: The apoptosis and autophagy play an important role in the pathogenesis of sepsis-induced cardiac dysfunction. Previous studies have demonstrated that melatonin protects against cardiac dysfunction during sepsis. In addition, silent information regulator 1 (SIRT1) is a therapeutic target for sepsis-induced myocardial dysfunction. The aims of this study were to investigate whether SIRT1 was involved in melatonin's cardioprotection during sepsis and the mechanisms. MATERIALS AND METHODS: In this study, twenty-four male C57BL/6 mice were randomly assigned to four groups: Control group, LPS group, LPS + Melatonin group and LPS + Melatonin + EX527 group. Mice were treated with lipopolysaccharide for 8 h with or without melatonin or EX527. The cardiac function, myocardial injury biomarkers, cardiac histopathology, cardiomyocyte apoptosis, autophagosome as well as the protein expressions of SIRT1, cleaved caspase-3, LC3-II/LC3-I ratio and p62 in the myocardium were assayed. KEY FINDINGS: The results demonstrated that melatonin significantly improved cardiac function, decreased creatine kinase (CK) and creatine kinase-MB (CK-MB) levels, attenuated myocardial architecture destruction, inhibited cardiomyocyte apoptosis and increased cardiac autophagy as compared with the LPS group. In addition, melatonin significantly increased SIRT1 protein expression in the myocardium of mice with sepsis, while inhibition of SIRT1 by EX527 abolished melatonin's cardioprotection during sepsis. SIGNIFICANCE: In this study, we found that melatonin protected against sepsis-induced cardiac dysfunction by regulating apoptosis and autophagy via activation of SIRT1 in mice.

[Neferine protects endothelial cells against damages induced by LPC and relationship with asymmetric dimethylarginine].

OBJECTIVE: To investigate the protective effect of neferine against damages of endothelial cells induced by lysophos-phatidylcholine (LPC) and the relationship with asymmetric dimethylarginine (ADMA). METHOD: The human umbilical vein endothelial cells (HUVEC-12) were treated with LPC (10 mg x L(-1)) for 24 h to establish the model of endothelial cells damages; HUVECs were prior exposed to neferine (0.1, 1.0 or 10.0 micromol x L(-1) ) for 1 h, and then exposed to LPC in the presence of the neferine for 24 h. At the end of the experiment, the cultured medium was collected for measuring the concentration of nitric oxide (NO), aleic dialdehyde (MDA) as well as ADMA and the cells were collected for measuring the level of intracellular reactive oxygen species (ROS). RESULT: Compared with control group, exposure of endothelial cells to LPC (10 mg x L(-1)) for 24 h significantly increased the concentration of MDA and ADMA in the medium and the level of intracellular ROS and coinstantaneously significantly decreased the concentration of NO in the medium. Neferine (0.1, 1.0 or 10.0 micromol x L(-1)) significantly inhibited the elevated concentration of MDA, ADMA as well as the level of intracellular ROS and coinstantaneously significantly attenuated the decreased level of NO induced by LPC. CONCLUSION: Neferine can protect the endothelial cells against damages induced by LPC and the protective effect is related to the decrease of the concentration of ADMA.

[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.

Increased local expressions of CX3CL1 and CCL2 are related to clinical severity in lumbar disk herniation patients with sciatic pain.

BACKGROUND: Chemokines have been identified to be involved in the modulation of pain through both peripheral and central mechanisms. However, the role of chemokines in lumbar disk herniation (LDH) with sciatic pain remains unknown. OBJECTIVE: The current study was performed to explore the expression of two most commonly studied chemokines CX3CL1 and CCL2 and assess their associations with clinical severity in LDH patients with sciatic pain. METHODS: The soft tissues around nerve root (STANR), annulus fibrosus (AF), and nucleus pulposus (NP) biopsies were obtained from 36 LDH patients with chronic sciatic pain and 10 scoliosis patients (painless controls). The serum and local expressions of CX3CL1 and CCL2 were determined using enzyme-linked immunosorbent assay and Western blot analysis, respectively. The visual analog scale (VAS) scores for low back pain and lower extremity pain and Japanese Orthopaedic Association (JOA) scores were recorded on the day of hospital admission to evaluate the clinical severity. LDH patients with sciatic pain were divided into severe pain (SP) group (VAS ≥7; n=18) and mild-to-moderate pain (M-MP) group (VAS <7; n=18) for lower extremity pain. RESULTS: Local expressions instead of CX3CL1 and CCL2 in STANR, AF, and NP were significantly higher in the SP group than in M-MP compared with scoliosis painless group. Expressions of both CX3CL1 and CCL2 in STANR and AF were positively correlated with VAS scores for lower extremity and for low back pain, respectively. In addition, CX3CL1 and CCL2 expressions in STANR were negatively associated with JOA scores. There were no significant differences of serum CX3CL1 and CCL2 levels among SP group, M-MP group, and scoliosis painless group. CONCLUSION: Both CX3CL1 and CCL2 may play important roles in maintaining pain in LDH patients. Local blockade of CX3CL1 and CCL2 in LDH patients with persistent pain deserves further intensive study.

IL-32 was involved in cigarette smoke-induced pulmonary inflammation in COPD.

PURPOSE: Previous study has proven the overexpression of interleukin 32 (IL-32) in lungs with chronic obstructive pulmonary disease (COPD). But the soluble IL-32 levels and the role of IL-32 in smokers and COPD are still unclear. METHODS: In this study, we enrolled 133 subjects who were divided into three groups: nonsmokers, control smokers and smokers with COPD. We detected the IL-32 levels in serum and induced sputum of all subjects. The pulmonary function, PaO2 and smoking exposure index were also collected. Moreover, macrophages were isolated and stimulated by cigarette smoke extraction (CSE). A special siRNA was used to suppress the IL-32 expression. RESULTS: There was no significant difference in IL-32 serum levels among the three groups. The IL-32 levels of induced sputum in COPD patients were markedly higher than control smokers and nonsmokers. The IL-32 levels in induced sputum of COPD patients were negatively correlated with forced expiratory volume (FEV1)/forced vital capacity and FEV1%. Moreover, a low concentration CSE could stimulate IL-32 expression and promote the release of several inflammatory factors (such as IL-6 and tumor necrosis factor-α). A special siRNA could significantly suppress the release of these inflammatory factors. CONCLUSIONS: This study revealed the critical role of IL-32 in pulmonary inflammation of COPD and smoker-associated diseases.

[Effects of insulin like growth factor-1 on cell viability and tissue factor in vascular endothelial cells].

OBJECTIVE: To study the effects of insulin like growth factor-1 (IGF-1) on cell viability and tissue factor (TF) in angiotensin II (Ang II) induced vascular endothelial cells and to investigate its mechanisms. METHODS: 10(-6) mol/L Ang II was added to human vascular endothelial cells (HUVECs) culture media alone or 30 min after pretreatment with IGF-1 (0.1 microg/ml , 0.5 microg/ml, 2.5 microg/ml). Cell viability and AngII type 1 receptor (AT1-R) mRNA were evaluated after 24 h incubation with AngII. At the optimum concentration of IGF-1 affecting cell viability, the time dependent manner for 12 - 48 h incubation with Ang II was evaluated. TF, NOS and NO were investigated after 24 h incubation with Ang II. In addition, NO synthase inhibitor Nomega-nitro-1-arginine methylester(L-NAME) was added 30 min before addition of IGF-1 and Ang II, and cell viability, TF, AT1-R mRNA, NOS and NO were evaluated after 24 h incubation. RESULTS: (1) Ang II induced a decrease in cell vitality, an upregulation of AT1-R mRNA, an increase in TF, and a decrease in the activity of NOS and content of NO. (2) Pretreatment with IGF-1 significantly inhibited the decreased cell viability and upregulation of AT1-R mRNA. IGF-1 at 0.5 microg/ml showed the most obvious effects. This effect of cell viability recovery was in a time dependent manner during 12 -48 h. (3) IGF-1 also inhibited the increased content of TF, the decreased activity of NOS and the decreased content of NO. (4) The beneficial effects of IGF-1 on cultured endothelial cells were completely abolished by L-NAME. CONCLUSION: IGF-1 pretreatment could enhance the ang II injured cell viability and anti-thrombosis capacity, and the protective effects may be related to activation of NOS-NO signaling pathway which inhibited AT1-R.