Emerging roles of lncRNA in cancer and therapeutic opportunities.

Cancer is difficult to cure due to frequent metastasis, and developing effective therapeutic approaches to treat cancer is urgently important. Long non-coding RNAs (lncRNAs) have diverse roles in regulating gene expression at both the transcriptional and translational levels and have been reported to be involved in tumorigenesis and tumor metastasis. In this article, we review the emerging roles of lncRNAs in cancer, especially in cancer immunity, cancer metabolism and cancer metastasis. We also discuss the use of novel technologies, such as antisense oligonucleotides, CRISPR-Cas9 and nanomedicines, to target lncRNAs and thus control cancers.

Pharmacological evidence: a new therapeutic approach to the treatment of chronic heart failure through SUR2B/Kir6.1 channel in endothelial cells.

Both iptakalim (Ipt) and natakalim (Nat) activate the SUR2B/Kir6.1 channel, an ATP-sensitive potassium channel (KATP) subtype, with high selectivity. In this study we investigated the therapeutic effects of Ipt and Nat against isoproterenol-induced chronic heart failure (ISO-CHF) in rats, and demonstrated a new therapeutic approach to the treatment of CHF through activation of the SUR2B/Kir6.1 channel in endothelial cells. In ISO-CHF rats, oral administration of Nat (1, 3, 9 mg·kg-1·d-1) or Ipt (3 mg·kg-1·d-1) for 60 days significantly improved cardiac dysfunction, reversed cardiac remodeling, significantly attenuated the pathological increases in BNP levels, and improved endothelial dysfunction by adjusting the balance between endothelin and NO systems. The therapeutic effects of Nat were prevented by the selective KATP blocker glibenclamine (Gli, 50 mg·kg-1·d-1), confirming that these effects were mediated through activation of the SUR2B/Kir6.1 channel in endothelial cells. The molecular mechanisms underlying the therapeutic effects of Nat were further addressed using proteomic methods. We identified 724 proteins in the plasma of ISO-CHF rats; 55 proteins were related to Nat. These differentially expressed proteins were mainly involved in single-organism processes and the regulation of biological quality relative to CHF, including proteasome (Psm) and ATP protein clusters. We screened out PRKAR2ß, GAS6/eNOS/NO and NO/PKG/VASP pathways involved in the amelioration of CHF among the 24 enriched pathways. We further confirmed 6 protein candidates, including PRKAR2ß, GAS6 and VASP, which were involved in the endothelial mechanisms, and ATP, TIMP3 and AGT, which contributed to its cardiovascular actions. This study demonstrates a new pharmacological approach to the treatment of CHF through activation of the SUR2B/Kir6.1 channel in endothelial cells, and that the eNOS/VASP pathways are involved in its signaling mechanisms.

[Construction of T vectors based on Xcm I recognition site and optimization of PCR fragments for ligation].

OBJECTIVE: To construct T vectors based on Xcm I recognition site and optimize the PCR fragments for its ligation. METHODS: We firstly cloned the human histone H4 cDNA containing one Xcm I recognition site at both its 5' and 3' end into pCDNA 3.0 vector and then generated T vector with pCDNA 3.0 backbone by cutting the recombinant plasmid with Xcm I. To increase the ligation efficiency, the primers were firstly phosphorylated before DNA fragments amplification and then the PCR products were treated with Taq DNA polymerase and dATP after PCR amplification. Two DNA fragments with the length of 312 bp and 1 329 bp were ligated to it and the ligation mixture was transformed into E. coli DH5α competent cells and the positive rates of the transformants were evaluated by PCR and DNA agarose gel electrophoresis. RESULTS: Our results showed that the T vector produced by our method could ligate to the target DNA fragments with high efficiency. Besides, the phosphorylation state of the primers used for PCR amplification is also an important factor determining the cloning efficiency. What's more, as for longer DNA fragments, retreatment with Taq DNA polymerase and dATP after PCR amplification and purification could improve the ligation efficiency significantly. CONCLUSION: Our protocol may overcome the dependence on blue/white screening to get positive clones and provide a potent way to generate T vectors and ligate them to the target PCR fragment.

Sensitivity of KATP channels to cellular metabolic disorders and the underlying structural basis.

AIM: ATP-sensitive potassium (KATP) channels formed by a combination of SUR/Kir6.x subunits play a crucial role in protection against hypoxic or ischemic injuries resulting from cell metabolic disorders. In this study we investigated the effects of Na-azide, a metabolic inhibitor, on KATP channels expressed in Xenopus oocytes, and explored the structure basis for their sensitivity to cell metabolic disorders. METHODS: Six subtypes of KATP channels (wild SUR1/Kir6.2, SUR2B/Kir6.2, SUR1/Kir6.1, SUR2B/Kir6.1, SUR2A/Kir6.2 and SUR2A/Kir6.1), as well as eleven subtypes of KATP channels with mutant subunits were expressed in Xenopus oocytes. KATP currents were recorded using a two-electrode voltage clamp recording technique. The drugs were applied through bath. RESULTS: Except SUR2A/Kir6.1, five subtypes of KATP channels were activated by Na-azide (3 mmol/L) with an order of the responses: SUR1/Kir6.2>SUR2B/Kir6.2>SUR1/Kir6.1>SUR2B/Kir6.1>SUR2A/Kir6.2, and the opening rate (t1/2) was SUR1/Kir6.x>SUR2B/Kir6.x>SUR2A/Kir6.2. Furthermore, Kir6.2, rather than Kir6.1, had intrinsic sensitivity to Na-azide, and the residues involved in ATP-binding (R50 and K185) or pH-sensing (H175) were associated with the sensitivity of the Kir6.2 subunit to Na-azide. Moreover, the residues (K707 and K1348) within the Walker A (WA) motifs of two nucleotide-binding domains (NBDs) were essential for SUR2B/Kir6.x (especially SUR2B/Kir6.1) channel activation by Na-azide, suggesting a key role for Mg-adenine nucleotide binding and/or hydrolysis in the SUR2B subunit. CONCLUSION: Among the six subtypes of KATP channels, SUR1/Kir6.2 is the most sensitive, whereas SUR2A/Kir6.1 is insensitive, to cell metabolic disorders. The Kir6.2 subunit, rather than the Kir6.1 subunit, has intrinsic sensitivity to cell metabolic disorders. The residues (K707 and K1348) within the WA motifs of SUR2B are important for the sensitivity of SUR2B/Kir6.x channels to cell metabolic disorders.

Differential modulation of GABAA and NMDA receptors by α7-nicotinic receptor desensitization in cultured rat hippocampal neurons.

AIM: To explore the modulatory effect of desensitized α7-containing nicotinic receptors (α7-nAChRs) on excitatory and inhibitory amino acid receptors in cultured hippocampal neurons and to identify the mechanism underlying this effect. METHODS: Whole-cell patch-clamp recordings were performed on cultured rat hippocampal neurons to measure α7-nAChR currents and to determine the role of desensitized α7-nAChRs on brain amino acid receptor activity. RESULTS: Pulse and perfusion applications of the α7-nAChR agonist choline were applied to induce different types of α7-nAChR desensitization in cultured hippocampal neurons. After a brief choline pulse, α7-nAChR was desensitized as a result of receptor activation, which reduced the response of the A type γ-aminobutyric acid (GABAA) receptor to its agonist, muscimol, and enhanced the response of the NMDA receptor to its agonist NMDA. By contrast, the responses of glycine or AMPA receptors to their agonists, glycine or AMPA, respectively, were not affected. Pretreatment with the α7-nAChR antagonist methyllycaconitine (MLA, 10 nmol/L) blocked the choline-induced negative modulation of the GABAA receptor and the positive modulation of the NMDA receptor. The regulation of the GABAA and NMDA receptors was confirmed using another type of α7-nAChR desensitization, which was produced by a low concentration of choline perfusion. The negative modulation of the GABAA receptor was characterized by choline-duration dependency and intracellular calcium dependency, but the positive modulation of the NMDA receptor was not associated with cytoplasmic calcium. CONCLUSION: Brain GABAA and NMDA receptors are modulated negatively and positively, respectively, by desensitized α7-nAChR as a result of choline pretreatment in cultured hippocampal neurons.

[Molecular of pulmonary arterioles relaxation through SUR2B/Kir6.1 channel opening].

OBJECTIVE: To study the dilatation characteristics of ATP-sensitive potassium channel (KATP) SUR2B/Kir6.1 subtype opener iptakalim (Ipt) in pulmonary arterioles, and to explore its possible mechanism. METHODS: Vessels pressure-diameter monitoring perfusion technique was used to observe the dilatation effects of Ipt in rats fourth pulmonary arterioles (n=6~8). After the pulmonary arterioles were pre-treated with removing endothelium or pre-incubated with KATP channel blocker glibenclamide (Gli), cyclo-oxygenase (COX) inhibitor indomethacin (Indo) and nitric oxide synthase (NOS) inhibitor L-Nω-Nitro-arginine methyl ester(L-NAME), the dilatation effects of Ipt were observed. RESULTS: Pulmonary arterioles could be relaxed by Ipt, the maximal relaxation rate was (60.53±2.08)%. Compaired with control group, the effects of Ipt in endothelium denuded arterioles were significantly decreased, the maximal relaxation rate was (9.47±1.56)% (P<0.01). The maximal relaxation rate were decreased to(17.49±1.47)%,(37.00±3.88)% and(24.91±2.30)% respectively after Gli,Indo,L-NAME were pre-incubated (P<0.01). CONCLUSIONS: Pulmonary arterioles can be relaxed by Ipt. The selective activation of KATP SUR2B/Kir6.1 subtype by Ipt was involved in its mechanisms. The endothelium-dependently dilatation of Ipt was related to nitric oxide (NO) and prostacyclin (PGI2) released by endothelial cells.

The new antihypertensive drug iptakalim activates ATP-sensitive potassium channels in the endothelium of resistance blood vessels.

AIM: To investigate the mechanisms underlying the activation of ATP-sensitive potassium channels (K(ATP)) by iptakalim in cultured rat mesenteric microvascular endothelial cells (MVECs). METHODS: Whole-cell KATP currents were recorded in MVECs using automated patch clamp devices. Nucleotides (ATP, ADP and UDP) were added to the internal perfusion system, whereas other drugs were added to the cell suspension on NPC-1 borosilicate glass chips. RESULTS: Application of iptakalim (10 and 100 µmol/L) significantly increased the whole-cell K(ATP) currents, which were prevented by the specific K(ATP) blocker glibenclamide (1.0 µmol/L). The opening of K(ATP) channels by iptakalim depended upon the intracellular concentrations of ATP or NDPs: iptakalim activated K(ATP) channels when the intracellular ATP or NDPs were at 100 or 1000 µmol/L, and was ineffective when the non-hydrolysable ATP analogue ATPγS (1000 µmol/L) was infused into the cells. In contrast, the K(ATP) opener pinacidil activated K(ATP) channels when the intracellular concentrations of ATP or NDPs ranged from 10 to 5000 µmol/L, and even ATPγS (1000 µmol/L) was infused into the cells. CONCLUSION: Iptakalim activates K(ATP) channels in the endothelial cells of resistance blood vessels with a low metabolic status, and this activation is dependent on both ATP hydrolysis and ATP ligands.

Synergisms of cardiovascular effects between iptakalim and amlodipine, hydrochlorothiazide or propranolol in anesthetized rats.

The primary object of this fundamental research was to survey the synergistic cardiovascular effects of iptakalim, a novel ATP-sensitive potassium channel (K(ATP)) opener, and clinical first-line antihypertensive drugs, such as calcium antagonists, thiazide diuretics and ß receptor blockers by a 2 x 2 factorial-design experiment. It would provide a theoretical basis for the development of new combined antihypertensive therapy program after iptakalim is applied to the clinic. Amlodipine besylate, hydrochlorothiazide and propranolol were chosen as clinical first-line antihypertensive drugs. Blood pressure, heart rate (HR) and cardiac functions were observed in anesthetized normal rats by an eight-channel physiological recorder. The results showed that iptakalim monotherapy in a low dose could produce significant antihypertensive effect. There was no interaction between iptakalim and amlodipine on the maximal changes of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MABP), the left ventricular systolic pressure (LVSP), and the left ventricular end-diastolic pressure (LVEDP) (P > 0.05). However, the effects of combination iptakalim/amlodipine on the maximal changes of SBP, DBP, MABP, LVSP and LVEDP were more obvious than those of iptakalim or amlodipine monotherapy. And there was strong positive interaction between iptakalim and amlodipine on the maximal changes of HR (P>0.05). According to the maximal changes of DBP, MABP, LVSP and LVEDP (P < 0.05) of combination iptakalim with hydrochlorothiazide, there was strong positive interaction between them. But there was no interaction between iptakalim and hydrochlorothiazide on the maximal drop of SBP and HR (P > 0.05). According to the maximal drops of DBP, MABP of combination iptakalim with propranolol, there was strong positive interaction between them (P < 0.05). But there was no interaction between iptakalim and propranolol on the maximal changes of SBP, LVSP, LVEDP and HR (P > 0.05). In conclusion, it was the first time to study the effects of amlodipine, hydrochlorothiazide or propranolol, which had different mechanisms of action from iptakalim, on cardiovascular effects of iptakalim in anesthetized normal rats. This study proved that the combination of iptakalim with hydrochlorothiazide or propranolol respectively had significant synergism on lowering blood pressure, while the combination of iptakalim/amlodipine had additive action on lowering blood pressure. Meanwhile the antihypertensive effect was explicit, stable and long-lasting. Iptakalim thus appears suitable for the clinical treatment of hypertensive people who need two or more kinds of antihypertensive agents.

[The construction and application of a novel apparatus for detecting oxygen consumption of mice under normobaric hypoxia].

OBJECTIVE: To establish a method for real-time recording the oxygen consumption of mice under normobaric hypoxia. METHODS: The experimental apparatus was made up of animal container, filling water control system, electronic balance, hose, a computer with weight recording software, etc. The working principle was that the oxygen consumed by animal was replaced by water filling which was controlled by the pneumatic and hydraulic actuator. The water was weighted by an electronic balance and the weight signal was recorded into excel file at the same time. The accuracy and precision of the apparatus were detected by a 10 ml syringe. The oxygen consumption characteristics of 6 acute repetitive hypoxia mice and 6 normal mice were observed. RESULTS: The P value for the paired t test was 1 and the CV value was 4%. The survival time and total oxygen consumption of acute repetitive hypoxia mice were both significantly increased compared to normal mice (P < 0.05), which were (58.8 +/- 6.8) min and (46.0 +/- 8.7) min respectively for the survival time and (85.1 +/- 8.5) ml and (73.6 +/- 5.4) ml respectively for total oxygen consumption. CONCLUSION: The hypoxia tolerance of the acute repetitive hypoxia mice can significantly improved by taking more oxygen in the animal cabin. The accuracy and precision of the apparatus are high and it can be used for the determination of oxygen consumption in hypoxia research.

[The effect of hypothermia on the vasoconstriction and vasodilatation and concerned with vasoactive drugs].

OBJECTIVE: To investigate the changes of vasoconstriction and vasodilatation under different temperature conditions and the protective effects of Vitamin E (Vit E) against endothelial injury induced by hypothermia. METHODS: The tail arterial rings were prepared for isometric tension recording using multi wire myograph system. The effect of temperature on relaxation and construction was evaluated. Incubate the arterial rings with different concentration of Vit E when they were exposed to hypothermia, then acetylcholine (ACh)-induced endothelium-dependent relaxation was investigated to evaluate the activity of endothelial. RESULTS: (1) The hypothermia could enhanced the dose-dependent construction induced by PE in mice tail artery. (2) Exposure to hypothermia also resulted in increase of sodium nitroprusside (SNP)-induced re-After incubation with Vit E, the vascular relaxation responses to ACh increased in an endothelium-dependent manner, when compared with the hypothermia-treated group. CONCLUSION: The vascular function of constriction was attenuated by hypothermia, while the relaxation was increased. Vit E could prevent the hypothermia-induced decrease in vascular endothelial cells.

Natakalim improves post-infarction left ventricular remodeling by restoring the coordinated balance between endothelial function and cardiac hypertrophy.

Endothelial dysfunction can lead to congestive heart failure and the activation of endothelial ATP-sensitive potassium (K(ATP)) channels may contribute to endothelial protection. Therefore, the present study was carried out to investigate the hypothesis that natakalim, a novel K(ATP) channel opener, ameliorates post-infarction left ventricular remodeling and failure by correcting endothelial dysfunction. The effects of myocardial infarction were assessed 8 weeks following left anterior descending coronary artery occlusion in male Wistar rats. Depressed blood pressure, cardiac dysfunction, evidence of left ventricular remodeling and congestive heart failure were observed in the rats with myocardial infarction. Treatment with natakalim at daily oral doses of 1, 3 or 9 mg/kg/day for 8 weeks prevented these changes. Natakalim also prevented the progression to cardiac failure, which was demonstrated by the increase in right ventricular weight/body weight (RVW/BW) and relative lung weight, signs of cardiac dysfunction, as well as the overexpression of atrial and brain natriuretic peptide mRNAs. Our results also demonstrated that natakalim enhanced the downregulation of endothelium-derived nitric oxide, attenuated the upregulation of inducible nitric oxide synthase-derived nitric oxide (NO), inhibited the upregulated endothelin system and corrected the imbalance between prostacyclin and thromboxane A(2). Overall, our findings suggest that natakalim prevents post-infarction hypertrophy and cardiac failure by restoring the coordinated balance between endothelial function and cardiac hypertrophy.

Proteomics reveals potential non-neuronal cholinergic receptor-effectors in endothelial cells.

AIM: The non-neuronal acetylcholine system (NNAS) in endothelial cells participates in modulating endothelial function, vascular tone, angiogenesis and inflammation, thus plays a critical role in cardiovascular diseases. In this study, we used a proteomic approach to study potential downstream receptor-effectors of NNAS that were involved in regulating cellular function in endothelial cells. METHODS: Human umbilical vein endothelial cells were incubated in the presence of acetylcholine, oxotremorine, pilocarpine or nicotine at the concentration of 10 µmol/L for 12 h, and the expressed proteins in the cells were separated and identified with two-dimensional electrophoresis (2-DE) and LC-MS. The protein spots with the largest changes were identified by LC-MS. Biowork software was used for database search of the peptide mass fingerprints. RESULTS: Over 1200 polypeptides were reproducibly detected in 2-DE with a pH range of 3-10. Acetylcholine, oxotremorine, pilocarpine and nicotine treatment caused 16, 9, 8 and 9 protein spots, respectively, expressed differentially. Four protein spots were identified as destrin, FK506 binding protein 1A (FKBP1A), macrophage migration inhibitory factor (MIF) and profilin-1. Western blotting analyses showed that treatment of the cells with cholinergic agonists significantly decreased the expression of destrin, FKBP1A and MIF, and increased the expression of profilin-1. CONCLUSION: A set of proteins differentially expressed in endothelial cells in response to cholinergic agonists may have important implications for the downstream biological effects of NNAS.

[Genome-wide association study of high altitude pulmonary edema].

OBJECTIVE: High altitue pulmonary edema (HAPE) impacts seriously people's health at high altitude. Screening of susceptibility genes for HAPE will be used for the evaluation and protection of susceptible people. METHODS: We performed a genome-wide association study (GWAS) using Affymetrix SNP array 6.0 in 23 HAPE patients and 17 healthy controls. GO and Pathway analysis softwares were used to analyze and draw gene network. RESULTS: Thirty-nine SNPs were found to be significantly different between case and control groups (P < 10(-4)). GO and Pathway analysis of 27 genes around the 39 SNPs indicated that these genes mainly participate in the regulating of cell proliferation, regulation of nitrogen compound metabolic process and G-protein coupled receptor protein signaling pathway and so on. CONCLUSION: It suggests that these SNPs and genes found in this study may be associated with the susceptibility of HAPE.

[Novel drug composition ameliorating thrombosis and its molecular mechanisms].

OBJECTIVE: To investigate the antithrombotic effects and its molecular mechanisms of prazosin combined with anisodamine (Ani). METHODS: Isolated rat tail artery rings model was employed to evaluate the vasodilative effects of drugs, mice tail thrombosis model induced by carrageenan was used to study the antithrombotic effects and its molecular mechanisms of the drug composition. RESULTS: Among alpha1-adrenoreceptor antagonists, prazosin(Pra) had the greatest relaxation rate, which was (82.6 +/- 8.9)%, and the EC50 value was 0.44 micromol/L. The drug composition of anisodamine and prazosin of different doses could decrease the length of the tail thrombosis from (24.6 +/- 4.6)mm to (6.9 +/- 2.7)mm, and the rate of thrombosis was decreased from 86.6% to 50.0%. The drug composition could prolong the prothrombin time (PT) distinctively, but it had no effect on the activated partial thromboplastin time (APTT). It also could restrain the decrease of serum levels of tissue plasminogen activator (t-PA) and 6- Keto -PGF1alpha as well as the increase of type-1 plasminogen activator inhibitor (PAI-1) and thromboxane B2 (TXB2) in the mice. CONCLUSION: The drug composition formed by anisodamine and prazosin has good effects of relaxing extremities tiny blood vessels and it can fight against thrombosis, its antithrombotic mechanisms may be related to the influence of the extrinsic coagulation pathway, inhibition of platelet activation functions and the promotion of fibrinolysis function.

Bioavailability, tissue distribution, and excretion characteristics of the novel carbonic anhydrase inhibitor tolsultazolamide in rats.

AIM: Tolsultazolamide, a novel carbonic anhydrase inhibitor, is designed for the prophylaxis and treatment of acute mountain sickness. The aim of this study was to investigate the pharmacokinetics, tissue distribution, and excretion characteristics of tolsultazolamide and the sex difference in pharmacokinetics in rats. METHODS: For pharmacokinetic study, rats were intravenously injected tolsultazolamide at 1 and 2 mg/kg or orally administered tolsultazolamide at 20, 40, or 80 mg/kg) in a pharmacokinetic study. The concentrations of tolsultazolamide in plasma were determined with high-performance liquid chromatography, with a liquid-liquid extraction. For tissue distribution study, tolsultazolamide (80 mg/kg) was orally administered to overnight fasted rats (six per group and three per sex). Samples were collected from the brain, heart, lung, liver, spleen, muscle, kidney, stomach, fat, intestines, pancreas and sexual gland. For excretion study, tolsultazolamide (40 mg/kg) was orally administered to 6 rats (three per sex). The urine, feces, and bile samples were collected at 24, 48, and 72 h. RESULTS: After its intravenous administration, tolsultazolamide was rapidly eliminated from the plasma, with T1/2 of about 60-90 min. The AUC0-t and the initial concentration (C0) values were proportional to the intravenous doses. After its oral administration, tolsultazolamide showed dose-independent pharmacokinetic characteristics, with Tmax and T1/2 of approximately 2 h and 5-7 h, respectively, and good oral absolute bioavailability of about 60%. Tolsultazolamide was distributed widely in various tissues. The highest tolsultazolamide levels were detected in the stomach, intestine, spleen, lung, and kidney. Total excretion of unchanged tolsultazolamide in the urine, feces, and bile was less than 2%. The Cmax and AUC of tolsultazolamide were significantly higher in female rats than those in male rats. Clearance and volume of distribution were greater in male rats than those in female rats. The oral absolute bioavailability was also significantly different between female rats (about 83%) and male rats (about 37%). CONCLUSION: Tolsultazolamide was well absorbed and widely distributed in the rat, and very little of the unchanged form was excreted. Sex had a significant effect on the pharmacokinetics of tolsultazolamide.

Stimulation of endothelial non-neuronal muscarinic receptor attenuates the progression of atherosclerosis via inhibiting endothelial cells activation.

OBJECTIVE: To investigate the effects of non-neuronal muscarinic receptors (NNMR) stimulation on atherosclerosis and endothelial cells activation. METHODS: Atherosclerosis model was established in ApoE-/- mice by a high fat diet for 7 weeks. During the experimental periods, animals were received a low (7 mg/kg/d) or a high (21 mg/kg/d) dose of arecoline by gavage. At the termination of the treatments, serum total cholesterol and NO levels were measured, and the aorta morphology was analyzed by hematoxylin and eosin staining. The gene expression of monocyte chemoattractant protein-1 (MCP-1) and adhesion molecules in the thoracic aortas was determined by RT-PCR, and the MCP-1 protein expression and NF-κB activity were detected by Western blot analysis. NO production, MCP-1 secretion in cultured rat aortic endothelial cells (RAECs), and monocyte-endothelium adhesion assay were also performed after arecoline treatments. RESULTS: Arecoline efficiently decreased atherosclerotic plaque areas, increased serum nitric oxide (NO) content, suppressed the mRNA and protein expression of MCP-1, and modulated the IκB-α degradation and P65 phosphorylation in the aortae of ApoE-/- mice. Furthermore, arecoline promoted NO production and suppressed MCP-1 secretion in cultured RAECs after ox-LDL exposure, and either atropine or NG-nitro-L-arginine methylester could abrogate these effects. Arecoline also significantly inhibited the adherence of U937 monocytes to the ox-LDL injured human umbilical vein endothelial cells, which could be abolished by atropine. CONCLUSION: Our results indicate that arecoline attenuates the progression of atherosclerosis and inhibits endothelial cells activation and adherence by stimulating endothelial NNMR. These effects, at least in part, are due to its modulation on NF-κB activity.

[Effects of ATP-sensitive potassium channel opener iptakalim against ventricular remodeling and its mechanisms of endothelial protection].

OBJECTIVE: To study the effects of iptakalim (Ipt), an ATP-sensitive potassium channel opener, on cardiac remodeling induced by isoproterenol (ISO) in Wistar rats. METHODS: ISO was given subcutaneously (85 mg/(kg x d), sc, 7 days) to induce cardiac remodeling in rats. The rats in Ipt treated group were administrated with Ipt 3 mg/kg (po) after ISO injection. After treated with Ipt for 6 weeks, the hemodynamic parameters were tested by an eight channel physiological recorder (RM-6000). Then the heart weight was weighed and the cardiac remodeling index was calculated. HE stain and Masson's stain were employed to perform histological analysis, the hydroxyproline(Hyp) content in cardiac tissue was detected by colorimetric method, radioimmunoassay was used to measure the plasma levels of endothelin-1 (ET-1) and prostacyclin (PGI2). RESULTS: Six weeks after ISO injection, the cardiac functions of model group were damaged markedly compared with those of normal group. The characteristics of ventricular remodeling in model group included that the heart weight index, myocyte cross-sectional area, myocardial fibrosis, and the hydroxyproline content in cardiac tissue were all increased significantly. The plasma level of ET-1 was increased, while the plasma level of PGI2 was decreased significantly. These changes could be reversed by Ipt treatment (3 mg/(kg x d) for 6 weeks). CONCLUSION: Ipt can reverse cardiac remodeling induced by isoproterenol in rats. The endothelial protective effect regulating effects of Ipt on the balance between the ET-1 and PGI2 system may be involved in its mechanisms.

[Choline promotes angiogenesis in chick embryo chorioallantoic membrane].

OBJECTIVE: To investigate choline promoting angiogenesis on chick embryo chorioallantoic membrane (CAM). METHODS: CAM model was prepared, the choline chloride, human vascular endothelial growth factor (hVEGF) and normal saline were added respectively onto the carrier on the CAM, the state of angiogenesis was observed and the number of new blood vessels was counted. RESULTS: Choline chloride was tested at the concentrations of 0.5 nmol/L - 1 mmol/L in this experiment, when its concentrations were increased to 0.01 micromol/L - 1 000 micromol/L, it could stimulate angiogenesis, the minimum effective concentration was tested as 0.01 micromol/L, and its effect for promoting the angiogenesis was equivalent to that of hVEGF, the potent stimulator for angiogenesis. CONCLUSION: The result shows that choline can promote angiogenesis in the chick embryo chorioallantoic membrane.

[Protective effect of anti-hypoxia shenggui tablet on cerebral ischemia injure].

OBJECTIVE: To investigate the protective effects of Shengui tablet (Chinese Traditional Medicine) on experimental cerebral ischemia by acute cerebral ischemia hypoxia in mice and bilateral ligation of the carotid artery in rats. METHODS: In the acute cerebral ischemia hypoxia model, the mice were randomly divided into control group, low-, middle- and high-dose (0.16, 0.33 and 1.00 g/kg) groups of Shengui tablet, after oral treatment for 30 d, gasping time of isolated heads of mice were observed. In bilateral ligation of the carotid artery cerebral ischemia model, the rats were randomly divided into control group, model group and low-, middle-, high-dose (0.072, 0.149 and 0.450 g/kg) groups of Shengui tablet. After oral treatment for 7 d, the cerebral index, superoxide dismutase (SOD) activity and the content of malondialdehyde (MDA) were measured. RESULTS: Compared with the control model, Shengui tablet middle- and high-dose could significantly prolong gasping time of isolate heads of mice. Compared with model group, Shengui tablet low-, middle- and high-dose could significantly decrease the cerebral index and enhance SOD activity in brain tissue; only high-dose could reduce the content of MDA. CONCLUSION: Shengui tablet has significant protective effect on the cerebral ischemia.

Stimulation of non-neuronal muscarinic receptors enhances chemerin/ChemR23 system in dysfunctional endothelial cells.

AIMS: Endothelial cells play a pivotal role in vascular intimal inflammation during cardiovascular diseases. The chemerin/ChemR23 system in endothelial cells is one of physiological mechanisms that regulate inflammatory responses. Our previous studies indicated that stimulation of non-neuronal muscarinic receptor (NNMR) improved endothelial dysfunction. However, the relationship between the chemerin/ChemR23 signaling axis and NNMR in endothelial cell is poorly understood. Here, we first investigated whether the modulation of chemerin/ChemR23 signaling axis is involved in NNMR-mediated endothelial protection. MAIN METHODS: Cultured rat aortic endothelial cells (RAECs) were used. The ChemR23 protein expression and chemerin secretion were measured using Western blot analysis. The gene expression level of ChemR23 was examined with reverse transcriptase PCR (RT-PCR). The production of nitric oxide (NO) was determined by a nitrate reductase assay kit. KEY FINDINGS: A sharp decline of chemerin secretion and ChemR23 protein/gene expression was observed in RAECs after exposed to homocysteine at concentration of 0.5 mmol/L. Arecoline (10 µmol/L) pretreatment increased ChemR23 protein expression as well as mRNA expression, and enhanced the secretion of chemerin. Arecoline could also reverse the decreased ChemR23 mRNA expression induced by uric acid, high glucose, or oxidized low-density lipoprotein. Furthermore, the modulation of arecoline on chemerin/ChemR23 signaling axis was absolutely abolished in the presence of the nonselective muscarinic receptors antagonist atropine 1 µmol/L. Additionally, arecoline improved endothelial dysfunction by increasing the reduced NO production induced by uric acid, which was blocked by anti-ChemR23 antibody. SIGNIFICANCE: The chemerin/ChemR23 signaling axis participates in NNMR-mediated protection against endothelial dysfunction in cardiovascular system.