AIM: To study the role of peroxisome proliferator-activated receptor-α (PPAR-α) signal transduction pathway in cardiac hypertrophy induced by high glucose and insulin (HGI). METHODS: The cultured neonatal rat cardiomyocytes were used to observe the effect of fenofibrate (FF), a selective PPAR-α agonist, on cardiomyocyte hypertrophy induced by HGI (glucose at concentration of 25.5 mmol/L and insulin at 0.1 μmol/L). The cardiomyocyte hypertrophic responses were assayed by measuring the cell surface area, protein content, and mRNA expression of atrial natriuretic factor (ANF). The expressions of mRNA and protein were assayed by real -time PCR and Western blotting. RESULTS: In cultured cardiomyocytes, HGI induced profound change of hypertrophic morphology, the significant increase in cell surface area, protein content and ANF mRNA expression compared to those in vehicle control (P<0.01), but the expressions of PPAR-α mRNA and protein decreased significantly (P<0.05). At the same time, the expression of cyclooxygenase 2 (COX-2), one of the PPAR-α downstream effectors was obviously elevated (P<0.05). However, FF (0.1, 0.3 and 1 μmol/L) inhibited the cardiomyocyte hypertrophy induced by HGI in a concentration-dependent manner (P<0.01). FF at concentration of 0.3 μmol/L increased the expressions of PPAR-α in both mRNA and protein levels (P<0.05) and inhibited the expressions of COX-2 (P<0.05), which were abolished by MK 886 (0.3 μmol/L), a selective PPAR-α antagonist (P<0.05). CONCLUSION: PPAR-α signal transduction pathway and its downstream effector COX-2 might involve in the cardiomyocyte hypertrophy induced by HGI.

AIM:To study the role of peroxisome proliferator-activated receptor-? (PPAR-?) signal transduction pathway in cardiac hypertrophy induced by high glucose and insulin (HGI). METHODS:The cultured neonatal rat cardiomyocytes were used to observe the effect of fenofibrate (FF),a selective PPAR-? agonist,on cardiomyocyte hypertrophy induced by HGI (glucose at concentration of 25.5 mmol/L and insulin at 0.1 ?mol/L). The cardiomyocyte hypertrophic responses were assayed by measuring the cell surface area,protein content,and mRNA expression of atrial natriuretic factor (ANF). The expressions of mRNA and protein were assayed by real -time PCR and Western blotting. RESULTS:In cultured cardiomyocytes,HGI induced profound change of hypertrophic morphology,the significant increase in cell surface area,protein content and ANF mRNA expression compared to those in vehicle control (P

ObjectiveTo investigate the effects of cardioplegic solution enriched with different doses of glutathione on myocardial injury in children undergoing cardiac surgery under cardiopulmonary bypass (CPB).MethodsForty-eight ASA [Ⅱ or Ⅲ patients aged 2-5 yr undergoing repair of ventricular septal defect under CPB were randomly divided into 4 groups (n ＝ 12 each):control group (group C) and cardioplegic solution containing 3 different-dose of glutathione groups ( group G1-3 ).Glutathione 50,75,100 mg/kg were added to cardioplegic solution in group G1-3 respectively.Blood samples were collected before operation (T0),at 30 min after release of aortic cross-clamp (T1),at 6,12,24 h after termination of CPB (T2-4) for determination of plasma cTnI concentration.Myocardial specimens were obtained from right auricle before aortic cross-clamp and 15 min after release of aortic cross-clamp.The ultrastructure of myocardium was examined with scanning electron microscope.A mitochondrial FlaMeng semiquantitative analysis was done.ResultsThe plasma concentration of cTnI at T3,4 were significantly lower in groups G1,2 than in group C.The plasma concentration of cTnI at T1-4 were significantly lower in group G3 than in group C and group G1,2.The quantization score of myocardial mitochondria at 15 min after release of aortic cross-clamp were significantly lower in group G3 than in group C and group G1,2.Micorscopic examination showed that the injury to myocardial ultrastructure was attenuated in group G3 compared with group C.Conclusion Cardioplegic solution enriched with glutathione can reduce myocardial injury induced by CPB in a dose dependent manner.Glutathione 100 mg/kg can exert a visibly protective effect on myocardium.

Objective To explore the value of color Doppler ultrasonography(CDU)as preoperative diagnosing and postoperative monitoring in patients with stenosis of subclavian or innominate artery(SIA)before and after percutaneous transluminal angioplasty and stent(PTAS).Methods A total of 45 patients with stenosis of SIA were selected.Their extracranial vertebral artery and subclavian artery were observed with CDU.In 36 patients with one-sided stenosis of SIA.blood flow direction and spectrum of extracranial vertebraI artery were analyzed.Subclavian steal grade confirmed by spectrum change of vertebral artery was compared with the stenosis grade on quantitative angiography(QA).Among 45 patients with stenosis of SIA,PTAS was performed successfully in 36 patients(36 stents implanted).After stents implanted, hemodynamie parameters such as peak systolic velocity(PSV)in stent, follow-up velocity ratio in stem(VR)were measured.Restenosis in stent were observed.Results In 36 patients with one-sided stenosis of SIA,the ultrasonographic steal grade correlated with the QA stenosis grade significantly(r=0.752,P<0.01).Among 36 patients with stent implanted,follow up 8-12 months, 4 patients with restenosis in stent were found.Compared with the patients without restenosis in stent,PSV and VR in stent increased significantly(P<0.01).Conclusions As a fast and non-invasive imaging technique,CDU could allow diagnosis of stenosis of SIA before PTAS,and detection of restenosis after PTAS.

Objective To investigate the suppressive effect of exogenous carbon monoxide (CO) on abnormal platelet exocytosis and its possible molecular mechanism. Methods Venous blood was collected from healthy volunteers. Platelet-rich plasma (PRP) was isolated from the blood by differential centrifugation. The PRP was randomly divided into five groups by random number table, namely normal control group, lipopolysaccharide (LPS) group (challenged with 10 mg/L LPS), inactively exogenous carbon monoxide releasing molecule 2 (iCORM-2) group (given 10 mg/L LPS + 50 μmol/L iCORM-2 for intervention), exogenous carbon monoxide releasing molecule 2 (CORM-2) 10 μmol/L and 50 μmol/L groups (given 10 mg/L LPS + CORM-2 10 μmol/L or 50 μmol/L for intervention). After 30 minutes, enzyme linked immunosorbent assay (ELISA) was used to determine the platelet-derived growth factor BB (PDGF-BB) and matrix metalloproteinase 2 (MMP-2). Chemical fluorescein method was used to determine the platelet adenosine triphosphate (ATP). Flow cytometer was used to determine the expression of P-selectin. The expressions of Toll-like receptor 4 (TLR4), phosphorylation of protein kinase Cθ (PKCθ) and syntaxin binding protein 1 (STXBP-1) were determined by Western Bolt. The soluble N-ethylmaleimide-sensitive factor-attachment protein receptors (SNAREs) complex formation [syntaxin 2-synaptosomal-associated protein 23-vesicle associated membrane protein 8 (STX2-SNAP23-VAMP8)] mediated by STXBP-1 was determined by immunoprecipitation. Results ① Compared with normal control group, the platelet release of PDGF-BB, MMP-2 and ATP was significantly increased after LPS challenge, and the P-selectin expression of platelet was also obviously up-regulated [PDGF-BB (μg/L): 127.53±1.78 vs. 94.35±5.84, MMP-2 (ng/L): 51.87±9.20 vs. 35.83±3.17, ATP (μmol/L): 1.288±0.056 vs. 0.975±0.010, P-selectin: (3.93±0.19)% vs. (0.44±0.10)%, all P < 0.05]. The increases in platelet release of PDGF-BB, MMP-2 and ATP were suppressed by 10 μmol/L or 50 μmol/L CORM-2 administration, as well as high-expression of P-selectin in a dose-dependent manner [PDGF-BB (μg/L): 114.68±1.35, 97.08±6.14 vs. 127.53±1.78, MMP-2 (ng/L): 32.67±8.00, 24.63±1.63 vs. 51.87±9.20, ATP (μmol/L): 0.999±0.015, 0.965±0.008 vs. 1.288±0.056, P-selectin: (1.95±0.27)%, (0.94±0.11)% vs. (3.93±0.19)%, all P < 0.05]. ② Compared with normal control group, LPS challenge resulted in a significant increase in the expression of TLR4 and the phosphorylation of PKCθ and STXBP-1 [TLR4 (gray value): 1.21±0.38 vs. 0.67±0.06, p-PKCθ (gray value): 1.36±0.20 vs. 0.44±0.03, p-STXBP-1 (gray value): 1.13±0.06 vs. 0.59±0.04, all P < 0.05]. The increases in above parameters were suppressed by 10 μmol/L or 50 μmol/L CORM-2 administration in a dose-dependent manner [TLR4 (gray value): 0.76±0.05, 0.65±0.04 vs. 1.21±0.38; p-PKCθ (gray value): 0.71±0.07, 0.47±0.10 vs. 1.36±0.20; p-STXBP-1 (gray value): 0.56±0.02, 0.48±0.01 vs. 1.13±0.06, all P < 0.05]. ③ Compared with normal control group, the SNAREs proteins in platelet that combined with STXBP-1, including STX2, SNAP23 and VAMP8, were obviously increased after LPS challenge [STX2 (gray value): 1.35±0.06 vs. 0.57±0.04, SNAP23 (gray value): 0.97±0.04 vs. 0.30±0.12, VAMP8 (gray value): 1.37±0.12 vs. 0.77±0.10, all P < 0.05]. The increases in SNAREs complex formation were suppressed by 10 μmol/L or 50 μmol/L CORM-2 administration in a dose-dependent manner [STX2 (gray value): 0.77±0.02, 0.39±0.03 vs. 1.35±0.06, SNAP23 (gray value): 0.41±0.03, 0.22±0.08 vs. 0.97±0.04, VAMP8 (gray value): 0.85±0.07, 0.66±0.07 vs. 1.37±0.12, all P < 0.05]. There was no significant difference in the above mentioned parameters between iCORM-2 group and LPS group. Conclusions LPS-induced abnormal secretion of platelet was suppressed by CORM-2 administration. The mechanism may involve the TLR4/PKCθ/STXBP-1 signaling pathway activation and the SNAREs complex formation.

OBJECTIVETo explore the effects of exogenous carbon monoxide-releasing molecule 2 (CORM-2) on formation of human neutrophil extracellular traps (NETs) stimulated by endotoxin/lipopolysaccharide (LPS) and its relevant mechanism.

METHODSVenous blood samples were collected from a healthy adult volunteer to isolate neutrophils. The neutrophils were divided into normal control (NC) group, LPS group, LPS+ 10 μmol/L CORM-2 group, LPS+ 50 μmol/L CORM-2 group, and LPS+ inactive CORM-2 (iCORM-2) group according to the random number table. No treatment was given to the neutrophils in NC group. The neutrophils in LPS group underwent LPS stimulation (1 μL, 1 μg/mL). The neutrophils in LPS+ 10 μmol/L CORM-2 group, LPS+ 50 μmol/L CORM-2 group, and LPS+ iCORM-2 group underwent the same LPS stimulation as that in LPS group and treatment of 10 μmol/L CORM-2, 50 μmol/L CORM-2, and 50 μmol/L iCORM-2, respectively, with the volune of 1 μL. After conventional culture for 1 h, the number of NETs was determined with propidium iodide staining method; the early cell apoptosis rate was determined with flow cytometer; the generation level of reactive oxygen species (ROS) was assessed with dihydrogenrhodamine 123 fluorescent probe staining method (denoted as mean fluorescence intensity); the expression level of phosphorylated extracellular regulated kinase 1/2 (p-ERK1/2) was determined by Western blotting. The sample numbers of each group in the 4 experiments were all 5. Data were processed with one-way analysis of variance and SNK test.

RESULTS(1) The numbers of NETs per 400-time visual field in cells of LPS and LPS+ iCORM-2 groups were close to the number in NC group (with P values above 0.05). The number of NETs per 400-time visual field was significantly larger in cells of LPS+ 10 μmol/L CORM-2 and LPS+ 50 μmol/L CORM-2 groups than in NC and LPS groups (with P values below 0.05). The number of NETs per 400-time visual field in cells of LPS+ iCORM-2 group was close to that of LPS group (P>0.05). (2) The early cell apoptosis rate was significantly increased in LPS, LPS+ 10 μmol/L CORM-2, LPS+ 50 μmol/L CORM-2, and LPS+ iCORM-2 groups than in NC group (with P values below 0.05). The early cell apoptosis rates in LPS+ 10 μmol/L CORM-2, LPS+ 50 μmol/L CORM-2, and LPS+ iCORM-2 groups were close to the rate in LPS group (with P values above 0.05). (3) The generation level of ROS was significantly higher in cells of LPS, LPS+ 10 μmol/L CORM-2, and LPS+ iCORM-2 groups than in NC group (with P values below 0.05). The generation level of ROS in cells of LPS+ 50 μmol/L CORM-2 group was close to that of NC group (P>0.05). The generation level of ROS was lower in cells of LPS+ 10 μmol/L CORM-2 and LPS+ 50 μmol/L CORM-2 groups than in LPS group (with P values below 0.05), while the generation level of ROS in cells of LPS+ iCORM-2 group was close to that of LPS group (P>0.05). (4) The expression levels of p-ERK1/2 in cells of LPS and LPS+ iCORM-2 groups (respectively 0.0311±0.001 and 0.0309±0.0018) were close to the level in NC group (0.0304±0.0046, with P values above 0.05). The expression level of p-ERK1/2 was significantly higher in cells of LPS+ 10 μmol/L CORM-2 and LPS+ 50 μmol/L CORM-2 groups (respectively 0.7891±0.0201 and 1.2970±0.0056) than in NC group (with P values below 0.05). The expression level of p-ERK1/2 was significantly higher in cells of LPS+ 10 μmol/L CORM-2 and LPS+ 50 μmol/L CORM-2 groups than in LPS group (with P values below 0.05). The expression level of p-ERK1/2 in cells of LPS+ iCORM-2 group was close to that of LPS group (P>0.05).

CONCLUSIONSCORM-2 can obviously increase the production of NETs in LPS-induced neutrophils, and it might be attributable to the promotion of inhibition of ROS generation and phosphorylation of ERK1/2.

Apoptosis ; Carbon Monoxide ; metabolism ; Extracellular Traps ; Humans ; Lipopolysaccharides ; pharmacology ; Organometallic Compounds ; pharmacology ; Phosphorylation ; drug effects