RESUMO
Objective@#To explore the clinical characteristics and prognosis of the new coronavirus 2019-nCoV patients combined with cardiovascular disease (CVD).@*Methods@#A retrospective analysis was performed on 112 COVID-19 patients with CVD admitted to the western district of Union Hospital in Wuhan, from January 20, 2020 to February 15, 2020. They were divided into critical group (ICU, n=16) and general group (n=96) according to the severity of the disease and patients were followed up to the clinical endpoint. The observation indicators included total blood count, C-reactive protein (CRP), arterial blood gas analysis, myocardial injury markers, coagulation function, liver and kidney function, electrolyte, procalcitonin (PCT), B-type natriuretic peptide (BNP), blood lipid, pulmonary CT and pathogen detection.@*Results@#Compared with the general group, the lymphocyte count (0.74×109 (0.34×109, 0.94×109)/L vs. 0.99×109 (0.71×109, 1.29×109)/L, P=0.03) was extremely lower in the critical group, CRP (106.98 (81.57, 135.76) mg/L vs. 34.34 (9.55,76.54) mg/L, P<0.001) and PCT (0.20 (0.15,0.48) μg/L vs. 0.11 (0.06,0.20)μg/L, P<0.001) were significantly higher in the critical group. The BMI of the critical group was significantly higher than that of the general group (25.5 (23.0, 27.5) kg/m2 vs. 22.0 (20.0, 24.0) kg/m2, P=0.003). Patients were further divided into non-survivor group (17, 15.18%) group and survivor group (95, 84.82%). Among the non-survivors, there were 88.24% (15/17) patients with BMI> 25 kg/m2, which was significantly higher than that of survivors (18.95% (18/95), P<0.001). Compared with the survived patients, oxygenation index (130 (102, 415) vs. 434 (410, 444), P<0.001) was significantly lower and lactic acid (1.70 (1.30, 3.00) mmol/L vs. 1.20 (1.10, 1.60) mmol/L, P<0.001) was significantly higher in the non-survivors. There was no significant difference in the proportion of ACEI/ARB medication between the critical group and the general group or between non-survivors and survivors (all P>0.05).@*Conclusion@#COVID-19 patients combined with CVD are associated with a higher risk of mortality. Critical patients are characterized with lower lymphocyte counts. Higher BMI are more often seen in critical patients and non-survivor. ACEI/ARB use does not affect the morbidity and mortality of COVID-19 combined with CVD. Aggravating causes of death include fulminant inflammation, lactic acid accumulation and thrombotic events.
RESUMO
<p><b>BACKGROUND</b>First generation drug-eluting stents (DES) were associated with a high incidence of late stent thrombosis (ST), mainly due to delayed healing and re-endothelization by the durable polymer coating. This study sought to assess the safety and efficacy of the Nano polymer-free sirolimus-eluting stent (SES) in the treatment of patients with de novo coronary artery lesions.</p><p><b>METHODS</b>The Nano trial is the first randomized trial designed to compare the safety and efficacy of the Nano polymer-free SES and Partner durable-polymer SES (Lepu Medical Technology, Beijing, China) in the treatment of patients with de novo native coronary lesions. The primary endpoint was in-stent late lumen loss (LLL) at 9-month follow-up. The secondary endpoint was major adverse cardiac events (MACE), a composite of cardiac death, myocardial infarction or target lesion revascularization.</p><p><b>RESULTS</b>A total of 291 patients (Nano group: n = 143, Partner group: n = 148) were enrolled in this trial from 19 Chinese centers. The Nano polymer-free SES was non-inferior to the Partner durable-polymer DES at the primary endpoint of 9 months (P < 0.001). The 9-month in-segment LLL of the polymer-free Nano SES was comparable to the Partner SES (0.34 ± 0.42) mm vs. (0.30 ± 0.48) mm, P = 0.21). The incidence of MACE in the Nano group were 7.6% compared to the Partner group of 5.9% (P = 0.75) at 2 years follow-up. The frequency of cardiac death and stent thrombosis was low for both Nano and Partner SES (0.8% vs. 0.7%, 0.8% vs. 1.5%, both P = 1.00).</p><p><b>CONCLUSIONS</b>In this multicenter randomized Nano trial, the Nano polymer-free SES showed similar safety and efficacy compared with the Partner SES in the treatment of patients with de novo coronary artery lesions. Trials in patients with complex lesions and longer term follow-up are necessary to confirm the clinical performance of this novel Nano polymer-free SES.</p>
Assuntos
Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença da Artéria Coronariana , Tratamento Farmacológico , Cirurgia Geral , Stents Farmacológicos , Imunossupressores , Usos Terapêuticos , Estudos Prospectivos , Sirolimo , Usos TerapêuticosRESUMO
This study examined the protective effect of ischemic postconditioning (IPoC) and minocycline postconditioning (MT) on myocardial ischemia-reperfusion (I/R) injury in atherosclerosis (AS) animals and the possible mechanism. Forty male healthy rabbits were injected with bovine serum albumin following feeding on a high fat diet for 6 weeks to establish AS model. AS rabbits were randomly divided into 3 groups: (1) I/R group, the rabbits were subjected to myocardial ischemia for 35 min and then reperfusion for 12 h; (2) IPoC group, the myocardial ischemia lasted for 35 min, and then reperfusion for 20 s and ischemia for 20 s [a total of 3 cycles (R20s/I20s×3)], and then reperfusion was sustained for 12 h; (3) MT group, minocycline was intravenously injected 10 min before reperfusion. The blood lipids, malondialdehyde (MDA), superoxide dismutase (SOD), soluble cell adhesion molecule (sICAM), myeloperoxidase (MPO), and cardiac troponin T (cTnT) were biochemically determined. The myocardial infarction size (IS) and apoptosis index (AI) were measured by pathological examination. The expression of bcl-2 and caspase-3 was detected in the myocardial tissue by using reverse transcription-polymerase chain reaction (RT-PCR). The results showed that the AS models were successfully established. The myocardial IS, the plasma levels of MDA, sICAM, MPO and cTnT, and the enzymatic activity of MPO were significantly decreased, and the plasma SOD activity was significantly increased in IPoC group and MT group as compared with I/R group (P<0.05 for all). The myocardial AI and the caspase-3 mRNA expression were lower and the bcl-2 mRNA expression was higher in IPoC and MT groups than those in I/R group (all P<0.05). It is concluded that the IPoC and MT can effectively reduce the I/R injury in the AS rabbits, and the mechanisms involved anti-oxidation, anti-inflammation, up-regulation of bcl-2 expression and down-regulation of caspase-3 expression. Minocycline can be used as an effective pharmacologic postconditioning drug to protect myocardia from I/R injury.
Assuntos
Animais , Masculino , Coelhos , Aterosclerose , Precondicionamento Isquêmico Miocárdico , Métodos , Minociclina , Farmacologia , Traumatismo por Reperfusão Miocárdica , Traumatismo por ReperfusãoRESUMO
This study examined the protective effect of ischemic postconditioning (IPoC) and minocycline postconditioning (MT) on myocardial ischemia-reperfusion (I/R) injury in atherosclerosis (AS) animals and the possible mechanism. Forty male healthy rabbits were injected with bovine serum albumin following feeding on a high fat diet for 6 weeks to establish AS model. AS rabbits were randomly divided into 3 groups: (1) I/R group, the rabbits were subjected to myocardial ischemia for 35 min and then reperfusion for 12 h; (2) IPoC group, the myocardial ischemia lasted for 35 min, and then reperfusion for 20 s and ischemia for 20 s [a total of 3 cycles (R20s/I20s×3)], and then reperfusion was sustained for 12 h; (3) MT group, minocycline was intravenously injected 10 min before reperfusion. The blood lipids, malondialdehyde (MDA), superoxide dismutase (SOD), soluble cell adhesion molecule (sICAM), myeloperoxidase (MPO), and cardiac troponin T (cTnT) were biochemically determined. The myocardial infarction size (IS) and apoptosis index (AI) were measured by pathological examination. The expression of bcl-2 and caspase-3 was detected in the myocardial tissue by using reverse transcription-polymerase chain reaction (RT-PCR). The results showed that the AS models were successfully established. The myocardial IS, the plasma levels of MDA, sICAM, MPO and cTnT, and the enzymatic activity of MPO were significantly decreased, and the plasma SOD activity was significantly increased in IPoC group and MT group as compared with I/R group (P<0.05 for all). The myocardial AI and the caspase-3 mRNA expression were lower and the bcl-2 mRNA expression was higher in IPoC and MT groups than those in I/R group (all P<0.05). It is concluded that the IPoC and MT can effectively reduce the I/R injury in the AS rabbits, and the mechanisms involved anti-oxidation, anti-inflammation, up-regulation of bcl-2 expression and down-regulation of caspase-3 expression. Minocycline can be used as an effective pharmacologic postconditioning drug to protect myocardia from I/R injury.
RESUMO
Mounting evidence supports that a newly identified regulatory T cell (Treg), CD4(+)LAP(+) Treg, is associated with oral tolerance induction and following inhibition of atherosclerosis, but little is described about whether nasal tolerance to antigen likewise induces the novel Tregs production and the relevant antiatherosclerotic benefit. We investigated the effect of nasal administration of heat shock protein-60 (HSP60) on atherogenesis. HSP60 or phosphate buffer solution (PBS) was nasally administered to six-week-old male ApoE(-/-) mice. At the 10th week after the nasal administration, there was a significant decrease in atherosclerotic plaque areas of aortic roots in the HSP60-treated mice as compared with those in the PBS-treated mice. Atherosclerosis suppression was accompanied with a significant increase in CD4(+)LAP(+) and CD4(+)CD25(+)Foxp3(+) Tregs and a concurrently increased production of TGF-β in the HSP60-treated mice. The protective effect of HSP60 was offset by injection of anti-TGF-β antibody. It is concluded that nasal administration of HSP60 can inhibit atherosclerotic formation through immune tolerance which is established by Tregs depending on the induction of anti-inflammatory cytokine TGF-β. Immune tolerance induced by nasal administration of HSP60 may provide an alternative therapeutic method for atherosclerosis.
RESUMO
This study examined the relationship between PDGF-induced proliferation of vascular smooth muscle cells (VSMCs) and Nur77 expression and the effect of atorvastatin on VSMC proliferation and Nur77 in PDGF-treated VSMCs. Rat VSMCs were isolated and cultured. After incubation with atorvastatin or Nur77 siRNA, the cells were stimulated with PDGF and detected for BrdU incorporation to measure the proliferation of the VSMCs. Quantitative PCR and Western blotting were used to determine the Nur77 protein and the CREB phosphorylation level, to observe their relations with PDGF-induced VSMC proliferation. Our results showed that PDGF increased the BrdU incorporation in VSMCs, suggesting that it induced the proliferation of the cells. The VSMC proliferation was associated with increased Nur77 expression and elevated CREB phosphorylation. Atorvastatin inhibited the PDGF-induced VSMC proliferation, suppressed Nur77 expression. After silencing of Nur77 gene, the PDGF-induced VSMC proliferation was decreased. It was concluded that PDGF-induced VSMC proliferation was related to the Nur77 expression and CREB phosphorylation. Atorvastatin reduced the Nur77 expression and, at the same time, inhibited the VSMC proliferation.
RESUMO
This study examined the effect of ischemia-reperfusion injury on the expression of Pim-3 gene in myocardial tissues and their underlying mechanism. Rat models of myocardial ischemia-reperfusion injury were established by ligating the left anterior descending coronary artery of the rats. A total of 30 SD male adult rats were randomly divided into 5 groups: group A (sham operation, n=6); group B (in which the rats were subjected to 15 min of ischemia by ligation of the left anterior descending coronary artery, n=6); group C (in which the rats received 30 min of ischemia, n=6), group D and group E (in which the left anterior descending coronary artery of the rats were ligated for 30 min and then reperfused for 30 min or 120 min, n=6 in each). The left ventricular tissues were removed immediately after the ischemia-reperfusion injury. Neonatal cardiomyocytes were cultured and treated with different concentrations of H(2)O(2) (0, 5, 10, 20 μmol/L) or tumor necrosis factor-α (TNF-α, 0, 1, 5, 10 ng/mL). The mRNA and protein expression of Pim-3 gene was determined by using RT-PCR, western blotting and immunohistochemistry. Additionally, neonatal cardiomyocytes were transfected with Pim-3 siRNA, and induced to develop apoptosis by using H(2)O(2). The results showed that normal myocardial tissues expressed a quantity of Pim-3 gene mRNA and protein. Ischemia-reperfusion injury could up-regulate the mRNA and protein expression of Pim-3 gene in myocardial tissues. Furthermore, H(2)O(2) but not TNF-α up-regulated the Pim-3 gene expression in cultured cardiomyocytes. And Pim-3 silencing failed to strengthen the H(2)O(2)-inducing apoptosis in cardiomyocytes. It was concluded that ischemia-reperfusion injury up-regulated the Pim-3 gene expression through oxidative stress signaling pathway in myocardial tissues.
Assuntos
Animais , Masculino , Ratos , Animais Recém-Nascidos , Isquemia Miocárdica , Metabolismo , Traumatismo por Reperfusão Miocárdica , Metabolismo , Miocárdio , Metabolismo , Estresse Oxidativo , Fisiologia , Proteínas Serina-Treonina Quinases , Genética , Metabolismo , Ratos Sprague-Dawley , Transdução de Sinais , Regulação para CimaRESUMO
AIM: To study the characteristic of liver X receptor alpha (LXRα), its target gene expression and cholesterol efflux in human macrophages treated with atorvastatin. METHODS: Human monocyte-derived macrophages were collected and cultured. Macrophages were treated with or without atorvastatin. Apolipoprotein A-I mediated human monocyte-derived macrophage cholesterol efflux was detected by liquid scintillation counting method. Reverse transcription-polymerase chain reaction (RT-PCR) was used to evaluate the mRNA expression of LXRα and some of its target genes ABCA1, SREBP2, CETP, PLTP, apoE, MMP-9 and MIP-1α. The protein expression of LXRα, ABCA1, MMP-9 and MIP-1α was determined by Western blotting. RESULTS: Pre-incubation of human monocyte-derived macrophages with atorvastatin dose dependently (1-2 μmol/L) stimulated cholesterol efflux mediated by apolipoprotein A-I. Atorvastatin also increased the mRNA expression of LXRα, ABCA1, SREBP2, CETP, PLTP, and protein expression of LXRα, ABCA1, but decreased the expression of MMP-9 and MIP-1α at both mRNA and protein levels. CONCLUSION: Atorvastatin enhances the cholesterol efflux, upregulates LXR and some genes associated with cholesterol metabolism and inhibits inflammatory responses in macrophages, indicating that statins may affect the formation of foam cells by activating LXR signaling pathway.
RESUMO
This study examined the effect of ischemia-reperfusion injury on the expression of Pim-3 gene in myocardial tissues and their underlying mechanism. Rat models of myocardial ischemia-reperfusion injury were established by ligating the left anterior descending coronary artery of the rats. A total of 30 SD male adult rats were randomly divided into 5 groups: group A (sham operation, n=6); group B (in which the rats were subjected to 15 min of ischemia by ligation of the left anterior descending coronary artery, n=6); group C (in which the rats received 30 min of ischemia, n=6), group D and group E (in which the left anterior descending coronary artery of the rats were ligated for 30 min and then reperfused for 30 min or 120 min, n=6 in each). The left ventricular tissues were removed immediately after the ischemia-reperfusion injury. Neonatal cardiomyocytes were cultured and treated with different concentrations of H(2)O(2) (0, 5, 10, 20 μmol/L) or tumor necrosis factor-α (TNF-α, 0, 1, 5, 10 ng/mL). The mRNA and protein expression of Pim-3 gene was determined by using RT-PCR, western blotting and immunohistochemistry. Additionally, neonatal cardiomyocytes were transfected with Pim-3 siRNA, and induced to develop apoptosis by using H(2)O(2). The results showed that normal myocardial tissues expressed a quantity of Pim-3 gene mRNA and protein. Ischemia-reperfusion injury could up-regulate the mRNA and protein expression of Pim-3 gene in myocardial tissues. Furthermore, H(2)O(2) but not TNF-α up-regulated the Pim-3 gene expression in cultured cardiomyocytes. And Pim-3 silencing failed to strengthen the H(2)O(2)-inducing apoptosis in cardiomyocytes. It was concluded that ischemia-reperfusion injury up-regulated the Pim-3 gene expression through oxidative stress signaling pathway in myocardial tissues.
RESUMO
Microthrombosis may be involved in the pathogenesis of cardiac microangiopathy due to diabetes. Recent studies have shown that fibrinogen-like protein 2 (fgl2) plays a pivotal role in microthrombosis in viral hepatitis, acute vascular xenograft rejection and cytokine-induced fetal loss syndrome. The current study was designed to examine the expression of fgl2 in microvascular endothelial cells and investigate the effects of microthrombi due to fgl2 on cardiac function and structure in rats with type 2 diabetes. Following induction of type 2 diabetes, 24 rats were observed dynamically. Fgl2 expression and related cardiac microthrombosis were examined. Local or circulating TNF-α was measured. Coronary flow (CF) per min was calculated as an index of cardiac microcirculation. Cardiac function and morphology were evaluated. It was found that Fgl2 was highly expressed in cardiac microvascular endothelial cells of rats with type 2 diabetes, which was promoted by local or circulating TNF-α. The Fgl2 expression was associated with cardiac hyaline microthrombosis. In parallel with the fgl2 expression, CF per min, cardiac diastolic or systolic function and cardiac morphology were aggravated to some extent. It was concluded that in rats with type 2 diabetes, microthrombosis due to fgl2 contributes to the impairment of cardiac diastolic or systolic function and morphological changes.
RESUMO
Objective To observe the effects of preconditioning with pioglitazone on infarct size and mito-chondrial ATP-sensitive potassium channel in rats with ischemia-repedusion, and to explore its possible mecha-nism. Method The whole experiment was divided into experiment Ⅰ and Ⅱ. In experiment Ⅰ, 24 rats were ran-domly divided into four groups (6 rats in each group): (1)Sham-operated (SO) group: the coronary artery of rat was threading without hgation, and the heart was removed by cutting immediately 4 hours later; (2) Isehemia-reperfusion (I/R) group: the rats were administered with 0.9% saline intravenously via caudal vein at 24 hours before iigating the left anterior descending branch of coronary artery for 30 minutes, and followed by reperfusion for 4 hours; (3)5-hydroxydecanoate plus pioglitazone(5HD+Pio) group: the rats were injected with 10 mg/kg 5-hy-droxydecanoate (the blocker of mitochondrial ATP-sensitive potassium channels,) at 24 hours before ligation, and 30 minutes later, 3 mg/kg pioglitazone was given in 5 minutes, and then the rats were subjected to ischemia for 30 minutes, followed by reperfusion for4 hours; (4)pioglitazone treatment group (Pio): the mrs were given 3 mg/kg pioglitazone at 24 hours before occlusion, and then they were treated as done in the 5HD+Pio group. In I/R, 5HD+Pio and Pio group, the hearts were removed by cutting after reperfusion. Western blotting was used to detect the protein expression of P38MAPK, .INK and NFκB P65. In experiment Ⅱ, 30 rats were randomly divided into five groups: SO, I/R, Pio, 5HD+Pio and 5-HD group (rats were treated as done in the rats of I/R group and were injected with 10 mg/kg 5-bydroxydecanoate 24 h before ischemia/reperfusion),and the size of myocardial in-farction and isehemia were measured after reperfusion. Statistical analyses were performed using SPSS10.0 soft-ware. Multiple comparisons were analyzed by one-way analysis of variance (SNK-q test). P<0.05 was consid-ered statistically significant. Results (1) The infarct size in i/R group was(34.93±5.55)%, while pioglita-zone reduced the infarct size to(20.24±3.93)% (P<0.05). There was no significant difference between I/R and 5-HD±Pio or 5-HD groups (P>0.05). Compared with the sham-operated group, the expression of P38MAPKmRNA, JNKmRNA and protein of P38MAPK, JNK and NFκB P65 in I/R increased (P<0.05). Com-pared with the I/R group, pioglitazone inhibited these undue expressions (P<0.05). Conclusions Pioglitazone could protect the heart from ischemia-reperfusion injury evidenced by reducing infarct size. These protective effects of pioglitazone may be related to opening mitochondrial ATP-seusitive potassium channels or downregulation of JNK and p38 MAPK signaling, leading to the overexpression of NFκB p65 activation.
RESUMO
Objective To study the effects of Wortmannin, inhibitor of PI3K and SB202190, inhibitor of P38 MAPK and PD98059, inhibitor of ERK1/2 on the migration of epidermal growth factor (EGF)-induced vascular smooth muscle cells (VSMCs). Methods There were fives groups in this experiment, including control group, EGF group, PD98059 (PD) group, SB202190(SB) group and Wortnannin (WT) group. The migration rate of the VSMCs was measured by wound healing assay. Results At the 24th hours after wounding, there was obvious migration in EGF group compared to control group. The migration of VSMCs was significantly inhibited in PD group, SB group and WT group compared to the EGF group, but there were no significant difference among three inhibitor groups. At the 30th hours after woun-ding, there was still obvious migration in EGF group compared to control group. The migration of VSMCs was significantly inhibited in the three iuhibitors group compared to the EGF group, and there were significant difference among three inhibitor groups. Furthermore, inhibiting effect on VSMCs in SB group was more obvious compared to PD group and WT group. Conclusion These results suggested that the migra-tion of EGF-induced VSMCs may play a role through PI3K, P38 MAPK and ERKI/2 signal pathways, and the effect of P38 MAPK signal pathway is very important.
RESUMO
The relation between the expression and activity of MMP-9 in C-reactive protein (CRP)-induced human THP-1 mononuclear cells and the activation of nuclear factor kappa-B (NF-kappaB) was studied to investigate the possible role of CRP in plaque destabilization. Human THP-1 cells were incubated in the presence of CRP at 0 (control group), 25, 50 and 100 mug/mL (CRP groups) for 24 h. In PDTC (a specific NF-kappaB inhibitor) group, the cells were pre-treated with PDTC at 10 mumol/L and then with 100 mug/mL CRP. The conditioned media (CM) and human THP-1 cells in different groups were harvested. MMP-9 expression in CM and human THP-1 cells was measured by ELISA and Western blotting. MMP-9 activity was assessed by fluorogenic substrates. The expression of NF-kappaB inhibitor alpha (IkappaB-alpha) and NF-kappaB P(65) was detected by Western blotting and ELISA respectively. The results showed that CRP increased the expression and activity of MMP-9 in a dose-dependent manner in the human THP-1 cells. Western blotting revealed that IkappaB-alpha expression was decreased in the cells with the concentrations of CRP and ELISA demonstrated that NF-kappaB P65 expression in the CRP-induced cells was increased. After pre-treatment of the cells with PDTC at 10 mumol/L, the decrease in IkappaB-alpha expression and the increase in NF-kappaB P(65) expression in the CRP-induced cells were inhibited, and the expression and activity of MMP-9 were lowered too. It is concluded that increased expression and activity of MMP-9 in CRP-induced human THP-1 cells may be associated with activation of NF-kappaB. Down-regulation of the expression and activity of MMP-9 may be a new treatment alternative for plaque stabilization by inhibiting the NF-kappaB activation.
RESUMO
Objective To observe the influence of bezafibrate on the apoptosis and expression of lectin-like oxidized low density lipoprotein receptor-1(LOX-1) mediated by oxidized low density lipoprotein(ox-LDL) in cultured human umbilical vein endothelial cells(HUVECs).Methodes The apoptosis of HUVECs mediated by ox-LDL were evaluated by flow cytometry and the expression of LOX-1 mRNA were detected by RT-PCR.Results Compared with the control group,ox-LDL could increase apoptosis and the expression of LOX-1(P<0.05),and Bezafibrate could decrease the apoptosis and the expression of LOX-1 in a concentration -dependent manner(P<0.05).Preincubation of HUVECs with polyinosinic acid for 2 hours,the apoptosis and the expression of LOX-1 decreased(P<0.05).Conclusions Bezafibrate inhibits the apoptosis of HUVECs mediated by ox-LDL by reducing the expression of LOX-1,which may be part of the reasons for bezafibrate to prevent and treat atherosclerosis.
RESUMO
To explore the role of mechanosensitive potassium channel TREK-1, Western blot analysis was used to investigate the expression changes of TREK-1 in left ventricle in acute mechanically stretched heart. Forty Wistar rats were randomly divided into 8 groups (n=5 in each group),subject to single Langendorff perfusion for 0, 30, 60, 120 min and acute mechanical stretch for 0, 30,60, 120 min respectively. With Langendorff apparatus, an acute mechanically stretched heart model was established. There was no significant difference in the expression of TREK-1 among single Langendorff perfusion groups (P＞0.05). As compared to non-stretched Langendorff-perfused heart, only the expression of TREK-1 in acute mechanically stretched heart (120 min) was greatly increased (P＜0.05). This result suggested that some course of mechanical stretch could up-regulate the expression of TREK-1 in left ventricle. TREK-1 might play an important role in mechanoelectric feedback,so it could reduce the occurrence of arrhythmia that was induced by extra mechanical stretch.
RESUMO
To explore the role of mechanosensitive potassium channel TREK-1, Western blot analysis was used to investigate the expression changes of TREK-1 in left ventricle in acute mechanically stretched heart. Forty Wistar rats were randomly divided into 8 groups (n=5 in each group), subject to single Langendorff perfusion for 0, 30, 60, 120 min and acute mechanical stretch for 0, 30, 60, 120 min respectively. With Langendorff apparatus, an acute mechanically stretched heart model was established. There was no significant difference in the expression of TREK-1 among single Langendorff perfusion groups (P>0.05). As compared to non-stretched Langendorff-perfused heart, only the expression of TREK-1 in acute mechanically stretched heart (120 min) was greatly increased (P<0.05). This result suggested that some course of mechanical stretch could up-regulate the expression of TREK-1 in left ventricle. TREK-1 might play an important role in mechanoelectric feedback, so it could reduce the occurrence of arrhythmia that was induced by extra mechanical stretch.
Assuntos
Retroalimentação , Ventrículos do Coração/metabolismo , Mecanotransdução Celular , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Distribuição Aleatória , Ratos Wistar , Estresse MecânicoRESUMO
To isolate and culture adipose stromal cells (ASCs), and study the effect of cytokines secreted by ASCs on endothelial cells, human adipose tissue was digested with collagenase type Ⅰ solution and ASCs were derived by culture. The cells surface phenotype was examined by flow cytometry. ELISA was used to detect the secretion of VEGF, HGF, SDF-1 α and RT-PCR was employed to detect the expression of their mRNA. Then the ASC medium was utilized to culture human umbilical vein endothelial cells ECV304. Cells were counted by hemacytometer to determine the proliferation and Annexin V/PI was employed for the examination of the apoptosis rate of ECV304. ASCs were derived by culture and expressed CD34, CD105 while they did not express CD31 or CD45. ASCs secreted cytokines such as VEGF, HGF and SDF-1 α so the ASC medium could stimulate proliferation and counteract apoptosis of endothelial cells (P＜0.05). Bcl-2 mRNA was also found to be up-regulated in the endothelial cells. It is concluded that ASCs can secrete cytokines and has significant effect on the proliferation of endothelial cells and apoptosis.
RESUMO
To investigate the protective effect of L-carnitine on myocardial ischemia-reperfusion injury in rat heart,all harvested isolated hearts were perfused on Langendorff apparatus with oxygenized K-H solution for 20 min. The hearts were then exposed to ischemia for 30 min. Following the ischemia the hearts were re-perfused with K-H solution for 120 min to serve as the control group A. Either 5 or 10 mmol/L of L-carnitine was added into the K-H solution for 20 min at the beginning of reperfusion to generate group B and group C, respectively. The derivatives of the intraventricular pressure curve (DP/DT), left ventricular developed pressure (LVDP), and coronary flux were monitored during the entire experiment. The levels of ATP, hepatin, malondialdehyde (MDA), and superoxide dismutase (SOD) in tissue, and lactic dehydrogenase (LDH), creatine phosphate kinase (CPK), malondialdehyde (MDA), and superoxide dismutase (SOD) concentration in the coronary efflux were all measured. Compared with the control group, the treatment with L-carnitine resulted in better results, i. e. , higher DP/DTmax and LVDP. At the same time, ventricular fibrillation was reduced, and the levels of ATP, hepatin and SOD were all elevated. However, the concentrations of MDA, CPK and LDH were all reduced. In conclusion, L-carnitine has a protective effect on ischemia-reperfusion injury, which is partly due to its prevention of energy loss and its antioxidant activity.
RESUMO
To isolate and culture adipose stromal cells (ASCs), and study the effect of cytokines secreted by ASCs on endothelial cells, human adipose tissue was digested with collagenase type I solution and ASCs were derived by culture. The cells surface phenotype was examined by flow cytometry. ELISA was used to detect the secretion of VEGF, HGF, SDF-1 alpha and RT-PCR was employed to detect the expression of their mRNA. Then the ASC medium was utilized to culture human umbilical vein endothelial cells ECV304. Cells were counted by hemacytometer to determine the proliferation and Annexin V/ PI was employed for the examination of the apoptosis rate of ECV304. ASCs were derived by culture and expressed CD34, CD105 while they did not express CD31 or CD45. ASCs secreted cytokines such as VEGF, HGF and SDF-1 alpha so the ASC medium could stimulate proliferation and counteract apoptosis of endothelial cells (P < 0.05). Bcl-2 mRNA was also found to be up-regulated in the endothelial cells. It is concluded that ASCs can secrete cytokines and has significant effect on the proliferation of endothelial cells and apoptosis.
RESUMO
To investigate the protective effect of L-carnitine on myocardial ischemia-reperfusion injury in rat heart,all harvested isolated hearts were perfused on Langendorff apparatus with oxygenized K-H solution for 20 min. The hearts were then exposed to ischemia for 30 min. Following the ischemia the hearts were re-perfused with K-H solution for 120 min to serve as the control group A. Either 5 or 10 mmol/L of L-carnitine was added into the K-H solution for 20 min at the beginning of reperfusion to generate group B and group C, respectively. The derivatives of the intraventricular pressure curve (DP/DT), left ventricular developed pressure (LVDP), and coronary flux were monitored during the entire experiment. The levels of ATP, hepatin, malondialdehyde (MDA), and superoxide dismutase (SOD) in tissue, and lactic dehydrogenase (LDH), creatine phosphate kinase (CPK), malondialdehyde (MDA), and superoxide dismutase (SOD) concentration in the coronary efflux were all measured. Compared with the control group, the treatment with L-carnitine resulted in better results, i. e., higher DP/DTmax and LVDP. At the same time, ventricular fibrillation was reduced, and the levels of ATP, hepatin and SOD were all elevated. However, the concentrations of MDA, CPK and LDH were all reduced. In conclusion, L-carnitine has a protective effect on ischemia-reperfusion injury, which is partly due to its prevention of energy loss and its antioxidant activity.