Protective effect and mechanism of LCZ696 on diabetic cardiomyopathy rats / 西安交通大学学报(医学版)

【Objective】 To investigate the possible mechanism of sacubitril valsartan sodium (LCZ696) and valsartan in protecting rat cardiomyocytes under diabetic cardiomyopathy (DCM) by observing their effects on CGRP, TGF-β1/Smad7, caspase-3/Bcl-2 and Fas/FasL signaling pathways. 【Methods】 The diabetic model was made by the method of high glucose and high-fat diet combined with intraperitoneal injection of streptozotocin (STZ). Two rats were killed at the 4th, 6th and 8th week, respectively, to observe the myocardial structure. The myocardial structure of the rats changed at the 8th week, which was regarded as the success construction of diabetic cardiomyopathy model. The rats were randomly divided into four groups: control+alcohol group, DCM+alcohol group, DCM+valsartan (DCM+VST) group, and DCM+LCZ696 (DCM+SVST) group. After that, equivalently intense alcohol was given to control+alcohol group and DCM+alcohol group, and 30 mg/(kg·d) valsartan was given to DCM+VST group, and 60 mg/(kg·d) LZC696 given to DCM+SVST group. At the end of the experiment, HE and Masson staining were used to observe the changes of myocardial histopathology; TUNEL used to observe the changes of myocardial apoptosis; immunohistochemistry used to detect the expressions of TGF-β1/ Smad7 and CGRP protein, Western blotting used to detect the expressions of caspase-3, Bcl-2, and Fas/FasL protein. 【Results】 Compared with those in control+alcohol group, rats in DCM+alcohol group had significantly decreased cardiac LVEF and LVFS values (P<0.05); cardiomyocyte hypertrophy; malalignment; more obvious interstitial fibrosis; more myocyte apoptosis (P<0.05); increased TGF-β1, caspase-3, and Fas/FasL protein expressions; and decreased CGRP, Smad7, and Bcl-2 protein expressions (P<0.05). Compared with DCM+alcohol group, DCM+VST group and DCM+SVST group ended up with improved rat cardiac function indicators and pathological changes; decreased TGF-β1, caspase-3 and Fas/FasL protein expressions(P<0.05); and increased CGRP, Smad7 and Bcl-2 protein expressions (P<0.05); DCM+SVST group was even superior to DCM+VST group in these aspects(P<0.05). 【Conclusion】 LCZ696 can antagonize the heart injury of DCM more effectively than valsartan. It protects the myocardium by regulating TGF-β1/Smad7, caspase-3/Bcl-2, and Fas/FasL signaling pathways and upregulating CGRP content.

An improved method for isolation of human atrial cardiomyocytes / 重庆医学

Objective To study an improved isolated method of single human atrial myocytes.Methods Enzyme digestion method was used to isolate single myocytes from human atrial and whole-cell patch clamp technique was used to record small conductance calcium activated potassium current.Results This method obtained a large number of atrial myocytes.The total amount of atrial myocytes in SR group was 320±30 while AF group was 230±20 and the difference was statistically significant(P<0.01).In this study,a large number of simple and striated single atrial myocytes were obtained,and a typical small-conductance calcium-activated potassium channel current was recorded on the isolated atrial myocytes.Conclusion The established isolated method is simple,stable and effective.We can acquire a large amount of single atrial myocytes with good quality.

Experiment of THP-1 macrophage foam-cell formation through mTOR signal pathway activation induced by inflammatory stress / 中国药理学通报

Aim To investigate if LPS increases the sterol regulatory element binding proteins ( SREBPs ) cleavage-activating protein ( SCAP )-SREBP2 expres-sion by activation of mTOR signal pathway in THP-1 macrophages , upgrading LDLr level , causing foam-cell formation .Methods THP-1 macrophages were incu-bated in serum free medium in the absence of 5 mg?L-1 LDL alone , or 5 mg? L-1 LDL plus 200 μg? L-1 LPS, or 5 mg? L-1 LDL plus 200 μg? L-1 LPS plus 10 μg? L-1 rapamycin .Morphological examination of macrophages was performed with Oil Red O staining . Expression changes of LDLr , SREBP2, SCAP, S6K1 and mTOR mRNA were detected by real time quantita-tive polymerase chain reaction ( PCR ) .Western blot was used to analyze protein expression changes of LD-Lr, S6K1 and mTOR.Translocation of SCAP-SREBP2 complex from the endoplasmic reticulum ( ER ) to the Golgi was determined by confocal microscopy .Results LPS enhanced transformation of THP-1 macrophages into foam cells by increased uptake of lipid as evi-denced by Oil Red O assay .LPS increased mRNA lev-els of LDLr, SREBP2, SCAP, S6K1 and mTOR ( P <0.05) .Rapamycin reduced the mRNA levels of LDLr , SREBP2,SCAP,S6K1 and mTOR induced by LPS ( P<0.05 ) .Western blot demonstrated that LPS also caused over-expression of protein of LDLr , S6K1 and mTOR(P<0.05).Rapamycin reduced the expression of protein of LDLr, S6K1 and mTOR induced by LPS ( P <0.05 ) .Confocal microscopy demonstrated LPS caused an escape of SCAP-SREBP2 complex from the ER to the Golgi .Rapamycin inhibited the translocation of SCAP-SREBP2 complex from the ER to the Golgi . Conclusions Inflammatory stress increases SCAP/SREBP2 expression by activation of mTOR signal path-way, resulting in an escape of SCAP-SREBP2 complex from the ER to the Golgi , furthermore elevating LDLr expression and causing foam-cell formation .Rapamy-cin reverses the activation of mTOR signal pathway and decreases lipid deposition in THP-1 macrophages in-duced by LPS .

Analysis on characteristics of 8 670 dead inpatients in Affiliated Hospital of Southwest Medical University / 重庆医学

Objective To understand the disease distribution and change rule of death causes by analyzing 8 670 dead cases in the First Affiliated Hospital of Southwest Medical University during Juhuary 1,2000 to December 31,2014.Methods The disease classification in 2000 and 2001 adopted the ICD-9 as the standard,which in other years adopted the ICD-10 as the standard.The medical records of dead hospitalized cases in our hospital during Juhuary 1,2000 to December 31,2014 were retrospectively analyzed by using the Excel 2007,SPSS17.0 software system.Results The sex ratio of male and female mortality was about 1.92 ∶ 1 in these 15 years,the sex ratio of heart disease death was 1.3 ∶ 1.In these 15 years,the number of hospitalized patients was increased rapidly,while the mortality rate was declined year by year.The age group of high mortality rate was 60 years old and over(4 281 cases),accounting for 49.38％.Especially heart disease patients over 60 years old accounted for 61.9％of total heart disease deaths.Followed by the age group of 45-59 years old,accounting for 20.30％.The top three causes of death were circulatory system diseases,respiratory diseases and malignant tumors.The top three causes of death in circulatory system diseases were coronary heart disease,cerebral hemorrhage and cerebral infarction.The top three causes of cardiovascular system were coronary heart disease,high blood pressure and congenital heart disease.The top three causes of respiratory disease were pneumonia,chronic obstructive pulmonary disease and respiratory failure.The top three death causes of malignant tumor were lung cancer,leukemia and liver cancer.According to the seasonal distribution,the number of deaths in winter was up to 2 362 cases,the constituent ratio was 27.24 ％.Hospitalization days,the number of hospitalization death≤1 d was up to 2 625 cases,the constituent ratio was 30.28％.Conclusion Analyzing the death causes,disease distribution and change trend of inpatients is conducive to the rational allocationof medical resources,promote the reform of hospital management programs and improve the level of clinical epidemiological research in this area.

TGR5 is a novel regulative factor in metabolism / 基础医学与临床

G protein-coupled bile acid receptor 1(TGR5) is a specific membrane receptor of bile acids , playing an important role in the bile acid signaling network .Its activation has been proved to increase the glycemic control , regulate of blood lipid balance , enhance energy expenditure , exert anti-inflammatory actions and so on .It suggests that TGR5 may play an important role in metabolic diseases .

The effect of TNF-alpha and G-CSF on the intracoronary transplantation rate of rabbit mesenchymal stem cells in vivo / 生物医学工程学杂志

To investigate effects of tumor necrosis factor-alpha(TNF-alpha) and granulocyte-colony stimulation factor(G-CSF) on the transplantation rate of rabbit mesenchymal stem cells (MSCs) through intracoronary injection. Japanese white ears rabbits (2-3 months old) were used as myocardial injury models by intravenously injecting adriamycin, then they were divided into three groups randomly: (1) Blank group, (2) TNF-alpha group; (3) G-CSF group. There were 7 rabbits each group. Before transplantation, MSCs and rabbit models were neither intervened by cytokine in blank group; in TNF-alpha group, rabbits were injected TNF-alpha (5 microg/kg) through ear-edge vein one day before transplantation, MSCs were pretreated by TNF-alpha (10ng/ml)12 hours before transplantation. In G-CSF group, rabbits were injected G-CSF(10 microg/kg) intramuscular each day 3 days before transplantation. MSCs were pretreated by G-CSF(10 ng/ ml) 12 hours before transplantation. Separated by density gradient centrifugation and labeled by 4,6-biamidine-2-phenyliodole (DAPI) after cells expanded in vitro, MSCs were then transplanted through the root of aorta when the ascending aorta occluded above the sinus aortae. Myocardial pathological sections were made after 4 weeks and count transplanted cells under laser scanning confocal microscope and statiscally analyze. The amount of cells transplanted in rabbit myocardial were much more in TNF-alpha group G-CSF group than in blank group, there was statistically significant difference (P < 0.001). It sugested that TNF-alpha and G-CSF intervened the cultured MSCs, and animal model of myocardial injury could elevate the transplantation rate of intracoronary injection rabbit mesenchymal stem cells. The mechanism may have relation to that cytokine can enhance the attachment of MSCs to cardiac microvascular endothelium (CMVE).

Changes of sarcolemma Na+/K+ ATPase and sarcoplasmic reticulum membrane Ca2+ ATPase activity after stem cell transplantation in chronic heart failure / 生物医学工程学杂志

To assess the changes of sarcolemma Na+/K+ ATPase (CMNKA) and sarcoplasmic reticulum membrane Ca2+ ATPase (SERCA) activities after stem cells transplantation in heart failure. Rabbit was used as heart failure model by intravenously injecting adriamycin. Autologous bone marrow mononuclear cells (BMCs), bone marrow mesenchymal stem cells (MSCs) or skeletal myoblasts (SMs) were introduced into coronary arteies through the root of aorta when two balloons occluding just above sinus of Valsalva. After 4 weeks, left ventricular ejection fraction (LVEF)was evaluated by echocardiography, and the activities of CMNKA and SERCA were measured by colorimeter. In BMCs (n=8)and MSCs (n=8) group, LVEF were significantly improved (P < 0.05). No significant improvement were seen in SMs group (n=6) compared to sham group (n=8). The CMNKA activity in all stem cells groups was significantly increased compared to sham group (P < 0.05). Meanwhile, in comparison with sham group, the incremental tendencies of SERCA activity were seen in stem cells groups. In conclusion, stem cells transplantation could increase the activities of CMNKA and SERCA in heart failure, a possible mechanism to improve heart function.

Changes of heart function after different cell type stem cell transplantation in chronic heart failure / 生物医学工程学杂志

To investigate the feasibility of introcoronary cell infusion into nonischemic heart failure (HF) heart and whether different types of stem cell transplantation would affect heart function to a similar degree. Japanese white ears rabbits were used as HF models by intravenous injection adriamycin. Autologous bone marrow mononuclear cells(BMCs), bone marrow stromal cells (MSCs), skeletal myoblasts (SMs) or culture medium were infused into coronary arteries respectively by occluding the root of ascending aorta. The mortality during and 4 weeks after the procedure the mortality was 7.1% and 16.7% respectively. After 4 weeks, the ejection fraction (EF) in BMCs group had significant improvement (P < 0.05, n=8). No significant difference was seen in MSCs (n =8), SMs (n=6) and sham groups (n=8) compared with pretransplantation (P > 0.05). In sham group,the left ventricular endostolic diameter (LVED) had significant enlargement (P < 0.05), No significant difference was seen in MBCs, MSCs and SMs groups compared with pretransplantation (P > 0.05). Immunofluorescence revealed de novo expression of cardiac troponin I in BMCs and MSCs groups, cardiac troponin I was not detected in SMs group. In conclusions, intracoronary cell transplantation could provide effective cell delivery into dilated cardiomyopathy hearts and could be a useful strategy for treating CHF, BMCs cell transplantation may be the first choice in all the above cell types.

Feasibility of stem cells transplantation through aorta in adriamycin-induced heart failure / 生物医学工程学杂志

Stem cells transplantation is a promising strategy for treating myocardial infarction and/or chronic heart failure; however, with respect to nonischemic heart failure, there are some limitations inherent in the current methods of transplantation. In this study, we investigated the feasibility of a novel method, i. e. transplantation through the root of aorta when the ascending aorta occluded above the sinus aortae. Japanese white ears rabbits were used as chronic heart failure models by intravenous injection of adriamycin. Autologous bone marrow mononuclear cells (MNC) were infused into the root of aorta when the ascending aorta was occluded by a couple of balloons above the sinus aortae. After 4 weeks, ejection fraction was significantly improved in MNC group. In conclusion, we have developed a unique method for efficient and safe cell transplantation based on infusion in aorta. This method, potentially suitable for nonischemic heart failure and could be used to achieve even and global supply of cells in heart.

Effects of insulin and glucose on secretion of tissue-type plasminogen activator and its inhibitor-1 in hypoxic vascular endothelial cells / 中国病理生理杂志

AIM: To study the effects of insulin and glucose on tissue-type plamingen activator (tPA) and its inhibitor-1 (PAI-1) secretion in cultured human endothelial cells. METHODS: Human endothelial cell line ECV-304 was cultured with glucose and/or insulin at different concentrations with or without hypoxic exposure. RESULTS: The tPA, PAI-1 secretion and ratio of tPA/PAI-1 increased in endothelial cells during hypoxia. Insulin and glucose increased the tPA and PAI-1 secretion in endothelial cells exposed to hypoxia, and increase in tPA/PAI-1 ratio was also observed at 4 h and 8 h. CONCLUSION: Hypoxia stimulates the release of tPA and PAI-1. Insulin and glucose also stimulate the tPA and PAI-1 secretion during hypoxia.