[Effects of Notch signaling pathway and vascular endothelial growth factor gene on the functions of endothelial cells derived from rat bone marrow mesenchymal stem cells].

OBJECTIVE: To explore the effects of Notch signaling pathway and the vascular endothelial growth factor [VEGF(165)] gene on the functions of endothelial cells derived from rat bone marrow mesenchymal stem cells (MSCs). METHODS: Isolated and cultivated rat bone marrow MSCs in vitro, then the cells were treated by VEGF165 and basic fibroblast growth factor (bFGF) for 2 weeks to induce them to differentiate into endothelial cells. The gene of VEGF165 was transfected into differentiated endothelial cells to promote the functions of the cells. The receptor Notch1 and the ligand Jagged1 of the Notch signaling were detected by reverse transcription-polymerase chain reaction (RT-PCR) before and after the transfection. γ-secretase inhibitor L-685458 was used to block Notch pathway. Migration ability of cells was detected by scarification test. Cells were inoculated on semisolid gel to study their ability of forming capillary-like structure. RESULTS: After transfection, VEGF165 mRNA could be detected on the differentiated endothelial cells. The expression of Jagged1 mRNA was up regulated(1.08 ± 0.01 vs. 1.01 ± 0.02,P < 0.01) and there was no change in Notch1 mRNA(0.60 ± 0.02 vs. 0.59 ± 0.01,P > 0.05). The ability of migration was enhanced (number of cells on the scratched area:46.45 ± 4.46 vs. 41.61 ± 1.42,P < 0.05), and the ability of forming capillary-like structure on semisolid gel showed no change (cells classification: 3.00 ± 0.89 vs. 2.00 ± 0.89,P > 0.05). After the transfection, using the γ-secretase inhibitor L-685458 to block the Notch signaling transduction, the ability of migration of the differentiated endothelial cells (number of cells on the scratched area: 51.72 ± 3.47 vs. 46.45 ± 4.46,P < 0.05), and that of forming capillary--like structure (cells classification: 4.17 ± 0.75 vs. 3.00 ± 0.89, P < 0.05), was also further enhanced. CONCLUSION: Transfection of the gene of VEGF165 into the differentiated endothelial cells can reinforce the function of these cells, and when Notch signaling was blocked, this effect can be further amplified.

[The role of Notch signaling during the differentiation of rat bone marrow mesenchymal stem cells into endothelial cells].

OBJECTIVE: To research the role of Notch signaling during the differentiation of bone marrow mesenchymal stem cells (MSCs) into endothelial cells and its effect on the functions of the differentiated cells. METHODS: Rat bone marrow MSCs were isolated and cultured in vitro, then the cells were treated with vascular endothelial growth factor (VEGF165) and basic fibroblast growth factor (bFGF) for 2 weeks to induce it to differentiate into endothelial cells. The differentiated cells were identified by fluorescence immunoassay. The receptors and ligands of the Notch signaling were detected by reverse transcription-polymerase chain reaction (RT-PCR) before and after the differentiation. γ-secretase inhibitor was used to block Notch pathway. Migration ability of cells were assessed by scarification test. Cells were inoculated on semisolid gel to study their ability of forming the capillary-like structure. RESULTS: After inducing MSCs to differentiate into endothelial cells by VEGF165 and bFGF, MSCs gained the characteristics of the endothelial cells with expression of CD31 and Flk1. There were Notch1 mRNA and Jagged1 mRNA expressions in rat bone marrow MSCs. The expression changes in the receptor Notch1 were not statistically significant on the differentiated cells (0.59±0.01 vs. 0.59±0.01, P>0.05), but there was a trend towards an increase of Jagged1 mRNA (1.01±0.02 vs. 0.99±0.03, P>0.05). When Notch pathway was blocked, the differentiated cells' migration ability was increased (number of cells on the scratched area: 44.61±4.34 vs. 40.06±2.43, P<0.05), and the ability of forming capillary-like structure was also increased (cells classification: 3.67±0.82 vs. 2.00±0.89, P<0.01). CONCLUSION: Notch signaling may have an important role during the differentiation of MSCs into endothelial cells. The function of differentiated cells were strengthened when Notch pathway was blocked.

[Effect of simvastatin on the reserve of heart function and endothelial function in X-syndrome].

OBJECTIVE: To determine the therapeutic effect of simvastatin combined with traditional medicine on patients with X-syndrome, and on the reserve of heart function and endothelial function. METHODS: Forty patients with X-syndrome were recruited from September 2006 to September 2007 and randomly divided into 2 groups (a simvastatin group and a control group). The control group received routine treatment including beta receptor blocker, calcium-channel blocker (CCB) and long active nitrate. The simvastatin group received simvastatin and the routine treatment. The clinical condition and exercise test (TET) were performed before and after the treatment.The levels of triglyeride (TG), total cholesterol (TC), low density lipoprotein (LDL-C), high density lipoprotein (HDL-C), endothelin-1 (ET-1) and nitric oxide (NO) were measured. RESULTS: The frequencies of chest pain in the simvastatin group were lower than those in the control group. The levels of ET-1, ET-1/NO, TG, TC, and LDL-C were significantly decreased in the simvastatin group as compared with the control group after the treatment. The levels of HDL-C and NO were significantly increased in the simvastatin group as compared with the control group after the treatment. The time in TET was significantly increased in the simvastatin group as compared with the control group. The frequencies of chest pain were positively related to the level of ET-1/NO and negatively related to the time in TET. CONCLUSION: Simvastatin is effective for patients with X-syndrome and may improve the endothelial function and the reserve of heart function.

[Expression of cardiotrophin-1 and effects of irbesartan in adriamycin induced cardiomyopathy in rats].

OBJECTIVE: To investigate cardiotrophin-1(CT-1) expression in the ventricle and the effects of angiotensin II type I receptor antagonist (AT(1)RA) irbesartan on the ventricular remodeling in adriamycin myocardiopathy. METHODS: Thirty male SD rats were randomized into 2 groups: a control group (n=10) and a model group (n=20). The model group was administered adriamycin and 18 rats survived. And theses rats were randomized again into 2 groups. One was treated with irbesartan [50 mg/(kg x d), with stomach-tube], and the other received equal saline, so did the control group. After 12 weeks, the protein level of CT-1 was detected by immunohistochemistry. RESULTS: Ventricular CT-1 in the model control group and the treatment group was higher than that in the control group and the correlation analysis showed that ventricular CT-1 of the model control group was positively correlated with the left ventricular weight index, and CT-1 of the treatment group was lower than that of the model control group. CONCLUSION: CT-1 was assumed to take part in the ventricular remodeling. The mechanism of irbesartan on the ventricular remodeling may be related to the downregulation of CT-1 expression.

[Effect of aspirin combined with perindopril on prostacyclin, thromboxone A2, and norepinephrine in the blood of arteriosclerosis rabbit models and the cardiac function].

OBJECTIVE: To explore the interactive effect of low-dosage aspirin (ASA) combined with perindopril (PER), on prostacyclin (PGI2), thromboxone A2 (TXA2), and norepinephrine (NE) in the blood of arteriosclerosis rabbit models and the cardiac function. METHODS: Sixty adult New Zealand rabbits were randomly distributed into 5 groups with 12 rabbits in each group. One group was fed with standard fodder; the others were fed with high lipoid-diet (1% cholesterol content). Before and after 8 weeks' administration consecutively, LVEDP, LVSP, HR, +/- dp/dtmax, plasma PGI2 and TXA2, serum NE, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-ch), high-density lipoprotein cholesterol (HDL-ch) and triglycerides (TG) were evaluated. RESULTS: TG, TC, LDL-ch and pathological results confirmed arteriosclerosis rabbit models successfully. ASA combined with PER led to a significant increase in PGI2/TXA2 (P < 0.01) together with a significant decrease in the NE levels (P < 0.01) in the rabbits' blood, and then improved the cardiac output, i.e. increased LVSP (P < 0.01), and decreased the heart rate (P < 0.01) and LVEDP (P < 0.01) to a greater extent in the arteriosclerosis rabbit models. CONCLUSION: The ratio of PGI2 to TXA2 increased, and the NE levels decreased significantly; meanwhile, the heart rate decreased and the cardiac function improved during the administration of aspirin combined with perindopril in arteriosclerosis rabbit models. The results suggest that there is a synergism-action between low-dosage aspirin and ACE inhibitors due to increased PGI2/TXA2 and decreased NE levels.

[Effect of low-dosage aspirin combined with perindopril on prostacyclin, thromboxone A2, and norepinephrine in rabbits' blood].

OBJECTIVE: To explore the interaction of low-dosage aspirin combined with angiotensin-converting enzyme (ACE) inhibitors by prostacyclin (PGI2), thromboxone A2 (TXA2) and norepinephrine (NE)) levels in rabbits' blood. METHODS: Forty healthy New Zealand rabbits were divided into four groups. Blood samples were drawn from the rabbits' heart before and after a consecutive four-week. NE was measured by high performance liquid chromatography, and PGI2 and TXA2 were measured by radioimmunoassay. RESULTS: ACE inhibitors increased PGI2 levels (P < 0.05, P < 0.01); low-dosage aspirin suppressed TXA2 productions (P < 0.05, P < 0.01) after the four-week administration. Aspirin combined with ACE inhibitors led to a significant increase in PGI2/TXA2(P < 0.01), together with a significant decrease in NE levels in the rabbits' blood (P < 0.001). CONCLUSION: Neither low-dosage aspirin nor ACE inhibitors influence NE levels alone. The ratio of PGI2 to TXA2 increased, and NE levels decreased significantly during the administration of aspirin combined with ACE inhibitors. The results suggest that there is a synergis-action between low-dosage aspirin and ACE inhibitors due to increased PGI2/TXA2 and decreased NE levels.