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To investigate the effects of inhibition of NF-κB activation on left ventricular (LV) remodelling in a rat model of myocardial infarction (MI).The acute MI model was established by ligation of left anterior descending coronary artery. Pyrrolidine dithiocarbamate (PDTC) (20mg/kg, Qd) was administered intraperitoneally to inhibit NF-κB activation. Eight weeks later, the cardiac structure and LV ejection fraction were assessed with echocardiography. The rat body, heart, and LV weights were measured to calculate LV mass indices. Activation of NF-κB in non-infarcted myocardium was detected by a TransAM NF-κB p65 Transcription Factor Assay Kit. Cardiac collagen volume fraction was evaluated by Masson staining.Eight weeks after the MI model was established, the LV posterior wall thickness in PDTC and MI group was 1.75±0.07mm and 1.85±0.07mm respectively (p0.05). The LV mass index in the PDTC group (2.53±0.09) was lower than in the MI group (2.65±0.08, p0.05). The LVEF in the PDTC group (63.89%±4.21%) was higher than in the MI group (42.73%±8.94%, p0.05). The interstitial collagen deposition in the non-infarcted myocardium in the PDTC group was less than in the MI group (7.25%±1.88% vs. 10.09%±2.19%, p0.05).Inhibition of activation of NF-κB may result in improvement of myocardial remodelling after myocardial infarction, which is possibly attributable to reduced collagen deposition in non-infarcted areas.

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).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.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,P0.01) and there was no change in Notch1 mRNA(0.60 ± 0.02 vs. 0.59 ± 0.01,P0.05). The ability of migration was enhanced (number of cells on the scratched area:46.45 ± 4.46 vs. 41.61 ± 1.42,P0.05), 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,P0.05). 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,P0.05), and that of forming capillary--like structure (cells classification: 4.17 ± 0.75 vs. 3.00 ± 0.89, P0.05), was also further enhanced.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.

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.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.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, P0.05), but there was a trend towards an increase of Jagged1 mRNA (1.01±0.02 vs. 0.99±0.03, P0.05). 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, P0.05), and the ability of forming capillary-like structure was also increased (cells classification: 3.67±0.82 vs. 2.00±0.89, P0.01).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.

To investigate the relationship between apoptosis of myocardial cell in the rats with sepsis and the expressions of Toll-like receptor 4 (TLR4), tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) mRNA, and the protective effect of glutamine (Gln) against apoptosis of myocardial cell.Rat model of sepsis was reproduced by peritoneal injection with lipopolysaccharide (LPS), and the animals were divided into control group, LPS group and Gln group. Rats in each group were further divided into four subgroups, 0, 6, 12 and 24 hours ( n =6). Apoptosis of myocardial cells was surveyed, and TLR4, TNF-alpha and IL-6 mRNA expressions were assessed with reverse transcription-polymerase chain reaction (RT-PCR). The pathological changes in myocardial cells were observed.Myocardial apoptosis rate in LPS group was higher. Compared with the control group, expressions of TLR4 mRNA, TNF-alpha mRNA and IL-6 mRNA were significantly higher at all time points after LPS administration in the LPS group and the Gln group (all P0.05). Compared with the LPS group, the rate of myocardial apoptosis in Gln group was lower, and expression of TLR4 mRNA in the Gln group was significantly lower at 12 hours and 24 hours; the expression of TNF-alpha mRNA was obviously lower at 6 hours and 24 hours; the expression of IL-6 mRNA in the Gln group was significantly lower at 12 hours (all P0.05).TLR4, TNF-alpha and IL-6 gene expressions play extremely important role in apoptosis of myocardial cell in the rat with sepsis. Gln can affect apoptosis-related gene expressions, thus alleviating the apoptosis of myocardial cell.

To examine whether urotensinII (UII) induces hypertrophy of neonatal rat cardiomyocytes cultured in vitro.The primary cardiac myocytes cultured for 40 h followed by further culture in serum-free media for another 24 h were subjected to exposure to UII of varied concentrations for 24 h, after which the changes in the size of the cells were analyzed by flow cytometry with (3)H-leucine incorporation also measured.At the concentration of 1x10(-7) mol/L, UIIcould increase the size of the cultured cardiac myocardial cells (P=0.021) and 3H-Leucine incorporation (P=0.015).UII may induce hypertrophy of neonatal rat cardiac myocytes cultured in vitro.