七氟烷对血管内皮细胞迁移能力的影响

目的:探讨七氟烷对血管内皮细胞迁移功能的影响及其分子生物学机制.方法:将人脐静脉内皮细胞(humanumbilical vein endothelial cells,HUVECs)随机分为4组(每组包含4个直径为10 cm的培养皿),对照组、七氟烷暴露组0.5 h组、lh组和2h组.对照组为正常环境培养的细胞,七氟烷暴露组培养环境包括5％ CO2、21％ 02和2％七氟烷(相当于1.6个MAC);对4组细胞分别进行划痕实验,观察HUVECs的迁移能力,并对各组HUVECs采用RT-PCR检测血管内皮细胞钙黏蛋白mRNA (VE-cadherin mRNA)的表达情况.采用SPSS13.0软件包对数据进行统计学分析.结果:划痕实验12h后,与对照组相比,在2％七氟烷中暴露2h的HUVECs迁移距离显著缩短(P＜0.01),细胞迁移功能受到显著抑制,而在2％七氟烷中暴露0.5 h和lh的HUVECs迁移距离与对照组相比均无显著差异.RT-PCR实验结果显示,在2％七氟烷中暴露2h的HUVECs与对照组相比,VE-cadherin mRNA表达显著上调(P＜0.05).结论:2％七氟烷暴露2h对HUVECs迁移功能具有显著抑制作用,其机制可能与七氟烷上调VE-cadherin的表达有关.     

Comparison of two proanthocyanidin cross-linked recombinant human collagen-peptide (RHC) – chitosan scaffolds

Cross-linking plays an important role in tissue engineering, which involves the alternative of cross-linker and the way of components interaction. We compared two proanthocyanidin (PA) cross-linked recombinant human collagen-peptide – chitosan scaffolds: immerse cross-linking (I-CLS) and premix cross-linking (P-CLS). Both of the scaffolds presented homogeneous pore structure with mean pore size of 110–115 μm. The swelling ratio was decreased to 29.6 in I-CLS, but increased to 37.1 in P-CLS while porosity of the two scaffolds was reduced about 8% comparing to 94.3% before cross-linking. The cross-linked scaffolds exhibited enhanced resistance to enzyme degradation and improved compressive modulus (I-CLS > P-CLS). The scaffolds transformed from elastic region to plastic region until the strain reached 60%, and the stress was 40.5, 133.2 and 84.1 kPa of uncross-linking scaffold, I-CLS and P-CLS individually. Thermal stability indicated molecular bonding between PA and the scaffold components, simultaneously, Fourier transform infrared spectroscopy mainly presented hydrogen bonding between the protein amide carbonyl and the phenolic hydroxyl with a particular transform due to pyrrolidine rings of proline in P-CLS. Both of the I-CLS and P-CLS could promote human umbilical vein endothelial cells attachment and proliferation. The characterization suggested in situ biodegradable application of P-CLS, while a potential long-term utilization of I-CLS in tissue engineering.     

Probucol and cilostazol exert a combinatorial anti-atherogenic effect in cholesterol-fed rabbits

Introduction

Probucol (PB) and cilostazol (CZ) both exhibit anti-atherogenic effects. However, their combinatorial effects are unclear. This study was designed to investigate their combinatorial anti-atherogenic effect in cholesterol-fed rabbits.

Materials and Methods

Rabbits were fed a cholesterol diet with PB or CZ alone or both PB and CZ for 16 weeks. The plasma levels of total cholesterol, LDL-cholesterol, HDL-cholesterol, C-reactive protein, superoxide dismutase, malondialdehyde, and nitric oxide (NO) were measured. The aortic atherosclerotic lesions were grossly and microscopically evaluated. Additionally, in vitro experiments were conducted using human umbilical vein endothelial cells.

Results and Conclusion

We found that the PB group and the PB + CZ group exhibited a reduction in the lesion areas (70% in the PB + CZ group, 56% in the PB group) compared with the vehicle group. However, although PB alone and PB + CZ led to a reduction in the lesion size, the histological analysis revealed that only PB + CZ significantly decreased the macrophage accumulation and smooth muscle cell proliferation in the lesions compared with the vehicle group. The plasma levels of total cholesterol in the PB + CZ group were decreased compared with the vehicle group, Moreover, PB + CZ exerted obvious anti-oxidant and anti-inflammatory effects. Interestingly, the PB + CZ treatment led to a marked increase in the levels of plasma NO. The in vitro experiments showed that the combinatorial treatment up-regulated the levels of NO and protein S-nitrosylation in endothelial cells treated with oxidized LDL. In summary, these results suggest that PB and CZ exert combinatorial anti-atherogenic effects.     

Protective effects of S‐carvedilol on doxorubicin‐induced damages to human umbilical vein endothelial cells and rats

Doxorubicin (DOX) is a highly active anticancer drug with severe cytotoxicity, which is strongly associated with oxidative stress. Carvedilol (CAR), used as its racemate with S‐CAR and R‐CAR (1:1), has been previously reported to ameliorate the DOX‐induced cytotoxicity. However, the main contributor from CAR of its protective effects has not been clear. Therefore, in this study, we aimed to investigate further the different effects of CAR enantiomers on DOX‐induced cytotoxicity in human umbilical vein endothelial cells and rats, respectively. Results indicated that S‐CAR could significantly attenuate DOX‐induced cell death, apoptotic morphological changes, decrease the mitochondrial membrane potential and oxidative stress responses by increasing the superoxide dismutase and catalase activities, and decreasing malondialdehyde contents and reactive oxygen species levels via the phosphoinositide 3‐kinase/AKT/endothelial nitric oxide synthase pathway in vitro. Consistent with the in vitro study, the protective effects of S‐CAR on the myocardial tissues and hemodynamics were also detected in rats suffering because of DOX treatment. With the obtained results, we can first conclude that S‐CAR provides superior protection to injury induced by DOX relative to that of racemic CAR and R‐CAR.     

MicroRNA-126对卵巢癌细胞SKOV3迁移和侵袭能力的影响

目的:探讨microRNA-126(miR-126)对卵巢癌细胞株SKOV3迁移和侵袭能力的影响,及其对人脐静脉内皮细胞(HUVECs)体外血管形成能力的影响。方法:利用脂质体瞬时转染miR-126 mimics、mimics NC于SKOV3细胞。Real-time PCR法检测卵巢癌组织及转染前后SKOV3细胞中miR-126的表达,Tanswell小室检测SKOV3细胞的迁移和侵袭情况。分离培养原代HUVECs,利用三维小管形成实验检测HUVECs体外血管形成情况。结果:卵巢癌组织中miR-126的相对表达量(0.29±0.38)显著低于正常卵巢上皮组织(1.18±0.47)(P<0.01)。miR-126 mimics组SKOV3细胞的miR-126相对表达量(5.15±1.00)显著高于未处理组(1.07±0.27)、NC组(0.99±0.20)。转染后,SKOV3细胞的迁移和侵袭能力均显著降低,但HUVECs三维成管数无显著变化。结论:miR-126表达上调能抑制卵巢癌细胞SKOV3的体外迁移和侵袭能力,miR-126低表达可能与卵巢癌的疾病进展有关。     

Suppression of NHE1 by small interfering RNA inhibits HIF-1α-induced angiogenesis in vitro via modulation of calpain activity

Hypoxia-inducible factor-1 (HIF-1) orchestrates angiogenesis under hypoxic conditions mainly due to increased expression of such target genes as vascular endothelial growth factor (VEGF). Na+/H + exchanger-1 (NHE1), a potential HIF target gene product, plays a pivotal role in proliferation, survival, migration, adhesion and so on. However, it is unknown whether NHE1 is involved in HIF-1α-induced angiogenesis. This present study demonstrated that the expression of NHE1 was much higher in human umbilical vein endothelial cells (HUVECs) infected with adenovirus encoding HIF-1α (rAd-HIF) than with vacuum adenovirus (vAd). HIF-1α also increased the expression of VEGF, the expression and activity of calpains, and the intracellular pH. Moreover, small interfering RNA targeting NHE1 (NHE1 siRNA) dramatically decreased the expression of NHE1 and thus lowered the intracellular pH, and it also attenuated the protein expression of calpain-2 but not calpain-1, resulting in the lower calpain activity. Furthermore, HIF-1α enhanced the proliferation, migration and Matrigel tube formation, which were inhibited by NHE1 siRNA. Finally, the inhibitory effect of NHE1 siRNA was reversed by VEGF and the reversibility of the later was abrogated by the calpain inhibitor ALLM. In conclusion, the findings have revealed that NHE1 might participate in HIF-1-induced angiogenesis due, at least in part, to the alteration of the calpain activity, suggesting that NHE1 as well as calpains might represent a potential target of controlling angiogenesis in response to the hypoxic stress under various pathological conditions.     

A novel marine compound xyloketal B protects against oxidized LDL-induced cell injury in vitro

Xyloketal B is a novel marine compound with unique chemical structure isolated from mangrove fungus Xylaria sp. (no. 2508). Pretreatment with xyloketal B (0.63-40 μM) significantly improved oxLDL (150 μg/ml)-induced injury in human umbilical vein endothelial cells (HUVECs) without either toxic or proliferative effects. Xyloketal B concentration-dependently attenuated oxLDL-induced ROS generation, peroxynitrite formation and decrease of Bcl-2 expression. In addition, xyloketal B significantly inhibited NADPH oxidase activity, as well as mRNA expression of gp91phox and p47phox. Furthermore, xyloketal B alone augmented the production of nitric oxide (NO). Collectively, these data indicate that xyloketal B protects against oxLDL-induced endothelial oxidative injury probably through inhibiting NADPH oxidase-derived ROS generation, promoting NO production and restoring Bcl-2 expression, making it a promising compound for further evaluation in the treatment of atherosclerosis.