Bone marrow-derived cells contribute to pulmonary vascular remodeling in hypoxia-induced pulmonary hypertension

STUDY OBJECTIVE: In these days, it was reported that bone marrow (BM) cells might take part in the remodeling of some systemic vascular diseases; however, it remains unknown whether the BM cells were involved in the vascular remodeling of pulmonary arteries and the progression of pulmonary hypertension (PH). The purpose of this study was to investigate whether BM-derived cells contribute to pulmonary vascular remodeling in hypoxia-induced PH. MATERIALS AND METHODS: To investigate the role of BM-derived cells, we transplanted the whole BM of enhanced green fluorescent protein (GFP)-transgenic mice to the lethally irradiated syngeneic mice (n = 30). After 8 weeks, chimera mice were exposed to consistent hypoxia using a hypoxic chamber (10% O(2)) for up to 4 or 8 weeks (10 mice per group). After hemodynamics and the ratio of right ventricular (RV) weight to left ventricle (LV) weight, RV/(LV + septum [S]), were measured, histologic and immunofluorescent staining were performed. RESULTS: BM-transplanted mice showed a high chimerism (mean [+/- SEM], 91 +/- 2.3%). RV systolic pressure and the RV/(LV + S) ratio increased significantly with time in PH mice, indicating RV hypertrophy. Marked vascular remodeling including medial hypertrophy and adventitial proliferation was observed in the pulmonary arteries of PH mice. Strikingly, a number of GFP(+) cells were observed at the pulmonary arterial wall, including the adventitia, in hypoxia-induced PH mice, while very few cells were observed in the control mice. Metaspectrometer measurements using confocal laser scanning microscopy confirmed that this green fluorescence was produced by GFP, suggesting that these GFP(+) cells were mobilized from the BM. Most of them expressed alpha-smooth muscle actin, a smooth muscle cell, or myofibroblast phenotype, and contributed to the pulmonary vascular remodeling. A semiquantitative polymerase chain reaction of the GFP gene revealed that the BM-derived GFP-positive cells in the PH group were observed more than eightfold as often compared with the control mice. CONCLUSION: The BM-derived cells mobilize to the hypertensive pulmonary arteries and contribute to the pulmonary vascular remodeling in hypoxia-induced PH mice.     

miR-219a-5p对皮肤鳞状细胞癌细胞凋亡的影响及机制

目的探讨miR-219a-5p对皮肤鳞状细胞癌细胞凋亡的影响以及潜在的作用机制。方法设置miR-con组、miR-219a-5p组、anti-miR-con组、anti-miR-219a-5p组、miR-219a-5p+pcDNA组、miR-219a-5p+pcDNA-SMC4组、miR-con+SMC4-WT组、miR-con+SMC4-MT组、miR-219a-5p+SMC4-WT组、miR-219a-5p+SMC4-MT组,转染均用脂质体法。qRT-PCR检测miR-219a-5p和SMC4 mRNA表达水平;Western Blot检测蛋白表达;MTT法检测细胞增殖活性;流式细胞术检测细胞凋亡;双荧光素酶报告基因检测实验检测荧光活性。结果相较于人正常皮肤细胞HaCaT,皮肤鳞状细胞癌细胞HSC-2、Colo-16、SCL-1中SMC4 mRNA和蛋白表达水平显著升高,miR-219a-5p表达水平显著降低(P<0.05)。过表达miR-219a-5p可抑制皮肤鳞状细胞癌细胞增殖,诱导细胞凋亡;促进Caspase-3蛋白表达,抑制Cyclin D1蛋的表达;抑制Wnt/β-catenin信号通路激活。miR-219a-5p靶向负调控SMC4的表达,转染SMC4野生型表达载体的HSC-2细胞荧光素酶活性显著降低(P<0.05);而转染SMC4突变型表达载体的HSC-2细胞荧光素酶活性差异不显著。且过表达miR-219a-5p,SMC4表达水平显著降低;抑制miR-219a-5p表达,SMC4表达水平显著升高。过表达SMC4能逆转miR-219a-5p对皮肤鳞状细胞癌细胞HSC-2的增殖抑制和凋亡促进的作用。结论miR-219a-5p可抑制皮肤鳞状细胞癌细胞增殖,诱导细胞凋亡,其机制可能与Wnt/β-catenin及SMC4信号通路有关,将为皮肤鳞状细胞癌的预防和治疗提供新靶点。     

A Thermo-Sensitive NIPA-Based Co-Polymer and Monosize Polycationic Nanoparticle for Non-viral Gene Transfer to Smooth Muscle Cells

Primary smooth muscle cells (SMC) isolated from the aorta of fetal calf were transfected with a green fluorescent protein (GFP)-encoding plasmid DNA, which was carried by a water-soluble and temperature-sensitive N-isopropylacrylamide-based (NIPAAm-based)-co-polymer, either poly(N-isopropylacrylamide-co-2-methacryloamidohistidine) (poly(NIPAAm-co-MAH)) or monosized PEGylated nanoparticle poly(styrene/poly(ethylene glycol) ethyl ether methacrylate/N-(3-(dimethylamino)propyl) methacrylamide) (poly(St/PEG-EEM/DMAPM)). Poly(NIPAAm-co-MAH) co-polymer was synthesized by solution polymerization of n-isopropylacrylamide (NIPAAm) and 2-methacrylamidohistidine (MAH). Monosized cationic nanoparticles were produced by emulsifier-free emulsion polymerization of styrene, PEG ethyl ether methacrylate and N-[3-(dimethyl-amino) propyl] methacrylamide, in the presence of a cationic initiator, 2,2-azobis (2-methylpropionamidine) dihydrochloride. The structure of poly(St/PEG-EEM/DMAPM) and poly(NIPAAm-co-MAH) was confirmed by¹ H-NMR and FT-IR spectroscopy. Particle size/size distribution and surface charges of both carriers were measured by Zeta Sizer. The LCST behavior of poly(NIPAAm-co-MAH) co-polymer was followed spectrophotometrically. Poly(St/PEG-EEM/DMAPM) nanoparticles, with an average size of 78 nm and zeta potential of 54.4 mV, and an average size of 200 nm with a zeta potential of 54.2 mV, and poly(NIPAAm-co-MAH) were used in the transfection studies. The cytotoxicity of the vectors was tested using the MTT method. According to conditions for the transfection study (polymer/cell ratio and polymer–cell incubation period), cell loss was only 4 and 15% with poly(St/PEG-EEM/DMAPM) sized 78 and 200 nm, respectively. Poly(NIPAAm-co-MAH) cytotoxicity was insignificant. Poly(NIPAAm-co-MAH) uptake efficiency in SMCs was around 85%, but gene expression efficiency were low compared to poly(St/PEG-EEM/DMAPM)/pEGFP-N2 conjugates because of the low zeta potential of the co-polymer. Polymer uptake efficiencies of the nanoparticles were 90–95%. GFP expression efficiency was 68 and 64% after transfection with pEGFP-N2 conjugate with 78 and 200 nm sized poly(St/PEG-EEM/DMAPM) nanoparticles.     

低分子量肝素抑制球囊损伤后兔血管内膜增生的实验研究

目的:探讨不同剂量、不同给药时间低分子量肝素(LMWH)对兔髂动脉内膜损伤后内膜增生和血管平滑肌细胞增殖的影响.方法:将96只纯种雌性家兔分为空白对照组6只(A),实验对照组18只(B)、小剂量(60u/Kg)LMWH组36只(C)、大剂量(120u/Kg)LMWH组36只(D).根据不同给药时间,C、D组分别分成三个亚组.三组均经左侧股动脉,近心端插入3FFogarty球囊导管,反复拉动导管制备髂动脉内膜损伤模型.分三批于用药后72h、14d和28d提取髂动脉标本;利用计算机成像系统测量内膜厚度,抗SMCα-ActinABC免疫组织化学方法行5-BrdU单抗标记和verhoff方法联合测定SMC增殖指数.结果:A组内膜厚度平均41.35±7.06μm;未见5-BrdU标记的阳性细胞.B、C、D组内膜厚度均明显高于A组(P＜0.01).C、D组的内膜厚度和SMC增殖指数高于B组,有显著性差异(P＜0.05),并可见5-BrdU标记的阳性细胞.C和D组比较,前者的内膜厚度和SMC增殖指数均小于后者,但两者间无统计学差异,P＞0.05.结论:兔髂动膜球囊导管损伤后,内膜明显增生,平滑肌细胞增殖;LMWH可抑制其血管内膜增生和平滑肌细胞增殖,尤其是小剂量、损伤后早期用药.     

西红花苷对平滑肌细胞增殖的影响及机制研究

目的:探讨西红花苷对平滑肌细胞增殖的影响及作用机制.方法:在体外培养牛主动脉平滑肌细胞,观察西红花苷对由20%新生牛血清及氧化性低密度脂蛋白(Ox-LDL)所致的血管平滑肌细胞增殖的作用,在鹌鹑饮食性动脉粥样硬化模型上观察了西红花苷预防性给药连续9周对血清低密度脂蛋白(LDL)和血清过氧化脂质(LPO)的影响.结果:西红花苷可抑制由20%新生牛血清及氧化性低密度脂蛋白(Ox-LDL)所致的牛主动脉血管平滑肌细胞增殖,西红花苷能显著降低血清低密度脂蛋白(LDL)及血清MDA的水平.结论:西红花苷对氧化性低密度脂蛋白所致的平滑肌细胞增殖的抑制作用与其能降低体内LDL水平及抗氧化作用有关.     

Role of DNA damage in atherosclerosis--bystander or participant?

Atherosclerosis leading to cardiovascular disease is the leading cause of death among western populations. Atherosclerosis in characterised by the development of a fibrofatty lesion that consists of a diverse cell population, including inflammatory cells that create an intensely oxidising environment within the vessel. Coupled with normal replication, the local intracellular and extracellular environment causes damage to cellular DNA that is recognised and repaired by the DNA damage response (DDR) pathway. The role of DNA damage and the resulting deregulation of ‘normal’ cellular behaviour and subsequent loss of cell cycle control checkpoints have been widely studied in cancer. However, despite the extensive evidence for DNA damage in atherosclerosis, it is only over the past two decades that a causative link between DNA damage and atherosclerosis has been hypothesised. Whilst atherosclerosis is a feature of human disease characterised by defects in DNA damage, currently the role of DNA damage in the initiation and progression of atherosclerosis remains highly debated, as a ‘chicken and egg’ situation. This review will analyse the evidence for, the causes of, and consequences of DNA damage in atherosclerosis, detail the DNA damage response pathway that results in these consequences, and highlight therapeutic opportunities in this area. We also outline the evidence that DNA damage is a cause of both initiation and progression of atherosclerosis, and not just a consequence of disease.