Graph Regularized L_p Smooth Non-negative Matrix Factorization for Data Representation

This paper proposes a Graph regularized Lpsmooth non-negative matrix factorization(GSNMF) method by incorporating graph regularization and L_p smoothing constraint, which considers the intrinsic geometric information of a data set and produces smooth and stable solutions. The main contributions are as follows: first, graph regularization is added into NMF to discover the hidden semantics and simultaneously respect the intrinsic geometric structure information of a data set. Second,the Lpsmoothing constraint is incorporated into NMF to combine the merits of isotropic(L_2-norm) and anisotropic(L_1-norm)diffusion smoothing, and produces a smooth and more accurate solution to the optimization problem. Finally, the update rules and proof of convergence of GSNMF are given. Experiments on several data sets show that the proposed method outperforms related state-of-the-art methods.

Homocysteine-induced Enhanced Expression of Tissue Factor in Human Vascular Smooth Muscle Cells

The homocysteine （Hcy）-induced tissue factor （TF） expression in human vascular smooth muscle cells （VSMCs） and the effect of Hcy on the activity of nuclear factor-kappaB （NF-кB） and the expression of inducible nitric oxide synthase （iNOS） were investigated. Human umbilical artery VSMCs were cultured by tissue explanting method, identified by α-actin immunohistochemistry, and incubated with different concentrations of Hcy/PTDC （NF-кB inhibitor）. Semi-quantitative RT-PCR was performed to detect the expression of TF mRNA in VSMCs. Flow cytometry was used to assay the expression of TF protein on the surface of VSMCs and the expression of iNOS in VSMCs. Western blot was carried out to detect the expression of NF-кB protein in nuclei. The results showed that Hcy could induce VSMCs expressing TF mRNA significantly after the VSMCs were incubated with Hcy at concentrations of 10, 100, 500 μmol/L respectively. There was low expression level of TF protein on the surface of the resting VSMCs and Hcy could also induce VSMCs expressing TF pro- tein on the cell surface in different concentrations. Additionally, Hcy could rapidly induce the activation of NF-кB and this effect could be significantly inhibited by PDTC. Hcy alone could not induce the expression of iNOS in VSMCs. It was concluded that Hcy could significantly induce the expression of TF in VSMCs and enhance the activation of NF-ΚB, subsequently mediate TF gene expression and protein synthesis. NF-кB-mediated expression of TF in VSMCs might be the important mechanism of atherosclerosis and thrombosis induced by Hcy.

Construction of human eukaryotic expression plasmid vascular endothelial growth factor 165 and its expression in transfected vascular smooth muscles

BACKGROUND: The highly specific vascular endothelialgrowth factor (VEGF) induces the growth of vascular en-dothelial cell. This study was to construct the eukaryoticexpression plasmid of vascular endothelial growth factorl65(VEGF165) and observe its expression in vascular smoothmuscles (VSMCs).METHODS: The primers were designed and synthesizedaccording to the gene sequences of human VEGF165. TheVEGF165 gene was obtained from umbilic artery tissue bythe method of RT-PCR, then it was cloned to eukaryoticexpression plasmid pBudCE4.1 by recombination strategy.The eukaryotic expression plasmid named pBudCE4.1/VEGF165 was identified by restriction enzyme digestion,and was sequenced. The pBudCE4.1/VEGF165 was trans-fected into VSMCs by using lipofection. The VEGF165 ex-pression of mRNA and protein was detected by RT-PCRand Western blot respectively.RESULTS: VEGF165 was shown about 576bp by RT-PCR.Sequencing revealed the amplified VEGF165 gene was iden-tical with that in the GeneBank. Restrictive enzyme (HindBam HI) digestion analysis showed that recombinantexpression plasmid pBudCE4. l/tVEGF165 had been con-structed successfully. The expression of VEGF165 at mRNAand protein levels in the transformed VSMCs had beendemonstrated by RT-PCR and Western blot.CONCLUSIONS: The recombinant eukaryotic expressionplasmid pBudCE4.1/VEGF165 has been successfully con-structed and expressed in transformed VSMCs. The presentstudy has laid a foundation for VEGF165 gene therapy ofvascular stenosis in the transplant organ.

Transforming growth factor-β and smooth muscle differentiation

Transforming growth factor(TGF)-β family members are multifunctional cytokines regulating diverse cel- lular functions such as growth,adhesion,migration, apoptosis,and differentiation.TGF-βs elicit their effects via specific typeⅠand typeⅡserine/threonine kinase receptors and intracellular Smad transcription factors. Knockout mouse models for the different components of the TGF-β signaling pathway have revealed their critical roles in smooth muscle cell(SMC)differentia- tion.Genetic studies in humans have linked mutations in these signaling components to specific cardiovascular disorders such as aorta aneurysm and congenital heart diseases due to SMC defects.In this review,the current understanding of TGF-β function in SMC differentiation is highlighted,and the role of TGF-βsignaling in SMC- related diseases is discussed.

Partial Purification of Smooth Muscle Cell Derived Growth Factor

The serum free medium conditioned by cultured rabbit aortic smooth muscle cells was partially purified using ultrafiltration and heparin affinity chromatography. Incorporation of [￣3H]-thymidine (￣3H-TdR) into cell DNA was used to measure the mitogenic activity of the fractions from chromatography for NIH 3T3 fibroblasts. The molecular weight and the iso-electric point of these fractions were determined by NaDodSO_4-polyacrylamide gel electrophoresis (SDS-PAGE)and iso-electric focusing, respectively. The results showed that the protein eluted in 1.0-1. 6 mol/L NaCl from the heparin-Sepharose was mitogenic for 3T3 cells,and this protein had a molecular weight of 22. 8-26. 7 ku and an iso-electric point of about 4. 6. The fact that the above-mentioned biochemical properties differed from that of PDGF, IGF and FGF suggests that this mitogenic protein may be a separate growth factor.

Different distributions of interstitial cells of Cajal and platelet-derived growth factor receptor-α positive cells in colonic smooth muscle cell/interstitial cell of Cajal/plateletderived growth factor receptor-α positive cell syncytium in mice

AIM To investigate the distribution and function of interstitialcells of Cajal(ICCs) and platelet-derived growth factor receptor-α positive(PDGFRα+) cells in the proximal and distal colon.METHODS The comparison of colonic transit in the proximal and distal ends was performed by colonic migrating motor complexes(CMMCs). The tension of the colonic smooth muscle was examined by smooth muscle spontaneous contractile experiments with both ends of the smooth muscle strip tied with a silk thread. Intracellular recordings were used to assess electrical field stimulation(EFS)-induced inhibitory junction potentials(IJP) on the colonic smooth muscle. Western blot analysis was used to examine the expression levels of ICCs and PDGFRα in the colonic smooth muscle.RESULTS Treatment with NG-nitro-L-arginine methyl ester hydrochloride(L-NAME) significantly increased the CMMC frequency and spontaneous contractions, especially in the proximal colon, while treatment with MRS2500 increased only distal CMMC activity and smooth muscle contractions. Both CMMCs and spontaneous contractions were markedly inhibited by NPPB, especially in the proximal colon. Accordingly, CyPPA sharply inhibited the distal contraction of both CMMCs and spontaneous contractions. Additionally, the amplitude of stimulationinduced nitric oxide(NO)/ICC-dependent slow IJPs(sIJPs) by intracellular recordings from the smooth muscles in the proximal colon was larger than that in the distal colon, while the amplitude of electric field stimulationinduced purinergic/PDGFRα-dependent fast IJPs(fIJPs) in the distal colon was larger than that in the proximal colon. Consistently, protein expression levels of c-Kit and anoctamin-1(ANO1) in the proximal colon were much higher, while protein expression levels of PDGFRα and small conductance calcium-activated potassium channel 3(SK3) in the distal colon were much higher.CONCLUSION The ICCs are mainly distributed in the proximal colon and there are more PDGFRα+ cells are in the distal colon, which generates a pressure gradient between the two ends of the colon to propel the feces to the anus.

Effect of Nuclear Factor-kappa B on Vascular Endothelial Growth Factor mRNA Expression of Human Pulmonary Artery Smooth Muscle Cells in Hypoxia

In order to investigate the effect of nuclear factor kappa B (NF κB) on vascular endothelial growth factor (VEGF) mRNA expression of human pulmonary artery smooth muscle cells (HPASMCs) in hypoxia, the cultured HPASMCs in vitro were stimulated with pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF κB. The NF κB p65 nuclei positive expression was detected by immunocytochemical technique. The IκBα protein expression was measured by Western blot. RT PCR was used to detect the VEGF mRNA expression of HPASMCs. The results showed that no significant change was observed in the NF κB p65 nuclei positive expression of cultured HPASMCs during 6 h-24 h in normoxia, but the levels of NF κB p65 nuclei positive expression of cultured HPASMCs were significantly increased in hypoxia groups as compared with those in all normoxia groups ( P <0.05). The IκBα protein expression of cultured HPASMCs showed no significant change during 6 h-24 h in normoxia, but significantly decreased in hypoxia as comapred with that in normoxia groups ( P <0.05). PDTC (1 to 100 μmol/L) could inhibit the VEGF mRNA expression of HPASMCs in a concentration dependent manner in hypoxia. In conclusion, NF κB can be partly translocation activated from cytoplasm into nuclei in the cultured HPASMCs under hypoxia. The inhibition of NF κB activation can decrease the VEGF mRNA expression. It is suggested that the activation of NF κB is involved in the VEGF mRNA expression of HPASMCs under hypoxia.

Up and Down Expression of Androgen Receptor, Estrogen Receptor beta and Platelet Derived Growth Factor beta by Testosterone in Aortic Vascular Smooth Muscle Tissues

Objectives To investigate the effects of testosterone enanthate (TE) on serum lip- ids and lipoproteins metabolism and the expression of androgen receptor (AR) , estrogen receptor beta ( ER - β) and platelet derived growth factor beta ( PDGFR - β) in aortic vascular smooth muscle tissues (VSMTs). Methods Forty aged male rats were ran- domly divided into 4 groups, group A (placebo group) , group B (2. 5 mg/kg intramuscular injection of TE once a week ) , group C (5.0 mg/kg intramuscular injection of TE once a week ) , group D ( 10. 0 mg/kg intramus- cular injection of TE once a week). All animals were fed freely during 16 - week treatment periods. The ex- pression of AR ,ER - βand PDGFR - β were studied by Western bolt. Results Average serum LDL - C was lower in group D than that in group A ( p < 0. 01 ). Compared with the other groups, average serum TC was also lower in group D (p <0. 05). AR expression in aortic vascular smooth muscle tissues could be regulated by TE: 99.50 ±21.74, 125.38 ±28.68 and 101.98 ± 15.42 for TE concentrations at 2.5 mg/kg, 5.0 mg/kg and 10.0 mg/kg, respectively , the expression of ER - β could be regulated by TE: 92. 34 ± 18. 68, 47. 72 ± 18.12, 82.13 ±23.50, and the expression of PDGFR - β could be regulated as well by TE: 219.70 ±45. 59, 50.16 ±9. 72, 125.36 ±15. 74(Data for AR ,ER-β and PDGFR - β protein band intensity were expressed with x ± s, with control group taken as 100 ).Conclusions This study indicates that androgens have significant effects on serum lipids and lipoprotein metabolism. Testosterone enanthate at 5. 0 mg/kg can stimulate the expression of AR, but inhibite the expres- sion of PDGFR. Testosterone enanthate at the concen- trations of 5. 0 mg/kg and 10. 0 mg/kg can inhibite the expression of ER - β.

Interleukin-1β,Tumor Necrosis Factor-α and Lipopolysaccharide Induce Expression of Monocyte Chemoattractant Protein-1 in Calf Aortic Smooth Muscle Cells

Summary: To investigate whether interleukin-1β(IL-1β), tumor necrosis factor-α (TNF-α) and lipopolysaccharide (LPS) induce expression of monocyte chemoattractant protein-1 (MCP-1 ) mRNA and protein in calf aortic smooth muscle cells(SMCs), calf aortic SMCs were cultured by a substrate-attached explant method. The cultured SMCs were used between the third to the fifth passage. After the cells became confluent, the SMCs were exposed to 2 ng/ml IL-1β, 20ng/ml TNF-1α and 100 ng/ml LPS respectively, and the total RNA of SMCs which were incubated for 4 h at 37℃ were extracted from the cells by using guanidinium isothiocyanate method. The expres- ion of MCP-1 mRNA in SMCs was detected by using dot blotting analysis using a probe of γ-32 P- end-labelled 35-mer oligonucleotide. After a 24-h incubation, the media conditioned by the cul- tured SMCs were collected. The MCP-1 protein content in the conditioned media was determined by using sandwich ELISA. The results were as follows: Dot blotting analysis showed that the cul- tured SMCs could express MCP-1 mRNA. After a 4-h exposure to IL-1β, TNF-α and LPS, the MCP-1 mRNA expression in SMCs was increased (3.6-fold, 2. 3-fold and 1. 6-fold, respectively). ELISA showed that the levels of MCP-1 protein in the conditioned media were also increased (2.9- fold, 1.7-fold and 1.1-fold, respectively). The results suggest that calf aortic SMCs could ex- press MCP-1 mRNA and protein. IL-1β and TNF-α can induce strong expression of MCP-1 mRNA and protein, and the former is more effective than the latter.

CXCL5通过诱导血管钙化参与颈动脉斑块的形成

背景:CXC基序趋化因子5(CXC-motif chemokine 5,CXCL5)为上皮细胞衍生的中性粒细胞激活肽,研究发现其可能参与动脉病变。然而,CXCL5在血管钙化中的作用未见报道。目的:探讨CXCL5在颈动脉粥样硬化的血管钙化中的作用。方法:①细胞实验:将小鼠血管平滑肌细胞分成以下各组:成骨培养基组,Vector组(空白质粒转染到细胞中),CXCL5组(CXCL5质粒转染到细胞中),si-NC组(CXCL5阴性对照siRNA转染到细胞中),si-CXCL5组(CXCL5 siRNA转染到细胞中),Vector+LY2157299组和CXCL5+LY2157299组(细胞转染24 h后,将转化生长因子β受体1激酶抑制剂LY2157299加入细胞中)。进行茜素红染色、碱性磷酸酶染色和钙含量测定以评估血管平滑肌细胞成骨分化水平。②动物实验:48只ApoE-/-小鼠随机分成4组:Con+si-NC组、Con+si-CXCL5组、CAS+si-NC组和CAS+si-CXCL5组,前2组不造模,尾静脉注射si-NC或si-CXCL5慢病毒;后2组制备颈动脉粥样硬化模型,尾静脉注射si-NC或si-CXCL5慢病毒。采用Von Kossa染色和免疫组织化学染色评估小鼠颈动脉血管钙化以及CXCL5、转化生长因子β受体1表达情况。结果与结论:①CXCL5组细胞Runt相关转录因子2蛋白水平上调、α-平滑肌肌动蛋白水平下调,si-CXCL5组中的发现与其相反;CXCL5过表达上调了转化生长因子β受体1水平,而CXCL5敲低抑制了转化生长因子β受体1水平。②与Vector组相比,CXCL5组细胞茜素红染色的强度、碱性磷酸酶活性和钙含量显著增加(P<0.05);与si-NC组相比,si-CXCL5组上述2项指标显著降低(P<0.05);当用LY2157299抑制转化生长因子β受体1表达时,CXCL5对平滑肌细胞的成骨转化作用减弱。③与Con+si-NC组相比,CAS+si-NC组大鼠颈动脉中CXCL5蛋白表达和血管钙化面积显著增加(P<0.05);与CAS+si-NC组相比,CAS+si-CXCL5组颈动脉中上述2项指标显著降低(P<0.05)。④与Con+si-NC组相比,CAS+si-NC组大鼠颈动脉中Runt相关转录因子2蛋白表达显著增加(P<0.05)和α-平滑肌肌动蛋白表达显著降低(P<0.05);与CAS+si-NC组相比,CAS+si-CXCL5组颈动脉中上述2项指标呈相反变化(P<0.05)。⑤结果说明,CXCL5通过激活转化生长因子β受体1通路诱导血管平滑肌细胞成骨样转化,抑制CXCL5表达对于改善颈动脉粥样硬化小鼠颈动脉血管钙化是有效的。

抗差Vondrak滤波方法在时间频率传递中的应用

时间频率传递的结果会受到非模型化误差和观测噪声的影响,其噪声常为高频信号,构建低通滤波器可在一定程度上消除观测值序列中的高频噪声信号.本文对Vondrak滤波函数的本质进行剖析,通过IGG3算法对钟差序列进行定权并采用频率响应法选择适合的滤波因子;对不同的链路分别进行卫星双向时间频率传递(two-way satellite time and frequency transfer,TWSTFT)、基于软件接收机的卫星双向时间传递(two-way satellite time and frequency transfer based on software defined receiver,SDR-TWSTFT)和短基线共视时间频率传递实验,并对钟差结果采用抗差Vondrak滤波进行平滑去噪.结果表明:滤波后的钟差序列能够很好地反映原始钟差序列的趋势;平滑后的TWSTFT钟差结果,日波动效应得到了有效的抑制,精度有明显提升;对于共视钟差结果,精度有明显提升,与精密单点定位(precise point positioning,PPP)时间传递结果的差值保持在−1.0~1.0 ns范围内.

光伏组件输出特性的异常分类研究

光伏组件异常直接影响到发电量与组件的使用寿命,及时发现光伏组件异常并消除异常,将直接提高光伏组件发电效率。为准确检测光伏组件的异常状态,以Matlab平台为基础,模拟6种光伏组件异常状态,并分析输出特性,提出以输出特性曲线的五特征法判断异常类型。用Python语言搭建概率神经网络,并用粒子群优化算法优化平滑因子。用粒子群优化概率神经网络(PSO-PNN)模型训练异常数据,结果表明:概率神经网络对数据集较敏感,在较大的数据集,模型分类准确率高,能有效检测光伏组件异常状态。

轻度慢性阻塞性肺疾病的病理特征及其与炎性因子的相关性

目的 探索轻度慢性阻塞性肺疾病(COPD)患者肺组织病理特征及其与炎性因子的相关性。方法 前瞻性纳入因肺小结节行手术治疗的患者70例,分为正常组10例、轻度COPD组50例、中重度COPD组10例。肺组织分别经HE、Masson、EVG染色后评估病理改变;免疫组化染色检测肺组织平滑肌肌动蛋白(SMA)、肌动蛋白(Actin)、CD31蛋白表达;免疫组化及q PCR检测肺组织肿瘤坏死因子(TNF)-α、白细胞介素(IL)-10蛋白及mRNA水平。结果 轻度COPD肺组织可见肺泡间隔增宽,小气道扩张,血管壁轻度增厚,多见以淋巴细胞为主的炎症反应。免疫组化染色提示轻度COPD肺组织中SMA、Actin蛋白含量较正常组升高(P<0.05)。此外,轻度COPD肺组织中TNF-α的mRNA水平及TNF-α阳性率明显高于正常组,而IL-10的mRNA水平明显低于正常组(均P<0.05)。SMA、Actin与炎性因子TNF-α阳性表达呈正相关,而与IL-10阳性表达呈负相关(均P<0.05)。结论 轻度COPD肺组织主要病理改变包括以小血管平滑肌层增厚为特征的肺小血管重构和以淋巴细胞浸润为主的炎症反应,同时促炎因子TNF-α升高和抗炎因子IL-10降低与COPD病理改变相关。

基于改进蚁群算法的机器人全局路径规划

针对传统蚁群算法存在初始信息素缺乏、收敛速度慢以及无法有效躲避障碍物等问题,文中提出了一种基于改进蚁群算法的全局路径规划。引入正态分布函数改进传统启发函数,提高了算法效率,缩短了算法收敛所需时间。自适应调整信息素挥发系数,限定信息素范围,避免过早收敛。对算法路径平滑处理,缩短路径长度,从而实现机器人的全局路径规划。仿真结果表明,在20×20环境下,文中算法平均迭代次数比传统蚁群算法减少了28代,收敛速度更快。平均拐点减少了33.3%,使路径更为平滑,克服了初始信息素缺乏,加快了收敛速度,减少了拐点数量,能够有效躲避环境中的障碍物,证明了该算法的可行性。

基于蚁群算法的物资运送小车路径规划研究

针对路径规划蚁群算法的盲目性、收敛速度慢、路径较长和路径折点多等问题,提出了一种改进蚁群路径规划算法。首先通过改进启发信息的数学模型,限制轮盘赌在8个方向的选择概率,降低迭代次数;然后建立自适应更新影响因子,通过实时监测目标点位置,进一步提高路径的选择方式和算法的鲁棒性;最后通过路径二次寻优,对改进蚁群路径规划算法形成的最优路径进一步消除冗余节点,在已知最优路径进一步寻优,从而提高路径平滑度、减少路径折点,以及缩短路径长度,提高物资运送小车的使用效率。通过栅格环境地图中障碍物不同占比的仿真试验,验证了所提出的改进蚁群算法的迭代速率更快、寻优能力更强、鲁棒性更好和路径更短。

骨形态发生蛋白2介导同型半胱氨酸促进血管钙化

背景:高同型半胱氨酸血症与血管钙化之间存在一定的内部联系。但是,目前有关高同型半胱氨酸血症促进血管钙化的发病机制还不清楚。目的:探讨骨形态发生蛋白2在高同型半胱氨酸血症诱导血管钙化中的作用。方法:人颈动脉蜡块标本根据有无钙化斑块分为钙化组(n=29)与非钙化组(n=13)。16只ApoE-/-小鼠随机分为对照组和高同型半胱氨酸血症组,每组8只。骨形态发生蛋白2转染大鼠胸大动脉平滑肌A7r5细胞,然后应用梯度浓度同型半胱氨酸(50,100,200,400μmol/L)干预A7r5细胞。茜素红染色和苏木精-伊红染色法检测钙化反应,免疫荧光法检测骨形态发生蛋白2与Runt相关转录因子2相互作用关系,免疫组化法和Western blot检测骨形态发生蛋白2、Runt相关转录因子2、α-平滑肌肌动蛋白的表达。结果与结论:①人体颈动脉组织染色显示,与非钙化组比较,钙化组炎性细胞增多,钙化阳性率增加(P<0.05);与非钙化组比较,钙化组骨形态发生蛋白2和Runt相关转录因子2表达量均上调,α-平滑肌肌动蛋白表达量下降(P均<0.05);②小鼠动脉标本染色显示,高同型半胱氨酸血症组钙化面积阳性率高于对照组(P<0.05);高同型半胱氨酸血症组血清同型半胱氨酸水平明显高于对照组(P<0.05);与对照组比较,高同型半胱氨酸血症组骨形态发生蛋白2和Runt相关转录因子2表达量均上调,α-平滑肌肌动蛋白表达量下降(P均<0.05);③A7r5细胞培养分析,随着同型半胱氨酸浓度梯度增加,A7r5细胞钙化程度、骨形态发生蛋白2和Runt相关转录因子2的蛋白表达增加(P<0.05),α-平滑肌肌动蛋白的蛋白表达降低(P<0.05);④过表达骨形态发生蛋白2的A7r5细胞培养分析,骨形态发生蛋白2过表达组较相对应的对照组、β-甘油磷酸钠组和同型半胱氨酸组钙化程度增加;Runt相关转录因子2表达上调(P<0.05),α-平滑肌肌动蛋白表达下调(P<0.05);⑤同型半胱氨酸钙化培养基培养的骨形态发生蛋白2过表达A7r5细胞中骨形态发生蛋白2表达量增加,且Runt相关转录因子2表达量随骨形态发生蛋白2表达量增加而增加;⑥结果表明,骨形态发生蛋白2是高同型半胱氨酸血症调控平滑肌细胞表型转化导致血管钙化的关键靶基因。靶向调控骨形态发生蛋白2可降低高同型半胱氨酸诱导的血管钙化。

沉默TUFM通过AMPK/mTOR信号通路调控线粒体自噬对肺源性心脏病模型大鼠肺动脉高压的影响

目的探讨线粒体翻译延伸因子Tu(TUFM)通过线粒体自噬促进肺动脉高压(PAH)血管重塑的作用机制。方法2022年1月—2023年6月于辽宁省人民医院中心实验室进行实验。将36只健康雄性Sprague-Dawley大鼠随机分为空白对照(Ctrl)组、模型(PAH)组、TUFM过表达(OE)组、OE阴性对照(OE-NC)组、短发夹RNA(Sh)敲除TUFM(Sh)组和Sh-NC阴性对照(Sh-NC)组,每组6只。除Ctrl组外,其余大鼠均一次性腹腔注射1%野百合碱(60 mg/kg)诱导心源性肺水肿PAH大鼠模型;大鼠肺动脉平滑肌细胞(PASMC)在低氧(3%O 2)条件下培养24 h模拟体内肺动脉高压微环境,分为常氧(Norm)组、低氧(Hyp)组、小干扰RNA(SiRNA)-1组、SiRNA-2组、Si-NC组、OE-NC组和OE组。右心导管插管和脉冲多普勒超声检测大鼠肺血流动力学;苏木素-伊红染色检测肺小动脉病理结构;免疫荧光共染检测TUFM组织定位;细胞计数法检测细胞增殖;透射电镜观察线粒体结构和自噬小体;蛋白免疫印迹检测TUFM、自噬、凋亡和磷酸腺苷活化蛋白激酶(AMPK)/哺乳动物雷帕霉素靶蛋白(mTOR)通路相关蛋白表达。结果与Ctrl组比较,PAH组大鼠TUFM蛋白表达升高,且主要与PASMC标志物α平滑肌肌动蛋白(α-SMA)在肺小动脉内膜存在共定位,而与内皮细胞标志物CD31无共定位,肺动脉收缩压(PASP)升高,肺动脉血流加速时间(PAAT)缩短,远端肺小动脉管壁呈向心性增厚,管腔狭窄几乎堵塞,TUFM、苄氯素1重组蛋白(BECN1)、人微管相关蛋白轻链3(LC3)II/I和B淋巴细胞瘤2(Bcl2)蛋白表达升高,P62、Bcl2相关X蛋白(Bax)和凋亡酶激活因子(Apaf)蛋白表达降低(P<0.05);与PAH组比较,OE组PASP升高,PAAT缩短,肺小动脉管壁厚度升高,肺动脉TUFM、BECN1、LC3II/I和Bcl2表达升高,P62、Bax和Apaf表达降低(P<0.05);与PAH组比较,Sh组PASP降低,PAAT延长,肺小动脉管壁厚度和管腔狭窄度有所改善,TUFM、BECN1、LC3II/I和Bcl2表达降低,P62、Bax和Apaf表达升高(P<0.05)。与Norm组比较,Hyp组PASMC细胞TUFM蛋白表达升高;与Si-NC组细胞相比,SiRNA-1和SiRNA-2组P62、Bax蛋白表达升高,BECN1、LC3II/I、Bcl2、TUFM表达降低,线粒体结构完整,PASMC细胞增殖活性降低,细胞p-AMPK表达降低,p-mTOR表达升高(P<0.05);与OE-NC组比较,OE组细胞P62和Bax蛋白表达降低,BECN1、LC3II/I、Bcl2和TUFM表达升高,部分线粒体损伤崩解,嵴断裂消失,PASMC细胞增殖活性明显升高,细胞p-AMPK表达升高,p-mTOR表达降低(P<0.05)。结论沉默TUFM可通过激活AMPK/mTOR信号通路促进线粒体自噬加速PAH肺动脉平滑肌细胞凋亡。

沉默FOXO1基因对人主动脉血管平滑肌细胞自噬和凋亡的影响

目的:探讨叉头框转录因子O1(FOXO1)基因对腹主动脉瘤(AAA)血管平滑肌细胞自噬和凋亡的影响,阐明其可能的作用机制。方法:收集19例AAA患者动脉瘤组织(AAA组)及邻近正常主动脉组织(对照组),采用实时荧光定量PCR(RT-qPCR)法检测2组研究对象动脉瘤组织中FOXO1 mRNA表达水平,透射电镜观察2组研究对象动脉瘤组织中自噬溶酶体形成情况;Western blotting法检测2组研究对象动脉瘤组织中FOXO1及自噬相关蛋白卷曲螺旋肌球蛋白样B细胞淋巴瘤2(Bcl-2)结合蛋白(Beclin1)、微管相关蛋白1轻链3α(LC3)和P62蛋白表达水平。体外培养人主动脉血管平滑肌细胞(hVSMCs),并采用FOXO1 siRNA(si-FOXO1)及其阴性对照(si-NC)慢病毒感染hVSMCs,10μmol·L^(-1)血管紧张素Ⅱ(AngⅡ)联合自噬激活剂雷帕霉素(Rap)进行干预,将细胞分为空白对照组、AngⅡ组、AngⅡ+si-NC组、AngⅡ+si-FOXO1组、AngⅡ+si-NC+Rap组和AngⅡ+si-FOXO1+Rap组。CCK-8法检测各组细胞增殖活性,流式细胞术检测各组细胞凋亡水平,ELISA法检测各组细胞上清中基质金属蛋白酶2(MMP-2)和基质金属蛋白酶9(MMP-9)水平,RT-qPCR法检测各组细胞中FOXO1 mRNA表达水平,Western blotting法检测各组细胞中FOXO1、Bcl-2、Bcl-2相关X蛋白(Bax)、剪切型含半胱氨酸的天冬氨酸蛋白水解酶3(Cleaved caspase-3)、Beclin1、LC3和P62蛋白表达水平。结果:与对照组比较,AAA组动脉瘤组织中FOXO1 mRNA表达水平升高(P<0.05),自噬溶酶体数量增多(P<0.05),Beclin1蛋白表达水平和LC3Ⅱ/LC3Ⅰ比值升高(P<0.05),P62蛋白表达水平降低(P<0.05)。与空白对照组比较,AngⅡ组hVSMCs增殖活性降低(P<0.05),细胞凋亡率升高(P<0.05),细胞上清中MMP-2和MMP-9水平升高(P<0.05),细胞中Bax、Cleaved caspase-3和Beclin1蛋白表达水平及LC3Ⅱ/LC3Ⅰ比值升高(P<0.05),Bcl-2和P62蛋白表达水平降低(P<0.05);与AngⅡ+si-NC组比较,AngⅡ+si-FOXO1组hVSMCs增殖活性升高(P<0.05),细胞凋亡率降低(P<0.05),细胞上清中MMP-2和MMP-9水平降低(P<0.05),细胞中Bax、Cleaved-caspase-3和Beclin1蛋白表达水平及LC3Ⅱ/LC3Ⅰ比值降低(P<0.05),Bcl-2和P62蛋白表达水平升高(P<0.05)。与AngⅡ+si-FOXO1组比较,AngⅡ+si-FOXO1+Rap组细胞凋亡率升高(P<0.05),细胞上清中MMP-2和MMP-9水平升高(P<0.05),细胞中Beclin1蛋白表达水平和LC3Ⅱ/LC3Ⅰ比值降低(P<0.05),P62蛋白表达水平升高(P<0.05)。结论:FOXO1基因沉默可能通过降低自噬水平来提高AngⅡ暴露下hVSMCs增殖活性,并抑制其凋亡,从而参与AAA的发病。

人尿源性干细胞的分离培养及诱导分化为平滑肌细胞

背景:传统尿路修复重建手段受限于供体短缺、并发症多以及生理功能恢复不理想等问题,组织工程策略为此领域提供了新方向。鉴于尿路主要由肌性组织构成,其中关键在于发掘适合的种子细胞并高效诱导分化为平滑肌细胞,但关于不同平滑肌细胞诱导方案效能的对比研究仍较为匮乏。目的:旨在分离、培养及鉴定人尿源性干细胞,并比较两种不同成平滑肌诱导方案的效果。方法:采用多次离心法从11份健康成人志愿者尿液中分离提取尿源性干细胞,使用流式细胞仪进行表面标志物的鉴定,通过成骨、成脂诱导分化来验证尿源性干细胞的多向分化潜能。尿源性干细胞分别在含转化生长因子β1以及转化生长因子β1联合血小板衍生生长因子的成平滑肌细胞诱导分化培养基中诱导分化14 d,采用免疫荧光染色和Western blot检测平滑肌特异性蛋白(α-SMA、SM22)的表达差异。结果与结论:①成功从8份健康人尿液中分离出尿源性干细胞,细胞呈“米粒”样,具有很好的分裂增殖能力;②尿源性干细胞高表达间充质干细胞表面标志物CD73、CD90和CD44,极低表达造血干细胞表面标志物CD34和CD45,不表达CD19、CD105和HLA-DR;③经成骨和成脂诱导分化后,可见明显的钙结节和脂滴形成,茜素红染色和油红O染色结果呈阳性;④成平滑肌诱导培养14 d,免疫荧光染色显示转化生长因子β1/血小板衍生生长因子组尿源性干细胞成平滑肌诱导分化率显著高于转化生长因子β1组(P<0.005);⑤成平滑肌诱导培养14 d,Western blot检测显示转化生长因子β1/血小板衍生生长因子组α-SMA和SM22蛋白表达量显著高于转化生长因子β1组(P<0.005)。结果表明:尿源性干细胞可以通过多次离心法无创分离获取;相较于单纯转化生长因子β1,转化生长因子β1/血小板衍生生长因子联合应用能显著提高尿源性干细胞诱导分化为平滑肌细胞的效率。

血管平滑肌细胞KLF4对高血压小鼠模型心脏重塑的调控作用

目的 探讨血管平滑肌细胞Krüppel样因子4(Krüppel-like factor 4,KLF4)对高血压小鼠心脏重塑的调控作用。方法 采用皮下埋植缓释泵灌注血管紧张素II(angiotensin II,Ang II)28 d建立小鼠高血压模型,剂量1 500 ng/(kg·min)。构建他莫昔芬诱导的血管平滑肌细胞Klf4基因特异敲除(Klf4-SMKO)小鼠,9~10周龄雄性Klf4-SMKO和Klf4-flox野生型小鼠各13只,分别随机分为2组,共4组:野生对照组(Klf4-flox+生理盐水灌注,6只),Klf4敲除对照组(Klf4-SMKO+生理盐水,6只),野生高血压模型组(Klf4-flox+Ang II,7只),Klf4敲除高血压模型组(Klf4-SMKO+Ang II,7只)。在建模0、7、14、21、28 d分别测量模型组小鼠血压;28 d心脏超声检测心功能;收取小鼠心脏检测心脏质量/体质量比值;切片进行麦胚凝集素和天狼猩红染色,分别检测心肌细胞大小和心脏纤维化重塑。结果 高血压建模后Klf4-SMKO和Klf4-flox两组小鼠的血压无明显差异,心脏超声检测平滑肌细胞Klf4特异性敲除降低了高血压模型小鼠左心室质量。Klf4敲除显著降低了高血压引起的心质量/体质量比值增加,并且抑制了高血压造成的心肌细胞肥大和心脏血管周围纤维化。结论 血管平滑肌细胞KLF4缺失改善了高血压小鼠心脏病理性重塑。