Cellular Thiol Production and Oxidation of Low-Density Lipoprotein

Compelling evidence suggests that low-density lipoprotein (LDL) is oxidized by cells within the arterial intima and that, once oxidized, it is profoundly atherogenic. The precise mechanism(s) by which cells promote the oxidation of LDL in vivo are not known; in vitro, however, oxidation of LDL can be enhanced by a number of differing mechanisms, including reaction with free and protein-bound metal ions, thiols, reactive oxygen species, lipoxygenase, myeloperoxidase and peroxynitrite. This review is concerned with the mechanisms by which cells enhance the oxidation of LDL in the presence of transition metals; in particular, the regulation, pro- and anti-oxidant consequences, and mechanism of action of cellular thiol production are examined, and contrasted with thiol-independent oxidation of LDL in the presence of transition metals.     

On-Chip Endothelial Inflammatory Phenotyping

Atherogenesis is potentiated by metabolic abnormalities that contribute to a heightened state of systemic inflammation resulting in endothelial dysfunction. However, early functional changes in endothelium that signify an individual''s level of risk are not directly assessed clinically to help guide therapeutic strategy. Moreover, the regulation of inflammation by local hemodynamics contributes to the non-random spatial distribution of atherosclerosis, but the mechanisms are difficult to delineate in vivo. We describe a lab-on-a-chip based approach to quantitatively assay metabolic perturbation of inflammatory events in human endothelial cells (EC) and monocytes under precise flow conditions. Standard methods of soft lithography are used to microfabricate vascular mimetic microfluidic chambers (VMMC), which are bound directly to cultured EC monolayers.¹ These devices have the advantage of using small volumes of reagents while providing a platform for directly imaging the inflammatory events at the membrane of EC exposed to a well-defined shear field. We have successfully applied these devices to investigate cytokine-,² lipid-^{3, 4} and RAGE-induced⁵ inflammation in human aortic EC (HAEC). Here we document the use of the VMMC to assay monocytic cell (THP-1) rolling and arrest on HAEC monolayers that are conditioned under differential shear characteristics and activated by the inflammatory cytokine TNF-α. Studies such as these are providing mechanistic insight into atherosusceptibility under metabolic risk factors.     

Effect of copper sulfate on experimental atherosclerosis

Serum copper concentration increases significantly (p<0.01) in rats with experimental atherosclerosis compared to a control group. The serum zinc, the zinc, and copper concentration in abdominal aorta and in liver decreases significantly (p<0.05) compared to the control group. Administration of copper sulfate for 100 d in these animals induces a significant increase of serum copper (p<0.01), decrease of serum cholesterol (p<0.05) and increase of liver copper concentration as compared with the group fed only a high cholesterol diet. In the aorta of these animals the copper concentration increases and edema and lipid infiltration are considerably less than in the group of animals fed only a high lipid diet.     

AREL1 resists the apoptosis induced by TGF-β by inhibiting SMAC in vascular endothelial cells

Abnormal apoptosis of vascular endothelial cells is an important feature of arteriosclerosis (AS). Here, we induced apoptosis in human umbilical vein endothelial cells (HUVECs) using transforming growth factor-β (TGF-β), and investigated the role of antiapoptotic E3 ubiquitin ligase (AREL1) in the apoptosis of vascular endothelial cells. We proved that AREL1 is downregulated in TGF-β treated HUVECs. The overexpression of AREL1 inhibits the activation of Caspase-3 and Caspase-9 and attenuates cell apoptosis induced by TGF-β. According to the result of coimmunoprecipitation, AREL1 interacts with the proapoptotic proteins the second mitochondria-derived activator of caspases (SMAC) in TGF-β treated HUVECs. In addition, miR-320b inhibits the expression of AREL1, and the overexpression of AREL1 attenuates the apoptosis induced by miR-320b mimics in HUVECs. In conclusion, AREL1 is downregulated by miR-320b. AREL1 overexpression inhibits TGF-β induced apoptosis through downregulating SMAC in vascular endothelial cells. Our study explores pathogenesis regulation mechanism and new biological therapeutic targets for vascular disease.     

依达拉奉右莰醇联合丁苯酞治疗对老年大动脉粥样硬化型脑卒中患者血清PTX3、lp-PLA2以及MES的影响

摘要 目的：探讨依达拉奉右莰醇联合丁苯酞对老年大动脉粥样硬化（LAA）型脑卒中患者血清五聚素3（PTX3）、脂蛋白相关磷脂酶A2（Lp-PLA2）以及微栓子信号（MES）的影响。方法：回顾性选取2021年9月-2022年9月在本院收治的120例老年LAA型脑卒中患者,根据其不同治疗方案分为对照组（56例）,采用依达拉奉右莰醇单独治疗,和观察组（64例）,采用依达拉奉右莰醇联合丁苯酞治疗。观察两组患者的临床疗效;对比两组患者治疗前后神经功能[脑卒中量表（NIHSS）及中枢神经特异性蛋白（S-100β）、神经元特异性烯醇化酶（NSE）]状态、炎症因子[血清五聚素3（PTX3）、脂蛋白相关磷脂酶A2（Lp-PLA2）]水平及脑血流微栓子信号（MES）阳性率变化。记录不良反应发生情况。结果：观察组患者治疗有效率为95.31%,高于对照组的78.57%（χ²=7.653 ,P=0.006）;治疗后,观察组患者NIHSS评分、S-100β及NSE水平低于对照组（P＜0.05）;观察组PTX3、Lp-PLA2水平及MES阳性率低于对照组（P<0.05）。观察组与对照组总不良反应发生率比较无差异（6.25 % vs 5.36 %）（Fisher=1.000）。结论：依达拉奉右莰醇联合丁苯酞可有效提高临床疗效,促进老年LAA型患者神经功能恢复,降低PTX3、lp-PLA2水平及MES阳性率,控制病情发展,且安全性较好。     

In vitro effect of prostaglandins,prostaglandin endoperoxides and thromboxane on rat intestinal alkaline phosphatase and (Ca2+-Mg2+) adenosine triphosphatase

The activity of alkaline phosphate and²⁺-Mg²⁺ adenosine triphosphatase, two of the enzymes involved in limpid and calcium uptake across the intestinal membrane, were increased in experimental atherosclerosis. Administration ofAnnapavala sindhooram, an antiatherosclerotic drug, lowers these enzyme levels to near normal values. Prostaglandin E2 stimulated the enzyme activitiesin vitro, while prostaglandin endoperoxide inhibited the activity. Thromboxane and other prostaglandins had no effect on the enzyme activities. Addition of the antiatherosclerotic drug to thein vitro assay system reversed the effect of both prostaglandin E₂ and prostaglandin endoperoxide.     

Long-term culture of human aortas

Summary Segments of human thoracic aorta were maintained in long-term explant culture for 18 weeks in serum-supplemented medium. The aortas were grossly normal in appearance, and random samples fixed for light microscopy prior to culture revealed a normal morphology. The intima contained no more than five layers of smooth muscle cells. After 7 days in culture, the intima was noticeably thicker than the uncultured segments. The increased thickness was due to proliferating smooth muscle cells and production of extracellular material. After several months in culture, extracellular material consisting of collagen and flocculent material was present in areas resembling atherosclerotic fibrous plaques. A peripheral growth, which formed around the explant, was composed of fibroblastlike cells and added to the overall thickness of the intima. However, aortic segment maintained for up to 2 months in serum-free culture medium showed no cellular proliferation. This study demonstrates that changes resembling early stages of atherosclerosis occur in human aortas maintained in explant culture using routine culture procedures. Supported in part by the Pangborn Fund and the Graduate School of the University of Maryland. This is publication 443 from the Cellular Pathobiology Laboratory.     

Role of PCK2 in the proliferation of vascular smooth muscle cells in neointimal hyperplasia

Vascular smooth muscle cell (VSMC) proliferation is a hallmark of neointimal hyperplasia (NIH) in atherosclerosis and restenosis post-balloon angioplasty and stent insertion. Although numerous cytotoxic and cytostatic therapeutics have been developed to reduce NIH, it is improbable that a multifactorial disease can be successfully treated by focusing on a preconceived hypothesis. We, therefore, aimed to identify key molecules involved in NIH via a hypothesis-free approach. We analyzed four datasets ({"type":"entrez-geo","attrs":{"text":"GSE28829","term_id":"28829"}}GSE28829, {"type":"entrez-geo","attrs":{"text":"GSE43292","term_id":"43292"}}GSE43292, {"type":"entrez-geo","attrs":{"text":"GSE100927","term_id":"100927"}}GSE100927, and {"type":"entrez-geo","attrs":{"text":"GSE120521","term_id":"120521"}}GSE120521), evaluated differentially expressed genes (DEGs) in wire-injured femoral arteries of mice, and determined their association with VSMC proliferation in vitro. Moreover, we performed RNA sequencing on platelet-derived growth factor (PDGF)-stimulated human VSMCs (hVSMCs) post-phosphoenolpyruvate carboxykinase 2 (PCK2) knockdown and investigated pathways associated with PCK2. Finally, we assessed NIH formation in Pck2 knockout (KO) mice by wire injury and identified PCK2 expression in human femoral artery atheroma. Among six DEGs, only PCK2 and RGS1 showed identical expression patterns between wire-injured femoral arteries of mice and gene expression datasets. PDGF-induced VSMC proliferation was attenuated when hVSMCs were transfected with PCK2 siRNA. RNA sequencing of PCK2 siRNA-treated hVSMCs revealed the involvement of the Akt-FoxO-PCK2 pathway in VSMC proliferation via Akt2, Akt3, FoxO1, and FoxO3. Additionally, NIH was attenuated in the wire-injured femoral artery of Pck2-KO mice and PCK2 was expressed in human femoral atheroma. PCK2 regulates VSMC proliferation in response to vascular injury via the Akt-FoxO-PCK2 pathway. Targeting PCK2, a downstream signaling mediator of VSMC proliferation, may be a novel therapeutic approach to modulate VSMC proliferation in atherosclerosis.     

切应力对内皮细胞膜微粘度的影响

目的：研究切应力对内皮细胞（EC）膜微粘度的影响。材料和方法：将EC置于脉动循环装置中,分别施加15dyne/cm^2,50dyne/cm^2,30Odyne/cm^2切应力,作用Oh,1h,2h,4h,6h,10h后,利用带偏振器的荧光分光光度计测量膜微粘度,结果：切应力使膜微粘度增加,且切应力越高,膜微粘度增加幅度越大。切应力作用4h,EC膜微粘度升至最高,4h-10h,膜微粘度开始缓慢恢复,但仍比静态对照显著升高,结论：在切应力作用下,EC膜微粘度增加,切应力是AS的致病因素,动脉狭窄处和大中动脉分叉处是AS好发的危险部位,也是防治的重点。     

PPARs调控巨噬细胞的活化与功能

巨噬细胞是先天性防御病原体的关键组分,它参与炎症的发生和消退,同时也参与了组织的修复。巨噬细胞的多种功能通过不同的活化状态完成,即从经典活化状态到替代性活化状态,再到失活状态。巨噬细胞活化的失调与代谢、炎症和免疫病变有关,调节蛋白控制巨噬细胞的活化可作为新的治疗靶点。主要综述过氧化物酶体增殖物激活受体（PPARs）调控巨噬细胞活化的作用。