Conditioned place aversion organized in the dorsal periaqueductal gray recruits the laterodorsal nucleus of the thalamus and the basolateral amygdala

The amygdala-ventral periaqueductal gray circuit is crucial for the expression of contextual conditioned fear. However, little is known about the neural circuits activated when the stimulation of the dorsal periaqueductal gray (dPAG) is used as unconditioned stimulus (US) in conditioned fear paradigms. The present paper examines the Fos-protein distribution in the brain of rats submitted to a conditioned place aversion (CPA) paradigm using the dPAG chemical stimulation with semicarbazide (SMC), an inhibitor of the GABA synthesizing enzyme, as US and the quadrant of an arena where the drug was injected as the paired neutral stimulus. Our results show that CPA associated with SMC injections caused a significant Fos labeling in the laterodorsal nucleus of the thalamus (LD), basolateral nucleus of amygdala (BLA) and in the dorsomedial PAG (dmPAG). This pattern of brain activation is clearly different from the neural substrates of the classical fear conditioning reported in the literature. Moreover, this paper shows that CPA with the use of chemical stimulation of the dPAG could be used as an experimental model of panic disorder with agoraphobia in the extent that panic attacks repeatedly associated with specific contexts may turn in this condition in the clinics. This condition activates the BLA probably through the LD. Besides, it indicates that the dPAG can be the link between amygdala and the brainstem motor regions that controls CPA when dPAG stimulation is used as US instead of footshocks. From this evidence we suggest that a loop dPAG-LD-BLA-dPAG is activated during the panic disorder with agoraphobia.     

Early Changes of Gene Expression Profiles in the Rat Model of Arterial Injury

PurposeRestenosis caused by intimal hyperplasia (IH) remains a significant drawback for vascular interventions. It is crucial to understand the molecular mechanisms that control activation of smooth muscle cells (SMCs) after the injury in order to develop strategies to prevent IH. The purpose of the present study was to investigate the early alterations in arterial-wall gene expression after balloon injury in the rat carotid artery with focus on the induction of an inflammatory response.Materials and MethodsTwenty-four male Sprague–Dawley rats were subjected to injury of the left common carotid artery by using a 2-F Fogarty catheter. The arteries were harvested 5, 10, and 20 hours after injury. Uninjured arteries from an additional eight rats were used as controls. RNA was isolated and used for genome-wide microarray expression analysis, followed by validation of selected genes with quantitative real-time polymerase chain reaction (qRT-PCR). Immunohistochemistry was performed on the cross-sectioned vessels.ResultsAnalysis of gene expression by microarrays showed that the most differentially expressed genes were primarily associated with inflammation, cell proliferation, migration, and adhesion. As confirmed by qRT-PCR, microarray data showed a significant (P < .005) upregulation of cytokines and chemokines (IL-6, CCL2, CXCL1, AIMP1, and CD44) just 5 hours after injury. Immunohistochemistry demonstrated that CCL2 and the adhesion receptor CD44 were expressed by SMCs in the early response to injury and in the absence of leukocyte infiltration.ConclusionsArterial injury is followed by an early induction of inflammatory genes in the vessel wall that appears to be confined to SMCs.     

A novel miR-219-SMC4-JAK2/Stat3 regulatory pathway in human hepatocellular carcinoma

Background

To understand the involvement of structural maintenance of chromosome 4 (SMC4) in the development and progression of hepatocellular carcinoma (HCC).

Methods

Real-time quantitative PCR and Western Blotting were applied to measure the expression of SMC4 in HCC samples and cell lines. The tumor-promoting effect of SMC4 was determined by WST-1, soft agar colony formation, cell motility and invasion assays. The SMC4 target signal pathway was identified by luciferase reporter and real-time quantitative PCR assays.

Results

The upregulation of SMC4 was frequently detected in HCC samples and cell lines. Functional assays demonstrated that SMC4 could effectively promote tumor cell growth rate, colony formation in soft agar, wound-healing and invasion. Further studies showed that increased miR-219 levels caused a significant decrease in the SMC4 expression, and SMC4 inhibitor downregulated JAK2/Stat3 expression at both the mRNA and protein levels.

Conclusions

Our findings provide new insight into SMC4 function and the mechanisms of growth and invasion of HCC.     

含紫杉醇可降解乙交酯/丙交酯共聚物材料能抑制动脉平滑肌细胞生长

目的研究含药物紫杉醇可降解支架材料--乙交酯/丙交酯共聚物(PLLGA)对人脐动脉平滑肌细胞(SMC)作用,检测此药物降解材料是否是血管内支架的理想材料.方法选取人脐动脉原代平滑肌细胞植块培养,得到传代细胞.然后与含不同紫杉醇药物浓度的降解材料一起培养,显微镜下观察降解材料远近处细胞形态发展的状态,观察金属支架组、Ⅰ组不含紫杉醇只含PLLGA对照组,Ⅱ～Ⅳ组分别含1、2、3μg紫杉醇PLLGA可降解材料对细胞生长的影响,并进行计数统计.结果降解材料对照组及金属支架组对平滑肌细胞生长无影响,含1、2、3μg紫杉醇的降解材料组细胞生长状态不佳.统计分析可见,72 h,对照组、金属支架组与各用药组有显著统计学意义(P＜0.01),但24 h无统计学意义(P＞0.05).结论此紫杉醇降解材料(PLLGA)可作为抑制平滑肌细胞生长的血管内支架材料.     

气囊导管法与尼龙丝襻法致大鼠颈总动脉内膜增厚模型对比研究

用气囊导管法和尼龙丝襻法分别制成大鼠颈总动脉内膜增厚模型。对比观察动脉壁各层的动脉硬化性改变，特别是中、内膜平滑肌增殖、游走方面的表现；观察到不同程度的动脉中膜平滑肌细胞损伤引起的动脉硬化性病变程度有显著差异。     

大鼠自体移植静脉PDGF及受体基因表达的实验研究

内膜增生是移植静脉失败的主要原因．发病机理尚不清楚。本研究取Wistar大鼠80只建立自体颈静脉移植于肾下腹主动脉动物模型．通过电镜和组织切片原位杂交分期于术后2h、24h及术后1周观察移植静脉超微结构和血小板源生长因子（PDGF）及受体基因表达动态变化。结果显示：（1）术后2h．内膜破裂翻卷，SMC线粒体轻度肿胀；PDGF－A及PDGFR－βmRNA表达增加．但PDGF－BmRNA表达量较大；（2）术后24h．大部分内皮细胞脱落，内膜被覆以丝状血栓；PDGF－A与PDGFR－β较术后2h表达明显增加；（3）术后1周，内皮开始重新再生；PDGF－AmRNA表达开始减少．PDGFR－β持续表达。结果表明PDGF在自体静脉移植中与SMC增殖及内膜增生有关。     

Oxidative stress in atherogenesis and arterial thrombosis: the disconnect between cellular studies and clinical outcomes.

Atherosclerosis is a multifactorial disease for which the molecular etiology of many of the risk factors is still unknown. As no single genetic marker or test accurately predicts cardiovascular death, phenotyping for markers of inflammation may identify the individuals at risk for vascular diseases. Reactive oxygen species (ROS) are key mediators of signaling pathways that underlie vascular inflammation in atherogenesis, starting from the initiation of fatty streak development through lesion progression to ultimate plaque rupture. Various animal models of atherosclerosis support the notion that ROS released from NAD(P)H oxidases, xanthine oxidase, lipoxygenases, and enhanced ROS production from dysfunctional mitochondrial respiratory chain indeed have a causatory role in atherosclerosis and other vascular diseases. Human investigations also support the oxidative stress hypothesis of atherogenesis. This is further supported by the observed impairment of vascular function and enhanced atherogenesis in animal models that have deficiencies in antioxidant enzymes. The importance of oxidative stress in atherosclerosis is further emphasized because of its role as a unifying mechanism across many vascular diseases. The main contraindicator for the role oxidative stress plays in atherosclerosis is the lack of effectiveness of antioxidants in reducing primary endpoints of cardiovascular death and morbidity. However, this lack of effectiveness by itself does not negate the existence or causatory role of oxidative stress in vascular disease. Lack of proven markers of oxidative stress, which could help to identify a subset of population that can benefit from antioxidant supplementation, and the complexity and subcellular localization of redox reactions, are among the factors responsible for the mixed outcomes in the use of antioxidants for the prevention of cardiovascular diseases. To better understand the role of oxidative stress in vascular diseases, future studies should be aimed at using advances in mouse and human genetics to define oxidative stress phenotypes and link phenotype with genotype.