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.     

Endothelial Transient Receptor Potential Conical Channel (TRPC)-3 Activation Induces Vasogenic Edema Formation in the Rat Piriform Cortex Following Status Epilepticus

Transient receptor potential canonical channel (TRPC) is a nonselective cation channel permeable to Ca²⁺, which express in many cell types, including neurons. However the alterations in TRPC receptor expressions in response to status epilepticus (SE) have not been explored. Therefore, the present study was designated to elucidate the roles of TRPC3 in neuronal death and vasogenic edema within the rat piriform cortex (PC) following SE. In non-SE animals, TRPC3 immunoreactivity was abundantly detected in the PC. Following SE, TRPC3 immunoreactivity was increased in neurons. Furthermore, TRPC3 expression was detected in endothelial cells that did not contain it in non-SE animals. Loss of SMI-71 (a blood–brain barrier antigen) immunoreactivity was also observed in TRPC3 positive endothelial cells. In addition, FJB positive neurons and vasogenic edema were noticeably detected in the PC. To directly determine whether TRPC3 activation is correlated to SE-induced vasogenic edema formation and neuronal damages in the PC, the effect of Pyr-3 (a TRPC3 antagonist) on SE-induced insults were investigated. Pyr-3 infusion effectively attenuated vasogenic edema in the PC as compared to the vehicle. Therefore, our findings indicate that TRPC3 activation/overexpression induced by SE may involve BBB disruption and neuronal damages in the rat PC following SE. Therefore, the present study was TRPC3 may play an important role in SE-induced vasogenic edema formation through BBB disruptions in the rat PC.     

Optimization of culture medium for cloned bovine embryos and its influence on pregnancy and delivery outcome

This study was conducted to establish an effective culture system for supporting in vitro development of cloned bovine embryos and to evaluate whether improved development in the optimal culture system could contribute to enhancing pregnancy and delivery outcomes after transfer. Enucleated oocytes at the metaphase II stage were reconstructed with serum-starved ear fibroblasts and cloned embryos were subsequently cultured for 168 h in vitro. In Experiment 1, cloned embryos were cultured in either modified Charles Rosenkrans 2 amino acid medium (mCR2aa) or modified synthetic oviduct fluid medium (mSOF). More (P < 0.05) 2-cell embryos (78% versus 92%), morulae (51% versus 69%) and blastocysts (2% versus 39%) were obtained after culture in mSOF than after culture in mCR2aa. In Experiment 2, cloned embryos were successively cultured in mSOF supplemented with various macromolecules during different periods of culture. A successive culture of oocytes in BSA-containing medium for 72 h and then in FBS-containing medium for the next 96 h yielded a higher rate of blastocyst formation (49% versus 25-36%) than other combinations (BSA to BSA or PVA to PVA, BSA or FBS). This macromolecule supplementation also significantly increased the number of total blastomeres (117.3 cells/blastocyst) and inner cell mass cells (ICM, 49.7 cells/blastocyst), and the ratio of ICM cells to trophoblast cells (TB, 0.98). In Experiment 3, a total of 85 blastocysts obtained from each 2-step culture were transferred individually to recipient cows at the end of the culture period and 32 pregnancies (38%) were diagnosed on Day 60 after transfer. However, no (P > 0.05) significant differences due to culture were apparent in the pregnancy outcome. Although six calves were produced using the 2-step culture regime of either BSA-BSA or PVA-FBS, no calves were produced using the successive culture of BSA then FBS, which optimized preimplantation development. In conclusion, mSOF has more potential to support the development of clone embryos than mCR2aa, and successive supplementation of BSA and FBS to mSOF further promotes blastocyst formation. However, enhanced development in vitro might not directly contribute to improving pregnancy outcomes.     

西安城市绿地生态功能研究

通过调查,将西安市片状绿地按种植结构分为乔灌草、乔草、灌草、乔木、灌木和草坪6种类型,并定点定时测定绿地中心和对照点的光强、湿度、温度、噪音、空气中细菌数.结果表明,在片状绿地中,除草坪外,其他绿地均具有一定的遮荫效应,不同结构绿地遮荫效应依次为灌木＞乔灌草＞乔草＞灌草＞乔木＞草坪;各绿地也有明显的降温效应,降温效应依次为乔灌草＞乔木＞灌木＞乔草＞灌草＞草坪;各绿地还有一定的增湿效应,增湿效应依次为乔草＞乔灌草＞乔木＞灌木＞灌草＞草坪;各绿地也具有降噪效应,降噪效应依次为乔灌草＞乔草＞乔木＞灌草＞灌木＞草坪;各绿地在灭菌方面也有明显的作用,灭菌效应依次为乔灌草＞乔草＞乔木＞灌草＞灌木＞草坪.相同种植结构的绿地中复层结构绿地的生态效益均大于单层结构的绿地.最后,根据以上结论提出了提高城市绿地生态功能的措施.     

A dynamic, architectural plant model simulating resource-dependent growth

BACKGROUND AND AIMS: Physiological and architectural plant models have originally been developed for different purposes and therefore have little in common, thus making combined applications difficult. There is, however, an increasing demand for crop models that simulate the genetic and resource-dependent variability of plant geometry and architecture, because man is increasingly able to transform plant production systems through combined genetic and environmental engineering. MODEL: GREENLAB is presented, a mathematical plant model that simulates interactions between plant structure and function. Dual-scale automaton is used to simulate plant organogenesis from germination to maturity on the basis of organogenetic growth cycles that have constant thermal time. Plant fresh biomass production is computed from transpiration, assuming transpiration efficiency to be constant and atmospheric demand to be the driving force, under non-limiting water supply. The fresh biomass is then distributed among expanding organs according to their relative demand. Demand for organ growth is estimated from allometric relationships (e.g. leaf surface to weight ratios) and kinetics of potential growth rate for each organ type. These are obtained through parameter optimization against empirical, morphological data sets by running the model in inverted mode. Potential growth rates are then used as estimates of relative sink strength in the model. These and other 'hidden' plant parameters are calibrated using the non-linear, least-square method. KEY RESULTS AND CONCLUSIONS: The model reproduced accurately the dynamics of plant growth, architecture and geometry of various annual and woody plants, enabling 3D visualization. It was also able to simulate the variability of leaf size on the plant and compensatory growth following pruning, as a result of internal competition for resources. The potential of the model's underlying concepts to predict the plant's phenotypic plasticity is discussed.     

间断低氧对大鼠下丘脑超微结构及前增食欲素水平的影响

目的探讨睡眠中间断低氧对大鼠下丘脑前增食欲素及受体水平的影响以及下丘脑超微结构的变化。方法大鼠分成对照组、间断低氧组和持续低氧组,分别给予吸入空气,持续低氧和间断低氧气体,并在实验开始后1d、3d、1w和4w应用RT-PCR方法测定大鼠下丘脑前增食欲素及受体水平,分析其间的变化关系,电镜观察下丘脑的超微结构变化。结果与对照组和持续低氧组比较,间断低氧4w后大鼠下丘脑前增食欲素mRNA水平明显降低,受体水平升高,但在持续低氧和对照组之间无明显差异。在低氧后1d、3d、7d后大鼠下丘脑前增食欲素mRNA降低,受体水平升高,在4w后,持续低氧组则接近正常。急性持续低氧大鼠超微结构变化更严重,而慢性间断低氧变化更持久。结论慢性间断低氧可以引起下丘脑前增食欲素下降及受体水平升高,急性持续低氧也可引起上述变化,而慢性持续低氧未引起增食欲素改变;慢性间断低氧大鼠下丘脑超微结构表现为严重而持久的变化。