Impact of the tissue factor pathway inhibitor gene on apoptosis in human vascular smooth muscle cells

Tissue factor pathway inhibitor (TFPI) plays a vitally important role in the blood coagulation pathway. Recent studies indicated that TFPI induces apoptosis in vascular smooth-muscle cells (VSMCs) in animals. The present study investigated whether the TFPI gene could also induce apoptosis in human vascular smooth-muscle cells (hVSMCs). Such cells were isolated from human umbilical arteries and subsequently transfected with pIRES-TFPI plasmid (2 μg/mL). MTT assaying and cell counting were applied to measure cell viability and proliferation, RT-PCR was utilized to analyze TFPI gene expression in the cells. Apoptosis was analyzed by fluorescence activated cell sorting (FACS). Several key proteins involved in apoptosis were examined through Western blotting. It was shown that TFPI gene transfer led to its increased cellular expression, with a subsequent reduction in hVSMC proliferation. Further investigation demonstrated that TFPI gene expression resulted in lesser amounts of procaspase-3, procaspase-8 and procascase-9, and an increased release of mitochondrial cytochrome c (cyt-c) into cytoplasm, thereby implying the involvement of both extrinsic and intrinsic pathways in TFPI gene-induced apoptosis in hVSMCs

Role of Macrophage Migration Inhibitory Factor in the Proliferation of Smooth Muscle Cell in Pulmonary Hypertension

Pulmonary hypertension (PH) contributes to the mortality of patients with lung and heart diseases. However, the underlying mechanism has not been completely elucidated. Accumulating evidence suggests that inflammatory response may be involved in the pathogenesis of PH. Macrophage migration inhibitory factor (MIF) is a critical upstream inflammatory mediator which promotes a broad range of pathophysiological processes. The aim of the study was to investigate the role of MIF in the pulmonary vascular remodeling of hypoxia-induced PH. We found that MIF mRNA and protein expression was increased in the lung tissues from hypoxic pulmonary hypertensive rats. Intensive immunoreactivity for MIF was observed in smooth muscle cells of large pulmonary arteries (PAs), endothelial cells of small PAs, and inflammatory cells of hypoxic lungs. MIF participated in the hypoxia-induced PASMCs proliferation, and it could directly stimulate proliferation of these cells. MIF-induced enhanced growth of PASMCs was attenuated by MEK and JNK inhibitor. Besides, MIF antagonist ISO-1 suppressed the ERK1/2 and JNK phosphorylation induced by MIF. In conclusion, the current finding suggested that MIF may act on the proliferation of PASMCs through the activation of the ERK1/2 and JNK pathways, which contributes to hypoxic pulmonary hypertension

Effects of iron on growth, pigment content, photosystem II efficiency, and siderophores production of Microcystis aeruginosa and Microcystis wesenbergii

Changes in growth, photosynthetic pigments, and photosystem II (PS II) photochemical efficiency as well as production of siderophores of Microcystis aeruginosa and Microcystis wesenbergii were determined in this experiment. Results showed growths of M. aeruginosa and M. wesenbergii, measured by means of optical density at 665 nm, were severely inhibited under an iron-limited condition, whereas they thrived under an iron-replete condition. The contents of chlorophyll-a, carotenoid, phycocyanin, and allophycocyanin under an iron-limited condition were lower than those under an iron-replete condition, and they all reached maximal contents on day 4 under the iron-limited condition. PS II photochemical efficiencies (maximal PS II quantum yield), saturating light levels (I-k ) and maximal electron transport rates (ETRmax) of M. aeruginosa and M. wesenbergii declined sharply under the iron-limited condition. The PS II photochemical efficiency and ETRmax of M. aeruginosa rose , whereas in the strain of M. wesenbergii, they declined gradually under the iron-replete condition. In addition, I-k of M. aeruginosa and M. wesenbergii under the iron-replete condition did not change obviously. Siderophore production of M. aeruginosa was higher than that of M. wesenbergii under the iron-limited condition. It was concluded that M. aeruginosa requires higher iron concentration for physiological and biochemical processes compared with M. wesenbergii, but its tolerance against too high a concentration of iron is weaker than M. wesenbergii.Changes in growth, photosynthetic pigments, and photosystem II (PS II) photochemical efficiency as well as production of siderophores of Microcystis aeruginosa and Microcystis wesenbergii were determined in this experiment. Results showed growths of M. aeruginosa and M. wesenbergii, measured by means of optical density at 665 nm, were severely inhibited under an iron-limited condition, whereas they thrived under an iron-replete condition. The contents of chlorophyll-a, carotenoid, phycocyanin, and allophycocyanin under an iron-limited condition were lower than those under an iron-replete condition, and they all reached maximal contents on day 4 under the iron-limited condition. PS II photochemical efficiencies (maximal PS II quantum yield), saturating light levels (I-k ) and maximal electron transport rates (ETRmax) of M. aeruginosa and M. wesenbergii declined sharply under the iron-limited condition. The PS II photochemical efficiency and ETRmax of M. aeruginosa rose , whereas in the strain of M. wesenbergii, they declined gradually under the iron-replete condition. In addition, I-k of M. aeruginosa and M. wesenbergii under the iron-replete condition did not change obviously. Siderophore production of M. aeruginosa was higher than that of M. wesenbergii under the iron-limited condition. It was concluded that M. aeruginosa requires higher iron concentration for physiological and biochemical processes compared with M. wesenbergii, but its tolerance against too high a concentration of iron is weaker than M. wesenbergii

Beta-estradiol attenuates hypoxic pulmonary hypertension by stabilizing the expression of p27kip1 in rats

<p>Abstract</p> <p>Background</p> <p>Pulmonary vascular structure remodeling (PVSR) is a hallmark of pulmonary hypertension. P27^kip1, one of critical cyclin-dependent kinase inhibitors, has been shown to mediate anti-proliferation effects on various vascular cells. Beta-estradiol (β-E2) has numerous biological protective effects including attenuation of hypoxic pulmonary hypertension (HPH). In the present study, we employed β-E2 to investigate the roles of p27^kip1and its closely-related kinase (Skp-2) in the progression of PVSR and HPH.</p> <p>Methods</p> <p>Sprague-Dawley rats treated with or without β-E2 were challenged by intermittent chronic hypoxia exposure for 4 weeks to establish hypoxic pulmonary hypertension models, which resemble moderate severity of hypoxia-induced PH in humans. Subsequently, hemodynamic and pulmonary pathomorphology data were gathered. Additionally, pulmonary artery smooth muscle cells (PASMCs) were cultured to determine the anti-proliferation effect of β-E2 under hypoxia exposure. Western blotting or reverse transcriptional polymerase chain reaction (RT-PCR) were adopted to test p27^kip1, Skp-2 and Akt-P changes in rat lung tissue and cultured PASMCs.</p> <p>Results</p> <p>Chronic hypoxia significantly increased right ventricular systolic pressures (RVSP), weight of right ventricle/left ventricle plus septum (RV/LV+S) ratio, medial width of pulmonary arterioles, accompanied with decreased expression of p27^kip1in rats. Whereas, β-E2 treatment repressed the elevation of RVSP, RV/LV+S, attenuated the PVSR of pulmonary arterioles induced by chronic hypoxia, and stabilized the expression of p27^kip1. Study also showed that β-E2 application suppressed the proliferation of PASMCs and elevated the expression of p27^kip1under hypoxia exposure. In addition, experiments both <it>in vivo </it>and <it>in vitro </it>consistently indicated an escalation of Skp-2 and phosphorylated Akt under hypoxia condition. Besides, all these changes were alleviated in the presence of β-E2.</p> <p>Conclusions</p> <p>Our results suggest that β-E2 can effectively attenuate PVSR and HPH. The underlying mechanism may partially be through the increased p27^kip1by inhibiting Skp-2 through Akt signal pathway. Therefore, targeting up-regulation of p27^kip1or down-regulation of Skp-2 might provide new strategies for treatment of HPH.</p

Roles of GARCH and ARCH effects on the stability in stock market crash

We theoretically stochastically simulate and empirically analyze the escape process of stock market price non-equilibrium dynamics under the influence of GARCH and ARCH effects, and explore the impact of ARCH and GARCH effects on stock market stability. Based on the nonlinear GARCH model of econophysics, and combined with GARCH and ARCH effects of volatility, we propose a delay stochastic monostable potential model. We use the mean escape time, or mean hitting time, as an indicator for measuring price stability, as first introduced in Valent

Effect of water bloom-forming cyanobacterial bio-substances on the growth of submerged macrophyte Ceratophyllum oryzetorum Kom.

The different forms of cyanobacterial bio-substances on the growth and photosynthetic activity of submerged macrophyte Ceratophyllum oryzetorum Kom was investigated in present study. Results showed that all kinds of cyanobacterial bio-substances ould enhance the growth of C. oryzetorum Kom. differently. Compared with the control, the plant length of C. oryzelorum could be increased by all forms of bio-substanees, in which the dry algal material has the strongest effect, while the decomposed material has the lowest. The fresh weight of C. oryzetorum also could be promoted by all kinds of algal bio-substanees, in which the dry algal material and the fresh algal material almost have the same obvious effect, and the decomposed algal material has the lowest, while in control, the fresh weight firstly increased, and then decreased. All forms of cyanobacerial material could promote the increase of branches in C. oryzetorum, in which the fresh algal material has the strongest effect and the dry and decomposed materials lower, while in control, the branches increased also less than the algal material treated groups. The photosynthetic activity expressed by chlorophyll fluorescence suggested that the (try algal material treated C. oryzetorum had the highest activity, and the fresh algae treated one lower, and the decomposed algae and the control treated ones were the lowest. In conclusion, the different forms of cyanobacterial bio-substances could supply nutrients or growth promoters for C. oryzetorum to grow, and at the same time, other growth inhibiters might exist to inhibit the growth of C. oryzetoritm. Factors of promoting and inhibiting worked together, thus resulted in the different promoting effects by different forms of cyanobacterial bio-substances to the growth in C. oryzetorum

Cre-miR914 Regulates Heat Shock Adaptation in Chlamydomonas reinhardtii

Heat shock is a common stress for life, while algae develops high efficient adaptation ability to heat shock during longtime evolution. Up to date, the researches about the mechanism of heat shock adaptation in algae focus just on physiological regulation and related coding genes, while there are few reports about non-coding genes on it. In the previous study, we found that Cre-miR914 were down-regulated significantly under multiple stresses (heat shock, UV-B and salinity) in Chlamydomonas reinhardtii through Q-PCR screening experiments, and bioinformatics analysis showed that the target gene of Cre-miR914 may be RPL18. But the functions of Cre-miR914 and its target gene in heat shock adaptation are unclear, this study addressed these issues through multiple experiments. In this study, we identified the target of Cre-miR914 through bioinfounatics and degradome sequencing, and validated expression of Cre-miR914 and RPL18 under heat shock through Q-PCR. Then we constructed cell lines of Cre-miR914 overexpression and RPL18 overexpression for further study. And finally we performed stress adaptation experiments under heat shock stress to check the function of microRNA and its target in stress adaptation, which includes cell growth assay, cell vitality counting, reactive oxygen species (ROS) production and lipid peroxidation (MDA) measurements. Bioinformatics and degradome sequencing indicated the target of Cre-miR914 is RPL18; Q-PCR results showed that Cre-miR914 expression reduced under heat shock, but RPL18 expression increased, which confirmed our previous results of screening experiment. Then we got more than 3 cell lines with overexpressing of Cre-miR914 and RPL18. Further growth experiment under heat shock indicated that Cre-miR914 overexpression lines had a lower growth than the wild-type line (cw15), while RPL18 overexpression lines had a higher growth than the wild-type line (cw15). Cells vitality (photosynthesis activity) experiment under stress also demonstrated that Cre-miR914 overexpression lines had a lower vitality than the wild-type line (cw15), while RPL18 overexpression lines had a higher vitality. The cell damage (ROS production and MDA content) experiments showed that there were more cell damages (ROS production and MDA content) in Cre-miR914 overexpression lines than the wild-type line (cw15), while that of RPL18 overexpression lines were lower than the wild-type line (cw15). These results illustrated that overexpression of Cre-miR914 reduced heat shock resistance ability in algae, while overexpression of RPL18 increased heat shock resistance ability. We maybe discovered a new regulation mechanism of heat shock adaptation in algae, in which Cre-miR914 and its target gene RPL18 are engaged in adaptation regulation to heat shock in Chlamydomonas reinhardtii.</p