Anti-hypertensive effects of Rosuvastatin are associated with decreased inflammation and oxidative stress markers in hypertensive rats

Among their pleiotropic effects, statins exert antioxidant and anti-inflammatory properties. The aim of this study was to evaluate in normotensive (WKY) and in spontaneously hypertensive rats (SHR) the effect of rosuvastatin (ROSU) treatment on (1) plasma inflammation markers and endogenous NO synthase inhibitor (ADMA) levels, (2) reactive oxygen species (ROS) generated by circulating leukocytes and (3) vascular oxidative stress and tissue inflammation markers. Plasma cytokines were higher in SHR than in WKY, except for IL-4, which was lower in SHR than in WKY. SHR monocytes exhibited higher production of ROS than did WKY monocytes. In the experimental conditions, ROSU did not modify plasma cholesterol levels in SHR but attenuated the increase in systolic blood pressure. In SHR only, ROSU lessened pro-inflammatory cytokines and ADMA levels, increased IL-4 and reduced ROS production in circulating monocytes. These results demonstrate the beneficial effects of ROSU in SHR, independently of any lowering of cholesterol levels.     

Synthesis of N,N'-disubstituted 3-aminobenzo[c] and [d]azepin-2-ones as potent and specific farnesyl transferase inhibitors

A structure-activity study was performed by synthesis on N,N'-disubstitution of 3-aminobenzo[c] and [d]azepin-2-one 2 and 3 to afford potent and specific farnesyl transferase inhibitors with low nM enzymatic and cellular activities.     

Islet Endothelial Activation and Oxidative Stress Gene Expression Is Reduced by IL-1Ra Treatment in the Type 2 Diabetic GK Rat

Background

Inflammation followed by fibrosis is a component of islet dysfunction in both rodent and human type 2 diabetes. Because islet inflammation may originate from endothelial cells, we assessed the expression of selected genes involved in endothelial cell activation in islets from a spontaneous model of type 2 diabetes, the Goto-Kakizaki (GK) rat. We also examined islet endotheliuml/oxidative stress (OS)/inflammation-related gene expression, islet vascularization and fibrosis after treatment with the interleukin-1 (IL-1) receptor antagonist (IL-1Ra).

Methodology/Principal Findings

Gene expression was analyzed by quantitative RT-PCR on islets isolated from 10-week-old diabetic GK and control Wistar rats. Furthermore, GK rats were treated s.c twice daily with IL-1Ra (Kineret, Amgen, 100 mg/kg/day) or saline, from 4 weeks of age onwards (onset of diabetes). Four weeks later, islet gene analysis and pancreas immunochemistry were performed. Thirty-two genes were selected encoding molecules involved in endothelial cell activation, particularly fibrinolysis, vascular tone, OS, angiogenesis and also inflammation. All genes except those encoding angiotensinogen and epoxide hydrolase (that were decreased), and 12-lipoxygenase and vascular endothelial growth factor (that showed no change), were significantly up-regulated in GK islets. After IL-1Ra treatment of GK rats in vivo, most selected genes implied in endothelium/OS/immune cells/fibrosis were significantly down-regulated. IL-1Ra also improved islet vascularization, reduced fibrosis and ameliorated glycemia.

Conclusions/Significance

GK rat islets have increased mRNA expression of markers of early islet endothelial cell activation, possibly triggered by several metabolic factors, and also some defense mechanisms. The beneficial effect of IL-1Ra on most islet endothelial/OS/immune cells/fibrosis parameters analyzed highlights a major endothelial-related role for IL-1 in GK islet alterations. Thus, metabolically-altered islet endothelium might affect the β-cell microenvironment and contribute to progressive type 2 diabetic β-cell dysfunction in GK rats. Counteracting islet endothelial cell inflammation might be one way to ameliorate/prevent β-cell dysfunction in type 2 diabetes.     

Kinetochore Localization of Spindle Checkpoint Proteins: Who Controls Whom?

The spindle checkpoint prevents anaphase onset until all the chromosomes have successfully attached to the spindle microtubules. The mechanisms by which unattached kinetochores trigger and transmit a primary signal are poorly understood, although it seems to be dependent at least in part, on the kinetochore localization of the different checkpoint components. By using protein immunodepletion and mRNA translation in Xenopus egg extracts, we have studied the hierarchic sequence and the interdependent network that governs protein recruitment at the kinetochore in the spindle checkpoint pathway. Our results show that the first regulatory step of this cascade is defined by Aurora B/INCENP complex. Aurora B/INCENP controls the activation of a second regulatory level by inducing at the kinetochore the localization of Mps1, Bub1, Bub3, and CENP-E. This localization, in turn, promotes the recruitment to the kinetochore of Mad1/Mad2, Cdc20, and the anaphase promoting complex (APC). Unlike Aurora B/INCENP, Mps1, Bub1, and CENP-E, the downstream checkpoint protein Mad1 does not regulate the kinetochore localization of either Cdc20 or APC. Similarly, Cdc20 and APC do not require each other to be localized at these chromosome structures. Thus, at the last step of the spindle checkpoint cascade, Mad1/Mad2, Cdc20, and APC are recruited at the kinetochores independently from each other.     

Placental growth factor contributes to micro-vascular abnormalization and blood-retinal barrier breakdown in diabetic retinopathy

Objective

There are controversies regarding the pro-angiogenic activity of placental growth factor (PGF) in diabetic retinopathy (DR). For a better understanding of its role on the retina, we have evaluated the effect of a sustained PGF over-expression in rat ocular media, using ciliary muscle electrotransfer (ET) of a plasmid encoding rat PGF-1 (pVAX2-rPGF-1).

Materials and Methods

pVAX2-rPGF-1 ET in the ciliary muscle (200 V/cm) was achieved in non diabetic and diabetic rat eyes. Control eyes received saline or naked plasmid ET. Clinical follow up was carried out over three months using slit lamp examination and fluorescein angiography. After the control of rPGF-1 expression, PGF-induced effects on retinal vasculature and on the blood-external barrier were evaluated respectively by lectin and occludin staining on flat-mounts. Ocular structures were visualized through histological analysis.

Results

After fifteen days of rPGF-1 over-expression in normal eyes, tortuous and dilated capillaries were observed. At one month, microaneurysms and moderate vascular sprouts were detected in mid retinal periphery in vivo and on retinal flat-mounts. At later stages, retinal pigmented epithelial cells demonstrated morphological abnormalities and junction ruptures. In diabetic retinas, PGF expression rose between 2 and 5 months, and, one month after ET, rPGF-1 over-expression induced glial activation and proliferation.

Conclusion

This is the first demonstration that sustained intraocular PGF production induces vascular and retinal changes similar to those observed in the early stages of diabetic retinopathy. PGF and its receptor Flt-1 may therefore be looked upon as a potential regulatory target at this stage of the disease.     

The food web in the lower part of the Seine estuary: a synthesis of existing knowledge

The Seine estuary illustrates the alterations to estuaries due to human activities heavy releases of pollutants of various origins and significant morphological changes beginning in the middle of the 19th century. The intertidal mudflat surface has been seriously reduced (< 30km²) since the channels of the Seine River came under management. While the role of the Seine estuary in the dynamics of the eastern English Channel ecosystem is recognized as important, the biological characteristics of the estuary remained relatively unknown until the 1990s. Biological diversity was progressively impoverished from the polyhaline zone to the oligohaline zone. In spite of a heavily contaminated environment, the macrobenthic and planktonic fauna of the Seine estuary remains similar to those of other northeastern Atlantic estuaries. The fauna exhibit clear contrasts between areas with very high abundance and others with very low abundance. The pelagic fauna, especially the copepod Eurytemora affinisand the shrimp Palaemon longirostris, are more abundant in the Seine estuary than in other estuaries. Diversified and abundant, Abra alba-Pectinaria koreni and Macoma balthica benthic communities occur, respectively, in the outer and inner parts of the estuary. In subtidal flats, benthic fauna is especially poor in terms of specific richness, abundance and biomass. Paradoxically, considering the high abundance of prey, fish are particularly scarce. Two food webs have been identified. In the oligohaline zone, where turbidity is maximum, the food web is exclusively planktonic, due to dredging that prevented benthic fauna from settling. In the polyhaline zone, fish populations that feed particularly on benthic fauna benefit from low turbidity and high oxygen concentrations. So, in spite of heavy organic and metallic contamination and human activities, the Seine estuary remains a highly productive ecosystem, which provides a nursery for marine fish and feeding grounds for migratory birds. A global management plan appears to be necessary in order to guarantee that the Seine estuary continues to function as it currently does.     

Expression and functional analysis of three isoforms of human heterochromatin-associated protein HP1 in Drosophila

Heterochromatin-associated protein 1 (HP1) is a nonhistone chromosomal protein associated with pericentromeric heterochromatin in Drosophila. HP1-like proteins have also been found associated with heterochromatin in human cells. The goal of this study was to determine whether proteins of the structurally conserved human HP1 family exhibit conserved heterochromatin targeting and silencing properties in Drosophila. We established transgenic lines of Drosophila melanogaster expressing each of the three human HP1 proteins, HP1Hsalpha, HP1HSbeta, and HP1Hsgamma, under the Hsp70 heat shock promoter. We show that all three isoforms of human HP1 are stably expressed in Drosophila and are associated with heterochromatin in Drosophila chromosomes. Like Drosophila HP1, all three human HP1 proteins are delocalized by an HP1-POLYCOMB chimeric protein, implying that both human HP1 and Drosophila HP1 interact in a common protein complex, and that at least some aspects of heterochromatin structure are highly conserved throughout the evolution of eukaryotes. Ectopic expression of two of the three human HP1 family proteins significantly enhances heterochromatic silencing in Drosophila.     

Peptide mapping of β-casein by capillary zone electrophoresis

A method to the study of -casein proteolysis by aspartic proteinases is developed. The 3% trichloroacetic acid-soluble peptides of -casein digested with cardosin A were separated by capillary zone electrophoresis under different experimental conditions in an uncoated fused silica capillary. The best separation was at pH 3.01, 30 kV and 30 °C.     

Capillary electrophoresis of caseino-peptides: influence of applied voltage and column temperature

The peptides formed upon action of purified cardoon rennet on the Ala₁₈₉-Phe₁₉₀-Leu₁₉₁-Leu₁₉₂-Tyr₁93 -casein fragment were separated by capillary electrophoresis in an uncoated fused silica capillary. There was a linear correlation between electrophoretic mobility and Z/M^2/3 (Z, net charge; M, molecular mass) under all experimental conditions tested; under the optimal condicitions, 25 kV and 40 °C, the correlation coefficient was 0.994. The reported method is fast (migration times less than 7 min) and may be used to study the action of aspartic proteinases on the C-terminal domain of -casein and thus to help elucidate their effect on cheese quality.