Functional Analysis of Two Haplotypes of the Human Endothelial Protein C Receptor Gene

Objective—

To confirm the effect of the endothelial protein receptor gene ( PROCR ) haplotypes H1 and H3 on venous thromboembolism (VTE), to study their effect on endothelial protein C receptor (EPCR) expression in human umbilical vein endothelial cells, and to investigate the functionality of H1 tagging single-nucleotide polymorphisms in an in vitro model.

Approach and Results—

Protein C (PC), activated PC, and soluble EPCR (sEPCR) levels were measured in 702 patients with VTE and 518 healthy individuals. All subjects were genotyped for PROCR H1 and H3. Human umbilical vein endothelial cells isolated from 111 umbilical cords were used to study the relation between PROCR haplotypes, PROCR mRNA, cellular distribution of EPCR, and rate of PC activation. Finally, the functionality of the intragenic PROCR H1 single-nucleotide polymorphisms was analyzed using a luciferase-based method. We confirmed that individuals carrying H1 have reduced VTE risk, increased plasma activated PC levels, and reduced plasma sEPCR levels and that individuals with the H3H3 genotype have an increased VTE risk and increased plasma sEPCR levels. In cultured human umbilical vein endothelial cells, H1 is associated with increased membrane-bound EPCR, increased rate of PC activation, and reduced sEPCR in conditioned medium, but does not significantly influence PROCR mRNA levels. In contrast, H3 is associated with reduced membrane-bound EPCR and increased sEPCR in human umbilical vein endothelial cell–conditioned medium, higher levels of a truncated mRNA isoform, and a lower rate of PC activation. Finally, we identified the g.2132T>C single-nucleotide polymorphism in intron 1 as an intragenic H1-specific functional single-nucleotide polymorphism.

Conclusions—

These results support a protective role of PROCR H1 against VTE and an increased risk of VTE associated with the H3 haplotype.

Contractile responses of human thyroid arteries to vasopressin

AIMS

In the present study we investigated the intervention of nitric oxide and prostacyclin in the responses to vasopressin of isolated thyroid arteries obtained from multi-organ donors.

MAIN METHODS

Paired artery rings from glandular branches of the superior thyroid artery, one normal and the other deendothelised, were mounted in organ baths for isometric recording of tension. Concentration-response curves to vasopressin were determined in the absence and in the presence of either the vasopressin V1 receptor antagonist d(CH2)5Tyr(Me)AVP (10(-8)M), the nitric oxide synthase inhibitor N(G)-monomethyl-l-arginine (L-NMMA, 10(-4)M), or the inhibitor of prostaglandins indomethacin (10(-6)M).

KEY FINDINGS

In artery rings under resting tension, vasopressin produced concentration-dependent, endothelium-independent contractions. The vasopressin V1 receptor antagonist d(CH2)5Tyr(Me)AVP (10(-8)M) displaced the control curve to vasopressin 19-fold to the right in a parallel manner. The contractile response to vasopressin was unaffected by L-NMMA or by indomethacin.

SIGNIFICANCE

Vasopressin causes constriction of human thyroid arteries by stimulation of V1 vasopressin receptors located on smooth muscle cells. These effects are not linked to the presence of an intact endothelium or to the release of nitric oxide or prostaglandins. The constriction of thyroid arteries may be particularly relevant in certain pathophysiological circumstances in which vasopressin is released in amounts that could interfere with the blood supply to the thyroid gland.

Kaolin and copper-based products applications: ecotoxicology on four natural enemies

Lethal and sublethal effects of kaolin clays and two copper-based products on four natural enemies found in olive orchards Anthocoris nemoralis (F.) (Hem. Anthocoridae), Chelonus inanitus (L.) (Hym. Braconidae), Chilocorus nigritus (F.) (Col. Coccinellidae) and Scutellysta cyanea Motschulsky (Hym. Pteromalidae) are described. Both kaolin and copper can be applied for controlling the olive fruit fly and the olive moth, two important pests of this crop. The products did not increase the mortality of any of the insects studied, with the exception of A. nemoralis. The sublethal effects, however, differed depending on the parameter evaluated and the insect studied. Both kaolin and coppers slightly, but significantly, reduced the life span of C. inanitus and S. cyanea. Number of eggs laid by A. nemoralis females were reduced, but not significantly compared to the controls. In the behavioural experiments, clear preference for remaining on kaolin-untreated surfaces when insects were able to choose was observed. Despite having some negative effects, the negative impact on natural enemies was lower than the impact caused by products commonly applied in this crop against the pests stated above. Therefore, both kaolin and copper can be considered as alternative products to be applied in olive orchards if an effective resistance management programme is to be developed. Furthermore, both of them are allowed in organic farming, in which the number of products that can be applied is more restricted.

Basal release of nitric oxide in the mesenteric artery in portal hypertension and cirrhosis: role of dimethylarginine dimethylaminohydrolase

BACKGROUND AND AIM

Increased basal release of nitric oxide (NO) in the splanchnic circulation contributes to elevated plasma levels of NO observed in decompensated cirrhosis. We evaluated in rat mesenteric arteries whether the differences in basal release of NO, revealed by asymmetric dimethylarginine (ADMA)- and N(G) -nitro-L-arginine methyl ester (L-NAME)-induced contractions, were associated with changes in messenger RNA (mRNA) expression of endothelial NO synthase (eNOS) and dimethylarginine dimethylaminohydrolases (DDAHs).

METHODS

Rat small mesenteric arteries from 14 Sham-control, from 14 with partial portal vein ligation (PPVL), and from 14 with bile duct excision (BDE)-induced cirrhosis were precontracted under isometric conditions with norepinephrine, and additional contractions were induced with ADMA and L-NAME. mRNA expression of eNOS, DDAH-1, and DDAH-2 in mesenteric arteries were evaluated by real-time polymerase chain reaction.

RESULTS

ADMA and L-NAME caused concentration- and endothelium-dependent contractions. pD2 values to L-NAME were similar in all groups. In contrast, pD2 values to ADMA were similar in PPVL and BDE but were significantly lower than those of the L-NAME and the Sham groups. Relaxation to acetylcholine was not modified by ADMA or L-NAME but was abolished by charybdotoxin plus apamin. There was an increased mRNA expression of eNOS, DDAH-1, and DDAH-2 in mesenteric arteries from PPVL and BDE compared with the Sham group.

CONCLUSION

Basal release of NO is increased in mesenteric arteries of PPVL and BDE rats. The rise in expression of DDAHs indicates a higher degradation of ADMA. This would result in an increased generation of endothelial NO and mesenteric vasodilation.

Aging enhances contraction to thromboxane A2 in aorta from female senescence-accelerated mice

The time-course for aging-associated effects on vascular reactivity to U46619, a stable analogue of thromboxane A(2) (TXA(2)), was studied in aorta from female senescence-accelerated mice-prone (SAMP8), a murine model of accelerated senescence. SAMP8 and senescence-accelerated mice-resistant (SAMR1) were divided into three groups: 3-, 6- and 10-month-old. Contractile curves to U46619 (10(-9) to 10(-6) M) were performed in aortic rings in the absence or in the presence of nitric oxide synthase (NOS) inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME; 10(-4) M) and/or cyclooxygenase (COX) inhibitor indomethacin (10(-5) M). Protein and gene expression for COX-1 and COX-2 were determined by immunofluorescence and real-time PCR, respectively. Maximal contraction to U46619 was markedly higher in SAMP8 at all ages. In SAMR1, increases were seen at 10 months, while SAMP8 displays augmented contraction at 6 months, which was further increased at 10 months. L-NAME enhanced U46619 contractions in both 6-month-old groups, although the increase was higher on vessels from SAMR1 at this age. Indomethacin equally increased U46619 contractions in both 3-month-old groups, suggesting the production of vasodilator prostaglandin in young animals. In contrast, at 6 and 10 months indomethacin decreased U46619 contractions in both groups, indicating an aging-associated swap to a release of contractile prostanoids in aorta. In conclusion, aging enhances contractile responses to TXA(2) in aorta from female mice by a mechanism involving a decrease of NO production and increased action of contractile prostanoids. This process occurs earlier in SAMP8 mice, establishing these mice as good model to study cardiovascular aging in a convenient and standard time-course.

Vascular Aging in Women: is Estrogen the Fountain of Youth?

Aging is associated with structural and functional changes in the vasculature, including endothelial dysfunction, arterial stiffening and remodeling, impaired angiogenesis, and defective vascular repair, and with increased prevalence of atherosclerosis. Cardiovascular risk is similar for older men and women, but lower in women during their fertile years. This age- and sex-related difference points to estrogen as a protective factor because menopause is marked by the loss of endogenous estrogen production. Experimental and some clinical studies have attributed most of the protective effects of estrogen to its modulatory action on vascular endothelium. Estrogen promotes endothelial-derived NO production through increased expression and activity of endothelial nitric oxide synthase, and modulates prostacyclin and thromboxane A(2) release. The thromboxane A(2) pathway is key to regulating vascular tone in females. Despite all the experimental evidence, some clinical trials have reported no cardiovascular benefit from estrogen replacement therapy in older postmenopausal women. The "Timing Hypothesis," which states that estrogen-mediated vascular benefits occur only before the detrimental effects of aging are established in the vasculature, offers a possible explanation for these discrepancies. Nevertheless, a gap remains in current knowledge of cardiovascular aging mechanisms in women. This review comprises clinical and experimental data on the effects of aging, estrogens, and hormone replacement therapy on vascular function of females. We aim to clarify how menopause and aging contribute jointly to vascular aging and how estrogen modulates vascular response at different ages.

The relationship of leukocyte anisocytosis to holotranscobalamin, a marker of cobalamin deficiency

INTRODUCTION

After measurement of the mean volumes of leukocyte subpopulations as well as the distribution widths (DW) of these volumes has become available, we investigated whether such morphometric leukocyte parameters are associated with a commonly used marker of cobalamin deficiency, i.e., holotranscobalamin (HoloTC). Further, we determined reference intervals for these parameters in an elderly population.

METHODS

Consecutive subjectively healthy and volunteering individuals ≥60 years were included. Using the UniCel DxH 800 Coulter Cellular Analysis System MoMV, mean neutrophil volume (NeMV), mean lymphocyte volume (LyMV), monocyte anisocytosis (MoV-DW), neutrophil anisocytosis (NeV-DW), and lymphocyte anisocytosis (LyV-DW) were assessed together with other parameters including HoloTC.

RESULTS

A total of 150 individuals were included in the study. Reference intervals were not dependent on age and gender. MoV-DW (P = 0.002) and NeV-DW (P = 0.02) were significantly lower, and LyMV was significantly higher (P = 0.04) in participants with a HoloTC concentration <28 pm. In contrast, MCV, MoMV, NeMV, and LyV-DW were not associated with HoloTC concentrations. The area under the curve (AUC) in the receiver operating characteristic analysis for detecting a HoloTC <28 pm was 0.81 [95% confidence interval (CI) (0.73, 0.87)] for MoV-DW and 0.73 (0.66, 0.80) for NeV-DW.

CONCLUSION

In this collective of subjectively healthy elderly individuals, monocyte anisocytosis, neutrophil anisocytosis and mean lymphocyte volume were associated with decreased HoloTC.

Post-epizootic chronic dolphin morbillivirus infection in Mediterranean striped dolphins Stenella coeruleoalba

Dolphin morbillivirus (DMV) has caused 2 epizootics with high mortality rates on the Spanish Mediterranean coast, in 1990 and 2006-07, mainly affecting striped dolphins Stenella coeruleoalba. Following the first epizootic unusual DMV infections affecting only the central nervous system of striped dolphins were found, with histological features similar to subacute sclerosing panencephalitis and old dog encephalitis, the chronic latent localised infections caused by defective forms of measles virus and canine distemper virus, respectively. Between 2008 and 2010, monitoring by microscopic and immunohistochemical (IHC) studies of 118 striped dolphins stranded along Catalonia, the Valencia Region and Andalusia showed similar localised DMV nervous system infections in 25.0, 28.6 and 27.4% of cases, respectively, with no significant differences among regions or sex. The body length of DMV-infected dolphins was statistically greater than that of non-infected dolphins (196.5 vs. 160.5 cm; p < 0.001). Molecular detection of DMV was performed by 2 different RT-PCR techniques amplifying a 429 bp fragment and a 78 bp fragment both within the phosphoprotein (P) gene. The 429 bp RT-PCR results contradicted the IHC-DMV results as only 3 of 6 dolphins with positive IHC-DMV had positive PCR results. All 6 cases were positive with the 78 bp RT-PCR. These findings contraindicate the use of the 429 bp RT-PCR protocol based on the P gene to detect this specific form of DMV. DMV localised nervous infection constitutes the most relevant single cause of stranding and death in Mediterranean striped dolphins in the years following a DMV epizootic, and it might even overwhelm the effects of the epizootic itself, at least in 2007.

Differences in expression and activity of 11beta-hydroxysteroid dehydrogenase type 1 and 2 in human placentas of term pregnancies according to birth weight and gender

BACKGROUND

Fetal exposure to maternal glucocorticoids may determine fetal growth and the programing of later disorders. Availability of the glucocorticoids in the placenta is regulated by the 11beta-hydroxysteroid dehydrogenase (11beta-HSDs) enzymes. To date, there are discrepancies with regard to cortisol (F) cord blood levels in fetuses with intrauterine growth retardation in different species. Objective To study the expression and activity of 11beta-HSDs in placentas from full term small for gestational age (SGA), appropriate for gestational age (AGA) and large for gestational age (LGA) newborns, and cortisol cord blood concentration.

METHODS

Twenty-five placentas from AGA, 24 SGA and 25 LGA were collected.

RESULTS

SGA newborns had significantly lower and LGA newborns had significantly higher birth weight, birth length, head circumference, and placental weight than AGA counterparts. We observed a direct correlation between placental weight and birth weight, birth length and head circumference, and higher cord F levels in SGA newborns. The 11beta-HSD1 expression was similar among the SGA, AGA, and LGA placentas. However, within the placentas of SGA newborns, the 11beta-HSD1 mRNA levels were significantly reduced in the chorionic plate compared with basal plate. An inverse correlation between cord F levels and activity of 11beta-HSD1 in the chorionic plate of the SGA placentas was detected. The 11beta-HSD2 activity was seven- to eightfold higher compared with 11beta-HSD1 in the placentas, and there was a lower 11beta-HSD2 activity in females' SGA placentas compared with the male SGA placentas.

CONCLUSION

We observed a lower expression and activity of 11beta-HSD1 in the chorionic plate of the SGA placentas, suggesting a possible compensatory mechanism to diminish the higher cortisol fetal concentrations observed in fetuses with intrauterine growth restriction.

Insights into the role of microRNAs in cardiac diseases: from biological signalling to therapeutic targets

microRNAs have recently opened new pathways to explain gene expression and disease biology in many scenarios, including cardiac diseases. microRNAs are endogenous small non-coding RNAs that mediate post-transcriptional repression or messenger RNA degradation. By annealing to inexactly complementary sequences in the 3' untranslated region of the target messenger RNA, protein level is down-regulated. Several microRNAs appear to act cooperatively through multiple target sites in one gene and, conversely, most microRNAs can target several genes. miR-133 and miR-1 are specifically expressed in cardiac and skeletal muscle and control myogenesis, cardiac development, cardiac performance and cardiomyocyte hypertrophy (mainly by tuning transcription factors and other growth-related targets). They also modulate the expression of certain cardiac ion channels and related proteins with proarrhythmic effect. Besides them, other microRNAs have been shown to exert influence on the myocardial growth, the electrical balance and the angiogenesis processes that take place in the heart. Bioinformatics is a useful tool to identify potential targets of a given microRNA, although there is still substantial concern about their reliability. Experimental manipulation of microRNAs has provided a tantalizing basis to speculate that future research on microRNAs may yield important progress in the prevention of sudden cardiac death and in the treatment of cardiac heart failure. However, the final effect of the blockage of microRNAs in vivo remains unclear, since each of them can target hundreds of genes with different intensity. The era of the microRNAs in cardiovascular diseases has just started.

The -589C>T polymorphism in the interleukin-4 gene (IL-4) is associated with a reduced risk of myocardial infarction in young individuals

BACKGROUND

Inflammatory reactions contribute to the development of arterial disease. We investigated the role of interleukin-4 (IL-4) in the development of myocardial infarction (MI) by genotyping patients with MI and control subjects for the -589C>T (rs2243250) single nucleotide polymorphism (SNP), which tags a functional haplotype of IL-4.

METHODS AND RESULTS

Study of Myocardial Infarctions Leiden (SMILE) included 560 men with a first MI and 646 control subjects. The Valencia study included 305 patients with MI at T genotype was found [odds ratio (OR) 0.84; 95% CI 0.37-1.95 for -589TT and 0.82; 95% CI 0.62-1.07 for -589CT compared with -589CC]. In patients younger than 50 years, carriership of one or two -589T alleles was associated with a reduced risk of MI (OR 0.57: 95% CI 0.34-0.95). This result was replicated in the Valencia study, where carriers of one or two -589T alleles had a reduced risk of MI (OR 0.67: 95% CI 0.47-0.95), with a strong protective effect of the -598T allele in homozygous -589T (OR 0.33: 95% CI 0.10-1.05). In the control subjects of the Valencia study, the -589T allele was associated with reduced levels of F1+2.

CONCLUSION

Our data indicate that the IL-4 haplotype tagged by the -589T allele reduces the risk of MI in young individuals.