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In pressure overload (PO), sex differences in humans and rodents have been well documented and estrogen receptor (ER) β is considered cardioprotective. However, the underlying mechanisms are poorly understood. Our aim was to investigate sex- and ERβ-specific effects in protein abundance in PO employing a 2-dimensional gel electrophoresis/mass spectrometry-based proteomics approach. We hypothesized major sex differences and ERβ-specific alterations consistent with cardioprotection in females. Two-month old male and female wild-type (WT) and ERβ knockout (BERKO) mice were subjected to transverse aortic constriction (TAC) for 9 weeks (n = 4/group). In WT mice, hypertrophy was significantly more pronounced in males than females, while this sex difference was abolished in BERKO mice. We found 82 protein spots modulated between TAC and sham in WT males, 31 in WT females, 114 in BERKO males, and 87 in BERKO females (P ≤ 0.05). Our analysis revealed in WT and BERKO females an altered pattern of various proteins involved in structure and suggests a link between female sex and cytoskeletal integrity. In males, a set of proteins was identified that associate with mitochondrial bioenergetics and energy supply. We confirmed protein regulation by immunoblotting analysis. In conclusion, the proteomic response of the heart to PO is significantly modulated by ERβ and sex. We put forward that the observed differences may identify sex-specific targets for the treatment of heart failure, contributing toward more personalized medical care.

Aims Oestrogen receptor alpha (ERα) and beta (ERβ) are involved in the regulation of pathological myocardial hypertrophy (MH). We hypothesize that both ER are also involved in physiological MH. Therefore, we investigated the role of ER in exercise-induced physiological MH in loss-of-function models and studied potential mechanisms of action. Methods and results We performed 1 and 8 weeks of voluntary cage wheel running (VCR) with male and female C57BL/6J wild-type (WT), ERα- and ERβ-deleted mice. In line with other studies, female WT mice ran more than males ( P ≤ 0.001). After 8 weeks of VCR, both sexes showed an increase in left ventricular mass (females: P ≤ 0.01 and males: P ≤ 0.05) with more pronounced MH in females ( P < 0.05). As previously shown, female ERα-deleted mice run less than female WT mice ( P ≤ 0.001). ERβ-deleted mice showed similar running performance as WT mice (females vs. male: P ≤ 0.001), but did not develop MH. Only female WT mice showed an increase in phosphorylation of serine/threonine kinase (AKT), ERK1/2, p38-mitogen-activated protein kinase (MAPK), and ribosomal protein s6, as well as an increase in the expression of key regulators of mitochondrial function and mitochondrial respiratory chain proteins (complexes I, III, and V) after VCR. However, ERβ deletion abolished all observed sex differences. Mitochondrial remodelling occurred in female WT-VCR mice, but not in female ERβ-deleted mice. Conclusion The sex-specific response of the heart to exercise is modulated by ERβ. The greater increase in physiological MH in females is mediated by induction of AKT signalling, MAPK pathways, protein synthesis, and mitochondrial adaptation via ERβ.

Background Estrogen improves cardiac recovery after ischemia/reperfusion (I/R) by yet incompletely understood mechanisms. Mitochondria play a crucial role in I/R injury through cytochrome c-dependent apoptosis activation. We tested the hypothesis that 17β-estradiol (E2) as well as a specific ERβ agonist improve cardiac recovery through estrogen receptor (ER)β-mediated mechanisms by reducing mitochondria-induced apoptosis and preserving mitochondrial integrity. Methods We randomized ovariectomized C57BL/6N mice 24h before I/R to pre-treatment with E2 or a specific ERβ agonist (ERβA). Isolated hearts were perfused for 20min prior to 30min global ischemia followed by 40min reperfusion. Results Compared with controls, ERβA and E2 treated groups showed a significant improvement in cardiac recovery, i.e. an increase in left ventricular developed pressure, dP/dtmax and dP/dtmin. ERβA and E2 pre-treatment led to a significant reduction in apoptosis with decreased cytochrome c release from the mitochondria and increased mitochondrial levels of anti-apoptotic Bcl2 and ACAA2. Protein levels of mitochondrial translocase inner membrane (TIM23) and mitochondrial complex I of respiratory chain were increased by ERβA and E2 pre-treatment. Furthermore, we found a significant increase of myosin light chain 2 (MLC2) phosphorylation together with ERK1/2 activation in E2, but not in ERβA treated groups. Conclusions Activation of ERβ is essential for the improvement of cardiac recovery after I/R through the inhibition of apoptosis and preservation of mitochondrial integrity and can be a achieved by a specific ERβ agonist. Furthermore, E2 modulates MLC2 activation after I/R independent of ERβ. Electronic supplementary material The online version of this article (doi:10.1186/s13293-016-0104-8) contains supplementary material, which is available to authorized users.

Exercise-induced cardiac hypertrophy has been recently identified to be regulated in a sex-specific manner. In parallel, women exhibit enhanced exercise-mediated lipolysis compared with men, which might be linked to cardiac responses. The aim of the present study was to assess if previously reported sex-dependent differences in the cardiac hypertrophic response during exercise are associated with differences in cardiac energy substrate availability/utilization. Female and male C57BL/6J mice were challenged with active treadmill running for 1.5 h/day (0.25 m/s) over 4 wk. Mice underwent cardiac and metabolic phenotyping including echocardiography, small-animal PET, peri-exercise indirect calorimetry, and analysis of adipose tissue (AT) lipolysis and cardiac gene expression. Female mice exhibited increased cardiac hypertrophic responses to exercise compared with male mice, measured by echocardiography [percent increase in left ventricular mass (LVM): female: 22.2 ± 0.8%, male: 9.0 ± 0.2%; P < 0.05]. This was associated with increased plasma free fatty acid (FFA) levels and augmented AT lipolysis in female mice after training, whereas FFA levels from male mice decreased. The respiratory quotient during exercise was significantly lower in female mice indicative for preferential utilization of fatty acids. In parallel, myocardial glucose uptake was reduced in female mice after exercise, analyzed by PET {injection dose (ID)/LVM [%ID/g]: 36.8 ± 3.5 female sedentary vs. 28.3 ± 4.3 female training; P < 0.05}, whereas cardiac glucose uptake was unaltered after exercise in male counterparts. Cardiac genes involved in fatty acid uptake/oxidation in females were increased compared with male mice. Collectively, our data demonstrate that sex differences in exercise-induced cardiac hypertrophy are associated with changes in cardiac substrate availability and utilization.

BACKGROUND Dilated cardiomyopathy (DCM) is responsible for over half of all heart transplants. Fewer women with DCM undergo heart transplants than men with DCM; the reasons for this state of affairs are unclear. METHODS AND RESULTS We analyzed prospectively a cohort of 698 DCM patients who were referred to our heart transplant center. Only 15.5% of them were women. Women and men did not differ in age or ejection fraction (24%). Women were more frequently in New York Heart Association class III-IV, had lower exercise tolerance, worse pulmonary function, and poorer kidney function (all P

Pressure overload (PO) first causes cardiac hypertrophy and then heart failure (HF), which are associated with sex differences in cardiac morphology and function. We aimed to identify genes that may cause HF-related sex differences. We used a transverse aortic constriction (TAC) mouse model leading to hypertrophy without sex differences in cardiac function after 2 weeks, but with sex differences in hypertrophy 6 and 9 weeks after TAC. Cardiac gene expression was analyzed 2 weeks after surgery. Deregulated genes were classified into functional gene ontology (GO) categories and used for pathway analysis. Classical marker genes of hypertrophy were similarly upregulated in both sexes (α-actin, ANP, BNP, CTGF). Thirty-five genes controlling mitochondrial function (PGC-1, cytochrome oxidase, carnitine palmitoyl transferase, acyl-CoA dehydrogenase, pyruvate dehydrogenase kinase) had lower expression in males compared to females after TAC. Genes encoding ribosomal proteins and genes associated with extracellular matrix remodeling exhibited relative higher expression in males (collagen 3, matrix metalloproteinase 2, TIMP2, and TGFβ2, all about twofold) after TAC. We confirmed 87% of the gene expression by real-time polymerase chain reaction. By GO classification, female-specific genes were related to mitochondria and metabolism and males to matrix and biosynthesis. Promoter studies confirmed the upregulation of PGC-1 by E2. Less downregulation of metabolic genes in female hearts and increased protein synthesis capacity and deregulation of matrix remodeling in male hearts characterize the sex-specific early response to PO. These differences could contribute to subsequent sex differences in cardiac function and HF. Electronic supplementary material The online version of this article (doi:10.1007/s00109-008-0385-4) contains supplementary material, which is available to authorized users.

We tested the hypothesis that female and male mice differ in terms of cardiac hypertrophy after deoxycorticosterone acetate (DOCA)+salt hypertension (uninephrectomy and 1% saline in drinking water) and focused on calcineurin signaling. We excluded confounding effects of blood pressure elevation or sex-related blood pressure differences by treating DOCA-salt mice with hydralazine (250 mg/L in drinking water). We found that directly measured mean arterial blood pressure was lowered to control values with hydralazine and corroborated this finding in separate mouse groups with radiotelemetry. Male mice were more responsive to DOCA-salt–related effects. They developed more left ventricular hypertrophy and more renal hypertrophy after 6 weeks of DOCA-salt+hydralazine compared with female mice. In hearts, transcripts for calcineurin Aβ and for myocyte-enriched calcineurin interacting protein 1 were upregulated in male but not in female mice. Enhanced activity of calcineurin Aβ, as indicated by diminished phosphorylation of NFATc2 in male mice, accounted for this sex-specific difference. Stretch-related, inflammatory, and profibrotic responses were also accentuated in male mice, as shown by higher transcript levels of atrial natriuretic peptide, monocyte chemoattractant protein-1, and transforming growth factor-β. Our results support sex-specific regulation of the calcineurin pathway in response to largely blood pressure–independent mineralocorticoid action. We suggest that sex-specific calcineurin activation determines the maladaptive cardiac and renal hypertrophic responses and accompanying organ injury in male mice.

Background: Pressure overload leads to myocardial remodelling with collagen accumulation, left ventricular hypertrophy (LVH), neurohormonal activation and myocardial dysfunction. Prolyl 4-hydroxylases (P4H) are involved in collagen maturation. Inhibition of P4H has been shown to prevent LV remodelling and improve survival post-myocardial infarction. Aim: To evaluate the role of P4H in pressure overload-induced myocardial remodelling. Methods: Male Wistar rats underwent thoracic aortic banding (AoB) and were treated with a P4H inhibitor (P4HI) or vehicle (control). Echocardiography and haemodynamic measurements were performed after 4 weeks. Collagens, matrix metalloproteinases (MMP), tissue inhibitors of MMPs (TIMP), growth factors and neurohormonal markers were quantitated in LV samples. Results: AoB led to LVH, increased LV enddiastolic pressure (LVEDP) and decreased contractility compared to sham. P4HI reversed these effects. AoB increased collagen I and III expression, which was normalized by P4HI. AoB led to deregulation of matrix remodelling enzymes, enhanced expression of growth factors and activation of the endothelin system. P4HI partially prevented deregulation of the MMP/TIMP system, inhibited upregulation of growth factors and normalized AoB-induced ECE-1 and ETB expression. Conclusions: P4HI leads to an improvement of AoB-associated LV dysfunction and reduces imbalance of extracellular matrix turnover and hypertrophy-associated gene expression. P4H inhibition could therefore be of value in treatment of myocardial remodelling accompanying pressure overload hypertrophy.

The X-linked ANG II type 2 receptor (AT2) is supposed to be involved in cardiovascular disorders. Two studies associated the A allele of the AT2 gene polymorphism (PM) 1675 G/A with left ventricular hypertrophy in men and coronary ischemia in women. Because the PM is located in the short intron 1 of the AT2 gene within a sequence motif similar to the splice branch site consensus, we tested whether it might affect pre-mRNA splicing and/or modulate AT2 receptor expression. We first analyzed the AT2 mRNA splice pattern by RT-PCR in myocardial samples from 12 explanted human hearts and compared it with the respective genotypes. All 12 patients, 10 hemizygous males (7 A, 3 G allele carriers) and 2 homozygous females (2 G/G allele carriers), exhibited the same myocardial AT2 splice pattern with a relative abundance of transcript exon 1/2/3 compared with exon 1/3. Next, AT2 minigene constructs were cloned from both alleles, comprising the core promoter and the complete transcribed region up to the translation start codon, upstream of a luciferase reporter gene. These constructs were transfected into human (HT1080) and rat (PC12W) cell lines and rat vascular smooth muscle cells, and luciferase activities were assessed, as well as the splice patterns of the chimeric AT2/luciferase mRNAs. In all transfected cell types, the mRNA expressed from the AT2 constructs was spliced like the endogenous myocardial AT2 mRNA. However, luciferase activities driven by the G allele construct were significantly higher than those expressed from the A allele. Taken together, these data indicate that individuals carrying the G allele may express higher levels of AT2 receptor protein, which may be protective during the development of ventricular hypertrophy and coronary ischemia.

OBJECTIVES There is an urgent need to discover new antimalarials, due to the spread of chloroquine resistance and the limited number of available drugs. Chalcones are one of the classes of natural products that are known to possess antiplasmodial properties. Therefore, the in vitro antiplasmodial activity of the main hop chalcone xanthohumol and seven derivatives was evaluated. In addition, the influence of the compounds on glutathione (GSH)-dependent haemin degradation was analysed to determine its contribution to the antimalarial effect of chalcones. METHODS In vitro antiplasmodial activity was evaluated against the chloroquine-sensitive strain poW and the multiresistant clone Dd2 using a [(3)H]hypoxanthine-incorporation assay. Inhibition of GSH-dependent haemin degradation was analysed by a multiwell plate assay at 11 microM. RESULTS Of the eight compounds tested, four possessed activity with IC(50) values

The cardiac response to pressure overload (PO) differs between the sexes and estrogen receptor (ER) β is considered cardioprotective. However, the underlying mechanisms are poorly understood. We ai...

Aims Melusin is a muscle-specific chaperone protein whose expression is required for a compensatory hypertrophy response to pressure overload. Here, we evaluated the consequences of melusin overexpression in the setting of myocardial infarction (MI) using a comprehensive multicentre approach. Methods and results Mice overexpressing melusin in the heart (TG) and wild-type controls (WT) were subjected to permanent LAD ligation and both the acute response (Day 3) and subsequent remodelling (2 weeks) were examined. Mortality in wild-type mice was significant between Days 3 and 7, primarily due to cardiac rupture, but melusin's overexpression strongly reduced mortality (43.2% in wild-type vs. 27.3% in melusin-TG, P = 0.005). At Day 3 after MI, a time point preceding the mortality peak, TG hearts had increased heat shock protein 70 expression, increased ERK1/2 signalling, reduced cardiomyocyte hyper-contractility and inflammatory cell infiltrates, and increased matricellular protein expression in the infarcted area. At 2 weeks after MI, melusin overexpression conferred a favourable adaptive remodelling characterized by reduced left ventricle dilatation and better preserved contractility in the presence of a comparable degree of hypertrophy. Adaptive remodelling in melusin TG mice was characterized by reduced apoptosis and fibrosis as well as increased cardiomyocyte contractility. Conclusions Consistent with its function as a chaperone protein, melusin overexpression exerts a dual protective action following MI reducing an array of maladaptive processes. In the early phase after MI, reduced inflammation and myocyte remodelling protect against cardiac rupture. Chronically, reduced myocyte loss and matrix remodelling, with preserved myocyte contractility, confer adaptive LV remodelling.

Maladaptive cardiac hypertrophy predisposes one to arrhythmia and sudden death. Cytochrome P450 (CYP)-derived epoxyeicosatrienoic acids (EETs) promote anti-inflammatory and antiapoptotic mechanisms, and are involved in the regulation of cardiac Ca(2+)-, K(+)- and Na(+)-channels. To test the hypothesis that enhanced cardiac EET biosynthesis counteracts hypertrophy-induced electrical remodeling, male transgenic mice with cardiomyocyte-specific overexpression of the human epoxygenase CYP2J2 (CYP2J2-TG) and wildtype littermates (WT) were subjected to chronic pressure overload (transverse aortic constriction, TAC) or β-adrenergic stimulation (isoproterenol infusion, ISO). TAC caused progressive mortality that was higher in WT (42% over 8 weeks after TAC), compared to CYP2J2-TG mice (6%). In vivo electrophysiological studies, 4 weeks after TAC, revealed high ventricular tachyarrhythmia inducibility in WT (47% of the stimulation protocols), but not in CYP2J2-TG mice (0%). CYP2J2 overexpression also enhanced ventricular refractoriness and protected against TAC-induced QRS prolongation and delocalization of left ventricular connexin-43. ISO for 14 days induced high vulnerability for atrial fibrillation in WT mice (54%) that was reduced in CYP-TG mice (17%). CYP2J2 overexpression also protected against ISO-induced reduction of atrial refractoriness and development of atrial fibrosis. In contrast to these profound effects on electrical remodeling, CYP2J2 overexpression only moderately reduced TAC-induced cardiac hypertrophy and did not affect the hypertrophic response to β-adrenergic stimulation. These results demonstrate that enhanced cardiac EET biosynthesis protects against electrical remodeling, ventricular tachyarrhythmia, and atrial fibrillation susceptibility during maladaptive cardiac hypertrophy.

The endothelial glycocalyx (eGC) plays a pivotal role in the physiology of the vasculature. By binding plasma proteins, the eGC forms the endothelial surface layer (ESL) which acts as an interface between bloodstream and endothelial cell surface. The functions of the eGC include mechanosensing of blood flow induced shear stress and thus flow dependent vasodilation. There are indications that levels of plasma sodium concentrations in the upper range of normal and beyond impair flow dependent regulation of blood pressure and may therefore increase the risk for hypertension. Substances, therefore, that prevent sodium induced endothelial dysfunction may be attractive for the treatment of cardiovascular disease. By means of combined atomic force - epifluorescence microscopy we studied the impact of the hawthorn (Crataegus spp.) extract WS 1442, a herbal therapeutic with unknown mechanism of action, on the mechanics of the ESL of ex vivo murine aortae. Furthermore, we measured the impact of WS 1442 on the sodium permeability of endothelial EA.hy 926 cell monolayer. The data show that (i) the ESL contributes by about 11% to the total endothelial barrier resistance for sodium and (ii) WS 1442 strengthens the ESL resistance for sodium up to about 45%. This mechanism may explain some of the vasoprotective actions of this herbal therapeutic.

We and others found sex differences in physiological myocardial hypertrophy (MH) in mice subjected to voluntary cage-wheel running (VCR) and forced exercise training. Female mice showed significantly more MH, suggesting the involvement of estrogen (E2) and estrogen receptors (ER). We therefore investigated the underlying mechanisms leading to sex differences in physiological MH and the role of E2 and ER beta (ERß). Male and female C57/Bl6 wild-type (WT) and ERß-deficient mice (ERß-/-) at the age of 12 weeks performed 8 weeks of VCR or were kept sedentary (sed). Exercise performance was monitored daily and left ventricular mass (LVM) was examined by echocardiography. RNA and protein were analyzed by Real-Time PCR and western blot. Luciferase-reporter Assays were performed with PGC-1a-, MEF2A- and MEF2C-promoter deletion constructs in a human cardiac myocyte cell line (AC16 cells) with/without E2 treatment. Female WT-mice run more than their male counterparts (6.7km/day vs. 4.2km/day; p

Background— In patients with aortic stenosis, pressure overload induces cardiac hypertrophy and fibrosis. Female sex and estrogens influence cardiac remodeling and fibrosis in animal models and in men. Sex differences and their molecular mechanisms in hypertrophy regression after aortic valve replacement have not yet been studied. Methods and Results— We prospectively obtained preoperative and early postoperative echocardiography in 92 patients, 53 women and 39 men, undergoing aortic valve replacement for isolated aortic stenosis. We analyzed in a subgroup of 10 patients matrix gene expression in left ventricular (LV) biopsies. In addition, we determined the effect of 17β-estradiol on collagen synthesis in isolated rat cardiac fibroblasts. Preoperatively, women and men had similar ejection fraction. Similar percentages of women and men had increased LV diameters (37% and 38%). Women more frequently exhibited LV hypertrophy than men (women: 86%; men: 56%; P P Conclusion— Women adapt to pressure overload differently from men. Less fibrosis before surgery may enable faster regression after surgery.

We investigated sex differences and the role of estrogen receptor-β (ERβ) on myocardial hypertrophy in a mouse model of pressure overload. We performed transverse aortic constriction (TAC) or sham surgery in male and female wild-type (WT) and ERβ knockout (ERβ−/−) mice. All mice were characterized by echocardiography and hemodynamic measurements and were killed 9 wk after surgery. Left ventricular (LV) samples were analyzed by microarray profiling, real-time RT-PCR, and histology. After 9 wk, WT males showed more hypertrophy and heart failure signs than WT females. Notably, WT females developed a concentric form of hypertrophy, while males developed eccentric hypertrophy. ERβ deletion augmented the TAC-induced increase in cardiomyocyte diameter in both sexes. Gene expression profiling revealed that WT male hearts had a stronger induction of matrix-related genes and a stronger repression of mitochondrial genes than WT female hearts. ERβ−/− mice exhibited a different transcriptional response. ERβ−/−/TAC mice of both sexes exhibited induction of proapoptotic genes with a stronger expression in ERβ−/− males. Cardiac fibrosis was more pronounced in male WT/TAC than in female mice. This difference was abolished in ERβ−/− mice. The number of apoptotic nuclei was increased in both sexes of ERβ−/−/TAC mice, most prominent in males. Female sex offers protection against ventricular chamber dilation in the TAC model. Both female sex and ERβ attenuate the development of fibrosis and apoptosis, thus slowing the progression to heart failure.

There is an urgent need to discover new antimalarials, due to the spread of chloroquine resistance and the limited number of available drugs. Chalcones are one of the classes of natural products that are known to possess antiplasmodial properties. Therefore, the in vitro antiplasmodial activity of the main hop chalcone xanthohumol and seven derivatives was evaluated against two strains of Plasmodium falciparum (poW, Dd2). Four compounds possessed an activity with IC50 values below 25 μM against either strain. Xanthohumol was most active with IC50 values of 8.2 ± 0.3 (poW) and 24.0 ± 0.8 μM (Dd2). In addition, the influence of the compounds on the glutathione-dependent hemin degradation was analyzed to determine its contribution to the antimalarial effect of chalcones.

Background: Peroxisome proliferator activated receptors (PPARs) are key regulators for cardiac energy metabolism after myocardial injury. We hypothesized, that PPARs are regulated in myocardial infarction (MI) and their activity is modulated by angiotensin receptor blockers (ARBs). Methods: Following induction of MI, male rats were treated with placebo or the ARB irbesartan for three weeks. PPARα, β/δ and γ protein expression and gene expression of PPAR target genes and glucose transporters were measured. PPARγ-protein expression was analyzed by immunofluorescence. Results: MI decreased LVP and dp/dtmax and increased LVEDP, this effect was counteracted by irbesartan. PPARα and PPARβ/δ protein expression was not altered in MI and was not affected by irbesartan. PPARγ protein content was increased in the infarcted area and localized to cardiac myocytes and fibroblasts. In parallel, expression of CTGF was increased 10-fold in the infarcted zone. PPAR target genes (CD36, MCAD, ACO and GLUT4) were significantly decreased in infarcted tissue, and this was unaffected by irbesartan. However, CD36 and ACO in the non-infarcted areas were up-regulated by irbesartan. Conclusion: Endogenous up-regulation of PPARγ in MI is insufficient to counteract the decrease in metabolic genes, but parallels an increase in the profibrotic mediator CTGF. Irbesartan increases fatty acid oxidating enzymes after MI independent of PPARγ regulation.

Estrogen combines beneficial and harmful actions by affecting many intracellular pathways in a large number of target organs related to the cardiovascular system. In observational studies and large outcome trials, an improvement of serum lipid profile and reduction of cardiovascular event rate were reported, whereas thrombembolic complications and stroke rate increased. Recognition of the diversity and tissue selectivity of estrogen's effects prompted the development of selective estrogen receptor modulators (SERMs), which were subsequently used to dissect the different mechanisms of action. SERMs are estrogen receptor (ER) ligands that exert partial agonist or antagonist actions on the ER in a tissue-, pathway- or isoform-specific manner. As ER ligands, they trigger a large variety of effects, including extranuclear ER actions, which can be further modulated by coactivators, corepressors and potential novel estrogen-binding proteins/receptors. Thus, SERMs can display tissue- or pathway-specific effects, or a combination of these. Pharmacological and clinical data are available for the classical SERM prototypes raloxifene and tamoxifene, as well as for new SERMs in different stages of development, isotype-specific agonists and pathway-selective ligands. These compounds exert many different effects, including vasodilatation in coronary arteries, altered responses to ischemic damage, hypertrophy of the myocardium, and improvement in serum cholesterol and lipid profile. The development of future SERMs will focus on different indications, including hormone therapy or cardiovascular disease. However, they all should antagonize estrogen action in female reproductive organs, yet protect from bone loss and not interfere with the beneficial effects of estrogen in the brain.

Purpose: The response of the heart to pressure overload (PO) differs considerably between males and females. We and others have previously shown that oestrogen receptor (ER) β may be cardioprotective. However, the underlying mechanisms remain incompletely defined. Our aim was the analysis of the effects of sex and ERβ in PO applying a proteomic approach. Methods: Two-month-old C57BL6 male (M) and female (F) wild-type (WT) and ERβ knockout (BERKO) mice were subjected to transverse aortic constriction (TAC) or sham surgery (n = 4/group). The proteome of left ventricular samples was separated by high-resolution 2-dimensional polyacrylamide gel electrophoresis. The proteomic data were analysed with empirical Bayesian-based linear models using the R and Bioconductor software. Results: At nine weeks post operation, TAC led to a greater increase in heart-weight-to-tibia-length ratio in WT M (TAC vs. sham 128%; P < 0.05) than in WT F (TAC vs. sham 54%; P < 0.05) mice, while this difference in BERKO mice between M (TAC vs. sham 53%; P < 0.05) and F (TAC vs. sham 55%; P < 0.05) was abolished. With the present proteomic approach, we were able to identify and analyse a total of 795 left ventricular protein spots. Our comparative proteomic analysis revealed that in WT M and F mice 82 and 31 protein spots, respectively, differed between sham and TAC (P ≤ 0.05). In BERKO M and F mice we found 114 and 87 altered protein spots, respectively (P ≤ 0.05). Overall, mitochondrial bioenergetics- and oxidative stress-related proteins were modulated. We also found that trifunctional enzyme subunit family members were repressed in M-WT-TAC mice, while cytoskeletal proteins were induced in F-WT-TAC mice. On the other hand, heat shock proteins were induced in both M and F-BERKO-TAC mice. Conclusions: Our findings demonstrate that both sex and ERβ influence the proteomic response of the heart to PO. Collectively, we consider our study a useful resource for the unravelling of the effects of sex and ERβ in PO.

MAPKAP kinase 2 (MK2) is one of several kinases that are regulated through direct phosphorylation by p38 MAP kinase. By introducing a targeted mutation into the mouse MK2 gene, we have determined the physiological function of MK2 in vivo. Mice that lack MK2 show increased stress resistance and survive LPS-induced endotoxic shock. This is due to a reduction of approximately 90% in the production of tumor necrosis factor-alpha (TNF-alpha) and not to a change in signalling from the TNF receptor. The level and stability of TNF-alpha mRNA is not reduced and TNF-alpha secretion is not affected. We conclude that MK2 is an essential component in the inflammatory response which regulates biosynthesis of TNF-alpha at a post-transcriptional level.

The aim of this study was to investigate the effects of 17β-estradiol (E2), the selective ERα agonist 16α-LE2, and the selective estrogen receptor modulator (SERM) raloxifene on remodeling processes during the development of myocardial hypertrophy (MH) in a mouse model of pressure overload. Myocardial hypertrophy in ovariectomized female C57Bl/6J mice was induced by transverse aortic constriction (TAC). Two weeks after TAC, placebo treated mice developed left ventricular hypertrophy and mild systolic dysfunction. Estrogen treatment, but not 16α-LE2 or raloxifene reduced TAC induced MH compared to placebo. E2, 16α-LE2 and raloxifene supported maintenance of cardiac function in comparison with placebo. Nine weeks after induction of pressure overload, MH was present in all TAC groups, most pronounced in the raloxifene treated group. Ejection fraction (EF) was decreased in all animals. However, 16α-LE2 treated animals showed a smaller reduction of EF than animals treated with placebo. E2 and 16α-LE2, but not raloxifene diminished the development of fibrosis and reduced the TGFβ and CTGF gene expression. Treatment with E2 or 16α-LE2 but not with raloxifene reduced survival rate after TAC significantly in comparison with placebo treatment. In conclusion, E2 and 16α-LE2 slowed down the progression of MH and reduced systolic dysfunction after nine weeks of pressure overload. Raloxifene did not reduce MH but improved cardiac function two weeks after TAC. However, raloxifene was not able to maintain EF in the long term period.

Leaves from Momordica foetida traditionally used to treat symptoms of malaria in parts of East Africa were studied for in vitro antimalarial activity. Using an [³H] hypoxanthine-incorporation assay the antiplasmodial activity of hydrophilic and lipophilic extracts against the chloroquine-sensitive strain poW and the multiresistant clone Dd2 of Plasmodium falciparum was determined. The petrol ether/ethyl acetate extract showed significant activity with IC50 values of 7.3 µg/mL (poW) and 13.0 µg/mL (Dd2). Cytotoxicity was estimated on two human cell lines HepG2 and ECV-304 and a selectivity index (SI) was calculated, ranging between 12 and 15. Phytochemical analysis led to the isolation of a number of phenolic glycosides, e.g. eriodictyol-, 5,7,4’-trihydroxyflavanone-, kaempferol- and 5,7-dihydroxychromone-7-O-beta-D-glucopyranoside, not previously known from M. foetida. In order to prove one possible mode of action the influence of the crude extracts as well as the isolated compounds on the heme degradation with chloroquine as reference compound was evaluated. The ethyl acetate extract showed about 88% inhibition of heme degradation, quite similar to chloroquine (84 %), and also eriodictyol-7-O-beta-D-glucopyranoside (2) inhibited heme degradation by 86 %.