Abstract Background The compensatory phase of left ventricular hypertrophy (LVH) is characterised by sufficient mitochondrial density and energy production, but prolonged stress leads to cardiac decompensation and decreased mitochondrial biogenesis. This results in energy deficiency and compromised contractile ability, eventually leading to heart failure (HF). Vascular endothelial growth factor B (VEGF-B) is a potent inducer of cardiac angiogenesis and LVH, and more recently it has been associated with lipid metabolism and cardiac function. However, its exact role in these processes has remained unresolved. Purpose We wanted to elucidate the effects of VEGF-B overexpression on cardiac metabolism and the development of LVH and HF. Methods We used mice expressing VEGF-B transgene under cardiac-specific MHCα promoter and induced pressure overload with angiotensin II infusion. We monitored the cardiac function with high-resolution transthoracic echocardiography and performed immunohistochemical analyses to assess the level of cardiac fibrosis. Furthermore, we analyzed cardiac lipid metabolism with non-targeted LC-MS metabolite profiling and performed functional 3H -labelled triolein uptake studies combined with quantitative RT-PCR. Results In this study, we show that the cardiac-specific overexpression of VEGF-B leads to increased plasma triglyceride and free fatty acid levels but reduced cardiac lipid accumulation. Non-targeted LC-MS profiling analysis revealed that the level of cardiac glycerolipids and glycerophospholipids were significantly downregulated although changes in cardiac lipid uptake on functional or gene expression level were not detected. To assess how these metabolic changes affect the development of LVH and HF, we subjected MHCα-VEGF-B mice to angiotensin II infusion. Surprisingly, the survival of MHCα-VEGF-B mice dramatically started to decline after four days of angiotensin II infusion and was only 30% at the 14-day time point. Echocardiographic measurements revealed that the MHCα-VEGF-B mice developed severe HF seen as reduced ejection fraction when compared to control mice (32.2% vs. 64.2% respectively), significantly increased LV end-diastolic diameter and LV volume when compared to the controls. VEGF-B overexpression during pressure overload resulted in severe cardiac fibrosis and downregulation of genes responsible for lipid and glucose uptake, metabolic regulation and mitochondrial function indicating severe cardiac energy deficit. Interestingly, a high fat diet feeding prevented the development of HFrEF by 100% and the suppression of all metabolic pathways. Conclusion VEGF-B regulates cardiac energy production and the overexpression of VEGF-B results in cardiac energy deficit that during pressure overload leads to HFrEF and severe mortality. Funding Acknowledgement Type of funding sources: Public grant(s) – EU funding. Main funding source(s): ERC and H2020

Abstract Background Calcific aortic valve disease (CAVD) is the most common valvular heart disease in Western world. CAVD is ranging from mild aortic valve sclerosis to severe obstructive aortic stenosis (AS). The development of AS has been associated with several risk factors including age, sex and hypertension. However, there is limited knowledge about factors that predict the development of aortic stenosis. Purpose We investigated if the circulating metabolite profile can predict the development of aortic stenosis in Finnish males. Methods We did a non-targeted LC-MS metabolomics analysis to baseline (1984–1989) serum samples from a prospective population-based Kuopio Ischemic Heart Disease risk factor study (KIHD) cohort of 2682 random Finnish males aged from 42 to 60 years. During the follow-up (until year 2020), 53 subjects developed either moderate (peak flow gradient 36–64mmHg or mean flow gradient 20–40mmHg) or severe aortic valvular stenosis (peak flow gradient over 64mmHg or mean gradient over 40mmHg). The AS patients were collected from the KIHD database using appropriate ICD-10 -codes for aortic valvular disease (from baseline to the end of the year 2017) and the diagnosis was checked manually using hospital medical records of the individuals. Results The AS patients seemed to have altered lipid metabolism and possibly altered composition of gut microbiota, since several acylcarnitines (e.g. octanoylcarnitine [Cohen's d=−0.40], decanoylcarnitine [d=−0.43], layroylcarnitine [d=−0.41], and oleoylcarnitine [d=−0.40]), and branched chain amino acids (BCAA, e.g. leucine [d=0.39], and isoleucine [d=0.49]) had p-values below 0.05. However, after correction for multiple testing, there were no significant differences between the cases and controls. Conclusions The present preliminary results, in need of verification with a larger set of samples, suggest that subjects, who will later develop AS might have reduced levels of acylcarnitines and increased levels of BCAA when compared to matched controls. However, these changes do not have large effects sizes and are likely not good candidates for biomarkers to predict future diagnosis of AS. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): The Finnish Cultural Foundation, The Finnish Foundation for Cardiovascular Research.

Ischemic stroke is amongst the leading causes of death and disabilities. The available treatments are suitable for only a fraction of patients and thus novel therapies are urgently needed. Blockage of one of the cerebral arteries leads to massive and persisting inflammatory reaction contributing to the nearby neuronal damage. Targeting the detrimental pathways of neuroinflammation has been suggested to be beneficial in conditions of ischemic stroke. Nuclear receptor 4A-family (NR4A) member Nurr1 has been shown to be a potent modulator of harmful inflammatory reactions, yet the role of Nurr1 in cerebral stroke remains unknown. Here we show for the first time that an agonist for the dimeric transcription factor Nurr1/retinoid X receptor (RXR), HX600, reduces microglia expressed proinflammatory mediators and prevents inflammation induced neuronal death in in vitro co-culture model of neurons and microglia. Importantly, HX600 was protective in a mouse model of permanent middle cerebral artery occlusion and alleviated the stroke induced motor deficits. Along with the anti-inflammatory capacity of HX600 in vitro, treatment of ischemic mice with HX600 reduced ischemia induced Iba-1, p38 and TREM2 immunoreactivities, protected endogenous microglia from ischemia induced death and prevented leukocyte infiltration. These anti-inflammatory functions were associated with reduced levels of brain lysophosphatidylcholines (lysoPCs) and acylcarnitines, metabolites related to proinflammatory events. These data demonstrate that HX600 driven Nurr1 activation is beneficial in ischemic stroke and propose that targeting Nurr1 is a novel candidate for conditions involving neuroinflammatory component.

Objective: To characterize transplacental transfer of melamine and related mechanisms as well as toxicity using human placental perfusion and cultured cells.Methods: Transfer and toxicity were analyzed in 4-h perfusions with 10 mu M or 1 mM melamine, or 10 mu M melamine with 10 nM cyanuric acid (CYA). Efflux transporters were studied in accumulation assay and toxicity in BeWo cells by MIT assay.Results: Of added melamine 34-45% was transferred to fetal circulation and CYA made no difference. Histology, hCG production, and PLAP activity indicated functionality of placental tissue with no grave toxicity. Highest concentration of melamine used (2 mM) with CYA and long treatment time decreased viability of BeWo cells. Inhibitors of ABCB1, ABCG2, ABCC2 did not affect the accumulation of melamine in cells.Conclusion: Melamine goes through human term placenta with no contribution of efflux transporters. Toxicity of melamine is low in placental tissue and BeWo cells. (C) 2011 Elsevier Ltd. All rights reserved.

Bisphosphonates are a class of drugs developed over the past three decades for the treatment of metabolic bone diseases with high bone turnover, such as Pagets disease, tumor associated osteolysis and osteoporosis. The exceptional pharmacokinetic profile of bisphosphonates makes them very suitable and safe drugs for the treatment of bone diseases, because, by conventional administration, osseous tissue and bone resorbing osteoclasts are the targets for these drugs as a result of the very high affinity of bisphosphonates for bone mineral. Several recent studies have demonstrated; however, that bisphosphonates decrease tumor burden in bone in rodent models of myeloma and metastatic bone disease, with suggestions of antitumor effects also in patients. Although, decreased tumor burden could be a consequence of inhibition of bone resorption, there is increasing evidence that bisphosphonates might also have direct effects on tumor cell in vivo, since effects on tumors outside of skeleton or at doses not inhibiting bone resorption have been reported. Recent studies also suggest that bisphosphonates have inhibitory effect also on endothelial cell function and angiogenesis in tumor tissue. These findings suggest that the target cells for bisphosphonates as well as their molecular mechanism of action may be more diverse and complex than realized so far. This review highlights the main methodologies used to monitor the action of BPs in vitro cell models, with a special emphasis on the detection of BP-induced ATP-analoques by mass spectrometry. In addition, cell death monitoring, immunomodulatory effects and inhibition of growth/proliferation are described.

Summary Currently the only treatment for coeliac disease is a lifelong gluten-free diet excluding food products containing wheat, rye and barley. There is, however, only scarce evidence as to harmful effects of rye in coeliac disease. To confirm the assumption that rye should be excluded from the coeliac patient's diet, we now sought to establish whether rye secalin activates toxic reactions in vitro in intestinal epithelial cell models as extensively as wheat gliadin. Further, we investigated the efficacy of germinating cereal enzymes from oat, wheat and barley to hydrolyse secalin into short fragments and whether secalin-induced harmful effects can be reduced by such pretreatment. In the current study, secalin elicited toxic reactions in intestinal Caco-2 epithelial cells similarly to gliadin: it induced epithelial cell layer permeability, tight junctional protein occludin and ZO-1 distortion and actin reorganization. In high-performance liquid chromatography and mass spectroscopy (HPLC-MS), germinating barley enzymes provided the most efficient degradation of secalin and gliadin peptides and was thus selected for further in vitro analysis. After germinating barley enzyme pretreatment, all toxic reactions induced by secalin were ameliorated. We conclude that germinating enzymes from barley are particularly efficient in the degradation of rye secalin. In future, these enzymes might be utilized as a novel medical treatment for coeliac disease or in food processing in order to develop high-quality coeliac-safe food products.

Acetaminophen is a widely used analgesic antipyretic agent. When used at low doses, it is a safe drug, but at higher doses it can cause acute hepatic necrosis in humans and experimental animals. The key mechanism in the hepatotoxicity is cytochrome P450 (CYP)-catalysed formation of the reactive metabolite, N-acetyl-p-benzoquinone imine (NAPQI) that is capable of binding to cellular macromolecules and in that way an LC/MS liquid chromatography/mass spectrometry (LC/MS) method was developed to measure NAPQI formation by trapping it to reduced glutathione. This method was used to determine the bioactivation of acetaminophen at two concentrations: 50 microM therapeutic and 1 mM toxic by using nine human recombinant CYP enzymes: CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4; and with different microsomes from experimental animals. At the toxic concentration the formation of NAPQI-glutathione was highest with CYP3A4 followed by CYP2E1, CYP1A2, and CYP2D6. At the therapeutic concentration, CYP3A4 had also the highest bioactivation capacity. In a comparison of the enzyme kinetics, CYP3A4 was the most efficient CYP with the lowest K(m) value 130 microM (95% confidence interval = 63-210 microM). Dexamethasone-induced rat liver microsomes had the most effective bioactivation capacity at therapeutic and toxic acetaminophen concentrations. This study suggests that CYP3A4 is the major CYP enzyme form catalysing acetaminophen oxidation to NAPQI in human liver.

This study aimed at elucidating the in vivo metabolism of nicotine both with and without inhibitors of nicotine metabolism. Second, the role of mouse CYP2A5 in nicotine oxidation in vitro was studied as such information is needed to assess whether the mouse is a suitable model for studying chemical inhibitors of the human CYP2A6. The oxidation of nicotine to cotinine was measured and the ability of various inhibitors to modify this reaction was determined. Nicotine and various inhibitors were co-administered to CD2F1 mice, and nicotine and urinary levels of nicotine and four metabolites were determined. In mouse liver microsomes anti-CYP2A5 antibody and known chemical inhibitors of the CYP2A5 enzyme blocked cotinine formation by 85-100%, depending on the pre-treatment of the mice. The amount of trans-3-hydroxycotine was five times higher than cotinine N-oxide, and ten times higher than nicotine N-1-oxide and cotinine. Methoxsalen, an irreversible inhibitor of CYP2A5, significantly reduced the metabolic elimination of nicotine in vivo, but the reversible inhibitors had no effect. It is concluded that the metabolism of nicotine in mouse is very similar to that in man and, therefore, that the mouse is a suitable model for testing novel chemical inhibitors of human CYP2A6.

OBJECTIVE:To analyze the effects of exogenously added glucose (Glc), glucosamine (GlcN) and glucosamine sulfate (GS) on the intracellular UDP-hexoses (UDP-Hex), UDP-N-acetylhexosamines (UDP-HexN) and UDP-glucuronic acid (UDP-GlcA) levels in bovine primary chondrocytes. METHODS:Chondrocytes were incubated with different concentrations of Glc, GlcN and GS either in high- or low-glucose DMEM for up to 120min to analyze the intracellular levels of UDP-Hex, UDP-GlcA and UDP-HexN by a reversed-phase high-performance liquid chromatography-electrospray ionization mass spectrometry analysis. Glycosaminoglycan (GAG) synthesis rate and aggrecan mRNA expression levels were quantified using (35)S-sulfate incorporation assay and quantitative real-time RT-PCR, respectively. The cells were cultivated for 2 days or 8 days before UDP-sugar analysis. RESULTS:Levels of UDP-HexN and UDP-GlcA were unchanged at 10microM concentration of GS in low-glucose DMEM, while addition of 1mM GlcN or GS in low-glucose DMEM for 10min increased UDP-HexN level. The highest intracellular level of UDP-HexN was reached at 30min after addition of 1mM GS to the cells. The intracellular contents of UDP-HexN and UDP-GlcA related to UDP-Hex were higher after prolonged cultivation of chondrocytes for 8 days compared with 2-day-old cultures. Aggrecan mRNA expression and GAG synthesis remained at control level after the cells were treated with 10, 100microM or 1mM of GS for 24h. CONCLUSION:Physiologically relevant level of GS could not increase the intracellular UDP-HexN and UDP-GlcA levels in bovine primary chondrocyte, while longer-time culture itself appeared to increase the intracellular UDP-HexN and UDP-GlcA levels.

Background Although knowledge of the IgE cross-reactivity between allergens is important for understanding the mechanisms of allergy, the regulation of the allergic immune response and the development of efficient modes of allergen immunotherapy, the cross-reactivity of animal allergens is poorly known.Objective The aim of this study was to characterize IgE cross-reactivities between lipocalin proteins, including five animal-derived lipocalin allergens and one human endogenous lipocalin, tear lipocalin (TL).Methods The recombinant proteins were validated by chromatography and mass spectrometry. The IgE-binding capacity of the allergens was confirmed by IgE. immunoblotting and IgE immunoblot inhibition. IgE ELISA was performed with sera from 42 atopic patients and 21 control subjects. The IgE cross-reactivities between the lipocalin proteins were determined by ELISA inhibition.Results ELISA inhibition revealed IgE cross-reactivities between Can f 1 and human TL, between Can f 1 and Can f 2, and between Equ c 1 and Mus m 1. Low levels of IgE to human TL were found in the sera of seven dog-allergic patients of whom six were IgE-positive for Can f 1.Conclusion Several lipocalins exhibited IgE cross-reactivity, probably due to the sequential identity of the proteins and also due to similarities in their three-dimensional structures. The clinical significance of the findings needs to be elucidated. Low-level IgE cross-reactivity can play a role in regulating immune response to lipocalin allergens.