Inducible NOS inhibition reverses tobacco-smoke-induced emphysema and pulmonary hypertension in mice.

Chronic obstructive pulmonary disease (COPD) is one of the most common causes of death worldwide. We report in an emphysema model of mice chronically exposed to tobacco smoke that pulmonary vascular dysfunction, vascular remodeling, and pulmonary hypertension (PH) precede development of alveolar destruction. We provide evidence for a causative role of inducible nitric oxide synthase (iNOS) and peroxynitrite in this context. Mice lacking iNOS were protected against emphysema and PH. Treatment of wild-type mice with the iNOS inhibitor N(6)-(1-iminoethyl)-L-lysine (L-NIL) prevented structural and functional alterations of both the lung vasculature and alveoli and also reversed established disease. In chimeric mice lacking iNOS in bone marrow (BM)-derived cells, PH was dependent on iNOS from BM-derived cells, whereas emphysema development was dependent on iNOS from non-BM-derived cells. Similar regulatory and structural alterations as seen in mouse lungs were found in lung tissue from humans with end-stage COPD.

Lipopolysaccharide of Legionella pneumophila Serogroup 1 Facilitates Interaction with Host Cells.

Legionella pneumophila is the primary causative agent of Legionnaires' disease. The mutant-type strain interrupted in the ORF7 gene region responsible for the lipopolysaccharide biosynthesis of the L. pneumophila strain Heysham-1, lacking the O-acetyl groups attached to the rhamnose of the core part, showed a higher surface polarity compared with the wild-type strain. The measurement of excitation energy transfer between fluorophores located on the surface of bacteria and eukaryotic cells showed that, at an early stage of interaction with host cells, the mutant exhibited weaker interactions with Acanthamoeba castellanii cells and THP-1-derived macrophages. The mutant displayed reduced adherence to macrophages but enhanced adherence to A. castellanii, suggesting that the O-acetyl group of the LPS core region plays a crucial role in facilitating interaction with macrophages. The lack of core rhamnose O-acetyl groups made it easier for the bacteria to multiply in amoebae and macrophages. The mutant induced TNF-α production more strongly compared with the wild-type strain. The mutant synthesized twice as many ceramides Cer(t34:0) and Cer(t38:0) than the wild-type strain. The study showed that the internal sugars of the LPS core region of L. pneumophila sg 1 can interact with eukaryotic cell surface receptors and mediate in contacting and attaching bacteria to host cells as well as modulating the immune response to infection.

Telmisartan induces a specific gut microbiota signature which may mediate its antiobesity effect.

Telmisartan prevents diet-induced obesity (DIO) in rodents. Given that the precise underlying mechanism is not known, we examined whether a gut-related mechanism might be involved. Sprague-Dawley rats received cafeteria diet (CD) for 3 months to develop DIO and were administered either telmisartan (8 mg/kgbw) or vehicle. In addition, pair-fed (PF) rats received CD adjusted to TEL and control rats (CON) only received chow. Stool samples were analysed by 16 S rRNA gene amplicon sequencing. CD-fed rats became obese while TEL, PF and CON rats remained lean. Alpha diversity analyses indicated that bacterial diversity was similar before the study but changed over time. Beta diversity revealed a time-, CD- and telmisartan-dependent effect. The Firmicutes/Bacteroidetes ratio and the abundance of Blautia, Allobaculum and Parasutterella were higher in DIO and PF than in CON, but not in TEL. Enterotype (ET)-like clustering analyses, Kleinberg's hub network scoring and random forest analyses also indicated that telmisartan induced a specific signature of gut microbiota. In response to stool transfer from telmisartan-pre-treated donor to high-fat fed acceptor mice, body weight gain was slightly attenuated. We attribute the anti-obesity action of telmisartan treatment to diet-independent alterations in gut microbiota as the microbiota from telmisartan-treated, CD-fed rats clearly differed from those of DIO and PF rats. ET-like clustering network, random forest classification and the higher stability in bacterial co-occurrence network analyses indicate that there is more than one indicator species for telmisartan's specific signature, which is further strengthened by the fact that we cannot identify a single indicator species.

A Mitochondrial Polymorphism Alters Immune Cell Metabolism and Protects Mice from Skin Inflammation.

Several genetic variants in the mitochondrial genome (mtDNA), including ancient polymorphisms, are associated with chronic inflammatory conditions, but investigating the functional consequences of such mtDNA polymorphisms in humans is challenging due to the influence of many other polymorphisms in both mtDNA and the nuclear genome (nDNA). Here, using the conplastic mouse strain B6-mtFVB, we show that in mice, a maternally inherited natural mutation (m.7778G > T) in the mitochondrially encoded gene ATP synthase 8 (mt-Atp8) of complex V impacts on the cellular metabolic profile and effector functions of CD4+ T cells and induces mild changes in oxidative phosphorylation (OXPHOS) complex activities. These changes culminated in significantly lower disease susceptibility in two models of inflammatory skin disease. Our findings provide experimental evidence that a natural variation in mtDNA influences chronic inflammatory conditions through alterations in cellular metabolism and the systemic metabolic profile without causing major dysfunction in the OXPHOS system.

Phospholipase A2 products predict the hematopoietic support capacity of horse serum.

Horse serum is commonly used as an additive to support the maintenance of hematopoietic progenitor cells in culture. However, the wide variability in the performance of different lots calls for parallel testing of multiple batches over extended periods of culture. Identification of the serum components that determine hematopoietic support would therefore save considerable time and effort and would help to standardize culture procedures. We report here that the ability of horse serum to support the self-renewal of multipotent murine hematopoietic progenitor FDCP-Mix cells is correlated to the concentration of specific fatty acid products of phospholipase A2 and more closely to the spectrum of eicosanoids generated by their further processing through cyclooxygenase and lipoxygenase pathways. Supportive sera have low levels of lysophosphatidylcholine and inflammatory eicosanoids. This links known markers of inflammation, infection and platelet activation to the ability of serum to maintain progenitor cells in an undifferentiated state, providing a means for prospective identification of suitable sera as well as quality control of the production process.

Stationary phase thickness determines the quality of thin-layer chromatography/matrix-assisted laser desorption and ionization mass spectra of lipids.

Normal phase thin-layer chromatography (NP TLC) is an established method of (phospho)lipid analysis. The determination of the fatty acyl composition is, however, a more challenging task by NP TLC. The direct coupling of TLC separation with mass spectrometric detection (e.g., matrix-assisted laser desorption/ionization mass spectrometry, MALDI MS), however, enables a detailed characterization of complex lipid mixtures. Here we show that the thickness of the silica gel layer has a considerable effect on the quality of the mass spectra recorded directly from the TLC plate. In particular, the intensity of the matrix background signals can be reduced if "thinner" TLC layers are used.

Mass spectrometry and inflammation--MS methods to study oxidation and enzyme-induced changes of phospholipids.

Many diseases such as arthritis or atherosclerosis are accompanied by inflammatory processes. Inflammation is characterized by the infiltration of cells such as neutrophilic granulocytes and (a) the release of phospholipases [particularly phospholipase A2 (PLA2)] and (b) the generation of reactive oxygen as well as nitrogen species (ROS and RNS). While PLA2 leads to defined lyso products (lacking one acyl residue), lipid oxidation is characterized by much more complex product patterns, including lipid peroxides, aldehydes (by double bond cleavage), and many others. Nevertheless, oxidation processes are highly important under in vivo conditions because molecules with regulatory functions are generated by the oxidation of lipids and/or free fatty acids. Therefore, lipid oxidation products as well as lysolipids are increasingly assumed to represent important disease (bio)markers. Consequently, there is also increasing interest in methods to characterize these products qualitatively and quantitatively.Mass spectrometry (MS) seems to be the method of choice to study (phospho)lipids changed under inflammatory conditions: nowadays, soft ionization MS methods are regularly used to study oxidative lipid modifications because of their high sensitivities and the tremendous mass resolutions that are achievable by using modern mass spectrometers. However, experimental care is required to be able to detect all relevant products. Although electrospray ionization (ESI) MS is so far most popular, applications of matrix-assisted laser desorption and ionization (MALDI) MS are continuously increasing. This review aims to summarize the so far available data on MS analyses of oxidized lipids as well as lysolipids. In addition to model systems, special attention will be paid to the monitoring of oxidized lipids and lysolipids under in vivo conditions. It is the aim of this review to provide a critical survey of the advantages and drawbacks of the different MS methods, with the focus on MALDI and ESI.

Classical transient receptor potential channel 1 in hypoxia-induced pulmonary hypertension.

RATIONALE: Pulmonary hypertension (PH) is a life-threatening disease, characterized by pulmonary vascular remodeling. Abnormal smooth muscle cell proliferation is a primary hallmark of chronic hypoxia-induced PH. Essential for cell growth are alterations in the intracellular Ca(2+) homeostasis. Classical transient receptor potential (TRPC) proteins have been suggested to contribute to PH development, as TRPC1 and TRPC6 are predominantly expressed in precapillary pulmonary arterial smooth muscle cells (PASMC). Studies in a TRPC6-deficient mouse model revealed an essential function of TRPC6 in acute but not in chronic hypoxia. OBJECTIVES: We aimed to identify the importance of TRPC1 in the pathogenesis of chronic hypoxia-induced PH in mice. METHODS: TRPC1 expression analysis was performed using real-time polymerase chain reaction. TRPC1 function was assessed by in vivo experiments in TRPC1(-/-) animals as well as in isolated precapillary murine PASMC after TRPC1 knockdown by TRPC1-specific small interfering RNAs. MEASUREMENTS AND MAIN RESULTS: Only TRPC1 mRNA was up-regulated under hypoxia in isolated murine PASMC (1% O2 for 72 h). Hypoxia-induced proliferation of murine PASMC was attenuated in cells treated with small interfering RNA against TRPC1 and in cells isolated from TRPC1(-/-) animals compared with untreated and wild-type cells. TRPC1(-/-) mice did not develop PH in response to chronic hypoxia (FI(O2) 0.10 for 21 d) and had less vascular muscularization but a similar degree of right ventricular hypertrophy compared with wild-type mice. CONCLUSIONS: Our results indicate an important role of TRPC1 in pulmonary vascular remodeling underlying the development of hypoxia-induced PH.

Use of FRET-Sensor 'Mermaid' to Detect Subtle Changes in Membrane Potential of Primary Mouse PASMCs.

Subtle changes in the membrane potential of pulmonary arterial smooth muscle cells (PASMCs) are pivotal for controlling pulmonary vascular tone, e.g., for initiating Hypoxic Pulmonary Vasoconstriction, a vital mechanism of the pulmonary circulation. In our study, we evaluated the ability of the fluorescence resonance energy transfer (FRET)-based voltage-sensor Mermaid to detect such subtle changes in membrane potential. Mouse PASMCs were isolated and transduced with Mermaid-encoding lentiviral vectors before the acceptor/donor emission ratio was assessed via live cell FRET-imaging. Mermaid's sensitivity was tested by applying specific potassium chloride (KCl) concentrations. These KCl concentrations were previously validated by patch clamp recordings to induce depolarization with predefined amplitudes that physiologically occur in PASMCs. Mermaid's emission ratio dose-dependently increased upon depolarization with KCl. However, Mermaid formed unspecific intracellular aggregates, which limited the usefulness of this voltage sensor. When analyzing the membrane rim only to circumvent these unspecific signals, Mermaid was not suitable to resolve subtle changes in the membrane potential of ≤10 mV. In summary, we found Mermaid to be a suitable alternative for reliably detecting qualitative membrane voltage changes of more than 10 mV in primary mouse PASMCs. However, one should be aware of the limitations associated with this voltage sensor.

Mitochondrial hyperpolarization in pulmonary vascular remodeling. Mitochondrial uncoupling protein deficiency as disease model.

Alterations of mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and mitochondrial respiration are possible triggers of pulmonary vascular remodeling in pulmonary hypertension (PH). We investigated the role of MMP in PH and hypothesized that deletion of the mitochondrial uncoupling protein 2 (UCP2) increases MMP, thus promoting pulmonary vascular remodeling and PH. MMP was measured by JC-1 in isolated pulmonary arterial smooth muscle cells (PASMCs) of patients with PH and animals with PH induced by exposure to monocrotaline (MCT) or chronic hypoxia. PH was quantified in vivo in UCP2-deficient (UCP2(-/-)) mice by hemodynamics, morphometry, and echocardiography. ROS were measured by electron spin resonance spectroscopy and proliferation by thymidine incorporation. Mitochondrial respiration was investigated by high-resolution respirometry. MMP was increased in PASMCs of patients and in animal models of PH. UCP2(-/-) mice exhibited pulmonary vascular remodeling and mild PH compared with wild-type (WT) mice. PASMCs of UCP2(-/-) mice showed increased proliferation, MMP, and ROS release. Increased proliferation of UCP2(-/-) PASMCs could be attenuated by ROS inhibitors and inhibited by carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone, which decreased MMP to the level of WT mice. Mitochondrial respiration was altered in PASMCs from MCT rats and PASMCs exposed to hypoxia but not in isolated pulmonary mitochondria of UCP2(-/-) mice or PASMCs after treatment with small interfering RNA for UCP2. Our data suggest that increased MMP causes vascular remodeling in UCP2(-/-) mice partially via increased ROS. In chronic hypoxia and MCT-induced PH, additional pathomechanisms such as decreased respiration may play a role.

A simple method to identify ether lipids in spermatozoa samples by MALDI-TOF mass spectrometry.

Plasmalogens (alkenylacyl glycerophospholipids) are important lipid constituents of many tissues and cells (e.g., selected spermatozoa). Since the molecular weights of plasmalogens overlap with that of diacyl- or alkyl acyl lipids, sophisticated mass spectrometry (MS; including MS/MS) analysis is normally used for the unequivocal identification of plasmalogens. We will show here that a simple matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (without MS/MS capability) in combination with acidic hydrolysis and subsequent derivatization with 2,4-dinitrophenylhydrazine (DNPH) and/or digestion with phospholipase A2 (PLA2) is sufficient to determine the contributions of ether lipids in spermatozoa extracts. As neither diacyl nor alkylacyl lipids are sensitive to acids and do not react with DNPH, the comparison of the mass spectra before and after treatment with acids and/or DNPH addition readily provides unequivocal information about the plasmalogen content. Additionally, the released aldehydes are readily converted into the 2,4-dinitrophenylhydrazones and can be easily identified in the corresponding negative ion mass spectra. Finally, PLA2 digestion is very useful in confirming the presence of plasmalogens. The suggested method was validated by analyzing roe deer, bovine, boar, and domestic cat spermatozoa extracts and comparing the results with isolated phospholipids.

Metabolic Pathway Modeling in Muscle of Male Marathon Mice (DUhTP) and Controls (DUC)-A Possible Role of Lactate Dehydrogenase in Metabolic Flexibility.

In contracting muscles, carbohydrates and fatty acids serve as energy substrates; the predominant utilization depends on the workload. Here, we investigated the contribution of non-mitochondrial and mitochondrial metabolic pathways in response to repeated training in a polygenic, paternally selected marathon mouse model (DUhTP), characterized by exceptional running performance and an unselected control (DUC), with both lines descended from the same genetic background. Both lines underwent three weeks of high-speed treadmill training or were sedentary. Both lines' muscles and plasma were analyzed. Muscle RNA was sequenced, and KEGG pathway analysis was performed. Analyses of muscle revealed no significant selection-related differences in muscle structure. However, in response to physical exercise, glucose and fatty acid oxidation were stimulated, lactate dehydrogenase activity was reduced, and lactate formation was inhibited in the marathon mice compared with trained control mice. The lack of lactate formation in response to exercise appears to be associated with increased lipid mobilization from peripheral adipose tissue in DUhTP mice, suggesting a specific benefit of lactate avoidance. Thus, results from the analysis of muscle metabolism in born marathon mice, shaped by 35 years (140 generations) of phenotype selection for superior running performance, suggest increased metabolic flexibility in male marathon mice toward lipid catabolism regulated by lactate dehydrogenase.

Unusual Lipid Components of Legionella gormanii Membranes.

Legionella spp. cause Legionnaires' disease with pneumonia as the predominant clinical symptom. L. gormanii is the second most prevalent causative agent of community-acquired pneumonia after L. pneumophila. The study aimed to characterize the lipidome of L. gormanii membranes and the importance of these analyses in bacterial chemotaxonomy. Lipidomic analyses based on ultra-high performance liquid chromatography-mass spectrometry allowed the detection of individual molecular species of a wide range of L. gormanii membrane lipids contained in the outer (OM) and inner membranes (IM). The lipid profile comprised glycerolipids (triglycerides, diglycerides), phospholipids (phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, cardiolipin), and sphingolipids (ceramides, hexosylceramides). The most abundant lipid fraction in the IM and OM were phospholipids. The lipidomic analysis showed that two independent phosphatidylcholine (PC) synthesis pathways operating in L. gormanii: the PE-methylation (PmtA) pathway and the PC synthase (Pcs) pathway. Comparison of the molecular profile of PC species contained in the lipids of L. gormanii membranes cultured on the medium, with and without exogenous choline, showed quantitative differences in the PC pool. An unusual feature of the L. gormanii lipids was the presence of ceramides and hexosylceramides, which are typical components of eukaryotic cells and a very small group of bacteria. To the best of our knowledge, this is the first report of the occurrence of ceramides in Legionella bacteria.

Prenatal transcript levels and metabolomics analyses reveal metabolic changes associated with intrauterine growth restriction and sex.

The metabolic changes associated with intrauterine growth restriction (IUGR) particularly affect the liver, which is a central metabolic organ and contributes significantly to the provision of energy and specific nutrients and metabolites. Therefore, our aim was to decipher and elucidate the molecular pathways of developmental processes mediated by miRNAs and mRNAs, as well as the metabolome in fetal liver tissue in IUGR compared to appropriate for gestational age groups (AGA). Discordant siblings representing the extremes in fetal weight at day 63 post conception (dpc) were selected from F2 fetuses of a cross of German Landrace and Pietrain. Most of the changes in the liver of IUGR at midgestation involved various lipid metabolic pathways, both on transcript and metabolite levels, especially in the category of sphingolipids and phospholipids. Differentially expressed miRNAs, such as miR-34a, and their differentially expressed mRNA targets were identified. Sex-specific phenomena were observed at both the transcript and metabolite levels, particularly in male. This suggests that sex-specific adaptations in the metabolic system occur in the liver during midgestation (63 dpc). Our multi-omics network analysis reveals interactions and changes in the metabolic system associated with IUGR and identified an important biosignature that differs between IUGR and AGA piglets.

Diacylglycerol regulates acute hypoxic pulmonary vasoconstriction via TRPC6.

BACKGROUND: Hypoxic pulmonary vasoconstriction (HPV) is an essential mechanism of the lung that matches blood perfusion to alveolar ventilation to optimize gas exchange. Recently we have demonstrated that acute but not sustained HPV is critically dependent on the classical transient receptor potential 6 (TRPC6) channel. However, the mechanism of TRPC6 activation during acute HPV remains elusive. We hypothesize that a diacylglycerol (DAG)-dependent activation of TRPC6 regulates acute HPV. METHODS: We investigated the effect of the DAG analog 1-oleoyl-2-acetyl-sn-glycerol (OAG) on normoxic vascular tone in isolated perfused and ventilated mouse lungs from TRPC6-deficient and wild-type mice. Moreover, the effects of OAG, the DAG kinase inhibitor R59949 and the phospholipase C inhibitor U73122 on the strength of HPV were investigated compared to those on non-hypoxia-induced vasoconstriction elicited by the thromboxane mimeticum U46619. RESULTS: OAG increased normoxic vascular tone in lungs from wild-type mice, but not in lungs from TRPC6-deficient mice. Under conditions of repetitive hypoxic ventilation, OAG as well as R59949 dose-dependently attenuated the strength of acute HPV whereas U46619-induced vasoconstrictions were not reduced. Like OAG, R59949 mimicked HPV, since it induced a dose-dependent vasoconstriction during normoxic ventilation. In contrast, U73122, a blocker of DAG synthesis, inhibited acute HPV whereas U73343, the inactive form of U73122, had no effect on HPV. CONCLUSION: These findings support the conclusion that the TRPC6-dependency of acute HPV is induced via DAG.

Phosphatidylcholine dimers can be easily misinterpreted as cardiolipins in complex lipid mixtures: a matrix-assisted laser desorption/ionization time-of-flight mass spectrometric study of lipids from hepatocytes.

The liver is an important organ that is particularly involved in the lipid metabolism of the organism. Thus, high interest is nowadays focused on the lipid composition of the liver and particularly the liver parenchymal cells, the hepatocytes. Hepatocytes contain common phospholipids (PL) such as phosphatidylcholines, -ethanolamines and -inositols, for instance, that can be easily analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) even without previous separation of the PL mixture. However, in addition to common PL, hepatocytes possess also significant amounts of cardiolipin (CLP). The MS analysis of this PL is quite challenging because it (a) has a higher mass than common lipids and (b) possesses a higher negative charge. We will show here that caution is required if CLP is analyzed directly from the total lipid extract because PC dimers may be interpreted as cardiolipins if the positive ion MALDI mass spectra are analyzed.

Recent Advances in Studying Age-Associated Lipids Alterations and Dietary Interventions in Mammals.

Lipids are involved in a broad spectrum of canonical biological functions, from energy supply and storage by triacylglycerols to membrane formation by sphingolipids, phospholipids and glycolipids. Because of this wide range of functions, there is an overlap between age-associated processes and lipid pathways. Lipidome analysis revealed age-related changes in the lipid composition of various tissues in mice and humans, which were also influenced by diet and gender. Some changes in the lipid profile can be linked to the onset of age-related neurodegenerative diseases like Alzheimer's disease. Furthermore, the excessive accumulation of lipid storage organelles, lipid droplets, has significant implications for the development of inflammaging and non-communicable age-related diseases. Dietary interventions such as caloric restriction, time-restrictive eating, and lipid supplementation have been shown to improve pertinent health metrics or even extend life span and thus modulate aging processes.

Phospholipases and Reactive Oxygen Species Derived Lipid Biomarkers in Healthy and Diseased Humans and Animals - A Focus on Lysophosphatidylcholine.

Phospholipids (PL) are converted into lipid biomarkers by the action of phospholipases and reactive oxygen species (ROS), which are activated or released under certain physiological and pathophysiological conditions. Therefore, the in vivo concentration of such lipid biomarkers [e.g., lysophospholipids (LPLs)] is altered in humans and animals under different conditions such as inflammation, stress, medication, and nutrition. LPLs are particularly interesting because they are known to possess pro- and anti-inflammatory properties and may be generated by two different pathways: either by the influence of phospholipase A2 or by different reactive oxygen species that are generated in significant amounts under inflammatory conditions. Both lead to the cleavage of unsaturated acyl residues. This review provides a short summary of the mechanisms by which lipid biomarkers are generated under in vitro and in vivo conditions. The focus will be on lysophosphatidylcholine (LPC) because usually, this is the LPL species which occurs in the highest concentration and is, thus, easily detectable by chromatographic and spectroscopic methods. Finally, the effects of lipid biomarkers as signaling molecules and their roles in different human and animal pathologies such as infertility, cancer, atherosclerosis, and aging will be shortly discussed.

Fatty acid composition and lipid profiles as chemotaxonomic markers of phytopathogenic fungi Puccinia malvacearum and P. glechomatis.

The analysis of the overall fatty acid pattern as well as their distribution in various lipid classes of phytopathogenic fungi Puccinia malvacearum and P. glechomatis are considered as chemotaxonomic biomarkers. Puccinia malvacearum on Alcea rosea and P. glechomatis on Glechoma hederacea collected from plants grown in various localities were analysed to determine their fatty acid composition. Both species synthesised significant amounts of saturated palmitic and stearic acids as well as 9,10-epoxy-octadecanoic acid, which rarely occurs in the nature. Both species synthesised hydroxy FAs including 9,10-dihydroxy octadecanoic acid and long-chain 2-hydroxy fatty acids.2-hydroxy 18:0 and 3-hydroxy 20:0 fatty acids were present only in P. malvacearum spores, and these may be the chemotaxonomic markers of the species. Ultra-high performance liquid chromatography mass spectrometry was performed for a comparative lipidomic analysis of P. malvacearum and P. glechomatis. The results revealed the complexity of molecular lipid species of these fungi. P. malvacearum and P. glechomatis lipids were characterised by the presence of a high number of triglyceride (TG) species. 9,10-epoxy octadecanoic fatty acid was found in TGs. Among the many types of oxidised TGs identified in P. glechomatis lipids, the most abundant species corresponds to TG(22:5+6O_17:0_18:2). P. malvacearum and P. glechomatis produced various ceramide species with different FAs from 14 to 24 chain-length. Unusual lipids like (O-acyl)-ω-hydroxy FA 18:0/18:0 in P. glechomatis and (O-acyl)-ω-hydroxy FA 18:0/20:0 and 18:0/22:0 in P. malvacearum were detected. The analysis of the polar lipid composition showed the presence of phosphatidylcholine and phosphatidylethanolamine as the main phospholipid classes of Puccinia spp. with the highest diversity of molecular species. Other phospholipids phosphatidic acid, phosphatidylglycerol phosphatidylserine and phosphatidylinositol were present in smaller amounts. The diversity of the neutral and polar lipid composition and fatty acid profile of P. malvacearum and P. glechomatis can be used in chemotaxonomic studies.

Carnosine retards tumor growth in vivo in an NIH3T3-HER2/neu mouse model.

BACKGROUND: It was previously demonstrated that the dipeptide carnosine inhibits growth of cultured cells isolated from patients with malignant glioma. In the present work we investigated whether carnosine also affects tumor growth in vivo and may therefore be considered for human cancer therapy. RESULTS: A mouse model was used to investigate whether tumor growth in vivo can be inhibited by carnosine. Therefore, NIH3T3 fibroblasts, conditionally expressing the human epidermal growth factor receptor 2 (HER2/neu), were implanted into the dorsal skin of nude mice, and tumor growth in treated animals was compared to control mice. In two independent experiments nude mice that received tumor cells received a daily intra peritoneal injection of 500 microl of 1 M carnosine solution. Measurable tumors were detected 12 days after injection. Aggressive tumor growth in control animals, that received a daily intra peritoneal injection of NaCl solution started at day 16 whereas aggressive growth in mice treated with carnosine was delayed, starting around day 19. A significant effect of carnosine on tumor growth was observed up to day 24. Although carnosine was not able to completely prevent tumor growth, a microscopic examination of tumors revealed that those from carnosine treated animals had a significant lower number of mitosis (p < 0.0003) than untreated animals, confirming that carnosine affects proliferation in vivo. CONCLUSION: As a naturally occurring substance with a high potential to inhibit growth of malignant cells in vivo, carnosine should be considered as a potential anti-cancer drug. Further experiments should be performed in order to understand how carnosine acts at the molecular level.