| 1. |
- Ückert, S., et al.
(författare)
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Expression and distribution of key proteins of the endocannabinoid system in the human seminal vesicles
- 2018
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Ingår i: Andrologia. - : Hindawi Limited. - 0303-4569. ; 50:2
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Tidskriftsartikel (refereegranskat)abstract
- The endocannabinoid system (ECS), comprising the cannabinoid receptors (CBR), their ligands, and enzymes controlling the turnover of endocannabinoids, has been suggested to be involved in male reproductive function. As information is scarce on the expression of the ECS in human male reproductive tissues, this study aimed to investigate by means of molecular biology (RT-PCR) and immunohistochemistry/immunofluorescence the expression and distribution of CB1 and CB2, GPR55 (an orphan G protein-coupled receptor that recognises cannabinoid ligands) and FAAH (isoforms 1 and 2) in the human seminal vesicles (SV). The specimens expressed PCR products corresponding to CB1 (66 bp), CB2 (141 bp), GPR55 (112 bp), FAAH1 (260 bp) and FAAH2 (387 bp). Immumohistochemistry revealed dense expression of CB1, CB2 and GPR55 located to the pseudo-stratified columnar epithelium and varicose nerves (also characterised by the expression of vasoactive intestinal polypeptide and calcitonin gene-related peptide). Cytosolic staining for FAAH1 and FAAH2 was seen in cuboidal cells of all layers of the epithelium. No immunoreactivity was detected in the smooth musculature or nerve fibres. CB1, CB2, GPR55, FAAH1 and FAAH2 are highly expressed in the human SV. Considering their localisation, the ECS may be involved in epithelial homeostasis, secretory function or autonomic mechano-afferent signalling.
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| 2. |
- Bettiga, Maurizio, 1978, et al.
(författare)
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Plasma membrane as a crucial player in acetic acid effect on yeast
- 2017
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Ingår i: IMYA12- 12th International Meeting on Yeast Apoptosis, Bari, Italy • 14-18 May 2017.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Weak organic acids such as formic, acetic or lactic acid are known inhibitors of microbial growth and fermentation. Acetic acid toxicity to yeast cells has been explained by different theories, involving specific signaling effects triggering an active cell death program, reduction of intracellular pH and acetate anion accumulation. Regardless of the fact whether the actual effect of acetate involves one of these mechanisms or a combination thereof, acetic acid inhibits yeast metabolism and affects yeast viability. This has a high impact on the feasibility of the new generation of fermentation processes, based on the naturally acetic acid-rich lignocellulosic substrates. It is therefore highly desirable to obtain a strain with increased capacity of coping with high acetic acid concentrations in the fermentation medium. Acetic acid is thought to be internalized by yeast cells in its undissociated form, by crossing the hydrophobic barrier of plasma membrane. Thus, in our work we focused on the investigation of membrane properties and how these influence the tolerance of yeast to acetic acid. First, we demonstrated with lipidomics analysis of membrane lipids that the yeast Zygosaccharomyces bailii, showing extraordinary tolerance to acetic acid, has a plasma membrane which is rich in sphingolipids. Next, we combined membrane molecular dynamics and in vivo measurements to confirm the specific role of sphingolipids in altering the permeability of plasma membrane to acetic acid. Finally, we investigated the effect of alcohols on the acetic acid permeation rate through the membrane. Our ultimate goal is to engineer the membrane composition of an industrial yeast strain towards reduced permeability, in order to obtain higher acetic acid tolerance.
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| 3. |
- Gandaglia, G., et al.
(författare)
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The fatty acid amide hydrolase inhibitor oleoyl ethyl amide counteracts bladder overactivity in female rats
- 2014
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Ingår i: Neurourology and Urodynamics. - : John Wiley & Sons. - 0733-2467 .- 1520-6777. ; 33:8, s. 1251-1258
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Tidskriftsartikel (refereegranskat)abstract
- AIMS:To study micturition and bladder overactivity in female rats after chronic treatment with the fatty acid amide hydrolase (FAAH) inhibitor oleoyl ethyl amide (OEtA).METHODS:Sprague-Dawley rats received daily subcutaneous injections of OEtA (0.3 mg/kg), or vehicle for 2 weeks. Cystometries, organ bath studies, Western blot, and immunofluorescence were then used. Expressions of FAAH, cannabinoid 1 and 2 receptors (CB1 and CB2), mitogen-activated protein kinase (MAPK), vesicular acetyl choline-transporter protein (VAChT), and calcitonin gene-related peptide (CGRP) were evaluated.RESULTS:At baseline, OEtA-treated rats had higher values (P < 0.05) of micturition intervals (MI) and volumes (MV), bladder capacity (BC), threshold pressure, and flow pressure than vehicle controls. Intravesical PGE2 reduced MI, MV, and BC, and increased basal pressure and the area under the curve in all rats. However, these urodynamic parameters were altered less by intravesical PGE2 in OEtA-treated rats (P < 0.05 vs. vehicle controls). Compared to vehicle controls, detrusor from OEtA-treated rats had larger contractions to carbachol at 10-0.1 µM, but no difference in Emax was recorded. FAAH, CB1, CB2, VAChT, or CGRP was similarly expressed in bladders from all rats. In separate experiments, intravesical OEtA increased mucosal expression of phosphorylated MAPK.CONCLUSIONS:Chronic FAAH inhibition altered sensory urodynamic parameters and reduced bladder overactivity. Even if it cannot be excluded that OEtA may act on central nervous sensory pathways to contribute to these effects, the presence of FAAH and CB receptors in the bladder and activation of intracellular signals for CB receptors by intravesical OEtA suggest a local role for FAAH in micturition control. Neurourol. Urodynam
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| 4. |
- Lindahl, Lina, 1984, et al.
(författare)
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Alcohols enhance the rate of acetic acid diffusion in S. cerevisiae: biophysical mechanisms and implications for acetic acid tolerance
- 2018
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Ingår i: Microbial Cell. - : Shared Science Publishers OG. - 2311-2638. ; 5:1, s. 42-55
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Tidskriftsartikel (refereegranskat)abstract
- Microbial cell factories with the ability to maintain high productivity in the presence of weak organic acids, such as acetic acid, are required in many industrial processes. For example, fermentation media derived from lignocellulosic biomass are rich in acetic acid and other weak acids. The rate of diffusional entry of acetic acid is one parameter determining the ability of microorganisms to tolerance the acid. The present study demonstrates that the rate of acetic acid diffusion in S. cerevisiae is strongly affected by the alcohols ethanol and n-butanol. Ethanol of 40 g/L and n-butanol of 8 g/L both caused a 65% increase in the rate of acetic acid diffusion, and higher alcohol concentrations caused even greater increases. Molecular dynamics simulations of membrane dynamics in the presence of alcohols demonstrated that the partitioning of alcohols to the head group region of the lipid bilayer causes a considerable increase in the membrane area, together with reduced membrane thickness and lipid order. These changes in physiochemical membrane properties lead to an increased number of water molecules in the membrane interior, providing biophysical mechanisms for the alcohol-induced increase in acetic acid diffusion rate. nbutanol affected S. cerevisiae and the cell membrane properties at lower concentrations than ethanol, due to greater and deeper partitioning in the membrane. This study demonstrates that the rate of acetic acid diffusion can be strongly affected by compounds that partition into the cell membrane, and highlights the need for considering interaction effects between compounds in the design of microbial processes.
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| 5. |
- Lindahl, Lina, 1984, et al.
(författare)
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Membrane engineering for reduced acetic acid stress: insights from Zygosaccharomyces bailii
- 2015
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Ingår i: Oral presentation at 12th Yeast Lipid Conference, May 20-22 2015, Ghent, Belgium.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The high concentration of acetic acid released during pretreatment of lignocellulose raw material is a major obstacle to the microbial production of bio-based products. Acetic acid enters the cell mainly by passive diffusion across the plasma membrane and inhibits yeast by mechanisms such as reduction of intracellular pH, accumulation of the acetate anion, and by signaling effects triggering cell death. Through extensive characterization of the acetic acid tolerant yeast Zygosaccharomyces bailii, we have identified the cell membrane as a target for strain engineering with potential to increase acetic acid tolerance in Saccharomyces cerevisiae. We propose membrane permeability as a key component for Z. bailii’s acetic acid tolerance. We have previously shown that Z. bailii has a unique ability to remodel its plasma membrane upon acetic acid stress, to strongly increase its fraction of complex sphingolipids, at the expense of a drastic reduction of glycerophospholipids1. Here we further demonstrate the involvement of complex sphingolipids in acetic acid tolerance by decreasing sphingolipid synthesis using the drug myriocin, and characterize the acetic acid tolerance in terms of growth and intracellular pH. Furthermore we show the impact of complex sphingolipids on membrane physical properties using in silico membrane simulations. Ongoing membrane engineering of S. cerevisiae can potentially give additional strength to our findings. References 1 Lindberg et al. (2013), Lipidomic Profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii Reveals Critical Changes in Lipid Composition in Response to Acetic Acid Stress, PLoS One 8: e73936.
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| 6. |
- Lindahl, Lina, 1984, et al.
(författare)
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Sphingolipids contribute to acetic acid resistance in Zygosaccharomyces bailii
- 2016
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Ingår i: Biotechnology and Bioengineering. - : Wiley. - 0006-3592 .- 1097-0290. ; 113:4, s. 744-753
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Tidskriftsartikel (refereegranskat)abstract
- Lignocellulosic raw material plays a crucial role in the development of sustainable processes for the production of fuels and chemicals. Weak acids such as acetic acid and formic acid are troublesome inhibitors restricting efficient microbial conversion of the biomass to desired products. To improve our understanding of weak acid inhibition, and to identify engineering strategies to reduce acetic acid toxicity, the highly acetic-acid-tolerant yeast Zygosaccharomyces bailii was studied. The impact of acetic acid membrane permeability on acetic acid tolerance in Z. bailii was investigated with particular focus on how the previously demonstrated high sphingolipid content in the plasma membrane influences acetic acid tolerance and membrane permeability. Through molecular dynamics simulations we concluded that membranes with a high content of sphingolipids are thicker and more dense, increasing the free energy barrier for the permeation of acetic acid through the membrane. Z. bailii cultured with the drug myriocin, known to decrease cellular sphingolipid levels, exhibited significant growth inhibition in the presence of acetic acid, while growth in medium without acetic acid was unaffected by the myriocin addition. Furthermore, following an acetic acid pulse, the intracellular pH decreased more in myriocin-treated cells than in control cells. This indicates a higher inflow rate of acetic acid, and confirms that the reduction in growth of cells cultured with myriocin in the medium with acetic acid, was due to an increase in membrane permeability, thereby demonstrating the importance of a high fraction of sphingolipids in the membrane of Z. bailii to facilitate acetic acid resistance; a property potentially transferable to desired production organisms suffering from weak acid stress
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| 7. |
- Lindahl, Lina, 1984, et al.
(författare)
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THE INFLUENCE OF MEMBRANE COMPOSTION ON ACETIC ACID PERMEABILITY AND POTENTIALLY ACETIC ACID TOLERANCE
- 2014
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Ingår i: ISSY31: 31st International Specialised Symposium on Yeast.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Compounds entering the cell do so either by passive diffusion over the plasma membrane or through transporters in the membrane. The specific lipid composition of the plasma membrane influences both the passive diffusion rate but also the activity of membrane proteins. Acetic acid, a major hurdle in fermentation processes using lignocellulosic material, is believed to pass through the membrane in its protonated from mainly by passive diffusion [1]. Sterols and sphingolipids are lipid classes thought to contribute to membrane rigidity. Sterols are often found to be involved in stress resistance [2, 3] and in our previous work sphingolipids were pointed at as an important constituent of the plasma membrane of the yeast Zygosaccharomyces bailii, known to be very tolerant to acetic acid, suggesting a possible link between acetic acid tolerance and sphingolipid relative abundance in the membrane [4]. Here we will provide supporting evidence of the importance of sphingolipids and sterols in acetic acid membrane permeability. We have combined biochemistry techniques with in silico membrane modeling to answer the question how membrane engineering can be used to decrease acetic acid membrane permeability. [1] Verduyn et al. Yeast (1992) 501-517. [2] Alexandre et al. FEMS Microbiology Letters (1994) 124:17-22. [3] Liu et al. Journal of Applied Microbiology (2013) 114:482-491. [4] Lindberg et al. PlosONE (2003) 8(9): e73936.
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| 8. |
- Maertens, Jeroen, 1990, et al.
(författare)
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Molecular-dynamics-simulation-guided membrane engineering allows the increase of membrane fatty acid chain length in Saccharomyces cerevisiae
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- The use of lignocellulosic-based fermentation media will be a necessary part of the transition to a circular bio-economy. These media contain many inhibitors to microbial growth, including acetic acid. Under industrially relevant conditions, acetic acid enters the cell predominantly through passive diffusion across the plasma membrane. The lipid composition of the membrane determines the rate of uptake of acetic acid, and thicker, more rigid membranes impede passive diffusion. We hypothesized that the elongation of glycerophospholipid fatty acids would lead to thicker and more rigid membranes, reducing the influx of acetic acid. Molecular dynamics simulations were used to predict the changes in membrane properties. Heterologous expression of Arabidopsis thaliana genes fatty acid elongase 1 (FAE1) and glycerol-3-phosphate acyltransferase 5 (GPAT5) increased the average fatty acid chain length. However, this did not lead to a reduction in the net uptake rate of acetic acid. Despite successful strain engineering, the net uptake rate of acetic acid did not decrease. We suggest that changes in the relative abundance of certain membrane lipid headgroups could mitigate the effect of longer fatty acid chains, resulting in a higher net uptake rate of acetic acid.
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| 9. |
- Mistretta, Francesco A., et al.
(författare)
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DFL23448, A Novel Transient Receptor Potential Melastin 8-Selective Ion Channel Antagonist, Modifies Bladder Function and Reduces Bladder Overactivity in Awake Rats
- 2016
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Ingår i: Journal of Pharmacology and Experimental Therapeutics. - : AMER SOC PHARMACOLOGY EXPERIMENTAL THERAPEUTICS. - 0022-3565 .- 1521-0103. ; 356:1, s. 200-211
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Tidskriftsartikel (refereegranskat)abstract
- The transient receptor potential melastin 8 ion channel (TRPM8) is implicated in bladder sensing but limited information on TRPM8 antagonists in bladder overactivity is available. This study characterizes a new TRPM8-selective antagonist (DFL23448 [5-(2-ethyl-2H-tetrazol-5-yl)-2-(3-fluorophenyl)-1,3-thiazol-4-ol]) and evaluates it in cold-induced behavioral tests and tests on bladder function and experimental bladder overactivity in vivo in rats. DFL23448 displayed IC50 values of 10 and 21 nM in hTRPM8 human embryonic kidney 293 cells activated by Cooling Agent 10 or cold, but it had limited activity (IC50 > 10 mu M) at transient receptor potential vanilloids TRPV1, TRPA1, or TRPV4 or at various G protein-coupled receptors. In rats, DFL23448 administered intravenously or orally had a half-life of 37 minutes or 4.9 hours, respectively. DLF23448 (10 mg/kg i.v.) reduced icilin-induced "wet dog-like" shakes in rats. Intravesical DFL23448 (10 mg/l), but not vehicle, increased micturition intervals, micturition volume, and bladder capacity. During bladder overactivity by intravesical prostaglandin E-2 (PGE(2)), vehicle controls exhibited reductions in micturition intervals, micturition volumes, and bladder capacity by 37%-39%, whereas the same parameters only decreased by 12%-15% (P < 0.05-0.01 versus vehicle) in DFL23448-treated rats. In vehicle-treated rats, but not in DFL23448-treated rats, intravesical PGE(2) increased bladder pressures. Intravenous DFL23448 at 10 mg/kg, but not 1 mg/kg DFL23448 or vehicle, increased micturition intervals, micturition volumes, and bladder capacity. During bladder overactivity by intravesical PGE(2), micturition intervals, micturition volumes, and bladder capacity decreased in vehicle- and 1 mg/kg DFL23448-treated rats, but not in 10 mg/kg DFL23448-treated rats. Bladder pressures increased less in rats treated with DFL23448 10 mg/kg than in vehicle-or 1 mg/kg DFL23448-treated rats. DFL23448 (10 mg/kg i.v.), but not vehicle, prevented cold stress-induced bladder overactivity. Our results support a role for bladder TRPM8-mediated signals in experimental bladder overactivity.
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| 10. |
- Mistretta, Francesco A, et al.
(författare)
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DFL23448, a novel TRPM8-selective ion channel antagonist, modifies bladder function and reduces bladder overactivity in awake rats.
- 2016
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Ingår i: Journal of Pharmacology and Experimental Therapeutics. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 1521-0103. ; 356:1, s. 200-211
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Tidskriftsartikel (refereegranskat)abstract
- The transient receptor potential (TRP) melastin 8 ion channel (TRPM8) is implicated in bladder sensing but limited information on TRPM8 antagonists in bladder overactivity (BO) is available. This study characterizes a new TRPM8-selective antagonist (DFL23448) and evaluates it in cold-induced behavioral tests and on bladder function and experimental BO in vivo in rats. DFL23448 displayed IC50 values of 10 and 21nM in hTRPM8 HEK-293 cells activated by Cooling Agent 10 or cold, but had limited activity (IC50 > 10μM) at TRPV1, TRPA1, TRPV4, or at various G-protein-coupled receptors. In rats, DFL23448 had a half-life of 37 minutes (intravenous; i.v.) or 4.9 hours (oral). DLF23448 (10mg/kg, i.v) reduced icilin-induced wet-dog shakes in rats. Intravesical (i.ves.) DFL23448 (10mg/L) but not vehicle increased micturition intervals (MI), micturition volumes (MV) and bladder capacity (BC). During BO by i.ves. PGE2, vehicle controls exhibited reductions of MI, MV and BC by 37-39%, whereas the same parameters only decreased by 12-15% (p<0.05-0.01 vs. vehicle) in DFL23448-treated rats. In vehicle-treated rats but not in DFL23448-treated rats, i.ves. PGE2 increased bladder pressures. Intravenous DFL23448 at 10mg/kg, but not 1mg/kg DFL23448 or vehicle, increased MI, MV, and BC. During BO by i.ves. PGE2, MI, MV, and BC decreased in vehicle- and in DFL23448 1mg/kg-treated rats, but not in DFL23448 10mg/kg-treated rats. Bladder pressures increased less in rats treated with DFL23448 10mg/kg than in vehicle- or DFL23448 1mg/kg- treated rats. DFL23448 (10mg/kg, i.v.), but not vehicle, prevented cold-stress BO. Our results support a role for bladder TRPM8-mediated signals in experimental BO.
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