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Liebe H, Liebe F, Sponder G, Hedtrich S, Stumpff F. Beyond Ca 2+ signalling: the role of TRPV3 in the transport of NH 4. Pflugers Arch 2021; 473:1859-1884. [PMID: 34664138 PMCID: PMC8599221 DOI: 10.1007/s00424-021-02616-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 12/11/2022]
Abstract
Mutations of TRPV3 lead to severe dermal hyperkeratosis in Olmsted syndrome, but whether the mutants are trafficked to the cell membrane or not is controversial. Even less is known about TRPV3 function in intestinal epithelia, although research on ruminants and pigs suggests an involvement in the uptake of NH4+. It was the purpose of this study to measure the permeability of the human homologue (hTRPV3) to NH4+, to localize hTRPV3 in human skin equivalents, and to investigate trafficking of the Olmsted mutant G573S. Immunoblotting and immunostaining verified the successful expression of hTRPV3 in HEK-293 cells and Xenopus oocytes with trafficking to the cell membrane. Human skin equivalents showed distinct staining of the apical membrane of the top layer of keratinocytes with cytosolic staining in the middle layers. Experiments with pH-sensitive microelectrodes on Xenopus oocytes demonstrated that acidification by NH4+ was significantly greater when hTRPV3 was expressed. Single-channel measurements showed larger conductances in overexpressing Xenopus oocytes than in controls. In whole-cell experiments on HEK-293 cells, both enantiomers of menthol stimulated influx of NH4+ in hTRPV3 expressing cells, but not in controls. Expression of the mutant G573S greatly reduced cell viability with partial rescue via ruthenium red. Immunofluorescence confirmed cytosolic expression, with membrane staining observed in a very small number of cells. We suggest that expression of TRPV3 by epithelia may have implications not just for Ca2+ signalling, but also for nitrogen metabolism. Models suggesting how influx of NH4+ via TRPV3 might stimulate skin cornification or intestinal NH4+ transport are discussed.
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Affiliation(s)
- Hendrik Liebe
- Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany.,Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany
| | - Franziska Liebe
- Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany
| | - Gerhard Sponder
- Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany
| | - Sarah Hedtrich
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada
| | - Friederike Stumpff
- Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany.
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Liebe F, Liebe H, Kaessmeyer S, Sponder G, Stumpff F. The TRPV3 channel of the bovine rumen: localization and functional characterization of a protein relevant for ruminal ammonia transport. Pflugers Arch 2020; 472:693-710. [PMID: 32458085 PMCID: PMC7293678 DOI: 10.1007/s00424-020-02393-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 03/31/2020] [Accepted: 05/06/2020] [Indexed: 12/28/2022]
Abstract
Large quantities of ammonia (NH3 or NH4+) are absorbed from the gut, associated with encephalitis in hepatic disease, poor protein efficiency in livestock, and emissions of nitrogenous climate gasses. Identifying the transport mechanisms appears urgent. Recent functional and mRNA data suggest that absorption of ammonia from the forestomach of cattle may involve TRPV3 channels. The purpose of the present study was to sequence the bovine homologue of TRPV3 (bTRPV3), localize the protein in ruminal tissue, and confirm transport of NH4+. After sequencing, bTRPV3 was overexpressed in HEK-293 cells and Xenopus oocytes. An antibody was selected via epitope screening and used to detect the protein in immunoblots of overexpressing cells and bovine rumen, revealing a signal of the predicted ~ 90 kDa. In rumen only, an additional ~ 60 kDa band appeared, which may represent a previously described bTRPV3 splice variant of equal length. Immunohistochemistry revealed staining from the ruminal stratum basale to stratum granulosum. Measurements with pH-sensitive microelectrodes showed that NH4+ acidifies Xenopus oocytes, with overexpression of bTRPV3 enhancing permeability to NH4+. Single-channel measurements revealed that Xenopus oocytes endogenously expressed small cation channels in addition to fourfold-larger channels only observed after expression of bTRPV3. Both endogenous and bTRPV3 channels conducted NH4+, Na+, and K+. We conclude that bTRPV3 is expressed by the ruminal epithelium on the protein level. In conjunction with data from previous studies, a role in the transport of Na+, Ca2+, and NH4+ emerges. Consequences for calcium homeostasis, ruminal pH, and nitrogen efficiency in cattle are discussed.
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Affiliation(s)
- Franziska Liebe
- Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany
| | - Hendrik Liebe
- Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Arnimallee 22, 14195, Berlin, Germany
| | - Sabine Kaessmeyer
- Institute of Veterinary Anatomy, Freie Universität Berlin, Koserstraße 20, 14195, Berlin, Germany
| | - Gerhard Sponder
- Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany
| | - Friederike Stumpff
- Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany.
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Schrapers KT, Sponder G, Liebe F, Liebe H, Stumpff F. The bovine TRPV3 as a pathway for the uptake of Na +, Ca 2+, and NH 4+. PLoS One 2018; 13:e0193519. [PMID: 29494673 PMCID: PMC5832270 DOI: 10.1371/journal.pone.0193519] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Accepted: 02/13/2018] [Indexed: 12/22/2022] Open
Abstract
Absorption of ammonia from the gastrointestinal tract results in problems that range from hepatic encephalopathy in humans to poor nitrogen efficiency of cattle with consequences for the global climate. Previous studies on epithelia and cells from the native ruminal epithelium suggest functional involvement of the bovine homologue of TRPV3 (bTRPV3) in ruminal NH4+ transport. Since the conductance of TRP channels to NH4+ has never been studied, bTRPV3 was overexpressed in HEK-293 cells and investigated using the patch-clamp technique and intracellular calcium imaging. Control cells contained the empty construct. Divalent cations blocked the conductance for monovalent cations in both cell types, with effects higher in cells expressing bTRPV3. In bTRPV3 cells, but not in controls, menthol, thymol, carvacrol, or 2-APB stimulated whole cell currents mediated by Na+, Cs+, NH4+, and K+, with a rise in intracellular Ca2+ observed in response to menthol. While only 25% of control patches showed single-channel events (with a conductance of 40.8 ± 11.9 pS for NH4+ and 25.0 ± 5.8 pS for Na+), 90% of bTRPV3 patches showed much larger conductances of 127.8 ± 4.2 pS for Na+, 240.1 ± 3.6 pS for NH4+, 34.0 ± 1.7 pS for Ca2+, and ~ 36 pS for NMDG+. Open probability, but not conductance, rose with time after patch excision. In conjunction with previous research, we suggest that bTRPV3 channels may play a role in the transport of Na+, K+, Ca2+ and NH4+ across the rumen with possible repercussions for understanding the function of TRPV3 in other epithelia.
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Affiliation(s)
- Katharina T. Schrapers
- Institute of Veterinary Physiology, Faculty of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Gerhard Sponder
- Institute of Veterinary Physiology, Faculty of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Franziska Liebe
- Institute of Veterinary Physiology, Faculty of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Hendrik Liebe
- Institute of Veterinary Physiology, Faculty of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Friederike Stumpff
- Institute of Veterinary Physiology, Faculty of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
- * E-mail:
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Meier JF, Austermann-Haun U, Fettig J, Liebe H, Wichern M. Operation of an anaerobic filter compared with an anaerobic moving bed bioreactor for the treatment of waste water from hydrothermal carbonisation of fine mulch. Water Sci Technol 2017; 76:2065-2074. [PMID: 29068336 DOI: 10.2166/wst.2017.379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This experimental study investigates the anaerobic digestion of waste water from hydrothermal carbonisation of fine mulch (wood chips) in combination with a co-substrate for the first time. Two anaerobic reactors, an anaerobic filter (AF) and an anaerobic moving bed bioreactor (AnMBBR), were operated over a period of 131 days at mesophilic conditions. The organic loading rate was increased to a maximum of 8.5 g L-l d-1 in the AF and the AnMBBR. Both reactors achieved similarly efficient chemical oxygen demand removal rates of 80% approximately (approx.) and high methane production rates of approx. 2.7 L L-1 d-1. Nevertheless, signs of an inhibition were observed during the experiments.
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Affiliation(s)
- J F Meier
- Hochschule Ostwestfalen-Lippe, University of Applied Sciences, DEPT 3 - Civil Engineering, Emilienstr. 45, 32756 Detmold, Germany E-mail:
| | - U Austermann-Haun
- Hochschule Ostwestfalen-Lippe, University of Applied Sciences, DEPT 3 - Civil Engineering, Emilienstr. 45, 32756 Detmold, Germany E-mail:
| | - J Fettig
- Hochschule Ostwestfalen-Lippe, University of Applied Sciences, DEPT 8 - Environmental Engineering and Applied Computer Science, An der Wilhelmshöhe 44, 37671 Höxter, Germany
| | - H Liebe
- Hochschule Ostwestfalen-Lippe, University of Applied Sciences, DEPT 8 - Environmental Engineering and Applied Computer Science, An der Wilhelmshöhe 44, 37671 Höxter, Germany
| | - M Wichern
- Institute of Urban Water Management and Environmental Engineering, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany
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Fettig J, Pick V, Liebe H. Particle separation from road runoff by a decentralised lamella system - laboratory tests and experiences in the field. Water Sci Technol 2017; 75:2056-2063. [PMID: 28498118 DOI: 10.2166/wst.2017.083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A new decentralised settling system based on the principle of lamella separation was developed for the treatment of road runoff. Two different laboratory test methods, the DIBt (Deutsches Institut für Bautechnik) procedure and our own approach, were applied in order to evaluate the efficiency of the system based on the separation of fine mineral particles and a mixture of mineral and organic particles, respectively. Overall efficiencies (88% after DIBt and 61% according to our own method) were comparable to results obtained for commercial systems. The lamella system was then applied in the field for 1 year to treat runoff from a road area of 420 m2. The amount of solids separated that was calculated from a mass balance (10.1 kg) was consistent with the amount of sediments measured (8.6 kg). However, the average separation efficiency was only 30% in the field study. This is related to the size and composition of the particles in runoff, which are not represented well by the material used for the test procedures. It is concluded that the test methods should be improved, and that more field studies are needed in order to obtain a better understanding of the settling behaviour of particles in road runoff.
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Affiliation(s)
- J Fettig
- University of Applied Sciences Ostwestfalen-Lippe, 37671 Hoexter, Germany E-mail:
| | - V Pick
- University of Applied Sciences Ostwestfalen-Lippe, 37671 Hoexter, Germany E-mail:
| | - H Liebe
- University of Applied Sciences Ostwestfalen-Lippe, 37671 Hoexter, Germany E-mail:
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Abstract
Granular-activated carbon (GAC) adsorption of biologically pre-treated process waters from hydrothermal carbonization (HTC) of different materials was investigated. Overall, isotherms showed that most of the dissolved organic substances are strongly adsorbable while the non-adsorbable fractions are small. The equilibrium data were modelled by using five fictive components to represent the organic matter. Mean film transfer coefficients and mean intraparticle diffusivities were derived from short-column and batch kinetic test data, respectively. Breakthrough curves in GAC columns could be predicted satisfactorily by applying the film-homogeneous diffusion model and using the equilibrium and kinetic parameters determined from batch tests. Thus, the approach is suited to model GAC adsorption of HTC process water under technical-scale conditions.
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Affiliation(s)
- J Fettig
- University of Applied Sciences Ostwestfalen-Lippe, An der Wilhelmshöhe 44, D-37671 Höxter, Germany E-mail:
| | - H Liebe
- University of Applied Sciences Ostwestfalen-Lippe, An der Wilhelmshöhe 44, D-37671 Höxter, Germany E-mail:
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Wei Q, Achazi K, Liebe H, Schulz A, Noeske PLM, Grunwald I, Haag R. Mussel-Inspired Dendritic Polymers as Universal Multifunctional Coatings. Angew Chem Int Ed Engl 2014; 53:11650-5. [DOI: 10.1002/anie.201407113] [Citation(s) in RCA: 174] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Indexed: 12/12/2022]
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Lentrodt J, Ahrens G, Maerker R, Liebe H. [Effect of combined wire arch and plastic splints on tooth mobility and periodontium]. Dtsch Zahnarztl Z 1973; 28:276-9. [PMID: 4512705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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