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Zhang Y, Liang Y, Xiang H, Li P, Zhan D, Ding D, Du S, Ding Y, Liu W, Qiu X, Feng H. Critical impact of pressure regulation on carbon dioxide biosynthesis. BIORESOURCE TECHNOLOGY 2024; 413:131445. [PMID: 39278365 DOI: 10.1016/j.biortech.2024.131445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Revised: 09/03/2024] [Accepted: 09/03/2024] [Indexed: 09/18/2024]
Abstract
Carbon dioxide (CO2) biosynthesis is a promising alternative to traditional chemical synthesis. However, its application in engineering is hampered by poor gas mass transfer rates. Pressurization is an effective method to enhance mass transfer and increase synthesis yield, although the underlying mechanisms remain unclear. This review examines the effects of high pressure on CO2 biosynthesis, elucidating the mechanisms behind yield enhancement from three perspectives: microbial physiological traits, gas mass transfer and synthetic pathways. The critical role of pressurization in improving microbial activity and gas transfer efficiency is emphasized, with particular attention to maintaining pressure within microbial tolerance limits to maximize yield without compromising cell structure integrity.
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Affiliation(s)
- Yanqing Zhang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang, China; International Science and Technology Cooperation Platform for Low-Carbon Recycling of Waste and Green Development, Zhejiang Gongshang University, Hangzhou 310012, Zhejiang, China
| | - Yuxiang Liang
- College of Environment and Resources, College of Carbon Neutral, Zhejiang Agriculture and Forestry University, Hangzhou, Zhejiang 311300, China
| | - Hai Xiang
- College of Environment and Resources, College of Carbon Neutral, Zhejiang Agriculture and Forestry University, Hangzhou, Zhejiang 311300, China
| | - Pingli Li
- College of Environment and Resources, College of Carbon Neutral, Zhejiang Agriculture and Forestry University, Hangzhou, Zhejiang 311300, China
| | - Dongqing Zhan
- College of Environment and Resources, College of Carbon Neutral, Zhejiang Agriculture and Forestry University, Hangzhou, Zhejiang 311300, China
| | - Danna Ding
- College of Environment and Resources, College of Carbon Neutral, Zhejiang Agriculture and Forestry University, Hangzhou, Zhejiang 311300, China
| | - Shuangwei Du
- College of Environment and Resources, College of Carbon Neutral, Zhejiang Agriculture and Forestry University, Hangzhou, Zhejiang 311300, China
| | - Yangcheng Ding
- College of Environment and Resources, College of Carbon Neutral, Zhejiang Agriculture and Forestry University, Hangzhou, Zhejiang 311300, China
| | - Wen Liu
- College of Environment and Resources, College of Carbon Neutral, Zhejiang Agriculture and Forestry University, Hangzhou, Zhejiang 311300, China
| | - Xiawen Qiu
- College of Environment and Resources, College of Carbon Neutral, Zhejiang Agriculture and Forestry University, Hangzhou, Zhejiang 311300, China
| | - Huajun Feng
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang, China; College of Environment and Resources, College of Carbon Neutral, Zhejiang Agriculture and Forestry University, Hangzhou, Zhejiang 311300, China; International Science and Technology Cooperation Platform for Low-Carbon Recycling of Waste and Green Development, Zhejiang Gongshang University, Hangzhou 310012, Zhejiang, China.
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Yamamoto E, Joo K, Lee J, Sansom MSP, Yasui M. Molecular mechanism of anion permeation through aquaporin 6. Biophys J 2024; 123:2496-2505. [PMID: 38894539 PMCID: PMC11365104 DOI: 10.1016/j.bpj.2024.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 04/07/2024] [Accepted: 06/12/2024] [Indexed: 06/21/2024] Open
Abstract
Aquaporins (AQPs) are recognized as transmembrane water channels that facilitate selective water permeation through their monomeric pores. Among the AQP family, AQP6 has an intriguing characteristic as an anion channel, which is allosterically controlled by pH conditions and is eliminated by a single amino acid mutation. However, the molecular mechanism of anion permeation through AQP6 remains unclear. Using molecular dynamics simulations in the presence of a transmembrane voltage utilizing an ion concentration gradient, we show that chloride ions permeate through the pore corresponding to the central axis of the AQP6 homotetramer. Under low pH conditions, a subtle opening of the hydrophobic selectivity filter (SF), located near the extracellular part of the central pore, becomes wetted and enables anion permeation. Our simulations also indicate that a single mutation (N63G) in human AQP6, located at the central pore, significantly reduces anion conduction, consistent with experimental data. Moreover, we demonstrate that the pH-sensing mechanism in which the protonation of H184 and H189 under low pH conditions allosterically triggers the gating of the SF region. These results suggest a unique pH-dependent allosteric anion permeation mechanism in AQP6 and could clarify the role of the central pore in some of the AQP tetramers.
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Affiliation(s)
- Eiji Yamamoto
- Department of System Design Engineering, Keio University, Yokohama, Kanagawa, Japan.
| | - Keehyoung Joo
- Center for Advanced Computation, Korea Institute for Advanced Study, Seoul, Korea
| | - Jooyoung Lee
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul, Korea
| | - Mark S P Sansom
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Masato Yasui
- Department of Pharmacology, Keio University School of Medicine, Tokyo, Japan
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3
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Joseph FM, Kaldenhoff R. Tobacco aquaporin NtAQP1 and human aquaporin hAQP1 contribute to single cell photosynthesis in Synechococcus. Biol Cell 2024; 116:e2470003. [PMID: 38653736 DOI: 10.1111/boc.202470003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/02/2024] [Accepted: 03/06/2024] [Indexed: 04/25/2024]
Abstract
BACKGROUND INFORMATION Aquaporins are H2O-permeable membrane protein pores. However, some aquaporins are also permeable to other substances such as CO2. In higher plants, overexpression of such aquaporins has already led to an enhanced photosynthetic performance due to improved CO2 mesophyll conductance. In this work, we investigated the effects of such aquaporins on unicellular photosynthetically active organisms, specifically cyanobacteria. RESULTS Overexpression of aquaporins NtAQP1 or hAQP1 that might have a function to improve CO2 membrane permeability lead to increased photosynthesis rates in the cyanobacterium Synechococcus sp. PCC7002 as concluded by the rate of evolved O2. A shift in the Plastoquinone pool state of the cells supports our findings. Water permeable aquaporins without CO2 permeability, such as NtPIP2;1, do not have this effect. CONCLUSIONS AND SIGNIFICANCE We conclude that also in single cell organisms like cyanobacteria, membrane CO2 conductivity could be rate limiting and CO2-porins reduce the respective membrane resistance. We could show that besides the tobacco aquaporin NtAQP1 also the human hAQP1 most likely functions as CO2 diffusion facilitator in the photosynthesis assay.
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Affiliation(s)
- Franziska M Joseph
- Department of Biology, Applied Plant Sciences, Technical University of Darmstadt, Darmstadt, Germany
| | - Ralf Kaldenhoff
- Department of Biology, Applied Plant Sciences, Technical University of Darmstadt, Darmstadt, Germany
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Yao X, Mu Y, Zhang L, Chen L, Zou S, Chen X, Lu K, Dong H. AtPIP1;4 and AtPIP2;4 Cooperatively Mediate H 2O 2 Transport to Regulate Plant Growth and Disease Resistance. PLANTS (BASEL, SWITZERLAND) 2024; 13:1018. [PMID: 38611547 PMCID: PMC11013698 DOI: 10.3390/plants13071018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 03/22/2024] [Accepted: 04/01/2024] [Indexed: 04/14/2024]
Abstract
The rapid production of hydrogen peroxide (H2O2) is a hallmark of plants' successful recognition of pathogen infection and plays a crucial role in innate immune signaling. Aquaporins (AQPs) are membrane channels that facilitate the transport of small molecular compounds across cell membranes. In plants, AQPs from the plasma membrane intrinsic protein (PIP) family are utilized for the transport of H2O2, thereby regulating various biological processes. Plants contain two PIP families, PIP1s and PIP2s. However, the specific functions and relationships between these subfamilies in plant growth and immunity remain largely unknown. In this study, we explore the synergistic role of AtPIP1;4 and AtPIP2;4 in regulating plant growth and disease resistance in Arabidopsis. We found that in plant cells treated with H2O2, AtPIP1;4 and AtPIP2;4 act as facilitators of H2O2 across membranes and the translocation of externally applied H2O2 from the apoplast to the cytoplasm. Moreover, AtPIP1;4 and AtPIP2;4 collaborate to transport bacterial pathogens and flg22-induced apoplastic H2O2 into the cytoplasm, leading to increased callose deposition and enhanced defense gene expression to strengthen immunity. These findings suggest that AtPIP1;4 and AtPIP2;4 cooperatively mediate H2O2 transport to regulate plant growth and immunity.
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Affiliation(s)
- Xiaohui Yao
- National Key Laboratory of Wheat Improvement, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Yanjie Mu
- National Key Laboratory of Wheat Improvement, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
- Qingdao King Agroot Crop Science, Qingdao 266071, China
| | - Liyuan Zhang
- National Key Laboratory of Wheat Improvement, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Lei Chen
- National Key Laboratory of Wheat Improvement, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Shenshen Zou
- National Key Laboratory of Wheat Improvement, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Xiaochen Chen
- National Key Laboratory of Wheat Improvement, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Kai Lu
- National Key Laboratory of Wheat Improvement, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
| | - Hansong Dong
- National Key Laboratory of Wheat Improvement, College of Plant Protection, Shandong Agricultural University, Taian 271018, China
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5
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Chen J, Yue K, Shen L, Zheng C, Zhu Y, Han K, Kai L. Aquaporins and CO 2 diffusion across biological membrane. Front Physiol 2023; 14:1205290. [PMID: 37383148 PMCID: PMC10293838 DOI: 10.3389/fphys.2023.1205290] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 06/05/2023] [Indexed: 06/30/2023] Open
Abstract
Despite the physiological significance of effective CO2 diffusion across biological membranes, the underlying mechanism behind this process is not yet resolved. Particularly debatable is the existence of CO2-permeable aquaporins. The lipophilic characteristic of CO2 should, according to Overton's rule, result in a rapid flux across lipid bilayers. However, experimental evidence of limited membrane permeability poses a challenge to this idea of free diffusion. In this review, we summarized recent progress with regard to CO2 diffusion, and discussed the physiological effects of altered aquaporin expression, the molecular mechanisms of CO2 transport via aquaporins, and the function of sterols and other membrane proteins in CO2 permeability. In addition, we highlight the existing limits in measuring CO2 permeability and end up with perspectives on resolving such argument either by determining the atomic resolution structure of CO2 permeable aquaporins or by developing new methods for measuring permeability.
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Affiliation(s)
- Junyu Chen
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Ke Yue
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Lulu Shen
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Chuncui Zheng
- Hangzhou Institute of Test and Calibration for Quality and Technology Supervision, Hangzhou, China
| | - Yiyong Zhu
- Jiangsu Provincial Key Laboratory for Organic Solid Waste Utilization, National Engineering Research Center for Organic-Based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
| | - Kun Han
- Jiangsu Keybio Co., Ltd, Xuzhou, China
| | - Lei Kai
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
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6
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Henderson SW, Nakayama Y, Whitelaw ML, Bruning JB, Anderson PA, Tyerman SD, Ramesh SA, Martinac B, Yool AJ. Proteoliposomes reconstituted with human aquaporin-1 reveal novel single-ion-channel properties. BIOPHYSICAL REPORTS 2023; 3:100100. [PMID: 36949749 PMCID: PMC10025285 DOI: 10.1016/j.bpr.2023.100100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 01/11/2023] [Indexed: 01/15/2023]
Abstract
Human aquaporin 1 (hAQP1) forms homotetrameric channels that facilitate fluxes of water and small solutes across cell membranes. In addition to water channel activity, hAQP1 displays non-selective monovalent cation-channel activity gated by intracellular cyclic GMP. Dual water and ion-channel activity of hAQP1, thought to regulate cell shape and volume, could offer a target for novel therapeutics relevant to controlling cancer cell invasiveness. This study probed properties of hAQP1 ion channels using proteoliposomes, which, unlike conventional cell-based systems such as Xenopus laevis oocytes, are relatively free of background ion channels. Histidine-tagged recombinant hAQP1 protein was synthesized and purified from the methylotrophic yeast, Pichia pastoris, and reconstituted into proteoliposomes for biophysical analyses. Osmotic water channel activity confirmed correct folding and channel assembly. Ion-channel activity of hAQP1-Myc-His6 was recorded by patch-clamp electrophysiology with excised patches. In symmetrical potassium, the hAQP1-Myc-His6 channels displayed coordinated gating, a single-channel conductance of approximately 75 pS, and multiple subconductance states. Applicability of this method for structure-function analyses was tested using hAQP1-Myc-His6 D48A/D185A channels modified by site-directed mutations of charged Asp residues estimated to be adjacent to the central ion-conducting pore of the tetramer. No differences in conductance were detected between mutant and wild-type constructs, suggesting the open-state conformation could differ substantially from expectations based on crystal structures. Nonetheless, the method pioneered here for AQP1 demonstrates feasibility for future work defining structure-function relationships, screening pharmacological inhibitors, and testing other classes in the broad family of aquaporins for previously undiscovered ion-conducting capabilities.
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Affiliation(s)
- Sam W. Henderson
- School of Biomedicine, University of Adelaide, Adelaide, SA 5005, Australia
| | - Yoshitaka Nakayama
- Victor Chang Cardiac Research Institute, Lowy Packer Building, Darlinghurst, NSW 2010, Australia
- School of Clinical Medicine, UNSW Medicine & Health, St Vincent’s Healthcare Clinical Campus, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW Australia
| | - Murray L. Whitelaw
- Institute of Photonics and Advanced Sensing, The School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - John B. Bruning
- Institute of Photonics and Advanced Sensing, The School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Peter A. Anderson
- School of Biological Sciences, Faculty of Science and Engineering, Flinders University, Adelaide, SA 5001, Australia
| | - Stephen D. Tyerman
- ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine & Waite Research Institute, University of Adelaide, Glen Osmond, SA 5064, Australia
| | - Sunita A. Ramesh
- School of Biological Sciences, Faculty of Science and Engineering, Flinders University, Adelaide, SA 5001, Australia
| | - Boris Martinac
- Victor Chang Cardiac Research Institute, Lowy Packer Building, Darlinghurst, NSW 2010, Australia
- School of Clinical Medicine, UNSW Medicine & Health, St Vincent’s Healthcare Clinical Campus, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW Australia
| | - Andrea J. Yool
- School of Biomedicine, University of Adelaide, Adelaide, SA 5005, Australia
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7
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Potential Novel Role of Membrane-Associated Carbonic Anhydrases in the Kidney. Int J Mol Sci 2023; 24:ijms24044251. [PMID: 36835660 PMCID: PMC9961601 DOI: 10.3390/ijms24044251] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 02/06/2023] [Accepted: 02/06/2023] [Indexed: 02/23/2023] Open
Abstract
Carbonic anhydrases (CAs), because they catalyze the interconversion of carbon dioxide (CO2) and water into bicarbonate (HCO3-) and protons (H+), thereby influencing pH, are near the core of virtually all physiological processes in the body. In the kidneys, soluble and membrane-associated CAs and their synergy with acid-base transporters play important roles in urinary acid secretion, the largest component of which is the reabsorption of HCO3- in specific nephron segments. Among these transporters are the Na+-coupled HCO3- transporters (NCBTs) and the Cl--HCO3- exchangers (AEs)-members of the "solute-linked carrier" 4 (SLC4) family. All of these transporters have traditionally been regarded as "HCO3-" transporters. However, recently our group has demonstrated that two of the NCBTs carry CO32- rather than HCO3- and has hypothesized that all NCBTs follow suit. In this review, we examine current knowledge on the role of CAs and "HCO3-" transporters of the SLC4 family in renal acid-base physiology and discuss how our recent findings impact renal acid secretion, including HCO3- reabsorption. Traditionally, investigators have associated CAs with producing or consuming solutes (CO2, HCO3-, and H+) and thus ensuring their efficient transport across cell membranes. In the case of CO32- transport by NCBTs, however, we hypothesize that the role of membrane-associated CAs is not the appreciable production or consumption of substrates but the minimization of pH changes in nanodomains near the membrane.
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8
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Aquaporins Display a Diversity in their Substrates. J Membr Biol 2023; 256:1-23. [PMID: 35986775 DOI: 10.1007/s00232-022-00257-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 07/13/2022] [Indexed: 02/07/2023]
Abstract
Aquaporins constitute a family of transmembrane proteins that function to transport water and other small solutes across the cell membrane. Aquaporins family members are found in diverse life forms. Aquaporins share the common structural fold consisting of six transmembrane alpha helices with a central water-transporting channel. Four such monomers assemble together to form tetramers as their biological unit. Initially, aquaporins were discovered as water-transporting channels, but several studies supported their involvement in mediating the facilitated diffusion of different solutes. The so-called water channel is able to transport a variety of substrates ranging from a neutral molecule to a charged molecule or a small molecule to a bulky molecule or even a gas molecule. This article gives an overview of a diverse range of substrates conducted by aquaporin family members. Prime focus is on human aquaporins where aquaporins show a wide tissue distribution and substrate specificity leading to various physiological functions. This review also highlights the structural mechanisms leading to the transport of water and glycerol. More research is needed to understand how one common fold enables the aquaporins to transport an array of solutes.
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9
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Krueger LA, Koester LR, Jones DF, Spangler DA. Carbon dioxide equivalent emissions from corn silage fermentation. Front Microbiol 2023; 13:1092315. [PMID: 36699579 PMCID: PMC9869070 DOI: 10.3389/fmicb.2022.1092315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 12/06/2022] [Indexed: 01/12/2023] Open
Abstract
The European Climate Law recently codified the goal for European climate neutrality by 2050, highlighting the need for sustainable farming practices within a robust and transparent carbon dioxide equivalent (CO2e) accounting system. In the present study, a series of equations were proposed for the estimation of CO2e emissions from corn silage fermentation. Systematic review of previous meta-analyses of corn silage fermentation identified the mean and standard deviation statistics for key model inputs of acetic acid, ethanol, lactic acid, ammonia, and volatile-corrected dry matter loss. Estimates of CO2e emissions were determined for a mock dataset comprising 1,000 iterations of randomly-generated values for each metric in accordance with mean and variance statistics of the source data. Estimates for CO2e emissions of corn silage based on meta-analysis review of laboratory experiments were 1.9 ± 5.6% (GWP20) and 0.2 ± 5.5% (GWP100) of silage dry matter. Furthermore, model results demonstrated a precedent for CO2 recycling by silage microorganisms, which was supported by genome annotation of strains belonging to common silage species. Linear model equations for GWP20 and GWP100 with inputs and outputs in mg kg-1 silage dry matter were developed, where inputs are acetic acid (A), ethanol (E), lactic acid (L), and volatile corrected dry matter loss (DV). Linear equations are (for GWP20; Eq. 11): GWP 20 = - 3626.1 - 0.04343 A + 0.8011 E - 0.03173 L + 1.46573 D V and for GWP100; Eq. 12: GWP 100 = - 8526.10 - 0.22403 A - 0.11963 E - 0.03173 L + 1.46573 D V . .
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Affiliation(s)
- Lucas A Krueger
- Department of Research, Development, and Biotechnology, Agri-King, Inc., Fulton, IL, United States
| | - Lucas R Koester
- Department of Research, Development, and Biotechnology, Agri-King, Inc., Fulton, IL, United States
| | - David F Jones
- Department of Research, Development, and Biotechnology, Agri-King, Inc., Fulton, IL, United States
| | - David A Spangler
- Department of Research, Development, and Biotechnology, Agri-King, Inc., Fulton, IL, United States
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10
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Al-Samir S, Yildirim AÖ, Sidhaye VK, King LS, Breves G, Conlon TM, Stoeger C, Gailus-Durner V, Fuchs H, Hrabé de Angelis M, Gros G, Endeward V. Aqp5 -/- mice exhibit reduced maximal body O 2 consumption under cold exposure, normal pulmonary gas exchange, and impaired formation of brown adipose tissue. Am J Physiol Regul Integr Comp Physiol 2023; 324:R109-R119. [PMID: 36409022 DOI: 10.1152/ajpregu.00130.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The fundamental body functions that determine maximal O2 uptake (V̇o2max) have not been studied in Aqp5-/- mice (aquaporin 5, AQP5). We measured V̇o2max to globally assess these functions and then investigated why it was found altered in Aqp5-/- mice. V̇o2max was measured by the Helox technique, which elicits maximal metabolic rate by intense cold exposure of the animals. We found V̇o2max reduced in Aqp5-/- mice by 20%-30% compared with wild-type (WT) mice. As AQP5 has been implicated to act as a membrane channel for respiratory gases, we studied whether this is caused by the known lack of AQP5 in the alveolar epithelial membranes of Aqp5-/- mice. Lung function parameters as well as arterial O2 saturation were normal and identical between Aqp5-/- and WT mice, indicating that AQP5 does not contribute to pulmonary O2 exchange. The cause for the decreased V̇o2max thus might be found in decreased O2 consumption of an intensely O2-consuming peripheral organ such as activated brown adipose tissue (BAT). We found indeed that absence of AQP5 greatly reduces the amount of interscapular BAT formed in response to 4 wk of cold exposure, from 63% in WT to 25% in Aqp5-/- animals. We conclude that lack of AQP5 does not affect pulmonary O2 exchange, but greatly inhibits transformation of white to brown adipose tissue. As under cold exposure, BAT is a major source of the animals' heat production, reduction of BAT likely causes the decrease in V̇o2max under this condition.
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Affiliation(s)
- Samer Al-Samir
- Zentrum Physiologie, AG Vegetative Physiologie, Medizinische Hochschule, Hannover, Germany
| | - Ali Önder Yildirim
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), München, Germany
| | - Venkataramana K Sidhaye
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Landon S King
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Gerhard Breves
- Institut für Physiologie und Zellbiologie, Tierärztliche Hochschule Hannover, Hannover, Germany
| | - Thomas M Conlon
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), München, Germany
| | - Claudia Stoeger
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, GmbH, Neuherberg, Germany
| | - Valerie Gailus-Durner
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, GmbH, Neuherberg, Germany
| | - Helmut Fuchs
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, GmbH, Neuherberg, Germany
| | - Martin Hrabé de Angelis
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health, GmbH, Neuherberg, Germany.,German Center for Diabetes Research, Neuherberg, Germany.,Chair of Experimental Genetics, Technische Universität München School of Life Sciences, Technische Universität München, Freising, Germany
| | - Gerolf Gros
- Zentrum Physiologie, AG Vegetative Physiologie, Medizinische Hochschule, Hannover, Germany
| | - Volker Endeward
- Zentrum Physiologie, AG Vegetative Physiologie, Medizinische Hochschule, Hannover, Germany
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11
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Xu L, Guo X, Wang W, Li C. Classification and Gene Structure of Aquaporins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1398:1-13. [PMID: 36717483 DOI: 10.1007/978-981-19-7415-1_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Aquaporins (AQPs) are a family of membrane water channels that basically function as regulators of intracellular and intercellular water flow. To date, 13 AQPs, distributed widely in specific cell types in various organs and tissues, have been characterized in humans. A pair of NPA boxes forming a pore is highly conserved among all aquaporins and is also key residues for the classification of AQP superfamily into four groups according to primary sequences. AQPs may also be classified based on their transport properties. So far, chromosome localization and gene structure of 13 human AQPs have been identified, which is definitely helpful for studying phenotypes and potential targets in naturally occurring and synthetic mutations in human or cells.
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Affiliation(s)
- Long Xu
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Xiangdong Guo
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Weidong Wang
- Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.
| | - Chunling Li
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.
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12
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Lee J, Chung JO, Park SY, Rajamohan N, Singh A, Kim J, Lowe VJ, Lee S. Natural COA water inhibits mitochondrial ROS-mediated apoptosis through Plk3 downregulation under STZ diabetic stress in pancreatic β-cell lines. Biochem Biophys Rep 2022; 30:101247. [PMID: 35300109 PMCID: PMC8921297 DOI: 10.1016/j.bbrep.2022.101247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 03/05/2022] [Accepted: 03/07/2022] [Indexed: 01/04/2023] Open
Abstract
Diabetes from pancreatic β cell death and insulin resistance is a serious metabolic disease in the world. Although the overproduction of mitochondrial reactive oxygen species (ROS) plays an important role in the pathogenesis of diabetes, its specific molecular mechanism remains unclear. Here, we show that the natural Charisma of Aqua (COA) water plays a role in Streptozotocin (STZ) diabetic stress-induced cell death inhibition. STZ induces mitochondrial ROS by increasing Polo-like kinase 3 (Plk3), a major mitotic regulator, in both Beta TC-6 and Beta TC-tet mouse islet cells and leads to apoptosis. Overexpression of Plk3 regulates an increase in mitochondrial ROS as well as cell death, also these events were inhibited by Plk3 gene knockdown in STZ diabetic stimulated-Beta TC-6 cells. Interestingly, we found that natural COA water blocks mitochondrial ROS generation through the reduction of Plk3 and prevents apoptosis in STZ-treated beta cells. Furthermore, using the 3D organoid (ex vivo) system, we confirmed that the insulin secretion of the supernatant medium under STZ treated pancreatic β-cells is protected by the natural COA water. These findings demonstrate that the natural water COA has a beneficial role in maintaining β cell function through the inhibition of mitochondrial ROS-mediated cell death, and it might be introduced as a potential insulin stabilizer. Pancreatic β cell is stabilized through natural COA water in STZ-induced diabetes. Mitochondrial membrane potential (ΔΨm) is controlled by natural COA water. Plk3 expression under STZ treatment is negatively regulated by natural COA water. Insulin secretion is stabilized by natural COA water under STZ treatment in ex vivo (3D organoid) model.
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Affiliation(s)
- Jeyeon Lee
- Division of Radiology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Jin Ook Chung
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, 501757, Republic of Korea
| | - Seon-Young Park
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, 501757, Republic of Korea
| | | | - Aparna Singh
- Division of Radiology, Mayo Clinic, Rochester, MN, 55905, USA
| | - JungJin Kim
- Division of Radiology, Mayo Clinic, Rochester, MN, 55905, USA
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA
- Corresponding author. Division of Radiology, Mayo Clinic, Rochester, MN, 55905, USA.
| | - Val J. Lowe
- Division of Radiology, Mayo Clinic, Rochester, MN, 55905, USA
- Corresponding author.
| | - SeungBaek Lee
- Division of Radiology, Mayo Clinic, Rochester, MN, 55905, USA
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA
- Corresponding author. Division of Radiology, Mayo Clinic, Rochester, MN, 55905, USA.
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13
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Bocchinfuso A, Calvetti D, Somersalo E. Modeling surface pH measurements of oocytes. Biomed Phys Eng Express 2022; 8. [PMID: 35594846 DOI: 10.1088/2057-1976/ac71d0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 05/20/2022] [Indexed: 11/11/2022]
Abstract
The transport of gases across cell membranes plays a key role in many different cell functions, from cell respiration to pH control. Mathematical models play a central role in understanding the factors affecting gas transport through membranes, and are the tool needed for testing the novel hypothesis of the preferential crossing through specific gas channels. Since the surface pH of cell membrane is regulated by the transport of gases such as CO2and NH3, inferring the membrane properties can be done indirectly from pH measurements. Numerical simulations based on recent models of the surface pH support the hypothesis that the presence of a measurement device, a liquid-membrane pH sensitive electrode on the cell surface may disturb locally the pH, leading to a systematic bias in the measured values. To take this phenomenon into account, it is necessary to equip the model with a description of the micro-environment created by the pH electrode. In this work we propose a novel, computationally lightweight numerical algorithm to simulate the surface pH data. The effect of different parameters of the model on the output are investigated through a series of numerical experiments with a physical interpretation.
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Affiliation(s)
- A Bocchinfuso
- Department of Mathematics, Applied Mathematics, and Statistics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States of America
| | - D Calvetti
- Department of Mathematics, Applied Mathematics, and Statistics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States of America
| | - E Somersalo
- Department of Mathematics, Applied Mathematics, and Statistics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, United States of America
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14
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Clarke VC, De Rosa A, Massey B, George AM, Evans JR, von Caemmerer S, Groszmann M. Mesophyll conductance is unaffected by expression of Arabidopsis PIP1 aquaporins in the plasmalemma of Nicotiana. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:3625-3636. [PMID: 35184158 PMCID: PMC9162178 DOI: 10.1093/jxb/erac065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 02/18/2022] [Indexed: 05/22/2023]
Abstract
In plants with C3 photosynthesis, increasing the diffusion conductance for CO2 from the substomatal cavity to chloroplast stroma (mesophyll conductance) can improve the efficiencies of both CO2 assimilation and photosynthetic water use. In the diffusion pathway from substomatal cavity to chloroplast stroma, the plasmalemma and chloroplast envelope membranes impose a considerable barrier to CO2 diffusion, limiting photosynthetic efficiency. In an attempt to improve membrane permeability to CO2, and increase photosynthesis in tobacco, we generated transgenic lines in Nicotiana tabacum L. cv Petite Havana carrying either the Arabidopsis PIP1;2 (AtPIP1;2) or PIP1;4 (AtPIP1;4) gene driven by the constitutive dual 2x35S CMV promoter. From a collection of independent T0 transgenics, two T2 lines from each gene were characterized, with western blots confirming increased total aquaporin protein abundance in the AtPIP1;2 tobacco lines. Transient expression of AtPIP1;2-mGFP6 and AtPIP1;4-mGFP6 fusions in Nicotiana benthamiana identified that both AtPIP1;2 and AtPIP1;4 localize to the plasmalemma. Despite achieving ectopic production and correct localization, gas exchange measurements combined with carbon isotope discrimination measurements detected no increase in mesophyll conductance or CO2 assimilation rate in the tobacco lines expressing AtPIP. We discuss the complexities associated with trying to enhance gm through modified aquaporin activity.
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Affiliation(s)
- Victoria C Clarke
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, Australian Capital Territory 2601, Australia
| | - Annamaria De Rosa
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, Australian Capital Territory 2601, Australia
| | - Baxter Massey
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, Australian Capital Territory 2601, Australia
| | - Aleu Mani George
- Division of Plant Sciences, Research School of Biology, The Australian National University, Acton, Australian Capital Territory 2601, Australia
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15
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Tricarico PM, Mentino D, De Marco A, Del Vecchio C, Garra S, Cazzato G, Foti C, Crovella S, Calamita G. Aquaporins Are One of the Critical Factors in the Disruption of the Skin Barrier in Inflammatory Skin Diseases. Int J Mol Sci 2022; 23:4020. [PMID: 35409378 PMCID: PMC8999368 DOI: 10.3390/ijms23074020] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/01/2022] [Accepted: 04/02/2022] [Indexed: 02/05/2023] Open
Abstract
The skin is the largest organ of the human body, serving as an effective mechanical barrier between the internal milieu and the external environment. The skin is widely considered the first-line defence of the body, with an essential function in rejecting pathogens and preventing mechanical, chemical, and physical damages. Keratinocytes are the predominant cells of the outer skin layer, the epidermis, which acts as a mechanical and water-permeability barrier. The epidermis is a permanently renewed tissue where undifferentiated keratinocytes located at the basal layer proliferate and migrate to the overlying layers. During this migration process, keratinocytes undertake a differentiation program known as keratinization process. Dysregulation of this differentiation process can result in a series of skin disorders. In this context, aquaporins (AQPs), a family of membrane channel proteins allowing the movement of water and small neutral solutes, are emerging as important players in skin physiology and skin diseases. Here, we review the role of AQPs in skin keratinization, hydration, keratinocytes proliferation, water retention, barrier repair, wound healing, and immune response activation. We also discuss the dysregulated involvement of AQPs in some common inflammatory dermatological diseases characterised by skin barrier disruption.
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Affiliation(s)
- Paola Maura Tricarico
- Institute for Maternal and Child Health IRCCS Burlo Garofolo, Via dell’Istria 65/1, 34137 Trieste, Italy;
| | - Donatella Mentino
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari “Aldo Moro”, Via E. Orabona, 4, 70125 Bari, Italy; (D.M.); (S.G.)
| | - Aurora De Marco
- Section of Dermatology, Department of Biomedical Sciences and Human Oncology, University of Bari “Aldo Moro”, Piazza Giulio Cesare, 11, 70121 Bari, Italy;
| | - Cecilia Del Vecchio
- Dermatology Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy;
| | - Sabino Garra
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari “Aldo Moro”, Via E. Orabona, 4, 70125 Bari, Italy; (D.M.); (S.G.)
| | - Gerardo Cazzato
- Section of Pathology, Department of Emergency and Organ Transplantation (DETO), University of Bari “Aldo Moro”, Piazza Giulio Cesare 11, 70121 Bari, Italy;
| | - Caterina Foti
- Section of Dermatology, Department of Biomedical Science and Human Oncology, University of Bari “Aldo Moro”, Piazza Giulio Cesare, 11, 70121 Bari, Italy;
| | - Sergio Crovella
- Biological Science Program, Department of Biological and Environmental Sciences, College of Arts and Sciences, University of Qatar, Doha 2713, Qatar;
| | - Giuseppe Calamita
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari “Aldo Moro”, Via E. Orabona, 4, 70125 Bari, Italy; (D.M.); (S.G.)
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16
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Zhang M, Shi H, Li N, Wei N, Tian Y, Peng J, Chen X, Zhang L, Zhang M, Dong H. Aquaporin OsPIP2;2 links the H2O2 signal and a membrane-anchored transcription factor to promote plant defense. PLANT PHYSIOLOGY 2022; 188:2325-2341. [PMID: 34958388 PMCID: PMC8968290 DOI: 10.1093/plphys/kiab604] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 11/19/2021] [Indexed: 06/14/2023]
Abstract
To overcome pathogen infection, plants deploy a highly efficient innate immune system, which often uses hydrogen peroxide (H2O2), a versatile reactive oxygen species, to activate downstream defense responses. H2O2 is a potential substrate of aquaporins (AQPs), the membrane channels that facilitate the transport of small compounds across plasma membranes or organelle membranes. To date, however, the functional relationship between AQPs and H2O2 in plant immunity is largely undissected. Here, we report that the rice (Oryza sativa) AQP OsPIP2;2 transports pathogen-induced apoplastic H2O2 into the cytoplasm to intensify rice resistance against various pathogens. OsPIP2;2-transported H2O2 is required for microbial molecular pattern flg22 to activate the MAPK cascade and to induce the downstream defense responses. In response to flg22, OsPIP2;2 is phosphorylated at the serine residue S125, and therefore gains the ability to transport H2O2. Phosphorylated OsPIP2;2 also triggers the translocation of OsmaMYB, a membrane-anchored MYB transcription factor, into the plant cell nucleus to impart flg22-induced defense responses against pathogen infection. On the contrary, if OsPIP2;2 is not phosphorylated, OsmaMYB remains associated with the plasma membrane, and plant defense responses are no longer induced. These results suggest that OsPIP2;2 positively regulates plant innate immunity by mediating H2O2 transport into the plant cell and mediating the translocation of OsmaMYB from plasma membrane to nucleus.
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Affiliation(s)
- Mou Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Haotian Shi
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Ningning Li
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Nana Wei
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Yan Tian
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Jinfeng Peng
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Xiaochen Chen
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Liyuan Zhang
- National Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, China
- Department of Plant Pathology, Shandong Agricultural University, Taian, China
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17
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Drechsel V, Schneebauer G, Fiechtner B, Cutler CP, Pelster B. Aquaporin expression and cholesterol content in eel swimbladder tissue. JOURNAL OF FISH BIOLOGY 2022; 100:609-618. [PMID: 34882794 PMCID: PMC9302985 DOI: 10.1111/jfb.14973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 05/08/2023]
Abstract
Leakiness of the swimbladder wall of teleost fishes must be prevented to avoid diffusional loss of gases out of the swimbladder. Guanine incrustation as well as high concentrations of cholesterol in swimbladder membranes in midwater and deep-sea fish has been connected to a reduced gas permeability of the swimbladder wall. On the contrary, the swimbladder is filled by diffusion of gases, mainly oxygen and CO2 , from the blood and the gas gland cells into the swimbladder lumen. In swimbladder tissue of the zebrafish and the Japanese eel, aquaporin mRNA has been detected, and the aquaporin protein has been considered important for the diffusion of water, which may accidentally be gulped by physostome fish when taking an air breath. In the present study, the expression of two aquaporin 1 genes (Aqp1aa and Aqp1ab) in the swimbladder tissue of the European eel, a functional physoclist fish, was assessed using immunohistochemistry, and the expression of both genes was detected in endothelial cells of swimbladder capillaries as well as in basolateral membranes of gas gland cells. In addition, Aqp1ab was present in apical membranes of swimbladder gas gland cells. The authors also found high concentrations of cholesterol in these membranes, which were several fold higher than in muscle tissue membranes. In yellow eels the cholesterol concentration exceeded the concentration detected in silver eel swimbladder membranes. The authors suggest that aquaporin 1 in swimbladder gas gland cells and endothelial cells facilitates CO2 diffusion into the blood, enhancing the switch-on of the Root effect, which is essential for the secretion of oxygen into the swimbladder. It may also facilitate CO2 diffusion into the swimbladder lumen along the partial gradient established by CO2 production in gas gland cells. Cholesterol has been shown to reduce the gas permeability of membranes and thus could contribute to the gas tightness of swimbladder membranes, which is essential to avoid diffusional loss of gas out of the swimbladder.
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Affiliation(s)
- Victoria Drechsel
- Institute of ZoologyUniversity of InnsbruckInnsbruckAustria
- Center for Molecular BiosciencesUniversity of InnsbruckInnsbruckAustria
| | - Gabriel Schneebauer
- Institute of ZoologyUniversity of InnsbruckInnsbruckAustria
- Center for Molecular BiosciencesUniversity of InnsbruckInnsbruckAustria
| | - Birgit Fiechtner
- Institute of ZoologyUniversity of InnsbruckInnsbruckAustria
- Center for Molecular BiosciencesUniversity of InnsbruckInnsbruckAustria
| | | | - Bernd Pelster
- Institute of ZoologyUniversity of InnsbruckInnsbruckAustria
- Center for Molecular BiosciencesUniversity of InnsbruckInnsbruckAustria
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18
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Szczygielski J, Kopańska M, Wysocka A, Oertel J. Cerebral Microcirculation, Perivascular Unit, and Glymphatic System: Role of Aquaporin-4 as the Gatekeeper for Water Homeostasis. Front Neurol 2021; 12:767470. [PMID: 34966347 PMCID: PMC8710539 DOI: 10.3389/fneur.2021.767470] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 11/12/2021] [Indexed: 12/13/2022] Open
Abstract
In the past, water homeostasis of the brain was understood as a certain quantitative equilibrium of water content between intravascular, interstitial, and intracellular spaces governed mostly by hydrostatic effects i.e., strictly by physical laws. The recent achievements in molecular bioscience have led to substantial changes in this regard. Some new concepts elaborate the idea that all compartments involved in cerebral fluid homeostasis create a functional continuum with an active and precise regulation of fluid exchange between them rather than only serving as separate fluid receptacles with mere passive diffusion mechanisms, based on hydrostatic pressure. According to these concepts, aquaporin-4 (AQP4) plays the central role in cerebral fluid homeostasis, acting as a water channel protein. The AQP4 not only enables water permeability through the blood-brain barrier but also regulates water exchange between perivascular spaces and the rest of the glymphatic system, described as pan-cerebral fluid pathway interlacing macroscopic cerebrospinal fluid (CSF) spaces with the interstitial fluid of brain tissue. With regards to this, AQP4 makes water shift strongly dependent on active processes including changes in cerebral microcirculation and autoregulation of brain vessels capacity. In this paper, the role of the AQP4 as the gatekeeper, regulating the water exchange between intracellular space, glymphatic system (including the so-called neurovascular units), and intravascular compartment is reviewed. In addition, the new concepts of brain edema as a misbalance in water homeostasis are critically appraised based on the newly described role of AQP4 for fluid permeation. Finally, the relevance of these hypotheses for clinical conditions (including brain trauma and stroke) and for both new and old therapy concepts are analyzed.
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Affiliation(s)
- Jacek Szczygielski
- Department of Neurosurgery, Institute of Medical Sciences, University of Rzeszów, Rzeszów, Poland.,Department of Neurosurgery, Faculty of Medicine and Saarland University Medical Center, Saarland University, Homburg, Germany
| | - Marta Kopańska
- Department of Pathophysiology, Institute of Medical Sciences, University of Rzeszów, Rzeszów, Poland
| | - Anna Wysocka
- Chair of Internal Medicine and Department of Internal Medicine in Nursing, Faculty of Health Sciences, Medical University of Lublin, Lublin, Poland
| | - Joachim Oertel
- Department of Neurosurgery, Faculty of Medicine and Saarland University Medical Center, Saarland University, Homburg, Germany
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19
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Aref M, Ranjbari E, García-Guzmán JJ, Hu K, Lork A, Crespo GA, Ewing AG, Cuartero M. Potentiometric pH Nanosensor for Intracellular Measurements: Real-Time and Continuous Assessment of Local Gradients. Anal Chem 2021; 93:15744-15751. [PMID: 34783529 PMCID: PMC8637545 DOI: 10.1021/acs.analchem.1c03874] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
![]()
We present a pH nanosensor
conceived for single intracellular measurements.
The sensing architecture consisted of a two-electrode system evaluated
in the potentiometric mode. We used solid-contact carbon nanopipette
electrodes tailored to produce both the indicator (pH nanosensor)
and reference electrodes. The indicator electrode was a membrane-based
ion-selective electrode containing a receptor for hydrogen ions that
provided a favorable selectivity for intracellular measurements. The
analytical features of the pH nanosensor revealed a Nernstian response
(slope of −59.5 mV/pH unit) with appropriate repeatability
and reproducibility (variation coefficients of <2% for the calibration
parameters), a fast response time (<5 s), adequate medium-term
drift (0.7 mV h–1), and a linear range of response
including physiological and abnormal cell pH levels (6.0–8.5).
In addition, the position and configuration of the reference electrode
were investigated in cell-based experiments to provide unbiased pH
measurements, in which both the indicator and reference electrodes
were located inside the same cell, each of them inside two neighboring
cells, or the indicator electrode inside the cell and the reference
electrode outside of (but nearby) the studied cell. Finally, the pH
nanosensor was applied to two cases: (i) the tracing of the pH gradient
from extra-to intracellular media over insertion into a single PC12
cell and (ii) the monitoring of variations in intracellular pH in
response to exogenous administration of pharmaceuticals. It is anticipated
that the developed pH nanosensor, which is a label-free analytical
tool, has high potential to aid in the investigation of pathological
states that manifest in cell pH misregulation, with no restriction
in the type of targeted cells.
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Affiliation(s)
- Mohaddeseh Aref
- Department of Chemistry, School of Engineering Science in Chemistry, Biochemistry and Health, Royal Institute of Technology, KTH, Stockholm SE-100 44, Sweden
| | - Elias Ranjbari
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, Gothenburg 41296, Sweden
| | - Juan José García-Guzmán
- Department of Chemistry, School of Engineering Science in Chemistry, Biochemistry and Health, Royal Institute of Technology, KTH, Stockholm SE-100 44, Sweden
| | - Keke Hu
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, Gothenburg 41296, Sweden
| | - Alicia Lork
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, Gothenburg 41296, Sweden
| | - Gaston A Crespo
- Department of Chemistry, School of Engineering Science in Chemistry, Biochemistry and Health, Royal Institute of Technology, KTH, Stockholm SE-100 44, Sweden
| | - Andrew G Ewing
- Department of Chemistry and Molecular Biology, University of Gothenburg, Kemivägen 10, Gothenburg 41296, Sweden
| | - Maria Cuartero
- Department of Chemistry, School of Engineering Science in Chemistry, Biochemistry and Health, Royal Institute of Technology, KTH, Stockholm SE-100 44, Sweden
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20
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Jennings ML. Cell Physiology and Molecular Mechanism of Anion Transport by Erythrocyte Band 3/AE1. Am J Physiol Cell Physiol 2021; 321:C1028-C1059. [PMID: 34669510 PMCID: PMC8714990 DOI: 10.1152/ajpcell.00275.2021] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The major transmembrane protein of the red blood cell, known as band 3, AE1, and SLC4A1, has two main functions: 1) catalysis of Cl-/HCO3- exchange, one of the steps in CO2 excretion; 2) anchoring the membrane skeleton. This review summarizes the 150 year history of research on red cell anion transport and band 3 as an experimental system for studying membrane protein structure and ion transport mechanisms. Important early findings were that red cell Cl- transport is a tightly coupled 1:1 exchange and band 3 is labeled by stilbenesulfonate derivatives that inhibit anion transport. Biochemical studies showed that the protein is dimeric or tetrameric (paired dimers) and that there is one stilbenedisulfonate binding site per subunit of the dimer. Transport kinetics and inhibitor characteristics supported the idea that the transporter acts by an alternating access mechanism with intrinsic asymmetry. The sequence of band 3 cDNA provided a framework for detailed study of protein topology and amino acid residues important for transport. The identification of genetic variants produced insights into the roles of band 3 in red cell abnormalities and distal renal tubular acidosis. The publication of the membrane domain crystal structure made it possible to propose concrete molecular models of transport. Future research directions include improving our understanding of the transport mechanism at the molecular level and of the integrative relationships among band 3, hemoglobin, carbonic anhydrase, and gradients (both transmembrane and subcellular) of HCO3-, Cl-, O2, CO2, pH, and NO metabolites during pulmonary and systemic capillary gas exchange.
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Affiliation(s)
- Michael L Jennings
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States
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21
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Molecular Mechanisms of Neuroimmune Crosstalk in the Pathogenesis of Stroke. Int J Mol Sci 2021; 22:ijms22179486. [PMID: 34502395 PMCID: PMC8431165 DOI: 10.3390/ijms22179486] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/26/2021] [Accepted: 08/28/2021] [Indexed: 12/21/2022] Open
Abstract
Stroke disrupts the homeostatic balance within the brain and is associated with a significant accumulation of necrotic cellular debris, fluid, and peripheral immune cells in the central nervous system (CNS). Additionally, cells, antigens, and other factors exit the brain into the periphery via damaged blood–brain barrier cells, glymphatic transport mechanisms, and lymphatic vessels, which dramatically influence the systemic immune response and lead to complex neuroimmune communication. As a result, the immunological response after stroke is a highly dynamic event that involves communication between multiple organ systems and cell types, with significant consequences on not only the initial stroke tissue injury but long-term recovery in the CNS. In this review, we discuss the complex immunological and physiological interactions that occur after stroke with a focus on how the peripheral immune system and CNS communicate to regulate post-stroke brain homeostasis. First, we discuss the post-stroke immune cascade across different contexts as well as homeostatic regulation within the brain. Then, we focus on the lymphatic vessels surrounding the brain and their ability to coordinate both immune response and fluid homeostasis within the brain after stroke. Finally, we discuss how therapeutic manipulation of peripheral systems may provide new mechanisms to treat stroke injury.
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22
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Al-Samir S, Prill M, Supuran CT, Gros G, Endeward V. CO 2 permeability of the rat erythrocyte membrane and its inhibition. J Enzyme Inhib Med Chem 2021; 36:1602-1606. [PMID: 34261373 PMCID: PMC8282279 DOI: 10.1080/14756366.2021.1952194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
We have studied the CO2 permeability of the erythrocyte membrane of the rat using a mass spectrometric method that employs 18 O-labelled CO2. The method yields, in addition, the intraerythrocytic carbonic anhydrase activity and the membrane HCO3- permeability. For normal rat erythrocytes, we find at 37 °C a CO2 permeability of 0.078 ± 0.015 cm/s, an intracellular carbonic anhydrase activity of 64,100, and a bicarbonate permeability of 2.1 × 10-3 cm/s. We studied whether the rat erythrocyte membrane possesses protein CO2 channels similar to the human red cell membrane by applying the potential CO2 channel inhibitors pCMBS, Dibac, phloretin, and DIDS. Phloretin and DIDS were able to reduce the CO2 permeability by up to 50%. Since these effects cannot be attributed to the lipid part of the membrane, we conclude that the rat erythrocyte membrane is equipped with protein CO2 channels that are responsible for at least 50% of its CO2 permeability.
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Affiliation(s)
- Samer Al-Samir
- AG Vegetative Physiologie 4220, Zentrum Physiologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Maximilian Prill
- AG Vegetative Physiologie 4220, Zentrum Physiologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Claudiu T Supuran
- Neurofarba Department, Section of Pharmaceutical and Nutritional Sciences, University of Florence, Florence, Italy
| | - Gerolf Gros
- AG Vegetative Physiologie 4220, Zentrum Physiologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Volker Endeward
- AG Vegetative Physiologie 4220, Zentrum Physiologie, Medizinische Hochschule Hannover, Hannover, Germany
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Coskun D, Deshmukh R, Shivaraj SM, Isenring P, Bélanger RR. Lsi2: A black box in plant silicon transport. PLANT AND SOIL 2021; 466:1-20. [PMID: 34720209 PMCID: PMC8550040 DOI: 10.1007/s11104-021-05061-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 06/22/2021] [Indexed: 05/12/2023]
Abstract
BACKGROUND Silicon (Si) is widely considered a non-essential but beneficial element for higher plants, providing broad protection against various environmental stresses (both biotic and abiotic), particularly in species that can readily absorb the element. Two plasma-membrane proteins are known to coordinate the radial transport of Si (in the form of Si(OH)4) from soil to xylem within roots: the influx channel Lsi1 and the efflux transporter Lsi2. From a structural and mechanistic perspective, much more is known about Lsi1 (a member of the NIP-III subgroup of the Major Intrinsic Proteins) compared to Lsi2 (a putative Si(OH)4/H+ antiporter, with some homology to bacterial anion transporters). SCOPE Here, we critically review the current state of understanding regarding the physiological role and molecular characteristics of Lsi2. We demonstrate that the structure-function relationship of Lsi2 is largely uncharted and that the standing transport model requires much better supportive evidence. We also provide (to our knowledge) the most current and extensive phylogenetic analysis of Lsi2 from all fully sequenced higher-plant genomes. We end by suggesting research directions and hypotheses to elucidate the properties of Lsi2. CONCLUSIONS Given that Lsi2 is proposed to mediate xylem Si loading and thus root-to-shoot translocation and biosilicification, it is imperative that the field of Si transport focus its efforts on a better understanding of this important topic. With this review, we aim to stimulate and advance research in the field of Si transport and thus better exploit Si to improve crop resilience and agricultural output. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s11104-021-05061-1.
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Affiliation(s)
- Devrim Coskun
- Département de Phytologie, Faculté Des Sciences de L’Agriculture Et de L’Alimentation (FSAA), Université Laval, Québec, Québec Canada
| | - Rupesh Deshmukh
- National Agri-Food Biotechnology Institute (NABI), Mohali, India
| | - S. M. Shivaraj
- National Agri-Food Biotechnology Institute (NABI), Mohali, India
- CSIR-National Chemical Laboratory, Pune, India
| | - Paul Isenring
- Département de Médecine, Faculté de Médecine, Université Laval, Québec, Québec Canada
| | - Richard R. Bélanger
- Département de Phytologie, Faculté Des Sciences de L’Agriculture Et de L’Alimentation (FSAA), Université Laval, Québec, Québec Canada
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24
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Soler DC, Kowatz T, Sloan AE, McCormick TS, Cooper KD, Stepanyan R, Engel A, Vahedi-Faridi A. A region within the third extracellular loop of rat Aquaporin 6 precludes trafficking to plasma membrane in a heterologous cell line. Sci Rep 2021; 11:13673. [PMID: 34211055 PMCID: PMC8249660 DOI: 10.1038/s41598-021-93117-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 05/31/2021] [Indexed: 11/09/2022] Open
Abstract
The inability to over-express Aquaporin 6 (AQP6) in the plasma membrane of heterologous cells has hampered efforts to further characterize the function of this aquaglyceroporin membrane protein at atomic detail using crystallographic approaches. Using an Aquaporin 3-tGFP Reporter (AGR) system we have identified a region within loop C of AQP6 that is responsible for severely hampering plasma membrane expression. Serine substitution corroborated that amino acids present within AQP6194–213 of AQP6 loop C contribute to intracellular endoplasmic reticulum (ER) retention. This intracellular retention signal may preclude proper plasma membrane trafficking and severely curtail expression of AQP6 in heterologous expression systems.
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Affiliation(s)
- D C Soler
- The Department of Neurosurgery, Case Western Reserve University, Cleveland, USA.
| | - T Kowatz
- Department of Physiology and Biophysics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106-4965, USA
| | - A E Sloan
- The Department of Neurosurgery, Case Western Reserve University, Cleveland, USA.,Brain Tumor and Neuro-Oncology Center, University Hospitals Cleveland Medical Center, Cleveland, USA
| | - T S McCormick
- Department of Dermatology, Case Western Reserve University, Cleveland, USA.,Murdough Family Center for Psoriasis, Case Western Reserve University, Cleveland, USA
| | - K D Cooper
- Department of Dermatology, Case Western Reserve University, Cleveland, USA.,Murdough Family Center for Psoriasis, Case Western Reserve University, Cleveland, USA
| | - R Stepanyan
- Department of Otolaryngology-HNS, Case Western Reserve University, Cleveland, USA.,Department of Neurosciences, Case Western Reserve University, Cleveland, USA
| | - A Engel
- Biozentrum, University of Basel, Basel, Switzerland
| | - A Vahedi-Faridi
- Department of Physiology and Biophysics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH, 44106-4965, USA
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25
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Kazokaitė-Adomaitienė J, Becker HM, Smirnovienė J, Dubois LJ, Matulis D. Experimental Approaches to Identify Selective Picomolar Inhibitors for Carbonic Anhydrase IX. Curr Med Chem 2021; 28:3361-3384. [PMID: 33138744 DOI: 10.2174/0929867327666201102112841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 08/14/2020] [Accepted: 08/16/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Carbonic anhydrases (CAs) regulate pH homeostasis via the reversible hydration of CO2, thereby emerging as essential enzymes for many vital functions. Among 12 catalytically active CA isoforms in humans, CA IX has become a relevant therapeutic target because of its role in cancer progression. Only two CA IX inhibitors have entered clinical trials, mostly due to low affinity and selectivity properties. OBJECTIVE The current review presents the design, development, and identification of the selective nano- to picomolar CA IX inhibitors VD11-4-2, VR16-09, and VD12-09. METHODS AND RESULTS Compounds were selected from our database, composed of over 400 benzensulfonamides, synthesized at our laboratory, and tested for their binding to 12 human CAs. Here we discuss the CA CO2 hydratase activity/inhibition assay and several biophysical techniques, such as fluorescent thermal shift assay and isothermal titration calorimetry, highlighting their contribution to the analysis of compound affinity and structure- activity relationships. To obtain sufficient amounts of recombinant CAs for inhibitor screening, several gene cloning and protein purification strategies are presented, including site-directed CA mutants, heterologous CAs from Xenopus oocytes, and native endogenous CAs. The cancer cell-based methods, such as clonogenicity, extracellular acidification, and mass spectrometric gas-analysis are reviewed, confirming nanomolar activities of lead inhibitors in intact cancer cells. CONCLUSIONS Novel CA IX inhibitors are promising derivatives for in vivo explorations. Furthermore, the simultaneous targeting of several proteins involved in proton flux upon tumor acidosis and the disruption of transport metabolons might improve cancer management.
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Affiliation(s)
- Justina Kazokaitė-Adomaitienė
- Department of Biothermodynamics and Drug Design, Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Holger M Becker
- Institute of Physiological Chemistry, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Joana Smirnovienė
- Department of Biothermodynamics and Drug Design, Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Ludwig J Dubois
- The M-Lab, Department of Precision Medicine, GROW - School for Oncology and Developmental Biology, Maastricht University, Netherlands
| | - Daumantas Matulis
- Department of Biothermodynamics and Drug Design, Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
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26
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Michenkova M, Taki S, Blosser MC, Hwang HJ, Kowatz T, Moss FJ, Occhipinti R, Qin X, Sen S, Shinn E, Wang D, Zeise BS, Zhao P, Malmstadt N, Vahedi-Faridi A, Tajkhorshid E, Boron WF. Carbon dioxide transport across membranes. Interface Focus 2021; 11:20200090. [PMID: 33633837 PMCID: PMC7898146 DOI: 10.1098/rsfs.2020.0090] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2021] [Indexed: 12/30/2022] Open
Abstract
Carbon dioxide (CO2) movement across cellular membranes is passive and governed by Fick's law of diffusion. Until recently, we believed that gases cross biological membranes exclusively by dissolving in and then diffusing through membrane lipid. However, the observation that some membranes are CO2 impermeable led to the discovery of a gas molecule moving through a channel; namely, CO2 diffusion through aquaporin-1 (AQP1). Later work demonstrated CO2 diffusion through rhesus (Rh) proteins and NH3 diffusion through both AQPs and Rh proteins. The tetrameric AQPs exhibit differential selectivity for CO2 versus NH3 versus H2O, reflecting physico-chemical differences among the small molecules as well as among the hydrophilic monomeric pores and hydrophobic central pores of various AQPs. Preliminary work suggests that NH3 moves through the monomeric pores of AQP1, whereas CO2 moves through both monomeric and central pores. Initial work on AQP5 indicates that it is possible to create a metal-binding site on the central pore's extracellular face, thereby blocking CO2 movement. The trimeric Rh proteins have monomers with hydrophilic pores surrounding a hydrophobic central pore. Preliminary work on the bacterial Rh homologue AmtB suggests that gas can diffuse through the central pore and three sets of interfacial clefts between monomers. Finally, initial work indicates that CO2 diffuses through the electrogenic Na/HCO3 cotransporter NBCe1. At least in some cells, CO2-permeable proteins could provide important pathways for transmembrane CO2 movements. Such pathways could be amenable to cellular regulation and could become valuable drug targets.
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Affiliation(s)
- Marie Michenkova
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Sara Taki
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Matthew C. Blosser
- Mork Family Department of Chemical Engineering & Materials Science, University of Southern California, Los Angeles, CA, USA
| | - Hyea J. Hwang
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Thomas Kowatz
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Fraser. J. Moss
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Rossana Occhipinti
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Xue Qin
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Soumyo Sen
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Eric Shinn
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Dengke Wang
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Brian S. Zeise
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Pan Zhao
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Noah Malmstadt
- Mork Family Department of Chemical Engineering & Materials Science, University of Southern California, Los Angeles, CA, USA
| | - Ardeschir Vahedi-Faridi
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Emad Tajkhorshid
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Walter F. Boron
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH, USA
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27
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Calamita G, Delporte C. Involvement of aquaglyceroporins in energy metabolism in health and disease. Biochimie 2021; 188:20-34. [PMID: 33689852 DOI: 10.1016/j.biochi.2021.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/23/2021] [Accepted: 03/01/2021] [Indexed: 11/27/2022]
Abstract
Aquaglyceroporins are a group of the aquaporin (AQP) family of transmembrane water channels. While AQPs facilitate the passage of water, small solutes, and gases across biological membranes, aquaglyceroporins allow passage of water, glycerol, urea and some other solutes. Thanks to their glycerol permeability, aquaglyceroporins are involved in energy homeostasis. This review provides an overview of what is currently known concerning the functional implication and control of aquaglyceroporins in tissues involved in energy metabolism, i.e. liver, adipose tissue and endocrine pancreas. The expression, role and (dys)regulation of aquaglyceroporins in disorders affecting energy metabolism, and the potential relevance of aquaglyceroporins as drug targets to treat the alterations of the energy balance is also addressed.
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Affiliation(s)
- Giuseppe Calamita
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari "Aldo Moro", Bari, Italy
| | - Christine Delporte
- Laboratory of Pathophysiological and Nutritional Biochemistry, Université Libre de Bruxelles, Brussels, Belgium.
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28
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Wang L, Huo D, Zhu H, Xu Q, Gao C, Chen W, Zhang Y. Deciphering the structure, function, expression and regulation of aquaporin-5 in cancer evolution. Oncol Lett 2021; 21:309. [PMID: 33732385 DOI: 10.3892/ol.2021.12571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 02/08/2021] [Indexed: 11/06/2022] Open
Abstract
In recent years, the morbidity rate resulting from numerous types of malignant tumor has increased annually, and the treatment of tumors has been attracting an increasing amount of attention. A number of recent studies have revealed that the water channel protein aquaporin-5 (AQP5) has become a major player in multiple types of cancer. AQP5 is abnormally expressed in a variety of tumor tissues or cells and has multiple effects on certain biological functions of tumors, such as regulating the proliferation, apoptosis and migration of tumor cells. It has been suggested that AQP5 may play an important role in the process of tumor development, opening up a new field of tumor research. The present review highlighted the structure of AQP5 and its role in tumor progression. Furthermore, the expression of AQP5 in different malignant neoplasms was summarized. In addition, the influence of not only drugs, but also different compounds on AQP5 were summarized. In conclusion, according to the findings in the present review, AQP5 has potential as a novel therapeutic target in human cancer, and other AQPs should be similarly investigated.
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Affiliation(s)
- Liping Wang
- Department of Oncology, Weifang People's Hospital, Weifang, Shandong 261000, P.R. China
| | - Da Huo
- Department of Oncology, Weifang People's Hospital, Weifang, Shandong 261000, P.R. China
| | - Haiyan Zhu
- Department of Oncology, Weifang People's Hospital, Weifang, Shandong 261000, P.R. China
| | - Qian Xu
- Department of Oncology, Weifang People's Hospital, Weifang, Shandong 261000, P.R. China
| | - Chengpeng Gao
- Department of Respiratory, Weifang People's Hospital, Weifang, Shandong 261000, P.R. China
| | - Wenfeng Chen
- Department of Science and Education, Weifang People's Hospital, Weifang, Shandong 261000, P.R. China
| | - Yixiang Zhang
- Department of Respiratory, Weifang People's Hospital, Weifang, Shandong 261000, P.R. China
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29
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Ablation of Aquaporin-9 Ameliorates the Systemic Inflammatory Response of LPS-Induced Endotoxic Shock in Mouse. Cells 2021; 10:cells10020435. [PMID: 33670755 PMCID: PMC7922179 DOI: 10.3390/cells10020435] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 02/14/2021] [Accepted: 02/15/2021] [Indexed: 12/12/2022] Open
Abstract
Septic shock is the most severe complication of sepsis, being characterized by a systemic inflammatory response following bacterial infection, leading to multiple organ failure and dramatically high mortality. Aquaporin-9 (AQP9), a membrane channel protein mainly expressed in hepatocytes and leukocytes, has been recently associated with inflammatory and infectious responses, thus triggering strong interest as a potential target for reducing septic shock-dependent mortality. Here, we evaluated whether AQP9 contributes to murine systemic inflammation during endotoxic shock. Wild type (Aqp9+/+; WT) and Aqp9 gene knockout (Aqp9−/−; KO) male mice were submitted to endotoxic shock by i.p. injection of lipopolysaccharide (LPS; 40 mg/kg) and the related survival times were followed during 72 h. The electronic paramagnetic resonance and confocal microscopy were employed to analyze the nitric oxide (NO) and superoxide anion (O2−) production, and the expression of inducible NO-synthase (iNOS) and cyclooxigenase-2 (COX-2), respectively, in the liver, kidney, aorta, heart and lung of the mouse specimens. LPS-treated KO mice survived significantly longer than corresponding WT mice, and 25% of the KO mice fully recovered from the endotoxin treatment. The LPS-injected KO mice showed lower inflammatory NO and O2− productions and reduced iNOS and COX-2 levels through impaired NF-κB p65 activation in the liver, kidney, aorta, and heart as compared to the LPS-treated WT mice. Consistent with these results, the treatment of FaO cells, a rodent hepatoma cell line, with the AQP9 blocker HTS13268 prevented the LPS-induced increase of inflammatory NO and O2−. A role for AQP9 is suggested in the early acute phase of LPS-induced endotoxic shock involving NF-κB signaling. The modulation of AQP9 expression/function may reveal to be useful in developing novel endotoxemia therapeutics.
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30
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Petersen LK, Christensen AB, Andersen J, Folkesson CG, Kristensen O, Andersen C, Alzu A, Sløk FA, Blakskjær P, Madsen D, Azevedo C, Micco I, Hansen NJV. Screening of DNA-Encoded Small Molecule Libraries inside a Living Cell. J Am Chem Soc 2021; 143:2751-2756. [DOI: 10.1021/jacs.0c09213] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Lars K. Petersen
- Vipergen ApS, Gammel Kongevej 23A, DK-1610 Copenhagen V, Denmark
| | | | - Jacob Andersen
- Vipergen ApS, Gammel Kongevej 23A, DK-1610 Copenhagen V, Denmark
| | | | - Ole Kristensen
- Vipergen ApS, Gammel Kongevej 23A, DK-1610 Copenhagen V, Denmark
| | | | - Amaya Alzu
- Vipergen ApS, Gammel Kongevej 23A, DK-1610 Copenhagen V, Denmark
| | - Frank A. Sløk
- Vipergen ApS, Gammel Kongevej 23A, DK-1610 Copenhagen V, Denmark
| | - Peter Blakskjær
- Vipergen ApS, Gammel Kongevej 23A, DK-1610 Copenhagen V, Denmark
| | - Daniel Madsen
- Vipergen ApS, Gammel Kongevej 23A, DK-1610 Copenhagen V, Denmark
| | - Carlos Azevedo
- Vipergen ApS, Gammel Kongevej 23A, DK-1610 Copenhagen V, Denmark
| | - Iolanda Micco
- Vipergen ApS, Gammel Kongevej 23A, DK-1610 Copenhagen V, Denmark
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31
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Schmidt JDR, Walloch P, Höger B, Beitz E. Aquaporins with lactate/lactic acid permeability at physiological pH conditions. Biochimie 2021; 188:7-11. [PMID: 33577940 DOI: 10.1016/j.biochi.2021.01.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 01/15/2021] [Accepted: 01/19/2021] [Indexed: 10/22/2022]
Abstract
The spectrum of putative and experimentally shown permeants of cellular water and solute channels of the ubiquitous aquaporin family is still increasing. Virtually all AQP substrates, e.g. water, glycerol, urea, hydrogen peroxide, or carbon dioxide, are permanently neutral small molecule compounds. Several reports, however, describe aquaporins that exhibit lactate permeability. Lactate in aqueous solution undergoes a pH-dependent protonation equilibrium with neutral lactic acid, which likely represents the actual substrate form passing the aquaporin channel. Certain aquaporins, however, appear to be better geared for lactate/lactic acid permeability even at low proton availability. Here, we discuss the structural properties of such aquaporins and compare them to the microbial protein family of the formate-nitrite (lactate) transporters that assume the aquaporin fold despite unrelated protein sequences.
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Affiliation(s)
- Jana D R Schmidt
- Department of Pharmaceutical and Medicinal Chemistry, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Philipp Walloch
- Department of Pharmaceutical and Medicinal Chemistry, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Bastian Höger
- Department of Pharmaceutical and Medicinal Chemistry, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Eric Beitz
- Department of Pharmaceutical and Medicinal Chemistry, Christian-Albrechts-University of Kiel, Kiel, Germany.
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32
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Targeting Aquaporins in Novel Therapies for Male and Female Breast and Reproductive Cancers. Cells 2021; 10:cells10020215. [PMID: 33499000 PMCID: PMC7911300 DOI: 10.3390/cells10020215] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/13/2021] [Accepted: 01/20/2021] [Indexed: 12/24/2022] Open
Abstract
Aquaporins are membrane channels in the broad family of major intrinsic proteins (MIPs), with 13 classes showing tissue-specific distributions in humans. As key physiological modulators of water and solute homeostasis, mutations, and dysfunctions involving aquaporins have been associated with pathologies in all major organs. Increases in aquaporin expression are associated with greater severity of many cancers, particularly in augmenting motility and invasiveness for example in colon cancers and glioblastoma. However, potential roles of altered aquaporin (AQP) function in reproductive cancers have been understudied to date. Published work reviewed here shows distinct classes aquaporin have differential roles in mediating cancer metastasis, angiogenesis, and resistance to apoptosis. Known mechanisms of action of AQPs in other tissues are proving relevant to understanding reproductive cancers. Emerging patterns show AQPs 1, 3, and 5 in particular are highly expressed in breast, endometrial, and ovarian cancers, consistent with their gene regulation by estrogen response elements, and AQPs 3 and 9 in particular are linked with prostate cancer. Continuing work is defining avenues for pharmacological targeting of aquaporins as potential therapies to reduce female and male reproductive cancer cell growth and invasiveness.
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33
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Al-Samir S, Itel F, Hegermann J, Gros G, Tsiavaliaris G, Endeward V. O 2 permeability of lipid bilayers is low, but increases with membrane cholesterol. Cell Mol Life Sci 2021; 78:7649-7662. [PMID: 34694438 PMCID: PMC8629883 DOI: 10.1007/s00018-021-03974-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 09/06/2021] [Accepted: 10/12/2021] [Indexed: 11/18/2022]
Abstract
Oxygen on its transport route from lung to tissue mitochondria has to cross several cell membranes. The permeability value of membranes for O2 (PO2), although of fundamental importance, is controversial. Previous studies by mostly indirect methods diverge between 0.6 and 125 cm/s. Here, we use a most direct approach by observing transmembrane O2 fluxes out of 100 nm liposomes at defined transmembrane O2 gradients in a stopped-flow system. Due to the small size of the liposomes intra- as well as extraliposomal diffusion processes do not affect the overall kinetics of the O2 release process. We find, for cholesterol-free liposomes, the unexpectedly low PO2 value of 0.03 cm/s at 35 °C. This PO2 would present a serious obstacle to O2 entering or leaving the erythrocyte. Cholesterol turns out to be a novel major modifier of PO2, able to increase PO2 by an order of magnitude. With a membrane cholesterol of 45 mol% as it occurs in erythrocytes, PO2 rises to 0.2 cm/s at 35 °C. This PO2 is just sufficient to ensure complete O2 loading during passage of erythrocytes through the lung's capillary bed under the conditions of rest as well as maximal exercise.
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Affiliation(s)
- Samer Al-Samir
- AG Vegetative Physiologie 4220, Zentrum Physiologie, Medizinische Hochschule Hannover, 30625, Hannover, Germany
| | - Fabian Itel
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstr. 5, CH-9014, St. Gallen, Switzerland
| | - Jan Hegermann
- Abteilung Funktionelle und Angewandte Anatomie, Elektronenmikroskopie 8840, Medizinische Hochschule Hannover, 30625, Hannover, Germany
| | - Gerolf Gros
- AG Vegetative Physiologie 4220, Zentrum Physiologie, Medizinische Hochschule Hannover, 30625, Hannover, Germany.
| | - Georgios Tsiavaliaris
- Abteilung Biophysikalische Chemie 4350, Medizinische Hochschule Hannover, 30625, Hannover, Germany
| | - Volker Endeward
- AG Vegetative Physiologie 4220, Zentrum Physiologie, Medizinische Hochschule Hannover, 30625, Hannover, Germany
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34
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Moss FJ, Boron WF. Carbonic anhydrases enhance activity of endogenous Na-H exchangers and not the electrogenic Na/HCO 3 cotransporter NBCe1-A, expressed in Xenopus oocytes. J Physiol 2020; 598:5821-5856. [PMID: 32969493 PMCID: PMC7747792 DOI: 10.1113/jp280143] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/07/2020] [Indexed: 12/16/2022] Open
Abstract
KEY POINTS According to the HCO 3 - metabolon hypothesis, direct association of cytosolic carbonic anhydrases (CAs) with the electrogenic Na/HCO3 cotransporter NBCe1-A speeds transport by regenerating/consuming HCO 3 - . The present work addresses published discrepancies as to whether cytosolic CAs stimulate NBCe1-A, heterologously expressed in Xenopus oocytes. We confirm the essential elements of the previous experimental observations, taken as support for the HCO 3 - metabolon hypothesis. However, using our own experimental protocols or those of others, we find that NBCe1-A function is unaffected by cytosolic CAs. Previous conclusions that cytosolic CAs do stimulate NBCe1-A can be explained by an unanticipated stimulatory effect of the CAs on an endogenous Na-H exchanger. Theoretical analyses show that, although CAs could stimulate non- HCO 3 - transporters (e.g. Na-H exchangers) by accelerating CO2 / HCO 3 - -mediated buffering of acid-base equivalents, they could not appreciably affect transport rates of NBCe1 or other transporters carrying HCO 3 - , CO 3 = , or NaCO 3 - ion pairs. ABSTRACT The HCO 3 - metabolon hypothesis predicts that cytosolic carbonic anhydrase (CA) binds to NBCe1-A, promotes HCO 3 - replenishment/consumption, and enhances transport. Using a short step-duration current-voltage (I-V) protocol with Xenopus oocytes expressing eGFP-tagged NBCe1-A, our group reported that neither injecting human CA II (hCA II) nor fusing hCA II to the NBCe1-A carboxy terminus affects background-subtracted NBCe1 slope conductance (GNBC ), which is a direct measure of NBCe1-A activity. Others - using bovine CA (bCA), untagged NBCe1-A, and protocols keeping holding potential (Vh ) far from NBCe1-A's reversal potential (Erev ) for prolonged periods - found that bCA increases total membrane current (ΔIm ), which apparently supports the metabolon hypothesis. We systematically investigated differences in the two protocols. In oocytes expressing untagged NBCe1-A, injected with bCA and clamped to -40 mV, CO2 / HCO 3 - exposures markedly decrease Erev , producing large transient outward currents persisting for >10 min and rapid increases in [Na+ ]i . Although the CA inhibitor ethoxzolamide (EZA) reduces both ΔIm and d[Na+ ]i /dt, it does not reduce GNBC . In oocytes not expressing NBCe1-A, CO2 / HCO 3 - triggers rapid increases in [Na+ ]i that both hCA II and bCA enhance in concentration-dependent manners. These d[Na+ ]i /dt increases are inhibited by EZA and blocked by EIPA, a Na-H exchanger (NHE) inhibitor. In oocytes expressing untagged NBCe1-A and injected with bCA, EIPA abolishes the EZA-dependent decreases in ΔIm and d[Na+ ]i /dt. Thus, CAs/EZA produce their ΔIm and d[Na+ ]i /dt effects not through NBCe1-A, but endogenous NHEs. Theoretical considerations argue against a CA stimulation of HCO 3 - transport, supporting the conclusion that an NBCe1-A- HCO 3 - metabolon does not exist in oocytes.
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Affiliation(s)
- Fraser J. Moss
- Department of Physiology and Biophysics, Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Walter F. Boron
- Department of Physiology and Biophysics, Western Reserve University School of Medicine, Cleveland, OH 44106, USA
- Department of Medicine and Department of Biochemistry Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
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Yadav E, Yadav N, Hus A, Yadav JS. Aquaporins in lung health and disease: Emerging roles, regulation, and clinical implications. Respir Med 2020; 174:106193. [PMID: 33096317 DOI: 10.1016/j.rmed.2020.106193] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 08/17/2020] [Accepted: 10/13/2020] [Indexed: 12/16/2022]
Abstract
Aquaporins (AQPs) aka water channels are a family of conserved transmembrane proteins (~30 kDa monomers) expressed in various organ systems. Of the 13 AQPs (AQP0 through AQP12) in the human body, four (AQPs 1, 3, 4, and 5) are expressed in the respiratory system. These channels are conventionally known for mediating transcellular fluid movements. Certain AQPs (aquaglyceroporins) have the capability to transport glycerol and potentially other solutes. There is an emerging body of literature unveiling the non-conventional roles of AQPs such as in cell proliferation and migration, gas permeation, signal potentiation, etc. Initial gene knock-out studies established a physiological role for lung AQPs, particularly AQP5, in maintaining homeostasis, by mediating fluid secretion from submucosal glands onto the airway surface liquid (ASL) lining. Subsequent studies have highlighted the functional significance of AQPs, particularly AQP1 and AQP5 in lung pathophysiology and diseases, including but not limited to chronic and acute lung injury, chronic obstructive pulmonary disease (COPD), other inflammatory lung conditions, and lung cancer. AQP1 has been suggested as a potential prognostic marker for malignant mesothelioma. Recent efforts are directed toward exploiting AQPs as targets for diagnosis, prevention, intervention, and/or treatment of various lung conditions. Emerging information on regulatory pathways and directed mechanistic research are posited to unravel novel strategies for these clinical implications. Future considerations should focus on development of AQP inhibitors, blockers, and modulators for therapeutic needs, and better understanding the role of lung-specific AQPs in inter-individual susceptibility to chronic lung diseases such as COPD and cancer.
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Affiliation(s)
- Ekta Yadav
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
| | - Niket Yadav
- Medical Scientist Training Program, University of Virginia School of Medicine, Charlottesville, VA, 22908-0738, USA
| | - Ariel Hus
- Department of Biology, University of Miami, Coral Gables, Florida, 33146, USA
| | - Jagjit S Yadav
- Department of Environmental and Public Health Sciences, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA.
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Blanco-Ameijeiras S, Stoll HM, Zhang H, Hopkinson BM. Influence of Temperature and CO 2 On Plasma-membrane Permeability to CO 2 and HCO 3- in the Marine Haptophytes Emiliania huxleyi and Calcidiscus leptoporus (Prymnesiophyceae). JOURNAL OF PHYCOLOGY 2020; 56:1283-1294. [PMID: 32418211 DOI: 10.1111/jpy.13017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/28/2020] [Indexed: 06/11/2023]
Abstract
Membrane permeabilities to CO2 and HCO3- constrain the function of CO2 concentrating mechanisms that algae use to supply inorganic carbon for photosynthesis. In diatoms and green algae, plasma membranes are moderately to highly permeable to CO2 but effectively impermeable to HCO3- . Here, CO2 and HCO3- membrane permeabilities were measured using an 18 O-exchange technique on two species of haptophyte algae, Emiliania huxleyi and Calcidiscus leptoporus, which showed that the plasma membranes of these species are also highly permeable to CO2 (0.006-0.02 cm · s-1 ) but minimally permeable to HCO3- . Increased temperature and CO2 generally increased CO2 membrane permeabilities in both species, possibly due to changes in lipid composition or CO2 channel proteins. Changes in CO2 membrane permeabilities showed no association with the density of calcium carbonate coccoliths surrounding the cell, which could potentially impede passage of compounds. Haptophyte plasma-membrane permeabilities to CO2 were somewhat lower than those of diatoms but generally higher than membrane permeabilities of green algae. One caveat of these measurements is that the model used to interpret 18 O-exchange data assumes that carbonic anhydrase, which catalyzes 18 O-exchange, is homogeneously distributed in the cell. The implications of this assumption were tested using a two-compartment model with an inhomogeneous distribution of carbonic anhydrase to simulate 18 O-exchange data and then inferring plasma-membrane CO2 permeabilities from the simulated data. This analysis showed that the inferred plasma-membrane CO2 permeabilities are minimal estimates but should be quite accurate under most conditions.
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Affiliation(s)
| | - Heather M Stoll
- Department of Earth Sciences, ETH Zurich, Sonnegstrasse 5, Zurich, 8092, Switzerland
| | - Hongrui Zhang
- Department of Earth Sciences, ETH Zurich, Sonnegstrasse 5, Zurich, 8092, Switzerland
- State Key Laboratory of Marine Geology, Tongji University, Shanghai, China
| | - Brian M Hopkinson
- Department of Marine Sciences, University of Georgia, Athens, Georgia, 30602, USA
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Ye M, Zhang Z, Huang G, Xiong Z, Peng S, Li Y. High leaf mass per area Oryza genotypes invest more leaf mass to cell wall and show a low mesophyll conductance. AOB PLANTS 2020; 12:plaa028. [PMID: 32765824 PMCID: PMC7396964 DOI: 10.1093/aobpla/plaa028] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 06/12/2020] [Indexed: 05/20/2023]
Abstract
The intraspecific variations of leaf structure and anatomy in rice leaves and their impacts on gas diffusion are still unknown. Researches about the tradeoff between structural compositions and intracellular chemical components within rice leaves are still lacking. The objectives of the present study were to investigate the varietal differences in leaf structure and leaf chemical compositions, and the tradeoff between leaf structural tissues and intracellular chemical components in rice leaves. Leaf structure, leaf anatomy, leaf chemical composition concentrations and gas exchange parameters were measured on eight Oryza sativa L. genotypes to investigate the intraspecific variations in leaf structure and leaf anatomy and their impacts on gas exchange parameters, and to study the tradeoff between leaf structural compositions (cell wall compounds) and intracellular chemical components (non-structural carbohydrates, nitrogen, chlorophyll). Leaf thickness increased with leaf mass per area (LMA), while leaf density did not correlate with LMA. Mesophyll cell surface area exposed to intercellular airspace (IAS) per leaf area, the surface area of chloroplasts exposed to IAS and cell wall thickness increased with LMA. Cell wall compounds accounted for 71.5 % of leaf dry mass, while mass-based nitrogen and chlorophyll concentrations decreased with LMA. Mesophyll conductance was negatively correlated with LMA and cell wall thickness. High LMA rice genotypes invest more leaf mass to cell wall and possess a low mesophyll conductance.
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Affiliation(s)
- Miao Ye
- Ministry of Agriculture Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Zhengcan Zhang
- Ministry of Agriculture Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Guanjun Huang
- Ministry of Agriculture Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Zhuang Xiong
- Ministry of Agriculture Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Shaobing Peng
- Ministry of Agriculture Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Yong Li
- Ministry of Agriculture Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, China
- Corresponding author’s e-mail address:
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Moss FJ, Mahinthichaichan P, Lodowski DT, Kowatz T, Tajkhorshid E, Engel A, Boron WF, Vahedi-Faridi A. Aquaporin-7: A Dynamic Aquaglyceroporin With Greater Water and Glycerol Permeability Than Its Bacterial Homolog GlpF. Front Physiol 2020; 11:728. [PMID: 32695023 PMCID: PMC7339978 DOI: 10.3389/fphys.2020.00728] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 06/04/2020] [Indexed: 12/27/2022] Open
Abstract
Xenopus oocytes expressing human aquaporin-7 (AQP7) exhibit greater osmotic water permeability and 3H-glycerol uptake vs. those expressing the bacterial glycerol facilitator GlpF. AQP7-expressing oocytes exposed to increasing extracellular [glycerol] under isosmolal conditions exhibit increasing swelling rates, whereas GlpF-expressing oocytes do not swell at all. To provide a structural basis for these observed physiological differences, we performed X-ray crystallographic structure determination of AQP7 and molecular-dynamics simulations on AQP7 and GlpF. The structure reveals AQP7 tetramers containing two monomers with 3 glycerols, and two monomers with 2 glycerols in the pore. In contrast to GlpF, no glycerol is bound at the AQP7 selectivity filter (SF), comprising residues F74, G222, Y223, and R229. The AQP7 SF is resolved in its closed state because F74 blocks the passage of small solutes. Molecular dynamics simulations demonstrate that F74 undergoes large and rapid conformational changes, allowing glycerol molecules to permeate without orientational restriction. The more rigid GlpF imposes orientational constraints on glycerol molecules passing through the SF. Moreover, GlpF-W48 (analogous to AQP7-F74) undergoes rare but long-lasting conformational changes that block the pore to H2O and glycerol.
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Affiliation(s)
- Fraser J. Moss
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Paween Mahinthichaichan
- Department of Biochemistry, Center for Biophysics and Quantitative Biology, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - David T. Lodowski
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Thomas Kowatz
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Emad Tajkhorshid
- Department of Biochemistry, Center for Biophysics and Quantitative Biology, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Andreas Engel
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Walter F. Boron
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
- Department of Medicine, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Ardeschir Vahedi-Faridi
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
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Calvetti D, Prezioso J, Occhipinti R, Boron WF, Somersalo E. Computational model of electrode-induced microenvironmental effects on pH measurements near a cell membrane. MULTISCALE MODELING & SIMULATION : A SIAM INTERDISCIPLINARY JOURNAL 2020; 18:1053-1075. [PMID: 34456639 PMCID: PMC8388135 DOI: 10.1137/19m1262875] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The mechanism of gas transport across cell membranes remains a topic of considerable interest, particularly regarding the extent to which lipids vs. specific membrane proteins provide conduction pathways. Studies of transmembrane (CO2) transport often rely on data collected under controlled conditions, using pH-sensitive microelectrodes at the extracellular surface to record changes due to extracellular CO2 diffusion and reactions. Although recent detailed computational models can predict a qualitatively correct behavior, a mismatch between the dynamical ranges of the predicted and observed pH curves raises the question whether the discrepancy may be due to a bias introduced by the pH electrode itself. More specifically, it is reasonable to ask whether bringing the electrode tip near or in contact with the membrane creates a local microenvironment between the electrode tip and the membrane, so that the measured data refer to the microenvironment rather than to the free surface. Here, we introduce a detailed computational model, designed to address this question. We find that, as long as a zone of free diffusion exists between the tip and the membrane, the microenvironment behaves effectively as the free membrane. However, according to our model, when the tip contacts the membrane, partial quenching of extracellular diffusion by the electrode rim leads to a significant increase in the pH dynamics under the electrode, matching values measured in physiological experiments. The computational schemes for the model predictions are based on semi-discretization by a finite-element method, and an implicit-explicit time integration scheme to capture the different time scales of the system.
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Affiliation(s)
- D Calvetti
- Department of Mathematics, Applied Mathematics and Statistics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106
| | - J Prezioso
- Department of Physiology and Biophysics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106
| | - R Occhipinti
- Department of Physiology and Biophysics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106
| | - WF Boron
- Department of Physiology and Biophysics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106
| | - E Somersalo
- Department of Mathematics, Applied Mathematics and Statistics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106
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Liu S, Fukumoto T, Gena P, Feng P, Sun Q, Li Q, Matsumoto T, Kaneko T, Zhang H, Zhang Y, Zhong S, Zeng W, Katsuhara M, Kitagawa Y, Wang A, Calamita G, Ding X. Ectopic expression of a rice plasma membrane intrinsic protein (OsPIP1;3) promotes plant growth and water uptake. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 102:779-796. [PMID: 31872463 DOI: 10.1111/tpj.14662] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 11/09/2019] [Accepted: 12/09/2019] [Indexed: 06/10/2023]
Abstract
Plasma membrane intrinsic proteins (PIPs) are known to be major facilitators of the movement of a number of substrates across cell membranes. From a drought-resistant cultivar of Oryza sativa (rice), we isolated an OsPIP1;3 gene single-nucleotide polymorphism (SNP) that is mostly expressed in rice roots and is strongly responsive to drought stress. Immunocytochemistry showed that OsPIP1;3 majorly accumulated on the proximal end of the endodermis and the cell surface around the xylem. Expression of GFP-OsPIP1;3 alone in Xenopus oocytes or rice protoplasts showed OsPIP1;3 mislocalization in the endoplasmic reticulum (ER)-like neighborhood, whereas co-expression of OsPIP2;2 recruited OsPIP1;3 to the plasma membrane and led to a significant enhancement of water permeability in oocytes. Moreover, reconstitution of 10×His-OsPIP1;3 in liposomes demonstrated water channel activity, as revealed by stopped-flow light scattering. Intriguingly, by patch-clamp technique, we detected significant NO3- conductance of OsPIP1;3 in mammalian cells. To investigate the physiological functions of OsPIP1;3, we ectopically expressed the OsPIP1;3 gene in Nicotiana benthamiana (tobacco). The transgenic tobacco plants exhibited higher photosynthesis rates, root hydraulic conductivity (Lpr ) and water-use efficiency, resulting in a greater biomass and a higher resistance to water deficit than the wild-type did. Further experiments suggested that heterologous expression of OsPIP1;3 in cyanobacterium altered bacterial growth under different conditions of CO2 gas supply. Overall, besides shedding light on the multiple functions played by OsPIP1;3, this work provides insights into the translational value of plant AQPs.
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Affiliation(s)
- Siyu Liu
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Tatsuya Fukumoto
- Graduate School of Bioresource Sciences, Akita Prefectural University, Akita, 010-0195, Japan
| | - Patrizia Gena
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari 'Aldo Moro', Bari, Italy
| | - Peng Feng
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Qi Sun
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Qiang Li
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Tadashi Matsumoto
- Graduate School of Bioresource Sciences, Akita Prefectural University, Akita, 010-0195, Japan
| | - Toshiyuki Kaneko
- Research Institute for Bioresources, Okayama University, Kurashiki, 710-0046, Japan
| | - Hang Zhang
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
| | - Yao Zhang
- College of Horticulture, Northeast Agricultural University, Harbin, 150030, China
| | - Shihua Zhong
- Department of Biochemistry, the University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Weizhong Zeng
- Department of Biophysics, the University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Maki Katsuhara
- Research Institute for Bioresources, Okayama University, Kurashiki, 710-0046, Japan
| | - Yoshichika Kitagawa
- Graduate School of Bioresource Sciences, Akita Prefectural University, Akita, 010-0195, Japan
| | - Aoxue Wang
- College of Horticulture, Northeast Agricultural University, Harbin, 150030, China
| | - Giuseppe Calamita
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari 'Aldo Moro', Bari, Italy
| | - Xiaodong Ding
- Key Laboratory of Agricultural Biological Functional Genes, Northeast Agricultural University, Harbin, 150030, China
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Abstract
Although students initially learn of ionic buffering in basic chemistry, buffering and acid-base transport in biology often is relegated to specialized classes, discussions, or situations. That said, for physiology, nephrology, pulmonology, and anesthesiology, these basic principles often are critically important for mechanistic understanding, medical treatments, and assessing therapy effectiveness. This short introductory perspective focuses on basic chemistry and transport of buffers and acid-base equivalents, provides an outline of basic science acid-base concepts, tools used to monitor intracellular pH, model cellular responses to pH buffer changes, and the more recent development and use of genetically encoded pH-indicators. Examples of newer genetically encoded pH-indicators (pHerry and pHire) are provided, and their use for in vitro, ex vivo, and in vivo experiments are described. The continued use and development of these basic tools provide increasing opportunities for both basic and potentially clinical investigations.
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Affiliation(s)
- Michael F Romero
- Physiology and Biomedical Engineering, Nephrology and Hypertension, Mayo Clinic College of Medicine and Science, Rochester, MN.
| | - Adam J Rossano
- Physiology and Biomedical Engineering, Nephrology and Hypertension, Mayo Clinic College of Medicine and Science, Rochester, MN
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Liu C, Li B, Tang K, Dong X, Xue L, Su G, Jin Y. Aquaporin 1 alleviates acute kidney injury via PI3K-mediated macrophage M2 polarization. Inflamm Res 2020; 69:509-521. [PMID: 32179955 DOI: 10.1007/s00011-020-01334-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/26/2020] [Accepted: 03/07/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Lipopolysaccharide (LPS)-induced acute kidney injury (AKI) is associated with an abnormal immune response. Accumulating evidence has demonstrated that aquaporin 1 (AQP1) prevents kidney tissue injury in LPS-induced AKI by mediating immune response. However, the underlying mechanisms remain obscure. Macrophages as immune cells with multiple phenotypes are important mediators in tissue homeostasis and host defense. We propose that macrophage polarization is implicated in AQP1-mediated immune response. METHODS Herein we established sepsis-induced AKI model rats through intraperitoneal injection of LPS into Wistar rats to reveal immune mechanism of damage. We also used LPS-induced mouse RAW264.7 cells to elucidate the molecular mechanism of macropage polarization. RESULTS Histopathology showed that renal tubular epithelial cells in the model group were swollen, inflammatory exudation was obvious and the inflammatory factors, interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) were increased. Western blotting showed PI3K was upregulated in the model group. Serum creatinine and urea nitrogen increased after LPS injection. Renal AQP1 mRNA is downregulated and serum AQP1 protein increased first and then decreased in LPS-induced AKI rats. M2 macrophage markers (Arg-1, CD206) were increased in repair stage. In addition, treatment of murine macrophages (RAW264.7) with AQP1 siRNA resulted in decreased PI3K activation and M2 polarization, but increased IL-6 and TNF-α. Moreover, inhibiting PI3K with wortmannin imitated the results of AQP1 silencing. CONCLUSIONS Macrophage M2 polarization is likely the cellular mechanism underlying the anti-AKI property of AQP1, and PI3K activation is involved in the AQP1-induced M2 phenotype switch.
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Affiliation(s)
- ChunMei Liu
- Department of Laboratory Diagnosis, The First Affiliated Hospital of Harbin Medical University, 23 Youzheng Street, Nangang District, Harbin, 150001, Heilongjiang, People's Republic of China
| | - BoHui Li
- Department of Laboratory Diagnosis, The First Affiliated Hospital of Harbin Medical University, 23 Youzheng Street, Nangang District, Harbin, 150001, Heilongjiang, People's Republic of China
| | - KaiHong Tang
- Department of Laboratory Diagnosis, The First Affiliated Hospital of Harbin Medical University, 23 Youzheng Street, Nangang District, Harbin, 150001, Heilongjiang, People's Republic of China
| | - XueNing Dong
- Department of Laboratory Diagnosis, The First Affiliated Hospital of Harbin Medical University, 23 Youzheng Street, Nangang District, Harbin, 150001, Heilongjiang, People's Republic of China
| | - LongGe Xue
- Department of Laboratory Diagnosis, The First Affiliated Hospital of Harbin Medical University, 23 Youzheng Street, Nangang District, Harbin, 150001, Heilongjiang, People's Republic of China
| | - Guangming Su
- Department of Laboratory Diagnosis, The First Affiliated Hospital of Harbin Medical University, 23 Youzheng Street, Nangang District, Harbin, 150001, Heilongjiang, People's Republic of China
| | - Yingyu Jin
- Department of Laboratory Diagnosis, The First Affiliated Hospital of Harbin Medical University, 23 Youzheng Street, Nangang District, Harbin, 150001, Heilongjiang, People's Republic of China.
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Specialized stellate cells offer a privileged route for rapid water flux in Drosophila renal tubule. Proc Natl Acad Sci U S A 2020; 117:1779-1787. [PMID: 31907321 PMCID: PMC6983416 DOI: 10.1073/pnas.1915943117] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Insects are highly successful, in part through an excellent ability to osmoregulate. The renal (Malpighian) tubules can secrete fluid faster on a per-cell basis than any other epithelium, but the route for these remarkable water fluxes has not been established. In Drosophila melanogaster, we show that 4 genes of the major intrinsic protein family are expressed at a very high level in the fly renal tissue: the aquaporins (AQPs) Drip and Prip and the aquaglyceroporins Eglp2 and Eglp4 As predicted from their structure, and by their transport function by expressing these proteins in Xenopus oocytes, Drip, Prip, and Eglp2 show significant and specific water permeability, whereas Eglp2 and Eglp4 show very high permeability to glycerol and urea. Knockdowns of any of these genes result in impaired hormone-induced fluid secretion. The Drosophila tubule has 2 main secretory cell types: active cation-transporting principal cells, wherein the aquaglyceroporins localize to opposite plasma membranes, and small stellate cells, the site of the chloride shunt conductance, with these AQPs localizing to opposite plasma membranes. This suggests a model in which osmotically obliged water flows through the stellate cells. Consistent with this model, fluorescently labeled dextran, an in vivo marker of membrane water permeability, is trapped in the basal infoldings of the stellate cells after kinin diuretic peptide stimulation, confirming that these cells provide the major route for transepithelial water flux. The spatial segregation of these components of epithelial water transport may help to explain the unique success of the higher insects in regulating their internal environments.
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Aquaporins and male (in)fertility: Expression and role throughout the male reproductive tract. Arch Biochem Biophys 2020; 679:108222. [DOI: 10.1016/j.abb.2019.108222] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/25/2019] [Accepted: 12/04/2019] [Indexed: 02/07/2023]
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Alishahi M, Kamali R. A novel molecular dynamics study of CO 2 permeation through aquaporin-5. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2019; 42:151. [PMID: 31773315 DOI: 10.1140/epje/i2019-11912-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Accepted: 10/24/2019] [Indexed: 06/10/2023]
Abstract
Aquaporins (AQPs) are protein channels which facilitate rapid water permeation across cell membrane. The AQPs are very vital for biological organs, as their malfunction causes severe diseases in human body. A particular family of AQPs, that is AQP5, has a significant role in lung fluid transport due to submucosal glands structure. However, it has not been yet well understood whether these protein channels can conduct gas molecules. Here, Molecular Dynamics (MD) simulations are used to investigate the CO2 permeability and diffusion in AQP5 during a 40-nanosecond period. For the first time, equilibrium and Steered MD (SMD) are used to simulate self and force-induced diffusion of CO2 molecules across AQP5 and POPE lipid bilayer. According to PMFs profile associated to CO2 permeation, the hydrophobic central pore provides a more suitable pathway for gas molecules compared to other AQP5 channels. Although CO2 molecules can also permeate across AQP5 water channels, the rate of CO2 permeation through four channels of the AQP5 monomers is much lower than the central pore. The rate of CO2 permeation through four AQP5 water channels is even lower than CO2 diffusion through POPE lipid membrane. The results reported in this investigation demonstrate that MD simulations of human AQP5 provide valuable insights into the gas permeation mechanism for both the equilibrium self-diffusion, and quasi-equilibrium condition.
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Affiliation(s)
- Marzieh Alishahi
- Department of Mechanical Engineering, Shiraz University, Shiraz, Iran
| | - Reza Kamali
- Department of Mechanical Engineering, Shiraz University, Shiraz, Iran.
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47
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Dong SH, Kim SS, Kim SH, Yeo SG. Expression of aquaporins in inner ear disease. Laryngoscope 2019; 130:1532-1539. [PMID: 31593306 DOI: 10.1002/lary.28334] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 09/05/2019] [Accepted: 09/10/2019] [Indexed: 12/22/2022]
Abstract
The inner ear is responsible for hearing and balance and consists of a membranous labyrinth within a bony labyrinth. The balance structure is divided into the otolith organ that recognizes linear acceleration and the semicircular canal that is responsible for rotational movement. The cochlea is the hearing organ. The external and middle ear are covered with skin and mucosa, respectively, and the space is filled with air, whereas the inner ear is composed of endolymph and perilymph. The inner ear is a fluid-filled sensory organ composed of hair cells with cilia on the upper part of the cells that convert changes in sound energy and balance into electric energy through the hair cells to transmit signals to the auditory nerve through synapses. Aquaporins (AQPs) are a family of transmembrane proteins present in all species that can be roughly divided into three subfamilies according to structure and function: 1) classical AQP, 2) aquaglyceroporin, and 3) superaquaporin. Currently, the subfamily of mammalian species is known to include 13 AQP members (AQP0-AQP12). AQPs have a variety of functions depending on their structure and are related to inner ear diseases such as Meniere's disease, sensorineural hearing loss, and presbycusis. Additional studies on the relationship between the inner ear and AQPs may be helpful in the diagnosis and treatment of inner ear disease. Laryngoscope, 130:1532-1539, 2020.
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Affiliation(s)
- Sung Hwa Dong
- Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School, Kyung Hee University, Seoul, South Korea
| | - Sung Su Kim
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, School of Medicine, Graduate School, Kyung Hee University, Seoul, South Korea
| | - Sang Hoon Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School, Kyung Hee University, Seoul, South Korea
| | - Seung Geun Yeo
- Department of Otorhinolaryngology-Head and Neck Surgery, Graduate School, Kyung Hee University, Seoul, South Korea.,Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, School of Medicine, Graduate School, Kyung Hee University, Seoul, South Korea
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48
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Occhipinti R, Boron WF. Role of Carbonic Anhydrases and Inhibitors in Acid-Base Physiology: Insights from Mathematical Modeling. Int J Mol Sci 2019; 20:E3841. [PMID: 31390837 PMCID: PMC6695913 DOI: 10.3390/ijms20153841] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 07/24/2019] [Accepted: 07/25/2019] [Indexed: 01/25/2023] Open
Abstract
Carbonic anhydrases (CAs) catalyze a reaction fundamental for life: the bidirectional conversion of carbon dioxide (CO2) and water (H2O) into bicarbonate (HCO3-) and protons (H+). These enzymes impact numerous physiological processes that occur within and across the many compartments in the body. Within compartments, CAs promote rapid H+ buffering and thus the stability of pH-sensitive processes. Between compartments, CAs promote movements of H+, CO2, HCO3-, and related species. This traffic is central to respiration, digestion, and whole-body/cellular pH regulation. Here, we focus on the role of mathematical modeling in understanding how CA enhances buffering as well as gradients that drive fluxes of CO2 and other solutes (facilitated diffusion). We also examine urinary acid secretion and the carriage of CO2 by the respiratory system. We propose that the broad physiological impact of CAs stem from three fundamental actions: promoting H+ buffering, enhancing H+ exchange between buffer systems, and facilitating diffusion. Mathematical modeling can be a powerful tool for: (1) clarifying the complex interdependencies among reaction, diffusion, and protein-mediated components of physiological processes; (2) formulating hypotheses and making predictions to be tested in wet-lab experiments; and (3) inferring data that are impossible to measure.
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Affiliation(s)
- Rossana Occhipinti
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
| | - Walter F Boron
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
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49
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Abstract
Spontaneous solute and solvent permeation through membranes is of vital importance to human life, be it gas exchange in red blood cells, metabolite excretion, drug/toxin uptake, or water homeostasis. Knowledge of the underlying molecular mechanisms is the sine qua non of every functional assignment to membrane transporters. The basis of our current solubility diffusion model was laid by Meyer and Overton. It correlates the solubility of a substance in an organic phase with its membrane permeability. Since then, a wide range of studies challenging this rule have appeared. Commonly, the discrepancies have their origin in ill-used measurement approaches, as we demonstrate on the example of membrane CO2 transport. On the basis of the insight that scanning electrochemical microscopy offered into solute concentration distributions in immediate membrane vicinity of planar membranes, we analyzed the interplay between chemical reactions and diffusion for solvent transport, weak acid permeation, and enzymatic reactions adjacent to membranes. We conclude that buffer reactions must also be considered in spectroscopic investigations of weak acid transport in vesicular suspensions. The evaluation of energetic contributions to membrane translocation of charged species demonstrates the compatibility of the resulting membrane current with the solubility diffusion model. A local partition coefficient that depends on membrane penetration depth governs spontaneous membrane translocation of both charged and uncharged molecules. It is determined not only by the solubility in an organic phase but also by other factors like cholesterol concentration and intrinsic electric membrane potentials.
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Affiliation(s)
- Christof Hannesschlaeger
- From the Institute of Biophysics , Johannes Kepler University Linz , Gruberstrasse 40 , 4020 Linz , Austria
| | - Andreas Horner
- From the Institute of Biophysics , Johannes Kepler University Linz , Gruberstrasse 40 , 4020 Linz , Austria
| | - Peter Pohl
- From the Institute of Biophysics , Johannes Kepler University Linz , Gruberstrasse 40 , 4020 Linz , Austria
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50
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Tang J, Sun B, Cheng R, Shi Z, Da Luo, Liu S, Centritto M. Effects of soil nitrogen (N) deficiency on photosynthetic N-use efficiency in N-fixing and non-N-fixing tree seedlings in subtropical China. Sci Rep 2019; 9:4604. [PMID: 30872731 PMCID: PMC6418086 DOI: 10.1038/s41598-019-41035-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 01/17/2019] [Indexed: 11/11/2022] Open
Abstract
Soil nitrogen (N) deficiencies can affect the photosynthetic N-use efficiency (PNUE), mesophyll conductance (gm), and leaf N allocation. However, lack of information about how these physiological characteristics in N-fixing trees could be affected by soil N deficiency and the difference between N-fixing and non-N-fixing trees. In this study, we chose seedlings of two N-fixing (Dalbergia odorifera and Erythrophleum fordii) and two non-N-fixing trees (Castanopsis hystrix and Betula alnoides) as study objects, and we conducted a pot experiment with three levels of soil N treatments (high nitrogen, set as Control; medium nitrogen, MN; and low nitrogen, LN). Our results showed that soil N deficiency significantly decreased the leaf N concentration and photosynthesis ability of the two non-N-fixing trees, but it had less influence on two N-fixing trees. The LN treatment had lower gm in D. odorifera and lower leaf N allocated to Rubisco (PR), leaf N allocated to bioenergetics (PB), and gm in B. alnoides, eventually resulting in low PNUE values. Our findings suggested that the D. odorifera and E. fordii seedlings could grow well in N-deficient soil, and adding N may increase the growth rates of B. alnoides and C. hystrix seedlings and promote the growth of artificial forests.
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Affiliation(s)
- Jingchao Tang
- Key Laboratory on Forest Ecology and Environmental Sciences of State Forestry Administration, Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, 100091, China.,School of Environmental and Municipal Engineering, Qingdao Technological University, Qingdao, 266033, China
| | - Baodi Sun
- School of Environmental and Municipal Engineering, Qingdao Technological University, Qingdao, 266033, China
| | - Ruimei Cheng
- Key Laboratory on Forest Ecology and Environmental Sciences of State Forestry Administration, Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, 100091, China.,Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China
| | - Zuomin Shi
- Key Laboratory on Forest Ecology and Environmental Sciences of State Forestry Administration, Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, 100091, China. .,Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, 210037, China. .,Tree and Timber Institute, National Research Council of Italy, Via Madonna del Piano 10, 50019, Sesto Fiorentino (FI), Italy.
| | - Da Luo
- Key Laboratory on Forest Ecology and Environmental Sciences of State Forestry Administration, Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, 100091, China.,Research Institute of Economic Forestry, Xinjiang Academy of Forestry Science, Urumqi, 830000, China
| | - Shirong Liu
- Key Laboratory on Forest Ecology and Environmental Sciences of State Forestry Administration, Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, 100091, China
| | - Mauro Centritto
- Tree and Timber Institute, National Research Council of Italy, Via Madonna del Piano 10, 50019, Sesto Fiorentino (FI), Italy
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