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Kim Y. Fisetin-Mediated Perturbations of Membrane Permeability and Intracellular pH in Candida albicans. J Microbiol Biotechnol 2024; 34:783-794. [PMID: 38213272 DOI: 10.4014/jmb.2311.11027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 12/26/2023] [Accepted: 12/29/2023] [Indexed: 01/13/2024]
Abstract
The antifungal activity of fisetin against Candida albicans is explored, elucidating a mechanism centered on membrane permeabilization and ensuing disruption of pH homeostasis. The Minimum Inhibitory Concentration (MIC) of fisetin, indicative of its interaction with the fungal membrane, increases in the presence of ergosterol. Hoechst 33342 and propidium-iodide staining reveal substantial propidium-iodide accumulation in fisetin-treated C. albicans cells at their MIC, with crystal violet uptake assays confirming fisetin-induced membrane permeabilization. Leakage analysis demonstrates a significant release of DNA and proteins in fisetin-treated cells compared to controls, underscoring the antifungal effect through membrane disruption. Green fluorescence, evident in both the cytoplasm and vacuoles of fisetin-treated cells under BCECF, AM staining, stands in contrast to controls where only acidic vacuoles exhibit staining. Ratiometric pH measurements using BCECF, AM reveal a noteworthy reduction in intracellular pH in fisetin-treated cells, emphasizing its impact on pH homeostasis. DiBAC4(3) uptake assays demonstrate membrane hyperpolarization in fisetin-treated cells, suggesting potential disruptions in ion flux and cellular homeostasis. These results provide comprehensive insights into the antifungal mechanisms of fisetin, positioning it as a promising therapeutic agent against Candida infections.
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Affiliation(s)
- Younhee Kim
- Department of Korean Medicine, Semyung University, Jecheon 27136, Republic of Korea
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2
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Gradogna A, Carpaneto A. Electrophysiology and fluorescence to investigate cation channels and transporters in isolated plant vacuoles. Stress Biol 2022; 2:42. [PMID: 37676514 PMCID: PMC10442027 DOI: 10.1007/s44154-022-00064-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 09/01/2022] [Indexed: 09/08/2023]
Abstract
The plant vacuole plays a fundamental role in cell homeostasis. The successful application of patch-clamp technique on isolated vacuoles allows the determination of the functional characteristics of tonoplast ion channels and transporters. The parallel use of a sensor-based fluorescence approach capable of detecting changes in calcium and proton concentrations opens up new possibilities for investigation. In excised patch, the presence of fura-2 in the vacuolar solution reveals the direct permeation of calcium in plant TPC channels. In whole-vacuole, the activity of non-electrogenic NHX potassium proton antiporters can be measured by using the proton sensitive dye BCECF loaded in the vacuolar lumen by the patch pipette. Both vacuolar NHXs and CLCa (chloride/nitrate antiporter) are inhibited by the phosphoinositide PI(3,5)P2, suggesting a coordinated role of these proteins in salt accumulation. Increased knowledge in the molecular mechanisms of vacuolar ion channels and transporters has the potential to improve our understanding on how plants cope with a rapidly changing environment.
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Affiliation(s)
- Antonella Gradogna
- Institute of Biophysics, National Research Council, Via De Marini 6, 16149, Genoa, Italy
| | - Armando Carpaneto
- Institute of Biophysics, National Research Council, Via De Marini 6, 16149, Genoa, Italy.
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, Viale Benedetto XV 5, 16132, Genoa, Italy.
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Kashirina A, Gavrina A, Mozherov A, Kozlov D, Kuznetsova D, Vorotelyak E, Zagaynova E, Kalabusheva E, Kashina A. FLIM for Evaluation of Difference in Metabolic Status between Native and Differentiated from iPSCs Dermal Papilla Cells. Cells 2022; 11. [PMID: 36078136 DOI: 10.3390/cells11172730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 08/25/2022] [Accepted: 08/29/2022] [Indexed: 12/29/2022] Open
Abstract
iPSCs and their derivatives are the most promising cell sources for creating skin equivalents. However, their properties are not fully understood. In addition, new approaches and parameters are needed for studying cells in 3D models without destroying their organization. Thus, the aim of our work was to study and compare the metabolic status and pH of dermal spheroids created from dermal papilla cells differentiated from pluripotent stem cells (iDP) and native dermal papilla cells (hDP) using fluorescence microscopy and fluorescence lifetime imaging microscopy (FLIM). For this purpose, fluorescence intensities of NAD(P)H and FAD, fluorescence lifetimes, and the contributions of NAD(P)H, as well as the fluorescence intensities of SypHer-2 and BCECF were measured. iDP in spheroids were characterized by a more glycolytic phenotype and alkaline intra-cellular pH in comparison with hDP cells. Moreover, the metabolic activity of iDP in spheroids depends on the source of stem cells from which they were obtained. So, less differentiated and condensed spheroids from iDP-iPSDP and iDP-iPSKYOU are characterized by a more glycolytic phenotype compared to dense spheroids from iDP-DYP0730 and iDP-hES. FLIM and fluorescent microscopy in combination with the metabolism and pH are promising tools for minimally invasive and long-term analyses of 3D models based on stem cells.
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Kashirina A, Gavrina A, Kryukov E, Elagin V, Kolesova Y, Artyuhov A, Momotyuk E, Abdyyev V, Meshcheryakova N, Zagaynova E, Dashinimaev E, Kashina A. Energy Metabolism and Intracellular pH Alteration in Neural Spheroids Carrying Down Syndrome. Biomedicines 2021; 9:1741. [PMID: 34829971 DOI: 10.3390/biomedicines9111741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 12/18/2022] Open
Abstract
Brain diseases including Down syndrome (DS/TS21) are known to be characterized by changes in cellular metabolism. To adequately assess such metabolic changes during pathological processes and to test drugs, methods are needed that allow monitoring of these changes in real time with minimally invasive effects. Thus, the aim of our work was to study the metabolic status and intracellular pH of spheroids carrying DS using fluorescence microscopy and FLIM. For metabolic analysis we measured the fluorescence intensities, fluorescence lifetimes and the contributions of the free and bound forms of NAD(P)H. For intracellular pH assay we measured the fluorescence intensities of SypHer-2 and BCECF. Data were processed with SPCImage and Fiji-ImageJ. We demonstrated the predominance of glycolysis in TS21 spheroids compared with normal karyotype (NK) spheroids. Assessment of the intracellular pH indicated a more alkaline intracellular pH in the TS21 spheroids compared to NK spheroids. Using fluorescence imaging, we performed a comprehensive comparative analysis of the metabolism and intracellular pH of TS21 spheroids and showed that fluorescence microscopy and FLIM make it possible to study living cells in 3D models in real time with minimally invasive effects.
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Gradogna A, Scholz-Starke J, Pardo JM, Carpaneto A. Beyond the patch-clamp resolution: functional activity of nonelectrogenic vacuolar NHX proton/potassium antiporters and inhibition by phosphoinositides. New Phytol 2021; 229:3026-3036. [PMID: 33098586 DOI: 10.1111/nph.17021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/12/2020] [Indexed: 05/12/2023]
Abstract
We combined the patch-clamp technique with ratiometric fluorescence imaging using the proton-responsive dye BCECF as a luminal probe. Upon application of a steep cytosol-directed potassium ion (K+ ) gradient in Arabidopsis mesophyll vacuoles, a strong and reversible acidification of the vacuolar lumen was detected, whereas no associated electrical currents were observed, in agreement with electroneutral cation/H+ exchange. Our data show that this acidification was generated by NHX antiport activity, because: it did not distinguish between K+ and sodium (Na+ ) ions; it was sensitive to the NHX inhibitor benzamil; and it was completely absent in vacuoles from nhx1 nhx2 double knockout plants. Our data further show that NHX activity could be reversed, was voltage-independent and specifically impaired by the low-abundance signaling lipid PI(3,5)P2 , which may regulate salt accumulation in plants by acting as a common messenger to coordinately shut down secondary active carriers responsible for cation and anion uptake inside the vacuole. Finally, we developed a theory based on thermodynamics, which supports the data obtained by our novel experimental approach. This work, therefore, represents a proof-of-principle that can be applied to the study of proton-dependent exchangers from plants and animals, which are barely detectable using conventional techniques.
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Affiliation(s)
- Antonella Gradogna
- Institute of Biophysics, National Research Council, Via De Marini 6, Genova, 16149, Italy
| | - Joachim Scholz-Starke
- Institute of Biophysics, National Research Council, Via De Marini 6, Genova, 16149, Italy
| | - José M Pardo
- Institute of Plant Biochemistry and Photosynthesis, CSIC-University of Seville, Seville, 41092, Spain
| | - Armando Carpaneto
- Institute of Biophysics, National Research Council, Via De Marini 6, Genova, 16149, Italy
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, Viale Benedetto XV 5, Genova, 16132, Italy
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Aranda Sicilia MN, Sánchez Romero ME, Rodríguez Rosales MP, Venema K. Plastidial transporters KEA1 and KEA2 at the inner envelope membrane adjust stromal pH in the dark. New Phytol 2021; 229:2080-2090. [PMID: 33111995 DOI: 10.1111/nph.17042] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 10/10/2020] [Indexed: 05/08/2023]
Abstract
Photosynthesis and carbon fixation depend critically on the regulation of pH in chloroplast compartments in the daylight and at night. While it is established that an alkaline stroma is required for carbon fixation, it is not known how alkaline stromal pH is formed, maintained or regulated. We tested whether two envelope transporters, AtKEA1 and AtKEA2, directly affected stromal pH in isolated Arabidopsis chloroplasts using the fluorescent probe 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF). External K+ -induced alkalinization of the stroma was observed in chloroplasts from wild-type (WT) plants but not from kea1kea2 mutants, suggesting that KEA1 and KEA2 mediate K+ uptake/H+ loss to modulate stromal pH. While light-stimulated alkalinization of the stroma was independent of KEA1 and KEA2, the rate of decay to neutral pH in the dark is delayed in kea1kea2 mutants. However, the dark-induced loss of a pH gradient across the thylakoid membrane was similar in WT and mutant chloroplasts. This indicates that proton influx from the cytosol mediated by envelope K+ /H+ antiporters contributes to adjustment of stromal pH upon light to dark transitions.
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Affiliation(s)
- María Nieves Aranda Sicilia
- Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, C/ Profesor Albareda 1, Granada, 18008, Spain
| | - María Elena Sánchez Romero
- Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, C/ Profesor Albareda 1, Granada, 18008, Spain
| | - María Pilar Rodríguez Rosales
- Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, C/ Profesor Albareda 1, Granada, 18008, Spain
| | - Kees Venema
- Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, C/ Profesor Albareda 1, Granada, 18008, Spain
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7
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Hosoda E, Chiba K. Fluorescence Measurement and Calibration of Intracellular pH in Starfish Oocytes. Bio Protoc 2020; 10:e3778. [PMID: 33659434 DOI: 10.21769/bioprotoc.3778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 07/27/2020] [Accepted: 08/17/2020] [Indexed: 11/02/2022] Open
Abstract
Oocyte maturation is a process wherein an oocyte arrested at prophase of meiosis I resumes meiosis to become a fertilizable egg. In starfish ovaries, a hormone released from follicle cells activates the oocytes, resulting in an increase in their intracellular pH (pHi), which is required for spindle assembly. Herein, we describe a protocol for pHi measurement in living oocytes microinjected with the pH-sensitive dye BCECF. For in vivo BCECF calibration, we treated oocytes with artificial seawater containing CH3COONH4 to clamp pHi, injected pH-standard solutions, and converted the BCECF fluorescence intensity ratios to pHi values. Of note, if the actual pHi is higher or lower than the known pH of injected standard solutions, the BCECF fluorescence intensity ratio will decrease or increase, respectively. On the other hand, the pH of the injected solution displaying no change in fluorescence intensity should be considered the actual pHi. These methods for pHi calibration and clamping are simple and reproducible.
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Affiliation(s)
- Enako Hosoda
- Department of Biological Sciences, Ochanomizu University, Tokyo, Japan
| | - Kazuyoshi Chiba
- Department of Biological Sciences, Ochanomizu University, Tokyo, Japan
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Lee SP, Chao SC, Chou MF, Huang SF, Dai NT, Wu GJ, Tsai CS, Loh SH, Tsai YT. Characterization of intracellular buffering power in human induced pluripotent stem cells and the loss of pluripotency is delayed by acidic stimulation and increase of NHE1 activity. J Cell Physiol 2020; 236:1515-1528. [PMID: 32841374 DOI: 10.1002/jcp.29959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/18/2020] [Accepted: 07/07/2020] [Indexed: 11/07/2022]
Abstract
The homeostasis of intracellular pH (pHi ) affects many cellular functions. Our previous study has established a functional and molecular model of the active pHi regulators in human induced pluripotent stem cells (hiPSCs). The aims of the present study were to further quantify passive pHi buffering power (β) and to investigate the effects of extracellular pH and Na+ -H+ exchanger 1 (NHE1) activity on pluripotency in hiPSCs. pHi was detected by microspectrofluorimetry with pH-sensitive dye-BCECF. Western blot, immunofluorescence staining, and flow cytometry were used to detect protein expression and pluripotency. Our study in hiPSCs showed that (a) the value of total (βtot ), intrinsic (βi ), and CO2 -dependent ( β C O 2 ) buffering power all increased while pHi increased; (b) during the spontaneous differentiation for 4 days, the β values of βtot and β C O 2 changed in a tendency of decrease, despite the absence of statistical significance; (c) an acidic cultured environment retained pluripotency and further upregulated expression and activity of NHE1 during spontaneous differentiation; (d) inhibition on NHE1 activity promoted the loss of pluripotency. In conclusion, we, for the first time, established a quantitative model of passive β during differentiation and demonstrated that maintenance of NHE1 at a higher level was of critical importance for pluripotency retention in hiPSCs.
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Affiliation(s)
- Shiao-Pieng Lee
- Department of Dentistry, School of Dentistry, Division of Oral and Maxillofacial Surgery, Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan
| | - Shih-Chi Chao
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Mei-Fang Chou
- Department of Pharmacy Practice, Tri-Service General Hospital, Taipei, Taiwan
| | - Shu-Fu Huang
- Department of Pharmacy Practice, Tri-Service General Hospital, Taipei, Taiwan
| | - Niann-Tzyy Dai
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Tri-Service General Hospital, Taipei, Taiwan
| | - Gwo-Jang Wu
- Department of Obstetrics and Gynecology, Tri-Service General Hospital, Taipei, Taiwan
| | - Chien-Sung Tsai
- Department of Surgery, Division of Cardiovascular Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
- Department of Pharmacology, National Defense Medical Center, Taipei, Taiwan
- Institute of Pharmacy, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Shih-Hurng Loh
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
- Department of Pharmacy Practice, Tri-Service General Hospital, Taipei, Taiwan
- Department of Surgery, Division of Cardiovascular Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yi-Ting Tsai
- Department of Surgery, Division of Cardiovascular Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
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Thiesen L, Belew ZM, Griem-Krey N, Pedersen SF, Crocoll C, Nour-Eldin HH, Wellendorph P. The γ-hydroxybutyric acid (GHB) analogue NCS-382 is a substrate for both monocarboxylate transporters subtypes 1 and 4. Eur J Pharm Sci 2020; 143:105203. [PMID: 31866563 DOI: 10.1016/j.ejps.2019.105203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 12/11/2019] [Accepted: 12/19/2019] [Indexed: 11/20/2022]
Abstract
The small-molecule ligand (E)-2-(5-hydroxy-5,7,8,9-tetrahydro-6H-benzo[7]annulen-6-ylidene)acetic acid (NCS-382) is an analogue of γ-hydroxybutyric acid (GHB) and is widely used for probing the brain-specific GHB high-affinity binding sites. To reach these, brain uptake is imperative, and it is therefore important to understand the molecular mechanisms of NCS-382 transport in order to direct in vivo studies. In this study, we hypothesized that NCS-382 is a substrate for the monocarboxylate transporter subtype 1 (MCT1) which is known to mediate blood-brain barrier (BBB) permeation of GHB. For this purpose, we investigated NCS-382 uptake by MCT subtypes endogenously expressed in tsA201 and MDA-MB-231 cell lines in assays of radioligand-based competition and fluorescence-based intracellular pH measurements. To further verify the results, we measured NCS-382 uptake by means of mass spectrometry in Xenopus laevis oocytes heterologously expressing MCT subtypes. As expected, we found that NCS-382 is a substrate for MCT1 with half-maximal effective concentrations in the low millimolar range. Surprisingly, NCS-382 also showed substrate activity at MCT4 as well as uptake in water-injected oocytes, suggesting a component of passive diffusion. In conclusion, transport of NCS-382 across membranes differs from GHB as it also involves MCT4 and/or passive diffusion. This should be taken into consideration when designing pharmacological studies with this compound and its closely related analogues. The combination of MCT assays used here exemplifies a setup that may be suitable for a reliable characterization of MCT ligands in general.
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Affiliation(s)
- Louise Thiesen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Zeinu Mussa Belew
- DynaMo Center, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark
| | - Nane Griem-Krey
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen Ø, Denmark
| | - Christoph Crocoll
- DynaMo Center, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark
| | - Hussam Hassan Nour-Eldin
- DynaMo Center, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark
| | - Petrine Wellendorph
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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Huang HK, Lee SY, Huang SF, Lin YS, Chao SC, Huang SF, Lee SC, Cheng TH, Loh SH, Tsai YT. Isoorientin Decreases Cell Migration via Decreasing Functional Activity and Molecular Expression of Proton-Linked Monocarboxylate Transporters in Human Lung Cancer Cells. Am J Chin Med 2020; 48:201-222. [PMID: 31918564 DOI: 10.1142/s0192415x20500111] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Aggressive tumor cells mainly rely on glycolysis, and further release vast amounts of lactate and protons by monocarboxylate transporter (MCT), which causes a higher intracellular pH (pHi) and acidic extracellular pH. Isoorientin, a principle flavonoid compound extracted from several plant species, shows various pharmacological activities. However, effects of isoorientin on anticancer and MCT await to explore in human lung cancer cells. Human lung cancer tissues were obtained from cancer patients undergoing surgery, while the human lung adenocarcinoma cells (A549) were bought commercially. Change of pHi was detected by microspectrofluorometry method with a pH-sensitive fluorescent dye, BCECF. MTT and wound-healing assay were used to detect the cell viability and migration, respectively. Western blot techniques and immunocytochemistry staining were used to detect the protein expression. Our results indicated that the expression of MCTs1/4 and CD147 were upregulated significantly in human lung tissues. In experiments of A549 cells, under HEPES-buffer, the resting pHi was 7.47, and isoorientin (1-300μM) inhibited functional activity of MCT concentration-dependently (up to -42%). Pretreatment with isoorientin (3-100μM) for 24h, MCT activity and cell migration were significantly inhibited (-25% and -40%, respectively), while the cell viability was not affected. Moreover, the expression of MCTs1/4, CD147, and matrix metalloproteinase (MMP) 2/9 were significantly down regulated. In summary, MCTs1/4 and CD147 are significantly upregulated in human lung adenocarcinoma tissues, and isoorientin inhibits cells-migration by inhibiting activity/expression of MCTs1/4 and MMPs2/9 in human lung cancer cells. These novel findings suggest that isoorientin could be a promising pharmacological agent for lung cancer.
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Affiliation(s)
- Hsu-Kai Huang
- Division of Thoracic Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan.,Department of Surgery, Tri-Service General Hospital, Penghu Branch, National Defense Medical Center, Taipei 11490, Taiwan
| | - Shin-Yi Lee
- Department of Pharmacology, National Defense Medical Center, Taipei 11490, Taiwan
| | - Shu-Fen Huang
- Clinical Pathology Division, Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan
| | - Yu-San Lin
- Department of Pharmacology, National Defense Medical Center, Taipei 11490, Taiwan
| | - Shih-Chi Chao
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 11490, Taiwan
| | - Shu-Fu Huang
- Department of Pharmacy Practice, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan
| | - Shih-Chun Lee
- Division of Thoracic Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan
| | - Tzu-Hurng Cheng
- Department of Pharmacology, National Defense Medical Center, Taipei 11490, Taiwan.,Department of Biochemistry, School of Medicine, College of Medicine, China Medical University, Taichung 40400, Taiwan
| | - Shih-Hurng Loh
- Department of Pharmacology, National Defense Medical Center, Taipei 11490, Taiwan.,Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 11490, Taiwan.,Department of Pharmacy Practice, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan
| | - Yi-Ting Tsai
- Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan
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Stumpp M, Dupont S, Hu MY. Measurement of feeding rates, respiration, and pH regulatory processes in the light of ocean acidification research. Methods Cell Biol 2019; 150:391-409. [PMID: 30777185 DOI: 10.1016/bs.mcb.2018.11.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The physiology of marine larvae has received considerable attention in the context of anthropogenic ocean acidification (OA). Many marine larvae including those of echinoderms, hemichordates, and mollusks are characterized by a developmental delay when exposed to reductions in seawater pH with the underlying mechanisms being largely unexplored. A key task in the frame of OA research lies in the identification of unifying physiological principles that may explain reductions in growth and development. The sea urchin larva has been identified as a good model organism, and energy allocations toward compensatory processes were found to be key factors affecting development. However, physiological approaches to assess the animal's energy budget, as well as methods to characterize energy consuming processes (e.g., gut pH homeostasis and biomineralization) were scarce. During the last decade, a suite of physiological techniques was developed, to accurately determine the larval energy budget including feeding and metabolic rate measurements. To identify and characterize energy consuming processes, gastroscopic pH measurements in the larval gut and intracellular pH measurements of primary mesenchyme cells were developed. These techniques helped to understand fundamental processes of gut homeostasis and biomineralization in the developing sea urchin larva and their interaction with the environment. Using the sea urchin larva as a model these methods were successfully transferred to other echinoderm and hemichordate early developmental stages. This chapter explains and provides the methodological basis for the determination of feeding and metabolic rates as well as intracellular and extracellular pH measurements using the sea urchin larva as an example.
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Chao SC, Wu GJ, Huang SF, Dai NT, Huang HK, Chou MF, Tsai YT, Lee SP, Loh SH. Functional and molecular mechanism of intracellular pH regulation in human inducible pluripotent stem cells. World J Stem Cells 2018; 10:196-211. [PMID: 30613313 PMCID: PMC6306555 DOI: 10.4252/wjsc.v10.i12.196] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/14/2018] [Accepted: 12/05/2018] [Indexed: 02/06/2023] Open
Abstract
AIM To establish a functional and molecular model of the intracellular pH (pHi) regulatory mechanism in human induced pluripotent stem cells (hiPSCs).
METHODS hiPSCs (HPS0077) were kindly provided by Dr. Dai from the Tri-Service General Hospital (IRB No. B-106-09). Changes in the pHi were detected either by microspectrofluorimetry or by a multimode reader with a pH-sensitive fluorescent probe, BCECF, and the fluorescent ratio was calibrated by the high K+/nigericin method. NH4Cl and Na-acetate prepulse techniques were used to induce rapid intracellular acidosis and alkalization, respectively. The buffering power (β) was calculated from the ΔpHi induced by perfusing different concentrations of (NH4)2SO4. Western blot techniques and immunocytochemistry staining were used to detect the protein expression of pHi regulators and pluripotency markers.
RESULTS In this study, our results indicated that (1) the steady-state pHi value was found to be 7.5 ± 0.01 (n = 20) and 7.68 ± 0.01 (n =20) in HEPES and 5% CO2/HCO3--buffered systems, respectively, which were much greater than that in normal adult cells (7.2); (2) in a CO2/HCO3--buffered system, the values of total intracellular buffering power (β) can be described by the following equation: βtot = 107.79 (pHi)2 - 1522.2 (pHi) + 5396.9 (correlation coefficient R2 = 0.85), in the estimated pHi range of 7.1-8.0; (3) the Na+/H+ exchanger (NHE) and the Na+/HCO3- cotransporter (NBC) were found to be functionally activated for acid extrusion for pHi values less than 7.5 and 7.68, respectively; (4) V-ATPase and some other unknown Na+-independent acid extruder(s) could only be functionally detected for pHi values less than 7.1; (5) the Cl-/ OH- exchanger (CHE) and the Cl-/HCO3- anion exchanger (AE) were found to be responsible for the weakening of intracellular proton loading; (6) besides the CHE and the AE, a Cl--independent acid loading mechanism was functionally identified; and (7) in hiPSCs, a strong positive correlation was observed between the loss of pluripotency and the weakening of the intracellular acid extrusion mechanism, which included a decrease in the steady-state pHi value and diminished the functional activity and protein expression of the NHE and the NBC.
CONCLUSION For the first time, we established a functional and molecular model of a pHi regulatory mechanism and demonstrated its strong positive correlation with hiPSC pluripotency.
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Affiliation(s)
- Shih-Chi Chao
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 11490, Taiwan
| | - Gwo-Jang Wu
- Department of Obstetrics and Gynecology, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan
| | - Shu-Fu Huang
- Department of Pharmacy Practice, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan
| | - Niann-Tzyy Dai
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan
| | - Hsu-Kai Huang
- Division of Chest Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan
| | - Mei-Fang Chou
- Department of Pharmacy Practice, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan
| | - Yi-Ting Tsai
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei 11490, Taiwan
- Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan
| | - Shiao-Pieng Lee
- Division of Oral and Maxillofacial Surgery, Department of Dentistry, School of Dentistry, Tri-Service General Hospital and National Defense Medical Center, Taipei 11490, Taiwan
| | - Shih-Hurng Loh
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 11490, Taiwan
- Department of Pharmacy Practice, Tri-Service General Hospital, National Defense Medical Center, Taipei 11490, Taiwan
- Department of Pharmacology, National Defense Medical Center, Taipei 11490, Taiwan
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13
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Lee SP, Chao SC, Huang SF, Chen YL, Tsai YT, Loh SH. Expressional and Functional Characterization of Intracellular pH Regulators and Effects of Ethanol in Human Oral Epidermoid Carcinoma Cells. Cell Physiol Biochem 2018; 47:2056-2068. [PMID: 29975935 DOI: 10.1159/000491473] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 04/30/2018] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND/AIMS To functionally characterize intracellular pH (pHi) regulating mechanisms, such as Na+-H+ exchanger (NHE) and Na+-HCO3- co-transporter (NBC), and further examine effects of ethanol on the pHi regulating mechanism in human oral epidermoid carcinoma (OEC-M1) cells. METHODS OEC-M1 cells were a gift from Tri-Service General Hospital. Changes of pHi were detected by microspectrofluroimetry with a pH-sensitive fluorescent dye, BCECF. Isoforms of transporters were examined by Western blot technique. RESULTS i) the steady-state pHi value shifted from alkaline (7.35∼7.49) to acidic (7.0∼7.03) following acid/base impacts; ii) in HEPES-buffer system, pHi recovery following induced-acidification was totally blocked by either removing [Na]o+ or adding HOE 694 (a NHE1 specific inhibitor), which demonstrates existence of NHE1; iii) in HCO3-/CO2-buffer system, the pHi recovery following induced-acidification was entirely blocked by either removing [Na]o+ or adding HOE 694 plus DIDS (a NBC specific inhibitor), which suggests existence of Na+- and HCO3-dependent acid-extruder, i.e. NBC; iv) the isoforms of the two acid extruders were NHE1, NBCn1, NBCe1 and NDCBE; v) ethanol (10-1000 mM) showed a biphasic and concentration-dependent effect on resting pHi (i.e. increase then decrease) by changing the activity of NHE1 and NBC accordingly; vi) treatment with ethanol for 24 hr (<unterline>></unterline> 300 mM) significantly inhibited the expression of NHE1, NBCn1 and NDCBE, while up-regulated NBCe1. CONCLUSIONS Ethanol affects pHi in a concentration-dependent manner by changing function and expression of NHE1 and NBC isoforms in OEC-M1 cells.
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Affiliation(s)
- Shiao-Pieng Lee
- Division of Oral and Maxillofacial Surgery, Department of Dentistry, School of Dentistry, Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan
| | - Shih-Chi Chao
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Shu-Fu Huang
- Department of Pharmacy Practice, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yen-Lin Chen
- Department of Radical Diagnostic, Taoyuan Armed Forced General Hospital, Taoyuan, Taiwan
| | - Yi-Ting Tsai
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan.,Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Shih-Hurng Loh
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.,Department of Pharmacology, National Defense Medical Center, Taipei, Taiwan
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14
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Abstract
The regulation of pH in glioblastoma (GBM) has received significant attention, because it has been linked to tumor metabolism and the stem cell phenotype. The variability in blood perfusion and oxygen tension within tumors suggests that ambient pH values fluctuate across different tumor territories. This chapter describes a detailed protocol for measuring intracellular pH in patient-derived GBM cells in vitro, using the fluorescent pH sensitive dye BCECF.
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Affiliation(s)
| | - Dimitris G Placantonakis
- Department of Neurosurgery, New York University School of Medicine, New York, NY, USA.,Kimmel Center for Stem Cell Biology, New York University School of Medicine, New York, NY, USA.,Perlmutter Cancer Center, New York University School of Medicine, New York, NY, USA.,Neuroscience Institute, New York University School of Medicine, New York, NY, USA.,Brain Tumor Center, New York University School of Medicine, New York, NY, USA
| | - Mitchell Chesler
- Department of Neurosurgery, New York University School of Medicine, New York, NY, USA.,Neuroscience Institute, New York University School of Medicine, New York, NY, USA
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15
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Su PH, Lai YH. A Reliable and Non-destructive Method for Monitoring the Stromal pH in Isolated Chloroplasts Using a Fluorescent pH Probe. Front Plant Sci 2017; 8:2079. [PMID: 29259618 PMCID: PMC5723387 DOI: 10.3389/fpls.2017.02079] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/21/2017] [Indexed: 05/08/2023]
Abstract
The proton gradient established by the pH difference across a biological membrane is essential for many physiological processes, including ATP synthesis and ion and metabolite transport. Currently, ionophores are used to study proton gradients, and determine their importance to biological functions of interest. Because of the lack of an easy method for monitoring the proton gradient across the inner envelope membrane of chloroplasts (ΔpHenv), whether the concentration of ionophores used can effectively abolish the ΔpHenv is not proven for most experiments. To overcome this hindrance, we tried to setup an easy method for real-time monitoring of the stromal pH in buffered, isolated chloroplasts by using fluorescent pH probes; using this method the ΔpHenv can be calculated by subtracting the buffer pH from the measured stromal pH. When three fluorescent dyes, BCECF-AM [2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein acetoxymethyl ester], CFDA-SE [5(6)-Carboxyfluorescein diacetate succinimidyl ester] and SNARF-1 carboxylic acid acetate succinimidyl ester were incubated with isolated chloroplasts, BCECF-AM and CFDA-SE, but not the ester-formed SNARF-1 were taken up by chloroplasts and digested with esterase to release high levels of fluorescence. According to its relatively higher pKa value (6.98, near the physiological pH of the stroma), BCECF was chosen for further development. Due to shielding of the excitation and emission lights by chloroplast pigments, the ratiometric fluorescence of BCECF was highly dependent on the concentration of chloroplasts. By using a fixed concentration of chloroplasts, a highly correlated standard curve of pH to the BCECF ratiometric fluorescence with an r-square value of 0.98 was obtained, indicating the reliability of this method. Consistent with previous reports, the light-dependent formation of ΔpHenv can be detected ranging from 0.15 to 0.33 pH units upon illumination. The concentration of the ionophore nigericin required to collapse the ΔpHenv was then studied. The establishment of a non-destructive method of monitoring the stromal pH will be valuable for studying the roles of the ΔpHenv in chloroplast physiology.
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Affiliation(s)
- Pai-Hsiang Su
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
- Biotechnology Center in Southern Taiwan, Academia Sinica, Tainan, Taiwan
- *Correspondence: Pai-Hsiang Su,
| | - Yen-Hsun Lai
- Biotechnology Center in Southern Taiwan, Academia Sinica, Tainan, Taiwan
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16
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Schumacher CH, Körschen HG, Nicol C, Gasser C, Seifert R, Schwärzel M, Möglich A. A Fluorometric Activity Assay for Light-Regulated Cyclic-Nucleotide-Monophosphate Actuators. Methods Mol Biol 2016; 1408:93-105. [PMID: 26965118 DOI: 10.1007/978-1-4939-3512-3_7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
As a transformative approach in neuroscience and cell biology, optogenetics grants control over manifold cellular events with unprecedented spatiotemporal definition, reversibility, and noninvasiveness. Sensory photoreceptors serve as genetically encoded, light-regulated actuators and hence embody the cornerstone of optogenetics. To expand the scope of optogenetics, ever more naturally occurring photoreceptors are being characterized, and synthetic photoreceptors with customized, light-regulated function are being engineered. Perturbational control over intracellular cyclic-nucleotide-monophosphate (cNMP) levels is achieved via sensory photoreceptors that catalyze the making and breaking of these second messengers in response to light. To facilitate discovery, engineering and quantitative characterization of such light-regulated cNMP actuators, we have developed an efficient fluorometric assay. Both the formation and the hydrolysis of cNMPs are accompanied by proton release which can be quantified with the fluorescent pH indicator 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF). This assay equally applies to nucleotide cyclases, e.g., blue-light-activated bPAC, and to cNMP phosphodiesterases, e.g., red-light-activated LAPD. Key benefits include potential for parallelization and automation, as well as suitability for both purified enzymes and crude cell lysates. The BCECF assay hence stands to accelerate discovery and characterization of light-regulated actuators of cNMP metabolism.
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Affiliation(s)
| | - Heinz G Körschen
- Department of Molecular Sensory Systems, Research Center Caesar, Bonn, Germany
| | - Christopher Nicol
- Institut für Biologie, Neurobiologie, Freie Universität Berlin, Berlin, Germany
| | - Carlos Gasser
- Institut für Biologie, Biophysikalische Chemie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Reinhard Seifert
- Department of Molecular Sensory Systems, Research Center Caesar, Bonn, Germany
| | - Martin Schwärzel
- Institut für Biologie, Neurobiologie, Freie Universität Berlin, Berlin, Germany
| | - Andreas Möglich
- Institut für Biologie, Biophysikalische Chemie, Humboldt-Universität zu Berlin, Berlin, Germany. .,Faculty of Biology, Chemistry and Earth Sciences, Lehrstuhl für Biochemie, Universität Bayreuth, Building NW III, Universitätsstraße 30, Bayreuth, 95440, Germany.
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17
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Tyrtyshnaia AA, Lysenko LV, Madamba F, Manzhulo IV, Khotimchenko MY, Kleschevnikov AM. Acute neuroinflammation provokes intracellular acidification in mouse hippocampus. J Neuroinflammation 2016; 13:283. [PMID: 27809864 PMCID: PMC5094044 DOI: 10.1186/s12974-016-0747-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 10/16/2016] [Indexed: 11/10/2022] Open
Abstract
Background Maintaining pH levels within the physiological norm is an important component of brain homeostasis. However, in some pathological or physiological conditions, the capacity of the pH regulatory system could be overpowered by various factors resulting in a transient or permanent alteration in pH levels. Such changes are often observed in pathological conditions associated with neuroinflammation. We hypothesized that neuroinflammation itself is a factor affecting pH levels in neural tissue. To assess this hypothesis, we examined the effects of acute LPS-induced neuroinflammation on intra- and extracellular pH (pHi and pHo) levels in the CA1 region of mouse hippocampus. Methods Acute neuroinflammation was induced using two approaches: (1) in vivo by i.p. injections of LPS (5 mg/kg) and (2) in vitro by incubating hippocampal slices of naïve animals in the LPS-containing media (1 μg/mL, 1 h at 35 °C). Standard techniques were used to prepare hippocampal slices. pHi was measured using ratiometric pH-sensitive fluorescent dye BCECF-AM. pHo was assessed using calibrated pH-sensitive micropipettes. The presence of neuroinflammation was verified with immunohistochemistry (IL-1β and Iba1) and ELISA (IL-1β and TNF-α). Results A significant reduction of pHi was observed in the slices of the LPS-injected 3-month-old (LPS 7.13 ± 0.03; Sal 7.22 ± 0.03; p = 0.043, r = 0.43) and 19-month-old (LPS 6.78 ± 0.08; Sal 7.13 ± 0.03; p = 0.0001, r = 0.32) mice. In contrast, the levels of pHo within the slice, measured in 19-month-old animals, were not affected (LPS 7.27 ± 0.02; Sal 7.26 ± 0.02; p = 0.6, r = 0.13). A reduction of pHi was also observed in the LPS-treated slices during the interval 3.5–7 h after the LPS exposure (LPS 6.92 ± 0.07; Veh 7.28 ± 0.05; p = 0.0001, r = 0.46). Conclusions Acute LPS-induced neuroinflammation results in a significant intracellular acidification of the CA1 neurons in mouse hippocampus, while the pHo remains largely unchanged. Such changes may represent a specific protective reaction of neural tissue in unfavorable external conditions or be a part of the pathological process. Electronic supplementary material The online version of this article (doi:10.1186/s12974-016-0747-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anna A Tyrtyshnaia
- Department of Neurosciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.,School of Biomedicine, Far Eastern Federal University, Sukhanova 8, Vladivostok, 690950, Russian Federation
| | - Larisa V Lysenko
- Department of Neurosciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.,Academy of Biology and Biotechnology of Southern Federal University, 194/1 Stachki Str, Rostov-na-Donu, 344090, Russian Federation
| | - Francisco Madamba
- Department of Neurosciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Igor V Manzhulo
- School of Biomedicine, Far Eastern Federal University, Sukhanova 8, Vladivostok, 690950, Russian Federation
| | - Maxim Y Khotimchenko
- School of Biomedicine, Far Eastern Federal University, Sukhanova 8, Vladivostok, 690950, Russian Federation
| | - Alexander M Kleschevnikov
- Department of Neurosciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA. .,School of Biomedicine, Far Eastern Federal University, Sukhanova 8, Vladivostok, 690950, Russian Federation.
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18
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Long R, Salouage I, Berdeaux A, Motterlini R, Morin D. CORM-3, a water soluble CO-releasing molecule, uncouples mitochondrial respiration via interaction with the phosphate carrier. Biochim Biophys Acta 2013; 1837:201-9. [PMID: 24161358 DOI: 10.1016/j.bbabio.2013.10.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 09/24/2013] [Accepted: 10/15/2013] [Indexed: 12/21/2022]
Abstract
Carbon monoxide is continuously produced in small quantities in tissues and is an important signaling mediator in mammalian cells. We previously demonstrated that CO delivered to isolated rat heart mitochondria using a water-soluble CO-releasing molecule (CORM-3) is able to uncouple mitochondrial respiration. The aim of this study was to explore more in depth the mechanism(s) of this uncoupling effect. We found that acceleration of mitochondrial O2 consumption and decrease in membrane potential induced by CORM-3 were associated with an increase in mitochondrial swelling. This effect was independent of the opening of the mitochondrial transition pore as cyclosporine A was unable to prevent it. Interestingly, removal of phosphate from the incubation medium suppressed the effects mediated by CORM-3. Blockade of the dicarboxylate carrier, which exchanges dicarboxylate for phosphate, decreased the effects induced by CORM-3 while direct inhibition of the phosphate carrier with N-ethylmaleimide completely abolished the effects of CORM-3. In addition, CORM-3 was able to enhance the transport of phosphate into mitochondria as evidenced by changes in mitochondrial phosphate concentration and mitochondrial swelling that evaluates the activity of the phosphate carrier in de-energized conditions. These results indicate that CORM-3 activates the phosphate carrier leading to an increase in phosphate and proton transport inside mitochondria, both of which could contribute to the non-classical uncoupling effect mediated by CORM-3. The dicarboxylate carrier amplifies this effect by increasing intra-mitochondrial phosphate concentration.
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Affiliation(s)
- Romain Long
- INSERM U955, équipe 3, Faculté de Médecine, Université Paris Est, 94010 Creteil, France.
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19
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Bloksgaard M, Brewer J, Bagatolli LA. Structural and dynamical aspects of skin studied by multiphoton excitation fluorescence microscopy-based methods. Eur J Pharm Sci 2013; 50:586-94. [PMID: 23608611 DOI: 10.1016/j.ejps.2013.04.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 04/08/2013] [Accepted: 04/10/2013] [Indexed: 11/19/2022]
Abstract
This mini-review reports on applications of particular multiphoton excitation microscopy-based methodologies employed in our laboratory to study skin. These approaches allow in-depth optical sectioning of the tissue, providing spatially resolved information on specific fluorescence probes' parameters. Specifically, by applying these methods, spatially resolved maps of water dipolar relaxation (generalized polarization function using the 6-lauroyl-2-(N,N-dimethylamino)naphthale probe), activity of protons (fluorescence lifetime imaging using a proton sensitive fluorescence probe--2,7-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein) and diffusion coefficients of distinct fluorescence probes (raster imaging correlation spectroscopy) can be obtained from different regions of the tissue. Comparative studies of different tissue strata, but also between equivalent regions of normal and abnormal excised skin, including applications of fluctuation correlation spectroscopy on transdermal penetration of liposomes are presented and discussed. The data from the different studies reported reveal the intrinsic heterogeneity of skin and also prove these strategies to be powerful noninvasive tools to explore structural and dynamical aspects of the tissue.
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Affiliation(s)
- Maria Bloksgaard
- Membrane Biophysics and Biophotonics group/MEMPHYS, Center for Biomembrane Physics, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
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