1
|
Mishra SK, Santana JG, Mihailovic J, Hyder F, Coman D. Transmembrane pH gradient imaging in rodent glioma models. NMR Biomed 2024; 37:e5102. [PMID: 38263680 PMCID: PMC10987279 DOI: 10.1002/nbm.5102] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 11/28/2023] [Accepted: 12/16/2023] [Indexed: 01/25/2024]
Abstract
A unique feature of the tumor microenvironment is extracellular acidosis in relation to intracellular milieu. Metabolic reprogramming in tumors results in overproduction of H+ ions (and lactate), which are extruded from the cells to support tumor survival and progression. As a result, the transmembrane pH gradient (ΔpH), representing the difference between intracellular pH (pHi) and extracellular pH (pHe), is posited to be larger in tumors compared with normal tissue. Controlling the transmembrane pH difference has promise as a potential therapeutic target in cancer as it plays an important role in regulating drug delivery into cells. The current study shows successful development of an MRI/MRSI-based technique that provides ΔpH imaging at submillimeter resolution. We applied this technique to image ΔpH in rat brains with RG2 and U87 gliomas, as well as in mouse brains with GL261 gliomas. pHi was measured with Amine and Amide Concentration-Independent Detection (AACID), while pHe was measured with Biosensor Imaging of Redundant Deviation in Shifts (BIRDS). The results indicate that pHi was slightly higher in tumors (7.40-7.43 in rats, 7.39-7.47 in mice) compared with normal brain (7.30-7.38 in rats, 7.32-7.36 in mice), while pHe was significantly lower in tumors (6.62-6.76 in rats, 6.74-6.84 in mice) compared with normal tissue (7.17-7.22 in rats, 7.20-7.21 in mice). As a result, ΔpH was higher in tumors (0.64-0.81 in rats, 0.62-0.65 in mice) compared with normal brain (0.13-0.16 in rats, 0.13-0.16 in mice). This work establishes an MRI/MRSI-based platform for ΔpH imaging at submillimeter resolution in gliomas.
Collapse
Affiliation(s)
- Sandeep Kumar Mishra
- Yale University, Department of Radiology & Biomedical Imaging, New Haven, CT 06510, USA
| | | | - Jelena Mihailovic
- Yale University, Department of Radiology & Biomedical Imaging, New Haven, CT 06510, USA
| | - Fahmeed Hyder
- Yale University, Department of Radiology & Biomedical Imaging, New Haven, CT 06510, USA
- Yale University, Department of Biomedical Engineering, New Haven, CT 06510, USA
| | - Daniel Coman
- Yale University, Department of Radiology & Biomedical Imaging, New Haven, CT 06510, USA
- Yale University, Department of Biomedical Engineering, New Haven, CT 06510, USA
| |
Collapse
|
2
|
Kim Y. Fisetin-Mediated Perturbations of Membrane Permeability and Intracellular pH in Candida albicans. J Microbiol Biotechnol 2024; 34:783-794. [PMID: 38213272 PMCID: PMC11091701 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.
Collapse
Affiliation(s)
- Younhee Kim
- Department of Korean Medicine, Semyung University, Jecheon 27136, Republic of Korea
| |
Collapse
|
3
|
Druzhkova I, Komarova A, Nikonova E, Baigildin V, Mozherov A, Shakirova Y, Lisitsa U, Shcheslavskiy V, Ignatova N, Shirshin E, Shirmanova M, Tunik S. Monitoring the Intracellular pH and Metabolic State of Cancer Cells in Response to Chemotherapy Using a Combination of Phosphorescence Lifetime Imaging Microscopy and Fluorescence Lifetime Imaging Microscopy. Int J Mol Sci 2023; 25:49. [PMID: 38203221 PMCID: PMC10779161 DOI: 10.3390/ijms25010049] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/09/2023] [Accepted: 12/15/2023] [Indexed: 01/12/2024] Open
Abstract
The extracellular matrix (ECM), in which collagen is the most abundant protein, impacts many aspects of tumor physiology, including cellular metabolism and intracellular pH (pHi), as well as the efficacy of chemotherapy. Meanwhile, the role of collagen in differential cell responses to treatment within heterogeneous tumor environments remains poorly investigated. In the present study, we simultaneously monitored the changes in pHi and metabolism in living colorectal cancer cells in vitro upon treatment with a chemotherapeutic combination, FOLFOX (5-fluorouracil, oxaliplatin and leucovorin). The pHi was followed using the new pH-sensitive probe BC-Ga-Ir, working in the mode of phosphorescence lifetime imaging (PLIM), and metabolism was assessed from the autofluorescence of the metabolic cofactor NAD(P)H using fluorescence lifetime imaging (FLIM) with a two-photon laser scanning microscope. To model the ECM, 3D collagen-based hydrogels were used, and comparisons with conventional monolayer cells were made. It was found that FOLFOX treatment caused an early temporal intracellular acidification (reduction in pHi), followed by a shift to more alkaline values, and changed cellular metabolism to a more oxidative state. The presence of unstructured collagen markedly reduced the cytotoxic effects of FOLFOX, and delayed and diminished the pHi and metabolic responses. These results support the observation that collagen is a factor in the heterogeneous response of cancer cells to chemotherapy and a powerful regulator of their metabolic behavior.
Collapse
Affiliation(s)
- Irina Druzhkova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 603005 Nizhny Novgorod, Russia; (A.K.); (A.M.); (U.L.); (V.S.); (N.I.); (M.S.)
| | - Anastasiya Komarova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 603005 Nizhny Novgorod, Russia; (A.K.); (A.M.); (U.L.); (V.S.); (N.I.); (M.S.)
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, 603950 Nizhny Novgorod, Russia
| | - Elena Nikonova
- Laboratory of Clinical Biophotonics, Sechenov First Moscow State Medical University (Sechenov University), 119991 Moscow, Russia; (E.N.); (E.S.)
| | - Vadim Baigildin
- Institute of Chemistry, Saint-Petersburg State University, 198504 St. Petersburg, Russia; (V.B.); (Y.S.)
| | - Artem Mozherov
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 603005 Nizhny Novgorod, Russia; (A.K.); (A.M.); (U.L.); (V.S.); (N.I.); (M.S.)
| | - Yuliya Shakirova
- Institute of Chemistry, Saint-Petersburg State University, 198504 St. Petersburg, Russia; (V.B.); (Y.S.)
| | - Uliana Lisitsa
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 603005 Nizhny Novgorod, Russia; (A.K.); (A.M.); (U.L.); (V.S.); (N.I.); (M.S.)
| | - Vladislav Shcheslavskiy
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 603005 Nizhny Novgorod, Russia; (A.K.); (A.M.); (U.L.); (V.S.); (N.I.); (M.S.)
| | - Nadezhda Ignatova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 603005 Nizhny Novgorod, Russia; (A.K.); (A.M.); (U.L.); (V.S.); (N.I.); (M.S.)
| | - Evgeny Shirshin
- Laboratory of Clinical Biophotonics, Sechenov First Moscow State Medical University (Sechenov University), 119991 Moscow, Russia; (E.N.); (E.S.)
- Faculty of Physics, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Marina Shirmanova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 603005 Nizhny Novgorod, Russia; (A.K.); (A.M.); (U.L.); (V.S.); (N.I.); (M.S.)
| | - Sergey Tunik
- Institute of Chemistry, Saint-Petersburg State University, 198504 St. Petersburg, Russia; (V.B.); (Y.S.)
| |
Collapse
|
4
|
Wu Y, Ge C, Zhang Y, Wang Y, Zhang D. ICT-based fluorescent probes for intracellular pH and biological species detection. Front Chem 2023; 11:1304531. [PMID: 38107254 PMCID: PMC10722144 DOI: 10.3389/fchem.2023.1304531] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 11/14/2023] [Indexed: 12/19/2023] Open
Abstract
Fluorescent probes, typically based on the intramolecular charge transfer (ICT) mechanism, have received considerable research attention in cell detection due to their non-invasiveness, fast response, easy regulation, high sensitivity, and low damage tolerance for in vivo bio-samples. Generally, intracellular pH and biological species such as various gases, metal ions, and anions constitute the foundation of cells and participate in the basic physiological processes, whose abnormal level can lead to poisoning, cardiovascular disease, and cancer in living organisms. Therefore, monitoring of their quantity plays an essential role in understanding the status of organisms and preventing, diagnosing, and treating diseases. In the last decades, remarkable progress has been made in developing ICT probes for the detection of biological elements. In this review, we highlight the recent ICT probes focusing primarily on the detection of intracellular pH, various gases (H2S, CO, H2O2, and NO), metal ions (Cu2+, Hg2+, Pb2+, Zn2+, and Al3+), and anions (ClO-, CN-, SO3 2-, and F-). In addition, we discuss the issues and limitations of ICT-based fluorescent probes for in vivo detection and explore the clinical translational potential and challenges of these materials, providing valuable guidance and insights for the design of fluorescent materials.
Collapse
Affiliation(s)
- You Wu
- Institute of Neuroregeneration and Neurorehabilitation, Qingdao University, Qingdao, China
| | - Chengyan Ge
- The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
| | - Ying Zhang
- Institute of Neuroregeneration and Neurorehabilitation, Qingdao University, Qingdao, China
| | - Yalong Wang
- State Key Laboratory of Digital Medical Engineering, School of Biomedical Engineering, Hainan University, Haikou, China
| | - Deteng Zhang
- Institute of Neuroregeneration and Neurorehabilitation, Qingdao University, Qingdao, China
| |
Collapse
|
5
|
Nakahari T, Suzuki C, Kawaguchi K, Hosogi S, Tanaka S, Asano S, Inui T, Marunaka Y. Ambroxol-Enhanced Frequency and Amplitude of Beating Cilia Controlled by a Voltage-Gated Ca 2+ Channel, Cav1.2, via pH i Increase and [Cl -] i Decrease in the Lung Airway Epithelial Cells of Mice. Int J Mol Sci 2023; 24:16976. [PMID: 38069298 PMCID: PMC10707002 DOI: 10.3390/ijms242316976] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 11/25/2023] [Accepted: 11/28/2023] [Indexed: 12/18/2023] Open
Abstract
Ambroxol (ABX), a frequently prescribed secretolytic agent which enhances the ciliary beat frequency (CBF) and ciliary bend angle (CBA, an index of amplitude) by 30%, activates a voltage-dependent Ca2+ channel (CaV1.2) and a small transient Ca2+ release in the ciliated lung airway epithelial cells (c-LAECs) of mice. The activation of CaV1.2 alone enhanced the CBF and CBA by 20%, mediated by a pHi increasei and a [Cl-]i decrease in the c-LAECs. The increase in pHi, which was induced by the activation of the Na+-HCO3- cotransporter (NBC), enhanced the CBF (by 30%) and CBA (by 15-20%), and a decrease in [Cl-]i, which was induced by the Cl- release via anoctamine 1 (ANO1), enhanced the CBA (by 10-15%). While a Ca2+-free solution or nifedipine (an inhibitor of CaV1.2) inhibited 70% of the CBF and CBA enhancement using ABX, CaV1.2 enhanced most of the CBF and CBA increases using ABX. The activation of the CaV1.2 existing in the cilia stimulates the NBC to increase pHi and ANO1 to decrease the [Cl-]i in the c-LAECs. In conclusion, the pHi increase and the [Cl-]i decrease enhanced the CBF and CBA in the ABX-stimulated c-LAECs.
Collapse
Affiliation(s)
- Takashi Nakahari
- Research Unit for Epithelial Physiology, Research Organization of Science and Technology, BKC, Ritsumeikan University, Kusatsu 525-8577, Japan;
- Medical Research Institute, Kyoto Industrial Health Association, Kyoto 604-8472, Japan
| | - Chihiro Suzuki
- Laboratory of Pharmacotherapy, Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, Takatsuki 569-1094, Japan; (C.S.); (S.T.)
| | - Kotoku Kawaguchi
- Department of Molecular Physiology, Faculty of Pharmacy, BKC, Ritsumeikan University, Kusatsu 525-8577, Japan; (K.K.); (S.A.)
| | - Shigekuni Hosogi
- Department of Clinical and Translational Physiology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan;
| | - Saori Tanaka
- Laboratory of Pharmacotherapy, Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, Takatsuki 569-1094, Japan; (C.S.); (S.T.)
| | - Shinji Asano
- Department of Molecular Physiology, Faculty of Pharmacy, BKC, Ritsumeikan University, Kusatsu 525-8577, Japan; (K.K.); (S.A.)
| | - Toshio Inui
- Saisei Mirai Clinics, Moriguchi 570-0012, Japan;
| | - Yoshinori Marunaka
- Research Unit for Epithelial Physiology, Research Organization of Science and Technology, BKC, Ritsumeikan University, Kusatsu 525-8577, Japan;
- Medical Research Institute, Kyoto Industrial Health Association, Kyoto 604-8472, Japan
| |
Collapse
|
6
|
Shaul D, Lev-Cohain N, Sapir G, Sosna J, Gomori JM, Joskowicz L, Katz-Brull R. Real-time influence of intracellular acidification and Na + /H + exchanger inhibition on in-cell pyruvate metabolism in the perfused mouse heart: A 31 P-NMR and hyperpolarized 13 C-NMR study. NMR Biomed 2023; 36:e4993. [PMID: 37424280 DOI: 10.1002/nbm.4993] [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] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 05/31/2023] [Accepted: 06/01/2023] [Indexed: 07/11/2023]
Abstract
Disruption of acid-base balance is linked to various diseases and conditions. In the heart, intracellular acidification is associated with heart failure, maladaptive cardiac hypertrophy, and myocardial ischemia. Previously, we have reported that the ratio of the in-cell lactate dehydrogenase (LDH) to pyruvate dehydrogenase (PDH) activities is correlated with cardiac pH. To further characterize the basis for this correlation, these in-cell activities were investigated under induced intracellular acidification without and with Na+ /H+ exchanger (NHE1) inhibition by zoniporide. Male mouse hearts (n = 30) were isolated and perfused retrogradely. Intracellular acidification was performed in two ways: (1) with the NH4 Cl prepulse methodology; and (2) by combining the NH4 Cl prepulse with zoniporide. 31 P NMR spectroscopy was used to determine the intracellular cardiac pH and to quantify the adenosine triphosphate and phosphocreatine content. Hyperpolarized [1-13 C]pyruvate was obtained using dissolution dynamic nuclear polarization. 13 C NMR spectroscopy was used to monitor hyperpolarized [1-13 C]pyruvate metabolism and determine enzyme activities in real time at a temporal resolution of a few seconds using the product-selective saturating excitation approach. The intracellular acidification induced by the NH4 Cl prepulse led to reduced LDH and PDH activities (-16% and -39%, respectively). This finding is in line with previous evidence of reduced myocardial contraction and therefore reduced metabolic activity upon intracellular acidification. Concomitantly, the LDH/PDH activity ratio increased with the reduction in pH, as previously reported. Combining the NH4 Cl prepulse with zoniporide led to a greater reduction in LDH activity (-29%) and to increased PDH activity (+40%). These changes resulted in a surprising decrease in the LDH/PDH ratio, as opposed to previous predictions. Zoniporide alone (without intracellular acidification) did not change these enzyme activities. A possible explanation for the enzymatic changes observed during the combination of the NH4 Cl prepulse and NHE1 inhibition may be related to mitochondrial NHE1 inhibition, which likely negates the mitochondrial matrix acidification. This effect, combined with the increased acidity in the cytosol, would result in an enhanced H+ gradient across the mitochondrial membrane and a temporarily higher pyruvate transport into the mitochondria, thereby increasing the PDH activity at the expense of the cytosolic LDH activity. These findings demonstrate the complexity of in-cell cardiac metabolism and its dependence on intracellular acidification. This study demonstrates the capabilities and limitations of hyperpolarized [1-13 C]pyruvate in the characterization of intracellular acidification as regards cardiac pathologies.
Collapse
Affiliation(s)
- David Shaul
- Department of Radiology, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- The Wohl Institute for Translational Medicine, Hadassah Medical Organization, Jerusalem, Israel
| | - Naama Lev-Cohain
- Department of Radiology, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Gal Sapir
- Department of Radiology, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- The Wohl Institute for Translational Medicine, Hadassah Medical Organization, Jerusalem, Israel
| | - Jacob Sosna
- Department of Radiology, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - J Moshe Gomori
- Department of Radiology, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Leo Joskowicz
- School of Computer Science and Engineering, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rachel Katz-Brull
- Department of Radiology, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- The Wohl Institute for Translational Medicine, Hadassah Medical Organization, Jerusalem, Israel
| |
Collapse
|
7
|
Sukhova EM, Yudina LM, Sukhov VS. Changes in Activity of the Plasma Membrane H+-ATPase as a Link Between Formation of Electrical Signals and Induction of Photosynthetic Responses in Higher Plants. Biochemistry (Mosc) 2023; 88:1488-1503. [PMID: 38105019 DOI: 10.1134/s0006297923100061] [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] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 09/05/2023] [Accepted: 09/13/2023] [Indexed: 12/19/2023]
Abstract
Action of numerous adverse environmental factors on higher plants is spatially-heterogenous; it means that induction of a systemic adaptive response requires generation and transmission of the stress signals. Electrical signals (ESs) induced by local action of stressors include action potential, variation potential, and system potential and they participate in formation of fast physiological changes at the level of a whole plant, including photosynthetic responses. Generation of these ESs is accompanied by the changes in activity of H+-ATPase, which is the main system of electrogenic proton transport across the plasma membrane. Literature data show that the changes in H+-ATPase activity and related changes in intra- and extracellular pH play a key role in the ES-induced inactivation of photosynthesis in non-irritated parts of plants. This inactivation is caused by both suppression of CO2 influx into mesophyll cells in leaves, which can be induced by the apoplast alkalization and, probably, cytoplasm acidification, and direct influence of acidification of stroma and lumen of chloroplasts on light and, probably, dark photosynthetic reactions. The ES-induced inactivation of photosynthesis results in the increasing tolerance of photosynthetic machinery to the action of adverse factors and probability of the plant survival.
Collapse
Affiliation(s)
- Ekaterina M Sukhova
- Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, 603022, Russia
| | - Lyubov' M Yudina
- Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, 603022, Russia
| | - Vladimir S Sukhov
- Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, 603022, Russia.
| |
Collapse
|
8
|
Gallo A, Murano C, Notariale R, Caramiello D, Tosti E, Cecchini Gualandi S, Boni R. Immune and Reproductive Biomarkers in Female Sea Urchins Paracentrotus lividus under Heat Stress. Biomolecules 2023; 13:1216. [PMID: 37627280 PMCID: PMC10452167 DOI: 10.3390/biom13081216] [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: 06/30/2023] [Revised: 07/31/2023] [Accepted: 08/02/2023] [Indexed: 08/27/2023] Open
Abstract
The functioning of the immune and reproductive systems is crucial for the fitness and survival of species and is strongly influenced by the environment. To evaluate the effects of short-term heat stress (HS) on these systems, confirming and deepening previous studies, female sea urchin Paracentrotus lividus were exposed for 7 days to 17 °C, 23 and 28 °C. Several biomarkers were detected such as the ferric reducing power (FRAP), ABTS-based total antioxidant capacity (TAC-ABTS), nitric oxide metabolites (NOx), total thiol levels (TTL), myeloperoxidase (MPO) and protease (PA) activities in the coelomic fluid (CF) and mitochondrial membrane potential (MMP), H2O2 content and intracellular pH (pHi) in eggs and coelomocytes, in which TAC-ABTS and reactive nitrogen species (RNS) were also analyzed. In the sea urchins exposed to HS, CF analysis showed a decrease in FRAP levels and an increase in TAC-ABTS, TTL, MPO and PA levels; in coelomocytes, RNS, MMP and H2O2 content increased, whereas pHi decreased; in eggs, increases in MMP, H2O2 content and pHi were found. In conclusion, short-term HS leads to changes in five out of the six CF biomarkers analyzed and functional alterations in the cells involved in either reproductive or immune activities.
Collapse
Affiliation(s)
- Alessandra Gallo
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; (A.G.); (R.N.); (E.T.)
| | - Carola Murano
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy;
| | - Rosaria Notariale
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; (A.G.); (R.N.); (E.T.)
| | - Davide Caramiello
- Unit Marine Resources for Research, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy;
| | - Elisabetta Tosti
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; (A.G.); (R.N.); (E.T.)
| | | | - Raffaele Boni
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; (A.G.); (R.N.); (E.T.)
- Department of Sciences, University of Basilicata, Via dell’Ateneo lucano, 10, 85100 Potenza, Italy
| |
Collapse
|
9
|
Michl J, Monterisi S, White B, Blaszczak W, Hulikova A, Abdullayeva G, Bridges E, Yin Z, Bodmer WF, Swietach P. Acid-adapted cancer cells alkalinize their cytoplasm by degrading the acid-loading membrane transporter anion exchanger 2, SLC4A2. Cell Rep 2023; 42:112601. [PMID: 37270778 DOI: 10.1016/j.celrep.2023.112601] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [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: 11/22/2022] [Revised: 03/16/2023] [Accepted: 05/19/2023] [Indexed: 06/06/2023] Open
Abstract
Acidic environments reduce the intracellular pH (pHi) of most cells to levels that are sub-optimal for growth and cellular functions. Yet, cancers maintain an alkaline cytoplasm despite low extracellular pH (pHe). Raised pHi is thought to be beneficial for tumor progression and invasiveness. However, the transport mechanisms underpinning this adaptation have not been studied systematically. Here, we characterize the pHe-pHi relationship in 66 colorectal cancer cell lines and identify the acid-loading anion exchanger 2 (AE2, SLC4A2) as a regulator of resting pHi. Cells adapt to chronic extracellular acidosis by degrading AE2 protein, which raises pHi and reduces acid sensitivity of growth. Acidity inhibits mTOR signaling, which stimulates lysosomal function and AE2 degradation, a process reversed by bafilomycin A1. We identify AE2 degradation as a mechanism for maintaining a conducive pHi in tumors. As an adaptive mechanism, inhibiting lysosomal degradation of AE2 is a potential therapeutic target.
Collapse
Affiliation(s)
- Johanna Michl
- Department of Physiology, Anatomy and Genetics, Parks Road, Oxford OX1 3PT, UK
| | - Stefania Monterisi
- Department of Physiology, Anatomy and Genetics, Parks Road, Oxford OX1 3PT, UK
| | - Bobby White
- Department of Physiology, Anatomy and Genetics, Parks Road, Oxford OX1 3PT, UK
| | - Wiktoria Blaszczak
- Department of Physiology, Anatomy and Genetics, Parks Road, Oxford OX1 3PT, UK
| | - Alzbeta Hulikova
- Department of Physiology, Anatomy and Genetics, Parks Road, Oxford OX1 3PT, UK
| | - Gulnar Abdullayeva
- MRC Weatherall Institute for Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Esther Bridges
- Department of NDM Experimental Medicine, MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, JR Hospital, Headington, Oxford OX3 9DS, UK
| | - Zinan Yin
- Department of NDM Experimental Medicine, MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, JR Hospital, Headington, Oxford OX3 9DS, UK
| | - Walter F Bodmer
- MRC Weatherall Institute for Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Pawel Swietach
- Department of Physiology, Anatomy and Genetics, Parks Road, Oxford OX1 3PT, UK.
| |
Collapse
|
10
|
Zhang C, Liu Y, An H, Wang X, Xu L, Deng H, Wu S, Zhang JR, Liu X. Amino Acid Starvation-Induced Glutamine Accumulation Enhances Pneumococcal Survival. mSphere 2023; 8:e0062522. [PMID: 37017541 PMCID: PMC10286718 DOI: 10.1128/msphere.00625-22] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 02/19/2023] [Indexed: 04/06/2023] Open
Abstract
Bacteria are known to cope with amino acid starvation by the stringent response signaling system, which is mediated by the accumulation of the (p)ppGpp alarmones when uncharged tRNAs stall at the ribosomal A site. While a number of metabolic processes have been shown to be regulatory targets of the stringent response in many bacteria, the global impact of amino acid starvation on bacterial metabolism remains obscure. This work reports the metabolomic profiling of the human pathogen Streptococcus pneumoniae under methionine starvation. Methionine limitation led to the massive overhaul of the pneumococcal metabolome. In particular, methionine-starved pneumococci showed a massive accumulation of many metabolites such as glutamine, glutamic acid, lactate, and cyclic AMP (cAMP). In the meantime, methionine-starved pneumococci showed a lower intracellular pH and prolonged survival. Isotope tracing revealed that pneumococci depend predominantly on amino acid uptake to replenish intracellular glutamine but cannot convert glutamine to methionine. Further genetic and biochemical analyses strongly suggested that glutamine is involved in the formation of a "prosurvival" metabolic state by maintaining an appropriate intracellular pH, which is accomplished by the enzymatic release of ammonia from glutamine. Methionine starvation-induced intracellular pH reduction and glutamine accumulation also occurred to various extents under the limitation of other amino acids. These findings have uncovered a new metabolic mechanism of bacterial adaptation to amino acid limitation and perhaps other stresses, which may be used as a potential therapeutic target for infection control. IMPORTANCE Bacteria are known to cope with amino acid starvation by halting growth and prolonging survival via the stringent response signaling system. Previous investigations have allowed us to understand how the stringent response regulates many aspects of macromolecule synthesis and catabolism, but how amino acid starvation promotes bacterial survival at the metabolic level remains largely unclear. This paper reports our systematic profiling of the methionine starvation-induced metabolome in S. pneumoniae. To the best of our knowledge, this represents the first reported bacterial metabolome under amino acid starvation. These data have revealed that the significant accumulation of glutamine and lactate enables S. pneumoniae to form a "prosurvival" metabolic state with a lower intracellular pH, which inhibits bacterial growth for prolonged survival. Our findings have provided insightful information on the metabolic mechanisms of pneumococcal adaptation to nutrient limitation during the colonization of the human upper airway.
Collapse
Affiliation(s)
- Chengwang Zhang
- Department of Basic Medical Science, School of Medicine, Lishui University, Lishui, Zhejiang, China
| | - Yanhong Liu
- Center for Infectious Disease Research, Department of Basic Medical Science, School of Medicine, Tsinghua University, Beijing, China
| | - Haoran An
- Center for Infectious Disease Research, Department of Basic Medical Science, School of Medicine, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
| | - Xueying Wang
- National Protein Science Facility, Tsinghua University, Beijing, China
| | - Lina Xu
- National Protein Science Facility, Tsinghua University, Beijing, China
| | - Haiteng Deng
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Songquan Wu
- Department of Basic Medical Science, School of Medicine, Lishui University, Lishui, Zhejiang, China
| | - Jing-Ren Zhang
- Center for Infectious Disease Research, Department of Basic Medical Science, School of Medicine, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
| | - Xiaohui Liu
- National Protein Science Facility, Tsinghua University, Beijing, China
- School of Life Sciences, Tsinghua University, Beijing, China
| |
Collapse
|
11
|
Tian H, Gu C, Li W, Tong T, Wang Y, Yang Y, Wang H, Dai Z, Chen P, Wang F, Lin X, Shangguan L, Wang L. Neutralization of Intracellular pH Homeostasis to Inhibit Osteoclasts Based on a Spatiotemporally Selective Delivery System. Nano Lett 2023; 23:4101-4110. [PMID: 37183806 DOI: 10.1021/acs.nanolett.2c04295] [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] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Osteoporosis is a global disease caused by abnormal overactivation of osteoclasts. The acidic environment in sealing zone of osteoclasts with H+ pumped from cytoplasm is critical to the maturation of osteoclasts. Therefore, reducing the intracellular H+ concentration can reduce the H+ secretion of osteoclasts from the source. In our study, we developed a novel nanovesicle which encapsulates Na2HPO4 with a liposome hybridizes with preosteoclast membrane (Na2HPO4@Lipo-pOCm). These nanovesicles release Na2HPO4 into the preosteoclast by targeting preosteoclasts and membrane fusion, reducing the intracellular H+ concentration, and achieve biological cascade regulation of osteoclasts through simple pH regulation. In vitro and in vivo experiments confirmed that these nanovesicles reduce mitochondrial membrane potential by decreasing intracellular H+ concentration, thereby reducing the ROS in osteoclasts as well as the expression of the upstream transcription factor FOXM1 of Acp5. In short, this nanovesicle can significantly inhibit the osteoclasts and ameliorate osteoporosis caused by OVX.
Collapse
Affiliation(s)
- Hongsen Tian
- Department of Spine Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei Province 050000, China
- Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, Zhejiang 310016, China
| | - Chenhui Gu
- Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, Zhejiang 310016, China
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, Zhejiang 310016, China
| | - Wenshuai Li
- Department of Spine Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei Province 050000, China
- Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, Zhejiang 310016, China
| | - Tong Tong
- Department of Spine Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei Province 050000, China
| | - Yunsheng Wang
- Department of Spine Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei Province 050000, China
| | - Yang Yang
- Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, Zhejiang 310016, China
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, Zhejiang 310016, China
| | - Haoli Wang
- Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, Zhejiang 310016, China
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, Zhejiang 310016, China
| | - Zhanqiu Dai
- Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, Zhejiang 310016, China
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, Zhejiang 310016, China
| | - Pengfei Chen
- Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, Zhejiang 310016, China
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, Zhejiang 310016, China
| | - Feng Wang
- Department of Spine Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei Province 050000, China
| | - Xianfeng Lin
- Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, Zhejiang 310016, China
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, Zhejiang 310016, China
| | - Liqing Shangguan
- Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang Province, Hangzhou, Zhejiang 310016, China
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Medical College of Zhejiang University, Hangzhou, Zhejiang 310016, China
| | - Linfeng Wang
- Department of Spine Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei Province 050000, China
| |
Collapse
|
12
|
Van Renterghem C, Nemecz Á, Delarue-Cochin S, Joseph D, Corringer PJ. Fumarate as positive modulator of allosteric transitions in the pentameric ligand-gated ion channel GLIC: Requirement of an intact vestibular pocket. J Physiol 2023. [PMID: 37026398 DOI: 10.1113/jp283765] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 04/03/2023] [Indexed: 04/08/2023] Open
Abstract
GLIC is a prokaryotic orthologue of brain pentameric neurotransmitter receptors. Using whole-cell patch-clamp electrophysiology in a host cell line, we show that short-chain di-carboxylate compounds are positive modulators of pHo 5-evoked GLIC activity, with a rank order of action fumarate > succinate > malonate > glutarate. Potentiation by fumarate depends on intracellular pH, mainly as a result of a strong decrease of the pHo 5-evoked current when intracellular pH decreases. The modulating effect of fumarate also depends on extracellular pH, as fumarate is a weak inhibitor at pHo 6 and shows no agonist action at neutral pHo. A mutational analysis of residue-dependency for succinate and fumarate effects, based on two carboxylate-binding pockets previously identified by crystallography (Fourati et al. 2020), shows that positive modulation involves both the inter-subunit pocket, homologous to the neurotransmitter-binding orthotopic site, and the intra-subunit (also called vestibular) pocket. An almost similar pattern of mutational impact is observed for the effect of caffeate, a known negative modulator. We propose, for both di-carboxylate compounds and caffeate, a model where the inter-subunit pocket is the actual binding site, and the region corresponding to the vestibular pocket is required either for inter-subunit binding itself, or for binding-to-gating coupling during the allosteric transitions involved in pore gating modulation. KEY POINTS: Using a bacterial orthologue of brain pentameric neurotransmitter receptors, we show that the orthotopic/orthosteric agonist site and the adjacent vestibular region are functionally inter-dependent in mediating compound-elicited modulation. We propose that the two sites in the extracellular domain are involved "in series", a mechanism which may have relevance to Eukaryote receptors. We show that short-chain di-carboxylate compounds are positive modulators of GLIC. The most potent compound identified is fumarate, known to occupy the orthotopic/orthosteric site in previously published crystal structures. We show that intracellular pH modulates GLIC allosteric transitions, as previously known for extracellular pH. We report a caesium to sodium permeability ratio (PCs/PNa) of 0.54 for GLIC ion pore. Abstract figure legends We show that a low-pH intracellular solution negatively modulates allosteric transitions (see Legend to Fig. 3E for details), in the Prokaryote pentameric ligand-gated ion channel (pLGIC) GLIC, known to be activated by the agonist action of low-pH extracellular solutions. We use this property in the characterization of fumarate, and other compounds, as positive modulators of allosteric transitions. Data from a mutational analysis in two carboxylate binding pockets, together with published crystallographic data, shows that the modulator action of compounds binding at the conserved orthotopic site (homologous to the neurotransmitter / agonist binding site in brain pLGICs) is under the strict control of the adjacent intra-subunit vestibular region. We propose that both positive and negative modulators of allosteric transitions act by binding to the orthotopic main binding site. The 2-site "in series" mechanism proposed may have some relevance to Eukaryote pLGICs. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
| | - Ákos Nemecz
- Institut Pasteur, Université Paris-Cité, Paris, France
| | | | - Delphine Joseph
- Université Paris-Saclay, CNRS, BioCIS, Châtenay-Malabry, France
| | | |
Collapse
|
13
|
Hammers DE, Donahue DL, Tucker Z, Ashfeld BL, Ploplis VA, Castellino FJ, Lee SW. Streptolysin S targets the sodium-bicarbonate cotransporter NBCn1 to induce inflammation and cytotoxicity in human keratinocytes during Group A Streptococcal infection. Front Cell Infect Microbiol 2022; 12:1002230. [PMID: 36389147 PMCID: PMC9663810 DOI: 10.3389/fcimb.2022.1002230] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 09/29/2022] [Indexed: 11/30/2022] Open
Abstract
Group A <i>Streptococcus</i> (GAS, <i>Streptococcus pyogenes</i>) is a Gram-positive human pathogen that employs several secreted and surface-bound virulence factors to manipulate its environment, allowing it to cause a variety of disease outcomes. One such virulence factor is Streptolysin S (SLS), a ribosomally-produced peptide toxin that undergoes extensive post-translational modifications. The activity of SLS has been studied for over 100 years owing to its rapid and potent ability to lyse red blood cells, and the toxin has been shown to play a major role in GAS virulence <i>in vivo</i>. We have previously demonstrated that SLS induces hemolysis by targeting the chloride-bicarbonate exchanger Band 3 in erythrocytes, indicating that SLS is capable of targeting host proteins to promote cell lysis. However, the possibility that SLS has additional protein targets in other cell types, such as keratinocytes, has not been explored. Here, we use bioinformatics analysis and chemical inhibition studies to demonstrate that SLS targets the electroneutral sodium-bicarbonate cotransporter NBCn1 in keratinocytes during GAS infection. SLS induces NF-κB activation and host cytotoxicity in human keratinocytes, and these processes can be mitigated by treating keratinocytes with the sodium-bicarbonate cotransport inhibitor S0859. Furthermore, treating keratinocytes with SLS disrupts the ability of host cells to regulate their intracellular pH, and this can be monitored in real time using the pH-sensitive dye pHrodo Red AM in live imaging studies. These results demonstrate that SLS is a multifunctional bacterial toxin that GAS uses in numerous context-dependent ways to promote host cell cytotoxicity and increase disease severity. Studies to elucidate additional host targets of SLS have the potential to impact the development of therapeutics for severe GAS infections.
Collapse
Affiliation(s)
- Daniel E. Hammers
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States,Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, United States
| | - Deborah L. Donahue
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States
| | - Zachary D. Tucker
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States
| | - Brandon L. Ashfeld
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States
| | - Victoria A. Ploplis
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States
| | - Francis J. Castellino
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States
| | - Shaun W. Lee
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States,Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States,*Correspondence: Shaun W. Lee,
| |
Collapse
|
14
|
Matt AS, Chang WW, Hu MY. Extracellular carbonic anhydrase activity promotes a carbon concentration mechanism in metazoan calcifying cells. Proc Natl Acad Sci U S A 2022; 119:e2203904119. [PMID: 36161891 DOI: 10.1073/pnas.2203904119] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Many calcifying organisms utilize metabolic CO2 to generate CaCO3 minerals to harden their shells and skeletons. Carbonic anhydrases are evolutionary ancient enzymes that have been proposed to play a key role in the calcification process, with the underlying mechanisms being little understood. Here, we used the calcifying primary mesenchyme cells (PMCs) of sea urchin larva to study the role of cytosolic (iCAs) and extracellular carbonic anhydrases (eCAs) in the cellular carbon concentration mechanism (CCM). Molecular analyses identified iCAs and eCAs in PMCs and highlight the prominent expression of a glycosylphosphatidylinositol-anchored membrane-bound CA (Cara7). Intracellular pH recordings in combination with CO2 pulse experiments demonstrated iCA activity in PMCs. iCA activity measurements, together with pharmacological approaches, revealed an opposing contribution of iCAs and eCAs on the CCM. H+-selective electrodes were used to demonstrate eCA-catalyzed CO2 hydration rates at the cell surface. Knockdown of Cara7 reduced extracellular CO2 hydration rates accompanied by impaired formation of specific skeletal segments. Finally, reduced pHi regulatory capacities during inhibition and knockdown of Cara7 underscore a role of this eCA in cellular HCO3- uptake. This work reveals the function of CAs in the cellular CCM of a marine calcifying animal. Extracellular hydration of metabolic CO2 by Cara7 coupled to HCO3- uptake mechanisms mitigates the loss of carbon and reduces the cellular proton load during the mineralization process. The findings of this work provide insights into the cellular mechanisms of an ancient biological process that is capable of utilizing CO2 to generate a versatile construction material.
Collapse
|
15
|
Kang J, Nagelkerken I, Rummer JL, Rodolfo‐Metalpa R, Munday PL, Ravasi T, Schunter C. Rapid evolution fuels transcriptional plasticity to ocean acidification. Glob Chang Biol 2022; 28:3007-3022. [PMID: 35238117 PMCID: PMC9310587 DOI: 10.1111/gcb.16119] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [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: 09/24/2021] [Revised: 12/20/2021] [Accepted: 01/22/2022] [Indexed: 05/16/2023]
Abstract
Ocean acidification (OA) is postulated to affect the physiology, behavior, and life-history of marine species, but potential for acclimation or adaptation to elevated pCO2 in wild populations remains largely untested. We measured brain transcriptomes of six coral reef fish species at a natural volcanic CO2 seep and an adjacent control reef in Papua New Guinea. We show that elevated pCO2 induced common molecular responses related to circadian rhythm and immune system but different magnitudes of molecular response across the six species. Notably, elevated transcriptional plasticity was associated with core circadian genes affecting the regulation of intracellular pH and neural activity in Acanthochromis polyacanthus. Gene expression patterns were reversible in this species as evidenced upon reduction of CO2 following a natural storm-event. Compared with other species, Ac. polyacanthus has a more rapid evolutionary rate and more positively selected genes in key functions under the influence of elevated CO2 , thus fueling increased transcriptional plasticity. Our study reveals the basis to variable gene expression changes across species, with some species possessing evolved molecular toolkits to cope with future OA.
Collapse
Affiliation(s)
- Jingliang Kang
- Swire Institute of Marine ScienceSchool of Biological SciencesThe University of Hong KongHong KongHong Kong SARChina
| | - Ivan Nagelkerken
- Southern Seas Ecology LaboratoriesSchool of Biological Sciences & The Environment InstituteThe University of AdelaideAdelaideSouth AustraliaAustralia
| | - Jodie L. Rummer
- Australian Research Council Centre of Excellence for Coral Reef StudiesJames Cook UniversityTownsvilleAustralia
- College of Science and EngineeringJames Cook UniversityTownsvilleQueenslandAustralia
| | - Riccardo Rodolfo‐Metalpa
- ENTROPIE – UMR 9220 (CNRS, IRD, UR, UNC, IFREMER)IRD Institut de Recherche pour le DéveloppementNouméa cedexNew Caledonia
| | - Philip L. Munday
- Australian Research Council Centre of Excellence for Coral Reef StudiesJames Cook UniversityTownsvilleAustralia
| | - Timothy Ravasi
- Australian Research Council Centre of Excellence for Coral Reef StudiesJames Cook UniversityTownsvilleAustralia
- Marine Climate Change UnitOkinawa Institute of Science and Technology Graduate UniversityOnna‐sonJapan
| | - Celia Schunter
- Swire Institute of Marine ScienceSchool of Biological SciencesThe University of Hong KongHong KongHong Kong SARChina
- State Key Laboratory of Marine PollutionCity University of Hong KongHong KongHong Kong SARChina
| |
Collapse
|
16
|
Pyrshev K, Khayyat NH, Stavniichuk A, Tomilin VN, Zaika O, Ramkumar N, Pochynyuk O. ClC-K2 Cl - channel allows identification of A- and B-type of intercalated cells in split-opened collecting ducts. FASEB J 2022; 36:e22275. [PMID: 35349181 PMCID: PMC9014849 DOI: 10.1096/fj.202200160r] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [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: 01/28/2022] [Revised: 03/01/2022] [Accepted: 03/14/2022] [Indexed: 11/11/2022]
Abstract
The collecting duct is a highly adaptive terminal part of the nephron, which is essential for maintaining systemic homeostasis. Principal and intercalated cells perform different physiological tasks and exhibit distinctive morphology. However, acid-secreting A- and base secreting B-type of intercalated cells cannot be easily separated in functional studies. We used BCECF-sensitive intracellular pH (pHi ) measurements in split-opened collecting ducts followed by immunofluorescent microscopy in WT and intercalated cell-specific ClC-K2-/- mice to demonstrate that ClC-K2 inhibition enables to distinguish signals from A- and B-intercalated cells. We show that ClC-K2 Cl- channel is expressed on the basolateral side of intercalated cells, where it governs Cl- -dependent H+ /HCO3 - transport. ClC-K2 blocker, NPPB, caused acidification or alkalization in different subpopulations of intercalated cells in WT but not ClC-K2-/- mice. Immunofluorescent assessment of the same collecting ducts revealed that NPPB increased pHi in AE1-positive A-type and decreased pHi in pendrin-positive B-type of intercalated cells. Induction of metabolic acidosis led to a significantly augmented abundance and H+ secretion in A-type and decreased proton transport in B-type of intercalated cells, whereas metabolic alkalosis caused the opposite changes in intercalated cell function, but did not substantially change their relative abundance. Overall, we show that inhibition of ClC-K2 can be employed to discriminate between A- and B-type of intercalated cells in split-opened collecting duct preparations. We further demonstrate that this method can be used to independently monitor changes in the functional status and abundance of A- and B-type in response to systemic acid/base stimuli.
Collapse
Affiliation(s)
- Kyrylo Pyrshev
- Department of Integrative Biology and Pharmacology, the University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Naghmeh Hassanzadeh Khayyat
- Department of Integrative Biology and Pharmacology, the University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Anna Stavniichuk
- Department of Integrative Biology and Pharmacology, the University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Viktor N Tomilin
- Department of Integrative Biology and Pharmacology, the University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Oleg Zaika
- Department of Integrative Biology and Pharmacology, the University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Nirupama Ramkumar
- Division of Nephrology and Hypertension, University of Utah Health, Salt Lake City, Utah, USA
| | - Oleh Pochynyuk
- Department of Integrative Biology and Pharmacology, the University of Texas Health Science Center at Houston, Houston, Texas, USA
| |
Collapse
|
17
|
Branson SR, Broadbent JR, Carpenter CE. Internal pH and Acid Anion Accumulation in Listeria monocytogenes and Escherichia coli Exposed to Lactic or Acetic Acids at Mildly Acidic pH. Front Microbiol 2022; 12:803271. [PMID: 35281309 PMCID: PMC8908002 DOI: 10.3389/fmicb.2021.803271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 10/27/2021] [Accepted: 12/20/2021] [Indexed: 12/19/2022] Open
Abstract
Organic acids are widely employed in the food industry to control growth of microbial pathogens such as Listeria monocytogenes and Escherichia coli. There is substantial evidence that intracellular accumulation of acid anions is a major inhibitor to cell viability, and that some bacteria are able to combat the toxic effects of anion accumulation via their ability to continue active metabolism at a lower intracellular pH (pHi). This study followed the accumulation of acid anion into the cell pellet and parallel changes in pHi in two human pathogenic strains of L. monocytogenes (N1-227 and R2-499) and in E. coli O157:H7 after exposure to sub-bacteriostatic levels of lactic and acetic acids at mildly acidic pH 6. The methodology employed in these studies included independent measures of pHi and intracellular anion accumulation. For the latter work, cells were pelleted through bromododecane to strip off extracellular water and solutes. Listeria strains accumulated 1.5-fold acetate or 2.5-fold lactate as compared to the external environment while mounting a defense against anion accumulation that included up to a 1-unit pHi drop from 7.5 to 6.5 for strain R2-499. E. coli accumulated 2.5-fold acetate but not lactate and apparently made use of combat mechanisms other than lowering pHi not explored in this study. Inulin was employed to estimate the fractional volume of cell pellet present as intracellular space. That intracellular fraction was 0.24 for E. coli, which infers that acid accumulation into the intercellular space was minimally 4 × that measured for the entire pellet. An intercellular fraction of pellet was not measurable for strains of L. monocytogenes. The data also bring into question the efficacy across bacterial species of the common, but confounding, practice of using intracellular anion accumulation as a measure of pHi, and vice versa.
Collapse
Affiliation(s)
- Savannah R Branson
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan, UT, United States
| | - Jeff R Broadbent
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan, UT, United States
| | - Charles E Carpenter
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan, UT, United States
| |
Collapse
|
18
|
Cure MC, Cure E. Prolonged NHE Activation may be both Cause and Outcome of Cytokine Release Syndrome in COVID-19. Curr Pharm Des 2022; 28:1815-1822. [PMID: 35838211 DOI: 10.2174/1381612828666220713121741] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [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: 03/03/2022] [Accepted: 06/27/2022] [Indexed: 02/06/2023]
Abstract
The release of cytokines and chemokines such as IL-1β, IL-2, IL-6, IL-7, IL-10, TNF-α, IFN-γ, CCL2, CCL3, and CXCL10 is increased in critically ill patients with COVID-19. Excessive cytokine release during COVID-19 is related to increased morbidity and mortality. Several mechanisms are put forward for cytokine release syndrome during COVID-19. Here we have mentioned novel pathways. SARS-CoV-2 increases angiotensin II levels by rendering ACE2 nonfunctional. Angiotensin II causes cytokine release via AT1 and AT2 receptors. Moreover, angiotensin II potently stimulates the Na+/H+ exchanger (NHE). It is a pump found in the membranes of many cells that pumps Na+ inward and H+ outward. NHE has nine isoforms. NHE1 is the most common isoform found in endothelial cells and many cells. NHE is involved in keeping the intracellular pH within physiological limits. When the intracellular pH is acidic, NHE is activated, bringing the intracellular pH to physiological levels, ending its activity. Sustained NHE activity is highly pathological and causes many problems. Prolonged NHE activation in COVID-19 may cause a decrease in intracellular pH through H+ ion accumulation in the extracellular area and subsequent redox reactions. The activation reduces the intracellular K+ concentration and leads to Na+ and Ca2+ overload. Increased ROS can cause intense cytokine release by stimulating NF-κB and NLRP3 inflammasomes. Cytokines also cause overstimulation of NHE. As the intracellular pH decreases, SARS-CoV-2 rapidly infects new cells, increasing the viral load. This vicious circle increases morbidity and mortality in patients with COVID-19. On the other hand, SARS-CoV-2 interaction with NHE3 in intestinal tissue is different from other tissues. SARS-CoV-2 can trigger CRS via NHE3 inhibition by disrupting the intestinal microbiota. This review aimed to help develop new treatment models against SARS-CoV-2- induced CRS by revealing the possible effects of SARS-CoV-2 on the NHE.
Collapse
Affiliation(s)
| | - Erkan Cure
- Department of Internal Medicine, Bagcilar Medilife Hospital, Istanbul, Turkey
| |
Collapse
|
19
|
Boyd PS, Breitling J, Korzowski A, Zaiss M, Franke VL, Mueller-Decker K, Glinka A, Ladd ME, Bachert P, Goerke S. Mapping intracellular pH in tumors using amide and guanidyl CEST-MRI at 9.4 T. Magn Reson Med 2021; 87:2436-2452. [PMID: 34958684 DOI: 10.1002/mrm.29133] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 11/26/2021] [Accepted: 12/07/2021] [Indexed: 12/11/2022]
Abstract
PURPOSE In principle, non-invasive mapping of the intracellular pH (pHi ) in vivo is possible using endogenous chemical exchange saturation transfer (CEST)-MRI of the amide and guanidyl signals. However, the application for cancer imaging is still impeded, as current state-of-the-art approaches do not allow for simultaneous compensation of concomitant effects that vary within tumors. In this study, we present a novel method for absolute pHi mapping using endogenous CEST-MRI, which simultaneously compensates for concentration changes, superimposing CEST signals, magnetization transfer contrast, and spillover dilution. THEORY AND METHODS Compensation of the concomitant effects was achieved by a ratiometric approach (i.e. the ratio of one CEST signal at different B1 ) in combination with the relaxation-compensated inverse magnetization transfer ratio MTRRex and a separate first-order polynomial-Lorentzian fit of the amide and guanidyl signals at 9.4 T. Calibration of pH values was accomplished using in vivo-like model suspensions from porcine brain lysates. Applicability of the presented method in vivo was demonstrated in n = 19 tumor-bearing mice. RESULTS In porcine brain lysates, measurement of pH was feasible over a broad range of physiologically relevant pH values of 6.2 to 8.0, while being independent of changes in concentration. A median pHi of approximately 7.2 was found in the lesions of 19 tumor-bearing mice. CONCLUSION The presented method enables non-invasive mapping of absolute pHi values in tumors using CEST-MRI, which was so far prevented by concomitant effects. Consequently, pre-clinical studies on pHi changes in tumors are possible allowing the assessment of pHi in vivo as a biomarker for cancer diagnosis or treatment monitoring.
Collapse
Affiliation(s)
- Philip S Boyd
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
| | - Johannes Breitling
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Andreas Korzowski
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Moritz Zaiss
- Division of Neuroradiology in Radiological Institute, University Hospital of Erlangen, Erlangen, Germany
| | - Vanessa L Franke
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
| | - Karin Mueller-Decker
- Core Facility Tumor Models (Center for Preclinical Research), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Andrey Glinka
- Division of Molecular Embryology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Mark E Ladd
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany.,Faculty of Medicine, University of Heidelberg, Heidelberg, Germany
| | - Peter Bachert
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
| | - Steffen Goerke
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| |
Collapse
|
20
|
Ponomareva D, Petukhova E, Bregestovski P. Simultaneous Monitoring of pH and Chloride (Cl -) in Brain Slices of Transgenic Mice. Int J Mol Sci 2021; 22:13601. [PMID: 34948398 PMCID: PMC8708776 DOI: 10.3390/ijms222413601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 11/16/2022] Open
Abstract
Optosensorics is the direction of research possessing the possibility of non-invasive monitoring of the concentration of intracellular ions or activity of intracellular components using specific biosensors. In recent years, genetically encoded proteins have been used as effective optosensory means. These probes possess fluorophore groups capable of changing fluorescence when interacting with certain ions or molecules. For monitoring of intracellular concentrations of chloride ([Cl-]i) and hydrogen ([H+] i) the construct, called ClopHensor, which consists of a H+- and Cl--sensitive variant of the enhanced green fluorescent protein (E2GFP) fused with a monomeric red fluorescent protein (mDsRed) has been proposed. We recently developed a line of transgenic mice expressing ClopHensor in neurons and obtained the map of its expression in different areas of the brain. The purpose of this study was to examine the effectiveness of transgenic mice expressing ClopHensor for estimation of [H+]i and [Cl-]i concentrations in neurons of brain slices. We performed simultaneous monitoring of [H+]i and [Cl-]i under different experimental conditions including changing of external concentrations of ions (Ca2+, Cl-, K+, Na+) and synaptic stimulation of Shaffer's collaterals of hippocampal slices. The results obtained illuminate different pathways of regulation of Cl- and pH equilibrium in neurons and demonstrate that transgenic mice expressing ClopHensor represent a reliable tool for non-invasive simultaneous monitoring of intracellular Cl- and pH.
Collapse
Affiliation(s)
- Daria Ponomareva
- Institut de Neurosciences des Systèmes, Aix-Marseille University, INSERM, INS, 13005 Marseille, France;
- Institute of Neurosciences, Kazan State Medical University, 420111 Kazan, Russia;
- Department of Normal Physiology, Kazan State Medical University, 420111 Kazan, Russia
| | - Elena Petukhova
- Institute of Neurosciences, Kazan State Medical University, 420111 Kazan, Russia;
- Department of Normal Physiology, Kazan State Medical University, 420111 Kazan, Russia
| | - Piotr Bregestovski
- Institut de Neurosciences des Systèmes, Aix-Marseille University, INSERM, INS, 13005 Marseille, France;
- Institute of Neurosciences, Kazan State Medical University, 420111 Kazan, Russia;
- Department of Normal Physiology, Kazan State Medical University, 420111 Kazan, Russia
| |
Collapse
|
21
|
Ishikawa-Ankerhold HC, Kurzbach S, Kinali AS, Müller-Taubenberger A. Formation of Cytoplasmic Actin-Cofilin Rods is Triggered by Metabolic Stress and Changes in Cellular pH. Front Cell Dev Biol 2021; 9:742310. [PMID: 34869330 PMCID: PMC8635511 DOI: 10.3389/fcell.2021.742310] [Citation(s) in RCA: 3] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 10/27/2021] [Indexed: 11/13/2022] Open
Abstract
Actin dynamics plays a crucial role in regulating essential cell functions and thereby is largely responsible to a considerable extent for cellular energy consumption. Certain pathological conditions in humans, like neurological disorders such as Alzheimer’s disease or amyotrophic lateral sclerosis (ALS) as well as variants of nemaline myopathy are associated with cytoskeletal abnormalities, so-called actin-cofilin rods. Actin-cofilin rods are aggregates consisting mainly of actin and cofilin, which are formed as a result of cellular stress and thereby help to ensure the survival of cells under unfavorable conditions. We have used Dictyostelium discoideum, an established model system for cytoskeletal research to study formation and principles of cytoplasmic actin rod assembly in response to energy depletion. Experimentally, depletion of ATP was provoked by addition of either sodium azide, dinitrophenol, or 2-deoxy-glucose, and the formation of rod assembly was recorded by live-cell imaging. Furthermore, we show that hyperosmotic shock induces actin-cofilin rods, and that a drop in the intracellular pH accompanies this condition. Our data reveal that acidification of the cytoplasm can induce the formation of actin-cofilin rods to varying degrees and suggest that a local reduction in cellular pH may be a cause for the formation of cytoplasmic rods. We hypothesize that local phase separation mechanistically triggers the assembly of actin-cofilin rods and thereby influences the material properties of actin structures.
Collapse
Affiliation(s)
- Hellen C Ishikawa-Ankerhold
- Department of Internal Medicine I, University Hospital, LMU Munich, Munich, Germany.,Walter Brendel Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Sophie Kurzbach
- Department of Cell Biology (Anatomy III), Biomedical Center (BMC), LMU Munich, Munich, Germany
| | - Arzu S Kinali
- Walter Brendel Centre of Experimental Medicine, University Hospital, LMU Munich, Munich, Germany
| | | |
Collapse
|
22
|
Abstract
Cancer stem cells (CSCs) are known for their superior tumor-initiating and tumor-repopulating potential, partly reflecting their pronounced ability to evade immune recognition. Liu and colleagues recently identified a new aldehyde dehydrogenase (ALDH)-dependent mechanism whereby triple-negative breast CSCs evade immunosurveillance upon recruitment of myeloid-derived suppressor cells.
Collapse
Affiliation(s)
- Carlos Jiménez-Cortegana
- Department of Radiation Oncology, Weill Cornell Medical College, New York, NY, USA; Department of Medical Biochemistry, Molecular Biology, and Immunology, Faculty of Medicine, University of Seville, Seville, Spain; Clinical Biochemistry, Virgen Macarena University Hospital, Seville, Spain
| | - Claudia Galassi
- Department of Radiation Oncology, Weill Cornell Medical College, New York, NY, USA
| | - Lorenzo Galluzzi
- Department of Radiation Oncology, Weill Cornell Medical College, New York, NY, USA; Sandra and Edward Meyer Cancer Center, New York, NY, USA; Caryl and Israel Englander Institute for Precision Medicine, New York, NY, USA.
| |
Collapse
|
23
|
Albacar M, Sacka L, Calafí C, Velázquez D, Casamayor A, Ariño J, Zimmermannova O. The Toxic Effects of Ppz1 Overexpression Involve Nha1-Mediated Deregulation of K + and H + Homeostasis. J Fungi (Basel) 2021; 7:1010. [PMID: 34946993 DOI: 10.3390/jof7121010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 10/19/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 11/17/2022] Open
Abstract
The alteration of the fine-tuned balance of phospho/dephosphorylation reactions in the cell often results in functional disturbance. In the yeast Saccharomyces cerevisiae, the overexpression of Ser/Thr phosphatase Ppz1 drastically blocks cell proliferation, with a profound change in the transcriptomic and phosphoproteomic profiles. While the deleterious effect on growth likely derives from the alteration of multiple targets, the precise mechanisms are still obscure. Ppz1 is a negative effector of potassium influx. However, we show that the toxic effect of Ppz1 overexpression is unrelated to the Trk1/2 high-affinity potassium importers. Cells overexpressing Ppz1 exhibit decreased K+ content, increased cytosolic acidification, and fail to properly acidify the medium. These effects, as well as the growth defect, are counteracted by the deletion of NHA1 gene, which encodes a plasma membrane Na+, K+/H+ antiporter. The beneficial effect of a lack of Nha1 on the growth vanishes as the pH of the medium approaches neutrality, is not eliminated by the expression of two non-functional Nha1 variants (D145N or D177N), and is exacerbated by a hyperactive Nha1 version (S481A). All our results show that high levels of Ppz1 overactivate Nha1, leading to an excessive entry of H+ and efflux of K+, which is detrimental for growth.
Collapse
|
24
|
Hande PE, Shelke YG, Datta A, Gharpure SJ. Recent Advances in Small Molecule-Based Intracellular pH Probes. Chembiochem 2021; 23:e202100448. [PMID: 34695287 DOI: 10.1002/cbic.202100448] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [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: 08/24/2021] [Revised: 10/23/2021] [Indexed: 01/04/2023]
Abstract
Intracellular pH plays an important role in many biological and pathological processes. Small-molecule based pH probes are found to be the most effective for pH sensing because of ease of preparation, high sensitivity, and quick response. They have many advantages such as small perturbation to the functions of the target, functional adaptability, cellular component-specific localization, etc. The present review highlights the flurry of recent activity in the development of such probes. The probes are categorized based on the type of fluorophore used like quinoline, coumarin, BODIPY, rhodamine, indolium, naphthalimide, etc., and their analytical performance is discussed.
Collapse
Affiliation(s)
- Pankaj E Hande
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Yogesh G Shelke
- Department of Chemistry, BioScience Research Collaborative, Rice University, 6100 Main Street, Houston, TX 77005, USA
| | - Anindya Datta
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Santosh J Gharpure
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| |
Collapse
|
25
|
Li X, Tu T, Quan S, Quintero FJ, Fahlman R, Fliegel L. Amino Acids 785, 787 of the Na +/H + Exchanger Cytoplasmic Tail Modulate Protein Activity and Tail Conformation. Int J Mol Sci 2021; 22:11349. [PMID: 34768780 DOI: 10.3390/ijms222111349] [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: 09/20/2021] [Revised: 10/14/2021] [Accepted: 10/18/2021] [Indexed: 11/30/2022] Open
Abstract
The mammalian Na+/H+ exchanger isoform 1 (NHE1) is a plasma membrane protein ubiquitously present in humans. It regulates intracellular pH by removing an intracellular proton in exchange for an extracellular sodium. It consists of a 500 amino acid membrane domain plus a 315 amino acid, regulatory cytosolic tail. Here, we investigated the effect of mutation of two amino acids of the regulatory tail, Ser785 and Ser787, that were similar in location and context to two amino acids of the Arabidopsis Na+/H+ exchanger SOS1. Mutation of these two amino acids to either Ala or phosphomimetic Glu did not affect surface targeting but led to a slight reduction in the level of protein expressed. The activity of the NHE1 protein was reduced in the phosphomimetic mutations and the effect was due to a decrease in Vmax activity. The Ser to Glu mutations also caused a change in the apparent molecular weight of both the full-length protein and of the cytosolic tail of NHE1. A conformational change in this region was indicated by differential trypsin sensitivity. We also found that a peptide containing amino acids 783–790 bound to several more proximal regions of the NHE1 tail in in vitro protein interaction experiments. The results are the first characterization of these two amino acids and show that they have significant effects on enzyme kinetics and the structure of the NHE1 protein.
Collapse
|
26
|
Stratmann AEP, Wohlgemuth L, Erber ME, Bernhard S, Hug S, Fauler M, Vidoni L, Mohamed AOK, Thomaß BD, Münnich F, Stukan L, Föhr KJ, Mannes M, Huber-Lang MS, Messerer DAC. Simultaneous Measurement of Changes in Neutrophil Granulocyte Membrane Potential, Intracellular pH, and Cell Size by Multiparametric Flow Cytometry. Biomedicines 2021; 9:1504. [PMID: 34829733 PMCID: PMC8614908 DOI: 10.3390/biomedicines9111504] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 10/14/2021] [Accepted: 10/18/2021] [Indexed: 01/10/2023] Open
Abstract
Neutrophils provide rapid and efficient defense mechanisms against invading pathogens. Upon stimulation with proinflammatory mediators, including complement factors and bacterial peptides, neutrophils respond with changes in their membrane potential, intracellular pH, and cellular size. This study provides an approach to quantify these important changes simultaneously using multiparametric flow cytometry, thereby revealing a typical sequence of neutrophil activation consisting of depolarization, alkalization, and increase in cellular size. Additionally, the time resolution of the flow cytometric measurement is improved in order to allow changes that occur within seconds to be monitored, and thus to enhance the kinetic analysis of the neutrophil response. The method is appropriate for the reliable semiquantitative detection of small variations with respect to an increase, no change, and decrease in those parameters as demonstrated by the screening of various proinflammatory mediators. As a translational outlook, the findings are put into context in inflammatory conditions in vitro as well as in a clinically relevant whole blood model of endotoxemia. Taken together, the multiparametric analysis of neutrophil responsiveness regarding depolarization, alkalization, and changes in cellular size may contribute to a better understanding of neutrophils in health and disease, thus potentially yielding innovative mechanistic insights and possible novel diagnostic and/or prognostic approaches.
Collapse
Affiliation(s)
| | - Lisa Wohlgemuth
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Maike Elisabeth Erber
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Stefan Bernhard
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Stefan Hug
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Michael Fauler
- Institute of General Physiology, Ulm University, 89081 Ulm, Germany
| | - Laura Vidoni
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Adam Omar Khalaf Mohamed
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Bertram Dietrich Thomaß
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Frederik Münnich
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Laura Stukan
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Ulm, 89081 Ulm, Germany
| | - Karl Josef Föhr
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Ulm, 89081 Ulm, Germany
| | - Marco Mannes
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Markus Stefan Huber-Lang
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - David Alexander Christian Messerer
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Ulm, 89081 Ulm, Germany
| |
Collapse
|
27
|
Mo L, Xu L, Jia M, Su B, Hu Y, Hu Z, Li H, Zhao C, Zhao Z, Li J. Shikonin suppresses the epithelial-to-mesenchymal transition by downregulating NHE1 in bladder cancer cells. J Cancer 2021; 12:6814-6824. [PMID: 34659570 PMCID: PMC8518005 DOI: 10.7150/jca.63429] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 06/01/2021] [Accepted: 09/19/2021] [Indexed: 12/01/2022] Open
Abstract
Shikonin (SK) is the major bioactive component extracted from the roots of Lithospermum erythrorhizon with anticancer activity. SK could inhibit the epithelial-to-mesenchymal transition (EMT) of cancer cells. However, the underlying mechanism is elusive. In the present study, the inhibitory activities of SK on proliferation, invasion and migration were examined in bladder cancer (BC) cells. SK potently decreased the viabilities of BC cells but showed less cytotoxicity to normal bladder epithelial cells. Moreover, SK reversed the EMT, suppressed the migration and invasion of BC cells. Intriguingly, NHE1, the major proton efflux pump, was dramatically down-regulated by SK. The EMT-inhibitory effect of SK was mediated by NHE1 down-regulation, as NHE1-overexpress alleviated while Cariporide (NHE1 inhibitor) enhanced this effect. Further, enforced alkalinization of intracellular pH (pHi) reversed the EMT-inhibitory effect of SK, indicating a key role of acidic pHi in this process. Finally, elevated NHE1 expression was observed in human bladder cancer tissues. Collectively, this research reveals a supportive effect of NHE1 and alkaline pHi on EMT. SK can suppress EMT through inhibiting NHE1 and hence inducing an acidic pHi.
Collapse
Affiliation(s)
- Lijun Mo
- Institute of Biotherapy, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong, China.,Shenzhen Ruipuxun Academy for Stem Cell & Regenerative Medicine, 14 Jinhui Road, Shenzhen 518118, People's Republic of China
| | - Lili Xu
- Institute of Biotherapy, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong, China.,Shenzhen Ruipuxun Academy for Stem Cell & Regenerative Medicine, 14 Jinhui Road, Shenzhen 518118, People's Republic of China
| | - Min Jia
- Shenzhen Ruipuxun Academy for Stem Cell & Regenerative Medicine, 14 Jinhui Road, Shenzhen 518118, People's Republic of China.,Department of Clinical Laboratory, Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Bijia Su
- Institute of Biotherapy, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong, China.,Shenzhen Ruipuxun Academy for Stem Cell & Regenerative Medicine, 14 Jinhui Road, Shenzhen 518118, People's Republic of China
| | - Yaolong Hu
- Institute of Biotherapy, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Zhiming Hu
- Institute of Biotherapy, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Hongwei Li
- Institute of Biotherapy, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong, China
| | - Chenye Zhao
- Shenzhen Ruipuxun Academy for Stem Cell & Regenerative Medicine, 14 Jinhui Road, Shenzhen 518118, People's Republic of China
| | - Zhenlin Zhao
- Shenzhen Ruipuxun Academy for Stem Cell & Regenerative Medicine, 14 Jinhui Road, Shenzhen 518118, People's Republic of China
| | - Jinlong Li
- Institute of Biotherapy, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong, China.,Shenzhen Ruipuxun Academy for Stem Cell & Regenerative Medicine, 14 Jinhui Road, Shenzhen 518118, People's Republic of China
| |
Collapse
|
28
|
Goryashchenko AS, Pakhomov AA, Ryabova AV, Romanishkin ID, Maksimov EG, Orsa AN, Serova OV, Mozhaev AA, Maksimova MA, Martynov VI, Petrenko AG, Deyev IE. FLIM-Based Intracellular and Extracellular pH Measurements Using Genetically Encoded pH Sensor. Biosensors (Basel) 2021; 11:340. [PMID: 34562930 DOI: 10.3390/bios11090340] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/07/2021] [Accepted: 09/10/2021] [Indexed: 02/04/2023]
Abstract
The determination of pH in live cells and tissues is of high importance in physiology and cell biology. In this report, we outline the process of the creation of SypHerExtra, a genetically encoded fluorescent sensor that is capable of measuring extracellular media pH in a mildly alkaline range. SypHerExtra is a protein created by fusing the previously described pH sensor SypHer3s with the neurexin transmembrane domain that targets its expression to the cytoplasmic membrane. We showed that with excitation at 445 nm, the fluorescence lifetime of both SypHer3s and SypHerExtra strongly depend on pH. Using FLIM microscopy in live eukaryotic cells, we demonstrated that SypHerExtra can be successfully used to determine extracellular pH, while SypHer3s can be applied to measure intracellular pH. Thus, these two sensors are suitable for quantitative measurements using the FLIM method, to determine intracellular and extracellular pH in a range from pH 7.5 to 9.5 in different biological systems.
Collapse
|
29
|
Yang S, Zhan Y, Shou W, Chen L, Lin Z, Guo L. 1,2,4-Triaminobenzene as a Fluorescent Probe for Intracellular pH Imaging and Point-of-Care Ammonia Sensing. ACS Appl Bio Mater 2021; 4:6065-6072. [PMID: 35006915 DOI: 10.1021/acsabm.1c00404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
As one of the health indicators, intracellular pH plays important roles in many processes of cell functions. Abnormal pH changes would result in the occurrence of inflammation, cancer, and other diseases. Thus, it is of significant importance to develop effective techniques for sensitive detection of pH changes for the clinical diagnosis of various diseases related to cells. In this paper, 1,2,4-triaminobenzene hydrochloride was explored as an organic molecular fluorescent probe for sensitive and selective detection of intracellular pH changes for the first time. Due to the protonation and deprotonation of amino groups of the probe, its fluorescent intensity at 599 nm or the ratio of absorbance at 505 and 442 nm has a good linear relationship with pH values in the range of 5.0-7.0. Benefiting from the excellent physical and chemical properties of 1,2,4-triaminobenzene hydrochloride, the fluorescent probe has good water solubility, low toxicity, high photostability, great reversibility, good cell penetration, fast response speed, and so on. As a proof-of-concept demonstration, the proposed probe is employed for the fluorescence imaging of cells and mouse tissue sections with satisfactory performance in pH differentiation. Additionally, the probe was successfully employed to prepare test strips as a kind of point-of-care testing device to detect ammonia, which showed great potential in practical applications.
Collapse
Affiliation(s)
- Shuangting Yang
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian Province 350116, China.,College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, Zhejiang Province, China
| | - Yuanjin Zhan
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian Province 350116, China
| | - Wen Shou
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian Province 350116, China.,College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, Zhejiang Province, China
| | - Lifen Chen
- College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, Zhejiang Province, China
| | - Zhenyu Lin
- Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Fuzhou University, Fuzhou, Fujian Province 350116, China
| | - Longhua Guo
- College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing 314001, Zhejiang Province, China
| |
Collapse
|
30
|
Cornejo M, Fuentes G, Valero P, Vega S, Grismaldo A, Toledo F, Pardo F, Moore‐Carrasco R, Subiabre M, Casanello P, Faas MM, Goor H, Sobrevia L. Gestational diabesity and foetoplacental vascular dysfunction. Acta Physiol (Oxf) 2021; 232:e13671. [PMID: 33942517 DOI: 10.1111/apha.13671] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [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: 02/19/2021] [Revised: 04/28/2021] [Accepted: 04/30/2021] [Indexed: 12/15/2022]
Abstract
Gestational diabetes mellitus (GDM) shows a deficiency in the metabolism of D-glucose and other nutrients, thereby negatively affecting the foetoplacental vascular endothelium. Maternal hyperglycaemia and hyperinsulinemia play an important role in the aetiology of GDM. A combination of these and other factors predisposes women to developing GDM with pre-pregnancy normal weight, viz. classic GDM. However, women with GDM and prepregnancy obesity (gestational diabesity, GDty) or overweight (GDMow) show a different metabolic status than women with classic GDM. GDty and GDMow are associated with altered l-arginine/nitric oxide and insulin/adenosine axis signalling in the human foetoplacental microvascular and macrovascular endothelium. These alterations differ from those observed in classic GDM. Here, we have reviewed the consequences of GDty and GDMow in the modulation of foetoplacental endothelial cell function, highlighting studies describing the modulation of intracellular pH homeostasis and the potential implications of NO generation and adenosine signalling in GDty-associated foetal vascular insulin resistance. Moreover, with an increase in the rate of obesity in women of childbearing age worldwide, the prevalence of GDty is expected to increase in the next decades. Therefore, we emphasize that women with GDty and GDMow should be characterized with a different metabolic state from that of women with classic GDM to develop a more specific therapeutic approach for protecting the mother and foetus.
Collapse
Affiliation(s)
- Marcelo Cornejo
- Cellular and Molecular Physiology Laboratory Department of Obstetrics Division of Obstetrics and Gynaecology School of Medicine Faculty of Medicine Pontificia Universidad Católica de Chile Santiago Chile
- Faculty of Health Sciences Universidad de Talca Talca Chile
- Faculty of Health Sciences Universidad de Antofagasta Antofagasta Chile
| | - Gonzalo Fuentes
- Cellular and Molecular Physiology Laboratory Department of Obstetrics Division of Obstetrics and Gynaecology School of Medicine Faculty of Medicine Pontificia Universidad Católica de Chile Santiago Chile
- Faculty of Health Sciences Universidad de Talca Talca Chile
- Department of Pathology and Medical Biology University of GroningenUniversity Medical Center Groningen Groningen The Netherlands
| | - Paola Valero
- Cellular and Molecular Physiology Laboratory Department of Obstetrics Division of Obstetrics and Gynaecology School of Medicine Faculty of Medicine Pontificia Universidad Católica de Chile Santiago Chile
- Faculty of Health Sciences Universidad de Talca Talca Chile
| | - Sofía Vega
- Cellular and Molecular Physiology Laboratory Department of Obstetrics Division of Obstetrics and Gynaecology School of Medicine Faculty of Medicine Pontificia Universidad Católica de Chile Santiago Chile
- Medical School (Faculty of Medicine) Sao Paulo State University (UNESP) Sao Paulo Brazil
| | - Adriana Grismaldo
- Cellular and Molecular Physiology Laboratory Department of Obstetrics Division of Obstetrics and Gynaecology School of Medicine Faculty of Medicine Pontificia Universidad Católica de Chile Santiago Chile
- Department of Nutrition and Biochemistry Faculty of Sciences Pontificia Universidad Javeriana Bogotá D.C. Colombia
| | - Fernando Toledo
- Cellular and Molecular Physiology Laboratory Department of Obstetrics Division of Obstetrics and Gynaecology School of Medicine Faculty of Medicine Pontificia Universidad Católica de Chile Santiago Chile
- Department of Basic Sciences Faculty of Sciences Universidad del Bío‐Bío Chillán Chile
| | - Fabián Pardo
- Cellular and Molecular Physiology Laboratory Department of Obstetrics Division of Obstetrics and Gynaecology School of Medicine Faculty of Medicine Pontificia Universidad Católica de Chile Santiago Chile
- Metabolic Diseases Research Laboratory Interdisciplinary Centre of Territorial Health Research (CIISTe) Biomedical Research Center (CIB) School of Medicine Faculty of Medicine Universidad de Valparaíso San Felipe Chile
| | | | - Mario Subiabre
- Cellular and Molecular Physiology Laboratory Department of Obstetrics Division of Obstetrics and Gynaecology School of Medicine Faculty of Medicine Pontificia Universidad Católica de Chile Santiago Chile
| | - Paola Casanello
- Department of Pathology and Medical Biology University of GroningenUniversity Medical Center Groningen Groningen The Netherlands
- Department of Obstetrics Division of Obstetrics and Gynaecology, and Department of Neonatology Division of Pediatrics School of Medicine Faculty of Medicine Pontificia Universidad Católica de Chile Santiago Chile
| | - Marijke M Faas
- Department of Pathology and Medical Biology University of GroningenUniversity Medical Center Groningen Groningen The Netherlands
| | - Harry Goor
- Department of Pathology and Medical Biology University of GroningenUniversity Medical Center Groningen Groningen The Netherlands
| | - Luis Sobrevia
- Cellular and Molecular Physiology Laboratory Department of Obstetrics Division of Obstetrics and Gynaecology School of Medicine Faculty of Medicine Pontificia Universidad Católica de Chile Santiago Chile
- Department of Pathology and Medical Biology University of GroningenUniversity Medical Center Groningen Groningen The Netherlands
- Medical School (Faculty of Medicine) Sao Paulo State University (UNESP) Sao Paulo Brazil
- Department of Physiology Faculty of Pharmacy Universidad de Sevilla Seville Spain
- University of Queensland Centre for Clinical Research (UQCCR) Faculty of Medicine and Biomedical Sciences University of Queensland Herston QLD Australia
| |
Collapse
|
31
|
Druzhkova I, Lukina M, Dudenkova V, Ignatova N, Snopova L, Gavrina A, Shimolina L, Belousov V, Zagaynova E, Shirmanova M. Tracing of intracellular pH in cancer cells in response to Taxol treatment. Cell Cycle 2021; 20:1540-1551. [PMID: 34308742 PMCID: PMC8409750 DOI: 10.1080/15384101.2021.1949106] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 05/11/2021] [Revised: 06/15/2021] [Accepted: 06/24/2021] [Indexed: 01/21/2023] Open
Abstract
Genetically encoded pH-sensors are the promising instrument for intracellular pH (pHi) registration. In tumor tissue the reversed pH gradient is known to be the important hallmark of cancer and regulator of tumor response on chemotherapy. However the effect of chemotherapeutic drugs on the pHi of tumor cells is largely unknown. Here we using genetically encoded ratiometric pH-sensor SypHer2 were able to monitor pHi in vitro in cell monolayer and tumor spheroids and in vivo in tumor xenografts. In tumor cell monolayer different pHi dynamic was revealed in the dying cell and division-arrested surviving cells. The treatment effect of taxol varied in monolayer and tumor spheroids and pHi changes were able to reflect these difference. The tend to pHi decrease in respect to taxol in vivo matched with results obtained for the cell monolayer. Also in both cases the cell cycle-arrest was the main treatment effect in contrast to tumor spheroid, where the cell death was the primary result. These findings elucidate the significance of pHi in the mechanisms of taxol action on cervical cancer cells and will be valuable for development of new approaches for cancer treatment.
Collapse
Affiliation(s)
- Irina Druzhkova
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
| | - Maria Lukina
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
| | - Varvara Dudenkova
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
- Lobachevsky State University of Nizhni Novgorod, Nizhny Novgorod, Russian Federation
| | - Nadezhda Ignatova
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
| | - Ludmila Snopova
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
| | - Alena Gavrina
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
| | - Lyubov Shimolina
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
| | - Vsevolod Belousov
- Pirogov Russian National Research Medical University, Laboratory of Experimental Oncology, Moscow, Russia
- Federal Center of Brain Research and Neurotechnologies, Federal Medical Biological Agency, Moscow, Russia
| | - Elena Zagaynova
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
- Lobachevsky State University of Nizhni Novgorod, Nizhny Novgorod, Russian Federation
| | - Marina Shirmanova
- Privolzhsky Research Medical University, Nizhny Novgorod, Russian Federation
| |
Collapse
|
32
|
Chang WW, Matt AS, Schewe M, Musinszki M, Grüssel S, Brandenburg J, Garfield D, Bleich M, Baukrowitz T, Hu MY. An otopetrin family proton channel promotes cellular acid efflux critical for biomineralization in a marine calcifier. Proc Natl Acad Sci U S A 2021; 118:e2101378118. [PMID: 34301868 DOI: 10.1073/pnas.2101378118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Otopetrins comprise a family of proton-selective channels that are critically important for the mineralization of otoliths and statoconia in vertebrates but whose underlying cellular mechanisms remain largely unknown. Here, we demonstrate that otopetrins are critically involved in the calcification process by providing an exit route for protons liberated by the formation of CaCO3 Using the sea urchin larva, we examined the otopetrin ortholog otop2l, which is exclusively expressed in the calcifying primary mesenchymal cells (PMCs) that generate the calcitic larval skeleton. otop2l expression is stimulated during skeletogenesis, and knockdown of otop2l impairs spicule formation. Intracellular pH measurements demonstrated Zn2+-sensitive H+ fluxes in PMCs that regulate intracellular pH in a Na+/HCO3 --independent manner, while Otop2l knockdown reduced membrane proton permeability. Furthermore, Otop2l displays unique features, including strong activation by high extracellular pH (>8.0) and check-valve-like outwardly rectifying H+ flux properties, making it into a cellular proton extrusion machine adapted to oceanic living conditions. Our results provide evidence that otopetrin family proton channels are a central component of the cellular pH regulatory machinery in biomineralizing cells. Their ubiquitous occurrence in calcifying systems across the animal kingdom suggest a conserved physiological function by mediating pH at the site of mineralization. This important role of otopetrin family proton channels has strong implications for our view on the cellular mechanisms of biomineralization and their response to changes in oceanic pH.
Collapse
|
33
|
Goode O, Smith A, Zarkan A, Cama J, Invergo BM, Belgami D, Caño-Muñiz S, Metz J, O'Neill P, Jeffries A, Norville IH, David J, Summers D, Pagliara S. Persister Escherichia coli Cells Have a Lower Intracellular pH than Susceptible Cells but Maintain Their pH in Response to Antibiotic Treatment. mBio 2021; 12:e0090921. [PMID: 34281389 DOI: 10.1128/mBio.00909-21] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [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] [Indexed: 01/22/2023] Open
Abstract
Persister and viable but non-culturable (VBNC) cells are two clonal subpopulations that can survive multidrug exposure via a plethora of putative molecular mechanisms. Here, we combine microfluidics, time-lapse microscopy, and a plasmid-encoded fluorescent pH reporter to measure the dynamics of the intracellular pH of individual persister, VBNC, and susceptible Escherichia coli cells in response to ampicillin treatment. We found that even before antibiotic exposure, persisters have a lower intracellular pH than those of VBNC and susceptible cells. We then investigated the molecular mechanisms underlying the observed differential pH regulation in persister E. coli cells and found that this is linked to the activity of the enzyme tryptophanase, which is encoded by tnaA. In fact, in a ΔtnaA strain, we found no difference in intracellular pH between persister, VBNC, and susceptible E. coli cells. Whole-genome transcriptomic analysis revealed that, besides downregulating tryptophan metabolism, the ΔtnaA strain downregulated key pH homeostasis pathways, including the response to pH, oxidation reduction, and several carboxylic acid catabolism processes, compared to levels of expression in the parental strain. Our study sheds light on pH homeostasis, proving that the regulation of intracellular pH is not homogeneous within a clonal population, with a subset of cells displaying a differential pH regulation to perform dedicated functions, including survival after antibiotic treatment. IMPORTANCE Persister and VBNC cells can phenotypically survive environmental stressors, such as antibiotic treatment, limitation of nutrients, and acid stress, and have been linked to chronic infections and antimicrobial resistance. It has recently been suggested that pH regulation might play a role in an organism's phenotypic survival to antibiotics; however, this hypothesis remains to be tested. Here, we demonstrate that even before antibiotic treatment, cells that will become persisters have a more acidic intracellular pH than clonal cells that will be either susceptible or VBNC upon antibiotic treatment. Moreover, after antibiotic treatment, persisters become more alkaline than VBNC and susceptible E. coli cells. This newly found phenotypic feature is remarkable because it distinguishes persister and VBNC cells that have often been thought to display the same dormant phenotype. We then show that this differential pH regulation is abolished in the absence of the enzyme tryptophanase via a major remodeling of bacterial metabolism and pH homeostasis. These new whole-genome transcriptome data should be taken into account when modeling bacterial metabolism at the crucial transition from exponential to stationary phase. Overall, our findings indicate that the manipulation of the intracellular pH represents a bacterial strategy for surviving antibiotic treatment. In turn, this suggests a strategy for developing persister-targeting antibiotics by interfering with cellular components, such as tryptophanase, that play a major role in pH homeostasis.
Collapse
|
34
|
Földes A, Sang-Ngoen T, Kádár K, Rácz R, Zsembery Á, DenBesten P, Steward MC, Varga G. Three-Dimensional Culture of Ameloblast-Originated HAT-7 Cells for Functional Modeling of Defective Tooth Enamel Formation. Front Pharmacol 2021; 12:682654. [PMID: 34149428 PMCID: PMC8206558 DOI: 10.3389/fphar.2021.682654] [Citation(s) in RCA: 3] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/19/2021] [Indexed: 01/04/2023] Open
Abstract
Background: Amelogenesis, the formation of dental enamel, is well understood at the histomorphological level but the underlying molecular mechanisms are poorly characterized. Ameloblasts secrete enamel matrix proteins and Ca2+, and also regulate extracellular pH as the formation of hydroxyapatite crystals generates large quantities of protons. Genetic or environmental impairment of transport and regulatory processes (e.g. dental fluorosis) leads to the development of enamel defects such as hypomineralization. Aims: Our aims were to optimize the culture conditions for the three-dimensional growth of ameloblast-derived HAT-7 cells and to test the effects of fluoride exposure on HAT-7 spheroid formation. Methods: To generate 3D HAT-7 structures, cells were dispersed and plated within a Matrigel extracellular matrix scaffold and incubated in three different culture media. Spheroid formation was then monitored over a two-week period. Ion transporter and tight-junction protein expression was investigated by RT-qPCR. Intracellular Ca2+ and pH changes were measured by microfluorometry using the fluorescent dyes fura-2 and BCECF. Results: A combination of Hepato-STIM epithelial cell differentiation medium and Matrigel induced the expansion and formation of 3D HAT-7 spheroids. The cells retained their epithelial cell morphology and continued to express both ameloblast-specific and ion transport-specific marker genes. Furthermore, like two-dimensional HAT-7 monolayers, the HAT-7 spheroids were able to regulate their intracellular pH and to show intracellular calcium responses to extracellular stimulation. Finally, we demonstrated that HAT-7 spheroids may serve as a disease model for studying the effects of fluoride exposure during amelogenesis. Conclusion: In conclusion, HAT-7 cells cultivated within a Matrigel extracellular matrix form three-dimensional, multi-cellular, spheroidal structures that retain their functional capacity for pH regulation and intracellular Ca2+ signaling. This new 3D model will allow us to gain a better understanding of the molecular mechanisms involved in amelogenesis, not only in health but also in disorders of enamel formation, such as those resulting from fluoride exposure.
Collapse
Affiliation(s)
- Anna Földes
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | | | - Kristóf Kádár
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Róbert Rácz
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Ákos Zsembery
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| | - Pamela DenBesten
- Department of Orofacial Sciences, University of California San Francisco, San Francisco, CA, United States
| | - Martin C Steward
- Department of Oral Biology, Semmelweis University, Budapest, Hungary.,School of Medical Sciences, University of Manchester, Manchester, United Kingdom
| | - Gábor Varga
- Department of Oral Biology, Semmelweis University, Budapest, Hungary
| |
Collapse
|
35
|
Innis T, Allen-Waller L, Brown KT, Sparagon W, Carlson C, Kruse E, Huffmyer AS, Nelson CE, Putnam HM, Barott KL. Marine heatwaves depress metabolic activity and impair cellular acid-base homeostasis in reef-building corals regardless of bleaching susceptibility. Glob Chang Biol 2021; 27:2728-2743. [PMID: 33784420 DOI: 10.1111/gcb.15622] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/18/2021] [Accepted: 03/21/2021] [Indexed: 06/12/2023]
Abstract
Ocean warming is causing global coral bleaching events to increase in frequency, resulting in widespread coral mortality and disrupting the function of coral reef ecosystems. However, even during mass bleaching events, many corals resist bleaching despite exposure to abnormally high temperatures. While the physiological effects of bleaching have been well documented, the consequences of heat stress for bleaching-resistant individuals are not well understood. In addition, much remains to be learned about how heat stress affects cellular-level processes that may be overlooked at the organismal level, yet are crucial for coral performance in the short term and ecological success over the long term. Here we compared the physiological and cellular responses of bleaching-resistant and bleaching-susceptible corals throughout the 2019 marine heatwave in Hawai'i, a repeat bleaching event that occurred 4 years after the previous regional event. Relative bleaching susceptibility within species was consistent between the two bleaching events, yet corals of both resistant and susceptible phenotypes exhibited pronounced metabolic depression during the heatwave. At the cellular level, bleaching-susceptible corals had lower intracellular pH than bleaching-resistant corals at the peak of bleaching for both symbiont-hosting and symbiont-free cells, indicating greater disruption of acid-base homeostasis in bleaching-susceptible individuals. Notably, cells from both phenotypes were unable to compensate for experimentally induced cellular acidosis, indicating that acid-base regulation was significantly impaired at the cellular level even in bleaching-resistant corals and in cells containing symbionts. Thermal disturbances may thus have substantial ecological consequences, as even small reallocations in energy budgets to maintain homeostasis during stress can negatively affect fitness. These results suggest concern is warranted for corals coping with ocean acidification alongside ocean warming, as the feedback between temperature stress and acid-base regulation may further exacerbate the physiological effects of climate change.
Collapse
Affiliation(s)
- Teegan Innis
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Kristen T Brown
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
- ARC Centre of Excellence for Coral Reef Studies and School of Biological Sciences, University of Queensland, St. Lucia, Qld, Australia
| | - Wesley Sparagon
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, Department of Oceanography and Sea Grant College Program, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | | | - Elisa Kruse
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Ariana S Huffmyer
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, USA
| | - Craig E Nelson
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, Department of Oceanography and Sea Grant College Program, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | - Hollie M Putnam
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, USA
| | - Katie L Barott
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| |
Collapse
|
36
|
Manoli SS, Kisor K, Webb BA, Barber DL. Ethyl isopropyl amiloride decreases oxidative phosphorylation and increases mitochondrial fusion in clonal untransformed and cancer cells. Am J Physiol Cell Physiol 2021; 321:C147-C157. [PMID: 34038242 DOI: 10.1152/ajpcell.00001.2021] [Citation(s) in RCA: 3] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Many cancer cells, regardless of their tissue origin or genetic landscape, have increased expression or activity of the plasma membrane Na-H exchanger NHE1 and a higher intracellular pH (pHi) compared with untransformed cells. A current perspective that remains to be validated is that increased NHE1 activity and pHi enable a Warburg-like metabolic reprogramming of increased glycolysis and decreased mitochondrial oxidative phosphorylation. We tested this perspective and find it is not accurate for clonal pancreatic and breast cancer cells. Using the pharmacological reagent ethyl isopropyl amiloride (EIPA) to inhibit NHE1 activity and decrease pHi, we observe no change in glycolysis, as indicated by secreted lactate and intracellular pyruvate, despite confirming increased activity of the glycolytic enzyme phosphofructokinase-1 at higher pH. Also, in contrast to predictions, we find a significant decrease in oxidative phosphorylation with EIPA, as indicated by oxygen consumption rate (OCR). Decreased OCR with EIPA is not associated with changes in pathways that fuel oxidative phosphorylation or with mitochondrial membrane potential but occurs with a change in mitochondrial dynamics that includes a significant increase in elongated mitochondrial networks, suggesting increased fusion. These findings conflict with current paradigms on increased pHi inhibiting oxidative phosphorylation and increased oxidative phosphorylation being associated with mitochondrial fusion. Moreover, these findings raise questions on the suggested use of EIPA-like compounds to limit metabolic reprogramming in cancer cells.
Collapse
Affiliation(s)
- Sagar S Manoli
- Department of Cell and Tissue Biology, University of California, San Francisco, California
| | - Kyle Kisor
- Department of Cell and Tissue Biology, University of California, San Francisco, California
| | - Bradley A Webb
- Department of Biochemistry, West Virginia University, Morgantown, West Virginia
| | - Diane L Barber
- Department of Cell and Tissue Biology, University of California, San Francisco, California
| |
Collapse
|
37
|
Abstract
Cancer cells exhibit increased glycolytic flux and adenosine triphosphate (ATP) hydrolysis. These processes increase the acidic burden on the cells through the production of lactate and protons. Nonetheless, cancer cells can maintain an alkaline intracellular pH (pHi) relative to untransformed cells, which sets the stage for optimal functioning of glycolytic enzymes, evasion of cell death, and increased proliferation and motility. Upregulation of plasma membrane transporters allows for H+ and lactate efflux; however, recent evidence suggests that the acidification of organelles can contribute to maintenance of an alkaline cytosol in cancer cells by siphoning off protons, thereby supporting tumor growth. The Golgi is such an acidic organelle, with resting pH ranging from 6.0 to 6.7. Here, we posit that the Golgi represents a "proton sink" in cancer and delineate the proton channels involved in Golgi acidification and the ion channels that influence this process. Furthermore, we discuss ion channel regulators that can affect Golgi pH and Golgi-dependent processes that may contribute to pHi homeostasis in cancer.
Collapse
Affiliation(s)
- Koen M. O. Galenkamp
- Cell and Molecular Biology of Cancer Program, NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, United States
| | - Cosimo Commisso
- Cell and Molecular Biology of Cancer Program, NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, United States
| |
Collapse
|
38
|
Abstract
Many invasive cancers emerge through a years-long process of somatic evolution, characterized by an accumulation of heritable genetic and epigenetic changes and the emergence of increasingly aggressive clonal populations. In solid tumors, such as breast ductal carcinoma, the extracellular environment for cells within the nascent tumor is harsh and imposes different types of stress on cells, such as hypoxia, nutrient deprivation, and cytokine inflammation. Acidosis is a constant stressor of most cancer cells due to its production through fermentation of glucose to lactic acid in hypoxic or normoxic regions (Warburg effect). Over a short period of time, acid stress can have a profound effect on the function of lysosomes within the cells exposed to this environment, and after long term exposure, lysosomal function of the cancer cells can become completely dysregulated. Whether this dysregulation is due to an epigenetic change or evolutionary selection has yet to be determined, but understanding the mechanisms behind this dysregulation could identify therapeutic opportunities.
Collapse
Affiliation(s)
- Bryce Ordway
- Department of Cancer Physiology, H Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA; (B.O.); (R.J.G.)
| | - Robert J. Gillies
- Department of Cancer Physiology, H Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA; (B.O.); (R.J.G.)
| | - Mehdi Damaghi
- Department of Cancer Physiology, H Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA; (B.O.); (R.J.G.)
- Department of Oncological Sciences, University of South Florida, Tampa, FL 33612, USA
| |
Collapse
|
39
|
Bertling E, Blaesse P, Seja P, Kremneva E, Gateva G, Virtanen MA, Summanen M, Spoljaric I, Uvarov P, Blaesse M, Paavilainen VO, Vutskits L, Kaila K, Hotulainen P, Ruusuvuori E. Carbonic anhydrase seven bundles filamentous actin and regulates dendritic spine morphology and density. EMBO Rep 2021; 22:e50145. [PMID: 33719157 PMCID: PMC8025036 DOI: 10.15252/embr.202050145] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 01/14/2021] [Accepted: 01/28/2021] [Indexed: 01/02/2023] Open
Abstract
Intracellular pH is a potent modulator of neuronal functions. By catalyzing (de)hydration of CO2 , intracellular carbonic anhydrase (CAi ) isoforms CA2 and CA7 contribute to neuronal pH buffering and dynamics. The presence of two highly active isoforms in neurons suggests that they may serve isozyme-specific functions unrelated to CO2 -(de)hydration. Here, we show that CA7, unlike CA2, binds to filamentous actin, and its overexpression induces formation of thick actin bundles and membrane protrusions in fibroblasts. In CA7-overexpressing neurons, CA7 is enriched in dendritic spines, which leads to aberrant spine morphology. We identified amino acids unique to CA7 that are required for direct actin interactions, promoting actin filament bundling and spine targeting. Disruption of CA7 expression in neocortical neurons leads to higher spine density due to increased proportion of small spines. Thus, our work demonstrates highly distinct subcellular expression patterns of CA7 and CA2, and a novel, structural role of CA7.
Collapse
Affiliation(s)
- Enni Bertling
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Minerva Institute for Medical ResearchBiomedicum Helsinki 2UHelsinkiFinland
| | - Peter Blaesse
- Institute of Physiology IWestfälische Wilhelms‐Universität MünsterMünsterGermany
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Patricia Seja
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | | | | | - Mari A Virtanen
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
- Department of Anesthesiology, PharmacologyIntensive Care and Emergency MedicineUniversity Hospitals of GenevaGenevaSwitzerland
| | - Milla Summanen
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Inkeri Spoljaric
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Pavel Uvarov
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | | | | | - Laszlo Vutskits
- Department of Anesthesiology, PharmacologyIntensive Care and Emergency MedicineUniversity Hospitals of GenevaGenevaSwitzerland
| | - Kai Kaila
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Pirta Hotulainen
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Minerva Institute for Medical ResearchBiomedicum Helsinki 2UHelsinkiFinland
| | - Eva Ruusuvuori
- Neuroscience CenterHiLIFEUniversity of HelsinkiHelsinkiFinland
- Faculty of Biological and Environmental SciencesMolecular and Integrative Biosciences, and HiLIFEUniversity of HelsinkiHelsinkiFinland
| |
Collapse
|
40
|
Olsen JSM, Svendsen S, Berg P, Dam VS, Sorensen MV, Matchkov VV, Leipziger J, Boedtkjer E. NBCn1 Increases NH 4 + Reabsorption Across Thick Ascending Limbs, the Capacity for Urinary NH 4 + Excretion, and Early Recovery from Metabolic Acidosis. J Am Soc Nephrol 2021; 32:852-865. [PMID: 33414245 PMCID: PMC8017549 DOI: 10.1681/asn.2019060613] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 06/20/2020] [Accepted: 11/23/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND The electroneutral Na+/HCO3 - cotransporter NBCn1 (Slc4a7) is expressed in basolateral membranes of renal medullary thick ascending limbs (mTALs). However, direct evidence that NBCn1 contributes to acid-base handling in mTALs, urinary net acid excretion, and systemic acid-base homeostasis has been lacking. METHODS Metabolic acidosis was induced in wild-type and NBCn1 knockout mice. Fluorescence-based intracellular pH recordings were performed and NH4 + transport measured in isolated perfused mTALs. Quantitative RT-PCR and immunoblotting were used to evaluate NBCn1 expression. Tissue [NH4 +] was measured in renal biopsies, NH4 + excretion and titratable acid quantified in spot urine, and arterial blood gasses evaluated in normoventilated mice. RESULTS Basolateral Na+/HCO3 - cotransport activity was similar in isolated perfused mTALs from wild-type and NBCn1 knockout mice under control conditions. During metabolic acidosis, basolateral Na+/HCO3 - cotransport activity increased four-fold in mTALs from wild-type mice, but remained unchanged in mTALs from NBCn1 knockout mice. Correspondingly, NBCn1 protein expression in wild-type mice increased ten-fold in the inner stripe of renal outer medulla during metabolic acidosis. During systemic acid loading, knockout of NBCn1 inhibited the net NH4 + reabsorption across mTALs by approximately 60%, abolished the renal corticomedullary NH4 + gradient, reduced the capacity for urinary NH4 + excretion by approximately 50%, and delayed recovery of arterial blood pH and standard [HCO3 -] from their initial decline. CONCLUSIONS During metabolic acidosis, NBCn1 is required for the upregulated basolateral HCO3 - uptake and transepithelial NH4 + reabsorption in mTALs, renal medullary NH4 + accumulation, urinary NH4 + excretion, and early recovery of arterial blood pH and standard [HCO3 -]. These findings support that NBCn1 facilitates urinary net acid excretion by neutralizing intracellular H+ released during NH4 + reabsorption across mTALs.
Collapse
Affiliation(s)
| | - Samuel Svendsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Peder Berg
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Vibeke S. Dam
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | | | - Jens Leipziger
- Department of Biomedicine, Aarhus University, Aarhus, Denmark,Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, Denmark
| | - Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| |
Collapse
|
41
|
Dumas E, Degraeve P, Trinh NTT, Le Thanh M, Oulahal N. Interstrains comparison of the antimicrobial effect and mode of action of a Vietnamese Cinnamomum cassia essential oil from leaves and its principal component against Listeria monocytogenes. Lett Appl Microbiol 2021; 72:757-766. [PMID: 33598964 DOI: 10.1111/lam.13465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 10/27/2020] [Revised: 02/15/2021] [Accepted: 02/15/2021] [Indexed: 11/29/2022]
Abstract
The antibacterial activity of a Cinnamomum cassia essential oil (EO) and of its main component trans-cinnamaldehyde (90% w/w) was examined against five Listeria monocytogenes strains. The minimal inhibitory concentrations (MICs) of C. cassia EO against the five L. monocytogenes strains were identical (250 µg ml-1 ), while the minimal bactericidal concentrations (MBCs) ranged between 800 and 1200 µg ml-1 . In order to study if this EO and trans-cinnamaldehyde altered the five strains at the membrane level, fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene (DPH) was measured in presence of different concentrations (1/2MIC, MIC, 2MIC) of these antibacterial agents. A concentration-dependent increase of fluorescence anisotropy of DPH in their presence reflecting a rigidification of the membrane was observed for the five strains. This modification of the membrane fluidity was associated with a perturbation of the selective membrane permeability, as a perturbation of the gradient between intracellular and extracellular pH was also observed.
Collapse
Affiliation(s)
- E Dumas
- Bioingénierie et Dynamique Microbienne aux Interfaces Alimentaires (BioDyMIA, EA n°3733), IUT Lyon 1 site de Bourg en Bresse - Technopole Alimentec, Université de Lyon, Université Claude Bernard, Lyon 1 - ISARA Lyon, rue Henri de Boissieu, Bourg en Bresse, France
| | - P Degraeve
- Bioingénierie et Dynamique Microbienne aux Interfaces Alimentaires (BioDyMIA, EA n°3733), IUT Lyon 1 site de Bourg en Bresse - Technopole Alimentec, Université de Lyon, Université Claude Bernard, Lyon 1 - ISARA Lyon, rue Henri de Boissieu, Bourg en Bresse, France
| | - N-T-T Trinh
- Bioingénierie et Dynamique Microbienne aux Interfaces Alimentaires (BioDyMIA, EA n°3733), IUT Lyon 1 site de Bourg en Bresse - Technopole Alimentec, Université de Lyon, Université Claude Bernard, Lyon 1 - ISARA Lyon, rue Henri de Boissieu, Bourg en Bresse, France.,Ecole de Biotechnologie et Technologie Alimentaire, Institut Polytechnique de Hanoi, Hanoi, Vietnam
| | - M Le Thanh
- Ecole de Biotechnologie et Technologie Alimentaire, Institut Polytechnique de Hanoi, Hanoi, Vietnam
| | - N Oulahal
- Bioingénierie et Dynamique Microbienne aux Interfaces Alimentaires (BioDyMIA, EA n°3733), IUT Lyon 1 site de Bourg en Bresse - Technopole Alimentec, Université de Lyon, Université Claude Bernard, Lyon 1 - ISARA Lyon, rue Henri de Boissieu, Bourg en Bresse, France
| |
Collapse
|
42
|
Hug S, Bernhard S, Stratmann AEP, Erber M, Wohlgemuth L, Knapp CL, Bauer JM, Vidoni L, Fauler M, Föhr KJ, Radermacher P, Hoffmann A, Huber-Lang M, Messerer DAC. Activation of Neutrophil Granulocytes by Platelet-Activating Factor Is Impaired During Experimental Sepsis. Front Immunol 2021; 12:642867. [PMID: 33796110 PMCID: PMC8007865 DOI: 10.3389/fimmu.2021.642867] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/15/2021] [Indexed: 11/13/2022] Open
Abstract
Platelet-activating factor (PAF) is an important mediator of the systemic inflammatory response. In the case of sepsis, proper activation and function of neutrophils as the first line of cellular defense are based on a well-balanced physiological response. However, little is known about the role of PAF in cellular changes of neutrophils during sepsis. Therefore, this study investigates the reaction patterns of neutrophils induced by PAF with a focus on membrane potential (MP), intracellular pH, and cellular swelling under physiological and pathophysiological conditions and hypothesizes that the PAF-mediated response of granulocytes is altered during sepsis. The cellular response of granulocytes including MP, intracellular pH, cellular swelling, and other activation markers were analyzed by multiparametric flow cytometry. In addition, the chemotactic activity and the formation of platelet-neutrophil complexes after exposure to PAF were investigated. The changes of the (electro-)physiological response features were translationally verified in a human ex vivo whole blood model of endotoxemia as well as during polymicrobial porcine sepsis. In neutrophils from healthy human donors, PAF elicited a rapid depolarization, an intracellular alkalization, and an increase in cell size in a time- and dose-dependent manner. Mechanistically, the alkalization was dependent on sodium-proton exchanger 1 (NHE1) activity, while the change in cellular shape was sodium flux- but only partially NHE1-dependent. In a pathophysiological altered environment, the PAF-induced response of neutrophils was modulated. Acidifying the extracellular pH in vitro enhanced PAF-mediated depolarization, whereas the increases in cell size and intracellular pH were largely unaffected. Ex vivo exposure of human whole blood to lipopolysaccharide diminished the PAF-induced intracellular alkalization and the change in neutrophil size. During experimental porcine sepsis, depolarization of the MP was significantly impaired. Additionally, there was a trend for increased cellular swelling, whereas intracellular alkalization remained stable. Overall, an impaired (electro-)physiological response of neutrophils to PAF stimulation represents a cellular hallmark of those cells challenged during systemic inflammation. Furthermore, this altered response may be indicative of and causative for the development of neutrophil dysfunction during sepsis.
Collapse
Affiliation(s)
- Stefan Hug
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Stefan Bernhard
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | | | - Maike Erber
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Lisa Wohlgemuth
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Christiane Leonie Knapp
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Jonas Martin Bauer
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Laura Vidoni
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Michael Fauler
- Institute of General Physiology, University of Ulm, Ulm, Germany
| | - Karl Josef Föhr
- Department of Anesthesiology and Intensive Care Medicine, University Hospital of Ulm, Ulm, Germany
| | - Peter Radermacher
- Institute of Anesthesiological Pathophysiology and Process Development, University Hospital of Ulm, Ulm, Germany
| | - Andrea Hoffmann
- Institute of Anesthesiological Pathophysiology and Process Development, University Hospital of Ulm, Ulm, Germany
| | - Markus Huber-Lang
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - David Alexander Christian Messerer
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany.,Department of Anesthesiology and Intensive Care Medicine, University Hospital of Ulm, Ulm, Germany.,Institute of Anesthesiological Pathophysiology and Process Development, University Hospital of Ulm, Ulm, Germany
| |
Collapse
|
43
|
Breitinger U, Farag NS, Ali NKM, Ahmed M, El-Azizi MA, Breitinger HG. Cell viability assay as a tool to study activity and inhibition of hepatitis C p7 channels. J Gen Virol 2021; 102. [PMID: 33709903 DOI: 10.1099/jgv.0.001571] [Citation(s) in RCA: 3] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The p7 viroporin of the hepatitis C virus (HCV) forms an intracellular proton-conducting transmembrane channel in virus-infected cells, shunting the pH of intracellular compartments and thus helping virus assembly and release. This activity is essential for virus infectivity, making viroporins an attractive target for drug development. The protein sequence and drug sensitivity of p7 vary between the seven major genotypes of the hepatitis C virus, but the essential channel activity is preserved. Here, we investigated the effect of several inhibitors on recombinant HCV p7 channels corresponding to genotypes 1a-b, 2a-b, 3a and 4a using patch-clamp electrophysiology and cell-based assays. We established a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-based cell viability assay for recombinant p7 expressed in HEK293 cells to assess channel activity and its sensitivity to inhibitors. The results from the cell viability assay were consistent with control measurements using established assays of haemadsorption and intracellular pH, and agreed with data from patch-clamp electrophysiology. Hexamethylene amiloride (HMA) was the most potent inhibitor of p7 activity, but possessed cytotoxic activity at higher concentrations. Rimantadine was active against p7 of all genotypes, while amantadine activity was genotype-dependent. The alkyl-chain iminosugars NB-DNJ, NN-DNJ and NN-DGJ were tested and their activity was found to be genotype-specific. In the current study, we introduce cell viability assays as a rapid and cost-efficient technique to assess viroporin activity and identify channel inhibitors as potential novel antiviral drugs.
Collapse
Affiliation(s)
- Ulrike Breitinger
- Department of Biochemistry, German University in Cairo, New Cairo, Egypt
| | - Noha S Farag
- Department of Microbiology and Immunology, German University in Cairo, New Cairo, Egypt
| | - Nourhan K M Ali
- Department of Biochemistry, German University in Cairo, New Cairo, Egypt
| | - Marwa Ahmed
- Present address: Institute of Biochemistry and Biophysics Friedrich-Schiller-University Jena, Hans-Knöll-Str. 2, D-07745, Jena, Germany.,Department of Biochemistry, German University in Cairo, New Cairo, Egypt
| | - Mohamed A El-Azizi
- Department of Microbiology and Immunology, German University in Cairo, New Cairo, Egypt
| | | |
Collapse
|
44
|
Shiozaki A, Marunaka Y, Otsuji E. Roles of Ion and Water Channels in the Cell Death and Survival of Upper Gastrointestinal Tract Cancers. Front Cell Dev Biol 2021; 9:616933. [PMID: 33777930 PMCID: PMC7991738 DOI: 10.3389/fcell.2021.616933] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 10/13/2020] [Accepted: 02/22/2021] [Indexed: 02/06/2023] Open
Abstract
Ion and water channels were recently shown to be involved in cancer cell functions, and various transporter types have been detected in upper gastrointestinal tract (UGI) cancers. Current information on the expression and roles of these channels and transporters in the death and survival of UGI cancer cells was reviewed herein, and the potential of their regulation for cancer management was investigated. Esophageal cancer (EC) and gastric cancer (GC) cells and tissues express many different types of ion channels, including voltage-gated K+, Cl-, and Ca2+, and transient receptor potential (TRP) channels, which regulate the progression of cancer. Aquaporin (AQP) 1, 3, and 5 are water channels that contribute to the progression of esophageal squamous cell carcinoma (ESCC) and GC. Intracellular pH regulators, including the anion exchanger (AE), sodium hydrogen exchanger (NHE), and vacuolar H+-ATPases (V-ATPase), also play roles in the functions of UGI cancer cells. We have previously conducted gene expression profiling and revealed that the regulatory mechanisms underlying apoptosis in ESCC cells involved various types of Cl- channels, Ca2+ channels, water channels, and pH regulators (Shimizu et al., 2014; Ariyoshi et al., 2017; Shiozaki et al., 2017, 2018a; Kobayashi et al., 2018; Yamazato et al., 2018; Konishi et al., 2019; Kudou et al., 2019; Katsurahara et al., 2020, 2021; Matsumoto et al., 2021; Mitsuda et al., 2021). We have also previously demonstrated the clinicopathological and prognostic significance of their expression in ESCC patients, and shown that their pharmacological blockage and gene silencing had an impact on carcinogenesis, indicating their potential as targets for the treatment of UGI cancers. A more detailed understanding of the molecular regulatory mechanisms underlying cell death and survival of UGI cancers may result in the application of cellular physiological methods as novel therapeutic approaches.
Collapse
Affiliation(s)
- Atsushi Shiozaki
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Yoshinori Marunaka
- Department of Molecular Cell Physiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.,Research Institute for Clinical Physiology, Kyoto Industrial Health Association, Kyoto, Japan.,Research Center for Drug Discovery and Pharmaceutical Development Science, Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Japan
| | - Eigo Otsuji
- Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan
| |
Collapse
|
45
|
Messerer DAC, Schmidt H, Frick M, Huber-Lang M. Ion and Water Transport in Neutrophil Granulocytes and Its Impairment during Sepsis. Int J Mol Sci 2021; 22:1699. [PMID: 33567720 PMCID: PMC7914618 DOI: 10.3390/ijms22041699] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/30/2021] [Accepted: 02/01/2021] [Indexed: 12/11/2022] Open
Abstract
Neutrophil granulocytes are the vanguard of innate immunity in response to numerous pathogens. Their activity drives the clearance of microbe- and damage-associated molecular patterns, thereby contributing substantially to the resolution of inflammation. However, excessive stimulation during sepsis leads to cellular unresponsiveness, immunological dysfunction, bacterial expansion, and subsequent multiple organ dysfunction. During the short lifespan of neutrophils, they can become significantly activated by complement factors, cytokines, and other inflammatory mediators. Following stimulation, the cells respond with a defined (electro-)physiological pattern, including depolarization, calcium influx, and alkalization as well as with increased metabolic activity and polarization of the actin cytoskeleton. Activity of ion transport proteins and aquaporins is critical for multiple cellular functions of innate immune cells, including chemotaxis, generation of reactive oxygen species, and phagocytosis of both pathogens and tissue debris. In this review, we first describe the ion transport proteins and aquaporins involved in the neutrophil ion-water fluxes in response to chemoattractants. We then relate ion and water flux to cellular functions with a focus on danger sensing, chemotaxis, phagocytosis, and oxidative burst and approach the role of altered ion transport protein expression and activity in impaired cellular functions and cell death during systemic inflammation as in sepsis.
Collapse
Affiliation(s)
- David Alexander Christian Messerer
- Institute of Clinical and Experimental Trauma-Immunology, University Hospital of Ulm, 89081 Ulm, Germany;
- Department of Anesthesiology and Intensive Care Medicine, University Hospital of Ulm, 89081 Ulm, Germany
| | - Hanna Schmidt
- Institute of General Physiology, Ulm University, 89081 Ulm, Germany; (H.S.); (M.F.)
- Department of Pediatrics and Adolescent Medicine, University Hospital of Ulm, 89081 Ulm, Germany
| | - Manfred Frick
- Institute of General Physiology, Ulm University, 89081 Ulm, Germany; (H.S.); (M.F.)
| | - Markus Huber-Lang
- Institute of Clinical and Experimental Trauma-Immunology, University Hospital of Ulm, 89081 Ulm, Germany;
| |
Collapse
|
46
|
Amiri M, Seidler UE, Nikolovska K. The Role of pH i in Intestinal Epithelial Proliferation-Transport Mechanisms, Regulatory Pathways, and Consequences. Front Cell Dev Biol 2021; 9:618135. [PMID: 33553180 PMCID: PMC7862550 DOI: 10.3389/fcell.2021.618135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 01/04/2021] [Indexed: 01/07/2023] Open
Abstract
During the maturation of intestinal epithelial cells along the crypt/surface axis, a multitude of acid/base transporters are differentially expressed in their apical and basolateral membranes, enabling processes of electrolyte, macromolecule, nutrient, acid/base and fluid secretion, and absorption. An intracellular pH (pHi)-gradient is generated along the epithelial crypt/surface axis, either as a consequence of the sum of the ion transport activities or as a distinctly regulated entity. While the role of pHi on proliferation, migration, and tumorigenesis has been explored in cancer cells for some time, emerging evidence suggests an important role of the pHi in the intestinal stem cells (ISCs) proliferative rate under physiological conditions. The present review highlights the current state of knowledge about the potential regulatory role of pHi on intestinal proliferation and differentiation.
Collapse
|
47
|
Gunderson SJ, Puga Molina LC, Spies N, Balestrini PA, Buffone MG, Jungheim ES, Riley J, Santi CM. Machine-learning algorithm incorporating capacitated sperm intracellular pH predicts conventional in vitro fertilization success in normospermic patients. Fertil Steril 2021; 115:930-9. [PMID: 33461755 DOI: 10.1016/j.fertnstert.2020.10.038] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 10/06/2020] [Accepted: 10/08/2020] [Indexed: 12/24/2022]
Abstract
OBJECTIVE To measure human sperm intracellular pH (pHi) and develop a machine-learning algorithm to predict successful conventional in vitro fertilization (IVF) in normospermic patients. DESIGN Spermatozoa from 76 IVF patients were capacitated in vitro. Flow cytometry was used to measure sperm pHi, and computer-assisted semen analysis was used to measure hyperactivated motility. A gradient-boosted machine-learning algorithm was trained on clinical data and sperm pHi and membrane potential from 58 patients to predict successful conventional IVF, defined as a fertilization ratio (number of fertilized oocytes [2 pronuclei]/number of mature oocytes) greater than 0.66. The algorithm was validated on an independent set of data from 18 patients. SETTING Academic medical center. PATIENT(S) Normospermic men undergoing IVF. Patients were excluded if they used frozen sperm, had known male factor infertility, or used intracytoplasmic sperm injection only. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Successful conventional IVF. RESULT(S) Sperm pHi positively correlated with hyperactivated motility and with conventional IVF ratio (n = 76) but not with intracytoplasmic sperm injection fertilization ratio (n = 38). In receiver operating curve analysis of data from the test set (n = 58), the machine-learning algorithm predicted successful conventional IVF with a mean accuracy of 0.72 (n = 18), a mean area under the curve of 0.81, a mean sensitivity of 0.65, and a mean specificity of 0.80. CONCLUSION(S) Sperm pHi correlates with conventional fertilization outcomes in normospermic patients undergoing IVF. A machine-learning algorithm can use clinical parameters and markers of capacitation to accurately predict successful fertilization in normospermic men undergoing conventional IVF.
Collapse
|
48
|
Matamoros-Volante A, Castillo-Viveros V, Torres-Rodríguez P, Treviño MB, Treviño CL. Time-Lapse Flow Cytometry: A Robust Tool to Assess Physiological Parameters Related to the Fertilizing Capability of Human Sperm. Int J Mol Sci 2020; 22:ijms22010093. [PMID: 33374265 PMCID: PMC7796328 DOI: 10.3390/ijms22010093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 12/16/2020] [Accepted: 12/16/2020] [Indexed: 11/17/2022] Open
Abstract
Plasma membrane (PM) hyperpolarization, increased intracellular pH (pHi), and changes in intracellular calcium concentration ([Ca2+]i) are physiological events that occur during human sperm capacitation. These parameters are potential predictors of successful outcomes for men undergoing artificial reproduction techniques (ARTs), but methods currently available for their determination pose various technical challenges and limitations. Here, we developed a novel strategy employing time-lapse flow cytometry (TLFC) to determine capacitation-related membrane potential (Em) and pHi changes, and progesterone-induced [Ca2+]i increases. Our results show that TLFC is a robust method to measure absolute Em and pHi values and to qualitatively evaluate [Ca2+]i changes. To support the usefulness of our methodology, we used sperm from two types of normozoospermic donors: known paternity (subjects with self-reported paternity) and no-known paternity (subjects without self-reported paternity and no known fertility problems). We found relevant differences between them. The incidences of membrane hyperpolarization, pHi alkalinization, and increased [Ca2+]i were consistently high among known paternity samples (100%, 100%, and 86%, respectively), while they varied widely among no-known paternity samples (44%, 17%, and 45%, respectively). Our results indicate that TLFC is a powerful tool to analyze key physiological parameters of human sperm, which pending clinical validation, could potentially be employed as fertility predictors.
Collapse
Affiliation(s)
- Arturo Matamoros-Volante
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca Morelos 62210, Mexico; (A.M.-V.); (V.C.-V.); (P.T.-R.)
| | - Valeria Castillo-Viveros
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca Morelos 62210, Mexico; (A.M.-V.); (V.C.-V.); (P.T.-R.)
| | - Paulina Torres-Rodríguez
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca Morelos 62210, Mexico; (A.M.-V.); (V.C.-V.); (P.T.-R.)
| | - Marcela B. Treviño
- Science Department, School of Pure and Applied Sciences, Florida SouthWestern State College, Fort Myers, FL 33919, USA;
| | - Claudia L. Treviño
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca Morelos 62210, Mexico; (A.M.-V.); (V.C.-V.); (P.T.-R.)
- Correspondence: ; Tel.: +52-777-329-1611
| |
Collapse
|
49
|
Mertsalova MP, Pronin IN, Zakharova NE, Podoprigora AE, Batalov AI, Tyurina AN, Shults EI, Pogosbekyan EL, Fadeeva LM, Golanov AV, Postnov AA, Rodionov PV. [ Intracellular pH measurement in glioblastoma cells: the possibilities of phosphorus-31 MR spectroscopy]. Zh Vopr Neirokhir Im N N Burdenko 2020; 84:26-32. [PMID: 33306297 DOI: 10.17116/neiro20208406126] [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] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To analyze intracellular pH measurement with phosphorus-31 MR spectroscopy in glioblastoma cells and to compare these data with intracellular pH in healthy volunteers. MATERIAL AND METHODS There were 10 patients aged 41 - 67 years with supratentorial glioblastomas. Intracellular pH in glioblastoma cells was compared with pH in healthy persons. RESULTS We found a tendency to increased intracellular pH in glioblastoma cells in comparison with pH in intact brain tissue. CONCLUSION Intracellular pH in brain tissue can be used as a potential marker of early abnormalities which could not be detected by conventional MRI. Moreover, these data may be valuable to estimate the efficacy of chemotherapy. The study was supported by Russian Science Foundation (grant No. 18-15-00337).
Collapse
Affiliation(s)
| | - I N Pronin
- Burdenko Neurosurgical Center, Moscow, Russia
| | | | | | - A I Batalov
- Burdenko Neurosurgical Center, Moscow, Russia
| | - A N Tyurina
- Burdenko Neurosurgical Center, Moscow, Russia
| | - E I Shults
- Burdenko Neurosurgical Center, Moscow, Russia
| | | | - L M Fadeeva
- Burdenko Neurosurgical Center, Moscow, Russia
| | - A V Golanov
- Burdenko Neurosurgical Center, Moscow, Russia
| | - A A Postnov
- National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow, Russia
| | | |
Collapse
|
50
|
Van Leemputte F, Vanthienen W, Wijnants S, Van Zeebroeck G, Thevelein JM. Aberrant Intracellular pH Regulation Limiting Glyceraldehyde-3-Phosphate Dehydrogenase Activity in the Glucose-Sensitive Yeast tps1Δ Mutant. mBio 2020; 11:e02199-20. [PMID: 33109759 DOI: 10.1128/mBio.02199-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [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] [Indexed: 11/20/2022] Open
Abstract
Glucose catabolism is the backbone of metabolism in most organisms. In spite of numerous studies and extensive knowledge, major controls on glycolysis and its connections to the other metabolic pathways remain to be discovered. A striking example is provided by the extreme glucose sensitivity of the yeast tps1Δ mutant, which undergoes apoptosis in the presence of just a few millimolar glucose. Previous work has shown that the conspicuous glucose-induced hyperaccumulation of the glycolytic metabolite fructose-1,6-bisphosphate (Fru1,6bisP) in tps1Δ cells triggers apoptosis through activation of the Ras-cAMP-protein kinase A (PKA) signaling pathway. However, the molecular cause of this Fru1,6bisP hyperaccumulation has remained unclear. We now provide evidence that the persistent drop in intracellular pH upon glucose addition to tps1Δ cells likely compromises the activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a major glycolytic enzyme downstream of Fru1,6bisP, due to its unusually high pH optimum. Our work highlights the potential importance of intracellular pH fluctuations for control of major metabolic pathways. Whereas the yeast Saccharomyces cerevisiae shows great preference for glucose as a carbon source, a deletion mutant in trehalose-6-phosphate synthase, tps1Δ, is highly sensitive to even a few millimolar glucose, which triggers apoptosis and cell death. Glucose addition to tps1Δ cells causes deregulation of glycolysis with hyperaccumulation of metabolites upstream and depletion downstream of glyceraldehyde-3-phosphate dehydrogenase (GAPDH). The apparent metabolic barrier at the level of GAPDH has been difficult to explain. We show that GAPDH isozyme deletion, especially Tdh3, further aggravates glucose sensitivity and metabolic deregulation of tps1Δ cells, but overexpression does not rescue glucose sensitivity. GAPDH has an unusually high pH optimum of 8.0 to 8.5, which is not altered by tps1Δ. Whereas glucose causes short, transient intracellular acidification in wild-type cells, in tps1Δ cells, it causes permanent intracellular acidification. The hxk2Δ and snf1Δ suppressors of tps1Δ restore the transient acidification. These results suggest that GAPDH activity in the tps1Δ mutant may be compromised by the persistently low intracellular pH. Addition of NH4Cl together with glucose at high extracellular pH to tps1Δ cells abolishes the pH drop and reduces glucose-6-phosphate (Glu6P) and fructose-1,6-bisphosphate (Fru1,6bisP) hyperaccumulation. It also reduces the glucose uptake rate, but a similar reduction in glucose uptake rate in a tps1Δ hxt2,4,5,6,7Δ strain does not prevent glucose sensitivity and Fru1,6bisP hyperaccumulation. Hence, our results suggest that the glucose-induced intracellular acidification in tps1Δ cells may explain, at least in part, the apparent glycolytic bottleneck at GAPDH but does not appear to fully explain the extreme glucose sensitivity of the tps1Δ mutant.
Collapse
|