1
|
Chang Z, Li S, Ye JH, Lin F, Chen Y, Guo Z, He W. A dual-response ratiometric near-infrared fluorescence probe based on cyanine platform for Cu 2+ detection and its imaging in vitro and vivo. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 325:125115. [PMID: 39299077 DOI: 10.1016/j.saa.2024.125115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2024] [Revised: 08/30/2024] [Accepted: 09/07/2024] [Indexed: 09/22/2024]
Abstract
A near-infrared fluorescent probe (NUST-Cy-1) was disclosed here, which displays ratiometric and dual-channel response for Cu2+ (λex1 = 450 nm, λex2 = 750 nm) with large Stokes shifts (143 nm, 375 nm, 75 nm respectively). This probe demonstrates high sensitivity with low detection limit (1.4 μM) and selectivity for Cu2+ detection. Furthermore, fluorescent imaging of Cu2+ in vitro and vivo were successfully achieved.
Collapse
Affiliation(s)
- Zhijian Chang
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China
| | - Shumeng Li
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China
| | - Jia-Hai Ye
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China.
| | - Fuyan Lin
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China
| | - Yuncong Chen
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
| | - Zijian Guo
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China
| | - Weijiang He
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
| |
Collapse
|
2
|
Yokawa K, Kodama Y. A green light-excitable FRET system for monitoring intracellular calcium levels in plant cells. PLANT SIGNALING & BEHAVIOR 2021; 16:1963104. [PMID: 34353232 PMCID: PMC8525944 DOI: 10.1080/15592324.2021.1963104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 07/28/2021] [Accepted: 07/28/2021] [Indexed: 06/13/2023]
Abstract
CFP/YFP-paired FRET is routinely used to estimate intracellular Ca2+ concentrations in vivo. This system, however, is excited with blue light, which is likely to invoke unexpected responses in plant cells. This report describes a new green light-excitable FRET system with an mKO2/mCherry pair. Plant cells expressing this newly constructed FRET system demonstrated its ability to monitor changes in cytosolic free calcium concentration. The new system is likely to find applications in studies of plant cells where undesirable blue light responses must be avoided.
Collapse
Affiliation(s)
- Ken Yokawa
- Center for Bioscience Research and Education, Utsunomiya University, Tochigi, Japan
- Department of Engineering, Kitami Institute of Technology, Kitami, Japan
| | - Yutaka Kodama
- Center for Bioscience Research and Education, Utsunomiya University, Tochigi, Japan
| |
Collapse
|
3
|
Redolfi N, Greotti E, Zanetti G, Hochepied T, Fasolato C, Pendin D, Pozzan T. A New Transgenic Mouse Line for Imaging Mitochondrial Calcium Signals. FUNCTION 2021; 2:zqab012. [PMID: 35330679 PMCID: PMC8788866 DOI: 10.1093/function/zqab012] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/19/2021] [Accepted: 02/24/2021] [Indexed: 01/06/2023] Open
Abstract
Mitochondria play a key role in cellular calcium (Ca2+) homeostasis. Dysfunction in the organelle Ca2+ handling appears to be involved in several pathological conditions, ranging from neurodegenerative diseases, cardiac failure and malignant transformation. In the past years, several targeted green fluorescent protein (GFP)-based genetically encoded Ca2+ indicators (GECIs) have been developed to study Ca2+ dynamics inside mitochondria of living cells. Surprisingly, while there is a number of transgenic mice expressing different types of cytosolic GECIs, few examples are available expressing mitochondria-localized GECIs, and none of them exhibits adequate spatial resolution. Here we report the generation and characterization of a transgenic mouse line (hereafter called mt-Cam) for the controlled expression of a mitochondria-targeted, Förster resonance energy transfer (FRET)-based Cameleon, 4mtD3cpv. To achieve this goal, we engineered the mouse ROSA26 genomic locus by inserting the optimized sequence of 4mtD3cpv, preceded by a loxP-STOP-loxP sequence. The probe can be readily expressed in a tissue-specific manner upon Cre recombinase-mediated excision, obtainable with a single cross. Upon ubiquitous Cre expression, the Cameleon is specifically localized in the mitochondrial matrix of cells in all the organs and tissues analyzed, from embryos to aged animals. Ca2+ imaging experiments performed in vitro and ex vivo in brain slices confirmed the functionality of the probe in isolated cells and live tissues. This new transgenic mouse line allows the study of mitochondrial Ca2+ dynamics in different tissues with no invasive intervention (such as viral infection or electroporation), potentially allowing simple calibration of the fluorescent signals in terms of mitochondrial Ca2+ concentration ([Ca2+]).
Collapse
Affiliation(s)
- Nelly Redolfi
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy
| | - Elisa Greotti
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy
- Neuroscience Institute, Italian National Research Council (CNR), Via U. Bassi 58/B, 35131 Padua, Italy
| | - Giulia Zanetti
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy
| | - Tino Hochepied
- VIB Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Cristina Fasolato
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy
| | - Diana Pendin
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy
- Neuroscience Institute, Italian National Research Council (CNR), Via U. Bassi 58/B, 35131 Padua, Italy
| | - Tullio Pozzan
- Department of Biomedical Sciences, University of Padua, Via U. Bassi 58/B, 35131 Padua, Italy
- Neuroscience Institute, Italian National Research Council (CNR), Via U. Bassi 58/B, 35131 Padua, Italy
- Veneto Institute of Molecular Medicine (VIMM), Via G. Orus 2, 35129 Padua, Italy
| |
Collapse
|
4
|
Wang X, Wang H, Jiang Q, Lee YI, Feng S, Liu HG. Highly selective and sensitive fluorogenic ferric probes based on aggregation-enhanced emission with -SiMe 3 substituted polybenzene. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 188:202-207. [PMID: 28715687 DOI: 10.1016/j.saa.2017.07.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/07/2017] [Accepted: 07/12/2017] [Indexed: 06/07/2023]
Abstract
In this study, thiophene was linked to polybenzene to generate novel fluorescent probes, namely 3,4-diphenyl-2,5-di(2-thienyl)phenyl-trimethylsilane (DPTB-TMS) with a -SiMe3 substituent and 3,4-diphenyl-2,5-di(2-thienyl)phenyl (DPTB) without the -SiMe3 substituent, respectively. Both of the two compounds exhibit aggregation-enhanced emission (AEE) properties in tetrahydrofuran/water mixtures due to restricted intramolecular rotation of the peripheral groups, which make the two compounds good candidates for the detection of Fe3+ ions in aqueous-based solutions. The fluorescence intensity of the two compounds decreases immediately and obviously upon addition of a trace amount of Fe3+, and decreases continuously as the amount of Fe3+ increases. The fluorescence was quenched to 92% of its initial intensity when the amount of Fe3+ ions reached 6μmol for DPTB-TMS and to 80% for DPTB in the systems, indicating that the compound with the -SiMe3 group is a more effective probe. The detection limit was found to be 1.17μM (65ppb). The detection mechanism is proposed to be static quenching. DPTB-TMS is highly efficient for the detection of ferric ions even in the presence of other metal ions. In addition, the method is also successfully applied to the detection of ferric ions in water, blood serum, or solid films. This indicates that these polybenzene compounds can be applied as low-cost, high selectivity, and high efficiency Fe3+ probes in water or in clinical applications.
Collapse
Affiliation(s)
- Xuefeng Wang
- Key Laboratory for Colloid and Interface Chemistry of Education Ministry and Special Functional Aggregated Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, PR China
| | - Hua Wang
- Key Laboratory for Colloid and Interface Chemistry of Education Ministry and Special Functional Aggregated Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, PR China
| | - Qin Jiang
- Key Laboratory for Colloid and Interface Chemistry of Education Ministry and Special Functional Aggregated Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, PR China
| | - Yong-Ill Lee
- Anastro Laboratory, Department of Chemistry, Changwon National University, Changwon 641-773, Republic of Korea
| | - Shengyu Feng
- Key Laboratory for Colloid and Interface Chemistry of Education Ministry and Special Functional Aggregated Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, PR China
| | - Hong-Guo Liu
- Key Laboratory for Colloid and Interface Chemistry of Education Ministry and Special Functional Aggregated Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, PR China.
| |
Collapse
|
5
|
Costa A, Kudla J. Colorful insights: advances in imaging drive novel breakthroughs in Ca2+ signaling. MOLECULAR PLANT 2015; 8:352-355. [PMID: 25655824 DOI: 10.1016/j.molp.2014.11.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 11/05/2014] [Accepted: 11/26/2014] [Indexed: 06/04/2023]
Affiliation(s)
- Alex Costa
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via G. Celoria 26, 20133 Milan, Italy; Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Via G. Celoria 26, 20133 Milan, Italy.
| | - Jörg Kudla
- Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 4, 48149 Münster, Germany.
| |
Collapse
|
6
|
Albrecht T, Zhao Y, Nguyen TH, Campbell RE, Johnson JD. Fluorescent biosensors illuminate calcium levels within defined beta-cell endosome subpopulations. Cell Calcium 2015; 57:263-74. [PMID: 25682167 DOI: 10.1016/j.ceca.2015.01.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 12/26/2014] [Accepted: 01/19/2015] [Indexed: 11/18/2022]
Abstract
Live cell imaging has revealed that calcium ions (Ca(2+)) pass in and out of many cellular organelles. However, technical hurdles have limited measurements of Ca(2+) in acidic organelles, such as endosomes. Although evidence hints that endosomes play a role in Ca(2+) signaling, direct measurements within endosomal lumina represent one of the final frontiers in organelle imaging. To measure Ca(2+) in a TiVAMP-positive endosome sub-population, the pH-resistant ratiometric Ca(2+) biosensor GEM-GECO1 and the ratiometric pH biosensor mKeima were used. A positive correlation between acidic endosomal pH and higher Ca(2+) was observed within these Rab5a- and Rab7-positive compartments. Ca(2+) concentration in most endosomes was estimated to be below 2μM, lower than Ca(2+) levels in several other intracellular stores, indicating that endosomes may take up Ca(2+) during physiological stimulation. Indeed, endosomes accumulated Ca(2+) during glucose-stimulation, a condition where endosomal pH did not change. Our biosensors permitted the first measurements revealing a role for endosomes in cellular Ca(2+) homeostasis during physiological stimulation.
Collapse
Affiliation(s)
- Tobias Albrecht
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Yongxin Zhao
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Trang Hai Nguyen
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Robert E Campbell
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - James D Johnson
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada.
| |
Collapse
|
7
|
Mahdavi A, Sajedi RH, Hosseinkhani S, Taghdir M. Hyperactive Arg39Lys mutated mnemiopsin: implication of positively charged residue in chromophore binding cavity. Photochem Photobiol Sci 2015; 14:792-800. [DOI: 10.1039/c4pp00191e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Mnemiopsin, a Ca2+-regulated photoprotein isolated fromMnemiopsis leidyi, belongs to the family of ctenophore photoproteins. While there are no charged amino acid residues in the coelenterazine binding cavity of cnidarian photoproteins, ctenophore photoproteins have a positively charged residue (Arg) in this region.
Collapse
Affiliation(s)
- Atiyeh Mahdavi
- Department of Biological Sciences
- Institute for Advanced Studies in Basic Sciences (IASBS)
- Zanjan 45195-1159
- Iran
| | - Reza H. Sajedi
- Department of Biochemistry
- Faculty of Biological Sciences
- Tarbiat Modares University
- Tehran 14115-154
- Iran
| | - Saman Hosseinkhani
- Department of Biochemistry
- Faculty of Biological Sciences
- Tarbiat Modares University
- Tehran 14115-154
- Iran
| | - Majid Taghdir
- Department of Biophysics
- Faculty of Biological Sciences
- Tarbiat Modares University
- Tehran 14115-154
- Iran
| |
Collapse
|
8
|
Abstract
This chapter introduces to electronic cameras, discusses the various parameters considered for evaluating their performance, and describes some of the key features of different camera formats. The chapter also presents the basic understanding of functioning of the electronic cameras and how these properties can be exploited to optimize image quality under low-light conditions. Although there are many types of cameras available for microscopy, the most reliable type is the charge-coupled device (CCD) camera, which remains preferred for high-performance systems. If time resolution and frame rate are of no concern, slow-scan CCDs certainly offer the best available performance, both in terms of the signal-to-noise ratio and their spatial resolution. Slow-scan cameras are thus the first choice for experiments using fixed specimens such as measurements using immune fluorescence and fluorescence in situ hybridization. However, if video rate imaging is required, one need not evaluate slow-scan CCD cameras. A very basic video CCD may suffice if samples are heavily labeled or are not perturbed by high intensity illumination. When video rate imaging is required for very dim specimens, the electron multiplying CCD camera is probably the most appropriate at this technological stage. Intensified CCDs provide a unique tool for applications in which high-speed gating is required. The variable integration time video cameras are very attractive options if one needs to acquire images at video rate acquisition, as well as with longer integration times for less bright samples. This flexibility can facilitate many diverse applications with highly varied light levels.
Collapse
|
9
|
Mahdavi A, Sajedi RH, Hosseinkhani S, Taghdir M, Sariri R. Site-directed mutagenesis of photoprotein mnemiopsin: implication of some conserved residues in bioluminescence properties. Photochem Photobiol Sci 2013. [DOI: 10.1039/c2pp25320h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
10
|
Mehta P, Gregor T. Approaching the molecular origins of collective dynamics in oscillating cell populations. Curr Opin Genet Dev 2010; 20:574-80. [PMID: 20934869 PMCID: PMC3132649 DOI: 10.1016/j.gde.2010.09.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Revised: 08/04/2010] [Accepted: 09/15/2010] [Indexed: 10/19/2022]
Abstract
From flocking birds, to organ generation, to swarming bacterial colonies, biological systems often exhibit collective behaviors. Here, we review recent advances in our understanding of collective dynamics in cell populations. We argue that understanding population-level oscillations requires examining the system under consideration at three different levels of complexity: at the level of isolated cells, homogenous populations, and spatially structured populations. We discuss the experimental and theoretical challenges this poses and highlight how new experimental techniques, when combined with conceptual tools adapted from physics, may help us overcome these challenges.
Collapse
Affiliation(s)
- Pankaj Mehta
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | | |
Collapse
|
11
|
Meyer JS, Tullis G, Pierret C, Spears KM, Morrison JA, Kirk MD. Detection of calcium transients in embryonic stem cells and their differentiated progeny. Cell Mol Neurobiol 2010; 29:1191-203. [PMID: 19475505 DOI: 10.1007/s10571-009-9413-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2009] [Accepted: 05/12/2009] [Indexed: 12/16/2022]
Abstract
A central issue in stem cell biology is the determination of function and activity of differentiated stem cells, features that define the true phenotype of mature cell types. Commonly, physiological mechanisms are used to determine the functionality of mature cell types, including those of the nervous system. Calcium imaging provides an indirect method of determining the physiological activities of a mature cell. Camgaroos are variants of yellow fluorescent protein that act as intracellular calcium sensors in transfected cells. We expressed one version of the camgaroos, Camgaroo-2, in mouse embryonic stem (ES) cells under the control of the CAG promoter system. Under the control of this promoter, Camgaroo-2 fluorescence was ubiquitously expressed in all cell types derived from the ES cells that were tested. In response to pharmacological stimulation, the fluorescence levels in transfected cells correlated with cellular depolarization and hyperpolarization. These changes were observed in both undifferentiated ES cells as well as ES cells that had been neurally induced, including putative neurons that were differentiated from transfected ES cells. The results presented here indicate that Camgaroo-2 may be used like traditional fluorescent proteins to track cells as well as to study the functionality of stem cells and their progeny.
Collapse
Affiliation(s)
- Jason S Meyer
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211, USA.
| | | | | | | | | | | |
Collapse
|
12
|
Yu M, Shi M, Chen Z, Li F, Li X, Gao Y, Xu J, Yang H, Zhou Z, Yi T, Huang C. Highly Sensitive and Fast Responsive Fluorescence Turn-On Chemodosimeter for Cu2+and Its Application in Live Cell Imaging. Chemistry 2008; 14:6892-900. [DOI: 10.1002/chem.200800005] [Citation(s) in RCA: 284] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
13
|
Garcia CRS, de Azevedo MF, Wunderlich G, Budu A, Young JA, Bannister L. Plasmodium in the postgenomic era: new insights into the molecular cell biology of malaria parasites. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2008; 266:85-156. [PMID: 18544493 DOI: 10.1016/s1937-6448(07)66003-1] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In this review, we bring together some of the approaches toward understanding the cellular and molecular biology of Plasmodium species and their interaction with their host red blood cells. Considerable impetus has come from the development of new methods of molecular genetics and bioinformatics, and it is important to evaluate the wealth of these novel data in the context of basic cell biology. We describe how these approaches are gaining valuable insights into the parasite-host cell interaction, including (1) the multistep process of red blood cell invasion by the merozoite; (2) the mechanisms by which the intracellular parasite feeds on the red blood cell and exports parasite proteins to modify its cytoadherent properties; (3) the modulation of the cell cycle by sensing the environmental tryptophan-related molecules; (4) the mechanism used to survive in a low Ca(2+) concentration inside red blood cells; (5) the activation of signal transduction machinery and the regulation of intracellular calcium; (6) transfection technology; and (7) transcriptional regulation and genome-wide mRNA studies in Plasmodium falciparum.
Collapse
Affiliation(s)
- Celia R S Garcia
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, CEP 05508-900, São Paulo, SP, Brazil
| | | | | | | | | | | |
Collapse
|
14
|
|
15
|
Affiliation(s)
- Ivan Rasnik
- Physics Department, Emory University, Atlanta, Georgia 30322, USA
| | | | | | | |
Collapse
|
16
|
Wong CKM, Lai T, Holly JMP, Wheeler MH, Stewart CEH, Farndon JR. Insulin-like growth factors (IGF) I and II utilize different calcium signaling pathways in a primary human parathyroid cell culture model. World J Surg 2006; 30:333-45. [PMID: 16485066 DOI: 10.1007/s00268-005-0339-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND In most cell types, influx of calcium (Ca2+) induces a growth or secretory response. The opposite occurs in parathyroid (PTH), cells where there is an inverse relationship between intracellular Ca2+ concentration and PTH secretion. We have examined the effects of calcium channel and metabolism modulators on insulin-like growth factors (IGFs) in a parathyroid cell culture model. METHODS Cell cultures were prepared from 9 patients undergoing operation for hyperparathyroidism. Following adhesion, the cells were transferred to serum-free medium and dosed with IGF I, II +/- ethyleneglycol-bis(beta-aminoethyl)-N,N,N',N'-tetraacetic acid (EGTA), nifedipine, nickel, 2-aminoethoxy-diphenylborate (2-APB), or dantrolene. Proliferation (96 hours) was assessed by measuring tritiated thymidine incorporation and PTH release (1 and 3 hours) assayed by IRMA. RESULTS Both IGF I and II increased DNA synthesis to 162.8% +/- 10.6% (SEM) and 131.1% +/- 7.7%, respectively (P < 0.05). EGTA at 0.2 mmol (ionized Ca2+ 0.2 mmol) did not affect the response to both IGFs. EGTA at 2 mmol (ionized Ca2+ 0 mmol) reduced the DNA synthesis of IGF I and II to 29% and 26%, respectively (P < 0.05). Nifedipine and nickel (nonspecific Ca2+ channel blocker) were equally potent in negating the mitogenic effects of both IGFs. 2-APB (IP3R blocker) reduced the basal DNA synthesis to 51.3% +/- 8.4% but had no effect on either IGF. Dantrolene (ryanodine receptor blocker) negated IGF II induced mitogenisis (74.2% +/- 6.7%) and partially inhibited IGF I mitogenesis (123% +/- 6%) (P < 0.05). The rate of PTH secretion was greater after IGF II stimulation than after IGF I stimulation. CONCLUSIONS IGFs I and II induce mitogenesis by different calcium signaling pathways. These data suggest that parathyroid cells may utilize different calcium signaling pathways to distinguish growth factors and serum calcium changes.
Collapse
Affiliation(s)
- C K M Wong
- Department of Endocrine Surgery, Frenchay Hospital, Frenchay Park, Bristol, BS16 1LE, United Kingdom.
| | | | | | | | | | | |
Collapse
|
17
|
Gerencser AA, Adam-Vizi V. Mitochondrial Ca2+ dynamics reveals limited intramitochondrial Ca2+ diffusion. Biophys J 2005; 88:698-714. [PMID: 15501949 PMCID: PMC1305047 DOI: 10.1529/biophysj.104.050062] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2004] [Accepted: 10/13/2004] [Indexed: 11/18/2022] Open
Abstract
To reveal heterogeneity of mitochondrial function on the single-mitochondrion level we have studied the spatiotemporal dynamics of the mitochondrial Ca2+ signaling and the mitochondrial membrane potential using wide-field fluorescence imaging and digital image processing techniques. Here we demonstrate first-time discrete sites--intramitochondrial hotspots--of Ca2+ uptake after Ca2+ release from intracellular stores, and spreading of Ca2+ rise within the mitochondria. The phenomenon was characterized by comparison of observations in intact cells stimulated by ATP and in plasma membrane permeabilized or in ionophore-treated cells exposed to elevated buffer [Ca2+]. The findings indicate that Ca2+ diffuses laterally within the mitochondria, and that the diffusion is limited for shorter segments of the mitochondrial network. These observations were supported by mathematical simulation of buffered diffusion. The mitochondrial membrane potential was investigated using the potentiometric dye TMRM. Irradiation-induced fluctuations (flickering) of TMRM fluorescence showed synchronicity over large regions of the mitochondrial network, indicating that certain parts of this network form electrical syncytia. The spatial extension of these syncytia was decreased by 2-aminoethoxydiphenyl borate (2-APB) or by propranolol (blockers of nonclassical mitochondrial permeabilities). Our data suggest that mitochondria form syncytia of electrical conductance whereas the passage of Ca2+ is restricted to the individual organelle.
Collapse
Affiliation(s)
- Akos A Gerencser
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | | |
Collapse
|
18
|
Ashworth R. Approaches to measuring calcium in zebrafish: focus on neuronal development. Cell Calcium 2004; 35:393-402. [PMID: 15003849 DOI: 10.1016/j.ceca.2004.01.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2003] [Revised: 12/20/2003] [Accepted: 01/06/2004] [Indexed: 02/03/2023]
Abstract
Calcium ions are known to act as important cellular signals during nervous system development. In vitro studies have provided significant information on the role of calcium signals during neuronal development; however, the function of this messenger in nervous system maturation in vivo remains to be established. The zebrafish has emerged as a valuable model for the study of vertebrate embryogenesis. Fertilisation is external and the rapid growth of the transparent embryo, including development of internal organs, can be observed easily making it well suited for imaging studies. The developing nervous system is relatively simple and has been well characterised, allowing individual neurons to be identified. Using the zebrafish model, both intracellular and intercellular calcium signals throughout embryonic development have been characterised. This review summarises technical approaches to measure calcium signals in developing embryonic and larval zebrafish, and includes recent developments that will facilitate the study of calcium signalling in vivo. The application of calcium imaging techniques to investigate the action of this messenger during embryogenesis in intact zebrafish is illustrated by discussion of their contribution to our understanding of neuronal development in vivo.
Collapse
Affiliation(s)
- Rachel Ashworth
- Department of Physiology, University College London, Rockefeller Building, University Street, London WC1E 6JJ, UK.
| |
Collapse
|
19
|
Affiliation(s)
- Keith Berland
- Physics Department, Emory University, Atlanta, Georgia 30322, USA
| | | | | | | |
Collapse
|
20
|
Galione A, Churchill GC. Interactions between calcium release pathways: multiple messengers and multiple stores. Cell Calcium 2002; 32:343-54. [PMID: 12543094 DOI: 10.1016/s0143416002001902] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The discovery of cyclic adenosine diphosphate ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate (NAADP) as Ca(2+) releasing messengers has provided additional insight into how complex Ca(2+) signalling patterns are generated. There is mounting evidence that these molecules along with the more established messenger, myo-inositol 1,4,5-trisphosphate (IP(3)), have a widespread messenger role in shaping Ca(2+) signals in many cell types. These molecules have distinct structures and act on specific Ca(2+) release mechanisms. Emerging principles are that cADPR enhances the Ca(2+) sensitivity of ryanodine receptors (RYRs) to produce prolonged Ca(2+) signals through Ca(2+)-induced Ca(2+) release (CICR), while NAADP acts on a novel Ca(2+) release mechanism to produce a local trigger Ca(2+) signal which can be amplified by CICR by recruiting other Ca(2+) release mechanisms. Whilst IP(3) and cADPR mobilise Ca(2+) from the endoplasmic reticulum (ER), recent evidence from the sea urchin egg suggests that the major NAADP-sensitive Ca(2+) stores are reserve granules, acidic lysosomal-related organelles. In this review we summarise the role of multiple Ca(2+) mobilising messengers, Ca(2+) release channels and Ca(2+) stores, and the interplay between them, in the generation of specific Ca(2+) signals. Focusing upon cADPR and NAADP, we discuss how cellular stimuli may draw upon different combinations of these messengers to produce distinct Ca(2+) signalling signatures.
Collapse
Affiliation(s)
- A Galione
- Department of Pharmacology, Oxford University, Mansfield Road, OX1 3QT, Oxford, UK.
| | | |
Collapse
|
21
|
Abstract
This review examines polarized calcium and calmodulin signaling in exocrine epithelial cells. The calcium ion is a simple, evolutionarily ancient, and universal second messenger. In exocrine epithelial cells, it regulates essential functions such as exocytosis, fluid secretion, and gene expression. Exocrine cells are structurally polarized, with the apical region usually dedicated to secretion. Recent advances in technology, in particular the development of videoimaging and confocal microscopy, have led to the discovery of polarized, subcellular calcium signals in these cell types. The properties of a rich variety of local and global calcium signals have now been described in secretory epithelial cells. Secretagogues stimulate apical-to-basal waves of calcium in many exocrine cell types, but there are some interesting exceptions to this rule. The shapes of intracellular calcium signals are determined by the distribution of calcium-releasing channels and mechanisms that limit calcium elevation. Polarized distribution of calcium-handling mechanisms also leads to transcellular calcium transport in exocrine epithelial cells. This transport can deliver considerable amounts of calcium into secreted fluids. Multicellular polarized calcium signals can coordinate the activity of many individual cells in epithelial secretory tissue. Certain particularly sensitive cells serve as pacemakers for initiation of intercellular calcium waves. Many calcium signaling pathways involve activation of calmodulin. This ubiquitous protein regulates secretion in exocrine cells and also activates interesting feedback interactions with calcium channels and transporters. Very recently it became possible to directly study polarized calcium-calmodulin reactions and to visualize the process of hormone-induced redistribution of calmodulin in live cells. The structural and functional polarity of secretory epithelia alongside the polarity of its calcium and calmodulin signaling present an interesting lesson in tissue organization.
Collapse
Affiliation(s)
- Michael C Ashby
- Medical Research Council Secretory Control Research Group, The Physiological Laboratory, University of Liverpool, Liverpool, United Kingdom
| | | |
Collapse
|
22
|
Gerencsér AA AA, Adam-Vizi V. Selective, high-resolution fluorescence imaging of mitochondrial Ca2+ concentration. Cell Calcium 2001; 30:311-21. [PMID: 11733937 DOI: 10.1054/ceca.2001.0238] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We have developed a digital image processing technique based on highpass filtering of microfluorimetric images for selective transmission of fine image details corresponding to mitochondria. This technique enabled the detection of the mitochondrial calcium signals with high selectivity, simultaneously with the cytosolic calcium signal. The validity of this technique was supported in primary cultures of rat brain capillary endothelial cells loaded with X-rhod-1 by the results that (i) inhibition of the mitochondrial Ca2+ uptake by discharging the mitochondrial membrane potential selectively abolished the transient of the highpass filtered signal evoked by ATP, and (ii) CGP-37157, a selective blocker of the mitochondrial Na+/Ca2+ exchanger, increased the peak amplitude of highpass filtered (mitochondrial) Ca2+ transients and caused a sustained plateau. The highpass filtering technique enabled the analysis of the mitochondrial Ca2+ transients in high temporal resolution. We found a uniform and monophasic rise of [Ca2+] in the mitochondrial population of the cell, following the cytosolic [Ca2+] with a delay at onset and peak. The introduced highpass filtering technique is a powerful tool in the high spatial and temporal resolution analysis of mitochondrial calcium transients, and it could be especially important in specimens where genetically targeted probes fail.
Collapse
Affiliation(s)
- A A Gerencsér AA
- Department of Medical Biochemistry, Semmelweis University, Budapest, H-1444 P.O. Box 262, Hungary
| | | |
Collapse
|
23
|
Rudd JJ, Franklin-Tong VE. Unravelling response-specificity in Ca 2+ signalling pathways in plant cells. THE NEW PHYTOLOGIST 2001; 151:7-33. [PMID: 33873376 DOI: 10.1046/j.1469-8137.2001.00173.x] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Considerable advances have been made, both in the technologies available to study changes in intracellular cytosolic free Ca2+ ([Ca2+ ]i ), and in our understanding of Ca2+ signalling cascades in plant cells, but how specificity can be generated from such a ubiquitous component as Ca2+ is questionable. Recently the concept of 'Ca2+ signatures' has been formulated; tight control of the temporal and spatial characteristics of alterations in [Ca2+ ]i signals is thought to be responsible, at least in part, for the specificity of the response. However, the way in which Ca2+ signatures are decoded, which depends on the nature and location of the targets of the Ca2+ signals, has received little attention. In a few key systems, progress is being made on how diverse Ca2+ signatures might be transduced within cells in response to specific signals. Valuable pieces of the signal-specificity puzzle are being put together and this is illustrated here using some key examples; these emphasize the global importance of Ca2+ -mediated signal-transduction cascades in the responses of plants to a wide diversity of extracellular signals. However, the way in which signal specificity is encoded and transduced is still far from clear. Contents Summary 7 I. Introduction: Ca2+ as a signal transducer 8 II. Alterations in intracellular [Ca2+ ] 8 1. Measuring alterations in [Ca2+ ] 8 Imaging [Ca2+ ]i using Ca2+ -sensitive dyes 8 Measuring [Ca2+ ]i using aequorin 9 Imaging [Ca2+ ]i using cameleon 10 2. The concept of the 'Ca2+ signature 10 3. How might specific Ca2+ signatures be generated? 11 Control of intracellular Ca2+ release 11 Control of influx of extracellular Ca2+ 12 4. Examples of Ca2+ signatures and cellular responses to increases in [Ca2+ ] 13 Ca2+ signatures in stomatal guard cells in response to abscisic acid signals 14 Ca2+ signals in response to abiotic stimuli1 8 Ca2+ signatures involved in plant-pathogen responses 19 Ca2+ signatures in control of plant reproduction 20 Ca2+ signatures in root hairs in response to nodulation signals 23 III. Decoding the [Ca2+ ]i signatures 24 1. Coupling Ca2+ signals to responses through CaM 26 2. Coupling Ca2+ signals to responses through CDPK 27 3. Novel Ca2+ binding proteins as primary Ca2+ sensors 28 Conclusions and Perspective 28 References 29.
Collapse
Affiliation(s)
- Jason J Rudd
- Institut fur Pflanzenbiochemie, Weinberg 3, D-06120 Halle/Saale, Germany
| | - Vernonica E Franklin-Tong
- Wolfson Laboratory for Plant Molecular Biology, School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| |
Collapse
|
24
|
Snedden WA, Fromm H. Calmodulin as a versatile calcium signal transducer in plants. THE NEW PHYTOLOGIST 2001; 151:35-66. [PMID: 33873389 DOI: 10.1046/j.1469-8137.2001.00154.x] [Citation(s) in RCA: 264] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The complexity of Ca2+ patterns observed in eukaryotic cells, including plants, has led to the hypothesis that specific patterns of Ca2+ propagation, termed Ca2+ signatures, encode information and relay it to downstream elements (effectors) for translation into appropriate cellular responses. Ca2+ -binding proteins (sensors) play a key role in decoding Ca2+ signatures and transducing signals by activating specific targets and pathways. Calmodulin is a Ca2+ sensor known to modulate the activity of many mammalian proteins, whose targets in plants are now being actively characterized. Plants possess an interesting and rapidly growing list of calmodulin targets with a variety of cellular roles. Nevertheless, many targets appear to be unique to plants and remain uncharacterized, calling for a concerted effort to elucidate their functions. Moreover, the extended family of calmodulin-related proteins in plants consists of evolutionarily divergent members, mostly of unknown function, although some have recently been implicated in stress responses. It is hoped that advances in functional genomics, and the research tools it generates, will help to explain themultiplicity of calmodulin genes in plants, and to identify their downstream effectors. This review summarizes current knowledge of the Ca2+ -calmodulin messenger system in plants and presents suggestions for future areas of research. Contents I. Introduction 36 II. CaM isoforms and CaM-like proteins 37 III. CaM-target proteins 42 IV. CaM and nuclear functions 46 V. Regulation of ion transport 49 VI. CaM and plant responses to environmental stimuli 52 VII. Conclusions and future studies 58 Acknowledgements 59 References 59.
Collapse
Affiliation(s)
- Wayne A Snedden
- Department of Biology, Queen's University, Kingston, Ontario, K7L 3N6, Canada
| | - Hillel Fromm
- Centre for Plant Sciences, Leeds Institute for Biotechnology and Agriculture (LIBA), School of Biology, University of Leeds, Leeds LS2 9JT, UK
| |
Collapse
|
25
|
Abstract
How is specificity encoded in calcium-based signal transduction systems? Recent evidence shows that oscillations in the cytosolic free calcium concentration of guard cells are necessary for stimulus-specific stomatal closure in plants.
Collapse
Affiliation(s)
- N H Evans
- Division of Biology, Lancaster University, LA1 4YQ, Lancaster, UK
| | | |
Collapse
|