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Using Wavelet Analysis to Examine Long-Term Variability of Phytoplankton Biomass in the Tropical, Saline Lake Alchichica, Mexico. WATER 2022. [DOI: 10.3390/w14091346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The phytoplankton biomass (chlorophyll-a, Chl-a) is directly related to the total production of lakes. Chl-a in temperate lakes oscillates on an annual scale. However, Chl-a oscillations in tropical lakes have hardly been documented, particularly over multiple years. Here, we described the periodicity of the Chl-a by performing a continuous wavelet analysis of 21 years (1998–2018), monthly Chl-a data from tropical, saline Lake Alchichica, Mexico. Parallel wavelet analyses were made on environmental time series (i.e., euphotic zone, mixed layer, temperature, dissolved oxygen concentration, dissolved inorganic nitrogen, soluble reactive phosphorus, soluble reactive silica). Throughout the time series, the wavelet transforms identified a regular and predictable annual cycle of the Chl-a associated with the warm-monomictic thermal-mixing pattern, the variability of the annual Chl-a cycle, and the presence of other cyclicities, 2-year and ~4–5 years, associated with external forcing agents (e.g., North Pacific Oscillation). The water quality variables display a recurrent annual cycle. At the same time, the trophic variables (nutrient concentration) showed the same cyclicity as Chl-a (1-year, 2-year, and 4-year), suggesting the external forcing agents promote Chl-a augment through nutrient increase made available from stronger, deeper, mixing periods.
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Ndyabawe K, Haidekker M, Asthana A, Kisaalita WS. Spheroid Trapping and Calcium Spike Estimation Techniques toward Automation of 3D Culture. SLAS Technol 2020; 26:265-273. [PMID: 32672140 DOI: 10.1177/2472630320938319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We present a spheroid trapping device, compatible with traditional tissue culture plates, to confine microtissues in a small area and allow suspension cultures to be treated like adherent cultures with minimal loss of spheroids due to aspiration. We also illustrate an automated morphology-independent procedure for cell recognition, segmentation, and a calcium spike detection technique for high-throughput analysis in 3D cultured tissue. Our cell recognition technique uses a maximum intensity projection of spatial-temporal data to create a binary mask, which delineates individual cell boundaries and extracts mean fluorescent data for each cell through a series of intensity thresholding and cluster labeling operations. The temporal data are subject to sorting for imaging artifacts, baseline correction, smoothing, and spike detection algorithms. We validated this procedure through analysis of calcium data from 2D and 3D SHSY-5Y cell cultures. Using this approach, we rapidly created regions of interest (ROIs) and extracted fluorescent intensity data from hundreds of cells in the field of view with superior data fidelity over hand-drawn ROIs even in dense (3D tissue) cell populations. We sorted data from cells with imaging artifacts (such as photo bleaching and dye saturation), classified nonfiring and firing cells, estimated the number of spikes in each cell, and documented the results, facilitating large-scale calcium imaging analysis in both 2D and 3D cultures. Since our recognition and segmentation technique is independent of morphology, our protocol provides a versatile platform for the analysis of large confocal calcium imaging data from neuronal cells, glial cells, and other cell types.
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Affiliation(s)
- Kenneth Ndyabawe
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, USA
| | - Mark Haidekker
- School of Electrical and Computer Engineering, College of Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, USA
| | - Amish Asthana
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, USA
| | - William S Kisaalita
- School of Chemical, Materials and Biomedical Engineering, College of Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA, USA
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3
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Okada H, Kajiya H, Omata Y, Matsumoto T, Sato Y, Kobayashi T, Nakamura S, Kaneko Y, Nakamura S, Koyama T, Sudo S, Shin M, Okamoto F, Watanabe H, Tachibana N, Hirose J, Saito T, Takai T, Matsumoto M, Nakamura M, Okabe K, Miyamoto T, Tanaka S. CTLA4-Ig Directly Inhibits Osteoclastogenesis by Interfering With Intracellular Calcium Oscillations in Bone Marrow Macrophages. J Bone Miner Res 2019; 34:1744-1752. [PMID: 31067348 DOI: 10.1002/jbmr.3754] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/15/2019] [Accepted: 04/27/2019] [Indexed: 12/31/2022]
Abstract
CTLA4-Ig (cytotoxic T-lymphocyte antigen 4-immunoglobulin; Abatacept) is a biologic drug for rheumatoid arthritis. CTLA4 binds to the CD80/86 complex of antigen-presenting cells and blocks the activation of T cells. Although previous reports showed that CTLA4-Ig directly inhibited osteoclast differentiation, the whole inhibitory mechanism of CTLA4-Ig for osteoclast differentiation is unclear. Bone marrow macrophages (BMMs) from WT mice were cultured with M-CSF and RANKL with or without the recombinant mouse chimera CTLA4-Ig. Intracellular calcium oscillations of BMMs with RANKL were detected by staining with calcium indicator fura-2 immediately after administration of CTLA4-Ig or after one day of treatment. Calcium oscillations were analyzed using Fc receptor gamma- (FcRγ-) deficient BMMs. CTLA4-Ig inhibited osteoclast differentiation and reduced the expression of the nuclear factor of activated T cells NFATc1 in BMMs in vitro. Calcium oscillations in BMMs were suppressed by CTLA4-Ig both immediately after administration and after one day of treatment. CTLA4-Ig did not affect osteoclastogenesis and did not cause remarkable changes in calcium oscillations in FcRγ-deficient BMMs. Finally, to analyze the effect of CTLA4-Ig in vivo, we used an LPS-induced osteolysis model. CTLA4-Ig suppressed LPS-induced bone resorption in WT mice, not in FcRγ-deficient mice. In conclusion, CTLA4-Ig inhibits intracellular calcium oscillations depending on FcRγ and downregulates NFATc1 expression in BMMs. © 2019 American Society for Bone and Mineral Research.
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Affiliation(s)
- Hiroyuki Okada
- Department of Orthopaedic Surgery, The University of Tokyo, Tokyo, Japan
| | - Hiroshi Kajiya
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Yasunori Omata
- Department of Orthopaedic Surgery, The University of Tokyo, Tokyo, Japan
| | - Takumi Matsumoto
- Department of Orthopaedic Surgery, The University of Tokyo, Tokyo, Japan
| | - Yuiko Sato
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Tami Kobayashi
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Satoshi Nakamura
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Yosuke Kaneko
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Shinya Nakamura
- Department of Orthopaedic Surgery, The University of Tokyo, Tokyo, Japan
| | - Takuma Koyama
- Department of Orthopaedic Surgery, The University of Tokyo, Tokyo, Japan
| | - Shunichi Sudo
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Masashi Shin
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Fujio Okamoto
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Hisato Watanabe
- Department of Orthopaedic Surgery, The University of Tokyo, Tokyo, Japan
| | - Naohiro Tachibana
- Department of Orthopaedic Surgery, The University of Tokyo, Tokyo, Japan
| | - Jun Hirose
- Department of Orthopaedic Surgery, The University of Tokyo, Tokyo, Japan
| | - Taku Saito
- Department of Orthopaedic Surgery, The University of Tokyo, Tokyo, Japan
| | - Toshiyuki Takai
- Department of Experimental Immunology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Fukuoka, Japan
| | - Morio Matsumoto
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Masaya Nakamura
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Koji Okabe
- Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Takeshi Miyamoto
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan.,Department of Orthopaedic Surgery, Kumamoto University, Kumamoto, Japan
| | - Sakae Tanaka
- Department of Orthopaedic Surgery, The University of Tokyo, Tokyo, Japan
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Ei Hsu Hlaing E, Ishihara Y, Wang Z, Odagaki N, Kamioka H. Role of intracellular Ca 2+-based mechanotransduction of human periodontal ligament fibroblasts. FASEB J 2019; 33:10409-10424. [PMID: 31238000 PMCID: PMC6704454 DOI: 10.1096/fj.201900484r] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Human periodontal ligament (hPDL) fibroblasts are thought to receive mechanical stress (MS) produced by orthodontic tooth movement, thereby regulating alveolar bone remodeling. However, the role of intracellular calcium ([Ca2+]i)-based mechanotransduction is not fully understood. We explored the MS-induced [Ca2+]i responses both in isolated hPDL fibroblasts and in intact hPDL tissue and investigated its possible role in alveolar bone remodeling. hPDL fibroblasts were obtained from healthy donors' premolars that had been extracted for orthodontic reasons. The oscillatory [Ca2+]i activity induced by static compressive force was measured by a live-cell Ca2+ imaging system and evaluated by several feature extraction method. The spatial pattern of cell-cell communication was investigated by Moran's I, an index of spatial autocorrelation and the gap junction (GJ) inhibitor. The Ca2+-transporting ionophore A23187 was used to further investigate the role of [Ca2+]i up-regulation in hPDL cell behavior. hPDL fibroblasts displayed autonomous [Ca2+]i responses. Compressive MS activated this autonomous responsive behavior with an increased percentage of responsive cells both in vitro and ex vivo. The integration, variance, maximum amplitude, waveform length, and index J in the [Ca2+]i responses were also significantly increased, whereas the mean power frequency was attenuated in response to MS. The increased Moran's I after MS indicated that MS might affect the pattern of cell-cell communication via GJs. Similar to the findings of MS-mediated regulation, the A23187-mediated [Ca2+]i uptake resulted in the up-regulation of receptor activator of NF-κB ligand (Rankl) and Sost along with increased sclerostin immunoreactivity, suggesting that [Ca2+]i signaling networks may be involved in bone remodeling. In addition, A23187-treated hPDL fibroblasts also showed the suppression of osteogenic differentiation and mineralization. Our findings suggest that augmented MS-mediated [Ca2+]i oscillations in hPDL fibroblasts enhance the production and release of bone regulatory signals via Rankl/Osteoprotegerin and the canonical Wnt/β-catenin pathway as an early process in tooth movement-initiated alveolar bone remodeling.-Ei Hsu Hlaing, E., Ishihara, Y., Wang, Z., Odagaki, N., Kamioka, H. Role of intracellular Ca2+-based mechanotransduction of human periodontal ligament fibroblasts.
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Affiliation(s)
- Ei Ei Hsu Hlaing
- Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | | | - Ziyi Wang
- Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan.,Japan Society for the Promotion of Science (JSPS DC2), Tokyo, Japan
| | - Naoya Odagaki
- Department of Orthodontics, Okayama University Hospital, Okayama, Japan
| | - Hiroshi Kamioka
- Department of Orthodontics, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
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Mishra A, Salari A, Berigan BR, Miguel KC, Amirshenava M, Robinson A, Zars BC, Lin JL, Milescu LS, Milescu M, Zars T. The Drosophila Gr28bD product is a non-specific cation channel that can be used as a novel thermogenetic tool. Sci Rep 2018; 8:901. [PMID: 29343813 PMCID: PMC5772361 DOI: 10.1038/s41598-017-19065-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 12/21/2017] [Indexed: 11/23/2022] Open
Abstract
Extrinsic control of single neurons and neuronal populations is a powerful approach for understanding how neural circuits function. Adding new thermogenetic tools to existing optogenetic and other forms of intervention will increase the complexity of questions that can be addressed. A good candidate for developing new thermogenetic tools is the Drosophila gustatory receptor family, which has been implicated in high-temperature avoidance behavior. We examined the five members of the Gr28b gene cluster for temperature-dependent properties via three approaches: biophysical characterization in Xenopus oocytes, functional calcium imaging in Drosophila motor neurons, and behavioral assays in adult Drosophila. Our results show that Gr28bD expression in Xenopus oocytes produces a non-specific cationic current that is activated by elevated temperatures. This current is non-inactivating and non-voltage dependent. When expressed in Drosophila motor neurons, Gr28bD can be used to change the firing pattern of individual cells in a temperature-dependent fashion. Finally, we show that pan-neuronal or motor neuron expression of Gr28bD can be used to alter fruit fly behavior with elevated temperatures. Together, these results validate the potential of the Gr28bD gene as a founding member of a new class of thermogenetic tools.
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Affiliation(s)
- Aditi Mishra
- Division of Biological Sciences, University of Missouri, Columbia, MO, 65211, USA
| | - Autoosa Salari
- Division of Biological Sciences, University of Missouri, Columbia, MO, 65211, USA
| | - Benton R Berigan
- Division of Biological Sciences, University of Missouri, Columbia, MO, 65211, USA
| | - Kayla C Miguel
- Division of Biological Sciences, University of Missouri, Columbia, MO, 65211, USA
| | - Marzie Amirshenava
- Division of Biological Sciences, University of Missouri, Columbia, MO, 65211, USA
| | - Abbey Robinson
- Division of Biological Sciences, University of Missouri, Columbia, MO, 65211, USA
| | - Benjamin C Zars
- Division of Biological Sciences, University of Missouri, Columbia, MO, 65211, USA
| | - Jenna L Lin
- Division of Biological Sciences, University of Missouri, Columbia, MO, 65211, USA
| | - Lorin S Milescu
- Division of Biological Sciences, University of Missouri, Columbia, MO, 65211, USA.
| | - Mirela Milescu
- Division of Biological Sciences, University of Missouri, Columbia, MO, 65211, USA.
| | - Troy Zars
- Division of Biological Sciences, University of Missouri, Columbia, MO, 65211, USA.
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6
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Lodola F, Laforenza U, Cattaneo F, Ruffinatti FA, Poletto V, Massa M, Tancredi R, Zuccolo E, Khdar DA, Riccardi A, Biggiogera M, Rosti V, Guerra G, Moccia F. VEGF-induced intracellular Ca 2+ oscillations are down-regulated and do not stimulate angiogenesis in breast cancer-derived endothelial colony forming cells. Oncotarget 2017; 8:95223-95246. [PMID: 29221123 PMCID: PMC5707017 DOI: 10.18632/oncotarget.20255] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 07/12/2017] [Indexed: 01/08/2023] Open
Abstract
Endothelial colony forming cells (ECFCs) represent a population of truly endothelial precursors that promote the angiogenic switch in solid tumors, such as breast cancer (BC). The intracellular Ca2+ toolkit, which drives the pro-angiogenic response to VEGF, is remodelled in tumor-associated ECFCs such that they are seemingly insensitive to this growth factor. This feature could underlie the relative failure of anti-VEGF therapies in cancer patients. Herein, we investigated whether and how VEGF uses Ca2+ signalling to control angiogenesis in BC-derived ECFCs (BC-ECFCs). Although VEGFR-2 was normally expressed, VEGF failed to induce proliferation and in vitro tubulogenesis in BC-ECFCs. Likewise, VEGF did not trigger robust Ca2+ oscillations in these cells. Similar to normal cells, VEGF-induced intracellular Ca2+ oscillations were triggered by inositol-1,4,5-trisphosphate-dependent Ca2+ release from the endoplasmic reticulum (ER) and maintained by store-operated Ca2+ entry (SOCE). However, InsP3-dependent Ca2+ release was significantly lower in BC-ECFCs due to the down-regulation of ER Ca2+ levels, while there was no remarkable difference in the amplitude, pharmacological profile and molecular composition of SOCE. Thus, the attenuation of the pro-angiogenic Ca2+ response to VEGF was seemingly due to the reduction in ER Ca2+ concentration, which prevents VEGF from triggering robust intracellular Ca2+ oscillations. However, the pharmacological inhibition of SOCE prevented BC-ECFC proliferation and in vitro tubulogenesis. These findings demonstrate for the first time that BC-ECFCs are insensitive to VEGF, which might explain at cellular and molecular levels the failure of anti-VEGF therapies in BC patients, and hint at SOCE as a novel molecular target for this disease.
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Affiliation(s)
- Francesco Lodola
- Laboratory of General Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia 27100, Italy.,Current address: Italian Institute of Technology, Center for Nano Science and Technology, Milano 20133, Italy
| | - Umberto Laforenza
- Department of Molecular Medicine, University of Pavia, Pavia 27100, Italy
| | - Fabio Cattaneo
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples 80131, Italy
| | | | - Valentina Poletto
- Laboratory of Biochemistry, Biotechnology and Advanced Diagnosis, Foundation IRCCS Policlinico San Matteo, Pavia 27100, Italy
| | - Margherita Massa
- Laboratory of Immunology Transplantation, Foundation IRCCS Policlinico San Matteo, Pavia 27100, Italy
| | - Richard Tancredi
- Medical Oncology Unit, Foundation IRCCS Salvatore Maugeri, Pavia 27100, Italy
| | - Estella Zuccolo
- Laboratory of General Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia 27100, Italy
| | - Dlzar Alì Khdar
- Laboratory of General Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia 27100, Italy
| | - Alberto Riccardi
- Medical Oncology Unit, Foundation IRCCS Salvatore Maugeri, Pavia 27100, Italy.,Department of Internal Medicine, University of Pavia, Pavia 27100, Italy
| | - Marco Biggiogera
- Laboratory of Cell Biology and Neurobiology, Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia 27100, Italy
| | - Vittorio Rosti
- Laboratory of Biochemistry, Biotechnology and Advanced Diagnosis, Foundation IRCCS Policlinico San Matteo, Pavia 27100, Italy
| | - Germano Guerra
- Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso 86100, Italy
| | - Francesco Moccia
- Laboratory of General Physiology, Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia 27100, Italy
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7
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Mackay L, Mikolajewicz N, Komarova SV, Khadra A. Systematic Characterization of Dynamic Parameters of Intracellular Calcium Signals. Front Physiol 2016; 7:525. [PMID: 27891096 PMCID: PMC5102910 DOI: 10.3389/fphys.2016.00525] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 10/24/2016] [Indexed: 12/14/2022] Open
Abstract
Dynamic processes, such as intracellular calcium signaling, are hallmark of cellular biology. As real-time imaging modalities become widespread, a need for analytical tools to reliably characterize time-series data without prior knowledge of the nature of the recordings becomes more pressing. The goal of this study is to develop a signal-processing algorithm for MATLAB that autonomously computes the parameters characterizing prominent single transient responses (TR) and/or multi-peaks responses (MPR). The algorithm corrects for signal contamination and decomposes experimental recordings into contributions from drift, TRs, and MPRs. It subsequently provides numerical estimates for the following parameters: time of onset after stimulus application, activation time (time for signal to increase from 10 to 90% of peak), and amplitude of response. It also provides characterization of the (i) TRs by quantifying their area under the curve (AUC), response duration (time between 1/2 amplitude on ascent and descent of the transient), and decay constant of the exponential decay region of the deactivation phase of the response, and (ii) MPRs by quantifying the number of peaks, mean peak magnitude, mean periodicity, standard deviation of periodicity, oscillatory persistence (time between first and last discernable peak), and duty cycle (fraction of period during which system is active) for all the peaks in the signal, as well as coherent oscillations (i.e., deterministic spikes). We demonstrate that the signal detection performance of this algorithm is in agreement with user-mediated detection and that parameter estimates obtained manually and algorithmically are correlated. We then apply this algorithm to study how metabolic acidosis affects purinergic (P2) receptor-mediated calcium signaling in osteoclast precursor cells. Our results reveal that acidosis significantly attenuates the amplitude and AUC calcium responses at high ATP concentrations. Collectively, our data validated this algorithm as a general framework for comprehensively analyzing dynamic time-series.
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Affiliation(s)
- Laurent Mackay
- Department of Physiology, McGill University Montreal, QC, Canada
| | - Nicholas Mikolajewicz
- Faculty of Dentistry, McGill UniversityMontreal, QC, Canada; Shriners Hospital for Children-CanadaMontreal, QC, Canada
| | - Svetlana V Komarova
- Faculty of Dentistry, McGill UniversityMontreal, QC, Canada; Shriners Hospital for Children-CanadaMontreal, QC, Canada
| | - Anmar Khadra
- Department of Physiology, McGill University Montreal, QC, Canada
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8
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Dysregulation of VEGF-induced proangiogenic Ca2+ oscillations in primary myelofibrosis-derived endothelial colony-forming cells. Exp Hematol 2015; 43:1019-1030.e3. [PMID: 26432919 DOI: 10.1016/j.exphem.2015.09.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 09/11/2015] [Accepted: 09/12/2015] [Indexed: 01/16/2023]
Abstract
Endothelial progenitor cells could be implicated in the aberrant neoangiogenesis that occurs in bone marrow and spleen in patients with primary myelofibrosis (PMF). However, antivascular endothelial growth factor (VEGF) monotherapy had only a modest and transient effect in these individuals. Recently it was found that VEGF-induced proangiogenic intracellular Ca(2+) oscillations could be impaired in endothelial progenitor cells of subjects with malignancies. Therefore, we employed Ca(2+) imaging, wavelet analysis, and functional assays to assess whether and how VEGF-induced Ca(2+) oscillations are altered in PMF-derived endothelial progenitor cells. We focused on endothelial colony-forming cells (ECFCs), which are the only endothelial progenitor cell subtype capable of forming neovessels both in vivo and in vitro. VEGF triggers repetitive Ca(2+) spikes in both normal ECFCs (N-ECFCs) and ECFCs obtained from PMF patients (PMF-ECFCs). However, the spiking response to VEGF is significantly weaker in PMF-ECFCs. VEGF-elicited Ca(2+) oscillations are patterned by the interaction between inositol-1,4,5-trisphosphate-dependent Ca(2+) mobilization and store-operated Ca(2+) entry. However, in most PMF-ECFCs, Ca(2+) oscillations are triggered by a store-independent Ca(2+) entry pathway. We found that diacylglycerol gates transient receptor potential canonical 1 channel to trigger VEGF-dependent Ca(2+) spikes by recruiting the phospholipase C/inositol-1,4,5-trisphosphate signaling pathway, reflected as a decrease in endoplasmic reticulum Ca(2+) content. Finally, we found that, apart from being less robust and dysregulated as compared with N-ECFCs, VEGF-induced Ca(2+) oscillations modestly stimulate PMF-ECFC growth and in vitro angiogenesis. These results may explain the modest effect of anti-VEGF therapies in PMF.
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9
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Interaction of SiO2 nanoparticles with neuronal cells: Ionic mechanisms involved in the perturbation of calcium homeostasis. Int J Biochem Cell Biol 2015. [DOI: 10.1016/j.biocel.2015.07.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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10
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Spatial wavelet analysis of calcium oscillations in developing neurons. PLoS One 2013; 8:e75986. [PMID: 24155880 PMCID: PMC3796547 DOI: 10.1371/journal.pone.0075986] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 08/19/2013] [Indexed: 01/17/2023] Open
Abstract
Calcium signals play a major role in the control of all key stages of neuronal development, and in particular in the growth and orientation of neuritic processes. These signals are characterized by high spatial compartmentalization, a property which has a strong relevance in the different roles of specific neuronal regions in information coding. In this context it is therefore important to understand the structural and functional basis of this spatial compartmentalization, and in particular whether the behavior at each compartment is merely a consequence of its specific geometry or the result of the spatial segregation of specific calcium influx/efflux mechanisms. Here we have developed a novel approach to separate geometrical from functional differences, regardless on the assumptions on the actual mechanisms involved in the generation of calcium signals. First, spatial indices are derived with a wavelet-theoretic approach which define a measure of the oscillations of cytosolic calcium concentration in specific regions of interests (ROIs) along a cell, in our case developing chick ciliary ganglion neurons. The resulting spatial profile demonstrates clearly that different ROIs along the neuron are characterized by specific patterns of calcium oscillations. Next we have investigated whether this inhomogeneity is due just to geometrical factors, namely the surface to volume ratio in the different subcompartments (e.g. soma vs. growth cone) or it depends on their specific biophysical properties. To this aim correlation functions are computed between the activity indices and the surface/volume ratio along the cell: the data thus obtained are validated by a statistical analysis on a dataset of different cells. This analysis shows that whereas in the soma calcium dynamics is highly correlated to the surface/volume ratio, correlations drop in the growth cone-neurite region, suggesting that in this latter case the key factor is the expression of specific mechanisms controlling calcium influx/efflux.
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11
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Zamburlin P, Ruffinatti FA, Gilardino A, Farcito S, Parrini M, Lovisolo D. Calcium signals and FGF-2 induced neurite growth in cultured parasympathetic neurons: spatial localization and mechanisms of activation. Pflugers Arch 2013; 465:1355-70. [PMID: 23529843 DOI: 10.1007/s00424-013-1257-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 02/25/2013] [Accepted: 02/27/2013] [Indexed: 11/28/2022]
Abstract
The growth of neuritic processes in developing neurons is tightly controlled by a wide set of extracellular cues that act by initiating downstream signaling cascades, where calcium signals play a major role. Here we analyze the calcium dependence of the neurite growth promoted by basic fibroblast growth factor (bFGF or FGF-2) in chick embryonic ciliary ganglion neurons, taking advantage of dissociated, organotypic, and compartmentalized cultures. We report that signals at both the growth cone and the soma are involved in the promotion of neurite growth by the factor. Blocking calcium influx through L- and N-type voltage-dependent calcium channels and transient receptor potential canonical (TRPC) channels reduces, while release from intracellular stores does not significantly affect, the growth of neuritic processes. Simultaneous recordings of calcium signals elicited by FGF-2 at the soma and at the growth cone show that the factor activates different patterns of responses in the two compartments: steady and sustained responses at the former, oscillations at the latter. At the soma, both voltage-dependent channel and TRPC blockers strongly affect steady-state levels. At the growth cone, the changes in the oscillatory pattern are more complex; therefore, we used a tool based on wavelet analysis to obtain a quantitative evaluation of the effects of the two classes of blockers. We report that the oscillatory behavior at the growth cone is dramatically affected by all the blockers, pointing to a role for calcium influx through the two classes of channels in the generation of signals at the leading edge of the elongating neurites.
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Affiliation(s)
- P Zamburlin
- Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123 Turin, Italy
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12
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Kőszeghy Á, Vincze J, Rusznák Z, Fu Y, Paxinos G, Csernoch L, Szücs G. Activation of muscarinic receptors increases the activity of the granule neurones of the rat dorsal cochlear nucleus--a calcium imaging study. Pflugers Arch 2012; 463:829-44. [PMID: 22547003 DOI: 10.1007/s00424-012-1103-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 03/26/2012] [Accepted: 03/30/2012] [Indexed: 12/20/2022]
Abstract
Acetylcholine modulates the function of the cochlear nucleus via several pathways. In this study, the effects of cholinergic stimulation were studied on the cytoplasmic Ca(2+) concentration of granule neurones of the rat dorsal cochlear nucleus (DCN). Ca(2+) transients were recorded in Oregon-Green-BAPTA 1-loaded brain slices using a calcium imaging technique. For the detection, identification and characterisation of the Ca(2+) transients, a wavelet analysis-based method was developed. Granule cells were identified on the basis of their size and localisation. The action potential-coupled character of the Ca(2+) transients of the granule cells was established by recording fluorescence changes and electrical activity simultaneously. Application of the cholinergic agonist carbamyl-choline (CCh) significantly increased the frequency of the Ca(2+) transients (from 0.37 to 6.31 min(-1), corresponding to a 17.1-fold increase; n = 89). This effect was antagonised by atropine, whereas CCh could still evoke an 8.3-fold increase of the frequency of the Ca(2+) transients when hexamethonium was present. Using immunolabelling, the expression of both type 1 and type 3 muscarinic receptors (M1 and M3 receptors, respectively) was demonstrated in the granule cells. Application of 1,1-dimethyl-4-diphenylacetoxypiperidinium iodide (an M3-specific antagonist) prevented the onset of the CCh effect, whereas an M1-specific antagonist (pirenzepine) was less effective. We conclude that cholinergic stimulation increases the activity of granule cells, mainly by acting on their M3 receptors. The modulation of the firing activity of the granule cells, in turn, may modify the firing of projection neurones and may adjust signal processing in the entire DCN.
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Affiliation(s)
- Áron Kőszeghy
- Department of Physiology, Medical and Health Science Center, University of Debrecen, PO Box 22, Nagyerdei krt 98, 4012 Debrecen, Hungary
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