1
|
Haak A, Lesslich HM, Dietzel ID. Visualization of the membrane surface and cytoskeleton of oligodendrocyte progenitor cell growth cones using a combination of scanning ion conductance and four times expansion microscopy. Biol Chem 2024; 405:31-41. [PMID: 37950644 DOI: 10.1515/hsz-2023-0217] [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: 05/16/2023] [Accepted: 10/17/2023] [Indexed: 11/13/2023]
Abstract
Growth cones of oligodendrocyte progenitor cells (OPCs) are challenging to investigate with conventional light microscopy due to their small size. Especially substructures such as filopodia, lamellipodia and their underlying cytoskeleton are difficult to resolve with diffraction limited microscopy. Light microscopy techniques, which surpass the diffraction limit such as stimulated emission depletion microscopy, often require expensive setups and specially trained personnel rendering them inaccessible to smaller research groups. Lately, the invention of expansion microscopy (ExM) has enabled super-resolution imaging with any light microscope without the need for additional equipment. Apart from the necessary resolution, investigating OPC growth cones comes with another challenge: Imaging the topography of membranes, especially label- and contact-free, is only possible with very few microscopy techniques one of them being scanning ion conductance microscopy (SICM). We here present a new imaging workflow combining SICM and ExM, which enables the visualization of OPC growth cone nanostructures. We correlated SICM recordings and ExM images of OPC growth cones captured with a conventional widefield microscope. This enabled the visualization of the growth cones' membrane topography as well as their underlying actin and tubulin cytoskeleton.
Collapse
Affiliation(s)
- Annika Haak
- Nanoscopy, RUBION, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany
| | - Heiko M Lesslich
- Nanoscopy, RUBION, Ruhr-Universität Bochum, Universitätsstraße 150, D-44801 Bochum, Germany
| | - Irmgard D Dietzel
- Department of Biochemistry II, Electrobiochemistry of Neural Cells, Ruhr-Universität Bochum, D-44801 Bochum, Germany
| |
Collapse
|
2
|
Lesslich HM, Klapal L, Wilke J, Haak A, Dietzel ID. Adjusting the neuron to astrocyte ratio with cytostatics in hippocampal cell cultures from postnatal rats: A comparison of cytarabino furanoside (AraC) and 5-fluoro-2'-deoxyuridine (FUdR). PLoS One 2022; 17:e0265084. [PMID: 35263366 PMCID: PMC8906639 DOI: 10.1371/journal.pone.0265084] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 02/22/2022] [Indexed: 01/29/2023] Open
Abstract
Cell culture studies offer the unique possibility to investigate the influence of pharmacological treatments with quantified dosages applied for defined time durations on survival, morphological maturation, protein expression and function as well as the mutual interaction of various cell types. Cultures obtained from postnatal rat brain contain a substantial number of glial cells that further proliferate with time in culture leading to an overgrowth of neurons with glia, especially astrocytes and microglia. A well-established method to decrease glial proliferation in vitro is to apply low concentrations of cytosine arabinoside (AraC). While AraC primarily effects dividing cells, it has been reported repeatedly that it is also neurotoxic, which is the reason why most protocols limit its application to concentrations of up to 5 μM for a duration of 24 h. Here, we investigated 5-fluoro-2'-deoxyuridine (FUdR) as a possible substitute for AraC. We applied concentrations of both cytostatics ranging from 4 μM to 75 μM and compared cell composition and cell viability in cultures prepared from 0-2- and 3-4-day old rat pups. Using FUdR as proliferation inhibitor, higher ratios of neurons to glia cells were obtained with a maximal neuron to astrocyte ratio of up to 10:1, which could not be obtained using AraC in postnatal cultures. Patch-clamp recordings revealed no difference in the amplitudes of voltage-gated Na+ currents in neurons treated with FUdR compared with untreated control cells suggesting replacement of AraC by FUdR as glia proliferation inhibitor if highly neuron-enriched postnatal cultures are desired.
Collapse
Affiliation(s)
- Heiko M. Lesslich
- Department of Biochemistry II, Ruhr-Universität Bochum, Bochum, Germany
- * E-mail:
| | - Lars Klapal
- Department of Biochemistry II, Ruhr-Universität Bochum, Bochum, Germany
| | - Justus Wilke
- Department of Biochemistry II, Ruhr-Universität Bochum, Bochum, Germany
| | - Annika Haak
- Nanoscopy Group, RUBION, Ruhr-Universität Bochum, Bochum, Germany
| | | |
Collapse
|
3
|
Feldhaus B, Dietzel ID, Heumann R, Berger R. Effects of Interferon-γ and Tumor Necrosis Factor-α on Survival and Differentiation of Oligodendrocyte Progenitors. ACTA ACUST UNITED AC 2016; 11:89-96. [PMID: 14980310 DOI: 10.1016/j.jsgi.2003.08.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE There is strong evidence from recent clinical studies that ascending intrauterine infection is associated with an increased incidence of periventricular leukomalacia in very premature fetuses. Periventricular leukomalacia is characterized by disrupted myelination from a loss of oligodendrocyte progenitors. We investigated the effects of proinflammatory cytokines on the survival and differentiation of this cell type. METHODS Cultures of more than 90% A2B5-positive progenitors were prepared from neonatal rats and kept for 3 days in medium supplemented with factors that stimulate cell proliferation. After 1 day in proliferation medium, cells were treated with interferon-gamma (100 U/mL) and tumor necrosis factor-alpha (100 ng/mL) for 48 hours triggering an increase in apoptotic A2B5 progenitor cells from 3.2 +/- 2.3% to 11.0 +/- 2.6%. After cytokine treatment cultures were transferred to medium containing factors to promote differentiation of progenitors into the myelinating phenotype. RESULTS In cytokine pretreated cultures, only 2.6 +/- 1.1% of total cells survived after a total of 9 days in vitro, whereas in untreated cultures most cells differentiated as shown by expression of myelin basic protein, myelin-associated glycoprotein, 2,3-cyclic nucleotide 3-phosphodiesterase, and myelin oligodendrocyte-specific protein. Using ten-fold reduced concentrations of combined interferon-gamma (10 U/mL) and tumor necrosis factor-alpha (10 ng/mL) pretreatment resulted in a survival to 11.2 +/- 4.9% of total cells with 36.3 +/- 11.6% A2B5-positive cells at day 9. This indicates a major enrichment of undifferentiated cells compared with untreated controls which harbored only 1.0 +/- 0.3% A2B5-positive cells. CONCLUSION Inflammatory cytokines not only induced apoptotic cell death but also prevented the differentiation of immature A2B5 oligodendrocyte progenitors into the myelinating phenotype.
Collapse
Affiliation(s)
- Beatrix Feldhaus
- Departments ofDepartment of Obstetrics and Gynecology, University of Bochum, Bochum, Germany
| | | | | | | |
Collapse
|
4
|
Igelhorst BA, Niederkinkhaus V, Karus C, Lange MD, Dietzel ID. Regulation of neuronal excitability by release of proteins from glial cells. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2014.0194. [PMID: 26009773 DOI: 10.1098/rstb.2014.0194] [Citation(s) in RCA: 18] [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] [Indexed: 12/25/2022] Open
Abstract
Effects of glial cells on electrical isolation and shaping of synaptic transmission between neurons have been extensively studied. Here we present evidence that the release of proteins from astrocytes as well as microglia may regulate voltage-activated Na(+) currents in neurons, thereby increasing excitability and speed of transmission in neurons kept at distance from each other by specialized glial cells. As a first example, we show that basic fibroblast growth factor and neurotrophin-3, which are released from astrocytes by exposure to thyroid hormone, influence each other to enhance Na(+) current density in cultured hippocampal neurons. As a second example, we show that the presence of microglia in hippocampal cultures can upregulate Na(+) current density. The effect can be boosted by lipopolysaccharides, bacterial membrane-derived stimulators of microglial activation. Comparable effects are induced by the exposure of neuron-enriched hippocampal cultures to tumour necrosis factor-α, which is released from stimulated microglia. Taken together, our findings suggest that release of proteins from various types of glial cells can alter neuronal excitability over a time course of several days. This explains changes in neuronal excitability occurring in states of thyroid hormone imbalance and possibly also in seizures triggered by infectious diseases.
Collapse
Affiliation(s)
- Birte A Igelhorst
- Department of Biochemistry II, Ruhr University Bochum, Universitätsstraße 150, Bochum 44780, Germany
| | - Vanessa Niederkinkhaus
- Department of Biochemistry II, Ruhr University Bochum, Universitätsstraße 150, Bochum 44780, Germany International Graduate School for Neuroscience, Ruhr University Bochum, Universitätsstraße 150, Bochum 44780, Germany
| | - Claudia Karus
- Department of Biochemistry II, Ruhr University Bochum, Universitätsstraße 150, Bochum 44780, Germany
| | - Maren D Lange
- Department of Biochemistry II, Ruhr University Bochum, Universitätsstraße 150, Bochum 44780, Germany
| | - Irmgard D Dietzel
- Department of Biochemistry II, Ruhr University Bochum, Universitätsstraße 150, Bochum 44780, Germany
| |
Collapse
|
5
|
Gesper A, Thatenhorst D, Wiese S, Tsai T, Dietzel ID, Happel P. Long-term, long-distance recording of a living migrating neuron by scanning ion conductance microscopy. Scanning 2015; 37:226-231. [PMID: 25728639 DOI: 10.1002/sca.21200] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [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: 12/19/2014] [Accepted: 02/06/2015] [Indexed: 06/04/2023]
Abstract
Bias-free, three-dimensional imaging of entire living cellular specimen is required for investigating shape and volume changes that occur during cellular growth or migration. Here we present fifty consecutive recordings of a living cultured neuron from a mouse dorsal root ganglion obtained by Scanning ion conductance microscopy (SICM). We observed a saltatory migration of the neuron with a mean velocity of approximately 20 μm/h. These results demonstrate the non-invasiveness of SICM, which makes it unique among the scanning probe microscopes. In contrast to SICM, most scanning probe techniques require a usually denaturating preparation of the cells, or they exert a non-negligible force on the cellular membrane, impeding passive observation. Moreover, the present series of recordings demonstrates the potential use of SICM for the detailed investigation of cellular migration and membrane surface dynamics even of such delicate samples as living neurons.
Collapse
Affiliation(s)
- Astrid Gesper
- Department of Biochemisty II, Electrobiochemistry of Neural Cells, Ruhr University Bochum, Bochum, Germany
- Central Unit for Ionbeams and Radionuclides (RUBION), Ruhr University Bochum, Bochum, Germany
| | - Denis Thatenhorst
- Department of Biochemisty II, Electrobiochemistry of Neural Cells, Ruhr University Bochum, Bochum, Germany
- International Graduate School of Neuroscience (IGSN), Ruhr University Bochum, Bochum, Germany
| | - Stefan Wiese
- Department of Cell Morphology and Molecular Neurobiology, Molecular Cell Biology, Ruhr-University Bochum, Bochum, Germany
| | - Teresa Tsai
- Department of Cell Morphology and Molecular Neurobiology, Molecular Cell Biology, Ruhr-University Bochum, Bochum, Germany
| | - Irmgard D Dietzel
- Department of Biochemisty II, Electrobiochemistry of Neural Cells, Ruhr University Bochum, Bochum, Germany
| | - Patrick Happel
- Central Unit for Ionbeams and Radionuclides (RUBION), Ruhr University Bochum, Bochum, Germany
| |
Collapse
|
6
|
Thatenhorst D, Rheinlaender J, Schäffer TE, Dietzel ID, Happel P. Effect of Sample Slope on Image Formation in Scanning Ion Conductance Microscopy. Anal Chem 2014; 86:9838-45. [DOI: 10.1021/ac5024414] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Denis Thatenhorst
- Department
of Biochemistry II, Electrobiochemistry of Neural Cells, Ruhr-University Bochum, Universitätsstraße 150, 44780 Bochum, Germany
- International
Graduate School of Neuroscience (IGSN), Ruhr-University Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - Johannes Rheinlaender
- Institute
of Applied Physics and LISA+, University of Tübingen, Auf
der Morgenstelle 10, 72076 Tübingen, Germany
| | - Tilman E. Schäffer
- Institute
of Applied Physics and LISA+, University of Tübingen, Auf
der Morgenstelle 10, 72076 Tübingen, Germany
| | - Irmgard D. Dietzel
- Department
of Biochemistry II, Electrobiochemistry of Neural Cells, Ruhr-University Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - Patrick Happel
- Central
Unit for Ionbeams and Radionuclides (RUBION), Ruhr-University Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| |
Collapse
|
7
|
Kleinsimlinghaus K, Marx R, Serdar M, Bendix I, Dietzel ID. Strategies for repair of white matter: influence of osmolarity and microglia on proliferation and apoptosis of oligodendrocyte precursor cells in different basal culture media. Front Cell Neurosci 2013; 7:277. [PMID: 24421756 PMCID: PMC3872727 DOI: 10.3389/fncel.2013.00277] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 12/10/2013] [Indexed: 11/28/2022] Open
Abstract
The aim of the present study has been to obtain high yields of oligodendrocyte precursor cells (OPCs) in culture. This is a first step in facilitation of myelin repair. We show that, in addition to factors, known to promote proliferation, such as basic fibroblast growth factor (FGF-2) and platelet derived growth factor (PDGF) the choice of the basal medium exerts a significant influence on the yield of OPCs in cultures from newborn rats. During a culture period of up to 9 days we observed larger numbers of surviving cells in Dulbecco's Modified Eagle Medium (DMEM), and Roswell Park Memorial Institute Medium (RPMI) compared with Neurobasal Medium (NB). A larger number of A2B5-positive OPCs was found after 6 days in RPMI based media compared with NB. The percentage of bromodeoxyuridine (BrdU)-positive cells was largest in cultures maintained in DMEM and RPMI. The percentage of caspase-3 positive cells was largest in NB, suggesting that this medium inhibits OPC proliferation and favors apoptosis. A difference between NB and DMEM as well as RPMI is the reduced Na+-content. The addition of equiosmolar supplements of mannitol or NaCl to NB medium rescued the BrdU-incorporation rate. This suggested that the osmolarity influences the proliferation of OPCs. Plating density as well as residual microglia influence OPC survival, BrdU incorporation, and caspase-3 expression. We found, that high density cultures secrete factors that inhibit BrdU incorporation whereas the presence of additional microglia induces an increase in caspase-3 positive cells, indicative of enhanced apoptosis. An enhanced number of microglia could thus also explain the stronger inhibition of OPC differentiation observed in high density cultures in response to treatment with the cytokines TNF-α and IFN-γ. We conclude that a maximal yield of OPCs is obtained in a medium of an osmolarity higher than 280 mOsm plated at a relatively low density in the presence of as little microglia as technically achievable.
Collapse
Affiliation(s)
| | - Romy Marx
- Department of Biochemistry II, Ruhr University Bochum Bochum, Germany
| | - Meray Serdar
- Department of Pediatrics I, Neonatology, University Hospital Essen Essen, Germany
| | - Ivo Bendix
- Department of Pediatrics I, Neonatology, University Hospital Essen Essen, Germany
| | - Irmgard D Dietzel
- Department of Biochemistry II, Ruhr University Bochum Bochum, Germany
| |
Collapse
|
8
|
Happel P, Möller K, Schwering NK, Dietzel ID. Migrating oligodendrocyte progenitor cells swell prior to soma dislocation. Sci Rep 2013; 3:1806. [PMID: 23657670 PMCID: PMC3648797 DOI: 10.1038/srep01806] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 04/24/2013] [Indexed: 11/09/2022] Open
Abstract
The migration of oligodendrocyte progenitor cells (OPCs) to the white matter is an indispensable requirement for an intact brain function. The mechanism of cell migration in general is not yet completely understood. Nevertheless, evidence is accumulating that besides the coordinated rearrangement of the cytoskeleton, a finetuned interplay of ion and water fluxes across the cell membrane is essential for cell migration. One part of a general hypothesis is that a local volume increase towards the direction of movement triggers a mechano-activated calcium influx that regulates various procedures at the rear end of a migrating cell. Here, we investigated cell volume changes of migrating OPCs using scanning ion conductance microscopy. We found that during accelerated migration OPCs undergo an increase in the frontal cell body volume. These findings are supplemented with time lapse calcium imaging data that hint an increase in calcium content the frontal part of the cell soma.
Collapse
Affiliation(s)
- Patrick Happel
- Central Unit for Ionbeams and Radionuclides (RUBION), Ruhr-University Bochum, Bochum, Germany.
| | | | | | | |
Collapse
|
9
|
Karus M, Samtleben S, Busse C, Tsai T, Dietzel ID, Faissner A, Wiese S. Normal sulfation levels regulate spinal cord neural precursor cell proliferation and differentiation. Neural Dev 2012; 7:20. [PMID: 22681904 PMCID: PMC3423038 DOI: 10.1186/1749-8104-7-20] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 03/06/2012] [Indexed: 12/26/2022] Open
Abstract
Background Sulfated glycosaminoglycan chains are known for their regulatory functions during neural development and regeneration. However, it is still unknown whether the sulfate residues alone influence, for example, neural precursor cell behavior or whether they act in concert with the sugar backbone. Here, we provide evidence that the unique 473HD-epitope, a representative chondroitin sulfate, is expressed by spinal cord neural precursor cells in vivo and in vitro, suggesting a potential function of sulfated glycosaminoglycans for spinal cord development. Results Thus, we applied the widely used sulfation inhibitor sodium chlorate to analyze the importance of normal sulfation levels for spinal cord neural precursor cell biology in vitro. Addition of sodium chlorate to spinal cord neural precursor cell cultures affected cell cycle progression accompanied by changed extracellular signal-regulated kinase 1 or 2 activation levels. This resulted in a higher percentage of neurons already under proliferative conditions. In contrast, the relative number of glial cells was largely unaffected. Strikingly, both morphological and electrophysiological characterization of neural precursor cell-derived neurons demonstrated an attenuated neuronal maturation in the presence of sodium chlorate, including a disturbed neuronal polarization. Conclusions In summary, our data suggest that sulfation is an important regulator of both neural precursor cell proliferation and maturation of the neural precursor cell progeny in the developing mouse spinal cord.
Collapse
Affiliation(s)
- Michael Karus
- Group for Molecular Cell Biology, Ruhr-University Bochum, Bochum, Germany
| | | | | | | | | | | | | |
Collapse
|
10
|
Happel P, Dietzel ID. Backstep scanning ion conductance microscopy as a tool for long term investigation of single living cells. J Nanobiotechnology 2009; 7:7. [PMID: 19860879 PMCID: PMC2777839 DOI: 10.1186/1477-3155-7-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Accepted: 10/27/2009] [Indexed: 11/10/2022] Open
Abstract
Scanning ion conductance microscopy (SICM) is a suitable tool for imaging surfaces of living cells in a contact-free manner. We have shown previously that SICM in backstep mode allows one to trace the outlines of entire cell somata and to detect changes in cellular shape and volume. Here we report that SICM can be employed to quantitatively observe cellular structures such as cell processes of living cells as well as cell somata of motile cells in the range of hours.
Collapse
Affiliation(s)
- Patrick Happel
- Department of Molecular Neurobiochemistry, Ruhr-University Bochum, D-44870 Bochum, Germany.
| | | |
Collapse
|
11
|
Neumann S, Kovtun A, Dietzel ID, Epple M, Heumann R. The use of size-defined DNA-functionalized calcium phosphate nanoparticles to minimise intracellular calcium disturbance during transfection. Biomaterials 2009; 30:6794-802. [PMID: 19766304 DOI: 10.1016/j.biomaterials.2009.08.043] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Accepted: 08/27/2009] [Indexed: 11/25/2022]
Abstract
Calcium phosphate-based transfection methods are frequently used to transfer DNA into living cells. However, it has so far not been studied in detail to what extend the different transfection methods lead to a net calcium uptake. Upon subsequent resolution of the calcium phosphate, intracellular free ionic calcium-surges could result, inducing as side effect various physiological responses that may finally result in cell death. Here we investigated the overall calcium uptake by the human bladder carcinoma cell line T24 during the standard calcium phosphate transfection method and also during transfection with custom-made calcium phosphate/DNA nanoparticles by isotope labelling with (45)calcium. (45)Calcium uptake was strongly increased after 7h of standard calcium phosphate transfection but not if the transfection was performed with calcium phosphate nanoparticles. Time lapse imaging microscopy using the calcium-sensitive dye Fura-2 revealed large transient increases of the intracellular free calcium level during the standard calcium phosphate transfection but not if calcium phosphate nanoparticles were used. Consistently, the viability of cells transfected by calcium phosphate/DNA nanoparticles was not changed, in remarkable contrast to the standard method where considerable cell death occurred.
Collapse
Affiliation(s)
- Sebastian Neumann
- Department of Biochemistry, Molecular Neurobiochemistry, University of Bochum, Universitaetsstrasse 150, D-44780 Bochum, Germany
| | | | | | | | | |
Collapse
|
12
|
Niederkinkhaus V, Marx R, Hoffmann G, Dietzel ID. Thyroid hormone (T3)-induced up-regulation of voltage-activated sodium current in cultured postnatal hippocampal neurons requires secretion of soluble factors from glial cells. Mol Endocrinol 2009; 23:1494-504. [PMID: 19460859 DOI: 10.1210/me.2009-0132] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
We have previously shown that treatment with the thyroid hormone T(3) increases the voltage-gated Na(+)current density (Nav-D) in hippocampal neurons from postnatal rats, leading to accelerated action potential upstrokes and increased firing frequencies. Here we show that the Na(+) current regulation depends on the presence of glial cells, which secrete a heat-instable soluble factor upon stimulation with T(3). The effect of conditioned medium from T(3)-treated glial cells was mimicked by basic fibroblast growth factor (bFGF), known to be released from cerebellar glial cells after T(3) treatment. Neutralization assays of astrocyte-conditioned media with anti-bFGF antibody inhibited the regulation of the Nav-D by T(3). This suggests that the up-regulation of the neuronal sodium current density by T(3) is not a direct effect but involves bFGF release and satellite cells. Thus glial cells can modulate neuronal excitability via secretion of paracrinely acting factors.
Collapse
Affiliation(s)
- Vanessa Niederkinkhaus
- Department of Molecular Neurobiochemistry, Ruhr-University Bochum, NC7-170, Universitätsstrasse 150, D-44780 Bochum, Germany
| | | | | | | |
Collapse
|
13
|
Mann SA, Versmold B, Marx R, Stahlhofen S, Dietzel ID, Heumann R, Berger R. Corticosteroids reverse cytokine-induced block of survival and differentiation of oligodendrocyte progenitor cells from rats. J Neuroinflammation 2008; 5:39. [PMID: 18808689 PMCID: PMC2562366 DOI: 10.1186/1742-2094-5-39] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2007] [Accepted: 09/22/2008] [Indexed: 01/25/2023] Open
Abstract
Background Periventricular leukomalacia (PVL) is a frequent complication of preterm delivery. Proinflammatory cytokines, such as interferon-γ (IFN-γ) and tumor necrosis factor α (TNF-α) released from astrocytes and microglia activated by infection or ischemia have previously been shown to impair survival and maturation of oligodendrocyte progenitors and could thus be considered as potential factors contributing to the generation of this disease. The first goal of the present study was to investigate whether exposure of oligodendrocyte precursors to these cytokines arrests the maturation of ion currents in parallel to its effects on myelin proteins and morphological maturation. Secondly, in the search for agents, that can protect differentiating oligodendrocyte precursor cells from cytokine-induced damage we investigated effects of coapplications of corticosteroids with proinflammatory cytokines on the subsequent survival and differentiation of oligodendrocyte progenitor cells. Methods To exclude influences from factors released from other cell types purified cultures of oligodendrocyte precursors were exposed to cytokines and/or steroids and allowed to differentiate for further 6 days in culture. Changes in membrane surface were investigated with capacitance recordings and Scanning Ion Conductance Microscopy. Na+- and K+- currents were investigated using whole cell patch clamp recordings. The expression of myelin specific proteins was investigated using western blots and the precursor cells were identified using immunostaining with A2B5 antibodies. Results Surviving IFN-γ and TNF-α treated cells continued to maintain voltage-activated Na+- and K+ currents characteristic for the immature cells after 6 days in differentiation medium. Corticosterone, dihydrocorticosterone and, most prominently dexamethasone, counteracted the deleterious effects of IFN-γ and TNF-α on cell survival, A2B5-immunostaining and expression of myelin basic protein. The most potent corticosteroid tested, dexamethasone, was shown to counteract cytokine effects on membrane surface extension and capacitance. Furthermore, coapplication of dexamethasone blocked the cytokine-induced downregulation of the inwardly rectifying potassium current in 80% of the precursor cells and restored the cytokine-blocked down-regulation of the voltage activated Na+- and K+ currents during subsequent differentiation. Conclusion Our results show that treatment of oligodendrocyte precursors with the inflammatory cytokines TNF-α and IFN-γ block the differentiation of oligodendrocyte precursors at the level of the differentiation of the voltage-gated ion currents. Co-treatment with corticosteroids at the time of cytokine application restores to a considerable extent survival and differentiation of oligodendrocytes at the level of morphological, myelin protein as well as ion current maturation suggesting the option for a functional restoration of cytokine-damaged immature oligodendrocytes.
Collapse
Affiliation(s)
- Stefan A Mann
- Department of Molecular Neurobiochemistry, Ruhr University Bochum 44780, Germany.
| | | | | | | | | | | | | |
Collapse
|
14
|
Chakrabarty K, Serchov T, Mann SA, Dietzel ID, Heumann R. Enhancement of dopaminergic properties and protection mediated by neuronal activation of Ras in mouse ventral mesencephalic neurones. Eur J Neurosci 2007; 25:1971-81. [PMID: 17439485 DOI: 10.1111/j.1460-9568.2007.05457.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The poor differentiation and survival of dopaminergic neurones are practical constraints in their therapeutic applications. Here we explored the role of neuronally activated Ras in ventral mesencephalon-derived neurospheres generated from synRas mouse embryos. The expression of Val12 Ha-Ras transgene and enhanced Ras activity was evident after differentiation of the neurospheres with a corresponding activating phosphorylation of mitogen-activated protein kinase. Phosphorylation of Akt/PKB, the target kinase of phosphoinositide 3-kinase, along with phosphorylation of Bad and CREB were enhanced in synRas-derived differentiated neurosphere cultures. Furthermore, increased Nurr1 expression was associated with elevated numbers of dopaminergic neurones in synRas-derived cultures compared with the wild-type. Correspondingly, tyrosine hydroxylase promoter assays revealed enhanced transcriptional activation of the promoter in synRas-derived cultures. synRas-derived dopaminergic neurones were greatly resistant to degeneration induced by various noxious stimuli. Consistently, the transgenic expression of activated Ras attenuated the adverse 6-hydroxydopamine effects on dopaminergic neurones. Dopaminergic neurones derived from both wild-type and synRas cultures expressed voltage-gated potassium and sodium currents, fired action potentials and exhibited electrical network activity. Thus, expression of the transgene promotes survival and enhances differentiation towards a dopaminergic cell fate without altering their basic electrical properties. Our results suggest that intracellular cell therapy mimicking trophic signalling may offer potential benefit in models of human disease associated with dopamine neurone dysfunction.
Collapse
Affiliation(s)
- Koushik Chakrabarty
- Department of Molecular Neurobiochemistry, NC7/174, Ruhr University, 44780 Bochum, Germany
| | | | | | | | | |
Collapse
|
15
|
Mann SA, Meyer JW, Dietzel ID. Integration of a scanning ion conductance microscope into phase contrast optics and its application to the quantification of morphological parameters of selected cells. J Microsc 2007; 224:152-7. [PMID: 17204062 DOI: 10.1111/j.1365-2818.2006.01693.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have previously described a pulse-mode scanning ion conductance microscope to investigate membrane surfaces and volume changes of individual cells in culture. We have now developed a miniaturized scanning headstage that enables us to select individual cells for recording under phase contrast optics, considerably improving the selection of individual cells for scanning as well as the positioning of the scanning frames with respect to the position of the cell somata. We show an application in which surfaces and volumes of somata and processes of cultured cells from the central nervous system were quantified separately.
Collapse
Affiliation(s)
- S A Mann
- Lehrstuhl für Molekulare Neurobiochemie, NC7-170, Ruhr-Universität Bochum, D-44780 Bochum, Germany
| | | | | |
Collapse
|
16
|
Abstract
In preterm fetuses an ascending intrauterine inflammation before or during birth can be associated with periventricular leukomalacia (PVL). PVL is characterised by a disrupted. myelination [corrected] due to a loss of oligodendrocyte progenitors. Inflammatory cytokines not only induce apoptotic cell death but in addition prevent the differentiation of the immature A2B5 oligodendrocytc progenitors into the myelinating phenotype. The aim of the present study was to clarify whether corticosteroids can protect oligodendrocyte progenitors from such injury. Cultures [corrected] of more than 90 % A2B5 positive progenitors were prepared from neonatal sprague dawley rats. After 1 day in proliferation medium, cells were treated with interferon-gamma [corrected] (IFN-gamma; 10 U/ml) and tumour necrosis factor-alpha [corrected] (TNF-alpha; 10 ng/ml) for 48 h. In addition, corticosterone (C), deoxycorticosterone (DC), or dexamethasone (DEX) (1 micro M) were applied to the incubation medium of the study groups. After treatment cultures were transferred to media containing factors to promote differentiation of progenitors into thc myelinating phenotype. At culture day 9 total cell [corrected] number was determined. In addition, cells were analysed by immunocytochemistry for A2B5 as well. as by RT-PCR [corrected] and western-blot-analysis of the [corrected] myelin-specific proteins [corrected] MBP, MAG and CNP. Application of INF-gamma and TNF-alpha caused a dramatic decrease in cell number culture day 9 [corrected] More than 30 % of the surviving cells were A2B5-positive compared to 1 % in control dishes. Protein expression of MBP, MAG and CNP as well as mRNA expression, of MAG and MBP were considerably reduced after administration of INF- and TNF-. Co-treatment with, corticosteroids significantly increased total cell count, dexamethasone showing the strongest protective effect.Moreover, corticosteroids alleviated the cytokine induced inhibition in protein- and mRNA-expression [corrected] of MBP, MAG and CNP. Corticosteroids therefore protect oligodendrocyte progenitors from cytokine-induced cell damage.
Collapse
Affiliation(s)
- B Feldhaus
- Molekulare Gynäko-Onkologie, Universitätsfrauenklinik Köln.
| | | | | | | |
Collapse
|
17
|
Abstract
A lack of thyroid hormone in the postnatal period causes an irreversible mental retardation, characterized by a slowing of thoughts and movements accompanied by prolonged latencies of several evoked potentials and slowed electroencephalographic rhythms. Here we show that in cultured hippocampal and cortical neurons from postnatal rats treatment with thyroid hormone not only up-regulates Na(+)-current densities but also increases rates of rise, amplitudes and firing frequencies of action potentials. Furthermore, we show that the regulation of the Na(+)-current density by thyroid hormones also occurs in vivo: recordings from acutely isolated cortical neurons obtained from hypothyroid, euthyroid and hyperthyroid postnatal rats showed that hypothyroidism decreases the ratio of Na(+) inward- to K(+) outward-currents while hyperthyroidism upregulates Na(+)-currents with respect to K(+)-currents. Our observation of a regulation of neuronal excitability by thyroid hormone offers a direct explanation for the origin of various neurological symptoms related to thyroid dysfunction.
Collapse
Affiliation(s)
- G Hoffmann
- Department of Molecular Neurobiochemistry, Ruhr-University Bochum, NC7-170, Universitätsstrasse 150, D-44780 Bochum, Germany
| | | |
Collapse
|
18
|
Etienne M, Schulte A, Mann S, Jordan G, Dietzel ID, Schuhmann W. Constant-Distance Mode Scanning Potentiometry. 1. Visualization of Calcium Carbonate Dissolution in Aqueous Solution. Anal Chem 2004; 76:3682-8. [PMID: 15228341 DOI: 10.1021/ac0349227] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Constant-distance mode scanning potentiometry was established by integrating potentiometric microsensors as ion-selective scanning probes into a SECM setup that was equipped with a piezoelectric shear force-based tip-to-sample distance control. The combination of specially designed micrometer-sized potentiometric tips with an advanced system for tip positioning allowed simultaneous acquisition of both topographic and potentiometric information at solid/liquid interfaces with high spatial resolution. The performance of the approach was evaluated by applying Ca(2+)-selective constant-distance mode potentiometry to monitor the dissolution of calcium carbonate occurring either at the (104) surface of calcite crystals or in proximity to the more complex surface of cross sections of a calcium carbonate shell of Mya arenaria exposed to slightly acidic aqueous solutions. Micrometer-scale heterogeneities in the apparent calcium activity profiles have successfully been resolved for both samples.
Collapse
Affiliation(s)
- Mathieu Etienne
- Analytische Chemie-Elektroanalytik & Sensorik, Lehrstuhl für Molekulare Neurobiochemie, Ruhr-Universität Bochum, D-44780 Bochum, Germany
| | | | | | | | | | | |
Collapse
|
19
|
Abstract
Here we describe the use of pulse-mode scanning ion conductance microscopy (SICM) to observe volume changes and cell membrane movements during the locomotion of cultured cells in the range of minutes to several hours. The microscope is based on the pulse-mode SICM previously developed for stable imaging of single cells in culture. Our instrument uses current pulses to control the distance between cell surface and electrode tip as well as a back-step mode to prevent contact of tip and membrane during lateral movements of the probe. We performed repeated scans of cell surfaces using feedback-controlled piezoactors to position the electrode. Using patch-clamp-type electrode tips the height of cells could reproducibly be measured with a standard deviation of 50 nm. To quantify and separate changes in cell position and volume occurring between consecutive scans, a program was written to subtract images and calculate volume changes. Examples of repeated scans show that membrane movements in the range of 30 min to a few hours can be quantitatively monitored with a lateral resolution of 500 nm using difference images and that faster movements in the range of minutes can be recorded at defined cell sections using the line scan mode. Difference images indicate that volume changes can affect cell surfaces inhomogeneously, emphasizing the role of the cytoskeleton in the stabilization of cell shape.
Collapse
Affiliation(s)
- P Happel
- Department of Molecular Neurobiochemistry, Ruhr-University Bochum, NC7-170, Universitätsstr 150, D-44780 Bochum, Germany
| | | | | | | |
Collapse
|
20
|
Mann SA, Hoffmann G, Hengstenberg A, Schuhmann W, Dietzel ID. Pulse-mode scanning ion conductance microscopy--a method to investigate cultured hippocampal cells. J Neurosci Methods 2002; 116:113-7. [PMID: 12044660 DOI: 10.1016/s0165-0270(02)00023-7] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Scanning ion conductance microscopy (SICM) takes advantage of the increase in the resistance which occurs if a glass microelectrode is closely approached to a poorly conducting membrane (Science 243 (1989) 641) and has been shown to be a promising technique to study membranes of living cells (Biophys J 73 (1997a) 653; J Microsc 188 (1997b) 17). Based on a newly designed set-up on top of an inverted light microscope in combination with a speed optimized low noise intracellular amplifier, a novel mode for control of the distance between the probe and surface has been developed. By application of current pulses, the change in the resistance is monitored independently from electrode drift and parasitic DC currents. We demonstrate the applicability by showing first high-resolution images of neural cells produced with the pulse-mode operated SICM.
Collapse
Affiliation(s)
- S A Mann
- Department of Molecular Neurobiochemistry-Electrobiochemistry of Neural Cells, Ruhr-University Bochum, NC7-170, Universitätsstr. 150, D-44780, Bochum, Germany.
| | | | | | | | | |
Collapse
|
21
|
Hengstenberg A, Blöchl A, Dietzel ID, Schuhmann W. Ortsaufgelöste Detektion der Sekretion von Neurotransmittern aus einzelnen Zellen durch elektrochemische Rastermikroskopie. Angew Chem Int Ed Engl 2001. [DOI: 10.1002/1521-3757(20010302)113:5<942::aid-ange942>3.0.co;2-c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
22
|
Hengstenberg A, Blöchl A, Dietzel ID, Schuhmann W. Spatially Resolved Detection of Neurotransmitter Secretion from Individual Cells by Means of Scanning Electrochemical Microscopy. Angew Chem Int Ed Engl 2001; 40:905-908. [PMID: 11241642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Affiliation(s)
- Andreas Hengstenberg
- Analytische Chemie-Elektroanalytik & Sensorik Ruhr-Universität Bochum, 44780 Bochum (Germany)
| | | | | | | |
Collapse
|
23
|
Hengstenberg A, Blöchl A, Dietzel ID, Schuhmann W. Spatially Resolved Detection of Neurotransmitter Secretion from Individual Cells by Means of Scanning Electrochemical Microscopy. Angew Chem Int Ed Engl 2001. [DOI: 10.1002/1521-3773(20010302)40:5<905::aid-anie905>3.0.co;2-#] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Andreas Hengstenberg
- Analytische Chemie—Elektroanalytik & Sensorik Ruhr‐Universität Bochum, 44780 Bochum (Germany) Fax: (+49) 234‐321‐4683
| | - Andrea Blöchl
- Lehrstuhl für Molekulare Neurobiochemie Ruhr‐Universität Bochum, 44780 Bochum (Germany)
| | - Irmgard D. Dietzel
- Lehrstuhl für Molekulare Neurobiochemie Ruhr‐Universität Bochum, 44780 Bochum (Germany)
| | - Wolfgang Schuhmann
- Analytische Chemie—Elektroanalytik & Sensorik Ruhr‐Universität Bochum, 44780 Bochum (Germany) Fax: (+49) 234‐321‐4683
| |
Collapse
|
24
|
Wu X, Ritter B, Schlattjan JH, Lessmann V, Heumann R, Dietzel ID. Protein expression patterns of identified neurons and of sprouting cells from the leech central nervous system. J Neurobiol 2000; 44:320-32. [PMID: 10942885 DOI: 10.1002/1097-4695(20000905)44:3<320::aid-neu3>3.0.co;2-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
It has previously been shown that cephalic, segmental, and caudal ganglia from the medicinal leech show differences in their protein composition. Here we studied whether the neuronal reorganization that occurs in cultured segmental ganglia from the medicinal leech is accompanied by detectable changes in the protein expression pattern. Using silver-stained two-dimensional gels we showed that after 5 and 12 days in culture changes in the protein patterns can be detected in isolated ganglia. The changes observed in the two-dimensional gels occurred concomitantly with a sprouting of serotoninergic neurites and a decreased transmitter content of dopaminergic neurites as shown by using the glyoxylic acid condensation reaction. In addition, we present evidence that Retzius cells, which can be identified by their characteristic morphology and action potential waveform, exhibit biochemically unique properties with respect to their protein expression pattern.
Collapse
Affiliation(s)
- X Wu
- Lehrstuhl für Molekulare Neurobiochemie, Ruhr-Universität Bochum, Gebäude NC7-170, Universitätsstrasse 150, D-44780 Bochum, Germany
| | | | | | | | | | | |
Collapse
|
25
|
Zhong J, Dietzel ID, Wahle P, Kopf M, Heumann R. Sensory impairments and delayed regeneration of sensory axons in interleukin-6-deficient mice. J Neurosci 1999; 19:4305-13. [PMID: 10341234 PMCID: PMC6782624] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
Interleukin-6 (IL-6) is a multifunctional cytokine mediating inflammatory or immune reactions. Here we investigated the possible role of IL-6 in the intact or lesioned peripheral nervous system using adult IL-6 gene knockout (IL-6(-/-)) mice. Various sensory functions were tested by applying electrophysiological, morphological, biochemical, and behavioral methods. There was a 60% reduction of the compound action potential of the sensory branch of IL-6(-/-) mice as compared with the motor branch in the intact sciatic nerve. Cross sections of L5 DRG of IL-6(-/-) mice showed a shift in the relative size distribution of the neurons. The temperature sensitivity of IL-6(-/-) mice was also significantly reduced. After crush lesion of the sciatic nerve, its functional recovery was delayed in IL-6(-/-) mice as analyzed from a behavioral footprint assay. Measurements of compound action potentials 20 d after crush lesion showed that there was a very low level of recovery of the sensory but not of the motor branch of IL-6(-/-) mice. Similar results of sensory impairments were obtained with mice showing slow Wallerian degeneration (Wlds) and a delayed lesion-induced recruitment of macrophages. However, in contrast to WldS mice, in IL-6(-/-) mice we observed the characteristic lesion-induced invasion of macrophages and the upregulation of low-affinity neurotrophin receptor p75 (p75LNTR) mRNA levels identical to those of IL-6(+/+) mice. Thus, the mechanisms leading to the common sensory deficiencies were different between IL-6(-/-) and WldS mice. Altogether, the results suggest that interleukin-6 is essential to modulate sensory functions in vivo.
Collapse
Affiliation(s)
- J Zhong
- Lehrstuhl für Molekulare Neurobiochemie, Ruhr-Universität Bochum, 44780 Bochum Germany
| | | | | | | | | |
Collapse
|
26
|
Hovemann BT, Ryseck RP, Walldorf U, Störtkuhl KF, Dietzel ID, Dessen E. The Drosophila ebony gene is closely related to microbial peptide synthetases and shows specific cuticle and nervous system expression. Gene 1998; 221:1-9. [PMID: 9852943 DOI: 10.1016/s0378-1119(98)00440-5] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The previously detected ebony (e) locus (Caizzi et al., 1987) consists of a complex gene structure that is divided into seven exons. An open reading frame encoding the putative Ebony protein of 98.5 kDa exhibits homology to a family of peptide synthetases (Stachelhaus and Marahiel, 1995), in good correlation with the proposed function as beta-alanyl-dopamine synthetase. Multiple ebony transcripts are detected throughout development. P-factor mediated transformation of genomic DNA rescues the cuticle, electrophysiological and behavioural phenotypes. Fusion of the ebony reading frame with that of beta-galactosidase of E. coli reveals expression in cuticle and nervous system. Strong staining in the first and, to a lesser extent, in the second optic neuropile may reflect the pronounced visual defect observed in ebony mutants. In addition, weak central brain and thoracic ganglion expression is detected in flies. Conservation of a multidomain protein structure known from peptide synthetases should have functional implications on the putative reaction mechanism of peptide bond formation.
Collapse
Affiliation(s)
- B T Hovemann
- Universidade de Sao Paulo, Instituto de Biociencias, Sao Paulo, Brazil.
| | | | | | | | | | | |
Collapse
|
27
|
Schürmann B, Wu X, Dietzel ID, Lessmann V. Differential modulation of AMPA receptor mediated currents by evans blue in postnatal rat hippocampal neurones. Br J Pharmacol 1997; 121:237-47. [PMID: 9154333 PMCID: PMC1564681 DOI: 10.1038/sj.bjp.0701125] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [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] [Indexed: 02/04/2023] Open
Abstract
1. The modulation of non-N-methyl-D-aspartate (NMDA) receptor-mediated whole cell currents and of glutamatergic synaptic transmission by purified Evans Blue (EB) was investigated in rat cultured postnatal hippocampal neurones by use of patch clamp recordings and a fast drug application system. 2. Three different groups of neurones could be distinguished with respect to the type of modulation obtained with 10 microM EB: EB was either a predominant inhibitor of desensitization (13% of the neurones), a predominant inhibitor of current amplitudes (42%) or a mixed inhibitor of both properties (45%). Both effects were not use-dependent and reached maximal levels after 30 s of pre-equilibration with the diazo dye. 3. Dose-response curves obtained from glutamate activated whole cell currents yielded an IC50 value for EB of 13.3 microM (Hill coefficient: 1.3) for the inhibition of desensitization, and an IC50 value of 10.7 microM (Hill coefficient: 1.2) for the inhibition of current amplitudes. 4. Chicago acid SS (100 microM) which is one of the synthesis precursors of EB had no effect on current amplitudes of glutamate activated whole cell currents but was a weak inhibitor of desensitization in all hippocampal neurones investigated, irrespective of the type of modulation obtained with EB in the same neurone. 5. Oxidatively modified EB (the so-called VIMP (10 microM)) had no effect on the kinetics but was a partial inhibitor of glutamate-activated whole cell currents in all hippocampal neurones investigated. 6. EB (10 microM) inhibited the amplitudes of non-NMDA receptor mediated autaptic currents to the same extent (to 39 +/- 19% of control) as observed for glutamate activated whole cell currents (to 41 +/- 17% and 56 +/- 20%). However, the decay of the autaptic responses remained uninfluenced upon EB application, indicating that either receptor desensitization does not dominate the time course of the synaptic response or that the non-NMDA receptors sensitive to modulation of desensitization by EB are not present in the postsynaptic membrane. 7. In conclusion, EB differentially modulates alpha-amino-3-hydroxy-5-methyl -4-isoxazole propionic acid (AMPA) receptor gating in different subsets of neurones. Upon identification of the cellular determinants for the differential modulation (e.g. AMPA receptor subunit composition) EB could become a useful tool to investigate receptor subtypes during electrophysiological recordings.
Collapse
Affiliation(s)
- B Schürmann
- Lehrstuhl für Molekulare Neurobiochemie, Ruhr-Universität Bochum, Germany
| | | | | | | |
Collapse
|
28
|
Abstract
The causes for mental retardation due to perinatal hypothyroidism are not fully understood. Here we show that the most potent component of thyroid hormone, 3,5,3'-triiodo-L-thyronine (T3), selectively increases the density of voltage-activated Na+ currents in hippocampal neurons from newborn rats. Thus, the well known effects of thyroid hormone on energy expenditure and Na+/K+ ATPase activity could to some extent result from the enhanced Na+ influx through voltage-activated Na+ channels. In addition, a down-regulation of the Na+ current density in neurons could contribute to some of the neurological symptoms accompanying hypothyroidism, including slowing of mentation, of neuronal conduction velocities, the alpha rhythm of the electroencephalogram, and increased latencies of evoked potentials and reflexes.
Collapse
Affiliation(s)
- O Potthoff
- Department of Molecular Neurobiochemistry, Ruhr-Universität Bochum, Germany
| | | |
Collapse
|
29
|
Abstract
Postsynaptic Ca2+ signals are a precondition for many types of synapse modification, including long-term potentiation. Here we describe a postsynaptic mechanism that augments synaptic currents at the serotonergic Retzius-P cell synapse of the leech. Depolarizations large enough to elicit Ca2+ currents evoked an increase in the amplitude of serotonin-activated Cl- currents in isolated embryonic neurons as well as at the Retzius-P cell synapse. The effect on embryonic whole cell currents lasted for up to one hour and was abolished in solutions containing Cd2+ as a Ca2+ channel blocker. Hence, Ca2+ influx into the postsynaptic neuron may be a common step regulating the plasticity of various vertebrate as well as invertebrate synapses.
Collapse
Affiliation(s)
- V Lessmann
- Lehrstuhl für Molekulare Neurobiochemie, Ruhr-Universität Bochum, F.R.G
| | | |
Collapse
|
30
|
Lessmann V, Dietzel ID. Two kinetically distinct 5-hydroxytryptamine-activated Cl- conductances at Retzius P-cell synapses of the medicinal leech. J Neurosci 1995; 15:1496-505. [PMID: 7869113 PMCID: PMC6577829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The properties of serotonin (5-HT)-activated Cl- receptor/ion channel complexes in neurons of the CNS of the medicinal leech were analyzed. These channels mediate the postsynaptic response at the serotoninergic Retzius P-cell as well as Retzius-Retzius cell synapses. 5-HT-induced Cl- currents were activated by fast superfusion of transmitter on cells dissociated from embryonic leeches including histochemically identified Retzius cells. Whole-cell currents elicited by partial superfusion of the membrane and summated single-channel currents of outside-out patches showed times to peak of 18 +/- 4 msec and 10 +/- 5 msec, respectively, and desensitized with time constants of 28 +/- 3 msec and 20 +/- 11 msec. Persistence of single-channel openings in the outside-out configuration as well as lack of effect of dialysis of the whole cell with AMP-PNP or GDP-beta-S indicated that 5-HT directly gates the Cl- channels without involving second messenger cascades. In outside-out patches, two single-channel conductances of 13 pS and 32 pS were identified. While the 13 pS conductance desensitized, the 32 pS conductance activated within several tens of msec and showed no desensitization. We postulate that two subtypes of channels are coactivated by 5-HT and that the activation of the fast desensitizing channel could be responsible for the fast decaying component of the post-synaptic response. The slow conductance explains the second slower decay time constant of the postsynaptic response and could account for the tonic component sometimes observed at Retzius P-cell synapses.
Collapse
Affiliation(s)
- V Lessmann
- Lehrstuhl für Molekulare Neurobiochemie, Ruhr-Universität Bochum, Germany
| | | |
Collapse
|
31
|
Lessmann V, Dietzel ID. Development of serotonin-induced ion currents in identified embryonic Retzius cells from the medicinal leech (Hirudo medicinalis). J Neurosci 1991; 11:800-9. [PMID: 1705969 PMCID: PMC6575337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Retzius cells and the cutaneous baroreceptive P-cells of adult medicinal leeches (Hirudo medicinalis) respond to 5-HT by Cl- as well as by monovalent cation conductances (Drapeau et al., 1989). However, chemical synaptic connections between Retzius cells (Liu and Nicholls, 1989) as well as Retzius cells and P-cells in culture (Drapeau and Sanchez-Armass, 1988) are mediated by postsynaptic Cl- currents in response to 5-HT release from the presynaptic cell. It was the aim of the present study to find out whether the response, which has been shown to be involved in synaptic transmission or whether the cation current, which has so far only been observed upon extrasynaptic 5-HT application, dominates during embryogenesis. Currents induced by transmitter application with a fast perfusion system were measured with a single-electrode voltage clamp and patch pipettes in whole-cell configuration. Control experiments, performed on Retzius cells from adult leeches after 1 d in culture, showed Cl- currents in response to 5-HT application in all cells investigated. Ninety percent of the cells tested showed additional 5-HT-elicited Na+, K+, or both currents. However, the conductance of cation currents amounted only to 10% of the Cl- currents. Embryonic Retzius cells were identified in dissociated cultures by their violet-blue fluorescence acquired by preincubation of intact ganglia or embryos in culture medium containing the autofluorescent 5-HT analog 5,7-dihydroxytryptamine. The first responses to 5-HT were measured at embryonic day 10 (E10), after voltage-activated Ca2+ and Na+ currents had already developed. 5-HT application induced exclusively Cl- currents until E16. This suggests that the receptor-channel complex, which also mediates synaptic responses, is expressed first in measurable quantities. Hence, there is currently no indication that extrasynaptic receptors dominate in immature cells in this preparation.
Collapse
Affiliation(s)
- V Lessmann
- Department of Neurophysiology, Max Planck Institute for Psychiatry, Planegg-Martinsried, Germany
| | | |
Collapse
|
32
|
Gottmann K, Dietzel ID, Lux HD, Ruedel C. Proton-induced Na+ current develops prior to voltage-dependent Na+ and Ca2+ currents in neuronal precursor cells from chick dorsal root ganglion. Neurosci Lett 1989; 99:90-4. [PMID: 2546110 DOI: 10.1016/0304-3940(89)90270-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Proton-induced Na+ currents (INa(H] were measured in precursor cells from chick dorsal root ganglia with whole-cell patch-clamp recording. Precursor cells were isolated using the method of Rohrer et al. (EMBO. J., 4 (1985) 1709-1714) and fast pH changes were applied with a technique developed by Davies et al. (J. Physiol. (Lond.), 400 (1988) 159-187). Proton-induced transient Na+ currents showing the same properties as in more mature neurons could be elicited already early in differentiation, before high-voltage activated Ca2+ currents and voltage-dependent Na+ currents develop.
Collapse
Affiliation(s)
- K Gottmann
- Max-Planck-Institute for Psychiatry, Department of Neurophysiology, Planegg-Martinsried F.R.G
| | | | | | | |
Collapse
|
33
|
Gottmann K, Dietzel ID, Lux HD. Proton-induced chloride current and voltage-activated Na+ and Ca2+ currents in embryonic neurons from the medicinal leech (Hirudo medicinalis). Neurosci Lett 1989; 96:173-8. [PMID: 2927721 DOI: 10.1016/0304-3940(89)90053-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Voltage-activated ionic currents and currents induced by step changes in proton concentration (pH 7.9-6.7) were studied in early embryonic neurons from Hirudo medicinalis. Ganglia were dissociated at embryonic day (E) 8-15, and the largest neurons were investigated using whole-cell patch clamp recording. All cells studied displayed voltage-activated Na+ and Ca2+ currents. Step changes in pH induced sustained currents which reversed at the equilibrium potential for Cl- and were blocked by substituting Cl- with acetate or sulfate. These currents thus differ in their ion selectivity from proton-induced currents in vertebrate neurons which are carried by Na+.
Collapse
Affiliation(s)
- K Gottmann
- Max-Planck-Institute for Psychiatry, Department of Neurophysiology, Planegg-Martinsried, F.R.G
| | | | | |
Collapse
|
34
|
Gottmann K, Dietzel ID, Lux HD, Huck S, Rohrer H. Development of inward currents in chick sensory and autonomic neuronal precursor cells in culture. J Neurosci 1988; 8:3722-32. [PMID: 2848106 PMCID: PMC6569614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The development of ionic inward currents was studied in cultured neuronal precursors from chick sensory dorsal root ganglia (DRG) and compared with neuronal precursors from the cholinergic ciliary ganglia (CG) using whole cell patch-clamp recording. Neuronal precursors devoid of neuron-specific surface markers were isolated during the period of neuronal birth, i.e., at embryonic day (E) 6 from DRG and at E4.5 from CG. All neuronal precursor cells from DRG, as well as CG, showed outward K+ currents directly after they had attached to the substrate. During the first 5 hr in culture, half of the DRG cells had no inward currents at all, whereas the other half displayed a rapidly and fully inactivating Ca2+ current, which was activated with small depolarizing pulses from a holding potential of -80 mV to a -50 mV membrane potential (low-voltage-activated current, LVA). At these early stages, no other inward currents were resolved. TTX-blockable Na+ currents and slowly inactivating classical Ca2+ currents, which were activated with larger depolarizing pulses to a -20 mV membrane potential (high-voltage-activated currents, HVA) appeared concurrently after 15-20 hr in culture. In contrast, more than half of the CG cells showed LVA currents, as well as Na+ currents, as early as during the first 5 hr in culture. The HVA Ca2+ currents from the majority of the cells could be recorded only after 10-15 hr in culture. In both types of precursor-derived neurons, the LVA Ca2+ current preceded the classical HVA Ca2+ current. However, the temporal relation of the first Na+ currents to the first HVA Ca2+ currents seemed to be different in the 2 preparations. In DRG cells, Na+ and HVA Ca2+ currents appeared at the same time, whereas in CG cells, the HVA Ca2+ current showed a time lag with respect to the Na+ current. In addition, the relative amplitudes of the currents differed in the CG and DRG cells. This shows that as early as E4-6, shortly after their terminal mitosis, neurons from distinct peripheral ganglia in chick vary in the development of their basic ionic currents.
Collapse
Affiliation(s)
- K Gottmann
- Department of Neurophysiology, Max Planck Institute for Psychiatry, Planegg-Martinsried, FRG
| | | | | | | | | |
Collapse
|
35
|
Abstract
The embryonic development of neurons which contain or take up dopamine was studied with glyoxylic acid histofluorescence in Hirudo medicinalis. Beginning at the time of the formation of the tail ganglion, one pair of dopamine-containing neurons was stained per segmental ganglion. The normal outgrowth of the cell bodies into the anterior roots was prevented in isolated and cultured chains of embryonic ganglia. Preincubation of intact embryos in dopamine led to the staining of additional neurons at certain developmental stages. These neurons presumably are the precursors of serotonin-containing cells, which have a temporary capability of taking up and storing dopamine.
Collapse
Affiliation(s)
- I D Dietzel
- Department of Neurophysiology, Max Planck Institute for Psychiatry, Planegg-Martinsried, Federal Republic of Germany
| | | |
Collapse
|
36
|
Dietzel ID, Drapeau P, Nicholls JG. Voltage dependence of 5-hydroxytryptamine release at a synapse between identified leech neurones in culture. J Physiol 1986; 372:191-205. [PMID: 3723408 PMCID: PMC1192758 DOI: 10.1113/jphysiol.1986.sp016004] [Citation(s) in RCA: 94] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The release of 5-hydroxytryptamine (5-HT) from presynaptic terminals has been studied by the voltage-clamp technique at synapses made by isolated Retzius and pressure (P) sensory neurones dissected from the leech C.N.S. and maintained in tissue culture. At these synapses facilitation, depression and modulation of release occur with action potentials and with voltage-clamp pulses. Depolarization of Retzius cells from a constant holding potential by steps of varying amplitude (5 ms in duration) caused graded release of 5-HT. The steep transfer function for release using these short test pulses resembled that seen at the giant synapse of the squid: synaptic potentials increased markedly with presynaptic depolarizations beyond -25 mV and decreased with large depolarizing pulses beyond +40 mV. When the steady holding potential of voltage-clamped Retzius cells was suddenly displaced to a new value within the range of -40 mV to -85 mV, there followed a slow but smaller change of the post-synaptic P-cell membrane potential in the same direction. After an initial delay of about 40 ms, the post-synaptic potential reached its new level with an exponential time course and a time constant of 0.7 s. Since Retzius and P cells are not electrically coupled, these effects can be accounted for by alterations in tonic release of transmitter. Changes of presynaptic holding potential to a more depolarized level resulted in an increase in voltage noise recorded in the P cell. Conversely, hyperpolarization from a depolarized level reduced noise. Noise analysis showed that these changes could be accounted for by quantal events with a mean amplitude of about 0.15 mV. This value is similar to that for spontaneous miniature potentials and quantal fluctuations observed at synapses between Retzius and P cells. Changes in steady holding potential also had marked effects upon the transfer function observed with brief depolarizing pulses of the Retzius cell. The post-synaptic responses evoked by depolarizations to 0 mV with pulses of 5 ms duration were reduced in amplitude as the holding potential of the Retzius cell was increased from the resting value of -45 to -75 mV. For example, depolarization to 0 mV starting from -45 mV evoked synaptic potentials as much as ten times larger than those evoked by depolarizations to 0 mV starting from -75 mV.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
|