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Pohlkamp T, Xian X, Wong CH, Durakoglugil MS, Werthmann GC, Saido TC, Evers BM, White CL, Connor J, Hammer RE, Herz J. NHE6 depletion corrects ApoE4-mediated synaptic impairments and reduces amyloid plaque load. eLife 2021; 10:72034. [PMID: 34617884 PMCID: PMC8547963 DOI: 10.7554/elife.72034] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 09/19/2021] [Indexed: 11/13/2022] Open
Abstract
Apolipoprotein E4 (ApoE4) is the most important and prevalent risk factor for late-onset Alzheimer’s disease (AD). The isoelectric point of ApoE4 matches the pH of the early endosome (EE), causing its delayed dissociation from ApoE receptors and hence impaired endolysosomal trafficking, disruption of synaptic homeostasis, and reduced amyloid clearance. We have shown that enhancing endosomal acidification by inhibiting the EE-specific sodium-hydrogen exchanger 6 (NHE6) restores vesicular trafficking and normalizes synaptic homeostasis. Remarkably and unexpectedly, loss of NHE6 (encoded by the gene Slc9a6) in mice effectively suppressed amyloid deposition even in the absence of ApoE4, suggesting that accelerated acidification of EEs caused by the absence of NHE6 occludes the effect of ApoE on amyloid plaque formation. NHE6 suppression or inhibition may thus be a universal, ApoE-independent approach to prevent amyloid buildup in the brain. These findings suggest a novel therapeutic approach for the prevention of AD by which partial NHE6 inhibition reverses the ApoE4-induced endolysosomal trafficking defect and reduces plaque load.
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Affiliation(s)
- Theresa Pohlkamp
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, Dallas, United States
| | - Xunde Xian
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, Dallas, United States.,Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University, Beijing, China
| | - Connie H Wong
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, Dallas, United States
| | - Murat S Durakoglugil
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, Dallas, United States
| | - Gordon Chandler Werthmann
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, Dallas, United States
| | - Takaomi C Saido
- Laboratory for Proteolytic Neuroscience, Riken Center for Brain Science, Wako, Japan
| | - Bret M Evers
- Center for Translational Neurodegeneration Research, Dallas, United States
| | - Charles L White
- Pathology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Jade Connor
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, Dallas, United States
| | - Robert E Hammer
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, Dallas, United States.,Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, United States
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2
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Durakoglugil MS, Wasser CR, Wong CH, Pohlkamp T, Xian X, Lane-Donovan C, Fritschle K, Naestle L, Herz J. Reelin Regulates Neuronal Excitability through Striatal-Enriched Protein Tyrosine Phosphatase (STEP 61) and Calcium Permeable AMPARs in an NMDAR-Dependent Manner. J Neurosci 2021; 41:7340-7349. [PMID: 34290083 PMCID: PMC8412985 DOI: 10.1523/jneurosci.0388-21.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 06/13/2021] [Accepted: 07/08/2021] [Indexed: 11/21/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease marked by the accumulation of amyloid-β (Aβ) plaques and neurofibrillary tangles. Aβ oligomers cause synaptic dysfunction early in AD by enhancing long-term depression (LTD; a paradigm for forgetfulness) via metabotropic glutamate receptor (mGluR)-dependent regulation of striatal-enriched tyrosine phosphatase (STEP61). Reelin is a neuromodulator that signals through ApoE (apolipoprotein E) receptors to protect the synapse against Aβ toxicity (Durakoglugil et al., 2009) Reelin signaling is impaired by ApoE4, the most important genetic risk factor for AD, and Aβ-oligomers activate metabotropic glutamate receptors (Renner et al., 2010). We therefore asked whether Reelin might also affect mGluR-LTD. To this end, we induced chemical mGluR-LTD using DHPG (Dihydroxyphenylglycine), a selective mGluR5 agonist. We found that exogenous Reelin reduces the DHPG-induced increase in STEP61, prevents the dephosphorylation of GluA2, and concomitantly blocks mGluR-mediated LTD. By contrast, Reelin deficiency increased expression of Ca2+-permeable GluA2-lacking AMPA receptors along with higher STEP61 levels, resulting in occlusion of DHPG-induced LTD in hippocampal CA1 neurons. We propose a model in which Reelin modulates local protein synthesis as well as AMPA receptor subunit composition through modulation of mGluR-mediated signaling with implications for memory consolidation or neurodegeneration.SIGNIFICANCE STATEMENT Reelin is an important neuromodulator, which in the adult brain controls synaptic plasticity and protects against neurodegeneration. Amyloid-β has been shown to use mGluRs to induce synaptic depression through endocytosis of NMDA and AMPA receptors, a mechanism referred to as LTD, a paradigm of forgetfulness. Our results show that Reelin regulates the phosphatase STEP, which plays an important role in neurodegeneration, as well as the expression of calcium-permeable AMPA receptors, which play a role in memory formation. These data suggest that Reelin uses mGluR LTD pathways to regulate memory formation as well as neurodegeneration.
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Affiliation(s)
- Murat S Durakoglugil
- Department of Molecular Genetics
- Center for Translational Neurodegeneration Research
| | - Catherine R Wasser
- Department of Molecular Genetics
- Center for Translational Neurodegeneration Research
| | - Connie H Wong
- Department of Molecular Genetics
- Center for Translational Neurodegeneration Research
| | - Theresa Pohlkamp
- Department of Molecular Genetics
- Center for Translational Neurodegeneration Research
| | - Xunde Xian
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University, Beijing 100871, China
| | - Courtney Lane-Donovan
- Weill Institute for Neurosciences, University of California San Francisco, San Francisco, California 94158
| | | | - Lea Naestle
- Ludwig-Maximilians University of Munich, 80539, Munich, Germany
| | - Joachim Herz
- Department of Molecular Genetics
- Center for Translational Neurodegeneration Research
- Departments of Neuroscience and
- Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas 75390
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Chang BJ, Manton JD, Sapoznik E, Pohlkamp T, Terrones TS, Welf ES, Murali VS, Roudot P, Hake K, Whitehead L, York AG, Dean KM, Fiolka R. Real-time multi-angle projection imaging of biological dynamics. Nat Methods 2021; 18:829-834. [PMID: 34183831 PMCID: PMC9206531 DOI: 10.1038/s41592-021-01175-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 05/05/2021] [Indexed: 02/03/2023]
Abstract
We introduce a cost-effective and easily implementable scan unit that converts any camera-based microscope with optical sectioning capability into a multi-angle projection imaging system. Projection imaging reduces data overhead and accelerates imaging by a factor of >100, while also allowing users to readily view biological phenomena of interest from multiple perspectives on the fly. By rapidly interrogating the sample from just two perspectives, our method also enables real-time stereoscopic imaging and three-dimensional particle localization. We demonstrate projection imaging with spinning disk confocal, lattice light-sheet, multidirectional illumination light-sheet and oblique plane microscopes on specimens that range from organelles in single cells to the vasculature of a zebrafish embryo. Furthermore, we leverage our projection method to rapidly image cancer cell morphodynamics and calcium signaling in cultured neurons at rates up to 119 Hz as well as to simultaneously image orthogonal views of a beating embryonic zebrafish heart.
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Affiliation(s)
- Bo-Jui Chang
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | - Etai Sapoznik
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Theresa Pohlkamp
- Department of Molecular Genetics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Tamara S Terrones
- Department of Molecular Genetics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Erik S Welf
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Vasanth S Murali
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Philippe Roudot
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Kayley Hake
- Calico Life Sciences LLC, South San Francisco, CA, USA
| | - Lachlan Whitehead
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Andrew G York
- Calico Life Sciences LLC, South San Francisco, CA, USA
| | - Kevin M Dean
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Reto Fiolka
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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Welf ES, Miles CE, Huh J, Sapoznik E, Chi J, Driscoll MK, Isogai T, Noh J, Weems AD, Pohlkamp T, Dean K, Fiolka R, Mogilner A, Danuser G. Actin-Membrane Release Initiates Cell Protrusions. Dev Cell 2020; 55:723-736.e8. [PMID: 33308479 DOI: 10.1016/j.devcel.2020.11.024] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 09/08/2020] [Accepted: 11/20/2020] [Indexed: 01/04/2023]
Abstract
Despite the well-established role of actin polymerization as a driving mechanism for cell protrusion, upregulated actin polymerization alone does not initiate protrusions. Using a combination of theoretical modeling and quantitative live-cell imaging experiments, we show that local depletion of actin-membrane links is needed for protrusion initiation. Specifically, we show that the actin-membrane linker ezrin is depleted prior to protrusion onset and that perturbation of ezrin's affinity for actin modulates protrusion frequency and efficiency. We also show how actin-membrane release works in concert with actin polymerization, leading to a comprehensive model for actin-driven shape changes. Actin-membrane release plays a similar role in protrusions driven by intracellular pressure. Thus, our findings suggest that protrusion initiation might be governed by a universal regulatory mechanism, whereas the mechanism of force generation determines the shape and expansion properties of the protrusion.
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Affiliation(s)
- Erik S Welf
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Christopher E Miles
- Courant Institute of Mathematical Sciences, New York University, New York, NY 10012, USA; Department of Biology, New York University, New York, NY 10012, USA
| | - Jaewon Huh
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Etai Sapoznik
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Joseph Chi
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Meghan K Driscoll
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Tadamoto Isogai
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jungsik Noh
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Andrew D Weems
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Theresa Pohlkamp
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kevin Dean
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Reto Fiolka
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Alex Mogilner
- Courant Institute of Mathematical Sciences, New York University, New York, NY 10012, USA; Department of Biology, New York University, New York, NY 10012, USA.
| | - Gaudenz Danuser
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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Sapoznik E, Chang BJ, Huh J, Ju RJ, Azarova EV, Pohlkamp T, Welf ES, Broadbent D, Carisey AF, Stehbens SJ, Lee KM, Marín A, Hanker AB, Schmidt JC, Arteaga CL, Yang B, Kobayashi Y, Tata PR, Kruithoff R, Doubrovinski K, Shepherd DP, Millett-Sikking A, York AG, Dean KM, Fiolka RP. A versatile oblique plane microscope for large-scale and high-resolution imaging of subcellular dynamics. eLife 2020; 9:57681. [PMID: 33179596 PMCID: PMC7707824 DOI: 10.7554/elife.57681] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 11/09/2020] [Indexed: 12/31/2022] Open
Abstract
We present an oblique plane microscope (OPM) that uses a bespoke glass-tipped tertiary objective to improve the resolution, field of view, and usability over previous variants. Owing to its high numerical aperture optics, this microscope achieves lateral and axial resolutions that are comparable to the square illumination mode of lattice light-sheet microscopy, but in a user friendly and versatile format. Given this performance, we demonstrate high-resolution imaging of clathrin-mediated endocytosis, vimentin, the endoplasmic reticulum, membrane dynamics, and Natural Killer-mediated cytotoxicity. Furthermore, we image biological phenomena that would be otherwise challenging or impossible to perform in a traditional light-sheet microscope geometry, including cell migration through confined spaces within a microfluidic device, subcellular photoactivation of Rac1, diffusion of cytoplasmic rheological tracers at a volumetric rate of 14 Hz, and large field of view imaging of neurons, developing embryos, and centimeter-scale tissue sections.
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Affiliation(s)
- Etai Sapoznik
- Department of Cell Biology, University of Texas Southwestern Medical CenterDallasUnited States,Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical CenterDallasUnited States
| | - Bo-Jui Chang
- Department of Cell Biology, University of Texas Southwestern Medical CenterDallasUnited States
| | - Jaewon Huh
- Department of Cell Biology, University of Texas Southwestern Medical CenterDallasUnited States,Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical CenterDallasUnited States
| | - Robert J Ju
- Institute for Molecular Bioscience, University of QueenslandQueenslandAustralia
| | - Evgenia V Azarova
- Department of Cell Biology, University of Texas Southwestern Medical CenterDallasUnited States
| | - Theresa Pohlkamp
- Department of Molecular Genetics, University of Texas Southwestern Medical CenterDallasUnited States
| | - Erik S Welf
- Department of Cell Biology, University of Texas Southwestern Medical CenterDallasUnited States,Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical CenterDallasUnited States
| | - David Broadbent
- Institute for Quantitative Health Sciences and Engineering, Michigan State UniversityEast LansingUnited States
| | - Alexandre F Carisey
- William T. Shearer Center for Human Immunobiology, Baylor College of Medicine and Texas Children’s HospitalHoustonUnited States
| | - Samantha J Stehbens
- Institute for Molecular Bioscience, University of QueenslandQueenslandAustralia
| | - Kyung-Min Lee
- Harold C. Simmons Comprehensive Cancer Center and the Department of Internal Medicine, University of Texas Southwestern Medical CenterDallasUnited States
| | - Arnaldo Marín
- Harold C. Simmons Comprehensive Cancer Center and the Department of Internal Medicine, University of Texas Southwestern Medical CenterDallasUnited States,Department of Basic and Clinical Oncology, Faculty of Medicine, University of ChileSantiagoChile
| | - Ariella B Hanker
- Harold C. Simmons Comprehensive Cancer Center and the Department of Internal Medicine, University of Texas Southwestern Medical CenterDallasUnited States
| | - Jens C Schmidt
- Institute for Quantitative Health Sciences and Engineering, Michigan State UniversityEast LansingUnited States,Department of Obstetrics, Gynecology, and Reproductive Biology, Michigan State UniversityEast LansingUnited States
| | - Carlos L Arteaga
- Harold C. Simmons Comprehensive Cancer Center and the Department of Internal Medicine, University of Texas Southwestern Medical CenterDallasUnited States
| | - Bin Yang
- Chan Zuckerberg BiohubSan FranciscoUnited States
| | - Yoshihiko Kobayashi
- Department of Cell Biology, Duke University School of MedicineDurhamUnited States
| | | | - Rory Kruithoff
- Center for Biological Physics and Department of Physics, Arizona State UniversityTempeUnited States
| | - Konstantin Doubrovinski
- Department of Cell Biology, University of Texas Southwestern Medical CenterDallasUnited States,Cecil H. and Ida Green Comprehensive Center for Molecular, Computational and Systems Biology, University of Texas Southwestern Medical CenterDallasUnited States
| | - Douglas P Shepherd
- Center for Biological Physics and Department of Physics, Arizona State UniversityTempeUnited States
| | | | - Andrew G York
- Calico Life Sciences LLCSouth San FranciscoUnited States
| | - Kevin M Dean
- Department of Cell Biology, University of Texas Southwestern Medical CenterDallasUnited States
| | - Reto P Fiolka
- Department of Cell Biology, University of Texas Southwestern Medical CenterDallasUnited States,Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical CenterDallasUnited States
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Xian X, Pohlkamp T, Durakoglugil MS, Wong CH, Beck JK, Lane-Donovan C, Plattner F, Herz J. Reversal of ApoE4-induced recycling block as a novel prevention approach for Alzheimer's disease. eLife 2018; 7:40048. [PMID: 30375977 PMCID: PMC6261251 DOI: 10.7554/elife.40048] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 10/29/2018] [Indexed: 12/13/2022] Open
Abstract
ApoE4 genotype is the most prevalent and also clinically most important risk factor for late-onset Alzheimer’s disease (AD). Available evidence suggests that the root cause for this increased risk is a trafficking defect at the level of the early endosome. ApoE4 differs from the most common ApoE3 isoform by a single amino acid that increases its isoelectric point and promotes unfolding of ApoE4 upon endosomal vesicle acidification. We found that pharmacological and genetic inhibition of NHE6, the primary proton leak channel in the early endosome, in rodents completely reverses the ApoE4-induced recycling block of the ApoE receptor Apoer2/Lrp8 and the AMPA- and NMDA-type glutamate receptors that are regulated by, and co-endocytosed in a complex with, Apoer2. Moreover, NHE6 inhibition restores the Reelin-mediated modulation of excitatory synapses that is impaired by ApoE4. Our findings suggest a novel potential approach for the prevention of late-onset AD. Alzheimer’s disease is a degenerative condition that destroys connections between brain cells leading to memory loss, confusion and difficulties in thinking. Apolipoprotein E is a protein that carries fatty substances called lipids and cholesterol around the brain, and plays an important role in repair mechanisms. There are three major forms of Apolipoprotein E, and individuals who carry a version known as ApoE4 are up to 10 times more likely to develop Alzheimer’s disease than those who carry other variations. In nerve cells, or neurons, Apolipoprotein E binds to a specific family of receptors. One of these receptors, called Apoer2, is found in the synaptic gap between neurons, where it regulates their activities. Both Apolipoprotein E and Apoer2 are taken into the cell within compartments known as endosomal vesicles. Usually, the Apoer2 receptor is quickly recycled back to the surface of the cell, but this recycling process is delayed in individuals with the ApoE4 version of Apolipoprotein E. Apoer2 is just one of many different receptors on the surface of neurons that are taken into vesicles before being recycled back to the cell surface. The fluid inside these vesicles becomes progressively more acidic as they move through the cell. This process helps to control the interaction of these receptors with their binding partners and to regulate their movement and recycling. Here, Xian, Pohlkamp et al. investigated whether changing the acidity of vesicles in rat neurons could overcome the block in recycling Apoer2 – and other receptors that travel with Apoer2 in the same compartments – in the presence of ApoE4. A protein called NHE6 is embedded in the membrane of vesicles called early endosomes and acts to make the vesicles less acidic. Xian, Pohlkamp et al. used drugs to block the activity of NHE6, which led to the vesicles becoming more acidic and allowed Apoer2 to be recycled faster. Using a genetic approach known as siRNA knockdown to decrease the amount of NHE6 produced in neurons also had a similar effect on Apoer2 recycling. Together these findings suggest that drugs that make vesicles in neurons more acidic may have the potential to help prevent individuals that carry the ApoE4 protein from developing Alzheimer’s disease. Current drugs that target NHE6 also affect other molecules, which can often lead to side effects. A next step will be to develop tailor-made, small molecule drugs that can enter the brain efficiently and selectively block NHE6.
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Affiliation(s)
- Xunde Xian
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Theresa Pohlkamp
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Murat S Durakoglugil
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Connie H Wong
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, United States
| | | | - Courtney Lane-Donovan
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, United States
| | - Florian Plattner
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, United States
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, United States
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7
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Abstract
The biological fates of the key initiator of Alzheimer’s disease (AD), the amyloid precursor protein (APP), and a family of lipoprotein receptors, the low-density lipoprotein (LDL) receptor-related proteins (LRPs) and their molecular roles in the neurodegenerative disease process are inseparably interwoven. Not only does APP bind tightly to the extracellular domains (ECDs) of several members of the LRP group, their intracellular portions are also connected through scaffolds like the one established by FE65 proteins and through interactions with adaptor proteins such as X11/Mint and Dab1. Moreover, the ECDs of APP and LRPs share common ligands, most notably Reelin, a regulator of neuronal migration during embryonic development and modulator of synaptic transmission in the adult brain, and Agrin, another signaling protein which is essential for the formation and maintenance of the neuromuscular junction (NMJ) and which likely also has critical, though at this time less well defined, roles for the regulation of central synapses. Furthermore, the major independent risk factors for AD, Apolipoprotein (Apo) E and ApoJ/Clusterin, are lipoprotein ligands for LRPs. Receptors and ligands mutually influence their intracellular trafficking and thereby the functions and abilities of neurons and the blood-brain-barrier to turn over and remove the pathological product of APP, the amyloid-β peptide. This article will review and summarize the molecular mechanisms that are shared by APP and LRPs and discuss their relative contributions to AD.
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Affiliation(s)
- Theresa Pohlkamp
- Department of Molecular Genetics, UT Southwestern Medical CenterDallas, TX, USA; Center for Translational Neurodegeneration Research, UT Southwestern Medical CenterDallas, TX, USA
| | - Catherine R Wasser
- Department of Molecular Genetics, UT Southwestern Medical CenterDallas, TX, USA; Center for Translational Neurodegeneration Research, UT Southwestern Medical CenterDallas, TX, USA
| | - Joachim Herz
- Department of Molecular Genetics, UT Southwestern Medical CenterDallas, TX, USA; Center for Translational Neurodegeneration Research, UT Southwestern Medical CenterDallas, TX, USA; Department of Neuroscience, UT Southwestern Medical CenterDallas, TX, USA; Department of Neurology and Neurotherapeutics, UT Southwestern Medical CenterDallas, TX, USA
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8
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Dean KM, Roudot P, Welf ES, Pohlkamp T, Garrelts G, Herz J, Fiolka R. Imaging Subcellular Dynamics with Fast and Light-Efficient Volumetrically Parallelized Microscopy. Optica 2017; 4:263-271. [PMID: 28944279 PMCID: PMC5609504 DOI: 10.1364/optica.4.000263] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
In fluorescence microscopy, the serial acquisition of 2D images to form a 3D volume limits the maximum imaging speed. This is particularly evident when imaging adherent cells in a light-sheet fluorescence microscopy format, as their elongated morphologies require ~200 image planes per image volume. Here, by illuminating the specimen with three light-sheets, each independently detected, we present a light-efficient, crosstalk free, and volumetrically parallelized 3D microscopy technique that is optimized for high-speed (up to 14 Hz) subcellular (300 nm lateral, 600 nm axial resolution) imaging of adherent cells. We demonstrate 3D imaging of intracellular processes, including cytoskeletal dynamics in single cell migration and collective wound healing for 1500 and 1000 time points, respectively. Further, we capture rapid biological processes, including trafficking of early endosomes with velocities exceeding 10 microns per second and calcium signaling in primary neurons.
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Affiliation(s)
- Kevin M. Dean
- Department of Cell Biology. UT Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, Texas, United States of America
- Lyda Hill Department of Bioinformatics. UT Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, Texas, United States of America
| | - Philippe Roudot
- Department of Cell Biology. UT Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, Texas, United States of America
- Lyda Hill Department of Bioinformatics. UT Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, Texas, United States of America
| | - Erik S. Welf
- Department of Cell Biology. UT Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, Texas, United States of America
- Lyda Hill Department of Bioinformatics. UT Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, Texas, United States of America
| | - Theresa Pohlkamp
- Department of Molecular Genetics. UT Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, Texas, United States of America
| | - Gerard Garrelts
- Coleman Technologies. 5131 West Chester Pike, Newtown Square, Pennsylvania, United States of America
| | - Joachim Herz
- Department of Molecular Genetics. UT Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, Texas, United States of America
| | - Reto Fiolka
- Department of Cell Biology. UT Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, Texas, United States of America
- Corresponding author:
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Pohlkamp T, Xiao L, Sultana R, Bepari A, Bock HH, Henkemeyer M, Herz J. Ephrin Bs and canonical Reelin signalling. Nature 2016; 539:E4-E6. [PMID: 27882975 DOI: 10.1038/nature20129] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 09/20/2016] [Indexed: 01/08/2023]
Affiliation(s)
- Theresa Pohlkamp
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Lei Xiao
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Rukhsana Sultana
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Asim Bepari
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Hans H Bock
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Mark Henkemeyer
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Gastroenterology, Hepatology and Infectious Diseases, Heinrich Heine University, Düsseldorf 40225, Germany
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Lane-Donovan C, Desai C, Pohlkamp T, Plautz EJ, Herz J, Stowe AM. Physiologic Reelin does not play a strong role in protection against acute stroke. J Cereb Blood Flow Metab 2016; 36:1295-303. [PMID: 27146512 PMCID: PMC4929708 DOI: 10.1177/0271678x16646386] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 03/25/2016] [Indexed: 11/17/2022]
Abstract
Stroke and Alzheimer's disease, two diseases that disproportionately affect the aging population, share a subset of pathological findings and risk factors. The primary genetic risk factor after age for late-onset Alzheimer's disease, ApoE4, has also been shown to increase stroke risk and the incidence of post-stroke dementia. One mechanism by which ApoE4 contributes to disease is by inducing in neurons a resistance to Reelin, a neuromodulator that enhances synaptic function. Previous studies in Reelin knockout mice suggest a role for Reelin in protection against stroke; however, these studies were limited by the developmental requirement for Reelin in neuronal migration. To address the question of the effect of Reelin loss on stroke susceptibility in an architecturally normal brain, we utilized a novel mouse with induced genetic reduction of Reelin. We found that after transient middle cerebral artery occlusion, mice with complete adult loss of Reelin exhibited a similar level of functional deficit and extent of infarct as control mice. Together, these results suggest that physiological Reelin does not play a strong role in protection against stroke pathology.
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Affiliation(s)
- Courtney Lane-Donovan
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA Center for Translational Neurodegeneration Research, Dallas, TX, USA
| | - Charisma Desai
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Theresa Pohlkamp
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA Center for Translational Neurodegeneration Research, Dallas, TX, USA
| | - Erik J Plautz
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA Center for Translational Neurodegeneration Research, Dallas, TX, USA Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, Freiburg, Germany
| | - Ann M Stowe
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA
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11
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Lane-Donovan C, Philips GT, Wasser CR, Durakoglugil MS, Masiulis I, Upadhaya A, Pohlkamp T, Coskun C, Kotti T, Steller L, Hammer RE, Frotscher M, Bock HH, Herz J. Reelin protects against amyloid β toxicity in vivo. Sci Signal 2015; 8:ra67. [PMID: 26152694 DOI: 10.1126/scisignal.aaa6674] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease (AD) is a currently incurable neurodegenerative disorder and is the most common form of dementia in people over the age of 65 years. The predominant genetic risk factor for AD is the ε4 allele encoding apolipoprotein E (ApoE4). The secreted glycoprotein Reelin enhances synaptic plasticity by binding to the multifunctional ApoE receptors apolipoprotein E receptor 2 (Apoer2) and very low density lipoprotein receptor (Vldlr). We have previously shown that the presence of ApoE4 renders neurons unresponsive to Reelin by impairing the recycling of the receptors, thereby decreasing its protective effects against amyloid β (Aβ) oligomer-induced synaptic toxicity in vitro. We showed that when Reelin was knocked out in adult mice, these mice behaved normally without overt learning or memory deficits. However, they were strikingly sensitive to amyloid-induced synaptic suppression and had profound memory and learning disabilities with very low amounts of amyloid deposition. Our findings highlight the physiological importance of Reelin in protecting the brain against Aβ-induced synaptic dysfunction and memory impairment.
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Affiliation(s)
- Courtney Lane-Donovan
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Gary T Philips
- Center for Neural Science, New York University, New York, NY 10003, USA
| | - Catherine R Wasser
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Murat S Durakoglugil
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Irene Masiulis
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Ajeet Upadhaya
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Theresa Pohlkamp
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, Freiburg 79085, Germany
| | - Cagil Coskun
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Tiina Kotti
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Laura Steller
- Institute for Structural Neurobiology, Center for Molecular Neurobiology, Hamburg 20251, Germany
| | - Robert E Hammer
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Michael Frotscher
- Institute for Structural Neurobiology, Center for Molecular Neurobiology, Hamburg 20251, Germany
| | - Hans H Bock
- Clinic for Gastroenterology, Hepatology and Infectiology, Heinrich-Heine-University, Düsseldorf 40225, Germany
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, Freiburg 79085, Germany. Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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12
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Pohlkamp T, Durakoglugil M, Lane-Donovan C, Xian X, Johnson EB, Hammer RE, Herz J. Lrp4 domains differentially regulate limb/brain development and synaptic plasticity. PLoS One 2015; 10:e0116701. [PMID: 25688974 PMCID: PMC4331535 DOI: 10.1371/journal.pone.0116701] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [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: 10/16/2014] [Accepted: 12/14/2014] [Indexed: 01/01/2023] Open
Abstract
Apolipoprotein E (ApoE) genotype is the strongest predictor of Alzheimer’s Disease (AD) risk. ApoE is a cholesterol transport protein that binds to members of the Low-Density Lipoprotein (LDL) Receptor family, which includes LDL Receptor Related Protein 4 (Lrp4). Lrp4, together with one of its ligands Agrin and its co-receptors Muscle Specific Kinase (MuSK) and Amyloid Precursor Protein (APP), regulates neuromuscular junction (NMJ) formation. All four proteins are also expressed in the adult brain, and APP, MuSK, and Agrin are required for normal synapse function in the CNS. Here, we show that Lrp4 is also required for normal hippocampal plasticity. In contrast to the closely related Lrp8/Apoer2, the intracellular domain of Lrp4 does not appear to be necessary for normal expression and maintenance of long-term potentiation at central synapses or for the formation and maintenance of peripheral NMJs. However, it does play a role in limb development.
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Affiliation(s)
- Theresa Pohlkamp
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
- * E-mail: (TP); (JH)
| | - Murat Durakoglugil
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
| | - Courtney Lane-Donovan
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
| | - Xunde Xian
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
| | - Eric B. Johnson
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
| | - Robert E. Hammer
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
- Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, Texas, 75390, United States of America
- * E-mail: (TP); (JH)
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13
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Pohlkamp T, Steller L, May P, Günther T, Schüle R, Frotscher M, Herz J, Bock HH. Generation and characterization of an Nse-CreERT2 transgenic line suitable for inducible gene manipulation in cerebellar granule cells. PLoS One 2014; 9:e100384. [PMID: 24950299 PMCID: PMC4065071 DOI: 10.1371/journal.pone.0100384] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [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: 12/20/2013] [Accepted: 05/27/2014] [Indexed: 12/15/2022] Open
Abstract
We created an Nse-CreERT2 mouse line expressing the tamoxifen-inducible CreERT2 recombinase under the control of the neuron-specific enolase (Nse) promoter. By using Cre reporter lines we could show that this Nse-CreERT2 line has recombination activity in the granule cells of all cerebellar lobules as well as in postmitotic granule cell precursors in the external granular layer of the developing cerebellum. A few hippocampal dentate gyrus granule cells showed Cre-mediated recombination as well. Cre activity could be induced in both the developing and adult mouse brain. The established mouse line constitutes a valuable tool to study the function of genes expressed by cerebellar granule cells in the developing and adult brain. In combination with reporter lines it is a useful model to analyze the development and maintenance of the cerebellar architecture including granule cell distribution, migration, and the extension of granule cell fibers in vivo.
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Affiliation(s)
- Theresa Pohlkamp
- Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, Freiburg, Germany
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- * E-mail: (TP); (JH); (HHB)
| | - Laura Steller
- Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, Freiburg, Germany
| | - Petra May
- Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, Freiburg, Germany
- Clinic for Gastroenterology, Hepatology and Infectiology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Thomas Günther
- Department of Urology, University Hospital Freiburg, Freiburg, Germany
| | - Roland Schüle
- Department of Urology, University Hospital Freiburg, Freiburg, Germany
| | - Michael Frotscher
- Institute for Structural Neurobiology, Center for Molecular Neurobiology, Hamburg, Germany
| | - Joachim Herz
- Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, Freiburg, Germany
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- * E-mail: (TP); (JH); (HHB)
| | - Hans H. Bock
- Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, Freiburg, Germany
- Clinic for Gastroenterology, Hepatology and Infectiology, Heinrich-Heine-University, Düsseldorf, Germany
- * E-mail: (TP); (JH); (HHB)
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Pohlkamp T, Dávid C, Cauli B, Gallopin T, Bouché E, Karagiannis A, May P, Herz J, Frotscher M, Staiger JF, Bock HH. Characterization and distribution of Reelin-positive interneuron subtypes in the rat barrel cortex. ACTA ACUST UNITED AC 2013; 24:3046-58. [PMID: 23803971 DOI: 10.1093/cercor/bht161] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [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: 12/17/2022]
Abstract
GABAergic inhibitory interneurons (IN) represent a heterogeneous population with different electrophysiological, morphological, and molecular properties. The correct balance between interneuronal subtypes is important for brain function and is impaired in several neurological and psychiatric disorders. Here we show the data of 123 molecularly and electrophysiologically characterized neurons of juvenile rat barrel cortex acute slices, 48 of which expressed Reelin (Reln). Reln mRNA was exclusively detected in Gad65/67-positive cells but was found in interneuronal subtypes in different proportions: all cells of the adapting-Somatostatin (SST) cluster expressed Reln, whereas 63% of the adapting-neuropeptide Y (NPY, 50% of the fast-spiking Parvalbumin (PVALB), and 27% of the adapting/bursting-Vasoactive Intestinal Peptide (VIP) cluster were Reln-positive. Silhouette analysis revealed a high impact of the parameter Reln on cluster quality. By analyzing the co-localization of RELN immunoreactivity with those of different IN-markers, we found that RELN is produced layer-independently in SST-, NPY-, and NOS1-expressing INs, whereas co-localization of RELN and VIP was mostly absent. Of note, RELN co-localized with PVALB, predominantly in INs of layers IV/V (>30%). Our findings emphasize RELN's role as an important IN-marker protein and provide a basis for the functional characterization of Reln-expressing INs and its role in the regulation of inhibitory IN networks.
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Affiliation(s)
- Theresa Pohlkamp
- Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, D79104 Freiburg, Germany Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | - Csaba Dávid
- Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, D79104 Freiburg, Germany Department of Human Morphology and Developmental Biology, Semmelweis University, H1094 Budapest, Hungary
| | - Bruno Cauli
- Neurobiologie des Processus Adaptatifs, CNRS UMR7102, Université Pierre et Marie Curie, F75005 Paris, France
| | - Thierry Gallopin
- Laboratoire de Neurobiologie, CNRS UMR7637, Ecole Supérieure de Physique et de Chimie Industrielles de Paris, F75005 Paris, France
| | - Elisabeth Bouché
- Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, D79104 Freiburg, Germany
| | - Anastassios Karagiannis
- Neurobiologie des Processus Adaptatifs, CNRS UMR7102, Université Pierre et Marie Curie, F75005 Paris, France
| | - Petra May
- Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, D79104 Freiburg, Germany Clinic for Gastroenterology, Hepatology and Infectiology, Heinrich-Heine-University, D40225 Düsseldorf, Germany
| | - Joachim Herz
- Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, D79104 Freiburg, Germany Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75235, USA
| | - Michael Frotscher
- Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, D79104 Freiburg, Germany Institute for Structural Neurobiology, Center for Molecular Neurobiology, D20251 Hamburg, Germany and
| | - Jochen F Staiger
- Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, D79104 Freiburg, Germany Institute for Neuroanatomy, UMG, Georg-August-University, D37075 Göttingen, Germany
| | - Hans H Bock
- Center for Neuroscience, Department of Neuroanatomy, Albert-Ludwigs-University, D79104 Freiburg, Germany Clinic for Gastroenterology, Hepatology and Infectiology, Heinrich-Heine-University, D40225 Düsseldorf, Germany
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Chlench S, Mecha Disassa N, Hohberg M, Hoffmann C, Pohlkamp T, Beyer G, Bongrazio M, Da Silva-Azevedo L, Baum O, Pries AR, Zakrzewicz A. Regulation of Foxo-1 and the angiopoietin-2/Tie2 system by shear stress. FEBS Lett 2007; 581:673-80. [PMID: 17258205 DOI: 10.1016/j.febslet.2007.01.028] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Revised: 12/20/2006] [Accepted: 01/12/2007] [Indexed: 11/30/2022]
Abstract
Transcription factor Foxo-1 can be inactivated via Akt-mediated phosphorylation. Since shear stress activates Akt, we determined whether Foxo-1 and the Foxo-1-dependent, angiogenesis-related Ang-2/Tie2-system are influenced by shear stress in endothelial cells. Expression of Foxo-1 and its target genes p27Kip1 and Ang-2 was decreased under shear stress (6dyn/cm(2), 24h), nuclear exclusion of Foxo-1 by phosphorylation increased. eNOS and Tie2 were upregulated. No effects on Ang-1 expression were detected. In conclusion, Foxo-1 and Ang-2/Tie2 are part of the molecular response to shear stress, which may regulate angiogenesis.
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Affiliation(s)
- Sven Chlench
- Charité, Campus Benjamin Franklin, Institute of Physiology, Arnimallee 22, 14195 Berlin, Germany
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