1
|
Božić M, Pirnat S, Fink K, Potokar M, Kreft M, Zorec R, Stenovec M. Ketamine Reduces the Surface Density of the Astroglial Kir4.1 Channel and Inhibits Voltage-Activated Currents in a Manner Similar to the Action of Ba 2+ on K + Currents. Cells 2023; 12:1360. [PMID: 37408194 DOI: 10.3390/cells12101360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 07/07/2023] Open
Abstract
A single sub-anesthetic dose of ketamine evokes rapid and long-lasting beneficial effects in patients with a major depressive disorder. However, the mechanisms underlying this effect are unknown. It has been proposed that astrocyte dysregulation of extracellular K+ concentration ([K+]o) alters neuronal excitability, thus contributing to depression. We examined how ketamine affects inwardly rectifying K+ channel Kir4.1, the principal regulator of K+ buffering and neuronal excitability in the brain. Cultured rat cortical astrocytes were transfected with plasmid-encoding fluorescently tagged Kir4.1 (Kir4.1-EGFP) to monitor the mobility of Kir4.1-EGFP vesicles at rest and after ketamine treatment (2.5 or 25 µM). Short-term (30 min) ketamine treatment reduced the mobility of Kir4.1-EGFP vesicles compared with the vehicle-treated controls (p < 0.05). Astrocyte treatment (24 h) with dbcAMP (dibutyryl cyclic adenosine 5'-monophosphate, 1 mM) or [K+]o (15 mM), which increases intracellular cAMP, mimicked the ketamine-evoked reduction of mobility. Live cell immunolabelling and patch-clamp measurements in cultured mouse astrocytes revealed that short-term ketamine treatment reduced the surface density of Kir4.1 and inhibited voltage-activated currents similar to Ba2+ (300 µM), a Kir4.1 blocker. Thus, ketamine attenuates Kir4.1 vesicle mobility, likely via a cAMP-dependent mechanism, reduces Kir4.1 surface density, and inhibits voltage-activated currents similar to Ba2+, known to block Kir4.1 channels.
Collapse
Affiliation(s)
- Mićo Božić
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
- Department of Medical Oncology, Institute of Oncology Ljubljana, Zaloška 2, 1000 Ljubljana, Slovenia
| | - Samo Pirnat
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
- Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia
| | - Katja Fink
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
| | - Maja Potokar
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
- Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia
| | - Marko Kreft
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
- Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
- Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia
| | - Matjaž Stenovec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
- Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia
| |
Collapse
|
2
|
Gonçalves PP, Stenovec M, Grácio L, Kreft M, Zorec R. Calcium-dependent subquantal peptide release from single docked lawn-resident vesicles of pituitary lactotrophs. Cell Calcium 2023; 109:102687. [PMID: 36528978 DOI: 10.1016/j.ceca.2022.102687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/08/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022]
Abstract
Regulated exocytosis consists of the fusion between vesicles and the plasma membranes, leading to the formation of a narrow fusion pore through which secretions exit the vesicle lumen into the extracellular space. An increase in the cytosolic concentration of free Ca2+ ([Ca2+]i) is considered the stimulus of this process. However, whether this mechanism can be preserved in a simplified system of membrane lawns with docked secretory vesicles, devoid of cellular components, is poorly understood. Here, we studied peptide discharge from individual secretory vesicles docked at the plasma membrane, prepared from primary endocrine pituitary cells (the lactotrophs), releasing hormone prolactin. To label secretory vesicles, we transfected lactotrophs to express the fluorescent atrial natriuretic peptide (ANP.emd), previously shown to be expressed in and released from prolactin-containing vesicles. We used stimulating solutions containing different [Ca2+] to evoke vesicle peptide discharge, which appeared similar in membrane lawns and in intact stimulated lactotrophs. All vesicles examined discharged peptides in a subquantal manner, either exhibiting a unitary or sequential time course. In the membrane lawns, the unitary vesicle peptide discharge was predominant and slightly slower than that recorded in intact cells, but with a shorter delay with respect to the stimulation onset. This study revealed directly that Ca2+ triggers peptide discharge from docked single vesicles in the membrane lawns with a half-maximal response of ∼8 µM [Ca2+], consistent with previous whole-cell patch-clamp studies in endocrine cells where the rapid component of exocytosis, interpreted to represent docked vesicles, was fully activated at <10 µM [Ca2+]. Interestingly, the sequential subquantal peptide vesicle discharge indicates that fluctuations between constricted and dilated fusion pore states are preserved in membrane lawns and that fusion pore regulation appears to be an autonomously controlled process.
Collapse
Affiliation(s)
- Paula P Gonçalves
- CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal
| | - Matjaž Stenovec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Zaloška 4, 1000, Ljubljana, Slovenia; Laboratory of Cell Engineering, Celica Biomedical, Tehnološki Park 24, 1000, Ljubljana, Slovenia
| | - Luciano Grácio
- CRACS & INESC-TEC - Centre for Research in Advanced Computing Systems & Institute for Systems and Computer Engineering, Technology and Science, Department of Computer Science, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Marko Kreft
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Zaloška 4, 1000, Ljubljana, Slovenia; Laboratory of Cell Engineering, Celica Biomedical, Tehnološki Park 24, 1000, Ljubljana, Slovenia; Department of Biology, University of Ljubljana, Biotechnical Faculty, 1000 Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Zaloška 4, 1000, Ljubljana, Slovenia; Laboratory of Cell Engineering, Celica Biomedical, Tehnološki Park 24, 1000, Ljubljana, Slovenia.
| |
Collapse
|
3
|
Škorjanc A, Kreft M, Benda J. Stimulator compensation and generation of Gaussian noise stimuli with defined amplitude spectra for studying input–output relations of sensory systems. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2022; 209:361-372. [PMID: 36527489 DOI: 10.1007/s00359-022-01597-4] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 11/14/2022] [Accepted: 11/17/2022] [Indexed: 12/23/2022]
Abstract
Gaussian noise is an important stimulus for the study of biological systems, especially sensory and neural systems. Since these systems are inherently nonlinear, the properties of the noise strongly influence the outcome of the analysis. Therefore, it is crucial to use a well-defined and controlled noise stimulus. In this paper, we first use the example of an insect filiform sensillum, a simple mechanoreceptor with a single sensory cell, to show that changes in the amplitude and spectral properties of the noise stimulus indeed affect the linear transfer function of the sensillum. We then explain step-by-step how to use the inverse fast Fourier transform to generate a Gaussian noise that has an arbitrary user-defined amplitude spectrum, including a band-limited white noise with a perfectly sharp cutoff edge. Finally, we demonstrate how such a perfect band-limited Gaussian white noise stimulus can also be generated with a non-perfect stimulator using a simple procedure that compensates for the filtering properties of the stimulator. With this approach, one can generate well-defined Gaussian noise stimuli that can be adapted to any application. For example, one can generate visual, sound, or vibrational stimuli for experimental research in visual physiology, auditory physiology, and biotremology, as well as inputs for testing various models in theoretical research.
Collapse
Affiliation(s)
- Aleš Škorjanc
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000, Ljubljana, Slovenia.
| | - Marko Kreft
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000, Ljubljana, Slovenia
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
- Laboratory of Cell Engineering, Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia
| | - Jan Benda
- Institute for Neurobiology, Eberhard Karls Universität, 72076, Tübingen, Germany
| |
Collapse
|
4
|
Grilc S, Kreft M, Luzar B, Gabrijel M, Bartenjev MS, Zorec R, Bartenjev I. Histological Skin Remodeling Following Autologous Fibroblast Application. Acta Dermatovenerol Croat 2022; 30:1-7. [PMID: 36153713] [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] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The aim of this study was to quantify the effectiveness of intradermal application of autologous fibroblasts on lean tissue structures. The histological sections of the skin were analysed and evaluated for the expansion potential of autologous fibroblasts in the control skin patch area and the nearby pre-treated skin patch into which we had injected expanded autologous fibroblasts nine month earlier. The results show that the pre-injection of fibroblasts into the dermis leads to a long-term rejuvenation of the skin, as evaluated from the histological appearance and from the significantly increased density of fibroblasts in the pre-injected skin vs. controls, from around 60% to over 80%, determined as the percent of lean tissue by a novel image analysis approach. Interestingly, the rate of the in vitro fibroblast expansion from the pre-injected area of the skin was reduced in comparison with the controls, consistent with the view that fibroblasts exhibit a limited cell-division potential and that fibroblasts from the pre-injected skin already experienced expansion nine month earlier prior to the injection into the skin. We conclude that autologous fibroblast application results in a significant long-term augmentation of the lean tissue elements of the skin.
Collapse
Affiliation(s)
| | | | | | | | | | - Robert Zorec
- Prof. Robert Zorec, MD, PhD, Celica Biomedical, Technology park 24, , 1000 Ljubljana, Slovenia,
| | - Igor Bartenjev
- Prof. Igor Bartenjev, MD, PhD, Dermatology Bartenjev, Ljubljana, Slovenia, Finžgarjeva 4, 1000 Ljubljana, Slovenia,
| |
Collapse
|
5
|
Liu W, Stenovec M, Lee W, Montana V, Kreft M, Zorec R, Parpura V. Probing single molecule mechanical interactions of syntaxin 1A with native synaptobrevin 2 residing on a secretory vesicle. Cell Calcium 2022; 104:102570. [PMID: 35314381 PMCID: PMC9119915 DOI: 10.1016/j.ceca.2022.102570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/04/2022] [Accepted: 03/09/2022] [Indexed: 11/25/2022]
Abstract
Interactive mechanical forces between pairs of individual SNARE proteins synaptobrevin 2 (Sb2) and syntaxin 1A (Sx1A) may be sufficient to mediate vesicle docking. This notion, based on force spectroscopy single molecule measurements probing recombinant Sx1A an Sb2 in silico, questioned a predominant view of docking via the ternary SNARE complex formation, which includes an assembly of the intermediate cis binary complex between Sx1A and SNAP25 on the plasma membrane to engage Sb2 on the vesicle. However, whether a trans binary Sx1A-Sb2 complex alone could mediate vesicle docking in a cellular environment remains unclear. To address this issue, we used atomic force microscopy (AFM) in the force spectroscopy mode combined with fluorescence imaging. Using AFM tips functionalized with the full Sx1A cytosolic domain, we probed native Sb2 studding the membrane of secretory vesicles docked at the plasma membrane patches, referred to as "inside-out lawns", identified based on fluorescence stains and prepared from primary culture of lactotrophs. We recorded single molecule Sx1A-Sb2 mechanical interactions and obtained measurements of force (∼183 pN) and extension (∼21.6 nm) necessary to take apart Sx1A-Sb2 binding interactions formed at tip-vesicle contact. Measured interactive force between a single pair of Sx1A-Sb2 molecules is sufficient to hold a single secretory vesicle docked at the plasma membrane within distances up to that of the measured extension. This finding further advances a notion that native vesicle docking can be mediated by a single trans binary Sx1A-Sb2 complex in the absence of SNAP25.
Collapse
Affiliation(s)
- Wei Liu
- Department of Neurobiology, Atomic Force Microscopy & Nanotechnology Laboratories, The University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - Matjaž Stenovec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, EU, Slovenia
| | - William Lee
- Department of Neurobiology, Atomic Force Microscopy & Nanotechnology Laboratories, The University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - Vedrana Montana
- Department of Neurobiology, Atomic Force Microscopy & Nanotechnology Laboratories, The University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - Marko Kreft
- University of Ljubljana, Biotechnical Faculty, Department of Biology, CPAE, Večna pot 111, 1000 Ljubljana, EU, Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, EU, Slovenia.
| | - Vladimir Parpura
- Department of Neurobiology, Atomic Force Microscopy & Nanotechnology Laboratories, The University of Alabama at Birmingham, Birmingham, AL 35294, United States of America.
| |
Collapse
|
6
|
Rituper B, Guček A, Lisjak M, Gorska U, Šakanović A, Bobnar ST, Lasič E, Božić M, Abbineni PS, Jorgačevski J, Kreft M, Verkhratsky A, Platt FM, Anderluh G, Stenovec M, Božič B, Coorssen JR, Zorec R. Vesicle cholesterol controls exocytotic fusion pore. Cell Calcium 2021; 101:102503. [PMID: 34844123 DOI: 10.1016/j.ceca.2021.102503] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [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: 09/02/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 12/24/2022]
Abstract
In some lysosomal storage diseases (LSD) cholesterol accumulates in vesicles. Whether increased vesicle cholesterol affects vesicle fusion with the plasmalemma, where the fusion pore, a channel between the vesicle lumen and the extracellular space, is formed, is unknown. Super-resolution microscopy revealed that after stimulation of exocytosis, pituitary lactotroph vesicles discharge cholesterol which transfers to the plasmalemma. Cholesterol depletion in lactotrophs and astrocytes, both exhibiting Ca2+-dependent exocytosis regulated by distinct Ca2+sources, evokes vesicle secretion. Although this treatment enhanced cytosolic levels of Ca2+ in lactotrophs but decreased it in astrocytes, this indicates that cholesterol may well directly define the fusion pore. In an attempt to explain this mechanism, a new model of cholesterol-dependent fusion pore regulation is proposed. High-resolution membrane capacitance measurements, used to monitor fusion pore conductance, a parameter related to fusion pore diameter, confirm that at resting conditions reducing cholesterol increases, while enrichment with cholesterol decreases the conductance of the fusion pore. In resting fibroblasts, lacking the Npc1 protein, a cellular model of LSD in which cholesterol accumulates in vesicles, the fusion pore conductance is smaller than in controls, showing that vesicle cholesterol controls fusion pore and is relevant for pathophysiology of LSD.
Collapse
Affiliation(s)
- Boštjan Rituper
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Alenka Guček
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Marjeta Lisjak
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Urszula Gorska
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Aleksandra Šakanović
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Saša Trkov Bobnar
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia; Celica Biomedical, 1000, Ljubljana, Slovenia
| | - Eva Lasič
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Mićo Božić
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Prabhodh S Abbineni
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109-5632, United States of America
| | - Jernej Jorgačevski
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia; Celica Biomedical, 1000, Ljubljana, Slovenia
| | - Marko Kreft
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia; Celica Biomedical, 1000, Ljubljana, Slovenia
| | - Alexei Verkhratsky
- Celica Biomedical, 1000, Ljubljana, Slovenia; Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, United Kingdom; Achucarro Center for Neuroscience, IKERBASQUE, 48011 Bilbao, Spain
| | - Frances M Platt
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, United Kingdom
| | - Gregor Anderluh
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Matjaž Stenovec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia; Celica Biomedical, 1000, Ljubljana, Slovenia
| | - Bojan Božič
- Institute of Biophysics, Faculty of Medicine, University of Ljubljana, Slovenia
| | - Jens R Coorssen
- Department of Health Sciences, Faculty of Applied Health Sciences and Department of Biological Sciences, Faculty of Mathematics & Science, Brock University, St Catherine's, Ontario, Canada
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia; Celica Biomedical, 1000, Ljubljana, Slovenia.
| |
Collapse
|
7
|
Dietz HP, Kreft M, Subramaniam N, Robledo K. Location of obstetric anal sphincter injury scars on translabial tomographic ultrasound. Ultrasound Obstet Gynecol 2021; 58:630-633. [PMID: 34170050 DOI: 10.1002/uog.23719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/19/2021] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
OBJECTIVE Obstetric anal sphincter injury (OASI) is a common preventable cause of anal incontinence. Both diagnosis and primary repair of OASI are often suboptimal, partly owing to the absence of effective clinical audit. The aim of this study was to evaluate the location of scars or defects of the external anal sphincter (EAS), diagnosed by translabial ultrasound (TLUS), following primary OASI repair. METHODS This was a retrospective analysis of 309 women who were seen at a tertiary obstetric unit after primary repair of OASI between June 2012 and May 2019. All women underwent a standardized interview, including St Mark's incontinence score, followed by clinical examination and TLUS assessment within 2-9 months after OASI repair. Postprocessing of TLUS volume datasets was performed by an investigator who was blinded to all other information. Tomographic ultrasound imaging was used to evaluate the presence of a scar or defect in the proximal and distal parts of the EAS. Women were classified into four groups according to the imaging findings: (1) no visible defect or distortion (likely false positive); (2) only proximal OASI; (3) only distal OASI; and (4) both proximal and distal OASI. RESULTS Of the 309 women seen during the study period, 34 were excluded because they were referred for reasons other than recent (< 1 year) OASI, 16 owing to missing data and four owing to poor image quality, leaving 255 patients for analysis. Women were seen on average 0.25 ± 0.1 years after the index birth, and their mean age at delivery was 29.1 ± 4.6 years. Anal incontinence was reported by 97 (38.0%) women. A scar or defect was seen only in the proximal part of the EAS in 64 (25.1%) women and only in the distal part in 19 (7.5%) (P < 0.001). In 165 (64.7%) women, the damage affected both the proximal and distal EAS. CONCLUSIONS EAS scars after primary OASI repair commonly affect the entire length of the EAS; however, partial tears seem to be more likely to occur proximally. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.
Collapse
Affiliation(s)
- H P Dietz
- Sydney Medical School Nepean, University of Sydney, Sydney, NSW, Australia
| | - M Kreft
- Sydney Medical School Nepean, University of Sydney, Sydney, NSW, Australia
| | - N Subramaniam
- Sydney Medical School Nepean, University of Sydney, Sydney, NSW, Australia
| | - K Robledo
- Sydney Medical School Nepean, University of Sydney, Sydney, NSW, Australia
| |
Collapse
|
8
|
Haque Chowdhury H, Hawlina S, Gabrijel M, Trkov Bobnar S, Kreft M, Lenart G, Cukjati M, Kopitar AN, Kejžar N, Ihan A, Ležaič L, Grmek M, Kmetec A, Jeras M, Zorec R. Survival of castration-resistant prostate cancer patients treated with dendritic-tumor cell hybridomas is negatively correlated with changes in peripheral blood CD56 bright CD16 - natural killer cells. Clin Transl Med 2021; 11:e505. [PMID: 34459140 PMCID: PMC8387785 DOI: 10.1002/ctm2.505] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 07/07/2021] [Accepted: 07/12/2021] [Indexed: 01/26/2023] Open
Affiliation(s)
- Helena Haque Chowdhury
- Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Simon Hawlina
- Clinical Department of Urology, University Medical Centre Ljubljana, Ljubljana, Slovenia.,Department of Surgery, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Mateja Gabrijel
- Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Saša Trkov Bobnar
- Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Marko Kreft
- Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,CPAE, Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Gordan Lenart
- Clinical Department of Urology, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Marko Cukjati
- Blood Transfusion Centre of Slovenia, Ljubljana, Slovenia
| | - Andreja Nataša Kopitar
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Nataša Kejžar
- Institute for Biostatistics and Medical Informatics, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Alojz Ihan
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Luka Ležaič
- Department of Nuclear Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia.,Department of Radiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Marko Grmek
- Department of Nuclear Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Andrej Kmetec
- Clinical Department of Urology, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Matjaž Jeras
- Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia.,Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| |
Collapse
|
9
|
D'Adamo P, Horvat A, Gurgone A, Mignogna ML, Bianchi V, Masetti M, Ripamonti M, Taverna S, Velebit J, Malnar M, Muhič M, Fink K, Bachi A, Restuccia U, Belloli S, Moresco RM, Mercalli A, Piemonti L, Potokar M, Bobnar ST, Kreft M, Chowdhury HH, Stenovec M, Vardjan N, Zorec R. Inhibiting glycolysis rescues memory impairment in an intellectual disability Gdi1-null mouse. Metabolism 2021; 116:154463. [PMID: 33309713 PMCID: PMC7871014 DOI: 10.1016/j.metabol.2020.154463] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 11/30/2020] [Accepted: 12/04/2020] [Indexed: 01/08/2023]
Abstract
OBJECTIVES GDI1 gene encodes for αGDI, a protein controlling the cycling of small GTPases, reputed to orchestrate vesicle trafficking. Mutations in human GDI1 are responsible for intellectual disability (ID). In mice with ablated Gdi1, a model of ID, impaired working and associative short-term memory was recorded. This cognitive phenotype worsens if the deletion of αGDI expression is restricted to neurons. However, whether astrocytes, key homeostasis providing neuroglial cells, supporting neurons via aerobic glycolysis, contribute to this cognitive impairment is unclear. METHODS We carried out proteomic analysis and monitored [18F]-fluoro-2-deoxy-d-glucose uptake into brain slices of Gdi1 knockout and wild type control mice. d-Glucose utilization at single astrocyte level was measured by the Förster Resonance Energy Transfer (FRET)-based measurements of cytosolic cyclic AMP, d-glucose and L-lactate, evoked by agonists selective for noradrenaline and L-lactate receptors. To test the role of astrocyte-resident processes in disease phenotype, we generated an inducible Gdi1 knockout mouse carrying the Gdi1 deletion only in adult astrocytes and conducted behavioural tests. RESULTS Proteomic analysis revealed significant changes in astrocyte-resident glycolytic enzymes. Imaging [18F]-fluoro-2-deoxy-d-glucose revealed an increased d-glucose uptake in Gdi1 knockout tissue versus wild type control mice, consistent with the facilitated d-glucose uptake determined by FRET measurements. In mice with Gdi1 deletion restricted to astrocytes, a selective and significant impairment in working memory was recorded, which was rescued by inhibiting glycolysis by 2-deoxy-d-glucose injection. CONCLUSIONS These results reveal a new astrocyte-based mechanism in neurodevelopmental disorders and open a novel therapeutic opportunity of targeting aerobic glycolysis, advocating a change in clinical practice.
Collapse
Affiliation(s)
- Patrizia D'Adamo
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy; University of Ljubljana, Faculty of Medicine, Institute of Pathophysiology, Laboratory of Neuroendocrinology - Molecular Cell Physiology, Ljubljana, Slovenia; Celica Biomedical, Laboratory for Cell Engineering, Ljubljana, Slovenia.
| | - Anemari Horvat
- University of Ljubljana, Faculty of Medicine, Institute of Pathophysiology, Laboratory of Neuroendocrinology - Molecular Cell Physiology, Ljubljana, Slovenia; Celica Biomedical, Laboratory for Cell Engineering, Ljubljana, Slovenia
| | - Antonia Gurgone
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | | | - Veronica Bianchi
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Michela Masetti
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Maddalena Ripamonti
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Stefano Taverna
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Jelena Velebit
- University of Ljubljana, Faculty of Medicine, Institute of Pathophysiology, Laboratory of Neuroendocrinology - Molecular Cell Physiology, Ljubljana, Slovenia; Celica Biomedical, Laboratory for Cell Engineering, Ljubljana, Slovenia
| | - Maja Malnar
- University of Ljubljana, Faculty of Medicine, Institute of Pathophysiology, Laboratory of Neuroendocrinology - Molecular Cell Physiology, Ljubljana, Slovenia
| | - Marko Muhič
- University of Ljubljana, Faculty of Medicine, Institute of Pathophysiology, Laboratory of Neuroendocrinology - Molecular Cell Physiology, Ljubljana, Slovenia
| | - Katja Fink
- University of Ljubljana, Faculty of Medicine, Institute of Pathophysiology, Laboratory of Neuroendocrinology - Molecular Cell Physiology, Ljubljana, Slovenia
| | - Angela Bachi
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy
| | | | - Sara Belloli
- Institute of Bioimaging and Physiology, CNR, Segrate (MI), Italy; Experimental Imaging Center (EIC), San Raffaele Scientific Institute, Milan, Italy
| | - Rosa Maria Moresco
- Experimental Imaging Center (EIC), San Raffaele Scientific Institute, Milan, Italy; Medicine and Surgery Department, University of Milano-Bicocca, Monza (MB), Italy
| | - Alessia Mercalli
- Diabetes Research Institute, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Lorenzo Piemonti
- Diabetes Research Institute, IRCCS Ospedale San Raffaele, Milano, Italy; Università Vita-Salute San Raffaele, Milano, Italy
| | - Maja Potokar
- University of Ljubljana, Faculty of Medicine, Institute of Pathophysiology, Laboratory of Neuroendocrinology - Molecular Cell Physiology, Ljubljana, Slovenia; Celica Biomedical, Laboratory for Cell Engineering, Ljubljana, Slovenia
| | - Saša Trkov Bobnar
- University of Ljubljana, Faculty of Medicine, Institute of Pathophysiology, Laboratory of Neuroendocrinology - Molecular Cell Physiology, Ljubljana, Slovenia; Celica Biomedical, Laboratory for Cell Engineering, Ljubljana, Slovenia
| | - Marko Kreft
- University of Ljubljana, Faculty of Medicine, Institute of Pathophysiology, Laboratory of Neuroendocrinology - Molecular Cell Physiology, Ljubljana, Slovenia; Celica Biomedical, Laboratory for Cell Engineering, Ljubljana, Slovenia; University of Ljubljana, Biotechnical Faculty, Department of Biology, Ljubljana, Slovenia
| | - Helena H Chowdhury
- University of Ljubljana, Faculty of Medicine, Institute of Pathophysiology, Laboratory of Neuroendocrinology - Molecular Cell Physiology, Ljubljana, Slovenia; Celica Biomedical, Laboratory for Cell Engineering, Ljubljana, Slovenia
| | - Matjaž Stenovec
- University of Ljubljana, Faculty of Medicine, Institute of Pathophysiology, Laboratory of Neuroendocrinology - Molecular Cell Physiology, Ljubljana, Slovenia; Celica Biomedical, Laboratory for Cell Engineering, Ljubljana, Slovenia
| | - Nina Vardjan
- University of Ljubljana, Faculty of Medicine, Institute of Pathophysiology, Laboratory of Neuroendocrinology - Molecular Cell Physiology, Ljubljana, Slovenia; Celica Biomedical, Laboratory for Cell Engineering, Ljubljana, Slovenia.
| | - Robert Zorec
- University of Ljubljana, Faculty of Medicine, Institute of Pathophysiology, Laboratory of Neuroendocrinology - Molecular Cell Physiology, Ljubljana, Slovenia; Celica Biomedical, Laboratory for Cell Engineering, Ljubljana, Slovenia.
| |
Collapse
|
10
|
Hawlina S, Chowdhury H, Gabrijel M, Trkov Bobnar S, Kreft M, Lenart G, Cukjati M, Kopitar A, Ihan A, Ležaić L, Gamek M, Kmetec A, Jeras M, Zorec R. 4P Immunohybridoma cell-based vaccine for the treatment of patients with castration-resistant prostate cancer. Ann Oncol 2021. [DOI: 10.1016/j.annonc.2021.01.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|
11
|
Horvat A, Muhič M, Smolič T, Begić E, Zorec R, Kreft M, Vardjan N. Ca 2+ as the prime trigger of aerobic glycolysis in astrocytes. Cell Calcium 2021; 95:102368. [PMID: 33621899 DOI: 10.1016/j.ceca.2021.102368] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 02/05/2021] [Accepted: 02/08/2021] [Indexed: 12/17/2022]
Abstract
Astroglial aerobic glycolysis, a process during which d-glucose is converted to l-lactate, a brain fuel and signal, is regulated by the plasmalemmal receptors, including adrenergic receptors (ARs) and purinergic receptors (PRs), modulating intracellular Ca2+ and cAMP signals. However, the extent to which the two signals regulate astroglial aerobic glycolysis is poorly understood. By using agonists to stimulate intracellular α1-/β-AR-mediated Ca2+/cAMP signals, β-AR-mediated cAMP and P2R-mediated Ca2+ signals and genetically encoded fluorescence resonance energy transfer-based glucose and lactate nanosensors in combination with real-time microscopy, we show that intracellular Ca2+, but not cAMP, initiates a robust increase in the concentration of intracellular free d-glucose ([glc]i) and l-lactate ([lac]i), both depending on extracellular d-glucose, suggesting Ca2+-triggered glucose uptake and aerobic glycolysis in astrocytes. When the glycogen shunt, a process of glycogen remodelling, was inhibited, the α1-/β-AR-mediated increases in [glc]i and [lac]i were reduced by ∼65 % and ∼30 %, respectively, indicating that at least ∼30 % of the utilization of d-glucose is linked to glycogen remodelling and aerobic glycolysis. Additional activation of β-AR/cAMP signals aided to α1-/β-AR-triggered [lac]i increase, whereas the [glc]i increase was unaltered. Taken together, an increase in intracellular Ca2+ is the prime mechanism of augmented aerobic glycolysis in astrocytes, while cAMP has only a moderate role. The results provide novel information on the signals regulating brain metabolism and open new avenues to explore whether astroglial Ca2+ signals are dysregulated and contribute to neuropathologies with impaired brain metabolism.
Collapse
Affiliation(s)
- Anemari Horvat
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia; Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
| | - Marko Muhič
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Tina Smolič
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Ena Begić
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia; Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
| | - Marko Kreft
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia; Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia; Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Nina Vardjan
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia; Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia.
| |
Collapse
|
12
|
Fink K, Velebit J, Vardjan N, Zorec R, Kreft M. Noradrenaline-induced l-lactate production requires d-glucose entry and transit through the glycogen shunt in single-cultured rat astrocytes. J Neurosci Res 2021; 99:1084-1098. [PMID: 33491223 DOI: 10.1002/jnr.24783] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [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: 11/19/2020] [Revised: 12/07/2020] [Accepted: 12/10/2020] [Indexed: 12/21/2022]
Abstract
During cognitive efforts mediated by local neuronal networks, approximately 20% of additional energy is required; this is mediated by chemical messengers such as noradrenaline (NA). NA targets astroglial aerobic glycolysis, the hallmark of which is the end product l-lactate, a fuel for neurons. Biochemical studies have revealed that astrocytes exhibit a prominent glycogen shunt, in which a portion of d-glucose molecules entering the cytoplasm is transiently incorporated into glycogen, a buffer and source of d-glucose during increased energy demand. Here, we studied single astrocytes by measuring cytosolic L-lactate ([lac]i ) with the FRET nanosensor Laconic. We examined whether NA-induced increase in [lac]i is influenced by: (a) 2-deoxy-d-glucose (2-DG, 3 mM), a molecule that enters the cytosol and inhibits the glycolytic pathway; (b) 1,4-dideoxy-1,4-imino-d-arabinitol (DAB, 300 µM), a potent inhibitor of glycogen phosphorylase and glycogen degradation; and (c) 3-nitropropionic acid (3-NPA, 1 mM), an inhibitor of the Krebs cycle. The results of these pharmacological experiments revealed that d-glucose uptake is essential for the NA-induced increase in [lac]i , and that this exclusively arises from glycogen degradation, indicating that most, if not all, d-glucose molecules in NA-stimulated cells transit the glycogen shunt during glycolysis. Moreover, under the defined transmembrane d-glucose gradient, the glycolytic intermediates were not only used to produce l-lactate, but also to significantly support oxidative phosphorylation, as demonstrated by an elevation in [lac]i when Krebs cycle was inhibited. We conclude that l-lactate production via aerobic glycolysis is an essential energy pathway in NA-stimulated astrocytes; however, oxidative metabolism is important at rest.
Collapse
Affiliation(s)
- Katja Fink
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
| | - Jelena Velebit
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia.,Celica Biomedical, Ljubljana, Slovenia
| | - Nina Vardjan
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia.,Celica Biomedical, Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia.,Celica Biomedical, Ljubljana, Slovenia
| | - Marko Kreft
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia.,Celica Biomedical, Ljubljana, Slovenia.,Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| |
Collapse
|
13
|
Birri J, Kreft M, Zimmermann R, Kimmich N. Assoziation zwischen der betroffenen Seite der Levatormuskelverletzung und der fetalen Position bei Geburt – eine prospektive Observationsstudie. Geburtshilfe Frauenheilkd 2020. [DOI: 10.1055/s-0040-1717900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Affiliation(s)
- J Birri
- Universitätsspital Zürich, Klinik für Geburtshilfe
| | - M Kreft
- Universitätsspital Zürich, Klinik für Geburtshilfe
| | - R Zimmermann
- Universitätsspital Zürich, Klinik für Geburtshilfe
| | - N Kimmich
- Universitätsspital Zürich, Klinik für Geburtshilfe
| |
Collapse
|
14
|
Richter A, Birri J, Kreft M, Zimmermann R, Kimmich N. Prädiktion von Levatoravulsionen anhand sichtbarer Geburtsverletzungen – eine prospektive Kohortenstudie. Geburtshilfe Frauenheilkd 2020. [DOI: 10.1055/s-0040-1717964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Affiliation(s)
- A Richter
- Universitätsspital Zürich, Klinik für Geburtshilfe
| | - J Birri
- Universitätsspital Zürich, Klinik für Geburtshilfe
| | - M Kreft
- Universitätsspital Zürich, Klinik für Geburtshilfe
| | - R Zimmermann
- Universitätsspital Zürich, Klinik für Geburtshilfe
| | - N Kimmich
- Universitätsspital Zürich, Klinik für Geburtshilfe
| |
Collapse
|
15
|
Kimmich N, Birri J, Kreft M, Zimmermann R. Assoziation zwischen Levatoravulsionen und der technischen Ausführung von Vakuumextraktionen – eine prospektive Observationsstudie. Geburtshilfe Frauenheilkd 2020. [DOI: 10.1055/s-0040-1717941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Affiliation(s)
- N Kimmich
- Universitätsspital Zürich, Klinik für Geburtshilfe
| | - J Birri
- Universitätsspital Zürich, Klinik für Geburtshilfe
| | - M Kreft
- Universitätsspital Zürich, Klinik für Geburtshilfe
| | - R Zimmermann
- Universitätsspital Zürich, Klinik für Geburtshilfe
| |
Collapse
|
16
|
Meglič A, Ilić M, Pirih P, Škorjanc A, Wehling MF, Kreft M, Belušič G. Horsefly object-directed polarotaxis is mediated by a stochastically distributed ommatidial subtype in the ventral retina. Proc Natl Acad Sci U S A 2019; 116:21843-21853. [PMID: 31591223 PMCID: PMC6815168 DOI: 10.1073/pnas.1910807116] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The ventral compound eye of many insects contains polarization-sensitive photoreceptors, but little is known about how they are integrated into visual functions. In female horseflies, polarized reflections from animal fur are a key stimulus for host detection. To understand how polarization vision is mediated by the ventral compound eye, we investigated the band-eyed brown horsefly Tabanus bromius using anatomical, physiological, and behavioral approaches. Serial electron microscopic sectioning of the retina and single-cell recordings were used to determine the spectral and polarization sensitivity (PS) of photoreceptors. We found 2 stochastically distributed subtypes of ommatidia, analogous to pale and yellow of other flies. Importantly, the pale analog contains an orthogonal analyzer receptor pair with high PS, formed by an ultraviolet (UV)-sensitive R7 and a UV- and blue-sensitive R8, while the UV-sensitive R7 and green-sensitive R8 in the yellow analog always have low PS. We tested horsefly polarotaxis in the field, using lures with controlled spectral and polarization composition. Polarized reflections without UV and blue components rendered the lures unattractive, while reflections without the green component increased their attractiveness. This is consistent with polarotaxis being guided by a differential signal from polarization analyzers in the pale analogs, and with an inhibitory role of the yellow analogs. Our results reveal how stochastically distributed sensory units with modality-specific division of labor serve as separate and opposing input channels for visual guidance.
Collapse
Affiliation(s)
- Andrej Meglič
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Marko Ilić
- Laboratory of Neuroethology, Sokendai - The Graduate University for Advanced Studies, 240-0193 Hayama, Japan
| | - Primož Pirih
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Aleš Škorjanc
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Martin F Wehling
- Nature-inspired Team, Sensor and Imaging Sciences Branch, Air Force Research Laboratory, Eglin Air Force Base, FL 32542
| | - Marko Kreft
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
- Celica Biomedical, 1000 Ljubljana, Slovenia
| | - Gregor Belušič
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia;
| |
Collapse
|
17
|
Stenovec M, Lasič E, Pužar Dominkuš P, Bobnar ST, Zorec R, Lenassi M, Kreft M. Correction to: Slow Release of HIV-1 Protein Nef from Vesicle-like Structures Is Inhibited by Cytosolic Calcium Elevation in Single Human Microglia. Mol Neurobiol 2019; 56:6668. [PMID: 31332764 DOI: 10.1007/s12035-019-01709-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The original version of this article unfortunately contained a mistake in Author name. In Pia Pužar Dominkuš, "Pužar" should be classified as Familyname.
Collapse
Affiliation(s)
- Matjaž Stenovec
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
| | - Eva Lasič
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
| | - Pia Pužar Dominkuš
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000, Ljubljana, Slovenia
| | - Saša Trkov Bobnar
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
| | - Robert Zorec
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia. .,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia.
| | - Metka Lenassi
- Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000, Ljubljana, Slovenia.
| | - Marko Kreft
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia. .,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia. .,CPAE, Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000, Ljubljana, Slovenia.
| |
Collapse
|
18
|
Morita M, Ikeshima-Kataoka H, Kreft M, Vardjan N, Zorec R, Noda M. Metabolic Plasticity of Astrocytes and Aging of the Brain. Int J Mol Sci 2019; 20:ijms20040941. [PMID: 30795555 PMCID: PMC6413111 DOI: 10.3390/ijms20040941] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 02/17/2019] [Accepted: 02/18/2019] [Indexed: 01/03/2023] Open
Abstract
As part of the blood-brain-barrier, astrocytes are ideally positioned between cerebral vasculature and neuronal synapses to mediate nutrient uptake from the systemic circulation. In addition, astrocytes have a robust enzymatic capacity of glycolysis, glycogenesis and lipid metabolism, managing nutrient support in the brain parenchyma for neuronal consumption. Here, we review the plasticity of astrocyte energy metabolism under physiologic and pathologic conditions, highlighting age-dependent brain dysfunctions. In astrocytes, glycolysis and glycogenesis are regulated by noradrenaline and insulin, respectively, while mitochondrial ATP production and fatty acid oxidation are influenced by the thyroid hormone. These regulations are essential for maintaining normal brain activities, and impairments of these processes may lead to neurodegeneration and cognitive decline. Metabolic plasticity is also associated with (re)activation of astrocytes, a process associated with pathologic events. It is likely that the recently described neurodegenerative and neuroprotective subpopulations of reactive astrocytes metabolize distinct energy substrates, and that this preference is supposed to explain some of their impacts on pathologic processes. Importantly, physiologic and pathologic properties of astrocytic metabolic plasticity bear translational potential in defining new potential diagnostic biomarkers and novel therapeutic targets to mitigate neurodegeneration and age-related brain dysfunctions.
Collapse
Affiliation(s)
- Mitsuhiro Morita
- Department of Biology, Graduate School of Sciences, Kobe University, 657-8501 Kobe, Japan.
| | - Hiroko Ikeshima-Kataoka
- Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.
| | - Marko Kreft
- Laboratory of Cell Engineering, Celica Biomedical, 1000 Ljubljana, Slovenia.
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia.
- Department of Biology, Biotechnical Faculty University of Ljubljana, 1000 Ljubljana, Slovenia.
| | - Nina Vardjan
- Laboratory of Cell Engineering, Celica Biomedical, 1000 Ljubljana, Slovenia.
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia.
| | - Robert Zorec
- Laboratory of Cell Engineering, Celica Biomedical, 1000 Ljubljana, Slovenia.
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia.
| | - Mami Noda
- Laboratory of Pathophysiology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
| |
Collapse
|
19
|
Stenovec M, Trkov Bobnar S, Smolič T, Kreft M, Parpura V, Zorec R. Presenilin PS1∆E9 disrupts mobility of secretory organelles in rat astrocytes. Acta Physiol (Oxf) 2018; 223:e13046. [PMID: 29392878 DOI: 10.1111/apha.13046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 01/17/2018] [Accepted: 01/25/2018] [Indexed: 12/14/2022]
Abstract
AIM Alzheimer's disease (AD) is largely considered a neuron-derived insult, but also involves failure of astroglia. A recent study indicated that mutated presenilin 1 (PS1M146V), a putative endoplasmic reticulum (ER) Ca2+ channel with decreased Ca2+ conductance, impairs the traffic of astroglial peptidergic vesicles. Whether other pathogenically relevant PS1 mutants, such as PS1ΔE9, which code for ER channel with putative increased Ca2+ conductance, similarly affect vesicle traffic, is unknown. METHODS Here, we cotransfected rat astrocytes with plasmids encoding mutant PS1ΔE9 and atrial natriuretic peptide or vesicular glutamate transporter 1 tagged with fluorescent proteins (pANP.emd or pVGLUT1-EGFP respectively), to microscopically examine whether alterations in vesicle mobility and Ca2+ -regulated release of gliosignalling molecules manifest as a general vesicle-based defect; control cells were transfected to co-express exogenous or native wild-type PS1 and pANP.emd or pVGLUT1-EGFP. The vesicle mobility was analysed at rest and after ATP stimulation that increased intracellular calcium activity. RESULTS In PS1ΔE9 astrocytes, spontaneous mobility of both vesicle types was reduced (P < .001) when compared to controls. Post-stimulatory recovery of fast vesicle mobility was hampered in PS1ΔE9 astrocytes. The ATP-evoked peptide release was less efficient in PS1ΔE9 astrocytes than in the controls (P < .05), as was the pre-stimulatory mobility of these vesicles. CONCLUSION Although the PS1 mutants PS1M146V and PS1ΔE9 differently affect ER Ca2+ conductance, our results revealed a common, vesicle-type indiscriminate trafficking defect in PS1ΔE9 astrocytes, indicating that reduced secretory vesicle-based signalling is a general deficit in AD astrocytes.
Collapse
Affiliation(s)
- M. Stenovec
- Celica BIOMEDICAL; Ljubljana Slovenia
- Faculty of Medicine; Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
| | - S. Trkov Bobnar
- Celica BIOMEDICAL; Ljubljana Slovenia
- Faculty of Medicine; Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
| | - T. Smolič
- Faculty of Medicine; Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
| | - M. Kreft
- Celica BIOMEDICAL; Ljubljana Slovenia
- Faculty of Medicine; Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
- Biotechnical Faculty; CPAE; Department of Biology; University of Ljubljana; Ljubljana Slovenia
| | - V. Parpura
- Department of Neurobiology; Civitan International Research Center and Center for Glial Biology in Medicine; Evelyn F. McKnight Brain Institute; Atomic Force Microscopy & Nanotechnology Laboratories; University of Alabama at Birmingham; Birmingham AL USA
| | - R. Zorec
- Celica BIOMEDICAL; Ljubljana Slovenia
- Faculty of Medicine; Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
| |
Collapse
|
20
|
Vardjan N, Chowdhury HH, Horvat A, Velebit J, Malnar M, Muhič M, Kreft M, Krivec ŠG, Bobnar ST, Miš K, Pirkmajer S, Offermanns S, Henriksen G, Storm-Mathisen J, Bergersen LH, Zorec R. Enhancement of Astroglial Aerobic Glycolysis by Extracellular Lactate-Mediated Increase in cAMP. Front Mol Neurosci 2018; 11:148. [PMID: 29867342 PMCID: PMC5953330 DOI: 10.3389/fnmol.2018.00148] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [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: 02/15/2018] [Accepted: 04/16/2018] [Indexed: 11/13/2022] Open
Abstract
Besides being a neuronal fuel, L-lactate is also a signal in the brain. Whether extracellular L-lactate affects brain metabolism, in particular astrocytes, abundant neuroglial cells, which produce L-lactate in aerobic glycolysis, is unclear. Recent studies suggested that astrocytes express low levels of the L-lactate GPR81 receptor (EC50 ≈ 5 mM) that is in fat cells part of an autocrine loop, in which the Gi-protein mediates reduction of cytosolic cyclic adenosine monophosphate (cAMP). To study whether a similar signaling loop is present in astrocytes, affecting aerobic glycolysis, we measured the cytosolic levels of cAMP, D-glucose and L-lactate in single astrocytes using fluorescence resonance energy transfer (FRET)-based nanosensors. In contrast to the situation in fat cells, stimulation by extracellular L-lactate and the selective GPR81 agonists, 3-chloro-5-hydroxybenzoic acid (3Cl-5OH-BA) or 4-methyl-N-(5-(2-(4-methylpiperazin-1-yl)-2-oxoethyl)-4-(2-thienyl)-1,3-thiazol-2-yl)cyclohexanecarboxamide (Compound 2), like adrenergic stimulation, elevated intracellular cAMP and L-lactate in astrocytes, which was reduced by the inhibition of adenylate cyclase. Surprisingly, 3Cl-5OH-BA and Compound 2 increased cytosolic cAMP also in GPR81-knock out astrocytes, indicating that the effect is GPR81-independent and mediated by a novel, yet unidentified, excitatory L-lactate receptor-like mechanism in astrocytes that enhances aerobic glycolysis and L-lactate production via a positive feedback mechanism.
Collapse
Affiliation(s)
- Nina Vardjan
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
| | - Helena H Chowdhury
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
| | - Anemari Horvat
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Jelena Velebit
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
| | - Maja Malnar
- Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
| | - Marko Muhič
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Marko Kreft
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia.,Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Špela G Krivec
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
| | - Saša T Bobnar
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
| | - Katarina Miš
- Laboratory for Molecular Neurobiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Sergej Pirkmajer
- Laboratory for Molecular Neurobiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Stefan Offermanns
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Gjermund Henriksen
- Nuclear and Energy Physics, Department of Physics, The Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway.,Norwegian Medical Cyclotron Centre Ltd., Oslo, Norway
| | - Jon Storm-Mathisen
- Division of Anatomy, Department of Molecular Medicine, CMBN/SERTA Healthy Brain Ageing Centre, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Linda H Bergersen
- Institute of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway.,Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Robert Zorec
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
| |
Collapse
|
21
|
Kreft M, Jorgačevski J, Stenovec M, Zorec R. Ångstrom-size exocytotic fusion pore: Implications for pituitary hormone secretion. Mol Cell Endocrinol 2018; 463:65-71. [PMID: 28457949 DOI: 10.1016/j.mce.2017.04.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 04/26/2017] [Accepted: 04/26/2017] [Indexed: 02/08/2023]
Abstract
In the past, vesicle content release was thought to occur immediately and completely after triggering of exocytosis. However, vesicles may merge with the plasma membrane to form an Ångstrom diameter fusion pore that prevents the exit of secretions from the vesicle lumen. The advantage of such a narrow pore is to minimize the delay between the trigger and the release. Instead of stimulating a sequence of processes, leading to vesicle merger with the plasma membrane and a formation of a fusion pore, the stimulus only widens the pre-established fusion pore. The fusion pore may be stable and may exhibit repetitive opening of the vesicle lumen to the cell exterior accompanied by a content discharge. Such release of vesicle content is partial (subquantal), and depends on fusion pore open time, diameter and the diffusibility of the cargo. Such transient mode of fusion pore opening was not confirmed until the development of the membrane capacitance patch-clamp technique, which enables high-resolution measurement of changes in membrane surface area. It allows millisecond dwell-time measurements of fusion pores with subnanometer diameters. Currently, the soluble N-ethylmaleimide-sensitive factor-attachment protein receptor (SNARE) proteins are considered to be key entities in end-stage exocytosis, and the SNARE complex assembly/disassembly may regulate the fusion pore. Moreover, lipids or other membrane constituents with anisotropic (non-axisymmetric) geometry may also favour the establishment of stable narrow fusion pores, if positioned in the neck of the fusion pore.
Collapse
Affiliation(s)
- Marko Kreft
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia; Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia; Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna Pot 111, 1000 Ljubljana, Slovenia
| | - Jernej Jorgačevski
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia; Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia
| | - Matjaž Stenovec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia; Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia; Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia.
| |
Collapse
|
22
|
Ilić M, Meglič A, Kreft M, Belušič G. The Fly Sensitizing Pigment Enhances UV Spectral Sensitivity While Preventing Polarization-Induced Artifacts. Front Cell Neurosci 2018; 12:34. [PMID: 29467626 PMCID: PMC5808286 DOI: 10.3389/fncel.2018.00034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 01/25/2018] [Indexed: 12/31/2022] Open
Abstract
Microvillar photoreceptors are intrinsically capable of detecting the orientation of e-vector of linearly polarized light. They provide most invertebrates with an additional sensory channel to detect important features of their visual environment. However, polarization sensitivity (PS) of photoreceptors may lead to the detection of polarization-induced false colors and intensity contrasts. Most insect photoreceptors are thus adapted to have minimal PS. Flies have twisted rhabdomeres with microvilli rotated along the length of the ommatidia to reduce PS. The additional UV-absorbing sensitizing pigment on their opsin minimizes PS in the ultraviolet. We recorded voltage from Drosophila photoreceptors R1-6 to measure the spectral dependence of PS and found that PS in the UV is invariably negligible but can be substantial above 400 nm. Using modeling, we demonstrate that in R1-6 without the sensitizing pigment, PS in the UV (PS UV ) would exceed PS in the visible part of the spectrum (PS VIS ) by a factor PS UV /PS VIS = 1.2-1.8, as lower absorption of Rh1 rhodopsin reduces self-screening. We use polarimetric imaging of objects relevant to fly polarization vision to show that their degree of polarization outdoors is highest in the short-wavelength part of the spectrum. Thus, under natural illumination, the sensitizing pigment in R1-6 renders even those cells with high PS in the visible part unsuitable for proper polarization vision. We assume that fly ventral polarization vision can be mediated by R7 alone, with R1-6 serving as an unpolarized reference channel.
Collapse
Affiliation(s)
| | | | | | - Gregor Belušič
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| |
Collapse
|
23
|
Eržen I, Janáček J, Kreft M, Kubínová L, Cvetko E. Capillary Network Morphometry of Pig Soleus Muscle Significantly Changes in 24 Hours After Death. J Histochem Cytochem 2018; 66:23-31. [PMID: 29095670 PMCID: PMC5761944 DOI: 10.1369/0022155417737061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 09/20/2017] [Indexed: 11/22/2022] Open
Abstract
Capillary network characteristics are invaluable for diagnostics of muscle diseases. Biopsy material is limited in size and mostly not accessible for intensive research. Therefore, especially in human tissue, studies are performed on autopsy material. To approach the problem whether it is reliable to deduce hypotheses from autopsy material to explain physiological and pathological processes, we studied capillarity in pig soleus muscle 1 and 24 hr after death. Capillaries and muscle fibers were immunofluorescently marked, and images were acquired with a confocal microscope. Characteristics of the capillary network were estimated by image analysis methods using several plugins of the Ellipse program. Twenty-four hours after death, the measured characteristics of the capillary network differ by up to 50% when compared with samples excised 1 hr after death. Muscle fiber diameter, the measured capillary length, and tortuosity were reduced, and capillary network became more anisotropic. The main postmortem change that affects capillaries is evidently geometric deformation of muscle tissue. In conclusion, when comparing results from biopsy samples with those from autopsy samples, the effect of postmortem changes on the measured parameters must be carefully considered.
Collapse
Affiliation(s)
- Ida Eržen
- Institute of Anatomy, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Jiří Janáček
- Department of Biomathematics, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Marko Kreft
- Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
- Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- Celica Biomedical, Ljubljana, Slovenia
| | - Lucie Kubínová
- Department of Biomathematics, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Erika Cvetko
- Institute of Anatomy, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| |
Collapse
|
24
|
Višnjar T, Chesi G, Iacobacci S, Polishchuk E, Resnik N, Robenek H, Kreft M, Romih R, Polishchuk R, Kreft ME. Uroplakin traffic through the Golgi apparatus induces its fragmentation: new insights from novel in vitro models. Sci Rep 2017; 7:12842. [PMID: 28993693 PMCID: PMC5634464 DOI: 10.1038/s41598-017-13103-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [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: 11/05/2015] [Accepted: 09/20/2017] [Indexed: 11/10/2022] Open
Abstract
Uroplakins (UPs) play an essential role in maintaining an effective urothelial permeability barrier at the level of superficial urothelial cell (UC) layer. Although the organization of UPs in the apical plasma membrane (PM) of UCs is well known, their transport in UCs is only partially understood. Here, we dissected trafficking of UPs and its differentiation-dependent impact on Golgi apparatus (GA) architecture. We demonstrated that individual subunits UPIb and UPIIIa are capable of trafficking from the endoplasmic reticulum to the GA in UCs. Moreover, UPIb, UPIIIa or UPIb/UPIIIa expressing UCs revealed fragmentation and peripheral redistribution of Golgi-units. Notably, expression of UPIb or UPIb/UPIIIa triggered similar GA fragmentation in MDCK and HeLa cells that do not express UPs endogenously. The colocalization analysis of UPIb/UPIIIa-EGFP and COPI, COPII or clathrin suggested that UPs follow constitutively the post-Golgi route to the apical PM. Depolymerisation of microtubules leads to complete blockade of the UPIb/UPIIIa-EGFP post-Golgi transport, while disassembly of actin filaments shows significantly reduced delivery of UPIb/UPIIIa-EGFP to the PM. Our findings show the significant effect of the UPs expression on the GA fragmentation, which enables secretory Golgi-outpost to be distributed as close as possible to the sites of cargo delivery at the PM.
Collapse
Affiliation(s)
- Tanja Višnjar
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, SI-1000, Ljubljana, Slovenia
| | - Giancarlo Chesi
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078, Pozzuoli, (NA), Italy
| | - Simona Iacobacci
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078, Pozzuoli, (NA), Italy
| | - Elena Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078, Pozzuoli, (NA), Italy
| | - Nataša Resnik
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, SI-1000, Ljubljana, Slovenia
| | - Horst Robenek
- Institute for experimental musculoskeletal medicine, University of Münster, Albert-Schweitzer-Campus 1, Domagkstrasse 3, 48149, Münster, Germany
| | - Marko Kreft
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, Ljubljana, Slovenia & LN-MCP, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana & Celica Biomedical Center, Ljubljana, Slovenia
| | - Rok Romih
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, SI-1000, Ljubljana, Slovenia
| | - Roman Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078, Pozzuoli, (NA), Italy.
| | - Mateja Erdani Kreft
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, SI-1000, Ljubljana, Slovenia.
| |
Collapse
|
25
|
Chowdhury HH, Velebit J, Mekjavic IB, Eiken O, Kreft M, Zorec R. Systemic Hypoxia Increases the Expression of DPP4 in Preadipocytes of Healthy Human Participants. Exp Clin Endocrinol Diabetes 2017; 126:91-95. [PMID: 28950392 DOI: 10.1055/s-0043-113451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Dipeptidyl peptidase 4 (DPP4) is a transmembrane glycoprotein involved in protein degradation. Due to its action on incretins, which increase insulin secretion, DPP4 is considered a therapeutic target for type 2 diabetes. Here we have studied the role of single and combined effects of hypoxia and inactivity on the expression of DPP4 in human adipose tissue of 12 adult normal-weight males. Fat biopsies were obtained at baseline and after each of three experimental campaigns. The results revealed that in isolated human preadipocytes the expression of DPP4 was significantly increased by exposure of participants to hypoxia. Physical inactivity per se had no apparent effect on the DPP4 expression. It is concluded that DPP4 may be a marker to monitor indirectly tissue hypoxia, as occurs in obese subjects.
Collapse
Affiliation(s)
- Helena H Chowdhury
- Laboratory for Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, Ljubljana, Slovenia.,Celica Biomedical, Tehnološki park 24, Ljubljana, Slovenia
| | - Jelena Velebit
- Laboratory for Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, Ljubljana, Slovenia.,Celica Biomedical, Tehnološki park 24, Ljubljana, Slovenia
| | - Igor B Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jožef Stefan Institute, Jamova 39, Ljubljana, Slovenia
| | - Ola Eiken
- Department of Environmental Physiology, Swedish Aerospace Physiology Centre, Royal Institute of Technology, Stockholm, Sweden
| | - Marko Kreft
- Laboratory for Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, Ljubljana, Slovenia.,Celica Biomedical, Tehnološki park 24, Ljubljana, Slovenia.,Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory for Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, Ljubljana, Slovenia.,Celica Biomedical, Tehnološki park 24, Ljubljana, Slovenia
| |
Collapse
|
26
|
Lasič E, Stenovec M, Kreft M, Robinson PJ, Zorec R. Dynamin regulates the fusion pore of endo- and exocytotic vesicles as revealed by membrane capacitance measurements. Biochim Biophys Acta Gen Subj 2017; 1861:2293-2303. [PMID: 28669852 DOI: 10.1016/j.bbagen.2017.06.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [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: 03/01/2017] [Revised: 05/24/2017] [Accepted: 06/27/2017] [Indexed: 02/06/2023]
Abstract
BACKGROUND Dynamin is a multidomain GTPase exhibiting mechanochemical and catalytic properties involved in vesicle scission from the plasmalemma during endocytosis. New evidence indicates that dynamin is also involved in exocytotic release of catecholamines, suggesting the existence of a dynamin-regulated structure that couples endo- to exocytosis. METHODS Thus we here employed high-resolution cell-attached capacitance measurements and super-resolution structured illumination microscopy to directly examine single vesicle interactions with the plasmalemma in cultured rat astrocytes treated with distinct pharmacological modulators of dynamin activity. Fluorescent dextrans and the lipophilic plasmalemmal marker DiD were utilized to monitor uptake and distribution of vesicles in the peri-plasmalemmal space and in the cell cytosol. RESULTS Dynamin inhibition with Dynole™-34-2 and Dyngo™-4a prevented vesicle internalization into the cytosol and decreased fusion pore conductance of vesicles that remained attached to the plasmalemma via a narrow fusion pore that lapsed into a state of repetitive opening and closing - flickering. In contrast, the dynamin activator Ryngo™-1-23 promoted vesicle internalization and favored fusion pore closure by prolonging closed and shortening open fusion pore dwell times. Immunocytochemical staining revealed dextran uptake into dynamin-positive vesicles and increased dextran uptake into Syt4- and VAMP2-positive vesicles after dynamin inhibition, indicating prolonged retention of these vesicles at the plasmalemma. CONCLUSIONS Our results have provided direct evidence for a role of dynamin in regulation of fusion pore geometry and kinetics of endo- and exocytotic vesicles, indicating that both share a common dynamin-regulated structural intermediate, the fusion pore.
Collapse
Affiliation(s)
- Eva Lasič
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
| | - Matjaž Stenovec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia; Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia.
| | - Marko Kreft
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia; Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia; University of Ljubljana, Biotechnical Faculty, Department of Biology, CPAE, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Phillip J Robinson
- Children's Medical Research Institute, The University of Sydney, Australia
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia; Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia.
| |
Collapse
|
27
|
Affiliation(s)
- Jernej Jorgačevski
- Laboratory of Neuroendocrinology, Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Celica Biomedical, Ljubljana, Slovenia
| | - Marko Kreft
- Laboratory of Neuroendocrinology, Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Celica Biomedical, Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology, Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Celica Biomedical, Ljubljana, Slovenia
| |
Collapse
|
28
|
Jorgačevski J, Potokar M, Kreft M, Guček A, Mothet JP, Zorec R. Astrocytic Vesicle-based Exocytosis in Cultures and Acutely Isolated Hippocampal Rodent Slices. J Neurosci Res 2017; 95:2152-2158. [PMID: 28370180 DOI: 10.1002/jnr.24051] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [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: 11/24/2016] [Revised: 02/02/2017] [Accepted: 02/22/2017] [Indexed: 01/05/2023]
Abstract
Astrocytes are excitable neural cells that contribute to brain information processing via bidirectional communication with neurons. This involves the release of gliosignaling molecules that affect synapses patterning and activity. Mechanisms mediating the release of these molecules likely consist of non-vesicular and vesicular-based mechanisms. It is the vesicle-based regulated exocytosis that is an evolutionary more complex process. It is well established that the release of gliosignaling molecules has profound effects on information processing in different brain regions (e.g., hippocampal astrocytes contribute to long-term potentiation [LTP]), which has traditionally been considered as one of the cellular mechanisms underlying learning and memory. However, the paradigm of vesicle-based regulated release of gliosignaling molecules from astrocytes is still far from being unanimously accepted. One of the most important questions is to what extent can the conclusions obtained from cultured astrocytes be translated to in vivo conditions. Here, we overview the properties of vesicle mobility and their fusion with the plasma membrane in cultured astrocytes and compare these parameters to those recorded in astrocytes from acute brain hippocampal slices. The results from both experimental models are similar, which validates experiments on isolated astrocytes and further supports arguments in favor of in vivo vesicle-based exocytotic release of gliosignaling molecules. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Jernej Jorgačevski
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia.,Celica Biomedical, Tehnološki Park 24, 1000, Ljubljana, Slovenia
| | - Maja Potokar
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia.,Celica Biomedical, Tehnološki Park 24, 1000, Ljubljana, Slovenia
| | - Marko Kreft
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia.,Celica Biomedical, Tehnološki Park 24, 1000, Ljubljana, Slovenia.,Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000, Ljubljana, Slovenia
| | - Alenka Guček
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
| | - Jean-Pierre Mothet
- Team Gliotransmission and Synaptopathies, Aix-Marseille Université, CNRS, CRN2M UMR7286, Marseille, France
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia.,Celica Biomedical, Tehnološki Park 24, 1000, Ljubljana, Slovenia
| |
Collapse
|
29
|
Huhn EA, Fischer T, Göbl CS, Todesco Bernasconi M, Kreft M, Kunze M, Schoetzau A, Dölzlmüller E, Eppel W, Husslein P, Ochsenbein-Koelble N, Zimmermann R, Bäz E, Prömpeler H, Bruder E, Hahn S, Hoesli I. Screening of gestational diabetes mellitus in early pregnancy by oral glucose tolerance test and glycosylated fibronectin: study protocol for an international, prospective, multicentre cohort trial. BMJ Open 2016; 6:e012115. [PMID: 27733413 PMCID: PMC5073542 DOI: 10.1136/bmjopen-2016-012115] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
INTRODUCTION As the accurate diagnosis and treatment of gestational diabetes mellitus (GDM) is of increasing importance; new diagnostic approaches for the assessment of GDM in early pregnancy were recently suggested. We evaluate the diagnostic power of an 'early' oral glucose tolerance test (OGTT) 75 g and glycosylated fibronectin (glyFn) for GDM screening in a normal cohort. METHODS AND ANALYSIS In a prospective cohort study, 748 singleton pregnancies are recruited in 6 centres in Switzerland, Austria and Germany. Women are screened for pre-existing diabetes mellitus and GDM by an 'early' OGTT 75 g and/or the new biomarker, glyFn, at 12-15 weeks of gestation. Different screening strategies are compared to evaluate the impact on detection of GDM by an OGTT 75 g at 24-28 weeks of gestation as recommended by the International Association of Diabetes and Pregnancy Study Groups (IADPSG). A new screening algorithm is created by using multivariable risk estimation based on 'early' OGTT 75 g and/or glyFn results, incorporating maternal risk factors. Recruitment began in May 2014. ETHICS AND DISSEMINATION This study received ethical approval from the ethics committees in Basel, Zurich, Vienna, Salzburg and Freiburg. It was registered under http://www.ClinicalTrials.gov (NCT02035059) on 12 January 2014. Data will be presented at international conferences and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER NCT02035059.
Collapse
Affiliation(s)
- E A Huhn
- Department of Obstetrics and Gynaecology, University Hospital Basel, Basel, Switzerland
| | - T Fischer
- Department of Obstetrics and Gynaecology, Salzburger Landeskrankenhaus, Paracelsus Medical University, Salzburg, Austria
| | - C S Göbl
- Division of Obstetrics and Feto-maternal Medicine, Department of Obstetrics and Gynaecology, Medical University of Vienna, Vienna, Austria
| | - M Todesco Bernasconi
- Department of Obstetrics and Gynaecology, Cantonal Hospital Aarau, Aarau, Switzerland
| | - M Kreft
- Department of Obstetrics and Gynaecology, University Hospital Zurich, Zurich, Switzerland
| | - M Kunze
- Department of Obstetrics and Gynaecology, University Hospital Freiburg, Freiburg, Germany
| | - A Schoetzau
- Department of Obstetrics and Gynaecology, University Hospital Basel, Basel, Switzerland
| | - E Dölzlmüller
- Department of Obstetrics and Gynaecology, Salzburger Landeskrankenhaus, Paracelsus Medical University, Salzburg, Austria
| | - W Eppel
- Division of Obstetrics and Feto-maternal Medicine, Department of Obstetrics and Gynaecology, Medical University of Vienna, Vienna, Austria
| | - P Husslein
- Division of Obstetrics and Feto-maternal Medicine, Department of Obstetrics and Gynaecology, Medical University of Vienna, Vienna, Austria
| | - N Ochsenbein-Koelble
- Department of Obstetrics and Gynaecology, University Hospital Zurich, Zurich, Switzerland
| | - R Zimmermann
- Department of Obstetrics and Gynaecology, University Hospital Zurich, Zurich, Switzerland
| | - E Bäz
- Department of Obstetrics and Gynaecology, University Hospital Freiburg, Freiburg, Germany
| | - H Prömpeler
- Department of Obstetrics and Gynaecology, University Hospital Freiburg, Freiburg, Germany
| | - E Bruder
- Department of Pathology, University Hospital Basel, Basel, Switzerland
| | - S Hahn
- Department of Biomedicine, Laboratory of Perinatology, University Basel, Basel, Switzerland
| | - I Hoesli
- Department of Obstetrics and Gynaecology, University Hospital Basel, Basel, Switzerland
| |
Collapse
|
30
|
Grilc S, Kuster V, Zorec R, Japelj I, Ilievski V, Budihna MV, Marhl M, Brumen M, Schuster S, Heinrich R, Martin TFJ, Pozzan T, Rupnik M, Kreft M, Sikdar SK, Zorec R, Sikdar SK, Kreft M, Smith SM, Namkung Y, Foletti D, Klingauf J, Shin HS, Scheller RH, Tsien RW, Zupančič G. Abstracts. Pflugers Arch 2016. [DOI: 10.1007/s004240000128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
31
|
Lasič E, Rituper B, Jorgačevski J, Kreft M, Stenovec M, Zorec R. Subanesthetic doses of ketamine stabilize the fusion pore in a narrow flickering state in astrocytes. J Neurochem 2016; 138:909-17. [DOI: 10.1111/jnc.13715] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 06/08/2016] [Accepted: 06/17/2016] [Indexed: 12/27/2022]
Affiliation(s)
- Eva Lasič
- Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; Faculty of Medicine; University of Ljubljana; Ljubljana Slovenia
| | - Boštjan Rituper
- Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; Faculty of Medicine; University of Ljubljana; Ljubljana Slovenia
| | - Jernej Jorgačevski
- Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; Faculty of Medicine; University of Ljubljana; Ljubljana Slovenia
- Celica BIOMEDICAL; Ljubljana Slovenia
| | - Marko Kreft
- Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; Faculty of Medicine; University of Ljubljana; Ljubljana Slovenia
- Celica BIOMEDICAL; Ljubljana Slovenia
- Biotechnical Faculty; University of Ljubljana; Ljubljana Slovenia
| | - Matjaž Stenovec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; Faculty of Medicine; University of Ljubljana; Ljubljana Slovenia
- Celica BIOMEDICAL; Ljubljana Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; Faculty of Medicine; University of Ljubljana; Ljubljana Slovenia
- Celica BIOMEDICAL; Ljubljana Slovenia
| |
Collapse
|
32
|
Sajko S, Kubínová L, Cvetko E, Kreft M, Wernig A, Erzen I. Frequency of M-Cadherin-stained Satellite Cells Declines in Human Muscles During Aging. J Histochem Cytochem 2016; 52:179-85. [PMID: 14729869 DOI: 10.1177/002215540405200205] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [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: 11/16/2022] Open
Abstract
To answer the question of whether the satellite cell pool in human muscle is reduced during aging, we detected satellite cells in 30-μm-thick transverse sections under the confocal microscope by binding of M-cadherin antibody. The basal lamina was detected with laminin. Nuclei were stained with bisbenzimide or propidium iodide. Satellite cells were counted by applying the disector method and unbiased sampling design. To determine if there are age-related differences in muscle fiber types, morphometric characteristics of muscle fibers were examined on thin sections stained for myofibrillar ATPase. Autopsy samples of vastus lateralis muscle from six young (28.7 ± 2.3 years) and six old (70.8 ± 1.3 years) persons who had suffered sudden death were analyzed. Numbers of satellite cells per fiber length (Nsc/Lfib) and number of satellite cells per total number of nuclei (satellite cell nuclei + myonuclei) (Nsc/Nnucl) were significantly lower in the old group ( p<0.05). We demonstrate the importance of proper sampling and counting in estimation of sparsely distributed structures such as satellite cells. Our results support the hypothesis that the satellite cell fraction declines during aging.
Collapse
Affiliation(s)
- Spela Sajko
- Institute of Anatomy, Medical Faculty, Ljubljana, Slovenia
| | | | | | | | | | | |
Collapse
|
33
|
Kreft M, Jorgačevski J, Vardjan N, Zorec R. Unproductive exocytosis. J Neurochem 2016; 137:880-9. [DOI: 10.1111/jnc.13561] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 01/21/2016] [Accepted: 01/25/2016] [Indexed: 01/04/2023]
Affiliation(s)
- Marko Kreft
- Laboratory of Neuroendocrinology-Molecular Cell Physiology; Faculty of Medicine; University of Ljubljana; Ljubljana Slovenia
- Celica BIOMEDICAL; Ljubljana Slovenia
- Department of Biology; Biotechnical Faculty; University of Ljubljana; Ljubljana Slovenia
| | - Jernej Jorgačevski
- Laboratory of Neuroendocrinology-Molecular Cell Physiology; Faculty of Medicine; University of Ljubljana; Ljubljana Slovenia
- Celica BIOMEDICAL; Ljubljana Slovenia
| | - Nina Vardjan
- Laboratory of Neuroendocrinology-Molecular Cell Physiology; Faculty of Medicine; University of Ljubljana; Ljubljana Slovenia
- Celica BIOMEDICAL; Ljubljana Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology; Faculty of Medicine; University of Ljubljana; Ljubljana Slovenia
- Celica BIOMEDICAL; Ljubljana Slovenia
| |
Collapse
|
34
|
Guček A, Jorgačevski J, Singh P, Geisler C, Lisjak M, Vardjan N, Kreft M, Egner A, Zorec R. Dominant negative SNARE peptides stabilize the fusion pore in a narrow, release-unproductive state. Cell Mol Life Sci 2016; 73:3719-31. [PMID: 27056575 DOI: 10.1007/s00018-016-2213-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 03/05/2016] [Accepted: 03/29/2016] [Indexed: 01/18/2023]
Abstract
Key support for vesicle-based release of gliotransmitters comes from studies of transgenic mice with astrocyte-specific expression of a dominant-negative domain of synaptobrevin 2 protein (dnSNARE). To determine how this peptide affects exocytosis, we used super-resolution stimulated emission depletion microscopy and structured illumination microscopy to study the anatomy of single vesicles in astrocytes. Smaller vesicles contained amino acid and peptidergic transmitters and larger vesicles contained ATP. Discrete increases in membrane capacitance, indicating single-vesicle fusion, revealed that astrocyte stimulation increases the frequency of predominantly transient fusion events in smaller vesicles, whereas larger vesicles transitioned to full fusion. To determine whether this reflects a lower density of SNARE proteins in larger vesicles, we treated astrocytes with botulinum neurotoxins D and E, which reduced exocytotic events of both vesicle types. dnSNARE peptide stabilized the fusion-pore diameter to narrow, release-unproductive diameters in both vesicle types, regardless of vesicle diameter.
Collapse
Affiliation(s)
- Alenka Guček
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Jernej Jorgačevski
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, 1000, Ljubljana, Slovenia
- Celica BIOMEDICAL, 1000, Ljubljana, Slovenia
| | - Priyanka Singh
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Claudia Geisler
- Department of Optical Nanoscopy, Laser-Laboratory Göttingen e.V., 37077, Göttingen, Germany
| | - Marjeta Lisjak
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Nina Vardjan
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, 1000, Ljubljana, Slovenia
- Celica BIOMEDICAL, 1000, Ljubljana, Slovenia
| | - Marko Kreft
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, 1000, Ljubljana, Slovenia
- Celica BIOMEDICAL, 1000, Ljubljana, Slovenia
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Alexander Egner
- Department of Optical Nanoscopy, Laser-Laboratory Göttingen e.V., 37077, Göttingen, Germany
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, 1000, Ljubljana, Slovenia.
- Celica BIOMEDICAL, 1000, Ljubljana, Slovenia.
| |
Collapse
|
35
|
Vardjan N, Horvat A, Anderson JE, Yu D, Croom D, Zeng X, Lužnik Z, Kreft M, Teng YD, Kirov SA, Zorec R. Adrenergic activation attenuates astrocyte swelling induced by hypotonicity and neurotrauma. Glia 2016; 64:1034-49. [PMID: 27018061 DOI: 10.1002/glia.22981] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [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: 09/11/2015] [Revised: 02/18/2016] [Accepted: 02/18/2016] [Indexed: 12/29/2022]
Abstract
Edema in the central nervous system can rapidly result in life-threatening complications. Vasogenic edema is clinically manageable, but there is no established medical treatment for cytotoxic edema, which affects astrocytes and is a primary trigger of acute post-traumatic neuronal death. To test the hypothesis that adrenergic receptor agonists, including the stress stimulus epinephrine protects neural parenchyma from damage, we characterized its effects on hypotonicity-induced cellular edema in cortical astrocytes by in vivo and in vitro imaging. After epinephrine administration, hypotonicity-induced swelling of astrocytes was markedly reduced and cytosolic 3'-5'-cyclic adenosine monophosphate (cAMP) was increased, as shown by a fluorescence resonance energy transfer nanosensor. Although, the kinetics of epinephrine-induced cAMP signaling was slowed in primary cortical astrocytes exposed to hypotonicity, the swelling reduction by epinephrine was associated with an attenuated hypotonicity-induced cytosolic Ca(2+) excitability, which may be the key to prevent astrocyte swelling. Furthermore, in a rat model of spinal cord injury, epinephrine applied locally markedly reduced neural edema around the contusion epicenter. These findings reveal new targets for the treatment of cellular edema in the central nervous system.
Collapse
Affiliation(s)
- Nina Vardjan
- Celica, BIOMEDICAL, Tehnološki park 24, Ljubljana, 1000, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, Ljubljana, 1000, Slovenia
| | - Anemari Horvat
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, Ljubljana, 1000, Slovenia
| | - Jamie E Anderson
- Departments of Neurosurgery and Physical Medicine & Rehabilitation, Harvard Medical School, Boston, Massachusetts
| | - Dou Yu
- Departments of Neurosurgery and Physical Medicine & Rehabilitation, Harvard Medical School, Boston, Massachusetts
| | - Deborah Croom
- Brain and Behaviour Discovery Institute, Medical College of Georgia, Augusta, Georgia.,Department of Neurosurgery, Medical College of Georgia, Augusta, Georgia
| | - Xiang Zeng
- Departments of Neurosurgery and Physical Medicine & Rehabilitation, Harvard Medical School, Boston, Massachusetts
| | - Zala Lužnik
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, Ljubljana, 1000, Slovenia
| | - Marko Kreft
- Celica, BIOMEDICAL, Tehnološki park 24, Ljubljana, 1000, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, Ljubljana, 1000, Slovenia.,Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, Ljubljana, 1000, Slovenia
| | - Yang D Teng
- Departments of Neurosurgery and Physical Medicine & Rehabilitation, Harvard Medical School, Boston, Massachusetts.,Division of SCI Research, VA Boston Healthcare System, Boston, Massachusetts
| | - Sergei A Kirov
- Brain and Behaviour Discovery Institute, Medical College of Georgia, Augusta, Georgia.,Department of Neurosurgery, Medical College of Georgia, Augusta, Georgia
| | - Robert Zorec
- Celica, BIOMEDICAL, Tehnološki park 24, Ljubljana, 1000, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, Ljubljana, 1000, Slovenia
| |
Collapse
|
36
|
Potokar M, Jorgačevski J, Lacovich V, Kreft M, Vardjan N, Bianchi V, D'Adamo P, Zorec R. Impaired αGDI Function in the X-Linked Intellectual Disability: The Impact on Astroglia Vesicle Dynamics. Mol Neurobiol 2016; 54:2458-2468. [PMID: 26971292 DOI: 10.1007/s12035-016-9834-1] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 03/04/2016] [Indexed: 11/25/2022]
Abstract
X-linked non-syndromic intellectual disability (XLID) is a common mental disorder recognized by cognitive and behavioral deficits. Mutations in the brain-specific αGDI, shown to alter a subset of RAB GTPases redistribution in cells, are linked to XLID, likely via changes in vesicle traffic in neurons. Here, we show directly that isolated XLID mice astrocytes, devoid of pathologic tissue environment, exhibit vesicle mobility deficits. Contrary to previous studies, we show that astrocytes express two GDI proteins. The siRNA-mediated suppression of expression of αGDI especially affected vesicle dynamics. A similar defect was recorded in astrocytes from the Gdi1 -/Y mouse model of XLID and in astrocytes with recombinant mutated human XLID αGDI. Endolysosomal vesicles studied here are involved in the release of gliosignaling molecules as well as in regulating membrane receptor density; thus, the observed changes in astrocytic vesicle mobility may, over the long time-course, profoundly affect signaling capacity of these cells, which optimize neural activity.
Collapse
Affiliation(s)
- Maja Potokar
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
| | - Jernej Jorgačevski
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
| | | | - Marko Kreft
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
- Biotechnical Faculty, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Nina Vardjan
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
| | - Veronica Bianchi
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132, Milan, Italy
| | - Patrizia D'Adamo
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132, Milan, Italy
| | - Robert Zorec
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia.
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia.
| |
Collapse
|
37
|
Abstract
In regulated exocytosis vesicular and plasma membranes merge to form a fusion pore in response to stimulation. The nonselective cation HCN channels are involved in the regulation of unitary exocytotic events by at least 2 mechanisms. They can affect SNARE-dependent exocytotic activity indirectly, via the modulation of free intracellular calcium; and/or directly, by altering local cation concentration, which affects fusion pore geometry likely via electrostatic interactions. By monitoring membrane capacitance, we investigated how extracellular cation concentration affects fusion pore diameter in pituitary cells and astrocytes. At low extracellular divalent cation levels predominantly transient fusion events with widely open fusion pores were detected. However, fusion events with predominately narrow fusion pores were present at elevated levels of extracellular trivalent cations. These results show that electrostatic interactions likely help determine the stability of discrete fusion pore states by affecting fusion pore membrane composition.
Collapse
Affiliation(s)
- Alenka Guček
- a Laboratory of Neuroendocrinology-Molecular Cell Physiology ; Institute of Pathophysiology ; Faculty of Medicine ; University of Ljubljana ; Ljubljana , Slovenia
| | | | | | | | | | | |
Collapse
|
38
|
Chowdhury HH, Velebit J, Radić N, Frančič V, Kreft M, Zorec R. Hypoxia Alters the Expression of Dipeptidyl Peptidase 4 and Induces Developmental Remodeling of Human Preadipocytes. J Diabetes Res 2016; 2016:7481470. [PMID: 26881257 PMCID: PMC4735901 DOI: 10.1155/2016/7481470] [Citation(s) in RCA: 9] [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] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 10/25/2015] [Indexed: 01/25/2023] Open
Abstract
Dipeptidyl peptidase 4 (DPP4), a transmembrane protein, has been identified in human adipose tissue and is considered to be associated with obesity-related type 2 diabetes. Since adipose tissue is relatively hypoxic in obese participants, we investigated the expression of DPP4 in human preadipocytes (hPA) and adipocytes in hypoxia, during differentiation and upon insulin stimulation. The results show that DPP4 is abundantly expressed in hPA but very sparsely in adipocytes. During differentiation in vitro, the expression of DPP4 in hPA is reduced on the addition of differentiation medium, indicating that this protein can be hPA marker. Long term hypoxia altered the expression of DPP4 in hPA. In in vitro hypoxic conditions the protease activity of shed DPP4 is reduced; however, in the presence of insulin, the increase in DPP4 expression is potentiated by hypoxia.
Collapse
Affiliation(s)
- Helena H. Chowdhury
- Laboratory for Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloska 4, SI-1000 Ljubljana, Slovenia
- Celica Biomedical Center, Tehnološki Park 24, SI-1000 Ljubljana, Slovenia
| | - Jelena Velebit
- Laboratory for Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloska 4, SI-1000 Ljubljana, Slovenia
- Celica Biomedical Center, Tehnološki Park 24, SI-1000 Ljubljana, Slovenia
| | - Nataša Radić
- Laboratory for Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloska 4, SI-1000 Ljubljana, Slovenia
- Celica Biomedical Center, Tehnološki Park 24, SI-1000 Ljubljana, Slovenia
| | - Vito Frančič
- Celica Biomedical Center, Tehnološki Park 24, SI-1000 Ljubljana, Slovenia
| | - Marko Kreft
- Laboratory for Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloska 4, SI-1000 Ljubljana, Slovenia
- Celica Biomedical Center, Tehnološki Park 24, SI-1000 Ljubljana, Slovenia
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna Pot 111, SI-1000 Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory for Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloska 4, SI-1000 Ljubljana, Slovenia
- Celica Biomedical Center, Tehnološki Park 24, SI-1000 Ljubljana, Slovenia
- *Robert Zorec:
| |
Collapse
|
39
|
Kimmich N, Engel W, Kreft M, Zimmermann R. „Uterus wrapping“: Ein neues Konzept in der Behandlung einer Uterusatonie während einer Sectio caesarea. Z Geburtshilfe Neonatol 2015. [DOI: 10.1055/s-0035-1566499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
40
|
Stenovec M, Trkov S, Lasič E, Terzieva S, Kreft M, Rodríguez Arellano JJ, Parpura V, Verkhratsky A, Zorec R. Expression of familial Alzheimer disease presenilin 1 gene attenuates vesicle traffic and reduces peptide secretion in cultured astrocytes devoid of pathologic tissue environment. Glia 2015; 64:317-29. [PMID: 26462451 DOI: 10.1002/glia.22931] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 09/22/2015] [Accepted: 09/22/2015] [Indexed: 02/06/2023]
Abstract
In the brain, astrocytes provide metabolic and trophic support to neurones. Failure in executing astroglial homeostatic functions may contribute to the initiation and propagation of diseases, including Alzheimer disease (AD), characterized by a progressive loss of neurones over years. Here, we examined whether astrocytes from a mice model of AD isolated in the presymptomatic phase of the disease exhibit alterations in vesicle traffic, vesicular peptide release and purinergic calcium signaling. In cultured astrocytes isolated from a newborn wild-type (wt) and 3xTg-AD mouse, secretory vesicles and acidic endosomes/lysosomes were labeled by transfection with plasmid encoding atrial natriuretic peptide tagged with mutant green fluorescent protein (ANP.emd) and by LysoTracker, respectively. The intracellular Ca(2+) concentration ([Ca(2+)]i) was monitored with Fluo-2 and visualized by confocal microscopy. In comparison with controls, spontaneous mobility of ANP- and LysoTracker-labeled vesicles was diminished in 3xTg-AD astrocytes; the track length (TL), maximal displacement (MD) and directionality index (DI) were all reduced in peptidergic vesicles and in endosomes/lysosomes (P < 0.001), as was the ATP-evoked attenuation of vesicle mobility. Similar impairment of peptidergic vesicle trafficking was observed in wt rat astrocytes transfected to express mutated presenilin 1 (PS1M146V). The ATP-evoked ANP discharge from single vesicles was less efficient in 3xTg-AD and PS1M146V-expressing astrocytes than in respective wt controls (P < 0.05). Purinergic stimulation evoked biphasic and oscillatory [Ca(2+)]i responses; the latter were less frequent (P < 0.001) in 3xTg-AD astrocytes. Expression of PS1M146V in astrocytes impairs vesicle dynamics and reduces evoked secretion of the signaling molecule ANP; both may contribute to the development of AD.
Collapse
Affiliation(s)
- Matjaž Stenovec
- Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Saša Trkov
- Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Eva Lasič
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Slavica Terzieva
- Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.,Department of Neuroscience, Faculty of Medicine and Odontology, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain
| | - Marko Kreft
- Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Department of Biology, University of Ljubljana, Biotechnical Faculty, CPAE, Ljubljana, Slovenia
| | - José Julio Rodríguez Arellano
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.,Department of Neuroscience, Faculty of Medicine and Odontology, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain
| | - Vladimir Parpura
- Department of Neurobiology, Civitan International Research Center and Center for Glial Biology in Medicine, Evelyn F. McKnight Brain Institute, Atomic Force Microscopy & Nanotechnology Laboratories, University of Alabama at Birmingham, Birmingham, Alabama
| | - Alexei Verkhratsky
- Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.,Department of Neuroscience, Faculty of Medicine and Odontology, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain.,Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Robert Zorec
- Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| |
Collapse
|
41
|
Muhič M, Vardjan N, Chowdhury HH, Zorec R, Kreft M. Insulin and Insulin-like Growth Factor 1 (IGF-1) Modulate Cytoplasmic Glucose and Glycogen Levels but Not Glucose Transport across the Membrane in Astrocytes. J Biol Chem 2015; 290:11167-76. [PMID: 25792745 DOI: 10.1074/jbc.m114.629063] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [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: 12/02/2014] [Indexed: 01/21/2023] Open
Abstract
Astrocytes contain glycogen, an energy buffer, which can bridge local short term energy requirements in the brain. Glycogen levels reflect a dynamic equilibrium between glycogen synthesis and glycogenolysis. Many factors that include hormones and neuropeptides, such as insulin and insulin-like growth factor 1 (IGF-1) likely modulate glycogen stores in astrocytes, but detailed mechanisms at the cellular level are sparse. We used a glucose nanosensor based on Förster resonance energy transfer to monitor cytosolic glucose concentration with high temporal resolution and a cytochemical approach to determine glycogen stores in single cells. The results show that after glucose depletion, glycogen stores are replenished. Insulin and IGF-1 boost the process of glycogen formation. Although astrocytes appear to express glucose transporter GLUT4, glucose entry across the astrocyte plasma membrane is not affected by insulin. Stimulation of cells with insulin and IGF-1 decreased cytosolic glucose concentration, likely because of elevated glucose utilization for glycogen synthesis.
Collapse
Affiliation(s)
- Marko Muhič
- From the Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
| | - Nina Vardjan
- From the Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia, Celica Biomedical, 1000 Ljubljana, Slovenia, and
| | - Helena H Chowdhury
- From the Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia, Celica Biomedical, 1000 Ljubljana, Slovenia, and
| | - Robert Zorec
- From the Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia, Celica Biomedical, 1000 Ljubljana, Slovenia, and
| | - Marko Kreft
- From the Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia, Celica Biomedical, 1000 Ljubljana, Slovenia, and the Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
| |
Collapse
|
42
|
Guček A, Jorgačevski J, Singh P, Geisler C, Vardjan N, Kreft M, Egner A, Zorec R. Fusion Properties of Gliotransmitter Vesicles in Cultured Astrocytes. Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
|
43
|
Kreft M, Krähenmann F, Kurmanavicius J, Zimmermann R, Ochsenbein-Kölble N. Optimal starting time for induction of labour with misoprostol. Geburtshilfe Frauenheilkd 2014. [DOI: 10.1055/s-0034-1388178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
|
44
|
Stenovec M, Trkov S, Kreft M, Zorec R. Alterations of calcium homoeostasis in cultured rat astrocytes evoked by bioactive sphingolipids. Acta Physiol (Oxf) 2014; 212:49-61. [PMID: 24825022 DOI: 10.1111/apha.12314] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 03/13/2014] [Accepted: 05/08/2014] [Indexed: 12/14/2022]
Abstract
AIM In the brain, alterations in sphingolipid metabolism contribute to several neurological disorders; however, their effect on astrocytes is largely unknown. Here, we identified bioactive sphingolipids that affect intracellular free calcium concentration ([Ca(2+)]i), mobility of peptidergic secretory vesicles, signalling pathways involved in alterations of calcium homoeostasis and explored the relationship between the stimulus-evoked increase in [Ca(2+)]i and attenuation of vesicle mobility. METHODS Confocal time-lapse images were acquired to explore [Ca(2+)]i signals, the mobility of fluorescently tagged peptidergic vesicles and the structural integrity of the microtubules and actin filaments before and after the addition of exogenous sphingolipids to astrocytes. RESULTS Fingolimod (FTY720), a recently introduced therapeutic for multiple sclerosis, and sphingosine, a releasable constituent of membrane sphingolipids, evoked long-lasting increases in [Ca(2+)]i in the presence and absence of extracellular Ca(2+); the evoked responses were diminished in the absence of extracellular Ca(2+). Activation of phospholipase C and inositol-1,4,5-triphosphate receptors was necessary and sufficient to evoke increases in [Ca(2+)]i as revealed by the pharmacologic inhibitors; Ca(2+) flux from the extracellular space intensified these responses several fold. The lipid-evoked increases in [Ca(2+)]i coincided with the attenuated vesicle mobility. High and positive correlation between increase in [Ca(2+)]i and decrease in peptidergic vesicle mobility was confirmed independently in astrocytes exposed to evoked, transient Ca(2+) signalling triggered by purinergic and glutamatergic stimulation. CONCLUSION Exogenously added cell-permeable sphingosine-like lipids exert complex, Ca(2+)-dependent effects on astrocytes and likely alter their homeostatic function in vivo.
Collapse
Affiliation(s)
- M. Stenovec
- Celica Biomedical Center d.o.o.; Ljubljana Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; Faculty of Medicine; University of Ljubljana; Ljubljana Slovenia
| | - S. Trkov
- Celica Biomedical Center d.o.o.; Ljubljana Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; Faculty of Medicine; University of Ljubljana; Ljubljana Slovenia
| | - M. Kreft
- Celica Biomedical Center d.o.o.; Ljubljana Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; Faculty of Medicine; University of Ljubljana; Ljubljana Slovenia
- Department of Biology; CPAE; Biotechnical Faculty; University of Ljubljana; Ljubljana Slovenia
| | - R. Zorec
- Celica Biomedical Center d.o.o.; Ljubljana Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; Faculty of Medicine; University of Ljubljana; Ljubljana Slovenia
| |
Collapse
|
45
|
Škulj M, Pezdirec D, Gaser D, Kreft M, Zorec R. Reduction in C-terminal amidated species of recombinant monoclonal antibodies by genetic modification of CHO cells. BMC Biotechnol 2014; 14:76. [PMID: 25123359 PMCID: PMC4146454 DOI: 10.1186/1472-6750-14-76] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [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: 05/30/2014] [Accepted: 08/08/2014] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND During development of recombinant monoclonal antibodies in Chinese hamster ovary (CHO) cells, C-terminal amidated species are observed. C-terminal amidation is catalysed by peptidylglycine α-amidating monooxygenase (PAM), an enzyme known to be expressed in CHO cells. The significant variations between clones during clone selection, and the relatively high content of amidated species (up to 15%) in comparison to reference material (4%), led us to develop a cell line with reduced production of C-terminal amidated monoclonal antibodies using genetic manipulation. RESULTS Initial target validation was performed using the RNA interference approach against PAM, which resulted in a CHO cell line with C-terminal amidation decreased to 3%. Due to the transient effects of small-interfering RNAs, and possible stability problems using short-hairpin RNAs, we knocked-down the PAM gene using zinc finger nucleases. Plasmid DNA and mRNA for zinc finger nucleases were used to generate a PAM knock-out, which resulted in two CHO cell lines with C-terminal amidation decreased to 6%, in CHO Der2 and CHO Der3 cells. CONCLUSION Two genetically modified cell lines were generated using a zinc finger nuclease approach to decrease C-terminal amidation on recombinant monoclonal antibodies. These two cell lines now represent a pool from which the candidate clone with the highest comparability to the reference molecule can be selected, for production of high-quality and safe therapeutics.
Collapse
Affiliation(s)
- Mihaela Škulj
- Sandoz Biopharmaceuticals, Mengeš, Lek Pharmacetucals d,d, Kolodvorska 27, 1234 Mengeš, Slovenia.
| | | | | | | | | |
Collapse
|
46
|
Vardjan N, Kreft M, Zorec R. Dynamics of β-adrenergic/cAMP signaling and morphological changes in cultured astrocytes. Glia 2014; 62:566-79. [PMID: 24464905 DOI: 10.1002/glia.22626] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 11/05/2013] [Accepted: 12/20/2013] [Indexed: 11/09/2022]
Abstract
The morphology of astrocytes, likely regulated by cAMP, determines the structural association between astrocytes and the synapse, consequently modulating synaptic function. β-Adrenergic receptors (β-AR), which increase cytosolic cAMP concentration ([cAMP]i ), may affect cell morphology. However, the real-time dynamics of β-AR-mediated cAMP signaling in single live astrocytes and its effect on cell morphology have not been studied. We used the fluorescence resonance energy transfer (FRET)-based cAMP biosensor Epac1-camps to study time-dependent changes in [cAMP]i ; morphological changes in primary rat astrocytes were monitored by real-time confocal microscopy. Stimulation of β-AR by adrenaline, noradrenaline, and isoprenaline, a specific agonist of β-AR, rapidly increased [cAMP]i (∼15 s). The FRET signal response, mediated via β-AR, was faster than in the presence of forskolin (twofold) and dibutyryl-cAMP (>35-fold), which directly activate adenylyl cyclase and Epac1-camps, respectively, likely due to slow entry of these agents into the cytosol. Oscillations in [cAMP]i have not been recorded, indicating that cAMP-dependent processes operate in a slow time domain. Most Epac1-camps expressing astrocytes revealed a morphological change upon β-AR activation and attained a stellate morphology within 1 h. The morphological changes exhibited a bell-shaped dependency on [cAMP]i . The 5-10% decrease in cell cross-sectional area and the 30-50% increase in cell perimeter are likely due to withdrawal of the cytoplasm to the perinuclear region and the appearance of protrusions on the surface of astrocytes. Because astrocyte processes ensheath neurons, β-AR/cAMP-mediated morphological changes can modify the geometry of the extracellular space, affecting synaptic, neuronal, and astrocyte functions in health and disease.
Collapse
Affiliation(s)
- Nina Vardjan
- Celica Biomedical Center, Tehnološki Park 24, Ljubljana, Slovenia; Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, Ljubljana, Slovenia
| | | | | |
Collapse
|
47
|
Vardjan N, Kreft M, Zorec R. Regulated Exocytosis in Astrocytes is as Slow as the Metabolic Availability of Gliotransmitters: Focus on Glutamate and ATP. Glutamate and ATP at the Interface of Metabolism and Signaling in the Brain 2014; 11:81-101. [DOI: 10.1007/978-3-319-08894-5_5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
48
|
Jorgačevski J, Vardjan N, Calejo AC, Guček A, Rituper B, Flašker A, Kreft M, Zorec R. Exocytotic Fusion Pore Intermediates of Dense-Core Vesicles. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
|
49
|
Cagnet S, Faraldo MM, Kreft M, Sonnenberg A, Raymond K, Glukhova MA. Signaling events mediated by α3β1 integrin are essential for mammary tumorigenesis. Oncogene 2013; 33:4286-95. [PMID: 24077284 DOI: 10.1038/onc.2013.391] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 07/26/2013] [Indexed: 12/23/2022]
Abstract
The constitutive activation of β-catenin signaling in the mammary basal epithelial cell layer in transgenic K5ΔNβcat mice leads to basal-type tumor development. Integrins of the β1 family and integrin-mediated signaling events have an important role in breast tumor growth and progression. We show here that the deletion of α3β1 integrin, a major laminin receptor, from the basal layer of the mammary epithelium of K5ΔNβcat mice completely prevented the tumorigenesis induced by β-catenin signaling. Moreover, the depletion of α3β1 integrin from a spontaneously transformed mouse mammary basal epithelial cell line (MEC) prevented the cells from forming colonies in soft agar and greatly reduced tumor development in orthotopic grafts. Inhibition of the integrin signaling intermediates Rac1 or PAK1 (P21-activated Kinase 1) in MEC affected tumor cell growth in soft agar, whereas the expression of activated forms of these effectors in α3-depleted cells rescued the capacity of these cells to grow in non-adherent conditions. Similarly, the tumorigenic potential of α3-depleted cells was restored by the expression of activated PAK1, as assessed by orthotopic transplantation assay. In three-dimensional Matrigel culture, MEC survival and proliferation were affected by the depletion of α3β1 integrin, which also significantly decreased the activation of focal adhesion kinase (FAK), mitogen-activated protein kinase (MAPK) and c-Jun NH2-terminal kinase (JNK). Our data suggest that the activation of signaling cascades downstream from α3β1 and involving the Rac1/PAK1 pathway, MAPK and JNK, promotes prosurvival and proproliferative signals required for the malignant growth of basal mammary epithelial cells, providing further insight into the molecular mechanisms underlying breast cancer initiation and progression.
Collapse
Affiliation(s)
- S Cagnet
- 1] Institut Curie, Centre de Recherche, Paris, France [2] Section de Recherche, UMR144 Centre National de la Recherche Scientifique-Institut Curie, Paris, France
| | - M M Faraldo
- 1] Institut Curie, Centre de Recherche, Paris, France [2] Section de Recherche, UMR144 Centre National de la Recherche Scientifique-Institut Curie, Paris, France
| | - M Kreft
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - A Sonnenberg
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - K Raymond
- 1] Institut Curie, Centre de Recherche, Paris, France [2] Section de Recherche, UMR144 Centre National de la Recherche Scientifique-Institut Curie, Paris, France
| | - M A Glukhova
- 1] Institut Curie, Centre de Recherche, Paris, France [2] Section de Recherche, UMR144 Centre National de la Recherche Scientifique-Institut Curie, Paris, France
| |
Collapse
|
50
|
Flašker A, Jorgačevski J, Calejo AI, Kreft M, Zorec R. Vesicle size determines unitary exocytic properties and their sensitivity to sphingosine. Mol Cell Endocrinol 2013; 376:136-47. [PMID: 23791846 DOI: 10.1016/j.mce.2013.06.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 06/11/2013] [Accepted: 06/11/2013] [Indexed: 11/23/2022]
Abstract
Neuroendocrine cells contain small and large vesicles, but the functional significance of vesicle diameter is unclear. We studied unitary exocytic events of prolactin-containing vesicles in lactotrophs by monitoring discrete steps in membrane capacitance. In the presence of sphingosine, which recruits VAMP2 for SNARE complex formation, the frequency of transient and full fusion events increased. Vesicles with larger diameters proceeded to full fusion, but smaller vesicles remained entrapped in transient exocytosis. The diameter of vesicle dense cores released by full fusion exocytosis into the extracellular space was larger than the diameter of the remaining intracellular vesicles beneath the plasma membrane. Labeling with prolactin- and VAMP2-antibodies revealed a correlation between the diameters of colocalized prolactin- and VAMP2-positive structures. It is proposed that sphingosine-mediated facilitation of regulated exocytosis is not only related to the number of SNARE complexes per vesicle but also depends on the vesicle size, which may determine the transition between transient and full fusion exocytosis.
Collapse
Affiliation(s)
- Ajda Flašker
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia.
| | | | | | | | | |
Collapse
|