The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform
Holger Gerhardt - One of the best experts on this subject based on the ideXlab platform.
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Vasohibin-1 mediated tubulin detyrosination selectively regulates secondary sprouting and lymphangiogenesis in the zebrafish trunk
'Cold Spring Harbor Laboratory', 2020Co-Authors: De Oliveira Marta Bastos, Katja Meier, Baptiste Coxam, Ilse Geudens, Simone Jung, Anna Szymborska, Holger GerhardtAbstract:ABSTRACT Previous studies have shown that Vasohibin-1 (Vash-1) is stimulated by VEGFs in endothelial cells and that its overexpression interferes with angiogenesis in vivo . Recently, Vasohibin-1 was found to mediate tubulin detyrosination, a post-translational modification that is implicated in many cell functions, such as cell division. Here we used the zebrafish embryo to investigate the cellular and subcellular mechanisms of Vash-1 on endothelial microtubules during formation of the trunk vasculature. We show that microtubules within venous-derived secondary sprouts are strongly and selectively detyrosinated in comparison with other endothelial cells, and that this difference is lost upon vash-1 knockdown. Vasohibin-1 depletion in zebrafish specifically affected secondary sprouting from the Posterior Cardinal Vein, increasing both the number of sprouts and endothelial cell divisions. We show that altering secondary sprout numbers and structure upon vash-1 depletion leads to a failure in the development and specification of lymphatic vessels of the zebrafish trunk. SUMMARY Vasohibin-1 mediated detyrosination of endothelial microtubules is selectively required for adequate behaviour of venous secondary sprouting and subsequent formation of functional lymphatics in the zebrafish trunk.status: publishe
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artery Vein specification in the zebrafish trunk is pre patterned by heterogeneous notch activity and balanced by flow mediated fine tuning
Development, 2019Co-Authors: Ilse Geudens, Katja Meier, Baptiste Coxam, Silvanus Alt, Veronique Gebala, Anneclemence Vion, Andre Rosa, Holger GerhardtAbstract:ABSTRACT How developing vascular networks acquire the right balance of arteries, Veins and lymphatic vessels to efficiently supply and drain tissues is poorly understood. In zebrafish embryos, the robust and regular 50:50 global balance of intersegmental Veins and arteries that form along the trunk prompts the intriguing question of how does the organism keep ‘count’? Previous studies have suggested that the ultimate fate of an intersegmental vessel (ISV) is determined by the identity of the approaching secondary sprout emerging from the Posterior Cardinal Vein. Here, we show that the formation of a balanced trunk vasculature involves an early heterogeneity in endothelial cell behaviour and Notch signalling activity in the seemingly identical primary ISVs that is independent of secondary sprouting and flow. We show that Notch signalling mediates the local patterning of ISVs, and an adaptive flow-mediated mechanism subsequently fine-tunes the global balance of arteries and Veins along the trunk. We propose that this dual mechanism provides the adaptability required to establish a balanced network of arteries, Veins and lymphatic vessels.
Steve F Perry - One of the best experts on this subject based on the ideXlab platform.
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the autonomic nervous system and chromaffin tissue neuroendocrine regulation of catecholamine secretion in non mammalian vertebrates
Autonomic Neuroscience: Basic and Clinical, 2011Co-Authors: Steve F Perry, Anna CapaldoAbstract:If severe enough, periods of acute stress in animals may be associated with the release of catecholamine hormones (noradrenaline and adrenaline) into the circulation; a response termed the acute humoral adrenergic stress response. The release of catecholamines from the sites of storage, the chromaffin cells, is under neuroendocrine control, the complexity of which appears to increase through phylogeny. In the agnathans, the earliest branching vertebrates, the chromaffin cells which are localized predominantly within the heart, lack neuronal innervation and thus catecholamine secretion in these animals is initiated solely by humoral mechanisms. In the more advanced teleost fish, the chromaffin cells are largely confined to the walls of the Posterior Cardinal Vein at the level of the head kidney where they are intermingled with the steroidogenic interrenal cells. Catecholamine secretion from teleost chromaffin cells is regulated by a host of cholinergic and non-cholinergic pathways that ensure sufficient redundancy and flexibility in the secretion process to permit synchronized responses to a myriad of stressors. The complexity of catecholamine secretion control mechanisms continues through the amphibians, reptiles and birds although neural (cholinergic) regulation may become increasingly important in birds. Discrete adrenal glands are present in the non-mammalian tetrapods but unlike in mammals, there is no clear division of a steroidogenic cortex and a chromaffin cell enriched medulla. However, in all groups, there is an obvious intermingling of chromaffin and steroiodogenic cells. The association of the two cell types may be particularly important in the amphibians and birds because like in mammals, the enzyme catalysing the methylation of noradrenaline to adrenaline, PNMT, is under the control of the steroid cortisol.
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desensitisation of chromaffin cell nicotinic receptors does not impede catecholamine secretion during acute hypoxia in rainbow trout oncorhynchus mykiss
The Journal of Experimental Biology, 2000Co-Authors: K N Lapner, C J Montpetit, Steve F PerryAbstract:Experiments were performed on adult rainbow trout (Oncorhynchus mykiss) in vivo using chronically cannulated fish and in situ using a perfused Posterior Cardinal Vein preparation (i) to characterise the desensitisation of chromaffin cell nicotinic receptors and (ii) to assess the ability of fish to secrete catecholamines during acute hypoxia with or without functional nicotinic receptors. Intra-arterial injection of nicotine (6.0×10(−)(7)mol kg(−)(1)) caused a rapid increase in plasma adrenaline and noradrenaline levels; the magnitude of this response was unaffected by an injection of nicotine given 60 min earlier. Evidence for nicotinic receptor desensitisation, however, was provided during continuous intravenous infusion of nicotine (1.3×10(−)(5)mol kg(−)(1)h(−)(1)) in which plasma catecholamine levels increased initially but then returned to baseline levels. To ensure that the decline in circulating catecholamine concentrations during continuous nicotine infusion was not related to changes in storage levels or altered rates of degradation/clearance, in situ Posterior Cardinal Vein preparations were derived from fish previously experiencing 60 min of saline or nicotine infusion. Confirmation of nicotinic receptor desensitisation was provided by demonstrating that the preparations derived from nicotine-infused fish were unresponsive to nicotine (10(−)(5)mol l(−)(1)), yet remained responsive to angiotensin II (500 pmol kg(−)(1)). The in situ experiments demonstrated that desensitisation of the nicotinic receptor occurred within 5 min of receptor stimulation and that resensitisation was established 40 min later. The ability to elevate plasma catecholamine levels during acute hypoxia (40–45 mmHg; 5.3-6.0 kPa) was not impaired in fish experiencing nicotinic receptor desensitisation. Indeed, peak plasma adrenaline levels were significantly higher in the desensitised fish during hypoxia than in controls (263+/−86 versus 69+/−26 nmol l(−)(1); means +/− s.e.m., N=6-9). Thus, the results of the present study demonstrate that activation of preganglionic sympathetic cholinergic nerve fibres and the resultant stimulation of nicotinic receptors is not the sole mechanism for eliciting catecholamine secretion during hypoxia.
Ilse Geudens - One of the best experts on this subject based on the ideXlab platform.
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Vasohibin-1 mediated tubulin detyrosination selectively regulates secondary sprouting and lymphangiogenesis in the zebrafish trunk
'Cold Spring Harbor Laboratory', 2020Co-Authors: De Oliveira Marta Bastos, Katja Meier, Baptiste Coxam, Ilse Geudens, Simone Jung, Anna Szymborska, Holger GerhardtAbstract:ABSTRACT Previous studies have shown that Vasohibin-1 (Vash-1) is stimulated by VEGFs in endothelial cells and that its overexpression interferes with angiogenesis in vivo . Recently, Vasohibin-1 was found to mediate tubulin detyrosination, a post-translational modification that is implicated in many cell functions, such as cell division. Here we used the zebrafish embryo to investigate the cellular and subcellular mechanisms of Vash-1 on endothelial microtubules during formation of the trunk vasculature. We show that microtubules within venous-derived secondary sprouts are strongly and selectively detyrosinated in comparison with other endothelial cells, and that this difference is lost upon vash-1 knockdown. Vasohibin-1 depletion in zebrafish specifically affected secondary sprouting from the Posterior Cardinal Vein, increasing both the number of sprouts and endothelial cell divisions. We show that altering secondary sprout numbers and structure upon vash-1 depletion leads to a failure in the development and specification of lymphatic vessels of the zebrafish trunk. SUMMARY Vasohibin-1 mediated detyrosination of endothelial microtubules is selectively required for adequate behaviour of venous secondary sprouting and subsequent formation of functional lymphatics in the zebrafish trunk.status: publishe
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artery Vein specification in the zebrafish trunk is pre patterned by heterogeneous notch activity and balanced by flow mediated fine tuning
Development, 2019Co-Authors: Ilse Geudens, Katja Meier, Baptiste Coxam, Silvanus Alt, Veronique Gebala, Anneclemence Vion, Andre Rosa, Holger GerhardtAbstract:ABSTRACT How developing vascular networks acquire the right balance of arteries, Veins and lymphatic vessels to efficiently supply and drain tissues is poorly understood. In zebrafish embryos, the robust and regular 50:50 global balance of intersegmental Veins and arteries that form along the trunk prompts the intriguing question of how does the organism keep ‘count’? Previous studies have suggested that the ultimate fate of an intersegmental vessel (ISV) is determined by the identity of the approaching secondary sprout emerging from the Posterior Cardinal Vein. Here, we show that the formation of a balanced trunk vasculature involves an early heterogeneity in endothelial cell behaviour and Notch signalling activity in the seemingly identical primary ISVs that is independent of secondary sprouting and flow. We show that Notch signalling mediates the local patterning of ISVs, and an adaptive flow-mediated mechanism subsequently fine-tunes the global balance of arteries and Veins along the trunk. We propose that this dual mechanism provides the adaptability required to establish a balanced network of arteries, Veins and lymphatic vessels.
Katja Meier - One of the best experts on this subject based on the ideXlab platform.
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Vasohibin-1 mediated tubulin detyrosination selectively regulates secondary sprouting and lymphangiogenesis in the zebrafish trunk
'Cold Spring Harbor Laboratory', 2020Co-Authors: De Oliveira Marta Bastos, Katja Meier, Baptiste Coxam, Ilse Geudens, Simone Jung, Anna Szymborska, Holger GerhardtAbstract:ABSTRACT Previous studies have shown that Vasohibin-1 (Vash-1) is stimulated by VEGFs in endothelial cells and that its overexpression interferes with angiogenesis in vivo . Recently, Vasohibin-1 was found to mediate tubulin detyrosination, a post-translational modification that is implicated in many cell functions, such as cell division. Here we used the zebrafish embryo to investigate the cellular and subcellular mechanisms of Vash-1 on endothelial microtubules during formation of the trunk vasculature. We show that microtubules within venous-derived secondary sprouts are strongly and selectively detyrosinated in comparison with other endothelial cells, and that this difference is lost upon vash-1 knockdown. Vasohibin-1 depletion in zebrafish specifically affected secondary sprouting from the Posterior Cardinal Vein, increasing both the number of sprouts and endothelial cell divisions. We show that altering secondary sprout numbers and structure upon vash-1 depletion leads to a failure in the development and specification of lymphatic vessels of the zebrafish trunk. SUMMARY Vasohibin-1 mediated detyrosination of endothelial microtubules is selectively required for adequate behaviour of venous secondary sprouting and subsequent formation of functional lymphatics in the zebrafish trunk.status: publishe
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artery Vein specification in the zebrafish trunk is pre patterned by heterogeneous notch activity and balanced by flow mediated fine tuning
Development, 2019Co-Authors: Ilse Geudens, Katja Meier, Baptiste Coxam, Silvanus Alt, Veronique Gebala, Anneclemence Vion, Andre Rosa, Holger GerhardtAbstract:ABSTRACT How developing vascular networks acquire the right balance of arteries, Veins and lymphatic vessels to efficiently supply and drain tissues is poorly understood. In zebrafish embryos, the robust and regular 50:50 global balance of intersegmental Veins and arteries that form along the trunk prompts the intriguing question of how does the organism keep ‘count’? Previous studies have suggested that the ultimate fate of an intersegmental vessel (ISV) is determined by the identity of the approaching secondary sprout emerging from the Posterior Cardinal Vein. Here, we show that the formation of a balanced trunk vasculature involves an early heterogeneity in endothelial cell behaviour and Notch signalling activity in the seemingly identical primary ISVs that is independent of secondary sprouting and flow. We show that Notch signalling mediates the local patterning of ISVs, and an adaptive flow-mediated mechanism subsequently fine-tunes the global balance of arteries and Veins along the trunk. We propose that this dual mechanism provides the adaptability required to establish a balanced network of arteries, Veins and lymphatic vessels.
Baptiste Coxam - One of the best experts on this subject based on the ideXlab platform.
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Vasohibin-1 mediated tubulin detyrosination selectively regulates secondary sprouting and lymphangiogenesis in the zebrafish trunk
'Cold Spring Harbor Laboratory', 2020Co-Authors: De Oliveira Marta Bastos, Katja Meier, Baptiste Coxam, Ilse Geudens, Simone Jung, Anna Szymborska, Holger GerhardtAbstract:ABSTRACT Previous studies have shown that Vasohibin-1 (Vash-1) is stimulated by VEGFs in endothelial cells and that its overexpression interferes with angiogenesis in vivo . Recently, Vasohibin-1 was found to mediate tubulin detyrosination, a post-translational modification that is implicated in many cell functions, such as cell division. Here we used the zebrafish embryo to investigate the cellular and subcellular mechanisms of Vash-1 on endothelial microtubules during formation of the trunk vasculature. We show that microtubules within venous-derived secondary sprouts are strongly and selectively detyrosinated in comparison with other endothelial cells, and that this difference is lost upon vash-1 knockdown. Vasohibin-1 depletion in zebrafish specifically affected secondary sprouting from the Posterior Cardinal Vein, increasing both the number of sprouts and endothelial cell divisions. We show that altering secondary sprout numbers and structure upon vash-1 depletion leads to a failure in the development and specification of lymphatic vessels of the zebrafish trunk. SUMMARY Vasohibin-1 mediated detyrosination of endothelial microtubules is selectively required for adequate behaviour of venous secondary sprouting and subsequent formation of functional lymphatics in the zebrafish trunk.status: publishe
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artery Vein specification in the zebrafish trunk is pre patterned by heterogeneous notch activity and balanced by flow mediated fine tuning
Development, 2019Co-Authors: Ilse Geudens, Katja Meier, Baptiste Coxam, Silvanus Alt, Veronique Gebala, Anneclemence Vion, Andre Rosa, Holger GerhardtAbstract:ABSTRACT How developing vascular networks acquire the right balance of arteries, Veins and lymphatic vessels to efficiently supply and drain tissues is poorly understood. In zebrafish embryos, the robust and regular 50:50 global balance of intersegmental Veins and arteries that form along the trunk prompts the intriguing question of how does the organism keep ‘count’? Previous studies have suggested that the ultimate fate of an intersegmental vessel (ISV) is determined by the identity of the approaching secondary sprout emerging from the Posterior Cardinal Vein. Here, we show that the formation of a balanced trunk vasculature involves an early heterogeneity in endothelial cell behaviour and Notch signalling activity in the seemingly identical primary ISVs that is independent of secondary sprouting and flow. We show that Notch signalling mediates the local patterning of ISVs, and an adaptive flow-mediated mechanism subsequently fine-tunes the global balance of arteries and Veins along the trunk. We propose that this dual mechanism provides the adaptability required to establish a balanced network of arteries, Veins and lymphatic vessels.