The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
Enhua Shao - One of the best experts on this subject based on the ideXlab platform.
-
regeneration of the zebrafish retinal pigment epithelium after widespread genetic ablation
PLOS Genetics, 2019Co-Authors: Nicholas J Hanovice, Lyndsay L Leach, Kayleigh Slater, Ana E Gabriel, Dwight K Romanovicz, Enhua Shao, Ross F Collery, Edward A Burton, Kira L LathropAbstract:The retinal pigment epithelium (RPE) is a specialized monolayer of pigmented cells within the eye that is critical for maintaining Visual System Function. Diseases affecting the RPE have dire consequences for vision, and the most prevalent of these is atrophic (dry) age-related macular degeneration (AMD), which is thought to result from RPE dysFunction and degeneration. An intriguing possibility for treating RPE degenerative diseases like atrophic AMD is the stimulation of endogenous RPE regeneration; however, very little is known about the mechanisms driving successful RPE regeneration in vivo. Here, we developed a zebrafish transgenic model (rpe65a:nfsB-eGFP) that enabled ablation of large swathes of mature RPE. RPE ablation resulted in rapid RPE degeneration, as well as degeneration of Bruch’s membrane and underlying photoreceptors. Using this model, we demonstrate for the first time that zebrafish are capable of regenerating a Functional RPE monolayer after RPE ablation. Regenerated RPE cells first appear at the periphery of the RPE, and regeneration proceeds in a peripheral-to-central fashion. RPE ablation elicits a robust proliferative response in the remaining RPE. Subsequently, proliferative cells move into the injury site and differentiate into RPE. BrdU incorporation assays demonstrate that the regenerated RPE is likely derived from remaining peripheral RPE cells. Pharmacological disruption using IWR-1, a Wnt signaling antagonist, significantly reduces cell proliferation in the RPE and impairs overall RPE recovery. These data demonstrate that the zebrafish RPE possesses a robust capacity for regeneration and highlight a potential mechanism through which endogenous RPE regenerate in vivo.
-
regeneration of the zebrafish retinal pigment epithelium after widespread genetic ablation
bioRxiv, 2018Co-Authors: Nicholas J Hanovice, Lyndsay L Leach, Kayleigh Slater, Ana E Gabriel, Dwight K Romanovicz, Enhua Shao, Ross F Collery, Edward A BurtonAbstract:ABSTRACT The retinal pigment epithelium (RPE) is a specialized monolayer of pigmented cells within the eye that is critical for maintaining Visual System Function. Diseases affecting the RPE have dire consequences for vision, and the most prevalent of these is atrophic (dry) age-related macular degeneration (AMD), which is thought to result from RPE dysFunction and degeneration. An intriguing possibility for treating RPE degenerative diseases like atrophic AMD is the stimulation of endogenous RPE regeneration; however, very little is known about the mechanisms driving successful RPE regeneration in vivo. Here, we developed a zebrafish transgenic model (rpe65a:nfsB-GFP) that enabled ablation of large swathes of mature RPE. RPE ablation resulted in rapid RPE degeneration, as well as degeneration of Bruch’s membrane and underlying photoreceptors. Using this model, we demonstrate for the first time that larval and adult zebrafish are capable of regenerating a Functional RPE monolayer after RPE ablation. Regenerated RPE cells first appear at the periphery of the RPE, and regeneration proceeds in a peripheral-to-central fashion. RPE ablation elicits a robust proliferative response in the remaining RPE. Subsequently, proliferative cells move into the injury site and differentiate into RPE. BrdU pulse-chase analyses demonstrate that the regenerated RPE is likely derived from remaining peripheral RPE cells. Pharmacological inhibition of Wnt signaling significantly reduces cell proliferation in the RPE and delays overall RPE recovery. These data demonstrate that the zebrafish RPE possesses a robust capacity for regeneration and highlight a potential mechanism through which endogenous RPE regenerate in vivo. SIGNIFICANCE STATEMENT Diseases resulting in RPE degeneration are among the leading causes of blindness worldwide, and no therapy exists that can replace RPE or restore lost vision. One intriguing possibility is the development of therapies focused on stimulating endogenous RPE regeneration. For this to be possible, we must first gain a deeper understanding of the mechanisms underlying RPE regeneration. Here, we ablate mature RPE in zebrafish and demonstrate that zebrafish regenerate RPE after widespread injury. Injury-adjacent RPE proliferate and regenerate RPE, suggesting that they are the source of regenerated tissue. Finally, we demonstrate that Wnt signaling is required for RPE regeneration. These findings establish an in vivo model through which the molecular and cellular underpinnings of RPE regeneration can be further characterized.
Kira L Lathrop - One of the best experts on this subject based on the ideXlab platform.
-
regeneration of the zebrafish retinal pigment epithelium after widespread genetic ablation
PLOS Genetics, 2019Co-Authors: Nicholas J Hanovice, Lyndsay L Leach, Kayleigh Slater, Ana E Gabriel, Dwight K Romanovicz, Enhua Shao, Ross F Collery, Edward A Burton, Kira L LathropAbstract:The retinal pigment epithelium (RPE) is a specialized monolayer of pigmented cells within the eye that is critical for maintaining Visual System Function. Diseases affecting the RPE have dire consequences for vision, and the most prevalent of these is atrophic (dry) age-related macular degeneration (AMD), which is thought to result from RPE dysFunction and degeneration. An intriguing possibility for treating RPE degenerative diseases like atrophic AMD is the stimulation of endogenous RPE regeneration; however, very little is known about the mechanisms driving successful RPE regeneration in vivo. Here, we developed a zebrafish transgenic model (rpe65a:nfsB-eGFP) that enabled ablation of large swathes of mature RPE. RPE ablation resulted in rapid RPE degeneration, as well as degeneration of Bruch’s membrane and underlying photoreceptors. Using this model, we demonstrate for the first time that zebrafish are capable of regenerating a Functional RPE monolayer after RPE ablation. Regenerated RPE cells first appear at the periphery of the RPE, and regeneration proceeds in a peripheral-to-central fashion. RPE ablation elicits a robust proliferative response in the remaining RPE. Subsequently, proliferative cells move into the injury site and differentiate into RPE. BrdU incorporation assays demonstrate that the regenerated RPE is likely derived from remaining peripheral RPE cells. Pharmacological disruption using IWR-1, a Wnt signaling antagonist, significantly reduces cell proliferation in the RPE and impairs overall RPE recovery. These data demonstrate that the zebrafish RPE possesses a robust capacity for regeneration and highlight a potential mechanism through which endogenous RPE regenerate in vivo.
Hollis T. Cline - One of the best experts on this subject based on the ideXlab platform.
-
Electrophysiological Recording for Study of Xenopus Retinotectal Circuitry.
Cold Spring Harbor protocols, 2021Co-Authors: Yuhao Luo, Wanhua Shen, Hollis T. ClineAbstract:The innervation of the optic tectum of Xenopus by retinal ganglion cells controls Visual information processing and behavioral output. Several indicators can be used to evaluate the Functional inputs/outputs of tectal neurons, such as spontaneous activity, Visually evoked currents, temporal receptive fields, and spatial receptive fields. Analysis of multiple Functional properties in the same neurons allows increased understanding of mechanisms underlying Visual System Function and plasticity. Patch-clamp recordings combined with gene expression or morpholino-mediated knockdown techniques have been especially powerful in the study of specific genes during development and circuit Function. The protocol described here provides instructions for performing in vivo electrophysiological recordings from individual tectal neurons to study retinotectal circuitry in the developing Xenopus tectum.
-
insulin receptor signaling regulates synapse number dendritic plasticity and circuit Function in vivo
Neuron, 2008Co-Authors: Shu Ling Chiu, Chih Ming Chen, Hollis T. ClineAbstract:Insulin receptor signaling has been postulated to play a role in synaptic plasticity; however, the Function of the insulin receptor in CNS is not clear. To test whether insulin receptor signaling affects Visual System Function, we recorded light-evoked responses in optic tectal neurons in living Xenopus tadpoles. Tectal neurons transfected with dominant-negative insulin receptor (dnIR), which reduces insulin receptor phosphorylation, or morpholino against insulin receptor, which reduces total insulin receptor protein level, have significantly smaller light-evoked responses than controls. dnIR-expressing neurons have reduced synapse density as assessed by EM, decreased AMPA mEPSC frequency, and altered experience-dependent dendritic arbor structural plasticity, although synaptic vesicle release probability, assessed by paired-pulse responses, synapse maturation, assessed by AMPA/NMDA ratio and ultrastructural criteria, are unaffected by dnIR expression. These data indicate that insulin receptor signaling regulates circuit Function and plasticity by controlling synapse density.
Nicholas J Hanovice - One of the best experts on this subject based on the ideXlab platform.
-
regeneration of the zebrafish retinal pigment epithelium after widespread genetic ablation
PLOS Genetics, 2019Co-Authors: Nicholas J Hanovice, Lyndsay L Leach, Kayleigh Slater, Ana E Gabriel, Dwight K Romanovicz, Enhua Shao, Ross F Collery, Edward A Burton, Kira L LathropAbstract:The retinal pigment epithelium (RPE) is a specialized monolayer of pigmented cells within the eye that is critical for maintaining Visual System Function. Diseases affecting the RPE have dire consequences for vision, and the most prevalent of these is atrophic (dry) age-related macular degeneration (AMD), which is thought to result from RPE dysFunction and degeneration. An intriguing possibility for treating RPE degenerative diseases like atrophic AMD is the stimulation of endogenous RPE regeneration; however, very little is known about the mechanisms driving successful RPE regeneration in vivo. Here, we developed a zebrafish transgenic model (rpe65a:nfsB-eGFP) that enabled ablation of large swathes of mature RPE. RPE ablation resulted in rapid RPE degeneration, as well as degeneration of Bruch’s membrane and underlying photoreceptors. Using this model, we demonstrate for the first time that zebrafish are capable of regenerating a Functional RPE monolayer after RPE ablation. Regenerated RPE cells first appear at the periphery of the RPE, and regeneration proceeds in a peripheral-to-central fashion. RPE ablation elicits a robust proliferative response in the remaining RPE. Subsequently, proliferative cells move into the injury site and differentiate into RPE. BrdU incorporation assays demonstrate that the regenerated RPE is likely derived from remaining peripheral RPE cells. Pharmacological disruption using IWR-1, a Wnt signaling antagonist, significantly reduces cell proliferation in the RPE and impairs overall RPE recovery. These data demonstrate that the zebrafish RPE possesses a robust capacity for regeneration and highlight a potential mechanism through which endogenous RPE regenerate in vivo.
-
regeneration of the zebrafish retinal pigment epithelium after widespread genetic ablation
bioRxiv, 2018Co-Authors: Nicholas J Hanovice, Lyndsay L Leach, Kayleigh Slater, Ana E Gabriel, Dwight K Romanovicz, Enhua Shao, Ross F Collery, Edward A BurtonAbstract:ABSTRACT The retinal pigment epithelium (RPE) is a specialized monolayer of pigmented cells within the eye that is critical for maintaining Visual System Function. Diseases affecting the RPE have dire consequences for vision, and the most prevalent of these is atrophic (dry) age-related macular degeneration (AMD), which is thought to result from RPE dysFunction and degeneration. An intriguing possibility for treating RPE degenerative diseases like atrophic AMD is the stimulation of endogenous RPE regeneration; however, very little is known about the mechanisms driving successful RPE regeneration in vivo. Here, we developed a zebrafish transgenic model (rpe65a:nfsB-GFP) that enabled ablation of large swathes of mature RPE. RPE ablation resulted in rapid RPE degeneration, as well as degeneration of Bruch’s membrane and underlying photoreceptors. Using this model, we demonstrate for the first time that larval and adult zebrafish are capable of regenerating a Functional RPE monolayer after RPE ablation. Regenerated RPE cells first appear at the periphery of the RPE, and regeneration proceeds in a peripheral-to-central fashion. RPE ablation elicits a robust proliferative response in the remaining RPE. Subsequently, proliferative cells move into the injury site and differentiate into RPE. BrdU pulse-chase analyses demonstrate that the regenerated RPE is likely derived from remaining peripheral RPE cells. Pharmacological inhibition of Wnt signaling significantly reduces cell proliferation in the RPE and delays overall RPE recovery. These data demonstrate that the zebrafish RPE possesses a robust capacity for regeneration and highlight a potential mechanism through which endogenous RPE regenerate in vivo. SIGNIFICANCE STATEMENT Diseases resulting in RPE degeneration are among the leading causes of blindness worldwide, and no therapy exists that can replace RPE or restore lost vision. One intriguing possibility is the development of therapies focused on stimulating endogenous RPE regeneration. For this to be possible, we must first gain a deeper understanding of the mechanisms underlying RPE regeneration. Here, we ablate mature RPE in zebrafish and demonstrate that zebrafish regenerate RPE after widespread injury. Injury-adjacent RPE proliferate and regenerate RPE, suggesting that they are the source of regenerated tissue. Finally, we demonstrate that Wnt signaling is required for RPE regeneration. These findings establish an in vivo model through which the molecular and cellular underpinnings of RPE regeneration can be further characterized.
Ronen Segev - One of the best experts on this subject based on the ideXlab platform.
-
Visual receptive field properties of cells in the optic tectum of the archer fish
Journal of neurophysiology, 2013Co-Authors: Mor Ben-tov, Ivgeny Kopilevich, Opher Donchin, Ohad Ben-shahar, Chen Giladi, Ronen SegevAbstract:The archer fish is well known for its extreme Visual behavior in shooting water jets at prey hanging on vegetation above water. This fish is a promising model in the study of Visual System Function because it can be trained to respond to artificial targets and thus to provide valuable psychophysical data. Although much behavioral data have indeed been collected over the past two decades, little is known about the Functional organization of the main Visual area supporting this Visual behavior, namely, the fish optic tectum. In this article we focus on a fundamental aspect of this Functional organization and provide a detailed analysis of receptive field properties of cells in the archer fish optic tectum. Using extracellular measurements to record activities of single cells, we first measure their retinotectal mapping. We then determine their receptive field properties such as size, selectivity for stimulus direction and orientation, tuning for spatial frequency, and tuning for temporal frequency. Finally, on the basis of all these measurements, we demonstrate that optic tectum cells can be classified into three categories: orientation-tuned cells, direction-tuned cells, and direction-agnostic cells. Our results provide an essential basis for future investigations of information processing in the archer fish Visual System.
