scholarly journals Evidence of Müller glia conversion into retina ganglion cells using Neurogenin2

2018 ◽  
Author(s):  
Roberta Pereira de Melo Guimarães ◽  
Bruna Soares Landeira ◽  
Diego Marques Coelho ◽  
Daiane Cristina Ferreira Golbert ◽  
Mariana S. Silveira ◽  
...  
Keyword(s):  
Ganglion Cells ◽  
Amacrine Cells ◽  
The Elderly ◽  
Retinal Cell ◽  
Muller Glia ◽  
Müller Glia ◽  
Neuronal Genes ◽  
Consistent Increase ◽  
Induced Neurons

AbstractMacular Degeneration, Glaucoma, and Retinitis Pigmentosa are all leading causes of irreversible visual impairment in the elderly, affecting hundreds of millions of patients. Müller glia cells (MGC), the main type of glia found in the vertebrate retina, can resume proliferation in the adult injured retina and contribute to tissue repair. Also, MGC can be genetically reprogrammed through the expression of the transcription factor (TF) Achaete-scute homolog 1 (ASCL1) into induced neurons (iNs), displaying key hallmarks of photoreceptors, bipolar and amacrine cells, which may contribute to regenerate the damaged retina. Here, we show that the TF neurogenin 2 (NEUROG2) is also sufficient to lineage-reprogram MGC into iNs. The efficiency of MGC lineage conversion by NEUROG2 is similar to that observed after expression of ASCL1. However, reprogramming efficiency is affected by previous exposure to EGF and FGF2 during the expansion of MGC population. Transduction of either Neurog2 or Ascl1 led to the upregulation of key retina neuronal genes in MGC-derived iNs, but only NEUROG2 induced a consistent increase in the expression of putative retinal ganglion cell (RGC) genes. In vivo electroporation of Neurog2 in the neonatal retina also induced a shift in the generation of retinal cell subtypes, favoring the differentiation RGCs at the expense of MGCs. Altogether, our data indicate that Neurog2 induces lineage conversion of MGCs into RGC-like iNs.

scholarly journals Pressure-dependent modulation of inward-rectifying K+ channels: implications for cation homeostasis and K+ dynamics in glaucoma

2019 ◽  
Vol 317 (2) ◽  
pp. C375-C389
Author(s):  
Rachel A. Fischer ◽  
Abigail L. Roux ◽  
Lauren K. Wareham ◽  
Rebecca M. Sappington
Keyword(s):  
Ganglion Cells ◽  
Primary Cultures ◽  
Elevated Pressure ◽  
Muller Glia ◽  
Müller Glia ◽  
Cation Homeostasis ◽  
K2p Channels ◽  
And Function

Glaucoma is the leading cause of blindness worldwide, resulting from degeneration of retinal ganglion cells (RGCs), which form the optic nerve. Prior to structural degeneration, RGCs exhibit physiological deficits. Müller glia provide homeostatic regulation of ions that supports RGC physiology through a process called K+ siphoning. Recent studies suggest that several retinal conditions, including glaucoma, involve changes in the expression of K+ channels in Müller glia. To clarify whether glaucoma-related stressors directly alter expression and function of K+ channels in Müller glia, we examined changes in the expression of inwardly rectifying K+ (Kir) channels and two-pore domain (K2P) channels in response to elevated intraocular pressure (IOP) in vivo and in vitro in primary cultures of Müller glia exposed to elevated hydrostatic pressure. We then measured outcomes of cell health, cation homeostasis, and cation flux in Müller glia cultures. Transcriptome analysis in a murine model of microbead-induced glaucoma revealed pressure-dependent downregulation of Kir and K2P channels in vivo. Changes in the expression and localization of Kir and K2P channels in response to elevated pressure were also found in Müller glia in vitro. Finally, we found that elevated pressure compromises the plasma membrane of Müller glia and induces cation dyshomeostasis that involves changes in ion flux through cation channels. Pressure-induced changes in cation flux precede both cation dyshomeostasis and membrane compromise. Our findings have implications for Müller glia responses to pressure-related conditions, i.e., glaucoma, and identify cation dyshomeostasis as a potential contributor to electrophysiological impairment observed in RGCs of glaucomatous retina.

scholarly journals Directed robust generation of functional retinal ganglion cells from Müller glia

2019 ◽  
Author(s):  
Dongchang Xiao ◽  
Suo Qiu ◽  
Xiuting Huang ◽  
Rong Zhang ◽  
Qiannan Lei ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Visual Pathway ◽  
Retinal Ganglion ◽  
Muller Glia ◽  
Müller Glia ◽  
Visual Responses ◽  
Promising Alternative

AbstractGlaucoma and optic neuropathies cause progressive and irreversible degeneration of retinal ganglion cells (RGCs) and the optic nerve and are currently without any effective treatment. Previous research into cell replacement therapy of these neurodegenerative diseases has been stalled due to the limited capability for grafted RGCs to integrate into the retina and project properly along the long visual pathway to reach their brain targets. In vivo RGC regeneration would be a promising alternative approach but mammalian retinas lack regenerative capacity even though cold-blood vertebrates such as zebrafish have the full capacity to regenerate a damaged retina using Müller glia (MG) as retinal stem cells. Nevertheless, mammalian MG undergo limited neurogenesis when stimulated by retinal injury. Therefore, a fundamental question that remains to be answered is whether MG can be induced to efficiently regenerate functional RGCs for vision restoration in mammals. Here we show that without stimulating proliferation, the transcription factor (TF) Math5 together with a Brn3 TF family member are able to reprogram mature mouse MG into RGCs with exceedingly high efficiency while either alone has no or limited capacity. The reprogrammed RGCs extend long axons that make appropriate intra-retinal and extra-retinal projections through the entire visual pathway including the optic nerve, optic chiasm and optic tract to innervate both image-forming and non-image-forming brain targets. They exhibit typical neuronal electrophysiological properties and improve visual responses in two glaucoma mouse models: Brn3b null mutant mice and mice with the optic nerve crushed (ONC). Together, our data provide evidence that mammalian MG can be reprogrammed by defined TFs to achieve robust in vivo regeneration of functional RGCs as well as a promising new therapeutic approach to restore vision to patients with glaucoma and other optic neuropathies.

Development of cholinergic amacrine cell stratification in the ferret retina and the effects of early excitotoxic ablation

2001 ◽  
Vol 18 (4) ◽  
pp. 559-570 ◽  
Author(s):  
B.E. REESE ◽  
M.A. RAVEN ◽  
K.A. GIANNOTTI ◽  
P.T. JOHNSON
Keyword(s):  
Ganglion Cell ◽  
Ganglion Cells ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Cell Types ◽  
Retinal Cell ◽  
Inner Plexiform Layer ◽  
Retinal Ganglion ◽  
Outer Border ◽  
Cholinergic Amacrine Cells

The present study has examined the emergence of cholinergic stratification within the developing inner plexiform layer (IPL), and the effect of ablating the cholinergic amacrine cells on the formation of other stratifications within the IPL. The population of cholinergic amacrine cells in the ferret's retina was identified as early as the day of birth, but their processes did not form discrete strata until the end of the first postnatal week. As development proceeded over the next five postnatal weeks, so the positioning of the cholinergic strata shifted within the IPL toward the outer border, indicative of the greater ingrowth and elaboration of processes within the innermost parts of the IPL. To examine whether these cholinergic strata play an instructive role upon the development of other stratifications which form within the IPL, one-week-old ferrets were treated with l-glutamate in an attempt to ablate the population of cholinergic amacrine cells. Such treatment was shown to be successful, eliminating all of the cholinergic amacrine cells as well as the alpha retinal ganglion cells in the central retina. The remaining ganglion cell classes as well as a few other retinal cell types were partially reduced, while other cell types were not affected, and neither retinal histology nor areal growth was compromised in these ferrets. Despite this early loss of the cholinergic amacrine cells, which are eliminated within 24 h, other stratifications within the IPL formed normally, as they do following early elimination of the entire ganglion cell population. While these cholinergic amacrine cells are present well before other cell types have differentiated, apparently neither they, nor the ganglion cells, play a role in determining the depth of stratification for other retinal cell types.

scholarly journals A high-density narrow-field inhibitory retinal interneuron with direct coupling to Müller glia

2020 ◽  
Author(s):  
William N Grimes ◽  
Didem Göz Aytürk ◽  
Mrinalini Hoon ◽  
Takeshi Yoshimatsu ◽  
Clare Gamlin ◽  
...  
Keyword(s):  
Gap Junctions ◽  
Glial Cells ◽  
Amacrine Cell ◽  
Electrical Coupling ◽  
Amacrine Cells ◽  
Muller Glia ◽  
Müller Glia ◽  
Cell Type ◽  
Mammalian Retina ◽  
Ganglion Neurons

AbstractAmacrine cells are interneurons comprising the most diverse cell type in the mammalian retina. They help encode visual features such as edges or directed motion by mediating excitatory and inhibitory interactions between input (i.e. bipolar) and output (i.e. ganglion) neurons in the inner plexiform layer (IPL). Like other brain regions, the retina also contains glial cells that contribute to neurotransmitter uptake, neurovascular control and metabolic regulation. Here, we report that a previously poorly characterized, but relatively abundant, inhibitory amacrine cell type in the mouse retina is coupled directly to Müller glia. Electron microscopic reconstructions of this amacrine type revealed extensive associations with Müller glia, whose processes often completely ensheathe the neurites of this amacrine cell type. Microinjections of small tracer molecules into the somas of these amacrine cells led to selective labelling of nearby Müller glia, leading us to suggest the name “Müller glia-coupled amacrine cell” or MAC. Our electrophysiological data also indicate that MACs release glycine at conventional chemical synapses with amacrine, bipolar and retinal ganglion cells (RGCs), and viral transsynaptic tracing showed connections to several known RGC types. Visually-evoked responses revealed a strong preference for light increments; these “ON” responses were primarily mediated by excitatory chemical synaptic input and direct electrical coupling to other cells. This initial characterization of the MAC provides the first evidence for neuron-glia coupling in the mammalian retina and identifies the MAC as a potential link between inhibitory processing and glial function.Significance StatementGap junctions between pairs of neurons or glial cells are commonly found throughout the nervous system, and play a myriad of roles including electrical coupling and metabolic exchange. In contrast, gap junctions between neurons and glia cells are rare and poorly understood. Here we report the first evidence for neuron-glia coupling in the mammalian retina, specifically between an abundant (but previously unstudied) inhibitory interneuron and Müller glia.

scholarly journals Expression of a Barhl1a reporter in subsets of retinal ganglion cells and commissural neurons of the developing zebrafish brain

2020 ◽  
Author(s):  
Shahad Albadri ◽  
Olivier Armant ◽  
Tairi Aljand-Geschwill ◽  
Filippo Del Bene ◽  
Matthias Carl ◽  
...  
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Amacrine Cells ◽  
Optic Chiasm ◽  
Retinal Ganglion ◽  
Commissural Neurons ◽  
Axonal Projections ◽  
Underlying Mechanisms ◽  
And Function

AbstractPromoting the regeneration or survival of retinal ganglion cells (RGCs) is one focus of regenerative medicine. Homeobox Barhl transcription factors might be instrumental in these processes. In mammals, only barhl2 is expressed in the retina and is required for both subtype identity acquisition of amacrine cells and for the survival of RGCs downstream of Atoh7, a transcription factor necessary for RGC genesis. The underlying mechanisms of this dual role of Barhl2 in mammals have remained elusive. Whole genome duplication in the teleost lineage generated the barhl1a and barhl2 paralogues. In the Zebrafish retina, Barhl2 functions as determinant of subsets of amacrine cells lineally related to RGCs independently of Atoh7. In contrast, barhl1a expression depends on Atoh7 but its expression dynamics and function have not been studied. Here we describe for the first time a Barhl1a:GFP reporter line in vivo showing that Barhl1a turns on exclusively in subsets of RGCs and their post-mitotic precursors. We also show transient expression of Barhl1a:GFP in diencephalic neurons extending their axonal projections as part of the post-optic commissure, at the time of optic chiasm formation. This work sets the ground for future studies on RGC subtype identity, axonal projections and genetic specification of Barhl1a-positive RGCs and commissural neurons.

Diversity of neuronal phenotypes expressed in monolayer cultures from immature rabbit retina

1994 ◽  
Vol 11 (4) ◽  
pp. 629-642 ◽  
Author(s):  
V. Möckel ◽  
S. Löhrke ◽  
H.-D. Hofmann
Keyword(s):  
Amacrine Cells ◽  
Cell Number ◽  
Retinal Cell ◽  
Gaba Uptake ◽  
Cell Type ◽  
Quisqualic Acid ◽  
Monolayer Cultures ◽  
Dendritic Fields

AbstractWe have used monolayer cultures prepared from early postnatal rabbit retinae (days 2–5) by the sandwich technique to study the capacity of immature neurons to express specific neuronal phenotypes in a homogeneous in vitro environment. Applying morphological, immunocytochemical, and autoradiographic criteria, we demonstrate that a variety of phenotypes could be distinguished after 7–14 days in vitro, and correlated with known retinal cell types. Bipolar cell-like neurons (approximately 4% of total cell number) were identified by cell type-specific monoclonal antibodies (115A10) and their characteristic bipolar morphology. Small subpopulations (about 1%) of GABA-immunoreactive neurons acquired elaborate morphologies strikingly similar to those of A- and B-type horizontal cells. Amongst putative amacrine cells several different subpopulations could be classified. GABA-immunoreactive amacrine-like neurons (6.5%), which also showed high affinity [3H]-GABA uptake, comprised cells of varying size and shape and could be subdivided into subpopulations with respect to their response to different glutamate receptor agonists (NMDA, kainic acid, quisqualic acid). In addition, a small percentage of [3H]-GABA accumulating cells with large dendritic fields showed tyrosine-hydroxylase immunoreactivity. Presumptive glycinergic amacrine cells (18.5%) were rather uniform in shape and had small dendritic fields. Release of [3H]-glycine from these neurons was evoked by kainic and quisqualic acid but not by NMDA. Small [3H]-glutamate accumulating neurons with few short processes were the most frequent cell type (73%). This cell type also exhibited opsin immunoreactivity and probably represented incompletely differentiated photoreceptor cells. Summing the numbers of characterized cells indicated that we were able to attribute a defined retinal phenotype to most, if not all of the cultured neurons. Thus, we have demonstrated that immature neuronal cells growing in monolayer cultures, in the absence of a structured environment, are capable of maintaining or producing specific morphological and functional properties corresponding to those expressed in vivo. These results stress the importance of intrinsic factors for the regulation of neuronal differentiation. On the other hand, morphological differentiation was far from perfect indicating the requirement for regulatory factors.

scholarly journals Characterization of retinal regeneration in adult zebrafish following multiple rounds of phototoxic lesion

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5646 ◽  
Author(s):  
Alexandra H. Ranski ◽  
Ashley C. Kramer ◽  
Gregory W. Morgan ◽  
Jennifer L. Perez ◽  
Ryan Thummel
Keyword(s):  
Cell Cycle ◽  
Cellular Localization ◽  
Ganglion Cells ◽  
Plexiform Layer ◽  
Inner Plexiform Layer ◽  
Muller Glia ◽  
Müller Glia ◽  
Light Damage ◽  
Retinal Regeneration ◽  
Adult Zebrafish

Müller glia in the zebrafish retina respond to retinal damage by re-entering the cell cycle, which generates large numbers of retinal progenitors that ultimately replace the lost neurons. In this study we compared the regenerative outcomes of adult zebrafish exposed to one round of phototoxic treatment with adult zebrafish exposed to six consecutive rounds of phototoxic treatment. We observed that Müller glia continued to re-enter the cell cycle to produce clusters of retinal progenitors in zebrafish exposed to multiple rounds of phototoxic light. Some abnormalities were noted, however. First, we found that retinas exposed to multiple rounds of damage exhibited a greater loss of photoreceptors at 36 hours of light damage than retinas that were exposed to their first round of light damage. In addition, we found that Müller glia appeared to have an increase in the acute gliotic response in retinas exposed to multiple rounds of light treatment. This was evidenced by cellular hypertrophy, changes in GFAP cellular localization, and transient increases in stat3 and gfap expression. Finally, following the sixth round of phototoxic lesion, we observed a significant increase in mis-localized HuC/D-positive amacrine and ganglion cells in the inner plexiform layer and outer retina, and a decreased number of regenerated blue cone photoreceptors. These data add to recent findings that retinal regeneration in adult zebrafish occurs concomitant with Müller glia reactivity and can result in the generation of aberrant neurons. These data are also the first to demonstrate that Müller glia appear to modify their phenotype in response to multiple rounds of phototoxic lesion, exhibiting an increase in acute gliosis while maintaining a remarkable capacity for long-term regeneration of photoreceptors.

Action Potentials in the Dendrites of Retinal Ganglion Cells

1999 ◽  
Vol 81 (3) ◽  
pp. 1412-1417 ◽  
Author(s):  
Toby J. Velte ◽  
Richard H. Masland
Keyword(s):  
Retinal Ganglion Cells ◽  
Action Potentials ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Muller Glia ◽  
Müller Glia ◽  
Whole Cell ◽  
The Absolute ◽  
Somatic Action Potentials ◽  
Site Of Stimulation

Action potentials in the dendrites of retinal ganglion cells. The somas and dendrites of intact retinal ganglion cells were exposed by enzymatic removal of the overlying endfeet of the Müller glia. Simultaneous whole cell patch recordings were made from a ganglion cell’s dendrite and the cell’s soma. When a dendrite was stimulated with depolarizing current, impulses often propagated to the soma, where they appeared as a mixture of small depolarizations and action potentials. When the soma was stimulated, action potentials always propagated back through the dendrite. The site of initiation of action potentials, as judged by their timing, could be shifted between soma and dendrite by changing the site of stimulation. Applying QX-314 to the soma could eliminate somatic action potentials while leaving dendritic impulses intact. The absolute amplitudes of the dendritic action potentials varied somewhat at different distances from the soma, and it is not clear whether these variations are real or technical. Nonetheless, the qualitative experiments clearly suggest that the dendrites of retinal ganglion cells generate regenerative Na+ action potentials, at least in response to large direct depolarizations.

Sign in / Sign up

Export Citation Format

Share Document