scholarly journals Glia-Neuron Interactions in the Retina Can Be Studied in Cocultures of Müller Cells and Retinal Ganglion Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
D. M. Skytt ◽  
A. K. Toft-Kehler ◽  
C. T. Brændstrup ◽  
S. Cejvanovic ◽  
I. S. Gurubaran ◽  
...  
Keyword(s):  
Cell Function ◽  
Ganglion Cells ◽  
Glutamate Uptake ◽  
Treatment Strategies ◽  
Müller Cells ◽  
Müller Cell ◽  
Retinal Ganglion ◽  
Muller Cells ◽  
Muller Cell ◽  
The Impact

Glia-neuron partnership is important for inner retinal homeostasis and any disturbances may result in retinal ganglion cell (RGC) death. Müller cells support RGCs with essential functions such as removing excess glutamate and providing energy sources. The aim was to explore the impact of Müller cells on RGC survival. To investigate the Müller cell/RGC interactions we developed a coculture model, in which primary Müller cells were grown in inserts on top of pure primary RGC cultures. The impact of starvation and mitochondrial inhibition on the Müller cell ability to protect RGCs was studied. Moreover, the ability of Müller cells to remove glutamate from the extracellular space was investigated. RGC survival was evaluated by cell viability assays and glutamate uptake was assessed by kinetic uptake assays. We demonstrated a significantly increased RGC survival in presence of untreated and prestarved Müller cells. Additionally, prestarved Müller cells significantly increased RGC survival after mitochondrial inhibition. Finally, we revealed a significantly increased ability to take up glutamate in starved Müller cells. Overall, our study confirms essential roles of Müller cells in RGC survival. We suggest that targeting Müller cell function could have potential for future treatment strategies to prevent blinding neurodegenerative retinal diseases.

Müller cell endfeet at the inner surface of the retina: light microscopy

1988 ◽  
Vol 1 (2) ◽  
pp. 169-180 ◽  
Author(s):  
Zofia Dreher ◽  
Mignon Wegner ◽  
Jonathan Stone
Keyword(s):  
Ganglion Cells ◽  
Müller Cells ◽  
Müller Cell ◽  
Postnatal Life ◽  
Muller Cells ◽  
Regular Array ◽  
Differential Growth ◽  
Cat Retina ◽  
Inner Surface ◽  
Muller Cell

AbstractUsing fractions of the protein spectrum of the cat retina as immunogens, we have generated antibodies with substantial specificity for the Müller cells of the retina of cat, rabbit, guinea pig, and rat. The antibodies appear to bind to the filamentous components of the Müller cells and allow demonstration of the pattern of Müller cell endfeet at the inner surface of the retina, best seen in wholemount preparations. In sections and at the edge of wholemount preparations the somas and processes of the cells can be observed. Müller cells are more evenly distributed over the retina than ganglion cells, indicating that their proliferation continues during the differential growth of retina which continues into postnatal life. The morphology and distribution of the endfeet varies with the structures present at the inner surface of the retina. Where the axon bundles are thick, the endfeet are relatively small and are confined to narrow rows between bundles. Müller cell endfeet are also separated widely by large blood vessels. In both situations, it seems likely that Müller cells and astrocytes both contribute, perhaps competitively, to form the glia limitans of the inner surface of the retina. Where the somas of neurones are densely packed in the ganglion cell layer, the endfeet are small and numerous, forming rings around the somas. Where axon bundles, vessels, and somas are sparse, the endfeet appear largest and form a regular array.

scholarly journals Activated Müller Cells Involved in ATP-Induced Upregulation of P2X7Receptor Expression and Retinal Ganglion Cell Death

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Ying Xue ◽  
Yuting Xie ◽  
Bo Xue ◽  
Nan Hu ◽  
Guowei Zhang ◽  
...  
Keyword(s):  
Protein Expression ◽  
Ganglion Cell ◽  
Intravitreal Injection ◽  
Retinal Ganglion Cell ◽  
Cell Activation ◽  
Müller Cells ◽  
Müller Cell ◽  
Retinal Ganglion ◽  
Muller Cells ◽  
Muller Cell

P2X7receptor (P2X7R), an ATP-gated ion channel, plays an important role in glaucomatous retinal ganglion cell (RGC) apoptotic death, in which activated retinal Müller glial cells may be involved by releasing ATP. In the present study, we investigated whether and how activated Müller cells may induce changes in P2X7R expression in RGCs by using immunohistochemistry and Western blot techniques. Intravitreal injection of DHPG, a group I metabotropic glutamate receptor (mGluR I) agonist, induced upregulation of GFAP expression, suggestive of Müller cell activation (gliosis), as we previously reported. Accompanying Müller cell activation, P2X7R protein expression was upregulated, especially in the cells of ganglion cell layer (GCL), which was reversed by coinjection of brilliant blue G (BBG), a P2X7R blocker. In addition, intravitreal injection of ATP also induced upregulation of P2X7R protein expression. Similar results were observed in cultured retinal neurons by ATP treatment. Moreover, both DHPG and ATP intravitreal injection induced a reduction in the number of fluorogold retrogradely labeled RGCs, and the DHPG effect was partially rescued by coinjection of BBG. All these results suggest that activated Müller cells may release ATP and, in turn, induce upregulation of P2X7R expression in the cells of GCL, thus contributing to RGC death.

scholarly journals VEGF-Independent Activation of Müller Cells by the Vitreous from Proliferative Diabetic Retinopathy Patients

2021 ◽  
Vol 22 (4) ◽  
pp. 2179
Author(s):  
Sara Rezzola ◽  
Jessica Guerra ◽  
Adwaid Manu Krishna Chandran ◽  
Alessandra Loda ◽  
Anna Cancarini ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
Growth Factor ◽  
Proliferative Diabetic Retinopathy ◽  
Cell Activation ◽  
Müller Cells ◽  
Müller Cell ◽  
Muller Cells ◽  
Anti Vegf ◽  
Muller Cell ◽  
The Impact

Proliferative diabetic retinopathy (PDR), a major complication of diabetes mellitus, results from an inflammation-sustained interplay among endothelial cells, neurons, and glia. Even though anti-vascular endothelial growth factor (VEGF) interventions represent the therapeutic option for PDR, they are only partially efficacious. In PDR, Müller cells undergo reactive gliosis, produce inflammatory cytokines/chemokines, and contribute to scar formation and retinal neovascularization. However, the impact of anti-VEGF interventions on Müller cell activation has not been fully elucidated. Here, we show that treatment of MIO-M1 Müller cells with vitreous obtained from PDR patients stimulates cell proliferation and motility, and activates various intracellular signaling pathways. This leads to cytokine/chemokine upregulation, a response that was not mimicked by treatment with recombinant VEGF nor inhibited by the anti-VEGF drug ranibizumab. In contrast, fibroblast growth factor-2 (FGF2) induced a significant overexpression of various cytokines/chemokines in MIO-M1 cells. In addition, the FGF receptor tyrosine kinase inhibitor BGJ398, the pan-FGF trap NSC12, the heparin-binding protein antagonist N-tert-butyloxycarbonyl-Phe-Leu-Phe-Leu-Phe Boc2, and the anti-inflammatory hydrocortisone all inhibited Müller cell activation mediated by PDR vitreous. These findings point to a role for various modulators beside VEGF in Müller cell activation and pave the way to the search for novel therapeutic strategies in PDR.

scholarly journals Contribution of Müller cells toward the regulation of photoreceptor outer segment assembly

2004 ◽  
Vol 1 (3) ◽  
pp. 291-296 ◽  
Author(s):  
XIAOFEI WANG ◽  
ALESSANDRO IANNACCONE ◽  
MONICA M. JABLONSKI
Keyword(s):  
Outer Segment ◽  
Cell Function ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Müller Cells ◽  
Müller Cell ◽  
Muller Cells ◽  
Outer Segments ◽  
Pigment Epithelium Derived Factor ◽  
Muller Cell

The assembly of photoreceptor outer segments into stacked discs is a complicated process, the precise regulation of which remains a mystery. It is known that the integrity of the outer segment is heavily dependent upon surrounding cell types including the retinal pigment epithelium and Müller cells; however the role played by Müller cells within this photoreceptor-specific process has not been fully explored. Using an RPE-deprived but otherwise intact Xenopus laevis eye rudiment preparation, we reveal that Müller cell involvement in outer segment assembly is dependent upon the stimulus provided to the retina. Pigment epithelium-derived factor is able to support proper membrane folding after inhibition of Müller cell metabolism by alpha-aminoadipic acid, while isopropyl beta-D-thiogalactoside, a permissive glycan, requires intact Müller cell function. These results demonstrate that both intrinsic and extrinsic redundant mechanisms exist to support the ability of photoreceptors to properly assemble their outer segments. Our study further suggests that the receptor for pigment epithelium-derived factor resides in photoreceptors themselves while that for permissive glycans is likely localized to Müller cells, which in turn communicate with photoreceptors to promote proper membrane assembly.

Relationships between Müller cells and neurons in a primitive tetrapod, the Australian lungfish

1997 ◽  
Vol 14 (4) ◽  
pp. 795-800 ◽  
Author(s):  
Stephen R. Robinson
Keyword(s):  
Ganglion Cells ◽  
Horizontal Cell ◽  
Müller Cells ◽  
Amacrine Cells ◽  
Müller Cell ◽  
Muller Cells ◽  
Cone Photoreceptors ◽  
Rod Photoreceptors ◽  
Muller Cell ◽  
Australian Lungfish

AbstractWe recently proposed a model of cytogenesis which assumes that primitive ancestral mammals and premammalian vertebrates had a retinal composition that consisted of about seven neurons per Müller cell, comprising 1–2 cone photoreceptors, 1–2 rod photoreceptors, 2–3 bipolar cells, 1–2 amacrine cells, less than 1 ganglion cell, and less than 1 horizontal cell (Reichenbach & Robinson, 1995). The Australian lungfish (Neoceratodus forsten) closely resembles the lobe-finned ancestors of land vertebrates, and has an extremely plesiomorphic nervous system. The present study, therefore, has examined the relative frequencies of retinal neurons and Müller cells (identified by immunolabelling for glutamine synthetase) in the lungfish retina. It was found that for each Müller cell there is an average of 1.9 cone photoreceptors, 1.7 rod photoreceptors, 3.1 amacrine/bipolar/horizontal cells, and 0.6 ganglion cells; amounting to a ratio of 7.3 neurons per Müller cell. These results support our conjecture that the sequence of cytogenesis in mammals is constrained by a developmental program that predates the evolution of mammals. The study also provides the first detailed morphological descriptions of lungfish Müller cells and their relationship with adjacent neurons. It was found that individual Müller cells in lungfish have a volume (more than 12,000 μm3) that is an order of magnitude higher than in mammals, yet the proportion of total retinal volume occupied by these cells (20%) is very similar.

scholarly journals Release of taurine and glutamate contributes to cell volume regulation in human retinal Müller cells: differences in modulation by calcium

2018 ◽  
Vol 120 (3) ◽  
pp. 973-984 ◽  
Author(s):  
Vanina Netti ◽  
Alejandro Pizzoni ◽  
Martha Pérez-Domínguez ◽  
Paula Ford ◽  
Herminia Pasantes-Morales ◽  
...  
Keyword(s):  
Cell Volume ◽  
Regulatory Volume Decrease ◽  
Cell Volume Regulation ◽  
Müller Cells ◽  
Anion Channel ◽  
Müller Cell ◽  
Regulatory Mechanisms ◽  
Muller Cells ◽  
Muller Cell ◽  
Volume Decrease

Neuronal activity in the retina generates osmotic gradients that lead to Müller cell swelling, followed by a regulatory volume decrease (RVD) response, partially due to the isoosmotic efflux of KCl and water. However, our previous studies in a human Müller cell line (MIO-M1) demonstrated that an important fraction of RVD may also involve the efflux of organic solutes. We also showed that RVD depends on the swelling-induced Ca2+ release from intracellular stores. Here we investigate the contribution of taurine (Tau) and glutamate (Glu), the most relevant amino acids in Müller cells, to RVD through the volume-regulated anion channel (VRAC), as well as their Ca2+ dependency in MIO-M1 cells. Swelling-induced [3H]Tau/[3H]Glu release was assessed by radiotracer assays and cell volume by fluorescence videomicroscopy. Results showed that cells exhibited an osmosensitive efflux of [3H]Tau and [3H]Glu (Tau > Glu) blunted by VRAC inhibitors 4-(2-butyl-6,7-dichloro-2-cyclopentylindan-1-on-5-yl)-oxybutyric acid and carbenoxolone reducing RVD. Only [3H]Tau efflux was mainly dependent on Ca2+ release from intracellular stores. RVD was unaffected in a Ca2+-free medium, probably due to Ca2+-independent Tau and Glu release, but was reduced by chelating intracellular Ca2+. The inhibition of phosphatidylinositol-3-kinase reduced [3H]Glu efflux but also the Ca2+-insensitive [3H]Tau fraction and decreased RVD, providing evidence of the relevance of this Ca2+-independent pathway. We propose that VRAC-mediated Tau and Glu release has a relevant role in RVD in Müller cells. The observed disparities in Ca2+ influence on amino acid release suggest the presence of VRAC isoforms that may differ in substrate selectivity and regulatory mechanisms, with important implications for retinal physiology. NEW & NOTEWORTHY The mechanisms for cell volume regulation in retinal Müller cells are still unknown. We show that swelling-induced taurine and glutamate release mediated by the volume-regulated anion channel (VRAC) largely contributes the to the regulatory volume decrease response in a human Müller cell line. Interestingly, the hypotonic-induced efflux of these amino acids exhibits disparities in Ca2+-dependent and -independent regulatory mechanisms, which strongly suggests that Müller cells may express different VRAC heteromers formed by the recently discovered leucine-rich repeat containing 8 (LRRC8) proteins.

scholarly journals Effects of Adult Müller Cells and Their Conditioned Media on the Survival of Stem Cell-Derived Retinal Ganglion Cells

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1759
Author(s):  
Xandra Pereiro ◽  
Adam M. Miltner ◽  
Anna La Torre ◽  
Elena Vecino
Keyword(s):  
Stem Cell ◽  
Cell Survival ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Müller Cells ◽  
Cell Types ◽  
Conditioned Media ◽  
Retinal Ganglion ◽  
Muller Cells ◽  
Müller Glia

Retinal neurons, particularly retinal ganglion cells (RGCs), are susceptible to the degenerative damage caused by different inherited conditions and environmental insults, leading to irreversible vision loss and, ultimately, blindness. Numerous strategies are being tested in different models of degeneration to restore vision and, in recent years, stem cell technologies have offered novel avenues to obtain donor cells for replacement therapies. To date, stem cell–based transplantation in the retina has been attempted as treatment for photoreceptor degeneration, but the same tools could potentially be applied to other retinal cell types, including RGCs. However, RGC-like cells are not an abundant cell type in stem cell–derived cultures and, often, these cells degenerate over time in vitro. To overcome this limitation, we have taken advantage of the neuroprotective properties of Müller glia (one of the main glial cell types in the retina) and we have examined whether Müller glia and the factors they secrete could promote RGC-like cell survival in organoid cultures. Accordingly, stem cell-derived RGC-like cells were co-cultured with adult Müller cells or Müller cell-conditioned media was added to the cultures. Remarkably, RGC-like cell survival was substantially enhanced in both culture conditions, and we also observed a significant increase in their neurite length. Interestingly, Atoh7, a transcription factor required for RGC development, was up-regulated in stem cell-derived organoids exposed to conditioned media, suggesting that Müller cells may also enhance the survival of retinal progenitors and/or postmitotic precursor cells. In conclusion, Müller cells and the factors they release promote organoid-derived RGC-like cell survival, neuritogenesis, and possibly neuronal maturation.

scholarly journals Mediation of FoxO1 in Activated Neuroglia Deficient for Nucleoside Diphosphate Kinase B during Vascular Degeneration

Neuroglia ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 280-291 ◽  
Author(s):  
Yi Qiu ◽  
Hongpeng Huang ◽  
Anupriya Chatterjee ◽  
Loïc Teuma ◽  
Fabienne Baumann ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
Cell Activation ◽  
Neurovascular Unit ◽  
Nucleoside Diphosphate Kinase ◽  
Müller Cells ◽  
Müller Cell ◽  
Muller Cells ◽  
Nucleoside Diphosphate Kinase B ◽  
Muller Cell ◽  
Underlying Mechanisms

The pathogenesis of diabetic retinopathy is closely associated with the breakdown of the neurovascular unit including the glial cells. Deficiency of nucleoside diphosphate kinase B (NDPK-B) results in retinal vasoregression mimicking diabetic retinopathy. Increased retinal expression of Angiopoietin-2 (Ang-2) initiates vasoregression. In this study, Müller cell activation, glial Ang-2 expression, and the underlying mechanisms were investigated in streptozotocin-induced diabetic NDPK-B deficient (KO) retinas and Müller cells isolated from the NDPK-B KO retinas. Müller cells were activated and Ang-2 expression was predominantly increased in Müller cells in normoglycemic NDPK-B KO retinas, similar to diabetic wild type (WT) retinas. Diabetes induction in the NDPK-B KO mice did not further increase its activation. Additionally, cultured NDPK-B KO Müller cells were more activated and showed higher Ang-2 expression than WT cells. Müller cell activation and Ang-2 elevation were observed upon high glucose treatment in WT, but not in NDPK-B KO cells. Moreover, increased levels of the transcription factor forkhead box protein O1 (FoxO1) were detected in non-diabetic NDPK-B KO Müller cells. The siRNA-mediated knockdown of FoxO1 in NDPK-B deficient cells interfered with Ang-2 upregulation. These data suggest that FoxO1 mediates Ang-2 upregulation induced by NDPK-B deficiency in the Müller cells and thus contributes to the onset of retinal vascular degeneration.

Ranibizumab prevents Müller cell edema by decreasing VEGF-A in diabetic retinopathy

2020 ◽  
Author(s):  
Tianqin Wang ◽  
Chaoyang Zhang ◽  
Hai Xie ◽  
Qiuxue Yi ◽  
Dandan Liu ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
Potassium Level ◽  
Müller Cells ◽  
Müller Cell ◽  
Intracellular Sodium ◽  
K Channel ◽  
Diabetic Rat ◽  
Muller Cells ◽  
Intracellular Potassium ◽  
Muller Cell

Abstract Background: Diabetic macular edema (DME) is the most common cause of vision loss in patients with diabetic retinopathy. The efficacy of anti-VEGF therapy has been well demonstrated and become the standard of care in the management of DME. The present study is to explore the possible mechanism(s) of ranibizumab in protecting Müller cells from cellular edema in experimental diabetic retinopathy. Methods: Sprague-Dawley rats were rendered diabetes with intraperitoneal injection of streptozotocin. Intravitreal injection of ranibizumab was performed 8 weeks after diabetes onset. Four weeks later, the rats were killed and the retinas were harvested for examination. rMC-1 cells (rat Müller cell line) were treated with glyoxal for 24 hours, with or without ranibizumab. Cell viability was detected with CCK-8 assay. The expressions of inwardly rectifying K + channel 4.1 (Kir4.1), aquaporin 4 (AQP4), Dystrophin 71 (Dp71), vascular endothelial growth factor A (VEGF-A), glutamine synthetase (GS) and sodium-potassium-ATPase (Na + -K + -ATPase) were examined with Western blot. VEGF-A in the supernatant of cell culture was detected with ELISA. The intracellular potassium and sodium levels were detected with specific indicators. Results: Compared to the normal control, the protein expressions of Kir4.1, AQP4 and Dp71 were down-regulated significantly in diabetic rat retinas, which were prevented by ranibizumab. The above changes were recapitulated in vitro . As compared with the control, the intracellular potassium level in glyoxal-treated rMC-1 cells was increased, while the intracellular sodium level and Na + -K + -ATPase protein level remained unchanged. However, ranibizumab treatment increased Na + -K + -ATPase protein expression and decreased intracellular sodium, but not potassium level. Conclusion: Ranibizumab protected Müller cells from intracellular edema through up-regulation of Kir4.1, AQP4, and Dp71 by directly binding VEGF-A. It also increased the expression of Na + -K + -ATPase, contributing to reduction of the intracellular osmotic pressure.

Sign in / Sign up

Export Citation Format

Share Document