Limits...
Pigment epithelium-derived factor released by Müller glial cells exerts neuroprotective effects on retinal ganglion cells.

Unterlauft JD, Eichler W, Kuhne K, Yang XM, Yafai Y, Wiedemann P, Reichenbach A, Claudepierre T - Neurochem. Res. (2012)

Bottom Line: Using Müller cell-RGC-co-cultures we observed that activity of Müller-cell derived soluble mediators can attenuate hypoxia-induced damage and RGC loss.Finally, neutralizing the activity of PEDF in glia-conditioned media partially abolished the neuroprotective effect of glia, leading to an increased neuronal death in hypoxic condition.Altogether our results suggest that PEDF is crucially involved in the neuroprotective process of reactive Müller cells towards RGC.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology and Eye Hospital, University of Leipzig, Liebigstrasse 10-14, 04103, Leipzig, Germany.

ABSTRACT
Survival of retinal ganglion cells (RGC) is compromised in several vision-threatening disorders such as ischemic and hypertensive retinopathies and glaucoma. Pigment epithelium-derived factor (PEDF) is a naturally occurring pleiotropic secreted factor in the retina. PEDF produced by retinal glial (Müller) cells is suspected to be an essential component of neuron-glial interactions especially for RGC, as it can protect this neuronal type from ischemia-induced cell death. Here we show that PEDF treatment can directly affect RGC survival in vitro. Using Müller cell-RGC-co-cultures we observed that activity of Müller-cell derived soluble mediators can attenuate hypoxia-induced damage and RGC loss. Finally, neutralizing the activity of PEDF in glia-conditioned media partially abolished the neuroprotective effect of glia, leading to an increased neuronal death in hypoxic condition. Altogether our results suggest that PEDF is crucially involved in the neuroprotective process of reactive Müller cells towards RGC.

Show MeSH

Related in: MedlinePlus

RGC and Müller glial cell co-cultures. Survival of RGC under normoxia or hypoxia (0.2% O2) and in the absence (−) or presence (+; bars ingrey) of co-cultured primary Müller glial cells. Significant differences to cultures without Müller cells (*P < 0.05, **P < 0.01) and to corresponding normoxic conditions (••P < 0.01, •••P < 0.001) are indicated (n = 6)
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3368109&req=5

Fig3: RGC and Müller glial cell co-cultures. Survival of RGC under normoxia or hypoxia (0.2% O2) and in the absence (−) or presence (+; bars ingrey) of co-cultured primary Müller glial cells. Significant differences to cultures without Müller cells (*P < 0.05, **P < 0.01) and to corresponding normoxic conditions (••P < 0.01, •••P < 0.001) are indicated (n = 6)

Mentions: Given the deposition of RPE-synthesized PEDF in the interphotoreceptor matrix [39], we hypothesized that the majority of PEDF produced by RPE cells is barely accessible across the retina and thus would be an inappropriate means to protect RGC from survival-compromising insults. We therefore investigated the possibility that Müller-cell derived PEDF acts as a neuroprotectant for RGC. In an approach in vitro, we performed co-cultures of Müller cells and RGC under normoxia and hypoxia (0.2% O2), respectively, and determined RGC survival. Inspection of RGC after 24 h (n = 6) revealed 65.9 ± 4.4% and 42.2 ± 3.5% viable cells under normoxia and hypoxia, respectively, when the cells were co-cultured with primary rat glial (Müller) cells. In contrast, homotypic RGC cultures demonstrated a cellular survival amounting to 47.3 ± 4.8% and 27.9 ± 3.5% of the total cell number under normoxia and hypoxia, respectively. Thus the survival rate of RGC was significantly (P < 0.05) higher when cultured together with Müller cells than alone, each under normoxia and hypoxia. Also, in hypoxia we have consistently detected a significantly (P < 0.05) reduced number of viable RGC even in co-culture with Müller cells (Fig. 3). However, if we analyse the increase of survival in co-cultures versus homotypic ones we found a increase of + 42.1 ± 7.1% in normoxic condition and + 55.8 ± 11.4% in hypoxic condition when Müller glial cells are present. These data indicate that hypoxia compromises the viability of RGC and that Müller cells release (a) neuroprotective factor(s), which is (are) able to compensate apoptotic loss of RGC.Fig. 3


Pigment epithelium-derived factor released by Müller glial cells exerts neuroprotective effects on retinal ganglion cells.

Unterlauft JD, Eichler W, Kuhne K, Yang XM, Yafai Y, Wiedemann P, Reichenbach A, Claudepierre T - Neurochem. Res. (2012)

RGC and Müller glial cell co-cultures. Survival of RGC under normoxia or hypoxia (0.2% O2) and in the absence (−) or presence (+; bars ingrey) of co-cultured primary Müller glial cells. Significant differences to cultures without Müller cells (*P < 0.05, **P < 0.01) and to corresponding normoxic conditions (••P < 0.01, •••P < 0.001) are indicated (n = 6)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3368109&req=5

Fig3: RGC and Müller glial cell co-cultures. Survival of RGC under normoxia or hypoxia (0.2% O2) and in the absence (−) or presence (+; bars ingrey) of co-cultured primary Müller glial cells. Significant differences to cultures without Müller cells (*P < 0.05, **P < 0.01) and to corresponding normoxic conditions (••P < 0.01, •••P < 0.001) are indicated (n = 6)
Mentions: Given the deposition of RPE-synthesized PEDF in the interphotoreceptor matrix [39], we hypothesized that the majority of PEDF produced by RPE cells is barely accessible across the retina and thus would be an inappropriate means to protect RGC from survival-compromising insults. We therefore investigated the possibility that Müller-cell derived PEDF acts as a neuroprotectant for RGC. In an approach in vitro, we performed co-cultures of Müller cells and RGC under normoxia and hypoxia (0.2% O2), respectively, and determined RGC survival. Inspection of RGC after 24 h (n = 6) revealed 65.9 ± 4.4% and 42.2 ± 3.5% viable cells under normoxia and hypoxia, respectively, when the cells were co-cultured with primary rat glial (Müller) cells. In contrast, homotypic RGC cultures demonstrated a cellular survival amounting to 47.3 ± 4.8% and 27.9 ± 3.5% of the total cell number under normoxia and hypoxia, respectively. Thus the survival rate of RGC was significantly (P < 0.05) higher when cultured together with Müller cells than alone, each under normoxia and hypoxia. Also, in hypoxia we have consistently detected a significantly (P < 0.05) reduced number of viable RGC even in co-culture with Müller cells (Fig. 3). However, if we analyse the increase of survival in co-cultures versus homotypic ones we found a increase of + 42.1 ± 7.1% in normoxic condition and + 55.8 ± 11.4% in hypoxic condition when Müller glial cells are present. These data indicate that hypoxia compromises the viability of RGC and that Müller cells release (a) neuroprotective factor(s), which is (are) able to compensate apoptotic loss of RGC.Fig. 3

Bottom Line: Using Müller cell-RGC-co-cultures we observed that activity of Müller-cell derived soluble mediators can attenuate hypoxia-induced damage and RGC loss.Finally, neutralizing the activity of PEDF in glia-conditioned media partially abolished the neuroprotective effect of glia, leading to an increased neuronal death in hypoxic condition.Altogether our results suggest that PEDF is crucially involved in the neuroprotective process of reactive Müller cells towards RGC.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology and Eye Hospital, University of Leipzig, Liebigstrasse 10-14, 04103, Leipzig, Germany.

ABSTRACT
Survival of retinal ganglion cells (RGC) is compromised in several vision-threatening disorders such as ischemic and hypertensive retinopathies and glaucoma. Pigment epithelium-derived factor (PEDF) is a naturally occurring pleiotropic secreted factor in the retina. PEDF produced by retinal glial (Müller) cells is suspected to be an essential component of neuron-glial interactions especially for RGC, as it can protect this neuronal type from ischemia-induced cell death. Here we show that PEDF treatment can directly affect RGC survival in vitro. Using Müller cell-RGC-co-cultures we observed that activity of Müller-cell derived soluble mediators can attenuate hypoxia-induced damage and RGC loss. Finally, neutralizing the activity of PEDF in glia-conditioned media partially abolished the neuroprotective effect of glia, leading to an increased neuronal death in hypoxic condition. Altogether our results suggest that PEDF is crucially involved in the neuroprotective process of reactive Müller cells towards RGC.

Show MeSH
Related in: MedlinePlus