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Microglial Activation Promotes Cell Survival in Organotypic Cultures of Postnatal Mouse Retinal Explants.

Ferrer-Martín RM, Martín-Oliva D, Sierra-Martín A, Carrasco MC, Martín-Estebané M, Calvente R, Martín-Guerrero SM, Marín-Teva JL, Navascués J, Cuadros MA - PLoS ONE (2015)

Bottom Line: Treatment of retinal explants with minocycline reduced microglial activation and simultaneously significantly decreased cell viability and increased the presence of TUNEL-labeled cell profiles.The LPS treatment increased microglial activation but had no effect on cell viability or microglial distribution.Finally, partial microglial removal with Lip-Clo diminished the cell viability in the retinal explants, showing a similar effect to that of minocycline.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, Granada, Spain.

ABSTRACT
The role of microglia during neurodegeneration remains controversial. We investigated whether microglial cells have a neurotoxic or neuroprotective function in the retina. Retinal explants from 10-day-old mice were treated in vitro with minocycline to inhibit microglial activation, with LPS to increase microglial activation, or with liposomes loaded with clodronate (Lip-Clo) to deplete microglial cells. Flow cytometry was used to assess the viability of retinal cells in the explants and the TUNEL method to show the distribution of dead cells. The immunophenotypic and morphological features of microglia and their distribution were analyzed with flow cytometry and immunocytochemistry. Treatment of retinal explants with minocycline reduced microglial activation and simultaneously significantly decreased cell viability and increased the presence of TUNEL-labeled cell profiles. This treatment also prevented the migration of microglial cells towards the outer nuclear layer, where cell death was most abundant. The LPS treatment increased microglial activation but had no effect on cell viability or microglial distribution. Finally, partial microglial removal with Lip-Clo diminished the cell viability in the retinal explants, showing a similar effect to that of minocycline. Hence, cell viability is diminished in retinal explants cultured in vitro when microglial cells are removed or their activation is inhibited, indicating a neurotrophic role for microglia in this system.

No MeSH data available.


Related in: MedlinePlus

Minocycline treatment inhibits activation of microglia.The release of TNF-α (A) and the percentage of proliferating microglial cells (determined by anti-Ki67 labeling, B) decreased after incubation of retinal explants with minocycline. Bars represent mean values ± SEM of 12 experimental explants with their respective controls for A, and 5 for B. Asterisks indicate significant differences between the control (CT, black bars) and minocycline (MIN, gray bars) conditions (** P<0.01, *** P<0.001, Student's t-test).
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pone.0135238.g004: Minocycline treatment inhibits activation of microglia.The release of TNF-α (A) and the percentage of proliferating microglial cells (determined by anti-Ki67 labeling, B) decreased after incubation of retinal explants with minocycline. Bars represent mean values ± SEM of 12 experimental explants with their respective controls for A, and 5 for B. Asterisks indicate significant differences between the control (CT, black bars) and minocycline (MIN, gray bars) conditions (** P<0.01, *** P<0.001, Student's t-test).

Mentions: Because TNF-α production is higher in activated microglia [57], the amount of TNF-α released into the culture medium can be used to estimate the activation level of microglia in cultured retinal explants. Our results show that TNF-α concentration was reduced by the minocycline treatment (Fig 4A), in agreement with previous data [58].


Microglial Activation Promotes Cell Survival in Organotypic Cultures of Postnatal Mouse Retinal Explants.

Ferrer-Martín RM, Martín-Oliva D, Sierra-Martín A, Carrasco MC, Martín-Estebané M, Calvente R, Martín-Guerrero SM, Marín-Teva JL, Navascués J, Cuadros MA - PLoS ONE (2015)

Minocycline treatment inhibits activation of microglia.The release of TNF-α (A) and the percentage of proliferating microglial cells (determined by anti-Ki67 labeling, B) decreased after incubation of retinal explants with minocycline. Bars represent mean values ± SEM of 12 experimental explants with their respective controls for A, and 5 for B. Asterisks indicate significant differences between the control (CT, black bars) and minocycline (MIN, gray bars) conditions (** P<0.01, *** P<0.001, Student's t-test).
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4529135&req=5

pone.0135238.g004: Minocycline treatment inhibits activation of microglia.The release of TNF-α (A) and the percentage of proliferating microglial cells (determined by anti-Ki67 labeling, B) decreased after incubation of retinal explants with minocycline. Bars represent mean values ± SEM of 12 experimental explants with their respective controls for A, and 5 for B. Asterisks indicate significant differences between the control (CT, black bars) and minocycline (MIN, gray bars) conditions (** P<0.01, *** P<0.001, Student's t-test).
Mentions: Because TNF-α production is higher in activated microglia [57], the amount of TNF-α released into the culture medium can be used to estimate the activation level of microglia in cultured retinal explants. Our results show that TNF-α concentration was reduced by the minocycline treatment (Fig 4A), in agreement with previous data [58].

Bottom Line: Treatment of retinal explants with minocycline reduced microglial activation and simultaneously significantly decreased cell viability and increased the presence of TUNEL-labeled cell profiles.The LPS treatment increased microglial activation but had no effect on cell viability or microglial distribution.Finally, partial microglial removal with Lip-Clo diminished the cell viability in the retinal explants, showing a similar effect to that of minocycline.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, Granada, Spain.

ABSTRACT
The role of microglia during neurodegeneration remains controversial. We investigated whether microglial cells have a neurotoxic or neuroprotective function in the retina. Retinal explants from 10-day-old mice were treated in vitro with minocycline to inhibit microglial activation, with LPS to increase microglial activation, or with liposomes loaded with clodronate (Lip-Clo) to deplete microglial cells. Flow cytometry was used to assess the viability of retinal cells in the explants and the TUNEL method to show the distribution of dead cells. The immunophenotypic and morphological features of microglia and their distribution were analyzed with flow cytometry and immunocytochemistry. Treatment of retinal explants with minocycline reduced microglial activation and simultaneously significantly decreased cell viability and increased the presence of TUNEL-labeled cell profiles. This treatment also prevented the migration of microglial cells towards the outer nuclear layer, where cell death was most abundant. The LPS treatment increased microglial activation but had no effect on cell viability or microglial distribution. Finally, partial microglial removal with Lip-Clo diminished the cell viability in the retinal explants, showing a similar effect to that of minocycline. Hence, cell viability is diminished in retinal explants cultured in vitro when microglial cells are removed or their activation is inhibited, indicating a neurotrophic role for microglia in this system.

No MeSH data available.


Related in: MedlinePlus