Microglia increases the proliferation of retinal precursor cells during postnatal development

Area of Science:

• Neuroscience
• Developmental Biology
• Ophthalmology

Background:

• Retinal development in mice extends through the postnatal period, involving retinal precursor cell proliferation.
• Microglia numbers increase significantly from postnatal day 0 to 7.
• The specific role of microglia in postnatal retinal development remains largely unexplored.

Purpose of the Study:

• To investigate the association between microglia and retinal development during the postnatal stage.
• To determine if microglia influence the proliferation of retinal precursor cells.

Main Methods:

• Microglial activation using lipopolysaccharide (LPS) in neonatal mice.
• Microglial depletion using PLX3397 (pexidartinib).
• Assessment of retinal precursor cell proliferation using 5-Bromo-2´-deoxyuridine (BrdU) incorporation and colocalization with Pax6.

Main Results:

• LPS treatment increased retinal microglia numbers and BrdU-positive proliferative cells, primarily colocalized with Pax6.
• PLX3397-induced microglial depletion reduced BrdU-positive proliferative cells.
• Progranulin deficiency led to decreased microglia and retinal precursor cell numbers.

Conclusions:

• Microglia actively regulate the proliferation of immature retinal cells during postnatal development.
• These findings highlight a novel function of microglia in retinal development.