Embryonic Pericytes Promote Microglial Homeostasis and Their Effects on Neural Progenitors in the Developing Cerebral...

Area of Science:

• Neuroscience
• Developmental Biology
• Cell Biology

Background:

• Microglia play vital roles in the developing brain, including neural progenitor differentiation and neuron survival.
• While endothelial cells and microglia interactions are known, the role of pericytes in this dynamic remains understudied.

Purpose of the Study:

• To investigate the role of pericytes in the distribution and function of microglia within developing mouse brains.
• To elucidate the mechanisms by which pericytes influence microglial proliferation and their support of neural stem cell differentiation.

Main Methods:

• Immunohistochemical analysis to determine microglial association with cerebral capillaries and pericytes.
• In vivo pericyte depletion using an antibody against platelet-derived growth factor receptor (PDGFR)β.
• In vitro co-culture of isolated microglia and pericytes to assess pericyte-mediated microglial proliferation.

Main Results:

• Microglia were found to preferentially associate with pericytes covering cerebral capillaries.
• Pericyte depletion significantly reduced microglial density due to decreased proliferation.
• Pericytes promote microglial proliferation through soluble factors and support neural stem cell differentiation into intermediate progenitors.

Conclusions:

• Pericytes are essential for maintaining microglial homeostasis in the developing brain.
• Pericytes indirectly support microglial functions in neural progenitor differentiation.
• These findings expand the understanding of pericyte functions beyond vascular maintenance to include neurodevelopmental roles.