Injection of neural progenitor cells attenuates decrease in level of connexin 43 in brain capillaries after cerebral...

Area of Science:

• Neuroscience
• Cell Biology
• Biochemistry

Background:

• The neurovascular unit (NVU) plays a critical role in brain function, and its disruption can worsen ischemic injury.
• Changes in gap junctional proteins within the NVU after brain injury are not fully understood.
• Neural progenitor cells (NPCs) show therapeutic potential for post-stroke cognitive and behavioral deficits.

Purpose of the Study:

• To investigate alterations in gap junctional proteins in brain capillaries following severe cerebral ischemia.
• To examine the effect of intravenous NPC injection on these protein levels.
• To explore the potential of NPCs in remodeling the NVU after ischemic stroke.

Main Methods:

• Induction of severe cerebral ischemia using microsphere embolism (ME) in a rat model.
• Isolation and analysis of brain capillaries to assess protein expression.
• Intravenous injection of NPCs or vehicle in ME rats.
• Immunohistochemical analysis to detect connexin 43 (Cx43), aquaporin 4 (AQP-4), and N-cadherin.

Main Results:

• Severe cerebral ischemia led to a sustained decrease in Cx43 and a transient increase in AQP-4 in isolated brain capillaries.
• NPC injection significantly increased Cx43 levels in ME rats compared to vehicle controls.
• Intravenously injected NPCs were observed to migrate into blood vessels in the peri-infarct area.
• NPC treatment did not alter AQP-4 or N-cadherin levels.

Conclusions:

• Severe cerebral ischemia disrupts the astrocyte-endothelial cell interface within the NVU, partly via Cx43 downregulation.
• Intravenous NPC administration can remodel the NVU by restoring Cx43 levels after ischemic injury.
• NPC-mediated NVU remodeling may contribute to functional recovery following cerebral ischemia.