Thymosin β4 stabilizes hypoxia induced brain microvascular endothelial cell dysfunction through S1PR1 dependent...

Area of Science:

• Neuroscience
• Cell Biology
• Pharmacology

Background:

• Acute ischemic injury and traumatic brain injury (TBI) impair blood-brain barrier (BBB) permeability, leading to secondary brain damage.
• Mechanisms of BBB disruption are poorly understood, limiting therapeutic interventions.
• Thymosin β4 (Tβ4) shows promise in TBI and ischemia, but its role in hypoxia-induced BBB damage is unclear.

Purpose of the Study:

• To investigate the protective effects of Tβ4 on hypoxia-induced BBB damage.
• To determine if Tβ4 modulates Sphingosine 1-phosphate receptor 1 (S1PR1) signaling in BBB integrity.
• To explore Tβ4 as a potential therapeutic agent for maintaining BBB function.

Main Methods:

• Utilized human brain microvascular endothelial cells (hBMVECs) to model BBB.
• Assessed Tβ4's effect on hypoxia-induced gene expression of tight junction proteins and S1PR1.
• Investigated endothelial cell permeability and tight junction dynamics.
• Examined the role of S1PR1 by using inhibition studies.

Main Results:

• Tβ4 pretreatment reversed hypoxia-induced damage to BBB components in hBMVECs.
• Tβ4's protective effect was dependent on S1PR1 signaling, identifying it as a key target.
• Inhibition of S1PR1 abolished the protective benefits of Tβ4, confirming its pivotal role.

Conclusions:

• Tβ4 protects against hypoxia-induced BBB disruption, likely through S1PR1 modulation.
• S1PR1 signaling is crucial in BBB pathophysiology under hypoxic conditions.
• Tβ4 represents a promising therapeutic candidate for BBB protection and warrants further investigation.