Adenosine prevents TNFα-induced decrease in endothelial mitochondrial mass via activation of eNOS-PGC-1α regulatory...

Area of Science:

• Endothelial cell biology
• Mitochondrial biogenesis
• Inflammation research

Background:

• Adenosine is a known cytoprotective mediator.
• Inflammation can induce mitochondrial dysfunction in endothelial cells.
• Endothelial nitric oxide synthase (eNOS) and PGC-1α are key regulators of cellular health.

Purpose of the Study:

• To investigate the protective role of adenosine against inflammation-induced mitochondrial deficits in human microvascular endothelial cells.
• To elucidate the signaling pathways involved in adenosine-mediated cytoprotection.

Main Methods:

• Human microvascular endothelial cells were exposed to TNFα.
• Measurements included mitochondrial membrane potential, ATP levels, mitochondrial mass, and apoptosis.
• Interventions involved adenosine, nitric oxide (NO) donors, guanylate cyclase (GC) activators, cGMP analogs, and inhibitors of NO synthesis and GC.
• Gene silencing techniques (siRNA, antisense oligonucleotides) were used to target eNOS and PGC-1α.

Main Results:

• TNFα decreased mitochondrial function, ATP levels, and mass, while increasing apoptosis.
• Adenosine, NO donors, GC activators, and cGMP analogs prevented these TNFα-induced effects.
• Adenosine's protective effects were dependent on eNOS, NO production, GC activity, cGMP signaling, and PGC-1α.
• TNFα reduced eNOS and PGC-1α expression, which adenosine reversed.

Conclusions:

• Adenosine protects endothelial cells from TNFα-induced mitochondrial dysfunction and apoptosis.
• This protection is mediated by a pathway involving eNOS-derived NO, soluble guanylate cyclase, cGMP, and PGC-1α.
• Adenosine activates a cytoprotective mechanism that preserves endothelial mitochondrial function and mass during inflammation.