Aldose reductase regulates TNF-alpha-induced cell signaling and apoptosis in vascular endothelial cells

Area of Science:

• Endothelial cell biology
• Molecular signaling pathways
• Apoptosis research

Background:

• Tumor necrosis factor-alpha (TNF-alpha) is a key mediator of endothelial cell apoptosis.
• The precise molecular mechanisms underlying TNF-alpha-induced apoptosis require further elucidation.
• Aldose reductase (AR) is an enzyme implicated in cellular stress responses.

Purpose of the Study:

• To investigate the role of aldose reductase (AR) in TNF-alpha-induced apoptosis of human umbilical vein endothelial cells.
• To determine the molecular targets and signaling pathways modulated by AR in this context.

Main Methods:

• Human umbilical vein endothelial cells were treated with TNF-alpha.
• Aldose reductase was inhibited using pharmacological inhibitors (sorbinil, tolrestat) or antisense ablation.
• Expression of apoptosis-related proteins (Bax, Bak, Bcl-2) was assessed.
• AP-1 DNA binding activity, caspase-3 activation, and MAPK signaling (JNK, p38) were analyzed.

Main Results:

• Inhibition of AR prevented TNF-alpha-induced increases in pro-apoptotic proteins Bax and Bak, and prevented downregulation of anti-apoptotic protein Bcl-2.
• AR inhibition abrogated AP-1 DNA binding activity.
• AR inhibition blocked the activation of caspase-3, JNK, and p38 MAPK.
• TNF-alpha-induced apoptotic cell death was significantly attenuated by AR inhibition or antisense ablation.

Conclusions:

• Aldose reductase plays a critical role in mediating TNF-alpha-induced apoptotic signaling in endothelial cells.
• AR inhibition represents a potential therapeutic strategy to mitigate TNF-alpha-driven endothelial cell death.