JAK Inhibitors and Oxidative Stress Control

Area of Science:

• Immunology
• Autoimmune Diseases
• Cell Biology

Background:

• Primary Sjögren's syndrome (SjS) is an autoimmune epithelitis with limited treatments.
• Oxidative stress and activated salivary gland epithelial cells (SGECs) play a key role in SjS pathogenesis.
• The JAK/STAT pathway is implicated in SjS, and its suppression by JAK inhibitors may improve symptoms.

Purpose of the Study:

• To investigate if Janus kinase (JAK) inhibitors can suppress salivary gland epithelial cell (SGEC) activation induced by oxidative stress.
• To explore the role of the JAK/STAT pathway in oxidative stress-induced SGEC activation relevant to Sjögren's syndrome (SjS).

Main Methods:

• Utilized the human salivary gland (HSG) cell line.
• Induced oxidative stress using hydrogen peroxide (H₂O₂) and used interferons (IFN) as positive controls.
• Measured ICAM-1 and PD-L1 expression via real-time PCR and flow cytometry.
• Assessed STAT1/3 phosphorylation using Western blotting.
• Treated cells with JAK inhibitors (AG490, ruxolitinib) and N-acetylcysteine.

Main Results:

• Oxidative stress (ROS) induces ICAM-1 and PD-L1 expression in SGECs via pSTAT3.
• JAK inhibitors (AG490, ruxolitinib) reversed ROS-induced ICAM-1 and PD-L1 upregulation.
• N-acetylcysteine, a ROS inhibitor, also reversed this activation pathway.

Conclusions:

• JAK inhibitors effectively suppress oxidative stress-induced activation of SGECs.
• The findings highlight the JAK/STAT pathway's role in SjS pathogenesis and suggest JAK inhibitors as a potential therapeutic strategy.
• This research opens new avenues for understanding SjS pathogenesis and developing targeted treatments.