THURSDAY, Feb. 16, 2017 (HealthDay News) — In patients with systemic lupus erythematosus (SLE), mitochondrial reactive oxygen species (ROS) induce oligomerization of mitochondrial antiviral signaling (MAVS) protein and type I interferon (IFN) production, according to a study published recently in Science Signaling.
Iwona A. Buskiewicz, Ph.D., from the University of Vermont in Burlington, and colleagues examined virus-independent activation of MAVS protein in patients with SLE.
Noting that MAVS protein usually forms a complex with retinoic acid gene I (RIG-I)-like helicases during viral infection, the researchers found that MAVS protein was activated by oxidative stress, independently of RIG-I helicases. Chemically generated oxidative stress stimulated formation of MAVS oligomers, leading to mitochondrial hyperpolarization and reduced adenosine triphosphate production and spare respiratory capacity; these responses were not seen in cells lacking MAVS that were treated in a similar way. Spontaneous MAVS oligomerization was seen in peripheral blood lymphocytes of SLE patients; this correlated with increased secretion of type I IFN and mitochondrial oxidative stress. MAVS oligomerization and type I IFN production were prevented by inhibition of mitochondrial ROS by the mitochondria-targeted antioxidant MitoQ. In cells expressing the MAVS-C79F variant, which is linked to reduced type I IFN secretion, there was reduced ROS-dependent MAVS oligomerization in plasma versus healthy controls.
“Our findings suggest that oxidative stress-induced MAVS oligomerization in SLE patients may contribute to the type I IFN signature that is characteristic of this syndrome,” the authors write.
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