Abstract
Neuroimmune signals regulate neuronal function and survival. We have obtained multiple pieces of evidence
indicating that activation of the heterodimeric interleukin-13 receptor alpha 1/interleukin-4 receptor alpha (IL-
13Rα1/IL-4Rα) affects the viability of midbrain dopaminergic (DA) neurons. We found that in the brain, IL-
13Rα1/IL-4Rα is preferentially expressed on the neurons of the substantia nigra pars compacta (SNc) that are lost
in Parkinson’s disease (PD). We also showed that interleukin 13 (IL-13), produced during neuroinflammation by
microglia and neurons, can modulate the activity of dopaminergic cells and increase their susceptibility to
oxidative damage. Thus, having established that activation of IL-13Rα1 signaling can affect the survival of
dopaminergic neurons during neuroinflammation, in the present application we wish to determine the molecular
and cellular mechanisms by which this occurs. Specifically, we wish to test the hypothesis that IL-13 and neuronal
IL-13Rα1 cause damage by stimulating a regulated cell death pathway called ferroptosis. We also wish to
determine to what extent IL-13 and IL-13Rα1 contribute to neurodegeneration in a mouse model of alpha-
synucleinopathy (α-Syn), a hallmark trait of PD that is associated with neuroinflammation and oxidative damage.
This will help us determine whether targeting IL-13Rα1 signaling might be a viable approach to slow
neurodegeneration in humans affected by an α-synucleinopathy such as PD. The ability of ruxolitinib, an FDA-
approved drug that inhibits IL-13Rα1 signaling, and that of the novel ferroptosis inhibitor CMS121 to reduce IL-
13-mediated damage in vivo will also be tested. Finally, we propose in vivo experiments to test the hypothesis
that a rare genetic variant of IL-13 found in individuals diagnosed with early-onset PD can contribute to more
rapid loss of dopaminergic neurons in a mouse with the homologue of this mutation. If successful, these
experiments will provide strong support for the hypothesis that IL-13 and IL-13Rα1 are novel targets for
preventing PD or slowing its progression, at least in a sub-set of PD patients.