JP1 peptide modulates oxidative stress and autophagy via Keap1-Nrf2-ARE in ALS model mice

Abstract

The simultaneous modulation of oxidative stress and autophagy represents a potential therapeutic strategy for amyotrophic lateral sclerosis (ALS), yet agents capable of coordinately regulating both processes remain scarce. The Keap1‑Nrf2‑ARE pathway serves as a critical hub linking redox homeostasis and autophagic regulation, making it an attractive target for ALS intervention. JWA is a stress‑responsive protein involved in cellular protection against oxidative injury, and its neuroprotective effects have been shown to depend on activation of the MEK/ERK‑Nrf2 axis. JP1 is a functional oligopeptide derived from the JWA protein that has been engineered to cross the blood–brain barrier and specifically target integrin αVβ3. Based on the link between JWA and Nrf2 signaling, we hypothesized that JP1 activates the Keap1‑Nrf2‑ARE pathway to coordinate antioxidant defense and autophagic clearance. Here, we evaluated this hypothesis in the SOD1‑G93A mouse model, a well‑established transgenic model of familial ALS, and elucidated the underlying mechanisms. We evaluated the efficacy of JP1 in the SOD1-G93A mice model using behavioral phenotyping and survival analysis. The coordinated mechanism was investigated in spinal cord tissues by profiling the Keap1-Nrf2-ARE pathway and oxidative stress, quantifying autophagic flux (by Western blotting and transmission electron microscopy) and neuronal apoptosis, and evaluating histology (by Nissl staining and immunofluorescence). Integrated transcriptomic and proteomic analyses further elucidated the global molecular landscape underlying the therapeutic effects of JP1. JP1 treatment ameliorated motor deficits and extended survival in SOD1-G93A mice without adversely affecting liver or kidney function. JP1 crossed the blood–brain barrier, targeted motor neurons expressing integrin αVβ3, and activated the ERK pathway. This promoted Keap1/Cul3 degradation and Nrf2 nuclear translocation, thereby activating the Keap1-Nrf2-ARE pathway to alleviate oxidative stress. Concurrently, JP1 restored autophagic flux, increased autophagic activity, attenuated motor neuron injury, suppressed neuronal apoptosis, and preserved neuronal structural integrity. The Nrf2 inhibitor ML385 reversed the protective effects of JP1 on survival, motor function, autophagy, oxidative stress, and neuronal apoptosis, which confirms that JP1 acts via the Nrf2 pathway. JP1 acts as a promising coordinator of antioxidant and autophagic processes by targeting the Keap1-Nrf2-ARE pathway, thus highlighting its therapeutic potential for ALS.