Zinc finger protein 580 (Zfp580) as a new therapeutic post-thrombectomy target for stroke

• Applicants: Professor Dr. Christoph Harms; Dr. Christian Johannes Hoffmann
• Subject Area: Molecular and Cellular Neurology and Neuropathology ; Experimental Models for the Understanding of Nervous System Diseases
• Term: since 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 417284923

Stroke is a disabling disease with severe consequences and few effective treatments. Interleukin 6 (IL6) has ambivalent effects in stroke pathophysiology. It is a risk factor for stroke, and high IL6 blood levels are associated with a poorer prognosis after stroke. However, IL6 is crucial for stroke recovery. We hypothesised this was due to paracrine IL6 effects in the brain. During the first funding period, we investigated how paracrine IL6 affects neuronal network rewiring and functional outcome. We showed that paracrine IL6 improves outcomes and discovered new target proteins to modulate paracrine IL6 responses. Out of these, Zinc finger protein 580 (Zfp580) appears to be an ideal target for stroke treatment: Zfp580 knock down protects both main cell types of the neurovascular unit, neurons and endothelial cells, and it targets multiple pathways, including endothelial and neuronal mechanisms of injury, growth factor responses, and inflammatory and immune responses. Zfp580 modulated post-stroke paracrine IL6 classical and trans-signalling responses. In addition, Zfp580 deletion improved endothelial cell resilience to ischemia, thus preserving ischemic area vascularization after stroke. Finally, Zfp580 deletion increased use-dependent neuroplasticity and long-term function after stroke in mice. In human brain slices from stroke and non-stroke patients, we discovered that human Zfp580 reacts similarly to mouse Zfp850. We propose that Zfp580 is a promising target for post-thrombectomy treatments aimed at preserving the ischemic vasculature and neurons to rescue the penumbra of the stroke. We will investigate the vasculoprotective effect of Zfp580 inhibition using endothelial-specific Zfp580 knockout, with vessel density as the primary outcome and functional long-term outcomes, ischemic lesion size progression, final lesion size, and neuronal density in the penumbra as secondary outcomes in the first objective. We aim to analyse the mechanisms of vascular resilience based on transcriptomics. We will study the impact of endothelial Zfp580 loss on the integrity of the blood brain barrier. Then, we will evaluate the potential of a Zfp580 inhibiting treatment for stroke outcome, mimicking a post-thrombectomy therapy by intracarotid artery injection with reperfusion after transient filamentous middle cerebral artery occlusion (MCAo) and using innovative stroke targeting lipid nanoparticles (LNPs) to deliver Zfp580 siRNA, competing mutant Zfp580 (Zfp580ZF) mRNA, or the combinatorial treatment. Additionally, we will evaluate the Zfp580 expression in human post-mortem and live-biopsy brain samples histologically. If the Zfp580 targeting strategy is successful in the post-thrombectomy setting, we will prospectively evaluate the efficacy of intravenous Zfp580 siRNA and/or Zfp580ZF mRNA LNP administration in a mouse model of thrombotic stroke with tPA treatment to mimic thrombolysis treatment in stroke patients.

• DFG Programme: Research Grants