Pilot: Exploring Neuroprotective Role of Leukemia Inhibitory Factor (LIF) on Brain Metabolomics and Mitochondrial Bioenergetics Following Ischemic Stroke

Abstract: Ischemic stroke is a leading cause of mortality and disability globally, affecting a significant portion of the population. The aftermath of stroke often results in enduring physical and neuropsychological consequences, with post-stroke depression and cognitive deficits being prevalent and underrecognized complications. Current stroke treatment options are limited to tissue plasminogen activator (tPA), with a narrow administration window and notable side effects. The need for novel therapies that not only target the acute phase of stroke-induced cellular dysfunction but also enhance chronic phase recovery and produce lasting benefits is urgent. Emerging evidence implicates inflammation and oxidative stress as primary drivers of post-stroke injuries, leading to neuronal injury and death. Mitochondrial dysfunction, a key player in these processes, results in disrupted tricarboxylic acid (TCA) cycle initiation, impaired mitochondrial oxidative phosphorylation (OXPHOS), ATP deficiency, and subsequent dysfunction. Thus, understanding the link between stroke and mitochondrial function is crucial, with neuroprotection showing promise as a therapeutic avenue for stroke management. Leukemia inhibitory factor (LIF) is as a cytokine with potent anti-inflammatory and anti-oxidative properties, promoting neural cell survival. LIF has emerged as a promising neuroprotective therapeutic agent in animal models of multiple sclerosis, spinal cord injury, and amyotrophic lateral sclerosis. Previous studies have highlighted LIF''s efficacy in reducing tissue damage and facilitating functional recovery post-stroke. LIF signals through a heterodimeric LIF receptor (LIFR), leading to neuroprotective cascades mediated by protein kinase Akt and transcription of antioxidant genes. Our preliminary investigations in aged rats following ischemic lesions revealed mitochondrial OXPOS dysfunction in the striatum and cortex 3 days post-stroke. Specifically focusing on electron transport chain (ETC) complexes activity, we observed consistent injury effects post-stroke. Intriguingly, LIF treatment appeared to protect against mitochondrial dysfunction without significant impact on ETC complexes activity, suggesting potential regulation of TCA cycle flux or other metabolic pathways by LIF. Our hypothesis posits that the protective impact of LIF treatment observed over a 3-day period on mitochondrial respiration can mitigate stroke-induced mitochondrial dysfunction, thereby improving long-term neurological recovery. This hypothesis is further supported by preliminary evidence suggesting that LIF''s regulatory mechanisms may influence broader metabolic flux. To functionally and mechanistically define the involvement of LIF in stroke outcomes, we will achieve the following specific aims. This study aims to comprehensively investigate the therapeutic effects of LIF on ischemic stroke, focusing on both acute and chronic aspects. Specific Aim 1 will assess the chronic impact of LIF on mitochondrial bioenergetics and neurobehavioral outcomes post-stroke. Specific Aim 2 seeks to elucidate the therapeutic impact of LIF on systemic metabolic pathways, focusing on central carbon metabolites using Stable Isotope Resolved Metabolomics (SIRM) techniques. By integrating investigations into LIF-mediated mitochondrial respiration with metabolomics, this study aims to unravel the metabolic networks involved in LIF''s neuroprotective effects post-stroke. The findings hold promise for enhancing therapeutic interventions targeting mitochondrial dysfunction and long-term neurobehavioral impairments in ischemic stroke. The study will utilize resources from multidisciplinary Center of Biomedical Research Excellence (COBRE) facilities, including the CNS-Met Metabolomics Core and Mitochondrial Bioenergetics Core. Results from this pilot translational study, combined with preliminary data, will be disseminated at international conferences and published in peer-reviewed journals, facilitating the development of LIF as a therapeutic intervention for post-stroke outcomes.