Exosomes, which are small extracellular vesicles produced from various cell types, contain a variety of molecular constituents, such as proteins, lipids, and RNA. Recently, exosomal biomarkers have been investigated to probe the understanding and diagnosis of neurodegenerative disorders. Previous reports have demonstrated increased exosomal α-synuclein (α-syn) in patients with Parkinson’s disease (PD) in comparison to healthy controls (HC). Interestingly, the cholinergic loss was revealed in the central and peripheral nervous systems in histopathology and molecular neuroimaging. Thereby, we simultaneously examined acetylcholinesterase (AChE) with α-syn as exosomal markers. Exosomes were isolated from the plasma of 34 FP-CIT PET proven patients with PD and 29 HC. Exosomal α-syn and AChE activity were quantified andthe relationship with clinical parameters was analyzed. Remarkably, exosomal AChE activity was significantly decreased in PD compared to HC (P = 0.002). Moreover, exosomal AChE activity in PD revealed a strong negative correlation with disease severity, including H&Y (P = 0.007) and UPDRS part III (P = 0.047) scores. By contrast, no significant difference in exosomal α-syn concentration was observed between groups. These results support the occurrence of cholinergic dysfunction in PD, and they could be implicated with disease progression, especially motor deficits. Exosomal AChE activity with advanced exosome isolation techniques may be a reliable biomarker for the early diagnosis and prognosis of PD.

Kidney diseases pose a tremendous burden to patients and healthcare facilities globally (Luyckx et al., 2018). A recent report indicates that over 700 million individuals are affected by chronic kidney disease (CKD) worldwide (Sundström et al., 2022). According to time frames, acute kidney injury (AKI) and CKD have a substantial impact on mortality and other health-related consequences, including end-stage kidney disease (ESKD) and cardiovascular events (Kellum et al., 2021;Kovesdy, 2022; Matsushita et al., 2022). Despite the recent development of promising therapeutics, such as sodium-glucose co-transporter 2 inhibitors, disease-specific therapies for diverse kidney diseases are still lacking (van Asbeck et al., 2020).Various forms of cell death including apoptosis, necroptosis, autophagy, and ferroptosis are involved in different types of kidney injuries (Priante et al., 2019;Maremonti et al., 2022). Among these cell death processes, non-apoptotic cell death is considered a potential therapeutic target. Regulated necrosis such as ferroptosis and necroptosis is a more immunogenic form of cell death that triggers the innate immune system by 599 According to recent evidence, ferroptosis is a major cell death mechanism in the pathogenesis of kidney injury and fibrosis. Despite the renoprotective effects of classical ferroptosis inhibitors, therapeutic approaches targeting kidney ferroptosis remain limited. In this study, we assessed the renoprotective effects of melatonin and zileuton as a novel therapeutic strategy against ferroptosis-mediated kidney injury and fibrosis. First, we identified RSL3-induced ferroptosis in renal tubular epithelial HK-2 and HKC-8 cells. Lipid peroxidation and cell death induced by RSL3 were synergistically mitigated by the combination of melatonin and zileuton. Combination treatment significantly downregulated the expression of ferroptosis-associated proteins, 4-HNE and HO-1, and upregulated the expression of GPX4. The expression levels of p-AKT and p-mTOR also increased, in addition to that of NRF2 in renal tubular epithelial cells. When melatonin (20 mg/kg) and zileuton (20 mg/kg) were administered to a unilateral ureteral obstruction (UUO) mouse model, the combination significantly reduced tubular injury and fibrosis by decreasing the expression of profibrotic markers, such as α-SMA and fibronectin. More importantly, the combination ameliorated the increase in 4-HNE levels and decreased GPX4 expression in UUO mice. Overall, the combination of melatonin and zileuton was found to effectively ameliorate ferroptosis-related kidney injury by upregulating the AKT/mTOR/ NRF2 signaling pathway, suggesting a promising therapeutic strategy for protection against ferroptosis-mediated kidney injury and fibrosis.

In the original article, we neglected to include the funder National Research Foundation of Korea, NRF-2020R1A2B5B01002463 to Seong Soo A. An.The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.