Search

The brominated flame retardant 2,2',4,4'-tetrabromodiphenyl ether (PBDE-47) is a ubiquitous environmental pollutant that causes neurotoxicity. However, incomplete understanding of the underlying mechanisms has hampered the development of effective intervention strategies. Oxidative stress and related cell death are the modes of action for PBDE-47 neurotoxicity, which are also the characteristics of ferroptosis. Nonetheless, the role of ferroptosis in PBDE-47-induced neurotoxicity remains unclear. In the present study, we found that PBDE-47 triggered ferroptosis in neuron-like PC12 cells, as evidenced by intracellular iron overload, lipid peroxidation, and mitochondrial damage. This was confirmed by ferroptosis inhibitors including the lipid reactive oxygen species scavenger ferrostatin-1 and iron chelator deferoxamine mesylate. Mechanistically, PBDE-47 impaired ferritinophagy by disrupting nuclear receptor coactivator 4-mediated lysosomal degradation of the iron storage protein ferritin. Moreover, PBDE-47 disturbed iron metabolism by increasing cellular iron import via upregulation of transferrin receptor 1 and decreasing cellular iron export via downregulation of ferroportin 1 (FPN1). Intriguingly, rescuing lysosomal function by overexpressing cathepsin B (CatB) mitigated PBDE-47-induced ferroptosis by partially restoring dysfunctional ferritinophagy and enhancing iron excretion via the upregulation of FPN1. However, FPN1 knockdown reversed the beneficial effects of CatB overexpression on the PBDE-47-induced iron overload. Finally, network pharmacology integrated with experimental validation revealed that Canolol, the main phenolic compound in canola oil, protected against PBDE-47-evoked iron overload, resulting in ferroptosis by restoring defective ferritinophagy and improving abnormal iron metabolism via lowering iron uptake and facilitating iron excretion. Overall, these data suggest that ferroptosis is a novel mechanism of PBDE-47-induced neuronal death and that manipulation of ferritinophagy and iron metabolism via Canolol represents a promising therapeutic strategy., Competing Interests: Declaration of competing interest The authors have declared that no competing interest exists., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Aging is a principal risk factor for neurodegenerative diseases and especially shares similar pathologic mechanisms to Alzheimer's disease (AD). Amyloid-β (Aβ) plaques deposition and neurofibrillary tangles (NFTs) are the prominent age-dependent pathologies implicated in the cognitive deficits. Accumulation of mis-folded proteins in the endoplasmic reticulum triggers a cellular stress response called the unfolded protein response (UPR), the activation of which is increased in AD patients. However, the UPR relates to the pathological hallmarks of aging is still elusive. In this study, we report that long-term supplement of α-linolenic acid (ALA), starting before the onset of disease symptoms (6month-old), prevents the age-related memory deficits during natural aging. The amelioration of the memory impairment is associated with a decrease in UPR related markers [glucose regulated protein 78 (GRP78), protein kinase RNA-like endoplasmic reticulum kinase (PERK), eukaryotic Initiation Factor 2α (eIF2α)]. ALA suppressed the PERK/eIF2α signaling, which may be responsible for multifaceted memory-deteriorating and neurodegenerative mechanisms, including inhibition of Aβ production by suppressing β-site APP-cleaving enzyme 1 (BACE1) expression, enhancement of cAMP response element binding protein (CREB) function via down-regulating activating transcription factor 4 (ATF4), and suppression of Tau phosphorylation by inhibiting glycogen synthase kinase 3β (GSK-3β) pathway. Taken together, our findings provide new insights into the link between ALA and PERK/eIF2α signaling, which could contribute to a better understanding of an ALA-mediated protective effect in aging-associated neuropathology., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The major purpose of this study was to determine the effect of procyanidins extracted from the lotus seedpod (LSPC) on the learning and memory impairments in cognitively impaired aged rats. Based on Morris water maze performance compared with young female rats, aged unimpaired (AU) and aged impaired (AI) rats were chosen from aged female rats. LSPC supplementation (50, 100 mg/kg BW, p.o.) for 7 weeks significantly improved learning and memory impairments in AI animals in the Morris water maze test, as evaluated by shortened escape latency and swimming distance. Aged rats had significantly declined antioxidant defense capacities and significantly increased lipid peroxidation and protein oxidation levels in hippocampus and cerebral cortex than young rats. Further, AI group had higher protein oxidation level compared with AU group. LSPC (50, 100 mg/kg BW, p.o.) significantly reversed the decline of antioxidant defense capacities and significantly reduced lipid peroxidation and protein oxidation levels in hippocampus and cerebral cortex of AI rats. In addition, LSPC significantly restored acetylcholine (ACh) contents and acetylcholinesterase (AChE) activities in hippocampus and cerebral cortex of AI animals. The results of this study suggest that LSPC may play a useful role in the treatment of cognitive impairment caused by Alzheimer's disease and aging.