👤 Yutaka Itokazu

The prevalence of neurodegenerative diseases and mental health disorders has been increasing over the past few decades. While genetic and lifestyle factors are important to the etiology of these illnesses, the pathogenic role of environmental factors, especially toxicants such as pesticides encountered over the life span, is receiving increased attention. As an environmental factor, organophosphates pose a constant threat to human health due to their widespread use as pesticides, their deployment by rogue militaries, and their use in terrorist attacks. The standard organophosphate-antidotal regimen provides modest efficacy against lethality, although morbidity remains high, and there is little evidence that it attenuates long-term neurobehavioral sequelae. Here we show that a novel intranasally administered treatment strategy with specific gangliosides can prevent the organophosphate-related alterations in important neurotrophin pathways that are involved in cognition and depression. We found that a single exposure to the organophosphate diisopropylfluorophosphate (DFP) in mice leads to persistent decreases in the neurotrophins NGF and BDNF and their receptors, TrkA and TrkB. Moreover, 7 days of repeated intranasal administration of gangliosides GM1 or GD3 24 h after the DFP injection prevented the neurotrophin receptor alterations. As NGF and BDNF signaling are involved in cognitive function and depression symptoms, respectively, intranasal administration of GM1 or GD3 may offer a preventative strategy against organophosphate-related alterations in these brain functions. Our study thus supports the potential of a novel therapeutic strategy for neurological and psychiatric deficits associated with a class of poisons that endangers millions of people worldwide. Show less

Alzheimer's Disease (AD) is a neurodegenerative disorder characterized by cognitive decline and memory loss. Among the genetic risk factors linked to AD, the Apolipoprotein E4 (ApoE4) remains the strongest. It is well known that carrying the ApoE4 isoform is associated with advanced AD pathology, blood-brain barrier (BBB) disruption, and changes in lipid metabolism. In this review, we provide an overview of the role of centrally and peripherally produced ApoE in AD. After this introduction, we focus on new findings regarding ApoE4's effects on AD pathology and BBB function. We then discuss ApoE's role in lipid metabolism in AD, highlighting examples of lipid changes caused by carrying the ApoE4 isoform. Next, the review explores the implications of ApoE4 isoforms for current treatments-whether they involve anti-amyloid therapy or other pharmacological agents used for AD-emphasizing the importance of personalized medicine approaches for patients with this high-risk allele. This review aims to provide an updated overview of ApoE4's effects on AD pathology and treatment. By integrating recent discoveries, it underscores the critical need to consider ApoE4 status in both research and clinical settings to enhance therapeutic strategies and outcomes for individuals with AD. Show less