ABSTRACT
Organophosphate (OP) nerve agent (OPNA) intoxication leads to long-term brain dysfunctions. The ineffectiveness of current treatments for OPNA intoxication prompts a quest for the investigation of the mechanism and an alternative effective therapeutic approach. Our previous studies on 1400W, a highly selective inducible nitric oxide synthase (iNOS) inhibitor, showed improvement in epilepsy and seizure-induced brain pathology in rat models of kainate and OP intoxication. In this study, magnetic resonance imaging (MRI) modalities, behavioral outcomes, and biomarkers were comprehensively investigated for brain abnormalities following soman (GD) intoxication in a rat model. T1 and T2 MRI robustly identified pathologic microchanges in brain structures associated with GD toxicity, and 1400W suppressed those aberrant alterations. Moreover, functional network reduction was evident in the cortex, hippocampus, and thalamus after GD exposure, and 1400W rescued the losses except in the thalamus. Behavioral tests showed protection by 1400W against GD-induced memory dysfunction, which also correlated with the extent of brain pathology observed in structural and functional MRIs. GD exposure upregulated iron-laden glial cells and ferritin levels in the brain and serum, 1400W decreased ferritin levels in the epileptic foci in the brain but not in the serum. The levels of brain ferritin also correlated with MRI parameters. Further, 1400W mitigated the overproduction of nitroxidative markers after GD exposure. Overall, this study provides direct evidence for the relationships of structural and functional MRI modalities with behavioral and molecular abnormalities following GD exposure and the neuroprotective effect of an iNOS inhibitor, 1400W. SIGNIFICANT STATEMENT: Our studies demonstrate the MRI microchanges in the brain following GD toxicity, which strongly correlate with neurobehavioral performances and iron homeostasis. The inhibition of iNOS with 1400W mitigates GD-induced cognitive decline, iron dysregulation, and aberrant brain MRI findings.
Subject(s)
Epilepsy , Ferroptosis , Soman , Rats , Animals , Nitric Oxide Synthase Type II/metabolism , Soman/toxicity , Epilepsy/drug therapy , Brain , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/therapeutic use , Magnetic Resonance Imaging , Ferritins/pharmacology , Iron , Benzylamines/pharmacology , Amidines/pharmacology , Amidines/therapeutic use , Nitric Oxide/metabolismABSTRACT
Background: The rapid increase in child and adolescent overweight and obesity (OAO) in China has a significant health and economic impact. This study undertook an investment case analysis to evaluate the health and economic impacts of child and adolescent OAO in China and the potential health and economic returns from implementing specific policies and interventions. Methods: The analysis estimates the reduction in mortality and morbidity from implementing a set of evidence-based interventions across China between 2025 and 2092 using a deterministic Markov cohort model. Modelled interventions were identified by literature review and expert recommendation and include fiscal and regulatory policies, eHealth breastfeeding promotion, school-based interventions, and nutritional counselling by physicians. The study applies a societal costing perspective to model the economic impact on healthcare cost savings, wages, and productivity during adulthood. By projecting and comparing the costs between a status quo scenario and an intervention scenario, the study estimates the return on investment (ROI) for interventions separately and in combination. Findings: Without intervention China will experience 3.3 billion disability-adjusted life years (DALYs) due its current levels of child and adolescent OAO and a lifetime economic impact of CNY 218 trillion (USD 31.6 trillion), or a lifetime CNY 2.5 million loss per affected child or adolescent (USD 350 thousand). National implementation of all five interventions would avert 179.4 million DALYs and result in CNY 13.1 trillion of benefits over the model cohort's lifetime. Implementing fiscal and regulatory policies had the strongest ROI, with benefits accruing at least 10 years after implementation. Scaling up China's current school-based interventions offers China significant health and economic gains, however, the ROI is lower than other modelled interventions. Interpretation: Effective prevention and treatment of child and adolescent OAO is critical to China's health and economic development. Multiple interventions offer a comprehensive approach to address the various factors that increase risk of child and adolescent OAO. Nonetheless, fiscal and regulatory policies offer the strongest health and economic gains. Funding: Funding was provided by UNICEF China.
ABSTRACT
NADPH oxidase (NOX) is a primary mediator of superoxides, which promote oxidative stress, neurodegeneration, and neuroinflammation after diisopropylfluorophosphate (DFP) intoxication. Although orally administered mitoapocynin (MPO, 10 mg/kg), a mitochondrial-targeted NOX inhibitor, reduced oxidative stress and proinflammatory cytokines in the periphery, its efficacy in the brain regions of DFP-exposed rats was limited. In this study, we encapsulated MPO in polyanhydride nanoparticles (NPs) based on 1,6-bis(p-carboxyphenoxy) hexane (CPH) and sebacic anhydride (SA) for enhanced drug delivery to the brain and compared with a high oral dose of MPO (30 mg/kg). NOX2 (GP91phox) regulation and microglial (IBA1) morphology were analyzed to determine the efficacy of MPO-NP vs. MPO-oral in an 8-day study in the rat DFP model. Compared to the control, DFP-exposed animals exhibited significant upregulation of NOX2 and a reduced length and number of microglial processes, indicative of reactive microglia. Neither MPO treatment attenuated the DFP effect. Neurodegeneration (FJB+NeuN) was significantly greater in DFP-exposed groups regardless of treatment. Interestingly, neuronal loss in DFP+MPO-treated animals was not significantly different from the control. MPO-oral rescued inhibitory neuronal loss in the CA1 region of the hippocampus. Notably, MPO-NP and MPO-oral significantly reduced astrogliosis (absolute GFAP counts) and reactive gliosis (C3+GFAP). An analysis of inwardly rectifying potassium channels (Kir4.1) in astroglia revealed a significant reduction in the brain regions of the DFP+VEH group, but MPO had no effect. Overall, both NP-encapsulated and orally administered MPO had similar effects. Our findings demonstrate that MPO effectively mitigates DFP-induced reactive astrogliosis in several key brain regions and protects neurons in CA1, which may have long-term beneficial effects on spontaneous seizures and behavioral comorbidities. Long-term telemetry and behavioral studies and a different dosing regimen of MPO are required to understand its therapeutic potential.