Decreased Glucose Utilization Contributes to Memory Impairment in Patients with Glufosinate Ammonium Intoxication

Indoxyl sulfate induces apoptotic cell death by inhibiting glycolysis in human astrocytes

BACKGROUND

Neurologic complications, such as cognitive and emotional dysfunction, have frequently been observed in chronic kidney disease (CKD) patients. Previous research shows that uremic toxins play a role in the pathogenesis of CKD-associated cognitive impairment. Since astrocytes contribute to the protection and survival of neurons, astrocyte function and brain metabolism may contribute to the pathogenesis of neurodegeneration. Indoxyl sulfate (IS) is the most popular uremic toxin. However, how IS-induced astrocyte injury brings about neurologic complications in CKD patients has not been elucidated.

METHODS

The rate of extracellular acidification was measured in astrocytes when IS (0.5-3 mM, 4 or 7 days) treatment was applied. The hexokinase 1 (HK1), pyruvate kinase isozyme M2 (PKM2), pyruvate dehydrogenase (PDH), and phosphofructokinase (PFKP) protein levels were also measured. The activation of the apoptotic pathway was investigated using a confocal microscope, fluorescence- activated cell sorting, and cell three-dimensional imaging was used.

RESULTS

In astrocytes, IS affected glycolysis in not only dose-dependently but also time-dependently. Additionally, HK1, PKM2, PDH, and PFKP levels were decreased in IS-treated group when compared to the control. The results were prominent in cases with higher doses and longer exposure duration. The apoptotic features after IS treatment were also observed.

CONCLUSION

Our results showed that the inhibition of glycolysis by IS in astrocytes leads to cell death via apoptosis. Specifically, longterm and higher-dose exposures had more serious effects on astrocytes. Our results suggest that the glycolysis pathway and related targets could provide a novel approach to cognitive dysfunction in CKD patients.

Forensic toxicological studies of acute glufosinate poisoning: A case series

Glufosinate is a widely and increasingly used non-selective, broad-spectrum herbicide. Although cases of glufosinate poisoning are frequently reported, they are rarely documented in forensic case reports, particularly in fatal instances. The present study examined six cases of glufosinate poisoning, including a fatal case involving a 25-year-old female found deceased by the roadside, with an empty 1000 mL bottle labeled "glufosinate" by her side. Biological specimens such as plasma or cardiac blood, gastric contents, and liver tissues were collected for quantitative analysis of glufosinate levels using LC-MS/MS. In five cases of acute glufosinate poisoning, glufosinate plasma concentrations ranged from 0.62 to 3.92 μg/mL. In the fatal case, the concentrations of glufosinate in cardiac blood, gastric contents, and liver tissues were 8.41 μg/mL, 31.25 μg/mL, and 66.1 μg/g, respectively. The pathological autopsy concluded that the cause of death was acute cardio-respiratory failure due to glufosinate poisoning, characterized by multi-organ congestion without specific pathological findings. The toxicological data provided in this study aim to serve as a critical reference for future clinical treatment and forensic validation of glufosinate poisoning-related deaths.

Seizure as the main presenting manifestation of three patients with acute glufosinate-ammonium poisoning

Glufosinate-ammonium herbicides are the most widely used broad-spectrum, non-selective herbicides in the world. Glufosinate-ammonium is a structural analogue of glutamate (Glu) which can irreversibly inhibit the activity of glutamine synthetase (GS) and Glu decarboxylase in plants, thereby blocking the synthesis of glutamine (Gln) from Glu and ammonia (Hoerlein, 1994). This causes the plants to die because of the nitrogen metabolism disorder and subsequent intracellular accumulation of ammonia. In humans, the characteristic features of glufosinate-ammonium herbicide poisoning include gastrointestinal symptoms and neurotoxicity (Watanabe and Sano, 1998). Currently, there are no antidotes for glufosinate-ammonium herbicide poisoning, and thus supportive care is the key treatment.

Developmental synapse pathology triggered by maternal exposure to the herbicide glufosinate ammonium

Environmental and genetic factors influence synapse formation. Numerous animal experiments have revealed that pesticides, including herbicides, can disturb normal intracellular signals, gene expression, and individual animal behaviors. However, the mechanism underlying the adverse outcomes of pesticide exposure remains elusive. Herein, we investigated the effect of maternal exposure to the herbicide glufosinate ammonium (GLA) on offspring neuronal synapse formation in vitro. Cultured cerebral cortical neurons prepared from mouse embryos with maternal GLA exposure demonstrated impaired synapse formation induced by synaptic organizer neuroligin 1 (NLGN1)-coated beads. Conversely, the direct administration of GLA to the neuronal cultures exhibited negligible effect on the NLGN1-induced synapse formation. The comparison of the transcriptomes of cultured neurons from embryos treated with maternal GLA or vehicle and a subsequent bioinformatics analysis of differentially expressed genes (DEGs) identified "nervous system development," including "synapse," as the top-ranking process for downregulated DEGs in the GLA group. In addition, we detected lower densities of parvalbumin (Pvalb)-positive neurons at the postnatal developmental stage in the medial prefrontal cortex (mPFC) of offspring born to GLA-exposed dams. These results suggest that maternal GLA exposure induces synapse pathology, with alterations in the expression of genes that regulate synaptic development via an indirect pathway distinct from the effect of direct GLA action on neurons.

Prediction Model of Acute Respiratory Failure in Patients with Acute Pesticide Poisoning by Intentional Ingestion: Prediction of Respiratory Failure in Pesticide Intoxication (PREP) Scores in Cohort Study

Acute respiratory failure is the primary cause of mortality in patients with acute pesticide poisoning. The aim of the present study was to develop a new and efficient score system for predicting acute respiratory failure in patients with acute pesticide poisoning. This study was a retrospective observational cohort study comprised of 679 patients with acute pesticide poisoning by intentional poisoning. We divided this population into a ratio of 3:1; training set (n = 509) and test set (n = 170) for model development and validation. Multivariable logistic regression models were used in developing a score-based prediction model. The Prediction of Respiratory failure in Pesticide intoxication (PREP) scoring system included a summation of the integer scores of the following five variables; age, pesticide category, amount of ingestion, Glasgow Coma Scale, and arterial pH. The PREP scoring system developed accurately predicted respiratory failure (AUC 0.911 [0.849−0.974], positive predictive value 0.773, accuracy 0.873 in test set). We came up with four risk categories (A, B, C and D) using PREP scores 20, 40 and 60 as the cut-off for mechanical ventilation requirement risk. The PREP scoring system developed in the present study could predict respiratory failure in patients with pesticide poisoning, which can be easily implemented in clinical situations. Further prospective studies are needed to validate the PREP scoring system.

The relationship between pesticide exposure during critical neurodevelopment and autism spectrum disorder: A narrative review

Agricultural pesticides have been one of the most extensively used compounds throughout the world. The main sources of contamination for humans are dietary intake and occupational exposure. The impairments caused by agricultural pesticide exposure have been a significant global public health problem. Recent studies have shown that low-level agricultural pesticide exposure during the critical period of neurodevelopment (pregnancy and lactation) is closely related to autism spectrum disorder (ASD). Inhibition of acetylcholinesterase, gut microbiota, neural dendrite morphology, synaptic function, and glial cells are targets for the effects of pesticides during nervous system development. In the present review, we summarize the associations between several highly used and frequently studied pesticides (e.g., glyphosate, chlorpyrifos, pyrethroids, and avermectins) and ASD. We also discusse future epidemiological and toxicological research directions on the relationship between pesticides and ASD.

Prolonged cognitive dysfunction in patient with splenial lesion of the corpus callosum caused by glufosinate ammonium poisoning

Glufosinate ammonium (GLA) is widely used as a commercial herbicide in many countries. Neurotoxicity of GLA has been associated with serious neurological complications such as loss of consciousness, convulsions, and memory impairment. Late-onset memory impairment due to GLA-induced hippocampal lesions is the most distinct clinical feature in GLA poisoning. However, the lesion of the splenium of the corpus callosum (SCC) is a rare condition in GLA poisoning, so the clinical features are not well known. We report the case of a 57-year-old male patient who developed SCC damage after GLA poisoning. The patient had various late-onset neurotoxic symptoms, including prolonged overall cognitive dysfunction and psychosis-like symptoms. Emergency physicians should be aware that GLA-induced SCC lesions may be associated with various late-onset neurotoxic symptoms.