Pharmacological elevation of glutathione inhibits status epilepticus-induced neuroinflammation and oxidative injury.

Glutathione (GSH) is a major endogenous antioxidant, and its depletion has been observed in several brain diseases including epilepsy. Previous studies in our laboratory have shown that dimercaprol (DMP) can elevate GSH via post-translational activation of glutamate cysteine ligase (GCL), the rate limiting GSH biosynthetic enzyme and inhibit neuroinflammation in vitro. Here we determined 1) the role of cysteamine as a new mechanism by which DMP increases GSH biosynthesis and 2) its ability to inhibit neuroinflammation and neuronal injury in the rat kainate model of epilepsy. DMP depleted cysteamine in a time- and concentration-dependent manner in a cell free system. To guide the in vivo administration of DMP, its pharmacokinetic profile was determined in the plasma, liver, and brain. The results confirmed DMP's ability to cross the blood-brain-barrier. Treatment of rats with DMP (30 mg/kg) depleted cysteamine in the liver and hippocampus that was associated with increased GCL activity in these tissues. GSH levels were significantly increased (20 %) in the hippocampus 1 h after 30 mg/kg DMP administration. Following DMP (30 mg/kg) administration once daily, a marked attenuation of GSH depletion was seen in the SE model. SE-induced inflammatory markers including cytokine release, microglial activation, and neuronal death were significantly attenuated in the hippocampus with DMP treatment. Taken together, these results highlight the importance of restoring redox status with rescue of GSH depletion by DMP in post epileptogenic insults.

Novel Catalytic Antioxidant Formulation Decreases Oxidative Stress, Neuroinflammation and Cognitive Dysfunction in a Model of Nerve Agent Intoxication.

Reactive oxygen species have an emerging role in the pathologic consequences of status epilepticus. We have previously demonstrated the efficacy of a water-for-injection formulation of the meso-porphyrin catalytic antioxidant, manganese (III) meso-tetrakis (N-N-diethylimidazole) porphyrin (AEOL10150) against oxidative stress, neuroinflammation, and neuronal death initiated by kainic acid, pilocarpine, diisopropylflurophosphate (DFP), and soman. This previous dose and dosing strategy of AEOL10150 required smaller multiple daily injections, precluding our ability to test its efficacy against delayed consequences of nerve agent exposure such as neurodegeneration and cognitive dysfunction. Therefore, we developed formulations of AEOL10150 designed to deliver a larger dose once daily with improved brain pharmacodynamics. We examined four new formulations of AEOL10150 that resulted in 8 times higher subcutaneous dose with lower acute toxicity, slower absorption, longer half-life, and higher maximal plasma concentrations compared with our previous strategy. AEOL10150 brain levels exhibited improved pharmacodynamics over 24 hours with all four formulations. We tested a subcutaneous dose of 40 mg/kg AEOL10150 in two formulations (2% carboxymethyl cellulose and 4% polyethylene glycol-4000) in the DFP rat model, and both formulations exhibited significant protection against DFP-induced oxidative stress. Additionally, and in one formulation (4% polyethylene glycol-4000), AEOL10150 significantly protected against DFP-induced neuronal death, microglial activation, delayed memory impairment, and mortality. These results suggest that reformulation of AEOL10150 can attenuate acute and delayed outcomes of organophosphate neurotoxicity. SIGNIFICANCE STATEMENT: Reformulation of manganese (III) meso-tetrakis (N-N-diethylimidazole) porphyrin allowed higher tolerated doses of the compound with improved pharmacodynamics. Specifically, one new formulation allowed fewer daily doses and improvement in acute and delayed outcomes of organophosphate toxicity.

Increasing glutathione levels by a novel posttranslational mechanism inhibits neuronal hyperexcitability.

Glutathione (GSH) depletion, and impaired redox homeostasis have been observed in experimental animal models and patients with epilepsy. Pleiotropic strategies that elevate GSH levels via transcriptional regulation have been shown to significantly decrease oxidative stress and seizure frequency, increase seizure threshold, and rescue certain cognitive deficits. Whether elevation of GSH per se alters neuronal hyperexcitability remains unanswered. We previously showed that thiols such as dimercaprol (DMP) elevate GSH via post-translational activation of glutamate cysteine ligase (GCL), the rate limiting GSH biosynthetic enzyme. Here, we asked if elevation of cellular GSH by DMP altered neuronal hyperexcitability in-vitro and in-vivo. Treatment of primary neuronal-glial cerebrocortical cultures with DMP elevated GSH and inhibited a voltage-gated potassium channel blocker (4-aminopyridine, 4AP) induced neuronal hyperexcitability. DMP increased GSH in wildtype (WT) zebrafish larvae and significantly attenuated convulsant pentylenetetrazol (PTZ)-induced acute 'seizure-like' swim behavior. DMP treatment increased GSH and inhibited convulsive, spontaneous 'seizure-like' swim behavior in the Dravet Syndrome (DS) zebrafish larvae (scn1Lab). Furthermore, DMP treatment significantly decreased spontaneous electrographic seizures and associated seizure parameters in scn1Lab zebrafish larvae. We investigated the role of the redox-sensitive mammalian target of rapamycin (mTOR) pathway due to the presence of several cysteine-rich proteins and their involvement in regulating neuronal excitability. Treatment of primary neuronal-glial cerebrocortical cultures with 4AP or l-buthionine-(S,R)-sulfoximine (BSO), an irreversible inhibitor of GSH biosynthesis, significantly increased mTOR complex I (mTORC1) activity which was rescued by pre-treatment with DMP. Furthermore, BSO-mediated GSH depletion oxidatively modified the tuberous sclerosis protein complex (TSC) consisting of hamartin (TSC1), tuberin (TSC2), and TBC1 domain family member 7 (TBC1D7) which are critical negative regulators of mTORC1. In summary, our results suggest that DMP-mediated GSH elevation by a novel post-translational mechanism can inhibit neuronal hyperexcitability both in-vitro and in-vivo and a plausible link is the redox sensitive mTORC1 pathway.

Behaviors of AlGaN Strain Relaxation on a GaN Porous Structure Studied with d-Spacing Crystal Lattice Analysis.

The high porosity of a GaN porous structure (PS) makes it mechanically semi-flexible and can shield against the stress from the thick growth template on an overgrown layer to control the lattice structure or composition within the overgrown layer. To understand this stress shield effect, we investigated the lattice constant variations among different growth layers in various samples of overgrown Al0.3Ga0.7N on GaN templates under different strain-relaxation conditions based on d-spacing crystal lattice analysis. The fabrication of a strain-damping PS in a GaN template shields against the stress from the thick GaN template on the GaN interlayer, which lies between the PS and the overgrown AlGaN layer, such that the stress counteraction of the AlGaN layer against the GaN interlayer can reduce the tensile strain in AlGaN and increase its critical thickness. If the GaN interlayer is thin, such that a strong AlGaN counteraction occurs, the increased critical thickness can become larger than the overgrown AlGaN thickness. In this situation, crack-free, thick AlGaN overgrowth is feasible.

Neuronal SIRT3 Deletion Predisposes to Female-Specific Alterations in Cellular Metabolism, Memory, and Network Excitability.

Mitochondrial dysfunction is an early event in the pathogenesis of neurologic disorders and aging. Sirtuin 3 (SIRT3) regulates mitochondrial function in response to the cellular environment through the reversible deacetylation of proteins involved in metabolism and reactive oxygen species detoxification. As the primary mitochondrial deacetylase, germline, or peripheral tissue-specific deletion of SIRT3 produces mitochondrial hyperacetylation and the accelerated development of age-related diseases. Given the unique metabolic demands of neurons, the role of SIRT3 in the brain is only beginning to emerge. Using mass spectrometry-based acetylomics, high-resolution respirometry, video-EEG, and cognition testing, we report targeted deletion of SIRT3 from select neurons in the cortex and hippocampus produces altered neuronal excitability and metabolic dysfunction in female mice. Targeted deletion of SIRT3 from neuronal helix-loop-helix 1 (NEX)-expressing neurons resulted in mitochondrial hyperacetylation, female-specific superoxide dismutase-2 (SOD2) modification, increased steady-state superoxide levels, metabolic reprogramming, altered neuronal excitability, and working spatial memory deficits. Inducible neuronal deletion of SIRT3 likewise produced female-specific deficits in spatial working memory. Together, the data demonstrate that deletion of SIRT3 from forebrain neurons selectively predisposes female mice to deficits in mitochondrial and cognitive function.SIGNIFICANCE STATEMENT Mitochondrial SIRT3 is an enzyme shown to regulate energy metabolism and antioxidant function, by direct deacetylation of proteins. In this study, we show that neuronal SIRT3 deficiency renders female mice selectively vulnerable to impairment in redox and metabolic function, spatial memory, and neuronal excitability. The observed sex-specific effects on cognition and neuronal excitability in female SIRT3-deficient mice suggest that mitochondrial dysfunction may be one factor underlying comorbid neuronal diseases, such as Alzheimer's disease and epilepsy. Furthermore, the data suggest that SIRT3 dysfunction may predispose females to age-related metabolic and cognitive impairment.

Sepsis-Associated Coagulopathy Predicts Hospital Mortality in Critically Ill Patients With Postoperative Sepsis.

BACKGROUND: The incidence of coagulopathy, which was responsible for poor outcomes, was commonly seen among patients with sepsis. In the current study, we aim to determine whether the presence of sepsis-associated coagulopathy (SAC) predicts the clinical outcomes among critically ill patients with postoperative sepsis. METHODS: We conducted a single-center retrospective cohort study by including patients with sepsis admitted to surgical ICU of Chinese PLA General Hospital from January 1, 2014 to December 31, 2018. Baseline characteristics and clinical outcomes were compared with respect to the presence of SAC. Kaplan-Meier analysis was applied to calculate survival rate, and Log-rank test was carried out to compare the differences between two groups. Furthermore, multivariable Cox and logistic and linear regression analysis were performed to assess the relationship between SAC and clinical outcomes, including hospital mortality, development of septic shock, and length of hospital stay (LOS), respectively. Additionally, both sensitivity and subgroup analyses were performed to further testify the robustness of our findings. RESULTS: A total of 175 patients were included in the current study. Among all included patients, 41.1% (72/175) ICU patients were identified as having SAC. In-hospital mortality rates were significantly higher in the SAC group when compared to that of the No SAC group (37.5% vs. 11.7%; p < 0.001). By performing univariable and multivariable regression analyses, presence of SAC was demonstrated to significantly correlate with an increased in-hospital mortality for patients with sepsis in surgical ICU [Hazard ratio (HR), 3.75; 95% Confidence interval (CI), 1.90-7.40; p < 0.001]. Meanwhile, a complication of SAC was found to be the independent predictor of the development of septic shock [Odds ratio (OR), 4.11; 95% CI, 1.81-9.32; p = 0.001], whereas it was not significantly associated with prolonged hospital LOS (OR, 0.97; 95% CI, 0.83-1.14; p = 0.743). CONCLUSION: The presence of SAC was significantly associated with increased risk of in-hospital death and septic shock among postoperative patients with sepsis admitted to ICU. Moreover, there was no statistical difference of hospital LOS between the SAC and no SAC groups.

Prevalence of celiac disease in China: Meta-analysis and serological survey in high-risk populations.

OBJECTIVE: To summarize data from a serological survey of high-risk populations in Guangdong Province, China, and to perform a meta-analysis to investigate the prevalence and seroprevalence of celiac disease (CD) in the Chinese general and high-risk populations. METHODS: We collected data from the serological survey of high-risk population of CD in Guangdong Province, China (N = 1390) by testing their serum tissue transglutaminase immunoglobulin A (tTG-IgA), deamidated gliadin peptides immunoglobulin A (DGP-IgA) and deamidated gliadin peptides immunoglobulin G (DGP-IgG). Additionally, a literature search was performed on PubMed, EMBASE, Cochrane Library and three Chinese databases for articles published up to 20 December 2020 to estimate the pooled prevalence and seroprevalence of CD in China. RESULTS: In the serological survey, 0.94% (13/1390) of individuals were positive for CD antibodies. In a meta-analysis of 18 studies, the seroprevalence of CD in the general Chinese population was 0.27% (95% confidence interval [CI] 0.02%-0.71%). While that in the high-risk population was 8.34% (95% CI 4.90%-12.54%) (odds ratio 7.27, 95% CI 4.06-13.04). The prevalence of biopsy-confirmed CD in high-risk Chinese populations was 4.44% (95% CI 1.53%-8.58%). The seroprevalence of CD varied with patients' geographical origin, being higher in northern China than in southern China. CONCLUSIONS: Early diagnosis of CD by serological screening in high-risk population and generous serological testing in those with vague symptoms, especially in northern China, are recommended.

Neuron-specific mitochondrial oxidative stress results in epilepsy, glucose dysregulation and a striking astrocyte response.

Mitochondrial superoxide (O2-) production is implicated in aging, neurodegenerative disease, and most recently epilepsy. Yet the specific contribution of neuronal O2- to these phenomena is unclear. Here, we selectively deleted superoxide dismutase-2 (SOD2) in neuronal basic helix-loop-helix transcription factor (NEX)-expressing cells restricting deletion to a subset of excitatory principle neurons primarily in the forebrain (cortex and hippocampus). This resulted in nSOD2 KO mice that lived into adulthood (2-3 months) with epilepsy, selective loss of neurons, metabolic rewiring and a marked mitohormetic gene response. Surprisingly, expression of an astrocytic gene, glial fibrillary acidic protein (GFAP) was significantly increased relative to WT. Further studies in rat primary neuron-glial cultures showed that increased mitochondrial O2-, specifically in neurons, was sufficient to upregulate GFAP. These results suggest that neuron-specific mitochondrial O2- is sufficient to drive a complex and catastrophic epileptic phenotype and highlights the ability of SOD2 to act in a cell-nonautonomous manner to influence an astrocytic response.

Optimization of Lipophilic Metalloporphyrins Modifies Disease Outcomes in a Rat Model of Parkinsonism.

Oxidative stress plays a crucial role in the pathogenesis of Parkinson disease (PD), and one strategy for neuroprotective therapy for PD is to scavenge reactive species using a catalytic antioxidant. Previous studies in our laboratory revealed that pretreatment of lipophilic metalloporphyrins showed protective effects in a mouse PD model. In this study, we optimized the formulations of these metalloporphyrins to deliver them orally and tested their efficacy on disease outcomes in a second species after initiation of an insult (i.e., disease modification). In this study, a pharmaceutical formulation of two metalloporphyrin catalytic antioxidants, AEOL11207 and AEOL11114, was tested for oral drug delivery. Both compounds showed gastrointestinal absorption, achieved high plasma concentrations, and readily penetrated the blood-brain barrier after intravenous or oral delivery. AEOL11207 and AEOL11114 bioavailabilities were calculated to be 24% and 25%, respectively, at a dose of 10 mg/kg via the oral route. In addition, both compounds significantly attenuated 6-hydroxydopamine (6-OHDA)-induced neurotoxic damage, including dopamine depletion, cytokine production, and microglial activation in the striata; dopaminergic neuronal loss in the substantia nigra; oxidative/nitrative stress indices (glutathione disulfide and 3-nitrotyrosine) in the ventral midbrain; and rotation behavioral abnormality in rats. These results indicate that AEOL11207 and AEOL11114 are orally active metalloporphyrins and protect against 6-OHDA neurotoxicity 1-3 days postlesioning, suggesting disease-modifying properties and translational potential for PD. SIGNIFICANCE STATEMENT: Two catalytic antioxidants showed gastrointestinal absorption, achieved high plasma concentrations, and readily penetrated the blood-brain barrier. Both compounds significantly attenuated dopamine depletion, cytokine production, microglial activation, dopaminergic neuronal loss, oxidative/nitrative stress indices, and behavioral abnormality in a Parkinson disease rat model. The results suggest that both metalloporphyrins possess disease-modifying properties that may be useful in treating Parkinson disease.

Targeting oxidative stress improves disease outcomes in a rat model of acquired epilepsy.

Epilepsy therapy is based on antiseizure drugs that treat the symptom, seizures, rather than the disease and are ineffective in up to 30% of patients. There are no treatments for modifying the disease-preventing seizure onset, reducing severity or improving prognosis. Among the potential molecular targets for attaining these unmet therapeutic needs, we focused on oxidative stress since it is a pathophysiological process commonly occurring in experimental epileptogenesis and observed in human epilepsy. Using a rat model of acquired epilepsy induced by electrical status epilepticus, we show that oxidative stress occurs in both neurons and astrocytes during epileptogenesis, as assessed by measuring biochemical and histological markers. This evidence was validated in the hippocampus of humans who died following status epilepticus. Oxidative stress was reduced in animals undergoing epileptogenesis by a transient treatment with N-acetylcysteine and sulforaphane, which act to increase glutathione levels through complementary mechanisms. These antioxidant drugs are already used in humans for other therapeutic indications. This drug combination transiently administered for 2 weeks during epileptogenesis inhibited oxidative stress more efficiently than either drug alone. The drug combination significantly delayed the onset of epilepsy, blocked disease progression between 2 and 5 months post-status epilepticus and drastically reduced the frequency of spontaneous seizures measured at 5 months without modifying the average seizure duration or the incidence of epilepsy in animals. Treatment also decreased hippocampal neuron loss and rescued cognitive deficits. Oxidative stress during epileptogenesis was associated with de novo brain and blood generation of high mobility group box 1 (HMGB1), a neuroinflammatory molecule implicated in seizure mechanisms. Drug-induced reduction of oxidative stress prevented HMGB1 generation, thus highlighting a potential novel mechanism contributing to therapeutic effects. Our data show that targeting oxidative stress with clinically used drugs for a limited time window starting early after injury significantly improves long-term disease outcomes. This intervention may be considered for patients exposed to potential epileptogenic insults.

[Ag-Ag]2+ Unit-Encapsulated Trimetallic Cages: One-Pot Syntheses and Modulation of Argentophilic Interactions by the Uncoordinated Substituents.

Four [Ag-Ag]2+ unit-encapsulated trimetallic cages 1-4 were synthesized from one new tripodal ligand L and silver salts in different solvent systems by a one-pot method. The formation of coordination cages occurred simultaneously with the condensation of amino groups and ketone. The remarkable structural feature of cages 1-4 is their spontaneous incorporation of [Ag-Ag]2+ cationic units. Moreover, the argentophilic interactions are modulated by the uncoordinated amino substituents. The study herein shows that modification and subtle changes of the cage structures could be realized by a one-pot synthetic method.

Echo signal envelope fitting based signal processing methods for ultrasonic gas flow-meter.

The echo signal of the ultrasonic gas flow-meter is difficult to locate, and the computation of signal processing methods proposed by others is extensive which affects the meter's real-time performance. Aiming at solving these problems the echo signal envelopes under different flow rates are analyzed. And three kinds of signal processing methods based on echo signal envelope fitting are proposed. The shape of the echo signal remains the "approximate spindle shape" as the flow rate increases, and the envelope gradient of the middle parts of the upper envelope's rising section and the lower envelope's falling section remains the same at different flow rates, so the mathematical models of the two sections are established to obtain the envelope gradient curves of the two sections. With the envelope gradient curves, the ranges of envelope and peak points that linearly distributed are obtained. The least squares fitting is performed on those peak points to obtain two feature straight lines for respectively representing the upper envelope's rising section and the lower envelope's falling section. According to the spatial characteristics of the feature straight lines, the points on the feature straight lines are selected as the feature points for quickly locating the echo signal. According to the offline verification and comparison, the best one of three kinds of signal processing methods is selected, and realized on the hardware system of the two-channel ultrasonic gas flow-meter. The transmitter of two-channel ultrasonic gas flow-meter is developed based on FPGA & DSP dual core structure. It utilizes the parallel processing capacity and logic control ability of FPGA to realize the controlling of the high-speed ADC & DAC and the storage of the data. At the same time, it adopts the high-speed computing capacity of DSP to implement the digital signal processing method. The gas flow calibration experiments were carried out in a national accredited testing agency to verify the effectiveness of the signal processing methods and system. The experimental results show that the improved signal processing method based on echo signal upper and lower envelope fitting can quickly and accurately locate the echo signal. And the measurable range of the ultrasonic gas flow meter based on this signal processing method is broadened to 10 m3/h to 1,300 m3/h, and the turndown ratio is broadened to 1:130.

Neuroprotective effects of a catalytic antioxidant in a rat nerve agent model.

Persistent inhibition of acetylcholinesterase resulting from exposure to nerve agents such as soman, is associated with prolonged seizure activity known as status epilepticus (SE). Without medical countermeasures, exposure to soman and resultant SE leads to high morbidity and mortality. Currently available therapeutics are effective in limiting mortality, however effects on morbidity are highly time-dependent and rely on the ability to suppress SE. We have previously demonstrated significant protection from secondary neuronal injury in surrogate nerve agent models by targeting oxidative stress. However, whether oxidative stress represents a relevant therapeutic target in genuine nerve agent toxicity is unknown. Here, we demonstrate that soman exposure results in robust region- and time-dependent oxidative stress. Targeting this oxidative stress in a post-exposure paradigm using a small molecular weight, broad spectrum catalytic antioxidant, was sufficient to attenuate brain and plasma oxidative stress, neuroinflammation and neurodegeneration. Thus, targeting of oxidative stress in a post-exposure paradigm can mitigate secondary neuronal injury following soman exposure.

Aneuploidy of chromosome 8 and mutation of circulating tumor cells predict pathologic complete response in the treatment of locally advanced rectal cancer.

Identifying patients who may or may not achieve pathologic complete response (pathCR) allows for treatment with alternative approaches in the preoperative setting. The aim of the current study was to investigate whether aneuploidy of chromosome 8 and mutations of circulating tumor cells (CTCs) could predict the response of patients with rectal cancer to preoperative chemoradiotherapy. A total of 33 patients with locally advanced rectal cancer (cT3-T4 and/or cN+) treated with neoadjuvant chemoradiotherapy between September 2014 and March 2015 were recruited. Blood samples were collected from 33 patients with pre-chemoradiotherapy rectal cancer. It was demonstrated that ≥5 copies of chromosome 8 was associated with pathCR (univariate logistic regression, P=0.042). Of the 6 patients whose CTCs had <5 copies of chromosome 8, 3 achieved pathCR (3/6, 50%), and of the 27 patients whose CTCs had ≥5 copies of chromosome 8 obtained 3 pathCR (3/27, 11.1%; Chi-square test, P=0.0255). Of the 33 patients with mutations assessed, 8 significant nonsynonymous mutations in CTCs were identified as associated with pathCR (Chi-square test, P-values range, 0.0004-0.0298; mutations in ARID1A, HDAC1, APC, ERBB3, TP53, AMER1 and AR). These results suggest that ≥5 copies of chromosome 8 and 8 nonsynonymous mutations in ARID1A, HDAC1, APC, ERBB3, TP53, AMER1 AR in CTCs were associated with pathCR. This conclusion should be validated further in larger prospective studies and the long-term follow-up survival data of this study will also be reported in the future.

Survival outcomes and patterns of failure after D2 dissection and adjuvant chemoradiotherapy for locally advanced gastric cancer: a retrospective study.

OBJECTIVE:   The goal of the study was to analyze the incidence and patterns of failure in patients with gastric cancer who received D2 dissection and adjuvant chemoradiotherapy (CRT). METHODS:   From January 2004 to October 2015, 324 patients with gastric cancer who underwent radical D2 resection followed by postoperative CRT were enrolled. Clinicopathological characteristics and patterns of failure were retrospectively reviewed to identify factors associated with survival and recurrence. RESULTS:   After a median follow-up of 30 months, the 3-year overall survival and 3-year disease-free survival rates of these patients were 60.3 and 51.1%, respectively. 117 patients had recurrence or metastasis, with peritoneal recurrence as the most frequent (20.7%), followed by distant metastasis (14.2%). The most commonly involved distant organs were the liver (5.9%) and bone (4.9%). Locoregional failure occurred in 39 patients (12.0%), with isolated regional failure occurring in only 23 (7.1%). Further multivariate Cox regression analysis revealed N stage to be an independent risk factor for distant failure-free survival (p = 0.012). Independent risk factors for peritoneal metastasis were tumor differentiation (p = 0.022), T stage (p =0.035) and vascular invasion (p = 0.016). CONCLUSION: Postoperative CRT has a potential effect on optimizing locoregional control, resulting in only 12.0% of locoregional failure. In patients after D2 resection and adjuvant CRT, peritoneal metastasis was the leading pattern of failure, followed by distant metastasis. Advances in knowledge: Peritoneal recurrence was the most common pattern of failure after D2 dissection and adjuvant CRT, followed by distant metastasis, whereas locoregional relapse was relatively rare. Selection of patients based on the predicted risk of each recurrence pattern may be a reasonable approach to the optimization of treatment strategies.

Altered mitochondrial acetylation profiles in a kainic acid model of temporal lobe epilepsy.

Impaired bioenergetics and oxidative damage in the mitochondria are implicated in the etiology of temporal lobe epilepsy, and hyperacetylation of mitochondrial proteins has recently emerged as a critical negative regulator of mitochondrial functions. However, the roles of mitochondrial acetylation and activity of the primary mitochondrial deacetylase, SIRT3, have not been explored in acquired epilepsy. We investigated changes in mitochondrial acetylation and SIRT3 activity in the development of chronic epilepsy in the kainic acid rat model of TLE. Hippocampal measurements were made at 48 h, 1 week and 12 weeks corresponding to the acute, latent and chronic stages of epileptogenesis. Assessment of hippocampal bioenergetics demonstrated a ≥ 27% decrease in the ATP/ADP ratio at all phases of epileptogenesis (p < 0.05), whereas cellular NAD+ levels were decreased by ≥ 41% in the acute and latent time points (p < 0.05), but not in chronically epileptic rats. In spontaneously epileptic rats, we found decreased protein expression of SIRT3 and a 60% increase in global mitochondrial acetylation, as well as enhanced acetylation of the known SIRT3 substrates MnSOD, Ndufa9 of Complex I and IDH2 (all p < 0.05), suggesting SIRT3 dysfunction in chronic epilepsy. Mass spectrometry-based acetylomics investigation of hippocampal mitochondria demonstrated a 79% increase in unique acetylated proteins from rats in the chronic phase vs. controls. Pathway analysis identified numerous mitochondrial bioenergetic pathways affected by mitochondrial acetylation. These results suggest SIRT3 dysfunction and aberrant protein acetylation may contribute to mitochondrial dysfunction in chronic epilepsy.

Error analysis and new dual-cosine window for estimating the sensor frequency response function from the step response data.

Aiming at reducing the estimation error of the sensor frequency response function (FRF) estimated by the commonly used window-based spectral estimation method, the error models of interpolation and transient errors are derived in the form of non-parameter models. Accordingly, window effects on the errors are analyzed and reveal that the commonly used hanning window leads to smaller interpolation error which can also be significantly eliminated by the cubic spline interpolation method when estimating the FRF from the step response data, and window with smaller front-end value can restrain more transient error. Thus, a new dual-cosine window with its non-zero discrete Fourier transform bins at -3, -1, 0, 1, and 3 is constructed for FRF estimation. Compared with the hanning window, the new dual-cosine window has the equivalent interpolation error suppression capability and better transient error suppression capability when estimating the FRF from the step response; specifically, it reduces the asymptotic property of the transient error from O(N-2) of the hanning window method to O(N-4) while only increases the uncertainty slightly (about 0.4 dB). Then, one direction of a wind tunnel strain gauge balance which is a high order, small damping, and non-minimum phase system is employed as the example for verifying the new dual-cosine window-based spectral estimation method. The model simulation result shows that the new dual-cosine window method is better than the hanning window method for FRF estimation, and compared with the Gans method and LPM method, it has the advantages of simple computation, less time consumption, and short data requirement; the actual data calculation result of the balance FRF is consistent to the simulation result. Thus, the new dual-cosine window is effective and practical for FRF estimation.

Regulation of kynurenine metabolism by a ketogenic diet.

Ketogenic diets (KDs) are increasingly utilized as treatments for epilepsy, other neurological diseases, and cancer. Despite their long history in suppressing seizures, the distinct molecular mechanisms of action of KDs are still largely unknown. The goal of this study was to identify key metabolites and pathways altered in the hippocampus and plasma of rats fed a KD versus control diet (CD) either ad libitum or calorically restricted to 90% of the recommended intake. This was accomplished using a combination of targeted methods and untargeted MS-based metabolomics analyses. Various metabolites of and related to the tryptophan (TRP) degradation pathway, such as kynurenine (KYN), kynurenic acid as well as enzyme cofactors, showed significant changes between groups fed different diets and/or calorie amounts in plasma and/or the hippocampus. KYN was significantly downregulated in both matrices in animals of the CD-calorically restricted, KD-ad libitum, and KD-calorically restricted groups compared with the CD-ad libitum group. Our data suggest that the TRP degradation pathway is a key target of the KD.

Neuroprotective Effects of AEOL10150 in a Rat Organophosphate Model.

Prolonged seizure activity or status epilepticus (SE) is one of the most critical manifestations of organophosphate exposure. Previous studies in our laboratory have demonstrated that oxidative stress is a critical mediator of SE-induced neuronal injury. The goal of this study was to determine if diisopropylflurorphoshate (DFP) exposure in rats resulted in oxidative stress and whether scavenging reactive oxygen species attenuated DFP-induced neurotoxicity. DFP treatment increased indices of oxidative stress in a time- and region- dependent manner. Neuronal loss measured by Fluoro-Jade B staining was significantly increased in the hippocampus, piriform cortex and amygdala following DFP. Similarly, levels of the proinflammatory cytokines, particularly TNF-α, IL-6, and KC/GRO were significantly increased in the piriform cortex and in the hippocampus following DFP treatment. The catalytic antioxidant AEOL10150, when treatment was initiated 5 min after DFP-induced SE, significantly attenuated indices of oxidative stress, neuroinflammation and neuronal damage. This study suggests that catalytic antioxidant treatment may be useful as a novel therapy to attenuate secondary neuronal injury following organophosphate exposure.

Scavenging reactive oxygen species inhibits status epilepticus-induced neuroinflammation.

Inflammation has been identified as an important mediator of seizures and epileptogenesis. Understanding the mechanisms underlying seizure-induced neuroinflammation could lead to the development of novel therapies for the epilepsies. Reactive oxygen species (ROS) are recognized as mediators of seizure-induced neuronal damage and are known to increase in models of epilepsies. ROS are also known to contribute to inflammation in several disease states. We hypothesized that ROS are key modulators of neuroinflammation i.e. pro-inflammatory cytokine production and microglial activation in acquired epilepsy. The role of ROS in modulating seizure-induced neuroinflammation was investigated in the pilocarpine model of temporal lobe epilepsy (TLE). Pilocarpine-induced status epilepticus (SE) resulted in a time-dependent increase in pro-inflammatory cytokine production in the hippocampus and piriform cortex. Scavenging ROS with a small-molecule catalytic antioxidant decreased SE-induced pro-inflammatory cytokine production and microglial activation, suggesting that ROS contribute to SE-induced neuroinflammation. Scavenging ROS also attenuated phosphorylation of ribosomal protein S6, the downstream target of the mammalian target of rapamycin (mTOR) pathway indicating that this pathway might provide one mechanistic link between SE-induced ROS production and inflammation. Together, these results demonstrate that ROS contribute to SE-induced cytokine production and antioxidant treatment may offer a novel approach to control neuroinflammation in epilepsy.