Up-regulation of antioxidative proteins TRX1, TXNL1 and TXNRD1 in the cortex of PTZ kindling seizure model mice

Proteomic-miRNA Biomics Profile Reveals 2D Cultures of Human iPSC-Derived Neural Progenitor Cells More Sensitive than 3D Spheroid System Against the Experimental Exposure to Arsenic

The iPSC-derived 3D models are considered to be a connective link between 2D culture and in vivo studies. However, the sensitivity of such 3D models is yet to be established. We assessed the sensitivity of the hiPSC-derived 3D spheroids against 2D cultures of neural progenitor cells. The sub-toxic dose of Sodium Arsenite (SA) was used to investigate the alterations in miRNA-proteins in both systems. Though SA exposure induced significant alterations in the proteins in both 2D and 3D systems, these proteins were uncommon except for 20 proteins. The number and magnitude of altered proteins were higher in the 2D system compared to 3D. The association of dysregulated miRNAs with the target proteins showed their involvement primarily in mitochondrial bioenergetics, oxidative and ER stress, transcription and translation mechanism, cytostructure, etc., in both culture systems. Further, the impact of dysregulated miRNAs and associated proteins on these functions and ultrastructural changes was compared in both culture systems. The ultrastructural studies revealed a similar pattern of mitochondrial damage, while the cellular bioenergetics studies confirm a significantly higher energy failure in the 2D system than to 3D. Such a higher magnitude of changes could be correlated with a higher amount of internalization of SA in 2D cultures than in 3D spheroids. Our findings demonstrate that a 2D culture system seems better responsive than a 3D spheroid system against SA exposure.

Melatonin antagonizes oxidative stress-induced apoptosis in retinal ganglion cells through activating the thioredoxin-1 pathway

This study aimed to explore the role of melatonin in oxidative stress-induced injury on retinal ganglion cells and the underlying mechanisms. The immortalized RGC-5 cells were treated with H2O2 to induce oxidative injury. Cell viability was measured by Cell Counting Kit-8, and apoptosis was determined by flow cytometry and western blot assays. Reactive oxygen species (ROS), lactate dehydrogenase (LDH), and malondialdehyde (MDA) levels were examined to evaluate oxidative stress levels. In addition, Thioredoxin-1 (Trx1) was silenced in RGC-5 cells using small interfering RNA followed by signaling pathway examination to explore the underlying mechanisms of melatonin in alleviating oxidative injury. Melatonin pre-treatment significantly alleviated H2O2-induced apoptosis in RGC-5 cells. Melatonin also markedly reversed the upregulation of cleaved-caspase 3, cleaved-caspase 9, and Bax expression and downregulation of Bcl-2 expression induced by H2O2. Further analyses presented that melatonin significantly attenuated the increase of ROS, LDH, and MDA levels in RGC-5 cells after H2O2 treatment. Melatonin also abolished the downregulated expression of Superoxide dismutase type 1, Trx1, and Thioredoxin reductase 1, and the reduced activity of thioredoxin reductase in RGC-5 cells after H2O2 treatment. Notably, Trx1 knockdown significantly mitigated the protective effect of melatonin in alleviating H2O2-induced apoptosis and oxidative stress, while administration of compound C, a common inhibitor of c-Jun N-terminal kinase (JNK) signaling, partially reversed the effect of Trx1 silencing, thereby ameliorating the apoptosis and oxidative injury induced by H2O2 in RGC-5 cells. Melatonin could significantly alleviate oxidative stress-induced injury of retinal ganglion cells via modulating Trx1-mediated JNK signaling pathway.

Cerebral Malaria Model Applying Human Brain Organoids

Neural injuries in cerebral malaria patients are a significant cause of morbidity and mortality. Nevertheless, a comprehensive research approach to study this issue is lacking, so herein we propose an in vitro system to study human cerebral malaria using cellular approaches. Our first goal was to establish a cellular system to identify the molecular alterations in human brain vasculature cells that resemble the blood-brain barrier (BBB) in cerebral malaria (CM). Through transcriptomic analysis, we characterized specific gene expression profiles in human brain microvascular endothelial cells (HBMEC) activated by the Plasmodium falciparum parasites. We also suggest potential new genes related to parasitic activation. Then, we studied its impact at brain level after Plasmodium falciparum endothelial activation to gain a deeper understanding of the physiological mechanisms underlying CM. For that, the impact of HBMEC-P. falciparum-activated secretomes was evaluated in human brain organoids. Our results support the reliability of in vitro cellular models developed to mimic CM in several aspects. These systems can be of extreme importance to investigate the factors (parasitological and host) influencing CM, contributing to a molecular understanding of pathogenesis, brain injury, and dysfunction.

Advances in the Functions of Thioredoxin System in Central Nervous System Diseases

Significance: The thioredoxin system comprises thioredoxin (Trx), thioredoxin reductase (TrxR), and nicotinamide adenine dinucleotide phosphate, besides an endogenous Trx inhibitor, the thioredoxin-interacting protein (TXNIP). The Trx system plays critical roles in maintaining the redox homeostasis in the central nervous system (CNS), in which oxidative stress damage is prone to occurrence due to its high-energy demand. Recent Advances: Increasing studies have demonstrated that the expression or activity of Trx/TrxR is usually decreased and that TXNIP expression is increased in patients with CNS diseases, including neurodegenerative diseases, cerebral ischemia, traumatic brain injury, and depression, as well as in their cellular and animal models. The compromise of Trx/TrxR enhances the susceptibility of neurons to related pathological state. Increased TXNIP not only enhances the inhibition of Trx activity, but also activates the NOD-like receptor protein 3 inflammasome, resulting in neuroinflammation in the brain. Critical Issues: In this review, we highlight the sources of oxidative stress in the CNS. The expression and function of the Trx system are summarized in different CNS diseases. This review also mentions that some inducers of Trx show neuroprotection in CNS diseases. Future Directions: Accumulating evidence has demonstrated the important roles of the Trx system in CNS diseases, suggesting that the Trx system may be a promising therapeutic target for CNS diseases. Further study should aim to develop the most effective inducers of Trx and specific inhibitors of TXNIP and to apply them in the clinical trials for the treatment of CNS diseases. Antioxid. Redox Signal. 38, 425-441.

Identification of the Acid-Sensitive Site Critical for Chloral Hydrate (CH) Activation of the Proton-Activated Chloride Channel

The transmembrane protein TMEM206 was recently identified as the molecular basis of the extracellular proton-activated Cl^- channel (PAC), which plays an essential role in neuronal death in ischemia-reperfusion. The PAC channel is activated by extracellular acid, but the proton-sensitive mechanism remains unclear, although different acid-sensitive pockets have been suggested based on the cryo-EM structure of the human PAC (hPAC) channel. In the present study, we firstly identified two acidic amino acid residues that removed the pH-dependent activation of the hPAC channel by neutralization all the conservative negative charged residues located in the extracellular domain of the hPAC channel and some positively charged residues at the hotspot combined with two-electrode voltage-clamp (TEVC) recording in the Xenopus oocytes system. Double-mutant cycle analysis and double cysteine mutant of these two residues proved that these two residues cooperatively form a proton-sensitive site. In addition, we found that chloral hydrate activates the hPAC channel depending on the normal pH sensitivity of the hPAC channel. Furthermore, the PAC channel knock-out (KO) male mice (C57BL/6J) resist chloral hydrate-induced sedation and hypnosis. Our study provides a molecular basis for understanding the proton-dependent activation mechanism of the hPAC channel and a novel drug target of chloral hydrate.SIGNIFICANCE STATEMENT Proton-activated Cl^- channel (PAC) channels are widely distributed in the nervous system and play a vital pathophysiological role in ischemia and endosomal acidification. The main discovery of this paper is that we identified the proton activation mechanism of the human proton-activated chloride channel (hPAC). Intriguingly, we also found that anesthetic chloral hydrate can activate the hPAC channel in a pH-dependent manner. We found that the chloral hydrate activates the hPAC channel and needs the integrity of the pH-sensitive site. In addition, the PAC channel knock-out (KO) mice are resistant to chloral hydrate-induced anesthesia. The study on PAC channels' pH activation mechanism enables us to better understand PAC's biophysical mechanism and provides a novel target of chloral hydrate.

The effects of vitamin D3 and melatonin combination on pentylenetetrazole-induced seizures in mice

BACKGROUND

Epileptic seizures are associated with the overproduction of free radicals in the brain leading to neuronal cell death. Therefore, reduction of oxidative stress may inhibit seizure-induced neuronal cell damage. Current study evaluated the effects of Vit D3 and melatonin and their combination on pentylenetetrazol (PTZ)-induced tonic clonic seizures in mice.

METHODS

Animals were divided into six groups. Group I was administrated with normal saline (0.5 ml, intraperitoneally (i.p.)) on the 15th day of experiment. Group II was injected with PTZ (60 mg/kg dissolved in 0.5 ml normal saline, i.p) on the 15th day. Groups III-IV were treated with diazepam (4 mg/kg/day), Vit D3 (6000 IU/kg/day), melatonin (20 mg/kg/day) and Vit D3 (6000 IU/kg/day)/melatonin (20 mg/kg/day), respectively, and were then injected with PTZ (60 mg/kg) on the 15th day of experiment. Immediately after the injection of PTZ on the 15th day, mice were observed for a 30-min period for the measurement of seizure latency and duration. For determination of oxidative stress markers, malondialdehyde (MDA) level and superoxide dismutase (SOD) activity were measured in mouse brains.

RESULTS

Treatment with Vit D3, melatonin, and Vit D3/melatonin significantly increased seizure latency and decreased seizure duration. The brain level of MDA was lower and SOD activity was greater than the PTZ group. Mice treated with Vit D3/melatonin had lower seizure duration compared to other treated groups.

CONCLUSIONS

Combination of Vit D3 and melatonin may reduce seizure frequency in epileptic patients; this effect may result from various mechanisms including inhibition of oxidative stress.

PM10 Alters Trophoblast Cell Function and Modulates miR-125b-5p Expression

Air pollution is one of the largest global environmental health hazards that threaten premature mortality or morbidity. Particulate matter 10 (PM10) has been demonstrated to contribute to several human diseases via dysregulated miRNA expression. Trophoblast cells play a key role in implantation and placentation for a successful pregnancy. Nonetheless, the PM10 associated trophoblast cell functions during pregnancy and miRNA expression are still unknown. Our study showed that PM10 affected HTR-8/SVneo cell viability and also decreased cell proliferation, migration, and invasion. A high concentration of PM10 caused an increase in HTR-8/SVneo cell apoptosis. Treatment with PM10 induced inflammation through the upregulated IL-1β, IL-6, and TNF-α expression in trophoblast cells. In PM10-treated HTR-8/SVneo cells, miR-125b-5p expression was considerably increased and TXNRD1 was found to be negatively related to miR-125b-5p. Collectively, our findings revealed that PM10 could alter miR-125b-5p expression by targeting TXNRD1 and suppressing trophoblast cell functions. Additional investigations relating to the function of miR-125b-5p and its target on particulate pollution exposure in trophoblast are warranted for future biomarker or effective therapeutic approaches.

Neuroprotective effects of tannic acid against kainic acid-induced seizures in mice

BACKGROUND

Epileptic seizures are associated with the release of potentially neurotoxic amount of glutamate, which results in the over-production of free radicals and inflammatory factors, and induction of neuronal cell death. Current study evaluated the effect of tannic acid (TA) on Kainic acid (KA)-induced seizures in mice.

METHODS

Mice were divided into the six groups. Group I was administrated with normal saline (NS; 1 mL/kg, intraperitoneally (i.p.)), Group II was injected with KA (15 mg/kg, i.p.), Groups III was treated with diazepam (DZ; 20 mg/kg, i.p.) and KA (15 mg/kg, i.p.), Groups IV-VI were treated with TA (25, 50 and 100 mg/kg, i.p.) and KA (15 mg/kg, i.p.). Animals received all treatments 30 min before injection of KA. After the injection of KA, mice were observed for seizure (latency, activity and duration) and mortality for 2 h. In the brain tissue, oxidative stress, apoptosis, and inflammatory markers were evaluated in addition to the determination of histological alterations in the CA1 molecular layer of hippocampus.

RESULTS

Treatment with TA significantly increased seizure latency and decreased seizure duration and activity, but could not significantly decrease mice mortality. This effect was associated with the reduction of oxidative stress, inflammation, and apoptosis. Furthermore, treatment with TA significantly improved KA-induced pyramidal cell loss and change in the arrangement of CA1 molecular layer.

CONCLUSIONS

Tannic acid may be useful in the control of epileptic seizures through regulating oxidative stress, inflammation and apoptosis.

D-SCRIPT translates genome to phenome with sequence-based, structure-aware, genome-scale predictions of protein-protein interactions

We combine advances in neural language modeling and structurally motivated design to develop D-SCRIPT, an interpretable and generalizable deep-learning model, which predicts interaction between two proteins using only their sequence and maintains high accuracy with limited training data and across species. We show that a D-SCRIPT model trained on 38,345 human PPIs enables significantly improved functional characterization of fly proteins compared with the state-of-the-art approach. Evaluating the same D-SCRIPT model on protein complexes with known 3D structure, we find that the inter-protein contact map output by D-SCRIPT has significant overlap with the ground truth. We apply D-SCRIPT to screen for PPIs in cow (Bos taurus) at a genome-wide scale and focusing on rumen physiology, identify functional gene modules related to metabolism and immune response. The predicted interactions can then be leveraged for function prediction at scale, addressing the genome-to-phenome challenge, especially in species where little data are available.

Chronic effects of different quercetin doses in penicillin-induced focal seizure model

AIM

The aim of the present study was to examine the effects of different quercetin pretreatment doses on focal epileptiform activity induced by penicillin in adult male rat cortex.

METHOD

Twenty-eight male Wistar rats weighing 200-235 g were randomly divided into four groups: control (only penicillin-injected group) and penicillin + 25, 50 or 100 mg/kg quercetin doses. All quercetin-treated rats had a daily single dose of 25, 50 or 100 mg/kg intraperitoneally administered quercetin for 21 days, and the last dose was given 30 min before the penicillin injection. Epileptiform activity was induced by a single intracortical (i.c.) microinjection of penicillin (500 units/2.5 μl) into left motor cortex. After penicillin injection ECoG was recorded for the following 180 min.

RESULTS

Quercetin pretreatments of 25, 50 and 100 mg/kg significantly increased the duration of latency (initial spike activity) and decreased spike frequency of the epileptiform activity compared to the control group (p < 0.05). Duration of latency was significantly longer in 25 mg/kg quercetin pretreatment group compared to 100 mg/kg group (p < 0.05). Spike amplitude of epileptiform activity was not different in the study groups (p > 0.05).

CONCLUSION

Quercetin had an anticonvulsant activity in penicillin-induced focal seizure model in the present study. In addition, lower quercetin doses had highest anticonvulsant effect in this model.

The role of TXNL1 in disease: treatment strategies for cancer and diseases with oxidative stress

Thioredoxin-like protein-1 (TXNL1; also known as thioredoxin-related 32 kDa protein, TRP32) is a thioredoxin involved in the regulation of oxidative stress, which protects cells from damage through redox balance. Studies have shown that TXNL1 has a variety of functions, including cell signal transduction, cell cycle regulation, protein synthesis, modification and degradation, vesicle transport, transcriptional regulation, cell apoptosis, virus replication and oxidative stress regulation, etc., and plays an important role in the occurrence and development of human diseases. Therefore, TXNL1 has a strong correlation with the treatment of cancer and oxidative stress diseases. In this paper, the basic structure, function and potential application value of TXNL1 in diseases are reviewed, so as to open up new targets for the treatment of cancer and oxidative stress-related diseases.

New In Vitro Model of Oxidative Stress: Human Prostate Cells Injured with 2,2-diphenyl-1-picrylhydrazyl (DPPH) for the Screening of Antioxidants

The antioxidant activity of natural compounds consists in their ability to modulate gene and protein expression, thus inducing an integrated cell protective response and repair processes against oxidative stress. New screening tools and methodologies are crucial for the actual requirement of new products with antioxidant activity to boost endogenous oxidative stress responsive pathways, Reactive Oxygen Species (ROS) metabolism and immune system activity, preserving human health and wellness. In this study, we performed and tested an integrated oxidative stress analysis, using DPPH assay and PNT2 cells injured with DPPH. We firstly investigated the mechanism of action of the oxidising agent (DPPH) on PNT2 cells, studying the variation in cell viability, oxidative stress genes, inflammatory mediator and ROS levels. The results reveal that DPPH activated ROS production and release of Prostaglandin E₂ in PNT2 at low and intermediate doses, while cells switched from survival to cell death signals at high doses of the oxidising agent. This new in vitro oxidative stress model was validated by using Trolox, β-carotene and total extract of the green microalga Testraselmis suecica. Only the T. suecica extract can completely counteract DPPH-induced injury, since its chemical complexity demonstrated a multilevel protecting and neutralising effect against oxidative stress in PNT2.

Effect of Captopril on Brain Oxidative Damage in Pentylenetetrazole-Induced Seizures in Mice

Background: Frequent seizure is followed by overproduction of free radicals and brain oxidative stress. Renin angiotensin system (RAS) has some effects on central nervous system. We designed this research to challenge the effect of captopril as an angiotensin converting enzyme (ACE) inhibitor against brain oxidative stress in pentylenetetrazole (PTZ) -induced seizures in mice. Methods: The groups were including (1) Control (saline); (2) PTZ (100 mg/kg, i.p.), (3-5) PTZ- captopril (Capto) that received three doses of Capto 10, 50 and 100 mg/kg 30 min before PTZ injection. Latency time in the onset minimal clonic seizures (MCS) and generalized tonic-clonic seizures (GTCS) were recorded. The level of malondialdehyde (MDA) and total thiol, as well as superoxide dismutase (SOD) and catalase (CAT) activity in the hippocampus and cortex were measured. Results: All doses of captopril postponed the onset of MCS and GTCS. Accumulation of MDA in the brain tissues of PTZ group was higher than control group, while total thiol content and CAT activity were lower. Pretreatment with captopril (100 mg/kg) diminished MDA concentration compared with PTZ group. Captopril (50 and 100 mg/kg) also increased the level of total thiol groups versus PTZ group. Captopril injection (50 and 100 mg/kg) elevated the activity of SOD and CAT in the brain tissues. In addition captopril administration diminished mortality rate caused by PTZ. Conclusion: Findings demonstrated that convulsions caused by PTZ were followed by oxidative stress status in the brain tissues. Pretreatment with captopril attenuated the effect of PTZ on brain tissue oxidative damage.<br />