Oxidative stress, mitochondrial dysfunction and neurodegenerative diseases; a mechanistic insight

Supplementation with aspalathin and sulforaphane protects cultured cardiac cells against dyslipidemia-associated oxidative damage

Dyslipidemia is a prominent pathological feature responsible for oxidative stress-induced cardiac damage. Due to their high antioxidant content, dietary compounds, such as aspalathin and sulforaphane, are increasingly explored for their cardioprotective effects against lipid-induced toxicity. Cultured H9c2 cardiomyoblasts, an in vitro model routinely used to assess the pharmacological effect of drugs, were pretreated with the dietary compounds, aspalathin (1 μM) and sulforaphane (10 μM) before exposure to palmitic acid (0.25 mM) to induce lipidemic-related complications. The results showed that both aspalathin and sulforaphane enhanced cellular metabolic activity and improved mitochondrial respiration correlating with improved mRNA expression of genes involved in mitochondrial function, including uncoupling protein 2, peroxisome proliferator-activated receptor, gamma coactivator 1-alpha, nuclear respiratory factor 1, and ubiquinol-cytochrome c reductase complex assembly factor 1. Beyond attenuating lipid peroxidation, the dietary compounds also suppressed intracellular reactive oxygen species and enhanced antioxidant responses, including the mRNA expression of nuclear factor erythroid 2-related factor 2. These envisaged benefits were associated with decreased cellular apoptosis. This preclinical study supports and warrants further investigation into the potential benefits of these dietary compounds or foods rich in aspalathin or sulforaphane in protecting against lipid-induced oxidative damage within the myocardium.

Mitochondria-targeting by small molecules against Alzheimer's disease: A mechanistic perspective

Alzheimer's disease (AD) poses a considerable worldwide health obstacle, marked by gradual cognitive deterioration and neuronal loss. While the molecular mechanisms underlying AD pathology have been elucidated to some extent, therapeutic options remain limited. Mitochondrial dysfunction has become recognized as a significant factor in the development of AD, with oxidative stress and disrupted energy metabolism being critical elements. This review explores the mechanistic aspects of small molecule targeting of mitochondria as a potential therapeutic approach for AD. The review explores the role of mitochondrial dysfunction in AD, including its involvement in the accumulation of β-amyloid plaques and neurofibrillary tangles, synaptic dysfunction, and neuronal death. Furthermore, the effects of oxidative stress on mitochondrial function were investigated, including the resulting damage to mitochondrial components. Mitochondrial-targeted therapies have attracted attention for their potential to restore mitochondrial function and reduce AD pathology. The review outlines the latest preclinical and clinical evidence supporting the effectiveness of small molecules in targeting mitochondrial dysfunction in AD. Additionally, it discusses the molecular pathways involved in mitochondrial dysfunction and examines how small molecules can intervene to address these abnormalities. By providing a comprehensive overview of the latest research in this field, this review aims to shed light on the therapeutic potential of small molecule targeting of mitochondria in AD and stimulate further research in this promising area of drug development.

The role of Tyr34 in proton coupled electron transfer and product inhibition of manganese superoxide dismutase

Human manganese superoxide dismutase (MnSOD) plays a crucial role in controlling levels of reactive oxygen species (ROS) by converting superoxide (O 2 ∙ - ) to molecular oxygen (O2) and hydrogen peroxide (H2O2) with proton-coupled electron transfers (PCETs). A key catalytic residue, Tyr34, determines the activity of human MnSOD and also becomes post-translationally inactivated by nitration in various diseases associated with mitochondrial dysfunction. Tyr34 has an unusual pKa due to its proximity to the Mn metal and undergoes cyclic deprotonation and protonation events to promote the electron transfers of MnSOD. Neutron diffraction, X-ray spectroscopy, and quantum chemistry calculations in oxidized, reduced and product inhibited enzymatic states shed light on the role of Tyr34 in MnSOD catalysis. The data identify the contributions of Tyr34 in MnSOD activity that support mitochondrial function and give a thorough characterization of how a single tyrosine modulates PCET catalysis. Product inhibition occurs by an associative displacement mechanism.

RAGE deficiency obstructs high uric acid-induced oxidative stress and inflammatory response

Hyperuricemia is a metabolic disorder primarily associated with gout and implicated in various metabolic inflammatory diseases. While the role of monosodium urate crystals triggering inflammation has been well-documented, recent findings suggest that soluble high uric acid (HUA) also induces pro-inflammatory cytokine production in human monocytes. However, the comprehensive effects of HUA levels on macrophage dysfunction and the underlying mechanisms remain underexplored. This study employs urate oxidase knockout (UOX-KO) and receptor for advanced glycation end products deficiency (RAGE-/-) mouse models to elucidate macrophage function and its mechanistic pathways. Our results demonstrate that HUA promotes M1 polarization and migration of macrophages while impairing their phagocytic ability. This process is mediated through the high mobility group box 1 (HMGB1)-RAGE- ROS axis. Notably, RAGE deficiency in bone marrow-derived cells partially mediates these effects. Pathologically, elevated HMGB1 and monocyte chemoattractant protein 1 levels in pancreatic islets increases macrophage infiltration in UOX-KO mice. Treatment with the FPS-ZM1, as a pharmacological RAGE inhibitor, effectively decreases serum UA levels, ameliorates islet inflammation and insulin resistance. These findings suggest that soluble HUA serves as a pro-inflammatory trigger through the HMGB1-RAGE-ROS axis, and that RAGE inhibition may mitigate these effects by decreasing inflammatory macrophage infiltration in the islets. Additionally, the influence of UA on macrophages extends beyond gout, potentially contributing to the pathogenesis of other metabolic inflammatory conditions, such as atherosclerosis, non-alcoholic steatohepatitis, obesity, and hyperlipidemia.

Development of a dual-sensing colorimetric probe for total antioxidant capacity measurement using iron(III)-o-phenanthroline reagent

In this study, a dual-mode sensing system was developed for the determination of total antioxidant capacity (TAC) using the Fe(III)-phenanthroline (Fe(III)-phen) reagent. The first detection mechanism of the system is based on the reduction of the Fe(III)-phen reagent by antioxidants, leading to the formation of the orange-red Fe(II)-phen chelate, which is quantified by the absorbance change at 510 nm. The second mechanism exploits the oxidase-like activity of the Fe(III)-phen complex. This complex generates superoxide anion radicals that oxidize 3,3',5,5'-tetramethylbenzidine (TMB) to produce a blue-colored oxidized TMB (ox-TMB) charge-transfer complex. In the presence of antioxidants, this reaction is inhibited, resulting in a decrease in ox-TMB formation, and the absorbance change at 652 nm correlates with the TAC of the tested sample. The proposed system was successfully applied to standard antioxidants, synthetic antioxidant mixtures, and real food extracts, demonstrating its applicability and sensitivity for TAC analysis. The linear equation of the calibration graphs obtained for different trolox (TR) concentrations were found to be A510 = 0.0221CTR + 0.0223 (A: absorbance and C: concentration in μM) and ΔA = 0.0301CTR + 0.0583 (ΔA: the difference of absorbance resulting from decreasing ox-TMB formation in the presence of TR, and C: concentration in μM) for the reduction-based Fe(III)-phen method and the TMB-based Fe(III)-phen method, respectively. The limits of detection (LOD) for the reduction based Fe(III)-phen method and the TMB-based Fe(III)-phen method were found to be 0.45 and 0.87 μM, respectively, for trolox. The LOD was calculated using the equation; LOD = 3 sbl/m (sbl: standard deviation of a blank, m: slope of the calibration line). This study presents an innovative approach by utilizing the same probe, Fe(III)-phen, through two distinct mechanisms for the simple, rapid, and sensitive determination of TAC.

Mitochondrial Alterations, Oxidative Stress, and Therapeutic Implications in Alzheimer's Disease: A Narrative Review

The relationship between aging, mitochondrial dysfunction, neurodegeneration, and the onset of Alzheimer's disease (AD) is a complex area of study. Aging is the primary risk factor for AD, and it is associated with a decline in mitochondrial function. This mitochondrial dysfunction is believed to contribute to the neurodegenerative processes observed in AD. Neurodegeneration in AD is characterized by the progressive loss of synapses and neurons, particularly in regions of the brain involved in memory and cognition. It is hypothesized that mitochondrial dysfunction plays a pivotal role by disrupting cellular energy metabolism and increasing the production of reactive oxygen species (ROS), which can damage cellular components and exacerbate neuronal loss. Despite extensive research, the precise molecular pathways linking mitochondrial dysfunction to AD pathology are not fully understood. Various hypotheses have been proposed, including the mitochondrial cascade hypothesis, which suggests that mitochondrial dysfunction is an early event in AD pathogenesis that triggers a cascade of cellular events leading to neurodegeneration. With this narrative review, we aim to summarize some specific issues in the literature on mitochondria and their involvement in AD onset, with a focus on the development of therapeutical strategies targeting the mitochondria environment and their potential application for the treatment of AD itself.

Cyclosorus terminans extract mitigates submandibular gland changes associated with high-fat diet consumption in male rats

OBJECTIVES

To investigate whether the prophylactic effect of Cyclosorus terminans extract mitigates metabolic impairment and submandibular gland changes, as indicated by increased aquaporin5 expression, decreased fibrosis, oxidative stress and inflammation, improved mitochondrial homeostasis/dynamics, and decreased cell death in the submandibular glands of high-fat diet (HFD)-feeding rats.

METHODS

Thirty-two male Wistar rats were assigned to either a normal diet (ND) as control rats (n=8) or a HFD (n=24) for 12 weeks. The HFD-treated rats were divided into 3 subgroups to receive either: 1) vehicle (HDV), 2) Cyclosorus terminans at a dose of 100 mg/kg/d (HF100), or 3) Cyclosorus terminans at a dose of 200 mg/kg/d (HF200). At week 13, metabolic parameters, systemic oxidative stress, and submandibular gland parameters were assessed.

RESULTS

Twelve weeks of HFD-feeding rats induced obese-insulin resistance and submandibular gland changes. Both HF100- and HF200-treated groups improved metabolic parameters and prevented gland changes by reducing fibrosis (TGF-β and p-38), malondialdehyde levels, inflammation (TNF-α, NF-κB, and Ifng), and cell death markers (Caspase 3, GSDMD, and MLKL). Both treatments supported balanced mitochondrial homeostasis/dynamics, as indicated by regulating related genes (Cpt1b, Ndufb8, Mfn1, Mfn2, Opa1, and Dnm1l). However, only the HF200-treated rats restored aquaporin-5 and antioxidants (SOD2 and GPX4) expression to control levels.

CONCLUSIONS

Cyclosorus terminans mitigates metabolic disturbances and submandibular gland changes in HFD-feeding rats. The high dose was more effective, improving gland function by increasing aquaporin5 and antioxidants. These results suggest Cyclosorus terminans may be a promising therapeutic for metabolic disturbances and submandibular gland changes in obese-insulin resistant patients.

Targeting Nrf2/HO-1 signaling by crocin: Role in attenuation of arsenic trioxide-induced neurotoxicity in mice

ETHNOPHARMACOLOGY RELEVANCE

Saffron is a valued herb, obtained from the stigmas of the C.sativus Linn (Iridaceae). Pharmacopoeias have described it as having a variety of actions, such as stimulant, anti-carcinogen, and anti-depressant. As a folk medicine, crocin has been reported to have anti-cardiotoxicity and anti-hepatotoxicity effects. This paper focuses on crocin, one of the bioactive molecules found in saffron that are known to have therapeutic effects. Crocin has been shown in numerous experimental studies to be beneficial in treating depression, however, there aren't many studies on its neurotoxicity.

AIM OF THE STUDY

Applications of arsenic trioxide (ATO) in medical settings is limited by its side effects. This study aims to examine crocin's protective effect against ATO-induced neurotoxicity and understand its potential molecular mechanism. Materialandmethods: A neurotoxicity model was created by administering ATO (4 mg/L/d). To counteract this, mice were intraperitoneally injected with crocin (100, 200 mg/kg/d). After 60 days, biochemical, histopathological, transmission electron microscopy, ELISA, and western blotting analyses were then performed.

RESULTS

Our results indicated that crocin decreased neuronal death and loss caused by ATO, countered oxidative stress damage, and mitigated pro-inflammatory cytokines. Mice treated with crocin also displayed positive signs of brain tissue recovery. Additionally, crocin reduced the protein expressions of NLRP1, apoptosis-associated speck-like protein containing a CARD (ASC), Caspase-1, GRP78, CHOP, and ATF4.

CONCLUSIONS

This study attests that crocin can reduce ATO-induced neurotoxicity by safeguarding nerves from oxidative stress, inflammation, and apoptosis, possibly through the activation of the Nrf2/HO-1 signaling pathway.

In vitro immunotoxic evaluation of herbicides in RAW 264.7 cells

Weeds are a concern in agriculture and the use of herbicides constitutes an effective, efficient, and economical way to control their growth. Recent discoveries of herbicides are promising for the management of resistant weeds. However, there is a gap in the knowledge of the toxic effects of some herbicides previously reported on immune cells. The present study aimed to examine cellular immunotoxicity of three herbicides (clomazone, glyphosate, and sulfentrazone) after 96 hr incubation utilizing RAW 264.7 BALB/c mouse monocyte/macrophage-like cell line to elucidate the role of some toxicological pathways. Data demonstrated the herbicides clomazone, glyphosate, and sulfentrazone initiated a cytotoxic effect as evidenced by EC50 values of 429.2; 53.7; 866.6 mg/L, respectively. Clomazone and sulfentrazone, at all concentrations, induced excess production of reactive oxygen (ROS) and reactive nitrogen (RNS) free radicals. An immunosuppression was observed in RAW 264.7 cells after incubation with 50 or 100 mg/L glyphosate and 500 or 1000 mg/L sulfentrazone. In addition, all herbicides produced mitochondrial depolarization and decreased tumor necrosis factor-α (TNF-α) levels. This constitutes the first report of the effects of clomazone and sulfentrazone on RAW 264.7 cells, including reduced TNF-α levels, indicating the adverse influence of herbicides on the immune system.

Reactive oxygen species-scavenging biomaterials for neural regenerative medicine

Reactive oxygen species (ROS) are natural by-products of oxygen metabolism. As signaling molecules, ROS can regulate various physiological processes in the body. However excessive ROS may be a major cause of inflammatory diseases. In the field of neurological diseases, ROS cause neuronal apoptosis and neurodegeneration, which severely impede neuroregeneration. Currently, ROS-scavenging biomaterials are considered as a promising therapeutic strategy for neurological injuries due to their ability to scavenge excessive ROS at defects and modulate the oxidative stress microenvironment. This review provides an overview of the generation and sources of ROS, briefly describes the dangers of generating excessive ROS in nervous system diseases, and highlights the importance of scavenging excessive ROS for neuroregeneration. We have classified ROS-scavenging biomaterials into three categories based on the different mechanisms of ROS clearance. The applications of ROS-responsive biomaterials for neurological diseases, such as spinal cord injury, brain injury, and peripheral nerve injury, are also discussed. Our review contributes to the development of ROS-scavenging biomaterials in the field of neural regeneration.

Reactive oxygen species favors Varicellovirus bovinealpha 5 (BoAHV-5) replication in neural cells

Varicellovirus bovinealpha (BoAHV) 1 and 5 are closely related neurotropic alphaherpesviruses with distinct neuropathogenic potential. BoAHV-5 causes meningoencephalitis in calves whereas encephalitis by BoAHV-1 infection is sporadic. the mechanisms underlying the differences in tropism and clinical outcomes of the infections are not yet completely understood. Here, we used neuroblastoma SH-SY5Y cells as non-differentiated in comparison with the SH-SY5Y neuronal-like cells obtained after exposing SH-SY5Y undifferentiated cells to trans-retinoic acid. We aimed to establish whether there was a relationship between the production of reactive oxygen species (ROS) and the kinetics of virus replication. We demonstrated that ROS production after BoAHV infection was higher in differentiated cells. Generation of ROS was also dependent on the infecting BoAHV strain. Higher ROS levels were produced during BoAHV-5 infection concomitantly with enhanced viral replication. We propose that increased ROS production mechanistically contributes to the tissue damage and neuroinflammation induced by BoAHV-5 infection. Future studies will determine specific targets of ROS that mediate the effects on viral replication.

A Multi-Enzyme Nanocascade to Target Disease-Relevant Metabolites

Metabolic processes in living organisms depend on the synergistic actions of enzymes working in proximity and in concert, catalyzing reactions effectively while regulating the formation of metabolites. This enzyme synergy offers promising therapeutic application for diseases such as alcohol intoxication, cancer, and hyperinflammation. Despite their potential, the clinical translation of enzyme cascades is restricted by challenges including poor enzyme stability, short half-life, and a lack of delivery strategies that maintain enzyme proximity. In this study, multi-enzyme nanocascades synthesized are developed through in situ atom transfer radical polymerization using a zwitterionic monomer. This method markedly enhances enzyme stability and proximity, thereby prolonging their circulation half-life after systemic administration. It is demonstrated that the nanocascades of uricase and catalase effectively reduce uric acid levels without excessive hydrogen peroxide production, providing a potential antidote for hyperuricemia. Moreover, in a murine breast cancer model, the nanocascades of glucose oxidase and catalase inhibited tumor progression and enhanced the therapeutic efficacy of doxorubicin. The prolonged circulation and promoted reaction efficacy of these nanocascades underscore their substantial potential in enzyme replacement therapy and the treatment of various diseases.

Roflumilast-loaded nanostructured lipid carriers attenuate oxidative stress and neuroinflammation in Parkinson's disease model

Parkinson's disease (PD) is a progressive neurodegenerative disorder with limited symptomatic treatment options. Targeting phosphodiesterase 4 (PDE4) has shown a promising result in several preclinical studies. In our study, we aim to repurpose US FDA-approved PDE4 inhibitor for PD. Through in-silico study, we identified roflumilast (ROF) as the potential candidate targeting PDE4B2. In Drosophila PD expressing the A30P mutant α-synuclein model, ROF exhibited anti-PD effects as indicated by negative geotaxis and antioxidant activities. Given the low brain distribution of ROF (<50%) at clinical doses, incorporation into nanostructured lipid carriers (NLCs) was carried out to enhanced blood-brain barrier permeability. In vitro release studies indicated sustained ROF release from NLCs (≈75%) over 24 h. Single-dose oral toxicity studies reported no mortality or toxicity signs. ROF-loaded NLCs significantly alleviated behavioural deficits, increased antioxidant parameters (p < 0.05), and reduced TNF-α and IL-6 levels (p < 0.5) in the striatum compared to pure ROF. ROF-loaded NLCs demonstrated potential anti-PD effects with high efficacy than pure ROF. Our study suggests that nanostructured lipid carriers (NLCs) can be a promising drug delivery system to overcome limitations associated with poor brain bioavailability of lipophilic drugs like ROF for PD treatment. Further investigation related to brain occupancy and underlying mechanisms of our formulation is warranted to confirm and strengthen our current findings.

Dynamic mRNA Stability Buffer Transcriptional Activation During Neuronal Differentiation and Is Regulated by SAMD4A

Neurons are exceptionally sensitive to oxidative stress, which is the basis for many neurodegenerative disease pathophysiologies. The posttranscriptional basis for neuronal differentiation and behavior is not well characterized. The steady-state levels of mRNA are outcomes of an interplay between RNA transcription and decay. However, the correlation between mRNA transcription, translation, and stability remains elusive. We utilized a SH-SY5Y-based neural differentiation model that is widely used to study neurodegenerative diseases. After neuronal differentiation, we observed enhanced sensitivity of mature neurons to mitochondrial stresses and ferroptosis induction. We employed a newly developed simplified mRNA stability profiling technique to explore the role of mRNA stability in SH-SY5Y neuronal differentiation model. Transcriptome-wide mRNA stability analysis revealed neural-specific RNA stability kinetics. Our analysis revealed that mRNA stability could either exert the buffering effect on gene products or change in the same direction as transcription. Importantly, we observed that changes in mRNA stability corrected over or under transcription of mRNAs to maintain mRNA translation dynamics. Furthermore, we conducted integrative analysis of our mRNA stability data set, and a published CRISPR-i screen focused on neuronal oxidative stress responses. Our analysis unveiled novel neuronal stress response genes that were not evident at the transcriptional or translational levels. SEPHS2 emerged as an important neuronal stress regulator based on this integrative analysis. Motif analysis unveiled SAMD4A as a major regulator of the dynamic changes in mRNA stability observed during differentiation. Knockdown of SAMD4A impaired neuronal differentiation and influenced the response to oxidative stress. Mechanistically, SAMD4A was found to alter the stability of several mRNAs. The novel insights into the interplay between mRNA stability and cellular behaviors provide a foundation for understanding neurodevelopmental processes and neurodegenerative disorders and highlight dynamic mRNA stability as an important layer of gene expression.

Oxidative/Nitrosative Stress, Apoptosis, and Redox Signaling: Key Players in Neurodegenerative Diseases

Neurodegenerative diseases are significant health concerns that have a profound impact on the quality and duration of life for millions of individuals. These diseases are characterized by pathological changes in various brain regions, specific genetic mutations associated with the disease, deposits of abnormal proteins, and the degeneration of neurological cells. As neurodegenerative disorders vary in their epidemiological characteristics and vulnerability of neurons, treatment of these diseases is usually aimed at slowing disease progression. The heterogeneity of genetic and environmental factors involved in the process of neurodegeneration makes current treatment methods inadequate. However, the existence of common molecular mechanisms in the pathogenesis of these diseases may allow the development of new targeted therapeutic strategies. Oxidative and nitrosative stress damages membrane components by accumulating ROS and RNS and disrupting redox balance. This process results in the induction of apoptosis, which is important in the pathogenesis of neurodegenerative diseases through oxidative stress. Studies conducted using postmortem human samples, animal models, and cell cultures have demonstrated that oxidative stress, nitrosative stress, and apoptosis are crucial factors in the development of diseases such as Alzheimer's, Parkinson's, Multiple Sclerosis, amyotrophic lateral sclerosis, and Huntington's disease. The excessive production of reactive oxygen and nitrogen species, elevated levels of free radicals, heightened mitochondrial stress, disturbances in energy metabolism, and the oxidation and nitrosylation of cellular macromolecules are recognized as triggers for neuronal cell death. Challenges in managing and treating neurodegenerative diseases require a better understanding of this field at the molecular level. Therefore, this review elaborates on the molecular mechanisms by which oxidative and nitrosative stress are involved in neuronal apoptosis.

Inhibitory Activity of N- and S-Functionalized Monoterpene Diols Towards Monoamine Oxidases A and B

Monoamine oxidase B (MAO-B) inhibitors are widely used as part of combination drug therapy for Parkinson's disease. As demonstrated in both in vitro and in vivo experiments, the monoterpenoid Prottremine and some of its derivatives exhibit high antiparkinsonian activity. In this study, the inhibitory activity of Prottremine and its derivatives (including 14 new 9-N- and S-derivatives) against MAO-A and MAO-B enzymes has been investigated for the first time. Compounds containing fragments of substituted anilines have demonstrated the highest activity against MAO-A; for example, compound 28 had an IC50 of 178 ± 44 μM. A significant proportion of the compounds tested, including Prottremine, exhibited moderate inhibitory activity towards MAO-B, with the most active being the o-aminoacetophenone derivative, which had an IC50 of 95 ± 5 μM. A molecular docking method for studying murine MAO-A and -B enzymes was developed using AlphaFold2 (v2.3.2), with further improvements. For the MAO-B enzyme, a strong correlation was observed between the molecular docking data and the measured activity of the compounds, with the maximum binding affinity registered for the most active compound. It is conceivable that the antiparkinsonian activity of Prottremine and some of its derivatives may be partially mediated, among other mechanisms, by MAO-B enzyme inhibition.

Pathology and Treatments of Alzheimer's Disease Based on Considering Changes in Brain Energy Metabolism Due to Type 2 Diabetes

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with cognitive dysfunction, memory decline, and behavioral disturbance, and it is pathologically characterized by the accumulation of amyloid plaques and neurofibrillary tangles in the brain. Although various hypotheses have been proposed to explain the pathogenesis of AD, including the amyloid beta hypothesis, oxidative stress hypothesis, and abnormal phosphorylation of tau proteins, the exact pathogenic mechanisms underlying AD remain largely undefined. Furthermore, effective curative treatments are very limited. Epidemiologic studies provide convincing evidence for a significant association between type 2 diabetes and AD. Here, we showed energy metabolism using glucose, lactate, ketone bodies, and lipids as energy substrates in a normal brain, and changes in such energy metabolism due to type 2 diabetes. We also showed the influences of such altered energy metabolism due to type 2 diabetes on the pathology of AD. Furthermore, we comprehensively searched for risk factors related with type 2 diabetes for AD and showed possible therapeutic interventions based on considering risk factors and altered brain energy metabolism due to type 2 diabetes for the development of AD.

Physiopathological mechanisms underlying Alzheimer's disease: a narrative review

The neuropathological signature of Alzheimer's disease (AD) comprises mainly amyloid plaques, and neurofibrillary tangles, resulting in synaptic and neuronal loss. These pathological structures stem from amyloid dysfunctional metabolism according to the amyloid cascade hypothesis, leading to the formation of plaques, and apparently inducing the initiation of the abnormal tau pathway, with phosphorylation and aggregation of these proteins, ultimately causing the formation of tangles. In this narrative review, the existing hypothesis related to the pathophysiology of AD were compiled, and biological pathways were highlighted in order to identify the molecules that could represent biological markers of the disease, necessary to establish early diagnosis, as well as the selection of patients for therapeutical interventional strategies.

Upregulation of ACSL, ND75, Vha26 and sesB genes by antiepileptic drugs resulted in genotoxicity in drosophila

Clobazam (CLB) and Vigabatrin (VGB) are commonly used antiepileptic drugs (AEDs) in the treatment of epilepsy. Here, we have examined the genotoxic effect of these AEDs in Drosophila melanogaster. The Drosophila larvae were exposed to different concentrations of CLB and VGB containing food media. The assessment encompassed oxidative stress, DNA damage, protein levels, and gene expression profiles. In the CLB-treated group, a reduction in reactive oxygen species (ROS) and lipid peroxidation (LPO) levels was observed, alongside increased levels of superoxide dismutase (SOD), catalase (CAT), and nitric oxide (NO). Conversely, the VGB-treated group displayed contrasting results, with increased ROS and LPO and decreased SOD, CAT, and NO levels. However, both CLB and VGB induced DNA damage in Drosophila. Proteomic analysis (SDS-PAGE and OHRLCMS) in the CLB and VGB groups identified numerous proteins, including Acyl-CoA synthetase long-chain, NADH-ubiquinone oxidoreductase 75 kDa subunit, V-type proton ATPase subunit E, ADP/ATP carrier protein, malic enzyme, and DNA-binding protein modulo. These proteins were found to be associated with pathways like growth promotion, notch signaling, Wnt signaling, neuromuscular junction (NMJ) signaling, bone morphogenetic protein (BMP) signaling, and other GABAergic mechanisms. Furthermore, mRNA levels of ACSL, ND75, Vha26, sesB, and Men genes were upregulated in both CLB and VGB-treated groups. These findings suggest that CLB and VGB could have the potential to induce genotoxicity and post-transcriptional modifications in humans, highlighting the importance of monitoring their effects when used as AEDs.

Role of Oxidative Stress in Blood-Brain Barrier Disruption and Neurodegenerative Diseases

Upregulation of reactive oxygen species (ROS) levels is a principal feature observed in the brains of neurodegenerative diseases such as Parkinson's disease (PD) and Alzheimer's disease (AD). In these diseases, oxidative stress can disrupt the blood-brain barrier (BBB). This disruption allows neurotoxic plasma components, blood cells, and pathogens to enter the brain, leading to increased ROS production, mitochondrial dysfunction, and inflammation. Collectively, these factors result in protein modification, lipid peroxidation, DNA damage, and, ultimately, neural cell damage. In this review article, we present the mechanisms by which oxidative damage leads to BBB breakdown in brain diseases. Additionally, we summarize potential therapeutic approaches aimed at reducing oxidative damage that contributes to BBB disruption in neurodegenerative diseases.

Remodeling of the Intracardiac Ganglia During the Development of Cardiovascular Autonomic Dysfunction in Type 2 Diabetes: Molecular Mechanisms and Therapeutics

Type 2 diabetes mellitus (T2DM) is one of the most significant health issues worldwide, with associated healthcare costs estimated to surpass USD 1054 billion by 2045. The leading cause of death in T2DM patients is the development of cardiovascular disease (CVD). In the early stages of T2DM, patients develop cardiovascular autonomic dysfunction due to the withdrawal of cardiac parasympathetic activity. Diminished cardiac parasympathetic tone can lead to cardiac arrhythmia-related sudden cardiac death, which accounts for 50% of CVD-related deaths in T2DM patients. Regulation of cardiovascular parasympathetic activity is integrated by neural circuitry at multiple levels including afferent, central, and efferent components. Efferent control of cardiac parasympathetic autonomic tone is mediated through the activity of preganglionic parasympathetic neurons located in the cardiac extensions of the vagus nerve that signals to postganglionic parasympathetic neurons located in the intracardiac ganglia (ICG) on the heart. Postganglionic parasympathetic neurons exert local control on the heart, independent of higher brain centers, through the release of neurotransmitters, such as acetylcholine. Structural and functional alterations in cardiac parasympathetic postganglionic neurons contribute to the withdrawal of cardiac parasympathetic tone, resulting in arrhythmogenesis and sudden cardiac death. This review provides an overview of the remodeling of parasympathetic postganglionic neurons in the ICG, and potential mechanisms contributing to the withdrawal of cardiac parasympathetic tone, ventricular arrhythmogenesis, and sudden cardiac death in T2DM. Improving cardiac parasympathetic tone could be a therapeutic avenue to reduce malignant ventricular arrhythmia and sudden cardiac death, increasing both the lifespan and improving quality of life of T2DM patients.

Deciphering the mechanistic impact of acupuncture on the neurovascular unit in acute ischemic stroke: Insights from basic research in a narrative review

Ischemic stroke(IS), a severe acute cerebrovascular disease, not only imposes a heavy economic burden on society but also presents numerous challenges in treatment. During the acute phase, while thrombolysis and thrombectomy serve as primary treatments, these approaches are restricted by a narrow therapeutic window. During rehabilitation, commonly used neuroprotective agents struggle with their low drug delivery efficiency and inadequate preclinical testing, and the long-term pharmacological and toxicity effects of nanomedicines remain undefined. Meanwhile, acupuncture as a therapeutic approach is widely acknowledged for its effectiveness in treating IS and has been recommended by the World Health Organization (WHO) as an alternative and complementary therapy, even though its exact mechanisms remain unclear. This review aims to summarize the known mechanisms of acupuncture and electroacupuncture (EA) in the treatment of IS. Research shows that acupuncture treatment mainly protects the neurovascular unit through five mechanisms: 1) reducing neuronal apoptosis and promoting neuronal repair and proliferation; 2) maintaining the integrity of the blood-brain barrier (BBB); 3) inhibiting the overactivation and polarization imbalance of microglia; 4) regulating the movement of vascular smooth muscle (VSM) cells; 5) promoting the proliferation of oligodendrocyte precursors. Through an in-depth analysis, this review reveals the multi-level, multi-dimensional impact of acupuncture treatment on the neurovascular unit (NVU) following IS, providing stronger evidence and a theoretical basis for its clinical application.

Bibliometric analysis of the inflammation expression after spinal cord injury: current research status and emerging frontiers

STUDY DESIGN

Bibliometric analysis.

OBJECTIVE

To analyze literature on inflammatory expression following spinal cord injury, highlighting development trends, current research status, and potential emerging frontiers.

SETTING

Not applicable.

METHODS

Articles were retrieved using terms related to spinal cord injury and inflammatory responses from the Web of Science Core Collection, covering January 1, 1980, to May 23, 2024. Tools like CiteSpace and VOSviewer assessed the research landscape, evaluating core authors, journals, and contributing countries. Keyword co-occurrence analyses identified research trends.

RESULTS

A total of 2504 articles were retrieved, showing a consistent increase in publications. The Journal of Neurotrauma had the highest publication volume and influence. The most prolific author was Cuzzocrea S, with Popovich PG having the highest H-index. China led in the number of publications, followed closely by the United States, which had the highest impact and extensive international collaboration. Research mainly focused on nerve function recovery, glial scar formation, and oxidative stress. Future research is expected to investigate cellular autophagy, vesicular transport, and related signaling pathways.

CONCLUSION

The growing interest in inflammation caused by spinal cord injury is evident, with current research focusing on oxidative stress, glial scar, and neurological recovery. Future directions include exploring autophagy and extracellular vesicles for new therapies. Interdisciplinary research and extensive clinical trials are essential for validating new treatments. Biomarker discovery is crucial for diagnosis and monitoring, while understanding autophagy and signaling pathways is vital for drug development. Global cooperation is needed to accelerate the application of scientific findings, improving spinal cord injury treatment.

Qifu-yin activates the Keap1/Nrf2/ARE signaling and ameliorates synaptic injury and oxidative stress in APP/PS1 mice

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional medicinal formulation, Qifu-yin (QFY), has been widely prescribed for Alzheimer's disease (AD) treatment in China, yet the comprehensive mechanisms through which QFY mitigates AD pathology remain to be fully delineated.

AIM OF THE STUDY

This study aimed to explore the therapeutic implications of QFY on the synaptic injury and oxidative stress in the hippocampus of APPswe/PS1dE9 (APP/PS1) mice, with a concerted effort to elucidate the molecular mechanisms related to synaptic preservation and memory improvement.

MATERIALS AND METHODS

The components of QFY were identified by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The neuroprotective effects of QFY was evaluated using six-month-old male APP/PS1 mice. Subsequent to a 15 days of QFY regimen, spatial memory was assessed utilizing the Morris water maze (MWM) test. Amyloid-beta (Aβ) aggregation was detected via immunostaining, while the quantification of Aβ1-40 and Aβ1-42 was achieved through enzyme-linked immunosorbent assay (ELISA). Transmission electron microscopy (TEM) was used to investigate the synaptic structure and mitochondrial morphology. Golgi staining was applied to examine dendritic spine density. Reactive oxygen species (ROS), 3-nitrotyrosine (3-NT) and 4-hydroxy-nonenal (4-HNE) assays were employed to assess oxidative stress. The expression profiles of Aβ metabolism-associated enzymes and the Keap1/Nrf2/ARE signaling pathway were determined by Western blot.

RESULTS

A total of 20 principal compounds in QFY were identified. QFY mitigated memory deficits of APP/PS1 mice, including reducing escape latency and search distance and increasing the time and distance spent in the target quadrant. In addition, QFY increased platform crossings of APP/PS1 mice in the probe trial of MWM tests. TEM analysis showed that QFY increased synapse number in the CA1 region of APP/PS1 mice. Further studies indicated that QFY elevated the expression levels of Post synaptic density protein 95 (PSD95) and synaptophysin, and mitigated the loss of dendritic spine density in the hippocampus of APP/PS1 mice. QFY has been shown to ameliorated the structural abnormalities of mitochondria, including mitochondrial dissolution and degradation, up-regulate ATP synthesis and membrane potential in the hippocampus of APP/PS1 mice. Moreover, QFY activated the Keap1/Nrf2/ARE signaling pathway in the hippocampus of APP/PS1 mice, which might contribute to the neuroprotective effects of QFY.

CONCLUSION

QFY activates the Keap1/Nrf2/ARE signaling, and protects against synaptic and mitochondrial dysfunction in APP/PS1 mice, proposing a potential alternative therapeutic strategy for AD management.

Omnidirectional improvement of mitochondrial health in Alzheimer's disease by multi-targeting engineered activated neutrophil exosomes

Alzheimer's disease (AD) is one kind of devasting neurodegenerative disorders affecting over 50 million people worldwide. Multi-targeted therapy has emerged as a new treatment for diagnosing and alleviating the pathogenesis process of AD; however, the current strategy is limited by its unsatisfactory efficiency. In our study, engineered activated neutrophil-derived exosomes (MP@Cur-MExo) were developed to improve the mitochondrial function in neurons by targeting and alleviating Aβ-induced neurotoxicity. MP@Cur-MExo are exosomes derived from IL-8-stimulated neutrophils decorated with mitochondria targeting ligand and Aβ targeted ligand modified SPION. Engineered exosomes can be cleaved by matrix metallopeptidase-2, which is overexpressed in the AD brain. Consequently, the released SPION and Curcumin-loaded engineered exosomes collaboratively protected neuron cells against Aβ-induced mitochondrial deficiency. In addition, MP@Cur-MExo effectively accumulated in the inflamed region of AD brain at an early stage, allowing early diagnosis of AD through bimodal (MRI/IVIS) imaging. Importantly, in a mouse model at an early stage of AD, intravenously injected MP@Cur-MExo restored mitochondrial function and reduced Aβ-induced mitochondrial damage, thereby attenuating AD progression. In conclusion, our designed engineered exosomes demonstrated that omnidirectional improvement of mitochondrial function can serve as a novel and practical approach for the diagnosis and treatment of neurodegenerative diseases. This study also reveals a promising therapeutic agent for impeding AD progression for future clinical applications.

The relationship between oxidative balance score and circadian syndrome: evidence from the NHANES 2005-2018

Background

The oxidative balance score (OBS) is a composite indicator that evaluates the balance between pro-oxidants and antioxidants in one's diet and lifestyle. However, the relationship between OBS and circadian syndrome (CircS) has remained unexplored. This investigation aimed to determine a correlation between OBS and CircS.

Methods

This population-based study examined 7,202 participants from the 2005 to 2018 National Health and Nutrition Examination Survey (NHANES), 1,433 of whom had CircS. We utilized weighted multivariate logistic regression, trend tests, subgroup analysis, and interaction tests to evaluate the correlation between OBS (total OBS, dietary OBS, and lifestyle OBS) and CircS. Restricted cubic splines (RCS) models and threshold effect analysis were used to explore nonlinear relationships.

Results

Multivariate logistic regression analysis indicated that the protective factor for CircS was a high OBS level (total OBS: Odds ratio (OR) = 0.95, 95% Confidence interval (CI): 0.93-0.97; dietary OBS: OR = 0.98, 95% CI: 0.96-1.00; lifestyle OBS: OR = 0.65, 95% CI: 0.61-0.69). Compared to the quartile 1 group, OBS (total OBS, dietary OBS, and lifestyle OBS) was negatively and statistically significantly associated with the risk of developing Circs in the quartile 4 group (total OBS: OR = 0.47, 95% CI: 0.32-0.70; dietary OBS: OR = 0.69, 95% CI: 0.48-0.99; lifestyle OBS: OR = 0.07, 95% CI: 0.04-0.11). According to subgroup analysis and interaction tests, there was an interaction effect between the association of lifestyle OBS and CircS in terms of education level (p for interaction = 0.01). Furthermore, we observed a nonlinear negative relationship between lifestyle OBS and CircS prevalence, with inflection points at 6 (p for nonlinearity = 0.002).

Conclusion

The results showed a substantial negative connection between OBS and CircS. Encouraging foods filled with antioxidants and antioxidant-rich lifestyles may reduce the risk of CircS.

Implications of COVID-19 in Parkinson's disease: the purinergic system in a therapeutic-target perspective to diminish neurodegeneration

The pathophysiology of Parkinson's disease (PD) is marked by degeneration of dopaminergic neurons in the substantia nigra. With advent of COVID-19, which is closely associated with generalized inflammation and multiple organ dysfunctions, the PD patients may develop severe conditions of disease leading to exacerbated degeneration. This condition is caused by the excessive release of pro-inflammatory markers, called cytokine storm, that is capable of triggering neurodegenerative conditions by affecting the blood-brain barrier (BBB). A possible SARS-CoV-2 infection, in serious cases, may compromise the immune system by triggering a hyperstimulation of the neuroimmune response, similar to the pathological processes found in PD. From this perspective, the inflammatory scenario triggers oxidative stress and, consequently, cellular dysfunction in the nervous tissue. The P2X7R seems to be the key mediator of the neuroinflammatory process, as it acts by increasing the concentration of ATP, allowing the influx of Ca2+ and the occurrence of mutations in the α-synuclein protein, causing activation of this receptor. Thus, modulation of the purinergic system may have therapeutic potential on the effects of PD, as well as on the damage caused by inflammation of the BBB, which may be able to mitigate the neurodegeneration caused by diseases. Considering all the processes of neuroinflammation, oxidative stress, and mitochondrial dysfunction that PD propose, we can conclude that the P2X7 antagonist acts in the prevention of viral diseases, and it also controls purinergic receptors formed by multi-target compounds directed to self-amplification circuits and, therefore, may be a viable strategy to obtain the desired disease-modifying effect. Thus, purinergic system receptor modulations have a high therapeutic potential for neurodegenerative diseases such as PD.

Vascular Impairment, Muscle Atrophy, and Cognitive Decline: Critical Age-Related Conditions

The triad of vascular impairment, muscle atrophy, and cognitive decline represents critical age-related conditions that significantly impact health. Vascular impairment disrupts blood flow, precipitating the muscle mass reduction seen in sarcopenia and the decline in neuronal function characteristic of neurodegeneration. Our limited understanding of the intricate relationships within this triad hinders accurate diagnosis and effective treatment strategies. This review analyzes the interrelated mechanisms that contribute to these conditions, with a specific focus on oxidative stress, chronic inflammation, and impaired nutrient delivery. The aim is to understand the common pathways involved and to suggest comprehensive therapeutic approaches. Vascular dysfunctions hinder the circulation of blood and the transportation of nutrients, resulting in sarcopenia characterized by muscle atrophy and weakness. Vascular dysfunction and sarcopenia have a negative impact on physical function and quality of life. Neurodegenerative diseases exhibit comparable pathophysiological mechanisms that affect cognitive and motor functions. Preventive and therapeutic approaches encompass lifestyle adjustments, addressing oxidative stress, inflammation, and integrated therapies that focus on improving vascular and muscular well-being. Better understanding of these links can refine therapeutic strategies and yield better patient outcomes. This study emphasizes the complex interplay between vascular dysfunction, muscle degeneration, and cognitive decline, highlighting the necessity for multidisciplinary treatment approaches. Advances in this domain promise improved diagnostic accuracy, more effective therapeutic options, and enhanced preventive measures, all contributing to a higher quality of life for the elderly population.

Role of hydrogen sulfide in health and disease

In the past, hydrogen sulfide (H2S) was recognized as a toxic and dangerous gas; in recent years, with increased research, we have discovered that H2S can act as an endogenous regulatory transmitter. In mammals, H2S-catalyzing enzymes, such as cystathionine-β-synthase, cystathionine-γ-lyase, and 3-mercaptopyruvate sulfurtransferase, are differentially expressed in a variety of tissues and affect a variety of biological functions, such as transcriptional and posttranslational modification of genes, activation of signaling pathways in the cell, and metabolic processes in tissues, by producing H2S. Various preclinical studies have shown that H2S affects physiological and pathological processes in the body. However, a detailed systematic summary of these roles in health and disease is lacking. Therefore, this review provides a thorough overview of the physiological roles of H2S in different systems and the diseases associated with disorders of H2S metabolism, such as ischemia-reperfusion injury, hypertension, neurodegenerative diseases, inflammatory bowel disease, and cancer. Meanwhile, this paper also introduces H2S donors and novel release modes, as well as the latest preclinical experimental results, aiming to provide researchers with new ideas to discover new diagnostic targets and therapeutic options.

Co-occurrence of azorubine and bisphenol A in beverages increases the risk of developmental toxicity: A study in zebrafish model

The prevalent use of Azorubine (E122) and the unintentional food additive, Bisphenol A (BPA), in ready-to-drink (RTD) beverages raises significant health concerns, especially for children. The combined impact on embryonic development must be explored despite individual safety assessments. Our investigation revealed that the combined exposure of E122 and BPA at beverage concentration significantly induces mortality and morphological deformities, including reduced growth, pericardial edema, and yolk sac edema. The co-exposure triggers oxidative stress, impairing antioxidant enzyme responses and resulting in lipid and cellular damage. Notably, apoptotic cells are observed in the neural tube and notochord of the co-exposed larvae. Critical genes related to the antioxidant response elements (nrf2, ho1, and nqo1), apoptosis activation (bcl2, bax, and p53), and pro/anti-inflammatory cytokines (nfkb, tnfa, il1b, tgfb, il10, and il12) displayed substantial changes, highlighting the molecular mechanisms. Behavior studies indicated hypo-locomotion with reduced thigmotaxis and touch response in co-exposed larvae, distinguishing it from individual exposures. These findings underscore the neurodevelopmental impacts of E122 and BPA at reported beverage concentrations, emphasizing the urgent need for comprehensive safety assessments, particularly for child consumption.

Alginate oligosaccharides exert protective effects on hydrogen peroxide-induced senescence in H9C2 cardiomyocytes by regulating the redox state of cells

Aging is a known independent risk factor for several cardiovascular diseases. Here, we evaluated potential effects and possible mechanisms through which alginate oligosaccharides (AOS) affect hydrogen peroxide (H2O2)-induced senescence in H9C2 cardiomyocytes. A series of AOS molecules, including oligoM, oligoG, M-5, and G-5, were investigated. AOS significantly decreased SA-β-gal and DAPI-stained positive cells, downregulated p53 and p21 (aging-related markers) expression, and eventually protected H9C2 cells from H2O2-induced senescence. AOS decreased reactive oxygen species and malondialdehyde production, recovered mitochondrial function, and alleviated the oxidative stress state by regulating PGC-1α and NADPH oxidase subunit expression. Furthermore, AOS treatment restored the expression of antioxidant enzymes in senescent H9C2 cells. Thus, our results show in vitro evidence that AOS alleviate senescence in H9C2 cells by regulating the redox state; thus, AOS may be an effective therapeutic agent that could protect against cardiomyocyte senescence.

Transplanting network pharmacology technology into food science research: A comprehensive review on uncovering food-sourced functional factors and their health benefits

Network pharmacology is an emerging interdisciplinary research method. The application of network pharmacology to reveal the nutritional effects and mechanisms of active ingredients in food is of great significance in promoting the development of functional food, facilitating personalized nutrition, and exploring the mechanisms of food health effects. This article systematically reviews the application of network pharmacology in the field of food science using a literature review method. The application progress of network pharmacology in food science is discussed, and the mechanisms of functional factors in food on the basis of network pharmacology are explored. Additionally, the limitations and challenges of network pharmacology are discussed, and future directions and application prospects are proposed. Network pharmacology serves as an important tool to reveal the mechanisms of action and health benefits of functional factors in food. It helps to conduct in-depth research on the biological activities of individual ingredients, composite foods, and compounds in food, and assessment of the potential health effects of food components. Moreover, it can help to control and enhance their functionality through relevant information during the production and processing of samples to guarantee food safety. The application of network pharmacology in exploring the mechanisms of functional factors in food is further analyzed and summarized. Combining machine learning, artificial intelligence, clinical experiments, and in vitro validation, the achievement transformation of functional factor in food driven by network pharmacology is of great significance for the future development of network pharmacology research.

Maladaptive regeneration and metabolic dysfunction associated steatotic liver disease: Common mechanisms and potential therapeutic targets

The normal liver has an extraordinary capacity of regeneration. However, this capacity is significantly impaired in steatotic livers. Emerging evidence indicates that metabolic dysfunction associated steatotic liver disease (MASLD) and liver regeneration share several key mechanisms. Some classical liver regeneration pathways, such as HGF/c-Met, EGFR, Wnt/β-catenin and Hippo/YAP-TAZ are affected in MASLD. Some recently established therapeutic targets for MASH such as the Thyroid Hormone (TH) receptors, Glucagon-like protein 1 (GLP1), Farnesoid X receptor (FXR), Peroxisome Proliferator-Activated Receptors (PPARs) as well as Fibroblast Growth Factor 21 (FGF21) are also reported to affect hepatocyte proliferation. With this review we aim to provide insight into common molecular pathways, that may ultimately enable therapeutic strategies that synergistically ameliorate steatohepatitis and improve the regenerating capacity of steatotic livers. With the recent rise of prolonged ex-vivo normothermic liver perfusion prior to organ transplantation such treatment is no longer restricted to patients undergoing major liver resection or transplantation, but may eventually include perfused (steatotic) donor livers or even liver segments, opening hitherto unexplored therapeutic avenues.

Treatment with walnut peptide ameliorates memory impairment in zebrafish and rats: promoting the expression of neurotrophic factors and suppressing oxidative stress

Walnut peptide, a low molecular weight peptide separated from walnuts by enzymatic hydrolysis, is considered as a potential nutraceutical with a variety of biological activities. In this study, we characterized the walnut peptide prepared by alkaline protease hydrolysis and evaluated its neuroprotective effect in zebrafish and rat models of memory disorders. Series of concentrations of the walnut peptide were orally administered to zebrafish and rats to examine its impact on the behavior and biochemical indicators. The results showed that the oral administration of walnut peptide significantly ameliorated the behavioral performance in zebrafish exposed to bisphenol AF (1 μg mL-1) and rats exposed to alcohol (30% ethanol, 10 mL kg-1). Furthermore, the walnut peptide upregulated the expression of neurotrophic-related molecules in zebrafish, such as the brain-derived neurotrophic factor (BDNF) and the glial cell-derived neurotrophic factor (GDNF). In the rat brain, the walnut peptide increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), while dramatically reduced malondialdehyde (MDA) level. Together, these findings elucidated that the walnut peptide might partially offset the declarative memory deficits via regulation of neurotrophic-related molecule expression and promotion of the antioxidant defense ability. Therefore, walnut peptide holds the potential for development into functional foods as a nutritional supplement for the management of certain neurodegenerative disorders.

Revealing the atomic and electronic mechanism of human manganese superoxide dismutase product inhibition

Human manganese superoxide dismutase (MnSOD) is a crucial oxidoreductase that maintains the vitality of mitochondria by converting superoxide (O2●-) to molecular oxygen (O2) and hydrogen peroxide (H2O2) with proton-coupled electron transfers (PCETs). Human MnSOD has evolved to be highly product inhibited to limit the formation of H2O2, a freely diffusible oxidant and signaling molecule. The product-inhibited complex is thought to be composed of a peroxide (O22-) or hydroperoxide (HO2-) species bound to Mn ion and formed from an unknown PCET mechanism. PCET mechanisms of proteins are typically not known due to difficulties in detecting the protonation states of specific residues that coincide with the electronic state of the redox center. To shed light on the mechanism, we combine neutron diffraction and X-ray absorption spectroscopy of the product-bound, trivalent, and divalent states of the enzyme to reveal the positions of all the atoms, including hydrogen, and the electronic configuration of the metal ion. The data identifies the product-inhibited complex, and a PCET mechanism of inhibition is constructed.

Deoxynivalenol Induces Drp-1-Mediated Mitochondrial Dysfunction via Elevating Oxidative Stress

Mitochondrial dysfunction is often linked to neurotoxicity and neurological diseases and stems from oxidative stress, yet effective therapies are lacking. Deoxynivalenol (DON or vomitoxin) is one of the most common and hazardous type-B trichothecene mycotoxins, which contaminates crops used for food and animal feed. Despite the abundance of preliminary reports, comprehensive investigations are scarce to explore the relationship between these fungal metabolites and neurodegenerative disorders. The present study aimed to elucidate the precise role of DON in mitochondrial dynamics and cell death in neuronal cells. Excessive mitochondrial fission is associated with the pathology of several neurodegenerative diseases. Human SH-SY5Y cells were treated with different concentrations of DON (250-1000 ng/mL). Post 24 and 48 h DON treatment, the indexes were measured as follows: generation of reactive oxygen species (ROS), ATP levels, mitochondrial membrane potential, calcium levels, and cytotoxicity in SH-SY5Y cells. The results showed that cytotoxicity, intracellular calcium levels, and ROS in the DON-treated group increased, while the ATP levels and mitochondrial membrane potential decreased in a dose-dependent manner. With increasing DON concentrations, the expression levels of P-Drp-1, mitochondrial fission proteins Mff, and Fis-1 were elevated with reduced activities of MFN1, MFN2, and OPA1, further resulting in an increased expression of autophagic marker LC3 and beclin-1. The reciprocal relationship between mitochondrial damage and ROS generation is evident as ROS can instigate structural and functional deficiencies within the mitochondria. Consequently, the impaired mitochondria facilitate the release of ROS, thereby intensifying the cycle of damage and exacerbating the overall process. Using specific hydroxyl, superoxide inhibitors, and calcium chelators, our study confirmed that ROS and Ca2+-mediated signaling pathways played essential roles in DON-induced Drp1 phosphorylation. Therefore, ROS and mitochondrial fission inhibitors could provide critical research tools for drug development in mycotoxin-induced neurodegenerative diseases.

Protective Effect of Arzanol against H2O2-Induced Oxidative Stress Damage in Differentiated and Undifferentiated SH-SY5Y Cells

Oxidative stress can damage neuronal cells, greatly contributing to neurodegenerative diseases (NDs). In this study, the protective activity of arzanol, a natural prenylated α-pyrone-phloroglucinol heterodimer, was evaluated against the H2O2-induced oxidative damage in trans-retinoic acid-differentiated (neuron-like) human SH-SY5Y cells, widely used as a neuronal cell model of neurological disorders. The pre-incubation (for 2 and 24 h) with arzanol (5, 10, and 25 μM) significantly preserved differentiated SH-SY5Y cells from cytotoxicity (MTT assay) and morphological changes induced by 0.25 and 0.5 mM H2O2. Arzanol reduced the generation of reactive oxygen species (ROS) induced by 2 h oxidation with H2O2 0.5 mM, established by 2',7'-dichlorodihydrofluorescein diacetate assay. The 2 h incubation of differentiated SH-SY5Y cells with H2O2 determined a significant increase in the number of apoptotic cells versus control cells, evaluated by propidium iodide fluorescence assay (red fluorescence) and NucView® 488 assay (green fluorescence). Arzanol pre-treatment (2 h) exerted a noteworthy significant protective effect against apoptosis. In addition, arzanol was tested, for comparison, in undifferentiated SH-SY5Y cells for cytotoxicity and its ability to protect against H2O2-induced oxidative stress. Furthermore, the PubChem database and freely accessible web tools SwissADME and pkCSM-pharmacokinetics were used to assess the physicochemical and pharmacokinetic properties of arzanol. Our results qualify arzanol as an antioxidant agent with potential neuroprotective effects against neuronal oxidative stress implicated in NDs.

Recent advances on signaling pathways and their inhibitors in spinal cord injury

Spinal cord injury (SCI) is a serious and disabling central nervous system injury. Its complex pathological mechanism can lead to sensory and motor dysfunction. It has been reported that signaling pathway plays a key role in the pathological process and neuronal recovery mechanism of SCI. Such as PI3K/Akt, MAPK, NF-κB, and Wnt/β-catenin signaling pathways. According to reports, various stimuli and cytokines activate these signaling pathways related to SCI pathology, thereby participating in the regulation of pathological processes such as inflammation response, cell apoptosis, oxidative stress, and glial scar formation after injury. Activation or inhibition of relevant pathways can delay inflammatory response, reduce neuronal apoptosis, prevent glial scar formation, improve the microenvironment after SCI, and promote neural function recovery. Based on the role of signaling pathways in SCI, they may be potential targets for the treatment of SCI. Therefore, understanding the signaling pathway and its inhibitors may be beneficial to the development of SCI therapeutic targets and new drugs. This paper mainly summarizes the pathophysiological process of SCI, the signaling pathways involved in SCI pathogenesis, and the potential role of specific inhibitors/activators in its treatment. In addition, this review also discusses the deficiencies and defects of signaling pathways in SCI research. It is hoped that this study can provide reference for future research on signaling pathways in the pathogenesis of SCI and provide theoretical basis for SCI biotherapy.

Effects of mid‑gestational sevoflurane and magnesium sulfate on maternal oxidative stress, inflammation and fetal brain histopathology

Models of inflammation, oxidative stress, hyperoxia and hypoxia have demonstrated that magnesium sulfate (MgSO4), a commonly used drug in obstetrics, has neuroprotective potential. In the present study, the effects of MgSO4 treatment on inflammation, oxidative stress and fetal brain histopathology were evaluated in an experimental rat model following sevoflurane (Sv) exposure during the mid-gestational period. Rats were randomly divided into groups: C (control; no injections or anesthesia), Sv (exposure to 2.5% Sv for 2 h), MgSO4 (administered 270 mg/kg MgSO4 intraperitoneally) and Sv + MgSO4 (Sv administered 30 min after MgSO4 injection). Inflammatory and oxidative stress markers were measured in the serum and neurotoxicity was investigated histopathologically in fetal brain tissue. Short-term mid-gestational exposure to a 1.1 minimum alveolar concentration of Sv did not significantly increase the levels of any of the measured biochemical markers, except for TNF-α. Histopathological evaluations demonstrated no findings suggestive of pathological apoptosis, neuroinflammation or oxidative stress-induced cell damage. MgSO4 injection prior to anesthesia caused no significant differences in biochemical or histopathological marker levels compared to the C and Sv groups. The present study indicated that short-term exposure to Sv could potentially be considered a harmless external stimulus to the fetal brain.

Binge alcohol induces NRF2-related antioxidant response in the skeletal muscle of female mice

BACKGROUND

Chronic alcohol enhances oxidative stress, but the temporal response of antioxidant genes in skeletal muscle following a binge drinking episode remains unknown.

METHODS

Experiment 1: C57BL/6Hsd female mice received an IP injection of saline (CON; n = 39) or ethanol (ETOH; n = 39) (5 g/kg). Gastrocnemius muscles were collected from baseline (untreated; n = 3), CON (n = 3), and ETOH (n = 3) mice every 4 h for 48 h. Experiment 2: Gastrocnemius muscles were collected from control-fed (CON-FED; n = 17), control-fasted (CON-FAST; n = 18), or alcohol-fed (ETOH-FED; n = 18) mice every 4hrs for 20hrs after saline or ethanol (5 g/kg).

RESULTS

EtOH enhanced Superoxide dismutase 1 (Sod1) and NADPH Oxidase 4 (Nox4) from 24 to 48hr after the binge, while Sod2 and Nox2 were suppressed. Nuclear factor erythroid-derived 2-like 2 (Nrf2) and Kelch-like ECH-associated protein 1 (Keap1) increased 12hrs after intoxication. Cytochrome P450 oxidoreductase (Por), Heme oxygenase 1 (Ho1), Peroxiredoxin 6 (Prdx6), Glutamate-cysteine ligase catalytic subunit (Gclc), Glutamate-cysteine ligase modifier subunit (Gclm), and Glutathione-disulfide reductase (Gsr) were increased by ETOH starting 12-16hrs post-binge. Fasting had similar effects on Nrf2 compared to alcohol, but downstream targets of NRF2, including Por, Ho1, Gclc, and Gclm, were differentially altered with fasting and EtOH.

CONCLUSION

These data suggest that acute alcohol intoxication induced markers of oxidative stress and antioxidant signaling through the NRF2 pathway and that there were effects of alcohol independent of a possible decrease in food intake caused by binge intoxication.

Identification of the central role of RNA polymerase mitochondrial for angiogenesis

Mitochondria are central to endothelial cell activation and angiogenesis, with the RNA polymerase mitochondrial (POLRMT) serving as a key protein in regulating mitochondrial transcription and oxidative phosphorylation. In our study, we examined the impact of POLRMT on angiogenesis and found that its silencing or knockout (KO) in human umbilical vein endothelial cells (HUVECs) and other endothelial cells resulted in robust anti-angiogenic effects, impeding cell proliferation, migration, and capillary tube formation. Depletion of POLRMT led to impaired mitochondrial function, characterized by mitochondrial depolarization, oxidative stress, lipid oxidation, DNA damage, and reduced ATP production, along with significant apoptosis activation. Conversely, overexpressing POLRMT promoted angiogenic activity in the endothelial cells. In vivo experiments demonstrated that endothelial knockdown of POLRMT, by intravitreous injection of endothelial specific POLRMT shRNA adeno-associated virus, inhibited retinal angiogenesis. In addition, inhibiting POLRMT with a first-in-class inhibitor IMT1 exerted significant anti-angiogenic impact in vitro and in vivo. Significantly elevated expression of POLRMT was observed in the retinal tissues of streptozotocin-induced diabetic retinopathy (DR) mice. POLRMT endothelial knockdown inhibited pathological retinal angiogenesis and mitigated retinal ganglion cell (RGC) degeneration in DR mice. At last, POLRMT expression exhibited a substantial increase in the retinal proliferative membrane tissues of human DR patients. These findings collectively establish the indispensable role of POLRMT in angiogenesis, both in vitro and in vivo.

Unveiling the Complex Role of Exosomes in Alzheimer's Disease

Alzheimer's disease (AD) is the most common neurodegenerative illness, characterized by memory loss and cognitive decline, accounting for 60-80% of dementia cases. AD is characterized by senile plaques made up of amyloid β (Aβ) protein, intracellular neurofibrillary tangles caused by hyperphosphorylation of tau protein linked with microtubules, and neuronal loss. Currently, therapeutic treatments and nanotechnological developments are effective in treating the symptoms of AD, but a cure for the illness has not yet been found. Recently, the increased study of extracellular vesicles (EVs) has led to a growing awareness of their significant involvement in neurodegenerative disorders, including AD. Exosomes are small extracellular vesicles that transport various components including messenger RNAs, non-coding RNAs, proteins, lipids, DNA, and other bioactive compounds from one cell to another, facilitating information transmission and material movement. There is growing evidence indicating that exosomes have complex functions in AD. Exosomes may have a dual role in Alzheimer's disease by contributing to neuronal death and also helping to alleviate the pathological progression of the disease. Therefore, the primary aim of this review is to outline the updated understandings on exosomes biogenesis and many functions of exosomes in the generation, conveyance, distribution, and elimination of hazardous proteins related to Alzheimer's disease. This review is intended to provide novel insights for understanding the development, specific treatment, and early detection of Alzheimer's disease.

The role of Tyr34 in proton-coupled electron transfer of human manganese superoxide dismutase

Human manganese superoxide dismutase (MnSOD) plays a crucial role in controlling levels of reactive oxygen species (ROS) by converting superoxide (O2 ●-) to molecular oxygen (O2) and hydrogen peroxide (H2O2) with proton-coupled electron transfers (PCETs). The reactivity of human MnSOD is determined by the state of a key catalytic residue, Tyr34, that becomes post-translationally inactivated by nitration in various diseases associated with mitochondrial dysfunction. We previously reported that Tyr34 has an unusual pKa due to its proximity to the Mn metal and undergoes cyclic deprotonation and protonation events to promote the electron transfers of MnSOD. To shed light on the role of Tyr34 MnSOD catalysis, we performed neutron diffraction, X-ray spectroscopy, and quantum chemistry calculations of Tyr34Phe MnSOD in various enzymatic states. The data identifies the contributions of Tyr34 in MnSOD activity that support mitochondrial function and presents a thorough characterization of how a single tyrosine modulates PCET catalysis.

The role of Tyr34 in proton-coupled electron transfer of human manganese superoxide dismutase

Human manganese superoxide dismutase (MnSOD) plays a crucial role in controlling levels of reactive oxygen species (ROS) by converting superoxide (O 2 •- ) to molecular oxygen (O 2 ) and hydrogen peroxide (H 2 O 2 ) with proton-coupled electron transfers (PCETs). The reactivity of human MnSOD is determined by the state of a key catalytic residue, Tyr34, that becomes post-translationally inactivated by nitration in various diseases associated with mitochondrial dysfunction. We previously reported that Tyr34 has an unusual pK a due to its proximity to the Mn metal and undergoes cyclic deprotonation and protonation events to promote the electron transfers of MnSOD. To shed light on the role of Tyr34 MnSOD catalysis, we performed neutron diffraction, X-ray spectroscopy, and quantum chemistry calculations of Tyr34Phe MnSOD in various enzymatic states. The data identifies the contributions of Tyr34 in MnSOD activity that support mitochondrial function and presents a thorough characterization of how a single tyrosine modulates PCET catalysis.

Protecting effects of 4-octyl itaconate on neonatal hypoxic-ischemic encephalopathy via Nrf2 pathway in astrocytes

BACKGROUND

Neonatal hypoxic-ischemic encephalopathy (HIE) is one of the most common neurological problems occurring in the perinatal period. However, there still is not a promising approach to reduce long-term neurodevelopmental outcomes of HIE. Recently, itaconate has been found to exhibit anti-oxidative and anti-inflammatory effects. However, the therapeutic efficacy of itaconate in HIE remains inconclusive. Therefore, this study attempts to explore the pathophysiological mechanisms of oxidative stress and inflammatory responses in HIE as well as the potential therapeutic role of a derivative of itaconate, 4-octyl itaconate (4OI).

METHODS

We used 7-day-old mice to induce hypoxic-ischemic (HI) model by right common carotid artery ligation followed by 1 h of hypoxia. Behavioral experiments including the Y-maze and novel object recognition test were performed on HI mice at P60 to evaluate long-term neurodevelopmental outcomes. We employed an approach combining non-targeted metabolomics with transcriptomics to screen alterations in metabolic profiles and gene expression in the hippocampal tissue of the mice at 8 h after hypoxia. Immunofluorescence staining and RT-PCR were used to evaluate the pathological changes in brain tissue cells and the expression of mRNA and proteins. 4OI was intraperitoneally injected into HI model mice to assess its anti-inflammatory and antioxidant effects. BV2 and C8D1A cells were cultured in vitro to study the effect of 4OI on the expression and nuclear translocation of Nrf2. We also used Nrf2-siRNA to further validate 4OI-induced Nrf2 pathway in astrocytes.

RESULTS

We found that in the acute phase of HI, there was an accumulation of pyruvate and lactate in the hippocampal tissue, accompanied by oxidative stress and pro-inflammatory, as well as increased expression of antioxidative stress and anti-inflammatory genes. Treatment of 4OI could inhibit activation and proliferation of microglial cells and astrocytes, reduce neuronal death and relieve cognitive dysfunction in HI mice. Furthermore, 4OI enhanced nuclear factor erythroid-2-related factor (Nfe2l2; Nrf2) expression and nuclear translocation in astrocytes, reduced pro-inflammatory cytokine production, and increased antioxidant enzyme expression.

CONCLUSION

Our study demonstrates that 4OI has a potential therapeutic effect on neuronal damage and cognitive deficits in HIE, potentially through the modulation of inflammation and oxidative stress pathways by Nrf2 in astrocytes.

Design, synthesis and biological evaluation of 1-aryldonepezil analogues as anti-Alzheimer's disease agents

Aim: To design and synthesize a novel series of 1-aryldonepezil analogues. Materials & methods: The 1-aryldonepezil analogues were synthesized through palladium/PCy3-catalyzed Suzuki reaction and were evaluated for cholinesterase inhibitory activities and neuroprotective effects. In silico docking of the most effective compound was conducted. Results: The 4-tert-butylphenyl analogue exhibited good inhibitory potency against acetylcholinesterase and butyrylcholinesterase and had a favorable neuroprotective effect on H2O2-induced SH-SY5Y cell injury. Conclusion: The 4-tert-butylphenyl derivative is a promising lead compound for anti-Alzheimer's disease drug development.

Excessive intragastric alcohol administration exacerbates hepatic encephalopathy and provokes neuronal cell death in male rats with chronic liver disease

Hepatic encephalopathy (HE) is defined as decline in neurological function during chronic liver disease (CLD). Alcohol is a major etiological factor in the pathogenesis of fibrosis/cirrhosis and has also been documented to directly impact the brain. However, the role of alcohol in the development of HE in CLD remains unclear. Here, we investigated the impact of excessive alcohol administration on neurological deterioration in rats with CLD. Starting day 7 post-BDL surgery, rats were administered alcohol twice daily (51% v/v ethanol, 3 g/kg, via gavage) for 4 weeks. Motor coordination was assessed weekly using rotarod and anxiety-like behavior was evaluated with open field and elevated plus maze at 5 weeks. Upon sacrifice, brains were collected for western blot and immunohistochemical analyses to investigate neuronal integrity and oxidative stress status. Alcohol worsened motor coordination performance and increased anxiety-like behavior in BDL rats. Impairments were associated with decreased neuronal markers of NeuN and SMI311, increased apoptotic markers of cleaved/pro-caspase-3 and Bax/Bcl2, increased necroptosis markers of pRIP3 and pMLKL, decreased total antioxidant capacity (TAC), and increased 4-hydroxynonenal (4-HNE)modified proteins in the cerebellum of BDL-alcohol rats when compared to respective controls. Immunofluorescence confirmed the colocalization of cleaved caspase-3 and pMLKL in the granular neurons of the cerebellum of BDL-alcohol rats. Excessive alcohol consumption exacerbates HE which leads to associated apoptotic and necroptotic neuronal loss in the cerebellum of BDL-alcohol rats. Additionally, higher levels of 4-HNE and decreased TAC in the cerebellum of BDL-alcohol rats suggest oxidative stress is the triggering factor of apoptotic and necroptotic neuronal loss/injury.

Deciphering mitochondrial dysfunction: Pathophysiological mechanisms in vascular cognitive impairment

Vascular cognitive impairment (VCI) encompasses a range of cognitive deficits arising from vascular pathology. The pathophysiological mechanisms underlying VCI remain incompletely understood; however, chronic cerebral hypoperfusion (CCH) is widely acknowledged as a principal pathological contributor. Mitochondria, crucial for cellular energy production and intracellular signaling, can lead to numerous neurological impairments when dysfunctional. Recent evidence indicates that mitochondrial dysfunction-marked by oxidative stress, disturbed calcium homeostasis, compromised mitophagy, and anomalies in mitochondrial dynamics-plays a pivotal role in VCI pathogenesis. This review offers a detailed examination of the latest insights into mitochondrial dysfunction within the VCI context, focusing on both the origins and consequences of compromised mitochondrial health. It aims to lay a robust scientific groundwork for guiding the development and refinement of mitochondrial-targeted interventions for VCI.

Arzanol, a natural phloroglucinol α-pyrone, protects HaCaT keratinocytes against H2O2-induced oxidative stress, counteracting cytotoxicity, reactive oxygen species generation, apoptosis, and mitochondrial depolarization

Skin oxidative stress results in structural damage, leading to premature senescence, and pathological conditions such as inflammation and cancer. The plant-derived prenylated pyrone-phloroglucinol heterodimer arzanol, isolated from Helichrysum italicum ssp. microphyllum (Willd.) Nyman aerial parts, exhibits anti-inflammatory, anticancer, antimicrobial, and antioxidant activities. This study explored the arzanol protection against hydrogen peroxide (H2O2) induced oxidative damage in HaCaT human keratinocytes in terms of its ability to counteract cytotoxicity, reactive oxygen species (ROS) generation, apoptosis, and mitochondrial membrane depolarization. Arzanol safety on HaCaT cells was preliminarily examined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and microscopic observation. The arzanol pre-incubation (5-100 μM, for 24 h) did not induce cytotoxicity and morphological alterations. The phloroglucinol, at 50 μM, significantly protected keratinocytes against cytotoxicity induced by 2 h-incubation with 2.5 and 5 mM H2O2, decreased cell ROS production induced by 1 h-exposure to all tested H2O2 concentrations (0.5-5 mM), as determined by the 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) assay, and lipid peroxidation (thiobarbituric acid reactive substances [TBARS] method). The 2-h incubation of keratinocytes with H2O2 determined a significant increase of apoptotic cells versus control cells, evaluated by NucView® 488 assay, from the dose of 2.5 mM. Moreover, an evident mitochondrial membrane potential depolarization, monitored by fluorescent mitochondrial dye MitoView™ 633, was assessed at 5 mM H2O2. Arzanol pre-treatment (50 μM) exerted a strong significant protective effect against apoptosis, preserving the mitochondrial membrane potential of HaCaT cells at the highest H2O2 concentrations. Our results validate arzanol as an antioxidant agent for the prevention/treatment of skin oxidative-related disorders, qualifying its potential use for cosmeceutical and pharmaceutical applications.

High-Fidelity Assay Based on Turn-Off Fluorescence to Detect the Perturbations of Cellular Proteostasis

The persistence of neurodegenerative diseases has necessitated the development of new strategies to monitor protein homeostasis (proteostasis). Previous efforts in our laboratory have focused on the development of fluorogenic strategies to observe the onset and progression of proteostatic stress. These works utilized solvatochromic and viscosity sensitive fluorophores to sense protein folded states, enabling stressor screening with an increase in the emission intensity upon aggregation. In this work, we present a novel, high-fidelity assay to detect perturbations of cellular proteostasis, where the fluorescence intensity decreases with the onset of proteostatic stress. Utilizing a fluorogenic, hydroxymethyl silicon-rhodamine probe to differentiate between protein folded states, we establish the validity of this technology in living cells by demonstrating a two-fold difference in fluorescence intensity between unstressed and stressed conditions.