SOD2 in mitochondrial dysfunction and neurodegeneration

Mitochondrial Dysfunction of the Subsynovial Connective Tissue in Patients With Carpal Tunnel Syndrome

In idiopathic carpal tunnel syndrome (CTS), fibrosis and thickening of the subsynovial connective tissue (SSCT) increase pressure within the carpal tunnel, resulting in median nerve entrapment. Mitochondrial dysfunction in tissues reportedly leads to senescent cell accumulation and various diseases through reduced adenosine triphosphate (ATP) and excessive reactive oxygen species (ROS) production; however, no reports have linked this to CTS. Therefore, this study aimed to evaluate mitochondrial function in SSCTs of patients with CTS. This study investigated SSCTs obtained during carpal tunnel release surgery in patients with CTS (CTS group) and those obtained during tendon transfer or tendon rupture surgery in patients without CTS (control group) from April 2021 to March 2023 at our hospital. Outcome measures included superoxide dismutase (SOD) activity, gene expression levels, immunofluorescence staining, ATP production assays, and transmission electron microscopy (TEM). p values were calculated using the Mann-Whitney U test. The CTS and control groups included 10 and 5 patients (mean age, 67.8 ± 9.57 and 65.4 ± 9.75 years), respectively. The CTS group exhibited decreased SOD activity (p = 0.026), increased gene expression of mitochondrial biosynthetic factors, and decreased mitochondrial ATP production (p = 0.027). The CTS group showed increased mitochondrial ROS production (p = 0.038) on immunofluorescence and larger mitochondrial area (p = 0.030) and fewer mitochondrial cristae (p = 0.045) on TEM. Multiple mitochondrial function assays suggested mitochondrial dysfunction of SSCTs in the CTS group. STATEMENT OF CLINICAL SIGNIFICANCE: This research provided important information on the histological changes in the subsynovial connective tissue within the carpal tunnel in carpal tunnel syndrome.

An atlas of transcriptomic changes in human immune cells driven by 364 endogenous and gut-microbiota-derived metabolites

Metabolites, particularly those derived from gut microbiota, play crucial roles in modulating immune responses, but the impact of most metabolites on immune cells remains unexplored. To systematically investigate the effect of metabolites on immune cells, we treated peripheral blood mononuclear cells (PBMCs) with 364 endogenous and gut microbiota metabolites and analyzed their impact on the PBMC transcriptome using RNA sequencing (RNA-seq). Clustering analysis revealed three distinct metabolite groups (Cluster 0, 1, 2), each exerting unique immunomodulatory effects. Cluster 1 metabolites, enhanced inflammatory pathways (e.g., cytokine signaling, neutrophil migration) and suppressed ferroptosis, potentially prolonging immune cell activity. In contrast, Cluster 0 metabolites promoted antigen presentation and extracellular matrix repair, while Cluster 2 metabolites upregulated autophagy-related pathways (e.g., GTPase signaling, ubiquitin-protein regulation), suggesting anti-inflammatory and tissue-homeostatic functions. Immune deconvolution highlighted Cluster 1-driven monocyte-to-M0 macrophage differentiation and elevated activated dendritic/mast cells, aligning with pro-inflammatory outcomes. Metabolites in Clusters 0/2 were enriched in the TCA cycle and alanine/aspartate metabolism, whereas Cluster 1 metabolites correlated with beta-alanine and branched-chain amino acid pathways. Gut microbiota analysis identified 23 species overrepresented in Cluster 1, linking dysbiosis to inflammatory metabolite profiles. Together, this high-throughput atlas elucidates how bloodborne metabolites shape PBMC function, offering insights into metabolic-immune crosstalk and potential therapeutic targets for inflammatory and autoimmune disorders.

EPAS1 induction drives myocardial degeneration in desmoplakin-cardiomyopathy

Arrhythmogenic cardiomyopathy (ACM) is frequently attributed to desmosomal mutations, such as those in the desmoplakin (DSP) gene. Patients with DSP-cardiomyopathy are predisposed to myocardial degeneration and arrhythmias. Despite advancements, the underlying molecular mechanisms remain incompletely understood, thus limiting therapeutic options. Here, we employed spatial transcriptomics on an explanted heart from a patient with a pathogenic DSP variant. Our transcriptional analysis revealed endothelial PAS domain-containing protein 1 (EPAS1) as a potential regulator of mitochondrial homeostasis in stressed cardiomyocytes. Elevated EPAS1 levels were associated with mitochondrial dysfunction and hypoxic stress in both human-relevant in vitro ACM models and additional explanted hearts with genetic cardiomyopathy. Collectively, cardiomyocytes bearing pathogenic DSP variants exhibit mitochondrial dysfunction, increased apoptosis, and impaired contractility, which are linked to the increased EPAS1 levels. These findings implicate EPAS1 as a key regulator of myocardial degeneration in DSP-cardiomyopathy, which expand to other forms of ACM.

Molecular insights into Parkinson's disease and type 2 diabetes mellitus: Metformin's role and genetic pathways explored

Background To explore whether there is a bidirectional relationship between Parkinson's disease (PD) and type 2 diabetes mellitus (T2DM), study the common pathogenic mechanisms, screen relevant genes involved in the pathological process, and predict the potential targets of metformin (Met), so as to develop new therapeutic strategies. Method A two-sample Mendelian randomization (MR) analysis was conducted to analyze the correlation between PD and T2DM. Common confounding genes identified in both PD and T2DM datasets were subjected to GO and KEGG analysis, PPI network analysis, and Hub gene identification. qPCR was used to verify the expression of hub genes in an animal model of T2DM complicated with PD. Subsequently, the analysis focused on whether metformin alleviates the behavioral and pathological manifestations of PD aggravated by T2DM. The intersection of metformin with T2DM and PD targets was identified, and the core targets and signaling pathways were analyzed. Finally, molecular docking analysis was performed between metformin and core proteins to identify the docking sites. Result Through MR analysis, a positive correlation between PD and T2DM was identified, indicating a mutual causal relationship. The hub genes RAC1, TPM2, MGA, and DENND3 are up-regulated in animal models of T2DM with PD. Met targets intersecting with T2DM and PD were analyzed, revealing 17 and 21 intersecting genes respectively, involved in various pathways related to oxidative stress, immune, and inflammation. PPI analysis identified hub genes for T2DM (MMP9, NCF1, CYCS, EIF4E, SOD2) and PD (GFAP, VIM, MOCOS, EIF1, TH, ACTA2, CDC42). Animal models validated the expression of these genes and pathways. Molecular docking analysis explored Met's binding sites on proteins, with lower binding energies indicating greater stability. Conclusion This study contributes to a deeper understanding of the co pathogenesis of PD and T2DM, and provides new insights into the role of metformin in this disease.

Effects of 3-(4-Hydroxy-3-methoxyphenyl)propionic Acid on Regulating Oxidative Stress and Muscle Fiber Composition

Background/Objectives: Our previous study demonstrated that 3-(4-hydroxy-3-methoxyphenyl)propionic acid (HMPA) administration improved grip strength and reduced blood urea nitrogen levels, but its underlying mechanisms remain unclear. This study aimed to investigate the effects of HMPA on oxidative stress and muscle fiber composition, emphasizing its potential role in modulating redox signaling pathways and influencing muscle development. Methods: Eight-week-old male C57BL/6 mice were orally administered HMPA solution (50 or 500 mg/kg/day) or distilled water (10 mL/kg) for 14 days, and then divided into sedentary and exhaustive exercise groups to evaluate oxidative stress status, myosin heavy chain (MHC) isoform expression, and underlying mechanisms. Results: Both low and high doses of HMPA reduced oxidative stress by decreasing plasma reactive oxygen metabolites. High-dose HMPA reduced plasma nitrite/nitrate levels and enhanced antioxidant capacity post-exercise, accompanied by changes in the mRNA abundance of antioxidant enzymes (e.g., Sod1 and Nqo1) and reductions in the mRNA abundance of nitric oxide synthases (e.g., Nos2 and Nos3) in the soleus. Additionally, high-dose HMPA administration increased the protein expression of MYH4 in the soleus, while low-dose HMPA enhanced the gene expression of Myh4 and Igf1, suggesting that HMPA may promote fast-twitch fiber hypertrophy through the activation of the IGF-1 pathway. Furthermore, low-dose HMPA significantly increased the gene expression of Sirt1 and Nrf1, as well as AMPK phosphorylation post-exercise, suggesting low-dose HMPA may improve mitochondrial biogenesis and exercise adaptation. Conclusions: These findings suggest that HMPA may serve as a dietary supplement to regulate redox balance, enhance antioxidant defenses, and promote the formation of fast-twitch fibers.

Polyethylene terephthalate nanoplastics-induced neurotoxicity in adult male Swiss albino mice with amelioration of betaine: a histopathological, neurochemical, and molecular investigation

Medicines, food packaging, personal care products, and cosmetics extensively use polyethylene terephthalate nanoplastics (PET-NaPs). However, they also have harmful impacts on several organs. Betaine demonstrates potent antioxidant and anti-inflammatory characteristics. Our goal was to investigate the detrimental impact of PET-NaPs on the mouse brain and evaluate the neuroprotective properties of betaine. We allocated 40 completely mature male Swiss albino mice into four distinct groups: control group, betaine group, PET-NaPs group, and betaine-co-treated group. Following a 30-day duration, euthanasia was performed on the mice, and analyzed tissue samples were obtained from the cerebrum, cerebellum, and hippocampus. PET-NaPs resulted in an elevated level of malondialdehyde and upregulated cyclooxygenase-2 and interleukin-1 beta (IL-1β) expression while significantly reducing the levels of glutathione and downregulating acetylcholinesterase. The PET-NPs also caused significant changes in the histopathology of the brain tissue, and there was a demonstrable rise in the immunostaining of IL-1β and glial fibrillary acidic proteins. Consequently, betaine effectively alleviated the negative consequences of PET-NaPs. Therefore, betaine possesses the capacity to mitigate the neurotoxic consequences induced by PET-NaPs.

Licochalcone A prevents cognitive decline in a lipopolysaccharide-induced neuroinflammation mice model

Inflammation plays a key role in the development of neurodegenerative disorders that are currently incurable. Licochalcone A (LCA) has been described as an emerging anti-inflammatory drug with multiple therapeutical properties that could potentially prevent neurodegeneration. However, its neuroprotective mechanism remains unclear. Here, we investigated if LCA prevents cognitive decline induced by Lipopolysaccharide (LPS) and elucidated its potential benefits. For that, 8-week-old C57BL6/J male mice were intraperitonially (i.p.) treated with saline solution or LCA (15 mg/kg/day, 3 times per week) for two weeks. The last day, a single i.p injection of LPS (1 mg/kg) or saline solution was administered 24 h before sacrifice. The results revealed a significant reduction in mRNA expression in genes involved in oxidative stress (Sod1, Cat, Pkm, Pdha1, Ndyfv1, Uqcrb1, Cycs and Cox4i1), metabolism (Slc2a1, Slc2a2, Prkaa1 and Gsk3b) and synapsis (Bdnf, Nrxn3 and Nlgn2) in LPS group compared to saline. These findings were linked to memory impairment and depressive-like behavior observed in this group. Interestingly, LCA protected against LPS alterations through its anti-inflammatory effect, reducing gliosis and regulating M1/M2 markers. Moreover, LCA-treated animals showed a significant improvement of antioxidant mechanisms, such as citrate synthase activity and SOD2. Additionally, LCA demonstrated protection against metabolic disturbances, downregulating GLUT4 and P-AKT, and enhanced the expression of synaptic-related proteins (P-CREB, BDNF, PSD95, DBN1 and NLG3), leading all together to dendritic spine preservation. In conclusion, our results demonstrate that LCA treatment prevents LPS-induced cognitive decline by reducing inflammation, enhancing the antioxidant response, protecting against metabolic disruptions and improving synapsis related mechanisms.

Exploring molecular disparities of H-type vasculature endothelial cells in osteonecrosis of the femoral head through single-cell analysis

OBJECTIVE

Recent studies highlight the role of H-type vasculature in bone regeneration. This study, based on single-cell RNA sequencing (scRNA-seq), aims to explore the changes in H-type vasculature endothelial cells (H_ECs) in osteonecrosis of the femoral head (ONFH) and hip osteoarthritis (HOA), focusing on the death modes such as ferroptosis, pyroptosis, and parthanatos.

METHODS

We re-analyzed the scRNA-seq data of femoral head samples publicly available in 2022. This study selected nine femoral head samples (3 each from HOA, ONFH stage 3 A, and ONFH stage 4). CD31 + EMCN + endothelial cells were classified as H_ECs. Molecular differences were assessed using Gene Ontology and KEGG analysis. Hypoxia, ferroptosis, pyroptosis, and parthanatos indices were calculated, and transcription factors were predicted using SENIC. Cell communication was analyzed with CellChat.

RESULTS

After integrating the 9 samples, 14 cell types were identified: B cells, Mesenchymal stem cells, Osteoblasts, Endothelial cells, Monocytes, T cells, NK cells, Fibroblasts, Macrophages, Common myeloid progenitors, Chondrocytes, Myelocytes, Osteoclasts, and Pericytes. The number of endothelial cells and H_ECs decreased with necrosis severity. H_ECs showed higher angiogenic capacity but lower stress resistance compared to other endothelial cells. Angiogenic capacity decreased in necrotic samples, accompanied by an elevation in inflammation levels. The hypoxia index was higher, with ferroptosis increased in stage 3 A and parthanatos in stages 3 A and 4. No change was observed in pyroptosis. Cell communication analysis revealed downregulation of SLIT3-ROBO4 signaling during necrosis.

CONCLUSION

H_ECs show molecular differences compared to other endothelial cells. Ferroptosis and parthanatos contribute to the demise of H_ECs in ONFH, with pericytes and fibroblasts supporting H_EC angiogenesis.

Reactive oxygen species in the pathogenesis of sarcopenia

One of the most critical factors impacting healthspan in the elderly is the loss of muscle mass and function, clinically referred to as sarcopenia. Muscle atrophy and weakness lead to loss of mobility, increased risk of injury, metabolic changes and loss of independence. Thus, defining the underlying mechanisms of sarcopenia is imperative to enable the development of effective interventions to preserve muscle function and quality in the elderly and improve healthspan. Over the past few decades, understanding the roles of mitochondrial dysfunction and oxidative stress has been a major focus of studies seeking to reveal critical molecular pathways impacted during aging. In this review, we will highlight how oxidative stress might contribute to sarcopenia by discussing the impact of oxidative stress on the loss of innervation and alteration in the neuromuscular junction (NMJ), on muscle mitochondrial function and atrophy pathways, and finally on muscle contractile function.

Convergent effects of synthetic glucocorticoid dexamethasone and amyloid beta in human olfactory neurosphere-derived cells

Stressful life events and glucocorticoid (stress) hormones appear to increase the risk of Alzheimer's disease and hasten its progression, but the reasons for this remain unclear. One potential explanation is that when amyloid β (Aβ) pathology is accumulating in the preclinical disease stage, glucocorticoid receptor signalling during stressful events exacerbates cellular dysfunction caused by Aβ. Alternatively, Aβ may disrupt glucocorticoid receptor signalling. To explore these possibilities, we investigated whether the synthetic glucocorticoid dexamethasone and Aβ have overlapping effects on the cellular proteome and whether Aβ influences canonical glucocorticoid receptor function. Human olfactory neurosphere-derived (ONS) cells, collected from the olfactory mucosa of six adult donors, were treated with soluble Aβ40 or Aβ42 followed by dexamethasone. Proteins were quantified by mass spectrometry. After 32 h treatment, Aβ40 and Aβ42 both induced profound changes in innate immunity-related proteins. After 72 h, Aβ42 formed widespread aggregates and induced few proteomic changes, whereas Aβ40 remained soluble and altered expression of mitochondrial and innate immunity-related proteins. ONS cells revealed overlapping impacts of Aβ40 and dexamethasone, with 23 proteins altered by both treatments. For 16 proteins (including eight mitochondrial proteins) dexamethasone counteracted the effects of Aβ40. For example, caspase 4 and methylmalonate-semialdehyde dehydrogenase were increased by Aβ40 and decreased by dexamethasone. Consistent with this finding, Aβ40 increased, but dexamethasone decreased, ONS cell proliferation. For seven proteins, including superoxide dismutase [Mn] mitochondrial, dexamethasone exacerbated the effects of Aβ40. For some proteins, including complement C3, the effects of dexamethasone differed depending on whether Aβ40 was present or absent. Neither Aβ species influenced glucocorticoid receptor nuclear translocation. Overall, this study revealed that glucocorticoid receptor signalling modifies the intracellular effects of Aß40, counteracting some effects and exacerbating others. It suggests that cellular mechanisms through which glucocorticoid receptor signalling influences Alzheimer's disease risk/progression are complex and determined by the balance of beneficial and detrimental glucocorticoid effects.

Assessment of the potential toxic of naringenin nanoparticles using ex vivo and in silico models

Naringenin is a flavonoid known for its anti-inflammatory, antineoplastic, antiatherogenic, and antioxidant properties. However, it has poor technological characteristics and limited bioavailability, which hinder its use in food applications. Nanoencapsulation could address these limitations, but safety concerns regarding nanoengineered bioactives need to be resolved before they can be effectively utilized as food additives. The objective of this study was to evaluate the potential cytotoxic, genotoxic, and mutagenic effects of both free and encapsulated naringenin through in vivo experiments using Allium cepa L. roots, along with pharmacokinetic and molecular docking analyses. The results showed that naringenin nanoparticles did not produce significant changes in the cell division index of meristematic cells in A. cepa roots. Additionally, no significant alterations in the mitotic spindle or chromosomal breaks were observed. Molecular docking studies indicated that naringenin effectively binds to the active site of the catalase enzyme (CAT) in a competitive manner, while it attaches to a site away from the active site of superoxide dismutase (SOD2), demonstrating a non-competitive interaction. ADMET property assessments suggested that naringenin exhibits relatively low toxicity and has favorable molecular characteristics for oral administration. In summary, this study supports the potential of naringenin, particularly in its nanoencapsulated form, as a safe and effective ingredient for functional foods, provided that safety concerns regarding nanoencapsulation are adequately addressed.

Reduced 17β-estradiol following ovariectomy induces mitochondrial dysfunction and degradation of synaptic proteins in the entorhinal cortex

Reductions in circulating estrogens can contribute to cognitive decline, in part by impairing mitochondrial function within the hippocampal region. The entorhinal cortex provides the hippocampus with its main cortical inputs. To assess the impact of estrogen deficiency on mitochondrial respiration and synaptic proteins in the entorhinal cortex, female wildtype rats received either sham surgery, bilateral ovariectomy, or ovariectomy with implantation of a subdermal capsule to maintain low levels of circulating 17β-estradiol (E2). Mitochondrial respiration in the entorhinal cortex was not significantly affected two weeks following ovariectomy, but there was a reduction in oxygen consumption four weeks after ovariectomy that was prevented by E2 supplementation. The expression of mitochondrial membrane integrity element voltage-dependent anion channel protein (VDAC1) was also reduced four weeks after ovariectomy, suggesting that respiration was reduced due to a decline in mitochondrial density. Ovariectomy also increased mitochondrial and cytoplasmic cytochrome c and upregulated superoxide dismutase 2 (SOD2) both two and four weeks after ovariectomy, reflecting mitochondrial electron leakage and oxidative redox imbalance. Further, the ovariectomy-induced changes in mitochondrial proteins were associated with reductions in postsynaptic density protein 95 (PSD95) and the presynaptic protein synaptophysin. There were no changes in mitochondrial or synaptic proteins in ovariectomized animals that received E2 supplementation. Our findings indicate that reductions in circulating 17β-estradiol induced by ovariectomy disrupt mitochondrial functions in the entorhinal cortex, and suggest that a resulting increase in oxidative stress contributes to the degradation in synaptic proteins that may affect cognitive functions mediated by the hippocampal region.

Abnormal redox balance at membrane contact sites causes axonopathy in GDAP1-related Charcot-Marie-Tooth disease

Pathogenic variants of GDAP1 cause Charcot-Marie-Tooth disease (CMT), an inherited neuropathy characterized by axonal degeneration. GDAP1, an atypical glutathione S-transferase, localizes to the outer mitochondrial membrane (OMM), regulating this organelle's dynamics, transport, and membrane contact sites (MCSs). It has been proposed that GDAP1 functions as a cellular redox sensor. However, its precise contribution to redox homeostasis remains poorly understood, as does the possible redox regulation at mitochondrial MCSs. Given the relationship between the peroxisomal redox state and overall cellular redox balance, we investigated the role of GDAP1 in peroxisomal function and mitochondrial MCSs maintenance by using high-resolution microscopy, live cell imaging with pH-sensitive fluorescent probes, and transcriptomic and lipidomic analyses in the Gdap1 -/- mice and patient-derived fibroblasts. We demonstrate that GDAP1 deficiency disrupts mitochondria-peroxisome MCSs and leads to peroxisomal abnormalities, which are reversible upon pharmacological activation of PPARγ or glutathione supplementation. These results identify GDAP1 as a new tether of mitochondria-peroxisome MCSs that maintain peroxisomal number and integrity. The supply of glutathione (GSH-MEE) or GDAP1 overexpression suffices to rescue these MCSs. Furthermore, GDAP1 may regulate the redox state within the microdomain of mitochondrial MCSs, as suggested by decreased pH at mitochondria-lysosome contacts in patient-derived fibroblasts, highlighting the relationship between GDAP1 and redox-sensitive targets. Finally, in vivo analysis of sciatic nerve tissue in Gdap1 -/- mice revealed significant axonal structural abnormalities, including nodes of Ranvier disruption and defects in the distribution and morphology of mitochondria, lysosomes, and peroxisomes, emphasizing the importance of GDAP1 in sustaining axon integrity in the peripheral nervous system. Taken together, this study positions GDAP1 as a multifunctional protein that mediates mitochondrial interaction with cellular organelles of diverse functions, contributes to redox state sensing, and helps maintain axonal homeostasis. In addition, we identify PPAR as a novel therapeutic target, based on knowledge of the underlying pathogenetic mechanisms.

Spatheliachromen mitigates methylglyoxal-induced myotube atrophy by activating Nrf2, inhibiting ubiquitin-mediated protein degradation, and restoring mitochondrial function

BACKGROUND

Methylglyoxal (MGO) is a potent precursor of glycative stress that leads to oxidative stress and muscle atrophy in diabetes. Spatheliachromen (FPATM-20), derived from Ficus pumila var. awkeotsang, exhibited potential antioxidant activity.

PURPOSE

This study aimed to evaluate the potential impact and underlying mechanisms of FPATM-20 on MGO-induced myotube atrophy and mitochondrial dysfunction in mouse skeletal C2C12 myotubes.

METHODS

Atrophic and antioxidant factors were evaluated using immunofluorescence, enzyme-linked immunosorbent assay, and western blotting. Mitochondrial function was assessed using the ATP assay and Seahorse Cell Mito Stress Test. The glycogen content was determined using periodic acid-Schiff staining. Molecular docking was performed to determine the interaction between FPATM-20 and Keap1.

RESULTS

In myotubes treated with MGO, FPATM-20 activated the Nrf2 pathway, reduced ROS levels, enhanced antioxidant defense, and increased glycogen content. FPATM-20 improved myotube viability and size, upregulated myosin heavy chain (MyHC) expression, modulated ubiquitin-proteasome molecules (nuclear FoxO3a, atrogin-1, MuRF-1, and p62/SQSTM1), and inhibited apoptosis (Bax/Bcl-2 ratio and cleaved caspase 3). Moreover, FPATM-20 restored mitochondrial function, including mitochondrial membrane potential, mitochondrial oxygen consumption rate, and mitochondrial biogenesis pathway (nuclear PGC-1α/TFAM/FNDC5). The inhibition of Nrf2 with ML385 reversed the effects of FPATM-20 on MGO. Furthermore, molecular docking confirmed the binding of FPATM-20 to Keap1, a suppressor of Nrf2, showing the crucial role of Nrf2 in protective effects.

CONCLUSIONS

FPATM-20 protects myotubes from MGO toxicity by activating the Nrf2 antioxidant defense, reducing protein degradation and apoptosis, and enhancing mitochondrial function. Thus, FPATM-20 may be a novel agent for preventing skeletal muscle atrophy.

Carotenoids modulate antioxidant pathways in In vitro models of Parkinson's disease: A comprehensive scoping review

Parkinson's disease (PD) is the second most common neurodegenerative disease, and it has affected the living quality of elderly people significantly. PD is characterised by the accumulation of α-Synuclein and progressive loss of dopaminergic neurons at the substantia nigra pars compacta. In the pathogenesis of Parkinson's disease, α-Synuclein, oxidative stress, and electron transport chain (ETC) are the three main factors that contribute to the production of reactive oxygen species (ROS). Currently, there is no commercial disease-modifying agent available for PD; the first-line treatment, Levodopa (l-DOPA), could only relieve the symptoms of PD, with many side effects. Carotenoids, which encompass red, orange, and yellow pigments found in nature and contribute to the colouration of plants, have been associated with various health benefits, including anti-cancer and neuroprotective effects due to their antioxidant properties. This scoping review delves into the impact and underlying mechanisms of carotenoids on cell-based models of neurodegenerative diseases.

Anti-inflammatory and remyelinating effects of fexagratinib in experimental multiple sclerosis

BACKGROUND AND PURPOSE

FGF, VEGFR-2 and CSF1R signalling pathways play a key role in the pathogenesis of multiple sclerosis (MS). Selective inhibition of FGFR by infigratinib in MOG35-55-induced experimental autoimmune encephalomyelitis (EAE) prevented severe first clinical episodes by 40%; inflammation and neurodegeneration were reduced, and remyelination was enhanced. Multi-kinase inhibition of FGFR1-3, CSFR and VEGFR-2 by fexagratinib (formerly known as AZD4547) may be more efficient in reducing inflammation, neurodegeneration and regeneration in the disease model.

EXPERIMENTAL APPROACH

Female C57BL/6J mice were treated with fexagratinib (6.25 or 12.5 mg·kg-1) orally or placebo over 10 days either from time of EAE induction (prevention experiment) or onset of symptoms (suppression experiment). Effects on inflammation, neurodegeneration and remyelination were assessed at the peak of the disease (Day 18/20 post immunization) and the chronic phase of EAE (Day 41/42).

KEY RESULTS

In the prevention experiment, treatment with 6.25 or 12.5 mg·kg-1 fexagratinib prevented severe first clinical episodes by 66.7% or 84.6% respectively. Mice treated with 12.5 mg·kg-1 fexagratinib hardly showed any symptoms in the chronic phase of EAE. In the suppression experiment, fexagratinib resulted in a long-lasting reduction of severe symptoms by 91 or 100%. Inflammation and demyelination were reduced, and axonal density, numbers of oligodendrocytes and their precursor cells, and remyelinated axons were increased by both experimental approaches.

CONCLUSION AND IMPLICATIONS

Multi-kinase inhibition by fexagratinib in a well-tolerated dose of 1 mg·kg-1 in humans may be a promising approach to reduce inflammation and neurodegeneration, to slow down disease progression and support remyelination in patients.

The protective role of quercetin against copper-induced female reproductive toxicity: Insights from transcriptome analysis

Quercetin has been shown to mitigate the cytotoxic effects of heavy metals. While copper is an essential trace element for bodily functions, excessive intake has been linked to impaired female reproductive function. Transcriptome analysis was employed to identify genes that are differentially expressed in response to high copper and were validated through qRT-PCR and western blotting. ATP content and Tunel were used to identify the damage of mitochondrial and cell apoptosis. PPI analysis revealed that MKI67, TOPII, ASPM, CASP3, PLK1, and TTK are central proteins within the network. Additionally, exposure to elevated levels of copper resulted in the dysregulation of 86 genes associated with mitochondria. Conversely, treatment with quercetin (QUE) in combination with high copper led to the normalization of 42 mitochondria-related genes previously affected by high copper levels. Furthermore, CuSO4 decreases ATP content and induces cell apoptosis, which can be reversed by QUE. Results suggest that elevated copper levels could lead to oxidative stress and apoptosis by inducing mitochondrial damage, while QUE has the potential to mitigate these effects, ultimately safeguarding granulosa cells and halting the progression of cell death. This study provides novel insights into the molecular pathways involved in female reproductive toxicity caused by excessive copper exposure.

Mendelian Randomization Study Reveals a Predicted Relationship between Sensorineural Hearing Loss and Mitochondrial Proteins

BACKGROUND

Mitochondrial proteins assume a pivotal role in the onset and progression of diverse diseases. Nonetheless, the causal interconnections with sensorineural hearing loss (SNHL) demand meticulous exploration. Mendelian randomization analysis is a method used in observational epidemiological studies to predict the relationship between exposure factors and outcomes using genetic variants as instrumental variables. In this study, we applied this analytical approach to two distinct samples to predict the causal impact of mitochondrial proteins on SNHL.

METHODS

Two-sample Mendelian randomization analyses were executed to scrutinize the predicted associations between 63 mitochondrial proteins (nuclear-encoded) and SNHL, utilizing summary statistics derived from genome-wide association studies. Assessments of pleiotropy and heterogeneity were carried out to gauge the robustness of the obtained findings.

RESULTS

Four mitochondrial proteins exhibited a suggestive causal relationship with the susceptibility to SNHL. Dihydrolipoamide dehydrogenase (DLD; OR = 0.9706, 95% CI = 0.9382-0.9953, p = 0.0230) was linked to a diminished risk of SNHL. Conversely, elevated levels of mitochondrial ribosomal protein L34 (MRPL34; OR = 1.0458, 95% CI = 1.0029-1.0906, p = 0.0362), single-pass membrane protein with aspartate-rich tail 1 (SMDT1; OR = 1.0619, 95% CI = 1.0142-1.1119, p = 0.0104), and superoxide dismutase 2 (SOD2; OR = 1.0323, 95% CI = 1.0020-1.0634, p = 0.0364) were associated with an elevated risk of SNHL.

CONCLUSION

This research utilized Mendelian randomization analysis to predict the relationship between mitochondrial proteins and SNHL. It provides a potential viewpoint on the etiology and diagnosis.

Exploring the Role of Reactive Oxygen Species in the Pathogenesis and Pathophysiology of Alzheimer's and Parkinson's Disease and the Efficacy of Antioxidant Treatment

Alzheimer's (AD) and Parkinson's Disease (PD) are life-altering diseases that are characterised by progressive memory loss and motor dysfunction. The prevalence of AD and PD is predicted to continuously increase. Symptoms of AD and PD are primarily mediated by progressive neuron death and dysfunction in the hippocampus and substantia nigra. Central features that drive neurodegeneration are caspase activation, DNA fragmentation, lipid peroxidation, protein carbonylation, amyloid-β, and/or α-synuclein formation. Reactive oxygen species (ROS) increase these central features. Currently, there are limited therapeutic options targeting these mechanisms. Antioxidants reduce ROS levels by the induction of antioxidant proteins and direct neutralisation of ROS. This review aims to assess the effectiveness of antioxidants in reducing ROS and neurodegeneration. Antioxidants enhance major endogenous defences against ROS including superoxide dismutase, catalase, and glutathione. Direct neutralisation of ROS by antioxidants protects against ROS-induced cytotoxicity. The combination of Indirect and direct protective mechanisms prevents ROS-induced α-synuclein and/or amyloid-β formation. Antioxidants ameliorate ROS-mediated oxidative stress and subsequent deleterious downstream effects that promote apoptosis. As a result, downstream harmful events including neuron death, dysfunction, and protein aggregation are decreased. The protective effects of antioxidants in human models have yet to directly replicate the success seen in cell and animal models. However, the lack of diversity in antioxidants for clinical trials prevents a definitive answer if antioxidants are protective. Taken together, antioxidant treatment is a promising avenue in neurodegenerative disease therapy and subsequent clinical trials are needed to provide a definitive answer on the protective effects of antioxidants. No current treatment strategies have significant impact in treating advanced AD and PD, but new mimetics of endogenous mitochondrial antioxidant enzymes (Avasopasem Manganese, GC4419 AVA) may be a promising innovative option for decelerating neurodegenerative progress in the future at the mitochondrial level of OS.

Preservation of Mitochondrial Function by SkQ1 in Skin Fibroblasts Derived from Patients with Leber's Hereditary Optic Neuropathy Is Associated with the PINK1/PRKN-Mediated Mitophagy

Increased or altered mitochondrial ROS production in the retinal ganglion cells is regarded as the chief culprit of the disease-causing Leber's hereditary optic neuropathy (LHON). SkQ1 is a rechargeable mitochondria-targeted antioxidant with high specificity and efficiency. SkQ1 has already been used to treat LHON patients, and a phase 2a randomized clinical trial of SkQ1 has demonstrated improvements in eyesight. However, the underlying mechanism of SkQ1 in LHON remains unclear. This study aimed to assess the effects and molecular mechanism of SkQ1 in the preservation of mitochondrial function using skin fibroblasts derived from LHON patients. Our study found that SkQ1 could reduce ROS production and stabilize the mitochondrial membrane. Mechanistically, through network pharmacology and molecular docking, we identified the key targets of SkQ1 as SOD2 and PINK1, which play crucial roles in redox and mitophagy. SkQ1 interacted with PINK1 and downregulated its expression to balance mitochondrial homeostasis. Collectively, the findings of our study reveal that by regulating PINK1/PRKN-mediated mitophagy, SkQ1 preserves mitochondrial function in LHON fibroblasts. The data indicate that SkQ1 may be a novel therapeutic intervention to prevent the progression of LHON.

Korean Red Ginseng and Rb1 restore altered social interaction, gene expressions in the medial prefrontal cortex, and gut metabolites under post-weaning social isolation in mice

Background

Post-weaning social isolation (SI) reduces sociability, gene expressions including myelin genes in the medial prefrontal cortex (mPFC), and alters microbiome compositions in rodent models. Korean Red Ginseng (KRG) and its major ginsenoside Rb1 have been reported to affect myelin formation and gut metabolites. However, their effects under post-weaning SI have not been investigated. This study investigated the effects of KRG and Rb1 on sociability, gene expressions in the mPFC, and gut metabolites under post-weaning SI.

Methods

C57BL/6J mice were administered with water or KRG (150, 400 mg/kg) or Rb1 (0.1 mg/kg) under SI or regular environment (RE) for 2 weeks during the post-weaning period (P21-P35). After this period, mice underwent a sociability test, and then brains and ceca were collected for qPCR/immunohistochemistry and non-targeted metabolomics, respectively.

Results

SI reduced sociability compared to RE; however, KRG (400 mg/kg) and Rb1 significantly restored sociability under SI. In the mPFC, expressions of genes related to myelin, neurotransmitter, and oxidative stress were significantly reduced in mice under SI compared to RE conditions. Under SI, KRG and Rb1 recovered the altered expressions of several genes in the mPFC. In gut metabolomics, 313 metabolites were identified as significant among 3027 detected metabolites. Among the significantly changed metabolites in SI, some were recovered by KRG or Rb1, including metabolites related to stress axis, inflammation, and DNA damage.

Conclusion

Altered sociability, gene expression levels in the mPFC, and gut metabolites induced by two weeks of post-weaning SI were at least partially recovered by KRG and Rb1.

Insights on early response to acute heat shock of bovine mammary epithelial cells through a multimethod approach

Heat stress is a significant challenge in dairy cattle herds, affecting milk production and quality, and generating important changes at the cellular level. Most in vitro research on heat shock (HS) effects on dairy cow mammary cells was focused on medium-long-term effects. In recent years, Fourier transform-infrared (FT-IR) micro-spectroscopy has been increasingly used to study the effects of several external stresses on different cell lines, down to the level of single cellular components, such as DNA/RNA, lipids, and proteins. In this study, the possible changes at the biochemical and molecular level induced by acute (30 min-2 h) HS in bovine mammary epithelial (BME-UV1) cells were investigated. The cells were exposed to different temperatures, thermoneutral (TN, 37 °C) and HS (42 °C), and FT-IR spectra were acquired to analyse the effects of HS on biochemical characteristics of BME-UV1 cellular components (proteins, lipids, and DNA/RNA). Moreover, cell viability assay, reactive oxygen species production, and mRNA expression of heat shock proteins (HSPA1A, HSP90AA1, GRP78, GRP94) and antioxidant genes (SOD1, SOD2) by RT-qPCR were also analysed. The FT-IR results showed a change already at 30 min of HS exposure, in the content of long-chain fatty acids, which probably acted as a response to a modification of membrane fluidity in HS cells compared with TN cells. After 2 h of HS exposure, modification of DNA/RNA activity and accumulation of aggregated proteins was highlighted in HS cells. The gene expression analyses showed the overexpression of HSPA1A and HSP90AA1 starting from 30 min up to 2 h in HS cells compared with TN cells. At 2 h of HS exposure, also the overexpression of GRP94 was observed in HS cells. Acute HS did not affect cell viability, reactive oxygen species level, and SOD1 and SOD2 gene expression of BME-UV1 cells. According to the results obtained, cells initiate early defence mechanisms in case of acute HS and probably this efficient response capacity may be decisive for tolerance to heat stress of dairy cattle.

Nesfatin-1 mitigates calcific aortic valve disease via suppressing ferroptosis mediated by GSH/GPX4 and ZIP8/SOD2 axes

OBJECTIVE

Calcific aortic valve disease (CAVD) predominantly affects the elderly and currently lacks effective medical treatments. Nesfatin-1, a peptide derived from the cleavage of Nucleobindin 2, has been implicated in various calcification processes, both physiological and pathological. This study explores the impact of Nesfatin-1 on the transformation of aortic valve interstitial cells (AVICs) in CAVD.

METHODS AND RESULTS

In vitro experiments showed that Nesfatin-1 treatment mitigated the osteogenic differentiation of AVICs. Corresponding in vivo studies demonstrated a deceleration in the progression of CAVD. RNA-sequencing of AVICs treated with and without Nesfatin-1 highlighted an enrichment of the Ferroptosis pathway among the top pathways identified by the Kyoto Encyclopedia of Genes and Genomes analysis. Further examination confirmed increased ferroptosis in both calcified valves and osteoblast-like AVICs, with a reduction in ferroptosis following Nesfatin-1 treatment. Within the Ferroptosis pathway, ZIP8 showed the most notable modulation by Nesfatin-1. Silencing ZIP8 in AVICs increased ferroptosis and osteogenic differentiation, decreased intracellular Mn2+ concentration, and reduced the expression and activity of superoxide dismutase (SOD2). Furthermore, the silencing of SOD2 exacerbated ferroptosis and osteogenic differentiation. Nesfatin-1 treatment was found to elevate the expression of glutathione peroxidase 4 (GPX4) and levels of glutathione (GSH), as confirmed by Western blotting and GSH concentration assays.

CONCLUSION

In summary, Nesfatin-1 effectively inhibits the osteogenic differentiation of AVICs by attenuating ferroptosis, primarily through the GSH/GPX4 and ZIP8/SOD2 pathways.

The toxic effects of polystyrene microplastic/nanoplastic particles on retinal pigment epithelial cells and retinal tissue

The increasing use of contact lenses, artificial tears, and anti-vascular endothelial growth factor (anti-VEGF) drug injections for age-related macular degeneration has heightened the likelihood of eye exposure to microplastic particles. Extensive research has established that microplastic particles can induce oxidative stress on the ocular surface, resulting in damage. However, the impact of these particles on the retina remains unclear. Therefore, this study investigated whether microplastics/nanoplastics (MPs/NPs) cause retinal damage. In vitro human retinal pigment epithelial (RPE) cells were exposed to polystyrene MPs and NPs for 48 h. Assessment of cell viability using WST-8; evaluation of TNF-α and IL-1β expression; observation of cell morphology and particle invasion via TEM; measurement of ROS levels using the DCFDA reagent; and western blot analysis of SOD2, FIS1, Drp1, and LC3B expression were conducted. In vivo experiments involved intravitreal injection of MPs/NPs in rats, followed by retinal H&E staining 24 h later and evaluation of TNF-α and IL-1β expression. Results indicated that exposure to MPs did not significantly alter RPE cell viability, whereas exposure to NPs led to a noticeable decrease. TEM images revealed NPs' penetration into cells, causing increased oxidative stress (SOD2), mitochondrial fission (FIS1, Drp1), and mitochondrial autophagy (LC3B). In vivo experiments demonstrated an increase in inflammatory cells in retinal tissues exposed to NPs, along with elevated levels of TNF-α and IL-1β. Conclusively, both MPs and NPs impact the retina, with NPs displaying greater toxicity. NPs significantly elevate ROS levels in the retina and induce mitochondrial fission and mitophagy in RPE cells compared to MPs.

Optimization of Zebrafish Larvae 6-OHDA Exposure for Neurotoxin Induced Dopaminergic Marker Reduction

Parkinson's disease (PD) is a neurodegenerative disorder that is clinically assessed by motor symptoms associated with the loss of midbrain dopaminergic neurons affecting the quality of life for over 8.5 million people worldwide. The neurotoxin 6-hydroxydopamine (6-OHDA) has been used to chemically induce a PD-like state in zebrafish larvae by several laboratories; however, highly variable concentration, methodology, and reagents have resulted in conflicting results suggesting a need to investigate these issues of reproducibility. We propose a protocol that addresses the differences in methodology and induces changes in 6 days postfertilization (dpf) larvae utilizing a 24-h exposure at 3 dpf with 30 μM 6-OHDA. Despite ∼50% lethality, no morphological or development differences in surviving fish are observed. Definition of our model is defined by downregulation of the expression of th1 by reverse transcriptase-quantitative polymerase chain reaction, a marker for dopaminergic neurons and a reduction in movement. Additionally, we observed a downregulation of pink1 and an upregulation of sod1 and sod2, indicators of mitochondrial dysfunction and response to reactive oxygen species, respectively.

Mitochondrial transfer between BMSCs and Müller promotes mitochondrial fusion and suppresses gliosis in degenerative retina

Mitochondrial dysfunction and Müller cells gliosis are significant pathological characteristics of retinal degeneration (RD) and causing blinding. Stem cell therapy is a promising treatment for RD, the recently accepted therapeutic mechanism is cell fusion induced materials transfer. However, whether materials including mitochondrial transfer between grafted stem cells and recipient's cells contribute to suppressing gliosis and mechanism are unclear. In present study, we demonstrated that bone marrow mesenchymal stem cells (BMSCs) transferred mitochondria to Müller cells by cell fusion and tunneling nanotubes. BMSCs-derived mitochondria (BMSCs-mito) were integrated into mitochondrial network of Müller cells, improving mitochondrial function, reducing oxidative stress and gliosis, which protected visual function partially in the degenerative rat retina. RNA sequencing analysis revealed that BMSCs-mito increased mitochondrial DNA (mtDNA) content and facilitated mitochondrial fusion in damaged Müller cells. It suggests that mitochondrial transfer from BMSCs remodels Müller cells metabolism and suppresses gliosis; thus, delaying the degenerative progression of RD.

Mitochondrial inorganic polyphosphate is required to maintain proteostasis within the organelle

The existing literature points towards the presence of robust mitochondrial mechanisms aimed at mitigating protein dyshomeostasis within the organelle. However, the precise molecular composition of these mechanisms remains unclear. Our data show that inorganic polyphosphate (polyP), a polymer well-conserved throughout evolution, is a component of these mechanisms. In mammals, mitochondria exhibit a significant abundance of polyP, and both our research and that of others have already highlighted its potent regulatory effect on bioenergetics. Given the intimate connection between energy metabolism and protein homeostasis, the involvement of polyP in proteostasis has also been demonstrated in several organisms. For example, polyP is a bacterial primordial chaperone, and its role in amyloidogenesis has already been established. Here, using mammalian models, our study reveals that the depletion of mitochondrial polyP leads to increased protein aggregation within the organelle, following stress exposure. Furthermore, mitochondrial polyP is able to bind to proteins, and these proteins differ under control and stress conditions. The depletion of mitochondrial polyP significantly affects the proteome under both control and stress conditions, while also exerting regulatory control over gene expression. Our findings suggest that mitochondrial polyP is a previously unrecognized, and potent component of mitochondrial proteostasis.

The neuron-specific IIS/FOXO transcriptome in aged animals reveals regulatory mechanisms of cognitive aging

Cognitive decline is a significant health concern in our aging society. Here, we used the model organism C. elegans to investigate the impact of the IIS/FOXO pathway on age-related cognitive decline. The daf-2 Insulin/IGF-1 receptor mutant exhibits a significant extension of learning and memory span with age compared to wild-type worms, an effect that is dependent on the DAF-16 transcription factor. To identify possible mechanisms by which aging daf-2 mutants maintain learning and memory with age while wild-type worms lose neuronal function, we carried out neuron-specific transcriptomic analysis in aged animals. We observed downregulation of neuronal genes and upregulation of transcriptional regulation genes in aging wild-type neurons. By contrast, IIS/FOXO pathway mutants exhibit distinct neuronal transcriptomic alterations in response to cognitive aging, including upregulation of stress response genes and downregulation of specific insulin signaling genes. We tested the roles of significantly transcriptionally-changed genes in regulating cognitive functions, identifying novel regulators of learning and memory. In addition to other mechanistic insights, a comparison of the aged vs young daf-2 neuronal transcriptome revealed that a new set of potentially neuroprotective genes is upregulated; instead of simply mimicking a young state, daf-2 may enhance neuronal resilience to accumulation of harm and take a more active approach to combat aging. These findings suggest a potential mechanism for regulating cognitive function with age and offer insights into novel therapeutic targets for age-related cognitive decline.

Inside the genome: understanding genetic influences on oxidative stress

Genetics is a key factor that governs the susceptibility to oxidative stress. In the body, oxidative burden is regulated by the balance between the prooxidant genes that orchestrate processes that produce oxidant species, while the antioxidant genes aid those involved in scavenging these species. Together, the two components aid in maintaining the oxidative balance in the body. Genetic variations can influence the expression and activity of the encoded proteins which can then affect their efficiency in regulating redox processes, thereby increasing the risk of oxidative stress. This review studies single nucleotide polymorphisms (SNPs) that bear relevance to oxidative stress by exploring the variations in the prooxidant genes, such as XDH, CYBA, CYP1A1, PTGS2, NOS, and MAO and antioxidant genes including SOD, CAT, GPX, GSS, GLUL, GSR, GSTM1, GSTM5, GSTP1, TXN and HMOX1. Early identification of individuals at the increased risk of oxidative stress is possible from the assessment of sequence of these genes. Integrating genetic insights into oxidative stress management measures can pave the way for personalized medicine that tailors' healthcare approaches to individual genetic profiles. Effective genetic assessment along with routine quantification of biological markers can improve and monitor treatment strategies, enhancing mitigation approaches that maintain cellular health and promote longevity.

Therapeutic Potential of Hydrogen Sulfide in Ischemia and Reperfusion Injury

Ischemia-reperfusion (I/R) injury, a prevalent pathological condition in medical practice, presents significant treatment challenges. Hydrogen sulfide (H2S), acknowledged as the third gas signaling molecule, profoundly impacts various physiological and pathophysiological processes. Extensive research has demonstrated that H2S can mitigate I/R damage across multiple organs and tissues. This review investigates the protective effects of H2S in preventing I/R damage in the heart, brain, liver, kidney, intestines, lungs, stomach, spinal cord, testes, eyes, and other tissues. H2S provides protection against I/R damage by alleviating inflammation and endoplasmic reticulum stress; inhibiting apoptosis, oxidative stress, and mitochondrial autophagy and dysfunction; and regulating microRNAs. Significant advancements in understanding the mechanisms by which H2S reduces I/R damage have led to the development and synthesis of H2S-releasing agents such as diallyl trisulfide-loaded mesoporous silica nanoparticles (DATS-MSN), AP39, zofenopril, and ATB-344, offering a new therapeutic avenue for I/R injury.

Systemic delivery of murine SOD2 mRNA to experimental abdominal aortic aneurysm mitigates expansion and rupture

Background

Oxidative stress is implicated in the pathogenesis and progression of abdominal aortic aneurysm (AAA). Antioxidant delivery as a therapeutic for AAA is of substantial interest although clinical translation of antioxidant therapy has met with significant challenges due to limitations in achieving sufficient antioxidant levels at the site of AAA. We posit that nanoparticle-based approaches hold promise to overcome challenges associated with systemic administration of antioxidants.

Methods

We employed a peptide-based nanoplatform to overexpress a key modulator of oxidative stress, superoxide dismutase 2 (SOD2). The efficacy of systemic delivery of SOD2 mRNA as a nanotherapeutic agent was studied in two different murine AAA models. Unbiased mass spectrometry-enabled proteomics and high-dimensional bioinformatics were used to examine pathways modulated by SOD2 overexpression.

Results

The murine SOD2 mRNA sequence was mixed with p5RHH, an amphipathic peptide capable of delivering nucleic acids in vivo to form self-assembled nanoparticles of ∼55 nm in diameter. We further demonstrated that the nanoparticle was stable and functional up to four weeks following self-assembly when coated with hyaluronic acid. Delivery of SOD2 mRNA mitigated the expansion of small AAA and largely prevented rupture. Mitigation of AAA was accompanied by enhanced SOD2 protein expression in aortic wall tissue. Concomitant suppression of nitric oxide, inducible nitric oxide synthase expression, and cell death was observed. Proteomic profiling of AAA tissues suggests that SOD2 overexpression augments levels of microRNAs that regulate vascular inflammation and cell apoptosis, inhibits platelet activation/aggregation, and downregulates mitogen-activated protein kinase signaling. Gene set enrichment analysis shows that SOD2 mRNA delivery is associated with activation of oxidative phosphorylation, lipid metabolism, respiratory electron transportation, and tricarboxylic acid cycle pathways.

Conclusions

These results confirm that SOD2 is key modulator of oxidative stress in AAA. This nanotherapeutic mRNA delivery approach may find translational application in the medical management of small AAA and the prevention of AAA rupture.

Senolytic treatment does not mitigate oxidative stress-induced muscle atrophy but improves muscle force generation in CuZn superoxide dismutase knockout mice

Oxidative stress is associated with tissue dysfunctions that can lead to reduced health. Prior work has shown that oxidative stress contributes to both muscle atrophy and cellular senescence, which is a hallmark of aging that may drive in muscle atrophy and muscle contractile dysfunction. The purpose of the study was to test the hypothesis that cellular senescence contributes to muscle atrophy or weakness. To increase potential senescence in skeletal muscle, we used a model of oxidative stress-induced muscle frailty, the CuZn superoxide dismutase knockout (Sod1KO) mouse. We treated 6-month-old wildtype (WT) and Sod1KO mice with either vehicle or a senolytic treatment of combined dasatinib (5 mg/kg) + quercetin (50 mg/kg) (D + Q) for 3 consecutive days every 15 days. We continued treatment for 7 months and sacrificed the mice at 13 months of age. Treatment with D + Q did not preserve muscle mass, reduce NMJ fragmentation, or alter muscle protein synthesis in Sod1KO mice when compared to the vehicle-treated group. However, we observed an improvement in muscle-specific force generation in Sod1KO mice treated with D + Q when compared to Sod1KO-vehicle mice. Overall, these data suggest that reducing cellular senescence via D + Q is not sufficient to mitigate loss of muscle mass in a mouse model of oxidative stress-induced muscle frailty but may mitigate some aspects of oxidative stress-induced muscle dysfunction.

Therapeutic Potential of Nitrogen-Doped Rutin-Bound Glucose Carbon Dots for Alzheimer's Disease

The blood-brain barrier (BBB) prevents the use of many drugs for the treatment of neurological disorders. Recently, nitrogen-doped carbon dots (NCDs) have emerged as promising nanocarriers to cross BBB. The primary focus of our study was to evaluate the effectiveness of NCDs for the symptomatic treatment of Alzheimer's disease (AD). In this study, we developed and characterized NCDs bound to rutin, a flavonoid with known benefits for AD. Despite its benefits, the transportation of rutin via NCDs for AD therapy has not been explored previously. We characterized the particles using FTIR and UV-visible spectroscopy followed by atomic force microscopy. Once the design was optimized and validated, we performed in vivo testing via a hemolytic assay to optimize the dosage. Preliminary in vitro testing was performed in AlCl3-induced rat models of AD whereby a single dose of 10 mg/kg NCDs-rutin was administered intraperitoneally. Interestingly, this single dose of 10 mg/kg NCDs-rutin produced the same behavioral effects as 50 mg/kg rutin administered intraperitoneally for 1 month. Similarly, histological and biomarker profiles (SOD2 and TLR4) also presented significant protective effects of NCDs-rutin against neuronal loss, inflammation, and oxidative stress. Hence, NCDs-rutin are a promising approach for the treatment of neurological diseases.

NMDA Receptor Antagonist Memantine Ameliorates Experimental Autoimmune Encephalomyelitis in Aged Rats

Aging is closely related to the main aspects of multiple sclerosis (MS). The average age of the MS population is increasing and the number of elderly MS patients is expected to increase. In addition to neurons, N-methyl-D-aspartate receptors (NMDARs) are also expressed on non-neuronal cells, such as immune cells. The aim of this study was to investigate the role of NMDARs in experimental autoimmune encephalomyelitis (EAE) in young and aged rats. Memantine, a non-competitive NMDAR antagonist, was administered to young and aged Dark Agouti rats from day 7 after immunization. Antagonizing NMDARs had a more favourable effect on clinical disease, reactivation, and apoptosis of CD4+ T cells in the target organ of aged EAE rats. The expression of the fractalkine receptor CX3CR1 was increased in memantine-treated rats, but to a greater extent in aged rats. Additionally, memantine increased Nrf2 and Nrf2-regulated enzymes' mRNA expression in brain tissue. The concentrations of superoxide anion radicals, malondialdehyde, and advanced oxidation protein products in brain tissue were consistent with previous results. Overall, our results suggest that NMDARs play a more important role in the pathogenesis of EAE in aged than in young rats.

Distinct mechanisms underlying the therapeutic effects of low-molecular-weight heparin and chondroitin sulfate on Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder influenced by various factors, including age, genetics, and the environment. Current treatments provide symptomatic relief without impeding disease progression. Previous studies have demonstrated the therapeutic potential of exogenous heparin and chondroitin sulfate in PD. However, their therapeutic mechanisms and structure-activity relationships remain poorly understood. In this study, low-molecular-weight heparin (L-HP) and chondroitin sulfate (L-CS) exhibited favorable therapeutic effects in a mouse model of PD. Proteomics revealed that L-HP attenuated mitochondrial dysfunction through its antioxidant properties, whereas L-CS suppressed neuroinflammation by inhibiting platelet activation. Two glycosaminoglycan (GAG)-binding proteins, manganese superoxide dismutase (MnSOD2) and fibrinogen beta chain (FGB), were identified as potential targets of L-HP and L-CS, and we investigated their structure-activity relationships. The IdoA2S-GlcNS6S/GlcNAc6S unit in HP bound to SOD2, whereas the GlcA-GalNAc4S and GlcA-GalNAc4S6S units in CS preferred FGB. Furthermore, N-S and 2-O-S in L-HP, and 4-O-S, 6-O-S, and -COOH in L-CS contributed significantly to the binding process. These findings provide new insights and evidence for the development and use of glycosaminoglycan-based therapeutics for PD.

Identification and analysis of mitochondria-related central genes in steroid-induced osteonecrosis of the femoral head, along with drug prediction

Purpose

Steroid-induced osteonecrosis of the femoral head (SONFH) is a refractory orthopedic hip joint disease that primarily affects middle-aged and young individuals. SONFH may be caused by ischemia and hypoxia of the femoral head, where mitochondria play a crucial role in oxidative reactions. Currently, there is limited literature on whether mitochondria are involved in the progression of SONFH. Here, we aim to identify and validate key potential mitochondrial-related genes in SONFH through bioinformatics analysis. This study aims to provide initial evidence that mitochondria play a role in the progression of SONFH and further elucidate the mechanisms of mitochondria in SONFH.

Methods

The GSE123568 mRNA expression profile dataset includes 10 non-SONFH (non-steroid-induced osteonecrosis of the femoral head) samples and 30 SONFH samples. The GSE74089 mRNA expression profile dataset includes 4 healthy samples and 4 samples with ischemic necrosis of the femoral head. Both datasets were downloaded from the Gene Expression Omnibus (GEO) database. The mitochondrial-related genes are derived from MitoCarta3.0, which includes data for all 1136 human genes with high confidence in mitochondrial localization based on integrated proteomics, computational, and microscopy approaches. By intersecting the GSE123568 and GSE74089 datasets with a set of mitochondrial-related genes, we screened for mitochondrial-related genes involved in SONFH. Subsequently, we used the good Samples Genes method in R language to remove outlier genes and samples in the GSE123568 dataset. We further used WGCNA to construct a scale-free co-expression network and selected the hub gene set with the highest connectivity. We then intersected this gene set with the previously identified mitochondrial-related genes to select the genes with the highest correlation. A total of 7 mitochondrial-related genes were selected. Next, we performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis on the selected mitochondrial-related genes using R software. Furthermore, we performed protein network analysis on the differentially expressed proteins encoded by the mitochondrial genes using STRING. We used the GSEA software to group the genes within the gene set in the GSE123568 dataset based on their coordinated changes and evaluate their impact on phenotype changes. Subsequently, we grouped the samples based on the 7 selected mitochondrial-related genes using R software and observed the differences in immune cell infiltration between the groups. Finally, we evaluated the prognostic significance of these features in the two datasets, consisting of a total of 48 samples, by integrating disease status and the 7 gene features using the cox method in the survival R package. We performed ROC analysis using the roc function in the pROC package and evaluated the AUC and confidence intervals using the ci function to obtain the final AUC results.

Results

Identification and analysis of 7 intersecting DEGs (differentially expressed genes) were obtained among peripheral blood, cartilage samples, hub genes, and mitochondrial-related genes. These 7 DEGs include FTH1, LACTB, PDK3, RAB5IF, SOD2, and SQOR, all of which are upregulated genes with no intersection in the downregulated gene set. Subsequently, GO and KEGG pathway enrichment analysis revealed that the upregulated DEGs are primarily involved in processes such as oxidative stress, release of cytochrome C from mitochondria, negative regulation of intrinsic apoptotic signaling pathway, cell apoptosis, mitochondrial metabolism, p53 signaling pathway, and NK cell-mediated cytotoxicity. GSEA also revealed enriched pathways associated with hub genes. Finally, the diagnostic value of these key genes for hormone-related ischemic necrosis of the femoral head (SONFH) was confirmed using ROC curves.

Conclusion

BID, FTH1, LACTB, PDK3, RAB5IF, SOD2, and SQOR may serve as potential diagnostic mitochondrial-related biomarkers for SONFH. Additionally, they hold research value in investigating the involvement of mitochondria in the pathogenesis of ischemic necrosis of the femoral head.

NRF2 attenuation aggravates detrimental consequences of metabolic stress on cultured porcine parthenote embryos

The nuclear factor erythroid 2-related factor 2 (NRF2) is a crucial transcription factor that plays a central role in regulating oxidative stress pathways by binding antioxidant response elements, but its involvement in early embryo development remains largely unexplored. In this study, we demonstrated that NRF2 mRNA is expressed in porcine embryos from day 2 to day 7 of development, showing a decrease in abundance from day 2 to day 3, followed by an increase on day 5 and day 7. Comparable levels of NRF2 mRNA were observed between early-cleaving and more developmental competent embryos and late-cleaving and less developmental competent embryos on day 4 and day 5 of culture. Attenuation of NRF2 mRNA significantly decreased development of parthenote embryos to the blastocyst stage. When NRF2-attenuated embryos were cultured in presence of 3.5 mM or 7 mM glucose, development to the blastocyst stage was dramatically decreased in comparison to the control group (15.9% vs. 27.8% for 3.5 mM glucose, and 5.4% vs. 25.3% for 7 mM glucose). Supplementation of melatonin moderately improved the development of NRF2-attenuated embryos cultured in presence of 0.6 mM glucose. These findings highlight the importance of NRF2 in early embryo development, particularly in embryos cultured under metabolically stressful conditions.

Shared Proteins and Pathways of Cardiovascular and Cognitive Diseases: Relation to Vascular Cognitive Impairment

One of the primary goals of systems medicine is the detection of putative proteins and pathways involved in disease progression and pathological phenotypes. Vascular cognitive impairment (VCI) is a heterogeneous condition manifesting as cognitive impairment resulting from vascular factors. The precise mechanisms underlying this relationship remain unclear, which poses challenges for experimental research. Here, we applied computational approaches like systems biology to unveil and select relevant proteins and pathways related to VCI by studying the crosstalk between cardiovascular and cognitive diseases. In addition, we specifically included signals related to oxidative stress, a common etiologic factor tightly linked to aging, a major determinant of VCI. Our results show that pathways associated with oxidative stress are quite relevant, as most of the prioritized vascular cognitive genes and proteins were enriched in these pathways. Our analysis provided a short list of proteins that could be contributing to VCI: DOLK, TSC1, ATP1A1, MAPK14, YWHAZ, CREB3, HSPB1, PRDX6, and LMNA. Moreover, our experimental results suggest a high implication of glycative stress, generating oxidative processes and post-translational protein modifications through advanced glycation end-products (AGEs). We propose that these products interact with their specific receptors (RAGE) and Notch signaling to contribute to the etiology of VCI.

Co-exposure to sodium hypochlorite and cadmium induced locomotor behavior disorder by influencing neurotransmitter secretion and cardiac function in larval zebrafish

Sodium hypochlorite (NaClO) and cadmium (Cd) are widely co-occurring in natural aquatic environment; however, no study has been conducted on effects of their combined exposure on aquatic organisms. To assess effects of exposure to NaClO and Cd in zebrafish larvae, we designed six treatment groups, as follows: control group, NaClO group (300 μg/L), 1/100 Cd group (48 μg/L), 1/30 Cd group (160 μg/L), NaClO+1/100 Cd group, and NaClO+1/30 Cd group analyzed behavior, neurological function and cardiac function. Results revealed that exposure to 1/30 Cd and NaClO+1/30 Cd caused abnormal embryonic development in larvae by altering body morphology and physiological indicators. Combined exposure to NaClO and 1/30 Cd affected the free-swimming activity and behavior of larvae in response to light-dark transition stimuli. Moreover, exposure to 1/30 Cd or NaClO+1/30 Cd resulted in a significant increase in tyrosine hydroxylase and acetylcholinesterase activities, as well as significant changes of various neurotransmitters. Lastly, exposure to 1/30 Cd or NaClO+1/30 Cd influenced the transcription of cardiac myosin-related genes and disturbed the myocardial contractile function. Altogether, our results suggested that combined exposure to NaClO and Cd induced oxidative damage in larvae, resulting in detrimental effects on nervous system and cardiac function, thus altering their swimming behavior.

Superoxide dismutase 2 deficiency is associated with enhanced central chemoreception in mice: Implications for breathing regulation

AIMS

In mammals, central chemoreception plays a crucial role in the regulation of breathing function in both health and disease conditions. Recently, a correlation between high levels of superoxide anion (O2.-) in the Retrotrapezoid nucleus (RTN), a main brain chemoreceptor area, and enhanced central chemoreception has been found in rodents. Interestingly, deficiency in superoxide dismutase 2 (SOD2) expression, a pivotal antioxidant enzyme, has been linked to the development/progression of several diseases. Despite, the contribution of SOD2 on O2.- regulation on central chemoreceptor function is unknown. Accordingly, we sought to determine the impact of partial deletion of SOD2 expression on i) O2.-accumulation in the RTN, ii) central ventilatory chemoreflex function, and iii) disordered-breathing. Finally, we study cellular localization of SOD2 in the RTN of healthy mice.

METHODS

Central chemoreflex drive and breathing function were assessed in freely moving heterozygous SOD2 knockout mice (SOD2+/- mice) and age-matched control wild type (WT) mice by whole-body plethysmography. O2.- levels were determined in RTN brainstem sections and brain isolated mitochondria, while SOD2 protein expression and tissue localization were determined by immunoblot, RNAseq and immunofluorescent staining, respectively.

RESULTS

Our results showed that SOD2+/- mice displayed reductions in SOD2 levels and high O2.- formation and mitochondrial dysfunction within the RTN compared to WT. Additionally, SOD2+/- mice displayed a heightened ventilatory response to hypercapnia and exhibited overt signs of altered breathing patterns. Both, RNAseq analysis and immunofluorescence co-localization studies showed that SOD2 expression was confined to RTN astrocytes but not to RTN chemoreceptor neurons. Finally, we found that SOD2+/- mice displayed alterations in RTN astrocyte morphology compared to RTN astrocytes from WT mice.

INNOVATION & CONCLUSION

These findings provide first evidence of the role of SOD2 in the regulation of O2.- levels in the RTN and its potential contribution on the regulation of central chemoreflex function. Our results suggest that reductions in the expression of SOD2 in the brain may contribute to increase O2.- levels in the RTN being the outcome a chronic surge in central chemoreflex drive and the development/maintenance of altered breathing patterns. Overall, dysregulation of SOD2 and the resulting increase in O2.- levels in brainstem respiratory areas can disrupt normal respiratory control mechanisms and contribute to breathing dysfunction seen in certain disease conditions characterized by high oxidative stress.

Methyltransferase METTL3-mediated maturation of miR-4654 facilitates high glucose-induced apoptosis and oxidative stress in lens epithelial cells via decreasing SOD2

N6-methyladenosine (m6 A) modification has been reported to have roles in modulating the development of diabetic cataract (DC). Methyltransferase-like 3 (METTL3) is a critical m6 A methyltransferase involving in m6 A modification activation. Here, we aimed to explore the action and mechanism of METTL3-mediated maturation of miR-4654 in DC progression. Human lens epithelial cells (HLECs) were exposed to high glucose (HG) to imitate DC condition in vitro. Levels of genes and proteins were tested via qRT-PCR and western blotting assays. The proliferation and apoptosis of HLECs were evaluated by cell counting kit-8, 5-ethynyl-2'-deoxyuridine (EdU), and flow cytometry assays, respectively. Oxidative stress was analyzed by detecting the contents of reactive oxygen species (ROS), superoxide dismutase (SOD) and malondialdehyde (MDA). The binding of miR-4654 and SOD2 was confirmed by dual-luciferase reporter assay. The m6 A-RNA immunoprecipitation (MeRIP) assay detected the m6 A modification profile. Thereafter, we found that miR-4654 expression was elevated in DC samples and HG-induced HLECs. MiR-4654 knockdown reversed HG-mediated apoptosis and oxidative stress in HLECs. Mechanistically, miR-4654 directly targeted SOD2, silencing of SOD2 abolished the protective effects of miR-4654 knockdown on HLECs under HG condition. In addition, METTL3 induced miR-4654 maturation through promoting pri-miR-4654 m6 A modification, thereby increasing miR-4654 content in HLECs. METTL3 was highly expressed in DC samples and HG-induced HLECs, METTL3 deficiency protected HLECs against HG-mediated apoptotic and oxidative injury via down-regulating miR-4654. In all, METTL3 induced miR-4654 maturation in a m6 A-dependent manner, which was then reduced SOD2 expression, thus promoting apoptosis and oxidative stress in HLECs, suggesting a novel path for DC therapy.

Molecular marker identification, antioxidant, antinociceptive, and anti-inflammatory responsiveness of malonic acid capped silver nanoparticle

Nano-sized silver has drawn a great deal of attention in the field of health sciences owing to its remarkable therapeutic applications. Interestingly, the method applied to synthesize nanoparticles and the choice of reagents considerably influence their therapeutic potential and toxicities. Current research has explored the toxicity, anti-inflammatory, antinociceptive, and antioxidant responses of the malonic acid-capped silver nanoparticles (MA-AgNPs (C) by using sodium borohydride as a reducing agent at low temperatures by employing both in vitro and in vivo approaches. Furthermore, it has highlighted the synergistic effect of these novel compounds with conventional anti-inflammatory therapeutic agents. Acute and sub-acute toxicity analysis performed following OECD guidelines showed that the studied MA-AgNPs (C) are safer, and prominent toxic signs have not been detected at the highest studied dose of 2,000 mg/kg. Cytotoxicity evaluation through brine shrimp lethality revealed 20% lethality at the highest concentration of 169.8 μg/mL. Significantly, positive anti-inflammatory and analgesic responses alone as well as synergism with the standard were identified through in vitro as well as in vivo methods which were more potent at a lower dose (200 mg/kg). Notably synergistic outcomes were more pronounced than individual ones, indicating their prominent effect as a feasible drug delivery system. IL-6 and TNF-α assessment in excised paw tissue through RTPCR technique further supported their anti-inflammatory potential. DPPH assay revealed eminent in vitro antioxidant activity which was further corroborated by in vivo antioxidant assessment through evaluation of SOD in excised paw tissue.

Role of oxidative stress in neurodegenerative disorders: a review of reactive oxygen species and prevention by antioxidants

Neurological disorders include a variety of conditions, including Alzheimer's disease, motor neuron disease and Parkinson's disease, affecting longevity and quality of life, and their pathogenesis is associated with oxidative stress. Several of the chronic neurodegenerative pathologies of the CNS share some common features, such as oxidative stress, inflammation, synapse dysfunctions, protein misfolding and defective autophagia. Neuroinflammation can involve the activation of mast cells, contributing to oxidative stress, in addition to other sources of reactive oxygen species. Antioxidants can powerfully neutralize reactive oxygen species and free radicals, decreasing oxidative damage. Antioxidant genes, like the manganese superoxide dismutase enzyme, can undergo epigenetic changes that reduce their expression, thus increasing oxidative stress in tissue. Alternatively, DNA can be altered by free radical damage. The epigenetic landscape of these genes can change antioxidant function and may result in neurodegenerative disease. This imbalance of free radical production and antioxidant function increases the reactive oxygen species that cause cell damage in neurons and is often observed as an age-related event. Increased antioxidant expression in mice is protective against reactive oxygen species in neurons as is the exogenous supplementation of antioxidants. Manganese superoxide dismutase requires manganese for its enzymic function. Antioxidant therapy is considered for age-related neurodegenerative diseases, and a new mimetic of a manganese superoxide dismutase, avasopasem manganese, is described and suggested as a putative treatment to reduce the oxidative stress that causes neurodegenerative disease. The aim of this narrative review is to explore the evidence that oxidative stress causes neurodegenerative damage and the role of antioxidant genes in inhibiting reactive oxygen species damage. Can the neuronal environment of oxidative stress, causing neuroinflammation and neurodegeneration, be reduced or reversed?

FNDC5/Irisin protects neurons through Caspase3 and Bax pathways

Irisin is a glycosylated protein formed from the hydrolysis of fibronectin type III domain-containing protein 5 (FNDC5). Recent studies have demonstrated that FNDC5/Irisin is involved in the regulation of glucose and lipid metabolism, it can inhibit inflammation and have neuroprotective effects. However, the effect and mechanism of FNDC5/Irisin on motor neuron-like cell lines (NSC-34) have not been reported. In this study, we used lipopolysaccharide to construct cellular oxidative stress injury models and investigated the potential roles of FNDC5/Irisin on neurons by different cellular and molecular pathways. Taken together, our findings showed that FNDC5/Irisin can protect neurons, and this effect might be associated with Caspase3 and Bax pathways. These results laid the foundation for neuronal protection and clinical translation of FNDC5/Irisin therapy.

Toolkit for cellular studies of mammalian mitochondrial inorganic polyphosphate

Introduction: Inorganic polyphosphate (polyP) is an ancient polymer which is extremely well-conserved throughout evolution, and found in every studied organism. PolyP is composed of orthophosphates linked together by high-energy bonds, similar to those found in ATP. The metabolism and the functions of polyP in prokaryotes and simple eukaryotes are well understood. However, little is known about its physiological roles in mammalian cells, mostly due to its unknown metabolism and lack of systematic methods and effective models for the study of polyP in these organisms. Methods: Here, we present a comprehensive set of genetically modified cellular models to study mammalian polyP. Specifically, we focus our studies on mitochondrial polyP, as previous studies have shown the potent regulatory role of mammalian polyP in the organelle, including bioenergetics, via mechanisms that are not yet fully understood. Results: Using SH-SY5Y cells, our results show that the enzymatic depletion of mitochondrial polyP affects the expression of genes involved in the maintenance of mitochondrial physiology, as well as the structure of the organelle. Furthermore, this depletion has deleterious effects on mitochondrial respiration, an effect that is dependent on the length of polyP. Our results also show that the depletion of mammalian polyP in other subcellular locations induces significant changes in gene expression and bioenergetics; as well as that SH-SY5Y cells are not viable when the amount and/or the length of polyP are increased in mitochondria. Discussion: Our findings expand on the crucial role of polyP in mammalian mitochondrial physiology and place our cell lines as a valid model to increase our knowledge of both mammalian polyP and mitochondrial physiology.

Promising 8-Aminoquinoline-Based Metal Complexes in the Modulation of SIRT1/3-FOXO3a Axis against Oxidative Damage-Induced Preclinical Neurons

The discovery of novel bioactive molecules as potential multifunctional neuroprotective agents has clinically drawn continual interest due to devastating oxidative damage in the pathogenesis and progression of neurodegenerative diseases. Synthetic 8-aminoquinoline antimalarial drug is an attractive pharmacophore in drug development and chemical modification owing to its wide range of biological activities, yet the underlying molecular mechanisms are not fully elucidated in preclinical models for oxidative damage. Herein, the neuroprotective effects of two 8-aminoquinoline-uracil copper complexes were investigated on the hydrogen peroxide-induced human neuroblastoma SH-SY5Y cells. Both metal complexes markedly restored cell survival, alleviated apoptotic cascades, maintained antioxidant defense, and prevented mitochondrial function by upregulating the sirtuin 1 (SIRT1)/3-FOXO3a signaling pathway. Intriguingly, in silico molecular docking and pharmacokinetic prediction suggested that these synthetic compounds acted as SIRT1 activators with potential drug-like properties, wherein the uracil ligands (5-iodoracil and 5-nitrouracil) were essential for effective binding interactions with the target protein SIRT1. Taken together, the synthetic 8-aminoquinoline-based metal complexes are promising brain-targeting drugs for attenuating neurodegenerative diseases.

Mitochondrial-targeted antioxidant attenuates preeclampsia-like phenotypes induced by syncytiotrophoblast-specific Gαq signaling

Syncytiotrophoblast stress is theorized to drive development of preeclampsia, but its molecular causes and consequences remain largely undefined. Multiple hormones implicated in preeclampsia signal via the Gαq cascade, leading to the hypothesis that excess Gαq signaling within the syncytiotrophoblast may contribute. First, we present data supporting increased Gαq signaling and antioxidant responses within villous and syncytiotrophoblast samples of human preeclamptic placenta. Second, Gαq was activated in mouse placenta using Cre-lox and DREADD methodologies. Syncytiotrophoblast-restricted Gαq activation caused hypertension, kidney damage, proteinuria, elevated circulating proinflammatory factors, decreased placental vascularization, diminished spiral artery diameter, and augmented responses to mitochondrial-derived superoxide. Administration of the mitochondrial-targeted antioxidant Mitoquinone attenuated maternal proteinuria, lowered circulating inflammatory and anti-angiogenic mediators, and maintained placental vascularization. These data demonstrate a causal relationship between syncytiotrophoblast stress and the development of preeclampsia and identify elevated Gαq signaling and mitochondrial reactive oxygen species as a cause of this stress.

Acetyl-11-Keto-Beta-Boswellic Acid Activates the Nrf2/HO-1 Signaling Pathway in Schwann Cells to Reduce Oxidative Stress and Promote Sciatic Nerve Injury Repair

Boswellia is a traditional medicine for bruises and injuries. Its main active ingredient, acetyl-11-keto-beta-boswellic acid, has antioxidant and antiapoptotic effects. In this experiment, we used Sprague-Dawley rats to make a sciatic nerve injury model to detect the transcription factor NF-E2-related factor 2/heme oxygenase 1 signaling pathway and apoptosis, combined with clinical indicators, for testing whether acetyl-11-keto-beta-boswellic acid can reduce oxidative stress and promote sciatic nerve repair. Our results showed that acetyl-11-keto-beta-boswellic acid administration promoted myelin regeneration and functional recovery in the rat sciatic nerve, reduced lipid peroxidation levels, upregulated the expression of various antioxidant enzymes and enhanced enzyme activity, decreased the expression levels of apoptosis-related proteins, and promoted nuclear translocation of the transcription factor NF-E2-related factor 2 protein. In vitro studies revealed that acetyl-11-keto-beta-boswellic acid reduced H2O2-induced reactive oxygen species production, restored mitochondrial membrane potential, upregulated the expression of various antioxidant enzymes, and downregulated apoptosis-related indicators in Schwann cells, and these therapeutic effects of acetyl-11-keto-beta-boswellic acid were reversed after ML385 treatment in Schwann cells. In summary, acetyl-11-keto-beta-boswellic acid alleviates oxidative stress and apoptosis caused by sciatic nerve injury in rats by activating the transcription factor NF-E2-related factor 2/heme oxygenase 1 signaling pathway, promotes the recovery of sciatic nerve function in rats, and is a promising therapeutic agent to promote sciatic nerve repair by alleviating excessive oxidative stress.

High-Resolution Structural Proteomics of Mitochondria Using the 'Build and Retrieve' Methodology

The application of integrated systems biology to the field of structural biology is a promising new direction, although it is still in the infant stages of development. Here we report the use of single particle cryo-EM to identify multiple proteins from three enriched heterogeneous fractions prepared from human liver mitochondrial lysate. We simultaneously identify and solve high-resolution structures of nine essential mitochondrial enzymes with key metabolic functions, including fatty acid catabolism, reactive oxidative species clearance, and amino acid metabolism. Our methodology also identified multiple distinct members of the acyl-CoA dehydrogenase family. This work highlights the potential of cryo-EM to explore tissue proteomics at the atomic level.

Bifenthrin induces cell death in bovine mammary epithelial cells via ROS generation, calcium ion homeostasis disruption, and MAPK signaling cascade alteration

Bifenthrin is one of the widely used synthetic pyrethroid insecticides, employed for various purposes worldwide. As lipophilic pyrethroids can easily bind to soil particles, which is why their residues are detected in various environments. Consequently, the toxicity of bifenthrin to non-target organisms can be regarded as an environmental concern. The toxic effects of bifenthrin have been studied in various animal models and cell lines; however, its toxic effects on cattle remain unclear. In particular, gaining insights into the toxic effects of bifenthrin on the mammary lactation system is crucial for the dairy industry. Therefore, we proceeded to investigate the toxic effects of bifenthrin on the bovine mammary epithelial cells (MAC-T cells). We established that bifenthrin inhibited cell proliferation and triggered apoptosis in MAC-T cells. Additionally, bifenthrin induced mitochondrial dysfunction and altered inflammatory gene expression by disrupting mitochondrial membrane potential (MMP) and generating excessive reactive oxygen species (ROS). We also demonstrated that bifenthrin disrupted both cytosolic and mitochondrial calcium ion homeostasis. Furthermore, bifenthrin altered mitogen-activated protein kinase (MAPK) signaling cascades and downregulated casein-related genes. Collectively, we confirmed the multiple toxic effects of bifenthrin on MAC-T cells, which could potentially reduce milk yield and quality.