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Journal of Bacteriology Jul 2024causes a serious diarrheal disease and is a common healthcare-associated bacterial pathogen. Although it has a major impact on human health, the mechanistic details of...
causes a serious diarrheal disease and is a common healthcare-associated bacterial pathogen. Although it has a major impact on human health, the mechanistic details of intestinal colonization remain undefined. is highly sensitive to oxygen and requires anaerobic conditions for growth. However, the mammalian gut is not devoid of oxygen, and tolerates moderate oxidative stress . The genome encodes several antioxidant proteins, including a predicted superoxide reductase (SOR) that is upregulated upon exposure to antimicrobial peptides. The goal of this study was to establish SOR enzymatic activity and assess its role in protecting against oxygen exposure. Insertional inactivation of rendered more sensitive to superoxide, indicating that SOR contributes to antioxidant defense. Heterologous expression in conferred protection against superoxide-dependent growth inhibition, and the corresponding cell lysates showed superoxide scavenging activity. Finally, a SOR mutant exhibited global proteome changes under oxygen stress when compared to the parent strain. Collectively, our data establish the enzymatic activity of SOR, confirm its role in protection against oxidative stress, and demonstrate SOR's broader impacts on the vegetative cell proteome.IMPORTANCE is an important pathogen strongly associated with healthcare settings and capable of causing severe diarrheal disease. While considered a strict anaerobe , has been shown to tolerate low levels of oxygen in the mammalian host. Among other well-characterized antioxidant proteins, the genome encodes a predicted superoxide reductase (SOR), an understudied component of antioxidant defense in pathogens. The significance of the research reported herein is the characterization of SOR's enzymatic activity, including confirmation of its role in protecting against oxidative stress. This furthers our understanding of pathogenesis and presents a potential new avenue for targeted therapies.
PubMed: 38953644
DOI: 10.1128/jb.00175-24 -
General Physiology and Biophysics Jul 2024Vitiligo is featured by manifestation of white maculae and primarily results from oxidative stress. Sphingosine kinase-1 (SPHK1) participates in oxidative stress. This...
Vitiligo is featured by manifestation of white maculae and primarily results from oxidative stress. Sphingosine kinase-1 (SPHK1) participates in oxidative stress. This paper was devised to explore the role of SPHK1 in vitiligo and to disclose the mechanism. PIG1 cell viability was appraised utilizing cell counting kit-8 assay while Western blot detected SPHK1 and four and a half LIM domains 2 (FHL2). The transduction efficacy of small interfering RNA (siRNA)-SPHK1, siRNA-FHL2 and pcDNA3.1 plasmid overexpressing FHL2 (Ov-FHL2) was checked using Western blot. Flow cytometry detected cell apoptotisis. Western blot detected mitochondrial cytochrome c (Mit-Cyt-c) and cytosolic cytochrome c (Cyto-Cyt-c). Dichloro-dihydro-fluorescein diacetate (DCFH-DA) detected reactive oxygen species (ROS) activity while oxidative stress markers were evaluated using corresponding assay kits. SPHK1 expression was discovered to be increased in hydrogen peroxide (H2O2)-challenged PIG1 cells and SPHK1 interference alleviated H2O2-challenged viability damage, apoptosis, oxidative stress and FHL2 expression in PIG1 cells. FHL2 depletion could suppress viability damage, apoptosis and oxidative stress in H2O2-challenged PIG1 cells. Rescue experiments demonstrated that the suppressive impacts of SPHK1 deficiency on PIG1 cell viability, apoptosis and oxidative stress induced by H2O2 were offset by FHL2 overexpression. Collectively, SPHK1 knockdown protected against vitiligo via the regulation of FHL2.
Topics: Oxidative Stress; Phosphotransferases (Alcohol Group Acceptor); Hydrogen Peroxide; LIM-Homeodomain Proteins; Humans; Melanocytes; Cell Survival; Apoptosis; Transcription Factors; Muscle Proteins; Cell Line
PubMed: 38953574
DOI: 10.4149/gpb_2024011 -
General Physiology and Biophysics Jul 2024This study aims to determine the effect of sevoflurane (Sev) on nasopharyngeal carcinoma (NPC) in malignant behavior and mitochondrial membrane potential (MMP). NPC...
This study aims to determine the effect of sevoflurane (Sev) on nasopharyngeal carcinoma (NPC) in malignant behavior and mitochondrial membrane potential (MMP). NPC cells (5-8F and CNE2) were exposed to Sev at different concentrations and then tested for proliferation by CCK-8 and colony formation assays, apoptosis by flow cytometry, and invasion and migration by Transwell assays. In addition, the Warburg effect was examined by measurements of glucose consumption, lactic acid production, and adenosine triphosphate (ATP). Mitochondrial function was evaluated by reactive oxygen species (ROS) production, oxidative stress-related indexes, and mitochondrial membrane potential. Sev suppressed 5-8F and CNE2 cell proliferation, invasion, and migration, and enhanced apoptosis. Moreover, Sev dampened the Warburg effect by reducing glucose consumption, lactic acid production, and ATP, as well as decreasing hexokinase 2 and pyruvate kinases type M2 protein expressions. Also, Sev induced ROS production and malondialdehyde content and reduced superoxide and glutathione peroxidase levels. Finally, Sev caused damage to mitochondrial homeostasis through induction of cleaved caspase-3, cleaved caspase-9, and cytochrome c protein expression and reduction of MMP. Sev inhibits the malignant behavior of NPC cells by regulating MMP.
Topics: Sevoflurane; Humans; Membrane Potential, Mitochondrial; Nasopharyngeal Carcinoma; Cell Line, Tumor; Nasopharyngeal Neoplasms; Apoptosis; Cell Proliferation; Reactive Oxygen Species; Antineoplastic Agents; Dose-Response Relationship, Drug
PubMed: 38953572
DOI: 10.4149/gpb_2024014 -
Journal of Cellular and Molecular... Jul 2024Both osteoporosis and tendinopathy are widely prevalent disorders, encountered in diverse medical contexts. Whilst each condition has distinct pathophysiological... (Review)
Review
Both osteoporosis and tendinopathy are widely prevalent disorders, encountered in diverse medical contexts. Whilst each condition has distinct pathophysiological characteristics, they share several risk factors and underlying causes. Notably, oxidative stress emerges as a crucial intersecting factor, playing a pivotal role in the onset and progression of both diseases. This imbalance arises from a dysregulation in generating and neutralising reactive oxygen species (ROS), leading to an abnormal oxidative environment. Elevated levels of ROS can induce multiple cellular disruptions, such as cytotoxicity, apoptosis activation and reduced cell function, contributing to tissue deterioration and weakening the structural integrity of bones and tendons. Antioxidants are substances that can prevent or slow down the oxidation process, including Vitamin C, melatonin, resveratrol, anthocyanins and so on, demonstrating potential in treating these overlapping disorders. This comprehensive review aims to elucidate the complex role of oxidative stress within the interlinked pathways of these comorbid conditions. By integrating contemporary research and empirical findings, our objective is to outline new conceptual models and innovative treatment strategies for effectively managing these prevalent diseases. This review underscores the importance of further in-depth research to validate the efficacy of antioxidants and traditional Chinese medicine in treatment plans, as well as to explore targeted interventions focused on oxidative stress as promising areas for future medical advancements.
Topics: Humans; Oxidative Stress; Osteoporosis; Antioxidants; Tendinopathy; Reactive Oxygen Species; Animals
PubMed: 38953556
DOI: 10.1111/jcmm.18508 -
Journal of Biochemical and Molecular... Jul 2024Cyclophosphamide (CP) is an antineoplastic drug widely used in chemotherapy. Curcumin (CUR) and piperine (PP) show a protective effect on neurodegenerative and...
Cyclophosphamide (CP) is an antineoplastic drug widely used in chemotherapy. Curcumin (CUR) and piperine (PP) show a protective effect on neurodegenerative and neurological diseases. This research was designed to measure several biochemical parameters in the brain tissue of CP-applied rats to investigate the impact of combined CUR-PP administration. The study evaluated six groups of eight rats: Group 1 was the control; Groups 2 and 3 were administered 200 or 300 mg/kg CUR-PP via oral gavage; Group 4 received only 200 mg/kg CP on day 1; Groups 5 and 6 received CP + CUR-PP for 7 days. Data from all parameters indicated that CP caused brain damage. Phosphorylated TAU (pTAU), amyloid-beta peptide 1-42 (Aβ1-42), glutamate (GLU), and gamma amino butyric acid (GABA) parameters were the same in Groups 4, 5, and 6. On the other hand, 8-hydroxy-2-deoxyguanosine (8-OHdG), nitric oxide (NO), interleukin-6 (IL-6), nuclear factor kappa beta (NF-kβ), malondialdehyde (MDA), and tumor necrosis factor-alpha (TNF-α) levels in the CP + CUR-PP groups were lower than those in the CP group (p < 0.05). However, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and reduced glutathione (GSH) parameters were higher in the CP + CUR-PP groups compared to the CP group (p < 0.05). It is thought that the similarity of Groups 5 and 6 with Group 4 in Aβ1-42, pTAU, GLU, and GABA parameters hinder the determination of treatment protection however, they might have a therapeutic effect if the applied dose or study duration were changed. This study attempted to evaluate the effects of a CUR-PP combination on CP-induced brain damage in rats by measuring biochemical parameters and performing histopathological examinations. Based on the findings, this CUR-PP combination could be considered an alternative medicine option in cases with conditions similar to those evaluated in this study.
Topics: Animals; Polyunsaturated Alkamides; Benzodioxoles; Curcumin; Piperidines; Alkaloids; Rats; Cyclophosphamide; Male; Brain Injuries; Rats, Wistar; Brain; Oxidative Stress; Neuroprotective Agents
PubMed: 38953502
DOI: 10.1002/jbt.23760 -
ACS Chemical Neuroscience Jul 2024Polychlorinated biphenyls (PCBs) are industrial chemicals that are ubiquitously found in the environment. Exposure to these compounds has been associated with neurotoxic...
Polychlorinated biphenyls (PCBs) are industrial chemicals that are ubiquitously found in the environment. Exposure to these compounds has been associated with neurotoxic outcomes; however, the underlying mechanisms for such outcomes remain to be fully understood. Recent studies have shown that astrocytes, the most abundant glial cell type in the brain, are susceptible to PCB exposure as well as exposure to human-relevant metabolites of PCBs. Astrocytes are critical for maintaining healthy brain function due to their unique functional attributes and positioning within the neuronal networks in the brain. In this study, we assessed the toxicity of PCB52, one of the most abundantly found PCB congeners in outdoor and indoor air, and two of its human-relevant metabolites, on astrocyte mitochondria. We exposed C6 cells, an astrocyte cell line, to PCB52 or its human-relevant metabolites and found that all the compounds showed increased toxicity in galactose-containing media compared to that in the glucose-containing media, indicating the involvement of mitochondria in observed toxicity. Additionally, we also found increased oxidative stress upon exposure to PCB52 metabolites. All three compounds caused a loss of mitochondrial membrane potential, distinct changes in the mitochondrial structure, and impaired mitochondrial function. The hydroxylated metabolite 4-OH-PCB52 likely functions as an uncoupler of mitochondria. This is the first study to report the adverse effects of exposure to PCB52 and its human-relevant metabolites on the mitochondrial structure and function in astrocytes.
PubMed: 38953493
DOI: 10.1021/acschemneuro.4c00116 -
Magnesium Research Jun 2024Pathogenic mechanisms implicated in the development of Parkinson disease (PD) are multifaceted and include alpha synuclein aggregation, oxidative stress due to... (Review)
Review
Pathogenic mechanisms implicated in the development of Parkinson disease (PD) are multifaceted and include alpha synuclein aggregation, oxidative stress due to generation of reactive oxygen species (ROS), mitochondrial dysfunction, apoptosis, imbalance of trace elements as well as endoplasmic reticulum stress, and inflammation. Alteration in the homeostasis of bivalent cations, such as iron, magnesium and calcium, has been implicated in the pathogenesis of PD. Low levels of magnesium have been associated with accelerated dopaminergic cell loss in animal PD models, and magnesium has been shown to have a neuroprotective effect in PD models. Evidence of a low magnesium level in the brain of PD individuals, with a low magnesium level in the diet, increasing the risk of PD, further strengthens the role of magnesium deficiency in the pathogenesis of PD. The presence of low-level magnesium in brain tissue and high level in CSF and serum support the possibility of dysfunctional magnesium transporters in PD. Indeed, variants in magnesium transport channels, such as TRPM7 and SLC41A1, have been recently detected in PD individuals. Magnesium, being an NMDA antagonist, could also have a therapeutic role in levodopa-induced dyskinesia. There are no clinical studies indicating a neuroprotective role of magnesium in PD, however, the Mediterranean diet and variants of the diet have been associated with a lower risk of PD, which may be due to the magnesium-rich constituents of the diet. Further clinical trials encompassing therapeutic models to optimize channel function, coupled with a high magnesium diet, may pave the way for promising neuroprotective intervention for PD.
Topics: Humans; Magnesium; Parkinson Disease; Neuroprotective Agents; Animals
PubMed: 38953416
DOI: 10.1684/mrh.2024.0523 -
MBio Jul 2024There are no licensed vaccines for human cytomegalovirus (HCMV), and current antiviral drugs that target viral proteins are toxic and prone to resistance. Targeting host...
UNLABELLED
There are no licensed vaccines for human cytomegalovirus (HCMV), and current antiviral drugs that target viral proteins are toxic and prone to resistance. Targeting host pathways essential for virus replication provides an alternate strategy that may reduce opportunities for drug resistance to occur. Oxidative stress is triggered by numerous viruses including HCMV. Peroxynitrite is a reactive nitrogen species that is formed during oxidative stress. Herein, we identified that HCMV rapidly induces the generation of intracellular peroxynitrite upon infection in a manner partially dependent upon xanthine oxidase generation. Peroxynitrite promoted HCMV infection in both cell-free and cell-associated infection systems in multiple cell types. Inhibiting peroxynitrite within the first 24 hours of infection prevented HCMV replication and peroxynitrite promoted cell entry and pp65 translocation into the host cell nuclei. Furthermore, using the murine cytomegalovirus model, we demonstrated that antagonizing peroxynitrite significantly reduces cytomegalovirus replication and pathogenesis . Overall, our study highlights a proviral role for peroxynitrite in CMV infection and implies that RNS and/or the mechanisms that induce their production could be targeted as a novel strategy to inhibit HCMV infection.
IMPORTANCE
Human cytomegalovirus (HCMV) causes significant disease in individuals with impaired or immature immune systems, such as transplant patients and after congenital infection. Antiviral drugs that target the virus directly are toxic and are susceptible to antiviral drug resistance due to virus mutations. An alternate strategy is to target processes within host cells that are required by the virus for replication. Herein, we show that HCMV infection triggers a highly reactive molecule, peroxynitrite, during the initial stages of infection. Peroxynitrite was required for the initial entry of the virus into the cell and promotes virus replication in multiple cell types, suggesting a broad pro-viral function. Importantly, targeting peroxynitrite dramatically inhibited cytomegalovirus replication in cells in the laboratory and in mice, suggesting that therapeutic targeting of this molecule and/or the cellular functions it regulates could represent a novel strategy to inhibit HCMV infection.
PubMed: 38953361
DOI: 10.1128/mbio.03152-23 -
MBio Jul 2024an opportunistic fungal pathogen, produces the quorum-sensing molecule farnesol, which we have shown alters the transcriptional response and phenotype of human...
an opportunistic fungal pathogen, produces the quorum-sensing molecule farnesol, which we have shown alters the transcriptional response and phenotype of human monocyte-derived dendritic cells (DCs), including their cytokine secretion and ability to prime T cells. This is partially dependent on the nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR-γ), which has numerous ligands, including the sphingolipid metabolite sphingosine 1-phosphate. Sphingolipids are a vital component of membranes that affect membrane protein arrangement and phagocytosis of by DCs. Thus, we quantified sphingolipid metabolites in monocytes differentiating into DCs by High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Farnesol increased the activity of serine palmitoyltransferase, leading to increased levels of 3-keto-dihydrosphingosine, dihydrosphingosine, and dihydrosphingosine 1-phosphate and inhibited dihydroceramide desaturase by inducing oxidative stress, leading to increased levels of dihydroceramide and dihydrosphingomyelin species and reduced ceramide levels. Accumulation of dihydroceramides can inhibit mitochondrial function; accordingly, farnesol reduced mitochondrial respiration. Dihydroceramide desaturase inhibition increases lipid droplet formation, which we observed in farnesol-treated cells, coupled with an increase in intracellular triacylglycerol species. Furthermore, inhibition of dihydroceramide desaturase with either farnesol or specific inhibitors impaired the ability of DCs to prime interferon-γ-producing T cells. The effect of farnesol on sphingolipid metabolism, triacylglycerol synthesis, and mitochondrial respiration was not dependent on PPAR-γ. In summary, our data reveal novel effects of farnesol on sphingolipid metabolism, neutral lipid synthesis, and mitochondrial function in DCs that affect their instruction of T cell cytokine secretion, indicating that can manipulate host cell metabolism via farnesol secretion.IMPORTANCE is a common commensal yeast, but it is also an opportunistic pathogen which is one of the leading causes of potentially lethal hospital-acquired infections. There is growing evidence that its overgrowth in the gut can influence diseases as diverse as alcohol-associated liver disease and COVID-19. Previously, we found that its quorum-sensing molecule, farnesol, alters the phenotype of dendritic cells differentiating from monocytes, impairing their ability to drive protective T cell responses. Here, we demonstrate that farnesol alters the metabolism of sphingolipids, important structural components of the membrane that also act as signaling molecules. In monocytes differentiating to dendritic cells, farnesol inhibited dihydroceramide desaturase, resulting in the accumulation of dihydroceramides and a reduction in ceramide levels. Farnesol impaired mitochondrial respiration, known to occur with an accumulation of dihydroceramides, and induced the accumulation of triacylglycerol and oil bodies. Inhibition of dihydroceramide desaturase resulted in the impaired ability of DCs to induce interferon-γ production by T cells. Thus, farnesol production by could manipulate the function of dendritic cells by altering the sphingolipidome.
PubMed: 38953353
DOI: 10.1128/mbio.00732-24 -
Journal of the Science of Food and... Jul 2024Giant salamander protein peptide is a peptide with rich functional properties. Giant salamander protein peptide KGEYNK (KK-6) is a peptide with both antioxidant and...
BACKGROUND
Giant salamander protein peptide is a peptide with rich functional properties. Giant salamander protein peptide KGEYNK (KK-6) is a peptide with both antioxidant and anti-inflammatory properties. The antioxidant and anti-inflammatory mechanisms of KK-6 are still unclear. When we studied the functional mechanism of KK-6, we found that the antioxidant property of KK-6 has a synergistic and promoting effect on anti-inflammatory properties.
RESULTS
KK-6 enhances cellular resistance to LPS via the MAPK/NF-κB signaling pathway, leading to increased levels of inflammatory factors: interleukin-1β (764.81 ng mL), interleukin-6 (1.06 ng mL) and tumor necrosis factor-α (4440.45 ng mL). KK-6 demonstrates potent antioxidant properties by activating the Nrf2 signaling pathway, resulting in elevated levels of antioxidant enzymes (glutathione peroxidase: 0.03 μg mL; superoxide dismutase: 0.589 μg mL) and a reduction in the concentration of the oxidative product malondialdehyde (967.05 μg mL).
CONCLUSION
Our findings highlight the great potential of KK-6, a peptide extracted from giant salamander protein, as a remedy for intestinal inflammation. Through its dual role as an antioxidant and anti-inflammatory agent, KK-6 offers a promising avenue for alleviating inflammation-related damage and oxidative stress. This study lays the foundation for further exploration of giant salamander products and highlights their importance in health and novel food development. © 2024 Society of Chemical Industry.
PubMed: 38953326
DOI: 10.1002/jsfa.13689