Reactive Oxygen Species Levels In Cells Research Articles

Photo‐Switchable Peroxidase/Catalase‐Like Activity of Carbon Quantum Dots

AbstractNanozymes possess multi‐enzyme activities over the natural enzymes, which produce multi‐pathway synergistic effects for varies of biomedical applications. Unfortunately, their multi‐enzyme activities are in fighting, significantly reducing the synergistic effects. Dynamic regulation of their multi‐enzyme activities is the bottleneck for intelligent therapies. Herein, we construct a novel oxygen‐nitrogen functionalized carbon quantum dots (O/N‐CQDs) with peroxidase‐like (Reactive oxygen species (ROS) producer) activity. Interestingly, the peroxidase‐like activity can be reversibly converted to catalase‐like (ROS scavenger) activity under visible light irradiation. It is found that both the peroxidase/catalase‐like activity of O/N‐CQDs can be precisely manipulated by the light intensity. The mechanism of switchable enzyme activities is attributed to the polarization of quinoid nitrogen in polyaniline (PANI) precursor retained on O/N‐CQDs under visible light, which consumes the ROS to produce O2 and H2O. As a proof‐of‐concept demonstration, we are able to non‐intrusively up and down regulate the ROS level in cells successfully by simply switching off and on the light respectively, potentially facilitating the precise medicine based on the development of the disease. Indeed, the photo‐switchable peroxidase/catalase‐like activity of O/N‐CQDs opens a non‐invasive strategy for better manipulations of the multi‐activity of nanozymes, promising their wider and more intelligent biomedical applications.

Photo-Switchable Peroxidase/Catalase-Like Activity of Carbon Quantum Dots.

Nanozymes possess multi-enzyme activities over the natural enzymes, which produce multi-pathway synergistic effects for varies of biomedical applications. Unfortunately, their multi-enzyme activities are in fighting, significantly reducing the synergistic effects. Dynamic regulation of their multi-enzyme activities is the bottleneck for intelligent therapies. Herein, we construct a novel oxygen-nitrogen functionalized carbon quantum dots (O/N-CQDs) with peroxidase-like (Reactive oxygen species (ROS) producer) activity. Interestingly, the peroxidase-like activity can be reversibly converted to catalase-like (ROS scavenger) activity under visible light irradiation. It is found that both the peroxidase/catalase-like activity of O/N-CQDs can be precisely manipulated by the light intensity. The mechanism of switchable enzyme activities is attributed to the polarization of quinoid nitrogen in polyaniline (PANI) precursor retained on O/N-CQDs under visible light, which consumes the ROS to produce O2 and H2O. As a proof-of-concept demonstration, we are able to non-intrusively up and down regulate the ROS level in cells successfully by simply switching off and on the light respectively, potentially facilitating the precise medicine based on the development of the disease. Indeed, the photo-switchable peroxidase/catalase-like activity of O/N-CQDs opens a non-invasive strategy for better manipulations of the multi-activity of nanozymes, promising their wider and more intelligent biomedical applications.

Polydatin prevent lung epithelial cell from Carbapenem-resistant Klebsiellapneumoniae injury by inhibiting biofilm formation and oxidative stress

Carbapenem-resistant Klebsiella pneumoniae (CRKP) causes severe inflammation in various infectious diseases, such as bloodstream infections, respiratory and urinary tract infections, which leads to high mortality. Polydatin (PD), an active ingredient of Yinhuapinggan granule, has attracted worldwide attention for its powerful antioxidant, anti-inflammatory, antitumor, and antibacterial capacity. However, very little is known about the effect of PD on CRKP. In this research, we evaluated the inhibitory effects of PD on both the bacterial level and the bacterial-cell co-culture level on anti-biofilm and efflux pumps and the other was the inhibitory effect on apoptosis, reactive oxygen species (ROS), mitochondrial membrane potential (MMP) after CRKP induction. Additionally, we validated the mechanism of action by qRT-PCR and western blot in human lung epithelial cells. Firstly, PD was observed to have an inhibitory effect on the biofilm of CRKP and the efflux pump AcrAB-TolC. Mechanically, CRKP not only inhibited the activation of Nuclear Factor erythroid 2-Related Factor 2 (Nrf-2) but also increased the level of ROS in cells. These results showed that PD could inhibit ROS and activate Nrf-2 production. Together, our research demonstrated that PD inhibited bacterial biofilm formation and efflux pump AcrAB—TolC expression and inhibited CRKP-induced cell damage by regulating ROS and Nrf-2-regulated antioxidant pathways.

High-Throughput Screening and Proteomic Characterization of Compounds Targeting Myeloid-Derived Suppressor Cells

Myeloid-derived suppressor cells (MDSC) are a heterogeneous cell population of incompletely differentiated immune cells. They are known to suppress T cell activity and are implicated in multiple chronic diseases, which make them an attractive cell population for drug discovery. Here, we characterized the baseline proteomes and phospho-proteomes of mouse MDSC differentiated from a progenitor cell line to a depth of 7000 proteins and phosphorylation sites. We also validated the cellular system for drug discovery by recapitulating and identifying known and novel molecular responses to the well-studied MDSC drugs entinostat and mocetinostat. We established a high-throughput drug screening platform using a MDSC/T cell coculture system and assessed the effects of ∼21,000 small molecule compounds on T cell proliferation and IFN-γ secretion to identify novel MDSC modulator. The most promising candidates were validated in a human MDSC system, and subsequent proteomic experiments showed significant upregulation of several proteins associated with the reduction of reactive oxygen species (ROS). Proteome-wide solvent-induced protein stability assays identified Acyp1 and Cd74 as potential targets, and the ROS-reducing drug phenotype was validated by measuring ROS levels in cells in response to compound, suggesting a potential mode of action. We anticipate that the data and chemical tools developed in this study will be valuable for further research on MDSC and related drug discovery.

Protective Effect and Mechanism of Autophagy in Endothelial Cell Injury Induced by Hyperoxia.

Bronchopulmonary dysplasia is a chronic lung disease in premature infants with alveolar simplification and pulmonary vascular development disorder as the main pathological feature and hyperoxia as the main etiology. Autophagy is a highly conserved cytological behavior of self-degrading cellular components and is accompanied by oxidative stress. Studies have reported that autophagy is regulated by FOXO1 posttranslational modification. However, whether autophagy can be involved in the regulation of endothelial cell injury induced by hyperoxia and its mechanism are still unclear. We have activated and inhibited autophagy in human umbilical vein endothelial cells under hyperoxia and verified the role of autophagy in endothelial cell-related functions from both positive and negative aspects. Our research showed that the expression level of autophagy-related proteins decreased, accompanied by decreased cell migration ability and tube formation ability and increased cell reactive oxygen species level and cell permeability under hyperoxia conditions. Using an autophagy agonist alleviated hyperoxia-induced changes and played a protective role. However, inhibition of autophagy aggravated the cell damage induced by hyperoxia. Moreover, the decrease in autophagy proteins was accompanied by the upregulation of FOXO1 phosphorylation and acetylation. We concluded that autophagy was a protective mechanism against endothelial cell injury caused by hyperoxia. Autophagy might participate in this process by coregulating posttranslational modifications of FOXO1. · Hyperoxia induces vascular endothelial cell injury.. · Autophagy may has a protective role under hyperoxia conditions.. · FOXO1 posttranslational modification may be involved in the regulation of autophagy..

Reactive Oxygen Species‐Activated CO Versatile Nanomedicine with Innate Gut Immune and Microbiome Remodeling Effects for Treating Inflammatory Bowel Disease

AbstractAbnormal activation of the gut mucosal immune system and a highly dysregulated gut microbiota play essential roles in the progression of inflammatory bowel disease (IBD). The clinical treatment of IBD remains highly challenging, with first‐line drugs showing limited efficacy and significant side effects. A reactive oxygen species (ROS)‐activated CO versatile nanomedicine (CMPs) capable of remodeling the gut immune‐microbiota microenvironment via potent anti‐oxidant, anti‐inflammatory, and antimicrobial effects is developed. CORM‐401‐loaded mannose‐modified peptide dendrimer nanogel: CMPs preferentially congregate on the surface of damaged colon mucosa after rectal administration and are subsequently internalized by activated immune cells. CORM‐401 can release numerous CO molecules in response to high ROS levels in cells and at the site of IBD, resulting in multiple therapeutic effects. In vitro and in vivo studies have demonstrated that CMPs scavenge ROS, suppress inflammatory responses, eliminate pathogens, and alleviate colitis in mouse models. RNA sequencing reveals that CMPs successfully remodel gut mucosal immune homeostasis by scavenging ROS, inhibiting NF‐κB/p38MAPK, activating PI3K‐Akt, and inhibiting HIF‐1‐induced glycolysis. 16S ribosomal RNA sequencing shows that CMPs can remodel the gut flora composition by restraining detrimental bacteria and augmenting beneficial bacteria. This study develops a promising and versatile nanomedicine for the management of IBD.

In-Vitro Study of Indium (III) Sulfate-Containing Medium on the Viability and Adhesion Behaviors of Human Dermal Fibroblast on Engineered Surfaces.

Tissues and organs consist of cells organized in specified patterns that support their function, as exemplified by tissues such as skin, muscle, and cornea. It is, therefore, important to understand how external cues, such as engineered surfaces or chemical contaminants, can influence the organization and morphology of cells. In this work, we studied the impact of indium sulfate on human dermal fibroblast (GM5565) viability, production of reactive oxygen species (ROS), morphology, and alignment behavior on tantalum/silicon oxide parallel line/trench surface structures. The viability of cells was measured using the alamarBlue™ Cell Viability Reagent probe, while the ROS levels in cells were quantified using cell-permeant 2',7'-dichlorodihydrofluorescein diacetate. Cell morphology and orientation on the engineered surfaces were characterized using fluorescence confocal and scanning electron microscopy. When cells were cultured in media containing indium (III) sulfate, the average cell viability decreased by as much as ~32% and the concentration of cellular ROS increased. Cell geometry became more circular and compact in the presence of indium sulfate. Even though actin microfilaments continue to preferentially adhere to tantalum-coated trenches in the presence of indium sulfate, the cells are less able to orient along the line axes of the chips. Interestingly, the indium sulfate-induced changes in cell alignment behavior are pattern dependent-a larger proportion of adherent cells on structures with line/trench widths in the range of 1 μm and 10 μm lose the ability to orient themselves, compared to those grown on structures with line widths smaller than 0.5 μm. Our results show that indium sulfate impacts the response of human fibroblasts to the surface structure to which they adhere and underscores the importance of evaluating cell behaviors on textured surfaces, especially in the presence of potential chemical contaminants.

Enhanced mitochondrial fission inhibits triple-negative breast cancer cell migration through an ROS-dependent mechanism

Mitochondria produce reactive oxygen species (ROS), which function in signal transduction. Mitochondrial dynamics, encompassing morphological shifts between fission and fusion, can directly impact ROS levels in cancer cells. In this study, we identified an ROS-dependent mechanism for how enhanced mitochondrial fission inhibits triple negative breast cancer (TNBC) cell migration. We found that enforcing mitochondrial fission in TNBC resulted in an increase in intracellular ROS levels and reduced cell migration and the formation of actin-rich migratory structures. Consistent with mitochondrial fission, increasing ROS levels in cells inhibited cell migration. Conversely, reducing ROS levels with either a global ormitochondrially targeted scavenger overcame the inhibitory effects of mitochondrial fission. Mechanistically, we found that the ROS sensitive SHP-1/2 phosphatases partially regulate inhibitory effects of mitochondrial fission on TNBC migration. Overall, our work reveals the inhibitory effects of ROS in TNBC and supports mitochondrial dynamics as a potential therapeutic target for cancer.

Nifuroxazide induces the apoptosis of human non‑small cell lung cancer cells through the endoplasmic reticulum stress PERK signaling pathway.

The aim of the present study was to investigate the molecular mechanism of nifuroxazide (NFZ) in the induction of apoptosis of NCI-H1299 human non-small cell lung cancer (NSCLC) cells through the reactive oxygen species (ROS)/Ca2+/protein kinase R-like ER kinase (PERK)-activating transcription factor 4 (ATF4)-DNA damage inducible transcript 3 (CHOP) signaling pathway. Morphological changes of cells were observed by microscopy, and the apoptosis and intracellular ROS levels of cells were observed by inverted fluorescence microscopy. Cell viability after the addition of the PERK inhibitor, GSK2606414, were detected by Cell Counting Kit-8 assay. Annexin V-FITC was used to detect cell apoptosis, Brite 670 was used to detect intracellular ROS and Fura Red AM was used to detect Ca2+ content. Western blotting was used to detect PERK, phosphorylated (P)-PERK, ATF4, CHOP, P-Janus kinase 2 and P-signal transducer and activator of transcription 3 expression levels. Compared with the dimethyl sulfoxide control group, NFZ inhibited the survival activity in the H1299 NSCLC cell line, in a time- and dose-dependent manner. However, GSK2606414 inhibited the NFZ-induced apoptosis of H1299 cells. GSK2606414 also inhibited the increase in ROS and Ca2+ in H1299 cells induced by NFZ. Western blotting results demonstrated that NFZ significantly increased the expression levels of P-PERK, ATF4 and CHOP, whereas GSK2606414 significantly reduced the NFZ-induced increase in these protein expression levels. In conclusion, NFZ may induce the apoptosis of H1299 NSCLC cells through the ROS/Ca2+/PERK-ATF4-CHOP signaling pathway.

Examination of the Antioxidant Activity of Psoralidin: Computational Mechanistic Study and Impact on the ROS Level in Human Keratinocytes.

Psoralidin (Pso) is a coumestan-type compound found in Psoralea corylifolia L. that exhibits a broad spectrum of pharmacological properties. The current work aimed to study, for the first time, the antioxidant capacities of Pso under physiological circumstances. Tandem experimental and computational approaches were used to fully understand the interaction of Pso with ROS (reactive oxygen species) at the molecular level as well as its impact on the basal ROS level in cells. Pso has been found to be a potent radical scavenger in physiological polar media, acting via the single electron-transfer mechanism rather than the hydrogen-transfer mechanism. In contrast, Pso is a moderate radical scavenger in lipid media, and its reaction is determined by hydrogen transfer from the 7OH group. The in vitro assays revealed that Pso moderately reduces the basal ROS level in human keratinocytes at non-toxic concentrations, which is in agreement with the computational study. These findings indicate that Pso is a promising antioxidant, but in its natural form it has no significant effects on basal cell conditions.

Persulfidation protects from oxidative stress under nonphotorespiratory conditions in Arabidopsis.

Hydrogen sulfide is a signaling molecule in plants that regulates essential biological processes through protein persulfidation. However, little is known about sulfide-mediated regulation in relation to photorespiration. Here, we performed label-free quantitative proteomic analysis and observed a high impact on protein persulfidation levels when plants grown under nonphotorespiratory conditions were transferred to air, with 98.7% of the identified proteins being more persulfidated under suppressed photorespiration. Interestingly, a higher level of reactive oxygen species (ROS) was detected under nonphotorespiratory conditions. Analysis of the effect of sulfide on aspects associated with non- or photorespiratory growth conditions has demonstrated that it protects plants grown under suppressed photorespiration. Thus, sulfide amends the imbalance of carbon/nitrogen and restores ATP levels to concentrations like those of air-grown plants; balances the high level of ROS in plants under nonphotorespiratory conditions to reach a cellular redox state similar to that in air-grown plants; and regulates stomatal closure, to decrease the high guard cell ROS levels and induce stomatal aperture. In this way, sulfide signals the CO2 -dependent stomata movement, in the opposite direction of the established abscisic acid-dependent movement. Our findings suggest that the high persulfidation level under suppressed photorespiration reveals an essential role of sulfide signaling under these conditions.

Mechanism of Action of Decitabine in the Treatment of Acute Myeloid Leukemia by Regulating LINC00599.

Acute myeloid leukemia (AML) is a heterogeneous malignancy with a low long-term survival rate. The aim of this study was to investigate the effects of decitabine (DAC) treatment cell proliferation and apoptosis in AML and role of the expression of LINC00599 and, consequently, miR-135a-5p. Human promyelocytic leukemia cells (HL-60) and human acute lymphatic leukemia (CCRF-CEM) cells were treated with various concentrations of DAC. Cell proliferation in each group was detected using the cell counting kit 8. For each group, apoptosis and reactive oxygen species (ROS) levels were detected using flow cytometry. Reverse transcription polymerase chain reaction (RT-PCR) was performed to examine the expression of lncRNA LINC00599. The expression of apoptosis-related proteins was analyzed using western blotting. The regulatory relationship between miR-135a-5p and LINC00599 was verified by constructing miR-135a-5p mimics, miR-135a-5p inhibit, wild type LINC00599 3'-untranslated region (UTR), and mutant LINC00599 3'-UTR. Ki-67 expression in the tumor tissues of nude mice was detected using immunofluorescent assays. Both DAC and LINC00599 Inhibit groups were able to significantly reduce the proliferation of HL60 and CCRF-CEM cells, increase apoptosis, upregulate the expression of Bad, cleaved caspase-3, and miR-135a-5p, downregulate the expression of Bcl-2, and elevate ROS levels in cells, with these effects being more pronounced after combined treatment with DAC and LINC00599 Inhibit. In comparison to mimic NC, the miR-135a-5p mimic group significantly decreased the relative fluorescence activity ratio of LINC00599 3'-UTR wild-type CCRF-CEM cells. The LINC00599 Inhibit and miR-135a-5p mimic groups exhibited substantially reduced proliferation of HL60 and CCRF-CEM cells, increased apoptosis, upregulated Bad, cleaved caspase-3, and miR-135a-5p expression, along with downregulated Bcl-2 and LINC00599 expression and increased ROS levels in cells; these effects were more pronounced after LINC00599 Inhibit was combined with miR-135a-5p mimics. In vivo experiments revealed that both DAC and LINC00599 Inhibit were able to considerably reduce the long diameter, short meridian, volume, and mass of tumors, increase miR-135a-5p expression, and decrease LINC00599 and ki-67 expression in tumor tissues of nude mice. This effect was more pronounced when the DAC and LINC00599 Inhibit were used in combination. DAC regulates the expression of miR-135a-5p by regulating the expression of LINC00599, which in turn affects cell proliferation, apoptosis, and tumor proliferation. Our findings provide a theoretical basis for improving the clinical outcome of AML.

The role of Nrf2 in the alteration of tight junction protein expression in choroid plexus epithelial cells created by lanthanum-activated MMP9

Objective: To investigate the effect of nuclear factor erythroid 2-related factor 2 (Nrf2) in the alteration of tight junction protein expression in choroid plexus epithelial cells created by lanthanum-activated matrix metalloproteinase 9 (MMP9) . Methods: In October 2020, immortalized rat choroid plexus epithelial cell line (Z310) cells were used as the blood-cerebrospinal fluid barrier in vitro, and were divided into control group and 0.125, 0.25, 0.5 mmol/L lanthanum chloride (LaCl(3)) treatment group. After treating Z310 cells with different concentrations of LaCl(3) for 24 hours, the morphological changes of Z310 cells were observed under inverted microscope, the protein expression levels of MMP9, occludin and zonula occludens-1 (ZO-1) were observed by cellular immunofluorescence method, and the protein expression levels of MMP9, tissue inhibitors of metalloproteinase1 (TIMP1) , occludin, ZO-1 and Nrf2 were detected by Western blotting. The level of reactive oxygen species (ROS) in cells was detected by flow cytometry. Results: Compared with the control group, Z310 cells in the LaCl(3) treatment group were smaller in size, with fewer intercellular junctions, and more dead cells and cell fragments. The expression level of MMP9 protein in cells treated with 0.25 and 0.5 mmol/L LaCl(3) was significantly higher than that in the control group (P<0.05) , and the expression level of TIMP1 and tight junction proteins occudin and ZO-1 was significantly lower than that in the control group (P<0.05) . Compared with the control group, the ROS production level in the 0.25, 0.5 mmol/L LaCl(3) treatment group was significantly increased (P<0.05) , and the Nrf2 protein expression level in the 0.125, 0.25, 0.5 mmol/L LaCl(3) treatment group was significantly decreased (P<0.05) . Conclusion: Lanthanum may increase the level of ROS in cells by down regulating the expression of Nrf2, thus activating MMP9 to reduce the expression level of intercellular tight junction proteins occludin and ZO-1.

Synergistic inhibition of calcium oxalate crystal formation and synergistic protection of HK-2 cells from crystal damage by sulfated Laminarin polysaccharide and potassium citrate.

Objective: The first objective is to study the synergistic inhibition of calcium oxalate (CaOx) formation by Laminarin polysaccharides (DLP and SDLP, before and after sulfation) and potassium citrate (K3cit) and determine the synergistic protection of renal epithelial cells (HK-2 cells) caused by CaOx crystal damage. The second objective is to explore new ways to prevent and treat kidney stones. Methods: The CaOx crystals regulated by five additives (K3cit group, DLP group, SDLP group, DLP-K3cit synergistic group and SDLP-K3cit synergistic group) were characterized by FT-IR, XRD, SEM, zeta potential, ICP, and TGA. The protective effect of each additive group on HK-2 cells damaged by nano-calcium oxalate monohydrate (nano-COM) was compared by detecting cell viability, the cell reactive oxygen species level, the cell survival rate, and mitochondrial membrane potential. Results: When DLP or SDLP acted synergically with K3cit, the synergistic group induced the same amount of COD at a lower concentration or more COD formation at the same concentration, highlighting the synergistic enhancement effect of 1 + 1 > 2. At 0.3 g L-1, the COD contents induced by DLP, SDLP, K3cit, DLP-K3cit, and SDLP-K3cit synergistic groups were 20.3%, 75.8%, 75.4%, 87.3%, and 100%, respectively. The synergistic group increased the concentration of soluble Ca2+ ions in the supernatant, increased the absolute value of the zeta potential on the surface of CaOx crystals, and inhibited the aggregation among the crystals. TGA and DTG analyses established the adsorption of polysaccharides in the crystals. Cell experiments showed the ability of the synergistic group to significantly inhibit the damage of nano-COM crystals on HK-2 cells, reduce the level of reactive oxygen species and mortality, and improve cell viability and the mitochondrial membrane potential. Conclusions: The synergistic group can more effectively induce COD formation and cell protection than the standalone polysaccharide group or K3cit group. The synergistic groups, especially SDLP-K3cit, may be a potential drug for inhibiting the formation of CaOx kidney stones.

DECREASE IN THE CONTENT OF REACTIVE OXYGEN SPECIES DURING INACTIVATION OF THE RESPIRATORY COMPLEX I IN ARABIDOPSIS CELLS

Background. The mitochondrial electron transport chain, in particular the respiratory complex I, is one of the main sources of reactive oxygen species (ROS) in living cells. Suppression of the complex I activity in human cells through chemical inhibition or mutations that disrupt the functionality of this complex leads to a significant increase in the content of ROS. The complex I mutants are also known for plants; however, it is still not clear whether the suppression of the activity of this complex leads to an increase in the level of ROS and the development of oxidative stress.&#x0D; Purpose. To study the level of superoxide, hydrogen peroxide and sensitivity to prooxidants in Arabidopsis ndufs4 cells with complex I inactivated by insertional mutagenesis.&#x0D; Materials and methods. A suspension culture of wild-type Arabidopsis cells and a line with knockout the NDUFS4 complex I subunit was used. The level of hydrogen peroxide in the cells was determined using dichlorofluorescein. The superoxide content was estimated by cell staining in the presence of nitroblue tetrazolium.&#x0D; Results. It has been shown that inactivation of the NADH-dehydrogenase complex in Arabidopsis cells due to the absence of one of its subunits leads to a decrease in the content of superoxide and hydrogen peroxide. It was also shown that the level of ROS in cells treated with the menadione and hydrogen peroxide increased several times in wild-type cells, but remained almost unchanged in ndufs4 cells.&#x0D; Conclusion. Suppression of the activity of the NADH dehydrogenase complex in plant cells, but not in animal cells, leads to a decrease in the content of both hydrogen peroxide and superoxide. Cells of ndufs4 line have an increased ability to detoxify ROS, possibly associated with the constant mobilization of antioxidant defense systems.

Application of Metal-Based Nanozymes in Inflammatory Disease: A Review.

Reactive oxygen species (ROS) are metabolites of normal cells in organisms, and normal levels of ROS in cells are essential for maintaining cell signaling and other intracellular functions. However, excessive inflammation and ischemia-reperfusion can cause an imbalance of tissue redox balance, and oxidative stress occurs in a tissue, resulting in a large amount of ROS, causing direct tissue damage. The production of many diseases is associated with excess ROS, such as stroke, sepsis, Alzheimer’s disease, and Parkinson’s disease. With the rapid development of nanomedicine, nanomaterials have been widely used to effectively treat various inflammatory diseases due to their superior physical and chemical properties. In this review, we summarize the application of some representative metal-based nanozymes in inflammatory diseases. In addition, we discuss the application of various novel nanomaterials for different therapies and the prospects of using nanoparticles (NPs) as biomedical materials.

Cold Atmospheric Plasma Inhibits the Proliferation of CAL-62 Cells through the ROS-Mediated PI3K/Akt/mTOR Signaling Pathway

This study aimed to investigate the inhibitory effects of cold atmospheric plasma (CAP) on anaplastic thyroid cancer cells (CAL-62 cells) and to reveal the molecular mechanism. The effects of CAP on CAL-62 cells were evaluated by cell viability, superoxide dismutase activity, apoptosis, cell cycle, and protein expression level, and the role of reactive oxygen species (ROS) produced by plasma was also investigated. The results showed that CAP dose-dependently inhibited cell viability and promotes cell apoptosis and G2/M arrest by increasing cell ROS levels. The activity of superoxide dismutase (SOD) was enhanced by CAP which indicated that the antioxidant system of the cell was activated. Additionally, the ROS produced by CAP can inhibit CAL-62 cell proliferation by inhibiting the PI3K/Akt/mTOR signaling pathway. Therefore, these findings will provide useful support for the application of CAP for treating anaplastic thyroid cancer.

Oxidative stress mediated by the TLR4/NOX2 signalling axis is involved in polystyrene microplastic-induced uterine fibrosis in mice

Microplastics (MPs), as a new environmental pollutant, have received widespread attention worldwide. Uterine fibrosis is one of the main factors of female reproductive disorders. However, it is unclear whether the female reproductive disorders caused by MPs are related to uterine fibrosis. Therefore, in this study, we constructed female mouse models exposed to polystyrene microplastics (PS-MPs). We found that PS-MP exposure resulted in endometrial thinning and severe collagen fibre deposition in female mice. Further mechanistic studies found that PS-MP exposure increased the expression of high mobility group Box 1 (HMGB1) and acetyl-HMGB1, further activating the Toll-like receptor 4/NADPH oxidase 2 (TLR4/NOX2) signalling axis and eventually causing oxidative stress. Afterwards, oxidative stress elicited the activation of Notch and the transforming growth factor β (TGF-β) signalling pathway, leading to increased levels of fibrotic proteins and collagen. Correspondingly, PS-MP treatment upregulated the expression of TLR4 and NOX2 and the level of reactive oxygen species (ROS) and increased the levels of fibrotic protein and collagen in mouse endometrial epithelial cells cultured in vitro. Conversely, inhibition of the TLR4/NOX2 signalling pathway effectively reduced the level of ROS in cells, weakened the upregulation of Notch and TGF-β signalling by PS-MPs, and efficiently reduced the expression of fibrotic and collagen genes. In summary, we demonstrated a new mechanism by which MPs induce uterine fibrosis in mice, that is, by inducing oxidative stress to activate the Notch and TGF-β signalling pathways by triggering the TLR4/NOX2 signalling axis. Targeting TLR4/NOX2 signalling may consequently prove to be an innovative therapeutic option that is effective in alleviating the reproductive toxicity of PS-MPs. Our study sheds new light on the reproductive toxicity of MPs and provides suggestions and references for comparative medicine and clinical medicine.

Cardamonin Antioxidant Effects Through the Modulation of Proteins and Genes Expressions in LPS‐Activated BV‐2 Microglial Cells

Neurodegeneration is characterized by slow and progressive loss of neuronal cells and synapses in different brain regions. These pathologic effects are the major feature of Alzheimer's disease (AD), leading to a decline in learning and memory function. The main hallmarks of AD are the aggregation and deposition of amyloid‐β peptides on the extracellular surface of neuronal cells. Hyperphosphorylation of tau protein and the formation of neurofibrillary tangles is another feature of AD. Neuroinflammation and oxidative stress follow the accumulation of amyloid‐β and neurofibrillary tangles. Continuous activation of microglia cells, known as the resident, innate immune cells in the brain, participates in producing numerous neurotoxic factors, including nitric oxide and reactive oxygen species (ROS), which induce neurodegeneration. Numerous natural compounds, such as cardamonin, a bioactive compound found in many plants, have been reported to exert multiple therapeutic properties, including anti‐cancer, anti‐inflammatory, antioxidant, antiviral antibiotic, antifungal, and antiallergic activities. This study examined the effects of cardamonin on LPS‐activated BV‐2 microglial cells. Results of this study showed that cardamonin concentrations of 6.25 to 50 µM reduced over 95% the release of NO in LPS‐activated BV‐2 cells, compared to the cells treated with LPS only (P&lt;0.001). Moreover, cardamonin significantly decreased the cellular production of SOD 3‐fold (P &lt; 0.05) and increased the levels of expression of CAT 2.5‐fold (P &lt; 0.05) and glutathione 2‐fold (p &lt; 0.05) in the LPS‐activated BV‐2 cells. In RT‐PCR assays, cardamonin increased the mRNA expression of CAT and decreased the levels of NOS2, the enzyme responsible for the production of NO and associated with inflammatory processes. Furthermore, cardamonin downregulated the mRNA expression of CCL5/RANTES (5‐fold), which promotes the recruitment and activation of inflammatory cells. Also, cardamonin downregulated SLC38A1 (3‐fold), whose expression is upregulated during oxidative stress, and TXNIP (2‐fold) that regulates thioredoxin, an important redox protein that controls levels of ROS in cells. The data show cardamonin efficacy in modulating proteins and genes involved in inflammation and the control of elevated intracellular levels of ROS. In conclusion, these findings suggest that cardamonin may have potential in the therapy of microglia‐derived neurodegeneration, helping to prevent or slow the progression of the disease in the CNS.

The ester derivatives obtained by C-ring modification of podophyllotoxin-induced apoptosis and inhibited proliferation in Hemangioma Endothelial Cells via downregulation of PI3K/Akt signaling pathway.

Infantile hemangioma (IH) is a common benign endothelial cell tumor in infants and young children, sometimes accompanied by potential complications, and may develop into malignant tumors. Hemangioma endothelial cells (HemECs) are one of the main components of IH. Podophyllotoxin (PPT) has been reported to have many pharmacological activities, especially anti-tumor, but its high toxicity, poor water solubility, and serious gastrointestinal side effects limit its clinical application. In this study, we have designed and synthesized 20 ester derivatives by introducing Boc-amino acids or organic acids at the C-4 position of podophyllotoxin through esterification reactions. The cytotoxicity of these compounds was evaluated on HemECs. Changes in cell proliferation and apoptotic signaling pathways were studied by DAPI staining, colony formation assay, migration assay, measurement of reactive oxygen species (ROS) levels flow cytometry, and Western blot analysis. We found that eight of the compounds were more potent than PPT. Of these, compound V-31 was the most active (IC50 =0.079±0.0049µM). Further research indicated that compound V-31 inhibited its proliferation and migration, increased the level of ROS in cells, and induced apoptosis by downregulating p-PI3K, p-Akt, and Bcl-2, and upregulating cleaved caspase-3 and Bax. Our research provides the first insight into the application of PPT derivatives in HemECs, may provide an effective medicine for IH treatment.