Decrease In Reactive Oxygen Species Research Articles

In vitro toxicity of Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) on Human Renal and Hepatoma Cells

We evaluate the cytotoxicity, intracellular redox conditions, apoptosis, and methylation of DNMTs/TETs upon exposure to LiTFSI, a novel Per and Polyfluoroalkyl Substances (PFAS) commonly found in lithium-ion batteries, on human renal carcinoma cells (A498) and hepatoma cells (HepG2). The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay showed both Perfluorooctane sulfonate (PFOS) and Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) had a dose-dependent effect on A498 and HepG2, with LiTFSI being less toxic. Intracellular redox conditions were assessed with a microplate reader and confocal, which showed a significant decrease in Reactive Oxygen Species (ROS) levels and an increase in Superoxide dismutase (SOD) content in both cells. Exposure to LiTFSI enhanced cell apoptosis, with HepG2 being more susceptible than A498. Quantitative analysis of mRNA expression levels of 19 genes associated with kidney injury, methylation, lipid metabolism and transportation was performed. LiTFSI exposure impacted kidney function by downregulating smooth muscle alpha-actin (Acta2) and upregulating transforming growth factor beta 1 (Tgfb1), B-cell lymphoma 2-like 1) Bcl2l1, hepatitis A virus cellular receptor 1 (Harvcr1), nuclear factor erythroid 2-like 2 (Nfe2l2), and hairy and enhancer of split 1 (Hes1) expression. LiTFSI exposure also affected the abundance of transcripts associated with DNA methylation by the expression of ten-eleven translocation (TET) and DNA methyltransferase (DNMT) genes. Furthermore, LiTFSI exposure induced an increase in lipid anabolism and alterations in lipid catabolism in HepG2. Our results provide new insight on the potential role of a new contaminant, LiTFSI in the regulation of oxidative stress, apoptosis and methylation in human renal carcinoma and hepatoma cells.

Carbon-Coated Iron Oxide Nanoparticles Promote Reductive Stress-Mediated Cytotoxic Autophagy in Drug-Induced Senescent Breast Cancer Cells.

The surface modification of magnetite nanoparticles (Fe3O4 NPs) is a promising approach to obtaining biocompatible and multifunctional nanoplatforms with numerous applications in biomedicine, for example, to fight cancer. However, little is known about the effects of Fe3O4 NP-associated reductive stress against cancer cells, especially against chemotherapy-induced drug-resistant senescent cancer cells. In the present study, Fe3O4 NPs in situ coated by dextran (Fe3O4@Dex) and glucosamine-based amorphous carbon coating (Fe3O4@aC) with potent reductive activity were characterized and tested against drug-induced senescent breast cancer cells (Hs 578T, BT-20, MDA-MB-468, and MDA-MB-175-VII cells). Fe3O4@aC caused a decrease in reactive oxygen species (ROS) production and an increase in the levels of antioxidant proteins FOXO3a, SOD1, and GPX4 that was accompanied by elevated levels of cell cycle inhibitors (p21, p27, and p57), proinflammatory (NFκB, IL-6, and IL-8) and autophagic (BECN1, LC3B) markers, nucleolar stress, and subsequent apoptotic cell death in etoposide-stimulated senescent breast cancer cells. Fe3O4@aC also promoted reductive stress-mediated cytotoxicity in nonsenescent breast cancer cells. We postulate that Fe3O4 NPs, in addition to their well-established hyperthermia and oxidative stress-mediated anticancer effects, can also be considered, if modified using amorphous carbon coating with reductive activity, as stimulators of reductive stress and cytotoxic effects in both senescent and nonsenescent breast cancer cells with different gene mutation statuses.

Targeting PI3K/Akt in Cerebral Ischemia Reperfusion Injury Alleviation: From Signaling Networks to Targeted Therapy.

Ischemia/reperfusion (I/R) injury is a pathological event that results in reperfusion due to low blood flow to an organ. Cerebral ischemia is a common cerebrovascular disease with high mortality, and reperfusion is the current standard intervention. However, reperfusion may further induce cellular damage and dysfunction known as cerebral ischemia/reperfusion injury (CIRI). Currently, strategies for the clinical management of CIRI are limited, necessitating the exploration of novel and efficacious treatment modalities for the benefit of patients. PI3K/Akt signaling pathway is an important cellular process associated with the disease. Stimulation of the PI3K/Akt pathway enhances I/R injury in multiple organs such as heart, brain, lung, and liver. It stands as a pivotal signaling pathway crucial for diminishing cerebral infarction size and safeguarding the functionality of brain tissue after CIRI. During CIRI, activation of the PI3K/Akt pathway exhibits a protective effect on CIRI. Furthermore, activation of the PI3K/Akt pathway has the potential to augment the activity of antioxidant enzymes, resulting in a decrease in reactive oxygen species (ROS) and the associated oxidative stress. Meanwhile, PI3K/Akt plays a neuroprotective role by inhibiting inflammatory responses and apoptosis. For example, PI3K/Akt interacts with NF-κB, Nrf2, and MAPK signaling pathways to mitigate CIRI. This article is aimed to explore the pivotal role and underlying mechanism of PI3K/Akt in ameliorating CIRI and investigate the influence of ischemic preconditioning and post-processing, as well as the impact of pertinent drugs or activators targeting the PI3K/Akt pathway on CIRI. The primary objective is to furnish compelling evidence supporting the activation of PI3K/Akt in the context of CIRI, elucidating its mechanistic intricacies. By doing so, the paper aims to underscore the critical contribution of PI3K/Akt in mitigating CIRI, providing a theoretical foundation for considering the PI3K/Akt pathway as a viable target for CIRI treatment.

The link between neutrophils, neutrophil extracellular traps, and NLRP3 inflammasomes: The dual effect of CD177 and its therapeutic potential in acute respiratory distress syndrome/acute lung injury.

Neutrophils are important inflammatory effector cells that protect against foreign invasion but also cause self-harm. Numerous neutrophils infiltrate the lungs in acute respiratory distress syndrome/acute lung injury (ARDS/ALI) patients. However, the exact impact of neutrophil infiltration on ARDS's onset and progression remains unclear. To investigate this, we analyzed two ARDS-related datasets from the Gene Expression Omnibus public database and discovered an association between CD177, a neutrophil-specific surface protein, and ARDS progression. We used quantitative flow cytometry to assess CD177+ neutrophils in the peripheral blood of clinical ARDS patients versus healthy controls, finding a significant increase in CD177+ neutrophils percentage among total neutrophils in ARDS patients. This finding was further confirmed in ALI mouse models. Subsequent animal experiments showed that anti-CD177 effectively reduces pulmonary edema, neutrophil infiltration, and inflammatory cytokine release, along with a decrease in reactive oxygen species (ROS) and myeloperoxidase (MPO) levels. We also established an in vitro co-culture system to mimic neutrophil and lung epithelial cell interactions. In the anti-CD177 group, we observed decreased expression of NLRP3, caspase 1, PAD4, MPO, and ROS, along with a reduction in certain inflammatory cytokines. These results indicate a crucial role for the CD177 gene in ARDS's development and progression. Inhibiting CD177 may help mitigate excessive activation of NLRP3 inflammasomes, ROS, and neutrophil extracellular traps (NETs), thus alleviating ARDS.

Diosmin ameliorates LPS-induced depression-like behaviors in mice: Inhibition of inflammation and oxidative stress in the prefrontal cortex

Diosmin is a flavone glycoside with a confirmed therapeutic effectiveness on the chronic venous disorders. In this paper, the classical mouse depression model induced by LPS was established to explore the effect of Diosmin on depression. Firstly, we found that Diosmin could inhibit the inflammation and neuronal damage in the prefrontal cortex (PFC) of mice, and thus alleviating the LPS-induced depressive-like behaviors. Specifically, Diosmin treatment significantly suppressed the secretion of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β), reduced the activation of microglia, and inhibited the expression of NLRP3 inflammasome and its downstream effector caspase-1 in both PFC of mice and BV2 microglial cells exposed to LPS. Then, we demonstrated that pretreatment with Diosmin dramatically suppressed the LPS-induced oxidative stress in the PFC of mice, manifested in the decrease of reactive oxygen species and malondialdehyde while increase of catalase activity. Consistently, Diosmin also alleviated the oxidative stress in BV2 cells exposed to LPS. Finally, we confirmed that Diosmin effectively suppressed the activation of NF-κB signaling pathway in the PFC of LPS-treated mice. Further in vitro experiments also verified that Diosmin could prevent the p65 transposition to nucleus in LPS-treated BV2 cells, suggesting that the antidepressant effects of Diosmin are partially mediated by blocking of NF-κB signaling. Taken together, this study proposes the potential antidepressant effect of Diosmin, which provides useful support to the development of new therapies for depression.

Allene oxide synthase 1 contributes to limiting grain arsenic accumulation and seedling detoxification in rice

Arsenic (As) is a cancerogenic metalloid ubiquitously distributed in the environment, which can be easily accumulated in food crops like rice. Jasmonic acid (JA) and its derivatives play critical roles in plant growth and stress response. However, the role of endogenous JA in As accumulation and detoxification is still poorly understood. In this study, we found that JA biosynthesis enzymes Allene Oxide Synthases, OsAOS1 and OsAOS2, regulate As accumulation and As tolerance in rice. Evolutionary bioinformatic analysis indicated that AOS1 and AOS2 have evolved from streptophyte algae (e.g. the basal lineage Klebsormidium flaccidum) – sister clade of land plants. Compared to other two AOSs, OsAOS1 and OsAOS2 were highly expressed in all examined rice tissues and their transcripts were highly induced by As in root and shoot. Loss-of-function of OsAOS1 (osaos1–1) showed elevated As concentration in grains, which was likely attributed to the increased As translocation from root to shoot when the plants were subjected to arsenate [As(V)] but not arsenite [As (III)]. However, the mutation of OsAOS2 (osaos2–1) showed no such effect. Moreover, osaos1–1 and osaos2–1 increased the sensitivity of rice plants to both As(V) and As(III). Disrupted expression of genes involved in As accumulation and detoxification, such as OsPT4, OsNIP3;2, and OsOASTL-A1, was observed in both osaos1–1 and osaos2–1 mutant lines. In addition, a As(V)-induced significant decrease in Reactive Oxygen Species (ROS) production was observed in the root of osaos1–1 but not in osaos2–1. Taken together, our results indicate OsAOS1 modulates both As allocation and detoxification, which could be partially attributed to the altered gene expression profiling and ROS homeostasis in rice while OsAOS2 is important for As tolerance.

Preclinical and Clinical Use of AB1, a DNMT1 Protein Depleter, to Upregulate Fetal Hemoglobin in Townes Sickle Cell Disease (SCD) Mice and Patients with SCD

Background: Sickle Cell Disease (SCD) is an inherited hematologic disorder characterized by lifelong hemolysis, vaso-occlusion and severe complications including pain, acute chest syndrome and stroke among others. Its complex pathophysiology is driven by polymerization of mutated sickle hemoglobin (HbS) in red blood cells. Fetal hemoglobin (HbF) has been well documented to interfere with HbS polymerization, however, γ-globin gene transcription is silenced after birth through the action of a repressor complex including DNA methyltransferase 1 (DNMT1) during hemoglobin switching. We previously demonstrated the ability of AB1, a potent non-cytotoxic agent which depletes DNMT1 protein, to induce HbF in sickle erythroid progenitors. To expand these findings, we aimed to 1) perform preclinical studies in the Townes SCD mouse model to determine the ability of AB1 to induce HbF and deplete DNMT1 protein; and 2) evaluate the safety of oral AB1 in patients with SCD through an open-label, dose escalating phase 1/2 study (NCT05261711). Methods: Preclinical. Townes SCD mice, 4 months old (6 mice per group) were treated by intraperitoneal injections of escalating AB1 doses of 0.5, 1.5 and 3.0 mg/dose, hydroxyurea (HU; 100 mg/kg/dose) alone or HU combined with AB1 (0.5mg/dose) and water control, 5 days/week for 6 weeks. Every 2 weeks, complete blood counts with differentials were performed along with flow cytometry for HbF positive cells (F-cells) and reticulocytes; RT-qPCR for γ- and β-globin mRNA levels was completed and the spleen was harvested for weights and DNMT1 protein levels by Western blot. Clinical Trial. After informed consent, patients with confirmed HbSS or HbSb 0 thalassemia, on stable HU doses (if on treatment), and no recent/chronic transfusions or pain crisis were approached for the study. Patients were enrolled at Duke and Augusta University, starting on 2 mg of AB1 with 4 additional cohorts (4mg, 8mg, 16mg, and 32mg) to be recruited. Doses were taken daily by mouth for 8 weeks. Safety and tolerability (primary outcomes), as well as pharmacokinetics, pharmacodynamics and HbF response (secondary outcomes) were assessed. The F-cells and mean fluorescence intensity were measured by flow cytometry and HbF% by HPLC. Results: Preclinical. In general, SCD mice treated with AB1 showed good weight gain without toxicity. Three deaths occurred in the HU and combination treatment groups along with a significant decrease in platelets, granulocytes, and monocytes; by contrast, one death occurred in the 3mg/kg AB1 group, but the blood or reticulocyte counts were not affected. By week 6, HU increased F-cells by 2.1-fold (p=0.02) compared to a 2.2-fold (p=0.006) and 1.5-fold (p=0.03) increase by AB1 1.5mg/kg and 3.0 mg/kg respectively. Likewise, γ-globin mRNA increased, and β-globin mRNA decreased at the highest dose. Spleen analysis showed decreased weights and an 80% decrease in reactive oxygen species by AB1. Finally, DNMT1 protein levels were depleted by AB1 in spleen tissue. Clinical Trial. The clinical trial opened for enrollment in the winter of 2022. Two patients completed cohort 1 and two patients have enrolled and started cohort 2. Both cohort 1 patients had HbSS with a median age of 29.5 years (range 28-31). No change in total hemoglobin or reticulocyte counts was observed in either subject treated with 2mg AB1 daily. During the treatment period two adverse events occurred (rash-drug related and elevated liver enzymes-unrelated), however there were no serious adverse events. AB1 increased F-cell levels in subject 1 by 5.7-fold (2.9% to 16.4%). Expanded analysis of subject 2 showed an increase in F-cells 3-fold (4.8% to 14.4%) and 3-fold increase in F-reticulocytes. At the lowest 2mg dose, by HPLC analysis both patients had an increase in HbF% from a mean of 6.3% to 7% supporting protein induction by AB1. Discussion: The goal of this project is to develop an oral-active HbF inducer for the treatment of individuals with SCD. Data generated in the SCD mouse showed a significant increase in F-cells and γ-globin gene transcription, along with DNMT1 protein depletion. Subsequent oral AB1 treatment of patients with HbSS confirmed increased F-cells and HbF protein levels without clinical toxicities. These findings support continuing the ongoing phase 1/2 study, which will provide further insights into the ability of AB1 to increase HbF without hematologic side effects in patients with SCD.

Caffeine Produced in Rice Plants Provides Tolerance to Water-Deficit Stress.

Exogenous or endogenous caffeine application confers resistance to diverse biotic stresses in plants. In this study, we demonstrate that endogenous caffeine in caffeine-producing rice (CPR) increases tolerance even to abiotic stresses such as water deficit. Caffeine produced by CPR plants influences the cytosolic Ca2+ ion concentration gradient. We focused on examining the expression of Ca2+-dependent protein kinase genes, a subset of the numerous proteins engaged in abiotic stress signaling. Under normal conditions, CPR plants exhibited increased expressions of seven OsCPKs (OsCPK10, OsCPK12, OsCPK21, OsCPK25, OsCPK26, OsCPK30, and OsCPK31) and biochemical modifications, including antioxidant enzyme (superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase) activity and non-enzymatic antioxidant (ascorbic acid) content. CPR plants exhibited more pronounced gene expression changes and biochemical alterations in response to water-deficit stress. CPR plants revealed increased expressions of 16 OsCPKs (OsCPK1, OsCPK2, OsCPK3, OsCPK4, OsCPK5, OsCPK6, OsCPK9, OsCPK10, OsCPK11, OsCPK12, OsCPK14, OsCPK16, OsCPK18, OsCPK22, OsCPK24, and OsCPK25) and 8 genes (OsbZIP72, OsLEA25, OsNHX1, OsRab16d, OsDREB2B, OsNAC45, OsP5CS, and OsRSUS1) encoding factors related to abiotic stress tolerance. The activity of antioxidant enzymes increased, and non-enzymatic antioxidants accumulated. In addition, a decrease in reactive oxygen species, an accumulation of malondialdehyde, and physiological alterations such as the inhibition of chlorophyll degradation and the protection of photosynthetic machinery were observed. Our results suggest that caffeine is a natural chemical that increases the potential ability of rice to cope with water-deficit stress and provides robust resistance by activating a rapid and comprehensive resistance mechanism in the case of water-deficit stress. The discovery, furthermore, presents a new approach for enhancing crop tolerance to abiotic stress, including water deficit, via the utilization of a specific natural agent.

Spermidine Suppresses Oral Carcinogenesis through Autophagy Induction, DNA Damage Repair, and Oxidative Stress Reduction

Autophagy has been proposed to play a dual role in cancer-as a tumor suppressor in early stages and oncogenicin late stages of tumorigenesis. This study investigated the role of autophagy in oral carcinogenesis using the model of oral squamous cell carcinoma (OSCC) induced by carcinogen 4-nitroquinoline 1-oxide (4NQO), mimicking molecular and histopathologic aspects of human OSCC. The induction of autophagy by spermidine (SPD) treatment reduced the severity of lesions and the incidence of OSCC in mice exposed to 4NQO. On the other hand, autophagy inhibition by chloroquine treatment had no protection. The comet assay indicated that SPD reduced 4NQO-induced DNA damage, likely related to the activation of DNA repair and the decrease of reactive oxygen species. As sphingolipid alterations have been reported in OSCC, sphingolipids in the tongue and plasma of animals were analyzed and plasma C16 ceramide levels were shown to increase proportionally to lesion severity, indicating its potential as a biomarker. Mice exposed to 4NQO plus SPD had lower levels of C16 ceramide than the 4NQO group, which indicated SPD's ability to prevent the 4NQO-induced carcinogenesis. Together, these data indicate that activation of autophagy has a tumor suppressor role during the early stages of oral carcinogenesis. Because of its ability to induce autophagy accompanied by reduced oxidative stress and DNA damage, SPD may have a protective action against chemically induced oral cancer.

Enantioselectivity in the Ecotoxicity of Amphetamine Using Daphnia magna as the Aquatic Model Organism: Morphophysiological, Behavioral, Reproductive and Biochemical Parameters.

Amphetamine (AMP) is a chiral psychoactive substance that exhibits enantioselectivity in its pharmacological properties. It has been detected in wastewaters and surface waters and can occur as enantiomeric mixtures, but little is known about its environmental risk and potential enantioselective toxicity to aquatic organisms. Our study aimed to target enantioselectivity in AMP toxicity to the freshwater invertebrate Daphnia magna. Daphnids were subchronically exposed to the racemate (rac-AMP: 0.1, 1.0, and 10 µg/L) and pure enantiomers, (R)-AMP and (S)-AMP (0.1, and 1.0 µg/L, respectively), for 8 days. Morphophysiological, swimming behavior, reproductive and biochemical variables were evaluated during critical life stages (juveniles vs. adults). Some responses were context-dependent and often enantioselective, varying between racemate and enantiomers and across the life stage of the organisms. Overall, rac-AMP stimulated D. magna growth, decreased heart rate and area, affected behavior, and stimulated reproduction. The effect of enantiomers was totally or partially concordant with rac-AMP, except for swimming behavior and reproduction. Enantioselectivity was observed for body size, number of eggs/daphnia, and heart rate (steeper decrease caused by (R)-AMP on day 3). Changes in biochemical parameters were also observed: AMP caused a significant decrease in catalase activity as racemate or pure enantiomers, whereas a decrease in acetylcholinesterase activity was found only for rac-AMP. Evidence for oxidative stress was contradictory, although both enantiomers caused a significant decrease in reactive oxygen species (unlike rac-AMP). Overall, these results show that AMP can interfere in an enantioselective way with aquatic organisms at low concentrations (e.g., 0.1 µg/L), demonstrating the relevance of this kind of study to an accurate environmental risk assessment regarding medium- to long-term exposure to this psychoactive drug. Environ Toxicol Chem 2023;00:1-13. © 2023 SETAC.

Phosphoinositide and redox dysregulation by the anticancer methylthioadenosine phosphorylase transition state inhibitor

Methylthio-DADMe-immucillin-A (MTDIA) is an 86 picomolar inhibitor of 5′-methylthioadenosine phosphorylase (MTAP) with potent and specific anti-cancer efficacy. MTAP salvages S-adenosylmethionine (SAM) from 5′-methylthioadenosine (MTA), a toxic metabolite produced during polyamine biosynthesis. Changes in MTAP expression are implicated in cancer growth and development, making MTAP an appealing target for anti-cancer therapeutics. Since SAM is involved in lipid metabolism, we hypothesised that MTDIA alters the lipidomes of MTDIA-treated cells. To identify these effects, we analysed the lipid profiles of MTDIA-treated Saccharomyces cerevisiae using ultra-high resolution accurate mass spectrometry (UHRAMS). MTAP inhibition by MTDIA, and knockout of the Meu1 gene that encodes for MTAP in yeast, caused global lipidomic changes and differential abundance of lipids involved in cell signaling. The phosphoinositide kinase/phosphatase signaling network was specifically impaired upon MTDIA treatment, and was independently validated and further characterised via altered localization of proteins integral to this network. Functional consequences of dysregulated lipid metabolism included a decrease in reactive oxygen species (ROS) levels induced by MTDIA that was contemporaneous with changes in immunological response factors (nitric oxide, tumour necrosis factor-alpha and interleukin-10) in mammalian cells. These results indicate that lipid homeostasis alterations and concomitant downstream effects may be associated with MTDIA mechanistic efficacy.

Guided Metabolic Detoxification Program Supports Phase II Detoxification Enzymes and Antioxidant Balance in Healthy Participants.

Adequate antioxidant supply is essential for maintaining metabolic homeostasis and reducing oxidative stress during detoxification. The emerging evidence suggests that certain classes of phytonutrients can help support the detoxification process by stimulating the liver to produce detoxification enzymes or acting as antioxidants that neutralize the harmful effects of free radicals. This study was designed to examine the effects of a guided 28-day metabolic detoxification program in healthy adults. The participants were randomly assigned to consume a whole food, multi-ingredient supplement (n = 14, education and intervention) or control (n = 18, education and healthy meal) daily for the duration of the trial. The whole food supplement contained 37 g/serving of a proprietary, multicomponent nutritional blend in the form of a rehydratable shake. Program readiness was ensured at baseline using a validated self-perceived wellness score and a blood metabolic panel, indicating stable emotional and physical well-being in both groups. No significant changes or adverse effects were found on physical or emotional health, cellular glutathione (GSH) and the GSH:GSSG ratio, porphyrin, and hepatic detoxification biomarkers in urine. The intervention was positively associated with a 23% increase in superoxide dismutase (p = 0.06) and a 13% increase in glutathione S-transferase (p = 0.003) activities in the blood. This resulted in a 40% increase in the total cellular antioxidant capacity (p = 0.001) and a 13% decrease in reactive oxygen species (p = 0.002) in isolated PBMCs from participants in the detoxification group. Our findings indicate that consuming a whole food nutritional intervention as a part of the guided detoxification program supported phase II detoxification, in part, by promoting enhanced free radical scavenging and maintaining redox homeostasis under the body's natural glutathione recycling capacity.

Mesenchymal Stem Cell-Derived Extracellular Vesicles Protect Rat Nucleus Pulposus Cells from Oxidative Stress.

Oxidative stress (OS) is mainly associated with the pathogenesis of intervertebral disc (IVD) degeneration; it causes nucleus pulposus cells (NPCs) to undergo senescence and triggers autophagy and apoptosis. This study aims to evaluate the regeneration potential of extracellular vesicles (EVs) derived from human umbilical cord-mesenchymal stem cells (hUC-MSCs) in an in vitro rat NPC-induced OS model. NPCs were isolated from rat coccygeal discs, propagated, and characterized. OS was induced by hydrogen peroxide (H2O2), which is confirmed by 2,7-dichlorofluorescein diacetate (H2DCFDA) assay. EVs were isolated from hUC-MSCs and characterized by analyzing the vesicles using fluorescence microscope, scanning electron microscope (SEM), atomic force microscope (AFM), dynamic light scattering (DLS), and Western blot (WB). The in vitro effects of EVs on migration, uptake, and survival of NPCs were determined. SEM and AFM topographic images revealed the size distribution of EVs. The phenotypes of isolated EVs showed that the size of EVs was 403.3 ± 85.94 nm, and the zeta potential was -0.270 ± 4.02 mV. Protein expression analysis showed that EVs were positive for CD81 and annexin V. Treatment of NPCs with EVs reduced H2O2-induced OS as evidenced by a decrease in reactive oxygen species (ROS) levels. Co-culture of NPCs with DiI-labeled EVs showed the cellular internalization of EVs. In the scratch assay, EVs significantly increased NPC proliferation and migration toward the scratched area. Quantitative polymerase chain reaction analysis showed that EVs significantly reduced the expression of OS genes. EVs protected NPCs from H2O2-induced OS by reducing intracellular ROS generation and improved NPC proliferation and migration.

Mitochondrial transfer from bone mesenchymal stem cells protects against tendinopathy both in vitro and in vivo

BackgroundAlthough mesenchymal stem cells (MSCs) have been effective in tendinopathy, the mechanisms by which MSCs promote tendon healing have not been fully elucidated. In this study, we tested the hypothesis that MSCs transfer mitochondria to injured tenocytes in vitro and in vivo to protect against Achilles tendinopathy (AT).MethodsBone marrow MSCs and H2O2-injured tenocytes were co-cultured, and mitochondrial transfer was visualized by MitoTracker dye staining. Mitochondrial function, including mitochondrial membrane potential, oxygen consumption rate, and adenosine triphosphate content, was quantified in sorted tenocytes. Tenocyte proliferation, apoptosis, oxidative stress, and inflammation were analyzed. Furthermore, a collagenase type I-induced rat AT model was used to detect mitochondrial transfer in tissues and evaluate Achilles tendon healing.ResultsMSCs successfully donated healthy mitochondria to in vitro and in vivo damaged tenocytes. Interestingly, mitochondrial transfer was almost completely blocked by co-treatment with cytochalasin B. Transfer of MSC-derived mitochondria decreased apoptosis, promoted proliferation, and restored mitochondrial function in H2O2-induced tenocytes. A decrease in reactive oxygen species and pro-inflammatory cytokine levels (interleukin-6 and -1β) was observed. In vivo, mitochondrial transfer from MSCs improved the expression of tendon-specific markers (scleraxis, tenascin C, and tenomodulin) and decreased the infiltration of inflammatory cells into the tendon. In addition, the fibers of the tendon tissue were neatly arranged and the structure of the tendon was remodeled. Inhibition of mitochondrial transfer by cytochalasin B abrogated the therapeutic efficacy of MSCs in tenocytes and tendon tissues.ConclusionsMSCs rescued distressed tenocytes from apoptosis by transferring mitochondria. This provides evidence that mitochondrial transfer is one mechanism by which MSCs exert their therapeutic effects on damaged tenocytes.

Versatile Platinum(IV) Prodrugs of Naproxen and Acemetacin as Chemo-Anti-Inflammatory Agents.

Developing new and versatile platinum(IV) complexes that incorporate bioactive moieties is a rapidly evolving research strategy for cancer drug discovery. In this study, six platinum(IV) complexes (1-6) that are mono-substituted in the axial position with a non-steroidal anti-inflammatory molecule, naproxen or acemetacin, were synthesised. A combination of spectroscopic and spectrometric techniques confirmed the composition and homogeneity of 1-6. The antitumour potential of the resultant complexes was assessed on multiple cell lines and proved to be significantly improved compared with cisplatin, oxaliplatin and carboplatin. The platinum(IV) derivatives conjugated with acemetacin (5 and 6) were determined to be the most biologically potent, demonstrating GI50 values ranging between 0.22 and 250 nM. Remarkably, in the Du145 prostate cell line, 6 elicited a GI50 value of 0.22 nM, which is 5450-fold more potent than cisplatin. A progressive decrease in reactive oxygen species and mitochondrial activity was observed for 1-6 in the HT29 colon cell line, up to 72 h. The inhibition of the cyclooxygenase-2 enzyme was also demonstrated by the complexes, confirming that these platinum(IV) complexes may reduce COX-2-dependent inflammation and cancer cell resistance to chemotherapy.

Abstract 2334: Reprogramming M2-like tumor associated macrophages using a natural compound, glycyrrhizin, as a potential therapeutic strategy against prostate cancer

Abstract Tumor Associated Macrophages (TAMs), copiously found in the Tumor Microenvironment (TME) are key players in creating an immunosuppressive environment, increasing angiogenesis and metastasis in prostate cancer (PCa). They are plastic in nature and usually exist as, M1 (anti-tumorigenic) or M2 (pro-tumorigenic) phenotype, with relative abundance of M2. In this study, we aimed to explore the phenotypic effects of TAMs on PCa and investigate the potential of glycyrrhizin, a natural compound, to reprogram M2 TAMs, as a feasible treatment approach against PCa. THP-1 monocytes and RAW 264.7 were used to study macrophage differentiation and glycyrrhizin-mediated repolarization. THP-1 cells were cultured in conditioned media (CM) of LNCaP and BPH-Cd to obtain PCa associated macrophages. Flow cytometric analysis revealed increase in expression of surface markers CD32, CD64, CD206 and CD163 confirming M1/M2 differentiation. qPCR analysis also demonstrated upregulation of CD80, CD86, CD68, TGF-β and IL10. M2 markers such as CD68, CD163, CCL2, CCL5 and TGF-β were expressed in BPH-Cd TAMs. LNCaP TAMs also co-expressed CD68 and CD163. In spheroid assay on BPH-Cd cells, treatment with BPH-Cd TAM resulted in abnormally shaped, enlarged spheroids. Furthermore, the CM enhanced migration of BPH-Cd cells in transwell migration assay and downregulated P21 in western blot analysis, thus confirming its tumor-promoting role. MTT assay performed prior to studying the polarization potential of glycyrrhizin showed an increase in viability of glycyrrhizin-treated THP-1 and RAW 264.7 and selectively promoted viability in M1. The M1-polarizing properties of glycyrrhizin was revealed in the qPCR analysis of glycyrrhizin-treated M0 macrophages. The reduction in the size of the spheroids and decreased migration of BPH-Cd upon treatment with glycyrrhizin-treated M0 CM confirmed the same. Differentiation media (DM) of glycyrrhizin-treated M2 TAMs resulted in smaller, disintegrated BPH-Cd spheroids indicating possible reprogramming effect. Interestingly, glycyrrhizin-treated M2 CM downregulated the gene expression of stemness-associated markers such as NANOG, SNAIL, OCT3/4 and COX2 with concurrent suppression of EMT marker, N-Cadherin in LNCaP cells. Cell cycle analysis on LNCaP revealed a decrease in the percentage of cells in S phase compared to glycyrrhizin-treated M2 CM, suggesting hindered proliferation. A notable observation to help understand the plausible mechanism of M2 TAM suppression was the decrease in Reactive Oxygen Species (ROS) levels in glycyrrhizin-treated M1 and M2 TAMs derived from THP-1 cells. The glycyrrhizin-mediated inhibition of ROS was also confirmed in RAW 264.7. In conclusion, our findings suggest that glycyrrhizin could potentially reprogram TAMs to intercept proliferation, metastasis and stemness characteristics in PCa. Citation Format: Amy Thomas, Gnanasekar Munirathinam. Reprogramming M2-like tumor associated macrophages using a natural compound, glycyrrhizin, as a potential therapeutic strategy against prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2334.

Effects of Date Palm Pollen Supplementations on The Expression of PRDX1 and PRDX6 Genes in Infertile Men: A Controlled Clinical Trial.

Accumulating evidences suggest that date palm pollen (DPP) induces antioxidant activity and improves semen parameters in male rats. However, there is a few scientific evidences in support of the DPP effects on human male fertility. Hence, the effect of oral consumption of DPP on sperm parameters and expression pattern of Peroxiredoxin- 1 (PRDX1) and Peroxiredoxin-6 (PRDX6) genes was evaluated in men with infertility. The current controlled clinical trial included 40 men with infertility (DPP group) and 10 normospermic fertile men as controls. The DPP group received gelatinous capsules of DPP (400 mg/kg) for 74 days. Semen sampling was done before and after treatment in the both groups. Semen analysis and 8-isoprostane concentration assessments were performed by computer-assisted sperm analysis and ELISA methods, respectively. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays were employed to explore expression of PRDX1 and PRDX6 genes. DPP consumption significantly improved semen volume (P=0.030), count (P<0.001) and morphology of sperm (P=0.023). Concentration of 8-isoprostane was significantly decreased after intervention in the DPP group (P<0.001). DPP consumption led to a significant elevation in the expression of PRDX1 and PRDX6 genes (P<0.001). Elevated gene expression of PRDX6 and PRDX1 was positively correlated with improved parameters of sperm including count, volume, motility and morphology. Taken together, DPP seems to promote sperm quality through a decrease in reactive oxygen species (ROS) by increasing expression of antioxidant genes. Further large-scale studies are required to challenge this hypothesis (registration number: IRCT2015021221014N2).

Low-density lipoprotein balances T cell metabolism and enhances response to anti-PD-1 blockade in a HCT116 spheroid model.

The discovery of immune checkpoints and the development of their specific inhibitors was acclaimed as a major breakthrough in cancer therapy. However, only a limited patient cohort shows sufficient response to therapy. Hence, there is a need for identifying new checkpoints and predictive biomarkers with the objective of overcoming immune escape and resistance to treatment. Having been associated with both, treatment response and failure, LDL seems to be a double-edged sword in anti-PD1 immunotherapy. Being embedded into complex metabolic conditions, the impact of LDL on distinct immune cells has not been sufficiently addressed. Revealing the effects of LDL on T cell performance in tumor immunity may enable individual treatment adjustments in order to enhance the response to routinely administered immunotherapies in different patient populations. The object of this work was to investigate the effect of LDL on T cell activation and tumor immunity in-vitro. Experiments were performed with different LDL dosages (LDLlow = 50 μg/ml and LDLhigh = 200 μg/ml) referring to medium control. T cell phenotype, cytokines and metabolism were analyzed. The functional relevance of our findings was studied in a HCT116 spheroid model in the context of anti-PD-1 blockade. The key points of our findings showed that LDLhigh skewed the CD4+ T cell subset into a central memory-like phenotype, enhanced the expression of the co-stimulatory marker CD154 (CD40L) and significantly reduced secretion of IL-10. The exhaustion markers PD-1 and LAG-3 were downregulated on both T cell subsets and phenotypical changes were associated with a balanced T cell metabolism, in particular with a significant decrease of reactive oxygen species (ROS). T cell transfer into a HCT116 spheroid model resulted in a significant reduction of the spheroid viability in presence of an anti-PD-1 antibody combined with LDLhigh. Further research needs to be conducted to fully understand the impact of LDL on T cells in tumor immunity and moreover, to also unravel LDL effects on other lymphocytes and myeloid cells for improving anti-PD-1 immunotherapy. The reason for improved response might be a resilient, less exhausted phenotype with balanced ROS levels.

Taraxasterol alleviates fatty acid-induced lipid deposition in calf hepatocytes by decreasing ROS production and endoplasmic reticulum stress.

Increased concentrations of free fatty acids (FFAs) induce reactive oxygen species (ROSs) generation and endoplasmic reticulum (ER) stress, thus, increasing the risk of fatty liver in dairy cows during the periparturient period. In non-ruminants, Taraxasterol (Tara; a pentacyclic triterpenoid found in medicinal plants) plays an important role in anti-inflammatory and antioxidant reactions. Whether Tara can alleviate or prevent fatty liver in ruminants is unknown. We addressed whether Tara supply could dampen lipid accumulation, ROSs production, and ER stress caused by FFAs in calf hepatocytes. Primary calf hepatocytes were isolated from five healthy calves (1 d old, female, 30-40 kg, fasting, rectal temperature 38.7-39.7 °C). In the first experiment, hepatocytes were incubated with various concentrations of Tara (2.5, 5, and 10 μg/mL) for 12 h prior to the 1.2-mM FFAs challenge. Results indicated that the level of ROSs was lowest with 5 μg/mL Tara. Thus, to further characterize the molecular mechanisms whereby Tara protects from FFAs-induced lipid deposition in calf hepatocytes, we performed incubations with 5 μg/mL Tara for 12 h prior to a 1.2-mM FFAs challenge for an additional 12 h. Results indicated that 1.2-mM FFAs challenge increased mitochondrial membrane potential (MMP), enhanced expression of proteins and mRNA associated with ER stress (PERK, IRE1, GRP78, ATF6, and CHOP) and fatty acid synthesis (FASN, ACC1, and SREBP-1c), and ultimately led to increased lipid droplet synthesis. In contrast, Tara treatment alleviated these negative effects after 1.2-mM FFAs challenge. To determine whether Tara protects against FFAs-induced lipid droplet synthesis by alleviating oxidative stress, hepatocytes were treated with 5 μg/mL Tara for 22 h prior to H2O2 (440 μM) challenge for 2 h. Compared with H2O2 treatment alone, results revealed a marked decrease in ROSs, MMP, and protein abundance of ER stress (GRP78, ATF6, and CHOP) and lipid droplet synthesis in response to Tara prior to H2O2 challenge. Data suggested that the increase in mitochondrial ROSs production contributes to lipid accumulation in calf hepatocytes. Collectively, our in vitro data indicate that Tara alleviates fatty acid-induced lipid deposition. Further research is warranted to ascertain that Tara can be helpful in the therapeutic management of early lactating cows to control or alleviate excessive hepatic lipid deposition.

Leucine Contributes to Copper Stress Tolerance in Peach (Prunus persica) Seedlings by Enhancing Photosynthesis and the Antioxidant Defense System.

Heavy metal contamination has a severe impact on ecological health and plant growth and is becoming increasingly serious globally. Copper (Cu) is a heavy metal that is essential for the growth and development of plants, including peach (Prunus persica L. Batsch); however, an excess is toxic. In plants, amino acids are involved in responses to abiotic and biotic stresses, such as water deficit, extreme temperatures, high salinity, and heavy metal stress. However, the role of leucine in the regulation of heavy metal stress is currently unclear. Therefore, we investigated the effects of exogenous leucine on the growth of peach seedlings under Cu stress. Exogenous leucine improved the leaf ultrastructure and ionic balance and increased the chlorophyll content, the net photosynthetic rate, and the maximum photochemical efficiency. Furthermore, it attenuated Cu-stress-induced oxidative damage via a decrease in reactive oxygen species (ROS) and the regulation of the antioxidant and osmotic systems. These effects, in turn, ameliorated the reductions in cell viability, cellular activity, and biomass under Cu stress. Moreover, exogenous leucine increased the activities of nitrate reductase (NR), glutamine synthetase (GS), and glutamic acid synthetase (GOGAT) and thus improved the nitrogen metabolism efficiency of plants. In conclusion, leucine significantly improved the photosynthetic performance and antioxidant capacity, reduced Cu accumulation, and promoted nitrogen metabolism, which in turn improved the resistance of peach seedlings to Cu stress.