Reactive Oxygen Species Function Research Articles

Sol Gel obtained Ti/Co/Mn oxides doped with 5wt% CuO for the photocatalytic removal of organic azo dyes from wastewater

Various organic pollutants continually poison natural water resources due to rapid modernization driven by industrial growth. As a result, communities throughout the globe are paying close attention to the health and environmental issues raised by these harmful organic pollutants. Here, we prepared TiO2-CuO(5wt%), TiO2-CuO(5wt%)@Co3O4, and TiO2-CuO(5wt%)@Mn2O3 photocatalysts by employing the sol-gel method for the photocatalytic removal of azo dyes. These composites' surface morphology, composition, band gap, and purity were analyzed using SEM, EDS, TEM/HRTEM, XRD, FTIR, Raman, XPS, DRS, and BET measurements. The 5 % CuO doping caused a significant change in the electronic structure of the composites and contributed to the superior photocatalytic performance of the composites against azo dyes at neutral pH and under visible light irradiation. The function of reactive oxygen species (ROS) was also studied using different scavengers and enhancers; •OH was found to be the main ROS for the photodegradation of azo dyes.

Antioxidant Systems of Plant Pathogenic Fungi: Functions in Oxidative Stress Response and Their Regulatory Mechanisms.

During the infection process, plant pathogenic fungi encounter plant-derived oxidative stress, and an appropriate response to this stress is crucial to their survival and establishment of the disease. Plant pathogenic fungi have evolved several mechanisms to eliminate oxidants from the external environment and maintain cellular redox homeostasis. When oxidative stress is perceived, various signaling transduction pathways are triggered and activate the downstream genes responsible for the oxidative stress response. Despite extensive research on antioxidant systems and their regulatory mechanisms in plant pathogenic fungi, the specific functions of individual antioxidants and their impacts on pathogenicity have not recently been systematically summarized. Therefore, our objective is to consolidate previous research on the antioxidant systems of plant pathogenic fungi. In this review, we explore the plant immune responses during fungal infection, with a focus on the generation and function of reactive oxygen species. Furthermore, we delve into the three antioxidant systems, summarizing their functions and regulatory mechanisms involved in oxidative stress response. This comprehensive review provides an integrated overview of the antioxidant mechanisms within plant pathogenic fungi, revealing how the oxidative stress response contributes to their pathogenicity.

Molecular Plant Physiology for Model Plants under Abiotic Stress Conditions

Extreme temperatures, drought, and high soil salinity are some of the significant abiotic stresses that can severely impact crop yields, posing a threat to global food production. Comprehensive studies on model plant species are crucial for understanding their biochemical, physiological, and molecular responses to abiotic stresses. Identifying stress response mechanisms and potential targets can aid in developing stress-tolerant crop varieties. Additionally, elucidating the functions of reactive oxygen species is essential for this research area. In model plants, the perception of abiotic stresses is a complex phenomenon that entails intricate interactions between hormones, gene regulation, and physiology. The presence of specific stress receptors and sensors contributes to this perception. Activating signaling pathways involves a cascade of events, starting with generating reactive oxygen species, then calcium signaling and MAP kinase signaling. Because of these processes, transcription factors and genes susceptible to stress are ultimately activated in the latter stages. It starts with a series of physiological and biochemical modifications, which entail adjustments in photosynthesis and the accumulation of osmoprotectants. We have gained significant insights from studying model plant stress responses, but there remain considerable challenges in effectively applying these findings to enhance crop resilience. These challenges contribute to reproducing the results across various species. These difficulties arise because of phenotypes, molecular mechanisms, and genetic differences. The utilization of model plants will persist in their crucial role as essential systems for unraveling the complexities of plant stress responses. They will play a vital role in overcoming present constraints, particularly in areas such as the mathematical modeling of plant physiology. The exploration of gene function across species can significantly contribute to efforts aimed at improving crops. The key to addressing threats to global food security and promoting crop stress resilience lies in adopting a multi-pronged approach that uses model plant systems.

Unlocking the distinctive enzymatic functions of the early plant biomass deconstructive genes in a brown rot fungus by cell-free protein expression.

Saprotrophic fungi that cause brown rot of woody biomass evolved a distinctive mechanism that relies on reactive oxygen species (ROS) to kick-start lignocellulosic polymers' deconstruction. These ROS agents are generated at incipient decay stages through a series of redox relays that shuttle electrons from fungus's central metabolism to extracellular Fenton chemistry. A list of genes has been suggested encoding the enzyme catalysts of the redox processes involved in ROS's function. However, navigating the functions of the encoded enzymes has been challenging due to the lack of a rapid method for protein synthesis. Here, we employed cell-free expression system to synthesize four redox or degradative enzymes, which were identified, by transcriptomic data, as conserved players of the ROS oxidation phase across brown rot fungal species. All four enzymes were successfully expressed and showed activities that enable confident assignment of function, namely, benzoquinone reductase (BQR), ferric reductase, α-L-arabinofuranosidase (ABF), and heme-thiolate peroxidase (HTP). Detailed analysis of their catalytic features within the context of brown rot environments allowed us to interpret their roles during ROS-driven wood decomposition. Specifically, we validated the functions of BQR as the driver redox enzyme of Fenton cycles and reconstructed its interactions with the co-occurring HTP or laccase and ABF. Taken together, this research demonstrated that the cell-free expression platform is adequate for synthesizing functional fungal enzymes and provided an alternative route for the rapid characterization of fungal proteins, escalating our understanding of the distinctive biocatalyst system for plant biomass conversion.IMPORTANCEBrown rot fungi are efficient wood decomposers in nature, and their unique degradative systems harbor untapped catalysts pursued by the biorefinery and bioremediation industries. While the use of "omics" platforms has recently uncovered the key "oxidative-hydrolytic" mechanisms that allow these fungi to attack lignocellulose, individual protein characterization is lagging behind due to the lack of a robust method for rapid synthesis of crucial fungal enzymes. This work delves into the studies of biochemical functions of brown rot enzymes using a rapid, cell-free expression platform, which allowed the successful depictions of enzymes' catalytic features, their interactions with Fenton chemistry, and their roles played during the incipient stage of brown rot when fungus sets off the reactive oxygen species for oxidative degradation. We expect this research could illuminate cell-free protein expression system's use to fulfill the increasing need for functional studies of fungal enzymes, advancing the discoveries of novel biomass-converting catalysts.

The pleiotropic functions of reactive oxygen species in cancer.

Cellular redox homeostasis is an essential, dynamic process that ensures the balance between reducing and oxidizing reactions within cells and thus has implications across all areas of biology. Changes in levels of reactive oxygen species can disrupt redox homeostasis, leading to oxidative or reductive stress that contributes to the pathogenesis of many malignancies, including cancer. From transformation and tumor initiation to metastatic dissemination, increasing reactive oxygen species in cancer cells can paradoxically promote or suppress the tumorigenic process, depending on the extent of redox stress, its spatiotemporal characteristics and the tumor microenvironment. Here we review how redox regulation influences tumorigenesis, highlighting therapeutic opportunities enabled by redox-related alterations in cancer cells.

ROS-scavenging materials for skin wound healing: advancements and applications.

The intricate healing process of skin wounds includes a variety of cellular and molecular events. Wound healing heavily relies on reactive oxygen species (ROS), which are essential for controlling various processes, including inflammation, cell growth, angiogenesis, granulation, and the formation of extracellular matrix. Nevertheless, an overabundance of reactive oxygen species (ROS) caused by extended oxidative pressure may result in the postponement or failure of wound healing. It is crucial to comprehend the function of reactive oxygen species (ROS) and create biomaterials that efficiently eliminate ROS to enhance the healing process of skin wounds. In this study, a thorough examination is presented on the role of reactive oxygen species (ROS) in the process of wound healing, along with an exploration of the existing knowledge regarding biomaterials employed for ROS elimination. In addition, the article covers different techniques and substances used in the management of skin wound. The future prospects and clinical applications of enhanced biomaterials are also emphasized, highlighting the potential of biomaterials that scavenge active oxygen to promote skin repair. This article seeks to enhance the understanding of the complex processes of ROS in the healing of wounds and the application of ROS-scavenging materials. Its objective is to create novel strategies for effective treatment skin wounds.

Rapid Induction of Astaxanthin in Haematococcus lacustris by Mild Electric Stimulation

Efficient induction of astaxanthin (AXT) biosynthesis remains a considerable challenge for the industrialization of the biorefinement of the microalga Haematococcus lacustris. In this study, we evaluated the technical feasibility of photosynthetic electrotreatment to enhance AXT accumulation in H. lacustris. The AXT content of H. lacustris electrotreated at an optimal current intensity (10 mA for 4 h) was 21.8% to 34.9% higher than that of the untreated control group, depending on the physiological state of the initial palmella cells. The contents of other carotenoids (i.e., canthaxanthin, zeaxanthin, and β-carotene) were also increased by this electrotreatment. However, when H. lacustris cells were exposed to more intense electric treatments, particularly at 20 and 30 mA, cell viability significantly decreased to 84.2% and 65.6%, respectively, with a concurrent reduction in the contents of both AXT and the three other carotenoids compared to those of the control group. The cumulative effect of electric stimulation is likely related to two opposing functions of reactive oxygen species, which facilitate AXT biosynthesis as signaling molecules while also causing cellular damage as oxidizing radicals. Collectively, our findings indicate that when adequately controlled, electric stimulation can be an effective and eco-friendly strategy for inducing targeted carotenoid pigments in photosynthetic microalgae.

Improved Photodynamic Therapy Based on Glutaminase Blockage via Tumor Membrane Coated CB-839/IR-780 Nanoparticles.

Photodynamic therapy (PDT) has promising applications. However, the lethal function of reactive oxygen species (ROS) produced during PDT is typically limited. This restriction is induced by oxygen shortage in the tumor microenvironment due to tumor cell hypermetabolism and reductive chemicals overexpression in tumor tissues. Glutamine (Gln) metabolism is crucial for malignancy development and is closely associated with redox. Herein, a novel nanoparticle (NP) named IRCB@M is constructed to boost PDT through dual effects. This NP simultaneously blocks aerobic respiration and inhibits cellular reduced substances by blocking the Gln metabolic pathway. Within the nanocomplex, a photosensitizer (IR-780) and a glutaminase inhibitor (CB-839) are self-assembled and then encapsulated by cancer cell membranes for homologous targeting. The Gln metabolism intervention relieves hypoxia and decreases the levels of nicotinamide adenine dinucleotide phosphate (NADPH) as well as reduced glutathione (GSH) in vitro and in vivo, which are the dual amplification effects on the IR-780-mediated lethal PDT. The antitumor effects against gastric cancer are ultimately evoked in vivo, thus offering a novel concept for enhancing PDT and other ROS-dependent therapeutic approaches.

Function of reactive oxygen species in myeloid-derived suppressor cells.

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous myeloid cell population and serve as a vital contributor to the tumor microenvironment. Reactive oxygen species (ROS) are byproducts of aerobic respiration and are involved in regulating normal biological activities and disease progression. MDSCs can produce ROS to fulfill their immunosuppressive activity and eliminate excessive ROS to survive comfily through the redox system. This review focuses on how MDSCs survive and function in high levels of ROS and summarizes immunotherapy targeting ROS in MDSCs. The distinctive role of ROS in MDSCs will inspire us to widely apply the blocked oxidative stress strategy in targeting MDSC therapy to future clinical therapeutics.

Differential Binding of NLRP3 to non-oxidized and Ox-mtDNA mediates NLRP3 Inflammasome Activation

The NLRP3 inflammasome is a key mediator of the innate immune response to sterile tissue injury and is involved in many chronic and acute diseases. Physically and chemically diverse agents activate the NLRP3 inflammasome. Here, we show that NLRP3 binds non-oxidized and Ox-mtDNA differentially, with a half maximum inhibitory concentration (IC50) for non-oxidized and Ox-mtDNA of 4 nM and 247.2 nM, respectively. The NLRP3 Neonatal-Onset Multisystem Inflammatory Disease (NOMID) gain of function mutant could bind non-oxidized mtDNA but had higher affinity for Ox-mtDNA compared to WT with an IC50 of 8.1 nM. NLRP3 lacking the pyrin domain can bind both oxidized and non-oxidized mtDNA. Isolated pyrin domain prefers Ox-mtDNA. The NLRP3 pyrin domain shares a protein fold with DNA glycosylases and generate a model for DNA binding based on the structure and sequence alignment to Clostridium acetobutylicum and human OGG1, an inhibitor of Ox-mtDNA generation, 8-oxoguanine DNA glycosylases. We provide a new model for how NLRP3 interacts with Ox-mtDNA supported by DNA binding in the presence of a monoclonal antibody against the pyrin domain. These results give new insights into the mechanism of inflammasome assembly, and into the function of reactive oxygen species in establishing a robust immune response.

Galvanized materials induce oxidative stress in Cryptocaryon irritans by releasing zinc ions

Mariculture fish often are infected with Cryptocaryon irritans, causing enormous losses to aquaculture. Our previous study indicated that galvanized materials showed good efficacy in controlling C. irritans infection. However, the toxic mechanism of galvanized materials on C. irritans is poorly understood. In this study, the mechanism of galvanized material toxicity on C. irritans was investigated, using seawater immersed with galvanized iron mesh (IGM seawater) and ZnSO4 solution. Furthermore, subcellular structural changes in C. irritans after treatment with zinc ions were determined. Finally, the content and function of reactive oxygen species (ROS) in the protomonts of C. irritans were assessed following treatment with zinc ions. The results showed that the parasite abundance in the IGM seawater group was significantly reduced compared with the control (P < 0.05). Furthermore, parasite abundance in the zinc ion-added groups (0.36 mg/L, 1.83 mg/L) which the zinc ions content was equal with IGM seawater group was significantly reduced compared with the control (P < 0.05). Zinc ions released from galvanized materials might be the most critical toxic agent to C. irritans. Additionally, deformation of mitochondrion was also found in the protomonts after treatment with zinc ions. The ROS content in protomonts of the Zn group was increased by 79.63% compared with the control group (P < 0.05). When the ROS were eliminated by an inhibitor, protomont mortality was decreased by 100% in the Zn group (P < 0.05). These results indicated that the toxic mechanism of galvanized materials to C. irritans may be from oxidative stress induced by releasing zinc ions.

Mesenchymal stem cells encapsulated in a reactive oxygen species-scavenging and O2-generating injectable hydrogel for myocardial infarction treatment

Stem cell especially mesenchymal stem cell (MSC) transplantation is a promising therapeutic strategy for myocardial infarction (MI) repair. However, major obstacles remain due to the poor retention and survival rate of transplanted MSCs in the harmful MI microenvironment (e.g., oxidative stress and hypoxia). Here, a novel injectable hydrogel (RCGel) with dual functions of reactive oxygen species (ROS)-scavenging and O2-generating was employed to encapsulate MSCs for MI treatment. The RCGel encapsulating exhibited anti-ROS protection through inhibiting JNK/p38 apoptosis signaling pathway to improve the viability of MSCs under oxidative stress conditions in vitro. The survival of cardiomyocytes was also improved both in the oxidative stress and hypoxia environments when being co-cultured with MSCs-encapsulated RCGel (MSC/RCGel). The RCGel encapsulating boosted the engraftment of transplanted MSCs in vivo. More viable MSCs endowed with regenerative abilities in the infarcted rat heart along with the ameliorated MI microenvironment (decreased oxidative stress and hypoxia) by the RCGel substantially inhibited cardiac apoptosis, enhanced cardiomyocyte viability, promoted angiogenesis and reduced fibrosis to improve the cardiac functions. The encapsulation of MSCs in RCGel, which exhibits beneficial effects in resisting harsh environments, provides a new way in MI repair and stem cell delivery, and has great potential in cell-based regenerative medicine.

Functions of reactive oxygen species in plant cells under normal conditions and during adaptation

The review considers the role of reactive oxygen species in the life of a plant cell. At the same time, attention is paid to both the negative aspects of their effect on cellular components (lipid peroxidation, protein carbonylation, and DNA damage) and positive functions (participation in signaling, stress response, and metabolism). The main types of reactive oxygen species and the sites of their generation in the plant cell are considered. It is concluded that reactive oxygen species, which inevitably arise in any aerobic organisms, should be considered as the most important regulator of a large number of plant processes, such as growth, development, metabolism, senescence, and stress reactions. Moreover, if the role of reactive oxygen species in signaling and under stress has been investigated in sufficient detail, the direct metabolic role has been studied relatively poorly, with the exception of lignin polymerization and softening of the cell wall, which indicates the need for further research in this area.

RORα Suppresses Cancer-Associated Inflammation by Repressing Respiratory Complex I-Dependent ROS Generation.

Breast cancer development is associated with macrophage infiltration and differentiation in the tumor microenvironment. Our previous study highlights the crucial function of reactive oxygen species (ROS) in enhancing macrophage infiltration during the disruption of mammary tissue polarity. However, the regulation of ROS and ROS-associated macrophage infiltration in breast cancer has not been fully determined. Previous studies identified retinoid orphan nuclear receptor alpha (RORα) as a potential tumor suppressor in human breast cancer. In the present study, we showed that retinoid orphan nuclear receptor alpha (RORα) significantly decreased ROS levels and inhibited ROS-mediated cytokine expression in breast cancer cells. RORα expression in mammary epithelial cells inhibited macrophage infiltration by repressing ROS generation in the co-culture assay. Using gene co-expression and chromatin immunoprecipitation (ChIP) analyses, we identified complex I subunits NDUFS6 and NDUFA11 as RORα targets that mediated its function in suppressing superoxide generation in mitochondria. Notably, the expression of RORα in 4T1 cells significantly inhibited cancer metastasis, reduced macrophage accumulation, and enhanced M1-like macrophage differentiation in tumor tissue. In addition, reduced RORα expression in breast cancer tissue was associated with an increased incidence of cancer metastasis. These results provide additional insights into cancer-associated inflammation, and identify RORα as a potential target to suppress ROS-induced mammary tumor progression.

Physiological Signaling Functions of Reactive Oxygen Species in Stem Cells: From Flies to Man.

Reactive oxygen species (ROS), superoxide anion and hydrogen peroxide, are generated as byproducts of oxidative phosphorylation in the mitochondria or via cell signaling-induced NADPH oxidases in the cytosol. In the recent two decades, a plethora of studies established that elevated ROS levels generated by oxidative eustress are crucial physiological mediators of many cellular and developmental processes. In this review, we discuss the mechanisms of ROS generation and regulation, current understanding of ROS functions in the maintenance of adult and embryonic stem cells, as well as in the process of cell reprogramming to a pluripotent state. Recently discovered cell-non-autonomous ROS functions mediated by growth factors are crucial for controlling cell differentiation and cellular immune response in Drosophila. Importantly, many physiological functions of ROS discovered in Drosophila may allow for deciphering and understanding analogous processes in human, which could potentially lead to the development of novel therapeutic approaches in ROS-associated diseases treatment.

Synergistic oxidation of dissolved As(III) and arsenopyrite in the presence of oxygen: Formation and function of reactive oxygen species

As an important source of arsenic (As) pollution in mine drainage, arsenopyrite undergoes redox and adsorption reactions with dissolved As, which further affects the fate of As in natural waters. This study investigated the interactions between dissolved As(III) and arsenopyrite and the factors influencing the geochemical behavior of As, including initial As(III) concentration, dissolved oxygen and pH. The hydrogen peroxide (H2O2) and hydroxyl radical (OH•) generated from the interaction between Fe(II) on arsenopyrite surface and oxygen were found to facilitate the rapid oxidation of As(III), and the production of As(V) in the reaction system increased with increasing initial As(III) concentration. An increase of pH from 3.0 to 7.0 led to a gradual decrease in the oxidation rate of As(III). At pH 3.0, the presence of As(III) accelerated the oxidation rate of arsenopyrite; while at pH 5.0 and 7.0, As(III) inhibited the oxidative dissolution of arsenopyrite. This work reveals the potential environmental process of the interaction between dissolved As(III) and arsenopyrite, and provides important implications for the prevention and control of As(III) pollution in mine drainage.

Dysregulation of nitric oxide synthases during early and late pathophysiological conditions of diabetes mellitus leads to amassing of microvascular impedement.

Diabetes is a major killer worldwide and its unprecedented rise poses a serious threat to mankind. According to recent estimation, 387million people worldwide are affected from the disease with a prevalence rate of 8.3 and 46.3 % still remains undiagnosed. Important characteristics of diabetes are abnormalities of the physiological signalling functions of reactive oxygen species and reactive nitrogen species. Increased oxidative stress contributes to the activation of stress-sensitive intracellular signalling pathways and the development of gene products that trigger cellular damage and contribute to the vascular complications of diabetes. Growing evidence from studies into many diseases suggests that the pathogenesis of diabetes, obesity, cancer, ageing, inflammation, neurodegenerative disorders, hypertension, apoptosis, cardiovascular diseases, and heart failure are correlated with oxidative stress. This leads to cell metabolism and cell-cell homeostasis to be complexly dysregulated. This review focuses to investigate the status of oxidative stress, nitric oxide and reactive species in early and diabetes. Significance of nitric oxide synthases Evidences has accumulated indicating that the generation of reactive oxygen species (oxidative stress) may play an important role in the etiology of diabetic complications thus attention was given on the reactive oxygen and reactive nitrogen species and their potential role in pathogenesis. Additionally, the therapeutic advances in diabetes management are included. Nanotechnology, statins and stem cell technology are some techniques which can be considered to have a possible future in the treatment sector of diabetes.

Functions of reactive oxygen species in apoptosis and ganoderic acid biosynthesis in Ganoderma lucidum.

Ganoderma lucidum is a medicinal fungus that is widely used in traditional medicine. Fungal PacC is recognized as an important transcription factor that functions during adaptation to environmental pH, fungal development and secondary metabolism. Previous studies have revealed that GlPacC plays important roles in mycelial growth, fruiting body development and ganoderic acid (GA) biosynthesis. In this study, using a terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay, we found that the apoptosis level was increased when PacC was silenced. The transcript and activity levels of caspase-like proteins were significantly increased in the PacC-silenced (PacCi) strains compared with the control strains. Silencing PacC also resulted in an increased reactive oxygen species (ROS) levels (∼2-fold) and decreased activity levels of enzymes involved in the antioxidant system. Further, we found that the intracellular ROS levels contributed to apoptosis and GA biosynthesis. Adding N-acetyl-cysteine and vitamin C decreased intracellular ROS and resulted in the inhibition of apoptosis in the PacCi strains. Additionally, the GA biosynthesis was different between the control strains and the PacCi strains after intracellular ROS was eliminated. Taken together, the findings showed that silencing PacC can result in an intracellular ROS burst, which increases cell apoptosis and GA biosynthesis levels. Our study provides novel insight into the functions of PacC in filamentous fungi.

Porous Se@SiO2 nanosphere-coated catheter accelerates prostatic urethra wound healing by modulating macrophage polarization through reactive oxygen species-NF-κB pathway inhibition

Benign prostatic hyperplasia (BPH) patients experience complications after surgery. We studied oxidative stress scavenging by porous Se@SiO2 nanospheres in prostatic urethra wound healing after transurethral resection of the prostate (TURP). Beagle dogs were randomly distributed into two groups after establishing TURP models. Wound recovery and oxidative stress levels were evaluated. Re-epithelialization and the macrophage distribution at the wound site were assessed by histology. The mechanism by which porous Se@SiO2 nanospheres regulated macrophage polarization was investigated by qRT-PCR, western blotting, flow cytometry, immunofluorescence and dual luciferase reporter gene assays. Our results demonstrated that Porous Se@SiO2 nanosphere-coated catheters advance re-epithelization of the prostatic urethra, accelerating wound healing in beagle dogs after TURP, and improve the antioxidant capacity to inhibit oxidative stress and induced an M2 phenotype transition of macrophages at the wound. By restraining the function of reactive oxygen species (ROS), porous Se@SiO2 nanospheres downregulated Ikk, IκB and p65 phosphorylation to block the downstream NF-κB pathway in macrophages in vitro. Since activation of NF-κB signaling cascades drives macrophage polarization, porous Se@SiO2 nanospheres promoted macrophage phenotype conversion from M1 to M2. Our findings suggest that porous Se@SiO2 nanosphere-coated catheters promote postoperative wound recovery in the prostatic urethra by promoting macrophage polarization toward the M2 phenotype through suppression of the ROS-NF-κB pathway, attenuating the inflammatory response. Statement of SignificanceThe inability to effectively control post-operative inflammatory responses after surgical treatment of benign prostatic hyperplasia (BPH) remains a challenge to researchers and surgeons, as it can lead to indirect cell death and ultimately delay wound healing. Macrophages at the wound site work as pivotal regulators of local inflammatory response. Here, we designed and produced a new type of catheter with a coating of porous Se@SiO2 nanosphere and demonstrated its role in promoting prostatic urethra wound repair by shifting macrophage polarization toward the anti-inflammatory M2 phenotype via suppressing ROS-NF-κB pathway. These results indicate that the use of porous Se@SiO2 nanosphere-coated catheter may provide a therapeutic strategy for postoperative complications during prostatic urethra wound healing to improve patient quality of life.

Effect of Vitamins and Amino Acids as Cryoprotectant Solution Supplementation for the Cryopreservation of Tambaqui Semen (Colossoma macropomum)

Background: The addition of antioxidant substances to a cryoprotective solution can increase its protective capacity, shielding spermatozoa from the oxidative stress caused by the seminal cryopreservation process. However, there is no record of a seminal cryopreservation protocol of tambaqui (Colossoma macropomum) using antioxidants as a supplement to the cryoprotective solution. Thus, the objective of this study was to evaluate the effects of adding vitamin C, vitamin E, cysteine, and/or taurine to the seminal cryopreservation of tambaqui.Materials, Methods &amp; Results: Pools of semen (n = 10) were diluted in cryoprotective solutions supplemented with: vitamin C (T1), vitamin E (T2), vitamin C + vitamin E (T3), cysteine (T4), taurine (T5), and taurine + cysteine (T6). The control treatment (T7) was not supplemented. Diluted semen was loaded in 0.5 mL straws, frozen in a dry-shipper, stored in a cryogenic cylinder, and then thawed in a water bath (45ºC for eight seconds). The quality of fresh and cryopreserved semen was evaluated by measuring total motility, progressive motility, curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), linearity, and straightness using a computerized system of sperm analysis. Sperm membrane integrity parameters were analyzed using eosin-nigrosin staining, sperm morphology was assessed using pink bengal staining, and motility duration was measured by a digital timer. Data were analyzed using the statistical program SAS (2002) and the results were expressed as means ± standard error of the mean. The results showed that, in general, there was no significant increase in seminal quality when antioxidants were added to the cryoprotective solution. The T5 treatment promoted an increase (P &lt; 0.05) in progressive motility when compared to T1 (6.33 ± 1.14% and 2.98 ± 0.88%, respectively). However, it did not differ significantly (P &gt; 0.05) from the other treatments. Treatments T2 and T5 presented the highest values of VCL (34.74 ± 2.58 and 33.60 ± 1.81 μm.s-1, respectively). These were higher (P &lt; 0.05) than T1 (26.31 ± 1.64 μm.s-1) but not different (P &gt; 0.05) from the T7 control (30.87 ± 1.49 μm.s-1). The VSL and VAP results showed that T1 presented the lowest velocity (9.89 ± 1.75 and 15.06 ± 1.92 μm.s-1, respectively) compared to the other treatments (P &lt; 0.05) that did not differ from each other. Combining the two vitamins (T3) or the two amino acids (T6) was not advantageous in relation to the use of only one of these antioxidants.Discussion: The present study reports, for the first time, results of the addition of antioxidants to the tambaqui seminal freezing medium. The addition of taurine and vitamin E, although not significantly different from the control treatment, resulted in a tendency to increase sperm kinetics. This effect may be due to the action of taurine as a regulator of Ca2+ transporters, which is necessary to trigger sperm activation, and to the ability of vitamin E to scavenge reactive oxygen species produced during lipid peroxidation. On the other hand, the reduced sperm quality observed when vitamin C was used may have been related to the toxicity caused by a high concentration of this vitamin. In addition, once the safe dose of antioxidants has been exceeded, the normal physiological functions of reactive oxygen species can be inhibited. Thus, it is concluded that the use of vitamin E and taurine promotes promising results of curvilinear velocity after thawing of sperm. Therefore, these treatments are recommended, as well as more tests to determine their optimal concentrations.