Decreased Reactive Oxygen Species Levels Research Articles

Mitigation of Surface Browning in Fresh-Cut Banana Blossom by Tamarind (Tamarindus indica L.) Pulp Extract: A Role in Regulating ROS Metabolism

T he surface browning of fresh-cut products not only diminishes their nutritional content but also lowers their market value. Fresh-cut banana blossom (FBB), an increasingly popular vegan food, is prone to browning on the cut surface, which poses a significant challenge for this fresh-cut produce. Chemicals and natural extracts are commonly used to address this issue in fresh-cut produce, offering alternatives to synthetic chemicals. Tamarind (Tamarindus indica L.) pulp extract (TPE), derived from the tamarind fruit, contains compounds such as polyphenols with antioxidant properties, making it an intriguing choice as an anti-browning agent. Therefore, this study investigated the effects of TPE on surface browning and reactive oxygen species (ROS) metabolism in FBB during storage at 30 ± 1 °C. FBB was immersed in 0 % (the control) and 2.5 % TPE for 5 min, then rinsed with distilled water, air-dried, and stored at 30 ± 1 °C for 60 h. The control group showed increasing surface browning and declining overall quality during storage. TPE immersion significantly enhanced antioxidant defense systems during storage compared to the control. The heightened activity of antioxidant enzymes and increased non-enzymatic antioxidant levels corresponded with decreased ROS levels, oxidative membrane damage, and surface browning. These findings suggest that TPE has the potential to effectively reduce browning in FBB and may serve as an effective anti-browning agent for other fresh-cut products.

Role of Quercetin in DNA Repair: Possible Target to Combat Drug Resistance in Diabetes.

Diabetes Mellitus (DM) is referred to as hyperglycemia in either fasting or postprandial phases. Oxidative stress, which is defined by an excessive amount of reactive oxygen species (ROS) production, increased exposure to external stress, and an excessive amount of the cellular defense system against them, results in cellular damage. Increased DNA damage is one of the main causes of genomic instability, and genetic changes are an underlying factor in the emergence of cancer. Through covalent connections with DNA and proteins, quercetin has been demonstrated to offer protection against the creation of oxidative DNA damage. It has been found that quercetin shields DNA from possible oxidative stress-related harm by reducing the production of ROS. Therefore, Quercetin helps to lessen DNA damage and improve the ability of DNA repair mechanisms. This review mainly focuses on the role of quercetin in repairing DNA damage and compensating for drug resistance in diabetic patients. Data on the target topic was obtained from major scientific databases, including SpringerLink, Web of Science, Google Scholar, Medline Plus, PubMed, Science Direct, and Elsevier. In preclinical studies, quercetin guards against DNA deterioration by regulating the degree of lipid peroxidation and enhancing the antioxidant defense system. By reactivating antioxidant enzymes, decreasing ROS levels, and decreasing the levels of 8-hydroxydeoxyguanosine, Quercetin protects DNA from oxidative damage. In clinical studies, it was found that quercetin supplementation was related to increased antioxidant capacity and decreased risk of type 2 diabetes mellitus in the experimental group as compared to the placebo group. It is concluded that quercetin has a significant role in DNA repair in order to overcome drug resistance in diabetes.

ZmmiR398b negatively regulates maize resistance to sugarcane mosaic virus infection by targeting ZmCSD2/4/9.

MicroRNAs (miRNAs) are widely involved in various biological processes of plants and contribute to plant resistance against various pathogens. In this study, upon sugarcane mosaic virus (SCMV) infection, the accumulation of maize (Zea mays) miR398b (ZmmiR398b) was significantly reduced in resistant inbred line Chang7-2, while it was increased in susceptible inbred line Mo17. Degradome sequencing analysis coupled with transient co-expression assays revealed that ZmmiR398b can target Cu/Zn-superoxidase dismutase2 (ZmCSD2), ZmCSD4, and ZmCSD9 invivo, of which the expression levels were all upregulated by SCMV infection in Chang7-2 and Mo17. Moreover, overexpressing ZmmiR398b (OE398b) exhibited increased susceptibility to SCMV infection, probably by increasing reactive oxygen species (ROS) accumulation, which were consistent with ZmCSD2/4/9-silenced maize plants. By contrast, silencing ZmmiR398b (STTM398b) through short tandem target mimic (STTM) technology enhanced maize resistance to SCMV infection and decreased ROS levels. Interestingly, copper (Cu)-gradient hydroponic experiments demonstrated that Cu deficiency promoted SCMV infection while Cu sufficiency inhibited SCMV infection by regulating accumulations of ZmmiR398b and ZmCSD2/4/9 in maize. These results revealed that manipulating the ZmmiR398b-ZmCSD2/4/9-ROS module provides a prospective strategy for developing SCMV-tolerant maize varieties.

The impact of sestrin2 on reactive oxygen species in diabetic retinopathy.

Diabetic retinopathy (DR) is a significant complication of diabetes that often leads to blindness, impacting Müller cells, the primary retinal macroglia involved in DR pathogenesis. Reactive oxygen species (ROS) play a crucial role in the development of DR. The objective of this study was to investigate the involvement of sestrin2 in DR using a high-glucose (HG)-induced Müller cell model and assessing cell proliferation with 5-ethynyl-2-deoxyuridine (EdU) labeling. Following this, sestrin2 was upregulated in Müller cells to investigate its effects on ROS, tube formation, and inflammation both in vitro and in vivo, as well as its interaction with the nuclear factor erythroid2-related factor 2 (Nrf2) signaling pathway. The findings demonstrated a gradual increase in the number of EdU-positive cells over time, with a subsequent decrease after 72 h of exposure to high glucose levels. Additionally, the expression of sestrin2 exhibited a progressive increase over time, followed by a decrease at 72 h. The rh-sestrin2 treatment suppressed the injury of Müller cells, decreased ROS level, and inhibited the tube formation. Rh-sestrin2 treatment enhanced the expression of sestrin2, Nrf2, heme oxygenase-1 (HO-1), and glutamine synthetase (GS); however, the ML385 treatment reversed the protective effect of rh-sestrin2. Finally, we evaluated the effect of sestrin2 in a DR rat model. Sestrin2 overexpression treatment improved the pathological injury of retina and attenuated the oxidative damage and inflammatory reaction. Our results highlighted the inhibitory effect of sestrin2 in the damage of retina, thus presenting a novel therapeutic sight for DR.

Protective effects of canthaxanthin-loaded seminal exosomes on the quality of human spermatozoa during cryopreservation

Sperm cryopreservation is a common strategy for preserving male fertility; however, it may cause detrimental alterations in the structure and biological role of spermatozoa. The objective of this study is to mitigate the damages caused by cryopreservation through the use of canthaxanthin-loaded seminal exosomes (CAN-loaded EXO). To achieve this, Exosomes were isolated from the human seminal fluid through serial ultracentrifugation and characterized using different methods. Canthaxanthin was loaded into exosomes using the sonication method and incubated with spermatozoa for 1 h. Then the semen was mixed with CryoSperm medium and transferred into straws. The straws were initially placed in nitrogen vapor and then submerged in liquid nitrogen. After one month, the samples were thawed, and sperm parameters, lipid peroxidation, total antioxidant capacity (TAC), reactive oxygen species (ROS) levels, sperm DNA fragmentation (SDF), and sperm apoptosis were assessed. The results demonstrated the successful isolation of exosomes with a spherical morphology, a particle size of 104.5 nm, and a zeta potential of −12.32 mV. Canthaxanthin was loaded into exosomes with an encapsulation efficiency of 63.7 %. Motility and vitality of spermatozoa were improved in the presence of CAN-loaded EXO compared to the control group (p < 0.05). Incubation of spermatozoa with CAN-loaded EXO enhanced TAC levels and decreased ROS levels, lipid peroxidation, SDF, and apoptosis compared to the control group (p < 0.05). However, CAN-loaded EXO had no significant effect on the morphology of spermatozoa. These findings suggest that exosomes have the potential to serve as a novel drug delivery platform for protecting spermatozoa from cryodamage while enhancing the bioavailability of antioxidants.

Critical role of endoplasmic reticulum stress on bisphenol A‐induced cytotoxicity in human keratinocyte HaCaT cells

AbstractBisphenol A (BPA) is widely used in plastic and paper products, and its exposure can occur through skin contact or oral ingestion. The hazardous effects of BPA absorbed through the skin may be more severe; however, few studies have investigated the skin toxicity of BPA. This study investigated the effects of BPA on human epidermal keratinocyte cell lines, which is relevant for skin exposure. BPA treatment reduced cell viability in a time‐ and concentration‐dependent manner and elevated oxidative and endoplasmic reticulum (ER) stress. N‐acetylcysteine (NAC), an oxidative stress inhibitor, reduced BPA‐induced reactive oxygen species (ROS) levels. However, only 10% of the decreased cell viability was restored at the highest NAC concentration. Treatment with tauroursodeoxycholic acid (TUDCA), which is an ER stress inhibitor, effectively countered the increase in ER stress‐related proteins induced by BPA. Moreover, TUDCA treatment led to a reduction in oxidative stress, as demonstrated by the decrease in ROS levels, maintenance of mitochondrial membrane potential, and modulation of stress signaling proteins. Consequently, TUDCA significantly improved BPA‐induced cytotoxicity in a concentration‐dependent manner. Notably, combined treatment using TUDCA and NAC further reduced the BPA‐induced ROS levels; however, no significant difference in cell viability was observed compared with that for TUDCA treatment alone. These findings indicated that the oxidative stress observed following BPA exposure was exacerbated by ER stress. Moreover, the principal factor driving BPA‐induced cytotoxicity was indeed ER stress, which has potential implications for developing therapeutic strategies for diseases associated with similar stress responses.

Thymoquinone Reverses Homocysteine-Induced Endothelial Dysfunction Via Inhibition of Endoplasmic Reticulum-Stress Induced Oxidative Stress Pathway

Hyperhomocysteinemia causes endoplasmic reticulum (ER) stress, which elevates reactive oxygen species (ROS) and induces endothelial dysfunction, the hallmark of cardiovascular diseases. Nigella sativa seeds contain thymoquinone (TQ), a cardioprotective bioactive component. Nevertheless, research on investigating the effectiveness of TQ in preventing endothelial dysfunction caused by homocysteine (Hcy) is scarce. Therefore, the purpose of this work was to examine the role of TQ in restoring Hcy-induced endothelial dysfunction as well as the mechanisms behind this role. Male Sprague-Dawley (SD) rat aortas were isolated and then co-treated in an organ bath with Hcy and TQ, tauroursodeoxycholic acid (TUDCA), apocynin, or Tempol to examine vascular function. Furthermore, human umbilical vein endothelial cells (HUVECs) were treated with Hcy and TQ, Tempol, apocynin, TUDCA or H2O2 to determine the cell viability via a phase contrast microscope and dye exclusion test. ER stress pathway involvement, ROS and NO bioavailability were investigated using immunoassays and fluorescence staining, respectively. The binding affinity of TQ to GRP78 has been identified using molecular docking. According to our findings, Hcy hindered endothelium-dependent relaxation in an isolated aorta and caused apoptosis in HUVECs. TQ, TUDCA, Tempol, and apocynin were able to counteract these negative effects. In HUVECs, treatment with TQ decreased ROS levels, increased NO bioavailability, and decreased GRP78 and NOX4 protein. According to the molecular docking study outcomes, TQ could attach to GRP78 effectively via a hydrogen bond and a hydrophobic connection to the amino acid at GRP78 ATP binding pocket. Taken together, the findings show that TQ protected endothelial function caused by Hcy via inhibiting ER stress-mediated ROS and eNOS uncoupling.

Abstract 5325: Cytokine CCL9, new downstream target of oncogene Kras to modulate acinar-to-ductal metaplasia during pancreatic cancer initiation

Abstract Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of cancer with a current five-year survival rate at 12% in the US, and is dominated by oncogenic Kras mutations. Accumulating evidence showed that PDAC can be originated from acinar-to-ductal metaplasia (ADM). In this process, pancreatic acini harboring oncogenic Kras mutations are transdifferentiated to a duct-like phenotype that further progresses to become pancreatic intraepithelial neoplasia (PanIN) lesions, giving rise to PDAC. Although ADM formation is commonly observed in KrasG12D transgenic mouse models of PDAC, the exact mechanisms of how oncogenic KrasG12D modulates this process remain unclear. Here, we unveil a new downstream target of oncogenic Kras, cytokine CCL9 during ADM formation. Either exogenously treating primary pancreatic acini with recombinant CCL9 or ectopically expressing CCL9 in primary pancreatic acini resulted in ADM formation in a 3D organoid culture system. Furthermore, knockdown of CCL9 in KrasG12D-expressed acini reduced KrasG12D-induced ADM. Higher levels of reactive oxygen species (ROS) were detected in the KrasG12D-expressed pancreatic acini, and knockdown of CCL9 in these acini decreased ROS levels. Overexpression of CCL9 in primary pancreatic acini elevated cellular ROS of pancreatic acinar cells. Furthermore, depletion of ROS in 3D organoid culture of CCL9-expressed acini reduced CCL9-induced ADM formation. In transgenic mice of p48cre:KrasG12D, blockade of CCL9 through its specific neutralizing antibody attenuated ADM formation as well as PanIN structures. Altogether, our results indicated oncogenic KrasG12D initiates PDAC through a new downstream target molecule, CCL9, to enhance ROS levels of pancreatic acinar cells. Citation Format: Geou-Yarh (Stancy) Liou, Justin K. Messex, Crystal J. Byrd. Cytokine CCL9, new downstream target of oncogene Kras to modulate acinar-to-ductal metaplasia during pancreatic cancer initiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5325.

Protective Effects of Astaxanthin on Post-Thaw Sperm Quality in Normozoospermic Men

Fighting against free radical accumulation during the cryopreservation process with the help of exogenous antioxidants has become an effective strategy to augment post-thaw sperm quality. The present study explored the effects of various concentrations of astaxanthin, as a potent antioxidant, on human sperm parameters during the freeze–thaw process. Twenty-five normozoospermic specimens were included in this prospective study. Each sample was divided into five equal parts: fresh group, and frozen–thawed groups including 0, 1, 10, and 50 μM of astaxanthin. The prepared spermatozoa were cryopreserved by rapid freezing technique. Precryopreservation and post-thaw sperm motility parameters, sperm morphology, vitality, DNA fragmentation, reactive oxygen species (ROS) levels, and mitochondrial membrane potential (MMP) were investigated. All sperm parameters after thawing significantly decreased compared to before freezing. Treatment of spermatozoa with 50 μM of astaxanthin significantly increased their total and progressive motility, viability, DNA integrity, and MMP and decreased their intracellular ROS levels compared with the control group. In total, 10 μM of astaxanthin significantly improved total and progressive motility, DNA integrity, MMP, and decreased ROS levels, whereas, in the 1 µM group, there were significant differences only in ROS levels. As a result, we found that astaxanthin can improve sperm quality after freezing/thawing and decrease the detrimental effects of this process on sperm parameters.

Emodin ameliorates myocardial fibrosis in mice by inactivating the ROS/PI3K/Akt/mTOR axis

ABSTRACT Background Emodin is a traditional medicine that has been shown to exert anti-inflammatory and anti-oxidative effects. Previous research has indicated that emodin can alleviate myocardial remodeling and inhibit myocardial hypertrophy and fibrosis. However, the mechanism by which emodin affects myocardial fibrosis (MF) has not yet been elucidated. Methods Fibroblasts were treated with ANGII, and a mouse model of MF was established by ligation of the left anterior descending coronary artery. Cell proliferation was examined by a Cell Counting Kit-8 (CCK8) assay. Dihydroethidium (DHE) was used to measure reactive oxygen species (ROS) levels, and Masson and Sirius red staining were used to examine changes in collagen fiber levels. PI3K was over-expressed by lentiviral transfection to verify the effect of emodin on the PI3K/AKT/mTOR signaling axis. Changes in cardiac function in each group were examined by echocardiography. Results Emodin significantly inhibited fibroblast proliferation, decreased intracellular ROS levels, significantly upregulated collagen II expression, downregulated α-SMA expression, and inhibited PI3K/AKT/mTOR pathway activation in vitro. Moreover, the in vivo results were consistent with the in vitro. Emodin significantly decreased ROS levels in heart tissue and reduced collagen fibrillogenesis. Emodin could regulate the activity of PI3K to increase the expression of collagen II and downregulate α-SMA expression in part through the PI3K/AKT/mTOR pathway, and emodin significantly improved cardiac structure and function in mice. Conclusions This study revealed that emodin targeted the PI3K/AKT/mTOR pathway to inhibit the development of myocardial fibrosis and may be an antifibrotic agent for the treatment of cardiac fibrosis.

Selenomethionine Alleviates Deoxynivalenol-Induced Oxidative Injury in Porcine Intestinal Epithelial Cells Independent of MAPK Pathway Regulation.

Deoxynivalenol (DON) is a prevalent contaminant in feed and food, posing a serious threat to the health of both humans and animals. The pig stands as an ideal subject for the study of DON due to its recognition as the most susceptible animal to DON. In this study, the IPEC-J2 cells were utilized as an in vitro model to explore the potential of SeMet in alleviating the intestinal toxicity and oxidative injury in intestinal epithelial cells when exposed to DON. Cells were treated either with or without 4.0 μM SeMet, in combination with or without a simultaneous treatment with 0.5 μg/mL DON, for a duration of 24 h. Then, cells or related samples were analyzed for cell proliferation, lactate dehydrogenase (LDH) release, reactive oxygen species (ROS) level, gene expressions, and protein expressions. The results showed that SeMet mitigated the cellular toxicity caused by DON, evidenced by elevated cell proliferation and the reduced LDH release of IPEC-J2 cells in the SeMet + DON group vs. the DON group. Moreover, the SeMet treatment markedly promoted antioxidant functions and decreased the oxidative injury in IPEC-J2 cell, which is indicated by the decreased ROS level and up-regulated mRNA levels of GPX1, TXNRD1, Nrf2, and GCLC in IPEC-J2 cells in the SeMet + DON group vs. the DON group. However, in both the absence and presence of exposure to DON, the SeMet treatment did not affect the protein expression of MAPK (JNK, Erk1/2, and P38) and phosphorylated MAPK (p-JNK, p-Erk1/2, and p-P38) in IPEC-J2 cells. Collectively, SeMet alleviated the DON-induced oxidative injury in porcine intestinal epithelial cells independent of the MAPK pathway regulation.

In vitro effects of the combination of serotonin, selenium, zinc, and vitamins D and E supplementation on human sperm motility and reactive oxygen species production.

Infertility affects 15% of all couples worldwide and 50% of cases of infertility are solely due to male factors. A decrease in motility in the semen is considered one of the main factors that is directly related to infertility. The use of supplementation to improve the overall sperm quality has become increasingly popular worldwide. The purpose of this study was to evaluate whether sperm motility was affected by the combination of serotonin (5-HT), selenium (Se), zinc (Zn), and vitamins D, and E supplementation. Semen samples were incubated for 75 min at 37°C in medium containing varying concentrations of 5-HT, Se, Zn, vitamin D, and E. 5-HT (200 μM), Se (2 μg/ml), Zn (10 μg/ml), vitamin D (100 nM), and vitamin E (2 mmol) have also been shown to increase progressive sperm motility. Three different mixtures of supplements were also tested for their combined effects on sperm motility and reactive oxygen species (ROS) production. While the total motility in the control group was 71.96%, this was found to increase to 82.85% in the first mixture. In contrast the average ROS level was 8.97% in the control group and decreased to 4.23% in the first mixture. Inclusion of a supplement cocktail (5-HT, Se, Zn, vitamins D and E) in sperm processing and culture medium could create an overall improvement in sperm motility while decreasing ROS levels during the incubation period. These molecules may enhance the success of assisted reproduction techniques when present in sperm preparation medium.

Antioxidative bioactive glass reinforced injectable hydrogel with reactive oxygen species scavenging capacity for diabetic wounds treatment

Diabetic wound healing remains a critical challenge due to its special hyperglycemic environment and disorder in wound healing process. The hyperglycemic microenvironment of diabetic wounds causes inhibitive angiogenesis and overproduction of reactive oxygen species (ROS), which leads to oxidative stress damage to biological macromolecules and cells, and hindrance of wound healing. Herein, an injectable thermo-sensitive methyl cellulose hydrogel with capacities of improving angiogenesis, scavenging ROS and antibiosis is developed to overcome the obstacles of diabetic wound healing. Through loading antioxidative cerium-doped bioactive glass nanoparticles (CeBG), the hydrogel demonstrates efficient ROS scavenging to protect cells from oxidative stress harm, as well as stimulation of dermal fibroblast proliferation and migration. Moreover, addition of quaternary chitosan (QCS) endows the hydrogel with antibacterial ability against E. coli and S. aureus. The hydrogel effectively accelerates diabetic wound healing in a mice model, and more importantly, the wound area presents improved angiogenesis, diminished inflammation and decreased ROS level. These data demonstrate that the hydrogel is a promising biomaterial for the clinical treatment of diabetic wounds, as well as facilitating the therapy of oxidative stress related diseases.

ABHD6 suppresses colorectal cancer progression via AKT signaling pathway.

Colorectal cancer (CRC) continues to be a prevalent malignancy, posing a significant risk to human health. The involvement of alpha/beta hydrolase domain 6 (ABHD6), a serine hydrolase family member, in CRC development was suggested by our analysis of clinical data. However, the role of ABHD6 in CRC remains unclear. This study seeks to elucidate the clinical relevance, biological function, and potential molecular mechanisms of ABHD6 in CRC. We investigated the role of ABHD6 in clinical settings, conducting proliferation, migration, and cell cycle assays. To determine the influence of ABHD6 expression levels on Oxaliplatin sensitivity, we also performed apoptosis assays. RNA sequencing and KEGG analysis were utilized to uncover the potential molecular mechanisms of ABHD6. Furthermore, we validated its expression levels using Western blot and reactive oxygen species (ROS) detection assays. Our results demonstrated that ABHD6 expression in CRC tissues was notably lower compared to adjacent normal tissues. This low expression correlated with a poorer prognosis for CRC patients. Moreover, ABHD6 overexpression impeded CRC cell proliferation and migration while inducing G0/G1 cell cycle arrest. In vivo experiments revealed that downregulation of ABHD6 resulted in an increase in tumor weight and volume. Mechanistically, ABHD6 overexpression inhibited the activation of the AKT signaling pathway and decreased ROS levels in CRC cells, suggesting the role of ABHD6 in CRC progression via the AKT signaling pathway. Our findings demonstrate that ABHD6 functions as a tumor suppressor, primarily by inhibiting the AKT signaling pathway. This role establishes ABHD6 as a promising prognostic biomarker and a potential therapeutic target for CRC patients.

Short communication: ROS production and mitochondrial membrane potential in hemocytes of marine bivalves, Mytilus galloprovincialis and Magallana gigas, under hypoosmotic stress.

Bivalve mollusks that inhabit low-depth coastal and estuarine areas frequently experience osmotic stress that may be also associated with alterations of antioxidant enzyme activities and markers of oxidative stress. Mitochondria are a major source of reactive oxygen species (ROS) in eucaryotic cells. Overpoduction of ROS induces oxidative stress leading to a damage of intracellular compartments and cell death. In euryhaline bivalves, information concerning cellular ROS production upon osmotic stress and changes in mitochondrial membrane potential is scarce. The present study investigates osmotic stability and hemocytes` regulatory volume decrease (RVD) of Mediterranean mussel (Mytilus galloprovincialis) and the Pacific oyster (Magallana gigas). We also studied dynamic changes in intracellular ROS levels and mitochondrial membrane potential in hemocytes undergoing the RVD response following hypoosmotic swelling. Our data revealed that osmotic stability of mussel and oyster hemocytes did not significantly differ. Loss of environmental osmolarity from 460.0±2.0mOsml-1 to 216.0±4.0mOsml-1 resulted in an increase of hemocyte volume by 60% of the initial cellular volume in mussels and by 28% in oysters. After rapid hypoosmotic swelling hemocytes of both species demonstrated the RVD response. At the end of 60min exposure to hypoosmotic environment, hemocyte volume significantly decreased in both species by 10-12% compared to the maximal hemocyte volume. Hypoosmotic shock induced an increase of mitochondrial membrane potential in hemocytes of mussels and oysters. In mussels, increased mitochondrial membrane potential was accompanied with decreased ROS levels in hemocytes, whereas oyster hemocytes showed enhanced ROS production.

Tanshinone I attenuates estrogen-deficiency bone loss via inhibiting RANKL-induced MAPK and NF-κB signaling pathways

Aim of the studyThis study aims to reveal the role of Tanshinone I (TI) in inhibiting osteoclast activity and bone loss in vitro and in vivo, as well as elucidate its underlying molecular mechanism. Materials and methodsA mouse model of estrogen deficiency was used to assess the inhibitory effect of TI on osteoclast activity and subsequent bone loss. To validate the impact of TI on osteoclast formation, TRAcP staining and pseudopodia belt staining were conducted. The expressions of osteoclast-specific genes and proteins were evaluated using RT-PCR and Western Blot analyses. Additionally, immunofluorescence staining was employed to examine the effect of TI on p65 nuclear translocation and the expression level of reactive oxygen species (ROS). ResultsTI demonstrated significant efficacy in alleviating bone mass loss and suppressing osteoclast activity and function in ovariectomized mice. This outcome was predominantly ascribed to a decrease in ROS levels, thereby impeding the NF-κB signaling pathway and the translocation of p65 to the nucleus. Additionally, TI hindered the RANKL-induced phosphorylation of the MAPK signaling pathway. Moreover, TI played a role in the reduction of osteoclast-specific genes and proteins. ConclusionsTo summarize, this study sheds light on TI's capacity to modulate various signaling pathways triggered by RANKL, effectively impeding osteoclast formation and mitigating bone loss resulting from estrogen deficiency. Consequently, TI emerges as a promising therapeutic option for estrogen-deficiency bone loss.

Sustained Release of Hydrogen by PdH‐Te Nanozyme for Anti‐Inflammatory Therapy Against Atherosclerosis

AbstractAtherosclerosis is induced by the persistent inflammation of the arterial wall. The regulation of inflammation through active drugs can mitigate atherosclerotic lesions, but the therapeutic outcome is limited due to its insufficient efficacy and stability. Herein, a PdH‐Te nanozyme with excellent reactive oxygen species (ROS) scavenging capability is designed for anti‐inflammatory therapy, thereby preventing foam cell formation to alleviate atherosclerosis. As expected, the PdH‐Te nanozyme shows outstanding multiple antioxidant enzyme activities and sustained hydrogen release properties. Benefiting from decreased ROS levels by enzyme catalysis, PdH‐Te nanozyme significantly suppresses the pro‐inflammatory cytokines for atherosclerosis treatment. Taken together, the presented results demonstrate that inhibition of inflammation based on PdH‐Te nanozyme can effectively treat atherosclerosis, identifying an attractive strategy against cardiovascular diseases.

Alternative oxidase 2 influences Arabidopsis seed germination under salt stress by modulating ABA signalling and ROS homeostasis

Seed germination is a critical checkpoint for plant survival under stresses, which requires functional mitochondria for energy and signal supply. Mitochondrial ALTERNATIVE OXIDASE 2 (AOX2) is specifically and highly expressed at early seed germination; however, its regulatory mechanism remains unknown. Here, the mutant (aox2), over-expression (AOX2OE) and complementation (aox2Comp, proAOX2::gAOX2/aox2) lines were used to investigate AOX2 roles. AOX2 transcript was significantly up-regulated under ABA, NaCl, H2O2, PEG6000 or mannitol treatments during seed germination. Compared with WT and aox2Comp, seed germination and greening were delayed in aox2 under NaCl treatment but enhanced in AOX2OE lines. The transcripts of key genes related to ABA biosynthesis and signal transduction were up-regulated in aox2 compared with those in WT under salt stress. Consequently, the higher ABA level was found in aox2. Na2WO4, the inhibitor of ABA biosynthesis, significantly enhanced germination rate of aox2. Mutation of ABA-INSENSITIVE 3 (ABI3) or ABI4 can partially reverse the salt-sensitive phenotypes of aox2. Yeast one-hybrid, D-luciferin enzyme (LUC) assay and transient expression experiments further revealed ABI3 and ABI4 can directly interact with AOX2 promoter and enhance its expression. Reactive oxygen species (ROS), mainly produced from the root tip mitochondria of germinated seeds, were accumulated more in aox2 than those in WT. Exogenous ascorbic acid (AsA) decreased ROS level and fully rescued the salt-hypersensitive phenotypes of aox2. Taken together, AOX2 plays an important role in Arabidopsis seed germination through regulating ABA signal and ROS homeostasis under salt stress; in the process, ABI3/ABI4 is indispensable for salinity-induced AOX2 expression.

Effect of Adrenocorticotropic Hormone Stimulation on Ischemiamodified Albumin Levels in vivo

Ischemia-modified albumin (IMA) formation is associated with increased reactive oxygen species (ROS) production, while increased cortisol leads to decreased ROS levels. We aimed to evaluate the effect of adrenocorticotropic hormone (ACTH) stimulation on IMA levels and whether the effect was dose-dependent or not. A total of 99 subjects with normal ACTH test results were included in the study. Of these, 80 had standard-dose ACTH test while 19 had low-dose ACTH test. Blood samples were collected to determine cortisol and IMA levels; at minutes 0, 30, and 60 following the standard-dose ACTH test and at minutes 0 and 30 following the low-dose ACTH test. IMA levels decreased significantly within 30 minutes and the decrease continued up to the sixtieth minute (p=0.002) after standard-dose ACTH stimulation. After ACTH stimulation, a weak negative correlation was found between peak cortisol and IMA levels at the thirtieth minute (r=0.233, p=0.02). There was no significant difference in IMA levels after low-dose ACTH stimulation, despite an increase in cortisol (p=0.161). IMA levels decreased rapidly after standard-dose ACTH stimulation, while a decrease in IMA levels was not observed after low-dose ACTH stimulation. The lack of decrease in IMA levels after low-dose ACTH stimulation suggests a possible dose-dependent relationship between ACTH and IMA. The moderate increase in cortisol with no reduction in IMA levels after low-dose ACTH stimulation and the weak correlation between peak cortisol and 30-minute IMA levels after standard-dose ACTH stimulation suggest that ACTH may have a direct effect on IMA.

Pathogenicity and Function Analysis of Two Novel SLC4A11 Variants in Patients With Congenital Hereditary Endothelial Dystrophy.

The purpose of this study was to explore the pathogenicity and function of two novel SLC4A11 variants associated with congenital hereditary endothelial dystrophy (CHED) and to study the function of a SLC4A11 (K263R) mutant in vitro. Ophthalmic examinations were performed on a 28-year-old male proband with CHED. Whole-exome and Sanger sequencing were applied for mutation screening. Bioinformatics and pathogenicity analysis were performed. HEK293T cells were transfected with the plasmids of empty vector, wild-type SLC4A11, and SLC4A11 (K263R) mutant. The transfected cells were treated with SkQ1. Oxygen consumption, cellular reactive oxygen species (ROS) level, mitochondrial membrane potential, and apoptosis rate were measured. The proband had poor visual acuity with nystagmus since childhood. Corneal foggy opacity was evident in both eyes. Two novel SLC4A11 variants were detected. Sanger sequencing showed that the proband's father and sister carried c.1464-1G>T variant, and the proband's mother and sister carried c.788A>G (p.Lys263Arg) variant. Based on the American College of Medical Genetics (ACMG) guidelines, SLC4A11 c.1464-1G>T was pathogenic, whereas c.788A>G, p.K263R was a variant of undetermined significance. In vitro, SLC4A11 (K263R) variant increased ROS level and apoptosis rate. Decrease in mitochondrial membrane potential and oxygen consumption rate were remarkable. Furthermore, SkQ1 decreased ROS levels and apoptosis rate but increased mitochondrial membrane potential in the transfected cells. Two novel heterozygous pathogenic variants of the SLC4A11 gene were identified in a family with CHED. The missense variant SLC4A11 (K263R) caused mitochondrial dysfunction and increased apoptosis in mutant transfected cells. In addition, SkQ1 presented a protective effect suggesting the anti-oxidant might be a novel therapeutic drug. This study verified the pathogenicity of 2 novel variants in the SLC4A11 gene in a CHED family and found an anti-oxidant might be a new drug.