Reactive Oxygen Species Signaling Research Articles

Reactive Oxygen Species Modulation in the Current Landscape of Anticancer Therapies.

Significance: Reactive oxygen species (ROS) are generated during mitochondrial oxidative metabolism, and are tightly controlled through homeostatic mechanisms to maintain intracellular redox, regulating growth and proliferation in healthy cells. However, ROS production is perturbed in cancers where abnormal accumulation of ROS leads to oxidative stress and genomic instability, triggering oncogenic signaling pathways on one hand, while increasing oxidative damage and triggering ROS-dependent death signaling on the other. Recent Advances: Our review illuminates how critical interactions between ROS and oncogenic signaling, the tumor microenvironment, and DNA damage response (DDR) pathways have led to interest in ROS modulation as a means of enhancing existing anticancer strategies and developing new therapeutic opportunities. Critical Issues: ROS equilibrium exists via a delicate balance of pro-oxidant and antioxidant species within cells. "Antioxidant" approaches have been explored mainly in the form of chemoprevention, but there is insufficient evidence to advocate its routine application. More progress has been made via the "pro-oxidant" approach of targeting cancer vulnerabilities and inducing oxidative stress. Various therapeutic modalities have employed this approach, including direct ROS-inducing agents, chemotherapy, targeted therapies, DDR therapies, radiotherapy, and immunotherapy. Finally, emerging delivery systems such as "nanosensitizers" as radiotherapy enhancers are currently in development. Future Directions: While approaches designed to induce ROS have shown considerable promise in selectively targeting cancer cells and dealing with resistance to conventional therapies, most are still in early phases of development and challenges remain. Further research should endeavor to refine treatment strategies, optimize drug combinations, and identify predictive biomarkers of ROS-based cancer therapies.

Understanding mechanisms for differential salinity tissue tolerance between quinoa and spinach: Zooming on ROS-inducible ion channels

Soil salinity is a worldwide issue and a major threat to global food security. Salinity tolerance is a complex mechanism that is conferred by numerous molecular, physiological, and biochemical traits. Of critical importance are plant’s ability to regulate redox balance without compromising reactive oxygen species (ROS) signalling and maintain cytosolic ion homeostasis. In this study, the mechanistic basis of K+ retention ability in leaf mesophyll (an important but highly sensitive plant tissue) was compared between halophytic quinoa and glycophytic spinach. Phenotypic data showed quinoa outperformed spinach under 100 to 500 mmol L−1 NaCl salinity. The major difference behind this differential salinity sensitivity was a differential K+ uptake in leaf mesophyll. Electrophysiological and molecular experiments revealed that a superior ability of mesophyll K+ retention in quinoa was conferred by three complementary mechanisms: (i) an intrinsically lower H+-ATPase activity in quinoa (potentially as an energy saving strategy); (ii) reduced sensitivity of K+ transporters to ROS; and (iii) increased sensitivity of ROS-inducible Ca2+-permeable channels. Moreover, the sensitivity of K+-transport systems to ROS was further examined in NaCl-acclimated quinoa and spinach plants. The key factors differentiating between K+ retention in acclimated leaf mesophyll was associated with the reduced sensitivity and gene expression of K+-permeable outward rectifying channel (GORK), Arabidopsis potassium transporter 1 (AKT1), and high affinity potassium transporter 5 (HAK5) to additional NaCl and ROS stress, along with the upregulation of ROS scavenging system. Taken together, our results showed that the tissue-specific and ROS-specific regulation of K+ retention are important for conferring salinity tolerant at least in the halophyte quinoa.

Adenosine triphosphate alleviates high temperature-enhanced glyphosate toxicity in maize seedlings

Extracellular ATP plays a key role in regulating plants stress responses. Here, we aimed to determine whether ATP can alleviate the glyphosate toxicity in maize seedlings under high temperature by regulating antioxidant responses. Foliar spraying with 100 μM glyphosate inhibited the growth of maize seedlings at room temperature (25 °C), leading to an increase in shikimic acid accumulation and oxidative stress (evaluated via lipid peroxidation, free proline, and H2O2 content) in the leaves, all of which were further exacerbated by high temperature (35 °C). The growth inhibition and oxidative stress caused by glyphosate were both alleviated by exogenous ATP. Moreover, the glyphosate-induced antioxidant enzyme activity and antioxidant accumulation were attenuated by high temperature, while ATP treatment reversed this inhibitory effect. Similarly, qPCR data showed that the relative expression levels of antioxidant enzyme-related genes (CAT1, GR1, and γ-ECS) in maize leaves were upregulated by ATP before exposure to GLY. Moreover, high temperature-enhanced GLY residue accumulation in maize leaves was reduced by ATP. ATP-induced detoxification was attenuated through NADPH oxidase (NOX) inhibition. Higher NOX activities and O2•− production were noted in ATP-treated maize leaves compared to controls prior to GLY treatment, indicating that the extracellular ATP-induced alleviation of GLY toxicity was closely associated with NOX-dependent reactive oxygen species signalling. The current findings present a new approach for reducing herbicide toxicity in crops exposed to high temperatures.

Targeting Peroxisome Proliferator-Activated Receptor-β/δ, Reactive Oxygen Species and Redox Signaling with Phytocompounds for Cancer Therapy.

Significance: Peroxisome proliferator-activated receptors (PPARs) have a moderately preserved amino-terminal domain, an extremely preserved DNA-binding domain, an integral hinge region, and a distinct ligand-binding domain that are frequently encountered with the other nuclear receptors. PPAR-β/δ is among the three nuclear receptor superfamily members in the PPAR group. Recent Advances: Emerging studies provide an insight on natural compounds that have gained increasing attention as potential anticancer agents due to their ability to target multiple pathways involved in cancer development and progression. Critical Issues: Modulation of PPAR-β/δ activity has been suggested as a potential therapeutic strategy for cancer management. This review focuses on the ability of bioactive phytocompounds to impact reactive oxygen species (ROS) and redox signaling by targeting PPAR-β/δ for cancer therapy. The rise of ROS in cancer cells may play an important part in the initiation and progression of cancer. However, excessive levels of ROS stress can also be toxic to the cells and cancer cells with increased oxidative stress are likely to be more vulnerable to damage by further ROS insults induced by exogenous agents, such as phytocompounds and therapeutic agents. Therefore, redox modulation is a way to selectively kill cancer cells without causing significant toxicity to normal cells. However, use of antioxidants together with cancer drugs may risk the effect of treatment as both act through opposite mechanisms. Future Directions: It is advisable to employ more thorough and detailed methodologies to undertake mechanistic explorations of numerous phytocompounds. Moreover, conducting additional clinical studies is recommended to establish optimal dosages, efficacy, and the impact of different phytochemicals on PPAR-β/δ.

OsRR26, a type-B response regulator, modulates salinity tolerance in rice via phytohormone-mediated ROS accumulation in roots and influencing reproductive development.

OsRR26 is a cytokinin-responsive response regulator that promotes phytohormone-mediated ROS accumulation in rice roots, regulates seedling growth, spikelet fertility, awn development, represses NADPH oxidases, and negatively affects salinity tolerance. Plant two-component systems (TCS) play a pivotal role in phytohormone signaling, stress responses, and circadian rhythm. However, a significant knowledge gap exists regarding TCS in rice. In this study, we utilized a functional genomics approach to elucidate the role of OsRR26, a type-B response regulator in rice. Our results demonstrate that OsRR26 is responsive to cytokinin, ABA, and salinity stress, serving as the ortholog of Arabidopsis ARR11. OsRR26 primarily localizes to the nucleus and plays a crucial role in seedling growth, spikelet fertility, and the suppression of awn development. Exogenous application of cytokinin led to distinct patterns of reactive oxygen species (ROS) accumulation in the roots of both WT and transgenic plants (OsRR26OE and OsRR26KD), indicating the potential involvement of OsRR26 in cytokinin-mediated ROS signaling in roots. The application of exogenous ABA resulted in varied cellular compartmentalization of ROS between the WT and transgenic lines. Stress tolerance assays of these plants revealed that OsRR26 functions as a negative regulator of salinity stress tolerance across different developmental stages in rice. Physiological and biochemical analyses unveiled that the knockdown of OsRR26 enhances salinity tolerance, characterized by improved chlorophyll retention and the accumulation of soluble sugars, K+ content, and amino acids, particularly proline.

Functional analysis of reactive oxygen species-driven stress systemic signalling, interplay and acclimation.

Reactive oxygen species (ROS) play a critical role in plant development and stress responses, acting as key components in rapid signalling pathways. The 'ROS wave' triggers essential acclimation processes, ultimately ensuring plant survival under diverse challenges. This review explores recent advances in understanding the composition and functionality of the ROS wave within plant cells. During their initiation and propagation, ROS waves interact with other rapid signalling pathways, hormonesand various molecular compounds. Recent research sheds light on the intriguing lack of a rigid hierarchy governing these interactions, highlighting a complex interplay between diverse signals. Notably, ROS waves culminate in systemic acclimation, a crucial outcome for enhanced stress tolerance. This review emphasizes the versatility of ROS, which act as flexible players within a network of short- and long-term factors contributing to plant stress resilience. Unveiling the intricacies of these interactions between ROS and various signalling molecules holds immense potential for developing strategies to augment plant stress tolerance, contributing to improved agricultural practices and overall ecosystem well-being.

Evolution of the WRKY Family in Angiosperms and Functional Diversity under Environmental Stress.

The transcription factor is an essential factor for regulating the responses of plants to external stimuli. The WRKY protein is a superfamily of plant transcription factors involved in response to various stresses (e.g., cold, heat, salt, drought, ions, pathogens, and insects). During angiosperm evolution, the number and function of WRKY transcription factors constantly change. After suffering from long-term environmental battering, plants of different evolutionary statuses ultimately retained different numbers of WRKY family members. The WRKY family of proteins is generally divided into three large categories of angiosperms, owing to their conserved domain and three-dimensional structures. The WRKY transcription factors mediate plant adaptation to various environments via participating in various biological pathways, such as ROS (reactive oxygen species) and hormone signaling pathways, further regulating plant enzyme systems, stomatal closure, and leaf shrinkage physiological responses. This article analyzed the evolution of the WRKY family in angiosperms and its functions in responding to various external environments, especially the function and evolution in Magnoliaceae plants. It helps to gain a deeper understanding of the evolution and functional diversity of the WRKY family and provides theoretical and experimental references for studying the molecular mechanisms of environmental stress.

A novel lectin receptor kinase gene, AtG-LecRK-I.2, enhances bacterial pathogen resistance through regulation of stomatal immunity in Arabidopsis

The S-locus lectin receptor kinases (G-LecRKs) have been suggested as receptors for microbe/damage-associated molecular patterns (MAMPs/DAMPs) and to be involved in the pathogen defense responses, but the functions of most G-LecRKs in biotic stress response have not been characterized. Here, we identified a member of this family, G-LecRK-I.2, that positively regulates flg22- and Pseudomonas syringae pv. tomato (Pst) DC3000-induced stomatal closure. G-LecRK-I.2 was rapidly phosphorylated under flg22 treatment and could interact with the FLS2/BAK1 complex. Two T-DNA insertion lines, glecrk-i.2–1 and glecrk-i.2–2, had lower levels of reactive oxygen species (ROS) and nitric oxide (NO) production in guard cells, as compared with the wild-type Col-0, under Pst DC3000 infection. Also, the immunity marker genes CBP60g and PR1 were induced at lower levels under Pst DC3000 hrcC- infection in glecrk-i.2–1 and glecrk-i.2–2. The GUS reporter system also revealed that G-LecRK-I.2 was expressed only in guard cells. We also found that G-LecRK-I.2 could interact H+-ATPase AHA1 to regulate H+-ATPase activity in the guard cells. Taken together, our results show that G-LecRK-I.2 plays an important role in regulating stomatal closure under flg22 and Pst DC3000 treatments and in ROS and NO signaling specifically in guard cells.

Activity-dependent mitochondrial ROS signaling regulates recruitment of glutamate receptors to synapses.

Our understanding of mitochondrial signaling in the nervous system has been limited by the technical challenge of analyzing mitochondrial function in vivo. In the transparent genetic model Caenorhabditis elegans, we were able to manipulate and measure mitochondrial reactive oxygen species (mitoROS) signaling of individual mitochondria as well as neuronal activity of single neurons in vivo. Using this approach, we provide evidence supporting a novel role for mitoROS signaling in dendrites of excitatory glutamatergic C. elegans interneurons. Specifically, we show that following neuronal activity, dendritic mitochondria take up calcium (Ca2+) via the mitochondrial Ca2+ uniporter (MCU-1) that results in an upregulation of mitoROS production. We also observed that mitochondria are positioned in close proximity to synaptic clusters of GLR-1, the C. elegans ortholog of the AMPA subtype of glutamate receptors that mediate neuronal excitation. We show that synaptic recruitment of GLR-1 is upregulated when MCU-1 function is pharmacologically or genetically impaired but is downregulated by mitoROS signaling. Thus, signaling from postsynaptic mitochondria may regulate excitatory synapse function to maintain neuronal homeostasis by preventing excitotoxicity and energy depletion.

Growth, Physiological, and Transcriptome Analyses Reveal Mongolian Oak Seedling Responses to Shading

Mongolian oak (Quercus mongolica) is a common building material and landscaping tree species in northern China, with significant economic and ecological value. Its seedling growth is inhibited by high light intensity, but the mechanism by which light stress affects the growth and development of its seedlings remains unclear. In this study, we investigated the phenotypes, physiological processes, and molecular responses of 3-year-old Mongolian oak seedlings under different light treatments: full light (Sck), light shading (S1; 40% light), moderate shading (S2; 20% light), and severe shading (S3; 3% light). Compared to Sck, the S1 and S2 treatments resulted in higher leaf area, photosynthetic pigment content, photosynthesis rates, soluble sugar contents, and soluble protein contents in Mongolian oak seedlings. The S1 and S2 treatments also promoted seedling height and diameter growth and resulted in lower degrees of membrane lipid peroxidation, cell membrane permeability, and antioxidant enzyme activity. In contrast, severe shading (S3) significantly inhibited seedling height and diameter growth due to the lower net photosynthetic rate, and exhibiting higher degrees of membrane lipid peroxidation and cell membrane permeability. Shading treatments (S1 and S2) alleviated the negative effects of strong light on the growth and development of Mongolian oak seedlings, with the S2 treatment having the greatest effect. However, severe shading (S3) inhibited growth and development. A total of 3726 differentially expressed genes (DEGs) were detected in leaves under different shading treatments in RNA sequencing analysis. Among these, 1691, 3150, and 824 DEGs were detected in the Sck-S1, Sck-S2, and S1-S2 comparison groups, respectively. The different shading treatments determined common expression regulation pathways, including carotenoid biosynthesis, photosynthetic antenna proteins, and mitogen activated protein kinase (MAPK) signal transduction. Shading induced increases in gene expression levels in light harvesting complexes, which are related to changes in gene expression in the photosynthetic system, leading to changes in photosynthetic physiology. The expression levels of genes related to reactive oxygen species signal perception and activation enzymes were upregulated in Sck. Together, these findings revealed the response mechanisms of Mongolian oak seedlings to different shading levels at the physiological and molecular levels, providing a scientific basis and technical support for the cultivation and large-scale production of Mongolian oak seedlings.

ROS signaling in innate immunity via oxidative protein modifications.

The innate immune response represents the first-line of defense against invading pathogens. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) have been implicated in various aspects of innate immune function, which involves respiratory bursts and inflammasome activation. These reactive species widely distributed within the cellular environment are short-lived intermediates that play a vital role in cellular signaling and proliferation and are likely to depend on their subcellular site of formation. NADPH oxidase complex of phagocytes is known to generate superoxide anion radical (O2 •-) that functions as a precursor for antimicrobial hydrogen peroxide (H2O2) production, and H2O2 is utilized by myeloperoxidase (MPO) to generate hypochlorous acid (HOCl) that mediates pathogen killing. H2O2 modulates the expression of redox-responsive transcriptional factors, namely NF-kB, NRF2, and HIF-1, thereby mediating redox-based epigenetic modification. Survival and function of immune cells are under redox control and depend on intracellular and extracellular levels of ROS/RNS. The current review focuses on redox factors involved in the activation of immune response and the role of ROS in oxidative modification of proteins in macrophage polarization and neutrophil function.

Glsirt1-mediated deacetylation of GlCAT regulates intracellular ROS levels, affecting ganoderic acid biosynthesis in Ganoderma lucidum

Lysine acetylation is a reversible, dynamic protein modification regulated by lysine acetyltransferases and deacetylases. However, in Basidiomycetes, the extent of lysine acetylation of nonhistone proteins remains largely unknown. Recently, we identified the deacetylase Glsirt1 as a key regulator of the biosynthesis of ganoderic acid (GA), a key secondary metabolite of Ganoderma lucidum. To gain insight into the characteristics, extent, and biological function of Glsirt1-mediated lysine acetylation in G. lucidum, we aimed to identify additional Glsirt1 substrates via comparison of acetylomes between wild-type (WT) and Glsirt1-silenced mutants. A large amount of Glsirt1-dependent lysine acetylation occurs in G. lucidum according to the results of this omics analysis, involving energy metabolism, protein synthesis, the stress response and other pathways. Our results suggest that GlCAT is a direct target of Glsirt1 and that the deacetylation of GlCAT by Glsirt1 reduces catalase activity, thereby leading to the accumulation of intracellular reactive oxygen species (ROS) and positively regulating the biosynthesis of GA. Our findings provide evidence for the involvement of nonhistone lysine acetylation in the biological processes of G. lucidum and help elucidate the involvement of important ROS signaling molecules in regulating physiological and biochemical processes in this organism. In conclusion, this proteomic analysis reveals a striking breadth of cellular processes affected by lysine acetylation and provides new nodes of intervention in the biosynthesis of secondary metabolites in G. lucidum.

Particulate matter stimulates the NADPH oxidase system via AhR-mediated epigenetic modifications

Stimulation of human keratinocytes with particulate matter 2.5 (PM2.5) elicits complex signaling events, including a rise in the generation of reactive oxygen species (ROS). However, the mechanisms underlying PM2.5-induced ROS production remain unknown. Here, we show that PM2.5-induced ROS production in human keratinocytes is mediated via the NADPH oxidase (NOXs) system and the Ca2+ signaling pathway. PM2.5 treatment increased the expression of NOX1, NOX4, and a calcium-sensitive NOX, dual oxidase 1 (DUOX1), in human epidermal keratinocyte cell line. PM2.5 bound to aryl hydrocarbon receptor (AhR), and this complex bound to promoter regions of NOX1 and DUOX1, suggesting that AhR acted as a transcription factor of NOX1 and DUOX1. PM2.5 increased the transcription of DUOX1 via epigenetic modification. Moreover, a link between DNA demethylase and histone methyltransferase with the promoter regions of DUOX1 led to an elevation in the expression of DUOX1 mRNA. Interestingly, PM2.5 increased NOX4 expression and promoted the interaction of NOX4 and Ca2+ channels within the cytoplasmic membrane or endoplasmic reticulum, leading to Ca2+ release. The increase in intracellular Ca2+ concentration activated DUOX1, responsible for ROS production. Our findings provide evidence for a PM2.5-mediated ROS-generating system network, in which increased NOX1, NOX4, and DUOX1 expression serves as a ROS signal through AhR and Ca2+ activation.

Platycodon D protects human nasal epithelial cells from pyroptosis through the Nrf2/HO-1/ROS signaling cascade in chronic rhinosinusitis

BackgroundPyroptosis has been demonstrated being closely associated with the inflammatory progression in chronic rhinosinusitis (CRS). However, platycodon D (PLD) has emerged as a key anti-inflammatory mediator in the inflammatory progression of various respiratory diseases. This study aims at investigating whether PLD could reduce inflammatory progression of CRS by inhibiting pyroptosis.MethodsNasal mucosal tissues from patients with CRS and the control group (simple nasal septal deviation) were analyzed for morphological difference using hematoxylin & eosin staining and for the expression of pyroptosis-related makers by immunofluorescence (IF). Human nasal epithelial cells (HNEpCs) were cultured and co-stimulated with lipopolysaccharide (LPS)/adenosine triphosphate (ATP) to construct an in vitro cellular model simulating CRS. After pretreatment with PLD, EthD-I staining, TUNEL staining, transmission electron microscopy (TEM), and GSDMD-NT detection were performed to evaluate pyroptosis markers. The NLRP3 inflammasome was detected by IF and western blotting (WB). Reactive oxygen species (ROS) were detected by H2DCFDA staining, and mitochondrial membrane potential was evaluated by JC-1 staining. Mitochondrial morphology and structure were observed using TEM. The Nrf2/HO-1 antioxidant signaling pathway was detected using WB.ResultsThe nasal mucosa structure of patients with CRS exhibited significant damage, with a marked increase in the expression of pyroptosis-related proteins compared with the control group. LPS/ATP co-stimulation resulted in an increased expression of IL-18 and IL-1β in HNEpCs, causing significant damage to nuclear and cell membranes, GSDMD-NT accumulation around the cell membrane, and intracellular NLRP3 inflammasome activation. Furthermore, it led to increased ROS expression, significantly decreased mitochondrial membrane potential, and damaged mitochondrial structure. However, pretreatment with PLD significantly reversed the aforementioned trends and activated the Nrf2/HO-1 antioxidant signaling pathway.ConclusionsThe results of this study confirm that NLRP3-mediated pyroptosis plays a crucial role in the pathological process of nasal mucosal impairment in patients with CRS. PLD inhibits NLRP3-mediated pyroptosis, preventing inflammatory damage in HNEpCs of patients with CRS by activating the Nrf2/HO-1 antioxidant signaling pathway, which in turn reduces ROS production and ameliorates mitochondrial damage.

Role of reactive oxygen species (ROS) signaling pathway in the wound-induced spore formation of Pyropia yezoensis

Asexual spore formation of Pyropia yezoensis significantly impacts yield. After mechanical sectioning of leafy thalli into fragments, somatic cells rapidly develop into a large number of wound-induced spores (WIS, a form of asexual spores). Recent studies on P. yezoensis have demonstrated a notable increase in reactive oxygen species (ROS) during this process; however, the regulatory mechanism underlying this ROS signaling remains largely unclear. This paper shows that in P. yezoensis, ROS signals play a crucial role in WIS formation. When treated with the ROS-producing enzyme NADPH oxidase inhibitor diphenyleneiodonium chloride, P. yezoensis thalli fragments strongly repressed WIS formation, accompanied by a significant decrease of ROS levels, malondialdehyde contents, and activities of NADPH oxidase and antioxidant enzymes. The expression levels of respiratory burst oxidase homolog genes, aquaporin protein genes, superoxide dismutase genes, glutathione S-transferase genes, and glutathioneperoxidase genes were also decreased, thus inhibiting WIS formation. As an upstream signal, ROS promote ion exchange and metabolism both inside and outside of cells within the first 12 h of wound stress. Following 12 h of wound stress, transcriptional activation of specific genes associated with cell cycle progression—which promotes cell division and dedifferentiation under normal conditions—was also blocked by diphenyleneiodonium chloride. In addition, the generated ROS signals also regulated the expression of mitogen-activated protein kinase family genes under wound stress. Overall, this study provides novel insights into the molecular mechanism underlying the ROS signaling regulation of WIS formation in P. yezoensis.

Reactive Oxygen Species Signaling and Oxidative Stress: Transcriptional Regulation and Evolution.

Since the evolution of the aerobic metabolism, reactive oxygen species (ROS) have represented significant challenges to diverse life forms. In recent decades, increasing knowledge has revealed a dual role for ROS in cell physiology, showing they serve as a major source of cellular damage while also functioning as important signaling molecules in various biological processes. Our understanding of ROS homeostasis and ROS-mediated cellular signaling pathways has presumed that they are ancient and highly conserved mechanisms shared by most organisms. However, emerging evidence highlights the complexity and plasticity of ROS signaling, particularly in animals that have evolved in extreme environments. In this review, we focus on ROS generation, antioxidative systems and the main signaling pathways that are influenced by ROS. In addition, we discuss ROS's responsive transcription regulation and how it may have been shaped over the course of evolution.

Chaihu Sanshen Capsules protect rats from myocardial ischemia reperfusion injury via PKCβⅡ/NOX2/ROS signaling pathway

This study aims to explore the pathogenesis of myocardial ischaemia reperfusion injury(MIRI) based on oxidative stress-mediated programmed cell death and the mechanism and targets of Chaihu Sanshen Capsules in treating MIRI via the protein kinase Cβ(PKCβⅡ)/NADPH oxidase 2(NOX2)/reactive oxygen species(ROS) signaling pathway. The rat model of MIRI was established by the ligation of the left anterior descending branch. Rats were randomized into 6 groups: sham group, model group, clinically equivalent-, high-dose Chaihu Sanshen Capsules groups, N-acetylcysteine group, and CGP53353 group. After drug administration for 7 consecutive days, the area of myocardial infarction in each group was measured. The pathological morphology of the myocardial tissue was observed by hematoxylin-eosin(HE) staining. The apoptosis in the myocardial tissue was observed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL). Enzyme-linked immunosorbent assay(ELISA) was employed to measure the le-vels of indicators of myocardial injury and oxidative stress. The level of ROS was detected by flow cytometry. The protein and mRNA levels of the related proteins in the myocardial tissue were determined by Western blot and real-time quantitative PCR(RT-qPCR), respectively. Compared with the sham group, the model group showed obvious myocardial infarction, myocardial structural disorders, interstitial edema and hemorrhage, presence of a large number of vacuoles, elevated levels of myocardial injury markers, myocardial apoptosis, ROS, and malondialdehyde(MDA), lowered superoxide dismutase(SOD) level, and up-regulated protein and mRNA le-vels of PKCβⅡ, NOX2, cysteinyl aspartate specific proteinase-3(caspase-3), and acyl-CoA synthetase long-chain family member 4(ACSL4) in the myocardial tissue. Compared with the model group, Chaihu Sanshen Capsules reduced the area of myocardial infarction, alleviated the pathological changes in the myocardial tissue, lowered the levels of myocardial injury and oxidative stress indicators and apoptosis, and down-regulated the mRNA and protein levels of PKCβⅡ, NOX2, caspase-3, and ACSL4 in the myocardial tissue. Chaihu Sanshen Capsules can inhibit oxidative stress and programmed cell death(apoptosis, ferroptosis) by regulating the PKCβⅡ/NOX2/ROS signaling pathway, thus mitigating myocardial ischemia reperfusion injury.

SlCathB2 as a negative regulator mediates a novel regulatory pathway upon high-temperature stress response in tomato.

High-temperature stress (HS) is a major abiotic stress that affects the yield and quality of plants. Cathepsin B-like protease 2 (CathB2) has been reported to play a role in developmental processes and stress response, but its involvement in HS response has not been identified. Here, overexpression, virus-induced gene silencing (VIGS)and RNA-sequencing analysis were performed to uncover the functional characteristics of SlCathB2-1 and SlCathB2-2 genes for HS response in tomato. The results showed that overexpression of SlCathB2-1 and SlCathB2-2 resulted in reduced heat tolerance of tomato to HS while silencing the genes resulted in enhanced heat tolerance. RNA-sequencing analysis revealed that the heat shock proteins (HSPs) exhibited higher expression in WT than in SlCathB2-1 and SlCathB2-2 overexpression lines. Furthermore, the possible molecular regulation mechanism underlying SlCathB2-1 and SlCathB2-2-mediated response to HS was investigated. We found that SlCathB2-1 and SlCathB2-2 negatively regulated antioxidant capacity by regulating a set of genes involved in antioxidant defence and reactive oxygen species (ROS) signal transduction. We also demonstrated that SlCathB2-1 and SlCathB2-2 positively regulated ER-stress-induced PCD (ERSID) by regulating unfolded protein response (UPR) gene expression. Furthermore, SlCathB2-1 and SlCathB2-2 interacting with proteasome subunit beta type-4 (PBA4) was identified in the ERSID pathway using yeast two-hybrid (Y2H) analysis and bimolecular fluorescence complementation (BiFC) screening. Overall, the study identified both SlCathB2-1 and SlCathB2-2 as new negative regulators to HS and presented a new HS response pathway. This provided the foundation for the construction of heat-tolerant molecular mechanisms and breeding strategies aiming to improve the thermotolerance of tomato plants.

A nondestructive asymptomatic early disease prediction method employing ROS-induced differential volatile emissions from dry rot-infected potatoes

Potatoes are a staple crop with many health benefits. Postharvest storage of potatoes takes a considerable amount of time. Potato dry rot is one of the most serious postharvest storage diseases, caused primarily by the fungus Fusarium sambucinum. It is possible to minimize losses if disease is detected early, which allows it to be controlled promptly. A phytopathogen infection can alter the volatile profile of plants. Identifying unique volatile organic compounds (VOCs) as biomarkers for early disease detection is an area of considerable research interest. In this study, we compared the VOC profiles of healthy and dry rot inoculated potatoes (cv. "Kufri Pukhraj") over a time course using gas chromatography-mass spectrometry (GC-MS). There were 29 differentially emitting VOCs between healthy and dry rot inoculated potatoes. Nevertheless, only four of these compounds (linalool tetrahydride, γ-muurolene, alloaromadendrene, and α-isomethyl ionone) were exclusively found in dry rot inoculated potatoes, and hence they were considered biomarkers. Furthermore, reactive oxygen species (ROS) levels were altered in potatoes that were inoculated with dry rot, suggesting a role for ROS signaling in differential VOC emissions. In the early stages of dry rot infection, when symptoms were barely visible, these four biomarker VOCs were robustly useful in distinguishing healthy and dry rot-infected potatoes. These novel biomarkers associated with this disease are promising candidates for non-destructive detection of dry rot in stored potatoes at an early asymptomatic stage. These biomarkers can be used to develop an e-nose sensor to predict dry rot in the future.

Network pharmacology analysis and experimental verification of the antitumor effect and molecular mechanism of isocryptomerin on HepG2 cells.

Isocryptomerin (ISO) is a flavonoid isolated from the natural medicine Selaginellae Herba, which has various pharmacological activities. This study investigated the antitumor effect and underlying molecular mechanism of ISO on hepatocellular carcinoma (HCC) HepG2 cells. The cell viability assay revealed that ISO has a considerable killing effect on HCC cell lines. The apoptosis assay showed that ISO induced mitochondria-dependent apoptosis through the Bad/cyto-c/cleaved (cle)-caspase-3/cleaved (cle)-PARP pathway. The network pharmacological analysis found 13 key target genes, and epidermal growth factor receptor (EGFR), AKT, mitogen-activated protein kinase(MAPK), and reactive oxygen species (ROS) signaling pathways were strongly associated with ISO against HCC. Further verification of the results showed that ISO induced apoptosis by increasing p-p38 and p-JNK expression and decreasing p-EGFR, p-SRC, p-ERK, and p-STAT3 expression. Furthermore, ISO induced G0/G1 phase arrest by downregulating p-AKT, Cyclin D, and CDK 4 expression and upregulating p21 and p27 expression in HepG2 cells. Moreover, ISO inhibited HepG2 cell migration by decreasing p-GSK-3β, β-catenin, and N-cadherin expression and increasing E-cadherin expression. Additionally, ISO promoted ROS accumulation in HepG2 cells, and ISO-induced apoptosis, arrest cell cycle, and inhibition of migration were reversed by an ROS scavenger, N-acetyl- l-cysteine. Overall, ISO induced cell apoptosis and cell cycle arrest and inhibited cell migration by ROS-mediated EGFR, AKT, and MAPK signaling pathways in HepG2 cells.