Regulation Of Enzyme Activity Research Articles

Cultivar-specific regulation of antioxidant enzyme activity and stomatal closure confer tolerance of wheat to elevated ozone: A two-year open-field study with five cultivars

Elevated concentrations of tropospheric ozone (O3) pose a significant threat to food production in many regions of the world. We conducted a two-year experiment with five winter wheat (Triticum aestivum L.) cultivars, Yangmai16 (Y16), Yangmai23 (Y23), Zhenmai12 (Z12), Yangmai29 (Y29), and Yangmai30 (Y30), to assess photosynthetic traits, lipid peroxidation, and antioxidant systems under ambient (A-O3) or elevated (E-O3; 1.5 times A-O3) O3 in a Free-Air O3-Concentration Enrichment system (FACE). E-O3 accelerated leaf senescence, manifested by marked reductions in photosynthetic rate, stomatal conductance, total antioxidant capacity, and photosynthetic pigment content, accompanied by altered antioxidant enzyme activity and a significant increase in malondialdehyde content (an indicator of lipid peroxidation). Most parameters showed significant inter-cultivar differences, as well as interactions between O3 and cultivar. The response of the antioxidant system in wheat flag leaves was influenced by O3 exposure levels. The response of antioxidant enzymes at the grain filling stage and the timely closure of stomata conferred tolerance to O3. This tolerance was associated with higher antioxidant enzyme activity at the anthesis stage but was not related to the size of stomata. This study provides a crucial theoretical foundation for further breeding O3-tolerant cultivars.

In Solution Identification of the Lysine-Cysteine Redox Switch with a NOS Bridge in Transaldolase by Sulfur K-Edge X-ray Absorption Spectroscopy.

A novel covalent post-translational modification (lysine-NOS-cysteine) was discovered in proteins, initially in the enzyme transaldolase of Neisseria gonorrhoeae (NgTAL) [Nature 2021, 593, 460-464], acting as a redox switch. The identification of this novel linkage in solution was unprecedented until now. We present detection of the NOS redox switch in solution using sulfur K-edge X-ray absorption spectroscopy (XAS). The oxidized NgTAL spectrum shows a distinct shoulder on the low-energy side of the rising edge, corresponding to a dipole-allowed transition from the sulfur 1s core to the unoccupied σ* orbital of the S-O group in the NOS bridge. This feature is absent in the XAS spectrum of reduced NgTAL, where Lys-NOS-Cys is absent. Our experimental and calculated XAS data support the presence of a NOS bridge in solution, thus potentially facilitating future studies on enzyme activity regulation mediated by the NOS redox switches, drug discovery, biocatalytic applications, and protein design.

Glucose Oxidase Energized Osmium with Dual-Active Centers and Triple Enzyme Activities for Infected Diabetic Wound Management.

Diabetic wounds are susceptible to bacterial infections, largely linked to high blood glucose levels (hyperglycemia). To treat such wounds, enzymes like glucose oxidase (GOx) can be combined with nanozymes (nanomaterials mimic enzymes) to use glucose effectively for purposes. However, there is still room for improvement in these systems, particularly in terms of process simplification, enzyme activity regulation, and treatment effects. Herein, the approach utilizes GOx to directly facilitate the biomineralized growth of osmium (Os) nanozyme (GOx-OsNCs), leading to dual-active centers and remarkable triple enzyme activities. Initially, GOx-OsNCs use vicinal dual-active centers, enabling a self-cascaded mechanism that significantly enhances glucose sensing performance compared to step-by-step reactions, surpassing the capabilities of other metal sources such as gold and platinum. In addition, GOx-OsNCs are integrated into a glucose-sensing gel, enabling instantaneous visual feedback. In the treatment of infected diabetic wounds, GOx-OsNCs exhibit multifaceted benefits by lowering blood glucose levels and exhibiting antibacterial properties through the generation of hydroxyl free radicals, thereby expediting healing by fostering a favorable microenvironment. Furthermore, the catalase-like activity of GOx-OsNCs aids in reducing oxidative stress, inflammation, and hypoxia, culminating in improved healing outcomes. Overall, this synergistic enzyme-nanozyme blend is user-friendly and holds considerable promise for diverse applications.

Protein succinylation, hepatic metabolism, and liver diseases.

Succinylation is a highly conserved post-translational modification that is processed via enzymatic and non-enzymatic mechanisms. Succinylation exhibits strong effects on protein stability, enzyme activity, and transcriptional regulation. Protein succinylation is extensively present in the liver, and increasing evidence has demonstrated that succinylation is closely related to hepatic metabolism. For instance, histone acetyltransferase 1 promotes liver glycolysis, and the sirtuin 5-induced desuccinylation is involved in the regulation of the hepatic urea cycle and lipid metabolism. Therefore, the effects of succinylation on hepatic glucose, amino acid, and lipid metabolism under the action of various enzymes will be discussed in this work. In addition, how succinylases regulate the progression of different liver diseases will be reviewed, including the desuccinylation activity of sirtuin 7, which is closely associated with fatty liver disease and hepatitis, and the actions of lysine acetyltransferase 2A and histone acetyltransferase 1 that act as succinyltransferases to regulate the succinylation of target genes that influence the development of hepatocellular carcinoma. In view of the diversity and significance of protein succinylation, targeting the succinylation pathway may serve as an attractive direction for the treatment of liver diseases.

Supramolecular Modulation of Fluid Flow in a Self-Powered Enzyme Micropump.

Regulating macroscopic fluid flow by catalytic harnessing of chemical energy could potentially provide a solution for powerless microfluidic devices. Earlier reports have shown that surface-anchored enzymes can actuate the surrounding fluid in the presence of the respective substrate in a concentration-dependent manner. It is also crucial to have control over the flow speed of a self-powered enzyme micropump in various applications where controlled dosing and mixing are required. However, modulating the flow speed independent of the fuel concentration remains a significant challenge. In a quest to regulate the fluid flow in such a system, a supramolecular approach has been adopted, where reversible regulation of enzyme activity was achieved by a two-faced synthetic receptor bearing sulfonamide and adamantane groups. The bovine carbonic anhydrase (BCA) enzyme containing a single binding site favorable to the sulfonamide group was used as a model enzyme, and the enzyme activity was inhibited in the presence of the two-faced inhibitor. The same effect was reflected when the immobilized enzyme was used as an engine to actuate the fluid flow. The flow velocity was reduced up to 53% in the presence of 100 μM inhibitor. Later, upon addition of a supramolecular "host" CB[7], the inhibitor was sequestered from the enzyme due to the higher binding affinity of CB[7] with the adamantane functionality of the inhibitor. As a result, the flow velocity was restored to ∼72%, thus providing successful supramolecular control over a self-powered enzyme micropump.

Ocimum gratissimum L. leaf flavonoid-rich extracts reduced the expression of p53 and VCAM in streptozotocin-induced cardiomyopathy rats

BackgroundThis study aimed to investigate the potential cardioprotective effects of flavonoid-rich extracts from Ocimum gratissimum leaves in a streptozotocin-induced diabetic rat model by assessing redox stress biomarkers, ATPase activities, gene expression levels, enzyme activities, and histopathological changes. MethodsDiabetic rats were administered low (LDOGFL) and high (HDOGFL) doses of O. gratissimum leaf flavonoid-rich extracts, metformin (MET), or served as diabetic (DC) and normal (NC) controls for twenty-one days. Various cardiac parameters were evaluated, including redox stress biomarkers, ATPase activities, relative gene expression of p53 and VCAM, phosphatase activities, transaminase activities, serum creatine kinase-MB (CKMB) activities, cardiac troponin levels, and natriuretic peptide levels. Additionally, heart histoarchitecture was also examined using hematoxylin and eosin (H&E) staining. ResultsFlavonoid-rich extracts of O. gratissimum significantly (p < 0.05) mitigated redox stress by decreasing malondialdehyde (MDA) levels and increasing reduced glutathione (GSH), glutathione-S-transferase (GST), catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) activities in diabetic treated rats. The extracts also notably (p < 0.05) improved ATPase activities and significantly (p < 0.05) modulated the relative gene expression of p53 and VCAM in diabetic treated rats. Furthermore, diabetic rat administered flavonoid-rich extracts markedly (p < 0.05) attenuated phosphatase activities, transaminase activities, CKMB activities, cardiac troponin levels, and natriuretic peptide levels. Histopathological examination of the diabetic rats revealed improved cardiac histoarchitecture in extract-treated groups compared to diabetic controls. ConclusionThese findings suggest that O. gratissimum leaf flavonoid-rich extracts confer cardioprotective effects in STZ-induced diabetic rats by ameliorating redox imbalance, modulating gene expression, regulating enzyme activities, and preserving cardiac histoarchitecture. These results highlight the potential therapeutic application of O. gratissimum flavonoids in managing diabetes-induced cardiomyopathy.

Extracellular ATP- and adenosine-mediated purinergic signaling modulates inducible nitric oxide synthase (iNOS) gene expression, enzyme activity and nitric oxide production in common carp (Cyprinus carpio) head kidney macrophages

Inducible nitric oxide (NO) synthase (iNOS) is a key immune mediator for production of inflammatory mediator NO from l-arginine. Tight regulation of iNOS expression and enzyme activity is critical for proper NO productions under inflammation and infection conditions. However, the regulatory mechanism for iNOS expression and enzyme activity in fish remains largely unknown. Here, we show that extracellular ATP treatment significantly up-regulates iNOS gene expression and enzyme activity, and consequently leads to enhanced NO production in Cyprinus carpio head kidney macrophages (HKMs). We further show that the extracellular ATP-induced iNOS enzyme activity and NO production can be attenuated by pharmacological inhibition of the ATP-gated P2X4 and P2X7 receptors with their respective specific antagonists, but enhanced by overexpression of P2X4 and P2X7 receptors in grass carp ovary cells. In contrast, adenosine administration significantly reduces iNOS gene expression, enzyme activity and NO production in carp HKMs, and these inhibitory effects can be reversed by pharmacological inhibition of adenosine receptors with the antagonist XAC. Furthermore, LPS- and poly(I:C)-induced iNOS gene expression, enzyme activity, and NO production are significantly attenuated by blockade of P2X4 and P2X7 receptors with their respective specific antagonists in carp HKMs, while overexpression of P2X and P2X7 receptors results in enhanced iNOS gene expression, enzyme activity and NO production in LPS- and poly(I:C)-treated grass carp ovary cells. Taken together, we firstly report an opposite role of extracellular ATP/adenosine-mediated purinergic signaling in modulating iNOS-NO system activity in fish.

POSTTRANSLATIONAL MODIFICATIONS OF THE SULFHYDRYL GROUP OF THE CYSTEINE RESIDUE OF GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE

This review considers the main types of oxidative posttranslational modi cations of the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) targeting the sulfhydryl group of the catalytic cysteine residue Cys152. The highly reactive sulfhydryl group of Cys152 in the active centre of GAPDH undergoes oxidation and S-nitrosylation, leading to enzyme inactivation and destabilization. Upon reversible oxidation of the sulfhydryl group to form cysteine-sulfenic acid, the enzyme loses dehydrogenase activity, but gains the ability to catalyze the acyl-phosphatase reaction. Hydrolysis of the product of the dehydrogenase reaction, 1,3-diphosphoglycerate, under the action of the oxidized GAPDH leads to uncoupling of oxidation and phosphorylation at this stage of glycolysis. The action of nitric oxide results in S-nitrosylation of Cys152 GAPDH and the subsequent formation of cysteine-sulfenic acid due to hydrolysis of the S-NO-group. Data are presented on the relationship between S-nitrosylation of the catalytic Cys152 of GAPDH and its oxidation followed by S-glutathionylation of the enzyme at Cys152. The role of posttranslational modi cations of the sulfhydryl group of the catalytic cysteine residue in the regulation of enzyme activity, as well as the mechanisms ensuring the reversibility of such modi cations are discussed.

Modulation of Metal Homeostasis for Cancer Therapy.

Metal ions such as iron, zinc, copper, manganese, and calcium are essential for normal cellular processes, including DNA synthesis, enzyme activity, cellular signaling, and oxidative stress regulation. When the balance of metal homeostasis is disrupted, it can lead to various pathological conditions, including cancer. Thus, understanding the role of metal homeostasis in cancer has led to the development of anti-tumor strategies that specifically target the metal imbalance. Up to now, diverse small molecule-based chelators, ionophores, metal complexes, and metal-based nanomaterials have been developed to restore the normal balance of metals or exploit the dysregulation for therapeutic purposes. They hold great promise in inhibiting tumor growth, preventing metastasis, and enhancing the effectiveness of existing cancer therapies. In this review, we aim to provide a comprehensive summary of the strategies employed to modulate the homeostasis of iron, zinc, copper, manganese, and calcium for cancer therapy. Their modulation mechanisms for metal homeostasis are succinctly described, and their recent applications in the field of cancer therapy are discussed. At the end, the limitations of these approaches are addressed, and potential avenues for future developments are explored.

Thioredoxin A regulates protein synthesis to maintain carbon and nitrogen partitioning in cyanobacteria.

Thioredoxins play an essential role in regulating enzyme activity in response to environmental changes, especially in photosynthetic organisms. They are crucial for metabolic regulation in cyanobacteria, but the key redox-regulated central processes remain to be determined. Physiological, metabolic, and transcriptomic characterization of a conditional mutant of the essential Synechocystis sp. PCC 6803 thioredoxin trxA gene (STXA2) revealed that decreased TrxA levels alter cell morphology and induce a dormant-like state. Furthermore, TrxA depletion in the STXA2 strain inhibited protein synthesis and led to changes in amino acid pools and nitrogen/carbon reserve polymers, accompanied by oxidation of the EF-Tu elongation factor. Transcriptomic analysis of TrxA depletion in STXA2 revealed a robust transcriptional response. Down-regulated genes formed a large cluster directly related to photosynthesis, ATP synthesis, and CO2 fixation. In contrast, up-regulated genes were grouped into different clusters related to respiratory electron transport, carotenoid biosynthesis, amino acid metabolism, and protein degradation, among others. These findings highlight the complex regulatory mechanisms that govern cyanobacterial metabolism, where TrxA acts as a critical regulator that orchestrates the transition from anabolic to maintenance metabolism and regulates carbon and nitrogen balance.

Importance of Non-Covalent Interactions in Yeast Cell Wall Molecular Organization.

This review covers a group of non-covalently associated molecules, particularly proteins (NCAp), incorporated in the yeast cell wall (CW) with neither disulfide bridges with proteins covalently attached to polysaccharides nor other covalent bonds. Most NCAp, particularly Bgl2, are polysaccharide-remodeling enzymes. Either directly contacting their substrate or appearing as CW lipid-associated molecules, such as in vesicles, they represent the most movable enzymes and may play a central role in CW biogenesis. The absence of the covalent anchoring of NCAp allows them to be there where and when it is necessary. Another group of non-covalently attached to CW molecules are polyphosphates (polyP), the universal regulators of the activity of many enzymes. These anionic polymers are able to form complexes with metal ions and increase the diversity of non-covalent interactions through charged functional groups with both proteins and polysaccharides. The mechanism of regulation of polysaccharide-remodeling enzyme activity in the CW is unknown. We hypothesize that polyP content in the CW is regulated by another NCAp of the CW-acid phosphatase-which, along with post-translational modifications, may thus affect the activity, conformation and compartmentalization of Bgl2 and, possibly, some other polysaccharide-remodeling enzymes.

A56 EVALUATING THE DYNAMICS OF CYP3A11 AND REG3G MODULATION BY IL-22

Abstract Background IL-22 is a cytokine produced by a number of immune cell populations, including type 3 innate lymphoid cells. We have shown previously that IL-22 suppresses the expression Cyp3a11 in the mouse intestine, a gene that encodes a drug metabolizing enzyme that accounts for roughly 70% of total drug metabolism. In addition, IL-22 induces the expression of Reg3g, the gene that encodes an antimicrobial C-type lectin that has bactericidal activity against Gram+ bacteria in the small intestine. Modulation of these proteins can influence both the oral bioavailability of drugs and microbial composition. Aims The aim of this study was to define the existence of reversible modulation of IL-22 on Cyp3a11 and Reg3g expression in the intestinal epithelium. Methods In vitro enteroids from each part of the mouse small intestine were cultured in 3D in the presence or absence of IL-22 for 5 days. Cyp3a11 and Reg3g transcript expression was evaluated by qPCR followed by protein analysis to define their modulation at varying timepoints after IL-22 treatment cessation. Results IL-22 reduced Cyp3a11 expression, an effect that normalized the day after treatment cessation. However, 4 days after treatment cessation there was rebound hyperexpression of Cyp3a11 in duodenal enteroids, which normalized the following day. IL-22 reduced the expression and activity of Cyp3a11 which normalized soon after stopping IL-22 treatment. In contrast, IL-22 induced the expression of Reg3g, an effect that lasted up to 5 days after treatment cessation. The effect of IL-22 on Cyp3a11 expression and activity was rapidly reversed in contrast to the effect on Reg3g which was more prolonged. Conclusions IL-22 suppresses the expression of Cyp3a11 and induces the expression of Reg3g. The reversible nature of these effects is different between both, with the increased expression of Reg3g 5 days after IL-22 treatment cessation. These data suggest that the regulation of gene expression, protein or enzyme activity by IL-22 may exhibit varying temporal effects and should be considered when assessing its role in intestinal mucosal biology. Funding Agencies This work was funded by the Dr. Lloyd Sutherland Chair in IBD/GI Research and the Weston Foundation.

Identification of miRNA, lncRNA and circRNA associated with gastric cancer metabolism through sequencing and bioinformatics analysis

Gastric cancer remains a highly prevalent malignancy worldwide with its molecular features poorly understood. To gain full insight into its genetic landscape, we performed whole-transcriptome sequencing on human tumors and adjacent non-tumors to predict the function of microRNA, long coding RNA, circular RNA, and mRNA, as well as estimate their correlation with gastric cancer characteristics through construction of ceRNA, WGCNA and PPI network. Functional enrichment analysis annotated nucleic acid binding, enzyme activity and binding related to differentially expressed miRNAs (dif-miRNAs); energy binding and enzyme binding related to dif-lncRNAs; protein binding and enzyme activity related to dif-circRNAs; protein digestion and absorption related to dif-mRNAs. The expression of key miR-135a-5p, lncRNAs-MSTRG.48856.1, ENST00000569981, MSTRG.22826.1, ENST00000564492, circRNAs-CCSER2, FNDC3B, CORO1C, FAM214A were validated by real-time PCR. The ceRNA network filtered 14 miRNAs, 30 lncRNAs, and 6 mRNA in the lncRNA-ceRNA axis and 8 miRNAs, 9 circRNAs, and 3 mRNA in the circRNA-ceRNA axis. Genes involved in ceRNA were annotated to be closely related to tumor material synthesis and metabolism. The WGCNA network filtered gene clusters related to TNM traits and extracted the hub genes CLDN10, CD177, newGene_35523, newGene_51201, CEACAM7, and newGene_46634. These genes were associated with cell proliferation, metabolism, and enzyme activity regulation. The PPI network analyzed the stable interaction relationships of the hub genes. Our research provides a valuable resource for understanding the molecular mechanisms of gastric cancer from the perspective of tumor metabolism.

Bidirectional Regulation of Intracellular Enzyme Activity Using Light-Driven Nano-Inhibitors.

Photochemical regulation provides precise control over enzyme activities with high spatiotemporal resolution. A promising approach involves anchoring "photoswitches" at enzyme active sites to modulate substrate recognition. However, current methods often require genetic mutations and irreversible enzyme modifications for the site-specific anchoring of "photoswitches", potentially compromising the enzyme activities. Herein, we present a pioneering reversible nano-inhibitor based on molecular imprinting technique for bidirectional regulation of intracellular enzyme activity. The nano-inhibitor employs a molecularly imprinted polymer nanoparticle as its body and azobenzene-modified inhibitors ("photoswitches") as the arms. By using a target enzyme as the molecular template, the nano-inhibitor acquires oriented binding sites on its surface, resulting in a high affinity for the target enzyme and non-covalently firm anchoring of the azobenzene-modified inhibitor to the enzyme active site. Harnessing the reversible isomerization of azobenzene units upon exposure to ultraviolet and visible light, the nano-inhibitor achieves bidirectional enzyme activity regulation by precisely docking and undocking inhibitor at the active site. Notably, this innovative approach enables the facile in situ regulation of intracellular endogenous enzymes, such as carbonic anhydrase. Our results represent a practical and versatile tool for precise enzyme activity regulation in complex intracellular environments.

Bidirectional Regulation of Intracellular Enzyme Activity Using Light‐Driven Nano‐Inhibitors

AbstractPhotochemical regulation provides precise control over enzyme activities with high spatiotemporal resolution. A promising approach involves anchoring “photoswitches” at enzyme active sites to modulate substrate recognition. However, current methods often require genetic mutations and irreversible enzyme modifications for the site‐specific anchoring of “photoswitches”, potentially compromising the enzyme activities. Herein, we present a pioneering reversible nano‐inhibitor based on molecular imprinting technique for bidirectional regulation of intracellular enzyme activity. The nano‐inhibitor employs a molecularly imprinted polymer nanoparticle as its body and azobenzene‐modified inhibitors (“photoswitches”) as the arms. By using a target enzyme as the molecular template, the nano‐inhibitor acquires oriented binding sites on its surface, resulting in a high affinity for the target enzyme and non‐covalently firm anchoring of the azobenzene‐modified inhibitor to the enzyme active site. Harnessing the reversible isomerization of azobenzene units upon exposure to ultraviolet and visible light, the nano‐inhibitor achieves bidirectional enzyme activity regulation by precisely docking and undocking inhibitor at the active site. Notably, this innovative approach enables the facile in situ regulation of intracellular endogenous enzymes, such as carbonic anhydrase. Our results represent a practical and versatile tool for precise enzyme activity regulation in complex intracellular environments.

AChE activity self-breathing control mechanisms regulated by H2Sn and GSH: Persulfidation and glutathionylation on sulfhydryl after disulfide bonds cleavage

Hydrogen sulfide (H2S), or dihydrogen sulfane (H2Sn), acts as a signal molecule through the beneficial mechanism of persulfidation, known as the post-translational transformation of cysteine residues to persulfides. We previously reported that Glutathione (GSH) could regulate enzyme activity through S-desulfurization or glutathionylation of residues to generate protein-SG or protein-SSG, releasing H2S. However, little is known about the mechanisms by which H2Sn and GSH affect the disulfide bonds. In this study, we provide direct evidences that H2Sn and GSH modify the sulfhydryl group on Cys272, which forms disulfide bonds in acetylcholinesterase (AChE), to generate Cys-SSH and Cys-SSG, respectively. Glutathionylation of disulfide is a two-step reaction based on nucleophilic substitution, in which the first CS bond is broken, then the SS bond is broken to release H2S. H2Sn and GSH controlled self-breathing motion in enzyme catalysis by disconnecting specific disulfide bonds and modifying cysteine residues, thereby regulating AChE activity. Here, we elucidated H2Sn and GSH mechanisms on disulfide in the AChE system and proposed a self-breathing control theory induced by H2Sn and GSH. These theoretical findings shed light on the biological functions of H2Sn and GSH on sulfhydryl and disulfide bonds and enrich the theory of enzyme activity regulation.

Transcriptome analysis of axillary buds in low phosphorus stress and functional analysis of TaWRKY74s in wheat

BackgroundWheat is one of the main grain crops in the world, and the tiller number is a key factor affecting the yield of wheat. Phosphorus is an essential element for tiller development in wheat. However, due to decreasing phosphorus content in soil, there has been increasing use of phosphorus fertilizer, while imposing risk of soil and water pollution. Hence, it is important to identify low phosphorus tolerance genes and utilize them for stress resistance breeding in wheat.ResultsWe subjected the wheat variety Kenong 199 (KN199) to low phosphorus stress and observed a reduced tiller number. Using transcriptome analysis, we identified 1651 upregulated genes and 827 downregulated of genes after low phosphorus stress. The differentially expressed genes were found to be enriched in the enzyme activity regulation related to phosphorus, hormone signal transduction, and ion transmembrane transport. Furthermore, the transcription factor analysis revealed that TaWRKY74s were important for low phosphorus tolerance. TaWRKY74s have three alleles: TaWRKY74-A, TaWRKY74-B, and TaWRKY74-D, and they all belong to the WRKY family with conserved WRKYGQK motifs. These proteins were found to be located in the nucleus, and they were expressed in axillary meristem, shoot apical meristem(SAM), young leaves, leaf primordium, and spikelet primordium. The evolutionary tree showed that TaWRKY74s were closely related to OsWRKY74s in rice. Moreover, TaWRKY74s-RNAi transgenic plants displayed significantly fewer tillers compared to wild-type plants under normal conditions. Additionally, the tiller numebr of the RNAi transgenic plants was also significantly lower than that of the wild-type plants under low-phosphorus stress, and increased the decrease amplitude. This suggestd that TaWRKY74s are related to phosphorus response and can affect the tiller number of wheat.ConclusionsThe results of this research showed that TaWRKY74s were key genes in wheat response to low phosphorus stress, which might regulate wheat tiller number through abscisic acid (ABA) and auxin signal transduction pathways. This research lays the foundation for further investigating the mechanism of TaWRKY74s in the low phosphorus environments and is significant for wheat stress resistance breeding.

Protective effects of EGCG on acrolein-induced Caenorhabditis elegans and its mechanism of life extension.

In this study, it was found that epigallocatechin-3-gallate (EGCG) could extend the lifespan of Caenorhabditis elegans (C. elegans) induced by 100 μM acrolein (ACR) at all test concentrations (300, 400, 500, 600, and 700 μM). Notably, 500 μM EGCG exhibited the most significant mean lifespan extension, increasing it by approximately 32.5%. Furthermore, 500 μM EGCG effectively reduced elevated levels of reactive oxygen species (ROS) and lipofuscin production caused by acrolein. It also bolstered the activity of antioxidant enzymes and mitigated malondialdehyde (MDA) levels compared to the ACR-only group. These effects appeared independent of dietary restrictions. Additionally, qPCR results revealed different changes in the transcription levels of 11 genes associated with antioxidative and anti-aging functions following EGCG treatment. At the expression level, GST-4::GFP, SOD-3::GFP and HSP-16.2::GFP exhibited an initial increase with ACR treatment followed by a decrease with EGCG treatment, while the expression pattern of these three GFPs remained consistent with the enzyme activity and transcription regulation level. EGCG treatment also reduced the nuclear localization of SKN-1 and DAF-16 in the MAPK and IIS pathways that were enhanced by ACR. Moreover, the longevity-promoting effects of EGCG were diminished or absent in 13 longevity gene-deletion mutants. In conclusion, EGCG demonstrates protective effects on ACR-induced C. elegans, with the IIS and MAPK pathways playing a critical role in enhancing resilience to ACR.

Dual-enzyme decorated semiconducting polymer nanoagents for second near-infrared photoactivatable ferroptosis-immunotherapy.

Enzymes provide a class of potential options to treat cancer, while the precise regulation of enzyme activities for effective and safe therapeutic actions has been poorly reported. Dual-enzyme decorated semiconducting polymer nanoagents for second near-infrared (NIR-II) photoactivatable ferroptosis-immunotherapy are reported in this study. Such nanoagents (termed SPHGA) consist of hemoglobin (Hb)-based semiconducting polymer (SP@Hb), adenosine deaminase (ADA) and glucose oxidase (GOx) with loadings in a thermal-responsive nanoparticle shell. NIR-II photoactivation of SPHGA results in the generation of heat to trigger on-demand releases of two enzymes (ADA and GOx) via destroying the thermal-responsive nanoparticle shells. In the tumor microenvironment, GOx oxidizes glucose to form hydrogen peroxide (H2O2), which promotes the Fenton reaction of iron in SP@Hb, resulting in an enhanced ferroptosis effect and immunogenic cell death (ICD). In addition, ADA degrades high-level adenosine to reverse the immunosuppressive microenvironment, thus amplifying antitumor immune responses. Via NIR-II photoactivatable ferroptosis-immunotherapy, SPHGA shows an improved effect to absolutely remove bilateral tumors and effectively suppress tumor metastases in subcutaneous 4T1 breast cancer models. This study presents a dual-enzyme-based nanoagent with controllable therapeutic actions for effective and precise cancer therapy.

Genome-wide identification of poplar GSTU gene family and its PtrGSTU23 and PtrGSTU40 to improve salt tolerance in poplar

Glutathione S-transferases (GSTs) are abundant proteins encoded by a highly differentiated family of ancient genes. GSTs play an important role in plant cell detoxification and growth and development. However, their precise function in growth and response to abiotic stresses in poplar remains unclear. We have identified 81 GST genes from Populus trichocarpa, which have been categorized into 8 subfamilies. Among these subfamilies, the Tau subfamily stands out as the largest, consisting of 58 members. We isolated two Tau-like Glutathione S-transferases encoding genes, PtrGSTU23 and PtrGSTU40, and investigated the biological functions of these two genes in transgenic poplar to regulate salt tolerance in poplar. Under salt stress, reactive oxygen species (ROS) accumulate in plants, and overexpression of PtrGSTU23/40 in 84 K poplar (Populus alba × Populus glandulosa) could play a crucial role in regulating ROS scavenging by controlling the activity of plant GST enzyme. This regulation of GST enzyme activity enhanced the tolerance of poplar to salt stress. Ultimately, our findings contribute to the availability of genetic resources that can be utilized in the breeding of salt tolerance traits within fast-growing tree species.