Publisher Correction: The transcriptional coactivator TAZ regulates reciprocal differentiation of TH17 cells and Treg cells.

In the version of this article initially published, the institution name for affiliation 3 (Maryland Anderson Cancer Center) was incorrect. The correct institution is MD Anderson Cancer Center. The error has been corrected in the HTML and PDF versions of the article.

Corrigendum: The transcriptional coactivator TAZ regulates reciprocal differentiation of TH17 cells and Treg cells.

This corrects the article DOI: 10.1038/ni.3748.

The transcriptional coactivator TAZ regulates reciprocal differentiation of TH17 cells and Treg cells.

An imbalance in the lineages of immunosuppressive regulatory T cells (Treg cells) and the inflammatory TH17 subset of helper T cells leads to the development of autoimmune and/or inflammatory disease. Here we found that TAZ, a coactivator of TEAD transcription factors of Hippo signaling, was expressed under TH17 cell-inducing conditions and was required for TH17 differentiation and TH17 cell-mediated inflammatory diseases. TAZ was a critical co-activator of the TH17-defining transcription factor RORγt. In addition, TAZ attenuated Treg cell development by decreasing acetylation of the Treg cell master regulator Foxp3 mediated by the histone acetyltransferase Tip60, which targeted Foxp3 for proteasomal degradation. In contrast, under Treg cell-skewing conditions, TEAD1 expression and sequestration of TAZ from the transcription factors RORγt and Foxp3 promoted Treg cell differentiation. Furthermore, deficiency in TAZ or overexpression of TEAD1 induced Treg cell differentiation, whereas expression of a transgene encoding TAZ or activation of TAZ directed TH17 cell differentiation. Our results demonstrate a pivotal role for TAZ in regulating the differentiation of Treg cells and TH17 cells.

Ion Pairing Enables Targeted Prodrug Activation via Red Light Photocatalysis: A Proof-of-Concept Study with Anticancer Gold Complexes.

Photocatalysis has found increasing applications in biological systems, for example, in localized prodrug activation; however, high-energy light is usually required without giving sufficient efficiency and target selectivity. In this work, we report that ion pairing between photocatalysts and prodrugs can significantly improve the photoactivation efficiency and enable tumor-targeted activation by red light. This is exemplified by a gold-based prodrug (1d) functionalized with a morpholine moiety. Such a modification causes 1d to hydrolyze in aqueous solution, forming a cationic species that tightly interacts with anionic photosensitizers including Eosin Y (EY) and Rose Bengal (RB), along with a significant bathochromic shift of absorption tailing to the far-red region. As a result, a high photoactivation efficiency of 1d by EY or RB under low-energy light was found, leading to an effective release of active gold species in living cells, as monitored by a gold-specific biosensor (GolS-mCherry). Importantly, the morpholine moiety, with pKa ∼6.9, in 1d brings in a highly pH-sensitive and preferential ionic interaction under a slightly acidic condition over the normal physiological pH, enabling tumor-targeted prodrug activation by red light irradiation in vitro and in vivo. Since a similar absorption change was found in other morpholine/amine-containing clinic drugs, photocages, and precursors of reactive labeling intermediates, it is believed that the ion-pairing strategy could be extended for targeted activation of different prodrugs and for mapping of an acidic microenvironment by low-energy light.

Modulating the Chemical Reactivity of Gold Complexes in Living Systems: From Concept to Biomedical Applications.

Over the past few decades, research on the chemistry of gold has progressed rapidly, encompassing topics like catalysis, supramolecular chemistry, molecular recognition, etc. These chemical properties are of great value in developing therapeutics or orthogonal catalysts in biology. However, the presence of concentrated nucleophiles and reductants, particularly thiol-containing serum albumin in blood and glutathione (GSH) inside cells that can strongly bind and quench the active gold species, makes it difficult to translate the chemistry of gold from test tubes into living systems. In this regard, modulating the chemical reactivity of gold complexes to conquer nonspecific interactions with thiols and meanwhile to controllably activate their reactivity in a spatiotemporal manner is of pivotal importance to develop gold complexes for biomedical applications. In this account, we aim to highlight the concept of developing stimuli-activatable gold complexes with masked chemical properties, the bioactivity of which can be spatiotemporally activated at the target site by leveraging approaches from classic structure design to recently emerged photo- and bioorthogonal-activation.A straightforward approach to tuning the reactivity of gold complexes is based on structure modification. This is achieved by introducing strong carbon donor ligands, such as N-heterocyclic carbene, alkynyl, and diphosphine, to improve the stability of gold(I) complexes against off-target thiols. Likewise, GSH-responsive gold(III) prodrug and supramolecular Au(I)-Au(I) interaction have been harnessed to keep a reasonable stability against serum albumin and confer tumor-targeted cytotoxicity by inhibiting thiol- and selenol-containing thioredoxin reductase (TrxR) for potent cancer treatment in vivo. To achieve better spatiotemporal controllability, photoactivatable prodrugs are developed. These complexes are equipped with cyclometalated pincer-type ligands and carbanion or hydride as ancillary ligands, rendering high thiol-stability in the dark, but upon photoirradiation, the complexes can undergo unprecedented photoinduced ligand substitution, ß-hydride elimination, and/or reduction to release active gold species for TrxR inhibition at the diseased tissue. To further improve the therapeutic activity, an oxygen-dependent conditional photoreactivity of gold(III) complexes by evolving from photodynamic into photoactivated chemotherapy has been achieved, resulting in highly potent antitumor efficacy in tumor-bearing mice. Of equal importance is harnessing the bioorthogonal activation approach by chemical inducers, as exemplified by a palladium-triggered transmetalation reaction to selectively activate the chemical reactivities of gold including its TrxR inhibition and catalytic activity in living cells and zebrafish. Collectively, strategies to modulate gold chemistry in vitro and in vivo are emerging, and it is hoped that this Account will spur the creation of better approaches to advance gold complexes closer to clinical application.

Photoactivation of Boronic Acid Prodrugs via a Phenyl Radical Mechanism: Iridium(III) Anticancer Complex as an Example.

Boronic acid (or ester) is a well-known temporary masking group for developing anticancer prodrugs responsive to tumoral reactive oxygen species (ROS), but their clinic application is largely hampered by the low activation efficiency. Herein, we report a robust photoactivation approach that can spatiotemporally convert boronic acid-caged iridium(III) complex IrBA into bioactive IrNH2 under hypoxic tumor microenvironments. Mechanistic studies show that the phenyl boronic acid moiety in IrBA is in equilibrium with phenyl boronate anion that can be photo-oxidized to generate phenyl radical, a highly reactive species that is capable of rapidly capturing O2 at extremely low concentrations (down to 0.02%). As a result, while IrBA could hardly be activated by intrinsic ROS in cancer cells, upon light irradiation, the prodrug is efficiently converted into IrNH2 even in limited O2 supply, along with direct damage to mitochondrial DNA and potent antitumor activities in hypoxic 2D monolayer cells, 3D tumor spheroids, and mice bearing tumor xenografts. Of note, the photoactivation approach could be extended to intermolecular photocatalytic activation by external photosensitizers with red absorption and to activate prodrugs of clinic compounds, thus offering a general approach for activation of anticancer organoboron prodrugs.

Towards Understanding the Molecular Mechanisms of Immunogenic Cell Death.

The discovery of immunogenic cell death (ICD) by small molecules (e. g., chemotherapeutic drugs) intrigued medicinal chemists and led them to exploit anticancer agents with such a trait because ICD agents provoke anticancer immune responses in addition to their cytotoxicity. However, the unclear molecular mechanism of ICD hampers further achievements in drug development. Fortunately, increasing efforts have been made in this area in recent years by using either chemical or biological approaches. Here, we review the current achievements towards understanding the mechanisms of small molecule-induced ICD effects. Based on the established role of the unfolded protein response (UPR) in ICD, we classify the mechanisms of different inducers by their dependency on UPR. Key proteins and pathways with important implications are discussed in depth. We also give our perspectives on the research strategies for future investigation in this field.

Target Profiling of an Iridium(III)-Based Immunogenic Cell Death Inducer Unveils the Engagement of Unfolded Protein Response Regulator BiP.

Clinical chemotherapeutic drugs have occasionally been observed to induce antitumor immune responses beyond the direct cytotoxicity. Such effects are coined as immunogenic cell death (ICD), representing a "second hit" from the host immune system to tumor cells. Although chemo-immunotherapy is highly promising, ICD inducers remain sparse with vague drug-target mechanisms. Here, we report an endoplasmic reticulum stress-inducing cyclometalated Ir(III)-bisNHC complex (1a) as a new ICD inducer, and based on this compound, a clickable photoaffinity probe was designed for target identification, which unveiled the engagement of the master regulator protein BiP (binding immunoglobulin protein)/GRP78 of the unfolded protein response pathway. This has been confirmed by a series of cellular and biochemical studies including fluorescence microscopy, cellular thermal shift assay, enzymatic assays, and so forth, showing the capability of 1a for BiP destabilization. Notably, besides 1a, the previously reported ICD inducers including KP1339, mitoxantrone, and oxaliplatin were also found to engage BiP interaction, suggesting the important role of BiP in eliciting anticancer immunity. We believe that the ICD-related target information in this work will help to understand the mode of action of ICD that is beneficial to designing new ICD agents with high specificity and improved efficacy.

Organogold(III) Complexes Display Conditional Photoactivities: Evolving From Photodynamic into Photoactivated Chemotherapy in Response to O2 Consumption for Robust Cancer Therapy.

Photodynamic therapy (PDT) is a spatiotemporally controllable, powerful approach in combating cancers but suffers from low activity under hypoxia, whereas photoactivated chemotherapy (PACT) operates in an O2 -independent manner but compromises the ability to harness O2 for potent photosensitization. Herein we report that cyclometalated gold(III)-alkyne complexes display a PDT-to-PACT evolving photoactivity for efficient cancer treatment. On the one hand, the gold(III) complexes can act as dual photosensitizers and substrates, leading to conditional PDT activity in oxygenated condition that progresses to highly efficient PACT (ϕ up to 0.63) when O2 is depleted in solution and under cellular environment. On the other hand, the conditional PDT-to-PACT reactivity can be triggered by external photosensitizers in a similar manner in vitro and in vivo, giving additional tumor-selectivity and/or deep tissue penetration by red-light irradiation that leads to robust anticancer efficacy.

Alkylgold(III) Complexes Undergo Unprecedented Photo-Induced ß-Hydride Elimination and Reduction for Targeted Cancer Therapy.

Spatiotemporally controllable activation of prodrugs within tumors is highly desirable for cancer therapy to minimize toxic side effects. Herein we report that stable alkylgold(III) complexes can undergo unprecedented photo-induced ß-hydride elimination, releasing alkyl ligands and forming gold(III)-hydride intermediates that could be quickly converted into bioactive [AuIII -S] adducts; meanwhile, the remaining alkylgold(III) complexes can photo-catalytically reduce [AuIII -S] into more bioactive AuI species. Such photo-reactivities make it possible to functionalize gold complexes on the auxiliary alkyl ligands without attenuating the metal-biomacromolecule interactions. As a result, the gold(III) complexes containing glucose-functionalized alkyl ligands displayed efficient and tumor-selective uptake; notably, after one- or two-photon activation, the complexes exhibited high thioredoxin reductase (TrxR) inhibition, potent cytotoxicity, and strong antiangiogenesis and antitumor activities in vivo.

Antifungal mechanisms of lavender essential oil in the inhibition of rot disease caused by Monilinia fructicola in postharvest flat peaches.

Lavender essential oil (LEO), a natural antimicrobial agent, is generally recognized as safe and effective in the inhibition of phytopathogenic fungi. Direct contact and fumigation (in vivo and in vitro) were used to study the fungistatic effect of LEO on Monilinia fructicola. Additionally, the effect on the ultrastructure of cells and the degree of destruction of the cell membrane of M. fructicola were revealed. In addition, the effects of LEO on the expression levels of apoptosis-related genes in M. fructicola cells were detected, and GC-MS was used to analyze the main components of LEO. LEO had a good inhibitory efficacy against M. fructicola in flat peaches, with almost complete growth inhibition at 800 µL/L. These effects were associated with the leakage of cytoplasmic contents, hyphal distortion, and spore disruption. Moreover, the expression of apoptosis RTG1 and RLM1 genes increased with LEO treatment. These results demonstrate that LEO can inhibit M. fructicola by inducing cytoplasmic membrane damage and cell apoptosis in fungi, and that the major ingredients of LEO are monoterpenes and sesquiterpenes, which are presumed to contribute to the inhibitory effects.

Bioorthogonal Activation of Dual Catalytic and Anti-Cancer Activities of Organogold(I) Complexes in Living Systems.

Controllably activating the bio-reactivity of metal complexes in living systems is challenging but highly desirable because it can minimize off-target bindings and improve spatiotemporal specificity. Herein, we report a new bioorthogonal activation approach by employing Pd(II)-triggered transmetallation reactions to conditionally activate the bio-reactivity of NHC-Au(I)-phenylacetylide complexes (1 a) in vitro and in vivo. A combination of 1 H NMR, LC-MS, DFT calculation and fluorescence screening assays reveals that 1 a displays a reasonable stability against biological thiols, but its phenylacetylide ligand can be efficiently transferred to Pd(II), leading to in situ formation of labile NHC-Au(I) species that is catalytically active inside living cells and zebrafish, and can meanwhile effectively suppress the activity of thioredoxin reductase, potently inhibit the proliferation of cancer cells and efficiently suppress angiogenesis in zebrafish models.

An alternative conformation of human TrpRS suggests a role of zinc in activating non-enzymatic function.

Tryptophanyl-tRNA synthetase (TrpRS) in vertebrates contains a N-terminal extension in front of the catalytic core. Proteolytic removal of the N-terminal 93 amino acids gives rise to T2-TrpRS, which has potent anti-angiogenic activity mediated through its extracellular interaction with VE-cadherin. Zinc has been shown to have anti-angiogenic effects and can bind to human TrpRS. However, the connection between zinc and the anti-angiogenic function of TrpRS has not been explored. Here we report that zinc binding can induce structural relaxation in human TrpRS to facilitate the proteolytic generation of a T2-TrpRS-like fragment. The zinc-binding site is likely to be contained within T2-TrpRS, and the zinc-bound conformation of T2-TrpRS is mimicked by mutation H130R. We determined the crystal structure of H130R T2-TrpRS at 2.8 Å resolution, which reveals drastically different conformation from that of wild-type (WT) T2-TrpRS. The conformational change creates larger binding surfaces for VE-cadherin as suggested by molecular dynamic simulations. Surface plasmon resonance analysis indicates more than 50-fold increase in binding affinity of H130R T2-TrpRS for VE-cadherin, compared to WT T2-TrpRS. The enhanced interaction is also confirmed by a cell-based binding analysis. These results suggest that zinc plays an important role in activating TrpRS for angiogenesis regulation.

Oxidation state of Cu in silicate melts at upper mantle conditions.

Beyond its economic value, copper (Cu) serves as a valuable tracer of deep magmatic processes due to its close relationship with magmatic sulfide evolution and sensitivity to oxygen fugacity (fO2). However, determining Cu's oxidation state (+ 1 or + 2) in silicate melts, crucial for interpreting its behavior and reconstructing fO2 in the Earth's interior, has long been a challenge. This study utilizes X-ray Absorption Near Edge Structure spectroscopy to investigate the Cu oxidation state in hydrous mafic silicate melts equilibrated under diverse fO2 (- 1.8 to 3.1 log units relative to the Fayalite-Magnetite-Quartz buffer), temperature (1150-1300 °C), and pressure (1.0-2.5 GPa) conditions. Our results reveal that Cu predominantly exists as Cu+ across all fO2 conditions, with a minor Cu2+ component. This dominance of Cu+ persists even in relatively oxidized melts, highlighting its limited sensitivity to fO2 under upper mantle conditions. This significantly constrains the utility of Cu as an oxybarometer in hydrous silicate melts in the deep Earth. However, our findings suggest that Cu isotopes primarily reflect the interplay of sulfide segregation/accumulation during magmatic differentiation, shedding light on these fundamental processes in Earth's interior.

Creep-type all-solid-state cathode achieving long life.

Electrochemical-mechanical coupling poses enormous challenges to the interfacial and structural stability but create new opportunities to design innovative all-solid-state batteries from scratch. Relying on the solid-solid constraint in the space-limited domain structure, we propose to exploit the lithiation-induced stress to drive the active materials creep, thereby improving the structural integrity. For demonstration, we fabricate the creep-type all-solid-state cathode using creepable Se material and an all-in-one rigid ionic/electronic conducting Mo6Se8 framework. As indicated by the in-situ experiment and numerical simulation, this cathode presents unique capabilities in improving interparticle contact and avoiding particle fracture, leading to its superior electrochemical performance, including a superior long-cycle life of more than 3000 cycles at 0.5 C and a high volumetric energy density of 2460 Wh/L at the cathode level. We believe this innovative strategy to utilize mechanics to boost the electrochemical performance could shed light on the future design of all-solid-state batteries for practical applications.

Ultraviolet C irradiation enhances the resistance of grape against postharvest black rot (Aspergillus carbonarius) by regulating the synthesis of phenolic compounds.

UV-C irradiation can maintain fruit quality by inducing fruit disease resistance and reducing decay during storage. Grape (Vitis Vinifera L.) was exposed to 2.4 kJ m-2 UV-C irradiation then inoculated with Aspergillus carbonarius to investigate the changes in nutritional quality, defense related substances and enzyme activities. Postharvest UV-C irradiation can increased the levels of defense-related substances and enzyme activities, such as phenols, flavanols, lignin, proline, glutathione, phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), and ß-1,3-glucanase (GLU). In addition, Resveratrol plays an important role in grape resistance to A. carbonarius infection through further verification by gene expression levels, the transcription factors VvWRKY24 and VvMYB14 are highly correlated with the regulation of VvSTS gene expression. This study revealed the molecular mechanism of postharvest grape fruit response to UV-C irradiation and the defense mechanism against black rot, and provided a theoretical basis for postharvest grape storage and preservation technology.

Rhodium(III) Complex Noncanonically Potentiates Antitumor Immune Responses by Inhibiting Wnt/ß-Catenin Signaling.

Metal-based chemoimmunotherapy has recently garnered significant attention for its capacity to stimulate tumor-specific immunity beyond direct cytotoxic effects. Such effects are usually caused by ICD via the activation of DAMP signals. However, metal complexes that can elicit antitumor immune responses other than ICD have not yet been described. Herein, we report that a rhodium complex (Rh-1) triggers potent antitumor immune responses by downregulating Wnt/ß-catenin signaling with subsequent activation of T lymphocyte infiltration to the tumor site. The results of mechanistic experiments suggest that ROS accumulation following Rh-1 treatment is a critical trigger of a decrease in ß-catenin and enhanced secretion of CCL4, a key mediator of T cell infiltration. Through these properties, Rh-1 exerts a synergistic effect in combination with PD-1 inhibitors against tumor growth in vivo. Taken together, our work describes a promising metal-based antitumor agent with a noncanonical mode of action to sensitize tumor tissues to ICB therapy.

Design, synthesis and biological evaluation of novel estrogen-derived steroid metal complexes.

A new series of estrogen-derived metal complexes were synthesized and characterized. The functionalized estrogen receptor ligands were prepared by a four-step synthetic strategy, and then three transition metal Pd, Ni, Zn were introduced readily to give the title metal complexes, in which the squaramide was introduced as ion acceptor for the first time in the development of estrogen-derived metal complexes for estrogen receptor. Upon binding to estrogen receptors, all of the estrogen conjugates exhibited acceptable binding affinity (up to 4.04% relative to estradiol), and in transcription assays, all the compounds are agonists on ERα. Molecular modeling studies suggest a structural basis for the agonist activity of these compounds.

Large volume collapse observed in the phase transition in cubic PbCrO3 perovskite.

When cubic PbCrO(3) perovskite (Phase I) is squeezed up to approximately 1.6 GPa at room temperature, a previously undetected phase (Phase II) has been observed with a 9.8% volume collapse. Because the structure of Phase II can also be indexed into a cubic perovskite as Phase I, the transition between Phases I and II is a cubic to cubic isostructural transition. Such a transition appears independent of the raw materials and synthesizing methods used for the cubic PbCrO(3) perovskite sample. In contrast to the high-pressure isostructural electronic transition that appears in Ce and SmS, this transition seems not related with any change of electronic state, but it could be possibly related on the abnormally large volume and compressibility of the PbCrO(3) Phase I. The physical mechanism behind this transition and the structural and electronic/magnetic properties of the condensed phases are the interesting issues for future studies.

A DNA phosphorothioation-based Dnd defense system provides resistance against various phages and is compatible with the Ssp defense system.

DndABCDE-catalyzed DNA phosphorothioation (PT), in which the nonbridging oxygen is swapped with a sulfur atom, was first identified in the bacterial genome. Usually, this modification gene cluster is paired with a restriction module consisting of DndF, DndG, and DndH. Although the mechanisms for the antiphage activity conferred by this Dnd-related restriction and modification (R-M) system have been well characterized, several features remain unclear, including the antiphage spectrum and potential interference with DNA methylation. Recently, a novel PT-related R-M system, composed of the modification module SspABCD paired with a single restriction enzyme, SspE, was revealed to be widespread in the bacterial kingdom, which aroused our interest in the interaction between Dnd- and Ssp-based R-M systems. In this study, we discussed the action of Dnd-related R-M systems against phages and demonstrated that the host could benefit from the protection provided by Dnd-related R-M systems against infection by various lytic phages as well as temperate phages. However, this defense barrier would fail against lysogenic phages. Interestingly, DNA methylation, even in the consensus sequence recognized by the Dnd system, could not weaken the restriction efficiency. Finally, we explored the interaction between Dnd- and Ssp-based R-M systems and found that these two systems were compatible. This study not only expands our knowledge of Dnd-associated R-M systems but also reveals a complex interaction between different defense barriers that coexist in the cell. IMPORTANCE Recently, we decoded the mechanism of Dnd-related R-M systems against genetic parasites. In the presence of exogenous DNA that lacks PT, the macromolecular machine consisting of DndF, DndG, and DndH undergoes conformational changes to perform DNA binding, translocation, and DNA nicking activities and scavenge the foreign DNA. However, several questions remain unanswered, including questions regarding the antiphage spectrum, potential interference by DNA methylation, and interplay with other PT-dependent R-M systems. Here, we revealed that the host could benefit from Dnd-related R-M systems for a broad range of antiphage activities, regardless of the presence of DNA methylation. Furthermore, we demonstrated that the convergence of Dnd- and Ssp-related R-M systems could confer to the host a stronger antiphage ability through the additive suppression of phage replication. This study not only deepens our understanding of PT-related defense barriers but also expands our knowledge of the arms race between bacteria and their predators.