The combination of Tanshinone IIA and Astragaloside IV attenuates myocardial ischemia-reperfusion injury by inhibiting the STING pathway.

BACKGROUND: Astragaloside IV (As-IV) and Tanshinone IIA (Ta-IIA) are the main ingredients of traditional Chinese medicinal Astragalus membranaceus (Fisch.) Bunge and Salvia miltiorrhiza Bunge, respectively, both of which have been employed in the treatment of cardiovascular diseases. Nevertheless, the efficacy of the combination (Co) of Ta-IIA and As-IV for cardiovascular diseases remain unclear and warrant further investigation. This study aimed to investigate the efficacy and the underlying molecular mechanism of Co in treating myocardial ischemia-reperfusion injury (MIRI). METHODS: In order to assess the efficacy of Co, an in vivo MIRI mouse model was created by temporarily blocking the coronary arteries for 30 min and then releasing the blockage. Parameters such as blood myocardial enzymes, infarct size, and ventricular function were measured. Additionally, in vitro experiments were conducted using HL1 cells in both hypoxia-reoxygenation model and oxidative stress models. The apoptosis rate, expression levels of apoptosis-related proteins, oxidative stress indexes, and release of inflammatory factors were detected. Furthermore, molecular docking was applied to examine the binding properties of Ta-IIA and As-IV to STING, and western blotting was performed to analyze protein expression of the STING pathway. Additionally, the protective effect of Ta-IIA, As-IV and Co via inhibiting STING was further confirmed in models of knockdown STING by siRNA and adding STING agonist. RESULTS: Both in vitro and in vivo data demonstrated that, compared to Ta-IIA or As-IV alone, the Co exhibited superior efficacy in reducing the area of myocardial infarction, lowering myocardial enzyme levels, and promoting the recovery of myocardial contractility. Furthermore, the Co showed more potent anti-apoptosis, antioxidant, and anti-inflammation effects. Additionally, the Co enhanced the inhibitory effects of Ta-IIA and As-IV on STING phosphorylation and the activation of STING signaling pathway. However, the administration of a STING agonist attenuated the protective effects of the Co, Ta-IIA, and As-IV by compromising their anti-apoptotic, antioxidant, and anti-inflammatory effects in MIRI. CONCLUSION: Compared to the individual administration of Ta-IIA or As-IV, the combined treatment demonstrated more potent ability in inhibiting apoptosis, oxidative stress, inflammation, and the STING signaling pathway in the context of MIRI, indicating a more powerful protective effect against MIRI.

Sequence Variation of Candida albicans Sap2 Enhances Fungal Pathogenicity via Complement Evasion and Macrophage M2-Like Phenotype Induction.

Candida albicans (C. albicans) is an opportunistic pathogen increasingly causing candidiasis worldwide. This study aims to investigate the pattern of systemic immune responses triggered by C. albicans with disease associated variation of Sap2, identifying the novel evasion strategies utilized by clinical isolates. Specifically, a variation in clinical isolates is identified at nucleotide position 817 (G to T). This homozygous variation causes the 273rd amino acid exchange from valine to leucine, close to the proteolytic activation center of Sap2. The mutant (Sap2-273L) generated from SC5314 (Sap2-273V) background carrying the V273L variation within Sap2 displays higher pathogenicity. In comparison to mice infected with Sap2-273V strain, mice infected with Sap2-273L exhibit less complement activation indicated by less serum C3a generation and weaker C3b deposition in the kidney. This inhibitory effect is mainly achieved by Sap2273L -mediated stronger degradation of C3 and C3b. Furthermore, mice infected with Sap2-273L strain exhibit more macrophage phenotype switching from M0 to M2-like and more TGF-ß release which further influences T cell responses, generating an immunosuppressed cellular microenvironment characterized by more Tregs and exhausted T cell formation. In summary, the disease-associated sequence variation of Sap2 enhances pathogenicity by complement evasion and M2-like phenotype switching, promoting a more efficient immunosuppressed microenvironment.

Timosaponin AIII promotes non-small-cell lung cancer ferroptosis through targeting and facilitating HSP90 mediated GPX4 ubiquitination and degradation.

Timosaponin AIII (Tim-AIII), a steroid saponin, exhibits strong anticancer activity in a variety of cancers, especially breast cancer and liver cancer. However, the underlying mechanism of the effects of Tim-AIII-mediated anti-lung cancer effects remain obscure. In this study, we showed that Tim-AIII suppressed cell proliferation and migration, induced G2/M phase arrest and ultimately triggered cell death of non-small cell lung cancer (NSCLC) cell lines accompanied by the release of reactive oxygen species (ROS) and iron accumulation, malondialdehyde (MDA) production, and glutathione (GSH) depletion. Interestingly, we found that Tim-AIII-mediated cell death was reversed by ferroptosis inhibitor ferrostatin-1 (Fer-1). Meanwhile, the heat shock protein 90 (HSP90) was predicted and verified as the direct binding target of Tim-AIII by SwissTargetPrediction (STP) and surface plasmon resonance (SPR) assay. Further study showed that Tim-AIII promoted HSP90 expression and Tim-AIII induced cell death was blocked by the HSP90 inhibitor tanespimycin, indicating that HSP90 was the main target of Tim-AIII to further trigger intracellular events. Mechanical analysis revealed that the Tim-AIII-HSP90 complex further targeted and degraded glutathione peroxidase 4 (GPX4), and promoted the ubiquitination of GPX4, as shown by an immunoprecipitation, degradation and in vitro ubiquitination assay. In addition, Tim-AIII inhibited cell proliferation, induced cell death, led to ROS and iron accumulation, MDA production, GSH depletion, as well as GPX4 ubiquitination and degradation, were markedly abrogated when HSP90 was knockdown by HSP90-shRNA transfection. Importantly, Tim-AIII also showed a strong capacity of preventing tumor growth by promoting ferroptosis in a subcutaneous xenograft tumor model, whether C57BL/6J or BALB/c-nu/nu nude mice. Together, HSP90 was identified as a new target of Tim-AIII. Tim-AIII, by binding and forming a complex with HSP90, further targeted and degraded GPX4, ultimately induced ferroptosis in NSCLC. These findings provided solid evidence that Tim-AIII can serve as a potential candidate for NSCLC treatment.

GAPDH Is a Novel Ferroptosis-Related Marker and Correlates with Immune Microenvironment in Lung Adenocarcinoma.

Lung adenocarcinoma (LUAD) is a prevalent form of lung cancer with high morbidity and fatality rates. Ferroptosis is a type of programmed cell death that is iron-dependent. Recent findings have suggested that ferroptosis inducers have promising prospects for the therapy of LUAD. However, ferroptosis-related gene expression in LUAD and its relationship with the tumor prognosis and tumor immune microenvironment remain unknown. We identified a total of 638 ferroptosis-related genes, built a LUAD ferroptosis-related risk model (FRRM) with the help of Least Absolute Shrinkage Selection Operator (LASSO) regression analysis based on The Cancer Genome Atlas (TCGA) database, split LUAD patients into high- and low-risk clusters, and verified the model utilizing the Gene Expression Omnibus (GEO) database. The results of the FRRM's principal component analysis (PCA) demonstrated its strong predictive power. Further, univariate and multivariate Cox and AUC curve analyses demonstrated that the model was independent of other clinical traits and served as an independent prognostic factor. The nomogram demonstrated strong predictive power for overall survival, according to calibration plots. We also explored variations in clinical characteristics, immune cell infiltration, immune-related function, and functional pathways between the high- and low-risk groups. Additionally, we used a protein-protein interaction (PPI) network of various genes in the two groups to search for potential target genes. GAPDH was then chosen for a follow-up investigation. An analysis was performed on the relationship between GAPDH and variations in survival prognosis, clinical traits, immune cell infiltration, immune checkpoints, and immunotherapy. In vitro tests further supported the probable functions of GAPDH as a ferroptosis marker in LUAD. In conclusion, a novel ferroptosis-related prognostic gene, GAPDH, was discovered, whose expression was connected to the tumor immune microenvironment. The combination of immunotherapy and the targeting of GAPDH to induce ferroptosis in LUAD may provide a novel therapeutical option.

Pyroptosis, inflammasome, and gasdermins in tumor immunity.

The gasdermins (GSDM), a family of pore-forming proteins, consist of gasdermin A (GSDMA), gasdermin B (GSDMB), gasdermin C (GSDMC), gasdermin D (GSDMD), gasdermin E (GSDME) and DFNB59 (Pejvakin (PJVK)) in humans. These proteins play an important role in pyroptosis. Among them, GSDMD is the most extensively studied protein and is identified as the executioner of pyroptosis. Other family members have also been implicated in certain cancers. As a unique form of programmed cell death, pyroptosis is closely related to tumor progression, and the inflammasome, an innate immune mechanism that induces inflammation and pyroptosis. In this review, we explore the current developments of pyroptosis, the inflammasome, and especially we review the gasdermin family members and their role in inducing pyroptosis and the possible therapeutic values in antitumor effects.

Multifaceted functions of STING in human health and disease: from molecular mechanism to targeted strategy.

Since the discovery of Stimulator of Interferon Genes (STING) as an important pivot for cytosolic DNA sensation and interferon (IFN) induction, intensive efforts have been endeavored to clarify the molecular mechanism of its activation, its physiological function as a ubiquitously expressed protein, and to explore its potential as a therapeutic target in a wide range of immune-related diseases. With its orthodox ligand 2'3'-cyclic GMP-AMP (2'3'-cGAMP) and the upstream sensor 2'3'-cGAMP synthase (cGAS) to be found, STING acquires its central functionality in the best-studied signaling cascade, namely the cGAS-STING-IFN pathway. However, recently updated research through structural research, genetic screening, and biochemical assay greatly extends the current knowledge of STING biology. A second ligand pocket was recently discovered in the transmembrane domain for a synthetic agonist. On its downstream outputs, accumulating studies sketch primordial and multifaceted roles of STING beyond its cytokine-inducing function, such as autophagy, cell death, metabolic modulation, endoplasmic reticulum (ER) stress, and RNA virus restriction. Furthermore, with the expansion of the STING interactome, the details of STING trafficking also get clearer. After retrospecting the brief history of viral interference and the milestone events since the discovery of STING, we present a vivid panorama of STING biology taking into account the details of the biochemical assay and structural information, especially its versatile outputs and functions beyond IFN induction. We also summarize the roles of STING in the pathogenesis of various diseases and highlight the development of small-molecular compounds targeting STING for disease treatment in combination with the latest research. Finally, we discuss the open questions imperative to answer.

Taraxasterol Inhibits Tumor Growth by Inducing Apoptosis and Modulating the Tumor Microenvironment in Non-Small Cell Lung Cancer.

Taraxasterol (TAX), one of the active components in Dandelion, demonstrated strong antitumor properties in several cancers. However, the effect and underlying mechanism of TAX in non-small cell lung cancer (NSCLC) is unclear. In this study, we showed that TAX inhibited the proliferation of cells by inducing S-phase cell cycle arrest and prevented cell migration by interfering epithelial-mesenchymal transition (EMT) in Lewis lung cancer (LLC) cells and lung carcinoma SPC-A1 cells. The pharmacological network analysis predicted that induction of apoptosis might be the potential mechanism of TAX-mediated cell deaths. Further in vitro experiments showed that TAX could significantly induce cancer cell apoptosis as verified by increased pro-apoptotic molecules including Bax, caspase-9, and PARP1 downregulated anti-apoptotic protein Bcl-2; and decreased mitochondrial potential. The LLC subcutaneous tumor model demonstrated that TAX inhibited tumor growth by induction of apoptosis and inhibition of proliferation in vivo, which is consistent with the in vitro data. Importantly, TAX administration downregulated the proportion of Treg cells and upregulated CD107a+ NK cells in the tumor microenvironment in the tumor model. Together, these data reveal that TAX performs its antitumor effect by inducing apoptosis and modulating the tumor microenvironment, providing evidence that TAX could serve as a potential natural drug for lung cancer therapy.

Hyaluronic acid synthesis is required for zebrafish tail fin regeneration.

Using genome-wide transcriptional profiling and whole-mount expression analyses of zebrafish larvae, we have identified hyaluronan synthase 3 (has3) as an upregulated gene during caudal fin regeneration. has3 expression is induced in the wound epithelium within hours after tail amputation, and its onset and maintenance requires fibroblast growth factor, phosphoinositide 3-kinase, and transforming growth factor-ß signaling. Inhibition of hyaluronic acid (HA) synthesis by the small molecule 4-methylumbelliferone (4-MU) impairs tail regeneration in zebrafish larvae by preventing injury-induced cell proliferation. In addition, 4-MU reduces the expression of genes associated with wound epithelium and blastema function. Treatment with glycogen synthase kinase 3 inhibitors rescues 4-MU-induced defects in cell proliferation and tail regeneration, while restoring a subset of wound epithelium and blastema markers. Our findings demonstrate a role for HA biosynthesis in zebrafish tail regeneration and delineate its epistatic relationships with other regenerative processes.

Broad-Spectrum Kinase Profiling in Live Cells with Lysine-Targeted Sulfonyl Fluoride Probes.

Protein kinases comprise a large family of structurally related enzymes. A major goal in kinase-inhibitor development is to selectively engage the desired kinase while avoiding myriad off-target kinases. However, quantifying inhibitor interactions with multiple endogenous kinases in live cells remains an unmet challenge. Here, we report the design of sulfonyl fluoride probes that covalently label a broad swath of the intracellular kinome with high efficiency. Protein crystallography and mass spectrometry confirmed a chemoselective reaction between the sulfonyl fluoride and a conserved lysine in the ATP binding site. Optimized probe 2 (XO44) covalently modified up to 133 endogenous kinases, efficiently competing with high intracellular concentrations of ATP. We employed probe 2 and label-free mass spectrometry to quantify intracellular kinase engagement by the approved drug, dasatinib. The data revealed saturable dasatinib binding to a small subset of kinase targets at clinically relevant concentrations, highlighting the utility of lysine-targeted sulfonyl fluoride probes in demanding chemoproteomic applications.

Antitumor Activity of IMC-038525, a Novel Oral Tubulin Polymerization Inhibitor.

Microtubules are a well-validated target for anticancer therapy. Molecules that bind tubulin affect dynamic instability of microtubules causing mitotic arrest of proliferating cells, leading to cell death and tumor growth inhibition. Natural antitubulin agents such as taxanes and Vinca alkaloids have been successful in the treatment of cancer; however, several limitations have encouraged the development of synthetic small molecule inhibitors of tubulin function. We have previously reported the discovery of two novel chemical series of tubulin polymerization inhibitors, triazoles (Ouyang et al. Synthesis and structure-activity relationships of 1,2,4-triazoles as a novel class of potent tubulin polymerization inhibitors. Bioorg Med Chem Lett. 2005; 15:5154-5159) and oxadiazole derivatives (Ouyang et al. Oxadiazole derivatives as a novel class of antimitotic agents: synthesis, inhibition of tubulin polymerization, and activity in tumor cell lines. Bioorg Med Chem Lett. 2006; 16:1191-1196). Here, we report on the anticancer effects of a lead oxadiazole derivative in vitro and in vivo. In vitro, IMC-038525 caused mitotic arrest at nanomolar concentrations in epidermoid carcinoma and breast tumor cells, including multidrug-resistant cells. In vivo, IMC-038525 had a desirable pharmacokinetic profile with sustained plasma levels after oral dosing. IMC-038525 reduced subcutaneous xenograft tumor growth with significantly greater efficacy than the taxane paclitaxel. At efficacious doses, IMC-038525 did not cause substantial myelosuppression or peripheral neurotoxicity, as evaluated by neutrophil counts and changes in myelination of the sciatic nerve, respectively. These data indicate that IMC-038525 is a promising candidate for further development as a chemotherapeutic agent.

Synthetic strategies for studying embryonic development.

Developmental biology has evolved from a descriptive science to one based on genetic principles and molecular mechanisms. Although molecular biology and genetic technologies have been the primary drivers of this transformation, synthetic strategies have been increasingly utilized to interrogate the mechanisms of embryonic patterning with spatial and temporal precision. In this review, we survey how chemical tools and engineered proteins have been used to perturb developmental processes at the DNA, RNA, protein, and cellular levels. We discuss the design principles, experimental capabilities, and limitations of each method, as well as future challenges for the chemical and developmental biology communities.

Discovery of Dual VEGFR-2 and Tubulin Inhibitors with in Vivo Efficacy.

In an effort to develop potent, orally bioavailable compounds for the treatment of neoplastic diseases, we developed a class of dual VEGFR-2 kinase and tubulin inhibitors. Targeting the VEGFR receptor kinase and tubulin structure allows for inhibition of both tumor cells and tumor vasculature. Previously, a combination of two compounds, a VEGF receptor tyrosine kinase inhibitor and tubulin agent, was demonstrated to produce an enhanced antitumor response in animal studies. We have reaffirmed their results, with the added benefit that both activities are found in one compound.

Versatile synthesis and rational design of caged morpholinos.

Embryogenesis is regulated by genetic programs that are dynamically executed in a stereotypic manner, and deciphering these molecular mechanisms requires the ability to control embryonic gene function with similar spatial and temporal precision. Chemical technologies can enable such genetic manipulations, as exemplified by the use of caged morpholino (cMO) oligonucleotides to inactivate genes in zebrafish and other optically transparent organisms with spatiotemporal control. Here we report optimized methods for the design and synthesis of hairpin cMOs incorporating a dimethoxynitrobenzyl (DMNB)-based bifunctional linker that permits cMO assembly in only three steps from commercially available reagents. Using this simplified procedure, we have systematically prepared cMOs with differing structural configurations and investigated how the in vitro thermodynamic properties of these reagents correlate with their in vivo activities. Through these studies, we have established general principles for cMO design and successfully applied them to several developmental genes. Our optimized synthetic and design methodologies have also enabled us to prepare a next-generation cMO that contains a bromohydroxyquinoline (BHQ)-based linker for two-photon uncaging. Collectively, these advances establish the generality of cMO technologies and will facilitate the application of these chemical probes in vivo for functional genomic studies.

Synthesis and evaluation of heteroaryl-ketone derivatives as a novel class of VEGFR-2 inhibitors.

We have discovered novel inhibitors of VEGFR-2 kinase with low nanomolar potency in both enzymatic and cell-based assays. Active series are heteroaryl-ketone compounds containing a central aromatic ring with either an indazolyl or indolyl keto group in the ortho orientation to the benzylic amine group (Fig. 1). The best compounds were demonstrated to be inactive against a small select panel of tyrosine and serine/threonine kinases with the exception of VEGFR-1 kinase, a close family member. In addition, the lead candidate 8 displayed acceptable exposure levels when administered orally to mice.

Discovery of N-phenyl nicotinamides as potent inhibitors of Kdr.

Inhibition of tumor-induced angiogenesis is a promising strategy in anticancer research. Neovascularization is a process required for both tumor growth and metastasis. Enhanced understanding of the underlying molecular mechanisms has led to the discovery of a variety of pharmaceutically attractive targets. Decades of investigation suggest that vascular endothelial growth factor (VEGF) and its receptors, in particular VEGFR2 or kinase insert-domain-containing receptor (Kdr), play a critical role in the growth and survival of endothelial cells in newly forming vasculature. The clinical utility of inhibitors of this receptor tyrosine kinase is currently under intense investigation. Herein we report our efforts in this arena.

1H-1,2,4-triazol-3-yl-anilines: novel potent inhibitors of vascular endothelial growth factor receptors 1 and 2.

Novel derivatives of 1,2,4-triazoles are described as potent ATP-competitive inhibitors of vascular endothelial growth factor receptors I and II (VEGFR-1/2). A number of compounds display VEGFR-2 inhibitory activity comparable to that of Vatalanib and Vandetanib in both homogenous time-resolved fluorescence enzymatic and cellular assays. Several active molecules feature high intrinsic permeability (>30 x 10(-5) cm/min) across Caco-2 cell monolayer.

Novel inhibitors of VEGF receptors-1 and -2 based on azole-5-carboxamide templates.

We have developed a series of novel potent 1-(2-(pyridin-4-yl)ethyl)-1H-azole-5-carboxamides active against kinases VEGFR-2 and -1. Both specific and dual ATP-competitive inhibitors of VEGFR-2 were identified. Kinase selectivity could be controlled by varying the 5-carboxamide substituent at the azole ring. The most specific molecules displayed >10-fold selectivity for VEGFR-2 over VEGFR-1. Compound activities in vitro and in cell-based assays (IC(50)<100 nM) were similar to those of reported clinical and development candidates, including PTK787 (Vatalanib(trade)) and ZD6474 (Vandetanib(trade mark)). High permeability of active compounds across the Caco-2 cell monolayer (>40 x 10(-5)cm/min) is indicative of their potential for intestinal absorption upon oral administration.

Tricyclic azepine derivatives: pyrimido[4,5-b]-1,4-benzoxazepines as a novel class of epidermal growth factor receptor kinase inhibitors.

A novel class of pyrimido[4,5-b]-1,4-benzoxazepines is described as inhibitors of epidermal growth factor receptor (EGFR) tyrosine kinase. Two compounds display potent EGFR inhibitory activity of less than 1 microM in cellular phosphorylation assays (IC(50) 0.47-0.69 microM) and are highly selective against a small kinase panel. Such compounds demonstrate anti-EGFR activity within a class that is different from any known EGFR inhibitor scaffolds. They also provide a basis for the design of kinase inhibitors with the desired selectivity profile.

Oxadiazole derivatives as a novel class of antimitotic agents: Synthesis, inhibition of tubulin polymerization, and activity in tumor cell lines.

Oxadiazole derivatives were synthesized and evaluated for their ability to inhibit tubulin polymerization and to cause mitotic arrest in tumor cells. The most potent compounds inhibited tubulin polymerization at concentrations below 1 microM. Lead analogs caused mitotic arrest of A431 human epidermoid cells and cells derived from multi-drug resistant tumors (10, EC(50)=7.8 nM). Competition for the colchicine binding site and pharmacokinetic properties of selected potent compounds were also investigated and are reported herein, along with structure-activity relationships for this novel series of antimitotic agents.

Synthesis and structure-activity relationships of 1,2,4-triazoles as a novel class of potent tubulin polymerization inhibitors.

A novel triazole-containing chemical series was shown to inhibit tubulin polymerization and cause cell cycle arrest in A431 cancer cells with EC(50) values in the single digit nanomolar range. Binding experiments demonstrated that representative active compounds of this class compete with colchicine for its binding site on tubulin. The syntheses and structure-activity relationship studies for the triazole derivatives are described herein.