Metabolic regulation of gene expression by histone lactylation.

The Warburg effect, which originally described increased production of lactate in cancer, is associated with diverse cellular processes such as angiogenesis, hypoxia, polarization of macrophages and activation of T cells. This phenomenon is intimately linked to several diseases including neoplasia, sepsis and autoimmune diseases1,2. Lactate, which is converted from pyruvate in tumour cells, is widely known as an energy source and metabolic by-product. However, its non-metabolic functions in physiology and disease remain unknown. Here we show that lactate-derived lactylation of histone lysine residues serves as an epigenetic modification that directly stimulates gene transcription from chromatin. We identify 28 lactylation sites on core histones in human and mouse cells. Hypoxia and bacterial challenges induce the production of lactate by glycolysis, and this acts as a precursor that stimulates histone lactylation. Using M1 macrophages that have been exposed to bacteria as a model system, we show that histone lactylation has different temporal dynamics from acetylation. In the late phase of M1 macrophage polarization, increased histone lactylation induces homeostatic genes that are involved in wound healing, including Arg1. Collectively, our results suggest that an endogenous 'lactate clock' in bacterially challenged M1 macrophages turns on gene expression to promote homeostasis. Histone lactylation thus represents an opportunity to improve our understanding of the functions of lactate and its role in diverse pathophysiological conditions, including infection and cancer.

Leveraging Radiation-triggered Metal Prodrug Activation Through Nanosurface Energy Transfer for Directed Radio-chemo-immunotherapy.

Metal-based drugs currently dominate the field of chemotherapeutic agents; however, achieving the controlled activation of metal prodrugs remains a substantial challenge. Here, we propose a universal strategy for the radiation-triggered activation of metal prodrugs via nanosurface energy transfer (NSET). The core-shell nanoplatform (Ru-GNC) is composed of gold nanoclusters (GNC) and ruthenium (Ru)-containing organic-inorganic hybrid coatings. Upon X-ray irradiation, chemotherapeutic Ru (II) complexes were released in a controlled manner through a unique NSET process involving the transfer of photoelectron energy from the radiation-excited Ru-GNCs to the Ru-containing hybrid layer. In contrast to the traditional radiation-triggered activation of prodrugs, such an NSET-based system ensures that the reactive species in the tumor microenvironment are present in sufficient quantity and are not easily quenched. Additionally, ultrasmall Ru-GNCs preferably target mitochondria and profoundly disrupt the respiratory chain upon irradiation, leading to radiosensitization by generating abundant reactive oxygen species. Consequently, Ru-GNC-directed radiochemotherapy induces immunogenic cell death, resulting in significant therapeutic outcomes when combined with the programmed cell death-ligand 1 (PD-L1) checkpoint blockade. This NSET strategy represents a breakthrough in designing radiation-triggered nanoplatforms for metal-prodrug-mediated cancer treatment in an efficient and controllable manner.

Development of Ruthenium Nanophotocages with Red or Near-Infrared Light-Responsiveness.

The development of light-triggered ruthenium (Ru) nanophotocages has revolutionized conventional methods of drug administration, thereby facilitating cancer therapy in a noninvasive and temperate manner. Ru nanophotocages employ a distinct approach known as photoactivated chemotherapy (PACT), wherein light-induced ligand dissociation yields a toxic metal complex or a ligand capable of performing other functions such as optically controlled protein degradation and drug delivery. Simultaneously, this process is accompanied by the generation of reactive oxygen species (ROS), which serve as an effective anticancer agent in combination with PACT and photodynamic therapy (PDT). Due to its exceptional attributes of extended tissue penetration, and minimized tissue damage, red light or near-infrared light is widely acknowledged as the "phototherapeutic window" (650-900 nm). In this Concept, we present an overview of the most recent advancements in Ru nanophotocages within the phototherapeutic range. Diverse aspects, including design principles, photocaging efficacy, photoactivation mechanisms, and potential applications in the field of biomedical chemistry, are discussed. Questions and challenges regarding their synthesis, characterization, and applications are also discussed. This Concept would foster further exploration into the realm of Ru nanophotocages.

Identification of lysine isobutyrylation as a new histone modification mark.

Short-chain acylations of lysine residues in eukaryotic proteins are recognized as essential posttranslational chemical modifications (PTMs) that regulate cellular processes from transcription, cell cycle, metabolism, to signal transduction. Lysine butyrylation was initially discovered as a normal straight chain butyrylation (Knbu). Here we report its structural isomer, branched chain butyrylation, i.e. lysine isobutyrylation (Kibu), existing as a new PTM on nuclear histones. Uniquely, isobutyryl-CoA is derived from valine catabolism and branched chain fatty acid oxidation which is distinct from the metabolism of n-butyryl-CoA. Several histone acetyltransferases were found to possess lysine isobutyryltransferase activity in vitro, especially p300 and HAT1. Transfection and western blot experiments showed that p300 regulated histone isobutyrylation levels in the cell. We resolved the X-ray crystal structures of HAT1 in complex with isobutyryl-CoA that gleaned an atomic level insight into HAT-catalyzed isobutyrylation. RNA-Seq profiling revealed that isobutyrate greatly affected the expression of genes associated with many pivotal biological pathways. Together, our findings identify Kibu as a novel chemical modification mark in histones and suggest its extensive role in regulating epigenetics and cellular physiology.

Liposomal Enzyme Nanoreactors Based on Nanoconfinement for Efficient Antitumor Therapy.

Enzymatic reactions can consume endogenous nutrients of tumors and produce cytotoxic species and are therefore promising tools for treating malignant tumors. Inspired by nature where enzymes are compartmentalized in membranes to achieve high reaction efficiency and separate biological processes with the environment, we develop liposomal nanoreactors that can perform enzymatic cascade reactions in the aqueous nanoconfinement of liposomes. The nanoreactors effectively inhibited tumor growth in vivo by consuming tumor nutrients (glucose and oxygen) and producing highly cytotoxic hydroxyl radicals (⋅OH). Co-compartmentalization of glucose oxidase (GOx) and horseradish peroxidase (HRP) in liposomes could increase local concentration of the intermediate product hydrogen peroxide (H2 O2 ) as well as the acidity due to the generation of gluconic acid by GOx. Both H2 O2 and acidity accelerate the second-step reaction by HRP, hence improving the overall efficiency of the cascade reaction. The biomimetic compartmentalization of enzymatic tandem reactions in biocompatible liposomes provides a promising direction for developing catalytic nanomedicines in antitumor therapy.

A Near-Infrared Light-Activated Photocage Based on a Ruthenium Complex for Cancer Phototherapy.

Conventional photocages only respond to short wavelength light, which is a significant obstacle to developing efficient phototherapy in vivo. The development of photocages activated by near-infrared (NIR) light at wavelengths from 700 to 950 nm is important for in vivo studies but remains challenging. Herein, we describe the synthesis of a photocage based on a ruthenium (Ru) complex with NIR light-triggered photocleavage reaction. The commercial anticancer drug, tetrahydrocurcumin (THC), was coordinated to the RuII center to create the Ru-based photocage that is readily responsive to NIR light at 760 nm. The photocage inherited the anticancer properties of THC. As a proof-of-concept, we further engineered a self-assembled photocage-based nanoparticle system with amphiphilic block copolymers. Upon exposure to NIR light at 760 nm, the Ru complex-based photocages were released from the polymeric nanoparticles and efficiently inhibited tumor proliferation in vivo.

Acid-Sensitive Surfactants Enhance the Delivery of Nucleic Acids.

The development of endosomal disruptive agents is a major challenge in the field of drug delivery and pharmaceutical chemistry. Current endosomal disruptive agents are composed of polymers, peptides, and nanoparticles and have had limited clinical impact. Alternatives to traditional endosomal disruptive agents are therefore greatly needed. In this report, we introduce a new class of low molecular weight endosomal disruptive agents, termed caged surfactants, that selectively disrupt endosomes via reversible PEGylation under acidic endosomal conditions. The caged surfactants have the potential to address several of the limitations hindering the development of current endosomal disruptive agents, such as high toxicity and low excretion, and are amenable to traditional medicinal chemistry approaches for optimization. In this report, we synthesized three generations of caged surfactants and demonstrated that they can enhance the ability of cationic lipids to deliver mRNA into primary cells. We also show that caged surfactants can deliver siRNA into cells when modified with the RNA-binding dye thiazole orange. We anticipate that the caged surfactants will have numerous applications in pharmaceutical chemistry and drug delivery given their versatility.

Umbilical cord blood metabolomics: association with intrauterine hyperglycemia.

BACKGROUND: Intrauterine hyperglycemia can harm a fetus's growth and development, and this can be seen in the umbilical cord blood metabolism disorder. However, the metabolites and metabolic mechanisms involved in the condition remain unknown. METHODS: Targeted metabolomics using liquid chromatography and MetaboAnalyst were conducted in this study to explore differences in metabolites and metabolic pathways between individuals with hyperglycemia or well-controlled gestational diabetes mellitus (GDM) and healthy controls. RESULTS: Univariate analysis found that the hyperglycemic and healthy control groups differed in 30 metabolites, while the well-controlled GDM and the healthy control groups differed only in three metabolites-ursodeoxycholic acid, docosahexaenoic acid, and 8,11,14-eicosatrienoic acid. Most of these metabolic variations were negatively associated with neonatal weights. Further research showed that the variations in the metabolites were primarily associated with the metabolic pathways of linoleic acid (LA) and alpha-linolenic acid (ALA). CONCLUSION: Gestational hyperglycemia and well-controlled GDM, which may play a major role by inhibiting the LA and ALA metabolic pathways, have detrimental effects on cord blood metabolism. IMPACT: The main point of this paper is that intrauterine hyperglycemia has a negative effect on cord blood metabolism mainly through the linoleic acid and alpha-linolenic acid metabolic pathways. This is a study to report a new association between well-controlled GDM and cord blood metabolism. This study provides a possible explanation for the association between intrauterine hyperglycemia and neonatal adverse birth outcomes.

Biodegradable Ru-Containing Polycarbonate Micelles for Photoinduced Anticancer Multitherapeutic Agent Delivery and Phototherapy Enhancement.

The lack of selectivity between tumor and healthy cells, along with inefficient reactive oxygen species production in solid tumors, are two major impediments to the development of anticancer Ru complexes. The development of photoinduced combination therapy based on biodegradable polymers that can be light activated in the "therapeutic window" would be beneficial for enhancing the therapeutic efficacy of Ru complexes. Herein, a biodegradable Ru-containing polymer (poly(DCARu)) is developed, in which two different therapeutics (the drug and the Ru complex) are rationally integrated and then conjugated to a diblock copolymer (MPEG-b-PMCC) containing hydrophilic poly(ethylene glycol) and cyano-functionalized polycarbonate with good degradability and biocompatibility. The polymer self-assembles into micelles with high drug loading capacity, which can be efficiently internalized into tumor cells. Red light induces the generation of singlet oxygen and the release of anticancer drug-Ru complex conjugates from poly(DCARu) micelles, hence inhibiting tumor cell growth. Furthermore, the phototherapy of polymer micelles demonstrates remarkable inhibition of tumor growth in vivo. Meanwhile, polymer micelles exhibit good biocompatibility with blood and healthy tissues, which opens up opportunities for multitherapeutic agent delivery and enhanced phototherapy.

The identification of pregnant women with renal colic who may need surgical intervention.

BACKGROUND: Renal colic is a surgical emergency in pregnancy that is caused by a range of non-obstetric factors and known to occur more frequently during the second and third trimesters. Several studies have reported that up to 70-80% of stones pass spontaneously during pregnancy. There are some patients will not pass their stones and will ultimately require surgical intervention. Through retrospective analysis of the clinical data of 212 pregnant women with renal colic, the predictive factors of pregnant women with renal colic in need of surgical intervention were determined. METHODS: We conducted a retrospective review of 212 pregnant women presenting with renal colic between 1st January 2009 and 31st December 2020. Univariate and multivariate analyses identified a range of predictive variables for surgical intervention. In addition, we used receiver operating characteristic curve analysis to evaluate the predictive power of our model and created a nomogram for clinical application. RESULTS: Of the 212 patients presenting with acute renal colic in pregnancy, 100 patients (47.2%) underwent surgical intervention and 112 patients (52.8%) were treated conservatively. Univariate analysis identified significant differences between the two groups with regards to fever, the duration of pain, white blood cells, C-reactive protein, ureteral stone size, hydronephrosis, and stone location. Multivariate analysis further identified a number of independent predictors for surgical intervention, including fever, a duration of pain ≥ 4 days, a ureteral stone size ≥ 8 mm, and moderate or severe hydronephrosis. CONCLUSIONS: We identified several independent predictors for surgical intervention for renal colic in pregnancy. Fever, a duration of pain ≥ 4 days, a ureteral stone size ≥ 8 mm, and moderate/severe hydronephrosis, play significant roles in predicting surgical intervention. Our nomogram can help to calculate the probability of surgical intervention in a simple and efficient manner. Prospective studies are now required to validate our model.

Mass Spectrometric Quantitation of Tubulin Acetylation from Pepsin-Digested Rat Brain Tissue Using a Novel Stable-Isotope Standard and Capture by Anti-Peptide Antibody (SISCAPA) Method.

Acetylation of α-tubulin at Lys-40 is a potential biomarker for cognitive deficits in various neurological disorders. However, this key post-translational modification (PTM) has not been previously studied with mass spectrometry, due to the inadequate distribution of tryptic cleavage sites. Following peptic digestion, a surrogate sequence containing this key PTM site was identified and was found to be stable and quantitatively reproducible. A highly sensitive and specific SISCAPA-LC-MS method for quantitating rat brain tubulin acetylation was developed, validated, and applied, and only required a small amount of tissue (2.2 mg). This workflow includes peptic digestion, stable-isotope dilution, capture with antiacetylated peptide antibody bound on protein G beads, and quantitation using LC-MS. The method allowed a lower limit of quantitation at 2.50 pmol/mg and provided a linear range of 2.50-62.50 pmol/mg. Selectivity, intra and interday precision and accuracy were also validated. This method has been successfully applied in a preclinical study of organophosphate neurotoxicity, and we found that chronic exposure to chlorpyrifos led to a significant and persistent inhibition of brain tubulin acetylation.

Chemical Biology Approaches for Investigating the Functions of Lysine Acetyltransferases.

The side-chain acetylation of lysine residues in histones and non-histone proteins catalyzed by lysine acetyltransferases (KATs) represents a widespread posttranslational modification (PTM) in the eukaryotic cells. Lysine acetylation plays regulatory roles in major cellular pathways inside and outside the nucleus. In particular, KAT-mediated histone acetylation has an effect on all DNA-templated epigenetic processes. Aberrant expression and activation of KATs are commonly observed in human diseases, especially cancer. In recent years, the study of KAT functions in biology and disease has greatly benefited from chemical biology tools and strategies. In this Review, we present the past and current accomplishments in the design of chemical biology approaches for the interrogation of KAT activity and function. These methods and probes are classified according to their mechanisms of action and respective applications, with both strengths and limitations discussed.

Intricate Effects of α-Amino and Lysine Modifications on Arginine Methylation of the N-Terminal Tail of Histone H4.

Chemical modifications of the DNA and nucleosomal histones tightly control the gene transcription program in eukaryotic cells. The "histone code" hypothesis proposes that the frequency, combination, and location of post-translational modifications (PTMs) of the core histones compose a complex network of epigenetic regulation. Currently, there are at least 23 different types and >450 histone PTMs that have been discovered, and the PTMs of lysine and arginine residues account for a crucial part of the histone code. Although significant progress has been achieved in recent years, the molecular basis for the histone code is far from being fully understood. In this study, we investigated how naturally occurring N-terminal acetylation and PTMs of histone H4 lysine-5 (H4K5) affect arginine-3 methylation catalyzed by both type I and type II PRMTs at the biochemical level. Our studies found that acylations of H4K5 resulted in decreased levels of arginine methylation by PRMT1, PRMT3, and PRMT8. In contrast, PRMT5 exhibits an increased rate of arginine methylation upon H4K5 acetylation, propionylation, and crotonylation, but not upon H4K5 methylation, butyrylation, or 2-hydroxyisobutyrylation. Methylation of H4K5 did not affect arginine methylation by PRMT1 or PRMT5. There was a small increase in the rate of arginine methylation by PRMT8. Strikingly, a marked increase in the rate of arginine methylation was observed for PRMT3. Finally, N-terminal acetylation reduced the rate of arginine methylation by PRMT3 but had little influence on PRMT1, -5, and -8 activity. These results together highlight the underlying mechanistic differences in substrate recognition among different PRMTs and pave the way for the elucidation of the complex interplay of histone modifications.

Reduced plasma corticotropin-releasing hormone levels during late gestation in patients with intrahepatic cholestasis of pregnancy.

OBJECTIVE: Intrahepatic cholestasis of pregnancy (ICP) may lead to sudden onset of stillbirth, which most likely is related to uteroplacental insufficiency and dysregulation of the fetal blood supply. The relaxing effect of corticotropin-releasing hormone (CRH) on blood vessels was measured to examine the role of CRH in the pathogenesis of ICP. METHODS: Eighty normal pregnant women and 80 ICP patients were divided into four groups of 20 cases, respectively, each based on gestational age from week 34 to 37. Radioimmunoassay was used to measure CRH in plasma samples collected from all of the subjects. RESULTS: Plasma CRH increased markedly from week 34 to 37 in both ICP and healthy patients, but the increase was lower in the ICP group. Plasma CRH was 322 ± 61 pg/ml in mild ICP cases at 37 weeks' compared to 1,066 ± 173 pg/ml in controls (p < 0.05), but only 218 ± 128 pg/ml in severe ICP (p < 0.05). Plasma CRH was significantly lower at all other measured time points in patients with severe ICP. In ICP patients, there was a negative correlation between plasma CRH and total bile acid (TBA). CONCLUSION: A limited increasing CRH level and negative correlation of CRH with TBA were unveiled in ICP patients.

Magnetic-Actuated Jumping of Droplets on Superhydrophobic Grooved Surfaces: A Versatile Strategy for Three-Dimensional Droplet Transportation.

On-demand droplet transportation is of great significance for numerous applications. Although various strategies have been developed for droplet transportation, out-of-surface three-dimensional (3D) transportation of droplets remains challenging. Here, a versatile droplet transportation strategy based on magnetic-actuated jumping (MAJ) of droplets on superhydrophobic grooved surfaces (SHGSs) is presented, which enables 3D, remote, and precise manipulation of droplets even in enclosed narrow spaces. To trigger MAJ, an electromagnetic field is utilized to deform the droplet on the SHGS with the aid of an attached magnetic particle, thereby the droplet acquires excess surface energy. When the electromagnetic field is quickly removed, the excess surface energy is partly converted into kinetic energy, allowing the droplet to jump atop the surface. Through high-speed imaging and numerical simulation, the working mechanism and size matching effect of MAJ are unveiled. It is found that the MAJ behavior can only be observed if the sizes of the droplets and the superhydrophobic grooves are matched, otherwise unwanted entrapment or pinch-off effects would lead to failure of MAJ. A regime diagram which serves as a guideline to design SHGSs for MAJ is proposed. The droplet transportation capacities of MAJ, including in-surface and out-of-surface directional transportation, climbing stairs, and crossing obstacles, are also demonstrated. With the ability to remotely manipulate droplets in enclosed narrow spaces without using any mechanical moving parts, MAJ can be used to design miniaturized fluidic platforms, which exhibit great potential for applications in bioassays, microfluidics, droplet-based switches, and microreactions.

Near-Infrared Fluorescence Probe for Monoamine Oxidase A with a Large Stokes Shift for Intraoperative Navigation.

Monoamine oxidase A (MAO-A) is a dimeric flavoprotein that is found in the mitochondrial membrane. Currently, there is a lack of near-infrared fluorescent probes (NIR-FPs) with good specificity and high sensitivity for detecting MAO-A, making it difficult to accurately recognize and image cells in vitro and in vivo. In this study, the NIR-FP DDM-NH2 was designed and synthesized in order to detect MAO-A specifically in live biological systems. The probe comprised two functional components: dicyanoisophosphone as an NIR dye precursor and alanine as a recognition moiety. After identifying MAO-A, the probe exhibited an NIR emission peak at 770 nm with a significant Stokes shift (180 nm), 11-fold response factor, low detection limit of 99.7 nM, and considerably higher affinity toward MAO-A than that toward MAO-B, indicating high sensitivity. In addition, DDM-NH2 was effective when applied to the image-based assessment of MAO-A activity in HeLa cells, zebrafish, and tumor-bearing mice, demonstrating great potential for visualization-based research and MAO-A application in vivo.

Charge-reversal polymeric nanomodulators for ferroptosis-enhanced photodynamic therapy.

The clinical application of photodynamic therapy (PDT) has some limitations including poor tumor targeting properties, a high reductive tumor microenvironment, and inefficient activation of single cell death machinery. We herein report pH-sensitive polymeric nanomodulators (NBS-PDMC NPs) for ferroptosis-enhanced photodynamic therapy. NBS-PDMC NPs were constructed using a positively charged type-I photosensitizer (NBS) coordinated with a demethylcantharidin (DMC)-decorated block copolymer via electrostatic interactions. NBS-PDMC NPs had a negative surface charge, which ensures their high stability in bloodstream circulation, while exposure to lysosomal acidic environments reverses their surface charge to positive for tumor penetration and the release of DMC and NBS. Under NIR light irradiation, NBS generated ROS to induce cell damage; in the meantime, DMC inhibited the expression of the GPX4 protein in tumor cells and promoted ferroptosis of tumor cells. This polymer design concept provides some novel insights into smart drug delivery and combinational action to amplify the antitumor effect.

Ferroptosis-inducing photosensitizers alleviate hypoxia tumor microenvironment for enhanced fluorescence imaging-guided photodynamic therapy.

This study describes H2O2-activated photosensitizer nanoparticles (ICyHD NPs), which inhibit histone deacetylase via binding Zn2+ to induce ferroptosis and upregulate the intracellular O2, thus resulting in enhanced photodynamic therapeutic effect. ICyHD NPs exert strong antitumor effects on mice and have improved the therapeutic precision via observing the increase in cellular fluorescence.

[Expression of corticotropin-releasing hormone receptor type-1 in intrahepatic cholestatic placental tissue].

OBJECTIVE: To explore the expression level of corticotropin-releasing hormone receptor type-1 (CRHR-1) in intrahepatic cholestatic placental (ICP) tissue. METHODS: Human placental samples were collected from 10 ICP patients and 10 healthy controls after parturition at 37-40 weeks of gestation. CRHR-1 protein and mRNA expression was assessed by western blotting and nested-real-time fluorescence quantitative PCR, respectively. Normally distributed data were summarized as mean +/- standard deviation, and intergroup comparisons were made by two-tailed Student's t-test. Non-normally distributed data were presented as median with interquartile range, and intergroup comparisons were made by Wilcoxon test. For all statistical analyses, a two-tailed P-value of less than 0.05 was considered statistically significant. RESULTS: The CRHR-1 fluorescence intensity was lower in ICP tissues (1.55 +/- 0.28) than in placental tissues from healthy controls (1.60 +/- 0.37), but the difference did not reach statistical significance (t = 0.349, P = 0.732). The CRHR-1 mRNA content was slightly higher in the ICP tissues [0.139(0.268)] than in the placental tissues from healthy controls [0.031(0.245)], but the difference did not reach statistical significance (t = 1.504, P = 0.136). CONCLUSION: CRHR-1 expression is decreased in ICP tissues, which may lead to a smaller volume of placental lobular villi vessels and restrict the CRH positive feedback loop, ultimately promoting acute hypoxic stress and possible harm to the fetus.

Mechanically Robust and Chemically Recyclable Polyhydroxyurethanes from CO2-Derived Six-Membered Cyclic Carbonates.

In the current context of sustainable chemistry development and new regulations, aminolysis of cyclic carbonate is one of the most promising routes to nonisocyanate polyurethanes, also called polyhydroxyurethanes (PHU). In this study, a new kind of shape memory PHU vitrimers with outstanding mechanical properties and chemical recyclability is prepared. The monomer employed for aminolysis to form the PHUs is bis(six-membered cyclic carbonate) of 4,4'-biphenol (BCC-BP), which is synthesized by bi(1,3-diol) precursors and CO2. The synthetic strategy, isocyanate-free and employing CO2 as a building block, is environmentally friendly and suits the concept of carbon neutrality. The thermal properties, mechanical properties, and dynamic behaviors of the PHUs are explored. The maximum breaking strength and elongation at break of the resultant PHUs reach 65 MPa and 452%, respectively, exceeding other reported PHU-based materials in combined performance. Such a PHU material can also lift up a load 4700 times heavier than its own weight by a shape recovery process. Finally, the bi(1,3-diol) can be regenerated through the alcoholysis of PHUs to realize chemical recycling. This work provides a feasibility study for a green synthetic approach and for designing a novel PHU material with outstanding properties.