Define Critical Parameters of Trastuzumab-Mediated ADCC Assays via Assay Optimization Processes, Focusing on the Impact of Cryopreserved Effector Cells on Assay Performance.

The mechanisms of mAb-induced ADCC have been well established. However, the ADCC bioassays used to quantify mAb-induced ADCC require continued development/refinement to properly assess and compare the potency of newly developed therapeutic mAbs and biosimilars to meet regulatory requirements. We used trastuzumab and a lactate dehydrogenase (LDH)-based ADCC bioassay as a model to define critical parameters of the ADCC bioassay, describing how several bioassay parameters, including preparation of effector cells, E/T ratio, target cell selection, bioassay media components, and treatment time can influence the data quality of the ADCC activity.

PAAN/MIF nuclease inhibition prevents neurodegeneration in Parkinson's disease.

Parthanatos-associated apoptosis-inducing factor (AIF) nuclease (PAAN), also known as macrophage migration inhibitor factor (MIF), is a member of the PD-D/E(X)K nucleases that acts as a final executioner in parthanatos. PAAN's role in Parkinson's disease (PD) and whether it is amenable to chemical inhibition is not known. Here, we show that neurodegeneration induced by pathologic α-synuclein (α-syn) occurs via PAAN/MIF nuclease activity.

Influence of stereochemistry on the activity of rapadocin, an isoform-specific inhibitor of the nucleoside transporter ENT1.

Rapadocin is a novel rapamycin-inspired polyketide-tetrapeptide hybrid macrocycle that possesses highly potent and isoform-specific inhibitory activity against the human equilibrative nucleoside transporter 1 (hENT1). Rapadocin contains an epimerizable chiral center in phenylglycine and an olefin group, and can thus exist as a mixture of four stereoisomers. Herein, we report the first total synthesis of the four stereoisomers of rapadocin using two different synthetic strategies and the assignment of their structures.

Design and Synthesis of Tetrazole- and Pyridine-Containing Itraconazole Analogs as Potent Angiogenesis Inhibitors.

Itraconazole, a widely used antifungal drug, was found to possess antiangiogenic activity and is currently undergoing multiple clinical trials for the treatment of different types of cancer. However, it suffers from extremely low solubility and strong interactions with many drugs through inhibition of CYP3A4, limiting its potential as a new antiangiogenic and anticancer drug. To address these issues, a series of analogs in which the phenyl group is replaced with pyridine or fluorine-substituted benzene was synthesized.

Discovery of a Potent GLUT Inhibitor from a Library of Rapafucins by Using 3D Microarrays.

Glucose transporters play an essential role in cancer cell proliferation and survival and have been pursued as promising cancer drug targets. Using microarrays of a library of new macrocycles known as rapafucins, which were inspired by the natural product rapamycin, we screened for new inhibitors of GLUT1. We identified multiple hits from the rapafucin 3D microarray and confirmed one hit as a bona fide GLUT1 ligand, which we named rapaglutin A (RgA).

Activation of BMP Signaling by FKBP12 Ligands Synergizes with Inhibition of CXCR4 to Accelerate Wound Healing.

The combination of AMD3100 and low-dose FK506 has been shown to accelerate wound healing in vivo. Although AMD3100 is known to work by releasing hematopoietic stem cells into circulation, the mechanism of FK506 in this setting has remained unknown. In this study, we investigated the activities of FK506 in human cells and a diabetic-rat wound model using a non-immunosuppressive FK506 analog named FKVP.

Rapamycin-inspired macrocycles with new target specificity.

Rapamycin and FK506 are macrocyclic natural products with an extraordinary mode of action, in which they form binary complexes with FK506-binding protein (FKBP) through a shared FKBP-binding domain before forming ternary complexes with their respective targets, mechanistic target of rapamycin (mTOR) and calcineurin, respectively. Inspired by this, we sought to build a rapamycin-like macromolecule library to target new cellular proteins by replacing the effector domain of rapamycin with a combinatorial library of oligopeptides. We developed a robust macrocyclization method using ring-closing metathesis and synthesized a 45,000-compound library of hybrid macrocycles (named rapafucins) using optimized FKBP-binding domains.

Diallyl trisulfide protects against high glucose-induced cardiac apoptosis by stimulating the production of cystathionine gamma-lyase-derived hydrogen sulfide.

Background: Cystathionine-γ-lyase (CSE)-derived hydrogen sulfide (H2S) is a potent cardioprotective agent. We investigated the effects of diallyl trisulfide (DATS) on CSE expression and H2S generation in myocardium and examined whether DATS-mediated H2S generation effectively protects rat heart from diabetes-induced cardiac damage.

Methods: The correlations between the effects of hyperglycemia and diabetes on CSE expression and the effects of DATS and H2S on hyperglycemia and diabetes were examined in vitro in the cardiomyocyte cell line H9c2 and in vivo in hearts from rats with streptozotocin-induced diabetes mellitus (DM).

Redox-based selective fluorometric detection of homocysteine.

Plasma homocysteine (Hcy) is an important risk factor for various diseases. A novel redox-sensitive fluorescent probe is developed for the selective detection of Hcy. A linear calibration curve has been obtained in buffer and plasma for the quantitative determination of Hcy in such media.

Recent advances in thiol and sulfide reactive probes.

Because of the biological relevance of thiols and sulfides such as cysteine, homocysteine, glutathione and hydrogen sulfide, their detection has attracted a great deal of research interest. Fluorescent probes are emerging as a new strategy for thiol and hydrogen sulfide analysis due to their high sensitivity, low cost, and ability to detect and image thiols in biological samples. In this short review, we have summarized recent advances in the development of thiol and hydrogen sulfide reactive fluorescent probes.

Hydrogen sulfide inhibits the renal fibrosis of obstructive nephropathy.

Hydrogen sulfide has recently been found decreased in chronic kidney disease. Here we determined the effect and underlying mechanisms of hydrogen sulfide on a rat model of unilateral ureteral obstruction. Compared with normal rats, obstructive injury decreased the plasma hydrogen sulfide level.

2,6-dansyl azide as a fluorescent probe for hydrogen sulfide.

A second-generation sulfonyl azide-based fluorescent probe, 2,6-DNS-Az, has been developed for the quantitative detection of H2S in aqueous media such as phosphate buffer and bovine serum. Compare to the first-generation 1,5-DNS-Az probe, this probe shows both high sensitivity in phosphate buffer without the need for addition of surfactant and selectivity for sulfide over other anions and biomolecules, and thus can be used as a useful tool for detection of H2S in the biological system.

An unexpected copper catalyzed 'reduction' of an arylazide to amine through the formation of a nitrene intermediate.

Azido nitrobenzoxadiazole (NBD) was observed to undergo a 'reduction' reaction in the absence of an obvious reducing agent, leading to amine formation. In the presence of an excess amount of DMSO, a sulfoxide conjugate was also formed. The ratio of these two products was both temperature- and solvent-dependent, with the addition of water significantly enhancing the ratio of the 'reduction' product.

Rapid and specific post-synthesis modification of DNA through a biocompatible condensation of 1,2-aminothiols with 2-cyanobenzothiazole.

Post-synthesis modification of DNA is an important way of functionalizing DNA molecules. Herein, we describe a method that first enzymatically incorporates a cyanobenzothiazole (CBT)-modified thymidine. The side-chain handle CBT can undergo a rapid and site-specific cyclization reaction with 1,2-aminothiols to afford DNA functionalization in aqueous solution.

Thiol reactive probes and chemosensors.

Thiols are important molecules in the environment and in biological processes. Cysteine (Cys), homocysteine (Hcy), glutathione (GSH) and hydrogen sulfide (H(2)S) play critical roles in a variety of physiological and pathological processes. The selective detection of thiols using reaction-based probes and sensors is very important in basic research and in disease diagnosis.

Novel AI-2 quorum sensing inhibitors in Vibrio harveyi identified through structure-based virtual screening.

In this letter, a high-throughput virtual screening was accomplished to identify potent inhibitors against AI-2 quorum sensing on the basis of Vibrio harveyi LuxPQ crystal structure. Seven compounds were found to inhibit AI-2 quorum sensing with IC(50) values in the micromolar range, and presented low cytotoxicity or no cytotoxicity in V. harveyi.

Design, synthesis, and polymerase-catalyzed incorporation of click-modified boronic acid-TTP analogues.

DNA molecules are known to be important materials in sensing, aptamer selection, nanocomputing, and construction of unique architectures. The incorporation of modified nucleobases affords unique DNA properties for applications in areas that would otherwise be difficult or not possible. Earlier, we demonstrated that the boronic acid moiety can be introduced into DNA through polymerase-catalyzed reactions.

The first chemical synthesis of boronic acid-modified DNA through a copper-free click reaction.

The first chemical incorporation of the boronic acid group into DNA using a copper-free click reagent was reported. Compared with the PCR-based method, this approach allows for site-specific incorporation and synthesis on a larger scale.

Carbohydrate biomarkers for future disease detection and treatment.

Carbohydrates are considered as one of the most important classes of biomarkers for cell types, disease states, protein functions, and developmental states. Carbohydrate "binders" that can specifically recognize a carbohydrate biomarker can be used for developing novel types of site specific delivery methods and imaging agents. In this review, we present selected examples of important carbohydrate biomarkers and how they can be targeted for the development of therapeutic and diagnostic agents.

Synthesis and evaluation of new antagonists of bacterial quorum sensing in Vibrio harveyi.

Bacterial quorum sensing has received much attention in recent years because of its relevance to pathological events such as biofilm formation. Based on the structures of two lead inhibitors (IC50: 35-55 microM) against autoinducer-2-mediated quorum sensing identified through virtual screening, we synthesized 39 analogues and examined their inhibitory activities. Twelve of these new analogues showed equal or better inhibitory activities than the lead inhibitors.

Inhibition of quorum sensing in Vibrio harveyi by boronic acids.

Bacterial quorum sensing refers to the ability of bacteria to control gene expression through the detection of a threshold concentration of certain chemicals called autoinducer(s), which are secreted by self and/or other bacteria. Quorum sensing is implicated in the regulation of pathologically relevant events such as biofilm formation, virulence, conjugation, sporulation, and swarming mobility. Inhibitors of bacterial quorum sensing are valuable research tools and potential antimicrobial agents.