Orally Bioavailable and Site-Selective Covalent STING Inhibitor Derived from a Macrocyclic Marine Diterpenoid.

Pharmacological inhibition of the cGAS-STING-controlled innate immune pathway is an emerging therapeutic strategy for a myriad of inflammatory diseases. Here, we report as an orally bioavailable covalent STING inhibitor. Late-stage diversification of the briarane-type diterpenoid excavatolide B allowed the installation of solubility-enhancing functional groups while enhancing its activity as a covalent STING inhibitor against multiple human STING variants, including the S154 variant responsible for a genetic autoimmune disease.

Targeting the Phosphatidylserine-Immune Checkpoint with a Small-Molecule Maytansinoid Conjugate.

Ligand-targeting drug delivery systems have made significant strides for disease treatments with numerous clinical approvals in this era of precision medicine. Herein, we report a class of small molecule-based immune checkpoint-targeting maytansinoid conjugates. From the ligand targeting ability, pharmacokinetics profiling, anti-pancreatic cancer, triple-negative breast cancer, and sorafenib-resistant liver cancer efficacies with quantitative mRNA analysis of treated-tumor tissues, we demonstrated that conjugate not only induced lasting regression of tumor growth, but it also rejuvenated the once immunosuppressive tumor microenvironment to an "inflamed hot tumor" with significant elevation of gene expressions that were not accessible in the vehicle-treated tumor.

Synthesis and Evaluation of Small Molecule Drug Conjugates Harnessing Thioester-Linked Maytansinoids.

Ligand-targeting drug conjugates are a class of clinically validated biopharmaceutical drugs constructed by conjugating cytotoxic drugs with specific disease antigen targeting ligands through appropriate linkers. The integrated linker-drug motif embedded within such a system can prevent the premature release during systemic circulation, thereby allowing the targeting ligand to engage with the disease antigen and selective accumulation. We have designed and synthesized new thioester-linked maytansinoid conjugates.

Click Chemistry and Multicomponent Reaction for Linker Diversification of Zinc Dipicolylamine-Based Drug Conjugates.

An efficient Ugi multicomponent reaction with strain promoted azide-alkyne cycloaddition protocol has been utilized in concert or independently to prepare a small family of bioactive zinc(II) dipicolylamine (ZnDPA)-based SN-38 conjugates. With sequential click chemistry coupling between the cytotoxic payload and phosphatidylserine-targeting ZnDPA ligand derived from structurally diverse carboxylic acids, aldehyde or ketones, and isocyanides, we demonstrated that this convergent synthetic strategy could furnish conjugates harnessing diversified linkers that exhibited different pharmacokinetic profiles in systemic circulation . Among the eight new conjugates, comparative studies on cytotoxicities, plasma stabilities, pharmacokinetic properties, and maximum tolerated doses were then carried out to identify a potent ZnDPA-based SN-38 conjugate that resulted in pancreatic cancer growth regression with an 80% reduction of cytotoxic payload used when compared to that of the marketed irinotecan.

BPRDP056, a novel small molecule drug conjugate specifically targeting phosphatidylserine for cancer therapy.

Zinc(II)-dipicolylamine (Zn-DPA) has been shown to specifically identify and bind to phosphatidylserine (PS), which exists in bulk in the tumor microenvironment. BPRDP056, a Zn-DPA-SN38 conjugate was designed to provide PS-targeted drug delivery of a cytotoxic SN38 to the tumor microenvironment, thereby allowing a lower dosage of SN38 that induces apoptosis in cancer cells. Micro-Western assay showed that BPRDP056 exhibited apoptotic signal levels similar to those of CPT-11 in the treated tumors growing in mice.

Implanted islet mass influences the effects of dipeptidyl peptidase-IV inhibitor LAF237 on transplantation outcomes in diabetic mice.

Background: Previous studies showed inconsistent Results of the effects of dipeptidyl peptidase (DPP)-IV inhibitors on syngeneic mouse islet transplantation. We hypothesized that the implanted islet numbers are critical for the effects of DPP-IV inhibitors on the outcomes of transplantation.

Methods: One hundred and fifty or three hundred islets were syngeneically transplanted under the renal capsule of each streptozocin-diabetic C57BL/6 mouse and recipients were then treated without or with LAF237 (10 mg/kg/day, po) for 6 weeks.

High-performance FRET biosensors for single-cell and in vivo lead detection.

Forms of lead (Pb) have been insidiously invading human life for thousands of years without obvious signs of their considerable danger to human health. Blood lead level (BLL) is the routine measure used for diagnosing the degree of lead intoxication, although it is unclear whether there is any safe range of BLL. To develop a practical detection tool for living organisms, we engineered a genetically encoded fluorescence resonance energy transfer (FRET)-based Pb biosensor, 'Met-lead 1.

Monitoring the Heavy Metal Lead Inside Living Drosophila with a FRET-Based Biosensor.

The harmful impact of the heavy metal lead on human health has been known for years. However, materials that contain lead remain in the environment. Measuring the blood lead level (BLL) is the only way to officially evaluate the degree of exposure to lead.

Impacts of Intralipid on Nanodrug Abraxane Therapy and on the Innate Immune System.

A major obstacle to nanodrugs-mediated cancer therapy is their rapid uptake by the reticuloendothelial system that decreases the systemic exposure of the nanodrugs to tumors and also increases toxicities. Intralipid has been shown to reduce nano-oxaliplatin-mediated toxicity while improving bioavailability. Here, we have found that Intralipid reduces the cytotoxicity of paclitaxel for human monocytic cells, but not for breast, lung, or pancreatic cancer cells.

Linker Optimization and Therapeutic Evaluation of Phosphatidylserine-Targeting Zinc Dipicolylamine-based Drug Conjugates.

We report that compound , a novel phosphatidylserine-targeting zinc(II) dipicolylamine drug conjugate, readily triggers a positive feedback therapeutic loop through the generation of phosphatidylserine in the tumor microenvironment. Linker modifications, pharmacokinetics profiling, in vivo antitumor studies, and micro-Western array of treated-tumor tissues were employed to show that this class of conjugates induced regeneration of apoptotic signals, which facilitated subsequent recruitment of the circulating conjugates through the zinc(II) dipicolylamine-phosphatidylserine association and resulted in compounding antitumor efficacy. Compared to the marketed compound , compound not only induced regressions in colorectal and pancreatic tumor models, it also exhibited at least 5-fold enhancement in antitumor efficacy with only 40% of the drug employed during treatment, culminating in a >12.

Soluble α-synuclein facilitates priming and fusion by releasing Ca from the thapsigargin-sensitive Ca pool in PC12 cells.

α-Synuclein is associated with Parkinson's disease, and is mainly localized in presynaptic terminals and regulates exocytosis, but its physiological roles remain controversial. Here, we studied the effects of soluble and aggregated α-synuclein on exocytosis, and explored the molecular mechanism by which α-synuclein interacts with regulatory proteins, including Rab3A, Munc13-1 (also known as Unc13a) and Munc18-1 (also known as STXBP1), in order to regulate exocytosis. Through fluorescence recovery after photobleaching experiments, overexpressed α-synuclein in PC12 cells was found to be in a monomeric form, which promotes exocytosis.

Clinical and biophysical characterization of 19 mutations.

Objective: Charcot-Marie-Tooth disease type X1 (CMTX1), which is caused by mutations in the gap junction (GJ) protein beta-1 gene (), is the second most common form of Charcot-Marie-Tooth disease (CMT). encodes the GJ beta-1 protein (GJB1), which forms GJs within the myelin sheaths of peripheral nerves. The process by which GJB1 mutants cause neuropathy has not been fully elucidated.

Interpolation based consensus clustering for gene expression time series.

Background: Unsupervised analyses such as clustering are the essential tools required to interpret time-series expression data from microarrays. Several clustering algorithms have been developed to analyze gene expression data. Early methods such as k-means, hierarchical clustering, and self-organizing maps are popular for their simplicity.

Downregulation of DAB2IP promotes mesenchymal-to-neuroepithelial transition and neuronal differentiation of human mesenchymal stem cells.

The DOC-2/DAB2 interactive protein (DAB2IP) is a new member of the Ras GTPase-activating protein family. Recent studies have shown that, in addition to its tumor suppressive role in various tumors, DAB2IP also plays an important role in regulating neuronal migration and positioning during brain development. In this study, we determined the roles of DAB2IP in the neuronal differentiation of human mesenchymal stem cells (hMSCs).

Live-cell dynamic sensing of Cd(2+) with a FRET-based indicator.

Cd(2+) causes damages to several human tissues. Although the toxicological and carcinogenetic mechanisms of Cd(2+) have been previously established, some basic questions on this toxicant remain unclear. In this study, we constructed Met-cad 1.

Intracellular Pb2+ content monitoring using a protein-based Pb2+ indicator.

Lead ion (Pb(2+)) is one of the most hazardous heavy metals to almost all life forms. The components of store-operated Ca(2+) entry as a molecular gateway have been previously found to participate in the cytotoxic entry of Pb(2+). However, the safe levels of intracellular Pb(2+) hiding in blood Pb(2+) levels are still not determined with full certainty.

Visualization of the Orai1 homodimer and the functional coupling of Orai1-STIM1 by live-cell fluorescence lifetime imaging.

The Orai1-STIM1 constructed store-operated Ca2+ channels (SOCs) have been found to exert several essential Ca2+ entry/signaling cascades, e.g., the generation of immune response in T lymphocytes.

Dominant role of Orai1 with STIM1 on the cytosolic entry and cytotoxicity of lead ions.

Pb(2+) ions cause severe damages to living cells. In particular, our previous study showed that the Orai-STIM1 (stromal interacting protein 1)-formed store-operated Ca(2+) channels (SOCs) allow Pb(2+) entry. In relation to this, the present study investigates the molecular gating mechanism of Pb(2+) entry by Orai1 with STIM1, as well as the resulting cytotoxicity on human embryonic kidney HEK293 cells.

Automated recognition system to classify subcellular protein localizations in images of different cell lines acquired by different imaging systems.

Systemic analysis of subcellular protein localization (location proteomics) provides clues for understanding gene functions and physiological condition of the cells. However, recognition of cell images of subcellular structures highly depends on experience and becomes the rate-limiting step when classifying subcellular protein localization. Several research groups have extracted specific numerical features for the recognition of subcellular protein localization, but these recognition systems are restricted to images of single particular cell line acquired by one specific imaging system and not applied to recognize a range of cell image sources.

Boosting multiclass learning with repeating codes and weak detectors for protein subcellular localization.

Motivation: Determining locations of protein expression is essential to understand protein function. Advances in green fluorescence protein (GFP) fusion proteins and automated fluorescence microscopy allow for rapid acquisition of large collections of protein localization images. Recognition of these cell images requires an automated image analysis system.

An automated tracking system to measure the dynamic properties of vesicles in living cells.

Recent technological improvements have made it possible to examine the dynamics of individual vesicles at a very high temporal and spatial resolution. Quantification of the dynamic properties of secretory vesicles is labor-intensive and therefore it is crucial to develop software to automate the process of analyzing vesicle dynamics. Dual-threshold and binary image conversion were applied to enhance images and define the areas of objects of interest that were to be tracked.