Sensing and Imaging Agents for Cyclooxygenase Enzyme.

In this concept, we present a comprehensive study on the development and application of COX-2-specific fluorescent probes for cancer imaging and diagnosis. To target cancer cells and measuring cancer-related activities in specific organelles quickly and accurately are crucial factors for early diagnosis and research on cancer pathology and treatment. This concept explores a variety of probes based on indomethacin (IMC), celecoxib, rofecoxib as well as CoxFluor and each one demonstrates unique mechanisms and high selectivity towards COX-2 enzymes.

Disaggregation-Activated pan-COX Imaging Agents for Human Soft tissue Sarcoma.

Cancer stem cells are pivotal players in tumors initiation, growth, and metastasis. While several markers have been identified, there remain challenges particularly in heterogeneous malignancies like adult soft tissue sarcomas, where conventional markers are inherently overexpressed. Here, we designed BODIPY scaffold fluorescence probes (BD-IMC-1, BD-IMC-2) that activate via disaggregation targeting for cyclooxygenase (COX), a potential marker for CSCs in sarcoma in clinical pathology.

Correction: Temporal control of protein labeling by a photo-caged benzaldehyde motif and discovery of host cell factors of avian influenza virus infection.

Correction for 'Temporal control of protein labeling by a photo-caged benzaldehyde motif and discovery of host cell factors of avian influenza virus infection' by Nicholas Asiimwe , , 2022, https://doi.org/10.1039/d2cc04091c.

Temporal control of protein labeling by a photo-caged benzaldehyde motif and discovery of host cell factors of avian influenza virus infection.

Photo-caged benzaldehyde probes using -nitrophenylethylene glycol were designed for photo-activated electrophile generation. Using photo-activated electrophile generating probes, we successfully revealed under-represented host cell response factors using an avian influenza virus infection model.

Chemical Probes and Activity-Based Protein Profiling for Cancer Research.

Chemical probes can be used to understand the complex biological nature of diseases. Due to the diversity of cancer types and dynamic regulatory pathways involved in the disease, there is a need to identify signaling pathways and associated proteins or enzymes that are traceable or detectable in tests for cancer diagnosis and treatment. Currently, fluorogenic chemical probes are widely used to detect cancer-associated proteins and their binding partners.

An efficient chemodosimeter for the detection of Hg(II) diselenide oxidation.

Mercury ions are toxic and exhibit hazardous effects on the environment and biological systems, and thus demand for the selective and sensitive detection of mercury has become considerably an important issue. Here, we have developed a diselenide containing coumarin-based probe 3 for the selective detection of Hg(II) with a "turn-on" response (a 48 fold increase in fluorescence intensity) at 438 nm. The probe could quantitatively detect Hg(II) with a detection limit of 1.

Role of microRNA and Oxidative Stress in Influenza A Virus Pathogenesis.

MicroRNAs (miRNAs) are non-coding RNAs that regulate diverse cellular pathways by controlling gene expression. Increasing evidence has revealed their critical involvement in influenza A virus (IAV) pathogenesis. Host-IAV interactions induce different levels of oxidative stress (OS) by disrupting the balance between reactive oxygen species (ROS) and antioxidant factors.

Crosstalk between Oxidative Stress and Tauopathy.

Tauopathy is a collective term for neurodegenerative diseases associated with pathological modifications of tau protein. Tau modifications are mediated by many factors. Recently, reactive oxygen species (ROS) have attracted attention due to their upstream and downstream effects on tauopathy.

Recent Developments in Metal-Catalyzed Bio-orthogonal Reactions for Biomolecule Tagging.

With the rapid advances in single-molecule and live-cell imaging studies to investigate biological problems, the role of chemical probes to monitor reactions in a live cell has considerably increased. However, selective labeling of a target protein or a specific residue is highly challenging due to the high complexity of the biological system. In particular, biological macromolecules (such as proteins, DNA, or RNA) share many functional groups that potentially cross-react with exogenous chemical probes.

Reinvestigation of an O-Salicylaldehyde Ester Functional Group in Aqueous Buffer and Discovery of a Coumarin Scaffold Probe for Selective N-Terminal Cysteine Labeling.

Many intracellular proteins are metabolically unstable, and their half-life was known to be controlled by the "N-end rule," that is, the N-terminal residue controlled protein stability. To visualize or measure the cellular stability of a protein, depending on the N-terminal residues, attention is being paid to the development of selective labeling methods for individual N-terminal amino acids. However, there are only a limited number of functional groups available for specific N-terminal amino acid labeling in a biological environment.

Discrimination of Avian Influenza Virus Subtypes using Host-Cell Infection Fingerprinting by a Sulfinate-based Fluorescence Superoxide Probe.

The current gold-standard diagnosis method for avian influenza (AI) is an embryonic egg-based hemagglutination assay followed by immunoblotting or PCR sequencing to confirm subtypes. It requires, however, specialized facilities to handle egg inoculation and incubation, and the subtyping methods relied on costly reagents. Now, the first differential sensing approach to distinguish AI subtypes is demonstrated using series of cell lines and a fluorescent sensor.

Chloro-Functionalized Photo-crosslinking BODIPY for Glutathione Sensing and Subcellular Trafficking.

Glutathione (GSH) is one of major antioxidants inside cells that regulates oxidoreduction homeostasis. Recently, there have been extensive efforts to visualize GSH in live cells, but most of the probes available today are simple detection sensors and do not provide details of cellular localization. A new fluorescent probe (pcBD2-Cl), which is cell permeable and selectively reacts with GSH in situ, has been developed.

Bulk Aggregation Based Fluorescence Turn-On Sensors for Selective Detection of Progesterone in Aqueous Solution.

Steroids are polycyclic compounds that share tetracyclic ring as core scaffold, and selective detection of a steroid is challenging owing to their structural similarities. The discovery of chemosensors that recognize progesterone by alteration of self-aggregation state is described, and these show significant fluorescence turn-on. A self-aggregated 48-membered dansyl library was screened against a series of metabolites in aqueous buffer and discovered two compounds (PG-1, PG-2) exhibited exceptional selectivity for progesterone.

Photo-affinity labeling (PAL) in chemical proteomics: a handy tool to investigate protein-protein interactions (PPIs).

Protein-protein interactions (PPIs) trigger a wide range of biological signaling pathways that are crucial for biomedical research and drug discovery. Various techniques have been used to study specific proteins, including affinity chromatography, activity-based probes, affinity-based probes and photo-affinity labeling (PAL). PAL has become one of the most powerful strategies to study PPIs.

Combinatorial Dansyl Library and its Applications to pH-Responsive Probes.

Herein, we report the first 48-membered, dansyl-based, combinatorial fluorescent library. From the electronic and structural properties of the probes, we analyzed their optical properties and chemical yields, with an average of 49 %. The molecules were examined for their pH responses, and DS-2 and DS-45 showed blue-shifts, whereas DS-7 and DS-40 showed red-shifts in wavelength with increasing pH.

Rational design of a photo-crosslinking BODIPY for in situ protein labeling.

Photo-crosslinking agents have emerged as critical tools to investigate protein-protein interactions in complex proteomes, but there are few photocrosslinkers available at the moment. Here, we report the first rational design of a photo-crosslinking BODIPY fluorophore (pcBD) and its biological application for biomolecule labeling. As a photosensitizing functional motif, an aryl ketone group was incorporated into the BODIPY fluorophore, and a series of proteins were labeled by pcBD compounds upon UV irradiation.

H(+)-Assisted fluorescent differentiation of Cu(+) and Cu(2+): effect of Al(3+)-induced acidity on chemical sensing and generation of two novel and independent logic gating pathways.

A novel Schiff base probe exhibited strong 'turn-ON' fluorescence for Cu(2+) at 345 nm, Al(3+) at 445 nm, and Cu(+) at 360 nm in the presence of Al(3+) in organic solvent (acetonitrile), which allowed for construction of molecular logic gates 'INH' and '1:2 DEMULTIPLEXING.' H(+) generated from Al(3+) contributed greatly to Cu(+) chemosensing based on a redox non-innocence mechanism.

Novel and selective detection of Tabun mimics.

Detection of nerve agent-related molecules based on BODIPY-salicylaldehyde oxime conjugation was studied. Fluorescence intensity of the B-SAL-OXIME species increases in the presence of DECP, whereas it decreases in the presence of DCP and DEMP (limit of detection = 997 nM). Benzonitrile formation in the novel fluorescent B-SAL-OXIME system was elucidated using model substrates.

Novel reversible and selective nerve agent simulant detection in conjunction with superoxide "turn-on" probing.

Herein, we present fluorescein as a reversible fluorescent sensor for nerve agent simulants diethylchlorophosphate (DCP), diethyl methylphosphonate (DEMP), and diethyl cyanophosphonate (DECP). The superoxide allows for an "off-on" mechanism to regenerate fluorescein. The order of decrease in fluorescence intensity for nerve agent simulants is DCP > DEMP ≫ DECP.

Fluorescence probing of the ferric Fenton reaction via novel chelation.

A new probe-chelator PET dyad was synthesised, which can be used to detect Fe(3+)via fluorescence enhancement to discriminate between Fe(2+) and Fe(3+)via Fenton chemistry involving hydrogen peroxide. This is the first BODIPY which works as a 2 : 1 multiplexer for Fe(3+), Fe(2+) and H2O2.

Highly selective excited state intramolecular proton transfer (ESIPT)-based superoxide probing.

Two novel fluorescent probe conjugates of 2-(benzothiazol-2-yl)-phenol (HBT) enable ratiometric and selective superoxide detection by an established excited state intramolecular proton transfer (ESIPT) mechanism giving a 60-fold intensity increase.

Highly fluorescent and specific molecular probing of (homo)cysteine or superoxide: biothiol detection confirmed in living neuronal cells.

Chemodosimetric action in detection of cysteine and homocysteine (310- and 290-fold) and superoxide inputs (336-fold increase) gives significant fluorescence intensity increases. Detection limits of 2.13 × 10(-5) M, 1.

Extremely selective "turn-on" fluorescence detection of hypochlorite confirmed by proof-of-principle neurological studies via esterase action in living cells.

Highly specific and sensitive fluorescence detection of hypochlorite in nonbiotic pure water (rapid "turn-on", ~400 fold, λ(em) ~ 560 nm) as well as in living neuronal cell cultures (neutral pH) involves oxidation of a 2-sulfide-2-benzoic acid pendent group in a new meso-thienyl-BODIPY donor-acceptor probe.

A novel, selective, and extremely responsive thienyl-based dual fluorogenic probe for tandem superoxide and Hg2+ chemosensing.

Novel, high "turn-on" Hg(2+) and O(2)(-) fluorescence behaviour (∼25-fold) with probes bearing [S(thi)N(py)] and [S(thi)N(py)N(py)] binding receptors, joined by oxidizable sulphides, may involve S-bound transient ROS species; such optical O(2)(-) behaviour operates moderately in neuroblastoma.

Novel sulphur-rich BODIPY systems that enable stepwise fluorescent O-atom turn-on and H2O2 neuronal system probing.

Bis-arylsulfide BODIPY systems were prepared and studied for multiple O-atom sensing (at 522 nm); 2- and 3-atom loading was optimal (50-fold, "turn on"). Neuronal studies showed greater H(2)O(2) sensitivity than 2',7'-dichlorofluorescein diacetate. The novel 1,3,6-trimethyl BODIPY formed as a biproduct under Lindsey conditions.