Etomoxir suppresses the expression of PPARgamma2 and inhibits the thermogenic gene induction of brown adipocytes through pathways other than β-oxidation inhibition.

Brown adipocytes are characterized by a high abundance of mitochondria, allowing them to consume fatty acids for heat production. Increasing the number of brown adipocytes is considered a promising strategy for combating obesity. However, the molecular mechanisms underlying their differentiation remain poorly understood.

Generation of a Nonbilayer Lipid Nanoenvironment after Epitope Binding Potentiates Neutralizing HIV-1 MPER Antibody.

Establishment of interactions with the envelope lipids is a cardinal feature of broadly neutralizing antibodies (bnAbs) that recognize the Env membrane-proximal external region (MPER) of HIV. The lipid envelope constitutes a relevant component of the full "quinary" MPER epitope, and thus antibodies may be optimized through engineering their capacity to interact with lipids. However, the role of the chemically complex lipid nanoenvironment in the mechanism of MPER molecular recognition and viral neutralization remains poorly understood.

Inhibition of dynamin-related protein 1-filamin interaction improves systemic glucose metabolism.

Background And Purpose: Maintaining mitochondrial quality is attracting attention as a new strategy to treat diabetes and diabetic complications. We previously reported that mitochondrial hyperfission by forming a protein complex between dynamin-related protein (Drp) 1 and filamin, mediates chronic heart failure and cilnidipine, initially developed as an L/N-type Ca channel blocker, improves heart failure by inhibiting Drp1-filamin protein complex. We investigated whether cilnidipine improves hyperglycaemia of various diabetic mice models.

Endogenous activation of peroxisome proliferator-activated receptor-α in proximal tubule cells in counteracting phosphate toxicity.

Increased dietary phosphate consumption intensifies renal phosphate burden. Several mechanisms for phosphate-induced renal tubulointerstitial fibrosis have been reported. Considering the dual nature of phosphate as both a potential renal toxin and an essential nutrient for the body, kidneys may possess inherent protective mechanisms against phosphate overload, rather than succumbing solely to injury.

Hericenone C attenuates the second phase of formalin-induced nociceptive behavior by suppressing the accumulation of CD11c-positive cells in the paw epidermis via phosphorylated P65.

Hericenone C is one of the most abundant secondary metabolites derived from Hericium erinaceus, under investigation for medicinal properties. Here, we report that Hericenone C inhibits the second phase of formalin-induced nociceptive behavior in mice. As the second phase is involved in inflammation, in a mechanistic analysis on cultured cells targeting NF-κB response element (NRE): luciferase (Luc)-expressing cells, lipopolysaccharide (LPS)-induced NRE::Luc luciferase activity was found to be significantly inhibited by Hericenone C.

Naturally occurring quercetin and myricetin as potent inhibitors for human ectonucleotide pyrophosphatase/phosphodiesterase 1.

Ecto-nucleotide pyrophosphatases/phosphodiesterases 1 (ENPP1) is a key enzyme in purinergic signaling pathways responsible for cell-to-cell communications and regulation of several fundamental pathophysiological processes. In this study, Kyoto Green, a rapid chemical sensor of pyrophosphate, was employed to screen for effective ENPP1 inhibitors among five representative flavonoids (quercetin, myricetin, morin, kaempferol, and quercetin-3-glucoside), five nucleosides (adenosine, guanosine, inosine, uridine, and cytidine), and five deoxynucleosides (2'- and 3'-deoxyadenosine, 2'-deoxyguanosine, 2'-deoxyinosine, and 2'-deoxyuridine). Conventional colorimetric, fluorescence, and bioluminescence assays revealed that ENPP1 was effectively inhibited by quercetin (K ~ 4 nM) and myricetin (K ~ 32 nM) when ATP was used as a substrate at pH 7.

Spatiotemporally quantitative in vivo imaging of mitochondrial fatty acid β-oxidation at cellular-level resolution in mice.

Mitochondrial fatty acid β-oxidation (FAO) plays a key role in energy homeostasis. Several FAO evaluation methods are currently available, but they are not necessarily suitable for capturing the dynamics of FAO in vivo at a cellular-level spatial resolution and seconds-level time resolution. FAOBlue is a coumarin-based probe that undergoes β-oxidation to produce a fluorescent substrate, 7-hydroxycoumarin-3-(-(2-hydroxyethyl))-carboxamide (7-HC).

Expanding the Chemistry of Dihaloacetamides as Tunable Electrophiles for Reversible Covalent Targeting of Cysteines.

The choice of an appropriate electrophile is crucial in the design of targeted covalent inhibitors (TCIs). In this report, we systematically investigated the glutathione (GSH) reactivity of various haloacetamides and the aqueous stability of their thiol adducts. Our findings revealed that dihaloacetamides cover a broad range of GSH reactivity depending on the combination of the halogen atoms and the structure of the amine scaffold.

Inhibition of Tumor-Derived C-C Motif Chemokine Ligand 2 Expression Attenuates Tactile Allodynia in NCTC 2472 Fibrosarcoma-Inoculated Mice.

Neuropathic pain associated with cancers is caused by tumor growth compressing and damaging nerves, which would also be enhanced by inflammatory factors through sensitizing nociceptor neurons. A troublesome hallmark symptom of neuropathic pain is hypersensitivity to innocuous stimuli, a condition known as "tactile allodynia", which is often refractory to NSAIDs and opioids. The involvement of chemokine CCL2 (monocyte chemoattractant protein-1) in cancer-evoked neuropathic pain is well established, but opinions remain divided as to whether CCL2 is involved in the production of tactile allodynia with tumor growth.

Improved polarized light microscopic detection of gouty crystals via dissolution with formalin and ethylenediamine tetraacetic acid.

Conventional polarized light microscopy has been widely used to detect gouty crystals, but its limited sensitivity increases the risk of misidentification. In this study, a number of methods were investigated to improve the sensitivity of polarized light microscopy for the detection of monosodium urate monohydrate (MSUM) and calcium pyrophosphate dihydrate (CPPD) crystals. We found that coating glass slides with poly-L-lysine, a positively charged polymer, improved the attachment of crystals to the glass surface, resulting in clearer crystal images compared to non-coated slides.

Fluorescence-Based Detection of Fatty Acid β-Oxidation in Cells and Tissues Using Quinone Methide-Releasing Probes.

Detection of metabolic activity enables us to reveal the inherent metabolic state of cells and elucidate mechanisms underlying cellular homeostasis and growth. However, a fluorescence approach for the study of metabolic pathways is still largely unexplored. Herein, we have developed a new chemical probe for the fluorescence-based detection of fatty acid β-oxidation (FAO), a key process in lipid catabolism, in cells and tissues.

Fluorescence identification of arthropathic calcium pyrophosphate single crystals using alizarin red S and a xanthene dipicolylamine Zn complex.

Calcium pyrophosphate deposition disease, previously known as pseudogout, is a type of chronic and painful joint arthropathy. Accurate identification of calcium pyrophosphate dihydrate (CPPD) single crystals is crucial for determining the best course of treatment. In this study, a two-step method involving alizarin red S (ARS) and a xanthene dipicolylamine Zn (XDZ) complex was employed for the identification of CPPD single crystals in both triclinic and monoclinic forms using a fluorescence microscope and a microplate reader.

[Covalent drug discovery exploiting the new warheads].

Covalent drug forms a covalent bond with desease-related target proteins irreversibly inhibits their function. In order to develop a safe and non-toxic covalent drug, it is important to device new reaction chemistry that realizes a sufficient reactivity and high target selectivity for targeted protein under the complicated biological systems such as our body. Currently, new reaction chemistry is being actively developed all over the world to achieve excellent target selectivity of covalent drugs.

Selective covalent targeting of SARS-CoV-2 main protease by enantiopure chlorofluoroacetamide.

The coronavirus disease 2019 (COVID-19) pandemic has necessitated the development of antiviral agents against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The main protease (M) is a promising target for COVID-19 treatment. Here, we report an irreversible SARS-CoV-2 M inhibitor possessing chlorofluoroacetamide (CFA) as a warhead for the covalent modification of M.

Spontaneously Recycling Synaptic Vesicles Constitute Readily Releasable Vesicles in Intact Neuromuscular Synapses.

Emerging evidence shows that spontaneous synaptic transmission plays crucial roles on neuronal functions through presynaptic molecular mechanisms distinct from that of action potential (AP)-evoked transmission. However, whether the synaptic vesicle (SV) population undergoing the two forms of transmission is segregated remains controversial due in part to the conflicting results observed in cultured neurons. Here we address this issue in intact neuromuscular synapses using transgenic zebrafish larvae expressing two different indicators targeted in the SVs: a pH-sensitive fluorescent protein, pHluorin, and a tag protein, HaloTag.

Recent progress in covalent warheads for in vivo targeting of endogenous proteins.

Covalent drugs exert potent and durable activity by chemical modification of the endogenous target protein in vivo. To maximize the pharmacological efficacy while alleviating the risk of toxicity due to nonspecific off-target reactions, current covalent drug discovery focuses on the development of targeted covalent inhibitors (TCIs), wherein a reactive group (warhead) is strategically incorporated onto a reversible ligand of the target protein to facilitate specific covalent engagement. Various aspects of warheads, such as intrinsic reactivity, chemoselectivity, mode of reaction, and reversibility of the covalent engagement, would affect the target selectivity of TCIs.

A multicolor and ratiometric fluorescent sensing platform for metal ions based on arene-metal-ion contact.

Despite continuous and active development of fluorescent metal-ion probes, their molecular design for ratiometric detection is restricted by the limited choice of available sensing mechanisms. Here we present a multicolor and ratiometric fluorescent sensing platform for metal ions based on the interaction between the metal ion and the aromatic ring of a fluorophore (arene-metal-ion, AM, coordination). Our molecular design provided the probes possessing a 1,9-bis(2'-pyridyl)-2,5,8-triazanonane as a flexible metal ion binding unit attached to a tricyclic fluorophore.

Fragment-Based Discovery of Irreversible Covalent Inhibitors of Cysteine Proteases Using Chlorofluoroacetamide Library.

Fragment-based approach combined with electrophilic reactive compounds is a powerful strategy to discover novel covalent ligands for protein target. However, the promiscuous reactivity often interferes with identification of the fragments possessing specific binding affinity to the targeted protein. In our study, we report the fragment-based covalent drug discovery using the chemically tuned weak reactivity of chlorofluoroacetamide (CFA).

Bicyclobutane Carboxylic Amide as a Cysteine-Directed Strained Electrophile for Selective Targeting of Proteins.

Expanding the repertoire of electrophiles with unique reactivity features would facilitate the development of covalent inhibitors with desirable reactivity profiles. We herein introduce bicyclo[1.1.

Affinity for the Interface Underpins Potency of Antibodies Operating In Membrane Environments.

The contribution of membrane interfacial interactions to recognition of membrane-embedded antigens by antibodies is currently unclear. This report demonstrates the optimization of this type of antibodies via chemical modification of regions near the membrane but not directly involved in the recognition of the epitope. Using the HIV-1 antibody 10E8 as a model, linear and polycyclic synthetic aromatic compounds are introduced at selected sites.

Trimethyl-Substituted Carbamate as a Versatile Self-Immolative Linker for Fluorescence Detection of Enzyme Reactions.

Self-immolative linker is a useful building block of molecular probes, with broad applications in the fields of enzyme activity analysis, stimuli-responsive material science, and drug delivery. This manuscript presents -methyl dimethyl methyl (i.e.

Fluorescence Detection of Deoxyadenosine in spp. by Indicator Displacement Assay.

A rapid, sensitive and reliable indicator displacement assay (IDA) for specific detection of 2'- and 3'-deoxyadenosine (2'-dAde and 3'-dAde), the latter is also known as cordycepin, was established. The formation of inclusion complex between protonated acridine orange (AOH) and cucurbit[7]uril (CB7) resulted in the hypochromic shift of fluorescent emission from 530 nm to 512 nm. Addition of cordycepin to the highly fluorescent AOH/CB7 complex resulted in a unique tripartite AOH/CB7/dAde complex with diminished fluorescence, and such reduction in emission intensity serves as the basis for our novel sensing system.