Efforts on developing transient receptor potential vanilloid 1 (TRPV1) drugs for pain management have been hampered by deleterious hypo- or hyperthermia caused by TRPV1 agonists/antagonists. Here, we compared the effects of four antagonists on TRPV1 polymodal gating and core body temperature (CBT) in Trpv1, Trpv1, and Trpv1. Neither the effect on proton gating nor drug administration route, hair coverage, CBT rhythmic fluctuations, or inflammation had any influence on the differential actions of TRPV1 drugs on CBT.
View Article and Find Full Text PDFBackground And Purpose: The P2X3 receptor, a trimeric ionotropic purinergic receptor, has emerged as a potential therapeutic target for refractory chronic cough (RCC). Nevertheless, gefapixant/AF-219, the only marketed P2X3 receptor antagonist, might lead taste disorders by modulating the human P2X2/3 (hP2X2/3) heterotrimer. Hence, in RCC drug development, compounds exhibiting strong affinity for the hP2X3 homotrimer and a weak affinity for the hP2X2/3 heterotrimer hold promise.
View Article and Find Full Text PDFP2X receptors are cation channels that sense extracellular ATP. Many therapeutic candidates targeting P2X receptors have begun clinical trials or acquired approval for the treatment of refractory chronic cough (RCC) and other disorders. However, the present negative allosteric modulation of P2X receptors is primarily limited to the central pocket or the site below the left flipper domain.
View Article and Find Full Text PDFTransient receptor potential vanilloid1 (TRPV1) channel plays an important role in a wide range of physiological and pathological processes, and a comprehensive understanding of TRPV1 gating will create opportunities for therapeutic intervention. Recent incredible advances in cryo-electron microscopy (cryo-EM) have yielded high-resolution structures of all TRPV subtypes (TRPV1-6) and all of them share highly conserved six transmembrane (TM) domains (S1-S6). As revealed by the open structures of TRPV1 in the presence of a bound vanilloid agonist (capsaicin or resiniferatoxin), TM helicesS1 to S4 form a bundle that remains quiescent during channel activation, highlighting differences in the gating mechanism of TRPV1 and voltage-gated ion channels.
View Article and Find Full Text PDFMorphine, the most widely used analgesic, relieves severe pain by activating the μ-opioid receptor (MOR), whereas naloxone, with only slight structural changes compared to morphine, exhibits inhibitory effect, and is used to treat opioid abuse. The mechanism by which the MOR distinguishes between the two is unclear. Molecular dynamics (MD) simulations on a 1-μs time scale and metadynamics-enhanced conformational sampling are used here to determine the different interactions of these two ligands with MOR: morphine adjusted its pose by continuously flipping deeper into the pocket, whereas naloxone failed to penetrate deeper because its allyl group conflicts with several residues of MOR.
View Article and Find Full Text PDFP2X receptors are a class of nonselective cation channels widely distributed in the immune and nervous systems, and their dysfunction is a significant cause of tumors, inflammation, leukemia, and immune diseases. P2X7 is a unique member of the P2X receptor family with many properties that differ from other subtypes in terms of primary sequence, the architecture of N- and C-terminals, and channel function. Here, we suggest that the observed lengthened β2- and β3-sheets and their linker (loop β2,3), encoded by redundant sequences, play an indispensable role in the activation of the P2X7 receptor.
View Article and Find Full Text PDFComput Struct Biotechnol J
March 2022
Gefapixant/AF-219, a selective inhibitor of the P2X3 receptor, is the first new drug other than dextromethorphan to be approved for the treatment of refractory chronic cough (RCC) in nearly 60 years. To date, seven P2X subtypes (P2X1-7) activated by extracellular ATP have been cloned, and subtype selectivity of P2X inhibitors is a prerequisite for reducing side effects. We previously identified the site and mechanism of action of Gefapixant/AF-219 on the P2X3 receptor, which occupies a pocket consisting of the left flipper (LF) and lower body (LB) domains.
View Article and Find Full Text PDFThymopentin (TP5) is an immunomodulatory pentapeptide that has been widely used in malignancy patients with immunodeficiency due to radiotherapy and chemotherapy. Here, we propose that TP5 directly inhibits the stemness of colon cancer cells HCT116 and therefore enhances the cytotoxicity of oxaliplatin (OXA) in HCT116 cells. In the absence of serum, TP5 was able to induce cancer stemness reduction in cultured HCT116 cells and significantly reduced stemness-related signals, such as the expression of surface molecular markers (CD133, CD44 and CD24) and stemness-related genes (ALDH1, SOX2, Oct-4 and Nanog), and resulted in altered Wnt/β-catenin signaling.
View Article and Find Full Text PDFTransient receptor potential canonical (TRPC) channels, as important membrane proteins regulating intracellular calcium (Ca) signaling, are involved in a variety of physiological and pathological processes. Activation and regulation of TRPC are more dependent on membrane or intracellular signals. However, how extracellular signals regulate TRPC6 function remains to be further investigated.
View Article and Find Full Text PDFChoriocarcinoma is a malignant trophoblastic tumor. The development of novel drugs is required to reduce the toxicity of current multi-agent chemotherapy and to successfully treat chemoresistant cases of the disease. The purpose of the present study was to investigate the effect of dihydromyricetin (DMY) on the human choriocarcinoma cell line, JAr, to identify a novel drug for the treatment of choriocarcinoma.
View Article and Find Full Text PDFBackground: The role of stress signals in regulating gastric cancer initiation and progression is not quite clear. It is known that stress signals modulate multiple processes such as immune function, cell migration and angiogenesis. However, few studies have investigated the mechanisms of how stress signals contribute to gastric cancer angiogenesis.
View Article and Find Full Text PDFRecently, chiral ionic liquids (ILs) have drawn increasing attention in chiral separation field; however, few papers reported the application of chiral ILs for chiral separation by capillary electrophoresis (CE), and among the papers, chiral ILs were mainly applied as additives to β-cyclodextrin derivatives systems to establish synergistic systems. The synergistic system based on antibiotics with chiral ILs as additives has never been reported before. In this paper, two chiral ionic liquids (ILs) based on amino acid ester, L-alanine and L-valine tert butyl ester bis (trifluoromethane) sulfonamide, were first applied to evaluate the synergistic effect with antibiotic selector for CE chiral separation.
View Article and Find Full Text PDFThe critical behavior of isobaric heat capacities per unit volume for a series of critical binary solutions {benzonitrile + octane, or dodecane, or hexadecane} and {dimethyl carbonate + nonane, or decane, or dodecane} were studied. The corresponding exponent was obtained to be in consistent with the 3D-Ising value. The amplitudes in one-phase and two-phase regions were deduced, which were used to test some critical amplitude ratios.
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