Loureirin A Promotes Cell Differentiation and Suppresses Migration and Invasion of Melanoma Cells via WNT and AKT/mTOR Signaling Pathways.

Resina Draconis is a traditional Chinese medicine, with the in-depth research, its medicinal value in anti-tumor has been revealed. Loureirin A is extracted from Resina Draconis, however, research on the anti-tumor efficacy of Loureirin A is rare. Herein, we investigated the function of Loureirin A in melanoma.

Altered allostery of the left flipper domain underlies the weak ATP response of rat P2X5 receptors.

Although the extracellular ATP-gated cation channel purinergic receptor P2X5 is widely expressed in heart, skeletal muscle, and immune and nervous systems in mammals, little is known about its functions and channel-gating activities. This lack of knowledge is due to P2X5's weak ATP responses in several mammalian species, such as humans, rats, and mice. WT human P2X5 (hP2X5) does not respond to ATP, whereas a full-length variant, hP2X5 (hP2X5-FL), containing exon 10 encoding the second hP2X5 transmembrane domain (TM2), does.

Druggable negative allosteric site of P2X3 receptors.

Allosteric modulation provides exciting opportunities for drug discovery of enzymes, ion channels, and G protein-coupled receptors. As cation channels gated by extracellular ATP, P2X receptors have attracted wide attention as new drug targets. Although small molecules targeting P2X receptors have entered into clinical trials for rheumatoid arthritis, cough, and pain, negative allosteric modulation of these receptors remains largely unexplored.

The nonproton ligand of acid-sensing ion channel 3 activates mollusk-specific FaNaC channels via a mechanism independent of the native FMRFamide peptide.

The degenerin/epithelial sodium channel (DEG/ENaC) superfamily of ion channels contains subfamilies with diverse functions that are fundamental to many physiological and pathological processes, ranging from synaptic transmission to epileptogenesis. The absence in mammals of some DEG/ENaCs subfamily orthologues such as FMRFamide peptide-activated sodium channels (FaNaCs), which have been identified only in mollusks, indicates that the various subfamilies diverged early in evolution. We recently reported that the nonproton agonist 2-guanidine-4-methylquinazoline (GMQ) activates acid-sensing ion channels (ASICs), a DEG/ENaC subfamily mainly in mammals, in the absence of acidosis.

Intersubunit physical couplings fostered by the left flipper domain facilitate channel opening of P2X4 receptors.

P2X receptors are ATP-gated trimeric channels with important roles in diverse pathophysiological functions. A detailed understanding of the mechanism underlying the gating process of these receptors is thus fundamentally important and may open new therapeutic avenues. The left flipper (LF) domain of the P2X receptors is a flexible loop structure, and its coordinated motions together with the dorsal fin (DF) domain are crucial for the channel gating of the P2X receptors.

Long noncoding RNA glypican 3 (GPC3) antisense transcript 1 promotes hepatocellular carcinoma progression via epigenetically activating GPC3.

Long noncoding RNA (lncRNA) have critical roles in various pathophysiological processes, and are frequently dysregulated in many diseases, particularly in cancer. The lncRNA glypican 3 antisense transcript 1 (GPC3-AS1) has been reported to be a potential biomarker for hepatocellular carcinoma (HCC) screening. However, the exact biological functions of GPC3-AS1 in HCC, and its roles and regulation mechanisms regarding GPC3 are still unknown.

Exploration of the Peptide Recognition of an Amiloride-sensitive FMRFamide Peptide-gated Sodium Channel.

FMRFamide (Phe-Met-Arg-Phe-NH2)-activated sodium channel (FaNaC) is an amiloride-sensitive sodium channel activated by endogenous tetrapeptide in invertebrates, and belongs to the epithelial sodium channel/degenerin (ENaC/DEG) superfamily. The ENaC/DEG superfamily differs markedly in its means of activation, such as spontaneously opening or gating by mechanical stimuli or tissue acidosis. Recently, it has been observed that a number of ENaC/DEG channels can be activated by small molecules or peptides, indicating that the ligand-gating may be an important feature of this superfamily.

A Highly Conserved Salt Bridge Stabilizes the Kinked Conformation of β2,3-Sheet Essential for Channel Function of P2X4 Receptors.

Significant progress has been made in understanding the roles of crucial residues/motifs in the channel function of P2X receptors during the pre-structure era. The recent structural determination of P2X receptors allows us to reevaluate the role of those residues/motifs. Residues Arg-309 and Asp-85 (rat P2X4 numbering) are highly conserved throughout the P2X family and were involved in loss-of-function polymorphism in human P2X receptors.

Relative motions between left flipper and dorsal fin domains favour P2X4 receptor activation.

Channel gating in response to extracellular ATP is a fundamental process for the physiological functions of P2X receptors. Here we identify coordinated allosteric changes in the left flipper (LF) and dorsal fin (DF) domains that couple ATP-binding to channel gating. Engineered disulphide crosslinking or zinc bridges between the LF and DF domains that constrain their relative motions significantly influence channel gating of P2X4 receptors, confirming the essential role of these allosteric changes.

Inherent dynamics of head domain correlates with ATP-recognition of P2X4 receptors: insights gained from molecular simulations.

P2X receptors are ATP-gated ion channels involved in many physiological functions, and determination of ATP-recognition (AR) of P2X receptors will promote the development of new therapeutic agents for pain, inflammation, bladder dysfunction and osteoporosis. Recent crystal structures of the zebrafish P2X4 (zfP2X4) receptor reveal a large ATP-binding pocket (ABP) located at the subunit interface of zfP2X4 receptors, which is occupied by a conspicuous cluster of basic residues to recognize triphosphate moiety of ATP. Using the engineered affinity labeling and molecular modeling, at least three sites (S1, S2 and S3) within ABP have been identified that are able to recognize the adenine ring of ATP, implying the existence of at least three distinct AR modes in ABP.

Role of hyaluronic acid and laminin as serum markers for predicting significant fibrosis in patients with chronic hepatitis B.

Objectives: The aim of this study was to evaluate the diagnostic performance of serum HA and LN as serum markers for predicting significant fibrosis in CHB patients.

Methods: Serum HA and LN levels of 87 patients with chronic hepatitis B and 19 blood donors were assayed by RIA. Liver fibrosis stages were determined according to the Metavir scoring-system.