Molecular Pharmacology最新文献

G protein-coupled receptors are known for their ability to generate a wide range of functional responses through interaction with various intracellular partners. This versatility is particularly evident within the chemokine receptor family, where conventional receptors signal primarily through classic G protein-coupled pathways while atypical chemokine receptors appear not to possess such ability but instead couple to alternative intracellular partners such as β-arrestins. Functional diversity in signaling presents unique opportunities for drug development, allowing different pathways to be selectively targeted to meet specific therapeutic needs. This minireview explores the mechanisms by which G protein-coupled receptor signaling, particularly within the chemokine receptor family, can be diversified at the modulatory, transmembrane, and intracellular levels. SIGNIFICANCE STATEMENT: This minireview explores how signaling in the chemokine receptor family diversifies at the ligand, transmembrane, and intracellular levels. This functional diversity presents unique opportunities for drug development by selectively targeting distinct pathways.

Ferroptosis represents a distinct form of cell death that differentiates it from conventional apoptosis. Numerous studies have demonstrated that ferroptosis holds significant potential for elucidating neuronal damage in Alzheimer disease (AD). In addition, liquid-liquid phase separation has emerged as a significant biological process in recent years. It plays a crucial role in the regulation of various proteins in vivo and is closely associated with ferroptosis. Meanwhile, nuclear factor erythroid 2-related factor 2 (Nrf2) serves as a crucial signaling pathway in ferroptosis and plays a significant role in regulating many key components of the ferroptosis pathway. In addition, an increasing volume of research is being conducted on natural medicines aimed at enhancing the treatment of AD. Cyclovirobuxine (Cyc) is an alkaloid compound extracted from the traditional Chinese medicinal plant, boxwood. It has demonstrated therapeutic potential in the treatment of neurodegenerative diseases. Therefore, in this study, we established an AD cell model using glutamate-induced SH-SY5Y. In glutamate-induced SH-SY5Y cells, Cyc treatment significantly improved mitochondrial function and effectively inhibited lipid peroxidation and restored the downregulation of FTH1 levels induced. Furthermore, Cyc treatment activated the Nrf2 signaling pathway, significantly elevated the nuclear levels of Nrf2, and inhibited both iron deposition and lipid peroxidation. Cyc treatment conferred resistance to ferroptosis in erastin-stimulated SH-SY5Y cells, wherein the Nrf2 signaling pathway and FTH1 protein play crucial roles. The collective findings presented here underscore the protective mechanism of action of Cyc in AD and emphasize its potential as a therapeutic agent for AD treatment. SIGNIFICANCE STATEMENT: It reveals at the cellular level the mechanism by which cyclovirobuxine improves Alzheimer disease through the inhibition of ferroptosis, providing a novel approach and strategy for the treatment of patients with Alzheimer disease.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most prevalent chronic liver disease worldwide. Fatty-acid metabolism disorders, especially long-chain fatty acids (LCFA) accumulation, is the main pathological feature of high fat diet-induced MASLD. Fenofibrate is mainly used for the treatment of hyperlipidemia and metabolic disorders in clinical settings. In recent years, its therapeutic effect on MASLD has also been reported, but the mechanism is still unclear. Here, we aimed to investigate the effect and mechanism of fenofibrate on hepatic steatosis via fatty-acid metabolism regulation. It was found that fenofibrate strongly reduced hepatic LCFA accumulation, especially decreased the content of erucic acid (EA). In AML-12 cells treated with EA, fenofibrate improved hepatic lipid accumulation by accelerating EA metabolism. In vivo and in vitro experiments have proven that peroxidase enoyl-CoA hydratase and 3-hydroxyacyl CoA dehydrogenase is the key enzyme of fenofibrate in promoting LCFA metabolism. This study confirmed that fenofibrate upregulated peroxisome enzyme enoyl-CoA hydratase and 3-hydroxyacyl CoA dehydrogenase expression to promote LCFA oxidation, which provided a novel strategy for the treatment of high-fat diet-induced steatotic liver disease in clinical settings. SIGNIFICANCE STATEMENT: We found that long-chain fatty acid overload was a characteristic of high-fat diet-induced fatty liver, and fenofibrate ameliorated high-fat diet-induced fatty liver by upregulating enoyl-CoA hydratase and 3-hydroxyacyl CoA dehydrogenase to promote the oxidation of long-chain fatty acids, especially erucic acid. This study may contribute to the use of fenofibrate in the treatment of fatty liver disease.

The hydroxy-1,4-naphthoquinones-lawsone, juglone, and plumbagin-widely used in dermatological and cosmetic applications, exhibit a broad spectrum of biological activities, including notable cytotoxic effects. Of the various cellular processes these quinones influence, signaling pathways hold utmost significance. This study elucidates the impact of lawsone, juglone, and plumbagin on a key tyrosine phosphatase, PTP1B, in vitro or within keratinocyte cell lines. Additionally, we assessed the phosphorylation status of EGFR and its subsequent consequences on cell migration. Our results reveal that juglone and plumbagin, but not lawsone, irreversibly inhibit PTP1B enzyme activity by up to 75% through modification of its catalytic cysteine 215 residue. These quinones also lead to an average of 3-fold increase in EGFR phosphorylation. These findings offer new insights into the molecular mechanisms through which hydroxy-1,4-naphthoquinones of dermatological or cosmetic interest modulate critical signaling pathways. SIGNIFICANCE STATEMENT: Hydroxy-1,4-naphthoquinones such as lawsone, juglone, and plumbagin are widely used in dermatological applications, yet their precise molecular and cellular effects remain underexplored. This study reveals that juglone and plumbagin irreversibly inhibit the phosphatase PTP1B by targeting its catalytic cysteine, leading to enhanced EGFR phosphorylation. These findings provide critical insights into how these compounds modulate key signaling pathways, advancing our understanding of their potential therapeutic applications in skin repair and diseases involving dysregulated cell signaling.

Endothelial dysfunction of pulmonary arteries is important in the initiation of pulmonary hypertension (PH). Pulmonary vascular tone is regulated by endothelium-dependent hyperpolarization (EDH) that induces vasodilation. Although K_Ca2.3 channels are involved as a key initiator of EDH response, therapeutic potential of endothelial K_Ca2.3 channels in PH remains unclear. Bioinformatic and biochemical analyses were used to explore K_Ca2.3 expression in patients with PH. Two mouse PH models were created by injection of Sugen 5416 plus hypoxia or injection with monocrotaline. Endothelial-specific K_Ca2.3 adeno-associated virus (AAV-Kcnn3) was constructed, and the efficacy in both PH models was tested using immunohistochemistry, myograph system, and echocardiography. Expression of K_Ca2.3 was decreased in pulmonary arterial endothelial cells or lung tissues from patients with PH and both experimental PH models. AAV-Kcnn3 treatment increased K_Ca2.3 expression in pulmonary endothelium and ameliorated K_Ca2.3-medieated vasodilation of small pulmonary arteries and pulmonary vascular endothelial dysfunction in both PH models. The key PH phenotypes, including elevated right ventricular pressure, Fulton index, pulmonary artery wall thickness, and the free wall thickness of the right ventricle, were remarkably alleviated by AAV-Kcnn3 treatment in both PH models. In conclusion, augmented expression of endothelium-specific K_Ca2.3 channels markedly inhibits the development of PH by improving endothelium-dependent relaxation. SIGNIFICANCE STATEMENT: This study demonstrated downregulated expression of K_Ca2.3 channels in lung tissues, specifically in pulmonary artery endothelial cells from patients or mice with pulmonary hypertension. Upregulation of endothelial K_Ca2.3 might serve as a therapeutic strategy in the early-stage pulmonary hypertension.

Class B G protein-coupled receptors (GPCRs) are peptide hormone receptors, many of which, such as parathyroid hormone receptor 1, calcitonin receptor (CTR), and corticotropin-releasing factor receptor (CRF1R), are established or emerging therapeutic targets. Previously, we showed that extracellular ATP and related molecules act as positive modulators of parathyroid hormone receptor 1 signaling through an undefined mechanism. Here, we investigated whether ATP enhances signaling by other members of the class B family of GPCRs. Cyclic AMP (cAMP) accumulation was monitored in cells expressing a bioluminescent sensor. Extracellular ATP, which did not induce cAMP accumulation on its own, potentiated agonist-induced cAMP accumulation mediated by CTR, CRF1R, calcitonin receptor-like receptor, pituitary adenylyl cyclase-activating polypeptide receptor 1, and vasoactive intestinal peptide receptors 1 and 2. ATP induced a comparable effect on agonist-stimulated recruitment of β-arrestin to pituitary adenylyl cyclase-activating polypeptide receptor 1. Depending on the receptor and agonist, ATP increased agonist potency by up to 50-fold. The enhancing effect of ATP was mimicked by cytidine 5'-monophosphate, ruling out involvement of purinergic receptors, ATPase activity, or ectokinase activity. For certain receptors (CTR, calcitonin receptor-like receptor + receptor activity-modifying protein 1, and CRF1R), there were temporal lags of up to 30 minutes following agonist application before maximal rates of cAMP accumulation were reached. Lag duration decreased with increasing agonist concentration, suggesting an inverse relationship with receptor occupancy. ATP virtually abolished this temporal lag, even at relatively low agonist concentrations. Thus, ATP both increases the potency of orthosteric agonists at class B GPCRs and reduces latency for adenylyl cyclase activation. SIGNIFICANCE STATEMENT: In addition to acting as a positive modulator of PTH1R signaling, extracellular ATP increases the potency of orthosteric agonists at other class B GPCRs and reduces the latency for adenylyl cyclase activation. Further insight into the precise mechanism of ATP-mediated potentiation of class B GPCR signaling may identify new targets for the development of therapeutic agents aimed at the treatment of endocrine disorders.

Bryostatin 1 is a protein kinase C (PKC α, β, δ) activator with anti-inflammatory effects. We hypothesized that bryostatins 1 and 3 could modulate transient receptor potential (TRP) channels via PKC and alter TRP-mediated proinflammatory signaling in lung epithelial cells challenged with a proinflammatory stimulus, coal fly ash (CFA). Bryostatins 1 and 3 inhibited icilin-induced calcium flux in HEK-293 cells overexpressing full-length human transient receptor potential melastatin-8 (TRPM8) but did not inhibit activation by menthol or the activities of human transient receptor potential ankyrin 1, transient receptor potential vanilloid 1 (TRPV1), TRPV3, or TRPV4; mouse and rat TRPM8 were less sensitive to inhibition. TRPM8 inhibition was transient (<24 hours), PKC-dependent, and involved differential phosphorylation of amino acids T17, S27, S850, and S1040. CFA particles stimulate interleukin-8 (IL8) and C-X-C motif chemokine ligand 1 (CXCL1) expression by human bronchial epithelial cells via activation of truncated TRPM8 (TRPM8-Δ801) and TRPV1. However, bryostatins 1 and 3 altered IL8 and CXCL1 mRNA expression with and without CFA treatment. At 4 hours, the bryostatins also suppressed TRPM8 mRNA and induced TRPV1 mRNA, which reversed at 24 hours. These effects were reversed by pharmacological inhibition of PKC isoforms (α, ζ, ε, or η) but not δ, implying a network comprised of presumably PKCα, TRPM8-Δ801, and TRPV1 that regulates IL8 and CXCL1 expression by airway epithelial cells. Finally, an unexpected interaction between TRPV1 and TRPM8, but not TRPM8-Δ801, was also identified. Specifically, the coexpression of TRPM8 and TRPV1 reduced TRPM8 expression and activity, which was reversed by TRPV1 inhibition, revealing novel mechanisms by which bryostatins and PKC affect TRP channel signaling in lung epithelial and potentially other cell types. SIGNIFICANCE STATEMENT: Bryostatins 1 and 3 selectively and transiently inhibit human TRPM8 activity via protein kinase C-dependent phosphorylation and temporally modify the expression and induction of interleukin-8 and C-X-C motif chemokine ligand 1 in lung epithelial cells by regulating TRPV1 and TRPM8 expression. This regulatory nexus may have therapeutic potential for treating airway inflammation.

G protein-coupled receptor (GPCR) signaling is a crucial physiological mechanism that encompasses a wide range of signaling phenomena. Although traditional GPCR signaling involves G protein or arrestin-related activation, other modes such as biphasic activation, dimer or oligomeric activation, and transactivation have also been observed. Herein, we focus on the increasingly recognized process of GPCR-transactivation. Transactivation refers to the ability of GPCRs to activate other receptor types, especially receptor tyrosine kinases, without engaging their own specific ligands. This cross-talk between GPCRs and other receptors facilitates the integration of multiple signaling pathways, thereby regulating diverse cellular responses, which underscores its physiological significance. In this review, we provide a comprehensive overview of the role of GPCR-transactivation in physiology. We also discuss the growing interest in this field and examine the various tools available for studying transactivation. Additionally, we highlight recent advancements in emerging tools and their application to GPCR-transactivation research. Finally, we propose future research directions and consider the potential impact of new technologies in this rapidly evolving field. SIGNIFICANCE STATEMENT: G protein-coupled receptor transactivation plays a key role in integrating multiple signaling pathways by activating other proteins, like receptor tyrosine kinases, without binding their specific ligands. Here, we focus on the significance of transactivation and the various approaches used to study this phenomenon.