RESUMEN
The activation of a G protein-coupled receptor (GPCR) leads to the formation of a ternary complex between agonist, receptor, and G protein that is characterized by high-affinity binding. Allosteric modulators bind to a distinct binding site from the orthosteric agonist and can modulate both the affinity and the efficacy of orthosteric agonists. The influence allosteric modulators have on the high-affinity active state of the GPCR-G protein ternary complex is unknown due to limitations on attempting to characterize this interaction in recombinant whole cell or membrane-based assays. Here, we use the purified M2 muscarinic acetylcholine receptor reconstituted into nanodiscs to show that, once the agonist-bound high-affinity state is promoted by the G protein, positive allosteric modulators stabilize the ternary complex that, in the presence of nucleotides, leads to an enhanced initial rate of signaling. Our results enhance our understanding of how allosteric modulators influence orthosteric ligand signaling and will aid the design of allosteric therapeutics.
Asunto(s)
Unión Proteica , Receptor Muscarínico M2 , Receptores Acoplados a Proteínas G , Regulación Alostérica , Humanos , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/química , Receptor Muscarínico M2/metabolismo , Receptor Muscarínico M2/química , Ligandos , Sitios de Unión , Transducción de Señal , Proteínas de Unión al GTP/metabolismo , Sitio AlostéricoRESUMEN
Aim: The aim of the study is to identify the regulatory role of intestinal sweet taste receptors (STRs) and glucose transporters (SGLT1, GLUT2) and gut peptide secretion in duodenal-jejunal bypass (DJB)-ameliorated glycemic control in Type 2 diabetes. Materials and Methods: DJB and sham surgeries were performed in streptozotocin-induced diabetic male rats. The blood GLP-1 and GLP-2 levels were evaluated under feeding and fasting conditions. The expression of STRs (T1R2, T1R3), sweet taste signaling effector (Gα-gustducin), SGLT1, and GLUT2 was detected in the intestinal alimentary limb (A limb), biliopancreatic limb (BP limb), and common limb (C limb). The effects of STR inhibition on glucose control were measured with lactisole. Results: Glucose tolerance was improved in DJB-operated rats compared with the sham group, similar to that of normal control rats, without significant differences in food intake and body weight. The plasma GLP-1 levels of DJB rats were increased under diet-fed condition, and GLP-2 levels were increased after fasting. The villus height and crypt depth were significantly increased in the A limb of DJB-operated rats. In addition, GLP-1 expression was restored in enterocytes. The expression of T1R2, Gα-gustducin, and SGLT1 was elevated in the A limb after DJB, while GLUT2 was downregulated in the A, BP, and C limbs. The localization of GLUT2 was normalized in the three intestinal limbs after DJB. However, the beneficial effects of DJB on glucose control were abolished in the presence of lactisole in vivo. Conclusion: DJB ameliorates glycemic control probably by restoring STR-mediated glucose sensing and absorption with the responses of GLP-1 and GLP-2 to carbohydrate.
Asunto(s)
Glucemia , Diabetes Mellitus Experimental , Duodeno , Péptido 1 Similar al Glucagón , Transportador de Glucosa de Tipo 2 , Yeyuno , Receptores Acoplados a Proteínas G , Transportador 1 de Sodio-Glucosa , Animales , Masculino , Transportador 1 de Sodio-Glucosa/metabolismo , Transportador de Glucosa de Tipo 2/metabolismo , Yeyuno/cirugía , Yeyuno/metabolismo , Duodeno/cirugía , Duodeno/metabolismo , Diabetes Mellitus Experimental/cirugía , Diabetes Mellitus Experimental/metabolismo , Ratas , Receptores Acoplados a Proteínas G/metabolismo , Glucemia/metabolismo , Péptido 1 Similar al Glucagón/metabolismo , Absorción Intestinal , Péptido 2 Similar al Glucagón/metabolismo , Glucosa/metabolismo , Ratas Sprague-Dawley , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/cirugía , Transducina/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/cirugíaRESUMEN
Inflammatory bowel disease (IBD) is a chronic inflammatory disorder in the intestines without a cure. Current therapies suppress inflammation to prevent further intestinal damage. However, healing already damaged intestinal epithelia is still an unmet medical need. Under physiological conditions, Lgr5+ intestinal stem cells (ISCs) in the intestinal crypts replenish the epithelia every 3-5 days. Therefore, understanding the regulation of Lgr5+ ISCs is essential. Previous data suggest vitamin D signaling is essential to maintain normal Lgr5+ ISC function in vivo. Our recent data indicate that to execute its functions in the intestines optimally, 1,25(OH)2D requires high concentrations that, if present systemically, can cause hypercalcemia (i.e., blood calcium levels significantly higher than physiological levels), leading to severe consequences. Using 5-bromo-2'-deoxyuridine (BrdU) to label the actively proliferating ISCs, our previous data suggested that de novo synthesized locally high 1,25(OH)2D concentrations effectively enhanced the migration and differentiation of ISCs without causing hypercalcemia. However, although sparse in the crypts, other proliferating cells other than Lgr5+ ISCs could also be labeled with BrdU. This current study used high-purity Lgr5+ ISC lines and a mouse strain, in which Lgr5+ ISCs and their progeny could be specifically tracked, to investigate the effects of de novo synthesized locally high 1,25(OH)2D concentrations on Lgr5+ ISC function. Our data showed that 1,25(OH)2D at concentrations significantly higher than physiological levels augmented Lgr5+ ISC differentiation in vitro. In vivo, de novo synthesized locally high 1,25(OH)2D concentrations significantly elevated local 1α-hydroxylase expression, robustly suppressed experimental colitis, and promoted Lgr5+ ISC differentiation. For the first time, this study definitively demonstrated 1,25(OH)2D's role in Lgr5+ ISCs, underpinning 1,25(OH)2D's promise in IBD therapy.
Asunto(s)
Receptores Acoplados a Proteínas G , Células Madre , Vitamina D , Animales , Receptores Acoplados a Proteínas G/metabolismo , Células Madre/metabolismo , Células Madre/efectos de los fármacos , Células Madre/citología , Vitamina D/farmacología , Vitamina D/análogos & derivados , Vitamina D/metabolismo , Ratones , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efectos de los fármacos , Regeneración/efectos de los fármacos , Ratones Endogámicos C57BL , Colitis/metabolismo , Colitis/inducido químicamente , Colitis/patología , Intestinos/efectos de los fármacosRESUMEN
A long-held tenet in inositol-lipid signaling is that cleavage of membrane phosphoinositides by phospholipase Cß (PLCß) isozymes to increase cytosolic Ca2+ in living cells is exclusive to Gq- and Gi-sensitive G protein-coupled receptors (GPCRs). Here we extend this central tenet and show that Gs-GPCRs also partake in inositol-lipid signaling and thereby increase cytosolic Ca2+. By combining CRISPR/Cas9 genome editing to delete Gαs, the adenylyl cyclase isoforms 3 and 6, or the PLCß1-4 isozymes, with pharmacological and genetic inhibition of Gq and G11, we pin down Gs-derived Gßγ as driver of a PLCß2/3-mediated cytosolic Ca2+ release module. This module does not require but crosstalks with Gαs-dependent cAMP, demands Gαq to release PLCß3 autoinhibition, but becomes Gq-independent with mutational disruption of the PLCß3 autoinhibited state. Our findings uncover the key steps of a previously unappreciated mechanism utilized by mammalian cells to finetune their calcium signaling regulation through Gs-GPCRs.
Asunto(s)
Señalización del Calcio , Calcio , Fosfolipasa C beta , Receptores Acoplados a Proteínas G , Humanos , Fosfolipasa C beta/metabolismo , Fosfolipasa C beta/genética , Células HEK293 , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Calcio/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gq-G11/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gq-G11/genética , Sistemas CRISPR-Cas , Subunidades alfa de la Proteína de Unión al GTP Gs/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gs/genética , AMP Cíclico/metabolismo , Animales , Edición Génica , Citosol/metabolismo , Subunidades beta de la Proteína de Unión al GTP/metabolismo , Subunidades beta de la Proteína de Unión al GTP/genética , Adenilil Ciclasas/metabolismo , Adenilil Ciclasas/genéticaRESUMEN
In humans, 15 genes encode the class B1 family of GPCRs, which are polypeptide hormone receptors characterized by having a large N-terminal extracellular domain (ECD) and receive signals from outside the cell to activate cellular response. For example, the insulinotropic polypeptide (GIP) stimulates the glucose-dependent insulinotropic polypeptide receptor (GIPR), while the glucagon receptor (GCGR) responds to glucagon by increasing blood glucose levels and promoting the breakdown of liver glycogen to induce the production of insulin. The glucagon-like peptides 1 and 2 (GLP-1 and GLP-2) elicit a response from glucagon-like peptide receptor types 1 and 2 (GLP1R and GLP2R), respectively. Since these receptors are implicated in the pathogenesis of diabetes, studying their activation is crucial for the development of effective therapies for the condition. With more structural information being revealed by experimental methods such as X-ray crystallography, cryo-EM, and NMR, the activation mechanism of class B1 GPCRs becomes unraveled. The available crystal and cryo-EM structures reveal that class B1 GPCRs follow a two-step model for peptide binding and receptor activation. The regions close to the C-termini of hormones interact with the N-terminal ECD of the receptor while the regions close to the N-terminus of the peptide interact with the TM domain and transmit signals. This review highlights the structural details of class B1 GPCRs and their conformational changes following activation. The roles of MD simulation in characterizing those conformational changes are briefly discussed, providing insights into the potential structural exploration for future ligand designs.
Asunto(s)
Receptores Acoplados a Proteínas G , Humanos , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/genética , Cristalografía por Rayos X/métodos , Conformación Proteica , Animales , Receptor del Péptido 1 Similar al Glucagón/metabolismo , Receptor del Péptido 1 Similar al Glucagón/genética , Receptores de la Hormona Gastrointestinal/metabolismo , Receptores de la Hormona Gastrointestinal/química , Receptores de la Hormona Gastrointestinal/genética , Péptido 1 Similar al Glucagón/metabolismo , Modelos Moleculares , Unión Proteica , Transducción de Señal , Receptores de Glucagón/metabolismo , Receptores de Glucagón/genética , Receptores de Glucagón/químicaRESUMEN
Reward processing dysfunctions e.g., anhedonia, apathy, are common in stress-related neuropsychiatric disorders including depression and schizophrenia, and there are currently no established therapies. One potential therapeutic approach is restoration of reward anticipation during appetitive behavior, deficits in which co-occur with attenuated nucleus accumbens (NAc) activity, possibly due to NAc inhibition of mesolimbic dopamine (DA) signaling. Targeting NAc regulation of ventral tegmental area (VTA) DA neuron responsiveness to reward cues could involve either the direct or indirect-via ventral pallidium (VP)-pathways. One candidate is the orphan G protein-coupled receptor GPR52, expressed by DA receptor 2 NAc neurons that project to VP. In mouse brain-slice preparations, GPR52 inverse agonist (GPR52-IA) attenuated evoked inhibitory postsynaptic currents at NAc-VP neurons, which could disinhibit VTA DA neurons. A mouse model in which chronic social stress leads to reduced reward learning and effortful motivation was applied to investigate GPR52-IA behavioral effects. Control and chronically stressed mice underwent a discriminative learning test of tone-appetitive behavior-sucrose reinforcement: stress reduced appetitive responding and discriminative learning, and these anticipatory behaviors were dose-dependently reinstated by GPR52-IA. The same mice then underwent an effortful motivation test of operant behavior-tone-sucrose reinforcement: stress reduced effortful motivation and GPR52-IA dose-dependently restored it. In a new cohort, GRABDA-sensor fibre photometry was used to measure NAc DA activity during the motivation test: in stressed mice, reduced motivation co-occurred with attenuated NAc DA activity specifically to the tone that signaled reinforcement of effortful behavior, and GPR52-IA ameliorated both deficits. These findings: (1) Demonstrate preclinical efficacy of GPR52 inverse agonism for stress-related deficits in reward anticipation during appetitive behavior. (2) Suggest that GPR52-dependent disinhibition of the NAc-VP-VTA-NAc circuit, leading to increased phasic NAc DA signaling of earned incentive stimuli, could account for these clinically relevant effects.
Asunto(s)
Dopamina , Neuronas Dopaminérgicas , Motivación , Núcleo Accumbens , Recompensa , Estrés Psicológico , Animales , Masculino , Ratones , Conducta Animal/efectos de los fármacos , Modelos Animales de Enfermedad , Dopamina/metabolismo , Neuronas Dopaminérgicas/efectos de los fármacos , Ratones Endogámicos C57BL , Motivación/efectos de los fármacos , Núcleo Accumbens/efectos de los fármacos , Núcleo Accumbens/metabolismo , Receptores de Dopamina D2/agonistas , Receptores de Dopamina D2/metabolismo , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/metabolismo , Estrés Psicológico/metabolismo , Área Tegmental Ventral/efectos de los fármacos , Área Tegmental Ventral/metabolismoRESUMEN
Bile acids (BAs) are cholesterol derivatives synthesized in the liver and released into the digestive tract to facilitate lipid uptake during the digestion process. Most of these BAs are reabsorbed and recycled back to the liver. Some of these BAs progress to other tissues through the bloodstream. The presence of BAs in the central nervous system (CNS) has been related to their capacity to cross the blood-brain barrier (BBB) from the systemic circulation. However, the expression of enzymes and receptors involved in their synthesis and signaling, respectively, support the hypothesis that there is an endogenous source of BAs with a specific function in the CNS. Over the last decades, BAs have been tested as treatments for many CNS pathologies, with beneficial effects. Although they were initially reported as neuroprotective substances, they are also known to reduce inflammatory processes. Most of these effects have been related to the activation of the Takeda G protein-coupled receptor 5 (TGR5). This review addresses the new challenges that face BA research for neuroscience, focusing on their molecular functions. We discuss their endogenous and exogenous sources in the CNS, their signaling through the TGR5 receptor, and their mechanisms of action as potential therapeutics for neuropathologies.
Asunto(s)
Ácidos y Sales Biliares , Sistema Nervioso Central , Receptores Acoplados a Proteínas G , Humanos , Receptores Acoplados a Proteínas G/metabolismo , Ácidos y Sales Biliares/metabolismo , Animales , Sistema Nervioso Central/metabolismo , Transducción de Señal , Barrera Hematoencefálica/metabolismoRESUMEN
The paradigm "one drug fits all" or "one dose fits all" will soon be challenged by pharmacogenetics research and application. Drug response-efficacy or safety-depends on interindividual variability. The current clinical practice does not include genetic screening as a routine procedure and does not account for genetic variation. Patients with the same illness receive the same treatment, yielding different responses. Integrating pharmacogenomics in therapy would provide critical information about how a patient will respond to a certain drug. Worldwide, great efforts are being made to achieve a personalized therapy-based approach. Nevertheless, a global harmonized guideline is still needed. Plasma membrane proteins, like receptor tyrosine kinase (RTK) and G protein-coupled receptors (GPCRs), are ubiquitously expressed, being involved in a diverse array of physiopathological processes. Over 30% of drugs approved by the FDA target GPCRs, reflecting the importance of assessing the genetic variability among individuals who are treated with these drugs. Pharmacogenomics of transmembrane protein receptors is a dynamic field with profound implications for precision medicine. Understanding genetic variations in these receptors provides a framework for optimizing drug therapies, minimizing adverse reactions, and advancing the paradigm of personalized healthcare.
Asunto(s)
Farmacogenética , Medicina de Precisión , Receptores Acoplados a Proteínas G , Humanos , Farmacogenética/métodos , Medicina de Precisión/métodos , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Variación GenéticaRESUMEN
The prevalence of obesity-induced asthma increases in women after menopause. We hypothesized that the increase in obese asthma in middle-aged women results from estrogen loss. In particular, we focused on the acute action of estrogen through the G protein-coupled estrogen receptor 1 (GPER), previously known as GPR30. We investigated whether GPER activation ameliorates obesity-induced asthma with a high-fat diet (HFD) using G-1, the GPER agonist, and G-36, the GPER antagonist. Administration of G-1 (0.5 mg/kg) suppressed HFD-induced airway hypersensitivity (AHR), and increased immune cell infiltration, whereas G-36 co-treatment blocked it. Histological analysis showed that G-1 treatment inhibited HFD-induced inflammation, fibrosis, and mucus hypersecretion in a GPER-dependent manner. G-1 inhibited the HFD-induced rise in the mRNA levels of pro-inflammatory cytokines in the gonadal white adipose tissue and lungs, whereas G-36 co-treatment reversed this effect. G-1 increased anti-inflammatory M2 macrophages and inhibited the HFD-induced rise in pro-inflammatory M1 macrophages in the lungs. In addition, G-1 treatment reversed the HFD-induced increase in leptin expression and decrease in adiponectin expression in the lungs and gonadal white adipose tissue. The results suggest that activation of GPER could be a therapeutic option for obesity-induced asthma.
Asunto(s)
Asma , Dieta Alta en Grasa , Macrófagos , Obesidad , Receptores de Estrógenos , Receptores Acoplados a Proteínas G , Animales , Receptores Acoplados a Proteínas G/metabolismo , Obesidad/complicaciones , Obesidad/metabolismo , Obesidad/tratamiento farmacológico , Asma/metabolismo , Asma/tratamiento farmacológico , Macrófagos/metabolismo , Macrófagos/efectos de los fármacos , Ratones , Receptores de Estrógenos/metabolismo , Dieta Alta en Grasa/efectos adversos , Ratones Endogámicos C57BL , Femenino , Quinolinas/farmacología , Pulmón/patología , Pulmón/metabolismo , Pulmón/efectos de los fármacos , Citocinas/metabolismoRESUMEN
G protein-coupled receptor (GPR)40 and GPR120 are receptors for medium- and long-chain free fatty acids. It has been well documented that GPR40 and GPR120 activation improves metabolic syndrome (MetS) and exerts anti-inflammatory effects. Since chronic periodontitis is a common oral inflammatory disease initiated by periodontal pathogens and exacerbated by MetS, we determined if GPR40 and GPR120 activation with agonists improves MetS-associated periodontitis in animal models in this study. We induced MetS and periodontitis by high-fat diet feeding and periodontal injection of lipopolysaccharide, respectively, and treated mice with GW9508, a synthetic GPR40 and GPR120 dual agonist. We determined alveolar bone loss, osteoclast formation, and periodontal inflammation using micro-computed tomography, osteoclast staining, and histology. To understand the underlying mechanisms, we further performed studies to determine the effects of GW9508 on osteoclastogenesis and proinflammatory gene expression in vitro. Results showed that GW9508 improved metabolic parameters, including glucose, lipids, and insulin resistance. Results also showed that GW9508 improves periodontitis by reducing alveolar bone loss, osteoclastogenesis, and periodontal inflammation. Finally, in vitro studies showed that GW9508 inhibited osteoclast formation and proinflammatory gene secretion from macrophages. In conclusion, this study demonstrated for the first time that GPR40/GPR120 agonist GW9508 reduced alveolar bone loss and alleviated periodontal inflammation in mice with MetS-exacerbated periodontitis, suggesting that activating GPR40/GPR120 with agonist GW9508 is a potential anti-inflammatory approach for the treatment of MetS-associated periodontitis.
Asunto(s)
Síndrome Metabólico , Metilaminas , Periodontitis , Propionatos , Receptores Acoplados a Proteínas G , Animales , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/metabolismo , Ratones , Síndrome Metabólico/tratamiento farmacológico , Síndrome Metabólico/metabolismo , Síndrome Metabólico/complicaciones , Propionatos/farmacología , Propionatos/uso terapéutico , Periodontitis/tratamiento farmacológico , Periodontitis/metabolismo , Metilaminas/farmacología , Masculino , Ratones Endogámicos C57BL , Pérdida de Hueso Alveolar/tratamiento farmacológico , Pérdida de Hueso Alveolar/etiología , Dieta Alta en Grasa/efectos adversos , Osteoclastos/efectos de los fármacos , Osteoclastos/metabolismo , Modelos Animales de Enfermedad , Osteogénesis/efectos de los fármacosRESUMEN
Drug discovery is a multi-disciplinary effort in which groups with expertise in a range of areas combine in a unified way to achieve a common goal: to deliver a clinical candidate to evaluate a hypothesis for improving human health. As a medicinal chemist this environment has provided multiple opportunities to be involved in cross-discipline interactions that have been both rewarding and led to outcomes that would not have been possible without an intimate interdisciplinary curiosity. Within this article I aim to share some of my experiences with the ß2-adrenoceptor that have fostered such synergistic relationships with several disciplines, but in particular with in vitro pharmacologists looking at different ways to stimulate this G protein-coupled receptor (GPCR). This interest now spans over a quarter of a century and has been intertwined with the delivery of three clinical candidates.
Asunto(s)
Receptores Adrenérgicos beta 2 , Humanos , Receptores Adrenérgicos beta 2/metabolismo , Descubrimiento de Drogas , Receptores Acoplados a Proteínas G/metabolismo , Agonistas de Receptores Adrenérgicos beta 2/farmacologíaRESUMEN
GPR56, an adhesion G-protein coupled receptor (aGPCRs) with constitutive and ligand-promoted activity, is involved in many physiological and pathological processes. Whether the receptor's constitutive or ligand-promoted activation occur through the same molecular mechanism, and whether different activation modes lead to functional selectivity between G proteins is unknown. Here we show that GPR56 constitutively activates both G12 and G13. Unlike constitutive activation and activation with 3-α-acetoxydihydrodeoxygedunin (3αDOG), stimulation with an antibody, 10C7, directed against GPR56's extracellular domain (ECD) led to an activation that favors G13 over G12. An autoproteolytically deficient mutant, GPR56-T383A, was also activated by 10C7 indicating that the tethered agonist (TA) exposed through autocatalytic cleavage, is not required for this activation modality. In contrast, this proteolysis-resistant mutant could not be activated by 3αDOG indicating different modes of activation by the two ligands. We show that an N-terminal truncated GPR56 construct (GPR56-Δ1-385) is devoid of constitutive activity but was activated by 3αDOG. Similarly to 3αDOG, 10C7 promoted the recruitment of ß-arrestin-2 but GPR56 internalization was ß-arrestin independent. Despite the slow activation mode of 10C7 that favors G13 over G12, it efficiently activated the downstream Rho pathway in BT-20 breast cancer cells. These data show that different GPR56 ligands have different modes of activation yielding differential G protein selectivity but converging on the activation of the Rho pathway both in heterologous expressions system and in cancer cells endogenously expressing the receptor. 10C7 is therefore an interesting tool to study both the processes underlying GPR56 activity and its role in cancer cells.
Asunto(s)
Receptores Acoplados a Proteínas G , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Humanos , Transducción de Señal , Células HEK293 , Subunidades alfa de la Proteína de Unión al GTP G12-G13/metabolismo , Subunidades alfa de la Proteína de Unión al GTP G12-G13/genética , Línea Celular Tumoral , Ligandos , Animales , Proteínas de Unión al GTP/metabolismo , Proteínas de Unión al GTP/genéticaRESUMEN
Acute kidney injury (AKI) is a clinical condition characterized by a rapid decline in kidney function, which is associated with local inflammation and programmed cell death in the kidney. The G protein-coupled receptors (GPCRs) represent the largest family of signaling transduction proteins in the body, and approximately 40% of drugs on the market target GPCRs. The expressions of various GPCRs, prostaglandin receptors and purinergic receptors, to name a few, are significantly altered in AKI models. And the role of GPCRs in AKI is catching the eyes of researchers due to their distinctive biological functions, such as regulation of hemodynamics, metabolic reprogramming, and inflammation. Therefore, in this review, we aim to discuss the role of GPCRs in the pathogenesis of AKI and summarize the relevant clinical trials involving GPCRs to assess the potential of GPCRs and their ligands as therapeutic targets in AKI and the transition to AKI-CKD.
Asunto(s)
Lesión Renal Aguda , Receptores Acoplados a Proteínas G , Lesión Renal Aguda/metabolismo , Lesión Renal Aguda/patología , Humanos , Receptores Acoplados a Proteínas G/metabolismo , Animales , Transducción de SeñalRESUMEN
Pseudomonas aeruginosa is a frequent cause of antimicrobial-resistant hospital-acquired pneumonia, especially in critically ill patients. Inflammation triggered by P. aeruginosa infection is necessary for bacterial clearance but must be spatially and temporally regulated to prevent further tissue damage and bacterial dissemination. Emerging data have shed light on the pro-resolving actions of angiotensin-(1-7) [Ang-(1-7)] signaling through the G protein-coupled receptor Mas (MasR) during infections. Herein, we investigated the role of the Ang-(1-7)/Mas axis in pneumonia caused by P. aeruginosa by using genetic and pharmacological approach and found that Mas receptor-deficient animals developed a more severe form of pneumonia showing higher neutrophilic infiltration into the airways, bacterial load, cytokines, and chemokines production and more severe pulmonary damage. Conversely, treatment of pseudomonas-infected mice with Ang-(1-7) was able to decrease neutrophilic infiltration in airways and lungs, local and systemic levels of pro-inflammatory cytokines and chemokines, and increase the efferocytosis rates, mitigating lung damage/dysfunction caused by infection. Notably, the therapeutic association of Ang-(1-7) with antibiotics improved the survival rates of mice subjected to lethal inoculum of P. aeruginosa, extending the therapeutic window for imipenem. Mechanistically, Ang-(1-7) increased phagocytosis of bacteria by neutrophils and macrophages to accelerate pathogen clearance. Altogether, harnessing the Ang-(1-7) pathway during infection is a potential strategy for the development of host-directed therapies to promote mechanisms of resistance and resilience to pneumonia.
Asunto(s)
Angiotensina I , Antibacterianos , Ratones Endogámicos C57BL , Fragmentos de Péptidos , Proto-Oncogenes Mas , Infecciones por Pseudomonas , Pseudomonas aeruginosa , Receptores Acoplados a Proteínas G , Animales , Angiotensina I/metabolismo , Pseudomonas aeruginosa/efectos de los fármacos , Ratones , Infecciones por Pseudomonas/tratamiento farmacológico , Infecciones por Pseudomonas/metabolismo , Infecciones por Pseudomonas/microbiología , Fragmentos de Péptidos/metabolismo , Fragmentos de Péptidos/farmacología , Receptores Acoplados a Proteínas G/metabolismo , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas/genética , Neumonía Bacteriana/tratamiento farmacológico , Neumonía Bacteriana/microbiología , Neumonía Bacteriana/patología , Neumonía Bacteriana/metabolismo , Citocinas/metabolismo , Ratones Noqueados , Neumonía/tratamiento farmacológico , Neumonía/metabolismo , Neumonía/microbiología , Masculino , Pulmón/microbiología , Pulmón/metabolismo , Pulmón/patología , Transducción de Señal/efectos de los fármacos , Infiltración Neutrófila/efectos de los fármacosRESUMEN
Melanoma incidence is increasing globally. Although novel therapies have improved the survival of primary melanoma patients over the past decade, the overall survival rate for metastatic melanoma remains low. In addition to traditional prognostic factors such as Breslow thickness, ulceration, and mitotic rate, novel genetic and molecular markers have been investigated. In our study, we analyzed the expression of G-protein coupled estrogen receptor 1 (GPER1) and the endodomain of collagen XVII (COL17) in relation to clinicopathological factors in primary cutaneous melanomas with known lymph node status in both sexes, using immunohistochemistry. We found, that GPER1 expression correlated with favorable clinicopathological factors, including lower Breslow thickness, lower mitotic rate and absence of ulceration. In contrast, COL17 expression was associated with poor prognostic features, such as higher tumor thickness, higher mitotic rate, presence of ulceration and presence of regression. Melanomas positive for both GPER1 and COL17 had significantly lower mean Breslow thickness and mitotic rate compared to cases positive for COL17 only. Our data indicate that GPER1 and COL17 proteins may be of potential prognostic value in primary cutaneous melanomas.
Asunto(s)
Autoantígenos , Biomarcadores de Tumor , Colágeno Tipo XVII , Melanoma , Colágenos no Fibrilares , Receptores de Estrógenos , Receptores Acoplados a Proteínas G , Neoplasias Cutáneas , Humanos , Melanoma/patología , Melanoma/metabolismo , Femenino , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Pronóstico , Masculino , Receptores de Estrógenos/metabolismo , Persona de Mediana Edad , Biomarcadores de Tumor/metabolismo , Anciano , Colágenos no Fibrilares/metabolismo , Colágenos no Fibrilares/genética , Autoantígenos/metabolismo , Adulto , Melanoma Cutáneo Maligno , Anciano de 80 o más AñosRESUMEN
Introduction: G-protein coupled receptors (GPCRs) expressed on neutrophils regulate their mobilization from the bone marrow into the blood, their half-live in the circulation, and their pro- and anti-inflammatory activities during inflammation. Chronic kidney disease (CKD) is associated with systemic inflammatory responses, and neutrophilia is a hallmark of CKD onset and progression. Nonetheless, the role of neutrophils in CKD is currently unclear. Methods: Blood and renal tissue were collected from non-dialysis CKD (grade 3 - 5) patients to evaluate GPCR neutrophil expressions and functions in CKD development. Results: CKD patients presented a higher blood neutrophil-to-lymphocyte ratio (NLR), which was inversely correlated with the glomerular filtration rate (eGFR). A higher frequency of neutrophils expressing the senescent GPCR receptor (CXCR4) and activation markers (CD18+CD11b+CD62L+) was detected in CKD patients. Moreover, CKD neutrophils expressed higher amounts of GPCR formyl peptide receptors (FPR) 1 and 2, known as neutrophil pro- and anti-inflammatory receptors, respectively. Cytoskeletal organization, migration, and production of reactive oxygen species (ROS) by CKD neutrophils were impaired in response to the FPR1 agonist (fMLP), despite the higher expression of FPR1. In addition, CKD neutrophils presented enhanced intracellular, but reduced membrane expression of the protein Annexin A1 (AnxA1), and an impaired ability to secrete it into the extracellular compartment. Secreted and phosphorylated AnxA1 is a recognized ligand of FPR2, pivotal in anti-inflammatory and efferocytosis effects. CKD renal tissue presented a low number of neutrophils, which were AnxA1+. Conclusion: Together, these data highlight that CKD neutrophils overexpress GPCRs, which may contribute to an unbalanced aging process in the circulation, migration into inflamed tissues, and efferocytosis.
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Neutrófilos , Receptores de Formil Péptido , Insuficiencia Renal Crónica , Humanos , Neutrófilos/inmunología , Neutrófilos/metabolismo , Receptores de Formil Péptido/metabolismo , Insuficiencia Renal Crónica/metabolismo , Insuficiencia Renal Crónica/inmunología , Masculino , Femenino , Persona de Mediana Edad , Anciano , N-Formilmetionina Leucil-Fenilalanina/farmacología , Receptores Acoplados a Proteínas G/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Receptores de Lipoxina/metabolismo , Receptores CXCR4/metabolismoRESUMEN
Effect of succinic acid on the processes of myogenesis was investigated in the study with the cells of C2C12 line. In the concentration range 10-1000 µM, succinic acid stimulated the process of myogenic differentiation, increasing the levels of myogenesis factors MyoD (at all stages of myogenesis) and myogenin (at the stage of terminal differentiation). Presence of the succinate receptors SUCNR1 was revealed in the C2C12 cells using Western blotting, level of which decreased during myogenesis. When succinic acid was added to the cells, the level of intracellular succinate did not change significantly and decreased during myogenic differentiation. Using a specific Gai protein inhibitor, pertussis toxin, it was found that stimulation of myogenesis in the C2C12 cells under the action of succinic acid is realized through SUCNR1-Gai interaction.
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Diferenciación Celular , Desarrollo de Músculos , Ácido Succínico , Ácido Succínico/metabolismo , Desarrollo de Músculos/efectos de los fármacos , Animales , Ratones , Diferenciación Celular/efectos de los fármacos , Línea Celular , Receptores Acoplados a Proteínas G/metabolismo , Proteína MioD/metabolismo , Miogenina/metabolismoRESUMEN
Chronic hepatitis B virus (HBV) infection continues to be a prominent cause of liver fibrosis and end-stage liver disease in China, necessitating the development of effective therapeutic strategies. This study investigated the potential of targeting TGR5 to alleviate liver fibrosis by impeding the activation of hepatic stellate cells (HSCs), which play a pivotal role in fibrotic progression. Using the human hepatic stellate cell line LX-2 overexpressing hepatitis B virus X protein (HBX), this study revealed that TGR5 activation through INT-777 inhibits HBX-induced LX-2 cell activation, thereby ameliorating liver fibrosis, which is associated with the attenuation of mitochondrial fission and introduces a novel regulatory pathway in liver fibrosis. Additional experiments with mitochondrial fission inducers and inhibitors confirm the crucial role of mitochondrial dynamics in TGR5-mediated effects. In vivo studies using TGR5 knockout mice substantiate these findings, demonstrating exacerbated fibrosis in the absence of TGR5 and its alleviation with the mitochondrial fission inhibitor Mdivi-1. Overall, this study provides insights into TGR5-mediated regulation of liver fibrosis through the modulation of mitochondrial fission in HSCs, suggesting potential therapeutic strategies for liver fibrosis intervention.
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Células Estrelladas Hepáticas , Cirrosis Hepática , Dinámicas Mitocondriales , Receptores Acoplados a Proteínas G , Animales , Humanos , Masculino , Ratones , Línea Celular , Células Estrelladas Hepáticas/metabolismo , Cirrosis Hepática/patología , Ratones Endogámicos C57BL , Ratones Noqueados , Quinazolinonas/farmacología , Quinazolinonas/uso terapéutico , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genéticaRESUMEN
As a typical G protein-coupled receptor, the adipokinetic hormone receptor (AKHR) has seven transmembrane domains (TMDs), and its structure and function are similar to the gonadotropin-releasing hormone receptor (GnRHR) in vertebrates. However, there is a dearth of information on other components of the AKHR signaling pathway and how it functions in the interaction between insect hosts and parasitoids. In this study, we cloned and analyzed the multifunctional Ostrinia furnacalis AKHR (OfAKHR) cDNA (GenBank accession number MF797868). OfAKHR has a 2206 bp full-length cDNA, which includes an open reading frame containing 1194 bp. OfAKHR contains the typical seven TMDs, and a "DRY" motif. OfAKHR has the highest relative expression in the fat body and the fifth instar larvae. The results revealed that ApoLpâ ¢, PPO2, GS, TPS, Cecropin, and Moricin decreased the transcription levels from 48 to 72 h after the knockdown of OfAKHR expression by dsOfAKHR injection in the fourth instar O. furnacalis larvae. The parasitization of Macrocentrus cingulum selectively upregulated the expression levels of nutrition metabolism and immune-related genes in parasitized O. furnacalis larvae, stimulated lysozyme activity, and obviously raised the concentrations of triglyceride and trehalose in the hemolymph of O. furnacalis larvae. However, they inhibited the activities of PO and trehalase. This study is conducive to a deeper cognition of the roles of OfAKHR in nutrition and immune homeostasis, coevolution, and coexistence between parasitic wasps and hosts. It also sheds light on the potential as the target of pest control reagents.
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Proteínas de Insectos , Larva , Mariposas Nocturnas , Avispas , Animales , Mariposas Nocturnas/parasitología , Mariposas Nocturnas/metabolismo , Mariposas Nocturnas/genética , Larva/metabolismo , Larva/crecimiento & desarrollo , Larva/genética , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Avispas/fisiología , Hormonas de Insectos/metabolismo , Hormonas de Insectos/genética , Secuencia de Aminoácidos , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Filogenia , Interacciones Huésped-Parásitos , Oligopéptidos/metabolismo , Ácido Pirrolidona Carboxílico/análogos & derivados , Ácido Pirrolidona Carboxílico/metabolismoRESUMEN
Long-term administration of exogenous estrogen is known to cause urinary retention and marked, often fatal, bladder distention in both male and female mice. Estrogen-treated mice have increased bladder pressure and decreased urine flow, suggesting that urinary retention in estrogen-treated mice is due to infravesicular obstruction to urine outflow. Thus, the condition is commonly referred to as bladder outlet obstruction (BOO). Obesity can also lead to urinary retention. As the effects of estrogen are mediated by multiple receptors, including estrogen receptors ERα and ERß and the G protein-coupled estrogen receptor (GPER), we sought to determine whether GPER plays a role in estrogen-induced BOO, particularly in the context of obesity. Wild type and GPER knockout (KO) mice fed a high-fat diet were ovariectomized or left ovary-intact (sham surgery) and supplemented with slow-release estrogen or vehicle-only pellets. Supplementing both GPER KO and wild type obese mice with estrogen for 8 weeks resulted in weight loss, splenic enlargement, and thymic atrophy, as expected. However, estrogen-treated obese GPER KO mice developed abdominal distension, debilitation, and ulceration of the skin surrounding the urogenital opening. At necropsy, these mice had prominently distended bladders and hydronephrosis. In contrast, estrogen-treated obese wild type mice only rarely displayed these signs. Our results suggest that, under conditions of obesity, estrogen induces BOO as a result of ERα-driven pathways and that GPER expression is protective against BOO.