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1.
Curr Top Med Chem ; 19(19): 1712-1733, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31659944

RESUMO

During the early preclinical phase, from hit identification and optimization to a lead compound, several medicinal chemistry strategies can be used to improve potency and/or selectivity. The conformational restriction is one of these approaches. It consists of introducing some specific structural constraints in a lead candidate to reduce the overall number of possible conformations in order to favor the adoption of a bioactive conformation and, as a consequence, molecular recognition by the target receptor. In this work, we focused on the application of the conformational restriction strategy in the last five years for the optimization of hits and/or leads of several important classes of therapeutic targets in the drug discovery field. Thus, we recognize the importance of several kinase inhibitors to the current landscape of drug development for cancer therapy and the use of G-protein Coupled Receptor (GPCR) modulators. Several other targets are also highlighted, such as the class of epigenetic drugs. Therefore, the possibility of exploiting conformational restriction as a tool to increase the potency and selectivity and promote changes in the intrinsic activity of some ligands intended to act on many different targets makes this strategy of structural modification valuable for the discovery of novel drug candidates.


Assuntos
Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico , Receptores Acoplados a Proteínas-G/antagonistas & inibidores , Antineoplásicos/química , Química Farmacêutica , Descoberta de Drogas , Humanos , Estrutura Molecular , Neoplasias/metabolismo , Neoplasias/patologia , Receptores Acoplados a Proteínas-G/metabolismo
2.
Zhongguo Zhong Yao Za Zhi ; 44(15): 3157-3161, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31602867

RESUMO

In order to study the interaction between Pterocephalus hookeri and bitter taste receptors,three-dimensional structural models of bitter taste receptors TAS2 R16,TAS2 R14 and TAS2 R13 were established by homology modeling in this paper. Maestro software was used for docking the chemical constituents of P. hookeri with bitter taste receptors. The results showed that 25 chemical components of P. hookeri can regulate three bitter taste receptors. And these components were mainly iridoid glycosides and phenolic acids.This research focused on the comprehensive application of homology modeling and molecular docking technology to explore the interaction between bitter chemical constituents of P. hookeri and bitter taste receptors. This study provided assistance in revealing pharmacodynamic basis of bitter Tibetan medicine at molecular level. It also provided new ideas and methods for the study of Tibetan medicine.


Assuntos
Caprifoliaceae/química , Medicina Tradicional Tibetana , Simulação de Acoplamento Molecular , Receptores Acoplados a Proteínas-G/metabolismo , Correlação de Dados , Humanos , Paladar
3.
Nature ; 574(7779): 581-585, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31645725

RESUMO

The tricarboxylic acid cycle intermediate succinate is involved in metabolic processes and plays a crucial role in the homeostasis of mitochondrial reactive oxygen species1. The receptor responsible for succinate signalling, SUCNR1 (also known as GPR91), is a member of the G-protein-coupled-receptor family2 and links succinate signalling to renin-induced hypertension, retinal angiogenesis and inflammation3-5. Because SUCNR1 senses succinate as an immunological danger signal6-which has relevance for diseases including ulcerative colitis, liver fibrosis7, diabetes and rheumatoid arthritis3,8-it is of interest as a therapeutic target. Here we report the high-resolution crystal structure of rat SUCNR1 in complex with an intracellular binding nanobody in the inactive conformation. Structure-based mutagenesis and radioligand-binding studies, in conjunction with molecular modelling, identified key residues for species-selective antagonist binding and enabled the determination of the high-resolution crystal structure of a humanized rat SUCNR1 in complex with a high-affinity, human-selective antagonist denoted NF-56-EJ40. We anticipate that these structural insights into the architecture of the succinate receptor and its antagonist selectivity will enable structure-based drug discovery and will further help to elucidate the function of SUCNR1 in vitro and in vivo.


Assuntos
Compostos de Bifenilo/química , Compostos de Bifenilo/farmacologia , Piperazinas/química , Piperazinas/farmacologia , Receptores Acoplados a Proteínas-G/antagonistas & inibidores , Receptores Acoplados a Proteínas-G/química , Animais , Apoproteínas/antagonistas & inibidores , Apoproteínas/química , Apoproteínas/metabolismo , Cristalografia por Raios X , Humanos , Modelos Moleculares , Ratos , Receptores Acoplados a Proteínas-G/metabolismo , Receptores Purinérgicos P2Y1/química , Transdução de Sinais , Anticorpos de Domínio Único/química , Especificidade da Espécie , Ácido Succínico/metabolismo
4.
BMC Evol Biol ; 19(1): 176, 2019 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-31470793

RESUMO

BACKGROUND: Vomeronasal type 1 receptor genes (V1Rs) are expected to detect intraspecific pheromones. It is believed that rodents rely heavily on pheromonal communication mediated by V1Rs, but pheromonal signals are thought to be confined in subterranean rodents that live in underground burrows. Thus, subterranean rodents may show a contrasting mode of V1R evolution compared with their superterranean relatives. RESULTS: We examined the V1R evolution in subterranean rodents by analyzing currently available genomes of 24 rodents, including 19 superterranean and 5 subterranean species from three independent lineages. We identified a lower number of putatively functional V1R genes in each subterranean rodent (a range of 22-40) compared with superterranean species (a range of 63-221). After correcting phylogenetic inertia, the positive correlation remains significant between the small V1R repertoire size and the subterranean lifestyle. To test whether V1Rs have been relaxed from functional constraints in subterranean rodents, we sequenced 22 intact V1Rs in 29 individuals of one subterranean rodent (Spalax galili) from two soil populations, which have been proposed to undergo incipient speciation. We found 12 of the 22 V1Rs to show significant genetic differentiations between the two natural populations, indicative of diversifying selection. CONCLUSION: Our study demonstrates convergent reduction of V1Rs in subterranean rodents from three independent lineages. Meanwhile, it is noteworthy that most V1Rs in the two Spalax populations are under diversifying selection rather than relaxed selection, suggesting that functional constraints on these genes may have retained in some subterranean species.


Assuntos
Evolução Molecular , Receptores Acoplados a Proteínas-G/metabolismo , Receptores Odorantes/metabolismo , Spalax/genética , Animais , Feromônios/metabolismo , Filogenia , Receptores Acoplados a Proteínas-G/genética , Receptores Odorantes/genética , Seleção Genética , Spalax/classificação , Spalax/fisiologia , Órgão Vomeronasal/metabolismo
5.
Curr Top Med Chem ; 19(16): 1436-1444, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31512997

RESUMO

Type 2 diabetes is a major health issue worldwide with complex metabolic and endocrine abnormalities. Hyperglycemia, defects in insulin secretion and insulin resistance are classic features of type 2 diabetes. Insulin signaling regulates metabolic homeostasis by regulating glucose and lipid turnover in the liver, skeletal muscle and adipose tissue. Major treatment modalities for diabetes include the drugs from the class of sulfonyl urea, Insulin, GLP-1 agonists, SGLT2 inhibitors, DPP-IV inhibitors and Thiazolidinediones. Emerging antidiabetic therapeutics also include classes of drugs targeting GPCRs in the liver, adipose tissue and skeletal muscle. Interestingly, recent research highlights several shared intermediates between insulin and GPCR signaling cascades opening potential novel avenues for diabetic drug discovery.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Descoberta de Drogas , Hipoglicemiantes/farmacologia , Receptor de Insulina/antagonistas & inibidores , Receptores Acoplados a Proteínas-G/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Animais , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Hipoglicemiantes/química , Receptor de Insulina/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo
7.
Cancer Sci ; 110(11): 3520-3532, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31505062

RESUMO

Cancer stem cells (CSC) are a subpopulation of tumor cells with properties of high tumorigenicity and drug resistance, which lead to recurrence and poor prognosis. Although a better understanding of CSC is essential for developing cancer therapies, scarcity of the CSC population has hindered such analyses. The aim of the present study was to elucidate whether the E-cadherin-Fc chimera protein (E-cad-Fc) enhances cancer stem-like properties because studies show that soluble E-cadherin stimulates human epithelial growth factor receptor (EGFR) and downstream signaling pathways that are reported to play a crucial role in CSC. For this purpose, we used ornithine decarboxylase (ODC)-degron-transduced (Degron(+)) KM12SM cells as a CSC model that retains relatively low CSC properties. Compared to cultures without E-cad-Fc treatment, we found that E-cad-Fc treatment further suppressed proteasome activity and largely enhanced cancer stem-like properties of ODC-degron-transduced KM12SM cells. These results include increased expression of stem cell markers Lgr5, Bmi-1, SOX9, CD44, and CD44v9, aldehyde dehydrogenase (ALDH), and enhancement of robust spheroid formation, and chemoresistance to 5-fluorouracil (5-FU) and oxaliplatin (L-OHP). These effects could be attributed to activation of the EGFR pathway as identified by extensive phosphorylation of EGFR, ERK, PI3K, AKT, and mTOR. In SW480 cells, E-cad-Fc matrix induced some CSC markers such as CD44v9 and ALDH. We also found that E-cad-Fc matrix showed high efficiency of inducing mesenchymal changes in colon cancer cells. Our data suggest that the E-cad-Fc matrix may enhance CSC properties such as enhancement of chemoresistance and sphere formation.


Assuntos
Neoplasias do Colo/patologia , Receptores ErbB , Fragmentos Fc das Imunoglobulinas , Células-Tronco Neoplásicas/patologia , Proteínas Recombinantes de Fusão/metabolismo , Aldeído Desidrogenase/metabolismo , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Neoplasias do Colo/metabolismo , Resistencia a Medicamentos Antineoplásicos , Fluoruracila/farmacologia , Humanos , Receptores de Hialuronatos/metabolismo , Células-Tronco Neoplásicas/metabolismo , Ornitina Descarboxilase , Oxaliplatina/farmacologia , Complexo Repressor Polycomb 1/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Fatores de Transcrição SOX9/metabolismo , Esferoides Celulares
8.
Biol Res ; 52(1): 44, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31426858

RESUMO

BACKGROUND: Free fatty acid receptor 1 (FFAR1) is G-protein coupled receptor predominantly expressed in pancreatic ß-cells that is activated by a variety of free fatty acids (FFAs). Once activated, it promotes glucose-stimulated insulin secretion (GSIS). However, increased levels of FFAs lead to lipotoxicity, inducing loss of ß-cell function. FFAR1 plays a key role in the development of type 2 diabetes (T2D), and previous studies have indicated the importance of developing anti-diabetic therapies against FFAR1, although its role in the regulation of ß-cell function remains unclear. The present study investigated the role of FFAR1 under lipotoxic conditions using palmitic acid (PA). The rat insulinoma 1 clone 832/13 (INS-1 832/13) cell line was used as a model as it physiologically resembles native pancreatic ß-cells. Key players of the insulin signaling pathway, such as mTOR, Akt, IRS-1, and the insulin receptor (INSR1ß), were selected as candidates to be analyzed under lipotoxic conditions. RESULTS: We revealed that PA-induced lipotoxicity affected GSIS in INS-1 cells and negatively modulated the activity of both IRS-1 and Akt. Reduced phosphorylation of both IRS-1 S636/639 and Akt S473 was observed, in addition to decreased expression of both INSR1ß and FFAR1. Moreover, transient knockdown of FFAR1 led to a reduction in IRS-1 mRNA expression and an increase in INSR1ß mRNA. Finally, PA affected localization of FFAR1 from the cytoplasm to the perinucleus. CONCLUSIONS: In conclusion, our study suggests a novel regulatory involvement of FFAR1 in crosstalk with mTOR-Akt and IRS-1 signaling in ß-cells under lipotoxic conditions.


Assuntos
Células Secretoras de Insulina/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Ácido Palmítico/toxicidade , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Apoptose , Linhagem Celular , Células Secretoras de Insulina/metabolismo , Ratos , Transdução de Sinais
9.
Medicine (Baltimore) ; 98(35): e16576, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31464892

RESUMO

OBJECTIVES: G protein-coupled receptor 137 (GPR137) was reported to be associated with several cancers, but its role in bladder cancer has not been reported. The purpose of this study was to evaluate clinical significance of GPR137 in bladder cancer. METHODS: The expressions of GPR137 in pathological tissues and corresponding normal tissues from bladder cancer patients were detected via quantitative real time polymerase chain reaction (qRT-PCR). Western blot was performed to detect GPR137 expression in bladder cancer tissues and adjacent normal tissues. Chi-Squared test analyzed the relationship between GPR137 expression and clinical features of bladder cancer patients. Additionally, Kaplan-Meier method was adopted in estimating overall survival of bladder cancer patients. Prognostic value of GPR137 was evaluated through Cox regression analysis. RESULTS: The expression of GPR137 mRNA and protein in pathological tissues was significantly higher than that in adjacent normal tissues (P < .001). Moreover, similar result was found for bladder cancer patients and healthy controls (P < .001). And GPR137 expression was associated with tumor size (P = .006) and TNM stage (P = .012). The results of Kaplan-Meier analysis suggested that patients with high expression of GPR137 had shorter overall survival time than those with low expression (Log rank test, P = .001). Cox regression analysis indicated that GPR137 could act as an independent biomarker for bladder cancer prognosis (HR = 1.850, 95% CI = 1.272-2.689, P = .001). CONCLUSION: Abnormal expression of GPR137 is associated with bladder cancer and GPR137 is a potential biomarker for the therapy and prognosis of bladder cancer.


Assuntos
Biomarcadores Tumorais/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Regulação para Cima , Neoplasias da Bexiga Urinária/metabolismo , Biomarcadores Tumorais/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptores Acoplados a Proteínas-G/genética , Análise de Sobrevida , Carga Tumoral , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia
10.
Clin Exp Rheumatol ; 37 Suppl 119(4): 69-75, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31365333

RESUMO

OBJECTIVES: Relaxin is a potent anti-fibrotic hormone that has been tested to ameliorate fibrosis in systemic sclerosis (SSc), but with controversial results. The aim of the study is to sequence relaxin receptor gene RXFP1 and to assess its mRNA expression and protein levels in the skin of SSc patients and healthy subjects. METHODS: Fibroblasts were isolated from unaffected/affected skin samples of (n=16) limited-cutaneous-SSc-(LcSSc) and from affected ones of (n=4) diffuse-cutaneous-SSc-(DcSSc) patients. Fibroblasts from healthy subjects were used as controls. Sequencing of exonic target regions of interest for RXFP1 gene was performed, coupled with mRNA transcript variant analysis. RXFP1 mRNA and protein levels were assessed by quantitative-real-time-PCR-(qRT-PCR) and by immunocytochemistry-(ICC). Alpha-smooth-muscle-actin-(α-SMA) synthesis induced by transforming-growth-factor-beta-1-(TGF-ß1) stimulation was investigated in all fibroblasts with and without pre-treatment with serelaxin (a recombinant form of human relaxin-2 targeting the receptor RXFP1). RESULTS: Sequencing of RXFP1 gene showed no relevant mutations in all fibroblast populations. The analysis of mRNA transcripts revealed the presence of 13 different mRNA isoforms of RXFP1 (7 coding and 6 non-coding) upregulated in LcSSc/DcSSc-affected samples and not in LcSSc-unaffected and in healthy ones. On the contrary, ICC demonstrated the absence of RXFP1 in LcSSc/DcSSc-affected fibroblasts and the presence in LcSSc-unaffected and in healthy ones. To prove these findings, serelaxin pre-incubation was unable to counteract TGF-ß1-driven upregulation of α-SMA in LcSSc/DcSSc-affected fibroblasts only, but not in LcSSc-unaffected and healthy ones. CONCLUSIONS: The absence/altered expression of relaxin receptor RXFP1 in the affected fibroblasts of SSc patients could explain the inefficacy of relaxin-based anti-fibrotic treatments in the disease.


Assuntos
Fibroblastos/metabolismo , Relaxina , Esclerodermia Difusa , Escleroderma Sistêmico , Idoso , Feminino , Fibroblastos/patologia , Fibrose/metabolismo , Fibrose/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Receptores Acoplados a Proteínas-G/metabolismo , Receptores de Peptídeos/metabolismo , Proteínas Recombinantes , Relaxina/metabolismo , Esclerodermia Difusa/metabolismo , Esclerodermia Difusa/patologia , Escleroderma Sistêmico/metabolismo , Escleroderma Sistêmico/patologia
11.
Cell Mol Life Sci ; 76(22): 4413-4421, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31422444

RESUMO

Mammalian arrestins are a family of four highly homologous relatively small ~ 45 kDa proteins with surprisingly diverse functions. The most striking feature is that each of the two non-visual subtypes can bind hundreds of diverse G protein-coupled receptors (GPCRs) and dozens of non-receptor partners. Through these interactions, arrestins regulate the G protein-dependent signaling by the desensitization mechanisms as well as control numerous signaling pathways in the G protein-dependent or independent manner via scaffolding. Some partners prefer receptor-bound arrestins, some bind better to the free arrestins in the cytoplasm, whereas several show no apparent preference for either conformation. Thus, arrestins are a perfect example of a multi-functional signaling regulator. The result of this multi-functionality is that reduction (by knockdown) or elimination (by knockout) of any of these two non-visual arrestins can affect so many pathways that the results are hard to interpret. The other difficulty is that the non-visual subtypes can in many cases compensate for each other, which explains relatively mild phenotypes of single knockouts, whereas double knockout is lethal in vivo, although cultured cells lacking both arrestins are viable. Thus, deciphering the role of arrestins in cell biology requires the identification of specific signaling function(s) of arrestins involved in a particular phenotype. This endeavor should be greatly assisted by identification of structural elements of the arrestin molecule critical for individual functions and by the creation of mutants where only one function is affected. Reintroduction of these biased mutants, or introduction of monofunctional stand-alone arrestin elements, which have been identified in some cases, into double arrestin-2/3 knockout cultured cells, is the most straightforward way to study arrestin functions. This is a laborious and technically challenging task, but the upside is that specific function of arrestins, their timing, subcellular specificity, and relations to one another could be investigated with precision.


Assuntos
Arrestinas/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Animais , Humanos , Transdução de Sinais/fisiologia
12.
Cell Mol Life Sci ; 76(22): 4461-4492, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31428838

RESUMO

GPCR-G protein signaling system recognizes a multitude of extracellular ligands and triggers a variety of intracellular signaling cascades in response. In humans, this system includes more than 800 various GPCRs and a large set of heterotrimeric G proteins. Complexity of this system goes far beyond a multitude of pair-wise ligand-GPCR and GPCR-G protein interactions. In fact, one GPCR can recognize more than one extracellular signal and interact with more than one G protein. Furthermore, one ligand can activate more than one GPCR, and multiple GPCRs can couple to the same G protein. This defines an intricate multifunctionality of this important signaling system. Here, we show that the multifunctionality of GPCR-G protein system represents an illustrative example of the protein structure-function continuum, where structures of the involved proteins represent a complex mosaic of differently folded regions (foldons, non-foldons, unfoldons, semi-foldons, and inducible foldons). The functionality of resulting highly dynamic conformational ensembles is fine-tuned by various post-translational modifications and alternative splicing, and such ensembles can undergo dramatic changes at interaction with their specific partners. In other words, GPCRs and G proteins exist as sets of conformational/basic, inducible/modified, and functioning proteoforms characterized by a broad spectrum of structural features and possessing various functional potentials.


Assuntos
Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Transdução de Sinais/fisiologia , Animais , Humanos , Ligantes , Processamento de Proteína Pós-Traducional/fisiologia
13.
Cell Mol Life Sci ; 76(22): 4447-4459, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31435698

RESUMO

G-protein ßγ subunits are key participants in G-protein signaling. These subunits facilitate interactions between receptors and G proteins that are critical for the G protein activation cycle at the plasma membrane. In addition, they play roles in directly transducing signals to an ever expanding range of downstream targets, including integral membrane and cytosolic proteins. Emerging data indicate that Gßγ may play additional roles at intracellular compartments including endosomes, the Golgi apparatus, and the nucleus. Here, we discuss the molecular and structural basis for their ability to coordinate this wide range of cellular activities.


Assuntos
Subunidades beta da Proteína de Ligação ao GTP/metabolismo , Subunidades gama da Proteína de Ligação ao GTP/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Transdução de Sinais/fisiologia , Animais , Membrana Celular/metabolismo , Membrana Celular/fisiologia , Núcleo Celular/metabolismo , Núcleo Celular/fisiologia , Endossomos/metabolismo , Endossomos/fisiologia , Complexo de Golgi/metabolismo , Complexo de Golgi/fisiologia , Humanos
14.
Nature ; 571(7765): 398-402, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31292548

RESUMO

A decline in stem cell function impairs tissue regeneration during ageing, but the role of the stem-cell-supporting niche in ageing is not well understood. The small intestine is maintained by actively cycling intestinal stem cells that are regulated by the Paneth cell niche1,2. Here we show that the regenerative potential of human and mouse intestinal epithelium diminishes with age owing to defects in both stem cells and their niche. The functional decline was caused by a decrease in stemness-maintaining Wnt signalling due to production of Notum, an extracellular Wnt inhibitor, in aged Paneth cells. Mechanistically, high activity of mammalian target of rapamycin complex 1 (mTORC1) in aged Paneth cells inhibits activity of peroxisome proliferator activated receptor α (PPAR-α)3, and lowered PPAR-α activity increased Notum expression. Genetic targeting of Notum or Wnt supplementation restored function of aged intestinal organoids. Moreover, pharmacological inhibition of Notum in mice enhanced the regenerative capacity of aged stem cells and promoted recovery from chemotherapy-induced damage. Our results reveal a role of the stem cell niche in ageing and demonstrate that targeting of Notum can promote regeneration of aged tissues.


Assuntos
Envelhecimento , Senescência Celular , Esterases/metabolismo , Mucosa Intestinal/patologia , Celulas de Paneth/metabolismo , Regeneração , Envelhecimento/fisiologia , Animais , Senescência Celular/fisiologia , Esterases/antagonistas & inibidores , Esterases/biossíntese , Feminino , Humanos , Mucosa Intestinal/fisiologia , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , PPAR alfa/metabolismo , Celulas de Paneth/patologia , Receptores Acoplados a Proteínas-G/metabolismo , Nicho de Células-Tronco , Células-Tronco/patologia , Proteínas Wnt/antagonistas & inibidores , Via de Sinalização Wnt
15.
Nat Commun ; 10(1): 2961, 2019 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-31273197

RESUMO

Persistent inflammation is a hallmark of many human diseases, including anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) and atherosclerosis. Here, we describe a dominant trigger of inflammation: human serum factor H-related protein FHR1. In vitro, this protein selectively binds to necrotic cells via its N-terminus; in addition, it binds near necrotic glomerular sites of AAV patients and necrotic areas in atherosclerotic plaques. FHR1, but not factor H, FHR2 or FHR3 strongly induces inflammasome NLRP3 in blood-derived human monocytes, which subsequently secrete IL-1ß, TNFα, IL-18 and IL-6. FHR1 triggers the phospholipase C-pathway via the G-protein coupled receptor EMR2 independent of complement. Moreover, FHR1 concentrations of AAV patients negatively correlate with glomerular filtration rates and associate with the levels of inflammation and progressive disease. These data highlight an unexpected role for FHR1 during sterile inflammation, may explain why FHR1-deficiency protects against certain diseases, and identifies potential targets for treatment of auto-inflammatory diseases.


Assuntos
Proteínas Inativadoras do Complemento C3b/metabolismo , Inflamassomos/metabolismo , Monócitos/metabolismo , Monócitos/patologia , Doenças Vasculares/metabolismo , Doenças Vasculares/patologia , Proteína C-Reativa/metabolismo , Proteínas do Sistema Complemento/metabolismo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Proteínas Imobilizadas/metabolismo , Inflamação/metabolismo , Inflamação/patologia , Mediadores da Inflamação/metabolismo , Interleucina-1beta/metabolismo , Lipoproteínas LDL/metabolismo , Malondialdeído/metabolismo , Modelos Biológicos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Necrose , Ligação Proteica , Receptores Acoplados a Proteínas-G/metabolismo , Soro/metabolismo , Fosfolipases Tipo C/metabolismo
16.
Curr Top Med Chem ; 19(16): 1464-1483, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31264549

RESUMO

The great clinical success of chimeric antigen receptor T cell (CAR-T) and PD-1/PDL-1 inhibitor therapies suggests the drawing of a cancer immunotherapy age. However, a considerable proportion of cancer patients currently receive little benefit from these treatment modalities, indicating that multiple immunosuppressive mechanisms exist in the tumor microenvironment. In this review, we mainly discuss recent advances in small molecular regulators targeting G Protein-Coupled Receptors (GPCRs) that are associated with oncology immunomodulation, including chemokine receptors, purinergic receptors, prostaglandin E receptor EP4 and opioid receptors. Moreover, we outline how they affect tumor immunity and neoplasia by regulating immune cell recruitment and modulating tumor stromal cell biology. We also summarize the data from recent clinical advances in small molecular regulators targeting these GPCRs, in combination with immune checkpoints blockers, such as PD-1/PDL-1 and CTLA4 inhibitors, for cancer treatments.


Assuntos
Imunoterapia , Terapia de Alvo Molecular , Neoplasias/metabolismo , Neoplasias/terapia , Receptores Acoplados a Proteínas-G/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Antígeno CTLA-4/antagonistas & inibidores , Antígeno CTLA-4/metabolismo , Humanos , Receptores Acoplados a Proteínas-G/metabolismo , Bibliotecas de Moléculas Pequenas/química
17.
Cell Prolif ; 52(5): e12661, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31318114

RESUMO

OBJECTIVES: Circular RNAs (circRNAs) are non-coding RNAs, some of which are thought to be involved in gastric cancer development. Here, we examined the functions of circRNA hsa_circ_006100 in gastric cancer cells and an animal model of gastric cancer. MATERIALS AND METHODS: The expression of hsa_circ_006100, miR-195 and various functional genes was determined by quantitative RT-PCR. Cell viability, clone formation, apoptosis and cell migration/invasion abilities were analysed by the CCK-8 assay, crystal violet staining, Hoechst staining and Transwell assay, respectively. A tumour model was established by subcutaneously injecting tumour cells into nude mice. Levels of protein expression were analysed by Western blotting and immunohistochemistry. RESULTS: A bioinformatics analysis showed that miR-195 was negatively co-expressed with hsa_circ_006100. Patients with a high hsa_circ_006100 level or low miR-195 level had tumours with a high TNM stage, poor cellular differentiation and lymph node metastasis. miR-195 was targeted and inhibited by hsa_circ_006100. Overexpression of hsa_circ_006100 enhanced cellular viability and proliferation, while miR-195 suppressed hsa_circ_006100-enhanced cell growth and induced apoptosis in MGC-803 and AGS cells. Forced hsa_circ_006100 expression promoted the migration and invasion of MGC-803 and AGS cells, while those activities were inhibited by miR-195. Mechanistically, GPRC5A was predicted as a target of miR-195 and was upregulated in gastric cancer. A miR-195 inhibitor restored cell viability, proliferation, migration and invasion, and repressed apoptosis via GPRC5A. In vivo studies showed that knockdown of hsa_circ_006100 delayed tumour growth, reduced PCNA expression and upregulated miR-195 and BCL-2 expression which was restored by miR-195 inhibition due to GPRC5A/EGFR signalling, and changed the EMT phenotype in vivo. CONCLUSIONS: Hsa_circ_006100 functions as an oncogene in gastric cancer and exerts its effects via miR-195/GPRC5A signalling.


Assuntos
MicroRNAs/metabolismo , RNA/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Neoplasias Gástricas/patologia , Animais , Antagomirs/metabolismo , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Metástase Linfática , Masculino , Camundongos , Camundongos Nus , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Pessoa de Meia-Idade , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA/antagonistas & inibidores , RNA/genética , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Receptores Acoplados a Proteínas-G/química , Receptores Acoplados a Proteínas-G/genética , Transdução de Sinais , Neoplasias Gástricas/metabolismo
18.
Cell Mol Life Sci ; 76(23): 4725-4743, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31359086

RESUMO

Targeted cell ablation is a powerful approach for studying the role of specific cell populations in a variety of organotypic functions, including cell differentiation, and organ generation and regeneration. Emerging tools for permanently or conditionally ablating targeted cell populations and transiently inhibiting neuronal activities exhibit a diversity of application and utility. Each tool has distinct features, and none can be universally applied to study different cell types in various tissue compartments. Although these tools have been developed for over 30 years, they require additional improvement. Currently, there is no consensus on how to select the tools to answer the specific scientific questions of interest. Selecting the appropriate cell ablation technique to study the function of a targeted cell population is less straightforward than selecting the method to study a gene's functions. In this review, we discuss the features of the various tools for targeted cell ablation and provide recommendations for optimal application of specific approaches.


Assuntos
Bacteriocinas/metabolismo , Ácido Clodrônico/química , Toxina Diftérica/genética , Optogenética/métodos , Simplexvirus/fisiologia , Animais , Ácido Clodrônico/toxicidade , Toxina Diftérica/metabolismo , Humanos , Intoxicação por MPTP/metabolismo , Intoxicação por MPTP/patologia , Neurônios/fisiologia , Receptores Acoplados a Proteínas-G/genética , Receptores Acoplados a Proteínas-G/metabolismo , Simplexvirus/enzimologia
19.
Cell Host Microbe ; 26(1): 114-122.e8, 2019 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-31278040

RESUMO

Quorum-sensing molecules (QSMs) are secreted by bacteria to signal population density. Upon reaching a critical concentration, QSMs induce transcriptional alterations in bacteria, which enable virulence factor expression and biofilm formation. It is unclear whether mammalian hosts can recognize QSMs to trigger responsive antibacterial immunity. We report that mouse mast-cell-specific G-protein-coupled receptor Mrgprb2 and its human homolog MRGPRX2 are receptors for Gram-positive QSMs, including competence-stimulating peptide (CSP)-1. CSP-1 activates Mrgprb2 and MRGPRX2, triggering mast cell degranulation, which inhibits bacterial growth and prevents biofilm formation. Such antibacterial functions are reduced in Mrgprb2-deficient mast cells, while wild-type mast cells fail to inhibit the growth of bacterial strains lacking CSP-1. Mrgprb2-knockout mice exhibit reduced bacterial clearance, while pharmacologically activating Mrgprb2 in vivo eliminates bacteria and improves disease score. These findings identify a host defense mechanism that uses QSMs as an "Achilles heel" and suggest MRGPRX2 as a potential therapeutic target for controlling bacterial infections.


Assuntos
Proteínas de Bactérias/metabolismo , Tecido Conjuntivo/imunologia , Imunidade Inata , Mastócitos/imunologia , Proteínas do Tecido Nervoso/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Receptores de Neuropeptídeos/metabolismo , Streptococcus pneumoniae/imunologia , Animais , Bacteriocinas/metabolismo , Enterococcus faecium/imunologia , Humanos , Camundongos , Camundongos Knockout , Streptococcus pyogenes/imunologia
20.
Eur J Med Chem ; 179: 608-622, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31279294

RESUMO

Based on an old phenoxyacetic acid scaffold, CPU014 (compound 14) has been identified as a superior agonist by comprehensive exploration of structure-activity relationship. In vitro toxicity study suggested that CPU014 has lower risk of hepatotoxicity than TAK-875. During acute toxicity study (5-500 mg/kg), a favorable therapeutic window of CPU014 was observed by evaluation of plasma profiles and liver slices. Moreover, CPU014 promotes insulin secretion in a glucose-dependent manner, while no GLP-1 secretion has been enhanced. Other than good pharmacokinetic properties, CPU014 significantly improved glucose tolerance both in normal and diabetic models without the risk of hypoglycemia. These subversive findings provided a safer candidate CPU014, which is currently in preclinical study to assess its potential for the treatment of diabetes.


Assuntos
Acetatos/farmacologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Desenho de Drogas , Hipoglicemiantes/farmacologia , Receptores Acoplados a Proteínas-G/agonistas , Acetatos/síntese química , Acetatos/química , Animais , Diabetes Mellitus Tipo 2/metabolismo , Relação Dose-Resposta a Droga , Teste de Tolerância a Glucose , Hipoglicemiantes/síntese química , Hipoglicemiantes/química , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Estrutura Molecular , Ratos , Ratos Sprague-Dawley , Receptores Acoplados a Proteínas-G/metabolismo , Relação Estrutura-Atividade
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