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1.
Invest Ophthalmol Vis Sci ; 65(8): 37, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-39042403

RESUMO

Purpose: Cell lines are being used in preclinical uveal melanoma (UM) research. Because not all cell lines harbor typical GNAQ or GNA11 hotspot mutations, we aimed at better classifying them and determining whether we could find genetic causes to explain the protein and mRNA expression profiles of the cell lines. Methods: We studied protein and mRNA expression of 14 UM cell lines and determined the presence of single nucleotide variants and small insertions and deletions with next-generation sequencing and copy number alterations with a single nucleotide polymorphism array. The lists of differentially expressed proteins and genes were merged, and shared lists were created, keeping only terms with concordant mRNA and protein expression. Enrichment analyses were performed on the shared lists. Results: Cell lines Mel285 and Mel290 are separate from GNA-mutated cell lines and show downregulation of melanosome-related markers. Both lack typical UM mutations but each harbors four putatively deleterious variants in CTNNB1, PPP1R10, LIMCH1, and APC in Mel285 and ARID1A, PPP1R10, SPG11, and RNF43 in Mel290. The upregulated terms in Mel285 and Mel290 did not point to a convincing alternative origin. Mel285 shows loss of chromosomes 1p, 3p, partial 3q, 6, and partial 8p, whereas Mel290 shows loss of 1p and 6. Expression in the other 12 cell lines was related to BAP1 expression. Conclusions: Although Mel285 and Mel290 have copy number alterations that fit UM, multi-omics analyses show that they belong to a separate group compared to the other analyzed UM cell lines. Therefore, they may not be representative models to test potential therapeutic targets for UM.


Assuntos
Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP , Subunidades alfa de Proteínas de Ligação ao GTP , Regulação Neoplásica da Expressão Gênica , Melanoma , Mutação , RNA Mensageiro , Proteínas Supressoras de Tumor , Ubiquitina Tiolesterase , Neoplasias Uveais , Neoplasias Uveais/genética , Neoplasias Uveais/metabolismo , Neoplasias Uveais/patologia , Melanoma/genética , Melanoma/metabolismo , Melanoma/patologia , Humanos , Ubiquitina Tiolesterase/genética , RNA Mensageiro/genética , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Proteínas Supressoras de Tumor/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Linhagem Celular Tumoral , Variações do Número de Cópias de DNA , Polimorfismo de Nucleotídeo Único , Análise Mutacional de DNA
2.
Am J Hum Genet ; 111(7): 1370-1382, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38917801

RESUMO

Extra-axial cavernous hemangiomas (ECHs) are complex vascular lesions mainly found in the spine and cavernous sinus. Their removal poses significant risk due to their vascularity and diffuse nature, and their genetic underpinnings remain incompletely understood. Our approach involved genetic analyses on 31 tissue samples of ECHs employing whole-exome sequencing and targeted deep sequencing. We explored downstream signaling pathways, gene expression changes, and resultant phenotypic shifts induced by these mutations, both in vitro and in vivo. In our cohort, 77.4% of samples had somatic missense variants in GNA14, GNAQ, or GJA4. Transcriptomic analysis highlighted significant pathway upregulation, with the GNAQ c.626A>G (p.Gln209Arg) mutation elevating PI3K-AKT-mTOR and angiogenesis-related pathways, while GNA14 c.614A>T (p.Gln205Leu) mutation led to MAPK and angiogenesis-related pathway upregulation. Using a mouse xenograft model, we observed enlarged vessels from these mutations. Additionally, we initiated rapamycin treatment in a 14-year-old individual harboring the GNAQ c.626A>G (p.Gln209Arg) variant, resulting in gradual regression of cutaneous cavernous hemangiomas and improved motor strength, with minimal side effects. Understanding these mutations and their pathways provides a foundation for developing therapies for ECHs resistant to current therapies. Indeed, the administration of rapamycin in an individual within this study highlights the promise of targeted treatments in treating these complex lesions.


Assuntos
Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP , Subunidades alfa de Proteínas de Ligação ao GTP , Humanos , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Animais , Camundongos , Feminino , Masculino , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Mutação , Adulto , Pessoa de Meia-Idade , Transdução de Sinais , Hemangioma Cavernoso/genética , Hemangioma Cavernoso/patologia , Adolescente , Sequenciamento do Exoma , Sirolimo/farmacologia , Sirolimo/uso terapêutico , Serina-Treonina Quinases TOR/metabolismo , Serina-Treonina Quinases TOR/genética
3.
Molecules ; 29(11)2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38893478

RESUMO

Transient receptor potential melastatin-8 (TRPM8) is a cation channel that is activated by cold and "cooling agents" such as menthol and icilin, which induce a cold sensation. The stimulation of TRPM8 activates an intracellular signaling cascade that ultimately leads to a change in the gene expression pattern of the cells. Here, we investigate the TRPM8-induced signaling pathway that links TRPM8 channel activation to gene transcription. Using a pharmacological approach, we show that the inhibition of phosphatidylinositol 4-phosphate 5 kinase α (PIP5K), an enzyme essential for the biosynthesis of phosphatidylinositol 4,5-bisphosphate, attenuates TRPM8-induced gene transcription. Analyzing the link between TRPM8 and Gq proteins, we show that the pharmacological inhibition of the ßγ subunits impairs TRPM8 signaling. In addition, genetic studies show that TRPM8 requires an activated Gα subunit for signaling. In the nucleus, the TRPM8-induced signaling cascade triggers the activation of the transcription factor AP-1, a complex consisting of a dimer of basic region leucine zipper (bZIP) transcription factors. Here, we identify the bZIP protein c-Jun as an essential component of AP-1 within the TRPM8-induced signaling cascade. In summary, with PIP5K, Gq subunits, and c-Jun, we identified key molecules in TRPM8-induced signaling from the plasma membrane to the nucleus.


Assuntos
Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP , Fosfotransferases (Aceptor do Grupo Álcool) , Transdução de Sinais , Canais de Cátion TRPM , Canais de Cátion TRPM/metabolismo , Canais de Cátion TRPM/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Humanos , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fator de Transcrição AP-1/metabolismo , Células HEK293 , Proteínas Proto-Oncogênicas c-jun/metabolismo , Animais
5.
Vestn Oftalmol ; 140(2): 5-13, 2024.
Artigo em Russo | MEDLINE | ID: mdl-38742493

RESUMO

Circumscribed choroidal hemangioma (CCH) and early non-pigmented choroidal melanoma (CM) have similar clinical, ultrasound and morphometric features, which in some cases makes their differential diagnosis difficult. There are few studies in the literature devoted to a comparative analysis of the molecular genetic features of CCH and non-pigmented CM, and the results of those studies are contradictory. PURPOSE: This study attempts to develop a method of non-invasive molecular genetic differential diagnostics of CCH and non-pigmented CM. MATERIAL AND METHODS: Based on the results of clinical and instrumental examination methods, 60 patients (60 eyes) with CCH (n=30) and non-pigmented CM (n=30) were included in this prospective study. The control group consisted of 30 individuals without intraocular tumors. Mutations in the GNAQ/GNA11 genes were determined by real-time PCR using the analysis of genomic circulating tumor DNA isolated from peripheral blood plasma. The average follow-up period was 12.1±1.8 months. RESULTS: The study revealed a significant association of mutations in exons 4 and 5 of the GNAQ/GNA11 genes with the presence of non-pigmented CM (27/30; 90%). These mutations were not detected in the group of patients with CCH. Mutations in exons 4 and 5 of the GNAQ/GNA11 genes were also not detected in the control group of healthy individuals. CONCLUSION: This study proposes a method of non-invasive and low-cost differential diagnostics based on molecular genetic analysis and detection of mutations in exons 4 and 5 of the GNAQ and GNA11 genes, which are specific for CM (90%).


Assuntos
Neoplasias da Coroide , Hemangioma , Melanoma , Humanos , Neoplasias da Coroide/genética , Neoplasias da Coroide/diagnóstico , Masculino , Feminino , Pessoa de Meia-Idade , Diagnóstico Diferencial , Hemangioma/genética , Hemangioma/diagnóstico , Adulto , Melanoma/genética , Melanoma/diagnóstico , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Mutação , Corioide/diagnóstico por imagem , Corioide/patologia , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Estudos Prospectivos
6.
Toxicol Appl Pharmacol ; 487: 116976, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38777097

RESUMO

Staff and animals in livestock buildings are constantly exposed to fine particulate matter (PM2.5), which affects their respiratory health. However, its exact pathogenic mechanism remains unclear. Regulator of G-protein signaling 2 (RGS2) has been reported to play a regulatory role in pneumonia. The aim of this study was to explore the therapeutic potential of RGS2 in cowshed PM2.5-induced respiratory damage. PM2.5 was collected from a cattle farm, and the alveolar macrophages (NR8383) of the model animal rat were stimulated with different treatment conditions of cowshed PM2.5. The RGS2 overexpression vector was constructed and transfected it into cells. Compared with the control group, cowshed PM2.5 significantly induced a decrease in cell viability and increased the levels of apoptosis and proinflammatory factor expression. Overexpression of RGS2 ameliorated the above-mentioned cellular changes induced by cowshed PM2.5. In addition, PM2.5 has significantly induced intracellular Ca2+ dysregulation. Affinity inhibition of Gq/11 by RGS2 attenuated the cytosolic calcium signaling pathway mediated by PLCß/IP3R. To further investigate the causes and mechanisms of action of differential RGS2 expression, the possible effects of oxidative stress and TLR2/4 activation were investigated. The results have shown that RGS2 expression was not only regulated by oxidative stress-induced nitric oxide during cowshed PM2.5 cells stimulation but the activation of TLR2/4 had also an important inhibitory effect on its protein expression. The present study demonstrates the intracellular Ca2+ regulatory role of RGS2 during cellular injury, which could be a potential target for the prevention and treatment of PM2.5-induced respiratory injury.


Assuntos
Macrófagos Alveolares , Material Particulado , Proteínas RGS , Receptor 2 Toll-Like , Receptor 4 Toll-Like , Animais , Proteínas RGS/genética , Proteínas RGS/metabolismo , Material Particulado/toxicidade , Receptor 4 Toll-Like/metabolismo , Receptor 4 Toll-Like/genética , Ratos , Macrófagos Alveolares/efeitos dos fármacos , Macrófagos Alveolares/metabolismo , Bovinos , Receptor 2 Toll-Like/metabolismo , Receptor 2 Toll-Like/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Linhagem Celular , Sinalização do Cálcio/efeitos dos fármacos , Cálcio/metabolismo , Apoptose/efeitos dos fármacos , Poluentes Atmosféricos/toxicidade
7.
Nat Commun ; 15(1): 4307, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38811567

RESUMO

G protein-coupled receptors (GPCRs) are sophisticated signaling machines able to simultaneously elicit multiple intracellular signaling pathways upon activation. Complete (in)activation of all pathways can be counterproductive for specific therapeutic applications. This is the case for the serotonin 2 A receptor (5-HT2AR), a prominent target for the treatment of schizophrenia. In this study, we elucidate the complex 5-HT2AR coupling signature in response to different signaling probes, and its physiological consequences by combining computational modeling, in vitro and in vivo experiments with human postmortem brain studies. We show how chemical modification of the endogenous agonist serotonin dramatically impacts the G protein coupling profile of the 5-HT2AR and the associated behavioral responses. Importantly, among these responses, we demonstrate that memory deficits are regulated by Gαq protein activation, whereas psychosis-related behavior is modulated through Gαi1 stimulation. These findings emphasize the complexity of GPCR pharmacology and physiology and open the path to designing improved therapeutics for the treatment of stchizophrenia.


Assuntos
Transtornos da Memória , Transtornos Psicóticos , Receptor 5-HT2A de Serotonina , Serotonina , Animais , Feminino , Humanos , Masculino , Camundongos , Encéfalo/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Células HEK293 , Transtornos da Memória/metabolismo , Transtornos Psicóticos/metabolismo , Transtornos Psicóticos/tratamento farmacológico , Receptor 5-HT2A de Serotonina/metabolismo , Esquizofrenia/metabolismo , Serotonina/metabolismo , Transdução de Sinais
8.
FEBS Lett ; 598(14): 1783-1791, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38757247

RESUMO

Certain amino acid sites of 5-HT2AR play crucial roles in interacting with various G proteins. Hallucinogens and non-hallucinogens both act on 5-HT2AR but mediate different pharmacological effects, possibly due to the coupling of different G proteins. Therefore, this study identified the binding sites of hallucinogens and non-hallucinogens with 5-HT2AR through molecular docking. We conducted site mutation to examine the impact of these sites on G proteins, in order to find out the sites that can distinguish the pharmacological effects of hallucinogens and non-hallucinogens. Our results indicate that I4.60A and S3.39A did not affect the ability of hallucinogens to activate Gq signaling, but significantly reduced Gs signaling activation by hallucinogens. These results suggest that S3.39 and I4.60 are important for the activation of Gs signaling by hallucinogens.


Assuntos
Receptor 5-HT2A de Serotonina , Serina , Transdução de Sinais , Receptor 5-HT2A de Serotonina/metabolismo , Receptor 5-HT2A de Serotonina/genética , Receptor 5-HT2A de Serotonina/química , Humanos , Células HEK293 , Serina/metabolismo , Serina/química , Sítios de Ligação , Isoleucina/metabolismo , Isoleucina/química , Simulação de Acoplamento Molecular , Alucinógenos/farmacologia , Alucinógenos/metabolismo , Alucinógenos/química , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/química , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Ligação Proteica
9.
Mol Pharmacol ; 105(6): 386-394, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38641412

RESUMO

The M3 muscarinic acetylcholine receptor (M3R) is a G protein-coupled receptor (GPCR) that regulates important physiologic processes, including vascular tone, bronchoconstriction, and insulin secretion. It is expressed on a wide variety of cell types, including pancreatic beta, smooth muscle, neuronal, and immune cells. Agonist binding to the M3R is thought to initiate intracellular signaling events primarily through the heterotrimeric G protein Gq. However, reports differ on the ability of M3R to couple to other G proteins beyond Gq. Using members from the four primary G protein families (Gq, Gi, Gs, and G13) in radioligand binding, GTP turnover experiments, and cellular signaling assays, including live cell G protein dissociation and second messenger assessment of cAMP and inositol trisphosphate, we show that other G protein families, particularly Gi and Gs, can also interact with the human M3R. We further show that these interactions are productive as assessed by amplification of classic second messenger signaling events. Our findings demonstrate that the M3R is more promiscuous with respect to G protein interactions than previously appreciated. SIGNIFICANCE STATEMENT: The study reveals that the human M3 muscarinic acetylcholine receptor (M3R), known for its pivotal roles in diverse physiological processes, not only activates intracellular signaling via Gq as previously known but also functionally interacts with other G protein families such as Gi and Gs, expanding our understanding of its versatility in mediating cellular responses. These findings signify a broader and more complex regulatory network governed by M3R and have implications for therapeutic targeting.


Assuntos
Proteínas de Ligação ao GTP , Receptor Muscarínico M3 , Transdução de Sinais , Receptor Muscarínico M3/metabolismo , Humanos , Transdução de Sinais/fisiologia , Proteínas de Ligação ao GTP/metabolismo , Animais , Células CHO , Cricetulus , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Células HEK293
10.
Nature ; 629(8011): 481-488, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38632411

RESUMO

The human calcium-sensing receptor (CaSR) detects fluctuations in the extracellular Ca2+ concentration and maintains Ca2+ homeostasis1,2. It also mediates diverse cellular processes not associated with Ca2+ balance3-5. The functional pleiotropy of CaSR arises in part from its ability to signal through several G-protein subtypes6. We determined structures of CaSR in complex with G proteins from three different subfamilies: Gq, Gi and Gs. We found that the homodimeric CaSR of each complex couples to a single G protein through a common mode. This involves the C-terminal helix of each Gα subunit binding to a shallow pocket that is formed in one CaSR subunit by all three intracellular loops (ICL1-ICL3), an extended transmembrane helix 3 and an ordered C-terminal region. G-protein binding expands the transmembrane dimer interface, which is further stabilized by phospholipid. The restraint imposed by the receptor dimer, in combination with ICL2, enables G-protein activation by facilitating conformational transition of Gα. We identified a single Gα residue that determines Gq and Gs versus Gi selectivity. The length and flexibility of ICL2 allows CaSR to bind all three Gα subtypes, thereby conferring capacity for promiscuous G-protein coupling.


Assuntos
Proteínas Heterotriméricas de Ligação ao GTP , Receptores de Detecção de Cálcio , Humanos , Cálcio/metabolismo , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/química , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/química , Subunidades alfa Gs de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gs de Proteínas de Ligação ao GTP/química , Modelos Moleculares , Ligação Proteica , Multimerização Proteica , Receptores de Detecção de Cálcio/metabolismo , Receptores de Detecção de Cálcio/química , Proteínas Heterotriméricas de Ligação ao GTP/química , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Sítios de Ligação , Estrutura Secundária de Proteína , Especificidade por Substrato
11.
Acta Neuropathol Commun ; 12(1): 47, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38532508

RESUMO

Sturge-Weber syndrome (SWS), a neurocutaneous disorder, is characterized by capillary malformations (CM) in the skin, brain, and eyes. Patients may suffer from seizures, strokes, and glaucoma, and only symptomatic treatment is available. CM are comprised of enlarged vessels with endothelial cells (ECs) and disorganized mural cells. Our recent finding indicated that the R183Q mutation in ECs leads to heightened signaling through phospholipase Cß3 and protein kinase C, leading to increased angiopoietin-2 (ANGPT2). Furthermore, knockdown of ANGPT2, a crucial mediator of pro-angiogenic signaling, inflammation, and vascular remodeling, in EC-R183Q rescued the enlarged vessel phenotype in vivo. This prompted us to look closer at the microenvironment in CM-affected vascular beds. We analyzed multiple brain histological sections from patients with GNAQ-R183Q CM and found enlarged vessels devoid of mural cells along with increased macrophage-like cells co-expressing MRC1 (CD206, a mannose receptor), CD163 (a scavenger receptor and marker of the monocyte/macrophage lineage), CD68 (a pan macrophage marker), and LYVE1 (a lymphatic marker expressed by some macrophages). These macrophages were not found in non-SWS control brain sections. To investigate the mechanism of increased macrophages in the perivascular environment, we examined THP1 (monocytic/macrophage cell line) cell adhesion to EC-R183Q versus EC-WT under static and laminar flow conditions. First, we observed increased THP1 cell adhesion to EC-R183Q compared to EC-WT under static conditions. Next, using live cell imaging, we found THP1 cell adhesion to EC-R183Q was dramatically increased under laminar flow conditions and could be inhibited by anti-ICAM1. ICAM1, an endothelial cell adhesion molecule required for leukocyte adhesion, was strongly expressed in the endothelium in SWS brain histological sections, suggesting a mechanism for recruitment of macrophages. In conclusion, our findings demonstrate that macrophages are an important component of the perivascular environment in CM suggesting they may contribute to the CM formation and SWS disease progression.


Assuntos
Capilares/anormalidades , Síndrome de Sturge-Weber , Malformações Vasculares , Humanos , Síndrome de Sturge-Weber/genética , Síndrome de Sturge-Weber/patologia , Síndrome de Sturge-Weber/terapia , Células Endoteliais/metabolismo , Capilares/patologia , Macrófagos/metabolismo , Microambiente Tumoral , Proteínas de Transporte Vesicular/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo
12.
Commun Biol ; 7(1): 362, 2024 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-38521872

RESUMO

Muscarinic acetylcholine receptor M3 (M3) and its downstream effector Gq/11 are critical drug development targets due to their involvement in physiopathological processes. Although the structure of the M3-miniGq complex was recently published, the lack of information on the intracellular loop 3 (ICL3) of M3 and extensive modification of Gαq impedes the elucidation of the molecular mechanism of M3-Gq coupling under more physiological condition. Here, we describe the molecular mechanism underlying the dynamic interactions between full-length wild-type M3 and Gq using hydrogen-deuterium exchange mass spectrometry and NanoLuc Binary Technology-based cell systems. We propose a detailed analysis of M3-Gq coupling through examination of previously well-defined binding interfaces and neglected regions. Our findings suggest potential binding interfaces between M3 and Gq in pre-assembled and functionally active complexes. Furthermore, M3 ICL3 negatively affected M3-Gq coupling, and the Gαq AHD underwent unique conformational changes during M3-Gq coupling.


Assuntos
Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP , Receptores Muscarínicos , Receptores Muscarínicos/química , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/química
13.
JCI Insight ; 9(9)2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38530370

RESUMO

Fibroblast growth factor 23 (FGF23) production has recently been shown to increase downstream of Gαq/11-PKC signaling in osteocytes. Inactivating mutations in the gene encoding Gα11 (GNA11) cause familial hypocalciuric hypercalcemia (FHH) due to impaired calcium-sensing receptor signaling. We explored the effect of Gα11 deficiency on FGF23 production in mice with heterozygous (Gna11+/-) or homozygous (Gna11-/-) ablation of Gna11. Both Gna11+/- and Gna11-/- mice demonstrated hypercalcemia and mildly raised parathyroid hormone levels, consistent with FHH. Strikingly, these mice also displayed increased serum levels of total and intact FGF23 and hypophosphatemia. Gna11-/- mice showed augmented Fgf23 mRNA levels in the liver and heart, but not in bone or bone marrow, and also showed evidence of systemic inflammation with elevated serum IL-1ß levels. Furin gene expression was significantly increased in the Gna11-/- liver, suggesting enhanced FGF23 cleavage despite the observed rise in circulating intact FGF23 levels. Gna11-/- mice had normal renal function and reduced serum levels of glycerol-3-phosphate, excluding kidney injury as the primary cause of elevated intact FGF23 levels. Thus, Gα11 ablation caused systemic inflammation and excess serum FGF23 in mice, suggesting that patients with FHH - at least those with GNA11 mutations - may be at risk for these complications.


Assuntos
Modelos Animais de Doenças , Fator de Crescimento de Fibroblastos 23 , Fatores de Crescimento de Fibroblastos , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP , Hipercalcemia , Camundongos Knockout , Animais , Feminino , Masculino , Camundongos , Fatores de Crescimento de Fibroblastos/sangue , Fatores de Crescimento de Fibroblastos/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Hipercalcemia/genética , Hipercalcemia/congênito , Hipercalcemia/sangue , Hipercalcemia/metabolismo , Hipofosfatemia/genética , Hipofosfatemia/metabolismo , Interleucina-1beta/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/sangue , Fígado/metabolismo , Hormônio Paratireóideo/sangue , Hormônio Paratireóideo/metabolismo , Transdução de Sinais
14.
Cancer Gene Ther ; 31(6): 884-893, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38360887

RESUMO

Recent pan-cancer genomic analyses have identified numerous oncogenic driver mutations that occur in a cell-type and tissue-specific distribution. For example, oncogenic mutations in Braf and Nras genes arise predominantly in melanocytic neoplasms of the epidermis, while oncogenic mutations in Gnaq/11 genes arise mostly in melanocytic lesions of the dermis or the uvea. The mechanisms promoting cell-type and tissue-specific oncogenic events currently remain poorly understood. Here, we report that Gnaq/11 hotspot mutations occur as early oncogenic drivers during the evolution of primary melanomas in Hgf-Cdk4 mice. Additional single base substitutions in the Trp53 gene and structural chromosomal aberrations favoring amplifications of the chromosomal region containing the Met receptor gene accumulate during serial tumor transplantation and in cell lines established in vitro. Mechanistically, we found that the GnaqQ209L mutation transactivates the Met receptor. Overexpression of oncogenic GnaqQ209L in the immortalized melanocyte cell line promoted in vivo growth that was enhanced by transgenic Hgf expression in the tumor microenvironment. This cross-signaling mechanism explains the selection of oncogenic Gnaq/11 in primary Hgf-Cdk4 melanomas and provides an example of how oncogenic driver mutations, intracellular signaling cascades, and microenvironmental cues cooperate to drive cancer development in a tissue-specific fashion.


Assuntos
Quinase 4 Dependente de Ciclina , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP , Fator de Crescimento de Hepatócito , Melanoma , Proteínas Proto-Oncogênicas c-met , Transdução de Sinais , Animais , Camundongos , Proteínas Proto-Oncogênicas c-met/genética , Proteínas Proto-Oncogênicas c-met/metabolismo , Quinase 4 Dependente de Ciclina/genética , Quinase 4 Dependente de Ciclina/metabolismo , Fator de Crescimento de Hepatócito/genética , Fator de Crescimento de Hepatócito/metabolismo , Humanos , Melanoma/genética , Melanoma/metabolismo , Melanoma/patologia , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Ativação Transcricional , Mutação , Linhagem Celular Tumoral , Camundongos Transgênicos , Microambiente Tumoral/genética
15.
Nature ; 626(8001): 1141-1148, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38326620

RESUMO

The calcium-sensing receptor (CaSR) is a family C G-protein-coupled receptor1 (GPCR) that has a central role in regulating systemic calcium homeostasis2,3. Here we use cryo-electron microscopy and functional assays to investigate the activation of human CaSR embedded in lipid nanodiscs and its coupling to functional Gi versus Gq proteins in the presence and absence of the calcimimetic drug cinacalcet. High-resolution structures show that both Gi and Gq drive additional conformational changes in the activated CaSR dimer to stabilize a more extensive asymmetric interface of the seven-transmembrane domain (7TM) that involves key protein-lipid interactions. Selective Gi and Gq coupling by the receptor is achieved through substantial rearrangements of intracellular loop 2 and the C terminus, which contribute differentially towards the binding of the two G-protein subtypes, resulting in distinct CaSR-G-protein interfaces. The structures also reveal that natural polyamines target multiple sites on CaSR to enhance receptor activation by zipping negatively charged regions between two protomers. Furthermore, we find that the amino acid L-tryptophan, a well-known ligand of CaSR extracellular domains, occupies the 7TM bundle of the G-protein-coupled protomer at the same location as cinacalcet and other allosteric modulators. Together, these results provide a framework for G-protein activation and selectivity by CaSR, as well as its allosteric modulation by endogenous and exogenous ligands.


Assuntos
Proteínas Heterotriméricas de Ligação ao GTP , Receptores de Detecção de Cálcio , Humanos , Regulação Alostérica/efeitos dos fármacos , Cinacalcete/farmacologia , Microscopia Crioeletrônica , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Ligantes , Lipídeos , Nanoestruturas/química , Poliaminas/metabolismo , Conformação Proteica/efeitos dos fármacos , Receptores de Detecção de Cálcio/química , Receptores de Detecção de Cálcio/metabolismo , Receptores de Detecção de Cálcio/ultraestrutura , Especificidade por Substrato , Triptofano/metabolismo , Cálcio/metabolismo
16.
Invest Ophthalmol Vis Sci ; 65(1): 15, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38175637

RESUMO

Purpose: The purpose of this study was to quantify specific aqueous humor (AH) proteins in eyes affected by posterior uveal melanoma (UM). Methods: Thirty-six eyes affected by primary UM were included. Tumor thickness and largest basal diameter were specific clinical characteristics. Tumors were staged with the American Joint Commission on Cancer Eighth Edition (AJCC) classification. During the brachytherapy (Iodine-125) surgical procedure, both the AH sample collection and the 25-gauge transscleral fine needle aspiration biopsy (FNAB) were performed. AH samples were analyzed by immunoprecipitation and SDS PAGE techniques to quantify GNAQ, BAP1, SF3B1, and EIF1AX proteins. Cytologic material underwent fluorescence in situ hybridization for chromosome 3. The AH of 36 healthy eyes was used as the control group. Cluster analysis of groups was also performed. Results: Compared with the control group, significantly higher protein levels of: GNAQ (P = 0.02), BAP1 (P = 0.01), and SF3B1 (P = 0.02) were detected in eyes with UM. Cluster analysis of UM group revealed 2 clusters, one showing higher expression of GNAQ and BAP1 protein and one of EIF1AX protein. Moreover, the 2 clusters corresponded with the chromosome 3 status of UM. Conclusions: Specific and selected proteins may be detected in the AH of eyes affected by UM. These findings confirm the possibilities provided by AH analysis in UM.


Assuntos
Humor Aquoso , Neoplasias Uveais , Humanos , Hibridização in Situ Fluorescente , Fatores de Transcrição , Proteínas Supressoras de Tumor , Ubiquitina Tiolesterase , Fatores de Processamento de RNA/genética , Fosfoproteínas , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP
17.
J Med Chem ; 67(2): 1447-1459, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38198520

RESUMO

Uveal melanoma (UM) is the most common primary intraocular malignancy in the adult eye. Despite the aggressive local management of primary UM, the development of metastases is common with no effective treatment options for metastatic disease. Genetic analysis of UM samples reveals the presence of mutually exclusive activating mutations in the Gq alpha subunits GNAQ and GNA11. One of the key downstream targets of the constitutively active Gq alpha subunits is the protein kinase C (PKC) signaling pathway. Herein, we describe the discovery of darovasertib (NVP-LXS196), a potent pan-PKC inhibitor with high whole kinome selectivity. The lead series was optimized for kinase and off target selectivity to afford a compound that is rapidly absorbed and well tolerated in preclinical species. LXS196 is being investigated in the clinic as a monotherapy and in combination with other agents for the treatment of uveal melanoma (UM), including primary UM and metastatic uveal melanoma (MUM).


Assuntos
Melanoma , Neoplasias Uveais , Adulto , Humanos , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Melanoma/tratamento farmacológico , Melanoma/patologia , Neoplasias Uveais/tratamento farmacológico , Neoplasias Uveais/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Mutação
18.
Angew Chem Int Ed Engl ; 63(10): e202317805, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38238265

RESUMO

Heterotrimeric G proteins are key mediators in the signaling of G protein-coupled receptors (GPCR) that are involved in a plethora of important physiological processes and thus major targets of pharmaceutical drugs. The cyclic depsipeptides YM-254890 and FR900359 are strong and selective inhibitors of the Gq subfamily of G proteins. FR900359 was first reported to be produced by unculturable plant symbiont, however, a culturable FR900359 producer was discovered recently by the standard strategy, screening of the producing strain from the environment. As another strategy, we introduce herein the different way to supply natural compounds of unculturable microorganism origin. We therefore embarked on constructing an artificial biosynthetic gene cluster (BGC) for FR900359 with YM-254890 BGC as a template using "in vitro module editing" technology, first developed for the modification of type-I PKS BGCs, to edit YM-254890 BGC. The resulting artificial BGCs coding FR900359 were heterologously expressed in the Pseudomonas putida KT2440 host strain.


Assuntos
Antineoplásicos , Depsipeptídeos , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Depsipeptídeos/química , Receptores Acoplados a Proteínas G/metabolismo
19.
Nat Cancer ; 5(3): 481-499, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38233483

RESUMO

Activating mutations in GNAQ/GNA11 occur in over 90% of uveal melanomas (UMs), the most lethal melanoma subtype; however, targeting these oncogenes has proven challenging and inhibiting their downstream effectors show limited clinical efficacy. Here, we performed genome-scale CRISPR screens along with computational analyses of cancer dependency and gene expression datasets to identify the inositol-metabolizing phosphatase INPP5A as a selective dependency in GNAQ/11-mutant UM cells in vitro and in vivo. Mutant cells intrinsically produce high levels of the second messenger inositol 1,4,5 trisphosphate (IP3) that accumulate upon suppression of INPP5A, resulting in hyperactivation of IP3-receptor signaling, increased cytosolic calcium and p53-dependent apoptosis. Finally, we show that GNAQ/11-mutant UM cells and patients' tumors exhibit elevated levels of IP4, a biomarker of enhanced IP3 production; these high levels are abolished by GNAQ/11 inhibition and correlate with sensitivity to INPP5A depletion. Our findings uncover INPP5A as a synthetic lethal vulnerability and a potential therapeutic target for GNAQ/11-mutant-driven cancers.


Assuntos
Melanoma , Humanos , Melanoma/tratamento farmacológico , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/uso terapêutico , Mutação , Transdução de Sinais , Inositol Polifosfato 5-Fosfatases/genética
20.
Am J Clin Pathol ; 161(5): 469-482, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38217527

RESUMO

OBJECTIVES: We aimed to investigate the clinicopathologic features of and genetic changes in Sturge-Weber syndrome (SWS) in patients with refractory epilepsy. METHODS: Clinical data were retrospectively analyzed. H&E and immunohistochemistry were performed to assess pathologic changes. Targeted amplicon sequencing was applied to investigate the somatic GNAQ (c.548G>A) mutation. The potential predictors of seizure outcomes were estimated by univariate and multivariate statistical analyses. RESULTS: Forty-eight patients with SWS and refractory epilepsy were enrolled. According to the imaging data and pathologic examination, ipsilateral hippocampal sclerosis (HS), calcification of leptomeningeal arteries, and focal cortical dysplasia were found in 14 (29.2%), 31 (64.6%), and 37 (77.1%) patients, respectively. A high frequency of GNAQ alteration was detected in both cerebral cortex (57.7%) and ipsilateral hippocampus (50.0%) from patients with SWS. During follow-up, 43 of 48 patients (85.4%) had achieved seizure control (Engel class I). Statistically, HS signs on imaging were found to be independent predictors of unfavorable seizure outcomes (P = .015). CONCLUSIONS: Calcification of leptomeningeal arteries, focal cortical dysplasia, and GNAQ alteration are common features in SWS pathology. Patients with refractory epilepsy caused by SWS can achieve satisfactory seizure control after surgery, but seizure control was compromised in patients with comorbid HS.


Assuntos
Epilepsia Resistente a Medicamentos , Síndrome de Sturge-Weber , Humanos , Síndrome de Sturge-Weber/complicações , Síndrome de Sturge-Weber/patologia , Masculino , Feminino , Epilepsia Resistente a Medicamentos/patologia , Epilepsia Resistente a Medicamentos/etiologia , Criança , Adolescente , Estudos Retrospectivos , Adulto , Pré-Escolar , Adulto Jovem , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Mutação , Hipocampo/patologia , Lactente , Pessoa de Meia-Idade
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