GTP-Binding Protein alpha Subunits, Gs

GTP - 结合蛋白 α 亚基,Gs
  • 文章类型: Journal Article
    McCune-Albright综合征(MAS)是一种罕见的遗传,非遗传性疾病,以纤维发育不良为特征,过度内分泌症,和咖啡-au-lait黄斑。垂体腺瘤可能与该综合征并发,但此类疾病的临床病理特征和手术治疗尚不清楚。
    我们回顾性回顾了在北京天坛医院随访的10例MAS相关垂体腺瘤患者,并分析了他们的临床组织学资料,手术策略,神经成像,基因突变,和预后。此外,还对英语语言文学进行了批判性审查。
    10例MAS相关腺瘤患者均接受手术切除肿瘤(9例经蝶入路和1例经颅入路)。这些患者均未进行视神经管减压。值得注意的是,生长激素(GH),催乳素(PRL),肿瘤切除后IGF-1水平显着降低,而大多数视力障碍患者(6/7)的视力改善。随访16~150个月,未见肿瘤复发。病理检查显示中度Ki-67LI(平均1.19%,范围从0.1%到3.3%)和Gsα和PKAC-β的阳性染色。在1例患者中检测到GNAS基因突变(R201C)。
    可以显着减少激素过量(包括GH和PRL),并且在不减压视神经管的情况下,手术后视力缺陷得到了极大改善。此外,MAS相关垂体腺瘤中Ki-67的中度表达和Gsα和PKACβ的阳性表达,表明这些肿瘤的轻度增殖性质以及MAS和腺瘤之间的可能联系。
    UNASSIGNED: McCune-Albright syndrome (MAS) is a rare genetic, non-inheritable disease and is characterized by fibrous dysplasia, hyperendocrinism, and café-au-lait macules. Pituitary adenomas could be concurrent with this syndrome but clinicopathological features and the surgical management of such disorders is unclear.
    UNASSIGNED: We retrospectively reviewed ten MAS-associated pituitary adenoma patients with follow-up in Beijing Tiantan Hospital and analyzed their clinicohistological data, surgical strategies, neuro-imaging, genetic mutations, and prognosis. Moreover, a critical review of the English language literature was also conducted.
    UNASSIGNED: All of the ten MAS-associated adenoma patients underwent surgeries to remove the tumor (nine transsphenoidal approaches and one transcranial approach). None of these patients had a decompression of the optic canal. Notably, the growth hormone (GH), prolactin (PRL), and IGF-1 level had a significant reduction after the resection of the tumor while vision improvement was observed in most patients (6/7) with visual deficits. No tumor recurrence was observed during the follow-up from 16 to 150 months. The pathological examination showed a moderate Ki-67 LI (mean 1.19%, range from 0.1% to 3.3%) and the positive staining of Gsα and PKA C-beta. GNAS gene mutation (R201C) was detected in one patient.
    UNASSIGNED: Hormone excess (including GH and PRL) could be significantly reduced and the visual deficits are greatly improved after the surgery without the decompression of the optic canal. In addition, MAS-associated pituitary adenomas have a moderate expression of Ki-67 and positive expression of Gsα and PKA C-beta, indicating a mildly proliferative nature of these tumors and the possible linking between MAS and adenomas.
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  • 文章类型: Journal Article
    In the early 2000s, emerging SARS-CoV-2, which is highly pathogenic, posed a great threat to public health. During COVID-19, epigenetic regulation is deemed to be an important part of the pathophysiology and illness severity. Using the Illumina Infinium Methylation EPIC BeadChip (850 K), we investigated genome-wide differences in DNA methylation between healthy subjects and COVID-19 patients with different disease severities. We conducted a combined analysis and selected 35 \"marker\" genes that could indicate a SARS-CoV-2 infection, including 12 (ATHL1, CHN2, CHST15, CPLX2, CRHR2, DCAKD, GNAI2, HECW1, HYAL1, MIR510, PDE11A, and SMG6) situated in the promoter region. The functions and pathways of differentially methylated genes were enriched in biological processes, signal transduction, and the immune system. In the \"Severe versus Mild\" group, differentially methylated genes, after eliminating duplicates, were used for PPI analyses. The four hub genes (GNG7, GNAS, PRKCZ, and PRKAG2) that had the highest degree of nodes were identified and among them, GNG7 and GNAS genes expressions were also downregulated in the severe group in sequencing results. Above all, the results suggest that GNG7 and GNAS may play a non-ignorable role in the progression of COVID-19. In conclusion, the identified key genes and related pathways in the current study can be used to study the molecular mechanisms of COVID-19 and may provide possibilities for specific treatments.
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  • 文章类型: Journal Article
    Fibrous dysplasia (FD) is a rare bone disease caused by activating mutations of GNAS encoding the Gsα protein, enhancing cyclic adenosine monophosphate (cAMP) production by overstimulation of adenylyl cyclase and impairing osteoblastic differentiation. The clinical presentation ranges from asymptomatic to polyostotic forms with severe disability, explained by the mosaic distribution of the GNAS mutation. Physicians have to deal with the gap of knowledge in FD pathogenesis, the absence of prognostic markers and the lack of specific treatment. The identification of specific biomarkers for FD is an important step to improve the clinical and therapeutic approaches. An epigenetic regulation driven by microRNAs (miRNAs), known as promising biomarkers in bone disease, could be involved in FD. We have sought circulating miRNAs that are differentially expressed in FD patients compared to controls and would reflect dysregulations of osteogenesis-related genes and bone disorder. The global miRNA profiling was performed using Next Generation Sequencing in patient serum collected from a discovery cohort of 20 patients (10 polyostotic and 10 monostotic) and 10 controls. From these, we selected 19 miRNAs for a miRNA validation phase from serum of 82 patients and 82 controls, using real-time qPCR. Discovery screening identified 111 miRNAs differentially expressed in patient serum, after adjusting for the false discovery rate (FDR). Among the 82 patients, 55% were polyostotic, and 73% were women with a mean age of 42 years. Six miRNAs (miR-25-3p, miR-93-5p, miR-182-5p, miR-324-5p, miR-363-3p, and miR-451a) were significantly overexpressed in serum, with FDR <0.05. The expression level of these six miRNAs was not associated with the FD severity. In conclusion, we identified a signature of circulating miRNAs associated with FD. These miRNAs are potential negative regulators of gene expression in bone cell progenitors, suggesting their activity in FD by interfering with osteoblastic and osteoclastic differentiation to impair bone mineralization and remodeling processes. © 2020 American Society for Bone and Mineral Research.
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  • 文章类型: Case Reports
    纤维发育不良可能表现为反映继发性病灶内变化的局部攻击行为,延伸到软组织,或恶性转化。我们报告了一例多发性纤维发育不良患者,该患者患有巨大的下颌骨病变,包括组织学上典型的,基因型证实,纤维异型增生合并纤维化和低细胞增生性纤维瘤样组织,其中检测到相同的Gsα-R201H突变。在纤维发育不良和促纤维增生性纤维瘤区域中发生相同的突变表明,纤维瘤样组织反映了在其他典型的纤维发育不良中异常的继发性组织变化。据我们所知,只有4例纤维发育不良伴纤维增生性纤维瘤样组织改变。
    Fibrous dysplasia may show locally aggressive behaviour reflecting secondary intralesional changes, extension to soft tissue, or malignant transformation. We report the case of a patient with polyostotic fibrous dysplasia who had a giant mandibular lesion consisting of histologically typical, genotypically-confirmed, fibrous dysplasia merged with a fibrotic and hypocellular desmoplastic fibroma-like tissue in which the same Gsα-R201H mutation was detected. The occurrence of the same mutation in both the fibrous dysplasia and areas of desmoplastic fibroma suggests that the fibroma-like tissue reflects an unusual secondary tissue change within an otherwise typical fibrous dysplasia. To the best of our knowledge, only four cases of fibrous dysplasia with desmoplastic fibroma-like tissue changes have been reported.
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  • 文章类型: Journal Article
    Fibrous dysplasia of bone/McCune-Albright syndrome (Polyostotic FD/MAS; OMIM#174800) is a crippling skeletal disease caused by gain-of-function mutations of Gs α. Enhanced bone resorption is a recurrent histological feature of FD and a major cause of fragility of affected bones. Previous work suggests that increased bone resorption in FD is driven by RANKL and some studies have shown that the anti-RANKL monoclonal antibody, denosumab, reduces bone turnover and bone pain in FD patients. However, the effect of RANKL inhibition on the histopathology of FD and its impact on the natural history of the disease remain to be assessed. In this study, we treated the EF1α-Gs αR201C mice, which develop an FD-like phenotype, with an anti-mouse RANKL monoclonal antibody. We found that the treatment induced marked radiographic and microscopic changes at affected skeletal sites in 2-month-old mice. The involved skeletal segments became sclerotic due to the deposition of new, highly mineralized bone within developing FD lesions and showed a higher mechanical resistance compared to affected segments from untreated transgenic mice. Similar changes were also detected in older mice with a full-blown skeletal phenotype. The administration of anti-mouse RANKL antibody arrested the growth of established lesions and, in young mice, prevented the appearance of new ones. However, after drug withdrawal, the newly formed bone was remodelled into FD tissue and the disease progression resumed in young mice. Taken together, our results show that the anti-RANKL antibody significantly affected the bone pathology and natural history of FD in the mouse. Pending further work on the prevention and management of relapse after treatment discontinuation, our preclinical study suggests that RANKL inhibition may be an effective therapeutic option for FD patients. © 2019 American Society for Bone and Mineral Research.
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  • 文章类型: Journal Article
    BACKGROUND: Mazabraud syndrome is a rare disorder, characterized by the presence of fibrous dysplasia (FD) with associated intramuscular myxomas. Data are scarce on the prevalence, clinical features, and natural history of this disorder and outcomes. In this multicenter study, we evaluated a series of patients from 6 European centers.
    METHODS: All centers affiliated with the European Musculo-Skeletal Oncology Society (EMSOS) were invited to include data on all patients with Mazabraud syndrome who were seen between 1980 and 2015. The study investigated the prevalence of Mazabraud syndrome, the type, severity, and localization of FD lesions in relation to myxomas, the histopathology of myxomas, and results of GNAS-mutation analysis, when available.
    RESULTS: Thirty-two patients (22 female) from 6 centers were included. The prevalence of Mazabraud syndrome was 2.2% in the combined cohort of 1,446 patients with FD, and the syndrome was diagnosed at a mean of 10.1 years after diagnosis of FD. The myxomas were predominantly localized in the upper leg. Excision was performed in 20 patients, recurrence occurred in 6 of these patients (30%) at a median of 8.5 years (range, 1.9 to 16.0 years), and revision surgery was necessary in 5 (25%). High cellularity of myxomas was associated with recurrence (p < 0.05). A GNAS mutation was identified in the myxoma tissue of 5 (83%) of 6 patients with GNAS-mutation analysis.
    CONCLUSIONS: This study is the first, to our knowledge, to provide data on the prevalence of Mazabraud syndrome in a relatively large cohort. Although the outcomes of surgical resection were good, a quarter of the patients required revision surgery despite clear resection margins. High cellularity of myxomas was associated with recurrence. GNAS mutations were identified in 83% (5 of 6), emphasizing the shared origin of FD and myxomas. Our data show that patients with FD who have disproportionate complaints, irrespective of FD type, extent, or severity, should be investigated for the possible presence of myxomas.
    METHODS: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.
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  • 文章类型: Journal Article
    Male infertility is a complex disease caused by a combination of genetic, environmental, and lifestyle factors. Abnormal epigenetic programming has been proposed as a possible mechanism compromising male fertility. Recent studies suggest that aberrant imprinting in spermatozoa in a subset of infertile men is a risk factor for congenital diseases in children conceived via assisted reproduction techniques. In this study, we examined the DNA methylation status of CpG sites within the differentially methylated regions (DMRs) of three imprinted genes, H19, GNAS, and DIRAS3, using combined bisulfite PCR restriction analysis and bisulfite sequencing in sperm obtained from 135 men with idiopathic male infertility, including normozoospermia (n = 39), moderate oligozoospermia (n = 45), and severe oligozoospermia (n = 51), and fertile controls (n = 59). The percentage of global methylation was compared between fertile controls and infertile patients displaying abnormal DNA methylation status of imprinted loci. Moreover, we also analyzed whether the DNA methyltransferases (DNMTs) polymorphisms impact upon the methylation patterns of imprinted genes in idiopathic infertile males.
    Aberrant methylation patterns of imprinted genes were more prevalent in idiopathic infertile males, especially in patients with oligozoospermia. Infertile males with aberrant methylation patterns of imprinted genes displayed a tendency of lower global methylation levels, although not reaching statistical significance (P = 0.13). In the genotype-epigenotype correlation analysis, no significant association was observed between aberrant methylation patterns of the three imprinted genes and genotypes of the four DNA methyltransferase (DNMT) genes.
    We conclude that abnormalities of DMR within imprinted genes may be associated with idiopathic male infertility. Disruption in methylation pattern of the three imprinted genes does not occur in high-risk genotypes of DNMTs.
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  • 文章类型: Journal Article
    Approximately half of all pancreatic cysts are neoplastic, mainly comprising intraductal papillary mucinous neoplasms (IPMN), which can progress to invasive carcinoma. Current Fukuoka guidelines have limited sensitivity and specificity in predicting progression of asymptomatic pancreatic cysts. We present first results of the prospective ZYSTEUS biomarker study investigating (i) whether detection of driver mutations in IPMN by liquid biopsy is technically feasible, (ii) which compartment of IPMN is most suitable for analysis, and (iii) implications for clinical diagnostics. Twenty-two patients with clinical inclusion criteria were enrolled in ZYSTEUS. Fifteen cases underwent endoscopic ultrasound (EUS)-guided fine-needle aspiration and cytological diagnostics. Cellular and liquid fraction of the cysts of each case were separated and subjected to deep targeted next generation sequencing (NGS). Clinical parameters, imaging findings (EUS and MRI), and follow-up data were collected continuously. All IPMN cases (n = 12) showed at least one mutation in either KRAS (n = 11) or GNAS (n = 4). Three cases showed both KRAS and GNAS mutations. Six cases harbored multiple KRAS/GNAS mutations. In the three cases with pseudocysts, no KRAS or GNAS mutations were detected. DNA yields were higher and showed higher mutation diversity in the cellular fraction. In conclusion, mutation detection in pancreatic cyst fluid is technically feasible with more robust results in the cellular than in the liquid fraction. Current results suggest that, together with imaging, targeted sequencing supports discrimination of IPMN from pseudocysts. The prospective design of ZYSTEUS will provide insight into diagnostic value of NGS in preoperative risk stratification. Our data provide evidence for an oligoclonal nature of IPMN.
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  • 文章类型: Journal Article
    OBJECTIVE: This study aimed to identify the pathological features of high-grade PanIN that presents with imaging-detectable abnormalities.
    RESULTS: Ten cases of isolated, main-duct, high-grade PanIN as the primary clinical presentation were identified. All patients presented with stenosis of the main pancreatic duct, with two being associated with extensive upstream duct dilatation (>5 mm in diameter). Pancreatic juice cytology suggested adenocarcinoma in all seven cases examined. In resected specimens, high-grade PanIN was present chiefly in the main pancreatic duct, with longitudinal extension ranging between 3 and 40 mm in length (median = 18 mm). In four cases, in which hypoechoic or hypovascular masses were observed on imaging, radiopathology correlations suggested that they represented parenchymal atrophy and subsequent fibrosis around affected ducts, but not invasive malignancy. On immunohistochemistry, the loss of p16 expression was found in five (50%), p53 overexpression in two (20%) and loss of SMAD4 expression in none (0%). KRAS mutations were detected in nine cases, with two dominant clones being found in three by ultrasensitive droplet digital polymerase chain reaction, suggesting the genetic heterogeneity of dysplastic cells composing individual lesions. Mutant GNAS was also observed in one case.
    CONCLUSIONS: Isolated high-grade PanIN may present with pancreatic duct stenosis. Therefore, intensive investigations including pancreatic juice cytology will be required for patients with unexplained pancreatic duct stenosis. The abnormal expression of p53 and SMAD4 is infrequent, while GNAS may be mutated in premalignant lesions mainly affecting the main pancreatic duct, similar to KRAS.
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  • 文章类型: Journal Article
    Adenylyl cyclases (ACs) are membrane bound enzymes that catalyze the production of cAMP from ATP in response to the activation by G-protein Gαs. Different isoforms of ACs are ubiquitously expressed in different tissues involved in regulatory mechanisms in response to specific stimulants. There are 9 AC isoforms present in humans, with AC5 and AC6 proposed to play a vital role in cardiac functions. The activity of AC6 is sensitive to nitric oxide, such that nitrosylation of the protein might regulate its function. However, the information on structural determinants of nitrosylation in ACs and how they interact with Gαs is limited. Here we used homology modeling to build a molecular model of human AC6 bound to Gαs. Based on this 3D model, we predict the nitrosylation amenable cysteines, and identify potential novel ligands of AC6 using virtual ligand screening. Our model suggests Cys1004 in AC6 (subunit C2) and Cys174 in Gαs present at the AC-Gαs interface as the possible residues that might undergo reversible nitrosylation. Docking analysis predicted novel ligands of AC6 that include forskolin-based compounds and its derivatives. Further work involving site-directed mutagenesis of the predicted residues will allow manipulation of AC activity using novel ligands, and crucial insights on the role of nitrosylation of these proteins in pathophysiological conditions.
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