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1.
EMBO Rep ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38918502

RESUMO

Cellular senescence is a hallmark of advanced age and a major instigator of numerous inflammatory pathologies. While endothelial cell (EC) senescence is aligned with defective vascular functionality, its impact on fundamental inflammatory responses in vivo at single-cell level remain unclear. To directly investigate the role of EC senescence on dynamics of neutrophil-venular wall interactions, we applied high resolution confocal intravital microscopy to inflamed tissues of an EC-specific progeroid mouse model, characterized by profound indicators of EC senescence. Progerin-expressing ECs supported prolonged neutrophil adhesion and crawling in a cell autonomous manner that additionally mediated neutrophil-dependent microvascular leakage. Transcriptomic and immunofluorescence analysis of inflamed tissues identified elevated levels of EC CXCL1 on progerin-expressing ECs and functional blockade of CXCL1 suppressed the dysregulated neutrophil responses elicited by senescent ECs. Similarly, cultured progerin-expressing human ECs exhibited a senescent phenotype, were pro-inflammatory and prompted increased neutrophil attachment and activation. Collectively, our findings support the concept that senescent ECs drive excessive inflammation and provide new insights into the mode, dynamics, and mechanisms of this response at single-cell level.

3.
Elife ; 122023 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-37589451

RESUMO

Co-regulated genes of the Imprinted Gene Network are involved in the control of growth and body size, and imprinted gene dysfunction underlies human paediatric disorders involving the endocrine system. Imprinted genes are highly expressed in the pituitary gland, among them, Dlk1, a paternally expressed gene whose membrane-bound and secreted protein products can regulate proliferation and differentiation of multiple stem cell populations. Dosage of circulating DLK1 has been previously implicated in the control of growth through unknown molecular mechanisms. Here we generate a series of mouse genetic models to modify levels of Dlk1 expression in the pituitary gland and demonstrate that the dosage of DLK1 modulates the process of stem cell commitment with lifelong impact on pituitary gland size. We establish that stem cells are a critical source of DLK1, where embryonic disruption alters proliferation in the anterior pituitary, leading to long-lasting consequences on growth hormone secretion later in life.


Assuntos
Proteínas de Ligação ao Cálcio , Comunicação Celular , Dosagem de Genes , Hipófise , Animais , Humanos , Camundongos , Transporte Biológico , Tamanho Corporal , Proteínas de Ligação ao Cálcio/genética , Diferenciação Celular
4.
Dis Model Mech ; 16(3)2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36916392

RESUMO

Understanding the molecular mechanisms that lead to birth defects is an important step towards improved primary prevention. Mouse embryos homozygous for the Kumba (Ku) mutant allele of Zic2 develop severe spina bifida with complete lack of dorsolateral hinge points (DLHPs) in the neuroepithelium. Bone morphogenetic protein (BMP) signalling is overactivated in Zic2Ku/Ku embryos, and the BMP inhibitor dorsomorphin partially rescues neural tube closure in cultured embryos. RhoA signalling is also overactivated, with accumulation of actomyosin in the Zic2Ku/Ku neuroepithelium, and the myosin inhibitor Blebbistatin partially normalises neural tube closure. However, dorsomorphin and Blebbistatin differ in their effects at tissue and cellular levels: DLHP formation is rescued by dorsomorphin but not Blebbistatin, whereas abnormal accumulation of actomyosin is rescued by Blebbistatin but not dorsomorphin. These findings suggest a dual mechanism of spina bifida origin in Zic2Ku/Ku embryos: faulty BMP-dependent formation of DLHPs and RhoA-dependent F-actin accumulation in the neuroepithelium. Hence, we identify a multi-pathway origin of spina bifida in a mammalian system that may provide a developmental basis for understanding the corresponding multifactorial human defects.


Assuntos
Defeitos do Tubo Neural , Disrafismo Espinal , Camundongos , Animais , Humanos , Tubo Neural/metabolismo , Actomiosina/metabolismo , Defeitos do Tubo Neural/genética , Neurulação , Mamíferos/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo
5.
Acta Neuropathol Commun ; 10(1): 138, 2022 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-36114575

RESUMO

Non-functioning pituitary tumours (NF-PitNETs) are common intracranial benign neoplasms that can exhibit aggressive behaviour by invading neighbouring structures and, in some cases, have multiple recurrences. Despite resulting in severe co-morbidities, no predictive biomarkers of recurrence have been identified for NF-PitNETs. In this study we have used high-throughput mass spectrometry-based analysis to examine the phosphorylation pattern of different subsets of NF-PitNETs. Based on histopathological, radiological, surgical and clinical features, we have grouped NF-PitNETs into non-invasive, invasive, and recurrent disease groups. Tumour recurrence was determined based on regular clinical and radiological data of patients for a mean follow-up of 10 years (SD ± 5.4 years). Phosphoproteomic analyses identified a unique phosphopeptide enrichment pattern which correlates with disease recurrence. Candidate phosphorylated proteins were validated in a large cohort of NF-PitNET patients by western blot and immunohistochemistry. We identified a cluster of 22 phosphopeptides upregulated in recurrent NF-PitNETs compared to non-invasive and invasive subgroups. We reveal significant phosphorylation of the ß-catenin at Ser552 in recurrent and invasive NF-PitNETs, compared to non-invasive/non-recurrent NF-PitNET subgroup. Moreover, ß-catenin pSer552 correlates with the recurrence free survival among 200 patients with NF-PitNET. Together, our results suggest that the phosphorylation status of ß-catenin at Ser552 could act as potential biomarker of tumour recurrence in NF-PitNETs.


Assuntos
Tumores Neuroendócrinos , Neoplasias Hipofisárias , Humanos , Recidiva Local de Neoplasia , Tumores Neuroendócrinos/metabolismo , Fosfopeptídeos/metabolismo , Fosforilação , Neoplasias Hipofisárias/metabolismo , beta Catenina/metabolismo
6.
Elife ; 112022 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-35049495

RESUMO

Genomic imprinting refers to the mono-allelic and parent-specific expression of a subset of genes. While long recognized for their role in embryonic development, imprinted genes have recently emerged as important modulators of postnatal physiology, notably through hypothalamus-driven functions. Here, using mouse models of loss, gain and parental inversion of expression, we report that the paternally expressed Zdbf2 gene controls neonatal growth in mice, in a dose-sensitive but parent-of-origin-independent manner. We further found that Zdbf2-KO neonates failed to fully activate hypothalamic circuits that stimulate appetite, and suffered milk deprivation and diminished circulating Insulin Growth Factor 1 (IGF-1). Consequently, only half of Zdbf2-KO pups survived the first days after birth and those surviving were smaller. This study demonstrates that precise imprinted gene dosage is essential for vital physiological functions at the transition from intra- to extra-uterine life, here the adaptation to oral feeding and optimized body weight gain.


Assuntos
Proteínas de Ligação a DNA/genética , Ingestão de Alimentos/genética , Impressão Genômica/genética , Hipotálamo , Aumento de Peso/genética , Animais , Animais Recém-Nascidos/genética , Animais Recém-Nascidos/fisiologia , Feminino , Hipotálamo/metabolismo , Hipotálamo/fisiologia , Masculino , Camundongos , Camundongos Knockout , Gravidez
7.
Oncogene ; 40(45): 6354-6368, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34588620

RESUMO

It is unclear how loss-of-function germline mutations in the widely-expressed co-chaperone AIP, result in young-onset growth hormone secreting pituitary tumours. The RET receptor, uniquely co-expressed in somatotrophs with PIT1, induces apoptosis when unliganded, while RET supports cell survival when it is bound to its ligand. We demonstrate that at the plasma membrane, AIP is required to form a complex with monomeric-intracellular-RET, caspase-3 and PKCδ resulting in PIT1/CDKN2A-ARF/p53-apoptosis pathway activation. AIP-deficiency blocks RET/caspase-3/PKCδ activation preventing PIT1 accumulation and apoptosis. The presence or lack of the inhibitory effect on RET-induced apoptosis separated pathogenic AIP variants from non-pathogenic ones. We used virogenomics in neonatal rats to demonstrate the effect of mutant AIP protein on the RET apoptotic pathway in vivo. In adult male rats altered AIP induces elevated IGF-1 and gigantism, with pituitary hyperplasia through blocking the RET-apoptotic pathway. In females, pituitary hyperplasia is induced but IGF-1 rise and gigantism are blunted by puberty. Somatotroph adenomas from pituitary-specific Aip-knockout mice overexpress the RET-ligand GDNF, therefore, upregulating the survival pathway. Somatotroph adenomas from patients with or without AIP mutation abundantly express GDNF, but AIP-mutated tissues have less CDKN2A-ARF expression. Our findings explain the tissue-specific mechanism of AIP-induced somatotrophinomas and provide a previously unknown tumorigenic mechanism, opening treatment avenues for AIP-related tumours.


Assuntos
Acromegalia/genética , Mutação em Linhagem Germinativa , Gigantismo/genética , Adenoma Hipofisário Secretor de Hormônio do Crescimento/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Acromegalia/metabolismo , Animais , Animais Recém-Nascidos , Apoptose , Linhagem Celular , Feminino , Técnicas de Inativação de Genes , Gigantismo/metabolismo , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Adenoma Hipofisário Secretor de Hormônio do Crescimento/metabolismo , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Camundongos , Especificidade de Órgãos , Proteínas Proto-Oncogênicas c-ret/metabolismo , Ratos , Transdução de Sinais
8.
J Extracell Vesicles ; 10(7): e12088, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34025953

RESUMO

Cartilage defects repair poorly. Recent genetic studies suggest that WNT3a may contribute to cartilage regeneration, however the dense, avascular cartilage extracellular matrix limits its penetration and signalling to chondrocytes. Extracellular vesicles actively penetrate intact cartilage. This study investigates the effect of delivering WNT3a into large cartilage defects in vivo using exosomes as a delivery vehicle. Exosomes were purified by ultracentrifugation from conditioned medium of either L-cells overexpressing WNT3a or control un-transduced L-cells, and characterized by electron microscopy, nanoparticle tracking analysis and marker profiling. WNT3a loaded on exosomes was quantified by western blotting and functionally characterized in vitro using the SUPER8TOPFlash reporter assay and other established readouts including proliferation and proteoglycan content. In vivo pathway activation was assessed using TCF/Lef:H2B-GFP reporter mice. Wnt3a loaded exosomes were injected into the knees of mice, in which large osteochondral defects were surgically generated. The degree of repair was histologically scored after 8 weeks. WNT3a was successfully loaded on exosomes and resulted in activation of WNT signalling in vitro. In vivo, recombinant WNT3a failed to activate WNT signalling in cartilage, whereas a single administration of WNT3a loaded exosomes activated canonical WNT signalling for at least one week, and eight weeks later, improved the repair of osteochondral defects. WNT3a assembled on exosomes, is efficiently delivered into cartilage and contributes to the healing of osteochondral defects.


Assuntos
Cartilagem/metabolismo , Exossomos/metabolismo , Proteína Wnt3A/metabolismo , Animais , Cartilagem/lesões , Cartilagem Articular/metabolismo , Diferenciação Celular , Linhagem Celular , Condrócitos/citologia , Meios de Cultivo Condicionados/farmacologia , Sistemas de Liberação de Medicamentos/métodos , Exossomos/fisiologia , Matriz Extracelular/metabolismo , Vesículas Extracelulares/metabolismo , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Via de Sinalização Wnt , Proteína Wnt3A/genética
9.
J Clin Endocrinol Metab ; 106(10): e4142-e4154, 2021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-33999151

RESUMO

CONTEXT: Developmental disorders of the pituitary gland leading to congenital hypopituitarism can either be isolated or associated with extrapituitary abnormalities (syndromic hypopituitarism). A large number of syndromic hypopituitarism cases are linked to mutations in transcription factors. The forkhead box A2 (FOXA2) is a transcription factor that plays a key role in the central nervous system, foregut, and pancreatic development. OBJECTIVE: This work aims to characterize 2 patients with syndromic hypopituitarism due to FOXA2 gene defects. RESULTS: We report a novel heterozygous nonsense c.616C > T(p.Q206X) variant that leads to a truncated protein that lacks part of the DNA-binding domain of FOXA2, resulting in impaired transcriptional activation of the glucose transporter type 2 (GLUT2)-luciferase reporter. The patient is the sixth patient described in the literature with a FOXA2 mutation, and the first patient exhibiting pancreatic hypoplasia. We also report a second patient with a novel de novo 8.53 Mb deletion of 20p11.2 that encompasses FOXA2, who developed diabetes mellitus that responded to sulfonylurea treatment. CONCLUSION: Our 2 cases broaden the molecular and clinical spectrum of FOXA2-related disease, reporting the first nonsense mutation and the first case of pancreatic dysgenesis.


Assuntos
Diabetes Mellitus/congênito , Fator 3-beta Nuclear de Hepatócito/genética , Hipopituitarismo/congênito , Pâncreas/anormalidades , Hipófise/anormalidades , Códon sem Sentido , Transportador de Glucose Tipo 2/genética , Humanos , Lactente , Masculino , Síndrome , Fatores de Transcrição/genética , Ativação Transcricional
10.
Nat Commun ; 12(1): 2028, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33795686

RESUMO

Germline mutations in BRAF and other components of the MAPK pathway are associated with the congenital syndromes collectively known as RASopathies. Here, we report the association of Septo-Optic Dysplasia (SOD) including hypopituitarism and Cardio-Facio-Cutaneous (CFC) syndrome in patients harbouring mutations in BRAF. Phosphoproteomic analyses demonstrate that these genetic variants are gain-of-function mutations leading to activation of the MAPK pathway. Activation of the MAPK pathway by conditional expression of the BrafV600E/+ allele, or the knock-in BrafQ241R/+ allele (corresponding to the most frequent human CFC-causing mutation, BRAF p.Q257R), leads to abnormal cell lineage determination and terminal differentiation of hormone-producing cells, causing hypopituitarism. Expression of the BrafV600E/+ allele in embryonic pituitary progenitors leads to an increased expression of cell cycle inhibitors, cell growth arrest and apoptosis, but not tumour formation. Our findings show a critical role of BRAF in hypothalamo-pituitary-axis development both in mouse and human and implicate mutations found in RASopathies as a cause of endocrine deficiencies in humans.


Assuntos
Mutação com Ganho de Função , Hipopituitarismo/genética , Hipotálamo/metabolismo , Hipófise/metabolismo , Proteínas Proto-Oncogênicas B-raf/genética , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Células Cultivadas , Criança , Pré-Escolar , Corticotrofos/citologia , Corticotrofos/metabolismo , Displasia Ectodérmica/genética , Fácies , Insuficiência de Crescimento/genética , Células HEK293 , Cardiopatias Congênitas/genética , Humanos , Lactente , Sistema de Sinalização das MAP Quinases/genética , Melanotrofos/citologia , Melanotrofos/metabolismo , Camundongos Knockout , Camundongos Transgênicos , Proteínas Proto-Oncogênicas B-raf/metabolismo , Sequenciamento do Exoma/métodos
11.
Neuroendocrinology ; 111(5): 421-441, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32365351

RESUMO

INTRODUCTION: Gonadotropin-releasing hormone (GnRH) deficiency causes hypogonadotropic hypogonadism (HH), a rare genetic disorder that impairs sexual reproduction. HH can be due to defective GnRH-secreting neuron development or function and may be associated with other clinical signs in overlapping genetic syndromes. With most of the cases being idiopathic, genetics underlying HH is still largely unknown. OBJECTIVE: To assess the contribution of mutated Semaphorin 3G (SEMA3G) in the onset of a syndromic form of HH, characterized by intellectual disability and facial dysmorphic features. METHOD: By combining homozygosity mapping with exome sequencing, we identified a novel variant in the SEMA3G gene. We then applied mouse as a model organism to examine SEMA3Gexpression and its functional requirement in vivo. Further, we applied homology modelling in silico and cell culture assays in vitro to validate the pathogenicity of the identified gene variant. RESULTS: We found that (i) SEMA3G is expressed along the migratory route of GnRH neurons and in the developing pituitary, (ii) SEMA3G affects GnRH neuron development, but is redundant in the adult hypothalamic-pituitary-gonadal axis, and (iii) mutated SEMA3G alters binding properties in silico and in vitro to its PlexinA receptors and attenuates its effect on the migration of immortalized GnRH neurons. CONCLUSION: In silico, in vitro, and in vivo models revealed that SEMA3G regulates GnRH neuron migration and that its mutation affecting receptor selectivity may be responsible for the HH-related defects.


Assuntos
Hormônio Liberador de Gonadotropina/deficiência , Hipogonadismo/genética , Sistema Hipotálamo-Hipofisário/crescimento & desenvolvimento , Sistema Hipotálamo-Hipofisário/metabolismo , Semaforinas/fisiologia , Animais , Células Cultivadas , Consanguinidade , Anormalidades Craniofaciais/etiologia , Deficiências do Desenvolvimento/etiologia , Homozigoto , Humanos , Hipogonadismo/complicações , Deficiência Intelectual/etiologia , Masculino , Camundongos , Linhagem , Irmãos , Síndrome
12.
FASEB J ; 34(8): 10027-10040, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32592197

RESUMO

Aspirin prevents thrombosis by inhibiting platelet cyclooxygenase (COX)-1 activity and the production of thromboxane (Tx)A2 , a pro-thrombotic eicosanoid. However, the non-platelet actions of aspirin limit its antithrombotic effects. Here, we used platelet-COX-1-ko mice to define the platelet and non-platelet eicosanoids affected by aspirin. Mass-spectrometry analysis demonstrated blood from platelet-COX-1-ko and global-COX-1-ko mice produced similar eicosanoid profiles in vitro: for example, formation of TxA2 , prostaglandin (PG) F2α , 11-hydroxyeicosatraenoic acid (HETE), and 15-HETE was absent in both platelet- and global-COX-1-ko mice. Conversely, in vivo, platelet-COX-1-ko mice had a distinctly different profile from global-COX-1-ko or aspirin-treated control mice, notably significantly higher levels of PGI2 metabolite. Ingenuity Pathway Analysis (IPA) predicted that platelet-COX-1-ko mice would be protected from thrombosis, forming less pro-thrombotic TxA2 and PGE2 . Conversely, aspirin or lack of systemic COX-1 activity decreased the synthesis of anti-aggregatory PGI2 and PGD2 at non-platelet sites leading to predicted thrombosis increase. In vitro and in vivo thrombosis studies proved these predictions. Overall, we have established the eicosanoid profiles linked to inhibition of COX-1 in platelets and in the remainder of the cardiovascular system and linked them to anti- and pro-thrombotic effects of aspirin. These results explain why increasing aspirin dosage or aspirin addition to other drugs may lessen antithrombotic protection.


Assuntos
Aspirina/farmacologia , Plaquetas/metabolismo , Ciclo-Oxigenase 1/fisiologia , Inibidores de Ciclo-Oxigenase/farmacologia , Eicosanoides/metabolismo , Proteínas de Membrana/fisiologia , Trombose/metabolismo , Animais , Ácido Araquidônico/administração & dosagem , Plaquetas/efeitos dos fármacos , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Trombose/tratamento farmacológico , Trombose/patologia
13.
Artigo em Inglês | MEDLINE | ID: mdl-31781041

RESUMO

The endocrine system coordinates a wide array of body functions mainly through secretion of hormones and their actions on target tissues. Over the last decades, a collective effort between developmental biologists, geneticists, and stem cell biologists has generated a wealth of knowledge related to the contribution of stem/progenitor cells to both organogenesis and self-renewal of endocrine organs. This review provides an up-to-date and comprehensive overview of the role of tissue stem cells in the development and self-renewal of endocrine organs. Pathways governing crucial steps in both development and stemness maintenance, and that are known to be frequently altered in a wide array of endocrine disorders, including cancer, are also described. Crucially, this plethora of information is being channeled into the development of potential new cell-based treatment modalities for endocrine-related illnesses, some of which have made it through clinical trials.

14.
Circ Res ; 125(9): 847-854, 2019 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-31510878

RESUMO

RATIONALE: Endothelial cells (ECs) and platelets, which respectively produce antithrombotic prostacyclin and prothrombotic thromboxane A2, both express COX1 (cyclooxygenase1). Consequently, there has been no way to delineate any antithrombotic role for COX1-derived prostacyclin from the prothrombotic effects of platelet COX1. By contrast, an antithrombotic role for COX2, which is absent in platelets, is straightforward to demonstrate. This has resulted in an incomplete understanding of the relative importance of COX1 versus COX2 in prostacyclin production and antithrombotic protection in vivo. OBJECTIVE: We sought to identify the role, if any, of COX1-derived prostacyclin in antithrombotic protection in vivo and compare this to the established protective role of COX2. METHODS AND RESULTS: We developed vascular-specific COX1 knockout mice and studied them alongside endothelial-specific COX2 knockout mice. COX1 immunoreactivity and prostacyclin production were primarily associated with the endothelial layer of aortae; freshly isolated aortic ECs released >10-fold more prostacyclin than smooth muscle cells. Moreover, aortic prostacyclin production, the ability of aortic rings to inhibit platelet aggregation and plasma prostacyclin levels were reduced when COX1 was knocked out in ECs but not in smooth muscle cells. When thrombosis was measured in vivo after FeCl3 carotid artery injury, endothelial COX1 deletion accelerated thrombosis to a similar extent as prostacyclin receptor blockade. However, this effect was lost when COX1 was deleted from both ECs and platelets. Deletion of COX2 from ECs also resulted in a prothrombotic phenotype that was independent of local vascular prostacyclin production. CONCLUSIONS: These data demonstrate for the first time that, in healthy animals, endothelial COX1 provides an essential antithrombotic tone, which is masked when COX1 activity is lost in both ECs and platelets. These results help us define a new 2-component paradigm wherein thrombotic tone is regulated by both COX1 and COX2 through complementary but mechanistically distinct pathways.


Assuntos
Ciclo-Oxigenase 1/deficiência , Endotélio Vascular/metabolismo , Epoprostenol/metabolismo , Fibrinolíticos/metabolismo , Deleção de Genes , Proteínas de Membrana/deficiência , Agregação Plaquetária/fisiologia , Animais , Aorta/metabolismo , Ciclo-Oxigenase 1/genética , Epoprostenol/genética , Feminino , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Camundongos Transgênicos
15.
Diabetes ; 68(7): 1473-1484, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31048369

RESUMO

ß-Cell failure is central to the development of type 2 diabetes mellitus (T2DM). Dysregulation of metabolic and inflammatory processes during obesity contributes to the loss of islet function and impaired ß-cell insulin secretion. Modulating the immune system, therefore, has the potential to ameliorate diseases. We report that inducing sustained expression of ß-catenin in conventional dendritic cells (cDCs) provides a novel mechanism to enhance ß-cell insulin secretion. Intriguingly, cDCs with constitutively activated ß-catenin induced islet expansion by increasing ß-cell proliferation in a model of diet-induced obesity. We further found that inflammation in these islets was reduced. Combined, these effects improved ß-cell insulin secretion, suggesting a unique compensatory mechanism driven by cDCs to generate a greater insulin reserve in response to obesity-induced insulin resistance. Our findings highlight the potential of immune modulation to improve ß-cell mass and function in T2DM.


Assuntos
Células Dendríticas/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Insulina/metabolismo , beta Catenina/metabolismo , Animais , Western Blotting , Citometria de Fluxo , Hibridização In Situ , Hibridização in Situ Fluorescente , Células Secretoras de Insulina/metabolismo , Gordura Intra-Abdominal/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase em Tempo Real
16.
J Med Genet ; 56(9): 629-638, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31129566

RESUMO

BACKGROUND: Pathogenic PLOD3 variants cause a connective tissue disorder (CTD) that has been described rarely. We further characterise this CTD and propose a clinical diagnostic label to improve recognition and diagnosis of PLOD3-related disease. METHODS: Reported PLOD3 phenotypes were compared with known CTDs utilising data from three further individuals from a consanguineous family with a homozygous PLOD3 c.809C>T; p.(Pro270Leu) variant. PLOD3 mRNA expression in the developing embryo was analysed for tissue-specific localisation. Mouse microarray expression data were assessed for phylogenetic gene expression similarities across CTDs with overlapping clinical features. RESULTS: Key clinical features included ocular abnormalities with risk for retinal detachment, sensorineural hearing loss, reduced palmar creases, finger contractures, prominent knees, scoliosis, low bone mineral density, recognisable craniofacial dysmorphisms, developmental delay and risk for vascular dissection. Collated clinical features showed most overlap with Stickler syndrome with variable features of Ehlers-Danlos syndrome (EDS) and epidermolysis bullosa (EB). Human lysyl hydroxylase 3/PLOD3 expression was localised to the developing cochlea, eyes, skin, forelimbs, heart and cartilage, mirroring the clinical phenotype of this disorder. CONCLUSION: These data are consistent with pathogenic variants in PLOD3 resulting in a clinically distinct Stickler-like syndrome with vascular complications and variable features of EDS and EB. Early identification of PLOD3 variants would improve monitoring for comorbidities and may avoid serious adverse ocular and vascular outcomes.


Assuntos
Artrite/diagnóstico , Artrite/genética , Doenças do Tecido Conjuntivo/diagnóstico , Doenças do Tecido Conjuntivo/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Variação Genética , Perda Auditiva Neurossensorial/diagnóstico , Perda Auditiva Neurossensorial/genética , Pró-Colágeno-Lisina 2-Oxoglutarato 5-Dioxigenase/genética , Descolamento Retiniano/diagnóstico , Descolamento Retiniano/genética , Doenças Vasculares/diagnóstico , Adolescente , Adulto , Animais , Artrite/complicações , Hibridização Genômica Comparativa , Doenças do Tecido Conjuntivo/complicações , Modelos Animais de Doenças , Fácies , Feminino , Expressão Gênica , Estudos de Associação Genética/métodos , Perda Auditiva Neurossensorial/complicações , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Modelos Moleculares , Mutação , Linhagem , Fenótipo , Filogenia , Pró-Colágeno-Lisina 2-Oxoglutarato 5-Dioxigenase/química , Conformação Proteica , Descolamento Retiniano/complicações , Relação Estrutura-Atividade , Doenças Vasculares/etiologia , Sequenciamento do Exoma , Adulto Jovem
17.
EBioMedicine ; 42: 470-480, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30878599

RESUMO

BACKGROUND: The heterotrimeric GTP-binding protein eIF2 forms a ternary complex with initiator methionyl-tRNA and recruits it to the 40S ribosomal subunit for start codon selection and thereby initiates protein synthesis. Mutations in EIF2S3, encoding the eIF2γ subunit, are associated with severe intellectual disability and microcephaly, usually as part of MEHMO syndrome. METHODS: Exome sequencing of the X chromosome was performed on three related males with normal head circumferences and mild learning difficulties, hypopituitarism (GH and TSH deficiencies), and an unusual form of glucose dysregulation. In situ hybridisation on human embryonic tissue, EIF2S3-knockdown studies in a human pancreatic cell line, and yeast assays on the mutated corresponding eIF2γ protein, were performed in this study. FINDINGS: We report a novel hemizygous EIF2S3 variant, p.Pro432Ser, in the three boys (heterozygous in their mothers). EIF2S3 expression was detectable in the developing pituitary gland and pancreatic islets of Langerhans. Cells lacking EIF2S3 had increased caspase activity/cell death. Impaired protein synthesis and relaxed start codon selection stringency was observed in mutated yeast. INTERPRETATION: Our data suggest that the p.Pro432Ser mutation impairs eIF2γ function leading to a relatively mild novel phenotype compared with previous EIF2S3 mutations. Our studies support a critical role for EIF2S3 in human hypothalamo-pituitary development and function, and glucose regulation, expanding the range of phenotypes associated with EIF2S3 mutations beyond classical MEHMO syndrome. Untreated hypoglycaemia in previous cases may have contributed to their more severe neurological impairment and seizures in association with impaired EIF2S3. FUND: GOSH, MRF, BRC, MRC/Wellcome Trust and NIGMS funded this study.


Assuntos
Fator de Iniciação 2 em Eucariotos/genética , Genes Ligados ao Cromossomo X , Glucose/metabolismo , Hipopituitarismo/etiologia , Hipopituitarismo/metabolismo , Fenótipo , Substituição de Aminoácidos , Apoptose , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Linhagem Celular , Pré-Escolar , Fator de Iniciação 2 em Eucariotos/química , Fator de Iniciação 2 em Eucariotos/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Hipopituitarismo/diagnóstico , Hibridização In Situ , Lactente , Imageamento por Ressonância Magnética , Mutação , Linhagem , Polimorfismo de Nucleotídeo Único , Biossíntese de Proteínas
18.
Oncogene ; 38(27): 5381-5395, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30867568

RESUMO

The molecular mechanisms leading to aryl hydrocarbon receptor interacting protein (AIP) mutation-induced aggressive, young-onset growth hormone-secreting pituitary tumors are not fully understood. In this study, we have identified that AIP-mutation-positive tumors are infiltrated by a large number of macrophages compared to sporadic tumors. Tissue from pituitary-specific Aip-knockout (AipFlox/Flox;Hesx1Cre/+) mice recapitulated this phenotype. Our human pituitary tumor transcriptome data revealed the "epithelial-to-mesenchymal transition (EMT) pathway" as one of the most significantly altered pathways in AIPpos tumors. Our in vitro data suggest that bone marrow-derived macrophage-conditioned media induces more prominent EMT-like phenotype and enhanced migratory and invasive properties in Aip-knockdown somatomammotroph cells compared to non-targeting controls. We identified that tumor-derived cytokine CCL5 is upregulated in AIP-mutation-positive human adenomas. Aip-knockdown GH3 cell-conditioned media increases macrophage migration, which is inhibited by the CCL5/CCR5 antagonist maraviroc. Our results suggest that a crosstalk between the tumor and its microenvironment plays a key role in the invasive nature of AIP-mutation-positive tumors and the CCL5/CCR5 pathway is a novel potential therapeutic target.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/genética , Mutação , Invasividade Neoplásica , Neoplasias Hipofisárias/genética , Microambiente Tumoral , Animais , Biomarcadores Tumorais/metabolismo , Quimiocina CCL5/metabolismo , Transição Epitelial-Mesenquimal , Humanos , Camundongos , Camundongos Knockout , Receptores CCR5/metabolismo
19.
Cell Metab ; 27(3): 588-601.e4, 2018 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-29514067

RESUMO

Visceral adipose tissue (VAT) has multiple roles in orchestrating whole-body energy homeostasis. In addition, VAT is now considered an immune site harboring an array of innate and adaptive immune cells with a direct role in immune surveillance and host defense. We report that conventional dendritic cells (cDCs) in VAT acquire a tolerogenic phenotype through upregulation of pathways involved in adipocyte differentiation. While activation of the Wnt/ß-catenin pathway in cDC1 DCs induces IL-10 production, upregulation of the PPARγ pathway in cDC2 DCs directly suppresses their activation. Combined, they promote an anti-inflammatory milieu in vivo delaying the onset of obesity-induced chronic inflammation and insulin resistance. Under long-term over-nutrition, changes in adipocyte biology curtail ß-catenin and PPARγ activation, contributing to VAT inflammation.


Assuntos
Adipócitos/metabolismo , Células Dendríticas/metabolismo , Homeostase/imunologia , Gordura Intra-Abdominal/imunologia , Obesidade/metabolismo , Animais , Diferenciação Celular , Inflamação/imunologia , Resistência à Insulina/imunologia , Interleucina-10/imunologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , PPAR gama/imunologia , Via de Sinalização Wnt
20.
Int J Mol Sci ; 19(2)2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29389897

RESUMO

Cohesin complex components exert fundamental roles in animal cells, both canonical in cell cycle and non-canonical in gene expression regulation. Germline mutations in genes coding for cohesins result in developmental disorders named cohesinopaties, of which Cornelia de Lange syndrome (CdLS) is the best-known entity. However, a basic description of mammalian expression pattern of cohesins in a physiologic condition is still needed. Hence, we report a detailed analysis of expression in murine and human tissues of cohesin genes defective in CdLS. Using both quantitative and qualitative methods in fetal and adult tissues, cohesin genes were found to be ubiquitously and differentially expressed in human tissues. In particular, abundant expression was observed in hematopoietic and central nervous system organs. Findings of the present study indicate tissues which should be particularly sensitive to mutations, germline and/or somatic, in cohesin genes. Hence, this expression analysis in physiological conditions may represent a first core reference for cohesinopathies.


Assuntos
Proteínas de Ciclo Celular/genética , Sistema Nervoso Central/metabolismo , Proteínas Cromossômicas não Histona/genética , Síndrome de Cornélia de Lange/genética , Regulação da Expressão Gênica no Desenvolvimento , Hematopoese/genética , Animais , Sistema Nervoso Central/embriologia , Sistema Nervoso Central/crescimento & desenvolvimento , Proteoglicanas de Sulfatos de Condroitina/genética , Proteínas de Ligação a DNA , Perfilação da Expressão Gênica , Predisposição Genética para Doença/genética , Histona Desacetilases/genética , Humanos , Camundongos , Mutação , Proteínas Nucleares/genética , Fosfoproteínas/genética , Proteínas/genética , Proteínas Repressoras/genética , Coesinas
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