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1.
Int J Neonatal Screen ; 8(4)2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36547380

RESUMO

Parents increasingly utilise the internet to obtain information on health practices, but the quality of online information about screening for inherited metabolic diseases (IMD) needs to be improved. A content analysis examined how IMD blood and urine tests were described online in local healthcare sectors between May and June 2021. Among the nine resources, four were blood test providers and five were urine test providers. All mentioned the test benefits and procedures. Other information, such as false-positive/negative or risk of pain, was infrequently mentioned. The descriptions of urine tests are advertised as outperforming blood tests and can be purchased from commercial laboratory sites without medical guidance. Two urine test providers claimed no false results were reported. A few commercial advertisements highlighted the simplicity of the urine test and potentially overstated the invasiveness of the blood test. We found that some advertisements described IMD as "silent killers" and emphasised the advantage of getting "reassurance" in controlling the child's developmental health and well-being. To better protect the parents, or broadly, the public interest, regulatory and oversight measures on the urine tests should be implemented to promote the proper use of genetic tests. Without timely regulation and oversight, the incorrect descriptions might create a public misconception about utilising these commercial laboratory tests to inform health decisions.

2.
Proc Natl Acad Sci U S A ; 115(20): 5265-5270, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29712852

RESUMO

Regulatory T cells (Tregs) control organ-specific autoimmunity in a tissue antigen-specific manner, yet little is known about their specificity in a natural repertoire. In this study, we used the nonobese diabetic (NOD) mouse model of autoimmune diabetes to investigate the antigen specificity of Tregs present in the inflamed tissue, the islets of Langerhans. Compared with Tregs present in spleen and lymph node, Tregs in the islets showed evidence of antigen stimulation that correlated with higher proliferation and expression of activation markers CD103, ICOS, and TIGIT. T cell receptor (TCR) repertoire profiling demonstrated that islet Treg clonotypes are expanded in the islets, suggesting localized antigen-driven expansion in inflamed islets. To determine their specificity, we captured TCRαß pairs from islet Tregs using single-cell TCR sequencing and found direct evidence that some of these TCRs were specific for islet-derived antigens including insulin B:9-23 and proinsulin. Consistently, insulin B:9-23 tetramers readily detected insulin-specific Tregs in the islets of NOD mice. Lastly, islet Tregs from prediabetic NOD mice were effective at preventing diabetes in Treg-deficient NOD.CD28-/- recipients. These results provide a glimpse into the specificities of Tregs in a natural repertoire that are crucial for opposing the progression of autoimmune diabetes.


Assuntos
Doenças Autoimunes/imunologia , Diabetes Mellitus Tipo 1/imunologia , Modelos Animais de Doenças , Tolerância Imunológica/imunologia , Insulina/imunologia , Transplante das Ilhotas Pancreáticas/imunologia , Linfócitos T Reguladores/imunologia , Animais , Autoantígenos/imunologia , Doenças Autoimunes/terapia , Diabetes Mellitus Tipo 1/terapia , Camundongos Endogâmicos NOD , Camundongos SCID
3.
Oncotarget ; 8(2): 2949-2959, 2017 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-27936464

RESUMO

Testicular germ cell tumors (TGCTs) are the most common cancers of young males. A substantial portion of TGCT patients are refractory to cisplatin. There are no effective therapies for these patients, many of whom die from progressive disease. Embryonal carcinoma (EC) are the stem cells of TGCTs. In prior in vitro studies we found that EC cells were highly sensitive to the DNA methyltransferase inhibitor, 5-aza deoxycytidine (5-aza). Here, as an initial step in bringing demethylation therapy to the clinic for TGCT patients, we evaluated the effects of the clinically optimized, second generation demethylating agent guadecitabine (SGI-110) on EC cells in an animal model of cisplatin refractory testicular cancer. EC cells were exquisitely sensitive to guadecitabine and the hypersensitivity was dependent on high levels of DNA methyltransferase 3B. Guadecitabine mediated transcriptional reprogramming of EC cells included induction of p53 targets and repression of pluripotency genes. As a single agent, guadecitabine completely abolished progression and induced complete regression of cisplatin resistant EC xenografts even at doses well below those required to impact somatic solid tumors. Low dose guadecitabine also sensitized refractory EC cells to cisplatin in vivo. Genome-wide analysis indicated that in vivo antitumor activity was associated with activation of p53 and immune-related pathways and the antitumor effects of guadecitabine were dependent on p53, a gene rarely mutated in TGCTs. These preclinical findings suggest that guadecitabine alone or in combination with cisplatin is a promising strategy to treat refractory TGCT patients.


Assuntos
Antineoplásicos/farmacologia , Azacitidina/análogos & derivados , Metilação de DNA/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Embrionárias de Células Germinativas/genética , Neoplasias Testiculares/genética , Animais , Azacitidina/farmacologia , Linhagem Celular Tumoral , Cisplatino/farmacologia , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/metabolismo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos , Neoplasias Embrionárias de Células Germinativas/tratamento farmacológico , Neoplasias Embrionárias de Células Germinativas/metabolismo , Neoplasias Embrionárias de Células Germinativas/patologia , Neoplasias Testiculares/tratamento farmacológico , Neoplasias Testiculares/metabolismo , Neoplasias Testiculares/patologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , DNA Metiltransferase 3B
4.
Cancer Res ; 76(5): 1204-13, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26837760

RESUMO

Methylation-mediated silencing of G0-G1 switch gene 2 (G0S2) has been detected in a variety of solid tumors, whereas G0S2 induction is associated with remissions in patients with acute promyelocytic leukemia, implying that G0S2 may possess tumor suppressor activity. In this study, we clearly demonstrate that G0S2 opposes oncogene-induced transformation using G0s2-null immortalized mouse embryonic fibroblasts (MEF). G0s2-null MEFs were readily transformed with HRAS or EGFR treatment compared with wild-type MEFs. Importantly, restoration of G0S2 reversed HRAS-driven transformation. G0S2 is known to regulate fat metabolism by attenuating adipose triglyceride lipase (ATGL), but repression of oncogene-induced transformation by G0S2 was independent of ATGL inhibition. Gene expression analysis revealed an upregulation of gene signatures associated with transformation, proliferation, and MYC targets in G0s2-null MEFs. RNAi-mediated ablation and pharmacologic inhibition of MYC abrogated oncogene-induced transformation of G0s2-null MEFs. Furthermore, we found that G0S2 was highly expressed in normal breast tissues compared with malignant tissue. Intriguingly, high levels of G0S2 were also associated with a decrease in breast cancer recurrence rates, especially in estrogen receptor-positive subtypes, and overexpression of G0S2 repressed the proliferation of breast cancer cells in vitro. Taken together, these findings indicate that G0S2 functions as a tumor suppressor in part by opposing MYC activity, prompting further investigation of the mechanisms by which G0S2 silencing mediates MYC-induced oncogenesis in other malignancies.


Assuntos
Proteínas de Ciclo Celular/fisiologia , Transformação Celular Neoplásica , Genes myc/fisiologia , Transcrição Gênica , Proteínas Supressoras de Tumor/fisiologia , Animais , Proliferação de Células , Células Cultivadas , Lipase/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Estrogênio/análise
5.
J Mol Endocrinol ; 52(3): T1-14, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24868104

RESUMO

In mammals, secretin is a 27-amino acid peptide that was first studied in 1902 by Bayliss and Starling from the extracts of the jejunal mucosa for its ability to stimulate pancreatic secretion. To date, secretin has only been identified in tetrapods, with the earliest diverged secretin found in frogs. Despite being the first hormone discovered, secretin's evolutionary origin remains enigmatic, it shows moderate sequence identity in nonmammalian tetrapods but is highly conserved in mammals. Current hypotheses suggest that although secretin has already emerged before the divergence of osteichthyans, it was lost in fish and retained only in land vertebrates. Nevertheless, the cognate receptor of secretin has been identified in both actinopterygian fish (zebrafish) and sarcopterygian fish (lungfish). However, the zebrafish secretin receptor was shown to be nonbioactive. Based on the present information that the earliest diverged bioactive secretin receptor was found in lungfish, and its ability to interact with both vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide potently suggested that secretin receptor was descended from a VPAC-like receptor gene before the Actinopterygii-Sarcopterygii split in the vertebrate lineage. Hence, secretin and secretin receptor have gone through independent evolutionary trajectories despite their concurrent emergence post-2R. A functional secretin-secretin receptor axis has probably emerged in the amphibians. Although the pleiotropic actions of secretin are well documented in the literature, only limited information of its physiological functions in nonmammalian tetrapods have been reported. To decipher the structural and functional divergence of secretin and secretin receptor, functional characterization of the ligand-receptor pair in nonmammals would be the next perspective for investigation.


Assuntos
Evolução Molecular , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptores dos Hormônios Gastrointestinais/genética , Receptores dos Hormônios Gastrointestinais/metabolismo , Secretina/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Evolução Biológica , Peixes , Humanos , Jejuno/enzimologia , Dados de Sequência Molecular , Pâncreas/metabolismo , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/metabolismo , Secretina/metabolismo , Alinhamento de Sequência , Transdução de Sinais , Peptídeo Intestinal Vasoativo/metabolismo
6.
Hum Gene Ther ; 25(7): 575-86, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24845847

RESUMO

Spinal muscular atrophy (SMA) is a severe autosomal recessive disease caused by a genetic defect in the survival motor neuron 1 (SMN1) gene, which encodes SMN, a protein widely expressed in all eukaryotic cells. Depletion of the SMN protein causes muscle weakness and progressive loss of movement in SMA patients. The field of gene therapy has made major advances over the past decade, and gene delivery to the central nervous system (CNS) by in vivo or ex vivo techniques is a rapidly emerging field in neuroscience. Despite Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis being among the most common neurodegenerative diseases in humans and attractive targets for treatment development, their multifactorial origin and complicated genetics make them less amenable to gene therapy. Monogenic disorders resulting from modifications in a single gene, such as SMA, prove more favorable and have been at the fore of this evolution of potential gene therapies, and results to date have been promising at least. With the estimated number of monogenic diseases standing in the thousands, elucidating a therapeutic target for one could have major implications for many more. Recent progress has brought about the commercialization of the first gene therapies for diseases, such as pancreatitis in the form of Glybera, with the potential for other monogenic disease therapies to follow suit. While much research has been carried out, there are many limiting factors that can halt or impede translation of therapies from the bench to the clinic. This review will look at both recent advances and encountered impediments in terms of SMA and endeavor to highlight the promising results that may be applicable to various associated diseases and also discuss the potential to overcome present limitations.


Assuntos
Doenças Genéticas Inatas/terapia , Terapia Genética/métodos , Atrofia Muscular Espinal/terapia , Mutação , Proteína 1 de Sobrevivência do Neurônio Motor/genética , Animais , Doenças Genéticas Inatas/genética , Doenças Genéticas Inatas/patologia , Doenças Genéticas Inatas/fisiopatologia , Terapia Genética/tendências , Humanos , Atrofia Muscular Espinal/genética , Atrofia Muscular Espinal/patologia , Atrofia Muscular Espinal/fisiopatologia
7.
PLoS One ; 8(11): e81803, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24312360

RESUMO

STK17A is a relatively uncharacterized member of the death-associated protein family of serine/threonine kinases which have previously been associated with cell death and apoptosis. Our prior work established that STK17A is a novel p53 target gene that is induced by a variety of DNA damaging agents in a p53-dependent manner. In this study we have uncovered an additional, unanticipated role for STK17A as a candidate promoter of cell proliferation and survival in glioblastoma (GBM). Unexpectedly, it was found that STK17A is highly overexpressed in a grade-dependent manner in gliomas compared to normal brain and other cancer cell types with the highest level of expression in GBM. Knockdown of STK17A in GBM cells results in a dramatic alteration in cell shape that is associated with decreased proliferation, clonogenicity, migration, invasion and anchorage independent colony formation. STK17A knockdown also sensitizes GBM cells to genotoxic stress. STK17A overexpression is associated with a significant survival disadvantage among patients with glioma which is independent of age, molecular phenotype, IDH1 mutation, PTEN loss, and alterations in the p53 pathway and partially independent of grade. In summary, we demonstrate that STK17A provides a proliferative and survival advantage to GBM cells and is a potential target to be exploited therapeutically in patients with glioma.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/enzimologia , Glioblastoma/tratamento farmacológico , Glioblastoma/enzimologia , Terapia de Alvo Molecular , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Reguladoras de Apoptose/deficiência , Proteínas Reguladoras de Apoptose/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Carcinogênese/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Gradação de Tumores , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Análise de Sobrevida
8.
PLoS One ; 8(1): e53482, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23308232

RESUMO

The evolutionary trajectories of growth hormone-releasing hormone (GHRH) receptor remain enigmatic since the discovery of physiologically functional GHRH-GHRH receptor (GHRHR) in non-mammalian vertebrates in 2007. Interestingly, subsequent studies have described the identification of a GHRHR(2) in chicken in addition to the GHRHR and the closely related paralogous receptor, PACAP-related peptide (PRP) receptor (PRPR). In this article, we provide information, for the first time, on the GHRHR in sarcopterygian fish and amphibians by the cloning and characterization of GHRHRs from lungfish (P. dolloi) and X. laevis. Sequence alignment and phylogenetic analyses demonstrated structural resemblance of lungfish GHRHR to their mammalian orthologs, while the X. laevis GHRHR showed the highest homology to GHRHR(2) in zebrafish and chicken. Functionally, lungfish GHRHR displayed high affinity towards GHRH in triggering intracellular cAMP and calcium accumulation, while X. laevis GHRHR(2) was able to react with both endogenous GHRH and PRP. Tissue distribution analyses showed that both lungfish GHRHR and X. laevis GHRHR(2) had the highest expression in brain, and interestingly, X. laevis(GHRHR2) also had high abundance in the reproductive organs. These findings, together with previous reports, suggest that early in the Sarcopterygii lineage, GHRHR and PRPR have already established diverged and specific affinities towards their cognate ligands. GHRHR(2), which has only been found in xenopus, zebrafish and chicken hitherto, accommodates both GHRH and PRP.


Assuntos
Cromossomos/genética , Peixes/genética , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Receptores de Neuropeptídeos/genética , Receptores de Hormônios Reguladores de Hormônio Hipofisário/genética , Xenopus/genética , Animais , Evolução Biológica , Cálcio/metabolismo , Galinhas/genética , Mapeamento Cromossômico , Cromossomos/química , AMP Cíclico/metabolismo , Feminino , Peixes/metabolismo , Expressão Gênica , Hormônio Liberador de Hormônio do Crescimento/genética , Masculino , Especificidade de Órgãos , Filogenia , Isoformas de Proteínas/química , Isoformas de Proteínas/classificação , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Receptores de Neuropeptídeos/química , Receptores de Neuropeptídeos/classificação , Receptores de Neuropeptídeos/metabolismo , Receptores de Hormônios Reguladores de Hormônio Hipofisário/química , Receptores de Hormônios Reguladores de Hormônio Hipofisário/classificação , Receptores de Hormônios Reguladores de Hormônio Hipofisário/metabolismo , Especificidade da Espécie , Xenopus/metabolismo , Peixe-Zebra/genética
9.
Tissue Eng Part A ; 18(17-18): 1837-48, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22519549

RESUMO

Biomaterials to be used as cell delivery systems for cardiac tissue engineering should be able to comply with cardiac muscle contractile activity, while favoring cell survival and neo-angiogenesis in a hostile environment. Biocompatible synthetic materials can be tailored to mimic cardiac tissue three-dimensional organization in the micro- and nanoscales. Nonetheless, they usually display mechanical properties that are far from those of the native myocardium and thus could affect host cell survival and activity. In the present investigation, inert poly-ε-caprolactone planar layers were manufactured to change the surface stiffness (with Young's modulus ranging from 1 to 133 MPa) without changing matrix chemistry. These substrates were challenged with neonatal murine cardiomyocytes to study the possible effect of substrate stiffness on such cell behavior without changing biological cues. Interestingly, softer substrates (0.91±0.08 and 1.53±0.16 MPa) were found to harbor mostly mature cardiomyocytes having assembled sarcomeres, as shown by the expression of alpha actinin and myosin heavy chain in typical striations and the upregulation of sarcomeric actin mRNA. On the other hand, a preferential expression of immature cardiac cell genes (Nkx-2.5) and proteins (GATA-4) in cardiac cells grown onto stiffer materials (49.67±2.56 and 133.23±8.67 MPa) was detected. This result could not be ascribed to significant differences in cell adhesion or proliferation induced by the substrates, but to the stabilization of cardiomyocyte differentiated phenotype induced by softer layers. In fact, cardiac cell electromechanical coupling was shown to be more organized on softer surfaces, as highlighted by connexin 43 distribution. Moreover, a differential regulation of genes involved in extracellular matrix remodeling was detected on soft films (0.91±0.08 MPa) as compared with the stiffest (133.23±8.67 MPa). Finally, the upregulation of a number of genes involved in inflammatory processes was detected when the stiffest polymer is used. These events highlight the differences in cell mechanosensitivity in a heterogeneous cell preparation and are likely to contribute to the differences encountered in cardiac cell phenotype induced by substrate stiffness.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Poliésteres/química , Poliésteres/farmacologia , Animais , Animais Recém-Nascidos , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Células Cultivadas , Conexina 43/metabolismo , Reagentes de Ligações Cruzadas/farmacologia , Fenômenos Mecânicos/efeitos dos fármacos , Camundongos , Miócitos Cardíacos/efeitos dos fármacos , Fenótipo , Sarcômeros/efeitos dos fármacos , Sarcômeros/metabolismo , Fatores de Tempo , Molhabilidade/efeitos dos fármacos
10.
Sci Technol Adv Mater ; 13(6): 064205, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27877532

RESUMO

The acknowledged ability of synthetic materials to induce cell-specific responses regardless of biological supplies provides tissue engineers with the opportunity to find the appropriate materials and conditions to prepare tissue-targeted scaffolds. Stem and mature cells have been shown to acquire distinct morphologies in vitro and to modify their phenotype when grown on synthetic materials with tunable mechanical properties. The stiffness of the substrate used for cell culture is likely to provide cells with mechanical cues mimicking given physiological or pathological conditions, thus affecting the biological properties of cells. The sensitivity of cells to substrate composition and mechanical properties resides in multiprotein complexes called focal adhesions, whose dynamic modification leads to cytoskeleton remodeling and changes in gene expression. In this study, the remodeling of focal adhesions in human mesenchymal stem cells in response to substrate stiffness was followed in the first phases of cell-matrix interaction, using poly-ε-caprolactone planar films with similar chemical composition and different elasticity. As compared to mature dermal fibroblasts, mesenchymal stem cells showed a specific response to substrate stiffness, in terms of adhesion, as a result of differential focal adhesion assembly, while their multipotency as a bulk was not significantly affected by matrix compliance. Given the sensitivity of stem cells to matrix mechanics, the mechanobiology of such cells requires further investigations before preparing tissue-specific scaffolds.

11.
Gen Comp Endocrinol ; 173(3): 405-10, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21703272

RESUMO

Pituitary adenylate cyclase-activating polypeptide (PACAP)-related peptide (PRP) is a peptide encoded with PACAP in the same precursor protein. Non-mammalian PRPs were previously termed growth hormone-releasing hormone (GHRH)-like peptide, and was regarded as the mammalian GHRH homologue in non-mammalian vertebrates until the discovery of authentic GHRH genes in teleosts and amphibians. Although a highly specific receptor for PRP, which is lost in mammals, is present in non-mammals, a clear function of PRP in vertebrates remains unknown. Using goldfish as a model, here we show the expression of PRP and its cognate receptor in the brain-pituitary-gonadal (BPG) axis, thus suggesting a function of goldfish (gf) PRP in regulating reproduction. We found that gfPRP controls the expression of reproductive hormones in the brain, pituitary and ovary. Goldfish PRP exerts stimulatory effects on the expression of salmon gonadotropin-releasing hormone (sGnRH) in the brain, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in pituitary primary culture cells, but inhibits the expression of LH in the ovary. Using the same technique, we showed that gfPRP did not alter the mRNA level of growth hormone in the pituitary primary culture. In summary, we have discovered the first function of vertebrate PRP in regulating reproduction, which provides a new research direction in studying the neuroendocrine control of reproduction not only in teleosts, but also in other non-mammalian vertebrates.


Assuntos
Proteínas de Peixes/fisiologia , Carpa Dourada/metabolismo , Fragmentos de Peptídeos/fisiologia , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/fisiologia , Precursores de Proteínas/fisiologia , Animais , Encéfalo/metabolismo , Feminino , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Carpa Dourada/genética , Carpa Dourada/fisiologia , Masculino , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/genética , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/metabolismo , Hipófise/metabolismo , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , RNA Mensageiro/metabolismo
12.
PLoS One ; 6(4): e19384, 2011 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-21559418

RESUMO

At present, secretin and its receptor have only been identified in mammals, and the origin of this ligand-receptor pair in early vertebrates is unclear. In addition, the elusive similarities of secretin and orexin in terms of both structures and functions suggest a common ancestral origin early in the vertebrate lineage. In this article, with the cloning and functional characterization of secretin receptors from lungfish and X. laevis as well as frog (X. laevis and Rana rugulosa) secretins, we provide evidence that the secretin ligand-receptor pair has already diverged and become highly specific by the emergence of tetrapods. The secretin receptor-like sequence cloned from lungfish indicates that the secretin receptor was descended from a VPAC-like receptor prior the advent of sarcopterygians. To clarify the controversial relationship of secretin and orexin, orexin type-2 receptor was cloned from X. laevis. We demonstrated that, in frog, secretin and orexin could activate their mutual receptors, indicating their coordinated complementary role in mediating physiological processes in non-mammalian vertebrates. However, among the peptides in the secretin/glucagon superfamily, secretin was found to be the only peptide that could activate the orexin receptor. We therefore hypothesize that secretin and orexin are of different ancestral origins early in the vertebrate lineage.


Assuntos
Evolução Biológica , Evolução Molecular , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neuropeptídeos/genética , Receptores Acoplados a Proteínas G/genética , Receptores dos Hormônios Gastrointestinais/genética , Secretina/genética , Animais , Clonagem Molecular , Feminino , Humanos , Ligantes , Masculino , Modelos Biológicos , Orexinas , Ranidae , Fatores de Tempo , Distribuição Tecidual , Xenopus laevis
13.
Peptides ; 28(9): 1920-9, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17714829

RESUMO

PACAP-related peptide (PRP) and PACAP are structurally related peptides that are encoded in the same transcripts. In the past, it was believed that the mammalian PRPs are evolved from GHRHs in non-mammals. With the recent discovery of authentic GHRH and receptor genes in frog and fish, this review aims to (1) coin the name of all GHRH-like peptides in previous literature as PRPs and (2) provide the background for new research direction for PRP in vertebrates. As a goldfish receptor highly specific for PRP with distinct tissue distribution has previously been characterized, it is highly possible that PRP plays a physiological role in non-mammalian vertebrates and the function of PRP has somehow been lost in mammals as a consequence of the loss of its receptor in the genome. This information may provide clues to elucidate functions of PRP in the future.


Assuntos
Evolução Molecular , Neuropeptídeos/genética , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/genética , Sequência de Aminoácidos , Animais , Humanos , Mamíferos/classificação , Mamíferos/genética , Dados de Sequência Molecular , Neuropeptídeos/fisiologia , Filogenia , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/fisiologia , Homologia de Sequência de Aminoácidos
14.
Proc Natl Acad Sci U S A ; 104(7): 2133-8, 2007 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-17283332

RESUMO

In mammals, growth hormone-releasing hormone (GHRH) is the most important neuroendocrine factor that stimulates the release of growth hormone (GH) from the anterior pituitary. In nonmammalian vertebrates, however, the previously named GHRH-like peptides were unable to demonstrate robust GH-releasing activities. In this article, we provide evidence that these GHRH-like peptides are homologues of mammalian PACAP-related peptides (PRP). Instead, GHRH peptides encoded in cDNAs isolated from goldfish, zebrafish, and African clawed frog were identified. Moreover, receptors specific for these GHRHs were characterized from goldfish and zebrafish. These GHRHs and GHRH receptors (GHRH-Rs) are phylogenetically and structurally more similar to their mammalian counterparts than the previously named GHRH-like peptides and GHRH-like receptors. Information regarding their chromosomal locations and organization of neighboring genes confirmed that they share the same origins as the mammalian genes. Functionally, the goldfish GHRH dose-dependently activates cAMP production in receptor-transfected CHO cells as well as GH release from goldfish pituitary cells. Tissue distribution studies showed that the goldfish GHRH is expressed almost exclusively in the brain, whereas the goldfish GHRH-R is actively expressed in brain and pituitary. Taken together, these results provide evidence for a previously uncharacterized GHRH-GHRH-R axis in nonmammalian vertebrates. Based on these data, a comprehensive evolutionary scheme for GHRH, PRP-PACAP, and PHI-VIP genes in relation to three rounds of genome duplication early on in vertebrate evolution is proposed. These GHRHs, also found in flounder, Fugu, medaka, stickleback, Tetraodon, and rainbow trout, provide research directions regarding the neuroendocrine control of growth in vertebrates.


Assuntos
Hormônio Liberador de Hormônio do Crescimento/genética , Receptores de Neuropeptídeos/genética , Receptores de Hormônios Reguladores de Hormônio Hipofisário/genética , Animais , Anuros , AMP Cíclico/biossíntese , Evolução Molecular , Carpa Dourada , Hormônio Liberador de Hormônio do Crescimento/análise , Dados de Sequência Molecular , Filogenia , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase , Receptores de Neuropeptídeos/análise , Receptores de Neuropeptídeos/metabolismo , Receptores de Hormônios Reguladores de Hormônio Hipofisário/análise , Receptores de Hormônios Reguladores de Hormônio Hipofisário/metabolismo , Distribuição Tecidual , Vertebrados , Peixe-Zebra
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