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1.
Int J Nanomedicine ; 19: 9109-9120, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39253061

RESUMO

Background and Purpose: Growth hormone-releasing hormone (GHRH) agonist, a 29-amino acid peptide, shows significant potential in treating myocardial infarction (MI) by aiding the repair of injured heart tissue. The challenge lies in the effective on-site delivery of GHRH agonist. This study explores the use of a targetable delivery system employing ROS-responsive PEG-PPS-PEG polymers to encapsulate and deliver GHRH agonist MR409 for enhanced therapeutic efficacy. Methods: We synthesized a self-assembling poly (ethylene glycol)-poly (propylene sulfide)-poly (ethylene glycol) polymer (PEG-PPS-PEG) amphiphilic polymer responsive to reactive oxygen species (ROS). The hydrophilic peptide GHRH agonist MR409 was encapsulated within these polymers to form nano PEG-PPS-PEG@MR409 vesicles (NPs). Cardiomyocyte apoptosis was induced under hypoxia and serum-free culture condition for 24 hours, and their production of ROS was detected by fluorescence dye staining. The cellular uptake of PEG-PPS-PEG@MR409 NPs was observed using fluorescence-labeled MR409. Targeting ability and therapeutic efficacy were evaluated using a mouse MI model. Results: PEG-PPS-PEG@MR409 NPs were efficiently internalized by cardiomyocytes, reducing ROS levels and apoptosis. These NPs exhibited superior targeting to the infarcted heart compared to naked MR409 peptide. With a reduced injection frequency (once every three days), PEG-PPS-PEG@MR409 NPs significantly promoted cardiac function recovery post-MI, matching the efficacy of daily MR409 injections. Conclusion: ROS-responsive PEG-PPS-PEG polymers provide a novel and effective platform for the targeted delivery of GHRH agonist peptides, improving cardiac function and offering a new approach for peptide therapy in MI treatment.


Assuntos
Infarto do Miocárdio , Miócitos Cardíacos , Polietilenoglicóis , Espécies Reativas de Oxigênio , Animais , Polietilenoglicóis/química , Polietilenoglicóis/farmacocinética , Polietilenoglicóis/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Camundongos , Infarto do Miocárdio/tratamento farmacológico , Miócitos Cardíacos/efeitos dos fármacos , Modelos Animais de Doenças , Hormônio Liberador de Hormônio do Crescimento/agonistas , Hormônio Liberador de Hormônio do Crescimento/farmacocinética , Hormônio Liberador de Hormônio do Crescimento/administração & dosagem , Apoptose/efeitos dos fármacos , Sulfetos/química , Sulfetos/farmacocinética , Sulfetos/farmacologia , Sulfetos/administração & dosagem , Peptídeos/química , Peptídeos/farmacologia , Peptídeos/farmacocinética , Peptídeos/administração & dosagem , Masculino , Camundongos Endogâmicos C57BL
2.
Int J Mol Sci ; 25(16)2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39201517

RESUMO

Hematological and oncological diseases are still among the leading causes of childhood mortality. Expression of growth hormone-releasing hormone (GHRH) and its receptors (GHRH-R) has been previously demonstrated in various human tumors, but very limited findings are available about the presence and potential function of GHRH-Rs in oncological and hematological disorders of children. In this study, we aimed to investigate the expression of mRNA for GHRH and splice variant 1 (SV) of GHRH-R in 15 pediatric hematological/oncological specimens by RT-PCR. The presence and binding characteristics of GHRH-R protein were also studied by Western blot and ligand competition assays. Of the fifteen specimens studied, eleven pediatric samples (73%) showed the expression of mRNA for GHRH. These eleven samples also expressed mRNA for GHRH receptor SV1. GHRH-R protein was found to be expressed in two benign tumor samples and five malignant tumors examined by Western blot. The presence of specific, high affinity binding sites on GHRH-R was demonstrated in all of the seven human pediatric solid tumor samples investigated. Our results show that the expression of GHRH and SV1 of GHRH-R in hemato-oncological diseases in children can pave the way for further investigation of GHRH-Rs as potential molecular targets for diagnosis and therapy.


Assuntos
Hormônio Liberador de Hormônio do Crescimento , Neoplasias , Receptores de Neuropeptídeos , Receptores de Hormônios Reguladores de Hormônio Hipofisário , Humanos , Receptores de Hormônios Reguladores de Hormônio Hipofisário/genética , Receptores de Hormônios Reguladores de Hormônio Hipofisário/metabolismo , Criança , Masculino , Feminino , Receptores de Neuropeptídeos/genética , Receptores de Neuropeptídeos/metabolismo , Projetos Piloto , Hormônio Liberador de Hormônio do Crescimento/genética , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Pré-Escolar , Adolescente , Neoplasias/genética , Neoplasias/metabolismo , Hungria , Lactente , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Doenças Hematológicas/genética , Doenças Hematológicas/metabolismo , Estudos de Coortes
3.
ASN Neuro ; 16(1): 2368382, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39024550

RESUMO

Ventromedial hypothalamic nucleus (VMN) growth hormone-releasing hormone (Ghrh) neurotransmission shapes counterregulatory hormone secretion. Dorsomedial VMN Ghrh neurons express the metabolic-sensitive transcription factor steroidogenic factor-1/NR5A1 (SF-1). In vivo SF-1 gene knockdown tools were used here to address the premise that in male rats, SF-1 may regulate basal and/or hypoglycemic patterns of Ghrh, co-transmitter biosynthetic enzyme, and estrogen receptor (ER) gene expression in these neurons. Single-cell multiplex qPCR analyses showed that SF-1 regulates basal profiles of mRNAs that encode Ghrh and protein markers for neurochemicals that suppress (γ-aminobutyric acid) or enhance (nitric oxide; glutamate) counterregulation. SF-1 siRNA pretreatment respectively exacerbated or blunted hypoglycemia-associated inhibition of glutamate decarboxylase67 (GAD67/GAD1) and -65 (GAD65/GAD2) transcripts. Hypoglycemia augmented or reduced nitric oxide synthase and glutaminase mRNAs, responses that were attenuated by SF-1 gene silencing. Ghrh and Ghrh receptor transcripts were correspondingly refractory to or increased by hypoglycemia, yet SF-1 knockdown decreased both gene profiles. Hypoglycemic inhibition of ER-alpha and G protein-coupled-ER gene expression was amplified by SF-1 siRNA pretreatment, whereas as ER-beta mRNA was amplified. SF-1 knockdown decreased (corticosterone) or elevated [glucagon, growth hormone (GH)] basal counterregulatory hormone profiles, but amplified hypoglycemic hypercorticosteronemia and -glucagonemia or prevented elevated GH release. Outcomes document SF-1 control of VMN Ghrh neuron counterregulatory neurotransmitter and ER gene transcription. SF-1 likely regulates Ghrh nerve cell receptivity to estradiol and release of distinctive neurochemicals during glucose homeostasis and systemic imbalance. VMN Ghrh neurons emerge as a likely substrate for SF-1 control of glucose counterregulation in the male rat.


Assuntos
Hormônio Liberador de Hormônio do Crescimento , Neurônios , Ratos Sprague-Dawley , Fator Esteroidogênico 1 , Núcleo Hipotalâmico Ventromedial , Animais , Masculino , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Hormônio Liberador de Hormônio do Crescimento/genética , Núcleo Hipotalâmico Ventromedial/metabolismo , Fator Esteroidogênico 1/metabolismo , Fator Esteroidogênico 1/genética , Neurônios/metabolismo , Ratos , Receptores de Estrogênio/metabolismo , Receptores de Estrogênio/genética , Glutamato Descarboxilase/metabolismo , Glutamato Descarboxilase/genética , Regulação da Expressão Gênica , Hipoglicemia/metabolismo , RNA Interferente Pequeno/farmacologia
5.
Cell Signal ; 121: 111260, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38871041

RESUMO

Growth hormone-releasing hormone antagonists (GHRHAnt) have been associated with antitumor and antioxidative activities. The present study investigates for the first time the effects of those compounds towards pro-inflammatory cytokine expression in a murine model of cecal ligation and puncture (CLP) - induced sepsis. The results indicate that GHRHAnt JV-1-36 significantly suppressed IL-1α, IL-6, and pSTAT3 activation in septic lungs. Moreover, GHRHAnt treatment reduced bronchoalveolar lavage fluid (BALF) protein concentration, suggesting a protective effect of that compound in sepsis-induced lung edema. Based on those findings, it is suggested that GHRHAnt may represent an exciting new therapeutic possibility in sepsis-induced endotoxemia and lung injury.


Assuntos
Hormônio Liberador de Hormônio do Crescimento , Pulmão , Sepse , Animais , Sepse/tratamento farmacológico , Hormônio Liberador de Hormônio do Crescimento/antagonistas & inibidores , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Camundongos , Pulmão/patologia , Pulmão/metabolismo , Pulmão/efeitos dos fármacos , Masculino , Fator de Transcrição STAT3/metabolismo , Líquido da Lavagem Broncoalveolar , Interleucina-6/metabolismo , Modelos Animais de Doenças
6.
AIDS ; 38(12): 1758-1764, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38905488

RESUMO

OBJECTIVE: Tesamorelin is the only FDA-approved therapy to treat abdominal fat accumulation in people with HIV (PWH). Phase III clinical trials were conducted prior to the introduction of integrase inhibitors (INSTIs), which are now a mainstay of HIV antiretroviral therapy. DESIGN: We leveraged a randomized double-blind trial of 61 PWH and metabolic dysfunction-associated steatotic liver disease to evaluate the efficacy and safety of tesamorelin 2 mg once daily vs. identical placebo among participants on INSTI-based regimens at baseline. METHODS: In the parent clinical trial, visceral fat cross-sectional area, hepatic fat fraction, and trunk-to-appendicular fat ratio were quantified using magnetic resonance imaging, proton magnetic resonance spectroscopy, and dual-energy x-ray absorptiometry, respectively, at baseline and 12 months. Metabolic and safety outcomes were compared between treatment arms. RESULTS: Among 38 participants on INSTI-based regimens at baseline, 15 individuals on tesamorelin and 16 individuals on placebo completed the 12-month study. Tesamorelin led to significant declines in visceral fat (median [interquartile range]: -25 [-93, -2] vs. 14 [3, 41] cm 2 , P  = 0.001), hepatic fat (-4.2% [-12.3%, -2.7%] vs. -0.5% [-3.9%, 2.7%], P  = 0.01), and trunk-to-appendicular fat ratio (-0.1 [-0.3, 0.0] vs. 0.0 [-0.1, 0.1], P  = 0.03). Tesamorelin was well tolerated with a similar frequency of adverse events, including hyperglycemia, between groups. CONCLUSIONS: The current analysis provides the first dedicated data on the efficacy and safety of tesamorelin among PWH on INSTI-based regimens. Despite the association of INSTI use with weight gain and adipose tissue dysfunction, tesamorelin had beneficial effects on body composition with no exacerbation of glycemic control.


Assuntos
Hormônio Liberador de Hormônio do Crescimento , Infecções por HIV , Humanos , Masculino , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/complicações , Pessoa de Meia-Idade , Método Duplo-Cego , Hormônio Liberador de Hormônio do Crescimento/análogos & derivados , Hormônio Liberador de Hormônio do Crescimento/uso terapêutico , Hormônio Liberador de Hormônio do Crescimento/antagonistas & inibidores , Adulto , Resultado do Tratamento , Placebos/administração & dosagem , Imageamento por Ressonância Magnética , Absorciometria de Fóton , Inibidores de Integrase de HIV/uso terapêutico , Inibidores de Integrase de HIV/efeitos adversos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos
7.
Int J Mol Sci ; 25(11)2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38892024

RESUMO

Inflammation, demyelination, and axonal damage to the central nervous system (CNS) are the hallmarks of multiple sclerosis (MS) and its representative animal model, experimental autoimmune encephalomyelitis (EAE). There is scientific evidence for the involvement of growth hormone (GH) in autoimmune regulation. Previous data on the relationship between the GH/insulin like growth factor-1 (IGF-1) axis and MS/EAE are inconclusive; therefore, the aim of our study was to investigate the changes in the GH axis during acute monophasic EAE. The results show that the gene expression of Ghrh and Sst in the hypothalamus does not change, except for Npy and Agrp, while at the pituitary level the Gh, Ghrhr and Ghr genes are upregulated. Interestingly, the cell volume of somatotropic cells in the pituitary gland remains unchanged at the peak of the disease. We found elevated serum GH levels in association with low IGF-1 concentration and downregulated Ghr and Igf1r expression in the liver, indicating a condition resembling GH resistance. This is likely due to inadequate nutrient intake at the peak of the disease when inflammation in the CNS is greatest. Considering that GH secretion is finely regulated by numerous central and peripheral signals, the involvement of the GH/IGF-1 axis in MS/EAE should be thoroughly investigated for possible future therapeutic strategies, especially with a view to improving EAE disease.


Assuntos
Encefalomielite Autoimune Experimental , Hormônio do Crescimento , Fator de Crescimento Insulin-Like I , Animais , Encefalomielite Autoimune Experimental/metabolismo , Encefalomielite Autoimune Experimental/patologia , Encefalomielite Autoimune Experimental/genética , Feminino , Ratos , Hormônio do Crescimento/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Fator de Crescimento Insulin-Like I/genética , Hipotálamo/metabolismo , Hipotálamo/patologia , Hipófise/metabolismo , Hipófise/patologia , Receptores da Somatotropina/metabolismo , Receptores da Somatotropina/genética , Receptores de Hormônios Reguladores de Hormônio Hipofisário/genética , Receptores de Hormônios Reguladores de Hormônio Hipofisário/metabolismo , Esclerose Múltipla/metabolismo , Esclerose Múltipla/patologia , Esclerose Múltipla/genética , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Hormônio Liberador de Hormônio do Crescimento/genética , Fígado/metabolismo , Fígado/patologia , Modelos Animais de Doenças
8.
Aging Cell ; 23(8): e14226, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38808779

RESUMO

Dysregulation of growth hormone (GH) signaling consistently leads to increased lifespan in laboratory rodents, yet the precise mechanisms driving this extension remain unclear. Understanding the molecular underpinnings of the beneficial effects associated with GH deficiency could unveil novel therapeutic targets for promoting healthy aging and longevity. In our pursuit of identifying metabolites implicated in aging, we conducted an unbiased lipidomic analysis of serum samples from growth hormone-releasing hormone knockout (GHRH-KO) female mice and their littermate controls. Employing a targeted lipidomic approach, we specifically investigated ceramide levels in GHRH-KO mice, a well-established model of enhanced longevity. While younger GHRH-KO mice did not exhibit notable differences in serum lipids, older counterparts demonstrated significant reductions in over one-third of the evaluated lipids. In employing the same analysis in liver tissue, GHRH-KO mice showed pronounced downregulation of numerous ceramides and hexosylceramides, which have been shown to elicit many of the tissue defects that accompany aging (e.g., insulin resistance, oxidative stress, and cell death). Additionally, gene expression analysis in the liver tissue of adult GHRH-KO mice identified substantial decreases in several ceramide synthesis genes, indicating that these alterations are, at least in part, attributed to GHRH-KO-induced transcriptional changes. These findings provide the first evidence of disrupted ceramide metabolism in a long-lived mammal. This study sheds light on the intricate connections between GH deficiency, ceramide levels, and the molecular mechanisms influencing lifespan extension.


Assuntos
Envelhecimento , Ceramidas , Hormônio Liberador de Hormônio do Crescimento , Camundongos Knockout , Animais , Ceramidas/metabolismo , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Hormônio Liberador de Hormônio do Crescimento/genética , Camundongos , Envelhecimento/metabolismo , Feminino , Longevidade/genética , Fígado/metabolismo
9.
Gen Comp Endocrinol ; 355: 114560, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38806133

RESUMO

Growth hormone-releasing hormone (GHRH) has been widely shown to stimulate growth hormone (GH) production via binding to GHRH receptor GHRHR in various species of vertebrates, but information regarding the functional roles of GHRH and GHRHR in the protochordate amphioxus remains rather scarce. We showed here that two mature peptides, BjGHRH-1 and BjGHRH-2, encoded by BjGHRH precursor, and a single BjGHRHR protein were identified in the amphioxus Branchiostoma. japonicum. Like the distribution profiles of vertebrate GHRHs and GHRHRs, both the genes Bjghrh and Bjghrhr were widely expressed in the different tissues of amphioxus, including in the cerebral vesicle, Hatschek's pit, neural tube, gill, hepatic caecum, notochord, testis and ovary. Moreover, both BjGHRH-1 and BjGHRH-2 interacted with BjGHRHR, and triggered the cAMP/PKA signal pathway in a dose-dependent manner. Importantly, BjGHRH-1 and BjGHRH-2 were both able to activate the expression of GH-like gene in the cells of Hatschek's pit. These indicate that a functional vertebrate-like GHRH-GHRHR axis had already emerged in amphioxus, which is a seminal innovation making physiological divergence including reproduction, growth, metabolism, stress and osmoregulation possible during the early evolution of vertebrates.


Assuntos
Hormônio Liberador de Hormônio do Crescimento , Anfioxos , Receptores de Neuropeptídeos , Receptores de Hormônios Reguladores de Hormônio Hipofisário , Animais , Anfioxos/metabolismo , Anfioxos/genética , Receptores de Neuropeptídeos/metabolismo , Receptores de Neuropeptídeos/genética , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Hormônio Liberador de Hormônio do Crescimento/genética , Receptores de Hormônios Reguladores de Hormônio Hipofisário/metabolismo , Receptores de Hormônios Reguladores de Hormônio Hipofisário/genética , Sistema Hipotálamo-Hipofisário/metabolismo
10.
ACS Chem Neurosci ; 15(11): 2350-2358, 2024 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-38757688

RESUMO

Growth hormone-releasing hormone (Ghrh) neurons in the dorsomedial ventromedial hypothalamic nucleus (VMNdm) express the metabolic transcription factor steroidogenic factor-1 and hypoglycemia-sensitive neurochemicals of diverse chemical structures, transmission modes, and temporal signaling profiles. Ghrh imposes neuromodulatory control of coexpressed transmitters. Multiple metabolic sensory mechanisms are employed in the brain, including screening of the critical nutrient glucose or the energy currency ATP. Here, combinatory laser-catapult-microdissection/single-cell multiplex qPCR tools were used to investigate whether these neurons possess molecular machinery for monitoring cellular metabolic status and if these biomarkers exhibit sex-specific sensitivity to insulin-induced hypoglycemia. Data show that hypoglycemia up- (male) or downregulated (female) Ghrh neuron glucokinase (Gck) mRNA; Ghrh gene silencing decreased baseline and hypoglycemic patterns of Gck gene expression in each sex. Ghrh neuron glucokinase regulatory protein (Gckr) transcript levels were respectively diminished or augmented in hypoglycemic male vs female rats; this mRNA profile was decreased by Ghrh siRNA in both sexes. Gene transcripts encoding catalytic alpha subunits of the energy monitor 5-AMP-activated protein kinase (AMPK), i.e., Prkaa1 and 2, were increased by hypoglycemia in males, yet only the former mRNA was hypoglycemia-sensitive in females. Ghrh siRNA downregulated baseline and hypoglycemia-associated Prkaa subunit mRNAs in males but elicited divergent changes in Prkaa2 transcripts in eu- vs hypoglycemic females. Results provide unique evidence that VMNdm Ghrh neurons express the characterized metabolic sensor biomarkers glucokinase and AMPK and that the corresponding gene profiles exhibit distinctive sex-dimorphic transcriptional responses to hypoglycemia. Data further document Ghrh neuromodulation of baseline and hypoglycemic transcription patterns of these metabolic gene profiles.


Assuntos
Hipoglicemia , Neurônios , RNA Mensageiro , Caracteres Sexuais , Núcleo Hipotalâmico Ventromedial , Animais , Feminino , Masculino , Ratos , Núcleo Hipotalâmico Dorsomedial/metabolismo , Glucoquinase/metabolismo , Glucoquinase/genética , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Hormônio Liberador de Hormônio do Crescimento/genética , Hipoglicemia/metabolismo , Neurônios/metabolismo , Ratos Sprague-Dawley , RNA Mensageiro/metabolismo , Núcleo Hipotalâmico Ventromedial/metabolismo
11.
Eur J Pharm Sci ; 197: 106768, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38643940

RESUMO

The negative coordination of growth hormone secretagogue receptor (GHS-R) and growth hormone-releasing hormone receptor (GHRH-R) involves in the repair processes of cellular injury. The allosteric U- or H-like modified GHRH dimer Grinodin and 2Y were comparatively evaluated in normal Kunming mice and hamster infertility models induced by CPA treatment. 1-3-9 µg of Grinodin or 2Y per hamster stem-cell-exhaustion model was subcutaneously administered once a week, respectively inducing 75-69-46 or 45-13-50 % of birth rates. In comparison, the similar mole of human menopausal gonadotropin (hMG) or human growth hormone (hGH) was administered once a day but caused just 25 or 20 % of birth rates. Grinodin induced more big ovarian follicles and corpora lutea than 2Y, hMG, hGH. The hMG-treated group was observed many distorted interstitial cells and more connective tissues and the hGH-treated group had few ovarian follicles. 2Y had a plasma lifetime of 21 days and higher GH release in mice, inducing lower birth rate and stronger individual specificity in reproduction as well as only promoting the proliferation of mesenchymal-stem-cells (MSCs) in the models. In comparison, Grinodin had a plasma lifetime of 30 days and much lower GH release in mice. It significantly promoted the proliferation and activation of ovarian MSCs together with the development of follicles in the models by increasing Ki67 and GHS-R expressions, and decreasing GHRH-R expression in a dose-dependent manner. However, the high GH and excessive estrogen levels in the models showed a dose-dependent reduction in fertility. Therefore, unlike 2Y, the low dose of Grinodin specifically shows low GHS-R and high GHRH-R expressions thus evades GH and estrogen release and improves functions of organs, resulting in an increase of fertility.


Assuntos
Proliferação de Células , Células-Tronco Mesenquimais , Ovário , Feminino , Animais , Camundongos , Proliferação de Células/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Ovário/efeitos dos fármacos , Ovário/metabolismo , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Fertilidade/efeitos dos fármacos , Receptores de Neuropeptídeos/metabolismo , Humanos , Regulação Alostérica/efeitos dos fármacos , Receptores de Grelina/metabolismo , Cricetinae , Receptores de Hormônios Reguladores de Hormônio Hipofisário/metabolismo , Dimerização
12.
Oncotarget ; 15: 248-254, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38588464

RESUMO

Acute myeloid leukemia (AML) is characterized by the rapid proliferation of mutagenic hematopoietic progenitors in the bone marrow. Conventional therapies include chemotherapy and bone marrow stem cell transplantation; however, they are often associated with poor prognosis. Notably, growth hormone-releasing hormone (GHRH) receptor antagonist MIA-602 has been shown to impede the growth of various human cancer cell lines, including AML. This investigation examined the impact of MIA-602 as monotherapy and in combination with Doxorubicin on three Doxorubicin-resistant AML cell lines, KG-1A, U-937, and K-562. The in vitro results revealed a significant reduction in cell viability for all treated wild-type cells. Doxorubicin-resistant clones were similarly susceptible to MIA-602 as the wild-type counterpart. Our in vivo experiment of xenografted nude mice with Doxorubicin-resistant K-562 revealed a reduction in tumor volume with MIA-602 treatment compared to control. Our study demonstrates that these three AML cell lines, and their Doxorubicin-resistant clones, are susceptible to GHRH antagonist MIA-602.


Assuntos
Hormônio Liberador de Hormônio do Crescimento , Leucemia Mieloide Aguda , Sermorelina/análogos & derivados , Camundongos , Animais , Humanos , Camundongos Nus , Proliferação de Células , Linhagem Celular Tumoral , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Doxorrubicina/farmacologia
13.
Best Pract Res Clin Endocrinol Metab ; 38(3): 101877, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38413286

RESUMO

Ectopic acromegaly is a rare condition caused by extrapituitary central or peripheral neuroendocrine tumours (NET) that hypersecrete GH or, more commonly, GHRH. It affects less than 1% of acromegaly patients and a misdiagnosis of classic acromegaly can lead to an inappropriate pituitary surgery. Four types of ectopic acromegaly have been described: 1) Central ectopic GH-secretion: Careful cross-sectional imaging is required to exclude ectopic pituitary adenomas. 2) Peripheral GH secretion: Extremely rare. 3) Central ectopic GHRH secretion: Sellar gangliocytomas immunohistochemically positive for GHRH are found after pituitary surgery. 4) Peripheral GHRH secretion: The most common type of ectopic acromegaly is due to peripheral GHRH-secreting NETs. Tumours are large and usually located in the lungs or pancreas. Pituitary hyperplasia resulting from chronic GHRH stimulation is difficult to detect or can be misinterpreted as pituitary adenoma in the MRI. Measurement of serum GHRH levels is a specific and useful diagnostic tool. Surgery of GHRH-secreting NETs is often curative.


Assuntos
Acromegalia , Hormônio Liberador de Hormônio do Crescimento , Humanos , Acromegalia/diagnóstico , Acromegalia/etiologia , Acromegalia/sangue , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Tumores Neuroendócrinos/diagnóstico , Tumores Neuroendócrinos/metabolismo , Tumores Neuroendócrinos/complicações , Hormônio do Crescimento Humano/sangue , Hormônio do Crescimento Humano/metabolismo , Neoplasias Hipofisárias/diagnóstico , Neoplasias Hipofisárias/cirurgia , Neoplasias Hipofisárias/complicações , Neoplasias Hipofisárias/metabolismo
14.
Gene ; 907: 148283, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38354915

RESUMO

BACKGROUND: Isolated growth hormone deficiency (IGHD) is a rare genetically heterogeneous disorder caused primarily by mutations in GH1 and GH releasing hormone receptor (GHRHR). The aim of this study was to identify the molecular etiology of a Chinese boy with IGHD. METHODS: Whole-exome sequencing, sanger sequencing and bioinformatic analysis were performed to screen for candidate mutations. The impacts of candidate mutation on gene expression, intracellular localization and protein function were further evaluated by in vitro assays. RESULTS: A novel heterozygous frameshift mutation in the GHRH gene (c.91dupC, p.R31Pfs*98) was identified in a Chinese boy clinically diagnosed as having IGHD. The mutation was absent in multiple public databases, and considered as deleterious using in silico prediction, conservative analysis and three-dimensional homology modeling. Furthermore, mRNA and protein expression levels of mutant GHRH were significantly increased than wild-type GHRH (p < 0.05). Moreover, mutant GHRH showed an aberrant accumulation within the cytoplasm, and obviously reduced ability to stimulate GH secretion and cAMP accumulation in human GHRHR-expressing pituitary GH3 cells compared to wild-type GHRH (p < 0.05). CONCLUSION: Our study discovered the first loss-of function mutation of GHRH in a Chinese boy with IGHD and provided new insights on IGHD pathogenesis caused by GHRH haploinsufficiency.


Assuntos
Nanismo Hipofisário , Hormônio Liberador de Hormônio do Crescimento , Hormônio do Crescimento Humano , Humanos , Masculino , China , Nanismo Hipofisário/genética , Mutação da Fase de Leitura , Hormônio do Crescimento , Hormônio do Crescimento Humano/genética , Mutação , Receptores de Neuropeptídeos/genética , Receptores de Hormônios Reguladores de Hormônio Hipofisário/genética , Hormônio Liberador de Hormônio do Crescimento/genética , População do Leste Asiático/genética
15.
Cytokine ; 173: 156416, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37952313

RESUMO

GHRH regulates the secretion of GH from the anterior pituitary gland. An emerging body of evidence suggests that the activities of that neuropeptide are not limited to the GH/IGF-I axis, but they expand towards the mediation of inflammatory processes. GHRHAnt were developed to oppose the activities of GHRH in malignancies, and have been associated with strong anti-inflammatory and anti-oxidative effects in a diverse variety of tissues, including the lungs. In the present study we report that GHRHAnt oppose interferon-γ - induced paracellular hyperpermeability and reactive oxygen species generation in bovine and human pulmonary endothelial cells; and suppress interferon-γ - triggered STAT3, cofilin and ERK1/2 activation. Our observations substantiate previous findings on the protective effects of GHRHAnt in endothelial inflammation and barrier break-down.


Assuntos
Hormônio do Crescimento , Adeno-Hipófise , Humanos , Animais , Bovinos , Interferon gama/farmacologia , Células Endoteliais , Hormônio Liberador de Hormônio do Crescimento/farmacologia
17.
Cells ; 12(22)2023 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-37998350

RESUMO

Growth hormone (GH)-releasing hormone (GHRH) has been suggested to play a crucial role in brain function. We aimed to further investigate the effects of a novel GHRH antagonist of the Miami (MIA) series, MIA-602, on emotional disorders and explore the relationships between the endocrine system and mood disorders. In this context, the effects induced by MIA-602 were also analyzed in comparison to vehicle-treated mice with GH deficiency due to generalized ablation of the GHRH gene (GHRH knock out (GHRHKO)). We show that the chronic subcutaneous administration of MIA-602 to wild type (+/+) mice, as well as generalized ablation of the GHRH gene, is associated with anxiolytic and antidepressant behavior. Moreover, immunohistochemical and Western blot analyses suggested an evident activation of Nrf2, HO1, and NQO1 in the prefrontal cortex of both +/+ mice treated with MIA-602 (+/+ MIA-602) and homozygous GHRHKO (-/- control) animals. Finally, we also found significantly decreased COX-2, iNOS, NFkB, and TNF-α gene expressions, as well as increased P-AKT and AKT levels in +/+ MIA-602 and -/- control animals compared to +/+ mice treated with vehicle (+/+ control). We hypothesize that the generalized ablation of the GHRH gene leads to a dysregulation of neural pathways, which is mimicked by GHRH antagonist treatment.


Assuntos
NF-kappa B , Proteínas Proto-Oncogênicas c-akt , Animais , Camundongos , Hormônio Liberador de Hormônio do Crescimento/genética , Hormônio Liberador de Hormônio do Crescimento/metabolismo , Homozigoto
18.
Aging Cell ; 22(12): e13985, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37667562

RESUMO

Our previous research has demonstrated that mice lacking functional growth hormone-releasing hormone (GHRH) exhibit distinct physiological characteristics, including an extended lifespan, a preference for lipid utilization during rest, mild hypoglycemia, and heightened insulin sensitivity. They also show a further increase in lifespan when subjected to caloric restriction. These findings suggest a unique response to fasting, which motivated our current study on the response to glucagon, a key hormone released from the pancreas during fasting that regulates glucose levels, energy expenditure, and metabolism. Our study investigated the effects of an acute glucagon challenge on female GHRH knockout mice and revealed that they exhibit reduced glucose production, likely due to suppressed gluconeogenesis. However, these mice showed an increase in energy expenditure. We also observed alterations in pancreatic islet architecture, with smaller islets and a reduction of insulin-producing beta cells but no changes in glucagon-producing alpha cells. Additionally, the analysis of hepatic glucagon signaling showed a decrease in glucagon receptor expression and phosphorylated CREB. In conclusion, our findings suggest that the unique metabolic phenotype observed in these long-lived mice may be partly explained by changes in glucagon signaling. Further exploration of this pathway may lead to new insights into the regulation of longevity in mammals.


Assuntos
Glucagon , Longevidade , Feminino , Camundongos , Animais , Glucagon/metabolismo , Glucagon/farmacologia , Camundongos Knockout , Longevidade/genética , Insulina/metabolismo , Hormônio Liberador de Hormônio do Crescimento , Glucose/metabolismo , Mamíferos/metabolismo
19.
Biomed Chromatogr ; 37(12): e5741, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37688464

RESUMO

Matrix effect and sample pretreatment significantly affect the percentage recovery of peptides in biological matrices, affecting the method robustness and accuracy. To counteract this effect, an internal standard (IS) is used; however, in most cases this is not available, which limits the analytical method. It is important to identify short peptides that can be used as ISs in the quantification of peptides in biological matrices. In this study, doping peptides GHRP-4, GHRP-5, GHRP-6, Sermorelin (1-11), Sermorelin (13-20) and Sermorelin (22-29) were synthesized using solid-phase peptide synthesis. Treatment with human blood, trypsin and chymotrypsin was used to determine the stability of the peptides. Products were evaluated using the high-performance liquid chromatography-diode array detector (HPLC-DAD) method. The analytical methodology and sample pretreatment were effective for the analysis of these molecules. A unique profile related to protein binding and enzymatic stability of each peptide was established. GHRP-4, GHRP-6 and Sermorelin (22-29) can be considered as in-house ISs as they were stable to enzyme and blood treatment and can be used for the quantification of peptides in biological samples. Peptides GHRP-6 and Sermorelin (22-29) were used to analyse a dimeric peptide (26 [F] LfcinB (20-30)2 ) in four different matrices to test these peptides as in-house IS.


Assuntos
Testes de Química Clínica , Dopagem Esportivo , Hormônio Liberador de Hormônio do Crescimento , Substâncias de Crescimento , Peptídeos/análise , Humanos , Soro/química , Estabilidade Proteica , Análise Química do Sangue/normas , Testes de Química Clínica/normas , Hormônio Liberador de Hormônio do Crescimento/análise , Substâncias de Crescimento/análise
20.
PLoS One ; 18(8): e0290867, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37651371

RESUMO

INTRODUCTION: Medical colleges globally have student organizations that serve to enable students' involvement in research. However, details of their approach and activities are seldom published to serve as learning for student organizations in other settings. The Student Research Forum (SRF), a student organization based at a private medical school in Pakistan aims to facilitate students in acquiring research skills. Following the observation of a downward trajectory of student initiative and interest, SRF leadership restructured the organization and improve its impact. This study describes the development and implementation evaluation of the interventions. METHODOLOGY: The operational framework was revised using the Theory of Change by the core group. Major interventions included enhanced social media and outreach coordination, research workshops, journal clubs, and mentorship to increase research output, mentorship opportunities, and knowledge of medical research; ultimately improving quality in research. The outcomes generated over the course of the study's duration from July 2019 to September 2021 were analyzed using the process metrics of reach, adoption, and efficacy. RESULTS: As a result of the interventions, SRF expanded its reach by conducting a total of 41 events during the duration of the study, facilitated by social media growth on each of SRF's online platforms, with a 300% increase in followers on Facebook, and a nationwide network of 91 student ambassadors. An annual workshop series taught research skills to more than 3800 participants. Students leading their own events, SRF featuring international speakers, and the abstracts submitted to SRF's annual conference, along with the conference's reach of 10,000 students, are seen as improvements in the ToC-informed interventions' adoption. The efficacy of the interventions manifested as the REACH program allocated 56 research projects to vetted applicants. CONCLUSION: The applied interventions have accelerated SRF's progress towards achieving its long-term outcome of increased quality in research as translated by increased research output quantity, mentorship, and knowledge of medical research. Further evaluation is required to assess the success of the ToC. As SRF continues to grow, a continued analysis of the implementation outcomes is imperative to gauge its effectiveness.


Assuntos
Pesquisa Biomédica , Estudantes de Medicina , Humanos , Benchmarking , Impulso (Psicologia) , Hormônio Liberador de Hormônio do Crescimento
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