Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49.804
Filtrar
1.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2217-2220, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018448

RESUMO

Type 1 diabetic patients characteristically exhibit a loss of insulin production, leading to chronic hyperglycemia and related complications. Herein we describe the design, synthesis and screening of novel oligopeptides for their potential to enhance the secretion of insulin from human pancreatic islets. The investigation of these compounds, based off the patented INGAP-PP sequence, aims to identify the peptide features key to maximizing insulin secretion.Clinical Relevance - This report describes the relative efficacy of selected novel compounds for potential Type 1 Diabetes Therapy. Tested on live human pancreatic islets, the compounds are evaluated for their enhancing/inhibitory effect on the secretion of insulin. These studies pave the way for future targeted drug therapies.


Assuntos
Diabetes Mellitus Tipo 1 , Ilhotas Pancreáticas , Diabetes Mellitus Tipo 1/tratamento farmacológico , Humanos , Insulina/metabolismo , Secreção de Insulina , Ilhotas Pancreáticas/metabolismo , Peptídeos/metabolismo
2.
Med Hypotheses ; 143: 110185, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33017914

RESUMO

COVID-19 pandemic is spreading rapidly worldwide, and drug selection can affect the morbidity and mortality of the disease positively or negatively. Alpha-lipoic acid (ALA) is a potent antioxidant and reduces oxidative stress and inhibits activation of nuclear factor-kappa B (NF-kB). ALA reduces ADAM17 activity and ACE2 upregulation. ALA is known to have antiviral effects against some viruses. ALA may show antiviral effect by reducing NF-kB activation and alleviating redox reactions. ALA increases the intracellular glutathione strengthens the human host defense. ALA activates ATP dependent K+ channels (Na+, K+-ATPase). Increased K+ in the cell raises the intracellular pH. As the intracellular pH increases, the entry of the virus into the cell decreases. ALA can increase human host defense against SARS-CoV-2 by increasing intracellular pH. ALA treatment increases antioxidant levels and reduces oxidative stress. Thus, ALA may strengthen the human host defense against SARS-CoV-2 and can play a vital role in the treatment of patients with critically ill COVID-19. It can prevent cell damage by decreasing lactate production in patients with COVID-19. Using ALA with insulin in patients with diabetes can show a synergistic effect against SARS-CoV-2. We think ALA treatment will be beneficial against COVID-19 in patients with diabetes.


Assuntos
Proteína ADAM17/metabolismo , Infecções por Coronavirus/prevenção & controle , Complicações do Diabetes/prevenção & controle , NF-kappa B/metabolismo , Pandemias/prevenção & controle , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/prevenção & controle , Ácido Tióctico/uso terapêutico , Antioxidantes/uso terapêutico , Betacoronavirus , Infecções por Coronavirus/complicações , Complicações do Diabetes/virologia , Diabetes Mellitus/tratamento farmacológico , Humanos , Concentração de Íons de Hidrogênio , Insulina/metabolismo , Oxirredução , Estresse Oxidativo , Pneumonia Viral/complicações
3.
Nat Commun ; 11(1): 4933, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004787

RESUMO

The influence of seasons on biological processes is poorly understood. In order to identify biological seasonal patterns based on diverse molecular data, rather than calendar dates, we performed a deep longitudinal multiomics profiling of 105 individuals over 4 years. Here, we report more than 1000 seasonal variations in omics analytes and clinical measures. The different molecules group into two major seasonal patterns which correlate with peaks in late spring and late fall/early winter in California. The two patterns are enriched for molecules involved in human biological processes such as inflammation, immunity, cardiovascular health, as well as neurological and psychiatric conditions. Lastly, we identify molecules and microbes that demonstrate different seasonal patterns in insulin sensitive and insulin resistant individuals. The results of our study have important implications in healthcare and highlight the value of considering seasonality when assessing population wide health risk and management.


Assuntos
Exposição Ambiental , Resistência à Insulina/fisiologia , Redes e Vias Metabólicas/fisiologia , Microbiota/fisiologia , Estações do Ano , Adulto , Idoso , Glicemia/análise , Glicemia/metabolismo , California , Análise por Conglomerados , Feminino , Nível de Saúde , Humanos , Insulina/metabolismo , Estudos Longitudinais , Masculino , Metabolômica , Pessoa de Meia-Idade , RNA-Seq
4.
Nat Commun ; 11(1): 4627, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009389

RESUMO

Animals have evolved responses to low oxygen conditions to ensure their survival. Here, we have identified the C. elegans zinc finger transcription factor PQM-1 as a regulator of the hypoxic stress response. PQM-1 is required for the longevity of insulin signaling mutants, but surprisingly, loss of PQM-1 increases survival under hypoxic conditions. PQM-1 functions as a metabolic regulator by controlling oxygen consumption rates, suppressing hypoxic glycogen levels, and inhibiting the expression of the sorbitol dehydrogenase-1 SODH-1, a crucial sugar metabolism enzyme. PQM-1 promotes hypoxic fat metabolism by maintaining the expression of the stearoyl-CoA desaturase FAT-7, an oxygen consuming, rate-limiting enzyme in fatty acid biosynthesis. PQM-1 activity positively regulates fat transport to developing oocytes through vitellogenins under hypoxic conditions, thereby increasing survival rates of arrested progeny during hypoxia. Thus, while pqm-1 mutants increase survival of mothers, ultimately this loss is detrimental to progeny survival. Our data support a model in which PQM-1 controls a trade-off between lipid metabolic activity in the mother and her progeny to promote the survival of the species under hypoxic conditions.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Hipóxia/metabolismo , Metabolismo dos Lipídeos , Transativadores/metabolismo , Animais , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Embrião de Mamíferos/metabolismo , Regulação da Expressão Gênica , Glicogênio/metabolismo , Insulina/metabolismo , Larva/metabolismo , Mutação/genética , Consumo de Oxigênio , Transdução de Sinais , Estresse Fisiológico , Análise de Sobrevida , Transativadores/genética , Transcrição Genética , Vitelogeninas/metabolismo
5.
Mol Cell ; 80(1): 87-101.e5, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32931746

RESUMO

Studies in three mouse models of breast cancer identified profound discrepancies between cell-autonomous and systemic Akt1- or Akt2-inducible deletion on breast cancer tumorigenesis and metastasis. Although systemic Akt1 deletion inhibits metastasis, cell-autonomous Akt1 deletion does not. Single-cell mRNA sequencing revealed that systemic Akt1 deletion maintains the pro-metastatic cluster within primary tumors but ablates pro-metastatic neutrophils. Systemic Akt1 deletion inhibits metastasis by impairing survival and mobilization of tumor-associated neutrophils. Importantly, either systemic or neutrophil-specific Akt1 deletion is sufficient to inhibit metastasis of Akt-proficient tumors. Thus, Akt1-specific inhibition could be therapeutic for breast cancer metastasis regardless of primary tumor origin. Systemic Akt2 deletion does not inhibit and exacerbates mammary tumorigenesis and metastasis, but cell-autonomous Akt2 deletion prevents breast cancer tumorigenesis by ErbB2. Elevated circulating insulin level induced by Akt2 systemic deletion hyperactivates tumor Akt, exacerbating ErbB2-mediated tumorigenesis, curbed by pharmacological reduction of the elevated insulin.


Assuntos
Neoplasias Mamárias Animais/enzimologia , Neoplasias Mamárias Animais/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Carcinogênese/patologia , Feminino , Deleção de Genes , Humanos , Insulina/metabolismo , Isoenzimas/metabolismo , Metástase Neoplásica , Neutrófilos/metabolismo , Receptor ErbB-2/metabolismo
6.
In Vivo ; 34(5): 3029-3032, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32871848

RESUMO

BACKGROUND/AIM: Reports indicate that coronaviridae may inhibit insulin secretion. In this report we aimed to describe the course of glycemia in critically ill patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. PATIENTS AND METHODS: We studied 36 SARS-CoV-2 patients (with no history of diabetes) in one intensive care unit (ICU). All the patients were admitted for hypoxemic respiratory failure; all but four required mechanical ventilation. The mean (±SD) age of the patients was 64.7 (9.7) years; 27 were men; the mean (±SD) duration of ICU stay was 12.9 (8.3 days). RESULTS: Twenty of 36 patients presented with hyperglycemia; brief intravenous infusions of short-acting insulin were administered in six patients. As of May 29 2020, 11 patients had died (seven with hyperglycemia). In 17 patients the Hyperglycemia Index [HGI; defined as the area under the curve of (hyper)glycemia level*time (h) divided by the total time in the ICU] was <16.21 mg/dl (0.90 mmol/l), whereas in three patients the HGI was ≥16.21 mg/dl (0.90 mol/l) and <32.25 mg/dl (1.79 mmol/l). CONCLUSION: In our series of ICU patients with SARS-CoV-2 infection, and no history of diabetes, a substantial number of patients had hyperglycemia, to a higher degree than would be expected by the stress of critical illness, lending credence to reports that speculated a tentative association between SARS-CoV-2 and hyperglycemia. This finding is important, since hyperglycemia can lead to further infectious complications.


Assuntos
Infecções por Coronavirus/terapia , Diabetes Mellitus/terapia , Hiperglicemia/terapia , Insulina/metabolismo , Pneumonia Viral/terapia , Betacoronavirus/patogenicidade , Glicemia/metabolismo , Infecções por Coronavirus/complicações , Infecções por Coronavirus/virologia , Diabetes Mellitus/genética , Diabetes Mellitus/virologia , Feminino , Hospitalização , Humanos , Hiperglicemia/complicações , Hiperglicemia/virologia , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/complicações , Pneumonia Viral/virologia , Respiração Artificial , Insuficiência Respiratória/fisiopatologia , Insuficiência Respiratória/terapia , Síndrome Respiratória Aguda Grave/complicações , Síndrome Respiratória Aguda Grave/terapia , Síndrome Respiratória Aguda Grave/virologia
7.
PLoS One ; 15(9): e0236081, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32960890

RESUMO

Type 2 diabetes mellitus (T2DM), one of the most common metabolic diseases, is characterized by insulin resistance and inadequate insulin secretion of ß cells. Glycogen phosphorylase (GP) is the key enzyme in glycogen breakdown, and contributes to hepatic glucose production during fasting or during insulin resistance. Pharmacological GP inhibitors are potential glucose lowering agents, which may be used in T2DM therapy. A natural product isolated from the cultured broth of the fungal strain No. 138354, called 2,3-bis(4-hydroxycinnamoyloxy)glutaric acid (FR258900), was discovered a decade ago. In vivo studies showed that FR258900 significantly reduced blood glucose levels in diabetic mice. We previously showed that GP inhibitors can potently enhance the function of ß cells. The purpose of this study was to assess whether an analogue of FR258900 can influence ß cell function. BF142 (Meso-Dimethyl 2,3-bis[(E)-3-(4-acetoxyphenyl)prop-2-enamido]butanedioate) treatment activated the glucose-stimulated insulin secretion pathway, as indicated by enhanced glycolysis, increased mitochondrial oxidation, significantly increased ATP production, and elevated calcium influx in MIN6 cells. Furthermore, BF142 induced mTORC1-specific phosphorylation of S6K, increased levels of PDX1 and insulin protein, and increased insulin secretion. Our data suggest that BF142 can influence ß cell function and can support the insulin producing ability of ß cells.


Assuntos
Cinamatos/farmacologia , Inibidores Enzimáticos/farmacologia , Glutaratos/farmacologia , Glicogênio Fosforilase/antagonistas & inibidores , Secreção de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/efeitos dos fármacos , Ácido Succínico/farmacologia , Animais , Linhagem Celular Tumoral , Cinamatos/química , Inibidores Enzimáticos/química , Glucose/metabolismo , Glutaratos/química , Glicogênio Fosforilase/metabolismo , Glicólise/efeitos dos fármacos , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Metilação , Camundongos , Ácido Succínico/química
8.
Medicine (Baltimore) ; 99(31): e21612, 2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32756217

RESUMO

BACKGROUND: Emerging evidence indicates the role of gut microbiota in the development of cardiovascular diseases. Thus, gut microbiota is increasingly recognized as a potential therapeutic target of cardiovascular disease. However, the effects of gut microbiome-targeted therapies on cardiometabolic outcomes in children and adolescents remain unclear. METHODS: We plan to perform a systematic search from PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science. Two authors will independently select the relevant studies and extract data according to a previously defined data extraction sheet. We will use the Stata 14.0 statistical software and RevMan V.5.3 software to conduct data analyses. RESULTS AND CONCLUSION: The results of this study will be published in a peer-reviewed journal and provide more evidence for the application of gut microbiome-targeted therapies in children and adolescents for the intervention of cardiovascular risk factors in clinical practice. PROTOCOL REGISTRATION NUMBER: INPLASY202060050.


Assuntos
Doenças Cardiovasculares/epidemiologia , Suplementos Nutricionais , Probióticos/administração & dosagem , Simbióticos/administração & dosagem , Adolescente , Glicemia , Pressão Sanguínea , Criança , Pré-Escolar , Feminino , Microbioma Gastrointestinal/fisiologia , Hemoglobina A Glicada , Humanos , Lactente , Insulina/metabolismo , Lipídeos/sangue , Masculino , Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa
9.
PLoS One ; 15(8): e0231806, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32817622

RESUMO

The cAMP-dependent protein kinase (PKA) signaling pathway is the primary means by which the heart regulates moment-to-moment changes in contractility and metabolism. We have previously found that PKA signaling is dysfunctional in the diabetic heart, yet the underlying mechanisms are not fully understood. The objective of this study was to determine if decreased insulin signaling contributes to a dysfunctional PKA response. To do so, we isolated adult cardiomyocytes (ACMs) from wild type and Akita type 1 diabetic mice. ACMs were cultured in the presence or absence of insulin and PKA signaling was visualized by immunofluorescence microscopy using an antibody that recognizes proteins specifically phosphorylated by PKA. We found significant decreases in proteins phosphorylated by PKA in wild type ACMs cultured in the absence of insulin. PKA substrate phosphorylation was decreased in Akita ACMs, as compared to wild type, and unresponsive to the effects of insulin. The decrease in PKA signaling was observed regardless of whether the kinase was stimulated with a beta-agonist, a cell-permeable cAMP analog, or with phosphodiesterase inhibitors. PKA content was unaffected, suggesting that the decrease in PKA signaling may be occurring by the loss of specific PKA substrates. Phospho-specific antibodies were used to discern which potential substrates may be sensitive to the loss of insulin. Contractile proteins were phosphorylated similarly in wild type and Akita ACMs regardless of insulin. However, phosphorylation of the glycolytic regulator, PFK-2, was significantly decreased in an insulin-dependent manner in wild type ACMs and in an insulin-independent manner in Akita ACMs. These results demonstrate a defect in PKA activation in the diabetic heart, mediated in part by deficient insulin signaling, that results in an abnormal activation of a primary metabolic regulator.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Diabetes Mellitus/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , Diabetes Mellitus Experimental/metabolismo , Modelos Animais de Doenças , Insulina/metabolismo , Insulina/farmacologia , Insulina/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/fisiologia , Inibidores de Fosfodiesterase/farmacologia , Fosforilação/efeitos dos fármacos , Cultura Primária de Células , Transdução de Sinais/efeitos dos fármacos
10.
N Engl J Med ; 383(8): 721-732, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32813948

RESUMO

BACKGROUND: Some studies have suggested that in people with type 2 diabetes, Roux-en-Y gastric bypass has therapeutic effects on metabolic function that are independent of weight loss. METHODS: We evaluated metabolic regulators of glucose homeostasis before and after matched (approximately 18%) weight loss induced by gastric bypass (surgery group) or diet alone (diet group) in 22 patients with obesity and diabetes. The primary outcome was the change in hepatic insulin sensitivity, assessed by infusion of insulin at low rates (stages 1 and 2 of a 3-stage hyperinsulinemic euglycemic pancreatic clamp). Secondary outcomes were changes in muscle insulin sensitivity, beta-cell function, and 24-hour plasma glucose and insulin profiles. RESULTS: Weight loss was associated with increases in mean suppression of glucose production from baseline, by 7.04 µmol per kilogram of fat-free mass per minute (95% confidence interval [CI], 4.74 to 9.33) in the diet group and by 7.02 µmol per kilogram of fat-free mass per minute (95% CI, 3.21 to 10.84) in the surgery group during clamp stage 1, and by 5.39 (95% CI, 2.44 to 8.34) and 5.37 (95% CI, 2.41 to 8.33) µmol per kilogram of fat-free mass per minute in the two groups, respectively, during clamp stage 2; there were no significant differences between the groups. Weight loss was associated with increased insulin-stimulated glucose disposal, from 30.5±15.9 to 61.6±13.0 µmol per kilogram of fat-free mass per minute in the diet group and from 29.4±12.6 to 54.5±10.4 µmol per kilogram of fat-free mass per minute in the surgery group; there was no significant difference between the groups. Weight loss increased beta-cell function (insulin secretion relative to insulin sensitivity) by 1.83 units (95% CI, 1.22 to 2.44) in the diet group and by 1.11 units (95% CI, 0.08 to 2.15) in the surgery group, with no significant difference between the groups, and it decreased the areas under the curve for 24-hour plasma glucose and insulin levels in both groups, with no significant difference between the groups. No major complications occurred in either group. CONCLUSIONS: In this study involving patients with obesity and type 2 diabetes, the metabolic benefits of gastric bypass surgery and diet were similar and were apparently related to weight loss itself, with no evident clinically important effects independent of weight loss. (Funded by the National Institutes of Health and others; ClinicalTrials.gov number, NCT02207777.).


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Derivação Gástrica , Obesidade/dietoterapia , Obesidade/cirurgia , Perda de Peso/fisiologia , Adulto , Glicemia/análise , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/dietoterapia , Diabetes Mellitus Tipo 2/cirurgia , Feminino , Técnica Clamp de Glucose , Humanos , Insulina/metabolismo , Resistência à Insulina/fisiologia , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Estudos Prospectivos , Indução de Remissão
11.
PLoS Biol ; 18(8): e3000548, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32745077

RESUMO

Sleep is vital for survival. Yet under environmentally challenging conditions, such as starvation, animals suppress their need for sleep. Interestingly, starvation-induced sleep loss does not evoke a subsequent sleep rebound. Little is known about how starvation-induced sleep deprivation differs from other types of sleep loss, or why some sleep functions become dispensable during starvation. Here, we demonstrate that down-regulation of the secreted cytokine unpaired 2 (upd2) in Drosophila flies may mimic a starved-like state. We used a genetic knockdown strategy to investigate the consequences of upd2 on visual attention and sleep in otherwise well-fed flies, thereby sidestepping the negative side effects of undernourishment. We find that knockdown of upd2 in the fat body (FB) is sufficient to suppress sleep and promote feeding-related behaviors while also improving selective visual attention. Furthermore, we show that this peripheral signal is integrated in the fly brain via insulin-expressing cells. Together, these findings identify a role for peripheral tissue-to-brain interactions in the simultaneous regulation of sleep quality and attention, to potentially promote adaptive behaviors necessary for survival in hungry animals.


Assuntos
Atenção/fisiologia , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Comportamento Alimentar/fisiologia , Inanição/genética , Percepção Visual/fisiologia , Animais , Encéfalo/citologia , Encéfalo/metabolismo , Proteínas de Drosophila/deficiência , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Corpo Adiposo/metabolismo , Feminino , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Insulina/genética , Insulina/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Transdução de Sinais , Sono/fisiologia , Privação do Sono/genética , Privação do Sono/metabolismo , Inanição/metabolismo
12.
PLoS One ; 15(7): e0236892, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32735622

RESUMO

There is a significant unmet need for a safe and effective therapy for the treatment of children with congenital hyperinsulinism. We hypothesized that amplification of the glucagon signaling pathway could ameliorate hyperinsulinism associated hypoglycemia. In order to test this we evaluated the effects of loss of Prkar1a, a negative regulator of Protein Kinase A in the context of hyperinsulinemic conditions. With reduction of Prkar1a expression, we observed a significant upregulation of hepatic gluconeogenic genes. In wild type mice receiving a continuous infusion of insulin by mini-osmotic pump, we observed a 2-fold increase in the level of circulating ketones and a more than 40-fold increase in Kiss1 expression with reduction of Prkar1a. Loss of Prkar1a in the Sur1-/- mouse model of KATP hyperinsulinism significantly attenuated fasting induced hypoglycemia, decreased the insulin/glucose ratio, and also increased the hepatic expression of Kiss1 by more than 10-fold. Together these data demonstrate that amplification of the hepatic glucagon signaling pathway is able to rescue hypoglycemia caused by hyperinsulinism.


Assuntos
Hiperinsulinismo Congênito/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Kisspeptinas/genética , Receptores Sulfonilureia/genética , Animais , Hiperinsulinismo Congênito/genética , Subunidade RIalfa da Proteína Quinase Dependente de AMP Cíclico/metabolismo , Modelos Animais de Doenças , Gluconeogênese/genética , Glucose/metabolismo , Hipoglicemia/metabolismo , Insulina/metabolismo , Cetonas/metabolismo , Kisspeptinas/metabolismo , Fígado/metabolismo , Camundongos , Camundongos Knockout , Transdução de Sinais
13.
Gene ; 761: 145036, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32777525

RESUMO

Lupinus albus γ-conglutin is proposed to positively affect glucose metabolism through inhibition of hepatic glucose production and insulin-mimetic activity; however, the action mechanism is not entirely known. Besides, most studies had focused on its effect on molecular targets directly related to glucose metabolism, and few studies have investigated how γ-conglutin may affect the liver gene expression or if it plays a role in other metabolic processes. Therefore, we investigated the influence of γ-conglutin on the liver transcriptome of streptozotocin-induced diabetic rats using DNA microarrays, ontological analyses, and quantitative PCR. Of the 22,000 genes evaluated, 803 and 173 were downregulated and upregulated, respectively. The ontological analyses of the differentially expressed genes revealed that among others, the mitochondria, microtubules, cytoskeleton, and oxidoreductase activity terms were enriched, implying a possible role of γ-conglutin on autophagy. To corroborate the microarray results, we selected and quantified, by PCR, the expression of two genes associated with autophagy (Atg7 and Snx18) and found their expression augmented two and threefold, respectively; indicating a higher autophagy activity in animals treated with γ-conglutin. Although complementary studies are required, our findings indicate for the first time that the hypoglycaemic effects of γ-conglutin may involve an autophagy induction mechanism, a pivotal process for the preservation of cell physiology and glucose homeostasis.


Assuntos
Colectinas/farmacologia , Lupinus/metabolismo , Soroglobulinas/farmacologia , Transcriptoma/genética , Animais , Glicemia/metabolismo , Colectinas/metabolismo , Colectinas/fisiologia , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Glucose/metabolismo , Insulina/metabolismo , Fígado/metabolismo , Fígado/patologia , Lupinus/genética , Masculino , Proteínas de Plantas/genética , Ratos , Ratos Wistar , Sementes/metabolismo , Soroglobulinas/metabolismo , Soroglobulinas/fisiologia
14.
PLoS One ; 15(8): e0237215, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32797106

RESUMO

In 1978, Thomas J. Sorensen defended a thesis in chemical engineering at the University of California, Berkeley, where he proposed an extensive model of glucose-insulin control, model which was thereafter widely employed for virtual patient simulation. The original model, and even more so its subsequent implementations by other Authors, presented however a few imprecisions in reporting the correct model equations and parameter values. The goal of the present work is to revise the original Sorensen's model, to clearly summarize its defining equations, to supplement it with a missing gastrio-intestinal glucose absorption and to make an implementation of the revised model available on-line to the scientific community.


Assuntos
Glucose/metabolismo , Insulina/metabolismo , Algoritmos , Glicemia/metabolismo , Absorção Gástrica , Mucosa Gástrica/metabolismo , Humanos , Absorção Intestinal , Modelos Biológicos
15.
Life Sci ; 257: 118028, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32615185

RESUMO

AIMS: Sertoli cells (SCs) play an important role in the process of spermatogenesis. SCs provide energy for germ cells (GCs) and themselves through glycolysis and fatty acid oxidation (FAO) respectively. High fat diet (HFD) impairs spermatogenesis by damaging function of SCs, however whether HFD disrupts energy metabolism in SCs remains unclear. MAIN METHODS: To explore this hypothesis, we built male Wistar rat model fed on HFD and cultured rats' primary SCs with palmitic acid (PA). Rats' fertility and sperm quality were evaluated in vivo. Glycolysis, lactate production and mitochondrial respiration were assessed by using extracellular flux analyzer, and the expression of enzymes involved in glucose and FAO was analyzed by Real-Time PCR or Western Blotting. KEY FINDINGS: The showed that the sperm concentration and pups per litter significantly decreased in rats fed on HFD compared to those rats fed on normal diet. There was an elevation of lactate levels in testicular tissue of rats fed on HFD and primary SCs exposed to PA. In vitro, PA increased glycolytic flux, and lactate production, and the levels of carnitine palmitoyltransferase I (CPT1) and long chain acyl-CoA dehydrogenase (LCAD) which were two key enzymes for fatty acid ß oxidation. Further analysis showed that mitochondrial respiration was impaired by PA, followed by the decrease in ATP turnover, maximal respiration and the increase in proton leak. SIGNIFICANCE: Taken together, the elevated lactate level, lipid metabolism disorder and mitochondrial dysfunction caused by HFD lead to SCs dysfunction, which ultimately leads to decreased sperm quality.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Células de Sertoli/metabolismo , Espermatogênese/fisiologia , Animais , Metabolismo Energético , Ácidos Graxos/metabolismo , Glucose/metabolismo , Glicólise , Insulina/metabolismo , Metabolismo dos Lipídeos/fisiologia , Masculino , Oxirredução , Ácido Palmítico , Ratos , Ratos Wistar , Triglicerídeos/metabolismo
16.
PLoS One ; 15(7): e0236603, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32706828

RESUMO

BACKGROUND AND OBJECTIVE: Dipeptidyl peptidase-4 (DPP-4) inhibitors have been suggested to have pancreatic beta-cell preserving effect according to studies using homeostatic model of assessment for beta-cell function (HOMA-ß). However, whether HOMA-ß is a suitable biomarker for comparisons between hypoglycemic drugs with different mechanisms of action remains unclear. Therefore, we conducted a meta-analysis to compare the effects of DPP-4 inhibitors and other classes of hypoglycemic drugs on HOMA-ß and proinsulin-to-insulin ratio (PIR). METHODS: We searched MEDLINE, CENTRAL, and Ichushi-web for the period of 1966 to May 2020. We collected randomized, controlled clinical trials in patients with type 2 diabetes mellitus comparing DPP-4 inhibitors and other classes of hypoglycemic agents [α-glucosidase inhibitors (α-GIs), glucagon-like peptide-1 (GLP-1) analogues, metformin, sodium-glucose cotransporter 2 (SGLT2) inhibitors, sulfonylureas, or thiazolidinediones]. Weighted mean differences and 95% confidence intervals of changes in HOMA-ß or PIR during study periods were calculated for pairwise comparisons. RESULTS: Thirty-seven and 21 relevant trials were retrieved for comparisons of HOMA-ß and PIR, respectively. HOMA-ß and PIR consistently showed superiority of DPP-4 inhibitors compared with α-GIs. Both biomarkers consistently supported inferiority of DPP-4 inhibitors compared with GLP-1 analogues. However, PIR showed inferiority of DPP-4 inhibitors compared with metformin, and superiority compared with SGLT2 inhibitors, whereas HOMA-ß showed no significant differences between DPP-4 inhibitors and the two other agents. CONCLUSION: DPP-4 inhibitors appear to be superior to α-GIs but inferior to GLP-1 analogues in preservation of beta-cell function assessed by either HOMA-ß or PIR. DPP-4 inhibitors seem to be superior to SGLT2 inhibitors but inferior to metformin on islet function assessed only by PIR. Because HOMA-ß and PIR may indicate different aspects of beta-cell function, results of beta-cell function preserving effects of hypoglycemic agents should be interpreted with caution.


Assuntos
Biomarcadores/metabolismo , Inibidores da Dipeptidil Peptidase IV/farmacologia , Hipoglicemiantes/farmacologia , Células Secretoras de Insulina/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/patologia , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Humanos , Hipoglicemiantes/uso terapêutico , Insulina/metabolismo , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/metabolismo , Metformina/farmacologia , Metformina/uso terapêutico , Proinsulina/metabolismo , Compostos de Sulfonilureia/farmacologia , Compostos de Sulfonilureia/uso terapêutico , Tiazolidinedionas/farmacologia , Tiazolidinedionas/uso terapêutico
17.
Gene ; 757: 144949, 2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-32679290

RESUMO

Melanocortin-2 receptor accessory protein (MRAP) has an unusual dual topology and influences the expression, localisation, signalling and internalisation of the melanocortin receptor 2 (MC2); the adrenocorticotropic hormone (ACTH) receptor. Mutations in MRAP are associated with familial glucocorticoid deficiency type-2 and evidence is emerging of the importance of MRAP in adrenal development and ACTH signalling. Human MRAP has two functional splice variants: MRAP-α and MRAP-ß, unlike MRAP-ß, MRAP-α has little expression in brain but is highly expressed in ovary. MRAP2, identified through whole human genome sequence analysis, has approximately 40% sequence homology to MRAP. MRAP2 facilitates MC2 localisation to the cell surface but not ACTH signalling. MRAP and MRAP2 have been found to regulate the surface expression and signalling of all melanocortin receptors (MC1-5). Additionally, MRAP2 moderates the signalling of the G-protein coupled receptors (GCPRs): orexin, prokineticin and GHSR1a; the ghrelin receptor. Whilst MRAP appears to be mainly involved in glucocorticoid synthesis, an important role is emerging for MRAP2 in regulating appetite and energy homeostasis. Transgenic models indicate the importance of MRAP in adrenal gland formation. Like MC3R and MC4R knockout mice, MRAP2 knockout mice have an obese phenotype. In vitro studies indicate that MRAP2 enhances the MC3 and MC4 response to the agonist αMSH, which, like ACTH, is produced through precursor polypeptide proopiomelanocortin (POMC) cleavage. Analysis of cohorts of individuals with obesity have revealed several MRAP2 genetic variants with loss of function mutations which are causative of monogenic hyperphagic obesity with hyperglycaemia and hypertension. MRAP2 may also be associated with female infertility. This review summarises current knowledge of MRAP and MRAP2, their influence on GPCR signalling, and focusses on pathophysiology, particularly familial glucocorticoid deficiency type-2 and obesity.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Insuficiência Adrenal/genética , Proteínas de Membrana/metabolismo , Erros Inatos do Metabolismo de Esteroides/genética , Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Adaptadoras de Transdução de Sinal/genética , Insuficiência Adrenal/metabolismo , Animais , Regulação do Apetite , Humanos , Insulina/metabolismo , Melanocortinas/metabolismo , Proteínas de Membrana/química , Proteínas de Membrana/genética , Erros Inatos do Metabolismo de Esteroides/metabolismo
18.
Maturitas ; 138: 36-41, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32631586

RESUMO

BACKGROUND: Menopause is often associated with a central accumulation of body fat. This provokes insulin resistance. The resulting hyperinsulinemia may increase the risk of diabetes, cardiovascular disease and breast cancer. Long-term studies indicate that menopausal hormone therapy (MHT) reduces insulin resistance. To broaden knowledge of the mechanisms behind the influence of MHT on glucose homeostasis we focused on the direct short-term effects of MHT with oral combined estradiol and drospirenone on glucose and insulin metabolism in healthy postmenopausal women. METHODS: This randomized, placebo-controlled study recruited 80 healthy postmenopausal women. Women were randomized to treatment with estradiol 1 mg continuously combined with drospirenone 2 mg or placebo for 6-8 weeks. All participants underwent an oral glucose tolerance test (OGTT) before and after the treatment period. Glucose, insulin, fructosamine and C-peptide levels were measured in serum before and 30, 60, 90, 120 and 150 min after a 75-gram oral glucose challenge. RESULTS: After intervention, significantly higher glucose levels at 120 min (p < 0.024) and 150 min (p < 0.030) were observed in the MHT group compared with the placebo group. These glucose levels remained within the normal range. A significantly lower insulin peak serum level (p < 0.040) and a non-significantly smaller area under the curve (AUC) for insulin levels (p = 0.192) was observed in the MHT group at the end of the study period relative to baseline. No significant change in the insulin AUC in the placebo group was observed. There were no significant differences in fructosamine, HOMA-IR and C-peptide levels between the MHT group and the placebo group. CONCLUSION: This double-blind randomized study (EC/2008/694) indicates that treating healthy, postmenopausal women with 1 mg estradiol continuously combined with 2 mg drospirenone significantly decreases peak insulin levels and increases peak glucose levels during an OGTT compared to placebo. These glucose levels remained within the normal range.


Assuntos
Androstenos/uso terapêutico , Estradiol/uso terapêutico , Estrogênios/uso terapêutico , Glucose/metabolismo , Terapia de Reposição Hormonal , Insulina/metabolismo , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Administração Oral , Glicemia/análise , Método Duplo-Cego , Combinação de Medicamentos , Feminino , Teste de Tolerância a Glucose , Humanos , Pessoa de Meia-Idade , Pós-Menopausa
19.
Diab Vasc Dis Res ; 17(4): 1479164120945675, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32722929

RESUMO

Activation of the prostaglandin E2 receptor EP4 alters polarization of adipose tissue macrophages towards the anti-inflammatory M2 phenotype to suppress chronic inflammation. However, the role of EP4 signalling in pancreatic macrophages that affect insulin secretion is unclear. We examined the role of EP4 signalling in islet inflammation in vitro and in vivo. Obese diabetic db/db mice were treated with an EP4-selective agonist or vehicle for 4 weeks. Islet morphology did not significantly differ and glucose-stimulated insulin secretion was increased, whereas the pancreatic M1/M2 ratio was decreased in the EP4 agonist-treated group compared to the vehicle group. Because EP4 activation in MIN6 cells did not affect insulin secretion, we used a MIN6/macrophage co-culture system to evaluate the role of EP4 signalling in islet inflammation and subsequent inhibition of insulin release. Co-culture with M1-polarized macrophages markedly suppressed insulin expression in MIN6 cells; however, modulation of M1 polarization by the EP4 agonist significantly reversed the negative impact of co-cultivation on insulin production. The enhanced expression levels of pro-inflammatory cytokines in co-cultured MIN6 cells were markedly inhibited by EP4 agonist treatment of M1 macrophages. Thus, EP4 activation may suppress islet inflammation and protect ß-cell function by altering inflammatory macrophages in the diabetic pancreas.


Assuntos
Plasticidade Celular , Diabetes Mellitus Tipo 2/metabolismo , Inflamação/metabolismo , Células Secretoras de Insulina/metabolismo , Macrófagos Peritoneais/metabolismo , Obesidade/metabolismo , Receptores de Prostaglandina E Subtipo EP4/metabolismo , Animais , Linhagem Celular Tumoral , Técnicas de Cocultura , Citocinas/metabolismo , Diabetes Mellitus Tipo 2/patologia , Modelos Animais de Doenças , Inflamação/patologia , Mediadores da Inflamação/metabolismo , Insulina/metabolismo , Células Secretoras de Insulina/patologia , Ativação de Macrófagos , Macrófagos Peritoneais/patologia , Camundongos , Obesidade/patologia , Fenótipo , Via Secretória , Transdução de Sinais
20.
Mol Genet Genomics ; 295(5): 1253-1262, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32556999

RESUMO

Monogenic diabetes is a rare type of diabetes resulting from mutations in a single gene. To date, most cases remain genetically unexplained, posing a challenge for accurate diabetes treatment, which leads to on a molecular diagnosis. Therefore, a trio exome scan was performed in a lean, nonsyndromic Caucasian girl with diabetes onset at 2½ years who was negative for autoantibodies. The lean father had diabetes from age 11 years. A novel heterozygous mutation in EDEM2, c.1271G > A; p.Arg424His, was found in the proband and father. Downregulation of Edem2 in rat RIN-m ß-cells resulted in a decrease in insulin genes Ins1 to 67.9% (p = 0.006) and Ins2 to 16.8% (p < 0.001) and reduced insulin secretion by 60.4% (p = 0.0003). Real-time PCR revealed a major disruption of endocrine pancreas-specific genes, including Glut2 and Pxd1, with mRNA suppression to 54% (p < 0.001) and 85.7% (p = 0.01), respectively. No other expression changes related to stress or apoptotic genes were observed. Extended clinical follow-up involving ten family members showed that two healthy individuals carried the same mutation with no sign of diabetes in the clinical screen except for a slight increase in IA-2 antibody in one of them, suggesting incomplete penetrance. In conclusion, we describe EDEM2 as a likely/potential novel diabetes gene, in which inhibition in vitro reduces the expression of ß-cell genes involved in the glucose-stimulated insulin secretion (GSIS) pathway, leading to an overall suppression of insulin secretion but not apoptosis.


Assuntos
Diabetes Mellitus/genética , Regulação para Baixo , Transportador de Glucose Tipo 2/genética , Glicoproteínas/genética , Proteínas de Homeodomínio/genética , Mutação Puntual , Transativadores/genética , alfa-Manosidase/genética , Idade de Início , Idoso , Animais , Linhagem Celular , Diabetes Mellitus/metabolismo , Grupo com Ancestrais do Continente Europeu/genética , Feminino , Inativação Gênica , Humanos , Insulina/genética , Insulina/metabolismo , Masculino , Pessoa de Meia-Idade , Linhagem , Ratos , Sequenciamento Completo do Exoma , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA