RESUMO
AIMS: Pancreatic polypeptide (PP) is elevated in people with vascular risk factors such as type 2 diabetes or increased visceral fat. We investigated potential relationships between PP and microvascular and macrovascular complications of diabetes. MATERIALS AND METHODS: Animal study: Subcutaneous PP infusion for 4 weeks in high fat diet mouse model. Retinal mRNA submitted for Ingenuity Pathway Analysis. Human study: fasting PP measured in 1478 participants and vascular complications recorded over median 5.5 (IQR 4.9-5.8) years follow-up. RESULTS: Animal study: The retinal transcriptional response to PP was indicative of cellular stress and damage, and this footprint matched responses described in previously published studies of retinal disease. Of mechanistic importance the transcriptional landscape was consistent with upregulation of folliculin, a recently identified susceptibility gene for diabetic retinopathy. Human study: Adjusting for established risk factors, PP was associated with prevalent and incident clinically significant retinopathy (odds ratio (OR) 1.289 (1.107-1.501) p = 0.001; hazard ratio (HR) 1.259 (1.035-1.531) p = 0.0213), albuminuria (OR 1.277 (1.124-1.454), p = 0.0002; HR 1.608 (1.208-2.141) p = 0.0011), and macrovascular disease (OR 1.021 (1.006-1.037) p = 0.0068; HR 1.324 (1.089-1.61), p = 0.0049), in individuals with type 2 diabetes, and progression to diabetes in non-diabetic individuals (HR 1.402 (1.081-1.818), p = 0.0109). CONCLUSIONS: Elevated fasting PP is independently associated with vascular complications of diabetes and affects retinal pathways potentially influencing retinal neuronal survival. Our results suggest possible new roles for PP-fold peptides in the pathophysiology of diabetes complications and vascular risk stratification.
Assuntos
Diabetes Mellitus Tipo 2 , Angiopatias Diabéticas , Retinopatia Diabética , Jejum , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/patologia , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Angiopatias Diabéticas/etiologia , Angiopatias Diabéticas/epidemiologia , Animais , Camundongos , Seguimentos , Retinopatia Diabética/etiologia , Retinopatia Diabética/epidemiologia , Retinopatia Diabética/patologia , Prognóstico , Incidência , Biomarcadores/análise , Fatores de Risco , IdosoRESUMO
Nonalcoholic fatty liver disease (NAFLD), the most common liver disease, has become a silent worldwide pandemic. The incidence of NAFLD correlates with the rise in obesity, type 2 diabetes, and metabolic syndrome. A hallmark featureof NAFLD is excessive hepatic fat accumulation or steatosis, due to dysregulated hepatic fat metabolism, which can progress to nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. Currently, there are no approved pharmacotherapies to treat this disease. Here, we have found that activation of the kisspeptin 1 receptor (KISS1R) signaling pathway has therapeutic effects in NAFLD. Using high-fat diet-fed mice, we demonstrated that a deletion of hepatic Kiss1r exacerbated hepatic steatosis. In contrast, enhanced stimulation of KISS1R protected against steatosis in wild-type C57BL/6J mice and decreased fibrosis using a diet-induced mouse model of NASH. Mechanistically, we found that hepatic KISS1R signaling activates the master energy regulator, AMPK, to thereby decrease lipogenesis and progression to NASH. In patients with NAFLD and in high-fat diet-fed mice, hepatic KISS1/KISS1R expression and plasma kisspeptin levels were elevated, suggesting a compensatory mechanism to reduce triglyceride synthesis. These findings establish KISS1R as a therapeutic target to treat NASH.
Assuntos
Diabetes Mellitus Tipo 2 , Hepatopatia Gordurosa não Alcoólica , Animais , Diabetes Mellitus Tipo 2/metabolismo , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Humanos , Kisspeptinas/genética , Fígado/metabolismo , Cirrose Hepática/patologia , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/metabolismo , Receptores de Kisspeptina-1/genética , Receptores de Kisspeptina-1/metabolismoRESUMO
Triple-negative breast cancer (TNBC) is a highly metastatic and deadly disease. TNBC tumors lack estrogen receptor (ERα), progesterone receptor (PR), and HER2 (ErbB2) and exhibit increased glutamine metabolism, a requirement for tumor growth. The G protein-coupled kisspeptin receptor (KISS1R) is highly expressed in patient TNBC tumors and promotes malignant transformation of breast epithelial cells. This study found that TNBC patients displayed elevated plasma kisspeptin levels compared with healthy subjects. It also provides the first evidence that in addition to promoting tumor growth and metastasis in vivo, KISS1R-induced glutamine dependence of tumors. In addition, tracer-based metabolomics analyses revealed that KISS1R promoted glutaminolysis and nucleotide biosynthesis by increasing c-Myc and glutaminase levels, key regulators of glutamine metabolism. Overall, this study establishes KISS1R as a novel regulator of TNBC metabolism and metastasis, suggesting that targeting KISS1R could have therapeutic potential in the treatment of TNBC.
Assuntos
Carcinogênese/metabolismo , Reprogramação Celular , Metabolismo Energético , Receptores de Kisspeptina-1/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Adulto , Idoso , Animais , Carcinogênese/genética , Carcinogênese/patologia , Estudos de Casos e Controles , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Glutaminase/genética , Glutaminase/metabolismo , Glutamina/metabolismo , Humanos , Camundongos Endogâmicos NOD , Camundongos SCID , Pessoa de Meia-Idade , Invasividade Neoplásica , Nucleotídeos/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Receptores de Kisspeptina-1/genética , Transdução de Sinais , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia , Carga Tumoral , Adulto JovemRESUMO
INTRODUCTION: Hyperglucagonemia is a key pathophysiological driver of type 2 diabetes. Although Roux-en-Y gastric bypass (RYGB) is a highly effective treatment for diabetes, it is presently unclear how surgery alters glucagon physiology. The aim of this study was to characterize the behavior of proglucagon-derived peptide (glucagon, glucagon-like peptide-1 (GLP-1), oxyntomodulin, glicentin) secretion after RYGB surgery. RESEARCH DESIGN AND METHODS: Prospective study of 19 patients with obesity and pre-diabetes/diabetes undergoing RYGB. We assessed the glucose, insulin, GLP-1, glucose-dependent insulinotropic peptide (GIP), oxyntomodulin, glicentin and glucagon responses to a mixed-meal test (MMT) before and 1, 3 and 12 months after surgery. Glucagon was measured using a Mercodia glucagon ELISA using the 'Alternative' improved specificity protocol, which was validated against a reference liquid chromatography combined with mass spectrometry method. RESULTS: After RYGB, there were early improvements in fasting glucose and glucose tolerance and the insulin response to MMT was accelerated and amplified, in parallel to significant increases in postprandial GLP-1, oxyntomodulin and glicentin secretion. There was a significant decrease in fasting glucagon levels at the later time points of 3 and 12 months after surgery. Glucagon was secreted in response to the MMT preoperatively and postoperatively in all patients and there was no significant change in this postprandial secretion. There was no significant change in GIP secretion. CONCLUSIONS: There is a clear difference in the dynamics of secretion of proglucagon peptides after RYGB. The reduction in fasting glucagon secretion may be one of the mechanisms driving later improvements in glycemia after RYGB. TRIAL REGISTRATION NUMBER: NCT01945840.
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Cirurgia Bariátrica , Diabetes Mellitus Tipo 2 , Derivação Gástrica , Humanos , Proglucagon , Estudos ProspectivosAssuntos
Biomarcadores Tumorais/sangue , Cromogranina A/sangue , Cromogranina B/sangue , Proteínas do Tecido Nervoso/sangue , Tumores Neuroendócrinos/sangue , Insuficiência Renal Crônica/sangue , Estudos de Casos e Controles , Taxa de Filtração Glomerular , Humanos , Tumores Neuroendócrinos/diagnóstico , Insuficiência Renal/sangue , Insuficiência Renal/fisiopatologia , Insuficiência Renal Crônica/fisiopatologia , Sensibilidade e EspecificidadeRESUMO
Congenital leptin deficiency, a rare genetic disorder due to a homozygous mutation in the leptin gene (LEP), is accompanied by extreme obesity and hyperphagia. A number of gastrointestinal hormones have been shown to critically regulate food intake but their physiological role in hyperphagic response in congenital leptin deficiency has not been elucidated. This study is the first to evaluate the fasting and postprandial profiles of gut-derived hormones in homozygous and heterozygous carriers of LEP mutation. The study subjects from two consanguineous families consisted of five homozygous and eight heterozygous carriers of LEP mutation, c.398delG. Ten wild-type normal-weight subjects served as controls. Fasting and 1-h postprandial plasma ghrelin, glucagon-like peptide (GLP) 1, peptide YY (PYY), leptin and insulin levels were measured by immunoassays. Fasting plasma ghrelin levels in homozygotes remained remarkably unchanged following food consumption (P = 0.33) in contrast to a significant decline in heterozygous (P < 0.03) and normal (P < 0.02) subjects. A significant postprandial increase in PYY was observed in heterozygous (P < 0.02) and control subjects (P < 0.01), but not in the homozygous group (P = 0.22). A postprandial rise in GLP-1 levels was significant (P < 0.02) in all groups. Interestingly, fasting leptin levels in heterozygotes were not significantly different from controls and did not change significantly following meal. Our results demonstrate that gut hormones play little or no physiological role in driving the hyperphagic response of leptin-deficient subjects. In contrast, fasting and postprandial levels of gut hormones in heterozygous mutation carriers were comparable to those of normal-weight controls.