Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
1.
PNAS Nexus ; 3(1): pgae001, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38239755

RESUMO

Transcriptional factor RFX6 is known to be a causal gene of Mitchell-Riley syndrome (MRS), an autosomal recessive neonatal diabetes associated with pancreatic hypoplasia and intestinal atresia/malformation. The morphological defects are limited to posterior foregut and mid-hindgut endodermal lineages and do not occur in the anterior foregut lineage; the mechanism remains to be fully elucidated. In this study, we generated RFX6+/eGFP heterozygous knockin and RFX6eGFP/eGFP homozygous knockin/knockout human-induced pluripotent stem cell (hiPSC) lines and performed in vitro endoderm differentiation to clarify the role of RFX6 in early endoderm development. RFX6 expression was found to surge at the primitive gut tube (PGT) stage in comparison with that in the undifferentiated or definitive endoderm stage. At the PGT stage, the expression of PDX1 and CDX2, posterior foregut and mid-hindgut master regulators, respectively, was decreased by the RFX6 deficit. PDX1+ and CDX2+ cells were mostly green fluorescent protein (GFP)+ in RFX6+/eGFP hiPSCs, but their cell number was markedly decreased in RFX6eGFP/eGFP hiPSCs. The expression of SOX2, an anterior foregut marker, was not affected by the RFX6 deficit. In addition, we found a putative RFX6-binding X-box motif using cap analysis of gene expression-seq and the motif-containing sequences in the enhancer regions of PDX1 and CDX2 bound to RFX6 in vitro. Thus, RFX6 regulates the ParaHox genes PDX1 and CDX2 but does not affect SOX2 in early endodermal differentiation, suggesting that defects in early stage endoderm patterning account for the morphological pathology of MRS.

2.
Diagn Pathol ; 18(1): 115, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37864201

RESUMO

BACKGROUND: Adult non-neoplastic hyperinsulinemic hypoglycemia (ANHH), also known as adult-onset nesidioblastosis, is a rare cause of endogenous hyperinsulinemic hypoglycemia in adults. This disease is characterized by diffuse hyperplasia of pancreatic endocrine cells and is diagnosed by a pathological examination. While diagnostic criteria for this disease have already been proposed, we established more quantitative criteria for evaluating islet morphology. METHODS: We measured the number, maximum diameter, total area, and circularity (representing how closely islets resemble perfect spheres) of islets contained in representative sections of ANHH (n = 4) and control cases (n = 5) using the NIS-Elements software program. We also measured the average cell size, percentage of cells with enlarged nuclei, and percentage of cells with recognizable nucleoli for each of three representative islets. We also assessed the interobserver diagnostic concordance of ANHH between five experienced and seven less-experienced pathologists. RESULTS: There was no significant difference in the number, maximum diameter, or total area of islets between the two groups, even after correcting for these parameters per unit area. However, the number of islets with low circularity (< 0.71) per total area of the pancreatic parenchyma was significantly larger in ANHH specimens than in controls. We also found that the percentage of cells with recognizable nucleoli was significantly higher in the ANHH group than in the controls. There were no significant differences in the average cell size or the number of cells with enlarged nuclei between the groups. The correct diagnosis rate with the blind test was 47.5% ± 6.12% for experienced pathologists and 50.0% ± 8.63% for less-experienced pathologists, with no significant differences noted. CONCLUSIONS: Low circularity, which indicates an irregular islet shape, referred to as "irregular shape and occasional enlargement of islets" and "lobulated islet structure" in a previous report, is a useful marker for diagnosing ANHH. An increased percentage of recognizable nucleoli, corresponding to "macronucleoli in ß-cells," has potential diagnostic value.


Assuntos
Hiperinsulinismo , Hipoglicemia , Ilhotas Pancreáticas , Nesidioblastose , Adulto , Humanos , Ilhotas Pancreáticas/patologia , Ilhotas Pancreáticas/cirurgia , Hipoglicemia/diagnóstico , Hipoglicemia/etiologia , Hiperinsulinismo/diagnóstico , Hiperinsulinismo/etiologia , Hiperinsulinismo/patologia , Pâncreas/patologia , Nesidioblastose/complicações , Nesidioblastose/patologia , Nesidioblastose/cirurgia
3.
J Diabetes Investig ; 14(10): 1187-1191, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37377043

RESUMO

It is crucial to develop practical and noninvasive methods to assess the functional beta-cell mass in a donor pancreas, in which monitoring and precise evaluation is challenging. A patient with type 1 diabetes underwent noninvasive imaging following simultaneous kidney-pancreas transplantation with positron emission tomography/computed tomography (PET/CT) using an exendin-based probe, [18 F]FB(ePEG12)12-exendin-4. Following transplantation, PET imaging with [18 F]FB(ePEG12)12-exendin-4 revealed simultaneous and distinct accumulations in the donor and native pancreases. The pancreases were outlined at a reasonable distance from the surrounding organs using [18 F]FB(ePEG12)12-exendin-4 whole-body maximum intensity projection and axial PET images. At 1 and 2 h after [18 F]FB(ePEG12)12-exendin-4 administration, the mean standardized uptake values were 2.96 and 3.08, respectively, in the donor pancreas and 1.97 and 2.25, respectively, in the native pancreas. [18 F]FB(ePEG12)12-exendin-4 positron emission tomography imaging allowed repeatable and quantitative assessment of beta-cell mass following simultaneous kidney-pancreas transplantation.


Assuntos
Transplante de Rim , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Humanos , Exenatida , Pancrelipase , Peptídeos , Pâncreas/diagnóstico por imagem
4.
Sci Rep ; 13(1): 8659, 2023 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-37248264

RESUMO

For pluripotent stem cell (PSC)-based regenerative therapy against diabetes, the differentiation efficiency to pancreatic lineage cells needs to be improved based on the mechanistic understanding of pancreatic differentiation. Here, we aimed to elucidate the molecular mechanisms underlying pancreatic endoderm differentiation by searching for factors that regulate a crucial pancreatic endoderm marker gene, NKX6.1. Unbiasedly screening an siRNA knockdown library, we identified a candidate transcription factor, HHEX. HHEX knockdown suppressed the expression of another pancreatic endoderm marker gene, PTF1A, as well as NKX6.1, independently of PDX1, a known regulator of NKX6.1 expression. In contrast, the overexpression of HHEX upregulated the expressions of NKX6.1 and PTF1A. RNA-seq analysis showed decreased expressions of several genes related to pancreatic development, such as NKX6.1, PTF1A, ONECUT1 and ONECUT3, in HHEX knockdown pancreatic endoderm. These results suggest that HHEX plays a key role in pancreatic endoderm differentiation.


Assuntos
Células-Tronco Pluripotentes Induzidas , Humanos , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Endoderma , Transativadores/genética , Transativadores/metabolismo , Diferenciação Celular/genética , Pâncreas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
J Diabetes Investig ; 13(11): 1939-1942, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35735779

RESUMO

Insulin antibodies (IAs) can cause glycemic variability. Islet transplantation (ITx) is a treatment for insulin-deficient diabetes that aims to establish on-target glycemic control in the absence of hypoglycemia. To date, there has not been a detailed case study of the association between ITx and IA levels. In this study, we identified a unique profile of IA titers, which differed from glutamic acid decarboxylase antibody titers, in four ITx patients. IA levels decreased with intensified immunosuppressive therapy, whereas glutamic acid decarboxylase antibodies increased transiently after ITx. These data suggest the possibility that IAs, unlike other islet autoantibodies, were eliminated due to immunosuppression after transplantation therapy. The disappearance of IAs, as well as the restoration of regulated insulin secretion after ITx, might have a positive effect on glycemic control in recipients with diabetes. Furthermore, this unique feature is suggestive of immunological pathogenesis and has implications for the treatment of IA-causing disease conditions.


Assuntos
Diabetes Mellitus Tipo 1 , Insulina , Humanos , Anticorpos Anti-Insulina , Glutamato Descarboxilase , Autoanticorpos
8.
Diabetol Int ; 13(1): 1-30, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34777929

RESUMO

Bariatric surgery has been shown to have a variety of metabolically beneficial effects for patients with type 2 diabetes (T2D), and is now also called metabolic surgery. At the 2nd Diabetes Surgery Summit held in 2015 in London, the indication for bariatric and metabolic surgery was included in the "algorithm for patients with type T2D". With this background, the Japanese Society for Treatment of Obesity (JSTO), the Japan Diabetes Society (JDS) and the Japan Society for the Study of Obesity (JASSO) have formed a joint committee to develop a consensus statement regarding bariatric and metabolic surgery for the treatment of Japanese patients with T2D. Eventually, the consensus statement was announced at the joint meeting of the 38th Annual Meeting of JSTO and the 41st Annual Meeting of JASSO convened in Toyama on March 21, 2021. In preparing the consensus statement, we used Japanese data as much as possible as scientific evidence to consider the indication criteria, and set two types of recommendation grades, "recommendation" and "consideration", for items for which recommendations are possible. We hope that this statement will be helpful in providing evidence-based high-quality care through bariatric and metabolic surgery for the treatment of obese Japanese patients with T2D. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13340-021-00551-0.

9.
Sci Rep ; 11(1): 15014, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34294854

RESUMO

Specifying the exact localization of insulinoma remains challenging due to the lack of insulinoma-specific imaging methods. Recently, glucagon-like peptide-1 receptor (GLP-1R)-targeted imaging, especially positron emission tomography (PET), has emerged. Although various radiolabeled GLP-1R agonist exendin-4-based probes with chemical modifications for PET imaging have been investigated, an optimal candidate probe and its scanning protocol remain a necessity. Thus, we investigated the utility of a novel exendin-4-based probe conjugated with polyethylene glycol (PEG) for [18F]FB(ePEG12)12-exendin-4 PET imaging for insulinoma detection. We utilized [18F]FB(ePEG12)12-exendin-4 PET/CT to visualize mouse tumor models, which were generated using rat insulinoma cell xenografts. The probe demonstrated high uptake value on the tumor as 37.1 ± 0.4%ID/g, with rapid kidney clearance. Additionally, we used Pdx1-Cre;Trp53R172H;Rbf/f mice, which developed endogenous insulinoma and glucagonoma, since they enabled differential imaging evaluation of our probe in functional pancreatic neuroendocrine neoplasms. In this model, our [18F]FB(ePEG12)12-exendin-4 PET/CT yielded favorable sensitivity and specificity for insulinoma detection. Sensitivity: 30-min post-injection 66.7%, 60-min post-injection 83.3%, combined 100% and specificity: 30-min post-injection 100%, 60-min post-injection 100%, combined 100%, which was corroborated by the results of in vitro time-based analysis of internalized probe accumulation. Accordingly, [18F]FB(ePEG12)12-exendin-4 is a promising PET imaging probe for visualizing insulinoma.


Assuntos
Radioisótopos de Flúor , Insulinoma/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Compostos Radiofarmacêuticos , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Insulinoma/patologia , Masculino , Camundongos , Camundongos Transgênicos , Tomografia por Emissão de Pósitrons/métodos , Ratos , Ensaios Antitumorais Modelo de Xenoenxerto
10.
J Diabetes Investig ; 12(2): 143-145, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32654418

RESUMO

Pancreas transplantation and islet transplantation are now established in the treatment of IDDM. Several trials of stem cell-derived cell transplantation therapy are underway and may offer an alternative to the limited supply of donor islets in the near future. This article summarizes recent developments in transplantation therapy for diabetes as well as research on the use of stem cells for complications of diabetes.


Assuntos
Diabetes Mellitus Tipo 1/terapia , Diabetes Mellitus Tipo 2/terapia , Transplante das Ilhotas Pancreáticas/métodos , Ilhotas Pancreáticas/citologia , Transplante de Células-Tronco/métodos , Humanos , Prognóstico
11.
J Diabetes Investig ; 11(6): 1677-1680, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32431082

RESUMO

To date, studies of patients with islet transplantation addressing intermittently scanned continuous glucose monitoring profile and the flexibility of the graft islet function under different doses of insulin administration, both of which reflect the real daily life of patients, are quite limited. Here, we report a case of a 46-year-old woman who received islet transplantation after kidney transplantation. The patient was followed up over a period of 2 years after initial islet transplantation. Our results show that intermittently scanned continuous glucose monitoring can be useful for monitoring the reduction of glycemic variability, and suggest the appropriate regulation of insulin secretion from graft islets during mixed-meal test by using different doses of exogenous insulin administration. Additionally, during the 2-year observational period, glucagon elevation was detected only at hypoglycemia, whereas the level was within the normal range at normoglycemia or hyperglycemia.


Assuntos
Automonitorização da Glicemia/métodos , Glicemia/análise , Hiperglicemia/prevenção & controle , Hipoglicemia/prevenção & controle , Transplante das Ilhotas Pancreáticas/métodos , Ilhotas Pancreáticas/fisiologia , Feminino , Humanos , Ilhotas Pancreáticas/efeitos dos fármacos , Pessoa de Meia-Idade
12.
J Diabetes Investig ; 11(2): 363-372, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31390159

RESUMO

AIMS/INTRODUCTION: To investigate the long-term efficacy and safety of islet transplantation (ITx) compared with multiple daily injections (MDI) or continuous subcutaneous insulin infusion (CSII). MATERIALS AND METHODS: Among 619 patients diagnosed as insulin-dependent diabetes mellitus or type 1 diabetes at Kyoto University, Kyoto, Japan, seven patients were selected as the ITx group and 26 age-matched patients with no endogenous insulin secretion were selected as the MDI/CSII group. Hemoglobin A1c, aspartate aminotransferase/alanine aminotransferase (AST/ALT) and creatinine were assessed retrospectively at 1, 2, 5 and 10 years for both groups; serum C-peptide immunoreactivity was assessed for the ITx group. Major clinical events were also assessed. RESULTS: Hemoglobin A1c improvement in ITx was significant at 1 year (8.4% [7.8-9.9%] at baseline to 7.1% [6.3-7.4%] in ITx vs 8.2% [7.4-9.8%] at baseline to 8.1% [7.3-9.5%] in MDI/CSII, P < 0.01 between groups), and was maintained at 2 years (7.4% [6.3-8.2%] vs 8.4% [7.4-9.6%], P = 0.11). The increase of stimulated C-peptide immunoreactivity was significant at 1 year (0.57 ng/mL [0.26-0.99 ng/mL], P < 0.05 from baseline) and 2 years (0.43 ng/mL [0.19-0.67 ng/mL], P < 0.05), although it became insignificant thereafter. There was no significant difference in AST/ALT or creatinine at 10 years, although a transient AST/ALT elevation was observed in ITx. In regard to clinical events, the occurrence of severe hypoglycemia was 14% vs 31% (relative risk 0.46, P = 0.64), that of infectious disease was 43% vs 12% (relative risk 3.71, P = 0.09) and digestive symptoms was 43% vs 7.7% (relative risk 5.57, P = 0.05) in ITx vs MDI/CSII, respectively. No patient died in either group. CONCLUSIONS: The present findings showed that ITx was considered to contribute to the reduction of hypoglycemia and better glycemic control with tolerable, but attention-requiring, risks over a period of 10 years compared with MDI/CSII.


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/cirurgia , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Transplante das Ilhotas Pancreáticas , Adulto , Estudos de Coortes , Feminino , Hemoglobinas Glicadas/análise , Humanos , Testes de Função Renal , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
13.
Neuropeptides ; 65: 10-20, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28434791

RESUMO

BACKGROUND: The preparation of human neurons derived from human induced pluripotent stem (iPS) cells can serve as a potential tool for evaluating the physiological and pathophysiological properties of human neurons and for drug development. METHODS: In the present study, the functional activity in neuronal cells differentiated from human iPS cells was observed. RESULTS: The differentiated cells expressed mRNAs for classical neuronal markers (microtubule-associated protein 2, ß-tubulin III, calbindin 1, synaptophysin and postsynaptic density protein 95) and for subunits of various excitatory and inhibitory transmitters (NR1, NR2A, NR2B, GABAA α1). Moreover, the differentiated cells expressed neuropeptides and receptors which are predominantly present in the hypothalamus. The expression of mRNA for preopiomelanocortin, agouti-related protein (AgRP), melanocortin-3 receptor (MC3R) and melanocortin-4 receptor (MC4R) increased in culture with a peak on Day 30 which subsequently decreased at Day 45. Immunoreactivities for MC3R and MC4R were also observed in cells differentiated from human iPS cells. Application of a potent agonist for MC3R and MC4R, [Nle4, D-Phe7]-α-melanocyte-stimulating hormone, significantly increased intracellular cAMP levels, but this was suppressed by AgRP (83-132) and SHU9119. CONCLUSIONS: These findings offer the possibility for drug developments using neurons differentiated from normal or disease-associated human iPS cells.


Assuntos
Células-Tronco Pluripotentes Induzidas/metabolismo , Melanocortinas/metabolismo , Neurônios/metabolismo , Adulto , Diferenciação Celular , Células Cultivadas , Feminino , Humanos , Subunidades Proteicas/metabolismo , RNA Mensageiro/metabolismo , Receptores de GABA/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo
14.
Sci Rep ; 6: 27192, 2016 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-27273361

RESUMO

Pharmacological blockade of the N- and L-type calcium channel lessens renal injury in kidney disease patients. The significance of specific blockade of α1 subunit of N-type calcium channel, Cav2.2, in diabetic nephropathy, however, remains to be clarified. To examine functional roles, we mated Cav2.2(-/-) mice with db/db (diabetic) mice on the C57BLKS background. Cav2.2 was localized in glomeruli including podocytes and in distal tubular cells. Diabetic Cav2.2(-/-) mice significantly reduced urinary albumin excretion, glomerular hyperfiltration, blood glucose levels, histological deterioration and systolic blood pressure (SBP) with decreased urinary catecholamine compared to diabetic Cav2.2(+/+) mice. Interestingly, diabetic heterozygous Cav2.2(+/-) mice also decreased albuminuria, although they exhibited comparable systolic blood pressure, sympathetic nerve activity and creatinine clearance to diabetic Cav2.2(+/+) mice. Consistently, diabetic mice with cilnidipine, an N-/L-type calcium channel blocker, showed a reduction in albuminuria and improvement of glomerular changes compared to diabetic mice with nitrendipine. In cultured podocytes, depolarization-dependent calcium responses were decreased by ω-conotoxin, a Cav2.2-specific inhibitor. Furthermore, reduction of nephrin by transforming growth factor-ß (TGF-ß) in podocytes was abolished with ω-conotoxin, cilnidipine or mitogen-activated protein kinase kinase inhibitor. In conclusion, Cav2.2 inhibition exerts renoprotective effects against the progression of diabetic nephropathy, partly by protecting podocytes.


Assuntos
Glicemia/metabolismo , Pressão Sanguínea/efeitos dos fármacos , Canais de Cálcio Tipo N/genética , Nefropatias Diabéticas/tratamento farmacológico , ômega-Conotoxinas/administração & dosagem , Animais , Glicemia/efeitos dos fármacos , Canais de Cálcio Tipo N/efeitos dos fármacos , Canais de Cálcio Tipo N/metabolismo , Células Cultivadas , Diabetes Mellitus Experimental , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/fisiopatologia , Modelos Animais de Doenças , Técnicas de Inativação de Genes , Túbulos Renais Distais/citologia , Túbulos Renais Distais/metabolismo , Camundongos , Podócitos/citologia , Podócitos/metabolismo , ômega-Conotoxinas/farmacologia
15.
Metabolism ; 65(4): 543-56, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26975546

RESUMO

OBJECTIVE: Congenital generalized lipodystrophy (CGL) is an autosomal recessive disorder characterized by marked scarcity of adipose tissue, extreme insulin resistance, hypertriglyceridemia, hepatic steatosis and early-onset diabetes. Mutation of the BSCL2/SEIPIN gene causes the most severe form of CGL. The aim of this study was to generate induced pluripotent stem (iPS) cells from patients with CGL harboring BSCL2/SEIPIN mutations. METHODS: Skin biopsies were obtained from two Japanese patients with CGL harboring different nonsense mutations (E189X and R275X) in BSCL2/SEIPIN. The fibroblasts thus obtained were infected with retroviruses encoding OCT4, SOX2, c-MYC, and KLF4. The generated iPS cells were evaluated for pluripotency by examining the expression of pluripotency markers (alkaline phosphatase, SSEA-4, TRA-1-60, and NANOG) and their ability to differentiate to three germ layers in vitro by forming embryoid bodies, and to form teratomas in vivo. Adipogenic capacity of differentiated BSCL2-iPS cells was determined by oil red O and adipose differentiation-related protein (ADRP) staining. Rescue experiments were also performed using stable expression of wild-type BSCL2. A coimmunoprecipitation assay was conducted to investigate the interaction of SEIPIN with ADRP. RESULTS: iPS cells were generated from fibroblasts of the two patients with CGL. Each of the patient-derived iPS (BSCL2-iPS) clones showed all of the hallmarks of pluripotency and could differentiate into derivatives of all three germ layers in vitro by forming embryoid bodies, and form teratomas after injection into mouse testes. BSCL2-iPS cells maintained the mutations in BSCL2 and lacked intact BSCL2. Upon adipogenic differentiation, BSCL2-iPS cells exhibited marked reduction of lipid droplet formation concomitant with diffuse cytoplasmic distribution of ADRP, compared with iPS cells from healthy individuals. Forced expression of BSCL2 not only rescued the lipid accumulation defects, but also restored cytoplasmic punctate localization of ADRP in BSCL2-iPS cells. Coimmunoprecipitation indicated SEIPIN interacted with ADRP. CONCLUSION: BSCL2-iPS cells that recapitulate the lipodystrophic phenotypes in vitro could provide valuable models with which to study the physiology of lipid accumulation and the pathology of human lipodystrophy. We found that BSCL2 defines the localization of ADRP, which has a role in lipid accumulation and adipogenic differentiation.


Assuntos
Adipogenia/genética , Subunidades gama da Proteína de Ligação ao GTP/genética , Células-Tronco Pluripotentes Induzidas/metabolismo , Lipodistrofia Generalizada Congênita/genética , Lipodistrofia Generalizada Congênita/metabolismo , Biópsia , Diferenciação Celular/genética , Códon sem Sentido/genética , Corpos Embrioides , Fibroblastos/metabolismo , Humanos , Fator 4 Semelhante a Kruppel , Proteínas de Membrana/metabolismo , Mutação/genética , Perilipina-2 , Pele/metabolismo , Teratoma/genética
16.
Artigo em Inglês | MEDLINE | ID: mdl-25309513

RESUMO

Free fatty acids (FFAs) play a pivotal role in metabolic control and cell signaling processes in various tissues. In particular, FFAs are known to augment glucose-stimulated insulin secretion by pancreatic beta cells, where fatty acid-derived metabolites, such as long-chain fatty acyl-CoAs, are believed to act as crucial effectors. Recently, G-protein-coupled receptor 40 (GPR40), a receptor for long-chain fatty acids, was reported to be highly expressed in pancreatic beta cells and involved in the regulation of insulin secretion. Hence, GPR40 is considered to be a potential therapeutic target for the treatment of diabetes. In this review, we summarize the identification and gene expression patterns of GPR40 and its role in glucose metabolism. We also discuss the potential application of GPR40 as a therapeutic target.

17.
Am J Physiol Endocrinol Metab ; 307(8): E712-9, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25159327

RESUMO

Leptin may reduce pancreatic lipid deposition, which increases with progression of obesity and can impair ß-cell function. The insulinotropic effect of glucagon-like peptide-1 (GLP-1) and the efficacy of GLP-1 receptor agonist are reduced associated with impaired ß-cell function. In this study, we examined whether leptin could restore the efficacy of exenatide, a GLP-1 receptor agonist, in type 2 diabetes with increased adiposity. We chronically administered leptin (500 µg·kg⁻¹·day⁻¹) and/or exenatide (20 µg·kg⁻¹·day⁻¹) for 2 wk in a mouse model of type 2 diabetes with increased adiposity induced by streptozotocin and high-fat diet (STZ/HFD mice). The STZ/HFD mice exhibited hyperglycemia, overweight, increased pancreatic triglyceride level, and reduced glucose-stimulated insulin secretion (GSIS); moreover, the insulinotropic effect of exenatide was reduced. However, leptin significantly reduced pancreatic triglyceride level, and adding leptin to exenatide (LEP/EX) remarkably enhanced GSIS. These results suggested that the leptin treatment restored the insulinotropic effect of exenatide in the mice. In addition, LEP/EX reduced food intake, body weight, and triglyceride levels in the skeletal muscle and liver, and corrected hyperglycemia to a greater extent than either monotherapy. The pair-feeding experiment indicated that the marked reduction of pancreatic triglyceride level and enhancement of GSIS by LEP/EX occurred via mechanisms other than calorie restriction. These results suggest that leptin treatment may restore the insulinotropic effect of exenatide associated with the reduction of pancreatic lipid deposition in type 2 diabetes with increased adiposity. Combination therapy with leptin and exenatide could be an effective treatment for patients with type 2 diabetes with increased adiposity.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Modelos Animais de Doenças , Hipoglicemiantes/uso terapêutico , Leptina/uso terapêutico , Sobrepeso/complicações , Pâncreas/efeitos dos fármacos , Peptídeos/uso terapêutico , Peçonhas/uso terapêutico , Adiposidade/efeitos dos fármacos , Animais , Fármacos Antiobesidade/administração & dosagem , Fármacos Antiobesidade/uso terapêutico , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/metabolismo , Dieta Hiperlipídica/efeitos adversos , Implantes de Medicamento , Sinergismo Farmacológico , Quimioterapia Combinada , Exenatida , Peptídeo 1 Semelhante ao Glucagon/agonistas , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Hiperglicemia/prevenção & controle , Hipoglicemiantes/administração & dosagem , Insulina/metabolismo , Secreção de Insulina , Leptina/administração & dosagem , Leptina/genética , Masculino , Camundongos Endogâmicos C57BL , Sobrepeso/tratamento farmacológico , Sobrepeso/etiologia , Sobrepeso/metabolismo , Pâncreas/metabolismo , Peptídeos/administração & dosagem , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/uso terapêutico , Estreptozocina , Triglicerídeos/metabolismo , Peçonhas/administração & dosagem
18.
Stem Cells Dev ; 22(21): 2895-905, 2013 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23750558

RESUMO

Human induced pluripotent stem (iPS) and embryonic stem (ES) cells can differentiate into a variety of cell types. We reported on adipogenic potential of human iPS and ES cells in vitro. In the present study, we investigate the survival and maintenance of adipocytes differentiated in vitro from human iPS and ES cells after transplantation. Following adipogenic induction in vitro, the differentiated cells exhibited functional properties of adipocytes such as lipid storage, lipolysis, and insulin responsiveness. Subsequently, Matrigel containing the differentiated human iPS and ES cells was transplanted into the subcutaneous tissue of nude mice. After 1-4 weeks, the cells with adipocyte-like features were observed in transplanted Matrigel by histological analysis. The human origin of the cells, their lipid accumulation, and gene expression of adipocyte markers in transplanted cells were then confirmed, suggesting the presence of adipocytes in transplanted Matrigel. When the relative areas of these cells were calculated by dividing the adipocyte areas by the total Matrigel areas, we found that they peaked at 2 weeks after transplantation, and that the adipocytes persisted at 4 weeks. The present study demonstrates that human iPS and ES cells can differentiate into adipocytes with functional properties and that adipocytes derived from human iPS and ES cells can survive and maintain the differentiated properties of adipocytes for at least 4 weeks after transplantation. Adipocytes derived from human iPS and ES cells thus have the potential to open new avenues for stem cell-based research into metabolic diseases and future therapeutic applications.


Assuntos
Adipócitos/citologia , Adipócitos/transplante , Diferenciação Celular , Células-Tronco Embrionárias/citologia , Células-Tronco Pluripotentes Induzidas/citologia , Adipócitos/metabolismo , Animais , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Linhagem Celular , Transplante de Células/métodos , Colágeno , Combinação de Medicamentos , Expressão Gênica , Humanos , Imuno-Histoquímica , Laminina , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , PPAR gama/genética , PPAR gama/metabolismo , Proteoglicanas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Transplante Heterólogo
19.
Endocr J ; 60(6): 697-708, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23719783

RESUMO

Experimental transplantation of endocrine tissues has led to significant advances in our understanding of endocrinology and metabolism. Endocrine cell transplantation therapy is expected to be applied to the treatment of metabolic endocriopathies. Restoration of functional pancreatic beta-cell mass or of functional adipose mass are reasonable treatment approaches for patients with diabetes or lipodystrophy, respectively. Human induced pluripotent stem (iPS) cell research is having a great impact on life sciences. Doctors Takahashi and Yamanaka discovered that the forced expression of a set of genes can convert mouse and human somatic cells into a pluripotent state [1, 2]. These iPS cells can differentiate into a variety of cell types. Therefore, iPS cells from patients may be a potential cell source for autologous cell replacement therapy. This review briefly summarizes the current knowledge about transplantation therapy for diabetes mellitus, the development of the endocrine pancreas and adipocytes, and endocrine-metabolic disease-specific iPS cells.


Assuntos
Adipócitos/fisiologia , Diabetes Mellitus/terapia , Células-Tronco Pluripotentes Induzidas/transplante , Células Secretoras de Insulina/transplante , Ilhotas Pancreáticas/fisiologia , Adipócitos/transplante , Animais , Humanos , Células Secretoras de Insulina/fisiologia , Ilhotas Pancreáticas/embriologia , Transplante das Ilhotas Pancreáticas/fisiologia , Camundongos
20.
Obesity (Silver Spring) ; 21(9): E350-3, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23703886

RESUMO

OBJECTIVE: To elucidate early change of intra-abdominal fat in response to calorie restriction in patients with obesity by weekly evaluation using a dual bioelectrical impedance analysis (Dual BIA) instrument. METHODS: For 67 Japanese patients with obesity, diabetes, or metabolic syndrome, intra-abdominal fat area (IAFA), initially with both Dual BIA and computed tomography (CT), and in subsequent weeks of calorie restriction, with Dual BIA were measured. RESULTS: IAFA by Dual BIA (Dual BIA-IAFA) correlated well with IAFA by CT (CT-IAFA) in obese patients (r = 0.821, P < .0001, n = 67). Ten males and 9 females (age 49.0 ± 14.4 years, BMI 33.2 ± 7.3 kg/m2) lost more than 5% of baseline body weight (BW) in 3 weeks, and their Dual BIA-IAFA, BW, and WC decreased by 18.9%, 5.3%, and 3.8%, respectively (P < .05, ANCOVA). CONCLUSION: Dual BIA instrument could detect the weekly change of Dual BIA-IAFA under calorie restriction in obese patients and demonstrated a substantially larger change of IAFA compared with changes of BW and WC in early weeks. This observation corroborates the significance of evaluating IAFA as a biomarker for obesity, and indicates the clinical usefulness of the Dual BIA instrument.


Assuntos
Adiposidade/fisiologia , Restrição Calórica , Gordura Intra-Abdominal/fisiopatologia , Obesidade/fisiopatologia , Circunferência da Cintura/fisiologia , Redução de Peso/fisiologia , Adulto , Biomarcadores/metabolismo , Diabetes Mellitus/diagnóstico por imagem , Diabetes Mellitus/metabolismo , Diabetes Mellitus/fisiopatologia , Impedância Elétrica , Feminino , Humanos , Gordura Intra-Abdominal/diagnóstico por imagem , Gordura Intra-Abdominal/metabolismo , Japão , Masculino , Síndrome Metabólica/diagnóstico por imagem , Síndrome Metabólica/metabolismo , Síndrome Metabólica/fisiopatologia , Pessoa de Meia-Idade , Obesidade/diagnóstico , Obesidade/diagnóstico por imagem , Obesidade/dietoterapia , Tomografia Computadorizada por Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...