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1.
Ir J Med Sci ; 193(1): 231-232, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37450257

RESUMO

Type 1 diabetes is an autoimmune disorder which is caused due to T-cell mediated destruction of ß cells of pancreas leading to insulin deficiency and hyperglycemia. The prevalence has been increasing in many countries especially Europe and America. The exogenous therapy which includes insulin administration is not sufficient in maintaining the glucose levels especially in patients with brittle T1D. Therefore, endogenous production of insulin via islet cell therapy has been a center of research for many years and results have largely supported the idea. The US. FDA approved the first cell therapy drug, Donislecel for brittle T1D which may be a crucial achievement in treatment of the autoimmune disorder.


Assuntos
Diabetes Mellitus Tipo 1 , Ilhotas Pancreáticas , Humanos , Ilhotas Pancreáticas/metabolismo , Pâncreas , Insulina , Terapia Baseada em Transplante de Células e Tecidos
2.
Mol Metab ; 75: 101775, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37451343

RESUMO

OBJECTIVE: Dextromethorphan (DXM) is a commonly used antitussive medication with positive effects in people with type 2 diabetes mellitus, since it increases glucose tolerance and protects pancreatic islets from cell death. However, its use as an antidiabetic medication is limited due to its central nervous side effects and potential use as a recreational drug. Therefore, we recently modified DXM chemically to reduce its blood-brain barrier (BBB) penetration and central side effects. However, our best compound interacted with the cardiac potassium channel hERG (human ether-à-go-go-related gene product) and the µ-opioid receptor (MOR). Thus, the goal of this study was to reduce the interaction of our compound with these targets, while maintaining its beneficial properties. METHODS: Receptor and channel binding assays were conducted to evaluate the drug safety of our DXM derivative. Pancreatic islets were used to investigate the effect of the compound on insulin secretion and islet cell survival. Via liquor collection from the brain and a behavioral assay, we analyzed the BBB permeability. By performing intraperitoneal and oral glucose tolerance tests as well as pharmacokinetic analyses, the antidiabetic potential and elimination half-life were investigated, respectively. To analyze the islet cell-protective effect, we used fluorescence microscopy as well as flow cytometric analyses. RESULTS: Here, we report the design and synthesis of an optimized, orally available BBB-impermeable DXM derivative with lesser binding to hERG and MOR than previous ones. We also show that the new compound substantially enhances glucose-stimulated insulin secretion (GSIS) from mouse and human islets and glucose tolerance in mice as well as protects pancreatic islets from cell death induced by reactive oxygen species and that it amplifies the effects of tirzepatide on GSIS and islet cell viability. CONCLUSIONS: We succeeded to design and synthesize a novel morphinan derivative that is BBB-impermeable, glucose-lowering and islet cell-protective and has good drug safety despite its morphinan and imidazole structures.


Assuntos
Diabetes Mellitus Tipo 2 , Ilhotas Pancreáticas , Morfinanos , Camundongos , Humanos , Animais , Diabetes Mellitus Tipo 2/metabolismo , Insulina/metabolismo , Morfinanos/metabolismo , Morfinanos/farmacologia , Ilhotas Pancreáticas/metabolismo , Glucose/metabolismo , Hipoglicemiantes/farmacologia , Estresse Oxidativo
3.
J Endocrinol ; 258(2)2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37256642

RESUMO

Cell protein biosynthesis is regulated by different factors, but implication of intercellular contacts on alpha and beta cell protein biosyntheses activity has not been yet investigated. Islet cell biosynthetic activity is essential in regulating not only the hormonal reserve within cells but also in renewing all the proteins involved in the control of secretion. Here we aimed to assess whether intercellular interactions affected similarly secretion and protein biosynthesis of rat alpha and beta cells. Insulin and glucagon secretion were analyzed by ELISA or reverse hemolytic plaque assay, and protein biosynthesis evaluated at single cell level using bioorthogonal noncanonical amino acid tagging. Regarding beta cells, we showed a positive correlation between insulin secretion and protein biosynthesis. We also observed that homologous contacts increased both activities at low or moderate glucose concentrations. By contrast, at high glucose concentration, homologous contacts increased insulin secretion and not protein biosynthesis. In addition, heterogeneous contacts between beta and alpha cells had no impact on insulin secretion and protein biosynthesis. Regarding alpha cells, we showed that when they were in contact with beta cells, they increased their glucagon secretion in response to a drop of glucose concentration, but, on the other hand, they decreased their protein biosynthesis under any glucose concentrations. Altogether, these results emphasize the role of intercellular contacts on the function of islet cells, showing that intercellular contacts increased protein biosynthesis in beta cells, except at high glucose, and decreased protein biosynthesis in alpha cells even when glucagon secretion is stimulated.


Assuntos
Glucagon , Ilhotas Pancreáticas , Ratos , Animais , Glucagon/metabolismo , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Secreção de Insulina , Glucose/metabolismo
4.
Stem Cell Res Ther ; 14(1): 1, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36600289

RESUMO

BACKGROUND: Transplantation of differentiated cells from human-induced pluripotent stem cells (hiPSCs) holds great promise for clinical treatments. Eliminating the risk factor of malignant cell transformation is essential for ensuring the safety of such cells. This study was aimed at assessing and mitigating mutagenicity that may arise during the cell culture process in the protocol of pancreatic islet cell (iPIC) differentiation from hiPSCs. METHODS: We evaluated the mutagenicity of differentiation factors used for hiPSC-derived pancreatic islet-like cells (iPICs). We employed Ames mutagenicity assay, flow cytometry analysis, immunostaining, time-resolved fluorescence resonance energy transfer-based (TR-FRET) cell-free dose-response assays, single-cell RNA-sequencing and in vivo efficacy study. RESULTS: We observed a mutagenic effect of activin receptor-like kinase 5 inhibitor II (ALK5iII). ALK5iII is a widely used ß-cell inducer but no other tested ALK5 inhibitors induced ß-cells. We obtained kinase inhibition profiles and found that only ALK5iII inhibited cyclin-dependent kinases 8 and 19 (CDK8/19) among all ALK5 inhibitors tested. Consistently, CDK8/19 inhibitors efficiently induced ß-cells in the absence of ALK5iII. A combination treatment with non-mutagenic ALK5 inhibitor SB431542 and CDK8/19 inhibitor senexin B afforded generation of iPICs with in vitro cellular composition and in vivo efficacy comparable to those observed with ALK5iII. CONCLUSION: Our findings suggest a new risk mitigation approach for cell therapy and advance our understanding of the ß-cell differentiation mechanism.


Assuntos
Células-Tronco Pluripotentes Induzidas , Humanos , Diferenciação Celular , Técnicas de Cultura de Células/métodos , Quinase 8 Dependente de Ciclina
5.
Animals (Basel) ; 12(20)2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36290169

RESUMO

Insulinomas are insulin-producing tumors of pancreatic beta cells that cause hypoglycemia. They are extremely common in ferrets but have also been reported in guinea pigs and rats. This is a case report of an older rat with spontaneous insulinoma, which was confirmed by histopathology. The patient was presented at a regular check-up due to a chronic respiratory disease. The owner noticed progressive weakness of the hind limbs, which is quite commonly seen in older rats. A blood exam revealed hypoglycemia, which could have been associated with paraparesis. The patient responded to treatment with oral dexamethasone and was regularly monitored. It survived nearly 4 months in good general condition. The rat finally died most probably due to severe hypoglycemia caused by progression of the pancreatic tumor. This is the first report of a pet rat with insulinoma that was successfully treated with glucocorticoids.

6.
Gut ; 71(5): 961-973, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-33849943

RESUMO

OBJECTIVE: Recent studies have found aristaless-related homeobox gene (ARX)/pancreatic and duodenal homeobox 1 (PDX1), alpha-thalassemia/mental retardation X-linked (ATRX)/death domain-associated protein (DAXX) and alternative lengthening of telomeres (ALT) to be promising prognostic biomarkers for non-functional pancreatic neuroendocrine tumours (NF-PanNETs). However, they have not been comprehensively evaluated, especially among small NF-PanNETs (≤2.0 cm). Moreover, their status in neuroendocrine tumours (NETs) from other sites remains unknown. DESIGN: An international cohort of 1322 NETs was evaluated by immunolabelling for ARX/PDX1 and ATRX/DAXX, and telomere-specific fluorescence in situ hybridisation for ALT. This cohort included 561 primary NF-PanNETs, 107 NF-PanNET metastases and 654 primary, non-pancreatic non-functional NETs and NET metastases. The results were correlated with numerous clinicopathological features including relapse-free survival (RFS). RESULTS: ATRX/DAXX loss and ALT were associated with several adverse prognostic findings and distant metastasis/recurrence (p<0.001). The 5-year RFS rates for patients with ATRX/DAXX-negative and ALT-positive NF-PanNETs were 40% and 42% as compared with 85% and 86% for wild-type NF-PanNETs (p<0.001 and p<0.001). Shorter 5-year RFS rates for ≤2.0 cm NF-PanNETs patients were also seen with ATRX/DAXX loss (65% vs 92%, p=0.003) and ALT (60% vs 93%, p<0.001). By multivariate analysis, ATRX/DAXX and ALT status were independent prognostic factors for RFS. Conversely, classifying NF-PanNETs by ARX/PDX1 expression did not independently correlate with RFS. Except for 4% of pulmonary carcinoids, ATRX/DAXX loss and ALT were only identified in primary (25% and 29%) and NF-PanNET metastases (62% and 71%). CONCLUSIONS: ATRX/DAXX and ALT should be considered in the prognostic evaluation of NF-PanNETs including ≤2.0 cm tumours, and are highly specific for pancreatic origin among NET metastases of unknown primary.


Assuntos
Deficiência Intelectual , Tumores Neuroendócrinos , Neoplasias Pancreáticas , Talassemia alfa , Proteínas Correpressoras/genética , Genes Homeobox , Proteínas de Homeodomínio , Humanos , Deficiência Intelectual/genética , Chaperonas Moleculares/genética , Recidiva Local de Neoplasia/genética , Tumores Neuroendócrinos/genética , Proteínas Nucleares/genética , Neoplasias Pancreáticas/patologia , Telômero/genética , Telômero/patologia , Fatores de Transcrição/genética , Proteína Nuclear Ligada ao X/genética , Talassemia alfa/genética
8.
Phytomedicine ; 83: 153478, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33567371

RESUMO

BACKGROUND: Protection of pancreatic islet cells against dysfunction or death by regulating autophagy is considered to be an effective method for treatment of type 2 diabetes mellitus (T2DM). Morus alba leaves (mulberry leaves), a popular herbal medicine, have been used for prevention of T2DM since ancient times. PURPOSE: This study aimed to clarify whether Morus alba leaves ethanol extract (MLE) could protect islet cells in vivo and in vitro by regulating autophagy in T2DM, and explore the possible mechanism of action. METHODS: The main chemical constituents in MLE were analyzed by HPLC. The T2DM rat model was induced via high-fat diet combined with peritoneal injection of low-dose streptozotocin, and MLE was administered by oral gavage. Fasting blood glucose (FBG) and plasma insulin were measured, and homeostatic model assessment of ß cell function (HOMA-ß) and insulin resistance (HOMA-IR) were determined. The histomorphology of pancreas islets was evaluated by haematoxylin and eosin staining. In palmitic acid (PA)-stressed INS-1 rat insulinoma cells, cell viability was assayed by an MTT method. Expression of the autophagy-related proteins LC3 I/II, p62, p-AMPK and p-mTOR in islet tissues and INS-1 cells was evaluated by western blotting or immunohistochemistry analysis. RESULTS: The four main chemical constituents in MLE were identified as chlorogenic acid, rutin, isoquercitrin and quercitrin. MLE ameliorated hyperglycemia, insulin resistance and dyslipidemia of T2DM rats with prominent therapeutic effect. Further study indicated that MLE observably improved islet function, alleviated islet injury of T2DM rats, and inhibited PA-induced INS-1 cell death. On the other hand, MLE significantly induced autophagy in islet cells both in vivo and in vitro, and autophagy inhibitors abolished its therapeutic effect on T2DM rats and protective effect on islet cells. Apart from this, MLE markedly activated the AMPK/mTOR pathway in INS-1 cells, and the AMPK inhibitor prevented the autophagy induction ability of MLE. CONCLUSION: Together, MLE could protect islet cells against dysfunction and death by inducing AMPK/mTOR-mediated autophagy in T2DM, and these findings provide a new perspective for understanding the treatment mechanism of Morus alba leaves against T2DM.


Assuntos
Autofagia/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Ilhotas Pancreáticas/efeitos dos fármacos , Morus/química , Extratos Vegetais/farmacologia , Animais , Morte Celular/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/etiologia , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 2/patologia , Dieta Hiperlipídica/efeitos adversos , Etanol/química , Hiperglicemia/tratamento farmacológico , Resistência à Insulina , Ilhotas Pancreáticas/patologia , Masculino , Extratos Vegetais/química , Folhas de Planta/química , Ratos Sprague-Dawley , Serina-Treonina Quinases TOR/metabolismo
9.
Endocrinology ; 162(3)2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33367617

RESUMO

A correct biosynthetic activity is thought to be essential for the long-term function and survival of islet cells in culture and possibly also after islet transplantation. Compared to the secretory activity, biosynthetic activity has been poorly studied in pancreatic islet cells. Here we aimed to assess biosynthetic activity at the single cell level to investigate if protein synthesis is dependent on secretagogues and increased as a consequence of hormonal secretion. Biosynthetic activity in rat islet cells was studied at the single cell level using O-propargyl-puromycin (OPP) that incorporates into newly translated proteins and chemically ligates to a fluorescent dye by "click" reaction. Heterogeneous biosynthetic activity was observed between the four islet cell types, with delta cells showing the higher relative protein biosynthesis. Beta cells protein biosynthesis was increased in response to glucose while 3-isobutyl-1-methylxanthine and phorbol-12-myristate-13-acetate, 2 drugs known to stimulate insulin secretion, had no similar effect on protein biosynthesis. However, after several hours of secretion, protein biosynthesis remained high even when cells were challenged to basal conditions. These results suggest that mechanisms regulating secretion and biosynthesis in islet cells are different, with glucose directly triggering beta cells protein biosynthesis, independently of insulin secretion. Furthermore, this OPP labeling approach is a promising method to identify newly synthesized proteins under various physiological and pathological conditions.


Assuntos
Glucose/farmacologia , Secreção de Insulina/fisiologia , Células Secretoras de Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Animais , Células Cultivadas , Secreção de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/efeitos dos fármacos , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/efeitos dos fármacos , Masculino , Puromicina/análogos & derivados , Puromicina/farmacologia , Ratos , Ratos Sprague-Dawley , Coloração e Rotulagem
10.
Gut ; 70(1): 194-203, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32973069

RESUMO

Acute pancreatitis (AP), an acute inflammatory disorder of the exocrine pancreas, is one of the most common gastrointestinal diseases encountered in emergency departments with no specific treatments. Laboratory-based research has formed the cornerstone of endeavours to decipher the pathophysiology of AP, because of the limitations of such study in human beings. While this has provided us with substantial understanding, we cannot answer several pressing questions. These are: (a) Why is it that only a minority of individuals with gallstones, or who drink alcohol excessively, or are exposed to other causative factors develop AP? (b) Why do only some develop more severe manifestations of AP with necrosis and/or organ failure? (c) Why have we been unable to find an effective therapeutic for AP? This manuscript provides a state-of-the-art review of our current understanding of the pathophysiology of AP providing insights into the unanswered clinical questions. We describe multiple protective factors operating in most people, and multiple stressors that in a minority induce AP, independently or together, via amplification loops. We present testable hypotheses aimed at halting progression of severity for the development of effective treatments for this common unpredictable disease.


Assuntos
Pancreatite/etiologia , Pancreatite/terapia , Humanos , Pancreatite/patologia
11.
J Gastrointest Oncol ; 11(3): 578-589, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32655937

RESUMO

Pancreatic neuroendocrine tumors (PanNETs) are the second most common malignancy of the pancreas, and their incidence is increasing. PanNETs are a diverse group of diseases which range from benign to malignant, can be sporadic or associated with genetic mutations, and be functional or nonfunctional. In as much, the treatment and management of PanNETs can vary from a "Wait and See" approach to orthotopic liver transplantation (OLT). Despite this, surgical resection is still the primary treatment modality to achieve cure. This review focuses on the surgical management of PanNETs.

12.
J Forensic Sci ; 65(3): 995-998, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31800970

RESUMO

Infants born to diabetic mothers are at increased risk for symptomatic hypoglycemia and death after birth. A 36-year-old G4P3 mother with a history of gestational diabetes and newly diagnosed type II insulin-dependent diabetes gave birth at home, in the care of a midwife, to a macrosomic infant girl (10 lbs.). Several hours after birth, the infant became lethargic and was found to be hypoglycemic (blood sugar: 28 mg/dL). Glucose and sugar water were administered by the midwife; however, the infant continued to decompensate. Emergency medical services were called, and the infant was transported to the hospital where, despite resuscitative efforts, she died. An autopsy and review of the literature was performed. At autopsy, characteristic features of maternal-fetal glucose dysregulation were identified, including fetal macrosomia, cardiomegaly, hepatomegaly, and severe pancreatic islet cell hypertrophy/hyperplasia. Developmental abnormalities and other potential causes of death were not identified. Although deaths due to hypoglycemia cannot be reliably diagnosed postmortem using vitreous glucose levels, a clinical history of maternal glucose dysregulation in combination with certain gross and histologic findings should prompt a pathologist to consider maternal-fetal glucose dysregulation as a diagnosis of exclusion and cause of death.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Diabetes Gestacional , Hipoglicemia/diagnóstico , Gravidez em Diabéticas , Cardiomegalia/patologia , Evolução Fatal , Feminino , Macrossomia Fetal/patologia , Hepatomegalia/patologia , Parto Domiciliar , Humanos , Hiperplasia , Hipertrofia , Hipoglicemia/etiologia , Recém-Nascido , Ilhotas Pancreáticas/patologia , Gravidez
13.
Frontline Gastroenterol ; 10(3): 269-274, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31290854

RESUMO

The incidence of pancreatic neuroendocrine tumours (PNET) is rising mainly due to the increased use of cross-sectional imaging. Although many PNETs are asymptomatic and non-functioning, the overall 5-year survival is still less than 50%. In this article, we review the advances in diagnosis, classification and staging of PNET that have evolved with the development of new cross-sectional imaging methods and biopsy techniques. With accurate classification, evidence-based, individualised prognostic outcomes and treatments are able to be given which are also discussed.

14.
Biol Pharm Bull ; 41(5): 761-769, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29709913

RESUMO

Ipragliflozin is a selective sodium glucose cotransporter 2 (SGLT2) inhibitor that increases urinary glucose excretion and subsequently improves hyperglycemia in patients with type 2 diabetes mellitus (T2DM). To assess the beneficial effect of ipragliflozin on the mass and function of pancreatic ß-cells under diabetic conditions, obese T2DM db/db mice were treated with ipragliflozin for 5 weeks. Glucose and lipid metabolism parameters, pathological changes in pancreatic islet cells and insulin content were evaluated. Pathological examination of pancreatic islet cells comprised measuring the ratios of insulin- and glucagon-positive cells and levels of oxidative stress markers. Hemoglobin A1c, plasma glucose, non-esterified fatty acid and triglyceride levels in ipragliflozin-treated groups were reduced compared to the diabetic control (DM-control) group. Histopathological examination of pancreatic islet cells revealed strong insulin staining and reduced glucagon staining in the ipragliflozin 10 mg/kg-treated group compared with the DM-control group. The ratio of α- to ß-cell mass was lower in the ipragliflozin 10 mg/kg-treated group than the DM-control group and was similar to that of the non-diabetic control group. The density of immunostaining for 4-hydroxy-2-nonenal, an oxidative stress marker, in pancreatic islets was significantly lower in the ipragliflozin 10 mg/kg-treated group than the DM-control group. Pancreatic insulin content tended to be higher in the ipragliflozin-treated groups than the DM-control group. Our findings demonstrate the benefit of ipragliflozin treatment in improving glucolipotoxicity and reducing oxidative stress in pancreatic islet cells. Treatment with ipragliflozin may protect against the progressive loss of islet ß-cells in patients with T2DM.


Assuntos
Glucosídeos/farmacologia , Hipoglicemiantes/farmacologia , Ilhotas Pancreáticas/efeitos dos fármacos , Tiofenos/farmacologia , Animais , Glicemia/análise , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/metabolismo , Ácidos Graxos/sangue , Hemoglobinas Glicadas/análise , Insulina/sangue , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/patologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Obesos , Obesidade/sangue , Obesidade/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Inibidores do Transportador 2 de Sódio-Glicose , Triglicerídeos/sangue
15.
Organ Transplantation ; (6): 290-296, 2018.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-731742

RESUMO

Objective To investigate the protective effect and mechanism of serum containing Euonymus fortunei on the rat pancreatic islet cells. Methods Forty male SD rats were randomly divided into 5 groups (n=8 in each group), including the control group (normal rat islet cells were cultured with normal rat serum), ischemic preconditioning group (abdominal aorta was blocked first and then re-opened before the pancreas was obtained, and the pancreatic islet cells were cultured with normal rat serum), Euonymus fortunei treatment group (normal rat islet cells were cultured with rat serum containing Euonymus fortunei), Euonymus fortunei group and blank group (normal rats were administered orally with Euonymus fortunei extract or distilled water for the preparation of rat serum). Diphenylthiocarbazone (DTZ) staining was utilized to observe and calculate the quantity of islets. Acridine orange (AO)/propidium iodide (PI) staining was adopted to calculate the survival rate of islet cells. The insulin release experiment was performed to calculate the stimulation index (SI) and evaluate islet cell function. The concentration of glutathione (GSH) and nitric oxide (NO) in islet cells was detected using GSH and NO kits. The expression level of inducible nitric oxide synthase (iNOS) messenger RNA (mRNA) was quantitatively measured by reverse transcription polymerase chain reaction (RT-PCR). Results Islet cells were observed in specifically scarlet color after DTZ staining. The quantity of islet cells did not significantly differ among different groups (all P>0.05). Along with the prolongation of culture time, the activity of islet cells in each group was gradually decreased. At 72 h after isolation and culture, compared with the control group, the survival rate of the cells was significantly higher in the Euonymus fortunei treatment group (P<0.05). The insulin release test results demonstrated that compared with the control group, the SI of the ischemic preconditioning and Euonymus fortunei treatment groups was significantly increased (both P<0.05). Compared with the control group, the GSH contents of pancreatic islet cells in the ischemic preconditioning and Euonymus fortunei treatment groups were considerably enhanced, the NO content was significantly decreased, and the expression level of iNOS mRNA was significantly down-regulated (all P<0.05). Conclusions Euonymus fortunei can increase the survival rate of islet cells and enhance the function of pancreatic islets by increasing the level of GSH, down-regulating the expression of iNOS and decreasing the NO production.

16.
Mater Sci Eng C Mater Biol Appl ; 77: 384-393, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28532044

RESUMO

The differentiation of induced pluripotent stem cells (iPSCs) in biomaterial scaffolds is an emerging area for biomedical applications. This study proposes, for the first time, the production of pancreatic cells from iPSCs in gelatin-poly(lactide-co-glycolide) nanoparticle (PLGA NP) scaffolds. The porosity and swelling ratio of the scaffolds decreased with increases in gelatin and PLGA NP concentrations. The adhesion efficiency of iPSCs in gelatin-PLGA NP scaffolds was found to be higher at 6.7% (w/w) PLGA NP. A 3-step induction of iPSCs was used to differentiate into pancreatic islet cells using activin A, 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002), and retinoic acid (RA). The ability of iPSCs to differentiate into pancreatic islet cells in a scaffold was demonstrated by immunofluorescence staining and flow-cytometry analysis. The results indicate that the concentration of activin A, LY294002, and RA plays a decisive role in the differentiation of iPSCs into pancreatic cells. Activin A and LY294002 induce the iPSCs into endoderm and RA induces endoderm into islet cells. A maximum insulin secretion by glucose stimulation was obtained with a higher concentration (2µM) of RA. The use of activin A-grafted gelatin-PLGA NP scaffolds induced by LY294002 and RA can be a promising approach to developing pancreatic islet cells from iPSCs.


Assuntos
Células-Tronco Pluripotentes Induzidas , Ativinas , Diferenciação Celular , Cromonas , Gelatina , Ácido Láctico , Morfolinas , Nanopartículas , Pâncreas , Poliglactina 910 , Ácido Poliglicólico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Engenharia Tecidual , Alicerces Teciduais , Tretinoína
17.
Nano Rev Exp ; 8(1): 1341758, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-30410709

RESUMO

Gene therapy that targets the pancreas and intestines with delivery systems using nano-sized carriers such as viral and non-viral vectors could improve the control of blood glucose levels, resulting in an improved prognosis for patients with diabetes mellitus. Allogenic pancreatic islet cell transplantations using such delivery systems have been developed as therapeutic options for diabetes mellitus. This review focuses on transgenes and islet cell delivery systems using nano-sized carriers for the treatment of diabetes mellitus.

18.
Cell Metab ; 24(4): 608-615, 2016 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-27667665

RESUMO

Pancreatic islet cells are critical for maintaining normal blood glucose levels, and their malfunction underlies diabetes development and progression. We used single-cell RNA sequencing to determine the transcriptomes of 1,492 human pancreatic α, ß, δ, and PP cells from non-diabetic and type 2 diabetes organ donors. We identified cell-type-specific genes and pathways as well as 245 genes with disturbed expression in type 2 diabetes. Importantly, 92% of the genes have not previously been associated with islet cell function or growth. Comparison of gene profiles in mouse and human α and ß cells revealed species-specific expression. All data are available for online browsing and download and will hopefully serve as a resource for the islet research community.


Assuntos
Diabetes Mellitus Tipo 2/genética , Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos , Animais , Perfilação da Expressão Gênica , Humanos , Camundongos , Transdução de Sinais/genética , Transcriptoma/genética
19.
Scand J Gastroenterol ; 51(10): 1172-8, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27191542

RESUMO

OBJECTIVE: Neuroendocrine tumors in the pancreas and the gastrointestinal tract may secrete hormones which cause specific syndromes. Well-known examples are gastrinomas, glucagonomas, and insulinomas. Cholecystokinin-producing tumors (CCKomas) have been induced experimentally in rats, but a CCKoma syndrome in man has remained unknown until now. MATERIAL AND METHODS: Using a panel of immunoassays for CCK peptides and proCCK as well as for chromogranin A, we have examined plasma samples from 284 fasting patients with gastroenteropancreatic neuroendocrine tumors. In hyperCCKemic samples, plasma CCK was further characterized by chromatography. RESULTS: One of the patients displayed gross hyperCCKemia. She was a 58-year old woman with a pancreatic endocrine tumor, liver metastases, 500-1000-fold elevated basal CCK concentration in plasma, diarrhea, severe weight loss, recurrent peptic ulcer and bilestone attacks from a contracted gallbladder. The CCK concentrations in plasma were not affected by resection of the pancreatic tumor, but decreased to normal after hemihepatectomy with removal of the metastases. CONCLUSION: A CCKoma syndrome with severe hypersecretion of CCK exists in man. The duodenal ulcer disease and diarrhea with permanently low gastrin in plasma suggest that CCKomas may mimic gastrinoma-like symptoms, because CCK peptides are full agonists of the gastrin/CCK-B receptor.


Assuntos
Colecistocinina/sangue , Gastrinas/sangue , Neoplasias Intestinais/sangue , Neoplasias Hepáticas/secundário , Tumores Neuroendócrinos/sangue , Neoplasias Pancreáticas/sangue , Neoplasias Gástricas/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Dinamarca , Feminino , Gastrinoma , Humanos , Neoplasias Intestinais/patologia , Masculino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/patologia , Pâncreas/patologia , Neoplasias Pancreáticas/patologia , Ratos , Neoplasias Gástricas/patologia , Adulto Jovem
20.
Clin Exp Metastasis ; 32(8): 799-817, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26445848

RESUMO

The present study sought to determine the anti-tumor effects of OXA-11, a potent, novel small-molecule amino pyrimidine inhibitor (1.2 pM biochemical IC(50)) of focal adhesion kinase (FAK). In studies of cancer cell lines, OXA-11 inhibited FAK phosphorylation at phospho-tyrosine 397 with a mechanistic IC(50) of 1 nM in TOV21G tumor cells, which translated into functional suppression of proliferation in 3-dimensional culture with an EC(50) of 9 nM. Studies of OXA-11 activity in TOV21G tumor-cell xenografts in mice revealed a pharmacodynamic EC(50) of 1.8 nM, indicative of mechanistic inhibition of pFAK [Y397] in these tumors. OXA-11 inhibited TOV21G tumor growth in a dose-dependent manner and also potentiated effects of cisplatin on tumor cell proliferation and apoptosis in vitro and on tumor growth in mice. Studies of pancreatic neuroendocrine tumors in RIP-Tag2 transgenic mice revealed OXA-11 suppression of pFAK [Y397] and pFAK [Y861] in tumors and liver. OXA-11 given daily from age 14 to 17 weeks reduced tumor vascularity, invasion, and when given together with the anti-VEGFR-2 antibody DC101 reduced the incidence, abundance, and size of liver metastases. Liver micrometastases were found in 100 % of mice treated with vehicle, 84 % of mice treated with OXA-11, and 79 % of mice treated with DC101 (19-24 mice per group). In contrast, liver micrometastases were found in only 52 % of 21 mice treated with OXA-11 plus DC101, and those present were significantly smaller and less numerous. Together, these findings indicate that OXA-11 is a potent and selective inhibitor of FAK phosphorylation in vitro and in vivo. OXA-11 slows tumor growth, potentiates the anti-tumor actions of cisplatin and--when combined with VEGFR-2 blockade--reduces metastasis of pancreatic neuroendocrine tumors in RIP-Tag2 mice.


Assuntos
Proteína-Tirosina Quinases de Adesão Focal/antagonistas & inibidores , Tumores Neuroendócrinos/tratamento farmacológico , Neoplasias Pancreáticas/tratamento farmacológico , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Proliferação de Células , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Humanos , Neoplasias Hepáticas/secundário , Camundongos , Invasividade Neoplásica , Micrometástase de Neoplasia , Tumores Neuroendócrinos/irrigação sanguínea , Tumores Neuroendócrinos/patologia , Neoplasias Pancreáticas/irrigação sanguínea , Neoplasias Pancreáticas/patologia , Fosforilação , Transdução de Sinais/efeitos dos fármacos , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/fisiologia
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