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1.
Nutr Cancer ; 71(2): 301-311, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30661403

RESUMEN

Natural falcarinol-type (FC-type) polyacetylenes are known to show anticancer activities. We studied the bioactivity of synthetic FC, 1,2-dihydrofalcarinol (FCH) and 3-acetoxyfalcarinol (FCA) and compared them with the natural bioactive polyacetylene [9,17-octadecadiene-12,14-diyne-1,11,16-triol,1-acetate] (DCA) isolated from Devil's club (DC) Oplopanax horridus. Antiproliferation activity of these polyacetylenes, along with DC inner stem bark 70% ethanol and water extracts, was tested on human pancreatic ductal adenocarcinoma cell lines PANC-1 and BxPC-3. Chemically synthesized FC and FCA showed consistent IC50 (50% inhibition concentration) and higher potency than DCA. FC and DCA's mechanism of action investigated by antibody array on apoptosis-associated genes, and cellular features confirmed by microscopy demonstrated that both compounds modulated genes related to pro-apoptosis, antiapoptosis, apoptosis, cell cycle, stress related, and death receptors. FC-type polyacetylenes with a terminal double bond (FC, FCA, and DCA) are potent inhibitors of pancreatic cancer cell proliferation compared to FCH with a terminal single bond. Liquid chromatography mass spectrometry confirmed the presence of FC and FCH in the inner stem bark of DC. For potential applications of FC-type polyacetylenes as anticancer agents, preparing them by chemical synthesis may provide an advantage over the labor intensive extraction process from raw plant material.


Asunto(s)
Carcinoma Ductal Pancreático/tratamiento farmacológico , Diinos/farmacología , Alcoholes Grasos/farmacología , Oplopanax/química , Neoplasias Pancreáticas/tratamiento farmacológico , Polímero Poliacetilénico/farmacología , Apoptosis/efectos de los fármacos , Carcinoma Ductal Pancreático/patología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Humanos , Neoplasias Pancreáticas/patología , Corteza de la Planta/química , Extractos Vegetales/farmacología
2.
Diabetes Obes Metab ; 19(5): 682-694, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28058779

RESUMEN

AIMS: Islet amyloid, formed by aggregation of human islet amyloid polypeptide (hIAPP), contributes to ß-cell failure in type 2 diabetes, cultured and transplanted islets. We previously showed that biosynthetic hIAPP aggregates induce ß-cell Fas upregulation and activation of the Fas apoptotic pathway. We used cultured human and hIAPP-expressing mouse islets to investigate: (1) the role of interleukin-1ß (IL-1ß) in amyloid-induced Fas upregulation; and (2) the effects of IL-1ß-induced ß-cell dysfunction on pro-islet amyloid polypeptide (proIAPP) processing and amyloid formation. RESEARCH DESIGN AND METHODS: Human and h IAPP -expressing mouse islets were cultured to form amyloid without or with the IL-1 receptor antagonist (IL-1Ra) anakinra, in the presence or absence of recombinant IL-1ß. Human islets in which amyloid formation was prevented (amyloid inhibitor or Ad-prohIAPP-siRNA) were cultured similarly. ß-cell function, apoptosis, Fas expression, caspase-8 activation, islet IL-1ß, ß-cell area, ß-/α-cell ratio, amyloid formation, and (pro)IAPP forms were assessed. RESULTS: hIAPP aggregates were found to increase IL-1ß levels in cultured human islets that correlated with ß-cell Fas upregulation, caspase-8 activation and apoptosis, all of which were reduced by IL-1Ra treatment or prevention of amyloid formation. Moreover, IL-1Ra improved culture-induced ß-cell dysfunction and restored impaired proIAPP processing, leading to lower amyloid formation. IL-1ß treatment potentiated impaired proIAPP processing and increased amyloid formation in cultured human and h IAPP -expressing mouse islets, which were prevented by IL-1Ra. CONCLUSIONS: IL-1ß plays a dual role by: (1) mediating amyloid-induced Fas upregulation and ß-cell apoptosis; (2) inducing impaired proIAPP processing thereby potentiating amyloid formation. Blocking IL-1ß may provide a new strategy to preserve ß cells in conditions associated with islet amyloid formation.


Asunto(s)
Amiloide/agonistas , Apoptosis , Interleucina-1beta/metabolismo , Polipéptido Amiloide de los Islotes Pancreáticos/metabolismo , Islotes Pancreáticos/metabolismo , Receptor fas/agonistas , Adulto , Amiloide/antagonistas & inhibidores , Amiloide/química , Amiloide/metabolismo , Animales , Cadáver , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patología , Diabetes Mellitus Tipo 2/cirugía , Hemicigoto , Humanos , Insulina/metabolismo , Secreción de Insulina , Proteína Antagonista del Receptor de Interleucina 1/genética , Proteína Antagonista del Receptor de Interleucina 1/metabolismo , Interleucina-1beta/antagonistas & inhibidores , Interleucina-1beta/genética , Polipéptido Amiloide de los Islotes Pancreáticos/antagonistas & inhibidores , Polipéptido Amiloide de los Islotes Pancreáticos/química , Polipéptido Amiloide de los Islotes Pancreáticos/genética , Islotes Pancreáticos/citología , Islotes Pancreáticos/patología , Trasplante de Islotes Pancreáticos/efectos adversos , Ratones Endogámicos C57BL , Ratones Transgénicos , Persona de Mediana Edad , Precursores de Proteínas/antagonistas & inhibidores , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , Procesamiento Proteico-Postraduccional , Interferencia de ARN , Proteínas Recombinantes/metabolismo , Técnicas de Cultivo de Tejidos , Receptor fas/metabolismo
3.
J Cell Physiol ; 231(9): 1964-73, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-26743772

RESUMEN

Indoleamine 2,3-dioxygenase (IDO) induces immunological tolerance in physiological and pathological conditions. Therefore, we used dermal fibroblasts with stable IDO expression as a cell therapy to: (i) Investigate the factors determining the efficacy of this cell therapy for autoimmune diabetes in non-obese diabetic (NOD) mice; (ii) Scrutinize the potential immunological mechanisms. Newly diabetic NOD mice were randomly injected with either 10 × 10(6) (10M) or 15 × 10(6) (15M) IDO-expressing dermal fibroblasts. Blood glucose levels (BGLs), body weight, plasma kynurenine levels, insulitis severity, islet beta cell function, autoreactive CD8(+) T cells, Th17 cells and regulatory T cells (Tregs) were then investigated in these mice. IL-1ß and cleaved caspase-3 levels were assessed in islets co-cultured with IDO-expressing fibroblasts. BGLs in 83% mice treated with 15M IDO-expressing fibroblasts recovered to normal up to 120 days. However, only 17% mice treated with 10M IDO-expressing cells were reversed to normoglycemia. A 15M IDO-expressing fibroblasts significantly reduced infiltrated immune cells in islets and recovered the functionality of remaining islet beta cells in NOD mice. Additionally, they successfully inhibited autoreactive CD8(+) T cells and Th17 cells as well as increased Tregs in different organs of NOD mice. Islet beta cells co-cultured with IDO-expressing fibroblasts had reduced IL-1ß levels and cell apoptosis. Both cell number and IDO enzymatic activity contributes to the efficiency of IDO cell therapy. Optimized IDO-expressing fibroblasts successfully reverse the progression of diabetes in NOD mice through induction of Tregs as well as inhibition of beta cell specific autoreactive CD8(+) T cells and Th17 cells. J. Cell. Physiol. 231: 1964-1973, 2016. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Diabetes Mellitus Experimental/inmunología , Fibroblastos/enzimología , Hiperglucemia/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Células Secretoras de Insulina/inmunología , Animales , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/inmunología , Diabetes Mellitus Tipo 1/metabolismo , Femenino , Hiperglucemia/inmunología , Células Secretoras de Insulina/enzimología , Masculino , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Linfocitos T Reguladores/inmunología
4.
Diabetologia ; 58(7): 1503-12, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25930156

RESUMEN

AIMS/HYPOTHESIS: There are potential advantages to the low-temperature (-196 °C) banking of isolated islets, including the maintenance of viable islets for future research. We therefore assessed the in vitro and in vivo function of islets cryopreserved for nearly 20 years. METHODS: Human islets were cryopreserved from 1991 to 2001 and thawed between 2012 and 2014. These were characterised by immunostaining, patch-clamp electrophysiology, insulin secretion, transcriptome analysis and transplantation into a streptozotocin (STZ)-induced mouse model of diabetes. RESULTS: The cryopreservation time was 17.6 ± 0.4 years (n = 43). The thawed islets stained positive with dithizone, contained insulin-positive and glucagon-positive cells, and displayed levels of apoptosis and transcriptome profiles similar to those of freshly isolated islets, although their insulin content was lower. The cryopreserved beta cells possessed ion channels and exocytotic responses identical to those of freshly isolated beta cells. Cells from a subset of five donors demonstrated similar perifusion insulin secretion profiles pre- and post-cryopreservation. The transplantation of cryopreserved islets into the diabetic mice improved their glucose tolerance but did not completely normalise their blood glucose levels. Circulating human insulin and insulin-positive grafts were detectable at 10 weeks post-transplantation. CONCLUSIONS/INTERPRETATION: We have demonstrated the potential for long-term banking of human islets for research, which could enable the use of tissue from a large number of donors with future technologies to gain new insight into diabetes.


Asunto(s)
Criopreservación , Islotes Pancreáticos/fisiología , Bancos de Tejidos , Adulto , Animales , Diabetes Mellitus Experimental/terapia , Exocitosis/fisiología , Femenino , Proteínas de Homeodominio/genética , Humanos , Insulina/sangre , Insulina/metabolismo , Células Secretoras de Insulina/fisiología , Canales Iónicos/metabolismo , Trasplante de Islotes Pancreáticos , Masculino , Ratones , Ratones Noqueados , Técnicas de Placa-Clamp , Transcriptoma/genética
5.
Nutr Cancer ; 67(6): 954-64, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26221768

RESUMEN

Devil's club Oplopanax horridus (DC) is a close relative of ginseng; its inner root and stem bark extract showed antiproliferation activity on human leukemia, ovarian, breast and colon cancer cells. We study here the effects of DC 70% ethanol extract alone, or in combination with cisplatin, gemcitabine, and paclitaxel on pancreatic endocrine HP62 and pancreatic ductal carcinoma PANC-1 and BxPC-3 cells. Antiproliferation activity assay, cell cycle analysis by flow cytometry, apoptosis-related markers by antibody array, and RT-PCR assay were used for this study. DC extract inhibited proliferation of HP62 with IC50 (50% inhibition concentration) at 0.037±0.002% (v/v), PANC-1 at 0.0058 ± 0.0004% and BxPC-3 at 0.021 ± 0.003%. DC at 0.0033% combined with 1 nM of paclitaxel showed inhibition synergy on PANC-1 cells with a combination index of 0.44. Apoptosis focused antibody array profile indicated upregulation of cytochrome C, claspin, cIAP-2 and HTRA2/Omi apoptosis-related markers in DC-treated HP62 and PANC-1. Our data suggest that DC acts through targeting the intrinsic mitochondrial apoptosis pathway in the pancreatic cancer cells. The high antiproliferation potency of DC on PANC-1 is potentially useful as an adjunct therapy for treating pancreatic cancer, which is known for developing resistance to conventional chemotherapeutics.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Oplopanax/química , Poliinos/farmacología , Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Cisplatino/farmacología , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacología , Humanos , Concentración 50 Inhibidora , Paclitaxel/farmacología , Neoplasias Pancreáticas/tratamiento farmacológico , Extractos Vegetales/farmacología , Raíces de Plantas/química , Transducción de Señal , Gemcitabina
6.
Diabetologia ; 57(4): 765-75, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24442508

RESUMEN

AIMS/HYPOTHESIS: Reduced beta cell mass due to increased beta cell apoptosis is a key defect in type 2 diabetes. Islet amyloid, formed by the aggregation of human islet amyloid polypeptide (hIAPP), contributes to beta cell death in type 2 diabetes and in islet grafts in patients with type 1 diabetes. In this study, we used human islets and hIAPP-expressing mouse islets with beta cell Casp8 deletion to (1) investigate the role of caspase-8 in amyloid-induced beta cell apoptosis and (2) test whether caspase-8 inhibition protects beta cells from amyloid toxicity. METHODS: Human islet cells were cultured with hIAPP alone, or with caspase-8, Fas or amyloid inhibitors. Human islets and wild-type or hIAPP-expressing mouse islets with or without caspase-8 expression (generated using a Cre/loxP system) were cultured to form amyloid. Caspase-8 and -3 activation, Fas and FLICE inhibitory protein (FLIP) expression, islet beta cell and amyloid area, IL-1ß levels, and the beta:alpha cell ratio were assessed. RESULTS: hIAPP treatment induced activation of caspase-8 and -3 in islet beta cells (via Fas upregulation), resulting in apoptosis, which was markedly reduced by blocking caspase-8, Fas or amyloid. Amyloid formation in cultured human and hIAPP-expressing mouse islets induced caspase-8 activation, which was associated with Fas upregulation and elevated islet IL-1ß levels. hIAPP-expressing mouse islets with Casp8 deletion had comparable amyloid, IL-1ß and Fas levels with those expressing hIAPP and Casp8, but markedly lower beta cell apoptosis, higher beta:alpha cell ratio, greater beta cell area, and enhanced beta cell function. CONCLUSIONS/INTERPRETATION: Beta cell Fas upregulation by endogenously produced and exogenously applied hIAPP aggregates promotes caspase-8 activation, resulting in beta cell apoptosis. The prevention of amyloid-induced caspase-8 activation enhances beta cell survival and function in islets.


Asunto(s)
Amiloide/toxicidad , Caspasa 8/metabolismo , Células Secretoras de Insulina/efectos de los fármacos , Células Secretoras de Insulina/enzimología , Islotes Pancreáticos/citología , Adulto , Animales , Caspasa 3/metabolismo , Caspasa 8/genética , Femenino , Humanos , Técnicas In Vitro , Masculino , Ratones , Persona de Mediana Edad
7.
Int J Cancer ; 135(7): 1511-6, 2014 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-24285244

RESUMEN

Biobanks have played a decisive role in all aspects of the field of cancer, including pathogenesis, diagnosis, prognosis and treatment. The significance of cancer biobanks is epitomized through the appropriate application of various "-omic" techniques (omics). The mutually motivated relationship between biobanks and omics has intensified the development of cancer research. Human cancer tissues that are maintained in intravital biobanks (or living tissue banks) retain native tumor microenvironment, tissue architecture, hormone responsiveness and cell-to-cell signalling properties. Intravital biobanks replicate the structural complexity and heterogeneity of human cancers, making them an ideal platform for preclinical studies. The application of omics with intravital biobanks renders them more active, which makes it possible for the cancer-related evaluations to be dynamically monitored on a real-time basis. Integrating intravital biobank and modern omics will provide a useful tool for the discovery and development of new drugs or novel therapeutic strategies. More importantly, intravital biobanks may play an essential role in the creation of meaningful patient-tailored therapies as for personalized medicine.


Asunto(s)
Bancos de Muestras Biológicas , Genómica/métodos , Metabolómica/métodos , Medicina de Precisión , Proteómica/métodos , Humanos
8.
BMC Cancer ; 14: 814, 2014 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-25373319

RESUMEN

BACKGROUND: Pancreatic adenocarcinoma is one of the most lethal cancers, yet it remains understudied and poorly understood. Hyperinsulinemia has been reported to be a risk factor of pancreatic cancer, and the rapid rise of hyperinsulinemia associated with obesity and type 2 diabetes foreshadows a rise in cancer incidence. However, the actions of insulin at the various stages of pancreatic cancer progression remain poorly defined. METHODS: Here, we examined the effects of a range of insulin doses on signalling, proliferation and survival in three human cell models meant to represent three stages in pancreatic cancer progression: primary pancreatic duct cells, the HPDE immortalized pancreatic ductal cell line, and the PANC1 metastatic pancreatic cancer cell line. Cells were treated with a range of insulin doses, and their proliferation/viability were tracked via live cell imaging and XTT assays. Signal transduction was assessed through the AKT and ERK signalling pathways via immunoblotting. Inhibitors of AKT and ERK signalling were used to determine the relative contribution of these pathways to the survival of each cell model. RESULTS: While all three cell types responded to insulin, as indicated by phosphorylation of AKT and ERK, we found that there were stark differences in insulin-dependent proliferation, cell viability and cell survival among the cell types. High concentrations of insulin increased PANC1 and HPDE cell number, but did not alter primary duct cell proliferation in vitro. Cell survival was enhanced by insulin in both primary duct cells and HPDE cells. Moreover, we found that primary cells were more dependent on AKT signalling, while HPDE cells and PANC1 cells were more dependent on RAF/ERK signalling. CONCLUSIONS: Our data suggest that excessive insulin signalling may contribute to proliferation and survival in human immortalized pancreatic ductal cells and metastatic pancreatic cancer cells, but not in normal adult human pancreatic ductal cells. These data suggest that signalling pathways involved in cell survival may be rewired during pancreatic cancer progression.


Asunto(s)
Carcinoma Ductal Pancreático/metabolismo , Transformación Celular Neoplásica/metabolismo , Insulina/farmacología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Neoplasias Pancreáticas/metabolismo , Bencilaminas/farmacología , Carcinoma Ductal Pancreático/patología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Progresión de la Enfermedad , Quinasas MAP Reguladas por Señal Extracelular/antagonistas & inhibidores , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Humanos , Indoles/farmacología , Modelos Biológicos , Conductos Pancreáticos , Neoplasias Pancreáticas/patología , Fenoles/farmacología , Fosforilación , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Proto-Oncogénicas c-raf/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-raf/efectos de los fármacos , Quinoxalinas/farmacología
9.
J Clin Endocrinol Metab ; 109(2): 413-423, 2024 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-37671625

RESUMEN

BACKGROUND: Macroencapsulated pancreatic endoderm cells (PECs) can reverse diabetes in rodents and preclinical studies revealed that thyroid hormones in vitro and in vivo bias PECs to differentiate into insulin-producing cells. In an ongoing clinical trial, PECs implanted in macroencapsulation devices into patients with type 1 diabetes were safe but yielded heterogeneous outcomes. Though most patients developed meal responsive C-peptide, levels were heterogeneous and explanted grafts had variable numbers of surviving cells with variable distribution of endocrine cells. METHODS: We measured circulating triiodothyronine and thyroxine levels in all patients treated at 1 of the 7 sites of the ongoing clinical trial and determined if thyroid hormone levels were associated with the C-peptide or glucagon levels and cell fate of implanted PECs. RESULTS: Both triiodothyronine and thyroxine levels were significantly associated with the proportion of cells that adopted an insulin-producing fate with a mature phenotype. Thyroid hormone levels were inversely correlated to circulating glucagon levels after implantation, suggesting that thyroid hormones lead PECs to favor an insulin-producing fate over a glucagon-producing fate. In mice, hyperthyroidism led to more rapid maturation of PECs into insulin-producing cells similar in phenotype to PECs in euthyroid mice. CONCLUSION: These data highlight the relevance of thyroid hormones in the context of PEC therapy in patients with type 1 diabetes and suggest that a thyroid hormone adjuvant therapy may optimize cell outcomes in some PEC recipients.


Asunto(s)
Diabetes Mellitus Tipo 1 , Humanos , Ratones , Animales , Diabetes Mellitus Tipo 1/metabolismo , Péptido C/metabolismo , Tiroxina/metabolismo , Triyodotironina/metabolismo , Endodermo/metabolismo , Endodermo/trasplante , Glucagón/metabolismo
10.
Cell Immunol ; 282(1): 1-8, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23623902

RESUMEN

Type 1 diabetes (T1D) is an autoimmune disease characterized by immunological destruction of insulin-producing pancreatic ß-cells and subsequent hyperglycemia. The non-obese diabetic (NOD) mouse strain spontaneously develops a disease similar to human T1D and is commonly used as an animal model for studying this disease. We have previously shown that the administration of B7-H4-immunoglobulin fusion protein (B7-H4.Ig), a newly identified T-cell co-inhibitory signaling molecule, blocks the onset of diabetes in NOD mice. However, the mechanism(s) by which B7-H4 protects NOD mice from T1D is not fully understood. IL-17 is a pro-inflammatory cytokine, produced by Th17 cells, that activates T cells and other immune cells to produce a variety of cytokines and chemokines. Increasing evidence has shown that therapeutic agents targeting the IL-17 molecule or directly inhibiting IL-17-producing cells regulate autoimmune diabetes in NOD mice, suggesting that IL-17 is involved in the pathogenesis of this disease. In this study, we investigate whether B7-H4.Ig treatment inhibits the generation of Th17 cells which subsequently decreases IL-17 production and prevents the onset of T1D in NOD mice. Pre-diabetic female NOD mice were injected intraperitoneally with control mouse IgG or B7-H4.Ig starting at 4 weeks of age for 12 weeks. Our data showed that the frequency of Th17 cells in B7-H4.Ig-treated mice was significantly decreased. In addition, our data showed that B7-H4.Ig-treated mice had decreased levels of pro-inflammatory cytokines and Th17-associated cytokines, and an increased level of the potent Th17 inhibitor IFN-γ. To further investigate the effect of B7-H4.Ig on differentiation of Th17 cells, we co-cultured splenocytes with Th17-polarizing cytokines in the absence or presence of B7-H4.Ig. Our results indicated that splenocytes, under the Th17 driving conditions in the presence of B7-H4.Ig, had significantly decreased the numbers of Th17 cells compared to cells co-cultured in the absence of B7-H4.Ig. Together, this study suggests that blocking the generation of Th17 cells with the administration of B7-H4.Ig effectively inhibits the development of T1D in NOD mice.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Diabetes Mellitus Tipo 1/prevención & control , Proteínas Recombinantes de Fusión/farmacología , Células Th17/efectos de los fármacos , Animales , Células Cultivadas , Técnicas de Cocultivo , Diabetes Mellitus Tipo 1/metabolismo , Femenino , Citometría de Flujo , Inmunoglobulinas/genética , Inmunoglobulinas/metabolismo , Inmunoglobulinas/farmacología , Células Secretoras de Insulina/citología , Células Secretoras de Insulina/efectos de los fármacos , Células Secretoras de Insulina/metabolismo , Interferón gamma/metabolismo , Interleucina-17/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Ratones , Ratones Endogámicos NOD , Proteínas Recombinantes de Fusión/administración & dosificación , Proteínas Recombinantes de Fusión/metabolismo , Bazo/citología , Bazo/efectos de los fármacos , Bazo/metabolismo , Linfocitos T Citotóxicos/citología , Linfocitos T Citotóxicos/efectos de los fármacos , Linfocitos T Citotóxicos/metabolismo , Células Th17/citología , Células Th17/metabolismo , Inhibidor 1 de la Activación de Células T con Dominio V-Set/genética , Inhibidor 1 de la Activación de Células T con Dominio V-Set/metabolismo , Inhibidor 1 de la Activación de Células T con Dominio V-Set/farmacología
11.
Am J Pathol ; 181(4): 1296-305, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22902430

RESUMEN

Islet transplantation provides a promising approach for treatment of type 1 diabetes mellitus. Amyloid formation and loss of extracellular matrix are two nonimmune factors contributing to death of isolated human islets. We tested the effects of two types of three-dimensional scaffolds, collagen matrix (CM) and fibroblast-populated collagen matrix (FPCM), on amyloid formation, viability, and function of isolated islets. Islets from cadaveric donors were cultured in FPCM, CM, or two-dimensional plate (2D) for 7 days. After 7 days, compared with the 2D culture condition, CM and FPCM markedly reduced amyloid formation of cultured islets and decreased apoptotic ß-cell rate by ∼75%. IL-1ß and Fas levels were also reduced in scaffold-embedded islets. Furthermore, ß/α cell ratios were increased by ∼18% and ∼36% in CM- and FPCM-embedded islets, respectively. Insulin content and insulin response to elevated glucose were also enhanced by both three-dimensional scaffolds. Moreover, culture in CM and FPCM (but not 2D) preserved insulin, GLUT-2, and PDX-1 mRNA expression. FPCM-embedded islets had significantly higher insulin response and lower amyloid formation than CM-embedded islets. These findings suggest that three-dimensional scaffolds reduce amyloid formation and improve viability and function of human islets in vitro, and that CM and fibroblasts have additive effects in enhancing islet function and reducing amyloid formation. Using this strategy is likely to improve outcome in human islet transplantation.


Asunto(s)
Amiloide/metabolismo , Islotes Pancreáticos/metabolismo , Técnicas de Cultivo de Tejidos/métodos , Andamios del Tejido/química , Supervivencia Tisular , Apoptosis , Caspasa 3/metabolismo , Recuento de Células , Activación Enzimática , Regulación de la Expresión Génica , Células Secretoras de Glucagón/metabolismo , Células Secretoras de Glucagón/patología , Transportador de Glucosa de Tipo 2/genética , Transportador de Glucosa de Tipo 2/metabolismo , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Humanos , Insulina/genética , Insulina/metabolismo , Células Secretoras de Insulina/enzimología , Células Secretoras de Insulina/patología , Interleucina-1beta/metabolismo , Masculino , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transactivadores/genética , Transactivadores/metabolismo , Receptor fas/metabolismo
12.
Surg Endosc ; 27(12): 4449-56, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23949484

RESUMEN

BACKGROUND: Obesity is a major public health issue and is associated with increased risk of several cancers, currently a leading cause of mortality. Obese patients undergoing bariatric surgery may allow for evaluation of the effect of intentional excess weight loss on subsequent risk of cancer. We aimed to evaluate cancer risk, incidence, and mortality after bariatric surgery. METHODS: A comprehensive literature search was conducted using PubMed/MEDLINE and Embase with literature published from the inception of both databases to January 2012. Inclusion criteria incorporated all human studies examining oncologic outcomes after bariatric surgery. Two authors independently reviewed selected studies and relevant articles from their bibliographies for data extraction, quality appraisal, and meta-analysis. RESULTS: Six observational studies (n = 51,740) comparing relative risk (RR) of cancer in obese patients undergoing bariatric surgery versus obese control subjects were analyzed. Overall, the RR of cancer in obese patients after undergoing bariatric surgery was 0.55 [95% confidence interval (CI) 0.41-0.73, p < 0.0001, I(2) = 83%]. The effect of bariatric surgery on cancer risk was modified by gender (p = 0.021). The pooled RR in women was 0.68 (95% CI 0.60-0.77, p < 0.0001, I(2) < 0.1%) and in men was 0.99 (95% CI 0.74-1.32, p = 0.937, I(2) < 0.1%). CONCLUSIONS: Bariatric surgery reduces cancer risk and mortality in formerly obese patients. When stratifying the meta-analysis by gender, the effect of bariatric surgery on oncologic outcomes is protective in women but not in men.


Asunto(s)
Cirugía Bariátrica , Neoplasias , Obesidad , Salud Global , Humanos , Incidencia , Neoplasias/epidemiología , Neoplasias/etiología , Neoplasias/prevención & control , Obesidad/complicaciones , Obesidad/mortalidad , Obesidad/cirugía , Factores de Riesgo , Tasa de Supervivencia/tendencias , Pérdida de Peso
13.
HPB (Oxford) ; 14(5): 310-6, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22487068

RESUMEN

INTRODUCTION: A pancreaticoduodenectomy is the reference treatment for a resectable pancreatic head ductal adenocarcinoma. The probability of 5-year survival in patients undergoing such treatment is 5-25% and is associated with relatively high peri-operative morbidity and mortality. The objective of the present study was to evaluate risk factors predictive of outcome for patients undergoing a pancreaticoduodenectomy for a pancreatic adenocarcinoma. METHODS: This retrospective analysis incorporated data from the Vancouver General Hospital and the British Columbia Cancer Agency (BCCA) from 1999-2007. RESULTS: The 5-year survival of 100 patients was 12% with a median survival of 16.5 months. Ninety-day mortality was 7%. Predictors of 90-day mortality included age ≥ 80 years (P < 0.001) and an American Society of Anesthesiologists (ASA) score = 3 (P= 0.012) by univariate analysis and age ≥80 years (P < 0.001) by multivariate analysis. The identifiable predictive factor for poor 5-year survival was an ASA score = 3 (P= 0.043) whereas a Dindo-Clavien surgical complication grade ≥ 3 was associated with a worse outcome (P= 0.013). Referral to the BCCA was associated with a favourable 5-year survival (P= 0.001). CONCLUSIONS: The present study identifies risk factors for patient selection to enhance survival benefit in this patient population.


Asunto(s)
Carcinoma Ductal Pancreático/cirugía , Neoplasias Pancreáticas/cirugía , Pancreaticoduodenectomía , Factores de Edad , Anciano , Anciano de 80 o más Años , Colombia Británica , Carcinoma Ductal Pancreático/mortalidad , Carcinoma Ductal Pancreático/patología , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Análisis Multivariante , Neoplasias Pancreáticas/mortalidad , Neoplasias Pancreáticas/patología , Pancreaticoduodenectomía/efectos adversos , Pancreaticoduodenectomía/mortalidad , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
14.
J Cell Physiol ; 226(7): 1813-9, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21506112

RESUMEN

Islet transplantation represents a viable treatment for type 1 diabetes. However, due to loss of substantial mass of islets early after transplantation, islets from two or more donors are required to achieve insulin independence. Islet-extracellular matrix disengagement, which occurs during islet isolation process, leads to subsequent islet cell apoptosis and is an important contributing factor to early islet loss. In this study, we developed a fibroblast populated collagen matrix (FPCM) as a novel scaffold to improve islet cell viability and function post-transplantation. FPCM was developed by embedding fibroblasts within type-I collagen and used as scaffold for islet grafts. Viability and insulin secretory function of islets embedded within FPCM was evaluated in vitro and in a syngeneic murine islet transplantation model. Islets embedded within acellular matrix or naked islets were used as control. Islet cell survival and function was markedly improved particularly after embedding within FPCM. The composite scaffold significantly promoted islet isograft survival and reduced the critical islet mass required for diabetes reversal by half (from 200 to 100 islets per recipient). Fibroblast embedded within FPCM produced fibronectin and growth factors and induced islet cell proliferation. No evidence of fibroblast over-growth within composite grafts was noticed. These results confirm that FPCM significantly promotes islet viability and functionality, enhances engraftment of islet grafts and decreases the critical islet mass needed to reverse hyperglycemia. This promising finding offers a new approach to reducing the number of islet donors per recipient and improving islet transplant outcome.


Asunto(s)
Colágeno Tipo I/metabolismo , Diabetes Mellitus Experimental/cirugía , Fibroblastos/trasplante , Supervivencia de Injerto , Trasplante de Islotes Pancreáticos , Islotes Pancreáticos/cirugía , Andamios del Tejido , Animales , Apoptosis , Glucemia/metabolismo , Proliferación Celular , Células Cultivadas , Técnicas de Cocultivo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Fibroblastos/metabolismo , Fibronectinas/metabolismo , Insulina/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Islotes Pancreáticos/metabolismo , Islotes Pancreáticos/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Factores de Tiempo , Técnicas de Cultivo de Tejidos
15.
Gastroenterology ; 138(5): 1966-75, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20138041

RESUMEN

BACKGROUND & AIMS: Glucose-dependent insulinotropic polypeptide (GIP) and the proglucagon product glucagon-like peptide-1 (GLP-1) are gastrointestinal hormones that are released in response to nutrient intake and promote insulin secretion. Interestingly, a subset of enteroendocrine cells express both GIP and GLP-1. We sought to determine whether GIP also might be co-expressed with proglucagon in pancreatic alpha-cells. METHODS: We assessed GIP expression via reverse-transcription polymerase chain reaction, in situ hybridization, and immunohistochemistry. We developed a novel bioassay to measure GIP release from isolated islets, compared the biological activities of full-length and truncated GIP, and assessed the impact of immunoneutralization of islet GIP on glucose-stimulated insulin secretion in isolated islets. RESULTS: GIP messenger RNA was present in mouse islets; GIP protein localized to islet alpha-cells of mouse, human, and snake pancreas, based on immunohistochemical analyses. However, using a C-terminal GIP antibody, immunoreactivity was detected in islets from prohormone convertase (PC) 2 knockout but not wild-type mice. Bioactive GIP was secreted from mouse and human islets after arginine stimulation. In the perfused mouse pancreas, GIP(1-42) and amidated GIP(1-30) had equipotent insulinotropic actions. Finally, immunoneutralization of GIP secreted by isolated islets decreased glucose-stimulated insulin secretion. CONCLUSIONS: GIP is expressed in and secreted from pancreatic islets; in alpha-cells, PC2 processes proGIP to yield a truncated but bioactive form of GIP that differs from the PC1/3-derived form from K-cells. Islet-derived GIP promotes islet glucose competence and also could support islet development and/or survival.


Asunto(s)
Polipéptido Inhibidor Gástrico/metabolismo , Células Secretoras de Glucagón/metabolismo , Glucosa/metabolismo , Insulina/metabolismo , Islotes Pancreáticos/metabolismo , Animales , Boidae , Línea Celular , Duodeno/metabolismo , Femenino , Polipéptido Inhibidor Gástrico/genética , Péptido 1 Similar al Glucagón/metabolismo , Humanos , Secreción de Insulina , Islotes Pancreáticos/embriología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fragmentos de Péptidos/metabolismo , Proglucagón/metabolismo , Proproteína Convertasa 2/deficiencia , Proproteína Convertasa 2/genética , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Receptores de la Hormona Gastrointestinal/genética , Receptores de la Hormona Gastrointestinal/metabolismo , Factores de Tiempo , Técnicas de Cultivo de Tejidos , Transfección
16.
Mol Cell Endocrinol ; 537: 111424, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-34400259

RESUMEN

Islet amyloid, formed by aggregation of human islet amyloid polypeptide (hIAPP), contributes to ß-cell death in type 2 diabetes. We previously showed that extracellular hIAPP aggregates promote Fas-mediated ß-cell apoptosis. Here, we tested if hIAPP aggregates can trigger the mitochondrial apoptotic pathway (MAP). hIAPP aggregation in Ad-hIAPP transduced INS-1 and human islet ß-cells promoted cytochrome c release, caspase-9 activation and apoptosis, which were reduced by Bax inhibitor. Amyloid formation in hIAPP-expressing mouse islets during culture increased caspase-9 activation in ß-cells. Ad-hIAPP transduced islets from CytcKA/KA and BaxBak ßDKO mice (models of blocked MAP), had lower caspase-9-positive and apoptotic ß-cells than transduced wild-type islets, despite comparable amyloid formation. Blocking Fas (markedly) and Bax or caspase-9 (modestly) reduced ß-cell death induced by extracellular hIAPP aggregates. These findings suggest a role for MAP in amyloid-induced ß-cell death and a potential strategy to reduce intracellular amyloid ß-cell toxicity by blocking cytochrome c apoptotic function.


Asunto(s)
Apoptosis , Células Secretoras de Insulina/patología , Polipéptido Amiloide de los Islotes Pancreáticos/toxicidad , Mitocondrias/metabolismo , Adenoviridae/metabolismo , Animales , Apoptosis/efectos de los fármacos , Caspasa 9/metabolismo , Citocromos c/metabolismo , Activación Enzimática/efectos de los fármacos , Humanos , Células Secretoras de Insulina/efectos de los fármacos , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Mitocondrias/efectos de los fármacos , Modelos Biológicos , Agregado de Proteínas , Transducción de Señal/efectos de los fármacos , Proteína X Asociada a bcl-2/antagonistas & inhibidores , Proteína X Asociada a bcl-2/metabolismo
17.
Cell Stem Cell ; 28(12): 2047-2061.e5, 2021 12 02.
Artículo en Inglés | MEDLINE | ID: mdl-34861146

RESUMEN

An open-label, first-in-human phase 1/2 study is being conducted to evaluate the safety and efficacy of pancreatic endoderm cells (PECs) implanted in non-immunoprotective macroencapsulation devices for the treatment of type 1 diabetes. We report an analysis on 1 year of data from the first cohort of 15 patients from a single trial site that received subcutaneous implantation of cell products combined with an immunosuppressive regimen. Implants were well tolerated with no teratoma formation or severe graft-related adverse events. After implantation, patients had increased fasting C-peptide levels and increased glucose-responsive C-peptide levels and developed mixed meal-stimulated C-peptide secretion. There were immunosuppression-related transient increases in circulating regulatory T cells, PD1high T cells, and IL17A+CD4+ T cells. Explanted grafts contained cells with a mature ß cell phenotype that were immunoreactive for insulin, islet amyloid polypeptide, and MAFA. These data, and associated findings (Shapiro et al., 2021), are the first reported evidence of meal-regulated insulin secretion by differentiated stem cells in patients.


Asunto(s)
Diabetes Mellitus Tipo 1 , Células Secretoras de Insulina , Péptido C , Diferenciación Celular , Diabetes Mellitus Tipo 1/terapia , Endodermo , Glucosa , Humanos , Insulina
18.
Biochim Biophys Acta ; 1790(6): 566-74, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19264107

RESUMEN

BACKGROUND: Amyloid fibrils created by misfolding and aggregation of proteins are a major pathological feature in a variety of degenerative diseases. Therapeutic approaches including amyloid vaccines and anti-aggregation compounds in models of amyloidosis point to an important role for amyloid in disease pathogenesis. Amyloid deposits derived from the beta-cell peptide islet amyloid polypeptide (IAPP or amylin) are a characteristic of type 2 diabetes and may contribute to loss of beta-cells in this disease. METHODS: We developed a cellular model of rapid amyloid deposition using cultured human islets and observed a correlation between fibril accumulation and beta-cell death. A series of overlapping peptides derived from IAPP was generated. RESULTS: A potent inhibitor (ANFLVH) of human IAPP aggregation was identified. This inhibitory peptide prevented IAPP fibril formation in vitro and in human islet cultures leading to a striking increase in islet cell viability. CONCLUSIONS: These findings indicate an important contribution of IAPP aggregation to beta-cell death in situ and point to therapeutic applications for inhibitors of IAPP aggregation in enhancing beta-cell survival. GENERAL SIGNIFICANCE: Anti-amyloid compounds could potentially reduce the loss of beta-cell mass in type 2 diabetes and maintain healthy human islet cultures for beta-cell replacement therapies.


Asunto(s)
Amiloide/antagonistas & inhibidores , Supervivencia Celular/fisiología , Islotes Pancreáticos , Secuencia de Aminoácidos , Amiloide/metabolismo , Animales , Apoptosis/fisiología , Células Cultivadas , Humanos , Polipéptido Amiloide de los Islotes Pancreáticos , Islotes Pancreáticos/fisiología , Islotes Pancreáticos/ultraestructura , Datos de Secuencia Molecular
19.
Can J Surg ; 52(5): 401-6, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19865575

RESUMEN

BACKGROUND: Research is an important mandate for academic surgical divisions. However, there is widespread concern that the current health care climate is leading to a decline in research activity. A University of British Columbia (UBC) academic surgical division attempted to address this concern by strategically recruiting PhD research scientists to prioritize research and develop collaborative research programs. The objective of our study was to determine whether this strategy resulted in increased research productivity. METHODS: We reviewed the UBC Department of Surgery database to assess research funding obtained by the Division of General Surgery for the years 1994-2004. We searched MEDLINE for peer-reviewed publications by faculty members during this period. RESULTS: Research funding increased from a mean of Can$417,292 per year in the 5 years (1994/95-1998/99) before the recruitment of dedicated PhD scientists to a mean of Can$1.3 million per year in the 5 years following the recruitment strategy (1999/2000-2003/04; p = 0.012). Funding for the initial 5 years was Can$2.1 million, including 1 Canadian Institutes of Health Research (CIHR) grant. Funding increased to Can$6.8 million, including 22 CIHR grants over the subsequent 5 years (p < 0.001). Collaborative research led to the awarding of multidisciplinary grants exceeding Can$4 million with divisional members as principle or coprinciple investigators. From 1994/05 to 1998/99, the total number of peer-reviewed publications was 116 (mean 23.2, standard deviation [SD] 7 per year), increasing to 144 from 1999/2000 to 2003/04 (mean 28.8, SD 13 per year). The trend was for publications in journals with higher impact factors in the latter 5-year period. CONCLUSION: Strategic recruitment resulted in increased and sustained research productivity. Interactions between research scientists and clinicians resulted in successful program grant funding support. These results have implications for sustaining the research mission within academic departments of surgery.


Asunto(s)
Centros Médicos Académicos/tendencias , Investigación Biomédica/organización & administración , Eficiencia , Docentes Médicos/organización & administración , Selección de Personal/tendencias , Centros Médicos Académicos/economía , Colombia Británica , Femenino , Financiación Gubernamental/tendencias , Predicción , Hospitales Universitarios/economía , Hospitales Universitarios/tendencias , Humanos , Masculino , Sistema de Registros , Apoyo a la Investigación como Asunto , Servicio de Cirugía en Hospital/economía , Servicio de Cirugía en Hospital/tendencias
20.
Can J Surg ; 52(4): 321-327, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19680520

RESUMEN

Despite the complexities of minimally invasive surgery (MIS), a Canadian approach to training surgeons in this field does not exist. Whereas a limited number of surgeons are fellowship-trained in the specialty, guidelines are still clearly needed to implement advanced MIS. Leaders in the field of gastrointestinal surgery and MIS attended a consensus conference where they proposed a comprehensive mentoring program that may evolve into a framework for a national mentoring and training system. Leadership and commitment from national experts to define the most appropriate template for introducing new surgical techniques into practice is required. This national framework should also provide flexibility for truly novel procedures such as natural orifice translumenal endoscopic surgery.

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