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1.
Support Care Cancer ; 31(8): 499, 2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37523097

RESUMO

PURPOSE: Routinely assessing quality of life (QoL) of patients with cancer is crucial for improving patient-centred cancer care. However, little is known about whether or how cancer centres assess QoL for clinical practice or for research purposes. Therefore, our study aimed to investigate if QoL data is collected and if so, how and for what purposes. METHOD: We conducted a cross-sectional survey study among 32 cancer centres in Europe and Canada. Centre representatives identified persons who they judged to have sufficient insight into QoL data collections in their wards to complete the survey. Descriptive statistics were used to summarise the information on QoL assessment and documentation. RESULTS: There were 20 (62.5%) responding cancer centres. In total, 30 questionnaires were completed, of which 13 were completed for cancer wards and 17 for palliative care wards. We found that 23.1% and 38.5% of the cancer wards routinely assessed QoL among inpatients and outpatients with cancer, respectively, whereas, in palliative care wards, 52.9% assessed QoL for outpatients with cancer and 70.6% for the inpatients. Wide variabilities were observed between the cancer centres in how, how often, when and which instruments they used to assess QoL. CONCLUSION: A sizable proportion of the cancer wards, especially, and palliative care wards apparently does not routinely assess patients' QoL, and we found wide variabilities between the cancer centres in how they do it. To promote routine assessment of patients' QoL, we proposed several actions, such as addressing barriers to implementing patient-reported outcome measures through innovative e-health platforms.


Assuntos
Neoplasias , Cuidados Paliativos , Humanos , Qualidade de Vida , Estudos Transversais , Pacientes Internados , Medidas de Resultados Relatados pelo Paciente , Neoplasias/terapia
2.
Cell Death Dis ; 14(8): 536, 2023 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-37604805

RESUMO

Acinar cell dedifferentiation is one of the most notable features of acute and chronic pancreatitis. It can also be the initial step that facilitates pancreatic cancer development. In the present study, we further decipher the precise mechanisms and regulation using primary human cells and murine experimental models. Our RNAseq analysis indicates that, in both species, early acinar cell dedifferentiation is accompanied by multiple pathways related to cell survival that are highly enriched, and where SLC7A11 (xCT) is transiently upregulated. xCT is the specific subunit of the cystine/glutamate antiporter system xC-. To decipher its role, gene silencing, pharmacological inhibition and a knock-out mouse model were used. Acinar cells with depleted or reduced xCT function show an increase in ferroptosis relating to lipid peroxidation. Lower glutathione levels and more lipid ROS accumulation could be rescued by the antioxidant N-acetylcysteine or the ferroptosis inhibitor ferrostatin-1. In caerulein-induced acute pancreatitis in mice, xCT also prevents lipid peroxidation in acinar cells. In conclusion, during stress, acinar cell fate seems to be poised for avoiding several forms of cell death. xCT specifically prevents acinar cell ferroptosis by fueling the glutathione pool and maintaining ROS balance. The data suggest that xCT offers a druggable tipping point to steer the acinar cell fate in stress conditions.


Assuntos
Ferroptose , Pancreatite , Humanos , Animais , Camundongos , Células Acinares , Doença Aguda , Ferroptose/genética , Pancreatite/genética , Espécies Reativas de Oxigênio , Ácido Glutâmico
3.
Gastroenterology ; 141(2): 731-41, 741.e1-4, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21703267

RESUMO

BACKGROUND & AIMS: Animal studies have indicated that pancreatic exocrine acinar cells have phenotypic plasticity. In rodents, acinar cells can differentiate into ductal precursors that can be converted to pancreatic ductal adenocarcinoma or insulin-producing endocrine cells. However, little is known about human acinar cell plasticity. We developed nongenetic and genetic lineage tracing methods to study the fate of human acinar cells in culture. METHODS: Human exocrine tissue was obtained from organ donors, dissociated, and cultured. Cell proliferation and survival were measured, and cell phenotypes were analyzed by immunocytochemistry. Nongenetic tracing methods were developed based on selective binding and uptake by acinar cells of a labeled lectin (Ulex europaeus agglutinin 1). Genetic tracing methods were developed based on adenoviral introduction of a Cre-lox reporter system, controlled by the amylase promoter. RESULTS: Both tracing methods showed that human acinar cells can transdifferentiate into cells that express specific ductal markers, such as cytokeratin 19, hepatocyte nuclear factor 1ß, SOX9, CD133, carbonic anhydrase II, and cystic fibrosis transmembrane conductance regulator. Within 1 week of culture, all surviving acinar cells had acquired a ductal phenotype. This transdifferentiation was decreased by inhibiting mitogen-activated protein kinase signaling. CONCLUSIONS: Human acinar cells have plasticity similar to that described in rodent cells. These results might be used to develop therapeutic strategies for patients with diabetes or pancreatic cancer.


Assuntos
Linhagem da Célula/genética , Transdiferenciação Celular/genética , Pâncreas Exócrino/citologia , Ductos Pancreáticos/citologia , RNA Mensageiro/metabolismo , Transdução de Sinais/fisiologia , Antígeno AC133 , Antígenos CD/metabolismo , Biomarcadores/metabolismo , Anidrase Carbônica II/metabolismo , Linhagem da Célula/fisiologia , Proliferação de Células , Sobrevivência Celular , Transdiferenciação Celular/fisiologia , Células Cultivadas , Quimotripsina/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Genes Reporter , Glicoproteínas/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Fator 1-beta Nuclear de Hepatócito/metabolismo , Humanos , Queratina-19/metabolismo , Antígeno Ki-67/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Pâncreas Exócrino/metabolismo , Ductos Pancreáticos/metabolismo , Peptídeos/metabolismo , Fenótipo , Lectinas de Plantas/farmacocinética , Regiões Promotoras Genéticas , Fatores de Transcrição SOX9/metabolismo , Transdução de Sinais/genética , Transdução Genética
4.
BMC Biotechnol ; 12: 74, 2012 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-23088534

RESUMO

BACKGROUND: Effective gene transfer to the pancreas or to pancreatic cells has remained elusive although it is essential for studies of genetic lineage tracing and modulation of gene expression. Different transduction methods and viral vectors were tested in vitro and in vivo, in rat and mouse pancreas. RESULTS: For in vitro transfection/transduction of rat exocrine cells lipofection reagents, adenoviral vectors, and Mokola- and VSV-G pseudotyped lentiviral vectors were used. For in vivo transduction of mouse and rat pancreas adenoviral vectors and VSV-G lentiviral vectors were injected into the parenchymal tissue. Both lipofection of rat exocrine cell cultures and transduction with Mokola pseudotyped lentiviral vectors were inefficient and resulted in less than 4% EGFP expressing cells. Adenoviral transduction was highly efficient but its usefulness for gene delivery to rat exocrine cells in vitro was hampered by a drastic increase in cell death. In vitro transduction of rat exocrine cells was most optimal with VSV-G pseudotyped lentiviral vectors, with stable transgene expression, no significant effect on cell survival and about 40% transduced cells. In vivo, pancreatic cells could not be transduced by intra-parenchymal administration of lentiviral vectors in mouse and rat pancreas. However, a high efficiency could be obtained by adenoviral vectors, resulting in transient transduction of mainly exocrine acinar cells. Injection in immune-deficient animals diminished leukocyte infiltration and prolonged transgene expression. CONCLUSIONS: In summary, our study remarkably demonstrates that transduction of pancreatic exocrine cells requires lentiviral vectors in vitro but adenoviral vectors in vivo.


Assuntos
Células Acinares/virologia , Técnicas de Transferência de Genes , Pâncreas/citologia , Células Acinares/citologia , Adenoviridae/genética , Adenoviridae/fisiologia , Animais , Células Cultivadas , Terapia Genética , Vetores Genéticos/genética , Vetores Genéticos/fisiologia , Humanos , Lentivirus/genética , Lentivirus/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Pâncreas/virologia , Ratos , Ratos Wistar , Transdução Genética , Transgenes
5.
Cell Mol Gastroenterol Hepatol ; 13(4): 1243-1253, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34875393

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is a devastating type of cancer. While many studies have shed light into the pathobiology of PDAC, the nature of PDAC's cell of origin remains under debate. Studies in adult pancreatic tissue have unveiled a remarkable exocrine cell plasticity including transitional states, mostly exemplified by acinar to ductal cell metaplasia, but also with recent evidence hinting at duct to basal cell transitions. Single-cell RNA sequencing has further revealed intrapopulation heterogeneity among acinar and duct cells. Transcriptomic and epigenomic relationships between these exocrine cell differentiation states and PDAC molecular subtypes have started to emerge, suggesting different ontogenies for different tumor subtypes. This review sheds light on these diverse aspects with particular focus on studies with human cells. Understanding the "masked ball" of exocrine cells at origin of PDAC and leaving behind the binary acinar vs duct cell classification may significantly advance our insights in PDAC biology.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Células Acinares/patologia , Carcinoma Ductal Pancreático/patologia , Plasticidade Celular , Humanos , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas
6.
Cell Death Differ ; 28(9): 2601-2615, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33762742

RESUMO

Maintenance of the pancreatic acinar cell phenotype suppresses tumor formation. Hence, repetitive acute or chronic pancreatitis, stress conditions in which the acinar cells dedifferentiate, predispose for cancer formation in the pancreas. Dedifferentiated acinar cells acquire a large panel of duct cell-specific markers. However, it remains unclear to what extent dedifferentiated acini differ from native duct cells and which genes are uniquely regulating acinar cell dedifferentiation. Moreover, most studies have been performed on mice since the availability of human cells is scarce. Here, we applied a non-genetic lineage tracing method of human pancreatic exocrine acinar and duct cells that allowed cell-type-specific gene expression profiling by RNA sequencing. Subsequent to this discovery analysis, one transcription factor that was unique for dedifferentiated acinar cells was functionally characterized. RNA sequencing analysis showed that human dedifferentiated acinar cells expressed genes in "Pathways of cancer" with a prominence of MECOM (EVI-1), a transcription factor that was not expressed by duct cells. During mouse embryonic development, pre-acinar cells also transiently expressed MECOM and in the adult mouse pancreas, MECOM was re-expressed when mice were subjected to acute and chronic pancreatitis, conditions in which acinar cells dedifferentiate. In human cells and in mice, MECOM expression correlated with and was directly regulated by SOX9. Mouse acinar cells that, by genetic manipulation, lose the ability to upregulate MECOM showed impaired cell adhesion, more prominent acinar cell death, and suppressed acinar cell dedifferentiation by limited ERK signaling. In conclusion, we transcriptionally profiled the two major human pancreatic exocrine cell types, acinar and duct cells, during experimental stress conditions. We provide insights that in dedifferentiated acinar cells, cancer pathways are upregulated in which MECOM is a critical regulator that suppresses acinar cell death by permitting cellular dedifferentiation.


Assuntos
Células Acinares/metabolismo , Morte Celular/genética , Proteína do Locus do Complexo MDS1 e EVI1/metabolismo , Oncogenes/genética , Animais , Desdiferenciação Celular , Modelos Animais de Doenças , Humanos , Camundongos , Transdução de Sinais
7.
Sci Rep ; 9(1): 4040, 2019 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-30858455

RESUMO

Human pancreatic exocrine cells were cultured in 3D suspension and formed pancreatospheres composed of acinar-derived and duct-like cells. We investigated, up to 6 days, the fate of human pancreatic acinar cells using fluorescein-conjugated Ulex Europaeus Agglutinin 1 lectin, a previously published acinar-specific non-genetic lineage tracing strategy. At day 4, fluorescence-activated cell sort for the intracellularly incorporated FITC-conjugated UEA1 lectin and the duct-specific CA19.9 surface marker, distinguished acinar-derived cells (UEA1+CA19.9-) from duct-like cells (UEA1-CA19.9+) and acinar-to-duct-like transdifferentiated cells (UEA1+CA19.9+). mRNA expression analysis of the acinar-derived (UEA1+CA19.9-) and duct-like (UEA1-CA19.9+) cell fractions with concomitant immunocytochemical analysis of the pancreatospheres revealed acquisition of an embryonic signature in the UEA1+CA19.9- acinar-derived cells characterized by de novo expression of SOX9 and CD142, robust expression of PDX1 and surface expression of GP2. The colocalisation of CD142, a multipotent pancreatic progenitor surface marker, PDX1, SOX9 and GP2 is reminiscent of a cellular state present during human embryonic development. Addition of TGF-beta signalling inhibitor Alk5iII, induced a 28-fold increased KI67-labeling in pancreatospheres, more pronounced in the CD142+GP2+ acinar-derived cells. These findings with human cells underscore the remarkable plasticity of pancreatic exocrine acinar cells, previously described in rodents, and could find applications in the field of regenerative medicine.


Assuntos
Células Acinares/citologia , Linhagem da Célula , Pâncreas Exócrino/citologia , Células Acinares/metabolismo , Adulto , Antígenos Glicosídicos Associados a Tumores/metabolismo , Biomarcadores/metabolismo , Plasticidade Celular , Células Cultivadas , Proteínas Ligadas por GPI/metabolismo , Proteínas de Homeodomínio/metabolismo , Humanos , Pâncreas Exócrino/metabolismo , Lectinas de Plantas/química , Fatores de Transcrição SOX9/metabolismo , Tromboplastina/metabolismo , Transativadores/metabolismo
8.
Sci Rep ; 7(1): 12643, 2017 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-28974717

RESUMO

Pancreatic acinar cells secrete digestive enzymes necessary for nutrient digestion in the intestine. They are considered the initiating cell type of pancreatic cancer and are endowed with differentiation plasticity that has been harnessed to regenerate endocrine beta cells. However, there is still uncertainty about the mechanisms of acinar cell formation during the dynamic period of early postnatal development. To unravel cellular contributions in the exocrine acinar development we studied two reporter mouse strains to trace the fate of acinar and duct cells during the first 4 weeks of life. In the acinar reporter mice, the labelling index of acinar cells remained unchanged during the neonatal pancreas growth period, evidencing that acinar cells are formed by self-duplication. In line with this, duct cell tracing did not show significant increase in acinar cell labelling, excluding duct-to-acinar cell contribution during neonatal development. Immunohistochemical analysis confirms massive levels of acinar cell proliferation in this early period of life. Further, also increase in acinar cell size contributes to the growth of pancreatic mass.We conclude that the growth of acinar cells during physiological neonatal pancreas development is by self-duplication (and hypertrophy) rather than neogenesis from progenitor cells as was suggested before.


Assuntos
Células Acinares/citologia , Células Endócrinas/citologia , Pâncreas/crescimento & desenvolvimento , Ductos Pancreáticos/crescimento & desenvolvimento , Animais , Diferenciação Celular/genética , Proliferação de Células/genética , Células Endócrinas/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Camundongos , Índice Mitótico , Pâncreas/citologia , Ductos Pancreáticos/citologia , Regeneração/genética , Células-Tronco/citologia , Células-Tronco/metabolismo
9.
Biosci Rep ; 36(3)2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26987985

RESUMO

The regenerative medicine field is expanding with great successes in laboratory and preclinical settings. Pancreatic acinar cells in diabetic mice were recently converted into ß-cells by treatment with ciliary neurotrophic factor (CNTF) and epidermal growth factor (EGF). This suggests that human acinar cells might become a cornerstone for diabetes cell therapy in the future, if they can also be converted into glucose-responsive insulin-producing cells. Presently, studying pancreatic acinar cell biology in vitro is limited by their high plasticity, as they rapidly lose their phenotype and spontaneously transdifferentiate to a duct-like phenotype in culture. We questioned whether human pancreatic acinar cell phenotype could be preserved in vitro by physico-chemical manipulations and whether this could be valuable in the study of ß-cell neogenesis. We found that culture at low temperature (4°C) resulted in the maintenance of morphological and molecular acinar cell characteristics. Specifically, chilled acinar cells did not form the spherical clusters observed in controls (culture at 37°C), and they maintained high levels of acinar-specific transcripts and proteins. Five-day chilled acinar cells still transdifferentiated into duct-like cells upon transfer to 37°C. Moreover, adenoviral-mediated gene transfer evidenced an active Amylase promoter in the 7-day chilled acinar cells, and transduction performed in chilled conditions improved acinar cell labelling. Together, our findings indicate the maintenance of human pancreatic acinar cell phenotype at low temperature and the possibility to efficiently label acinar cells, which opens new perspectives for the study of human acinar-to-ß-cell transdifferentiation.


Assuntos
Linhagem da Célula , Células Secretoras de Insulina/citologia , Pâncreas Exócrino/citologia , Amilases/genética , Animais , Técnicas de Cultura de Células , Diferenciação Celular , Transdiferenciação Celular , Células Cultivadas , Temperatura Baixa , Humanos , Células Secretoras de Insulina/metabolismo , Camundongos , Pâncreas Exócrino/metabolismo , Fenótipo , Regiões Promotoras Genéticas , Transcriptoma
10.
Cancer Res ; 74(1): 24-30, 2014 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-24220244

RESUMO

Tumor-associated macrophages (TAM) are exposed to multiple microenvironmental cues in tumors, which collaborate to endow these cells with protumoral activities. Hypoxia, caused by an imbalance in oxygen supply and demand because of a poorly organized vasculature, is often a prominent feature in solid tumors. However, to what extent tumor hypoxia regulates the TAM phenotype in vivo is unknown. Here, we show that the myeloid infiltrate in mouse lung carcinoma tumors encompasses two morphologically distinct CD11b(hi)F4/80(hi)Ly6C(lo) TAM subsets, designated as MHC-II(lo) and MHC-II(hi) TAM, both of which were derived from tumor-infiltrating Ly6C(hi) monocytes. MHC-II(lo) TAM express higher levels of prototypical M2 markers and reside in more hypoxic regions. Consequently, MHC-II(lo) TAM contain higher mRNA levels for hypoxia-regulated genes than their MHC-II(hi) counterparts. To assess the in vivo role of hypoxia on these TAM features, cancer cells were inoculated in prolyl hydroxylase domain 2 (PHD2)-haplodeficient mice, resulting in better-oxygenated tumors. Interestingly, reduced tumor hypoxia did not alter the relative abundance of TAM subsets nor their M2 marker expression, but specifically lowered hypoxia-sensitive gene expression and angiogenic activity in the MHC-II(lo) TAM subset. The same observation in PHD2(+/+) → PHD2(+/-) bone marrow chimeras also suggests organization of a better-oxygenized microenvironment. Together, our results show that hypoxia is not a major driver of TAM subset differentiation, but rather specifically fine-tunes the phenotype of M2-like MHC-II(lo) TAM.


Assuntos
Hipóxia Celular/fisiologia , Macrófagos/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Animais , Diferenciação Celular/fisiologia , Modelos Animais de Doenças , Feminino , Macrófagos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neoplasias/genética , Transcriptoma
11.
Nat Rev Endocrinol ; 9(10): 598-606, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23877422

RESUMO

The endocrine pancreas represents an interesting arena for regenerative medicine and cell therapeutics. One of the major pancreatic diseases, diabetes mellitus is a metabolic disorder caused by having an insufficient number of insulin-producing ß cells. Replenishment of ß cells by cell transplantation can restore normal metabolic control. The shortage in donor pancreata has meant that the demand for transplantable ß cells has outstripped the supply, which could be met by using alternative sources of stem cells. This situation has opened up new areas of research, such as cellular reprogramming and in vivo ß-cell regeneration. Pluripotent stem cells seem to be the best option for clinical applications of ß-cell regeneration in the near future, as these cells have been demonstrated to represent an unlimited source of functional ß cells. Although compelling evidence shows that the adult pancreas retains regenerative capacity, it remains unclear whether this organ contains stem cells. Alternatively, specialized cell types within or outside the pancreas retain plasticity in proliferation and differentiation. Cellular reprogramming or transdifferentiation of exocrine cells or other types of endocrine cells in the pancreas could provide a long-term solution.


Assuntos
Diabetes Mellitus/terapia , Pâncreas/citologia , Regeneração/fisiologia , Animais , Diferenciação Celular/fisiologia , Transdiferenciação Celular/fisiologia , Humanos , Células Secretoras de Insulina/citologia , Células-Tronco/citologia
12.
Diabetes ; 62(8): 2821-33, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23610058

RESUMO

Because of the lack of tissue available for islet transplantation, new sources of ß-cells have been sought for the treatment of type 1 diabetes. The aim of this study was to determine whether the human exocrine-enriched fraction from the islet isolation procedure could be reprogrammed to provide additional islet tissue for transplantation. The exocrine-enriched cells rapidly dedifferentiated in culture and grew as a mesenchymal monolayer. Genetic lineage tracing confirmed that these mesenchymal cells arose, in part, through a process of epithelial-to-mesenchymal transitioning (EMT). A protocol was developed whereby transduction of these mesenchymal cells with adenoviruses containing Pdx1, Ngn3, MafA, and Pax4 generated a population of cells that were enriched in glucagon-secreting α-like cells. Transdifferentiation or reprogramming toward insulin-secreting ß-cells was enhanced, however, when using unpassaged cells in combination with inhibition of EMT by inclusion of Rho-associated kinase (ROCK) and transforming growth factor-ß1 inhibitors. Resultant cells were able to secrete insulin in response to glucose and on transplantation were able to normalize blood glucose levels in streptozotocin diabetic NOD/SCID mice. In conclusion, reprogramming of human exocrine-enriched tissue can be best achieved using fresh material under conditions whereby EMT is inhibited, rather than allowing the culture to expand as a mesenchymal monolayer.


Assuntos
Diferenciação Celular/fisiologia , Transição Epitelial-Mesenquimal/fisiologia , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Pâncreas Exócrino/metabolismo , Animais , Células Cultivadas , Diabetes Mellitus Experimental/metabolismo , Glucose/farmacologia , Humanos , Secreção de Insulina , Células Secretoras de Insulina/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Pâncreas Exócrino/efeitos dos fármacos , Quinases Associadas a rho/metabolismo
13.
Methods Mol Biol ; 933: 303-15, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22893416

RESUMO

Restoring a functional ß cell mass in diabetes patients by ß cell transplantation or stimulation of ß cell regeneration are promising approaches. It requires knowledge on the mechanisms of ß cell neogenesis, an issue that is still quite controversial. Postnatal islet regeneration may or may not depend on an influx of new islet cells from adult progenitors. To solve this issue in animal models, genetic lineage tracing has become a crucial research method. This method allows to test the various hypotheses that have been proposed concerning ß cell neogenesis and regeneration.


Assuntos
Células-Tronco Adultas/citologia , Linhagem da Célula , Células Secretoras de Insulina/citologia , Ilhotas Pancreáticas/fisiologia , Pâncreas/citologia , Regeneração , Células-Tronco Adultas/metabolismo , Animais , Diferenciação Celular , Transdiferenciação Celular , Humanos , Ilhotas Pancreáticas/citologia , Camundongos , Modelos Animais , Pâncreas/fisiologia , Ratos
14.
Methods Mol Biol ; 933: 317-22, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22893417

RESUMO

Genetic lineage tracing is an invaluable tool to demonstrate and measure neogenesis of beta cells from putative precursor cells. Cre-Lox recombination technology can be used for indelible labeling of a cohort of cells and following the fate of these cells and their progeny in animal models. Here, the combination is described of beta-galactosidase enzymatic staining with immunohistochemical staining to demonstrate labeled cells. This technique is performed in tissue cryosections.


Assuntos
Linhagem da Célula , Células Secretoras de Insulina/citologia , Coloração e Rotulagem/métodos , beta-Galactosidase/análise , Animais , Humanos , Imuno-Histoquímica/métodos , Insulina/análise , Integrases/genética , Integrases/metabolismo , Camundongos , Camundongos Transgênicos , Tamoxifeno/administração & dosagem
15.
Cancer Res ; 72(16): 4165-77, 2012 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-22719068

RESUMO

Tumor-associated macrophages (TAM) are an important component of the tumor stroma and exert several tumor-promoting activities. Strongly pro-angiogenic TAMs that reside in hypoxic tumor areas highly express macrophage mannose receptor (MMR, CD206). In this study, we targeted MMR+ TAMs using nanobodies, which are single-domain antigen-binding fragments derived from Camelidae heavy-chain antibodies. MMR-specific nanobodies stained TAMs in lung and breast tumor single-cell suspensions in vitro, and intravenous injection of 99mTc-labeled anti-MMR nanobodies successfully targeted tumor in vivo. Retention of the nanobody was receptor-specific and absent in MMR-deficient mice. Importantly, co-injection of excess unlabeled, bivalent anti-MMR nanobodies reduced nanobody accumulation in extratumoral organs to background levels, without compromising tumor uptake. Within tumors, the 99mTc-labeled nanobodies specifically labeled MMR+ TAMs, as CCR2-deficient mice that contain fewer TAMs showed significantly reduced tumor uptake. Further, anti-MMR nanobodies accumulated in hypoxic regions, thus targeting pro-angiogenic MMR+ TAMs. Taken together, our findings provide preclinical proof of concept that anti-MMR nanobodies can be used to selectively target and image TAM subpopulations in vivo.


Assuntos
Carcinoma Pulmonar de Lewis/diagnóstico por imagem , Lectinas Tipo C/química , Macrófagos/diagnóstico por imagem , Lectinas de Ligação a Manose/química , Receptores de Superfície Celular/química , Anticorpos de Domínio Único/química , Tecnécio/química , Sequência de Aminoácidos , Animais , Carcinoma Pulmonar de Lewis/imunologia , Carcinoma Pulmonar de Lewis/metabolismo , Hipóxia Celular/fisiologia , Feminino , Lectinas Tipo C/imunologia , Macrófagos/química , Macrófagos/imunologia , Receptor de Manose , Lectinas de Ligação a Manose/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Receptores de Superfície Celular/imunologia , Anticorpos de Domínio Único/imunologia , Anticorpos de Domínio Único/metabolismo , Distribuição Tecidual , Tomografia Computadorizada de Emissão de Fóton Único/métodos
16.
Rev Diabet Stud ; 7(2): 112-23, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21060970

RESUMO

Adult stem cell research has drawn a lot of attention by many researchers, due to its medical hope of cell replacement or regenerative therapy for diabetes patients. Despite the many research efforts to date, there is no consensus on the existence of stem cells in adult pancreas. Genetic lineage tracing experiments have put into serious doubt whether ß-cell neogenesis from stem/progenitor cells takes place postnatally. Different in vitro experiments have suggested centroacinar, ductal, acinar, stellate, or yet unidentified clonigenic cells as candidate ß-cell progenitors. As in the rest of the adult stem cell field, sound and promising observations have been made. However, these observations still need to be replicated. As an alternative to committed stem/progenitor cells in the pancreas, transdifferentiation or lineage reprogramming of exocrine acinar and endocrine α-cells may be used to generate new ß-cells. At present, it is unclear which approach is most medically promising. This article highlights the progress being made in knowledge about tissue stem cells, their existence and availability for therapy in diabetes. Particular attention is given to the assessment of methods to verify the existence of tissue stem cells.


Assuntos
Células-Tronco Adultas/citologia , Diferenciação Celular , Diabetes Mellitus/terapia , Células Secretoras de Insulina/citologia , Pâncreas/citologia , Células-Tronco Adultas/metabolismo , Animais , Linhagem da Célula , Humanos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/transplante , Pâncreas/embriologia , Pâncreas/crescimento & desenvolvimento , Pâncreas/metabolismo , Transplante de Células-Tronco
17.
Dev Cell ; 17(6): 849-60, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20059954

RESUMO

A longstanding unsettled question is whether pancreatic beta cells originate from exocrine duct cells. We have now used genetic labeling to fate map embryonic and adult pancreatic duct cells. We show that Hnf1beta+ cells of the trunk compartment of the early branching pancreas are precursors of acinar, duct, and endocrine lineages. Hnf1beta+ cells subsequent form the embryonic duct epithelium, which gives rise to both ductal and endocrine lineages, but not to acinar cells. By the end of gestation, the fate of Hnf1beta+ duct cells is further restrained. We provide compelling evidence that the ductal epithelium does not make a significant contribution to acinar or endocrine cells during neonatal growth, during a 6 month observation period, or during beta cell growth triggered by ligation of the pancreatic duct or by cell-specific ablation with alloxan followed by EGF/gastrin treatment. Thus, once the ductal epithelium differentiates it has a restricted plasticity, even under regenerative settings.


Assuntos
Células Secretoras de Insulina/citologia , Pâncreas/embriologia , Animais , Feminino , Fator 1-beta Nuclear de Hepatócito/genética , Fator 1-beta Nuclear de Hepatócito/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pâncreas/citologia , Pâncreas Exócrino/embriologia
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