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1.
Clin Exp Immunol ; 204(2): 167-178, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33368173

RESUMO

When Thetis dipped her son Achilles into the River Styx to make him immortal, she held him by the heel, which was not submerged, and thus created a weak spot that proved deadly for Achilles. Millennia later, Achilles heel is part of today's lexicon meaning an area of weakness or a vulnerable spot that causes failure. Also implied is that an Achilles heel is often missed, forgotten or under-appreciated until it is under attack, and then failure is fatal. Paris killed Achilles with an arrow 'guided by the Gods'. Understanding the pathogenesis of type 1 diabetes (T1D) in order to direct therapy for prevention and treatment is a major goal of research into T1D. At the International Congress of the Immunology of Diabetes Society, 2018, five leading experts were asked to present the case for a particular cell/element that could represent 'the Achilles heel of T1D'. These included neutrophils, B cells, CD8+ T cells, regulatory CD4+ T cells, and enteroviruses, all of which have been proposed to play an important role in the pathogenesis of type 1 diabetes. Did a single entity emerge as 'the' Achilles heel of T1D? The arguments are summarized here, to make this case.


Assuntos
Diabetes Mellitus Tipo 1/imunologia , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Humanos , Neutrófilos/imunologia
2.
Diabet Med ; 37(12): 2160-2168, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32634859

RESUMO

AIMS: Misclassification of diabetes is common due to an overlap in the clinical features of type 1 and type 2 diabetes. Combined diagnostic models incorporating clinical and biomarker information have recently been developed that can aid classification, but they have not been validated using pancreatic pathology. We evaluated a clinical diagnostic model against histologically defined type 1 diabetes. METHODS: We classified cases from the Network for Pancreatic Organ donors with Diabetes (nPOD) biobank as type 1 (n = 111) or non-type 1 (n = 42) diabetes using histopathology. Type 1 diabetes was defined by lobular loss of insulin-containing islets along with multiple insulin-deficient islets. We assessed the discriminative performance of previously described type 1 diabetes diagnostic models, based on clinical features (age at diagnosis, BMI) and biomarker data [autoantibodies, type 1 diabetes genetic risk score (T1D-GRS)], and singular features for identifying type 1 diabetes by the area under the curve of the receiver operator characteristic (AUC-ROC). RESULTS: Diagnostic models validated well against histologically defined type 1 diabetes. The model combining clinical features, islet autoantibodies and T1D-GRS was strongly discriminative of type 1 diabetes, and performed better than clinical features alone (AUC-ROC 0.97 vs. 0.95; P = 0.03). Histological classification of type 1 diabetes was concordant with serum C-peptide [median < 17 pmol/l (limit of detection) vs. 1037 pmol/l in non-type 1 diabetes; P < 0.0001]. CONCLUSIONS: Our study provides robust histological evidence that a clinical diagnostic model, combining clinical features and biomarkers, could improve diabetes classification. Our study also provides reassurance that a C-peptide-based definition of type 1 diabetes is an appropriate surrogate outcome that can be used in large clinical studies where histological definition is impossible. Parts of this study were presented in abstract form at the Network for Pancreatic Organ Donors Conference, Florida, USA, 19-22 February 2019 and Diabetes UK Professional Conference, Liverpool, UK, 6-8 March 2019.


Assuntos
Diabetes Mellitus Tipo 1/patologia , Diabetes Mellitus Tipo 2/patologia , Ilhotas Pancreáticas/patologia , Adulto , Idade de Início , Autoanticorpos/imunologia , Índice de Massa Corporal , Peptídeo C/sangue , Diabetes Mellitus/classificação , Diabetes Mellitus/genética , Diabetes Mellitus/imunologia , Diabetes Mellitus/patologia , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 2/diagnóstico , Diagnóstico Diferencial , Feminino , Predisposição Genética para Doença , Humanos , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Masculino , Pessoa de Meia-Idade , Pâncreas/metabolismo , Pâncreas/patologia , Reprodutibilidade dos Testes , Adulto Jovem , Transportador 8 de Zinco/imunologia
3.
Diabetologia ; 56(1): 185-93, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23064357

RESUMO

AIMS/HYPOTHESIS: Immunohistochemical staining reveals that the enteroviral capsid protein VP1 is present at higher frequency in the insulin-containing islets of patients with recent-onset type 1 diabetes than in controls. This is consistent with epidemiological evidence suggesting that enteroviral infection may contribute to the autoimmune response in type 1 diabetes. However, immunostaining of VP1 is not definitive since the antibody widely used to detect the protein (Clone 5D8/1) might also cross-react with additional proteins under some conditions. Therefore, we sought to verify that VP1 immunopositivity correlates with additional markers of viral infection. METHODS: Antigen immunoreactivity was examined in formalin-fixed, paraffin-embedded, pancreases from two different collections of type 1 diabetes and control cases: a historical collection from the UK and the nPOD (network of Pancreatic Organ donors with Diabetes) cohort from the USA. RESULTS: VP1 immunoreactivity was present in ~20% of insulin-containing islets of both cohorts under stringent conditions but was absent from insulin-deficient islets. The presence of VP1 was restricted to beta cells but only a minority of these contained the antigen. The innate viral sensor, protein kinase R (PKR) was upregulated selectively in beta cells that were immunopositive for VP1. The anti-apoptotic protein myeloid cell leukaemia sequence-1 (Mcl-1) was abundant in beta cells that were immunonegative for VP1 but Mcl-1 was depleted in cells containing VP1. CONCLUSIONS/INTERPRETATION: The presence of immunoreactive VP1 within beta cells in type 1 diabetes is associated with a cellular phenotype consistent with the activation of antiviral response pathways and enhanced sensitivity to apoptosis. However, definitive studies confirming whether viral infections are causal to beta cell loss in human diabetes are still awaited.


Assuntos
Proteínas do Capsídeo/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Enterovirus/metabolismo , Indução Enzimática , Ilhotas Pancreáticas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , eIF-2 Quinase/biossíntese , Adolescente , Adulto , Antígenos Virais/metabolismo , Biomarcadores/metabolismo , Criança , Pré-Escolar , Estudos de Coortes , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/patologia , Diabetes Mellitus Tipo 1/virologia , Regulação para Baixo , Enterovirus/imunologia , Enterovirus/isolamento & purificação , Infecções por Enterovirus/imunologia , Infecções por Enterovirus/metabolismo , Infecções por Enterovirus/microbiologia , Infecções por Enterovirus/patologia , Humanos , Lactente , Células Secretoras de Insulina/imunologia , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Células Secretoras de Insulina/virologia , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/patologia , Ilhotas Pancreáticas/virologia , Proteína de Sequência 1 de Leucemia de Células Mieloides , Reino Unido , Estados Unidos , eIF-2 Quinase/metabolismo
4.
Diabetologia ; 56(5): 1068-77, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23397292

RESUMO

AIMS/HYPOTHESIS: Sirtuin (SIRT)3 is a mitochondrial protein deacetylase that regulates reactive oxygen species (ROS) production and exerts anti-inflammatory effects. As chronic inflammation and mitochondrial dysfunction are key factors mediating pancreatic beta cell impairment in type 2 diabetes, we investigated the role of SIRT3 in the maintenance of beta cell function and mass in type 2 diabetes. METHODS: We analysed changes in SIRT3 expression in experimental models of type 2 diabetes and in human islets isolated from type 2 diabetic patients. We also determined the effects of SIRT3 knockdown on beta cell function and mass in INS1 cells. RESULTS: SIRT3 expression was markedly decreased in islets isolated from type 2 diabetes patients, as well as in mouse islets or INS1 cells incubated with IL1ß and TNFα. SIRT3 knockdown in INS1 cells resulted in lowered insulin secretion, increased beta cell apoptosis and reduced expression of key beta cell genes. SIRT3 knockdown also blocked the protective effects of nicotinamide mononucleotide on pro-inflammatory cytokines in beta cells. The deleterious effects of SIRT3 knockdown were mediated by increased levels of cellular ROS and IL1ß. CONCLUSIONS/INTERPRETATION: Decreased beta cell SIRT3 levels could be a key step in the onset of beta cell dysfunction, occurring via abnormal elevation of ROS levels and amplification of beta cell IL1ß synthesis. Strategies to increase the activity or levels of SIRT3 could generate attractive therapies for type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Regulação para Baixo , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Sirtuína 3/metabolismo , Idoso , Idoso de 80 Anos ou mais , Animais , Apoptose , Linhagem Celular , Citocinas/metabolismo , Diabetes Mellitus Tipo 2/imunologia , Diabetes Mellitus Tipo 2/patologia , Regulação da Expressão Gênica , Humanos , Secreção de Insulina , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Interferência de RNA , Ratos , Espécies Reativas de Oxigênio/metabolismo , Sirtuína 3/antagonistas & inibidores , Sirtuína 3/genética , Técnicas de Cultura de Tecidos
5.
Philos Trans R Soc Lond B Biol Sci ; 378(1879): 20220169, 2023 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-37122219

RESUMO

Cardiac ryanodine receptors (RyR2) release the Ca2+ from intracellular stores that is essential for cardiac myocyte contraction. The ion channel opening is tightly regulated by intracellular factors, including the FK506 binding proteins, FKBP12 and FKBP12.6. The impact of these proteins on RyR2 activity and cardiac contraction is debated, with often apparently contradictory experimental results, particularly for FKBP12. The isoform that regulates RyR2 has generally been considered to be FKBP12.6, despite the fact that FKBP12 is the major isoform associated with RyR2 in some species and is bound in similar proportions to FKBP12.6 in others, including sheep and humans. Here, we show time- and concentration-dependent effects of adding FKBP12 to RyR2 channels that were partly depleted of FKBP12/12.6 during isolation. The added FKBP12 displaced most remaining endogenous FKBP12/12.6. The results suggest that FKBP12 activates RyR2 with high affinity and inhibits RyR2 with lower affinity, consistent with a model of negative cooperativity in FKBP12 binding to each of the four subunits in the RyR tetramer. The easy dissociation of some FKBP12/12.6 could dynamically alter RyR2 activity in response to changes in in vivo regulatory factors, indicating a significant role for FKBP12/12.6 in Ca2+ signalling and cardiac function in healthy and diseased hearts. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.


Assuntos
Canal de Liberação de Cálcio do Receptor de Rianodina , Proteína 1A de Ligação a Tacrolimo , Humanos , Animais , Ovinos , Proteína 1A de Ligação a Tacrolimo/metabolismo , Proteína 1A de Ligação a Tacrolimo/farmacologia , Canal de Liberação de Cálcio do Receptor de Rianodina/química , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Miocárdio/metabolismo , Sinalização do Cálcio , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/farmacologia , Cálcio/metabolismo
6.
Diabetologia ; 55(9): 2417-20, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22699564

RESUMO

AIMS/HYPOTHESIS: Endoplasmic reticulum (ER) stress may play a role in cytokine-mediated beta cell death in type 1 diabetes, but it remains controversial whether ER stress markers are present in islets from type 1 diabetic individuals. Therefore, we evaluated by immunostaining the expression of markers of the three main branches of the ER stress response in islets from 13 individuals with and 15 controls without type 1 diabetes (eight adults and seven children). METHODS: Antibodies against the ER stress markers C/EBP homologous protein (CHOP), immunoglobulin heavy chain (BIP) and X-box binding protein 1 (XBP-1) were validated using HeLa cells treated with the ER stressor thapsigargin. These antibodies were then used to stain serial sections of paraffin-embedded pancreas from type 1 diabetic and non-diabetic individuals; samples were also immunostained for CD45, insulin and glucagon. Immunostaining intensities of the ER stress markers were quantified using a software-based, unbiased quantitative approach. RESULTS: Islets from individuals with type 1 diabetes showed increased levels of CHOP and, at least for insulitis-positive and beta cell-containing islets, BIP. XBP-1 expression was not, however, increased. CONCLUSIONS/INTERPRETATION: Islet cells from individuals with type 1 diabetes display a partial ER stress response, with evidence of the induction of some, but not all, components of the unfolded protein response.


Assuntos
Diabetes Mellitus Tipo 1/metabolismo , Estresse do Retículo Endoplasmático , Ilhotas Pancreáticas/metabolismo , Pâncreas/patologia , Adolescente , Adulto , Apoptose , Biomarcadores/metabolismo , Criança , Proteínas de Ligação a DNA/metabolismo , Diabetes Mellitus Tipo 1/patologia , Feminino , Regulação da Expressão Gênica , Humanos , Ilhotas Pancreáticas/patologia , Masculino , Pessoa de Meia-Idade , Fatores de Transcrição de Fator Regulador X , Fator de Transcrição CHOP/metabolismo , Fatores de Transcrição/metabolismo , Proteína 1 de Ligação a X-Box , Adulto Jovem
7.
Diabetologia ; 55(9): 2421-31, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22772764

RESUMO

AIMS/HYPOTHESIS: Histone deacetylases (HDACs) are promising pharmacological targets in cancer and autoimmune diseases. All 11 classical HDACs (HDAC1-11) are found in the pancreatic beta cell, and HDAC inhibitors (HDACi) protect beta cells from inflammatory insults. We investigated which HDACs mediate inflammatory beta cell damage and how the islet content of these HDACs is regulated in recent-onset type 1 diabetes. METHODS: The rat beta cell line INS-1 and dispersed primary islets from rats, either wild type or HDAC1-3 deficient, were exposed to cytokines and HDACi. Molecular mechanisms were investigated using real-time PCR, chromatin immunoprecipitation and ELISA assays. Pancreases from healthy children and children with type 1 diabetes were assessed using immunohistochemistry and immunofluorescence. RESULTS: Screening of 19 compounds with different HDAC selectivity revealed that inhibitors of HDAC1, -2 and -3 rescued INS-1 cells from inflammatory damage. Small hairpin RNAs against HDAC1 and -3, but not HDAC2, reduced pro-inflammatory cytokine-induced beta cell apoptosis in INS-1 and primary rat islets. The protective properties of specific HDAC knock-down correlated with attenuated cytokine-induced iNos expression but not with altered expression of the pro-inflammatory mediators Il1α, Il1ß, Tnfα or Cxcl2. HDAC3 knock-down reduced nuclear factor κB binding to the iNos promoter and HDAC1 knock-down restored insulin secretion. In pancreatic sections from children with type 1 diabetes of recent onset, HDAC1 was upregulated in beta cells whereas HDAC2 and -3 were downregulated in comparison with five paediatric controls. CONCLUSIONS/INTERPRETATION: These data demonstrate non-redundant functions of islet class I HDACs and suggest that targeting HDAC1 and HDAC3 would provide optimal protection of beta cell mass and function in clinical islet transplantation and recent-onset type 1 diabetic patients.


Assuntos
Apoptose , Diabetes Mellitus Tipo 1/metabolismo , Histona Desacetilase 1/metabolismo , Inibidores de Histona Desacetilases/metabolismo , Histona Desacetilases/metabolismo , Células Secretoras de Insulina/metabolismo , Pâncreas/metabolismo , Animais , Apoptose/genética , Criança , Pré-Escolar , Citocinas , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/patologia , Feminino , Humanos , Lactente , Masculino , NF-kappa B/metabolismo , Pâncreas/patologia , RNA Interferente Pequeno , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Regulação para Cima
8.
Diabetologia ; 54(9): 2417-20, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21597997

RESUMO

AIMS/HYPOTHESIS: The enteroviral capsid protein, VP1, was recently shown to be present in some beta cells in more than 60% of patients with recent-onset type 1 diabetes but in very few age-matched controls. The rate of proliferation of islet cells was also markedly increased in the type 1 diabetic patients. As it has been suggested that enteroviruses replicate most efficiently in proliferating cells, we have investigated whether VP1 is preferentially present in proliferating beta cells in type 1 diabetes. METHODS: Combined immunoperoxidase and immunofluorescence staining was used to record the presence of enteroviral VP1, insulin and Ki67 in the islets of recent-onset type 1 diabetic patients. RESULTS: From a total of 1,175 islets, 359 (30.5%) contained insulin. VP1-producing endocrine cells were found in 72 islets (6.1% of total), all of which retained insulin. Ki67(+) endocrine cells were present in 52 (4.4%) islets, with 44 (84.6%) of these being insulin-positive. Overall, 28 of 1,175 (2.4%) islets contained both Ki67(+) cells and VP1(+) cells. Dual positivity of these markers accounted for 38.9% of the total VP1(+) islets and 53.8% of the total Ki67(+) islets. No individual islet cells were dual-positive for Ki67 and VP1. CONCLUSIONS/INTERPRETATION: Ki67(+) cells were frequently observed in islets that also contained VP1(+) cells, suggesting that the factors facilitating viral replication may also drive islet cell proliferation. However, in an individual cell, VP1 production does not require concurrent beta cell proliferation.


Assuntos
Proteínas do Capsídeo/metabolismo , Proliferação de Células , Diabetes Mellitus Tipo 1/metabolismo , Enterovirus/metabolismo , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/patologia , Adolescente , Adulto , Criança , Diabetes Mellitus Tipo 1/patologia , Enterovirus/isolamento & purificação , Feminino , Humanos , Imuno-Histoquímica , Lactente , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Células Secretoras de Insulina/virologia , Ilhotas Pancreáticas/virologia , Antígeno Ki-67/metabolismo , Masculino , Estudos Retrospectivos , Replicação Viral , Adulto Jovem
9.
Earth Space Sci ; 8(7): e2020EA001634, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34435081

RESUMO

The ACT-America project is a NASA Earth Venture Suborbital-2 mission designed to study the transport and fluxes of greenhouse gases. The open and freely available ACT-America data sets provide airborne in situ measurements of atmospheric carbon dioxide, methane, trace gases, aerosols, clouds, and meteorological properties, airborne remote sensing measurements of aerosol backscatter, atmospheric boundary layer height and columnar content of atmospheric carbon dioxide, tower-based measurements, and modeled atmospheric mole fractions and regional carbon fluxes of greenhouse gases over the Central and Eastern United States. We conducted 121 research flights during five campaigns in four seasons during 2016-2019 over three regions of the US (Mid-Atlantic, Midwest and South) using two NASA research aircraft (B-200 and C-130). We performed three flight patterns (fair weather, frontal crossings, and OCO-2 underflights) and collected more than 1,140 h of airborne measurements via level-leg flights in the atmospheric boundary layer, lower, and upper free troposphere and vertical profiles spanning these altitudes. We also merged various airborne in situ measurements onto a common standard sampling interval, which brings coherence to the data, creates geolocated data products, and makes it much easier for the users to perform holistic analysis of the ACT-America data products. Here, we report on detailed information of data sets collected, the workflow for data sets including storage and processing of the quality controlled and quality assured harmonized observations, and their archival and formatting for users. Finally, we provide some important information on the dissemination of data products including metadata and highlights of applications of ACT-America data sets.

10.
Diabetologia ; 53(9): 2020-8, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20532863

RESUMO

AIMS/HYPOTHESIS: In adults, the rate of beta cell replication is normally very low, but recent evidence suggests that it may increase during insulitis. We therefore studied tissue from donors with recent-onset type 1 diabetes to establish whether islet cell proliferation is increased during the disease process. METHODS: Paraffin-embedded pancreatic sections from ten donors with recent-onset type 1 diabetes and a range of relevant controls were stained by immunohistochemical techniques with antibodies against the proliferation markers Ki67 and minichromosome maintenance protein-2 (MCM-2). A combination staining technique involving immunoperoxidase and immunofluorescence methods was developed to quantify the numbers of alpha and beta cells with Ki67-positive nuclei and to investigate the relationship between insulitis and islet cell proliferation. RESULTS: In non-diabetic control donors, only 1.1 +/- 0.3% (mean +/- SEM) of islets contained one or more Ki67(+) islet cells, whereas this proportion was increased markedly in recent-onset type 1 diabetes (10.88 +/- 2.5%; p < 0.005). An equivalent increase in Ki67(+) staining occurred in alpha and beta cells and was correlated positively with the presence of insulitis. A significant increase in the labelling of islet cells from type 1 diabetic donors was also seen when MCM-2 staining was employed. Increased islet cell proliferation was not evident in three donors with longer duration type 1 diabetes or in ten type 2 diabetic donors. CONCLUSIONS/INTERPRETATION: Alpha and beta cells undergo a marked increase in proliferation during the progression of type 1 diabetes in humans. The results imply that islet cell proliferation is re-initiated in response to the autoimmune attack associated with type 1 diabetes.


Assuntos
Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/patologia , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Adolescente , Adulto , Proteínas de Ciclo Celular/metabolismo , Proliferação de Células , Criança , Pré-Escolar , Feminino , Células Secretoras de Glucagon/metabolismo , Células Secretoras de Glucagon/patologia , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Lactente , Antígeno Ki-67/metabolismo , Masculino , Componente 2 do Complexo de Manutenção de Minicromossomo , Proteínas Nucleares/metabolismo , Pâncreas/metabolismo , Pâncreas/patologia , Adulto Jovem
11.
Acta Haematol ; 123(1): 21-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19907157

RESUMO

Thalidomide and lenalidomide are immunomodulatory drugs that show promise in mantle cell lymphoma (MCL). In this study, their potential mechanisms of action against MCL cells were investigated, both alone and in combination with rituximab. Thalidomide, lenalidomide and rituximab have no direct effect on MCL cell viability. However, both immunomodulatory drugs indirectly affect viability by enhancing peripheral blood mononuclear cell-mediated cytotoxicity, with lenalidomide inducing significantly higher levels of toxicity than thalidomide. Rituximab induces both complement-dependent and antibody-dependent cellular cytotoxicity (ADCC) against MCL cells. Rituximab-induced ADCC is enhanced by lenalidomide and, to a lesser extent, thalidomide. Preliminary in vivo findings in MCL patients treated with thalidomide support a role for natural killer cells in the efficacy of these drugs. In conclusion, our data support a role for immunomodulatory drugs in the treatment of MCL.


Assuntos
Fatores Imunológicos/farmacologia , Linfoma de Célula do Manto/tratamento farmacológico , Talidomida/análogos & derivados , Talidomida/farmacologia , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais Murinos , Citotoxicidade Celular Dependente de Anticorpos/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Proteínas do Sistema Complemento/metabolismo , Citotoxicidade Imunológica/efeitos dos fármacos , Sinergismo Farmacológico , Humanos , Fatores Imunológicos/administração & dosagem , Técnicas In Vitro , Lenalidomida , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Linfoma de Célula do Manto/imunologia , Linfoma de Célula do Manto/patologia , Linfoma de Célula do Manto/terapia , Rituximab , Talidomida/administração & dosagem
12.
J Comp Pathol ; 176: 133-144, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32359626

RESUMO

Osteosarcoma (OS) is an aggressive malignant bone neoplasm that occurs mostly in the appendicular skeleton of dogs and people. OS is classified based on the presence of malignant stroma and the formation of extracellular matrix into osteoblastic, chondroblastic and fibroblastic forms. This study investigated the correlation between the three histological subtypes of canine OS and clinical outcome. Additionally, we examined whether there was any difference in the immunolabelling of desmin, S100 and neuron-specific enolase (NSE) between the three histological subtypes. Formalin-fixed and paraffin wax-embedded tissues from 87 dogs with primary OS were available for this study. The survival times were correlated with appendicular OS subtypes in dogs that were treated surgically, received adjuvant chemotherapy and had no pulmonary metastasis at the time of diagnosis. Dogs with an appendicular fibroblastic OS had significantly prolonged mean average survival times (546 ± 105 days) in comparison with dogs having appendicular osteoblastic (257 ± 48 days) or appendicular chondroblastic (170 ± 28 days) OS (P = 0.003, Log Rank). The results also revealed that the appendicular chondroblastic subtype is a significant indicator for poor prognosis in dogs compared with the fibroblastic or osteoblastic subtypes (P = 0.006, Cox regression). Moreover, the findings indicated that there was no significant correlation between the localization of desmin, NSE or S100 and histological subtypes. Importantly, dogs with appendicular fibroblastic OS were found to have a better prognosis when compared with dogs with other subtypes. This may suggest that histological subtypes of appendicular OS have diverse behaviour and could be used to categorize patients for risk-based assessment.


Assuntos
Neoplasias Ósseas/veterinária , Doenças do Cão/patologia , Osteossarcoma/veterinária , Animais , Cães , Feminino , Fibroblastos/patologia , Masculino , Prognóstico
13.
Diabetologia ; 52(6): 1143-51, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19266182

RESUMO

AIMS/HYPOTHESIS: Evidence that the beta cells of human patients with type 1 diabetes can be infected with enterovirus is accumulating, but it remains unclear whether such infections occur at high frequency and are important in the disease process. We have now assessed the prevalence of enteroviral capsid protein vp1 (vp1) staining in a large cohort of autopsy pancreases of recent-onset type 1 diabetic patients and a range of controls. METHODS: Serial sections of paraffin-embedded pancreatic autopsy samples from 72 recent-onset type 1 diabetes patients and up to 161 controls were immunostained for insulin, glucagon, vp1, double-stranded RNA activated protein kinase R (PKR) and MHC class I. RESULTS: vp1-immunopositive cells were detected in multiple islets of 44 out of 72 young recent-onset type 1 diabetic patients, compared with a total of only three islets in three out of 50 neonatal and paediatric normal controls. vp1 staining was restricted to insulin-containing beta cells. Among the control pancreases, vp1 immunopositivity was also observed in some islets from ten out of 25 type 2 diabetic patients. A strong correlation was established between islet cell vp1 positivity and PKR production in insulin-containing islets of both type 1 and type 2 diabetic patients, consistent with a persistent viral infection of the islets. CONCLUSIONS/INTERPRETATION: Immunoreactive vp1 is commonly found in the islets of recent-onset type 1 diabetes patients, but only rarely in normal paediatric controls. vp1 immunostaining was also observed in some islets of type 2 diabetes patients, suggesting that the phenomenon is not restricted to type 1 diabetes patients.


Assuntos
Proteínas do Capsídeo/metabolismo , Diabetes Mellitus Tipo 1/virologia , Enterovirus/metabolismo , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/virologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Imuno-Histoquímica , Lactente , Masculino , Adulto Jovem
14.
Clin Exp Immunol ; 155(2): 173-81, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19128359

RESUMO

The immunopathology of type 1 diabetes (T1D) has proved difficult to study in man because of the limited availability of appropriate samples, but we now report a detailed study charting the evolution of insulitis in human T1D. Pancreas samples removed post-mortem from 29 patients (mean age 11.7 years) with recent-onset T1D were analysed by immunohistochemistry. The cell types constituting the inflammatory infiltrate within islets (insulitis) were determined in parallel with islet insulin content. CD8(+) cytotoxic T cells were the most abundant population during insulitis. Macrophages (CD68(+)) were also present during both early and later insulitis, although in fewer numbers. CD20(+) cells were present in only small numbers in early insulitis but were recruited to islets as beta cell death progressed. CD138(+) plasma cells were infrequent at all stages of insulitis. CD4(+) cells were present in the islet infiltrate in all patients but were less abundant than CD8(+) or CD68(+) cells. Forkhead box protein P3(+) regulatory T cells were detected in the islets of only a single patient. Natural killer cells were detected rarely, even in heavily inflamed islets. The results suggest a defined sequence of immune cell recruitment in human T1D. They imply that both CD8(+) cytotoxic cells and macrophages may contribute to beta cell death during early insulitis. CD20(+) cells are recruited in greatest numbers during late insulitis, suggesting an increasing role for these cells as insulitis develops. Natural killer cells and forkhead box protein P3(+) T cells do not appear to be required for beta cell death.


Assuntos
Diabetes Mellitus Tipo 1/imunologia , Ilhotas Pancreáticas/imunologia , Pancreatite/imunologia , Adolescente , Criança , Pré-Escolar , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/patologia , Progressão da Doença , Feminino , Humanos , Lactente , Insulina/análise , Células Secretoras de Insulina/imunologia , Células Secretoras de Insulina/patologia , Ilhotas Pancreáticas/química , Ilhotas Pancreáticas/patologia , Células Matadoras Naturais/imunologia , Masculino , Pancreatite/patologia , Plasmócitos/imunologia , Linfócitos T Reguladores/imunologia , Adulto Jovem
16.
Nanoscale ; 9(29): 10227-10232, 2017 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-28665429

RESUMO

In this paper, we monitor the real-time growth of mesoporous platinum during electrodeposition using small-angle X-ray scattering (SAXS). Previously, we have demonstrated that platinum films featuring the 'single diamond' (Fd3m) morphology can be produced from 'double diamond' (Pn3m) lipid cubic phase templates; the difference in symmetry provides additional scattering signals unique to the metal. Taking advantage of this, we present simultaneous in situ SAXS/electrochemical measurement as the platinum nanostructures grow within the lipid template. This measurement allows us to correlate the nanostructure appearance with the deposition current density and to monitor the evolution of the orientational and lateral ordering of the lipid and platinum during deposition and after template removal. In other periodic metal nanomaterials deposited within any of the normal topology liquid crystal, mesoporous silica or block copolymer templates previously published, the template and emerging metal have the same symmetry, so such a study has not been possible previously.

17.
J Comp Pathol ; 156(4): 352-365, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28449818

RESUMO

Canine mixed mammary tumours (CMMTs) and human metaplastic breast carcinomas (HMBCs) share several histopathological features and risk factors. In both species, these tumours display epithelial and stromal components. HMBCs are rare malignant tumours, but CMMTs are one of the most common mammary tumours in dogs and are more often benign than malignant. In this study, benign (n = 88) and malignant (n = 13) CMMTs were characterized using specific antibodies against oestrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, cytokeratin 5/6, cytokeratin AE1/AE3, vimentin, Ki67, E-cadherin and p63. Cartilage and bone matrices associated with benign and malignant CMMTs were characterized using specific antibodies against BMP4, Runx2, Sox9 and osteopontin. The current study suggested that CMMTs are of epithelial origin, but display a myoepithelial-like differentiation. The findings suggest key roles for Sox9, Runx2 and BMP4 in chondrogenesis and bone formation in CMMTs. The high expression of osteopontin in CMMTs appears to be unrelated to tumour malignancy.


Assuntos
Biomarcadores Tumorais/análise , Doenças do Cão/patologia , Neoplasias Mamárias Animais/patologia , Animais , Osso e Ossos/patologia , Modelos Animais de Doenças , Doenças do Cão/metabolismo , Cães , Feminino , Humanos , Glândulas Mamárias Animais/patologia , Neoplasias Mamárias Animais/metabolismo , Metaplasia/veterinária
18.
J Comp Pathol ; 157(4): 256-265, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29169619

RESUMO

Osteosarcoma (OS) originates from bone-forming mesenchymal cells and represents one of the primary bone tumours. It is the most common primary bone tumour in dogs and man. The characterization of an appropriate natural disease animal model to study human OS is essential to elucidate the pathogenesis of the disease. This study aimed to validate canine OS as a model for the human disease by evaluating immunohistochemically the expression of markers known to be important in human OS. The immunohistochemical panel included vimentin, alkaline phosphatase (ALP), desmin, S100, neuron-specific enolase (NSE), runt-related transcription factor 2 (Runx2) and bone morphogenetic protein 4 (BMP4). Immunohistochemistry was conducted on formalin-fixed, paraffin wax-embedded tissue sections from 59 dogs with confirmed primary OS. Vimentin, ALP, Runx2 and BMP4 were highly expressed by all tumours, while desmin, S100 and NSE were expressed variably. The findings were similar to those described previously for human OS and suggest that canine OS may represent a useful model for the study of the human disease.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias Ósseas/patologia , Modelos Animais de Doenças , Osteossarcoma/patologia , Animais , Neoplasias Ósseas/metabolismo , Cães , Humanos , Osteossarcoma/metabolismo , Projetos Piloto
19.
Nanoscale ; 8(5): 2850-6, 2016 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-26763739

RESUMO

Mesoporous metal structures featuring a bicontinuous cubic morphology have a wide range of potential applications and novel opto-electronic properties, often orientation-dependent. We describe the production of nanostructured metal films 1-2 microns thick featuring 3D-periodic 'single diamond' morphology that show high out-of-plane alignment, with the (111) plane oriented parallel to the substrate. These are produced by electrodeposition of platinum through a lipid cubic phase (Q(II)) template. Further investigation into the mechanism for the orientation revealed the surprising result that the Q(II) template, which is tens of microns thick, is polydomain with no overall orientation. When thicker platinum films are grown, they also show increased orientational disorder. These results suggest that polydomain Q(II) samples display a region of uniaxial orientation at the lipid/substrate interface up to approximately 2.8 ± 0.3 µm away from the solid surface. Our approach gives previously unavailable information on the arrangement of cubic phases at solid interfaces, which is important for many applications of Q(II) phases. Most significantly, we have produced a previously unreported class of oriented nanomaterial, with potential applications including metamaterials and lithographic masks.

20.
J Neuroendocrinol ; 27(5): 303-23, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25737004

RESUMO

Transthyretin (TTR) is a protein that binds and distributes thyroid hormones (THs). TTR synthesised in the liver is secreted into the bloodstream and distributes THs around the body, whereas TTR synthesised in the choroid plexus is involved in movement of thyroxine from the blood into the cerebrospinal fluid and the distribution of THs in the brain. This is important because an adequate amount of TH is required for normal development of the brain. Nevertheless, there has been heated debate on the role of TTR synthesised by the choroid plexus during the past 20 years. We present both sides of the debate and how they can be reconciled by the discovery of TH transporters. New roles for TTR have been suggested, including the promotion of neuroregeneration, protection against neurodegeneration, and involvement in schizophrenia, behaviour, memory and learning. Recently, TTR synthesis was revealed in neurones and peripheral Schwann cells. Thus, the synthesis of TTR in the central nervous system (CNS) is more extensive than previously considered and bolsters the hypothesis that TTR may play wide roles in neurobiological function. Given the high conservation of TTR structure, function and tissue specificity and timing of gene expression, this implies that TTR has a fundamental role, during development and in the adult, across vertebrates. An alarming number of 'unnatural' chemicals can bind to TTR, thus potentially interfering with its functions in the brain. One role of TTR is delivery of THs throughout the CNS. Reduced TH availability during brain development results in a reduced IQ. The combination of the newly discovered sites of TTR synthesis in the CNS, the increasing number of neurological diseases being associated with TTR, the newly discovered functions of TTR and the awareness of the chemicals that can interfere with TTR biology render this a timely review on TTR in neurobiology.


Assuntos
Doenças do Sistema Nervoso Central/fisiopatologia , Sistema Nervoso Central/crescimento & desenvolvimento , Cognição/fisiologia , Disruptores Endócrinos/farmacologia , Pré-Albumina/fisiologia , Hormônios Tireóideos/metabolismo , Vertebrados/fisiologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/crescimento & desenvolvimento , Sistema Nervoso Central/metabolismo , Plexo Corióideo/metabolismo , DNA/metabolismo , Humanos , Neurônios/metabolismo , Pré-Albumina/biossíntese , Pré-Albumina/efeitos dos fármacos , Proteínas de Ligação ao Retinol/metabolismo , Células de Schwann/metabolismo , Vertebrados/metabolismo
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