Assuntos
Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Animais , Diferenciação Celular/imunologia , Células Cultivadas , Diabetes Mellitus Tipo 1/patologia , Contagem de Linfócitos , Ratos , Ratos Endogâmicos BB , Receptores de Antígenos de Linfócitos T/deficiência , Linfócitos T Auxiliares-Indutores/patologia , Linfócitos T Reguladores/patologiaRESUMO
Finding alternatives for insulin therapy and making advances in etiology of type 1 diabetes benefits from a full structural and functional insight into Islets of Langerhans. Electron microscopy (EM) can visualize Islet morphology at the highest possible resolution, however, conventional EM only provides biased snapshots and lacks context. We developed and employed large scale EM and compiled a resource of complete cross sections of rat Islets during immuno-destruction to provide unbiased structural insight of thousands of cells at macromolecular resolution. The resource includes six datasets, totalling 25.000 micrographs, annotated for cellular and ultrastructural changes during autoimmune diabetes. Granulocytes are attracted to the endocrine tissue, followed by extravasation of a pleiotrophy of leukocytes. Subcellullar changes in beta cells include endoplasmic reticulum stress, insulin degranulation and glycogen accumulation. Rare findings include erythrocyte extravasation and nuclear actin-like fibers. While we focus on a rat model of autoimmune diabetes, our approach is general applicable.
Assuntos
Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Tipo 1/patologia , Ilhotas Pancreáticas/patologia , Animais , Nucléolo Celular/metabolismo , Nucléolo Celular/patologia , Nucléolo Celular/ultraestrutura , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Progressão da Doença , Células Endócrinas/metabolismo , Células Endócrinas/patologia , Células Endócrinas/ultraestrutura , Estresse do Retículo Endoplasmático/fisiologia , Eritrócitos/metabolismo , Eritrócitos/patologia , Eritrócitos/ultraestrutura , Glicogênio/metabolismo , Granulócitos/metabolismo , Granulócitos/patologia , Granulócitos/ultraestrutura , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Células Secretoras de Insulina/ultraestrutura , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/ultraestrutura , Leucócitos/metabolismo , Leucócitos/patologia , Leucócitos/ultraestrutura , Microscopia Eletrônica/métodos , RatosRESUMO
INTRODUCTION: Impairment of the mucosal barrier plays an important role in the pathophysiology of acute pancreatitis. The myosin IXB (MYO9B) gene and the two tight-junction adaptor genes, PARD3 and MAGI2, have been linked to gastrointestinal permeability. Common variants of these genes are associated with celiac disease and inflammatory bowel disease, two other conditions in which intestinal permeability plays a role. We investigated genetic variation in MYO9B, PARD3 and MAGI2 for association with acute pancreatitis. METHODS: Five single nucleotide polymorphisms (SNPs) in MYO9B, two SNPs in PARD3, and three SNPs in MAGI2 were studied in a Dutch cohort of 387 patients with acute pancreatitis and over 800 controls, and in a German cohort of 235 patients and 250 controls. RESULTS: Association to MYO9B and PARD3 was observed in the Dutch cohort, but only one SNP in MYO9B and one in MAGI2 showed association in the German cohort (p < 0.05). Joint analysis of the combined cohorts showed that, after correcting for multiple testing, only two SNPs in MYO9B remained associated (rs7259292, p = 0.0031, odds ratio (OR) 1.94, 95% confidence interval (95% CI) 1.35-2.78; rs1545620, p = 0.0006, OR 1.33, 95% CI 1.16-1.53). SNP rs1545620 is a non-synonymous SNP previously suspected to impact on ulcerative colitis. None of the SNPs showed association to disease severity or etiology. CONCLUSION: Variants in MYO9B may be involved in acute pancreatitis, but we found no evidence for involvement of PARD3 or MAGI2.
Assuntos
Miosinas/genética , Pancreatite/genética , Polimorfismo de Nucleotídeo Único , Doença Aguda , Proteínas Adaptadoras de Transdução de Sinal , Adulto , Idoso , Proteínas de Transporte/genética , Proteínas de Ciclo Celular/genética , Estudos de Coortes , Feminino , Alemanha , Guanilato Quinases , Humanos , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Países BaixosAssuntos
Regulação da Expressão Gênica/imunologia , Glucocorticoides/farmacologia , Imunossupressores/uso terapêutico , Interleucina-10/uso terapêutico , Receptores de Interleucina/genética , Sinergismo Farmacológico , Regulação da Expressão Gênica/efeitos dos fármacos , Glucocorticoides/uso terapêutico , Humanos , Receptores de Interleucina-10 , Linfócitos T/imunologiaRESUMO
Biobreeding (BB) rats model type 1 autoimmune diabetes (T1D). BB diabetes-prone (BBDP) rats develop T1D spontaneously. BB diabetes-resistant (BBDR) rats develop T1D after immunological perturbations that include regulatory T cell (Treg) depletion plus administration of low doses of a TLR ligand, polyinosinic-polycytidylic acid. Using both models, we analyzed CD4+CD25+ and CD4+CD45RC- candidate rat Treg populations. In BBDR and control Wistar Furth rats, CD25+ T cells comprised 5-8% of CD4+ T cells. In vitro, rat CD4+CD25+ T cells were hyporesponsive and suppressed T cell proliferation in the absence of TGF-beta and IL-10, suggesting that they are natural Tregs. In contrast, CD4+CD45RC(-) T cells proliferated in vitro in response to mitogen and were not suppressive. Adoptive transfer of purified CD4+CD25+ BBDR T cells to prediabetic BBDP rats prevented diabetes in 80% of recipients. Surprisingly, CD4+CD45RC-CD25- T cells were equally protective. Quantitative studies in an adoptive cotransfer model confirmed the protective capability of both cell populations, but the latter was less potent on a per cell basis. The disease-suppressing CD4+CD45RC-CD25- population expressed PD-1 but not Foxp3, which was confined to CD4+CD25+ cells. We conclude that CD4+CD25+ cells in the BBDR rat act in vitro and in vivo as natural Tregs. In addition, another population that is CD4+CD45RC-CD25- also participates in the regulation of autoimmune diabetes.