OBJECTIVEFulminant type 1 diabetes is characterized by the rapid onset of severe hyperglycemia and ketoacidosis, with subsequent poor prognosis of diabetes complications. Causative mechanisms for accelerated β-cell failure are unclear.RESEARCH DESIGN AND METHODSSubjects comprised three autopsied patients who died from diabetic ketoacidosis within 2–5 days after onset of fulminant type 1 diabetes. We examined islet cell status, including the presence of enterovirus and chemokine/cytokine/major histocompatibility complex (MHC) expressions in the pancreata using immunohistochemical analyses and RT-PCR.RESULTSImmunohistochemical analysis revealed the presence of enterovirus-capsid protein in all three affected pancreata. Extensive infiltration of CXCR3 receptor–bearing T-cells and macrophages into islets was observed. Dendritic cells were stained in and around the islets. Specifically, interferon-γ and CXC chemokine ligand 10 (CXCL10) were strongly coexpressed in all subtypes of islet cells, including β-cells and α-cells. No CXCL10 was expressed in exocrine pancreas. Serum levels of CXCL10 were increased. Expression of MHC class II and hyperexpression of MHC class I was observed in some islet cells.CONCLUSIONSThese results strongly suggest the presence of a circuit for the destruction of β-cells in fulminant type 1 diabetes. Enterovirus infection of the pancreas initiates coexpression of interferon-γ and CXCL10 in β-cells. CXCL10 secreted from β-cells activates and attracts autoreactive T-cells and macrophages to the islets via CXCR3. These infiltrating autoreactive T-cells and macrophages release inflammatory cytokines including interferon-γ in the islets, not only damaging β-cells but also accelerating CXCL10 generation in residual β-cells and thus further activating cell-mediated autoimmunity until all β-cells have been destroyed.

OBJECTIVEThe contribution of innate immunity responsible for aggressive β-cell destruction in human fulminant type 1 diabetes is unclear.RESEARCH DESIGN AND METHODSIslet cell expression of Toll-like receptors (TLRs), cytoplasmic retinoic acid–inducible gene I (RIG-I)-like receptors, downstream innate immune markers, adaptive immune mediators, and apoptotic markers was studied in three autopsied pancreata obtained 2 to 5 days after onset of fulminant type 1 diabetes.RESULTSRIG-I was strongly expressed in β-cells in all three pancreata infected with enterovirus. Melanoma differentiation–associated gene-5 was hyperexpressed in islet cells, including β- and α-cells. TLR3 and TLR4 were expressed in mononuclear cells that infiltrated islets. Interferon (IFN)-α and IFN-β were strongly expressed in islet cells. Major histocompatibility complex (MHC)-class I, IFN-γ, interleukin-18, and CXC motif ligand 10 were expressed and colocalized in affected islets. CD11c+ MHC-class II+ dendritic cells and macrophage subsets infiltrated most islets and showed remarkable features of phagocytosis of islet cell debris. CD4+ forkhead box P3+ regulatory T cells were not observed in and around the affected islets. Mononuclear cells expressed the Fas ligand and infiltrated most Fas-expressing islets. Retinoic acid–receptor responder 3 and activated caspases 8, 9, and 3 were preferentially expressed in β-cells. Serum levels of IFN-γ were markedly increased in patients with fulminant type 1 diabetes.CONCLUSIONSThese findings demonstrate the presence of specific innate immune responses to enterovirus infection connected with enhanced adoptive immune pathways responsible for aggressive β-cell toxicity in fulminant type 1 diabetes.

Insulin intervention to preserve beta-cell function is effective and safe for patients with SPIDDM or latent autoimmune diabetes in adults.

Iodide uptake by the thyroid is mediated by the sodium/iodide symporter. Upon iodide uptake, thyroperoxidase catalyzes iodination of tyrosine residues in thyroglobulin, retaining iodide within thyroid follicles. Dedifferentiation-induced loss of these functions in cancers, rendering them unresponsive to radioiodide, occurs with most poorly differentiated and anaplastic tumors. We focused on the histone deacetylase (HDAC) inhibitors (HDACI) as a way to induce differentiation of thyroid cancer cells. We assessed re-expression of thyroid-specific genes mRNA induced by HDACI using quantitative RT-PCR and immunostaining in poorly differentiated papillary and anaplastic thyroid cancer cells. HDACI induced expression of thyroid-specific gene mRNAs and proteins, and accumulation of radioiodide through iodination of generic cellular proteins were detected. HDACI-treated tumors could specifically accumulate (125)I as revealed by imaging experiments and radioiodide concentration in vivo. In an attempt to determine the mechanism by which these gene expressions occurred, we detected the inhibition of protein synthesis by cycloheximide, which up-regulated the expression of thyroperoxidase and thyroglobulin mRNA in HDACI-treated cells and down-regulated that of sodium/iodide symporter mRNA. Together, our results suggest that HDACI-induced expression of thyroid-specific genes, some of which is mediated by some protein synthesis, may contribute to development of novel strategy against thyroid cancer.

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