ABSTRACT
The histologic hallmark of the development of type 1 diabetes (T1D) is insulitis, characterized by leukocytic infiltration of the pancreatic islets. The molecules controlling the early influx of leukocytes into the islets are poorly understood. Tumor necrosis factor alpha (TNFalpha)-stimulated gene 6 (TSG-6) is involved in inflammation, extracellular matrix formation, cell migration, and development. In the present study, we examined the expression and cellular localization of TSG-6 protein in islets of female non-obese diabetic (NOD) mice using frozen section immunofluorescence staining. Pancreata from nondiabetic (8 and 25 weeks old), prediabetic (230-280 mg/dl blood glucose) and diabetic (>300 mg/dl blood glucose) NOD mice were stained for TSG-6, insulin, CD3, CD11c, Mac3 and CD31. TSG-6 protein was detected in 67% of islets of prediabetic mice, 27% of islets of 25-week old nondiabetic mice, and less than 7% of islets of diabetic mice and 8-week old nondiabetic mice. Lastly, islet-derived TSG-6 protein was localized to the infiltrating CD3 and CD11c positive leukocytes.
Subject(s)
Cell Adhesion Molecules/metabolism , Islets of Langerhans/metabolism , Animals , CD11c Antigen/metabolism , CD3 Complex/metabolism , Cell Adhesion Molecules/genetics , Diabetes Mellitus, Type 1/metabolism , Female , HeLa Cells , Humans , Islets of Langerhans/cytology , Mice , Mice, Inbred C57BL , Mice, Inbred NODABSTRACT
Strategies inhibiting cell death signaling pathways may enhance the availability of islet transplantation for patients with type 1 diabetes mellitus. The epsilon isoform of protein kinase C (PKC epsilon) has been shown to have an anti-apoptotic effect in many cell types. The present study investigated whether activation of PKC epsilon may improve the yield of functional islet cells for transplantation. Islet cells were isolated from wild-type BALB/c mice preconditioned with either a PKC epsilon activator (psi epsilon RACK) or a TAT carrier control peptide and further treated with the same agents during isolation and in vitro for either 0, 1, 16, or 40 hours. Islet cells were assessed at each time point for viability, apoptosis, and function. psi epsilon RACK-treated islets showed significantly decreased islet cell death up to 40 hours after isolation compared with TAT-treated control islets. Beta-cell function in response to high glucose challenge remained unchanged.
Subject(s)
Cell Survival/physiology , Islets of Langerhans/cytology , Islets of Langerhans/enzymology , Protein Kinase C-epsilon/metabolism , Animals , Cell Culture Techniques , Cell Separation/methods , Diabetes Mellitus, Type 1/surgery , Enzyme Activation , Humans , Islets of Langerhans Transplantation , Male , Mice , Mice, Inbred BALB C , Tissue and Organ Harvesting/methodsABSTRACT
A single nucleotide polymorphism (SNP) C5507G of the complement receptor 1 (CR1) gene has been associated with genetic susceptibility to sarcoidosis in an Italian population. In order to provide further data on the possible involvement of CR1 gene polymorphisms in sarcoidosis, CR1 SNPs C5507G and A3650G were investigated in Czech (n = 210) and Dutch (n = 116) patients with sarcoidosis with ethnically matched groups of healthy control subjects (Czech, n = 203; Dutch, n = 112). CR1 C5507G and A3650G SNPs were not associated with susceptibility to sarcoidosis or its clinical course. Further, CR1 messenger RNA expression in bronchoalveolar lavage cells investigated by quantitative reverse transcriptase-polymerase chain reaction did not differ between sarcoidosis patients and control subjects and was not associated with the presence of the CR1 5507*G allele.
