Previous studies have suggested more than 20 genetic intervals that are associated with susceptibility to type 1 diabetes (T1D), but identification of specific genes has been challenging and largely limited to known candidate genes. Here, we report evidence for an association between T1D and multiple single-nucleotide polymorphisms in 197 kb of genomic DNA in the IDDM5 interval. We cloned a new gene (SUMO4), encoding small ubiquitin-like modifier 4 protein, in the interval. A substitution (M55V) at an evolutionarily conserved residue of the crucial CUE domain of SUMO4 was strongly associated with T1D (P = 1.9 x 10(-7)). SUMO4 conjugates to I kappa B alpha and negatively regulates NF kappa B transcriptional activity. The M55V substitution resulted in 5.5 times greater NF kappa B transcriptional activity and approximately 2 times greater expression of IL12B, an NF kappa B-dependent gene. These findings suggest a new pathway that may be implicated in the pathogenesis of T1D.
OBJECTIVE -Children who develop cerebral edema (CE) during diabetic ketoacidosis (DKA) exhibit definable signs and symptoms of neurological collapse early enough to allow intervention to prevent brain damage. Our objective was to develop a model for early detection of CE in children with DKA. RESEARCH DESIGN AND METHODS-A training sample of 26 occurrences of DKA complicated by severe CE and 69 episodes of uncomplicated DKA was reviewed. Signs of neurological disease were incorporated into a bedside evaluation protocol that was applied to an independent test sample of 17 patients previously reported to have developed symptomatic CE during treatment for DKA. Head computed tomograms and their reports were reviewed.RESULTS -The protocol allowed 92% sensitivity and 96% specificity for the recognition of CE sufficiently early for intervention. The diagnostic criteria were fulfilled in two temporal patterns, defining early-and late-onset CE. Although initial computed tomograms were often normal, the findings also included diffuse CE and focal brain injury, the latter only in patients with an early onset of abnormal neurological signs.CONCLUSIONS -CE may occur in the absence of acute changes on head computed tomograms. Early detection of CE at the bedside using an evidence-based protocol permits intervention in time to prevent permanent brain damage. Diabetes Care 27:1541-1546, 2004M ost children with diabetic ketoacidosis (DKA) exhibit abnormal neurological function. Therefore, evidence-based guidance for discerning the patients who require lifesaving intervention is needed. Cerebral dysfunction in DKA is usually a manifestation of metabolic derangement, but cerebral edema (CE) arises in ϳ1% of episodes and is a complication that frequently causes irreversible brain damage and death (1-7). Neurological collapse from CE is typically described as having sudden onset and progressing rapidly, with recovery depending on prompt reduction of intracranial pressure (4,8 -10). The object of this study was to delineate the signs and symptoms of neurological compromise that predict progression to severe CE in children with DKA.CE occurs rarely in patients older than age 20 years (8,11,12), despite the presence of asymptomatic CE in most adults and children with DKA (13-16). This age dependence may point to developmental changes in cerebral metabolism as critical elements in the pathogenesis of CE. For example, children's brains are reported to have higher fuel and oxygen requirements than those of adults (17,18). Hypoxia is further implicated because the brains of patients with DKA may extract blood oxygen less efficiently than healthy individuals (16) and the reported association of symptomatic CE with low partial pressures of carbon dioxide in arterial blood may reflect harmful cerebral vasoconstriction (5,6). Exuberant rehydration with hypotonic fluid and bicarbonate administration may aggravate the CE (5,6,9,11,12,19 -22); however, the evidence that CE is primarily iatrogenic is not compelling (6,8,(23)(24)(25)(26)(27)(28)(29)...
We reported previously that daily injections of isophane insulin prevented both hyperglycemia and insulitis in nonobese diabetic (NOD) mice and R. Luchetta. 1990. . The possible mechanisms responsible include reduced immunogenicity of pancreatic fl-cells from ",B-cell rest" and induced active immunoregulation to insulin (Aaen, K., J. Rygaard, K. Josefsen, H. Petersen, C. H. Brogren, T. Horn, and K. Buschard. 1990. Diabetes. 39:697-701). We report here that intermittent immunizations with insulin or its metabolically inactive B-chain in incomplete Freund's adjuvant also prevent diabetes in NOD mice, whereas immunizations with A-chain insulin or with BSA do not. Adoptive transfer of splenocytes from B-chain insulin-immunized mice prevented diabetes in recipients co-infused with diabetogenic spleen cells, an effect that was abolished by prior in vivo elimination of either CD4+ or CD8+ cells. Insulin immunization did not reduce the extent of intraislet inflammation (insulitis); however, it did abolish expression of IFN-y mRNA within the insulitis lesions. Immunizations with insulin thus induce an active suppressive response to determinants on the B-chain that converts the insulitis lesion from one that is destructive to one that is protective. (J. Clin. Invest. 1995. 95:628-634.)
Summary The epidermal growth factor receptor ligand Amphiregulin has a well-documented role in the restoration of tissue homeostasis after injury; however, the mechanism by which Amphiregulin contributes to wound repair remains unknown. Here we show that Amphiregulin functioned by releasing bioactive transforming growth factor beta (TGF-β) from latent complexes via integrin-α V activation. Using acute injury models in two different tissues, we found that by inducing TGF-β activation on mesenchymal stromal cells (pericytes), Amphiregulin induced their differentiation into myofibroblasts, thereby selectively contributing to the restoration of vascular barrier function within injured tissue. Furthermore, we identified macrophages as a critical source of Amphiregulin, revealing a direct effector mechanism by which these cells contribute to tissue restoration after acute injury. Combined, these observations expose a so far under-appreciated mechanism of how cells of the immune system selectively control the differentiation of tissue progenitor cells during tissue repair and inflammation.
Juvenile Diabetes Research Foundation (JDRF), NIH, Diabetes UK.
The development of spontaneous autoimmune diabetes in nonobese diabetic (NOD) mice provides for their use as a model of human type 1 diabetes. To test the feasibility of muscle-directed gene therapy to prevent type 1 diabetes, we developed recombinant adeno-associated virus (rAAV) vectors containing murine cDNAs for immunomodulatory cytokines IL-4 or IL-10. Skeletal muscle transduction of female NOD mice with IL-10, but not IL-4, completely abrogated diabetes. rAAV-IL-10 transduction attenuated the production of insulin autoantibodies, quantitatively reduced pancreatic insulitis, maintained islet insulin content, and altered splenocyte cytokine responses to mitogenic stimulation. The beneficial effects were host specific, as adoptive transfer of splenocytes from rAAV IL-10-treated animals rapidly imparted diabetes in naive hosts, and the cells contained no protective immunomodulatory capacity, as defined through adoptive cotransfer analyses. These results indicate the utility for rAAV, a vector with advantages for therapeutic gene delivery, to transfer immunoregulatory cytokines capable of preventing type 1 diabetes. In addition, these studies provide foundational support for the concept of using immunoregulatory agents delivered by rAAV to modulate a variety of disorders associated with deleterious immune responses, including allergic reactions, transplantation rejection, immunodeficiencies, and autoimmune disorders.
Acquired hypoparathyroidism (AH) has been considered to result from an autoimmune process but the self-antigens have not been identified. We studied 25 patients with AH, of which 17 had type I autoimmune polyglandular syndrome and 8 had AH associated with autoimmune hypothyroidism. Five of 25 (20%) AH sera reacted to a membraneassociated antigen of 120-140 kD in human parathyroid gland extracts using immunoblot analysis. This is the exact size of the calcium sensing receptor (Ca-SR). The AH sera were then tested by immunoblot using a membrane fraction of HEK-293 cells transfected with Ca-SR cDNA. Eight of 25 (32%) AH sera reacted to a 120-140-kD protein, which closely matched that recognized by the anti-Ca-SR IgG raised in rabbits. The Ca-SR cDNA was translated in vitro into two parts in order to identify the antigenic epitopes. By using this technique, 14 of 25 (56%) AH sera were positive to the extracellular domain of the Ca-SR, whereas none of the AH patient sera reacted to the intracellular domain. The reactivity of the positive sera was completely removed after pre-absorption with the Ca-SR containing membranes. Sera from 50 patients with various other autoimmune diseases as well as 22 normal controls were also tested, and none of them was positive. In conclusion, the Ca-SR has been identified as an autoantigen in AH. ( J. Clin. Invest . 1996. 97: 910-914.)
IntroductionIslet cell antibodies (ICA) in the sera of nondiabetic relatives of patients with insulin-dependent diabetes (IDD) are predictive of the disease, a finding that permits the design of intervention strategies to prevent it. However, 85% or more of patients with new onset IDD have no affected relative. We therefore screened 9,696 schoolchildren between the ages of 5 and 18 yr (mean age 10.7 yr) in Pasco County, Florida for ICA in three surveys during 1984/5, 1987/8, and 1990/1 and have followed them prospectively. Approximately 4,000 of these children have been followed for nearly 8 yr. ICA titers 2 10 Juvenile Diabetes Foundation units on replicate tests were detected in 57 of the children (0.59%). 10 children have developed diabetes so far, and all had ICA detected beforehand. The likelihood of developing IDD among the ICA-positive children was compared with 2,959 age-matched nondiabetic first degree relatives of IDD probands who were screened for ICA by our laboratory during the same time period and also followed prospectively. Of 103 (3.5%) ICA-positive relatives, 31 have developed IDD. Life table analysis reveals no statistically significant differences in the probability of developing IDD between the ICApositive schoolchildren and ICA-positive first degree relatives (P = 0.3). The estimated risk of developing IDD by 7 yr in the ICA-positive schoolchildren was 45% (95% confidence interval 15-74%) compared with 43% (confidence interval 22-63%) in the relatives. We conclude that ICA appear to be as predictive of IDD in low-risk schoolchildren as they are in high-risk relatives. These data suggest that it is feasible to predict IDD by screening a general population of schoolchildren for ICA and that those found to be positive could be considered, in addition to relatives, for intervention protocols to prevent the disease.
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