Stem cell transplantation for type 1 diabetes mellitus

<p>Abstract</p> <p>Background</p> <p>The use of stem cells to treat type 1 diabetes mellitus has been proposed for many years, both to downregulate the immune system and to provide β cell regeneration.</p> <p>Conclusion</p> <p>High dose immunosuppression followed by autologous hematopoietic stem cell transplantation is able to induce complete remission (insulin independence) in most patients with early onset type 1 diabetes mellitus.</p

Association of the CpG Methylation Pattern of the Proximal Insulin Gene Promoter with Type 1 Diabetes

The insulin (INS) region is the second most important locus associated with Type 1 Diabetes (T1D). The study of the DNA methylation pattern of the 7 CpGs proximal to the TSS in the INS gene promoter revealed that T1D patients have a lower level of methylation of CpG -19, -135 and -234 (p = 2.10−16) and a higher methylation of CpG -180 than controls, while methylation was comparable for CpG -69, -102, -206. The magnitude of the hypomethylation relative to a control population was 8–15% of the corresponding levels in controls and was correlated in CpGs -19 and -135 (r = 0.77) and CpG -135 and -234 (r = 0.65). 70/485 (14%) of T1D patients had a simultaneous decrease in methylation of CpG -19, -135, -234 versus none in 317 controls. CpG methylation did not correlate with glycated hemoglobin or with T1D duration. The methylation of CpG -69, -102, -180, -206, but not CpG -19, -135, -234 was strongly influenced by the cis-genotype at rs689, a SNP known to show a strong association with T1D. We hypothesize that part of this genetic association could in fact be mediated at the statistical and functional level by the underlying changes in neighboring CpG methylation. Our observation of a CpG-specific, locus-specific methylation pattern, although it can provide an epigenetic biomarker of a multifactorial disease, does not indicate whether the reported epigenetic pattern preexists or follows the establishment of T1D. To explore the effect of chronic hyperglycemia on CpG methylation, we studied non obese patients with type 2 diabetes (T2D) who were found to have decreased CpG-19 methylation versus age-matched controls, similar to T1D (p = 2.10−6) but increased CpG-234 methylation (p = 5.10−8), the opposite of T1D. The causality and natural history of the different epigenetic changes associated with T1D or T2D remain to be determined

An AAVrh10-CAG-CYP21-HA vector allows persistent correction of 21-hydroxylase deficiency in a Cyp21−/− mouse model

International audienceThe treatment of severe forms of 21-hydroxylase deficiency (21OHD) remains unsatisfactory in many respects. As a monogenic disease caused by loss-of-function mutations, 21OHD is a potential candidate for a gene therapy (GT) approach. The first step of GT is to demonstrate positive effects of the therapeutic vector in the Cyp21-/- mouse model. Thus, we tested the adrenal tropism of an AAVrh10-CAG-GFP vector ('GFP vector') then attempted to correct the phenotypic and biochemical alterations in Cyp21-/- mice using an AAVrh10-CAG-humanCYP21A2-HA vector ('CYP21 vector'). Cyp21-/- mice had decreased body mass, high progesterone (4 ×), impaired stress response, increased adrenal expression of genes involved in steroidogenesis or ACTH signaling. Following injection of the GFP vector, Cyp21-/- mice showed abundant GFP expression in the adrenal cortex. Intravenous injection of the therapeutic CYP21 vector allowed 21OH expression in adrenal tissue, resulting in increased body weight and near normalization of urinary progesterone for more than 15 weeks, improved response to stress and restoration of near-normal expression of (several important genes) in the adrenal cortex. The adrenal tropism of AAVrh10 and the persistent correction of phenotypic and biochemical traits in Cyp21-/- mice pave a first step on the way to GT of 21OHD in humans

The P2 promoter of the IGF1 gene is a major epigenetic locus for GH responsiveness

International audienceShort children using growth hormone (GH) to accelerate their growth respond to this treatment with a variable efficacy. The causes of this individual variability are multifactorial and could involve epigenetics. Quantifying the impact of epigenetic variation on response to treatments is an emerging challenge. Here we show that methylation of a cluster of CGs located within the P2 promoter of the insulin-like growth factor 1 (IGF1) gene, notably CG-137, is inversely closely correlated with the response of growth and circulating IGF1 to GH administration. For example, variability in CG-137 methylation contributes 25% to variance of growth response to GH. Methylation of CGs in the P2 promoter is negatively associated with the increased transcriptional activity of P2 promoter in patients' mononuclear blood cells following GH administration. Our observation indicates that epigenetics is a major determinant of GH signaling (physiology) and of individual responsiveness to GH treatment (pharmacoepigenetics)

[Localization of B-cell Adenoma By Transhepatic Portal Catheterization]

Background. The procedures used to locate pancreatic endocrine tumors have only limited success in infants and children in whom the nodules may be small. Portal catheterization may therefore be useful. Cass report. A child aged 6 yrs 4 months was admitted because of several recent episodes of pallor and sweating associated with hypoglycemia. Further investigation showed moderate hyperinsulinemia and low blood levels of ketone bodies and branched amino-acids after a 15 hr fast. Celiac angiography was normal. The hypoglycemic episodes recurred despite treatment with diazoxide for 6 months. A transparietal portal catheterization was therefore performed. Selective pancreatic venous sampling showed high concentrations of insulin in two small veins draining one part of the head of the pancreas (117 and 89 mu U/ml). The head of pancreas was removed 16 months later. Extemporaneous examination revealed an adenoma 0.8 cm in diameter. This patient has completely recovered, 8 months after surgery. Conclusion. Transparietal portal catheterization can detect pancreatic areas with high insulin secretion. It may also help the interpretation of celiac angiographs in children, as diagnosis may be obscured by the normal rich vascularity of the pancreas in these patients