25 research outputs found
The “Perfect Storm” for Type 1 Diabetes: The Complex Interplay Between Intestinal Microbiota, Gut Permeability, and Mucosal Immunity
It is often stated that type 1 diabetes results from a complex interplay between varying degrees of genetic susceptibility and environmental factors. While agreeing with this principal, our desire is that this Perspectives article will highlight another complex interplay potentially associated with this disease involving facets related to the gut, one where individual factors that, upon their interaction with each another, form a “perfect storm” critical to the development of type 1 diabetes. This trio of factors includes an aberrant intestinal microbiota, a “leaky” intestinal mucosal barrier, and altered intestinal immune responsiveness. Studies examining the microecology of the gastrointestinal tract have identified specific microorganisms whose presence appears related (either quantitatively or qualitatively) to disease; in type 1 diabetes, a role for microflora in the pathogenesis of disease has recently been suggested. Increased intestinal permeability has also been observed in animal models of type 1 diabetes as well as in humans with or at increased-risk for the disease. Finally, an altered mucosal immune system has been associated with the disease and is likely a major contributor to the failure to form tolerance, resulting in the autoimmunity that underlies type 1 diabetes. Herein, we discuss the complex interplay between these factors and raise testable hypotheses that form a fertile area for future investigations as to the role of the gut in the pathogenesis and prevention of type 1 diabetes
Aberrant regulation of interleukin-12 receptor beta2 chain on type 1 cytokine-stimulated T lymphocytes in type 1 diabetes
Poor in vitro induction of FOXP3 and ICOS in type 1 cytokine environment activated T-cells from children with type 1 diabetes
Reduced CCR4, interleukin-13 and GATA-3 up-regulation in response to type 2 cytokines of cord blood T lymphocytes in infants at genetic risk of type 1 diabetes
Poor in vitro maturation and pro-inflammatory cytokine response of dendritic cells in children at genetic risk of type 1 diabetes.
Decreased in vitro type 1 immune response against Coxsackie virus B4 in children with type 1 diabetes
Monocyte gene-expression profiles associated with childhood-onset type 1 diabetes and disease risk: a study of identical twins.
OBJECTIVE: Monocytes in childhood-onset type 1 diabetes show distinct gene expression. We hypothesize that monocyte activation in monozygotic (MZ) twin pairs discordant for childhood-onset type 1 diabetes could reflect distinct stages of the disease process including diabetes susceptibility (differences between twins, both diabetic and nondiabetic, and control subjects) and/or disease progression (differences between diabetic and nondiabetic twins). RESEARCH DESIGN AND METHODS: We studied patterns of inflammatory gene expression in peripheral blood monocytes of MZ twin pairs (n = 10 pairs) discordant for childhood-onset type 1 diabetes, normal control twin pairs (n = 10 pairs), and healthy control subjects (n = 51) using quantitative-PCR (Q-PCR). We tested the 24 genes previously observed by whole genome analyses and verified by Q-PCR in autoimmune diabetes and performed a hierarchical cluster analysis. RESULTS: Of 24 genes abnormally expressed in childhood-onset type 1 diabetes, we revalidated abnormal expression in 16 of them in diabetic twins including distinct sets of downregulated (P < 0.03) and upregulated (P < 0.02) genes. Of these 16 genes, 13 were abnormally expressed in nondiabetic twins, implicating these genes in diabetes susceptibility (P < 0.044 for all). Cluster analysis of monocyte gene-expression in nondiabetic twins identified two distinct, mutually exclusive clusters, while diabetic twins had a network of positively correlated genes. CONCLUSIONS: Patients with childhood-onset type 1 diabetes show abnormal monocyte gene-expression levels with an altered gene-expression network due to gene-environment interaction. Importantly, perturbed gene-expression clusters were also detected in nondiabetic twins, implicating monocyte abnormalities in susceptibility to diabetes.The authors thank the British Diabetic Twin Trust (H.B.
and R.D.L.) and the Juvenile Diabetes Research Foundation
International (JDRFI) (R.D.L.). The studies were also
supported by the European Union (MONODIAB, contract
no. QLRT-1999-00276), JDRFI, aand the Dutch Diabetic
Foundation (contract no. 96.606)