14 research outputs found
Chemokine (C-C Motif) Ligand 2 (CCL2) in Sera of Patients with Type 1 Diabetes and Diabetic Complications
Chemokine (C-C motif) ligand 2 (CCL2), commonly known as monocyte chemoattractant protein-1 (MCP-1), has been implicated in the pathogenesis of many diseases characterized by monocytic infiltration. However, limited data have been reported on MCP-1 in type 1 diabetes (T1D) and the findings are inconclusive and inconsistent.In this study, MCP-1 was measured in the sera from 2,472 T1D patients and 2,654 healthy controls using a Luminex assay. The rs1024611 SNP in the promoter region of MCP-1 was genotyped for a subset of subjects (1764 T1D patients and 1323 controls) using the TaqMan-assay.Subject age, sex or genotypes of MCP-1 rs1024611SNP did not have a major impact on serum MCP-1 levels in either healthy controls or patients. While hemoglobin A1c levels did not have a major influence on serum MCP-1 levels, the mean serum MCP-1 levels are significantly higher in patients with multiple complications (meanβ=β242 ng/ml) compared to patients without any complications (meanβ=β201 ng/ml) (pβ=β3.5Γ10(-6)). Furthermore, mean serum MCP-1 is higher in controls (meanβ=β261 ng/ml) than T1D patients (meanβ=β208 ng/ml) (p<10(-23)). More importantly, the frequency of subjects with extremely high levels (>99(th) percentile of patients or 955 ng/ml) of serum MCP-1 is significantly lower in the T1D group compared to the control group (odds ratioβ=β0.11, p<10(-33)).MCP-1 may have a dual role in T1D and its complications. While very high levels of serum MCP-1 may be protective against the development of T1D, complications are associated with higher serum MCP-1 levels within the T1D group
Large-Scale Discovery and Validation Studies Demonstrate Significant Reductions in Circulating Levels of IL8, IL-1Ra, MCP-1, and MIP-1Ξ² in Patients With Type 1 Diabetes
Proteins of TNF-Ξ± and IL6 Pathways Are Elevated in Serum of Type-1 Diabetes Patients with Microalbuminuria
Soluble cytokine receptors may play an important role in development of microalbuminuria (MA) in type-1 diabetes (T1D). In this study, we measured 12 soluble receptors and ligands from TNF-Ξ±/IL6/IL2 pathways in T1D patients with MA (nβ=β89) and T1D patients without MA (nβ=β483) participating in the PAGODA study. Twelve proteins in the sera from T1D patients with and without MA were measured using multiplex Luminex assays. Ten serum proteins (sTNFR1, sTNFR2, sIL2RΞ±, MMP2, sgp130, sVCAM1, sIL6R, SAA, CRP, and sICAM1) were significantly elevated in T1D patients with MA. After adjusting for age, duration of diabetes, and sex in logistic regression, association remained significant for seven proteins. MA is associated with increasing concentrations of all 10 proteins, with the strongest associations observed for sTNFR1 (ORβ=β108.3, Pβ<β10β32) and sTNFR2 (ORβ=β65.5, Pβ<β10β37), followed by sIL2RΞ± (ORβ=β12.9, Pβ<β10β13), MMP2 (ORβ=β5.5, Pβ<β10β6), sgp130 (ORβ=β5.2, Pβ<β10β3), sIL6R (ORβ=β4.6, Pβ<β10β4), and sVCAM1 (ORβ=β3.3, Pβ<β10β4). We developed a risk score system based on the combined odds ratios associated with each quintile for each protein. The risk scores cluster MA patients into three subsets, each associated with distinct risk for MA attributable to proteins in the TNF-Ξ±/IL6 pathway (mean ORβ=β1, 13.5, and 126.3 for the three subsets, respectively). Our results suggest that the TNF-Ξ±/IL6 pathway is overactive in approximately 40% of the MA patients and moderately elevated in the middle 40% of the MA patients. Our results suggest the existence of distinct subsets of MA patients identifiable by their serum protein profiles
Genetically dependent ERBB3 expression modulates antigen presenting cell function and type 1 diabetes risk.
Type 1 diabetes (T1D) is an autoimmune disease resulting from the complex interaction between multiple susceptibility genes, environmental factors and the immune system. Over 40 T1D susceptibility regions have been suggested by recent genome-wide association studies; however, the specific genes and their role in the disease remain elusive. The objective of this study is to identify the susceptibility gene(s) in the 12q13 region and investigate the functional link to the disease pathogenesis. A total of 19 SNPs in the 12q13 region were analyzed by the TaqMan assay for 1,434 T1D patients and 1,865 controls. Thirteen of the SNPs are associated with T1D (best p = 4x10(-11)), thus providing confirmatory evidence for at least one susceptibility gene in this region. To identify candidate genes, expression of six genes in the region was analyzed by real-time RT-PCR for PBMCs from 192 T1D patients and 192 controls. SNP genotypes in the 12q13 region are the main factors that determine ERBB3 mRNA levels in PBMCs. The protective genotypes for T1D are associated with higher ERBB3 mRNA level (p<10(-10)). Furthermore, ERBB3 protein is expressed on the surface of CD11c(+) cells (dendritic cells and monocytes) in peripheral blood after stimulation with LPS, polyI:C or CpG. Subjects with protective genotypes have significantly higher percentages of ERBB3(+) monocytes and dendritic cells (p = 1.1x10(-9)); and the percentages of ERBB3(+) cells positively correlate with the ability of APC to stimulate T cell proliferation (R(2) = 0.90, p<0.0001). Our results indicate that ERBB3 plays a critical role in determining APC function and potentially T1D pathogenesis
Discovery and Validation of Serum Protein Changes in Type 1 Diabetes Patients Using High Throughput Two Dimensional Liquid Chromatography-Mass Spectrometry and Immunoassays
Serum MCP-1 values are plotted for each subject based on their β2518A/G SNP genotypes.
<p>Means for each group are marked by the solid lines and the values on the right side.</p
Regression graphs of the relationship between serum levels of MCP-1 relative to age of subjects (a, b & c) and duration of T1D (d, e & f).
<p>a) Relative levels of MCP-1 as a function of Age in females (Ξ²β=ββ0.005, Rβ=ββ0.06) and males (Ξ²β=ββ0.0013, Rβ=ββ0.02) in the control group. b) Relative expression of MCP-1 in serum of T1D females (Ξ²β=β0.005, Rβ=β0.11) and males (Ξ²β=β0.002, Rβ=β0.04). c) Mean serum MCP-1 levels (regression lines) according to age. d) Regression for duration of disease for female patients (Ξ²β=β0.009, Rβ=β0.14). e) Regression for duration of disease for male patients (Ξ²β=β0.005, Rβ=β0.08). f) Mean serum MCP-1 levels (regression lines) according to duration of T1D. Ξ²: slope of regression, R: correlation coefficient.</p
Genotypic and allelic frequencies of MCP-1 SNP.
<p>Genotypic and allelic frequencies of MCP-1 SNP.</p
Serum MCP-1 levels (Log2) in T1D patients with diabetic complications.
<p>*Ratio was calculated for each specific category of complication in comparison to the group without any complication.</p