Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0011849 (diabetes)
277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The critical initiating event in atherogenesis involves the invasion of monocytes through the endothelial wall of arteries, and their transformation from macrophages into foam cells. Human THP-1 monocytic cells can be induced to differentiate into macrophages by phorbol myristate acetate (PMA) treatment, and can then be converted into foam cells by exposure to oxidized low-density lipoprotein (oxLDL). To define genes that are specifically expressed during the transformation of macrophages into foam cells, we have performed a subtractive library screening utilizing mRNA isolated from THP-1 macrophages and foam cells. From this analysis, we have identified adipocyte lipid binding protein (ALBP/aP2) as a gene that is highly upregulated in foam cells in response to oxLDL. Furthermore, overexpression the ALBP gene using an adenovirus construct enhanced the accumulation of cholesterol ester in macrophage foam cells, probably due to an increase in transcription since oxLDL enhanced ALBP promoter activity in experiments using a promoter-luciferase reporter gene construct. The induction of ALBP by oxLDL probably involved activation of peroxisome proliferator-activated receptor gamma (PPARgamma) transcription factors, since four different endogenous PPARgamma ligands, including 9-hydroxyoctadecadienoic acid (9-HODE) and 13-hydroxyoctadecadienoic acid (13-HODE), two oxidized lipid components of oxLDL, as well as 15-deoxy-delta12,14 prostaglandin J2 (15d-PGJ2) and retinoic acid (RA), all induced ALBP expression in macrophage/foam cells. Finally, ALBP was found to be highly expressed in vivo in macrophage/foam cells of human atherosclerotic plaques. These observations suggest that oxLDL-mediated increase in ALBP gene expression accelerate cholesterol ester accumulation, and that this is an important component of the genetic program regulating conversion of macrophages to foam cells. The observation that ALBP is readily detected in foam cells in active atherosclerotic lesions implicates a role for ALBP in human vascular disease. The induction of ALPB expression by oxLDL likely involves activation of PPARgamma by components of oxLDL (9-HODE and 13-HODE) that also function as PPARgamma ligands. Our results add to the concern that the clinical use of insulin-sensitizing PPARgamma agonists (i.e. thiazolidinediones) to treat Type 2 Diabetes could exacerbate atherosclerosis, and highlight the need for clinical trials that address this issue.
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PMID:The adipocyte lipid binding protein (ALBP/aP2) gene facilitates foam cell formation in human THP-1 macrophages. 1241 76

In many organisms, normoglycemia is achieved by a tight coupling of nutrient-stimulated insulin secretion in the pancreatic beta-cell (acute insulin response [AIR]) and the metabolic action of insulin to stimulate glucose disposal (insulin action [M]). It is widely accepted that in healthy individuals with normal glucose tolerance, normoglycemia can always be maintained by compensatorily increasing AIR in response to decreasing M (and vice versa). This has been mathematically described by the hyperbolic relationship between AIR and M and referred to as glucose homeostasis, with glucose concentration assumed to remain constant along the hyperbola. Conceivably, glucose is one of the signals stimulating AIR in response to decreasing M. Hypothetically, as with any normally functioning feed-forward system, AIR should not fully compensate for worsening M, since this would remove the stimulus for the compensation. We provide evidence from cross-sectional, longitudinal, and prospective data from Pima Indians (n = 413) and Caucasians (n = 60) that fasting and postprandial glucose concentrations increase with decreasing M despite normal compensation of AIR. For this physiologic adaptation to chronic stress (insulin resistance), we propose to use the term "glucose allostasis." Allostasis (stability through change) ensures the continued homeostatic response (stability through staying the same) to acute stress at some cumulative costs to the system. With increasing severity and over time, the allostatic load (increase in glycemia) may have pathological consequences, such as the development of type 2 diabetes.
Diabetes 2003 Apr
PMID:Glucose allostasis. 1266 59

Documented differences in measures of insulin secretion and action between African Americans and European Americans may be due to either genetic or environmental factors. This study used genetic admixture (ADM), determined from approximately 20 ancestry informative markers, and a questionnaire designed to assess socioeconomic status (SES) to examine potential genetic and environmental contributions to minimal model-derived measures of insulin sensitivity (S(I)), fasting insulin, and the acute insulin response to glucose (AIR(g)) in 125 children residing in Birmingham, Alabama. The study was longitudinal in design and yielded multiple outcome measures on each subject. Mixed models analysis was used to determine if ADM and SES were independently related to S(I), fasting insulin, and AIR(g) after adjusting for confounding factors (pubertal status, adiposity, age) and for repeated testing of individuals. In this cohort, African ADM ranged from 0% (individuals with no markers reflecting African ancestry) to 100% (individuals with all 20 markers reflecting African ancestry). Results indicated that ADM was independently related to S(I) (P < 0.001) and fasting insulin (P < 0.01), with individuals having greater African ADM having a lower S(I) and a higher fasting insulin concentration. Both ADM (P < 0.001) and SES (P < 0.05) were independently related to AIR(g); children with greater African ADM or lower SES had a higher AIR(g), even after adjusting for S(I). These observations suggest that use of ADM can replace assignment of individuals to categorical racial groups; that lower S(I) and higher fasting insulin among African Americans compared with European Americans may have a genetic basis; and that higher AIR(g) among African Americans may be due to both genetic factors and to environmental factors that remain to be identified.
Diabetes 2003 Apr
PMID:Using genetic admixture to explain racial differences in insulin-related phenotypes. 1266 79

Monocyte activation and adhesion to the endothelium play important roles in inflammatory and cardiovascular diseases. These processes are further aggravated by hyperglycemia, leading to cardiovascular complications in diabetes. We have previously shown that high glucose (HG) treatment activates monocytes and induces the expression of tumor necrosis factor (TNF)-alpha via oxidant stress and nuclear factor-kB transcription factor. To determine the effects of HG on the expression of other inflammatory genes, in the present study, HG-induced gene profiling was performed in THP-1 monocytes using cytokine gene arrays containing 375 known genes. HG treatment upregulated the expression of 41 genes and downregulated 15 genes that included chemokines, cytokines, chemokines receptors, adhesion molecules, and integrins. RT-PCR analysis further confirmed that HG significantly increased the expression of monocyte chemoattractant protein-1 (MCP-1), TNF-alpha, beta(2)-integrin, interleukin-1beta, and others. HG treatment increased transcription of the MCP-1 gene, MCP-1 protein levels, and adhesion of THP-1 cells to endothelial cells. HG-induced MCP-1 mRNA expression and monocyte adhesion were blocked by specific inhibitors of oxidant stress, protein kinase C, ERK1/2, and p38 mitogen-activated protein kinases. These results show for the first time that multiple inflammatory cytokines and chemokines relevant to the pathogenesis of diabetes complications are induced by HG via key signaling pathways.
Diabetes 2003 May
PMID:High glucose-induced expression of proinflammatory cytokine and chemokine genes in monocytic cells. 1271 61

Insulin receptor substrate (IRS)-2 plays an important role in insulin signaling and its disruption results in diabetes in mice. In humans, the IRS-2 Gly1057Asp substitution was associated with lower risk of type 2 diabetes in lean individuals, but with a higher risk in obese individuals. To clarify the role of IRS-2 on the development of type 2 diabetes and obesity in Pima Indians, and particularly to investigate whether the effects of the Gly1057Asp polymorphism on metabolism are mediated by obesity, molecular scanning of the gene for mutations was performed and interaction of the polymorphism with obesity was tested. We identified the previously described Gly1057Asp mutation as well as a rare Asp819His mutation and four silent polymorphisms. The effect of the Gly1057Asp mutation on type 2 diabetes and obesity was tested in a large cohort of Pima Indians (n = 998). A subgroup of nondiabetic full-heritage Pima Indians (n = 233) had measurements of body composition, glucose tolerance, insulin action (M), endogenous glucose production (EGP; hyperinsulinemic clamp), acute insulin response (AIR, 25-g intravenous glucose tolerance test, n = 118 normal glucose-tolerant subjects), and percutaneous fat biopsy specimens from the periumbilical region (n = 160). A total of 132 nondiabetic subjects were included in longitudinal analyses. The frequency of the Asp1057 allele was 0.6. In cross-sectional analyses, subjects homozygous for the Asp1057 allele (Asp/Asp) had a higher prevalence of type 2 diabetes than heterozygote individuals and subjects homozygous for the Gly1057 allele (X/Gly, P = 0.04). There was no effect on BMI (P = 0.78) or gene-BMI interaction on the prevalence of type 2 diabetes (P = 0.57). In the nondiabetic subgroup, subjects with Asp/Asp had higher percent body fat (P = 0.01), BMI (P = 0.02), and waist circumference (P = 0.004), but there was no difference in metabolic characteristics (all P > 0.2). However, the relationship between percent body fat and fasting glucose, basal EGP, EGP during the clamp, AIR, and subcutaneous abdominal adipocyte size was significantly different in the Asp/Asp group (P for interaction = 0.02, 0.06, 0.0007, 0.08, and 0.006, respectively) compared with the X/Gly group, suggesting a more detrimental effect of Asp homozygosity on these traits with increasing percent body fat. In longitudinal analyses, among subjects in the upper tertile of change in percent body fat, those with Asp/Asp had a larger increase in fasting and postprandial glycemia and basal EGP and a larger decrease in M and AIR than subjects with X/Gly, independent of change in obesity (all P < 0.05). In conclusion, our findings suggest that the association of homozygosity for the Asp1057 allele in IRS-2 with type 2 diabetes in Pima Indians may be mediated by interaction of the polymorphism with obesity on several diabetes-related traits.
Diabetes 2003 Jun
PMID:Metabolic effects of the Gly1057Asp polymorphism in IRS-2 and interactions with obesity. 1276 68

A 65-year-old woman with diabetes mellitus was hospitalized for heart failure and anemia in August 2001, and recovered with conservative treatment. An endoscopic examination revealed an ulcerative mass located in the duodenal bulb to the 2nd portion. Abdominal CT scan demonstrated tumor involvement in the pancreas head. The diagnosis of a diffuse large B-cell lymphoma, clinical stage IIE, was made by endoscopic biopsy. Although surgical resection of the localized intestinal tumor would have been a common choice for initial treatment, polychemotherapy was selected; the patient had diabetes mellitus and preferred polychemotherapy to surgical operation. Because of bulky intestinal mass, transmural disease and sensitive histological type, standard-dose chemotherapy was considered to include a high risk of intestinal perforation. We performed dose-escalating chemotherapy: A half dose of THP-COP (pirarubicin, cyclophosphamide, vincristine) was given at the start in October 2001, 60% THP-COP as the next cycle, 80% THP-COP as the 3rd cycle and thereafter. Without serious complications of the intestine, she received a total of 6 cycles of chemotherapy and subsequent involved field radiation. There has been no evidence of recurrence of disease 14 months from the start of chemotherapy. When conditions make surgical treatment difficult, dose-escalating chemotherapy in a treatment cycle may be considered as an alternative.
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PMID:[A case of primary malignant lymphoma of the duodenum successfully treated with dose escalating chemotherapy]. 1293 76

The PPAR gamma agonists, thiazolidinediones (TZDs), have anti-inflammatory properties as well as increasing insulin sensitivity. This has widened their therapeutic scope to treat inflammatory diseases such as atherosclerosis in addition to Type 2 Diabetes. TZDs are known to reduce monocyte/macrophage expression of Matrix metalloproteinase (MMP)-9, which is implicated in atherosclerotic plaque destabilization. This study aims to identify other metalloproteinase genes of the ADAM (A Disintegin And Metalloproteinase) and ADAMTS families that are regulated by PPAR gamma or RXR agonists, which are potentially important in type 2 diabetes and/or related atherosclerosis. The synthetic PPAR gamma agonist, GW7845, and the natural agonist 15d-PGJ2, suppressed PMA stimulated MMP-9 in human monocyte-like cells (THP-1) only in the presence of 9-cis-retinoic acid. Quantitative Real-Time PCR showed that this reduction was regulated at the mRNA level. Expression of ADAMs 8, 9, and 17 were increased, and ADAM15 was decreased by stimulation of THP-1 with PMA, although these ADAMs were not regulated by PPAR gamma or RXR agonists. PMA-induced ADAM28 expression was further enhanced by the addition of 9-cis-retinoic acid. ADAMTS4, implicated in rheumatoid arthritis, was expressed in THP-1 cells, and significantly increased after 24 h of PMA stimulation. ADAMTS4 expression was suppressed by both PPAR gamma and RXR agonists and was undetectable when the agonists were combined. Pretreatment of THP-1 cells with the PPAR gamma antagonist, GW9662, suggests that PPAR gamma plays subtly different roles in the regulation of MMP-9, ADAMTS4 and ADAM28 gene expression. These results indicate that PPAR gamma and RXR agonists have complex effects on monocyte metalloproteinase expression, which may have implications for therapeutic strategies.
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PMID:Metalloproteinase expression in PMA-stimulated THP-1 cells. Effects of peroxisome proliferator-activated receptor-gamma (PPAR gamma) agonists and 9-cis-retinoic acid. 1453 4

The transcription factor NF-kappaB (NF-kappaB) plays a pivotal role in regulating inflammatory gene expression. Its effects are optimized by various coactivators including histone acetyltransferases (HATs) such as CBP/p300 and p/CAF. Evidence shows that high glucose (HG) conditions mimicking diabetes can activate the transcription of NF-kappaB-regulated inflammatory genes. However, the underlying in vivo transcription and nuclear chromatin remodeling events are unknown. We therefore carried out chromatin immunoprecipitation (ChIP) assays in monocytes to identify 1) chromatin factors bound to the promoters of tumor necrosis factor-alpha (TNF-alpha) and related NF-kappaB-regulated genes under HG or diabetic conditions, 2) specific lysine (Lys (K)) residues on histone H3 (HH3) and HH4 acetylated in this process. HG treatment of THP-1 monocytes increased the transcriptional activity of NF-kappaB p65, which was augmented by CBP/p300 and p/CAF. ChIP assays showed that HG increased the recruitment of NF-kappaB p65, CPB, and p/CAF to the TNF-alpha and COX-2 promoters. Interestingly, ChIP assays also demonstrated concomitant acetylation of HH3 at Lys(9) and Lys(14), and HH4 at Lys(5), Lys(8), and Lys(12) at the TNF-alpha and COX-2 promoters. Overexpression of histone deacetylase (HDAC) isoforms inhibited p65-mediated TNF-alpha transcription. In contrast, a HDAC inhibitor stimulated gene transcription and histone acetylation. Finally, we demonstrated increased HH3 acetylation at TNF-alpha and COX-2 promoters in human blood monocytes from type 1 and type 2 diabetic subjects relative to nondiabetic. These results show for the first time that diabetic conditions can increase in vivo recruitment of NF-kappaB and HATs, as well as histone acetylation at the promoters of inflammatory genes, leading to chromatin remodeling and transcription.
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PMID:In vivo chromatin remodeling events leading to inflammatory gene transcription under diabetic conditions. 1497 18

beta-Cell replacement in diabetes using pancreatic islets or beta-cell surrogates is a research area undergoing intense scrutiny. Once this approach is demonstrated to be reproducibly successful, the next major issue will be the length of time that success will be sustained. Whole and segmental pancreas transplants are now successful for up to two decades. Study of these grafts can provide insight into and predictions about beta-cell function and reserve when islet transplantation becomes a routine. The studies described herein investigated 102 human whole and segmental transplant recipients and control subjects to address the following five questions. 1) Is the usual reciprocal relationship between the acute insulin response to intravenous glucose (AIR(gluc)) and the level of fasting plasma glucose (FPG) maintained in pancreas transplant recipients? 2) Do recipients who have no AIR(gluc) have an acute insulin response to intravenous arginine (AIR(arg))? 3) Do recipients of whole pancreata from cadaveric donors have twice the amount of insulin secretory reserve as that found in recipients of 50% segmental grafts from living, related donors? 4) What clinically accessible measure of insulin secretion best correlates with glucose potentiation of arginine-induced insulin secretion (GPAIS)? 5) Do successful pancreas transplant recipients evince time-dependent declines in beta-cell function and glycemic regulation when studied long term and longitudinally? The results demonstrate that 1) the normal relationship between AIR(gluc) and fasting glucose levels is maintained despite systemic venous drainage of allografts and consequent hyperinsulinemia; 2) AIR(gluc) and AIR(arg) decrease in parallel as fasting glucose levels rise, although AIR(arg) is still present after AIR(gluc) disappears; 3) AIR(arg) and AIR(gluc) are strongly predictive of beta-cell mass; 4) AIR(arg) and AIR(gluc) are strongly predictive of insulin secretory reserve; and 5) transplant recipients who have successfully maintained normoglycemia for an average of 10 years and up to 22 years nonetheless experience time-related declines in beta-cell function.
Diabetes 2004 Mar
PMID:Consequences on beta-cell function and reserve after long-term pancreas transplantation. 1498 47

The cyclooxygenase (COX)-2 enzyme has been implicated in the pathogenesis of several inflammatory diseases. However, its role in diabetic vascular disease is unclear. In this study, we evaluated the hypothesis that diabetic conditions can induce COX-2 in monocytes. High glucose treatment of THP-1 monocytic cells led to a significant three- to fivefold induction of COX-2 mRNA and protein expression but not COX-1 mRNA. High glucose-induced COX-2 mRNA was blocked by inhibitors of nuclear factor-kappaB (NF-kappaB), protein kinase C, and p38 mitogen-activated protein kinase. In addition, an antioxidant and inhibitors of mitochondrial superoxide, NADPH oxidase, and glucose metabolism to glucosamine also blocked high glucose-induced COX-2 expression to varying degrees. High glucose significantly increased transcription from a human COX-2 promoter-luciferase construct (twofold, P < 0.001). Promoter deletion analyses and inhibition of transcription by NF-kappaB superrepressor and cAMP-responsive element binding (CREB) mutants confirmed the involvement of NF-kappaB and CREB transcription factors in high glucose-induced COX-2 regulation. In addition, isolated peripheral blood monocytes from type 1 and type 2 diabetic patients had high levels of COX-2 mRNA, whereas those from normal volunteers showed no expression. These results show that high glucose and diabetes can augment inflammatory responses by upregulating COX-2 via multiple signaling pathways, leading to monocyte activation relevant to the pathogenesis of diabetes complications.
Diabetes 2004 Mar
PMID:Molecular mechanisms of high glucose-induced cyclooxygenase-2 expression in monocytes. 1498 66


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