Isao Uchimura

The Effect of Glucose and Advanced Glycosylation End Products on IL‐6 Production by Human Monocytes

To clarify the mechanism that causes elevation of plasma fibrinogen levels in diabetes, we examined the effect of high concentration of glucose and/or advanced glycosylation end products (AGEs) on the production of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) by human monocytes. Monocytes isolated from nine healthy volunteers were incubated with glucose, glucose with mannitol, or glucose with AGE-BSA for 24 or 48 h, respectively. IL-6 and TNF-alpha levels of culture supernatants were measured by ELISA methods. IL-6 and TNF-alpha levels of culture supernatants incubated with 22 mM or 33 mM glucose showed considerable increase over basal levels incubated with 11 mM glucose, whereas those levels incubated with high concentration of mannitol showed no increase. These two cytokine levels of culture supernatants, especially IL-6 level, showed synergistic elevation with AGE-BSA concentration. Our serial observation with treatment for lowering glucose levels showed that the diabetics with decreasing plasma fibrinogen levels also showed decrease in plasma IL-6 levels. In this study, we revealed the effect of glucose and AGEs on the production of IL-6 or TNF-alpha by human monocytes. These results suggest that hyperglycemia and AGEs will cause disregulated production of IL-6 and hyperfibrinogenemia in diabetics.

Expression of transcriptional repressor ATF3/LRF1 in human atherosclerosis: colocalization and possible involvement in cell death of vascular endothelial cells

Vascular endothelial cell death contributes to the progression of atherosclerotic lesion, and several transcriptional regulators are involved in the process. Activating transcription factor 3/liver regenerating factor-1 (ATF3/LRF-1), a stress-inducible transcriptional repressor, was shown to be highly expressed in vascular endothelial cells and macrophages of human atherosclerotic lesions by immunohistological assay. The expression was colocalized in these cells which were positive for TdT-mediated dUTP nick-end labeling (TUNEL) and annexin V. Treatment of human umbilical vein endothelial cells (HUVECs) by tumor necrosis factor (TNF)-alpha, oxidized low density lipoprotein (oxLDL), and lysophosphatidylcholine (LPC) rapidly induced ATF3/LRF-1, which showed an increased DNA binding to the consensus ATF/CRE sequence by supershift of gel shift assay. Flow cytometry analysis and immunostaining analysis with TUNEL assay showed that ATF3/LRF-1 was highly expressed in cell death induced by these agents. Moreover, antisense ATF3/LRF-1 cDNA partly suppressed the cell death induced by TNF-alpha, oxLDL, and LPC. From these results, it is indicated that ATF3/LRF-1 is one of the immediate early response genes in vascular endothelial cells in response to atherogenic stimuli, and may play a role in the endothelial cell death associated with atherogenesis.

Multi-center intervention study on glycohemoglobin (HbA1c) and serum, high-sensitivity CRP (hs-CRP) after local anti-infectious periodontal treatment in type 2 diabetic patients with periodontal disease

The purpose of this study was to examine whether periodontal treatment incorporating topical antibiotic therapy affects on levels of glycohemoglobin (HbA1c) and serum high-sensitivity C-reactive protein (hs-CRP) in type 2 diabetic patients with periodontal disease, and to explore the relationship between CRP and glycemic control. The whole intervention group (n=32), which underwent anti-infectious periodontal treatment, showed only transient reduction in HbA1c levels without any change in hs-CRP, while the control group (n=17) did not show any changes in HbA1c or hs-CRP. Multiple regression analysis of all subjects revealed that BMI and change in hs-CRP correlated significantly with the reduction of HbA1c at 6 months after the periodontal treatment. Based on the results of multiple regression analysis, the intervention group was subdivided into two groups: those in which hs-CRP levels decreased (CRP-D group), and those in which hs-CRP levels unchanged or increased (CRP-N group) (n=16, respectively), and re-analysis was conducted based upon these subgroups. In the CRP-D subgroup, HbA1c was significantly reduced at the end of the study, but it did not decrease in the CRP-N subgroup. The decrease of HbA1c in the CRP-D subgroup following periodontal treatment was significantly greater than that in the CRP-N subgroup. BMI of each group remained unchanged in this study at the end of the study. Thus, the results suggested that periodontal treatment with topical antibiotics improves HbA1c through reduction of CRP, which may relate to amelioration of insulin resistance, in type 2 diabetic patients with periodontal disease.

Dielectric coagulometry: a new approach to estimate venous thrombosis risk.

We present dielectric coagulometry as a new technique to estimate the risk of venous thrombosis by measuring the permittivity change associated with the blood coagulation process. The method was first tested for a simple system of animal erythrocytes suspended in fibrinogen solution, where the coagulation rate was controlled by changing the amount of thrombin added to the suspension. Second, the method was applied to a more realistic system of human whole blood, and the inherent coagulation process was monitored without artificial acceleration by a coagulation initiator. The time dependence of the permittivity at a frequency around 1 MHz showed a distinct peak at a time that corresponds to the clotting time. Our theoretical modeling revealed that the evolution of heterogeneity and the sedimentation in the system cause the peak of the permittivity.

Remnant‐like Particles and Restenosis of Coronary Arteries after PTCA

We developed a simple and rapid assay method for the determination of remnantlike particles (RLP) using an immunoaffinity gel mixture of monoclonal antibody (Mab) to apolipoprotein (apo) B-100 with unique binding properties and Mab to A-I.’ The epitope of the Mab to apo B-100 is situated beyond the C-terminus of apo-48. The immunoaffinity mixed gels adsorb lipoproteins containing apo A-I as well as most lipoproteins containing apo B-100. RLP are the unbound particles to both antibodies. RLP were shown to consist mainly of lipoproteins of VLDL size and to be enriched in apo E and cholesteryl ester.‘ These characteristics are consistent with those described for remnants of triglyceride-rich lipoproteins.2 We showed high values of RLP in patients with coronary heart disease (CHD).’ Remnants of triglyceride-rich lipoproteins are taken up very rapidly into the liver by receptordependent mechanisms involving apo E.3 However, it is unlikely that the unbound particles are subject to such efficient uptake, at least in patients with CHD. We thus designated the unbound particles as “remnant like” based upon their physical and chemical properties.2 We investigated the relationship between RLP and restenosis of coronary artery after PTCA.

Periodontal treatment with topical antibiotics improves glycemic control in association with elevated serum adiponectin in patients with type 2 diabetes mellitus.

OBJECTIVES Chronic inflammation of periodontitis aggravates glycemic control in type 2 diabetic patients through aggravation of insulin resistance. Increased or decreased release of various inflammatory mediators, such as high sensitivity C-reactive protein (hs-CRP), tumor necrosis factor (TNF)-α, interleukin (IL)-6 and adipokines, such as adiponectin, leptin, and resistin, are presumed to be responsible for developing and progressing insulin resistance. The purpose of this study was to examine the effects of periodontal treatment on glycemic control, serum inflammatory mediators and adipokines in type 2 diabetes patients with periodontitis. METHODS Twenty-one type 2 diabetic patients with periodontitis received periodontal treatment with topical antibiotics (intervention group) and 8 patients did not receive periodontal treatment (control group). Periodontal examination, including probing pocket depth (PPD) and bleeding on probing (BOP), and blood sampling were performed at baseline, 2 and 6 months after periodontal treatments. Glycated hemoglobin (HbA1c), hs-CRP, TNF-α, IL-6, adiponectin, leptin, and resistin were analyzed. RESULTS In the intervention group, improvements of PPD and BOP, decrease in HbA1c and elevation of serum adiponectin were observed, while in the control group, all parameters were not changed. Generalized linear model revealed that changes of serum adiponectin and TNF-α and change of BOP correlated significantly with the reduction of HbA1c at 6 months after periodontal treatments. CONCLUSION The results demonstrated that periodontal treatment improves periodontal status and glycemic control with elevation of serum adiponectin in type 2 diabetic patients. The results suggest that HbA1c is reduced by amelioration of insulin resistance due to elevated serum adiponectin after periodontal treatments.

Improvement of glycemic control after periodontal treatment by resolving gingival inflammation in type 2 diabetic patients with periodontal disease.

Aims/Introduction:  Chronic inflammation aggravates glycemic control in patients with type 2 diabetes mellitus. An increase or decrease in the release and activities of various inflammatory mediators, such as tumor necrosis factor (TNF)‐α, interleukin (IL)‐6, and C‐reactive protein (CRP), are presumed to be responsible for inducing insulin resistance. The purpose of the present study was to examine the effects of non‐surgical periodontal treatment incorporating topical antibiotics on glycemic control and serum inflammatory mediators in patients with type 2 diabetes mellitus with periodontitis.

Production of Interleukin-6 Induced by Hypoxia Linked to Peripheral Arterial Disease

Patients with peripheral arterial disease (PAD) show a high mortality rate mainly due to cardiac di~ease.l-~ Fibrinogen is a major risk factor for cardiovascular disea~e.43~ Elevated fibrinogen levels have been proposed to cause cardiac event^.^ An elevated fibrinogen level was found to enhance the progression of atherosclerosis and was associated with an increased risk for thromboembolic events. Fibrinogen is mainly induced by interleukin 6 (IL-6).6 IL-6, a cytokine, is thought to mediate host-defense systems, especially during the acute-phase responses. It is the most potent stimulator of acute-phase protein synthesis in hepatocyte~.~ IL-6 is secreted from fibroblasts,* endothelial cells? mononuclear cells,1° and rat myocytes.” Although high serum IL-6 values have been reported in patients with bacterial infection,12 sepsis,13 rheumatoid arthritis,14 cardiac myxoma,I5 as well as autoimmune diseases,I6 patients with peripheral arterial disease have not been studied in this respect. Various factors stimulate IL-6 production. They include interleukin-1 (ILl),I7 tumor necrotizing factor (TNF),I* lipopoly~accharide,’~ and viral infections.12 No study has investigated the influence of these factors on IL-6 during PAD. In this study, we investigated the relationship between IL-6 and PAD in symptomatic patients. We incubated peripheral mononuclear cells under normal and hypoxic conditions and assessed IL-6 mRNA levels by using RT-PCR.

The number of microvascular complications is associated with an increased risk for severity of periodontitis in type 2 diabetes patients: Results of a multicenter hospital-based cross-sectional study

To explore the relationships between periodontitis and microvascular complications as well as glycemic control in type 2 diabetes patients.

Effect of circulating tissue factor on hypercoagulability in type 2 diabetes mellitus studied by rheometry and dielectric blood coagulometry

Background: Hypercoagulability in type 2 diabetes mellitus (T2DM) patients increases their risk of cardiovascular diseases. Objective: The aim of this work was to investigate the hypercoagulation mechanism in T2DM patients in terms of circulating tissue factor (TF). Methods: Whole blood coagulation tests by damped oscillation rheometry and dielectric blood coagulometry (DBCM) were performed. Results: The average coagulation time was significantly shorter for T2DM patients than for healthy controls. In vitro addition of either anti-TF or anti-activated factor VII (FVIIa) antibody to hypercoagulable blood samples prolonged coagulation times for one group of patients, while coagulation times remained short for another group. The levels of circulating TF were estimated in the former group by measuring the coagulation times for blood samples from healthy subjects with addition of various concentrations of TF and comparing them with the coagulation times for the group. The results indicated that the levels of circulating TF were on the order of subpicomolar at most. Conclusions: Circulating TF is at least partially responsible for a hypercoagulable group of T2DM patients, while an abnormality in the intrinsic coagulation pathway probably occurs in the other group.