Yukiteru Asakimori

T-786→C Polymorphism of the Endothelial Nitric Oxide Synthase Gene Influences the Progression of Renal Disease

Background/Aims: Polymorphism of the endothelial nitric oxide synthase (ecNOS) gene may be involved in renal disease. Recently, T-786→C polymorphism affecting ecNOS gene transcription has been reported. To clarify the role of T-786→C polymorphism in renal disease, we investigated hemodialysis patients and healthy controls for this polymorphism and we compared its frequency with that of intron 4 polymorphism in the hemodialysis patients. Methods: The subjects were 252 patients who had been on hemodialysis for less than 2 years (168 with nondiabetic nephropathy and 84 with diabetic nephropathy) and 187 healthy controls. T-786→C polymorphism was detected using polymerase chain reaction-restriction fragment length polymorphism analysis. Results: The frequencies of the T/C and C/C genotypes were significantly higher in the nondiabetic hemodialysis patients than in the controls (odds ratio 1.41; 95% Cl 1.03–2.00), and were also significantly higher in the diabetic hemodialysis patients than in the controls (odds ratio 1.56; 95% Cl 1.02–2.41). In addition, T-786→C polymorphism and intron 4 polymorphism showed strong linkage disequilibrium. Conclusion: T-786→C polymorphism may be involved in the progression of both nondiabetic and diabetic nephropathy, along with intron 4 polymorphism.

Endothelial nitric oxide synthase intron 4 polymorphism influences the progression of renal disease

Background/Aim: Nitric oxide is a potent regulator of intrarenal hemodynamics and may influence the renal function. We investigated whether polymorphism of intron 4 of the endothelial constitutive nitric oxide synthase (ecNOS) gene is related to the progression of chronic renal failure. Methods: Polymorphism of ecNOS intron 4 was studied in 1,005 hemodialysis patients (710 with nondiabetic nephropathy and 295 with diabetic nephropathy) and was compared with the findings in 189 healthy subjects. ecNOS genotypes were determined by the polymerase chain reaction, followed by agarose gel electrophoresis. Results: The frequencies of ecNOS4a/a, ecNOS4a/b, and ecNOS4b/b genotypes were, respectively, 0% (0/189), 13.8% (26/189), and 86.2% (163/189) in the control group; 1.7% (12/710), 22.1% (157/710), and 76.2% (541/710) in the nondiabetic nephropathy group, and 1.0% (3/295), 22.7% (67/295), and 76.3% (225/295) in the diabetic nephropathy group. The frequency of ecNOS4a (ecNOSa/a and ecNOSa/b) was significantly higher in both the nondiabetic group and in the diabetic group than in the controls (p = 0.0025 and p = 0.0438, respectively). Conclusion: There was a significantly higher frequency of the a allele of intron 4 in both nondiabetic and diabetic hemodialysis patients, so the polymorphism of intron 4 of the ecNOS gene may have a wide influence on the progression of renal disease.

Effect of polymorphism of the endothelial nitric oxide synthase and apolipoprotein E genes on carotid atherosclerosis in hemodialysis patients.

BACKGROUND Decreased synthesis of nitric oxide (NO) and dyslipidemia are implicated in the development of atherosclerosis. METHODS We investigated the relationship between endothelial NO synthase (eNOS) gene polymorphism, apolipoprotein E (apoE) polymorphism, and carotid atherosclerosis in 163 hemodialysis patients with nondiabetic nephropathy. Intima media thickness of the carotid artery was measured by ultrasonography, and subjects were classified according to the presence or absence of carotid plaque. Multivariate odds ratios were calculated to assess the combined influence of several variables on the existence of carotid plaque, with clinical factors, the intron 4 polymorphism, T(-786)-->C polymorphism, and Glu298Asp polymorphism of eNOS and the apoE polymorphism tested as independent predictors. We also investigated the combined effect of these polymorphisms on risk for plaque. RESULTS The odds ratio for carotid plaque positivity was increased to 3.72 by the a allele of the intron 4 polymorphism and increased to 3.36 by the C allele of the T(-786)-->C polymorphism, but was not increased in subjects with the T allele of the Glu298Asp polymorphism or those with the epsilon4 allele of the apoE polymorphism. However, the odds ratio for plaque positivity was significantly increased to 4.00 by possession of the a allele and/or epsilon4 allele and also increased to 4.04 by the C allele and/or epsilon4 allele. CONCLUSION This cross-sectional study showed a synergistic effect between the intron 4 polymorphism or T(-786)-->C polymorphism of the eNOS gene and the apoE polymorphism with respect to risk for carotid atherosclerosis in nondiabetic hemodialysis patients.

Localization of Transforming Growth Factors ß1 and ß2 and Epidermal Growth Factor in IgA Nephropathy

OBJECTIVE The localization of transforming growth factor (TGF)-beta1. TGF-beta2 and epidermal growth factor (EGF) was investigated in IgA nephropathy, and was compared with the severity of histological damage (including tubulointerstitial lesions). MATERIALS AND METHODS The enzyme antibody method was used to stain paraffin-embedded sections of renal tissue from 42 patients with IgA nephropathy (19 males and 23 females). RESULTS There was a significant correlation between glomerular positivity for TGF-beta1 and TGF-beta2 and the severity of histological damage. There was also a significant correlation between positivity for TGF-beta1 and TGF-beta2 in the tubular epithelium and tubulointerstitial lesions. In contrast, there was no relationship between glomerular positivity for EGF and histological damage, although there was a significant correlation between positivity for EGF in the tubular epithelium and tubulointerstitial lesions. CONCLUSIONS These findings suggest that TGF-beta1 and TGF-beta2 may be important in the progression of IgA nephropathy, and that the distribution of EGF may also be a useful marker for the progression of renal damage, including tubulointerstitial lesions.

Effect of Glucose polymer on the intercellular junctions of cultured human peritoneal mesothelial cells

Background: Glucose polymer is an active osmotic agent that is increasingly used as an alternative to glucose in peritoneal dialysis fluids. It was recently reported that the duration of peritoneal dialysis can be extended by using glucose polymer in patients with poor ultrafiltration. We previously demonstrated that high glucose levels damage the intercellular junctions of cultured human peritoneal mesothelial cells (HPMC), but little is known about the influence of glucose polymer. Therefore, we investigated the effects of glucose polymer on the intercellular junctions of HPMC. Methods: HPMC were isolated, cultured, and identified according to the modified method of Stylianou. M199 medium was supplemented with peritoneal dialysis solutions containing 7.5% glucose polymer or 1.5, 2.5, and 4.25% glucose. After 6 h, cell viability was assessed, intercellular junction proteins were examined by immunofluorescence techniques, and the concentration of transforming growth factor-β1 in the culture supernatant was determined. Results: Glucose significantly suppressed cell viability and significantly increased transforming growth factor-β1 production when compared with control or glucose polymer cultures. Peritoneal dialysis solutions containing 4.25% glucose caused the detachment of HPMC. Immunofluorescence of intercellular junction proteins (tight junctions: ZO-1, occludin, and claudin-1; adherens junctions: β-catenin) became weak and uneven after culture with glucose. On the other hand, glucose polymer caused little change in the immunofluorescence of these proteins when compared with control cultures. Conclusions: Glucose polymer seems to be less toxic to HPMC than glucose itself, suggesting that the glucose polymer may be better for peritoneal dialysis.

Bone mineral density may be related to atherosclerosis in hemodialysis patients

Biological interactions between the bone and the blood vessels are gradually being clarified. To investigate the relationship between bone mineral density and atherosclerosis in hemodialysis patients, we examined the bone mineral density and the intima-media thickness of the carotid artery in 83 dialysis patients with non-diabetic nephropathy (44 men and 39 women) aged from 23 to 83 years. The duration of hemodialysis ranged from 2 to 344 months. The bone mineral density of the radius was measured by dual-energy X-ray adsorptiometry, and the ratio of this value to the standard value for the same age and gender was calculated (Z-score). As an index of atherosclerosis, the intima-media thickness of the carotid artery was measured by high resolution B-mode ultrasonography. Then the relationship between the Z-score and various factors was examined using Spearmans rank correlation analysis and multiple regression analysis. The Z-score showed a negative correlation with the duration of hemodialysis, the carotid intima-media thickness, and the levels of alkaline phosphatase, intact parathyroid hormone, and low-density lipoprotein cholesterol by Spearmans rank correlation analysis. In addition, the Z-score showed a positive correlation with the lipoprotein (a) level and a negative correlation with the duration of hemodialysis, intima-media thickness, intact parathyroid hormone, and low-density lipoprotein cholesterol by multiple regression analysis. These findings suggest that the decrease of bone mineral density in hemodialysis patients is correlated with secondary hyperparathyroidism and hyperlipidemia, which are factors known to promote atherosclerosis, and thus bone density changes might be related to the progression of atherosclerosis, or vice versa.

Reiter's syndrome associated with HLA-B51: a case report.

A 32-year-old Japanese man developed polyarthritis with mild fever and conjunctivitis. Clinical assessment indicated non-specific arthritis, aseptic pyuria induced by infection with Chlamydia, and conjunctivitis. He was diagnosed with reactive arthritis (Reiters syndrome). Serotyping of human leucocyte antigen (HLA) class I and II revealed positivity for B51(5), A2, A33(19), B44(12), Cw1, DR4 and DR6, but B27 was negative. He was treated with a combination of doxycycline, oral prednisolone, diclofenac sodium and salazosulphapyridine. Fever and arthralgia improved and he became negative for anti-Chlamydia immunoglobulin (Ig) A and IgG antibodies. HLA-B51 may be involved in the pathogenesis of Reiters syndrome in this Japanese patient.

INTERMEDIATE-DENSITY LIPOPROTEIN IS A DNA SYNTHESIS STIMULATION FACTOR IN CULTURED HUMAN MESANGIAL CELLS

Noriaki Yorioka, MD, 2nd Department of Internal Medicine, Hiroshima University School of Medicine, 1-2-3 Kasumi, Minami-ku, Hiroshima City 734 (Japan) Dear Sir, Based on the hypothesis of Moorhead et al. [1], abnormalities of the lipid metabolism are now considered aggravating factors for glomerulonephritis. Low-density lipoprotein (LDL), a cholesterol-rich lipoprotein, attracted attention, initially, and many reports appeared on LDL as a proliferation factor in cultured mesangial cells [2-4]. The presence of LDL receptors and scavenger receptors in mesangial cells has been proved [3, 4], and the uptake of LDL by mesangial cells has been confirmed using an isotopebinding method and the fluorescent antibody technique [3, 5, 6]. It is also known that mesangial cells, with incorporated LDL, secrete various chemical mediators and alter the mesangial microen-vironment [7]. For example, there are reports on the expression of messenger RNA of growth factors and cytokines such as platelet-derived growth factor [2] and macro-phage chemoattractant protein 1 [8], extracellular matrix such as fibronectin [8] and type IV collagen [9], and eicosanoids such as PG-E2 [4] from mesangial cells when stimulated with LDL or oxidized LDL. A cyto-toxic effect of oxidized LDL on mesangial cells and the mechanism of progression to glomerulosclerosis due to this cytotoxicity have been proposed [7, 10]. However, no reports have appeared, as yet, on the action of the triglyceride-rich intermediate-density lipoprotein (IDL) on the mesangial cells. Therefore, we observed the effects on DNA synthesis in mesangial cells stimulated by IDL. The method involved isolation and culture of human mesangial cells as previously 1,400 g 1,200 o 1,000 600 400 200 5 10 50 100 500 1,000 IDL (μg/ml)

Direct infusion of ascites into the blood circuit during hemodiafiltration in uremic patients with cirrhosis.

Two chronic dialysis patients with massive ascites caused by cirrhosis were treated by infusion of their ascites directly into the blood circuit. This stabilized their hemodynamics during dialysis, facilitating the control of weight gain and ascites, and thus markedly improving their general condition. Long-term use of this therapy was able to prevent the accumulation of ascitic fluid. Interestingly, fever occurred when this therapy was performed with hemodialysis, but not with hemofiltration or hemodiafiltration, suggesting that a pyrogen in the ascites was removed by filtration.

HLA typing of a family with nephronophthisis-medullary cystic disease complex

A 25-year-old man developed renal dysfunction and his family showed autosomal dominant inheritance of endstage renal disease. The proband had trace albuminuria and a slightly raised serum creatinine level. Renal biopsy showed tubulointerstitial nephritis, which was compatible with the nephronophthisis-medullary cystic disease complex (N-MCD). His older brother (aged 31 years) had progressed to endstage renal failure by the age of 23 years after renal biopsy revealed N-MCD when he was 20 years old. Human leukocyte-associated (HLA) antigen typing was performed for the proband, the older brother, the mother (who showed endstage renal failure at the age of 50 years), and the sister (who showed no signs of renal disease at the age of 28 years). The HLA loci A24(9), B62(15), and DR2 were common to all 4 family members, while Cw1 was only found in the 3 with renal disease. These findings suggested the possible participation of the Cw1 locus in autosomal dominant N-MCD.