CiteULike: jyuh's Tone

Clinical features of non-diabetic renal diseases in patients with type 2 diabetes.

A Tone — 2008-07-06T16:09:18-00:00

Diabetes research and clinical practice, Vol. 69, No. 3. (September 2005), pp. 237-242.

Although persistent proteinuria is characteristic of diabetic nephropathy (DN), it is important to differentiate non-diabetic renal diseases (NDRD) in diabetic patients with proteinuria. In order to re-evaluate the indications for renal biopsy in the diabetic patients, we retrospectively analyzed the relationship between clinical features and histological diagnosis in 97 Japanese patients with type 2 diabetes manifesting overt proteinuria. Renal biopsy was performed because they were clinically suspected to have NDRD. Patients were divided into three groups according to the histological diagnosis: (1) the DN group (n=35) had only diabetic lesions, (2) the complicated group (n=16) had histological changes of NDRD superimposed on DN and (3) the non-DN group (n=46) had NDRD without diabetic lesions. We evaluated the specificity and sensitivity of four clinical parameters (duration of diabetes, presence or absence of diabetic retinopathy, microscopic hematuria and granular casts as urinary sediments) for the prediction of NDRD. Short duration of diabetes (<5 years) showed high sensitivity (75%) and specificity (70%). Diabetic retinopathy showed the highest sensitivity (87%) and specificity (93%). The sensitivity and specificity of microscopic hematuria (56 and 58%) and granular casts (68 and 47%) were lower. Our study confirmed that the absence of retinopathy and short duration of diabetes are useful clinical indications for renal biopsy in diabetic patients with overt proteinuria.

Smad3 and NFAT cooperate to induce Foxp3 expression through its enhancer

Yukiko Tone — 2008-01-19T06:11:54-00:00

Nature Immunology, Vol. 9, No. 2. (23 December 2007), pp. 194-202.

Methotrexate prevents renal injury in experimental diabetic rats via anti-inflammatory actions.

K Yozai — 2008-01-14T15:30:44-00:00

J Am Soc Nephrol, Vol. 16, No. 11. (November 2005), pp. 3326-3338.

Recent studies suggested the involvement of inflammatory processes in the pathogenesis of diabetic nephropathy. Methotrexate (MTX), a folic acid antagonist, is widely used for the treatment of inflammatory diseases. Recently, it has been shown that treatment with low-dose MTX reduces the cardiovascular mortality in patients with rheumatoid arthritis, suggesting that MTX has anti-atherosclerotic effects via its anti-inflammatory actions. This study was designed to determine the anti-inflammatory effects of this agent on diabetic nephropathy. Diabetes was induced in Sprague-Dawley rats with streptozotocin, and MTX (0.5 or 1.0 mg/kg) was administered once a week for 8 wk. Treatment with MTX reduced urinary albumin excretion, mesangial matrix expansion, macrophage infiltration, expression of TGF-beta and type IV collagen, and intercellular adhesion molecule-1 in glomeruli. MTX also reduced the high glucose-induced NF-kappaB activation in vitro and in vivo. The results indicate that intermittent administration of MTX prevented renal injuries without changes in blood glucose level and BP in experimental diabetic rats. The protective effects of MTX are suggested to be mediated by its anti-inflammatory actions through inhibition of NF-kappaB activation and consequent reduction of intercellular adhesion molecule-1 expression and macrophage infiltration. The results suggest that anti-inflammatory agents might be beneficial for the treatment of diabetic nephropathy.

Erythromycin ameliorates renal injury via anti-inflammatory effects in experimental diabetic rats.

A Tone — 2008-01-14T15:08:36-00:00

Diabetologia, Vol. 48, No. 11. (November 2005), pp. 2402-2411.

AIMS/HYPOTHESIS: Recent studies have shown that the inflammatory process is involved in the pathogenesis of diabetic nephropathy. Fourteen-membered ring macrolides, including erythromycin, have anti-inflammatory, as well as antibacterial effects. The aim of this study was to investigate the renoprotective effects of erythromycin in streptozotocin (STZ)-induced diabetic rats. METHODS: STZ-induced diabetic rats were treated orally with erythromycin (5 mg/kg body weight) or vehicle every day for 8 weeks. To evaluate the effect of erythromycin treatment, we measured urinary albumin excretion, and examined the following in the kidney: histological changes, the expression of intercellular adhesion molecule-1 (ICAM-1), macrophage infiltration, and nuclear factor-kappa B (NF-kappaB) activity. RESULTS: Erythromycin significantly reduced urinary albumin excretion without affecting blood glucose levels and blood pressure. Erythromycin also attenuated glomerular hypertrophy, mesangial expansion, macrophage infiltration and ICAM-1 expression in renal tissues. The expression of the gene encoding TGFB1 (also known as TGF-beta1), type IV collagen protein production and NF-kappaB activity in renal tissues were increased in diabetic rats and reduced by erythromycin treatment. CONCLUSIONS/INTERPRETATION: Erythromycin prevented renal injuries without changes of blood glucose levels and blood pressure in experimental diabetic rats. These results suggest that the renoprotective effects of erythromycin are based on its anti-inflammatory effect via suppression of NF-kappaB activation. Modulation of microinflammation with erythromycin may provide a new approach for diabetic nephropathy.

Macrophage scavenger receptor-a-deficient mice are resistant against diabetic nephropathy through amelioration of microinflammation.

HK Usui — 2007-10-21T14:14:11-00:00

Diabetes, Vol. 56, No. 2. (February 2007), pp. 363-372.

Microinflammation is a common major mechanism in the pathogenesis of diabetic vascular complications, including diabetic nephropathy. Macrophage scavenger receptor-A (SR-A) is a multifunctional receptor expressed on macrophages. This study aimed to determine the role of SR-A in diabetic nephropathy using SR-A-deficient (SR-A(-/-)) mice. Diabetes was induced in SR-A(-/-) and wild-type (SR-A(+/+)) mice by streptozotocin injection. Diabetic SR-A(+/+) mice presented characteristic features of diabetic nephropathy: albuminuria, glomerular hypertrophy, mesangial matrix expansion, and overexpression of transforming growth factor-beta at 6 months after induction of diabetes. These changes were markedly diminished in diabetic SR-A(-/-) mice, without differences in blood glucose and blood pressure levels. Interestingly, macrophage infiltration in the kidneys was dramatically decreased in diabetic SR-A(-/-) mice compared with diabetic SR-A(+/+) mice. DNA microarray revealed that proinflammatory genes were overexpressed in renal cortex of diabetic SR-A(+/+) mice and suppressed in diabetic SR-A(-/-) mice. Moreover, anti-SR-A antibody blocked the attachment of monocytes to type IV collagen substratum but not to endothelial cells. Our results suggest that SR-A promotes macrophage migration into diabetic kidneys by accelerating the attachment to renal extracellular matrices. SR-A may be a key molecule for the inflammatory process in pathogenesis of diabetic nephropathy and a novel therapeutic target for diabetic vascular complications.