Neutrophil-lymphocyte ratio correlates with limited joint mobility of hand in patients with type 2 diabetes.

Limited joint mobility (LJM) of hand, which is one of the complications of diabetic hand, is associated with diabetic micro- and macroangiopathy although the precise pathogenesis is not completely understood. Neutrophil-lymphocyte ratio (NLR), a simple and novel inflammatory marker, has been reported to have a predictive effect to some diabetic complications in recent years. However, it is not elucidated about the relationship between LJM of hand and NLR in patients with type 2 diabetes. We evaluated the relationships between LJM of hand and NLR in 335 consecutive patients with type 2 diabetes in this cross-sectional study. LJM of hand was diagnosed by a 'prayer sign' or 'table test'. LJM of hand was present in 80 patients. The patients with LJM of hand had significantly older age, longer duration of diabetes, worse renal function, and higher proportion of diabetic neuropathy, retinopathy and nephropathy. NLR in patients with LJM of hand was higher than that in patients without LJM of hand (2.54 ± 1.46 vs. 2.11 ± 1.04, p = 0.004). Multivariate logistic regression analysis revealed that LJM of hand was positively correlated with NLR (odds ratio, 1.31; 95% confidence interval 1.03-1.69, p = 0.027) after adjustment for age, sex, duration of diabetes, body mass index, hemoglobin A1c, hypertension and dyslipidemia. Our results demonstrate a positive relation between LJM of hand and NLR in patients with type 2 diabetes.

Relationship between limited joint mobility of hand and carotid atherosclerosis in patients with type 2 diabetes.

AIM: Limited joint mobility (LJM) of hand, which is one of a complication of diabetic hand, has a close association with diabetic microangiopathy. However, it remains to be elucidated about the relationships between LJM of hand and subclinical atherosclerosis in patients with type 2 diabetes. Therefore, we conducted a cross-sectional study to evaluate the relationships between LJM of hand and carotid intima-media thickness (IMT) and plaque score in patients with type 2 diabetes. METHODS: We evaluated the relationships between LJM of hand, and carotid IMT and plaque score, evaluated by carotid ultrasound examination, in 341 consecutive patients with type 2 diabetes. LJM of hand was diagnosed using a 'prayer sign' or 'table test'. RESULTS: LJM of hand was present in 72 patients. Carotid IMT and plaque score were higher in patients with LJM of hand than those in patients without (1.45±0.66vs. 1.14±0.68mm, P=0.013 and 8.0±5.3vs. 5.4±4.8mm, P<0.001). Multivariate linear regression analysis revealed that LJM of hand was positively correlated with plaque score (ß=0.423, P=0.043) after adjusted for age, sex, durations of diabetes, body mass index, hemoglobin A1c, creatinine, uric acid, smoking, hypertension and dyslipidemia. CONCLUSIONS: Our results demonstrate a relation between LJM of hand and subclinical atherosclerosis, especially plaque score, in patients with type 2 diabetes. Diagnosis of diabetic hand is simple and non-invasive, and thus is a useful method for assessment of subclinical atherosclerosis in patients with type 2 diabetes.

Relationship between limited joint mobility of the hand and diabetic foot risk in patients with type 2 diabetes.

BACKGROUND: Foot ulceration is a serious problem for patients with type 2 diabetes (T2D), and the early detection of risks for this condition is important to prevent complications. The present cross-sectional study in T2D patients determined the relationship between limited joint mobility (LJM) of the hand and diabetic foot risk classified using the criteria of the International Working Group on the Diabetic Foot (IWGDF). METHODS: Relationships between LJM of the hand and foot risk according to IWGDF category, HbA1c, age, body mass index, blood pressure, estimated glomerular filtration (eGFR), and diabetic complications (including diabetic peripheral neuropathy [DPN] and peripheral arterial disease [PAD]) were evaluated in 528 consecutive T2D patients. Poor glycemic control was defined as HbA1c ≥ 7%. RESULTS: Patients with LJM of the hand were older and had a longer duration of diabetes, a higher prevalence of diabetic complications, including DPN and PAD, and a higher IWDGF category (all P < 0.001). Multivariate logistic regression analysis revealed that the foot risk assessed with IWDGF category was correlated with age (odds ratio [OR] 1.04; 95% confidence interval [CI] 1.01-1.06; P = 0.001), poor glycemic control (OR 1.66; 95% CI 1.00-2.77; P = 0.04), eGFR (OR 0.98; 95% CI 0.97-0.99; P = 0.02), and the presence of LJM of the hand (OR 3.86; 95% CI 2.21-6.86; P < 0.001). CONCLUSIONS: The results demonstrate a correlation between LJM of the hand and foot risk. Diagnosis of diabetic hand is simple and non-invasive, and is thus a useful method for assessing the risk of diabetic foot in T2D patients.

Glycated albumin predicts the risk of mortality in type 2 diabetic patients on hemodialysis: evaluation of a target level for improving survival.

Glycated albumin (GA) is considered a more reliable marker than glycated hemoglobin (HbA1c) for monitoring glycemic control, particularly in diabetic hemodialysis patients. We investigated the associations of GA, HbA1c, and random serum glucose levels with survival, and evaluated possible targets for improving survival in diabetic hemodialysis patients. In this prospective, longitudinal, observational study, we enrolled 90 diabetic hemodialysis patients across six dialysis centers in Japan. The median duration of follow-up was 36.0 months (mean follow-up, 29.8 months; range, 3-36 months). There were 11 deaths during the observation period. GA was a significant predictor for mortality (hazard ratio, 1.143 per 1% increase in GA; 95% confidence interval, 1.011-1.292; P = 0.033), whereas HbA1c and random glucose levels were not predictors for mortality. Receiver operating characteristics curve analysis showed that the cutoff value of GA for predicting the risk of mortality was 25%. In the Kaplan-Meier analysis, the cumulative survival rate was significantly greater in patients with GA ≤ 25% than in patients with GA >25%. GA predicted the risk of all-cause and cardiovascular mortality in diabetic hemodialysis patients. Our results suggest that GA ≤ 25% is an appropriate target for improving survival in diabetic hemodialysis patients.

18F-FDG PET/CT useful for the early detection of rapidly progressive fatal interstitial lung disease in dermatomyositis.

Interstitial lung disease (ILD) frequently accompanies polymyositis (PM) and dermatomyositis (DM) and is a major cause of mortality. The rapid diagnosis of ILD is paramount. However, the early changes of presymptomatic ILD are difficult to detect. We present a patient with DM who had positive uptake in the lung of FDG-PET/CT as well as 'mechanic's hands' appearance, increased serum ferritin and serum anti-CADM-140 antibody, all before the detection of ILD by CT. Although aggressive treatment was initiated, the patient died of diffuse alveolar damage. These observations suggest that the pulmonary uptake of (18)F-FDG predicts rapidly progressive ILD in DM.

[Case of MPO-ANCA-positive Wegener's granulomatosis with hepatitis C virus infection].

A 77-year-old Japanese man was referred to our hospital because of the progression of renal dysfunction. Two months prior to the admission he had been diagnosed with otitis media. Urinalysis showed proteinuria and microscopic hematuria. Blood examination revealed renal dysfunction, hepatitis C virus (HCV)infection and positive myeloperoxidase (MPO)-ANCA. A chest CT revealed small infiltrates in the right middle lobe. The renal biopsy demonstrated crescentic glomerulonephritis with tubulitis. He was diagnosed as having Wegener's granulomatosis according to the American College of Rheumatology classification criteria. Methylprednisolone pulse therapy followed by oral prednisolone improved all of the otitis media, lung infiltrates and renal function. Recently, a high prevalence of ANCA has been reported in patients with HCV. It has also been reported that the prevalence of HCV infection is high in patients with Wegener's granulomatosis. Therefore, our case points to the clinical significance of HCV infection in ANCA-associated systemic vasculitis including Wegener's granulomatosis.

Plasma diafiltration therapy in patients with postoperative liver failure.

Plasma diafiltration (PDF) is a blood purification therapy in which simple plasma exchange (PE) is performed using a selective membrane plasma separator while the dialysate flows outside of the hollow fibers. A prospective, multicenter study was undertaken to evaluate the changes in biochemical examination of blood and the 28-day and 90-day survival rates of patients with postoperative liver failure (PLF). Eleven patients with PLF were studied with the therapy performed 98 times. The Model for End-Stage Liver Disease (MELD) score was categorized into three grades: 20-29, 30-39, and 40 or higher. The survival rate was assessed by the severity of MELD score. The 28-day survival rate was 45.5% and that at 90 days was 27.3%. The levels of total bilirubin, BUN, and creatinine decreased significantly after treatment. On the other hand, the levels of total protein increased after treatment and those of albumin did not change significantly. PDF may be the useful blood purification therapies for use in cases of PLF in terms of medical economics and the removal of water-soluble and albumin-bound toxins.

Diffuse alveolar hemorrhage in lupus nephritis complicated by microscopic polyangiitis.

Diffuse alveolar hemorrhage (DAH) is a rare but fatal complication in patients with systemic lupus erythematosus (SLE). We describe a case of a 74-year-old woman who presented with DAH as an initial presentation of SLE. She also had microscopic polyangiitis clinically manifesting as crescentic glomerulonephritis and purpura with positive myeloperoxidase (MPO)-antineutrophil cytoplasmic antibodies (ANCA). The patient transiently improved when treated with plasma exchange and methylprednisolone pulse therapy; however, she died of recurrent pulmonary hemorrhage and concurrent cryptococcal pneumonia. This case indicates that MPO-ANCA is associated with severe organ involvement such as pulmonary hemorrhage and crescentic glomerulonephritis in SLE.

Replacement of neutral protamine Hagedorn insulin with the long-acting insulin analogue, detemir, improves glycemic control without weight gain in basal-bolus insulin therapy in Japanese patients with type 1 diabetes.

UNLABELLED: Aims/Introduction: The aim of the present study was to evaluate the efficacy of replacing neutral protamine Hagedorn insulin (NPH) with the long-acting insulin analogue, detemir, in clinical practice. MATERIALS AND METHODS: We carried out a retrospective study to compare the effects of replacing NPH with detemir in basal-bolus insulin therapy in Japanese patients with type 1 diabetes. A total of 19 patients were enrolled in the study, and changes in hemoglobin A1c (HbA1c), insulin dose, bodyweight, fasting blood glucose levels (FBG), within-patient variability in FBG and prevalence in hypoglycemia were monitored for 12 weeks before replacement and during three periods after replacement; 1-12 weeks (period 1), 13-24 weeks (period 2) and 25-36 weeks (period 3). RESULTS: HbA1c values improved significantly in periods 2 and 3. Despite the total insulin dose remaining unchanged throughout the study, the basal insulin dose increased from 0.24 to 0.27 IU/kg/day in period 2 and 0.28 IU/kg/day in period 3. Bodyweight decreased from 61.8 to 60.8 kg in period 1, whereas FBG improved throughout the study. Within-patient variability in FBG was lower with detemir treatment than with NPH, despite the number of hypoglycemic episodes increasing significantly after replacement. CONCLUSIONS: These findings show that the weight loss observed in patients was independent of the reduction in calorie intake resulting from less frequent hypoglycemic attacks. In Japanese patients with diabetes who received NPH, replacing NPH with detemir led to improvements in glycemic control without any weight gain. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2010.00066.x, 2010).

Pulmonary hemorrhage and acute renal failure as an initial presentation of multiple myeloma.

The combined clinical presentation of acute renal failure with pulmonary hemorrhage is known as pulmonary-renal syndrome. We describe a case of an 84-year-old woman who presented with acute renal failure and pulmonary hemorrhage at onset. Renal biopsy and bone marrow aspiration showed cast nephropathy and an abnormal increase in plasma cells, respectively. She was diagnosed with multiple myeloma and successfully treated with plasma exchange and corticosteroids. This case indicates that multiple myeloma should be considered as a cause of pulmonary-renal syndrome.

Iron status and the use of non-steroidal anti-inflammatory drugs in hemodialysis patients.

We examined whether the use of non-steroidal anti-inflammatory drugs (NSAIDs) can affect the anemia and iron status of hemodialysis patients. We recruited patients from six dialysis centers who had undergone maintenance hemodialysis for at least four months. We examined the use of NSAIDs during the past three months based on their medical records and assigned the patients to three groups (group A, non-NSAID group; group B, aspirin group; and group C, non-aspirin NSAID group). Of the 446 patients, 95 (21.3%) were treated with aspirin and 103 (23.1%) were treated with non-aspirin NSAIDs. The serum iron level and transferrin saturation (TSAT) were significantly lower in group C patients than those in group A. However, the ratio of the patients who were administrated iron preparations during the past three months was significantly higher than that in the other two groups. The incidences of positive fecal occult blood tests did not differ substantially between the three groups. The ratios of the patients who were administrated recombinant human erythropoietin were the same between three groups. Using a multiple regression analysis, the administration of non-aspirin NSAIDs was identified as an independent factor for the decreased serum iron and the decreased TSAT levels. A multiple logistic regression analysis revealed that the patients using non-aspirin NSAIDs had an increased the requirement for iron preparation therapy (OR 2.03, 95% CI, 1.28-3.22). The use of non-aspirin NSAIDs may therefore increase the risk of the iron deficiency in patients undergoing hemodialysis.

Reduction in microalbuminuria as an integrated indicator for renal and cardiovascular risk reduction in patients with type 2 diabetes.

OBJECTIVE: Microalbuminuria in diabetic patients is a predictor for diabetic nephropathy and cardiovascular disease. The aim of this study is to investigate the clinical impact of reducing microalbuminuria in type 2 diabetic patients in an observational follow-up study. RESEARCH DESIGN AND METHODS: We enrolled 216 type 2 diabetic patients with microalbuminuria during an initial 2-year evaluation period and observed them for the next 8 years. Remission and a 50% reduction of microalbuminuria were defined as a shift to normoalbuminuria and a reduction <50% from the initial level of microalbuminuria. The association between reducing microalbuminuria and first occurrence of a renal or cardiovascular event and annual decline rate of estimated glomerular filtration rate (eGFR) was evaluated. RESULTS: Twelve events occurred in 93 patients who attained a 50% reduction of microalbuminuria during the follow-up versus 35 events in 123 patients without a 50% reduction. The cumulative incidence rate of events was significantly lower in patients with a 50% reduction. A pooled logistic regression analysis revealed that the adjusted risk for events in subjects after a 50% reduction was 0.41 (95% CI 0.15-0.96). In addition, the annual decline rate of eGFR in patients with a 50% reduction was significantly slower than in those without such a reduction. The same results were also found in the analysis regarding whether remission occurred. CONCLUSIONS: The present study provides clinical evidence implying that a reduction of microalbuminuria in type 2 diabetic patients is an integrated indicator for renal and cardiovascular risk reduction.

SIRT1 inhibits transforming growth factor beta-induced apoptosis in glomerular mesangial cells via Smad7 deacetylation.

SIRT1, a class III histone deacetylase, is considered a key regulator of cell survival and apoptosis through its interaction with nuclear proteins. In this study, we have examined the likelihood and role of the interaction between SIRT1 and Smad7, which mediates transforming growth factor beta (TGFbeta)-induced apoptosis in renal glomerular mesangial cells. Immunoprecipitation analysis revealed that SIRT1 directly interacts with the N terminus of Smad7. Furthermore, SIRT1 reversed acetyl-transferase (p300)-mediated acetylation of two lysine residues (Lys-64 and -70) on Smad7. In mesangial cells, the Smad7 expression level was reduced by SIRT1 overexpression and increased by SIRT1 knockdown. SIRT1-mediated deacetylation of Smad7 enhanced Smad ubiquitination regulatory factor 1 (Smurf1)-mediated ubiquitin proteasome degradation, which contributed to the low expression of Smad7 in SIRT1-overexpressing mesangial cells. Stimulation by TGFbeta or overexpression of Smad7 induced mesangial cell apoptosis, as assessed by morphological apoptotic changes (nuclear condensation) and biological apoptotic markers (cleavages of caspase3 and poly(ADP-ribose) polymerase). However, TGFbeta failed to induce apoptosis in Smad7 knockdown mesangial cells, indicating that Smad7 mainly mediates TGFbeta-induced apoptosis of mesangial cells. Finally, SIRT1 overexpression attenuated both Smad7- and TGFbeta-induced mesangial cell apoptosis, whereas SIRT1 knockdown enhanced this apoptosis. We have concluded that Smad7 is a new target molecule for SIRT1 and SIRT1 attenuates TGFbeta-induced mesangial cell apoptosis through acceleration of Smad7 degradation. Our results suggest that up-regulation of SIRT1 deacetylase activity is a potentially useful therapeutic strategy for prevention of TGFbeta-related kidney disease through its effect on cell survival.

Silent information regulator 2 (SIRT1) attenuates oxidative stress-induced mesangial cell apoptosis via p53 deacetylation.

Oxidative stress-induced apoptosis of renal glomerular cells is an important factor for the development of various kidney diseases. Identification of molecules that modulate this process could lead to the development of new strategies for preventing kidney diseases. In this study, we evaluated whether mammalian silent information regulator 2 (SIRT1), which has been recently identified as a cell survival factor countering various stressors, is a key regulator of oxidative stress-induced mesangial cell apoptosis. Morphological features of apoptotic cell death (nuclear condensation) and the expression of biochemical proapoptotic markers [cleavages of caspase-3 and poly (ADP-ribose) polymerase (PARP)] were assessed in murine mesangial cells (MMCs) exposed to hydrogen peroxide (H(2)O(2)). H(2)O(2) increased mesangial cell apoptosis, predominantly through p53 activation by acetylation, which is a posttranscriptional modification for p53 activation. H(2)O(2)-induced apoptosis was significantly attenuated in SIRT1-overexpressing MMCs, but enhanced in SIRT1-knockdown MMCs. Although SIRT1 did not affect H(2)O(2)-mediated phosphorylation of mitogen-activated protein (MAP) kinase, it interacted with p53 and inhibited H(2)O(2)-mediated p53 acetylation but not phosphorylation in MMCs. Our results indicate that SIRT1 can prevent oxidative stress-induced apoptosis through p53 deacetylation in mesangial cells. Upregulation of SIRT1 may provide a new strategy for preventing kidney glomerular diseases.

Polymorphisms of the protein kinase C-beta gene (PRKCB1) accelerate kidney disease in type 2 diabetes without overt proteinuria.

OBJECTIVE: We investigated the contribution of PKC-beta gene (PRKCB1) polymorphisms to diabetic kidney disease in a prospective observational follow-up study. RESEARCH DESIGN AND METHODS: A total of 364 Japanese subjects with type 2 diabetes without overt proteinuria were enrolled during 1996-1998 and followed until 2004. Five single nucleotide polymorphisms (-1504C/T, -546C/G, -348A/G, -278C/T, and -238C/G) in the promoter region of PRKCB1 were genotyped. The end points were transition from stage to stage of diabetic nephropathy as a time-to-event outcome and the annual decline rate of estimated glomerular filtration rate (eGFR) as a slope-based outcome. RESULTS: During the study (median 6 years), 34 of 364 subjects (9.3%) progressed. Kaplan-Meier estimation revealed that subjects with both T allele at -1054 C/T and G allele at -546 C/G polymorphisms frequently showed transition to advanced stages of diabetic nephropathy (P = 0.015). The annual change rate in eGFR in the subjects with both alleles was also significantly higher than in others (-2.96 +/- 0.62 vs. -1.63 +/- 0.15 ml/min per 1.73 m(2)/year, P = 0.02). The estimated frequency of this risk T-G haplotype was significantly higher in the progressors who showed transition to advanced nephropathy stages (12%) than in the nonprogressors (5%) (odds ratio 2.3 [95% CI 1.0-5.2]), and it was also higher in those with accelerated decline of the Delta eGFR (> or =3 ml/min per 1.73 m(2)/year) than in those without (2.1 [1.1-3.9]). CONCLUSIONS: Our study indicates that PRKCB1 is a predictor for worsening of kidney disease in Japanese subjects with type 2 diabetes.

N-acetyl-seryl-aspartyl-lysyl-proline inhibits DNA synthesis in human mesangial cells via up-regulation of cell cycle modulators.

N-Acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) was originally reported as a natural inhibitor of the proliferation of stem cells. To elucidate whether Ac-SDKP inhibits the proliferation of human mesangial cells, we examined the effect of Ac-SDKP on fetal calf serum (FCS)- or platelet-derived growth factor (PDGF)-BB-induced DNA synthesis and a cell proliferation. Ac-SDKP inhibited PDGF-BB- or FCS-induced DNA synthesis without cellular toxicity. The protein expression of p53 and p27kip1 was significantly increased by Ac-SDKP. Ac-SDKP also up-regulated the PDGF-BB-stimulated expression of p21cip1 and suppressed PDGF-BB-induced cyclin D1 expression. In p53 knock-out human mesangial cells made with small interference RNA, the protein expression of p21cip1 and p27kip1 was also decreased and the inhibitory effect of Ac-SDKP on mesangial proliferation was completely abolished. Ac-SDKP increased the stability of p53 protein as demonstrated by pulse-chase experiment. These results suggest that p53 is the key mediator of Ac-SDKP-induced inhibition of DNA synthesis through the up-regulation of cell cycle modulators, highlighting a potential effect of Ac-SDKP on various progressive renal diseases.

Inhibition of mTOR signaling with rapamycin attenuates renal hypertrophy in the early diabetic mice.

Early diabetic nephropathy is characterized by renal hypertrophy that is mainly due to proximal tubular hypertrophy. Mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase, and its signaling has been reported to regulate protein synthesis and cellular growth, specifically, hypertrophy. Therefore, we examined the effect of mTOR signaling on diabetic renal hypertrophy by using the specific inhibitor for mTOR, rapamycin. Ten days after streptozotocin-induced diabetes, mice showed kidney hypertrophy with increases in the phosphorylation of p70S6kinase and the expression of cyclin kinase inhibitors, p21(Cip1) and p27(Kip1), in the kidneys. The intraperitoneal injection of rapamycin (2 mg/kg/day) markedly attenuated the enhanced phosphorylation of p70S6kinase, the increment of cyclin-dependent kinase inhibitors, and renal enlargement without any changes of clinical parameters, including blood glucose, blood pressure, and food intake. Overexpression of a constitutive active form of p70S6kinase resulted in increased cell size of cultured mouse proximal tubule cells; thus, activation of p70S6kinase causes hypertrophy of proximal tubular cells. Our findings suggest that activation of mTOR signaling causes renal hypertrophy at the early stage of diabetes.

Factors associated with frequent remission of microalbuminuria in patients with type 2 diabetes.

To estimate the frequency of remission/regression of microalbuminuria and to identify factors affecting such outcomes in Japanese patients with type 2 diabetes, we observed 216 patients with type 2 diabetes and microalbuminuria enrolled during an initial 2-year evaluation period for the next 6 years. Remission was defined as shift to normoalbuminuria and regression as a 50% reduction in urinary albumin excretion rate (AER) from one 2-year period to the next. Reduction of urinary AER was frequent, with a 6-year cumulative incidence of 51% (95% CI 42-60) for remission and 54% (45-63) for regression, whereas the frequency of progression to overt proteinuria was 28% (19-37). Microalbuminuria of short duration, the use of renin-angiotensin system-blocking drugs, and lower tertiles for HbA(1c) (<6.95%) and systolic blood pressure (<129 mmHg) were independently associated with remission or regression in the pooled logistic regression analysis. The results indicate that reduction in urinary AER occurs frequently in Japanese patients with type 2 diabetes. Early detection of microalbuminuria and a multifactorial control may result in improved outcomes for diabetic nephropathy and cardiovascular events.

MAPK/AP-1-dependent regulation of PAI-1 gene expression by TGF-beta in rat mesangial cells.

BACKGROUND: Receptor-regulated Smads and/or mitogen-activated protein kinases (MAPKs) are involved in transforming growth factor-beta (TGF-beta)-induced expression of various genes, including plasminogen activator inhibitor-1 (PAI-1). Because the sequence of the promoter region in rat PAI-1 gene differs from that in the human gene, we examined the mechanisms of TGF-beta-induced rat PAI-1 expression in rat mesangial cells. METHODS: TGF-beta1-induced PAI-1 and c-fos mRNA expressions were determined by Northern blot analysis. Activation of MAPKs and Smad proteins was evaluated by an immunoblot analysis. DNA binding activities of nuclear protein were examined by using an electrophoretic mobility shift assay (EMSA). The activities of PAI-1 promoter were measured by a luciferase reporter assay. RESULTS: Extracellular-regulated kinase (ERK) and c-Jun NH-terminal kinase (JNK) phosphorylation, c-fos mRNA expression, and activator protein-1 (AP-1) DNA binding activity stimulated by TGF-beta1 were completely suppressed by the ERK kinase (MEK) inhibitors. EMSA and reporter analysis revealed that an AP-1-like sequence located in the proximal region of the rat PAI-1 promoter was the target for TGF-beta1, and the disruption of this AP-1-like sequence suppressed basal and TGF-beta1-induced promoter activation. TGF-beta1 also stimulated nuclear translocation of Smads and binding to palindromic Smad binding element (SBE) located in the rat PAI-1 promoter, without being affected by MEK inhibitor. Point mutation and deletion of palindromic SBE did not affect TGF-beta1-induced rat PAI-1 promoter activity. Moreover, interferon-gamma (IFN-gamma) inhibited TGF-beta1-induced PAI-1 expression through selectively suppressing the ERK-AP-1 pathway. CONCLUSION: These results suggest that the essential requirement of MAPK/AP-1 activation for TGF-beta1-induced PAI-1 expression is unique to rat mesangial cells.