Severe acute interstitial nephritis induced by α-glucosidase inhibitor miglitol in an elderly patient with type 2 diabetic nephropathy.

A 79-year-old male patient with type 2 diabetic nephropathy and hypertension was admitted to our hospital because of acute kidney injury with significantly elevated serum creatinine (8.12 mg/dL) and urinary ß2-microglobulin (ß2MG, 31,748 µg/L) levels. α-Glucosidase inhibitor (α-GI) miglitol, started two weeks prior to presentation, was discontinued because drug-induced acute interstitial nephritis (AIN) was suspected. Renal biopsy revealed AIN and diabetic nephropathy. The drug-induced lymphocyte stimulation test for miglitol was also positive. After the discontinuation of miglitol, the urinary ß2MG levels decreased to the normal range. This case raises the possibility that α-GI miglitol can worsen the renal function in patients with underlying renal dysfunction.

Decreased Podocyte Vesicle Transcytosis and Albuminuria in APC C-Terminal Deficiency Mice with Puromycin-Induced Nephrotic Syndrome.

In minimal change nephrotic syndrome, podocyte vesicle transport is enhanced. Adenomatous polyposis coli (APC) anchors microtubules to cell membranes and plays an important role in vesicle transport. To clarify the role of APC in vesicle transport in podocytes, nephrotic syndrome was induced by puromycin amino nucleoside (PAN) injection in mice expressing APC1638T lacking the C-terminal of microtubule-binding site (APC1638T mouse); this was examined in renal tissue changes. The kidney size and glomerular area of APC1638T mice were reduced (p = 0.014); however, the number of podocytes was same between wild-type (WT) mice and APC1638T mice. The ultrastructure of podocyte foot process was normal by electron microscopy. When nephrotic syndrome was induced, the kidneys of WT+PAN mice became swollen with many hyaline casts, whereas these changes were inhibited in the kidneys of APC1638T+PAN mice. Electron microscopy showed foot process effacement in both groups; however, APC1638T+PAN mice had fewer vesicles in the basal area of podocytes than WT+PAN mice. Cytoplasmic dynein-1, a motor protein for vesicle transport, and α-tubulin were significantly reduced in APC1638T+PAN mice associated with suppressed urinary albumin excretion compared to WT+PAN mice. In conclusion, APC1638T mice showed reduced albuminuria associated with suppressed podocyte vesicle transport when minimal change nephrotic syndrome was induced.

Eucommia ulmoides (Tochu) and its extract geniposidic acid reduced blood pressure and improved renal hemodynamics.

INTRODUCTION: Eucommia ulmoides leaves are used as Tochu tea, which has a blood pressure lowering effect of unknown mechanism. PURPOSE AND METHODS: The effects of Tochu tea and its component, geniposidic acid, on blood pressure and renal hemodynamics were investigated in Dahl salt-sensitive (DS) rats received 1% saline solution from 4 weeks of age. At 9 weeks of age, 1% saline alone (DSHS), Tochu tea extract added 1% saline (DSHS+T), or geniposidic acid added 1% saline (DSHS+G) was administered for another 4 weeks. DS rats fed with tap water were used as controls (DSLS). At 13 weeks, the blood pressure, the renal plasma flow (RPF) and the renal NADPH oxidase, endothelial nitric oxide synthase (eNOS) were examined. RESULTS: Blood pressure in DSHS rats was significantly increased in comparison to DSLS (144 vs. 196 mmHg, p < 0.01), and was significantly reduced in DSHS+T (158 mmHg) and DSHS+G (162 mmHg) rats. RPF in DSHS+T rats was significantly higher than in DSHS rats (p < 0.05). The expression of NADPH oxidase in DSHS rats was enhanced in comparison to DSLS rats; however, it was suppressed in DSHS+T and DSHS+G rats, and the NO production by eNOS was increased; thus, RPF was improved. The urinary Na excretion in DSHS rats was higher than that in DSLS rats; however it was further increased in DSHS+T rats without changes in the tubular Na transporters. CONCLUSION: Tochu tea and geniposidic acid suppressed NADPH oxidase, increased eNOS, and improved blood pressure and renal hemodynamics.

Gestational Hypertension as Risk Factor of Hypertension in Middle-Aged and Older Women.

The association of gestational hypertension (GH) with future hypertension in Japanese women is unclear. Hence, this study aimed to examine the association between GH and the risk of future hypertension in middle-aged-to-older Japanese women. A case-control study was performed, including 62 hypertensive women (case) and 75 nonhypertensive women (control). GH during the first pregnancy was diagnosed on the basis of the Maternal and Child Health Handbook record. Hypertensive women were recruited from outpatients in the hospital and residents who completed an annual health check-up in a community. Hypertension was defined as blood pressure with systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg, or taking antihypertensive medications. The average age (SD) of the cases and controls at the time of recruitment was 63.1 (8.4) and 57.7 (9.4), respectively. The multivariable-adjusted odds ratio of GH for hypertension in middle-aged-to-older women was 4.2 (95% confidence interval, 1.0-17.5) after adjustment for potential confounding factors such as age and body-mass index (BMI) upon recruitment, prepregnancy BMI, and age at first delivery. In conclusion, GH can be an independent risk factor for future hypertension among Japanese women.

V-ATPase blockade reduces renal gluconeogenesis and improves insulin secretion in type 2 diabetic rats.

Vacuolar H+-adenosine triphosphatase (V-ATPase) stimulates vesicular acidification that may activate cytoplasmic enzymes, hormone secretion and membrane recycling of transporters. We investigated the effect of blockade of V-ATPase by bafilomycin B1 on renal gluconeogenesis, mitochondrial enzymes, and insulin secretion in type 2 diabetic rats. Spontaneous type 2 diabetic Torii rats were treated with intraperitoneal injection of bafilomycin B1 for 1 week, and the kidneys were examined after 24 h of starvation in metabolic cages. The renal expression and activity of V-ATPase were increased in the brush border membrane of the proximal tubules in diabetic rats. The blockade of V-ATPase by bafilomycin B1 reduced renal V-ATPase activity and urinary ammonium in diabetic rats. Treatment with bafilomycin suppressed the enhanced renal gluconeogenesis enzymes and mitochondrial electron transport enzymes in type 2 diabetic rats and reduced the renal cytoplasmic glucose levels. The insulin index and pancreatic insulin granules were decreased in diabetic rats with increased V-ATPase expression in islet cells, and treatment with bafilomycin B1 reversed these changes and increased the insulin secretion index. Hepatosteatosis in type 2 diabetic rats was ameliorated by bafilomycin treatment. As a consequence, treatment with bafilomycin B1 significantly decreased the plasma glucose level after 24 h of starvation in diabetic rats. In conclusion, a V-ATPase inhibitor improved plasma glucose levels in type 2 diabetes by inhibiting renal mitochondrial gluconeogenesis and improving insulin secretion.

Rituximab in treatment of anti-GBM antibody glomerulonephritis: A case report and literature review.

RATIONALE: Anti-glomerular basement membrane (GBM) disease is a T cell-mediated disease that has a poor prognosis with conventional therapy. We tested rituximab as a primary therapy to reduce anti-GBM antibody produced by B cells. PATIENT CONCERNS: A 53-year old woman with complaints of a fever, headache and abdominal discomfort showed renal failure with elevated anti-GBM antibody, and renal biopsy revealed crescentic necrotizing glomerulonephritis with linear immunoglobulin G (IgG) 1 deposition along GBM. DIAGNOSES: The patient's plasma contained autoantibodies against Goodpasture antigen, which is the NC domain of collagen IVα3, and CD4-positive helper T cells were found surrounding crescent glomeruli with the coexistence CD20-positive B cells. INTERVENTIONS: Rituximab with steroid and plasma exchange. OUTCOMES: The levels of autoantibody for Goodpasture antigen were reduced, and the patient was able to temporarily withdraw from hemodialysis. LESSONS: B cell depletion with rituximab is effective as an initial therapy for anti-GBM disease.

Optimal blood pressure targets for patients with hypertension: a systematic review and meta-analysis.

Optimal blood pressure (BP) targets for hypertension have been an important clinical issue but have been elusive. The Systolic Blood Pressure Intervention Trial (SPRINT) showed significant benefits of intensive BP-lowering treatment with a target systolic BP level of < 120 mm Hg on major cardiovascular (CV) events and mortality, whereas there was a modest increase in renal events related to BP-lowering treatment. We searched the PubMed, Cochrane CENTRAL, and ICHUSHI databases for randomized trials that assigned participants to intensive versus usual BP-lowering treatment with different BP targets. The outcomes were major CV events, all-cause death, myocardial infarction, stroke, heart failure, renal events, and adverse events. Nineteen trials that enrolled a total of 55,529 participants with a mean follow-up duration ranging from 1.6 to 12.2 years were included in the present analysis. There was a significant reduction in major CV events, myocardial infarction, and stroke and a trend toward a reduction in heart failure associated with intensive BP-lowering treatment, but no differences in the risks of all-cause death, renal events, or adverse events were observed between the randomized groups. Subgroup analyses indicated that intensive BP-lowering treatment with a target of < 130/80 mm Hg and/or achievement of BP < 130/80 mm Hg were associated with a significant reduction in major CV events compared with the usual group. In conclusion, intensive BP-lowering treatment reduces the risk of CV events. A target BP level of < 130/80 mm Hg appears to be optimal for CV protection in patients with hypertension.

Involvement of P2Y12 receptor in vascular smooth muscle inflammatory changes via MCP-1 upregulation and monocyte adhesion.

Antiplatelet drugs, frequently used for cardiovascular events with thrombotic involvement, are also regarded as possible promising agents for cardiovascular primary prevention. The roles of P2Y12, an ADP receptor and the target of thienopyridine antiplatelet drugs, are not satisfactorily known in the vascular wall. We investigated the hypothesis that vascular smooth muscle cell (VSMC) P2Y12 is involved in vascular wall inflammatory changes by upregulating monocyte chemoattractant protein-1 (MCP-1) and promoting monocyte adhesion. ADP at 10(-5) M induced a 3.6 ± 0.3-fold upregulation of MCP-1 mRNA in cultured rat VSMCs, which was significantly inhibited by R-138727, the active metabolite of P2Y12 inhibitor prasugrel and siRNAs against P2Y12. ADP also induced MCP-1 protein upregulation, which was diminished by R-138727 and P2Y12 siRNAs. JNK (c-Jun NH2-terminal kinase) inhibition attenuated ADP-induced MCP-1 mRNA and protein upregulation. R-138727 and P2Y12 siRNAs inhibited ADP-induced JNK activation. The reactive oxygen species (ROS) inhibitors N-acetylcysteine (NAC), diphenyleneiodonium (DPI), and Tempol also diminished MCP-1 upregulation and JNK activation induced by ADP. ADP induced MCP-1 promoter activation, which was inhibited by R-138727 and P2Y12 siRNAs. Nuclear factor-κB (NF-κB) consensus sites in the MCP-1 promoter region were involved in this activation. ADP-induced NF-κB pathway activation, examined by a plasmid containing multiple NF-κB sites, was diminished by P2Y12 inhibition. For cellular function analysis, stimulation of VSMC with ADP increased subsequent THP-1 monocyte adhesion. P2Y12 siRNAs and CCR2 antagonism diminished this ADP-induced monocyte adhesion. These data suggested that ADP, via the VSMC P2Y12 receptor, induces vascular inflammatory changes by upregulating MCP-1 and promoting monocyte adhesion.

Telmisartan activates endothelial nitric oxide synthase via Ser1177 phosphorylation in vascular endothelial cells.

Because endothelial nitric oxide synthase (eNOS) has anti-inflammatory and anti-arteriosclerotic functions, it has been recognized as one of the key molecules essential for the homeostatic control of blood vessels other than relaxation of vascular tone. Here, we examined whether telmisartan modulates eNOS function through its pleiotropic effect. Administration of telmisartan to mice significantly increased the phosphorylation level of eNOS (Ser1177) in the aortic endothelium, but administration of valsartan had no effect. Similarly, telmisartan treatment of human umbilical vein endothelial cells significantly increased the phosphorylation levels of AMP-activated protein kinase (Thr172) and eNOS and the concentration of intracellular guanosine 3',5'-cyclic monophosphate (cGMP). Furthermore, pretreatment with a p38 mitogen-activated protein kinase (p38 MAPK) inhibitor suppressed the increased phosphorylation level of eNOS and intracellular cGMP concentration. These data show that telmisartan increases eNOS activity through Ser1177 phosphorylation in vascular endothelial cells mainly via p38 MAPK signaling.

Effects of atorvastatin and ezetimibe on endothelial function in dyslipidemic patients with chronic kidney disease.

BACKGROUD: Chronic kidney disease (CKD) is a staple risk factor not only for renal failure but also for cardiovascular diseases. In addition, because dyslipidemia facilitates atherosclerosis and renal dysfunction, antihyperlipidemic treatment is important to prevent cardiac and renal events in CKD patients. METHODS: We compared the effects of a statin and an intestinal cholesterol transporter inhibitor in 20 dyslipidemic patients with CKD presenting with proteinuria and/or glomerular filtration rate <60 mL/min/1.73 m(2). Either 5-10 mg atorvastatin or 10 mg ezetimibe was given for 3 months each in a randomized crossover manner and the parameters of oxidative stress, inflammation and endothelial function were compared. RESULTS: Atorvastatin lowered serum low-density lipoprotein (LDL) cholesterol more prominently than ezetimibe (103 ± 38 vs 130 ± 45 mg/dL, p < 0.001), while serum γ-glutamyl transpeptidase was higher in atorvastatin than in ezetimibe (29 ± 16 vs 25 ± 11 U/L, p = 0.013). On the other hand, serum oxidized LDL and high-sensitivity C-reactive protein were lower in the atorvastatin treatment period than in the ezetimibe treatment period (109 ± 38 vs 146 ± 67 U/L, p = 0.002; 1.02 ± 1.46 vs 1.47 ± 1.77 µg/mL, p = 0.003). Although serum adiponectin was not significantly different between the two drugs, the reactive hyperemia index, an index of endothelial function, was higher in atorvastatin than in ezetimibe (1.94 ± 0.58 vs 1.60 ± 0.44, p = 0.023). CONCLUSION: It is concluded that atorvastatin is more potent than ezetimibe in improving the serum lipid profile, reducing oxidative stress, suppressing inflammation and preserving endothelial function, while ezetimibe may be advantageous in reducing the hepatic lipid load.

Efficacy of vitamin E-bonded polysulfone dialyzer and polysulfone dialyzer on a series of non-anticoagulant hemodialysis.

Non-anticoagulant hemodialysis is conducted occasionally at limited numbers of hospitals on an empirical basis. This study examines the efficacy of polysulfone and vitamin E-bonded polysulfone dialyzer for non-anticoagulant hemodialysis. These dialyzers were assigned one after the other for a vintage hemodialysis patient complicated with uncontrollable bleeding. The patient's vital and console data throughout non-anticoagulant hemodialysis were monitored serially. Both dialyzers were reasonably applicable to hemodialysis without major clotting. The scheduled treatment period was completed. Vitamin E-bonded polysulfone dialyzer was superior to non-anticoagulant hemodialysis based on venous pressure observed during treatment.

Aldosterone-induced osteopontin gene transcription in vascular smooth muscle cells involves glucocorticoid response element.

Osteopontin (OPN) is known to be one of the cytokines that is involved in the vascular inflammation caused by aldosterone (Aldo). Previous reports have shown that Aldo increases OPN transcripts, and the mechanisms for this remain to be clarified. In this study, we investigated how Aldo increases OPN transcripts in the vascular smooth muscle cells of rats. Aldosterone increased OPN transcripts time-dependently as well as dose-dependently. This increase was diminished by eplerenone, a mineralocorticoid receptor (MR) antagonist. Luciferase promoter assays showed that the OPN promoter deleted to the -1599 site retained the same promoting ability as the full-length OPN promoter when stimulated by 10(-7) M Aldo, but the promoter deleted to the -1300 site lost the promoting ability. A glucocorticoid response element (GRE) is located in that deleted region. Luciferase assays of a mutated promoter without the GRE lost the luciferase upregulation, although mutated promoters with the deletion of other consensus sites maintained the promoter activity. The binding of the Aldo-MR complex to the GRE fragment was confirmed by an electrophoretic-mobility shift assay. This is the first report showing that Aldo regulates the transcriptional levels of OPN and inflammatory responses in the vasculature through a specific GRE site in the OPN promoter region.

Virus removal and eradication by modified double filtration plasmapheresis decreases factor XIII levels.

Factor XIII (FXIII) deficiency increases the chance for pathological bleeding, but this disorder cannot be detected by routine laboratory tests. Virus removal and eradication (VRAD, the trademark of Asahikasei Kuraray Medical) by double filtration plasmapheresis (DFPP) is an effective technique used to eradicate the hepatitis C virus in people afflicted with the disease. We have previously reported that DFPP significantly reduced FXIII in those undergoing this treatment. VRAD is a modified type of DFPP with a larger pore size of the second filter compared to conventional DFPP. Because VRAD may have similar effects on FXIII levels, we investigated the kinetics of FXIII during the course of VRAD therapy. A retrospective, observational study of the patients who underwent VRAD between July 2008 and May 2009 was performed. Reduction ratios and sieving coefficients of FXIII and other marker proteins were examined. FXIII levels were decreased to 20% after each therapy. The reduction ratio and sieving coefficients of FXIII were between those of IgG (0.4-0.5) and LDL cholesterol (0.35). Similar to other blood purification therapies, therapeutic intensity, molecular weight, and half life are crucial factors for solute removal. Although the coexistence of liver disease might modify the course of FXIII during VRAD, the therapy itself effectively reduced FXIII levels. FXIII levels should be closely monitored during VRAD in order to reduce the chance of negative clinical sequelae.

Platelet-derived microparticles are removed by a membrane plasma separator.

Platelet-derived microparticles (PDMPs) are released from activated platelets and are closely related to various diseases. Using the enzyme-linked immunosorbent assay, PDMP concentrations in blood and separated plasma of eight patients who underwent apheresis using membrane plasma separator at our hospital were tested. Considerable amounts of PDMPs were filtrated using plasma separators. However, the concentrations of PDMPs within the blood at the end of the therapy did not differ significantly from those before the session. Plasmapheresis itself might have activated platelets to release PDMPs or perhaps PDMPs within the supplementary fluid increased PDMPs during the therapy. After resolving these points, plasmapheresis could become an effective therapy against elevated PDMP conditions.

A new constitutively active mutant of AMP-activated protein kinase inhibits anoxia-induced apoptosis of vascular endothelial cell.

The inhibition of apoptotic changes in vascular endothelial cells is important for preventing vascular damage from hypoxia. AMP-activated protein kinase (AMPK) has recently been identified as playing a role in vascular protection. Although the chemical reagent 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR) has been used to stimulate AMPK activity, AICAR has been associated with several nonspecific reactions. We therefore constructed a new constitutively active mutant of AMPK alpha 1 (NcaAMPK), which lacks the autoinhibitory domain in AMPK alpha 1 and in which threonine 172 has been replaced with aspartate. We investigated whether NcaAMPK has an anti-apoptotic effect in vascular endothelial cells under anoxic conditions. NcaAMPK, or green fluorescent protein (GFP) as a control, was overexpressed in human umbilical vein endothelial cells (HUVECs). After HUVECs were incubated for 40 h under normoxic or anoxic conditions, we examined cell viability, caspase 3/7 activity, and expression and phosphorylation levels of apoptosis-related proteins. Cell viabilities under anoxic conditions were improved in NcaAMPK-overexpressing cells. Anoxia increased caspase 3/7 activity, but NcaAMPK reduced this increase significantly. NcaAMPK overexpression increased protein kinase B/Akt Ser473 and endothelial nitric oxide synthase Ser1177 phosphorylation, but pretreatment with the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) did not decrease the viability of NcaAMPK-overexpressing HUVECs. Furthermore, co-expression of a dominant-negative Akt reduced the improvement in cell viability and the suppression of poly (ADP-ribose) polymerase cleavage by NcaAMPK under anoxic conditions. In conclusion, NcaAMPK inhibited anoxia-induced apoptosis in vascular endothelial cells through Akt activation, suggesting that activation of AMPK might protect against ischemic vascular injury.

Progression of renal dysfunction in patients with cardiovascular disease.

It has been established that patients with chronic kidney disease (CKD) suffer from frequent cardiovascular events. On the other hand, recent studies suggest that renal damage tends to worsen in patients with cardiovascular diseases (CVD). Although the mechanisms for the cardiorenal association are unclear, the presence of arteriosclerotic risk factors common to both CVD and CKD is important. In arteriosclerosis, vascular derangement progresses not only in the heart but also in the kidney. In addition, heart failure, cardiac catheterization and hesitation of medical treatments due to renal dysfunction may explain the progression of renal damage. Therefore, the goal of treatments is a total control of arteriosclerotic risk factors. Medication should be selected among agents with protective effects on both heart and kidney. It is important to always consider the presence of CKD for the treatment of the cardiovascular disease and strictly control the risk factors.

Ghrelin improves renal function in mice with ischemic acute renal failure.

Growth hormone and IGF-1 have been suggested to have tissue-protective effects. Ghrelin is a stomach-derived growth hormone secretagogue. The effects of ghrelin on ischemia/reperfusion-induced renal failure in mice were examined. Ischemic acute renal failure was induced by bilateral renal artery clamping for 45 min and reperfusion for 24 h. Ghrelin (100 microg/kg mouse) or vehicle was injected subcutaneously six times before surgery and three times after surgery every 8 h. Twenty-four hours after reperfusion, the right kidney was isolated and perfused. Acetylcholine (ACh)- and adrenomedullin-induced endothelium-dependent vasorelaxation of renal vessels significantly improved in ghrelin-pretreated mice (%Delta renal perfusion pressure by 10(-7) M ACh -63.5 +/- 3.7 versus -41.2 +/- 5.5%; P < 0.05). This change was associated with significant increases of nitric oxide release in the kidneys of ghrelin-treated mice (10(-7) M ACh 35.5 +/- 5.8 versus 16.9 +/- 3.5 fmol/g kidney per min; P < 0.05). Serum concentration of urea nitrogen (53 +/- 7 versus 87 +/- 15 mg/dl; P < 0.05) and renal injury score were significantly lower in the ghrelin group (2.5 +/- 0.8 versus 5.3 +/- 1.5; P < 0.01). Tubular apoptotic index was significantly lower in the ghrelin group (5 +/- 5 versus 28 +/- 4; P < 0.05). Furthermore, the survival rate after the 60-min ischemic period was higher in the ghrelin group (80 versus 20%; P < 0.05). Ghrelin treatment significantly increased the serum level of IGF-1. However, such renal protective effects of ghrelin on ischemia/reperfusion injury were not observed in insulin receptor substrate-2 knockout mice. These results suggest that ghrelin may protect the kidneys from ischemia/reperfusion injury and that this effect is related to an improvement of endothelial function through an IGF-1-mediated pathway.

Long-term effect of imidapril hydrochloride compared with dilazep hydrochloride administration on blood pressure and renal function in patients with chronic glomerulonephritis.

The objective of the present study was to compare the effects of imidapril hydrochloride, an angiotensin converting enzyme inhibitor, and dilazep hydrochloride, an antiplatelet agent, on urinary protein excretion and renal function in patients with chronic glomerulonephritis. Imidapril (2.5 or 5 mg/day) or dilazep (300 or 450 mg/day) was administered for 3 years. Blood pressure, proteinuria, and renal function were measured before and during the treatment. In the group administered imidapril (n = 11), urinary protein decreased by approximately 50% (2.16 +/- 1.57 versus 0.90 +/- 0.53 g/g Cr, P < 0.01) and blood pressure by 14/10 mmHg (139.6 +/- 17.4/93.6 +/- 8.7 mmHg versus 122.7 +/- 10.5/81.8 +/- 9.9 mmHg, P < 0.01) and both remained at low levels during the three years of treatment. No correlation was observed between the extent of blood pressure reduction and changes in urinary protein. Serum creatinine concentrations did not change significantly (1.3 +/- 0.3 versus 1.3 +/- 0.3 mg/dL, NS). In the dilazep group (n = 12), there were no significant changes in blood pressure, urinary protein, or serum creatinine. These findings demonstrate that imidapril reduces proteinuria and contributes to preserve renal function, suggesting its usefulness in the treatment of patients with chronic glomerulonephritis.

Blockade of endogenous cytokines mitigates neointimal formation in obese Zucker rats.

BACKGROUND: It is well known that diabetes mellitus is a major risk factor for vascular diseases such as atherosclerosis and restenosis after angioplasty. It has become clear that advanced glycation end products (AGE) and their receptor (RAGE) are implicated in vascular diseases, especially in diabetes mellitus. Nevertheless, the mechanisms by which diabetes mellitus is often associated with vascular diseases remain unclear. METHODS AND RESULTS: To study the role of endogenous cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 in the development of vascular diseases and in the expression of RAGE, we used semapimod, a pharmacological inhibitor of cytokine production, and examined its effect on neointimal formation in the femoral artery of obese Zucker (OZ) rats. We also used an adenovirus construct expressing a dominant negative mutant of the receptor for TNF-alpha (AdTNFRDeltaC) to block the action of endogenous TNF-alpha. Semapimod significantly suppressed neointimal formation and RAGE expression in OZ rats compared with untreated OZ rats. This inhibitory effect of semapimod on neointimal formation was overcome by infection of an adenovirus expressing RAGE into the femoral artery of OZ rats. Furthermore, AdTNFRDeltaC infection significantly suppressed neointimal formation and RAGE expression in the femoral artery of OZ rats. CONCLUSIONS: These results suggest that endogenous cytokines, especially TNF-alpha, were implicated in neointimal formation in OZ rats and that RAGE was a mediator of the effect of these cytokines on neointimal formation.

Endothelial dysfunction and hypercontractility of vascular myocytes are ameliorated by fluvastatin in obese Zucker rats.

To study the mechanisms of vascular dysfunction in diabetes mellitus, we examined the responses of the aorta to adrenomedullin (AM) and ANG II in obese Zucker (OZ), lean Zucker (LZ), and OZ rats administered fluvastatin (OZ + Flu). AM-induced endothelium-dependent vasorelaxation was impaired in OZ rats compared with LZ rats, and fluvastatin restored AM-induced, endothelium-dependent vasorelaxation (%Deltatension at 10(-7) mol/l AM; LZ, -85.1 +/- 3.1%; OZ, -50.7 +/- 2.5%; OZ + Flu, -75.6 +/- 2.7%). Expression of endothelial nitric oxide synthase (eNOS) and Akt phosphorylation in response to AM (10(-7) mol/l) were also diminished in OZ rats. Fluvastatin restored the eNOS expression and Akt phosphorylation [eNOS expression (relative intensity): LZ, 2.3 +/- 0.4; OZ, 1.0 +/- 0.2; OZ + Flu, 1.8 +/- 0.3; Akt phosphorylation (relative intensity): LZ, 2.3 +/- 0.2; OZ, 1.0 +/- 0.3; OZ + Flu, 1.9 +/- 0.2]. ANG II-induced vasoconstriction was enhanced in the aortic rings of OZ rats compared with LZ rats, and this enhanced vasoconstriction was partially normalized by fluvastatin and was abolished when the aorta of OZ rats was preincubated with the Rho kinase inhibitor Y-27632. GTPgammaS-induced contraction of permeabilized aortic smooth muscle cells, which is an indicator of the Rho-dependent Ca(2+) sensitization of contraction, was enhanced in OZ rats compared with LZ rats, and this enhanced contraction was suppressed in OZ + Flu rats. These results suggested that endothelium-dependent vasorelaxation was impaired, Ca(2+) sensitization of contraction was augmented in blood vessels of OZ rats and that fluvastatin restored vascular function by activating the Akt-dependent pathway and inhibiting the Rho-dependent pathway.