A Clinical Case of Probable Sitosterolemia.

Sitosterolemia is a rare genetic lipid disorder characterized by elevated plant sterols in the serum. A 24-year-old Japanese woman was referred to our hospital due to a high serum low-density lipoprotein cholesterol (LDL-C) level of 332 mg/dL. At first, she was suspected to suffer from familial hypercholesterolemia, and thus received lipid-lowering agents. Although her LDL-C level remained high (220 mg/dL) with diet therapy plus 10 mg/day rosuvastatin, it was drastically decreased to 46 mg/dL with the addition of 10 mg/day ezetimibe. Finally, her LDL-C level was well-controlled at about 70 mg/dL with 10 mg/day ezetimibe alone. Furthermore, while her serum sitosterol level was elevated at 10.5 µg/mL during the first visit to our hospital, it decreased to 3.6 µg/mL with the 10 mg/day ezetimibe treatment alone. These observations suggest that she might probably suffer from sitosterolemia. Therefore, targeted gene sequencing analysis was performed using custom panels focusing on the exome regions of 21 lipid-associated genes, including ABCG5, ABCG8, and familial hypercholesterolemia-causing genes (LDL receptor, LDLRAP1, PCSK9, and apolipoprotein B). We finally identified a heterozygous ABCG8 variant (NM_022437.2:c.1285A>G or NP_071882.1:p.Met429Val) in our patient. The same gene mutation was detected in her mother. We report here a rare case exhibiting probable sitosterolemia caused by a heterozygous Met429Val variant in the ABCG8 gene and additional unknown variants.

DNA Aptamer Raised against Advanced Glycation End Products Improves Sperm Concentration, Motility, and Viability by Suppressing Receptors for Advanced Glycation End Product-Induced Oxidative Stress and Inflammation in the Testes of Diabetic Mice.

Type 2 diabetes mellitus (T2DM) is a risk factor for male infertility, but the underlying molecular mechanisms remain unclear. Advanced glycation end products (AGEs) are pathogenic molecules for diabetic vascular complications. Here, we investigated the effects of the DNA aptamer raised against AGEs (AGE-Apt) on testicular and sperm abnormalities in a T2DM mouse model. KK-Ay (DM) and wild-type (non-DM) 4- and 7-week-old male mice were sacrificed to collect the testes and spermatozoa for immunofluorescence, RT-PCR, and histological analyses. DM and non-DM 7-week-old mice were subcutaneously infused with the AGE-Apt or control-aptamer for 6 weeks and were then sacrificed. Plasma glucose, testicular AGEs, and Rage gene expression in 4-week-old DM mice and plasma glucose, testicular AGEs, oxidative stress, and pro-inflammatory gene expressions in 7-week-old DM mice were higher than those in age-matched non-DM mice, the latter of which was associated with seminiferous tubular dilation. AGE-Apt did not affect glycemic parameters, but it inhibited seminiferous tubular dilation, reduced the number of testicular macrophages and apoptotic cells, and restored the decrease in sperm concentration, motility, and viability of 13-week-old DM mice. Our findings suggest that AGEs-Apt may improve sperm abnormality by suppressing AGE-RAGE-induced oxidative stress and inflammation in the testes of DM mice.

Effects of olmesartan and amlodipine on blood pressure, endothelial function, and vascular inflammation.

BACKGROUND: Anti-hypertensive drugs can improve vascular endothelial function. However, the mechanism remains to be elucidated. OBJECTIVES: This study sought to investigate mechanisms of anti-hypertensive drugs on improvement of vascular endothelial function in patients with essential hypertension. METHODS: Forty-five patients (mean age 58.5 ± 11.2 years) with uncontrolled essential hypertension were randomly assigned to receive olmesartan, an angiotensin II type 1 receptor blocker (ARB) (N = 23), or amlodipine, a calcium channel blocker (CCB) (N = 22), for 6 months. Endothelial function was evaluated by flow-mediated dilatation (FMD) of the brachial artery. Vascular inflammation was measured by blood-normalized standardized uptake value, known as a target-to-background ratio (TBR) within the carotid arteries using 18F-fluorodeoxyglucose-positron emission tomography combined with computed tomography. RESULTS: There were no significant differences of baseline clinical data between the ARB and CCB groups. Both anti-hypertensive drugs comparably lowered blood pressure and increased %FMD. TBR values were reduced by olmesartan (P < .001), while blood pressure variability was decreased by amlodipine (P = .004). Changes in %FMD from baseline (Δ%FMD) were inversely associated with ΔTBR in the olmesartan group (r = - .606, P = .003) and with Δsystolic blood pressure variability in the amlodipine group (r = - .434, P = .039). CONCLUSION: Our study indicated that olmesartan and amlodipine could improve endothelial function in patients with essential hypertension in different manners, suppression of vascular inflammation, and decrease in blood pressure variability, respectively.

SMTP-44D Inhibits Atherosclerotic Plaque Formation in Apolipoprotein-E Null Mice Partly by Suppressing the AGEs-RAGE Axis.

SMTP-44D has been reported to have anti-oxidative and anti-inflammatory reactions, including reduced expression of receptor for advanced glycation end products (RAGE) in experimental diabetic neuropathy. Although activation of RAGE with its ligands, and advanced glycation end products (AGEs), play a crucial role in atherosclerotic cardiovascular disease, a leading cause of death in diabetic patients, it remains unclear whether SMTP-44D could inhibit experimental atherosclerosis by suppressing the AGEs-RAGE axis. In this study, we investigated the effects of SMTP-44D on atherosclerotic plaque formation and expression of AGEs in apolipoprotein-E null (Apoe-/-) mice. We further studied here whether and how SMTP-44D inhibited foam cell formation of macrophages isolated from Apoe-/- mice ex vivo. Although administration of SMTP-44D to Apoe-/- mice did not affect clinical or biochemical parameters, it significantly decreased the surface area of atherosclerotic lesions and reduced the atheromatous plaque size, macrophage infiltration, and AGEs accumulation in the aortic roots. SMTP-44D bound to immobilized RAGE and subsequently attenuated the interaction of AGEs with RAGE in vitro. Furthermore, foam cell formation evaluated by Dil-oxidized low-density lipoprotein (ox-LDL) uptake, and gene expression of RAGE, cyclin-dependent kinase 5 (Cdk5) and CD36 in macrophages isolated from SMTP-44D-treated Apoe-/- mice were significantly decreased compared with those from saline-treated mice. Gene expression levels of RAGE and Cdk5 were highly correlated with each other, the latter of which was also positively associated with that of CD36. The present study suggests that SMTP-44D may inhibit atherosclerotic plaque formation in Apoe-/- mice partly by blocking the AGEs-RAGE-induced ox-LDL uptake into macrophages via the suppression of Cdk5-CD36 pathway.

Efficacy of a new enzyme-linked immunosorbent assay system for three islet cell autoantibodies in Japanese patients with acute-onset type 1 diabetes.

To evaluate the clinical efficacy of a new enzyme-linked immunosorbent assay (ELISA) system for simultaneously detecting three islet cell autoantibodies against glutamic acid decarboxylase (GADA), insulinoma-associated antigen-2 (IA-2A), and zinc transporter 8 (ZnT8A) (3 Screen ICA ELISA) in Japanese patients with acute-onset type 1 diabetes (T1D). In addition, clinical factors affecting the 3 Screen ICA ELISA index were investigated. We compared the positivity values of 3 Screen ICA ELISA with that of each autoantibody alone in 97 patients with acute-onset T1D (mean age 48.7 years, 49% male) and 100 non-diabetic subjects (mean age 47.0 years, 50% male). Serum thyroid stimulating hormone receptor antibody, thyroid peroxidase antibody (TPOAb) and thyroglobulin autoantibody levels were also evaluated. The cut-off value of the 3 Screen ICA ELISA was determined based on the 97th percentile of 100 non-diabetic controls (threshold for positivity, ≥14 index). The mean age of disease onset and duration of diabetes were 34.2 years and 14.5 years, respectively. Among all T1D patients, the positivity of 3 Screen ICA ELISA was 71.1%, while that of GADA, IA-2A, and ZnT8A were 59.8%, 25.8%, and 25.8%, respectively. The median 3 Screen ICA index was 121.9 (8.7-468.2) and was associated with titers of each autoantibody, most so with GADA, and was significantly higher in TPOAb-positive patients than in TPOAb-negative patients. Our findings suggests that the 3 Screen ICA ELISA may be a time-saving diagnostic tool for evaluating islet autoantibodies in acute-onset T1D patients.

New Estimation Formulas for Daily Sodium Intake in Hemodialysis Patients by a Duplicate Portion Method.

OBJECTIVE: Excess sodium intake is associated with volume overload and increased blood pressure. Therefore, to prevent future cardiovascular events, a sodium-restricted diet is strongly recommended for patients on maintenance hemodialysis (HD). However, only one formula for estimating dietary sodium intake in HD patients is available, and its validity has not been adequately evaluated. This study aimed to measure daily sodium intake using the duplicate portion method and provide a new formula for estimating dietary sodium intake. DESIGN AND METHODS: Nineteen Japanese patients undergoing HD were enrolled in this cross-sectional multicenter study. The daily sodium intake of these patients was measured directly using the duplicate portion method. Two formulas for estimating sodium intake were developed by stepwise regression analysis. Their validities were compared with the validity of the previous formula. Furthermore, using these new formulas, we estimated the daily consumption of sodium in a large number of Japanese HD patients. RESULTS: The previous formula underestimated true sodium intake using Bland-Altman diagrams. No significant correlation was noted between the measured sodium intake and the estimated intake (r = 0.30, P = .23, Fisher's Z-transformation). The new formulas 1 and 2, which included age, predialysis and postdialysis serum sodium levels, predialysis body weight, and interdialytic body weight gain, accurately estimated sodium consumption. The coefficients of correlation between the estimated values and the true sodium intake were r = 0.858 and r = 0.805, respectively. The simulation model using data from the Japanese Society for Dialysis Therapy showed that the distribution of the estimated sodium intake using the previous formula shifted left compared with that using the new formulas. CONCLUSIONS: The new formulas accurately estimated the daily sodium consumption in HD patients. Further longitudinal studies are required to determine whether the estimated sodium intake level calculated using the new formulas would serve as a potential marker and/or therapeutic target to prevent cardiovascular events in HD patients.

A Novel Mucidosphaerium sp. Downregulates Inflammatory Gene Expression in Skin and Articular Cells.

CONTEXT: Hot-spring therapy is occasionally used for the treatment of inflammatory diseases. Microorganisms might contribute to the anti-inflammatory functions seen in thermal mud therapies. Natural microorganisms, derived from traditional spa resorts, could be useful as a preventive strategy for alternative medical applications. OBJECTIVE: The aim of the study was to find effective microalgae from prominent hot springs to use for the treatment of inflammatory diseases. DESIGN: The research team performed an in-vitro study. Microalgae, derived from Beppu hot springs, were isolated and homogeneously cultured. SETTING: The study took place at the Saravio Central Institute at Saravio Cosmetics in Oita, Japan and the Department of Bioscience and Biotechnology in the Graduate School of Agriculture at Shinshu University in Nagano, Japan. INTERVENTION: For identification, the 18S ribosomal RNA genes of microalgae were investigated by DNA sequencing and homology search, together with microscopic observation. OUTCOME MEASURES: To examine the pharmacological activities of the algal extracts, real-time polymerase chain reactions were performed, using either primary dermal fibroblasts (DFs), dermal papilla cells (DPCs), or fibroblast-like synoviocytes (FLSs). To test the antioxidant activity, both the oxygen radical absorbance capacity and the generation of intracellular reactive oxygen species (ROS) were evaluated. RESULTS: A novel strain of green algae, Mucidosphaerium sp., was isolated from a Beppu hot spring. The algal extract downregulated gene-expression levels of pro-inflammatory cytokines, such as interleukin-1ß (IL-1ß), IL-6, and tumor necrosis factor- alpha (TNF-α), in various primary cells pre-exposed to IL-1ß. The protein level of the risk factors was concomitantly reduced. In addition, the algal extract suppressed the IL-1ß-induced upregulation of cyclooxygenase-2, nerve growth factor, and matrix metalloproteinase-1 (MMP-1) and MMP-3 in DFs. It also inhibited that of MMP-1, -3, and -9 in FLSs. Moreover, the extract inhibited total MMP protease activities. The microalgae decreased the intracellular reactive oxygen species (ROS) level in FLSs with an antioxidant activity of 178.3 ± 0.9 µmol of trolox equivalent/g. CONCLUSIONS: The present study showed that the novel Mucidosphaerium sp., derived from a Beppu hot spring, suppressed inflammatory reactions in both cutaneous and articular cells, partly due to its antioxidative properties. The novel algal strain may be a useful tool as an alternative medicine for skin and joint inflammatory disorders.

Oral administration of spa-derived green alga improves insulin resistance in overweight subjects: Mechanistic insights from fructose-fed rats.

Advanced glycation end products (AGEs) and their receptor (RAGE) system evoke inflammatory reactions and insulin resistance in adipocytes. Spa-derived green alga Mucidosphaerium sp. (MS) had anti-inflammatory properties in vitro. We examined here whether and how MS could ameliorate insulin resistance in fructose-rich diet-fed rats, and conducted a randomized, double blind, placebo-controlled trial to investigate the effects of MS on insulin resistance in overweight subjects. Oral administration of MS for 8 weeks significantly decreased random blood glucose, and fasting insulin, oxidative stress levels, and improved homeostasis model assessment of insulin resistance (HOMA-IR) values in fructose-fed rats, which were associated with the reduction of AGEs, RAGE, 8-hydroxy-2'-deoxy-guanosine, NADPH oxidase activity, macrophage and lymphocyte infiltration, monocyte chemoattractant protein-1 (MCP-1) expression, and adipocyte size in the adipose tissues as well as restoration of adiponectin levels. MS decreased the AGE-induced NADPH oxidase activity, ROS generation, MCP-1 and RAGE gene expression, and lipid accumulation in differentiated adipocytes, while it restored the decrease in adiponectin mRNA levels. An anti-oxidant, N-acetylcysteine mimicked the effects of MS on ROS generation, RAGE gene expression, and lipid accumulation. Oral intake of MS for 12 weeks significantly decreased systolic and diastolic blood pressure, fasting plasma glucose, fasting insulin, HOMA-IR, HDL-cholesterol and creatinine in overweight subjects. Baseline-adjusted diastolic blood pressure, fasting plasma glucose, fasting insulin, and HOMA-IR values were significantly lower in MS treatment group than in placebo. Our present findings suggest that MS may improve insulin resistance by blocking the AGE-RAGE-oxidative stress axis in the adipose tissues.

Two-hour postload plasma glucose and pigment epithelium-derived factor levels are markers of coronary artery inflammation in type 2 diabetic patients.

BACKGROUND: We have previously found that pioglitazone attenuates inflammation in the left main trunk of coronary artery (LMT), evaluated as target-to-background ratio (TBR) by 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in patients with impaired glucose tolerance or type 2 diabetes. OBJECTIVES: We assessed which clinical variables could predict the change in TBR in the LMT after 4-month add-on therapy with oral hypoglycemic agents (OHAs). METHODS: A total of 38 type 2 diabetic patients with carotid atherosclerosis who had already received OHAs except for pioglitazone was enrolled. At baseline and 4 months after add-on therapy with pioglitazone or glimepiride, all patients underwent 75 g oral glucose tolerance test, blood chemistry analysis, and FDG-PET/CT. RESULTS: Fasting plasma glucose, 30-, 60-, 90-, 120-minutes postload plasma glucose, HbA1c, and LMT-TBR values were significantly decreased by add-on therapy, whereas high-density lipoprotein-cholesterol and adiponectin levels were increased. Increased serum levels of pigment epithelium-derived factor (PEDF), a marker of insulin resistance and non-use of aspirin at baseline could predict the favorable response of LMT-TBR to add-on therapy. Moreover, Δ120-minutes postload plasma glucose and ΔPEDF were independent correlates of ΔLMT-TBR. CONCLUSIONS: Our present study suggests that 120-minutes postload plasma glucose and PEDF values may be markers and potential therapeutic targets of coronary artery inflammation in type 2 diabetic patients. CLINICAL TRIAL REGISTRATION: URL: http://clinicaltrials.gov . Unique identifier: NCT00722631. New markers for diabetes and CAD is on the horizon! Two-hour postload plasma glucose and pigment epithelium derived factor are markers of coronary artery inflammation in type 2 diabetic patients.

GIP as a Potential Therapeutic Target for Atherosclerotic Cardiovascular Disease-A Systematic Review.

Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are gut hormones that are secreted from enteroendocrine L cells and K cells in response to digested nutrients, respectively. They are also referred to incretin for their ability to stimulate insulin secretion from pancreatic beta cells in a glucose-dependent manner. Furthermore, GLP-1 exerts anorexic effects via its actions in the central nervous system. Since native incretin is rapidly inactivated by dipeptidyl peptidase-4 (DPP-4), DPP-resistant GLP-1 receptor agonists (GLP-1RAs), and DPP-4 inhibitors are currently used for the treatment of type 2 diabetes as incretin-based therapy. These new-class agents have superiority to classical oral hypoglycemic agents such as sulfonylureas because of their low risks for hypoglycemia and body weight gain. In addition, a number of preclinical studies have shown the cardioprotective properties of incretin-based therapy, whose findings are further supported by several randomized clinical trials. Indeed, GLP-1RA has been significantly shown to reduce the risk of cardiovascular and renal events in patients with type 2 diabetes. However, the role of GIP in cardiovascular disease remains to be elucidated. Recently, pharmacological doses of GIP receptor agonists (GIPRAs) have been found to exert anti-obesity effects in animal models. These observations suggest that combination therapy of GLP-1R and GIPR may induce superior metabolic and anti-diabetic effects compared with each agonist individually. Clinical trials with GLP-1R/GIPR dual agonists are ongoing in diabetic patients. Therefore, in this review, we summarize the cardiovascular effects of GIP and GIPRAs in cell culture systems, animal models, and humans.

Glyceraldehyde-Derived Pyridinium Evokes Renal Tubular Cell Damage via RAGE Interaction.

Glyceraldehyde-derived advanced glycation end products (glycer-AGEs) contribute to proximal tubulopathy in diabetes. However, what glycer-AGE structure could evoke tubular cell damage remains unknown. We first examined if deleterious effects of glycer-AGEs on reactive oxygen species (ROS) generation in proximal tubular cells were blocked by DNA-aptamer that could bind to glyceraldehyde-derived pyridinium (GLAP) (GLAP-aptamer), and then investigated whether and how GLAP caused proximal tubular cell injury. GLAP-aptamer and AGE-aptamer raised against glycer-AGEs were prepared using a systemic evolution of ligands by exponential enrichment. The binding affinity of GLAP-aptamer to glycer-AGEs was measured with a bio-layer interferometry. ROS generation was evaluated using fluorescent probes. Gene expression was analyzed by reverse transcription-polymerase chain reaction (RT-PCR). GLAP-aptamer bound to glycer-AGEs with a dissociation constant of 7.7 × 10-5 M. GLAP-aptamer, glycer-AGE-aptamer, or antibodies directed against receptor for glycer-AGEs (RAGE) completely prevented glycer-AGE- or GLAP-induced increase in ROS generation, MCP-1, PAI-1, or RAGE gene expression in tubular cells. Our present results suggest that GLAP is one of the structurally distinct glycer-AGEs, which may mediate oxidative stress and inflammatory reactions in glycer-AGE-exposed tubular cells. Blockade of the interaction of GLAP-RAGE by GLAP-aptamer may be a therapeutic target for proximal tubulopathy in diabetic nephropathy.

AGE-RAGE Axis Stimulates Oxidized LDL Uptake into Macrophages through Cyclin-Dependent Kinase 5-CD36 Pathway via Oxidative Stress Generation.

Advanced glycation end products (AGEs) are localized in macrophage-derived foam cells within atherosclerotic lesions, which could be associated with the increased risk of atherosclerotic cardiovascular disease under diabetic conditions. Although foam cell formation of macrophages has been shown to be enhanced by AGEs, the underlying molecular mechanism remains unclear. Since cyclin-dependent kinase 5 (Cdk5) is reported to modulate inflammatory responses in macrophages, we investigated whether Cdk5 could be involved in AGE-induced CD36 gene expression and foam cell formation of macrophages. AGEs significantly increased Dil-oxidized low-density lipoprotein (ox-LDL) uptake, and Cdk5 and CD36 gene expression in U937 human macrophages, all of which were inhibited by DNA aptamer raised against RAGE (RAGE-aptamer). Cdk5 and CD36 gene expression levels were correlated with each other. An antioxidant, N-acetyl-l-cysteine, mimicked the effects of RAGE-aptamer on AGE-exposed U937 cells. A selective inhibitor of Cdk5, (R)-DRF053, attenuated the AGE-induced Dil-ox-LDL uptake and CD36 gene expression, whereas anti-CD36 antibody inhibited the Dil-ox-LDL uptake but not Cdk5 gene expression. The present study suggests that AGEs may stimulate ox-LDL uptake into macrophages through the Cdk5-CD36 pathway via RAGE-mediated oxidative stress.

A Dipeptidyl Peptidase-4 Inhibitor Inhibits Foam Cell Formation of Macrophages in Type 1 Diabetes via Suppression of CD36 and ACAT-1 Expression.

Dipeptidyl peptidase-4 (DPP-4) inhibitors have been reported to play a protective role against atherosclerosis in both animal models and patients with type 2 diabetes (T2D). However, since T2D is associated with dyslipidemia, hypertension and insulin resistance, part of which are ameliorated by DPP-4 inhibitors, it remains unclear whether DPP-4 inhibitors could have anti-atherosclerotic properties directly by attenuating the harmful effects of hyperglycemia. Therefore, we examined whether a DPP-4 inhibitor, teneligliptin, could suppress oxidized low-density lipoprotein (ox-LDL) uptake, foam cell formation, CD36 and acyl-coenzyme A: cholesterol acyltransferase-1 (ACAT-1) gene expression of macrophages isolated from streptozotocin-induced type 1 diabetes (T1D) mice and T1D patients as well as advanced glycation end product (AGE)-exposed mouse peritoneal macrophages and THP-1 cells. Foam cell formation, CD36 and ACAT-1 gene expression of macrophages derived from T1D mice or patients increased compared with those from non-diabetic controls, all of which were inhibited by 10 nmol/L teneligliptin. AGEs mimicked the effects of T1D; teneligliptin attenuated all the deleterious effects of AGEs in mouse macrophages and THP-1 cells. Our present findings suggest that teneligliptin may inhibit foam cell formation of macrophages in T1D via suppression of CD36 and ACAT-1 gene expression partly by attenuating the harmful effects of AGEs.

Concerns about clinical efficacy and safety of warfarin in diabetic patients with atrial fibrillation.

Atrial fibrillation (AF) is one of the most common arrhythmias in elderly people. The risk of thromboembolic stroke is increased in AF patients, especially those with diabetes. Anticoagulant therapy, such as warfarin and non-vitamin K oral anticoagulants (NOACs), is recommended for diabetic patients with AF. However, recent guidelines do not preferentially recommend NOACs over warfarin for diabetic patients. Variability of glycemic control in diabetic patients could affect the pharmacokinetics and anticoagulant activity of warfarin, therefore, the risk-benefit balance of warfarin is prone to be compromised in diabetic patients with AF. Furthermore, since warfarin inhibits the vitamin K-dependent gamma-glutamyl carboxylation of proteins, including osteocalcin and matrix Gla protein, use of warfarin may increase the risk of osteoporotic bone fracture and vascular calcification, both of which are the leading causes of morbidity that diminish the quality of life in diabetic patients. Even though the cost of NOACs is high, NOACs may be preferable to warfarin for the treatment of diabetic patients with AF.

Luseogliflozin attenuates neointimal hyperplasia after wire injury in high-fat diet-fed mice via inhibition of perivascular adipose tissue remodeling.

BACKGROUND: Excess fat deposition could induce phenotypic changes of perivascular adipose tissue (PVAT remodeling), which may promote the progression of atherosclerosis via modulation of adipocytokine secretion. However, it remains unclear whether and how suppression of PVAT remodeling could attenuate vascular injury. In this study, we examined the effect of sodium-glucose cotransporter 2 (SGLT2) inhibitor, luseogliflozin on PVAT remodeling and neointima formation after wire injury in mice. METHODS: Wilt-type mice fed with low-fat diet (LFD) or high-fat diet (HFD) received oral administration of luseogliflozin (18 mg/kg/day) or vehicle. Mice underwent bilateral femoral artery wire injury followed by unilateral removal of surrounding PVAT. After 25 days, injured femoral arteries and surrounding PVAT were analyzed. RESULTS: In LFD-fed lean mice, neither luseogliflozin treatment or PVAT removal attenuated the intima-to-media (I/M) ratio of injured arteries. However, in HFD-fed mice, luseogliflozin or PVAT removal reduced the I/M ratio, whereas their combination showed no additive reduction. In PVAT surrounding injured femoral arteries of HFD-fed mice, luseogliflozin treatment decreased the adipocyte sizes. Furthermore, luseogliflozin reduced accumulation of macrophages expressing platelet-derived growth factor-B (PDGF-B) and increased adiponectin gene expression. Gene expression levels of Pdgf-b in PVAT were correlated with the I/M ratio. CONCLUSIONS: Our present study suggests that luseogliflozin could attenuate neointimal hyperplasia after wire injury in HFD-fed mice partly via suppression of macrophage PDGF-B expression in PVAT. Inhibition of PVAT remodeling by luseogliflozin may be a novel therapeutic target for vascular remodeling after angioplasty.

Role of Advanced Glycation Endproduct (AGE)-Receptor for Advanced Glycation Endproduct (RAGE) Axis in Cardiovascular Disease and Its Therapeutic Intervention.

Despite the early loss of glycemic differences between the original intensive therapy group and conventional treatment in the DCCT/EDIC and UKPDS 80 trials, a continued reduction in microvascular risk and risk reductions for emergency myocardial infarction and all-cause death were observed 10-30 years after the end of these trials. These observations demonstrated that so-called "metabolic memory" could cause chronic abnormalities in diabetic vessels that are not easily reversed, even by subsequent improvement in blood glucose levels, thus suggesting a long-term beneficial influence of early metabolic control; that is, legacy effects on the risk of vascular complications and death in patients with both type 1 and type 2 diabetes. Formation and accumulation of advanced glycation endproducts (AGEs) are known to progress at an accelerated rate under diabetes. Furthermore, AGEs are hardly degraded and remain for a long time in diabetic vessels even after glycemic control is improved. Therefore, AGEs could explain why former cumulative diabetic exposure could contribute to current progression of vascular complications in diabetes. Here, the clinical utility of measurement of serum and tissue accumulation levels of AGEs for evaluating the prevalence and severity of numerous types of cardiovascular disease is reviewed and novel therapeutic strategies that could target the AGE-RAGE axis in CVD are discussed.

Advanced glycation end products evoke inflammatory reactions in proximal tubular cells via autocrine production of dipeptidyl peptidase-4.

We have previously shown that albuminuria and renal levels of advanced glycation end products (AGEs), receptor for AGEs (RAGE), and oxidative stress are suppressed in dipeptidyl peptidase-4 (DPP-4)-deficient diabetic rats, thus suggesting the crosstalk between AGE-RAGE axis and DPP-4 in experimental diabetic nephropathy. Therefore, we examined here the role of DPP-4 in AGE-evoked inflammatory reactions in human proximal tubular cells. Proteins were extracted from proximal tubular cells, and conditioned medium was collected, both of which were subjected to western blot analysis using anti-DPP-4 antibody. RAGE-aptamer was prepared using a systemic evolution of ligands by exponential enrichment. NF-κB p65 and monocyte chemoattractant protein-1 (MCP-1) gene expression was analyzed by reverse transcription-polymerase chain reaction. AGEs significantly increased DPP-4 expression and soluble DPP-4 production by tubular cells, the latter of which was attenuated by RAGE-aptamer or an anti-oxidant, N-acetylcysteine. AGEs or DPP-4 up-regulated NF-κB p65 or MCP-1 mRNA levels in tubular cells, which were suppressed by linagliptin, an inhibitor of DPP-4. AGEs stimulated NF-κB p65 gene expression in tubular cells isolated from control rats, but not from DPP-4-deficient rats. Our present results suggest that the AGE-RAGE-mediated oxidative stress could evoke inflammatory reactions in proximal tubular cells via autocrine production of DPP-4.

Compared effects of calcium and sodium polystyrene sulfonate on mineral and bone metabolism and volume overload in pre-dialysis patients with hyperkalemia.

BACKGROUND: Hyperkalemia is prevalent in end-stage renal disease patients, being involved in life-threatening arrhythmias. Although polystyrene sulfonate (PS) is commonly used for the treatment of hyperkalemia, direct comparison of effects between calcium and sodium PS (CPS and SPS) on mineral and bone metabolism has not yet been studied. METHODS: In a randomized and crossover design, 20 pre-dialysis patients with hyperkalemia (>5 mmol/l) received either oral CPS or SPS therapy for 4 weeks. RESULTS: After 4-week treatments, there was no significant difference of changes in serum potassium (K) from the baseline (ΔK) between the two groups. However, SPS significantly decreased serum calcium (Ca) and magnesium (Mg) and increased intact parathyroid hormone (iPTH) values, whereas CPS reduced iPTH. ΔiPTH was inversely correlated with ΔCa and ΔMg (r = -0.53 and r = -0.50, respectively). Furthermore, sodium (Na) and atrial natriuretic peptide (ANP) levels were significantly elevated in patients with SPS, but not with CPS, whereas ΔNa and ΔANP were significantly correlated with each other in all the patients. We also found that ΔNa and Δ(Na to chloride ratio) were positively correlated with ΔHCO3-. In artificial colon fluid, CPS increased Ca and decreased Na. Furthermore, SPS greatly reduced K, Mg, and NH3. CONCLUSION: Compared with SPS, CPS may be safer for the treatment of hyperkalemia in pre-dialysis patients, because it did not induce hyperparathyroidism or volume overload.

Asymmetric Dimethylarginine Contributes to the Impaired Response to Erythropoietin in CKD-Anemia.

Erythropoietin-resistant anemia is associated with adverse cardiovascular events in patients with ESRD, but the underlying mechanism remains unclear. Here, we evaluated the role of the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA). In 54 patients with advanced CKD, erythrocyte but not plasma ADMA levels independently associated with low hemoglobin values, although levels of both types of ADMA were elevated compared with those in healthy volunteers. Furthermore, erythrocyte ADMA level associated with the erythropoietin resistance index in patients receiving a weekly injected dose of erythropoiesis-stimulating agents standardized for hemoglobin levels and body weight, whereas it correlated with the erythropoietin demand index (plasma erythropoietin units divided by the hemoglobin value) in patients not receiving erythropoiesis-stimulating agents. Compared with sham-operated controls, wild-type mice with 5/6 subtotal nephrectomy (Nx), a remnant kidney model with advanced CKD, had decreased hemoglobin, hematocrit, and mean corpuscular volume values but increased erythrocyte and plasma ADMA and plasma erythropoietin levels. In comparison, dimethylarginine dimethlaminohydrolase-1 transgenic (DDAH-1 Tg) mice, which efficiently metabolized ADMA, had significant improvements in all of the values except those for erythropoietin after 5/6 Nx. Additionally, wild-type Nx mice, but not DDAH-1 Tg Nx mice, had reduced splenic gene expression of erythropoietin receptor and erythroferrone, which regulates iron metabolism in response to erythropoietin. This study suggests that erythrocyte ADMA accumulation contributes to impaired response to erythropoietin in predialysis patients and advanced CKD mice via suppression of erythropoietin receptor expression.

RAGE-aptamer Attenuates the Growth and Liver Metastasis of Malignant Melanoma in Nude Mice.

Epidemiological studies have suggested the link between cumulative diabetic exposure and cancer. Interaction of advanced glycation end products (AGEs) with their receptor (RAGE) may contribute to the phenomenon. We examined here the effects of DNA aptamer raised against RAGE (RAGE-aptamer) on growth and liver metastasis of G361 melanoma in nude mice. Malignant melanoma cells were intradermally injected into the upper flank region of nude mice, which received continuous administration of RAGE-aptamer (38.4 pmol/day/g body weight) or vehicle intraperitoneally by an osmotic pump up to 42 days. RAGE-aptamer significantly reduced levels of 8-hydroxy-2'-deoxy-guanosine, AGEs, RAGE, proliferating nuclear antigen, cyclin D1, vascular endothelial growth factor (VEGF), monocyte chemoattractant protein-1 (MCP-1), and CD31 and Mac-3, respective markers of endothelial cells and macrophages in tumors of nude mice and suppressed the proliferation and liver metastasis of malignant melanoma. Furthermore, RAGE-aptamer attenuated the AGE-induced oxidative stress generation, proliferation, and VEGF and MCP-1 gene expression in both G361 melanoma cells and endothelial cells. The present findings suggest that RAGE-aptamer could attenuate melanoma growth and liver metastasis in nude mice by suppressing the tumor angiogenesis and macrophage infiltration via inhibition of the AGE-RAGE system. RAGE-aptamer may be a novel therapeutic tool for the treatment of malignant melanoma.