Linagliptin exacerbates heart failure due to energy deficiency via downregulation of glucose utilization and absorption in a mouse model.

Use of dipeptidyl peptidase-4 (DPP4) inhibitor in some clinical trials might have caused heart failure (HF), leading to increased hospitalizations. The aim of the present study was to determine whether linagliptin has any effect on chronic dilated HF, and its underlying mechanisms. Physiologic and pathologic studies were conducted on heart/muscle-specific manganese superoxide dismutase-deficient mice, which exhibited dilated cardiomyopathy, and were randomized to receive a low dose (1 mg/kg, HF-L group) or high dose (10 mg/kg, HF-H group) mixed with food, or normal food (HF group), for 8 weeks. Linagliptin increased mortality and heart/body weight ratio in mice with HF. Cardiac contractility and fibrosis worsened, whereas hepatic glycogen content and individual carbohydrate consumption decreased significantly in the HF-H group, when compared with the HF control group. Therefore, we performed a complementary experiment by supplementing glucose to the mice treated with high-dose linagliptin (HF-HG group). Adequate glucose supplementation reduced heart/body weight ratio and cardiac fibrosis, and improved cardiac contractility, without changing mortality. Following oral administration of 13C glucose, the respiratory 13C decreased in the HF-H and HF-HG groups, when compared with that in the HF group; the fecal 13C increased, suggesting that linagliptin inhibited glucose absorbance in the intestine. In addition, the expression of GLUT2, a glucose transporter was downregulated in the small intestine. Linagliptin treatment exacerbated HF, which increased mortality, cardiac function, and fibrosis. DPP4 inhibitors might boost cardiac cachexia and exacerbate HF, at least in part, through the modification of glucose utilization and absorption.

Empagliflozin improves cardiac mitochondrial function and survival through energy regulation in a murine model of heart failure.

BACKGROUND: Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been demonstrated to have beneficial effects on HF in large clinical trials; however, the mechanisms remain to be elucidated. The aim of this study was to clarify the mechanisms by which empagliflozin, one of SGLT2 inhibitors, affects heart failure. METHOD AND RESULTS: Eight-week-old male mice deficient for heart and skeletal muscle-specific manganese superoxide dismutase (MnSOD-cKO mice), a murine model of dilated cardiomyopathy, were given food mixed with or without 10 mg/kg empagliflozin for 7 weeks and evaluated. Both the survival rate and cardiac fibrosis were significantly improved in the empagliflozin group. The capacity for oxidative phosphorylation in cardiac mitochondria was significantly upregulated as measured with Oxygraph-2k respirometer, and blood lactate levels produced by anaerobic metabolism were significantly lower in the empagliflozin group. Energy expenditure was significantly improved in the empagliflozin group, measured by respiratory gas analysis, with a concomitant reduction in serum leptin concentration and increase in food intake. A moderate amount of glucose was excreted in urine in the empagliflozin group; however, the available energy substrate in the body nonetheless expanded because of the much higher caloric intake. CONCLUSIONS: We conclude that empagliflozin improved cardiac mitochondrial function and upregulated energy metabolism even in HF in mice. These findings provide novel mechanisms for the beneficial effects of SGLT2 inhibitors on HF.

A novel soluble epoxide hydrolase vaccine protects murine cardiac muscle against myocardial infarction.

Myocardial infarction is still a life-threatening disease, even though its prognosis has been improved through the development of percutaneous coronary intervention and pharmacotherapy. In addition, heart failure due to remodeling after myocardial infarction requires lifelong management. The aim of this study was to develop a novel treatment suppressing the myocardial damage done by myocardial infarction. We focused on inhibition of soluble epoxide hydrolase to prolong the activation of epoxyeicosatrienoic acids, which have vasodilatory and anti-inflammatory properties. We successfully made a new vaccine to inactivate soluble epoxide hydrolase, and we have evaluated the effect of the vaccine in a rat myocardial infarction model. In the vaccinated group, the ischemic area was significantly reduced, and cardiac function was significantly preserved. Vaccine treatment clearly increased microvessels in the border area and suppressed fibrosis secondary to myocardial infarction. This soluble epoxide hydrolase vaccine is a novel treatment for improving cardiac function following myocardial infarction.

Simple risk-score model for in-hospital major bleeding based on multiple blood variables in patients with acute myocardial infarction.

BACKGROUND: In-hospital bleeding is associated with poor prognosis in patients with acute myocardial infarction (AMI). We sought to investigate whether a combination of pre-procedural blood tests could predict the incidence of in-hospital major bleeding in patients with AMI. METHODS AND RESULTS: A total of 1684 consecutive AMI patients who underwent primary percutaneous coronary intervention (PCI) were recruited and randomly divided into derivation (n = 1010) and validation (n = 674) cohorts. A risk-score model was created based on a combination of parameters assessed on routine blood tests on admission. In the derivation cohort, multivariate analysis revealed that the following 5 variables were significantly associated with in-hospital major bleeding: hemoglobin level < 12 g/dL (odds ratio [OR], 3.32), white blood cell count >10,000/µL (OR, 2.58), platelet count <150,000/µL (OR, 2.51), albumin level < 3.8 mg/dL (OR, 2.51), and estimated glomerular filtration rate < 60 mL/min/1.73 m2 (OR, 2.31). Zero to five points were given according to the number of these factors each patient had. Incremental risk scores were significantly associated with a higher incidence of in-hospital major bleeding in both cohorts (P < 0.001). Receiver operating characteristic curve analysis of risk models showed adequate discrimination between patients with and without in-hospital major bleeding (derivation cohort: area under the curve [AUC], 0.807; 95% confidence interval [CI], 0.759-0.848; validation cohort: AUC, 0.793; 95% CI, 0.725-0.847). CONCLUSIONS: Our novel laboratory-based bleeding risk model could be useful for simple and objective prediction of in-hospital major bleeding events in patients with AMI.

GLP-1 analog liraglutide-induced cardiac dysfunction due to energetic starvation in heart failure with non-diabetic dilated cardiomyopathy.

BACKGROUND: Glucagon-like peptide-1 (GLP-1) reduces cardiovascular events in diabetic patients; however, its counter-protective effects have also been suggested in patients with heart failure and the clear explanation for its mechanisms have not yet been offered. METHODS: The effects of GLP-1 analog on cardiac function and energy metabolism, especially glycemic and lipid metabolisms were elucidated using non-diabetic J2N-k hamsters which showed spontaneous dilated cardiomyopathy. J2N-k hamsters were treated with PBS (HF group), low-dose (HF-L group) or high-dose liraglutide (HF-H group). RESULTS: In failing heart, GLP-1 analog exerted further deteriorated cardiac function (e.g. positive and negative dP/dt; p = 0.01 and p = 0.002, respectively) with overt fibrosis and cardiac enlargement (heart/body weight, 5.7 ± 0.2 in HF group versus 7.6 ± 0.2 in HF-H group; p = 0.02). The protein expression of cardiac muscles indicated the energy starvation status. Indirect calorimetry showed that failing hearts consumed higher energy and carbohydrate than normal hearts; moreover, this tendency was augmented by GLP-1 analog administration. Upon 10% glucose solution loading with GLP-1 analog administration (HF-H-G group) as complementary experiments, the cardiac function and fibrosis significantly ameliorated, whereas carbohydrate utilization augmented further and lipid utilization reduced more. The prognosis of HF-H-G group also significantly improved (p = 0.025). CONCLUSIONS: Glucagon-like peptide-1 analog caused the relative but desperate shortage of glycemic energy source for the failing cardiac muscles and it may restrict ATP synthesis, resulting in cardiac function deterioration. Therefore, appropriate energy supply and amount of carbohydrate intake should be carefully considered when administrating incretin-related drugs to patients with heart failure.

COA-Cl (2-Cl-C.OXT-A) can promote coronary collateral development following acute myocardial infarction in mice.

2-Cl-C.OXT-A (COA-Cl) is a novel nucleic acid analogue that promotes tube-forming activity of human umbilical vein endothelial cells (HUVEC) through vascular endothelial growth factor (VEGF). The development of coronary collateral circulation is critical to rescue the ischemic myocardium and to prevent subsequent irreversible ischemic injury. We evaluated whether COA-Cl can promote angiogenesis in ischemic tissue, reduce infarct size and preserve cardiac contractility in vivo. Mice received COA-Cl or placebo daily for three days after myocardial infarction (MI) by coronary ligation. The degree of angiogenesis in ischemic myocardium was assessed by staining endothelial cells and vascular smooth muscle cells, and measuring infarct size/area-at-risk. In mice treated with COA-Cl, enhanced angiogenesis and smaller infarct size were recognized, even given a similar area at risk. We observed increases in the protein expression levels of VEGF and in the protein phosphorylation level of eNOS. In addition, the heart weight to body weight ratio and myocardial fibrosis in COA-Cl mice were decreased on Day 7. Administration of COA-Cl after MI promotes angiogenesis, which is associated with reduced infarct size and attenuated cardiac remodeling. This may help to prevent heart failure due to cardiac dysfunction after MI.

Azelnidipine Inhibits the Differentiation and Activation of THP-1 Macrophages through the L-Type Calcium Channel.

AIM: Recently, calcium channel blockers (CCBs) have been reported to reduce atherosclerosis with anti-inflammatory or antiatherosclerotic effects in vivo. It is well established that monocytes and macrophages play important roles in promoting atherosclerosis. However, the effects of CCBs on macrophage activation remain unclear. The aim of this study was to evaluate the effects of azelnidipine, a dihydropyridine L-type CCB, on the activation of macrophages and to clarify the mechanisms of the effects of CCBs on atherosclerosis. METHODS: THP-1 monocytes, a human leukemic cell line, were stimulated with 50 ng/mL of phorbol-12-myristate-13-acetate (PMA) 1 h after pretreatment with 10 µM azelnidipine or dimethyl sulfoxide (DMSO), and harvested. RESULTS: Azelnidipine blocked the expression of intercellular adhesion molecule-1 quantified by FACS analysis. The expression levels of Apo E and MMP9, which are markers of macrophage differentiation, were inhibited by azelnidipine as evaluated by quantitative RT-PCR. The level of LOX-1 mRNA, a scavenger receptor, was also reduced significantly by pretreatment with 10 µM azelnidipine. Azelnidipine also lowered the uptake of acetylated LDL. The expression of the L-type calcium channel Cav1.2 was 10-fold higher after 24 h of PMA stimulation. A knockdown of the CACNA1C gene, which encodes Cav1.2 protein in humans, with siRNA blocked the effect of reducing adhesion by azelnidipine, indicating that the effects of azelnidipine on macrophage differentiation were expressed through the CACNA1C gene. CONCLUSION: Our results suggest that azelnidipine has potent antiatherosclerotic properties by inhibition of macrophage activation through Cav1.2.

Efficacy and safety of sitagliptin in elderly patients with type 2 diabetes mellitus.

AIM: The aim of the present study was to assess the efficacy and safety of sitagliptin in elderly patients with type 2 diabetes mellitus. METHODS: A total of 188 patients were enrolled who had type 2 diabetes mellitus with poor glycemic profiles (hemoglobin A1c [HbA1c] ≥6.2%). Patients were assigned to one of three age groups (<65, 65-74 and ≥75 years) and received 50-100 mg of sitagliptin daily for 12 months. Changes in HbA1c classified by age and body mass index (BMI) were assessed in addition to physiological parameters. RESULTS: Mean HbA1c decreased significantly in all age groups (<65 years 8.01 ± 1.59% to 7.29 ± 1.23%; 65-74 years 7.61 ± 1.11% to 7.05 ± 0.99%; ≥75 years 7.21 ± 0.87% to 6.74 ± 0.96%). Reductions in HbA1c were not significantly different among age groups (P = 0.324). In older patients aged 65-74 years and ≥75 years, HbA1c decreased significantly in lean (BMI <25 kg/m2 ) patients (7.52 ± 1.10% to 6.99 ± 1.08%; P < 0.001) and in obese (BMI ≥25 kg/m2 ) patients (7.25% ± 0.90% to 6.86% ± 0.86%; P = 0.015); the changes in HbA1c were not significantly different between the lean and the obese groups (P = 0.943). Adverse events occurred in 12 patients (10.3%) aged ≥65 years, although there was no significant difference among the three age groups. CONCLUSIONS: Sitagliptin treatment offers elderly patients aged ≥65 years efficacious and safe reductions in HbA1c values regardless of BMI. Geriatr Gerontol Int 2018; 18: 631-639.

EGCG, a green tea catechin, attenuates the progression of heart failure induced by the heart/muscle-specific deletion of MnSOD in mice.

BACKGROUND: Manganese superoxide dismutase (MnSOD) is an important antioxidant enzyme affected in heart/muscle-specific MnSOD-deficient mice (H/M-SOD2-/-), which develop progressive congestive heart failure and exhibit pathology typical of dilated cardiomyopathy. METHODS: In this study we investigated the beneficial effects of epigallocatechin gallate (EGCG) on the cardiac remodeling and telomere biology in H/M-SOD2-/- mice. H/M-SOD2-/- mice were divided into three groups: those receiving normal drinking water (KO), a low dose of EGCG (L: 10mg/L), and a high dose of EGCG (H: 100mg/L) beginning at eight weeks of age and lasting for eight weeks. RESULTS: The mice in the KO group exhibited significantly dilated cardiac remodeling with reduced contractility, which was prevented by the administration of EGCG. Although the mortality of KO mice was about 50% at 16 weeks of age, the mice that received EGCG had a high survival rate. The cardiac dilatation with reduced cardiac contraction in KO mice was prevented by EGCG treatment. The levels of myocardial oxidative stress and free fatty acids were lower in the group treated with EGCG compared with the KO group. The increased expression of nitric oxide synthase 2, nitrotyrosine, fatty acid synthase, Toll-like receptor 4, and Sirt1 in the KO mice were prevented by EGCG treatment. The shortening of the telomere length, decreased telomerase activity in KO mice were also prevented by EGCG. CONCLUSIONS: H/M-SOD2-/- mice receiving EGCG have a lower mortality rate and exhibit less inflammation and a better preserved cardiac function and telomere biology.

A possible role for HLA-DRB1*04:06 in statin-related myopathy in Japanese patients.

Statin-related myopathy (SRM) is a clinically important adverse reaction. Recent pharmacogenetic research, mainly in non-Asian populations, have indicated clinical relevance of some of genetic biomarkers to SRM, but predictive markers for SRM in Asian populations including Japanese has not yet been established. This study was aimed to identify clinically important genetic markers associated with SRM in Japanese patients. Allele frequencies of the three reported candidate markers - SLCO1B1 rs4149056, RYR2 rs2819742, and GATM rs9806699 - and carrier frequencies of HLA types were compared between patients with SRM patients (n = 52) and healthy Japanese subjects (n = 2878 or 86 (for rs9806699) as controls). No significant association of RYR2, SLCO1B1, and GATM variants with SRM were observed in our Japanese patients, but a significant association was detected for HLA-DRB1*04:06 with SRM (odds ratio: 3.19; 95% confidence interval: 1.53-6.66). This study suggested that HLA-DRB1*04:06 might be associated with SRM onset in a Japanese population. Further studies are required to validate these results.

Deletion of Apoptosis Inhibitor of Macrophage (AIM)/CD5L Attenuates the Inflammatory Response and Infarct Size in Acute Myocardial Infarction.

BACKGROUND: An excessive inflammatory response after myocardial infarction (MI) increases myocardial injury. The toll-like receptor (TLR)-4 is activated by the recognition of endogenous ligands and is proinflammatory when there is myocardial tissue injury. The apoptosis inhibitor of the macrophage (AIM) is known to provoke an efflux of saturated free fatty acids (FFA) due to lipolysis, which causes inflammation via the TLR-4 pathway. Therefore, this study investigated the hypothesis that AIM causes a proinflammatory response after MI. METHODS AND RESULTS: The left anterior descending coronary artery was ligated to induce MI in both AIM-knockout (AIM(-/-)) and wild-type (WT) mice. After 3 days, the inflammatory response from activation of the TLR-4/NFκB pathway was assessed, and infarct size was measured by staining with triphenyltetrazolium chloride. In addition, left ventricular remodeling was examined after 28 days. Although the area at risk was similar between AIM(-/-) and WT mice, the infarct size was significantly smaller in AIM(-/-) mice (P=0.02). The heart weight-to-body weight ratio and myocardial fibrosis were also decreased in the AIM(-/-) mice, and the 28-day survival rate was improved (P<0.01). With the reduction of plasma FFA in AIM(-/-) mice, myocardial IRAK4 and NFκB activity were decreased (all P<0.05). Moreover, there was a reduction in myeloperoxidase activity and inducible nitric oxide synthase as part of the inflammatory response (P<0.01, P=0.03, respectively). Furthermore, NFκB DNA-binding activation via TLR-4, neutrophil infiltration, and inflammatory mediators were decreased in AIM(-/-) mice. CONCLUSIONS: The deletion of AIM reduced the inflammatory response and infarct size and improved survival after myocardial infarction.

The relationship between neutrophil to lymphocyte ratio, endothelial function, and severity in patients with obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea (OSA) is characterized by repetitive intermittent hypoxia and reoxygenation during sleep with elevated oxidative stress and promotes the development of atherosclerosis, as demonstrated by vascular dysfunction and chronic inflammation. An increased neutrophil to lymphocyte ratio (NLR) has been recognized to be a novel inflammatory biomarker for systemic inflammation. OBJECTIVES: We evaluated whether the NLR reflects the severity of OSA and if continuous positive airway pressure (CPAP) treatment ameliorates the endothelial function and NLR in patients with OSA. METHODS: We enrolled 95 patients with suspected OSA and 29 patients who received CPAP therapy for 3 months. We evaluated the number of endothelial progenitor cells (EPCs) and NLR, the levels of nitric oxide (NOx) and asymmetric dimethylarginine (ADMA), and the endothelial function according to the flow-mediated dilatation (FMD) before and after CPAP treatment. RESULTS: The levels of apnea-hypopnea index demonstrated an inverse relationship with the FMD and a positive relationship with the NLR. Moreover, NLR is an independent factor suggested for the presence of severe OSA. CPAP therapy increased the levels of EPC and NOx and decreased the level of ADMA. CPAP treatment also improved the FMD and decreased the NLR. CONCLUSIONS: NLR and endothelial dysfunction significantly correlates with the severity of OSA and FMD and other biochemical parameters improved and NLR decreased significantly after CPAP treatment.

Pentraxin-3 regulates the inflammatory activity of macrophages.

BACKGROUND AND AIMS: Pentraxin-3 (PTX3) reportedly has protective roles in atherosclerosis and myocardial infarction, and is a useful biomarker of vascular inflammation. However, the detailed functions of PTX3 in inflammation are yet to be elucidated. This study aimed to investigate the function of PTX3 in macrophages. METHODS: PMA-treated THP-1 cell line (THP-1 macrophage) and monocyte-derived human primary macrophages were treated with recombinant PTX3. Cytokine and chemokine levels in the THP-1 culture medium were measured as well as monocyte chemoattractant protein (MCP-1) concentrations in the Raw 264.7 cell culture medium. PTX3-silenced apoptotic macrophages (THP-1 cell line) were generated to investigate the roles of PTX3 in phagocytosis. RESULTS: In the presence of PTX3, macrophage interleukin-1ß (IL-1ß), tumor necrosis factor-alpha (TNF-α) and MCP-1 levels were reduced significantly (-39%, P=0.007; -21%, P=0.008; and -67%, P=0.0003, respectively), whilst activated transforming growth factor-ß (TGF-ß) was detected in the THP-1 macrophages (P=0.0004). Additionally, PTX3 induced Akt phosphorylation and reduced nuclear factor-kappa B (NF-κB) activation by 35% (P=0.002), which was induced by TNF-α in THP-1 macrophages. Furthermore, silencing of PTX3 in apoptotic cells resulted in increased macrophage binding, elevated expression rate of HLA-DR (+30%, P=0.015) and CD86 (+204%, P=0.004) positive cells, and induction of IL-1ß (+36%, P=0.024) production. Conversely, adding recombinant PTX3 to macrophages reduced CD86 and HLA-DR expression in a dose-dependent manner. CONCLUSIONS: We identified PTX3 as a novel regulator of macrophage activity, and this function suggests that PTX3 acts to resolve inflammation.

Possible effects of glimepiride beyond glycemic control in patients with type 2 diabetes: a preliminary report.

BACKGROUND: The purpose of this study was to elucidate the effects of glimepiride on the levels of biomarkers related to cardiovascular regulation in patients with type 2 diabetes mellitus. METHODS AND RESULTS: Thirty-four patients with type 2 diabetes received glimepiride for 24 weeks. Significant decreases in the levels of glyceraldehyde-derived advanced glycation end products, (glycer-AGE: toxic AGE), eotaxin and fibroblast growth factor (FGF)-2 were recognized after the administration of glimepiride. Moreover, there were trends for there to be increases in the levels of granulocyte-colony stimulating factor (G-CSF) and granulocyte macrophage-colony stimulating factor (GM-CSF), and decreases in the levels of fractalkine, soluble CD40 ligand (sCD40L), macrophage inflammatory protein (MIP)-ß, vascular endothelial growth factor (VEGF) and soluble receptor for AGE (sRAGE). CONCLUSIONS: Glimepiride may have potent anti-oxidative, anti-inflammatory and angiogenic properties and it may potentially repair tissue damage by decreasing the levels of toxic AGE and increasing colony-stimulating factors.

The glucagon-like peptide 1 analog liraglutide reduces TNF-α-induced oxidative stress and inflammation in endothelial cells.

OBJECTIVE: Glucagon-like peptide 1 (GLP-1), one of the incretin hormones, has been reported to increase positive inotropic activity in cardiac myocytes and protect against myocardial injury. However, the effects upon endothelial cells and the mechanisms involved are not fully understood. We assessed the hypothesis that GLP-1 has protective effects against inflammation and oxidative stress on human endothelial cells. METHODS AND RESULTS: The effects of the GLP-1 analog liraglutide upon TNF-α-induced injury of the human umbilical vein endothelial cells (HUVECs) were evaluated. First, ROS induced by TNF-α was measured by staining with CM-H(2)DCFDA. Intracellular ROS production of HUVECs was significantly decreased in a dose-dependent manner until 30 nM while liraglutide inhibited the induction of gp91(phox) and p22(phox), subunit of NADPH oxidase, by TNF-α. In addition, protein levels of SOD-2, catalase and GPx were significantly increased by liraglutide. Second, rapid translocation of PKC-α into the membrane following TNF-α was evident. Liraglutide significantly inhibited this very rapid TNF-α-induced translocation of PKC-α into membrane at 2.5 min. Third, liraglutide significantly inhibited NF-κB activation and upregulated I-κB family while phosphorylation of IKK-α/ß, which is upstream of NF-κB signaling, was also downregulated after 15 min of TNF-α treatment. Finally, liraglutide inhibited apoptosis of HUVEC and expression of Pentraxin-3 induced by TNF-α. CONCLUSION: Liraglutide exerts marked anti-oxidative and anti-inflammatory effects on endothelial cells with inhibition of PKC-α, NADPH oxidase, NF-κB signaling and upregulation of protective anti-oxidative enzymes.

Identification of pendrin as a common mediator for mucus production in bronchial asthma and chronic obstructive pulmonary disease.

Excessive production of airway mucus is a cardinal feature of bronchial asthma and chronic obstructive pulmonary disease (COPD) and contributes to morbidity and mortality in these diseases. IL-13, a Th2-type cytokine, is a central mediator in the pathogenesis of bronchial asthma, including mucus overproduction. Using a genome-wide search for genes induced in airway epithelial cells in response to IL-13, we identified pendrin encoded by the SLC26A4 (PDS) gene as a molecule responsible for airway mucus production. In both asthma and COPD mouse models, pendrin was up-regulated at the apical side of airway epithelial cells in association with mucus overproduction. Pendrin induced expression of MUC5AC, a major product of mucus in asthma and COPD, in airway epithelial cells. Finally, the enforced expression of pendrin in airway epithelial cells in vivo, using a Sendai virus vector, rapidly induced mucus overproduction in the lumens of the lungs together with neutrophilic infiltration in mice. These findings collectively suggest that pendrin can induce mucus production in airway epithelial cells and may be a therapeutic target candidate for bronchial asthma and COPD.