Pharmacologic Activation of Angiotensin-Converting Enzyme II Alleviates Diabetic Cardiomyopathy in db/db Mice by Reducing Reactive Oxidative Stress

Background@#Diabetes mellitus is one of the most common chronic diseases worldwide, and cardiovascular disease is the leading cause of morbidity and mortality in diabetic patients. Diabetic cardiomyopathy (DCM) is a phenomenon characterized by a deterioration in cardiac function and structure, independent of vascular complications. Among many possible causes, the renin-angiotensin-aldosterone system and angiotensin II have been proposed as major drivers of DCM development. In the current study, we aimed to investigate the effects of pharmacological activation of angiotensin-converting enzyme 2 (ACE2) on DCM. @*Methods@#The ACE2 activator diminazene aceturate (DIZE) was administered intraperitoneally to male db/db mice (8 weeks old) for 8 weeks. Transthoracic echocardiography was used to assess cardiac mass and function in mice. Cardiac structure and fibrotic changes were examined using histology and immunohistochemistry. Gene and protein expression levels were examined using quantitative reverse transcription polymerase chain reaction and Western blotting, respectively. Additionally, RNA sequencing was performed to investigate the underlying mechanisms of the effects of DIZE and identify novel potential therapeutic targets for DCM. @*Results@#Echocardiography revealed that in DCM, the administration of DIZE significantly improved cardiac function as well as reduced cardiac hypertrophy and fibrosis. Transcriptome analysis revealed that DIZE treatment suppresses oxidative stress and several pathways related to cardiac hypertrophy. @*Conclusion@#DIZE prevented the diabetes mellitus-mediated structural and functional deterioration of mouse hearts. Our findings suggest that the pharmacological activation of ACE2 could be a novel treatment strategy for DCM.

Exploring the Genetic Associations Between the Use of Statins and Alzheimer's Disease

Objective@#Alzheimer's disease (AD) is the most common cause of dementia. The statins have shown beneficial effects on cognitive functions and reduced the risk of dementia development. However, the exact mechanisms of statin effects in AD are not yet fully understood. In this study, we aimed to explore the underlying mechanisms of statin on AD. @*Methods@#We downloaded AD blood dataset (GSE63060) and statin-related blood gene expression dataset (GSE86216). Then we performed gene expression analysis of each dataset and compared blood gene expressions between AD patients and statin-treated patients. Then, we downloaded mouse embryonic neural stem cell dataset (GSE111945) and performed gene expression analysis. @*Results@#From the human blood dataset, we identified upregulated/downregulated genes in AD patients and statin-treated patients. Some of the upregulated genes (AEN, MBTPS1, ABCG1) in the blood of AD patients are downregulated in statin-treated patients. Several downregulated genes (FGL2, HMGCS1, PSME2, SRSF3, and ATG3) are upregulated in statintreated patients. Gene set enrichment analysis using mouse stem cell dataset revealed a significant relationship of Kyoto Encyclopedia of Genes and Genomes-defined pathway of AD in statin-treated neural stem cells compared to vehicle-treated neural stem cells (normalized enrichment score: −2.24 in male and −1.6 in female). @*Conclusion@#These gene expression analyses from human blood and mouse neural stem cell demonstrate the important clues on the molecular mechanisms of impacts of statin on AD disease. Further studies are needed to investigate the exact role of candidate genes and pathways suggested in our AD pathogenesis study.

Serotonergic Regulation of Hepatic Energy Metabolism

The liver is a vital organ that regulates systemic energy metabolism and many physiological functions. Nonalcoholic fatty liver disease (NAFLD) is the commonest cause of chronic liver disease and end-stage liver failure. NAFLD is primarily caused by metabolic disruption of lipid and glucose homeostasis. Serotonin (5-hydroxytryptamine [5-HT]) is a biogenic amine with several functions in both the central and peripheral systems. 5-HT functions as a neurotransmitter in the brain and a hormone in peripheral tissues to regulate systemic energy homeostasis. Several recent studies have proposed various roles of 5-HT in hepatic metabolism and inflammation using tissue-specific knockout mice and 5-HT-receptor agonists/antagonists. This review compiles the most recent research on the relationship between 5-HT and hepatic metabolism, and the role of 5-HT signaling as a potential therapeutic target in NAFLD.

Efficacy and Safety of the New Appetite Suppressant, Liraglutide: A Meta-Analysis of Randomized Controlled Trials

Background@#Obesity is a chronic disease associated with metabolic diseases such as diabetes and cardiovascular disease. Since the U.S. Food and Drug Administration approved liraglutide as an anti-obesity drug for nondiabetic patients in 2014, it has been widely used for weight control in overweight and obese people. This study aimed to systematically analyze the effects of liraglutide on body weight and other cardiometabolic parameters. @*Methods@#We investigated articles from PubMed, EMBASE, and the Cochrane Library to search randomized clinical trials that examined body weight changes with liraglutide treatment. @*Results@#We included 31 studies with 8,060 participants for this meta-analysis. The mean difference (MD) between the liraglutide group and the placebo group was −4.19 kg (95% confidence interval [CI], −4.84 to −3.55), with a −4.16% change from the baseline (95% CI, −4.90 to −3.43). Liraglutide treatment correlated with a significantly reduced body mass index (MD: −1.55; 95% CI, −1.76 to −1.34) and waist circumference (MD: −3.11 cm; 95% CI, −3.59 to −2.62) and significantly decreased blood pressure (systolic blood pressure, MD: −2.85 mm Hg; 95% CI, −3.36 to −2.35; diastolic blood pressure, MD: −0.66 mm Hg; 95% CI, −1.02 to −0.30), glycated hemoglobin (MD: −0.40%; 95% CI, −0.49 to −0.31), and low-density lipoprotein cholesterol (MD: –2.91 mg/dL; 95% CI, −5.28 to −0.53; MD: −0.87% change from baseline; 95% CI, −1.17 to −0.56). @*Conclusion@#Liraglutide is effective for weight control and can be a promising drug for cardiovascular protection in overweight and obese people.

Efficacy and Safety of the New Appetite Suppressant, Liraglutide: A Meta-Analysis of Randomized Controlled Trials

Background@#Obesity is a chronic disease associated with metabolic diseases such as diabetes and cardiovascular disease. Since the U.S. Food and Drug Administration approved liraglutide as an anti-obesity drug for nondiabetic patients in 2014, it has been widely used for weight control in overweight and obese people. This study aimed to systematically analyze the effects of liraglutide on body weight and other cardiometabolic parameters. @*Methods@#We investigated articles from PubMed, EMBASE, and the Cochrane Library to search randomized clinical trials that examined body weight changes with liraglutide treatment. @*Results@#We included 31 studies with 8,060 participants for this meta-analysis. The mean difference (MD) between the liraglutide group and the placebo group was −4.19 kg (95% confidence interval [CI], −4.84 to −3.55), with a −4.16% change from the baseline (95% CI, −4.90 to −3.43). Liraglutide treatment correlated with a significantly reduced body mass index (MD: −1.55; 95% CI, −1.76 to −1.34) and waist circumference (MD: −3.11 cm; 95% CI, −3.59 to −2.62) and significantly decreased blood pressure (systolic blood pressure, MD: −2.85 mm Hg; 95% CI, −3.36 to −2.35; diastolic blood pressure, MD: −0.66 mm Hg; 95% CI, −1.02 to −0.30), glycated hemoglobin (MD: −0.40%; 95% CI, −0.49 to −0.31), and low-density lipoprotein cholesterol (MD: –2.91 mg/dL; 95% CI, −5.28 to −0.53; MD: −0.87% change from baseline; 95% CI, −1.17 to −0.56). @*Conclusion@#Liraglutide is effective for weight control and can be a promising drug for cardiovascular protection in overweight and obese people.

Mitochondrial Quality Control in the Heart: New Drug Targets for Cardiovascular Disease

Despite considerable efforts to prevent and treat cardiovascular disease (CVD), it has become the leading cause of death worldwide. Cardiac mitochondria are crucial cell organelles responsible for creating energy-rich ATP and mitochondrial dysfunction is the root cause for developing heart failure. Therefore, maintenance of mitochondrial quality control (MQC) is an essential process for cardiovascular homeostasis and cardiac health. In this review, we describe the major mechanisms of MQC system, such as mitochondrial unfolded protein response and mitophagy. Moreover, we describe the results of MQC failure in cardiac mitochondria. Furthermore, we discuss the prospects of 2 drug candidates, urolithin A and spermidine, for restoring mitochondrial homeostasis to treat CVD.

Serotonin Regulates De Novo Lipogenesis in Adipose Tissues through Serotonin Receptor 2A

Background@#Obesity is defined as excessive fat mass and is a major cause of many chronic diseases such as diabetes, cardiovascular disease, and cancer. Increasing energy expenditure and regulating adipose tissue metabolism are important targets for the treatment of obesity. Serotonin (5-hydroxytryptophan [5-HT]) is a monoamine metabolite of the essential amino acid tryptophan. Here, we demonstrated that 5-HT in mature adipocytes regulated energy expenditure and lipid metabolism. @*Methods@#Tryptophan hydroxylase 1 (TPH1) is the rate-limiting enzyme during 5-HT synthesis in non-neural peripheral tissues. We generated adipose tissue-specific Tph1 knockout (Tph1 FKO) mice and adipose tissue-specific serotonin receptor 2A KO (Htr2a FKO) mice and analyzed their phenotypes during high-fat diet (HFD) induced obesity. @*Results@#Tph1 FKO mice fed HFD exhibited reduced lipid accumulation, increased thermogenesis, and resistance to obesity. In addition, Htr2a FKO mice fed HFD showed reduced lipid accumulation in white adipose tissue and resistance to obesity. @*Conclusion@#These data suggest that the inhibition of serotonin signaling might be an effective strategy in obesity.

Mitochondrial Quality Control in the Heart: New Drug Targets for Cardiovascular Disease

Despite considerable efforts to prevent and treat cardiovascular disease (CVD), it has become the leading cause of death worldwide. Cardiac mitochondria are crucial cell organelles responsible for creating energy-rich ATP and mitochondrial dysfunction is the root cause for developing heart failure. Therefore, maintenance of mitochondrial quality control (MQC) is an essential process for cardiovascular homeostasis and cardiac health. In this review, we describe the major mechanisms of MQC system, such as mitochondrial unfolded protein response and mitophagy. Moreover, we describe the results of MQC failure in cardiac mitochondria. Furthermore, we discuss the prospects of 2 drug candidates, urolithin A and spermidine, for restoring mitochondrial homeostasis to treat CVD.

Cardioprotective Potential of an SGLT2 Inhibitor Against Doxorubicin-Induced Heart Failure

BACKGROUND AND OBJECTIVES@#Recent studies have shown that sodium-glucose co-transporter 2 (SGLT2) inhibitors reduce the risk of heart failure (HF)-associated hospitalization and mortality in patients with diabetes. However, it is not clear whether SGLT2 inhibitors have a cardiovascular benefit in patients without diabetes. We aimed to determine whether empagliflozin (EMPA), an SGLT2 inhibitor, has a protective role in HF without diabetes.@*METHODS@#Cardiomyopathy was induced in C57BL/6J mice using intraperitoneal injection of doxorubicin (Dox). Mice with HF were fed a normal chow diet (NCD) or an NCD containing 0.03% EMPA. Then we analyzed their phenotypes and performed in vitro experiments to reveal underlying mechanisms of the EMPA's effects.@*RESULTS@#Mice fed NCD with EMPA showed improved heart function and reduced fibrosis. In vitro studies showed similar results. Phloridzin, a non-specific SGLT inhibitor, did not show any protective effect against Dox toxicity in H9C2 cells. SGLT2 inhibitor can cause increase in blood ketone levels. Beta hydroxybutyrate (βOHB), which is well known ketone body associated with SGLT2 inhibitor, showed a protective effect against Dox in H9C2 cells and in Dox-treated mice. These results suggest elevating βOHB might be a convincing mechanism for the protective effects of SGLT2 inhibitor.@*CONCLUSIONS@#SGLT2 inhibitors have a protective effect in Dox-induced HF in mice. This implied that SGLT2 inhibitor therapy could be a good treatment strategy even in HF patients without diabetes.

Essential Role of Protein Arginine Methyltransferase 1 in Pancreas Development by Regulating Protein Stability of Neurogenin 3

BACKGROUND: Protein arginine methyltransferase 1 (PRMT1) is a major enzyme responsible for the formation of methylarginine in mammalian cells. Recent studies have revealed that PRMT1 plays important roles in the development of various tissues. However, its role in pancreas development has not yet been elucidated. METHODS: Pancreatic progenitor cell-specific Prmt1 knock-out (Prmt1 PKO) mice were generated and characterized for their metabolic and histological phenotypes and their levels of Neurog3 gene expression and neurogenin 3 (NGN3) protein expression. Protein degradation assays were performed in mPAC cells. RESULTS: Prmt1 PKO mice showed growth retardation and a severely diabetic phenotype. The pancreatic size and β-cell mass were significantly reduced in Prmt1 PKO mice. Proliferation of progenitor cells during the secondary transition was decreased and endocrine cell differentiation was impaired. These defects in pancreas development could be attributed to the sustained expression of NGN3 in progenitor cells. Protein degradation assays in mPAC cells revealed that PRMT1 was required for the rapid degradation of NGN3. CONCLUSION: PRMT1 critically contributes to pancreas development by destabilizing the NGN3 protein.

Cardioprotective Potential of an SGLT2 Inhibitor Against Doxorubicin-Induced Heart Failure

BACKGROUND AND OBJECTIVES: Recent studies have shown that sodium-glucose co-transporter 2 (SGLT2) inhibitors reduce the risk of heart failure (HF)-associated hospitalization and mortality in patients with diabetes. However, it is not clear whether SGLT2 inhibitors have a cardiovascular benefit in patients without diabetes. We aimed to determine whether empagliflozin (EMPA), an SGLT2 inhibitor, has a protective role in HF without diabetes. METHODS: Cardiomyopathy was induced in C57BL/6J mice using intraperitoneal injection of doxorubicin (Dox). Mice with HF were fed a normal chow diet (NCD) or an NCD containing 0.03% EMPA. Then we analyzed their phenotypes and performed in vitro experiments to reveal underlying mechanisms of the EMPA's effects. RESULTS: Mice fed NCD with EMPA showed improved heart function and reduced fibrosis. In vitro studies showed similar results. Phloridzin, a non-specific SGLT inhibitor, did not show any protective effect against Dox toxicity in H9C2 cells. SGLT2 inhibitor can cause increase in blood ketone levels. Beta hydroxybutyrate (βOHB), which is well known ketone body associated with SGLT2 inhibitor, showed a protective effect against Dox in H9C2 cells and in Dox-treated mice. These results suggest elevating βOHB might be a convincing mechanism for the protective effects of SGLT2 inhibitor. CONCLUSIONS: SGLT2 inhibitors have a protective effect in Dox-induced HF in mice. This implied that SGLT2 inhibitor therapy could be a good treatment strategy even in HF patients without diabetes.

Inhibition of Serotonin Synthesis Induces Negative Hepatic Lipid Balance

BACKGROUND: Hepatic steatosis is caused by metabolic stress associated with a positive lipid balance, such as insulin resistance and obesity. Previously we have shown the anti-obesity effects of inhibiting serotonin synthesis, which eventually improved insulin sensitivity and hepatic steatosis. However, it is not clear whether serotonin has direct effect on hepatic lipid accumulation. Here, we showed the possibility of direct action of serotonin on hepatic steatosis. METHODS: Mice were treated with para-chlorophenylalanine (PCPA) or LP-533401 to inhibit serotonin synthesis and fed with high fat diet (HFD) or high carbohydrate diet (HCD) to induce hepatic steatosis. Hepatic triglyceride content and gene expression profiles were analyzed. RESULTS: Pharmacological and genetic inhibition of serotonin synthesis reduced HFD-induced hepatic lipid accumulation. Furthermore, short-term PCPA treatment prevented HCD-induced hepatic steatosis without affecting glucose tolerance and browning of subcutaneous adipose tissue. Gene expression analysis revealed that the expressions of genes involved in de novo lipogenesis and triacylglycerol synthesis were downregulated by short-term PCPA treatment as well as long-term PCPA treatment. CONCLUSION: Short-term inhibition of serotonin synthesis prevented hepatic lipid accumulation without affecting systemic insulin sensitivity and energy expenditure, suggesting the direct steatogenic effect of serotonin in liver.

Serotonin as a New Therapeutic Target for Diabetes Mellitus and Obesity

Serotonin (5-hydroxytryptamine [5-HT]) is a monoamine that has various functions in both neuronal and non-neuronal systems. In the central nervous system, 5-HT regulates mood and feeding behaviors as a neurotransmitter. Thus, there have been many trials aimed at increasing the activity of 5-HT in the central nervous system, and some of the developed methods are already used in the clinical setting as anti-obesity drugs. Unfortunately, some drugs were withdrawn due to the development of unwanted peripheral side effects, such as valvular heart disease and pulmonary hypertension. Recent studies revealed that peripheral 5-HT plays an important role in metabolic regulation in peripheral tissues, where it suppresses adaptive thermogenesis in brown adipose tissue. Inhibition of 5-HT synthesis reduced the weight gain and improved the metabolic dysfunction in a diet-induced obesity mouse model. Genome-wide association studies also revealed genetic associations between the serotonergic system and obesity. Several genetic polymorphisms in tryptophan hydroxylase and 5-HT receptors were shown to have strong associations with obesity. These results support the clinical significance of the peripheral serotonergic system as a therapeutic target for obesity and diabetes.

A Case of POEMS Syndrome that Presented with a Moderate Pericardial Effusion / 대한내과학회지

Pericardial effusions can be caused by a wide variety of infectious or noninfectious diseases. After a conventional diagnostic work-up, the etiology of pericardial effusion often remains idiopathic. We report a patient with POEMS syndrome whose main clinical problem was recurrent pericardial effusions. Patients with POEMS syndrome often have generalized edema and a pleural effusion, while a pericardial effusion is a very rare complication. A 44-year-old man visited our hospital because of a recurrent pericardial effusion. He was initially diagnosed with idiopathic pericarditis five months prior. We reassessed the patient meticulously and found IgG lambda type monoclonal gammopathy, polyneuropathy, lymphadenopathy, peripheral edema, pleural effusion, hypothyroidism, pulmonary hypertension, hyperpigmentation, hypertrichosis, and papilledema, which we diagnosed as POEMS syndrome.

A Newly Formed and Ruptured Atheromatous Plaque within Neointima after Drug-Eluting Stent Implantation: 2-Year Follow-Up Intravascular Ultrasound and Optical Coherence Tomography Studies

Late stent thrombosis (LST) which is a life threatening complication has emerged as a serious problem of drug-eluting stents (DES). Several studies have suggested that incomplete neointimal coverage of stent struts contributes to LST. Progressive atherosclerosis within the neointima is an another possible cause of LST, but this phenomenon has seldom been reported in DES. We present a case of LST following DES implantation after a period of 28 months due to ruptured atheromatous plaque, despite complete neointimal coverage of stent struts proven by optical coherence tomography.

Gender-Based Differences in the Management and Prognosis of Acute Coronary Syndrome in Korea

PURPOSE: Gender-based differences exist in the characteristics, management, and prognosis of acute coronary syndrome (ACS). However, their impact on prognosis remains unclear. We aimed to identify factors causing these differences in Koreans. MATERIALS AND METHODS: We examined 6,636 ACS patients (66.2% males) visiting 72 Korean hospitals between April-2007 and December-2008. Gender-based differences in clinical demographics, therapy, and outcomes were analyzed over 6 months. RESULTS: Women were older than men [mean (standard deviation, SD) age, 67.6 (9.8) vs. 60.6 (11.2) years; p<0.001]; had higher rates of hypertension, diabetes mellitus, and lack of exercise (p<0.001 for all); and lower rates of obesity, familial history of cardiovascular disease (CVD), and smoking (p<0.05 for all). Atypical symptoms were more common in women (20.5% vs. 15.1% in men, p<0.001), whereas myocardial infarction with ST-segment elevation was less common (17.1% vs. 27.8%, p<0.001). Mean (SD) time lapse from symptom onset to arrival at hospital was longer in women [11.44 (18.19) vs. 8.26 (14.89) hours in men, p<0.001], as was the duration of hospitalization [7.58 (7.61) vs. 7.04 (7.72) days, p=0.007]. Fewer women underwent revascularization procedures, including thrombolytic therapy, balloon angioplasty, stent implantation, and coronary artery bypass grafting (79.4% vs. 83.3% men, p<0.001). No significant differences were observed in CVD-related death, recurrent ACS, stroke, refractory angina, or rehospitalization for angina. CONCLUSION: Female ACS patients were older than male subjects and had more atypical presentation. They arrived at the hospital later than men and had longer hospital stays, but less often required revascularization therapy. However, no gender-based differences were noted in ACS-related mortality and morbidity.

Percutaneous Cardiopulmonary Support-Supported Percutaneous Coronary Intervention: A Single Center Experience

BACKGROUND AND OBJECTIVES: Percutaneous cardiopulmonary support (PCPS) has proven to be a valuable technique in high-risk coronary patients undergoing percutaneous coronary intervention (PCI). However, there have been few studies on PCI associated with PCPS in Korea. We summarized our experience with PCPS-supported PCI. SUBJECTS AND METHODS: We retrospectively reviewed 19 patients with PCPS-supported PCI between August 2005 and June 2009. PCPS was used as an elective procedure for 10 patients with at least two of the following conditions: left-ventricular ejection fraction <35%, target vessel(s) supplying more than 50% of the viable myocardium, high risk surgical patients, and patients who refused coronary bypass surgery. In the remaining 9 patients PCPS was used as an emergency procedure, to stabilize and even resuscitate patients with acute myocardial infarction and cardiogenic shock, in order to attempt urgent PCI. RESULTS: Among the 19 patients who were treated with PCPS-supported PCI, 11 (57.9%) survived and 8 (42.1%) patients did not. ST elevation myocardial infarction with cardiogenic shock was more prevalent in the non-survivors than in the survivors (75% vs. 27.3%, p=0.04). The elective PCPS-supported PCI was practiced more frequently in the survivors than in the non-survivors (72.7% vs. 25%, p=0.04). In the analysis of the event-free survival curve between elective and emergency procedures, there was a significant difference in the survival rate (p=0.025). Among the survivors there were more patients with multi-vessel disease, but a lower Thrombolysis in Myocardial Infarction grade in the culprit lesions was detected in the non-survivors, before PCI. Although we studied high-risk patients, there was no procedure-related mortality. CONCLUSION: Our experience suggests that PCPS may be helpful in high risk patients treated with PCI, especially in elective cases. More aggressive and larger scale studies of PCPS should follow.

Constrictive Pericarditis Accompanied by Swine-Origin Influenza A (H1N1) Infection

Swine-origin influenza A (H1N1) is caused by a new strain of the influenza virus. The disease has spread rapidly and was declared a pandemic in April, 2009. So far, however, there is a scarcity of information regarding the complications of swine influenza. A report of the disease in the winter of 2009 in the Southern Hemisphere found that the most common manifestations of influenza A virus infection are upper respiratory tract infection and pneumonia. Although there may be an association between fulminant myocarditis and Swine influenza, cardiovascular complications resulting from swine Influenza A infection are exceedingly rare. We report a case of acute constrictive pericarditis in a healthy subject infected by the swine-origin influenza A (H1N1) virus.

Pulmonary Hypertension Associated with Use of Phentermine

Weight-control drugs (known as anorexigens) such as fenfluramine have been linked with pulmonary hypertension in previous reports. In our case, a 29 year old woman was admitted for shortness of breath and was diagnosed with pulmonary hypertension. Three months ago, she had been taking phentermine for five weeks. Other factors that might have contributed to the development of pulmonary hypertension were excluded. With treatment, her symptoms improved. This is the first case that can suggest a possible connection between phenermine single medication with pulmonary hypertension. Phentermine has been considered a relatively safe drug to treat obesity, and further investigation is needed to decide the safety and dosage of phentermine.

Normal coronary CT angiography with subsequent adverse cardiac events / 대한내과학회지

Multi-detector row coronary computed tomography (CT) angiography is an emerging noninvasive diagnostic tool for coronary artery disease. Because of the high negative predictive value of the test, coronary CT angiography is useful for ruling out significant coronary artery stenosis in patients with chest pain. Between 2003 and 2009, 2,148 (50%) of 4,337 patients who underwent coronary CT angiography had a normal coronary artery. Of the 2,148 patients, only two (0.09%) experienced cardiovascular events within three months of their index visit. One patient underwent invasive coronary angiography based on a positive exercise test result, while the second underwent invasive coronary angiography due to an episode of chest pain. Coronary angiographic examination of these two patients revealed significant luminal narrowing of the proximal left anterior descending artery; both patients underwent revascularization at the discretion of their physician.