Sacubitril/valsartan reduces endoplasmic reticulum stress in a rat model of doxorubicin-induced cardiotoxicity.

The induction of endoplasmic reticulum (ER) stress has been reported as a key contributor to the cardiotoxicity of doxorubicin. Previous in vitro and in vivo studies suggest that sacubitril/valsartan, a novel angiotensin receptor-neprilysin inhibitor, could be effective against doxorubicin-induced cardiotoxicity. However, the precise mechanisms are not fully understood. Therefore, we investigated whether the cardioprotective effects of sacubitril/valsartan are associated with ER stress modulation in a rat model of doxorubicin-induced cardiotoxicity. Male Sprague-Dawley rats were treated with intraperitoneal injections of doxorubicin (15 mg/kg; cumulative) or saline for 3 weeks. From the day before the first treatment, control animals were gavaged daily with water (n = 8), whereas doxorubicin-treated animals were gavaged daily with water (n = 8) or sacubitril/valsartan (60 mg/kg/day; n = 8) for 6 weeks. Echocardiography was performed 6 weeks after the initiation of doxorubicin. In addition, serum troponin I and N-terminal brain natriuretic peptide levels were determined, and the extent of apoptosis and protein levels related to ER stress in the cardiac tissue and doxorubicin-treated H9c2 cardiomyocytes were analyzed. Sacubitril/valsartan significantly reduced doxorubicin-induced cardiac dysfunction and apoptosis in the myocardium. In addition, sacubitril/valsartan significantly downregulated the expression levels of proteins related to apoptosis and ER stress, including BAX, caspase 3, GRP78, PERK, IRE-1α, ATF-6, eIF-2α, ATF-4, and CHOP, in the myocardium of a rat model of doxorubicin-induced cardiotoxicity in vivo and doxorubicin-treated H9c2 cardiomyocytes in vitro. Sacubitril/valsartan significantly alleviated doxorubicin-induced cardiotoxicity, which may be associated with the reduction of ER stress.

Granulocyte colony-stimulating factor reduces the endoplasmic reticulum stress in a rat model of diabetic cardiomyopathy.

Prolonged endoplasmic reticulum (ER) stress contributes to the apoptosis of cardiomyocytes, which leads to the development of diabetic cardiomyopathy. Previously, we reported that the granulocyte colony-stimulating factor (G-CSF) reduces the cardiomyocyte apoptosis in diabetic cardiomyopathy; however, the precise mechanisms associated with this process are not yet fully understood. Therefore, in this study, we investigated whether the mechanism of the anti-apoptotic effect of G-CSF was associated with ER stress in a rat model of diabetic cardiomyopathy. Diabetic cardiomyopathy was induced in rats using a high-fat diet combined with the administration of a low-dose of streptozotocin. Diabetic rats were treated with G-CSF or saline for 5 days. Cardiac function was evaluated using serial echocardiography before and 4 weeks after treatment. The rate of cardiomyocyte apoptosis and the expression levels of proteins related to ER stress, including glucose-regulated protein 78 (GRP78), caspase-9, and caspase-12 were analyzed in the cardiac tissue. G-CSF treatment significantly reduced cardiomyocyte apoptosis in the diabetic myocardium and downregulated the expression levels of these proteins in diabetic rats treated with low-dose streptozotocin when compared to that in rats treated with saline. In addition, G-CSF treatment significantly downregulated the expression levels of proteins related to ER stress, such as GRP78, inositol-requiring enzyme-1α (IRE-1α), and C/EBP homologous protein (CHOP) in H9c2 cells under high glucose (HG) conditions. Moreover, G-CSF treatment significantly improved the diastolic dysfunction in serial echocardiography assessments. In conclusion, the anti-apoptotic effect of G-CSF may be associated with the downregulation of ER stress.

Role of Autophagy in Granulocyte-Colony Stimulating Factor Induced Anti-Apoptotic Effects in Diabetic Cardiomyopathy.

BACKGROUND: We previously, reported that granulocyte-colony stimulating factor (G-CSF) reduces cardiomyocyte apoptosis in diabetic cardiomyopathy. However, the underlying mechanisms are not yet fully understood. Therefore, we investigated whether the mechanisms underlying of the anti-apoptotic effects of G-CSF were associated with autophagy using a rat model of diabetic cardiomyopathy. METHODS: Diabetic cardiomyopathy was induced in rats through a high-fat diet combined with low-dose streptozotocin and the rats were then treated with G-CSF for 5 days. Rat H9c2 cardiac cells were cultured under high glucose conditions as an in vitro model of diabetic cardiomyopathy. The extent of apoptosis and protein levels related to autophagy (Beclin-1, microtubule-binding protein light chain 3 [LC3]-II/LC3-I ratio, and P62) were determined for both models. Autophagy determination was performed using an Autophagy Detection kit. RESULTS: G-CSF significantly reduced cardiomyocyte apoptosis in the diabetic myocardium in vivo and led to an increase in Beclin-1 level and the LC3-II/LC3-I ratio, and decreased P62 level. Similarly, G-CSF suppressed apoptosis, increased Beclin-1 level and LC3-II/LC3-I ratio, and decreased P62 level in high glucose-induced H9c2 cardiac cells in vitro. These effects of G-CSF were abrogated by 3-methyladenine, an autophagy inhibitor. In addition, G-CSF significantly increased autophagic flux in vitro. CONCLUSION: Our results suggest that the anti-apoptotic effect of G-CSF might be significantly associated with the up-regulation of autophagy in diabetic cardiomyopathy.

Modified method for effective primary vascular smooth muscle progenitor cell culture from peripheral blood.

In previous studies, vascular smooth muscle progenitor cells (vSMPCs) isolated from peripheral blood mononuclear cells (PBMCs) were cultured using medium containing platelet-derived growth factor-BB (PDGF-BB) for 4 weeks. However, this method requires long culture periods of up to 4 weeks and yields low cell counts. Therefore, we proposed the modified method to improve the cell yield and purity and to reduce the cell culture period. PBMCs were isolated from human peripheral blood and cultured by the conventional method using medium containing PDGF-BB alone or the modified method using medium containing PDGF-BB, basic fibroblast growth factor (bFGF), and insulin-transferrin-selenium ITS for 4 weeks. The purity of vSMPCs was analyzed for the expression of a- smooth muscle actin (SMA) by flow cytometry and significantly higher in the modified method than conventional methods at the 1st and 2nd weeks. Also, mRNA expression of a-SMA by real-time PCR was significantly higher in the modified method than conventional method at the 2 weeks. The yield of vSMPCs by trypan blue exclusion assay was significantly higher in the modified method than conventional method at the 1st, 2nd and 3rd weeks. The primary culture using the modified method with PDGF-BB, bFGF, and ITS not only improved cell purity and yield, but also shortened the culture period, compared to the conventional culture method for vSMPCs. The modified method will be a time-saving and useful tool in various studies related to vascular pathology.

Granulocyte Colony Stimulating Factor Ameliorates Hepatic Steatosis Associated with Improvement of Autophagy in Diabetic Rats.

Background: We previously reported that the granulocyte colony stimulating factor (G-CSF) ameliorated hepatic steatosis with the enhancement of ß-oxidation-related gene expression. However, the mechanisms underlying this process remain unclear. This study aimed to determine whether the improvement of hepatic steatosis by G-CSF was associated with autophagy in a rat model of diabetes. Methods: Eight rats were fed a standard diet, and 16 rats were fed high-fat diet (HFD) for 5 weeks. All HFD-fed rats were then injected with streptozotocin (STZ). One week later, HFD rats injected with STZ were randomly treated with either G-CSF (200 µg/kg/day; diabetes mellitus (DM)/G-CSF) or saline (DM/saline) for 5 consecutive days. Four weeks later, serum biochemical and histology analyses were conducted. The expression of autophagy-associated proteins was determined by Western blotting. The mRNA expression of ß-oxidation-related genes was determined by quantitative real-time polymerase chain reaction. HepG2 cells were cultured under high glucose (HG) conditions with G-CSF treatment, followed by Oil Red O staining for quantification of lipids. Results: Histological analysis showed lower lipid accumulation in the DM/G-CSF group than in the DM/saline-treated rats. Protein levels of LC3 and beclin-1 were higher, and those of p62 were lower in the DM/G-CSF rats than in the DM/saline-treated rats. The mRNA expression of ß-oxidation-related genes was higher in DM/G-CSF rats than in the DM/saline-treated rats. Quantification of lipid levels in HepG2 cells cultured with HG and G-CSF treatment revealed no significant differences. Conclusions: Our data suggested that G-CSF potentially improves hepatic steatosis and autophagy in the liver of diabetic rats.

Jakyakgamcho-tang in the relief of delayed-onset muscle soreness in healthy adults: study protocol for a randomized, double-blind, placebo-controlled, crossover design clinical trial.

BACKGROUND: Muscle soreness after exercise, called delayed-onset muscle soreness (DOMS), may cause significant changes in muscle function and may increase the risk of sports injuries. Therefore, various therapeutic strategies have been studied to help recovery after exercise. Jakyakgamcho-tang (JGT) is a widely prescribed herbal medicine to treat muscle pain and cramps in traditional Eastern medicine. The aim of this study is to evaluate the effect of JGT for reducing pain and improving muscle damage after exercise. METHODS: This study is a randomized, double-blind, placebo-controlled, crossover design clinical trial. A total of 30 healthy male adults will be recruited. Subjects who voluntarily wish to participate in this study will be hospitalized for 4 days. On the first day, the subjects will perform a standardized treadmill exercise for 1 h to induce DOMS. After the exercise, the subjects will take either JGT or a placebo for 3 days. After a more than 1 week wash-out period, the subjects will repeat the same process with the other drug. Pain intensity, calf circumference, and pain threshold will be measured as outcome measures. Blood tests and blood pressure will be measured as safety assessments. In addition, blood tests for muscle damage and inflammation markers, such as creatine kinase, interleukin-6, and C-reactive protein, will be analyzed. DISCUSSION: This will be the first trial to assess the effect of JGT on exercise-induced muscle soreness. Our findings will provide valuable data to determine the clinical effects of JGT on DOMS. TRIAL REGISTRATION: Clinical Research Information Sevice, KCT0003457. Registered on 29 January 2019.

Effects of taichi on grade 1 hypertension: A study protocol for a randomized controlled trial.

BACKGROUND: Medication is generally recommended to reduce the morbidity and mortality caused by cardiovascular disease in hypertensive patients. However, considering the difficulties and economic factors associated with long-term medication, interest in taichi as an exercise treatment method has increased recently in Korean medical practice. Numerous studies have suggested that taichi can be used to treat various diseases and that is can affect psychosomatic factors such as anxiety. This study aims to evaluate the effect of taichi in reducing blood pressure among grade 1 hypertensive patients. METHODS/DESIGN: In this randomized, active-controlled, assessor-blinded, two parallel-armed trial, 80 grade 1 hypertension patients will be recruited and randomly assigned to the usual care group or to the taichi group (n = 40 in each group). Subjects who voluntarily sign a study agreement will be educated in managing their own blood pressure by restricting salt intake, losing weight, moderating alcohol consumption, performing exercise, and regulating dietary intake at their first visit. In addition to self-management, the taichi group will perform two 60-min taichi sessions per week for a total of 8 weeks. Blood pressure will be measured as the primary outcome. In addition, body composition, heart rate, and the perceived intensity and difficulty of the exercise will be measured as secondary outcomes. DISCUSSION: This study is a randomized controlled trial of taichi, which is not widely practiced in Korea. It may provide valuable data on the effects of taichi on hypertension, which will inform non-pharmaceutical treatment options for this disorder. TRIAL REGISTRATION: Clinical Research Information Service, KCT0003632. Registered on 18 March 2019.

Role of MicroRNA-34a in Anti-Apoptotic Effects of Granulocyte-Colony Stimulating Factor in Diabetic Cardiomyopathy.

BACKGROUND: Recent studies have shown that microRNAs (miRNAs) are involved in the process of cardiomyocyte apoptosis. We have previously reported that granulocyte-colony stimulating factor (G-CSF) ameliorated diastolic dysfunction and attenuated cardiomyocyte apoptosis in a rat model of diabetic cardiomyopathy. In this study, we hypothesized a regulatory role of cardiac miRNAs in the mechanism of the anti-apoptotic effect of G-CSF in a diabetic cardiomyopathy rat model. METHODS: Rats were given a high-fat diet and low-dose streptozotocin injection and then randomly allocated to receive treatment with either G-CSF or saline. H9c2 rat cardiomyocytes were cultured under a high glucose (HG) condition to induce diabetic cardiomyopathy in vitro. We examined the extent of apoptosis, miRNA expression, and miRNA target genes in the myocardium and H9c2 cells. RESULTS: G-CSF treatment significantly decreased apoptosis and reduced miR-34a expression in diabetic myocardium and H9c2 cells under the HG condition. G-CSF treatment also significantly increased B-cell lymphoma 2 (Bcl-2) protein expression as a target for miR-34a. In addition, transfection with an miR-34a mimic significantly increased apoptosis and decreased Bcl-2 luciferase activity in H9c2 cells. CONCLUSION: Our results indicate that G-CSF might have an anti-apoptotic effect through down-regulation of miR-34a in a diabetic cardiomyopathy rat model.

Bone marrow mesenchymal stem cell-derived vascular endothelial growth factor attenuates cardiac apoptosis via regulation of cardiac miRNA-23a and miRNA-92a in a rat model of myocardial infarction.

Bone marrow-mesenchymal stem cell (BM-MSC) therapy improves the recovery of cardiac function after myocardial infarction (MI); however, the underlying molecular mechanisms are not completely understood. Recent studies have shown that microRNAs (miRNAs) modulate the pathophysiology of cardiovascular diseases. Here, we investigated the mechanisms underlying the effects of BM-MSC-derived paracrine factors and cardiac miRNAs on myocardial regeneration after MI. In our study, MI was induced by permanent ligation of the left anterior descending (LAD) coronary artery. BM-MSCs transplanted in infarcted rats significantly downregulated the expression of miRNA-23a and miRNA-92a and inhibited apoptosis in the myocardium. An in vitro experiment showed that supernatant from BM-MSCs cultured under hypoxia contained higher levels of vascular endothelial growth factor (VEGF) than that from BM-MSCs under normoxia. In addition, inhibition of miRNA-23a and miRNA-92a reduced cardiac apoptosis. Moreover, the VEGF-containing BM-MSC supernatant inhibited miRNA-23a and miRNA-92a expression and reduced apoptotic signaling in cardiomyocytes under hypoxia. These effects were inhibited when the supernatant was treated with neutralizing antibodies against VEGF. Our results indicate that the paracrine factor, VEGF, derived from transplanted BM-MSCs, regulated the expression of miRNAs such as miRNA-23a and miRNA-92a and exerted anti-apoptotic effects in cardiomyocytes after MI.

The Effects of Granulocyte-Colony Stimulating Factor on Regeneration in Nerve Crush Injuries in Rats.

Granulocyte-colony stimulating factor (G-CSF) is widely known to have a neuroprotective effect, but its effects on function and morphology in mechanical nerve injury are not well understood. The aim of this study was to confirm the time course of the functional changes and morphological effects of G-CSF in a rat model of nerve crush injury. Twelve-eight rats were divided into three group: sham-operated control group, G-CSF-treated group, and saline treated group. 2 weeks after the nerve crush injury, G-CSF was injected for 5 days. After 4 weeks, functional tests such as motor nerve conduction velocity (MNCV), mechanical and cold allodynia tests, and morphological studies were performed. G-CSF-treated rats had significantly improved nerve function including MNCV and mechanical and cold allodynia. In addition, G-CSF-treated rats had significantly higher the density of myelinated fibers than saline-treated rats. In conclusion, we found that 100 µg/kg administration of G-CSF promoted long-term functional recovery in a rat model of nerve crush injury.

Local injection of granulocyte-colony stimulating factor accelerates wound healing in a rat excisional wound model.

A systemic treatment of granulocyte-colony stimulating factor (G-CSF) is known to improve healings of damaged tissues. However, recent studies suggested local actions of G-CSF on the healing processes of damaged tissues. We investigated the treatment effect of locally injected G-CSF and compared to that of systemically injected G-CSF in a rat model. A wound was created on the rat dorsum and treated either by local injection or by systemic injection of G-CSF. Wound healing rate, deposition of collagen, and gene expression were evaluated. G-CSF receptor (G-CSFR) protein was detected by Western blotting. The wound healing rate in the local injection group was significantly higher than that in the systemic injection group at days 9 and 15; it was also significantly higher than that in the control group at days 3, 9, and 15. The expression of G-CSFR protein in wound tissues was higher than in normal skin tissues. The local injection of G-CSF is more effective than systemic injection of G-CSF in promoting wound healing, which may implicate the local action of G-CSF treatment in wound healing processes.

Proposal on the Establishment of Telemedicine Guidelines for Korea.

OBJECTIVES: An official guideline must be prepared for legalizing the doctor-patient telemedicine system based on the evaluations of the ongoing telemedicine demonstration project performed by the Korean government. In this study, critical items of the Korean telemedicine guideline are suggested based on the guidelines of developed countries. METHODS: To investigate the telemedicine guidelines of developed countries, a keyword of 'telemedicine guidelines' was used for Google search to find out US, Australian, and Japanese guidelines. The common items included in two or more of the followings were screened: US Core Operational Guidelines for Telehealth Services Involving Provider-Patient Interactions, the Australian New South Wales (NSW) Agency for Clinical Innovation Guidelines for the use of Telehealth for Clinical and Non Clinical Settings in NSW, and the Japanese Guidelines for the practice of home telemedicine. RESULTS: A total of 22 common items of the following four domains, which could be used for the Korean guideline were screened: the common features in overall considerations (6 items), the common features in clinical considerations (6 items), the common features in technical considerations (5 items), and the common features in privacy considerations (5 items). These 22 items were suggested as the critical items of the Korean telemedicine guideline. CONCLUSIONS: The screened 22 items of the telemedicine guideline must be further organized for details. Additional studies and professional opinions on the telemedicine cases and on the guidelines of developed countries are required to establish the Korean guideline in the near future.

Granulocyte-colony stimulating factor prevents the development of hepatic steatosis in rats.

BACKGROUND AND AIMS: Previously, we reported that granulocyte-colony stimulating factor (G-CSF) improves hepatic steatosis in experimental animals. It may also have preventive effects on the development of hepatic steatosis. Therefore, we investigated the preventive effects of G-CSF by using a high-fat diet (HFD) rat model. MATERIALS AND METHODS: Twelve rats were fed HFD and 6 rats were fed control diet from 10 weeks of age. Once little steatosis was confirmed in the liver (after 10 weeks of feeding the HFD; at 20 weeks of age), HFD rats were randomly divided into two groups and treated with either G-CSF (100 µg kg-1 day-1 for 5 consecutive days every other week; HFD/G-CSF rats) or saline (HFD/saline rats) for 10 weeks at 20 weeks of age. All rats were sacrificed at 30 weeks of age. Histology was examined by hematoxylin and eosin (H-E) and Oil Red O staining, and the expression levels of genes of associated with lipogenesis and ß-oxidation enzymes were determined by qRT-PCR. RESULTS: Histological examinations revealed that HFD/G-CSF rats had significantly lower lipid accumulation in their hepatocytes than did HFD/saline rats (p < 0.05). HFD/G-CSF rats also showed lower expression levels of genes associated with lipogenesis and higher expression levels of genes associated with ß-oxidation than HFD/saline rats (p < 0.05). CONCLUSION: In conclusion, we found that G-CSF prevented development of hepatic steatosis in an HFD rat model. The preventive effect may be associated with the regulation of gene expression involved in hepatic lipogenesis and ß-oxidation.

Transplanted Human Amniotic Epithelial Cells Secrete Paracrine Proangiogenic Cytokines in Rat Model of Myocardial Infarction.

Human amniotic epithelial cells (h-AECs) have been shown to differentiate into cardiomyocyte-like cells in vivo that can regenerate myocardial tissue and improve cardiac function in a rat model of myocardial infarction (MI). In this study, we investigated the paracrine factors released from h-AECs under hypoxic conditions to elucidate the possible mechanisms underlying this previously reported phenomenon of h-AEC-mediated cardiac repair. We used hypoxic cell culture conditions to simulate myocardial infarction in vitro. In comparison to normal conditions, we found that h-AECs secreted higher levels of several cytokines, including angiogenin (ANG), epidermal growth factor (EGF), interleukin (IL)-6, and monocyte chemoattractant protein (MCP)-1. To determine whether transplanted h-AECs express these proangiogenic cytokines in vivo, we ligated the coronary artery of rats to cause MI and injected either h-AECs or saline into the infarcted area. We found that the infarct and border zones of rat myocardium treated with h-AECs had higher expression levels of the human-origin cytokines ANG, EGF, IL-6, and MCP-1 compared to the tissues of saline-treated rats. In conclusion, h-AECs secreted proangiogenic cytokines in a rat model of MI, which may suggest that the paracrine effect by h-AECs could regenerate myocardial tissue and improve cardiac function.

Anti-obesity effects of granulocyte-colony stimulating factor in Otsuka-Long-Evans-Tokushima fatty rats.

Granulocyte-colony stimulating factor (G-CSF) has molecular structures and intracellular signaling pathways that are similar to those of leptin and ciliary neurotropic factor (CNTF). It also has immune-modulatory properties. Given that leptin and CNTF play important roles in energy homeostasis and that obesity is an inflammatory condition in adipose tissue, we hypothesized that G-CSF could also play a role in energy homeostasis. We treated 12 38-week-old male Otsuka-Long-Evans-Tokushima fatty rats (OLETF, diabetic) and 12 age-matched male Long-Evans-Tokushima rats (LETO, healthy) with 200 µg/day G-CSF or saline for 5 consecutive days. Body weight reduction was greater in G-CSF-treated OLETF (G-CSF/OLETF) than saline-treated OLETF (saline/OLETF) following 8 weeks of treatment (-6.9±1.6% vs. -3.1±2.2%, p<0.05). G-CSF treatment had no effect on body weight in LETO or on food intake in either OLETF or LETO. Body fat in G-CSF/OLETF was more reduced than in saline/OLETF (-32.2±3.1% vs. -20.8±6.2%, p<0.05). Energy expenditure was higher in G-CSF/OLETF from 4 weeks after the treatments than in saline/OLETF. Serum levels of cholesterol, triglyceride, interleukin-6 and tumor necrosis factor-α were lower in G-CSF/OLETF than in saline/OLETF. Uncoupling protein-1 (UCP-1) expression in brown adipose tissue (BAT) was higher in G-CSF/OLETF than in saline/OLETF, but was unaffected in LETO. Immunofluorescence staining and PCR results revealed that G-CSF receptors were expressed in BAT. In vitro experiments using brown adipocyte primary culture revealed that G-CSF enhanced UCP-1 expression from mature brown adipocytes via p38 mitogen-activated protein kinase pathway. In conclusion, G-CSF treatment reduced body weight and increased energy expenditure in a diabetic model, and enhanced UCP-1 expression and decreased inflammatory cytokine levels may be associated with the effects of G-CSF treatment.