Sodium-dependent glucose cotransporter-2 (SGLT2) inhibitors, antidiabetic drugs that reduce blood sugar levels by inhibiting glucose reabsorption in the renal proximal tubules, also ameliorate nonalcoholic fatty liver disease (NAFLD). This study aimed to examine the effects of SGLT2 inhibition on hepatic steatosis and nonalcoholic steatohepatitis (NASH) using an in vitro model of NAFLD progression. HepG2 cells and a coculture of Hepa1c1c7 and Raw 264.
View Article and Find Full Text PDFBackgruound: Polyunsaturated fatty acids (PUFAs) reportedly have protective effects on pancreatic β-cells; however, the underlying mechanisms are unknown.
Methods: To investigate the cellular mechanism of PUFA-induced cell protection, mouse insulinoma 6 (MIN6) cells were cultured with palmitic acid (PA) and/or docosahexaenoic acid (DHA), and alterations in cellular signaling and apoptosis were examined.
Results: DHA treatment remarkably repressed caspase-3 cleavage and terminal deoxynucleotidyl transferase-mediated UTP nick end labeling (TUNEL)-positive red dot signals in PA-treated MIN6 cells, with upregulation of autophagy, an increase in microtubule- associated protein 1-light chain 3 (LC3)-II, autophagy-related 5 (Atg5), and decreased p62.
Backgruound: Glucagon-like peptide-1 receptor agonist (GLP-1RA), which is a therapeutic agent for the treatment of type 2 diabetes mellitus, has a beneficial effect on the cardiovascular system.
Methods: To examine the protective effects of GLP-1RAs on proliferation and migration of vascular smooth muscle cells (VSMCs), A-10 cells exposed to angiotensin II (Ang II) were treated with either exendin-4, liraglutide, or dulaglutide. To examine the effects of GLP-1RAs on vascular calcification, cells exposed to high concentration of inorganic phosphate (Pi) were treated with exendin-4, liraglutide, or dulaglutide.
Backgruound: Sodium-dependent glucose cotransporter 2 (SGLT2) mediates glucose reabsorption in the renal proximal tubules, and SGLT2 inhibitors are used as therapeutic agents for treating type 2 diabetes mellitus. This study aimed to elucidate the effects and mechanisms of SGLT2 inhibition on hepatic glucose metabolism in both serum deprivation and serum supplementation states.
Methods: Huh7 cells were treated with the SGLT2 inhibitors empagliflozin and dapagliflozin to examine the effect of SGLT2 on hepatic glucose uptake.
Endocrinol Metab (Seoul)
February 2022
Background: Dulaglutide, a long-acting glucagon-like peptide-1 receptor agonist (GLP-1RA), has been shown to reduce body weight and liver fat content in patients with type 2 diabetes. Family with sequence similarity 3 member A (FAM3A) plays a vital role in regulating glucose and lipid metabolism. The aim of this study was to determine the mechanisms by which dulaglutide protects against hepatic steatosis in HepG2 cells treated with palmitic acid (PA).
View Article and Find Full Text PDFBackground: The rapid response system has been implemented in many hospitals worldwide and, reportedly, the timing of medical emergency team (MET) attendance in relation to the duration of hospitalization is associated with the mortality of MET patients. We evaluated the relationship between duration of hospitalization before MET activation and patient mortality. We compared cases of MET activation for early, intermediate, and late deterioration to patient characteristics, activation characteristics, and patient outcomes.
View Article and Find Full Text PDFBackground: There is a great need to discover factors that could protect pancreatic β-cells from apoptosis and thus prevent diabetes mellitus. Clusterin (CLU), a chaperone protein, plays an important role in cell protection in numerous cells and is involved in various cellular mechanisms, including autophagy. In the present study, we investigated the protective role of CLU through autophagy regulation in pancreatic β-cells.
View Article and Find Full Text PDFBiochem Biophys Res Commun
September 2020
Vascular calcification increases the risk of developing cardiovascular disease, and it is closely associated with metabolic disorders such as diabetes mellitus and non-alcoholic fatty liver disease. We investigated whether the activators of AMP-activated protein kinase (AMPK), metformin, resveratrol, and exendin-4, improved inorganic phosphate (Pi)-induced vascular calcification in rat vascular smooth muscle cells (VSMCs) and whether these effects were via AMPK. Pi increased calcium deposition in a dose-dependent manner, and metformin, resveratrol, and exendin-4 significantly decreased calcium deposition in the Pi-treated VSMCs.
View Article and Find Full Text PDFAim: The Good Outcome Following Attempted Resuscitation (GO-FAR) score is useful for identifying patients post-arrest with very poor neurologic outcomes and may thus be utilized when counseling family members on do-not-attempt-resuscitation (DNAR) order. We validated the GO-FAR score for neurologically intact survival in patients with in-hospital cardiac arrest (IHCA) in an East Asian country in which DNAR order not common.
Methods: Retrospective study about patients who experienced IHCA from 2013 to 2017 with a primary outcome of neurologically intact survival, defined as a CPC score 1 or 2 at discharge.
Endoplasmic reticulum stress (ER stress) is involved in lipid metabolism and lipotoxicity and can lead to apoptosis. Resveratrol, a sirtuin 1 (SIRT1) agonist, prevents ER stress and improves ER stress-induced hepatic steatosis and cell death. Clusterin is a secreted chaperone and has roles in various physiological processes.
View Article and Find Full Text PDFBackground: Emerging evidence suggests that sphingolipids may be involved in type 2 diabetes. However, the exact signaling defect through which disordered sphingolipid metabolism induces β-cell dysfunction remains unknown. The current study demonstrated that sphingosine-1-phosphate (S1P), the product of sphingosine kinase (SphK), is an essential factor for maintaining β-cell function and survival via regulation of mitochondrial action, as mediated by prohibitin (PHB).
View Article and Find Full Text PDFLipin-1 performs dual function during lipid metabolism, i.e., it functions as a transcriptional coactivator and as a phosphatidate phosphatase during triglyceride biosynthesis.
View Article and Find Full Text PDFBackground: The nuclear receptor peroxisome proliferator-activator gamma (PPARγ) is a useful therapeutic target for obesity and diabetes, but its role in protecting β-cell function and viability is unclear.
Methods: To identify the potential functions of PPARγ in β-cells, we treated mouse insulinoma 6 (MIN6) cells with the PPARγ agonist pioglitazone in conditions of lipotoxicity, endoplasmic reticulum (ER) stress, and inflammation.
Results: Palmitate-treated cells incubated with pioglitazone exhibited significant improvements in glucose-stimulated insulin secretion and the repression of apoptosis, as shown by decreased caspase-3 cleavage and poly (adenosine diphosphate [ADP]-ribose) polymerase activity.
Purpose: To compare the ability of a score based on vital signs and laboratory data with that of the modified early warning score (MEWS) to predict ICU transfer of patients with gastrointestinal disorders.
Materials And Methods: Consecutive events triggering medical emergency team activation in adult patients admitted to the gastroenterology wards of the Asan Medical Center were reviewed. Binary logistic regression was used to identify factors predicting transfer to the ICU.
The aim of this study is to investigate whether the beneficial effect of exendin-4 on hepatic steatosis is mediated by β-catenin signaling. After the HepG2 human hepatoma cells were treated with PA for 24 hours, total triglycerides levels were increased in a dose-dependent manner, and the expression levels of perilipin family members were upregulated in cells treated with 400 μM PA. For our in vitro model of hepatic steatosis, HepG2 cells were treated with 400 μM palmitic acid (PA) in the presence or absence of 100 nM exendin-4 for 24 hours.
View Article and Find Full Text PDFRationale, Aims And Objectives: The aim of this study was to analyse the effects of the follow-up programme implemented by the Asan Medical Center Medical Emergency Team (MET).
Method: A quasi-experimental pre-post intervention design was used, retrospectively reviewed. The follow-up programme includes respiratory care, regular visits and communication between the attending doctors and MET nurse for patients discharged from the medical intensive care unit (MICU) to the general ward.
ANGPTL8 is a liver-derived secretory protein that leads to elevated serum triglyceride and the level of circulating ANGPTL8 is strongly associated with obesity and diabetes. Here we investigated the mechanisms of activation and inhibition of ANGPTL8 expression in hepatocytes. The expression of ANGPTL8 was significantly increased in HepG2 cells exposed to palmitic acid, tunicamycin, or T0901317, and was reversed in cells treated with AICAR.
View Article and Find Full Text PDFBackground: Selenoprotein P (SEPP1) and fetuin-A, both circulating liver-derived glycoproteins, are novel biomarkers for insulin resistance and nonalcoholic fatty liver disease. However, the effect of exendin-4 (Ex-4), a glucagon-like peptide-1 receptor agonist, on the expression of hepatokines, SEPP1, and fetuin-A, is unknown.
Methods: The human hepatoma cell line HepG2 was treated with palmitic acid (PA; 0.
Background: Tumor necrosis factor (TNF)-α and AMP-activated protein kinase (AMPK) are known to stimulate and repress lipolysis in adipocytes, respectively; however, the mechanisms regulating these processes have not been completely elucidated.
Methods: The key factors and mechanism of action of TNF-α and AMPK in lipolysis were investigated by evaluating perilipin expression and activity of protein kinase RNA-like endoplasmic reticulum kinase (PERK)/eukaryotic initiation factor 2 α (eIF2α) by Western blot and an immunofluorescence assay in 24-hour TNF-α-treated 3T3-L1 adipocytes with artificial manipulation of AMPK activation.
Results: Enhancement of AMPK activity by the addition of activator minoimidazole carboxamide ribonucleotide (AICAR) suppressed TNF-α-induced lipolysis, whereas the addition of compound C, an inhibitor of AMPK phosphorylation, enhanced lipolysis.
Objective: Hepatokine fibroblast growth factor (FGF) 21 takes part in the regulation of lipid metabolism in the liver and adipose tissue. We investigated whether exendin-4 regulates the expression of FGF21 in the liver, and whether the effects of exendin-4 on the regulation of FGF21 expression are mediated via silent mating type information regulation 2 homolog (SIRT) 1 or SIRT6.
Materials/methods: The C57BL/6J mice were fed a low fat diet, high fat diet, or high fat diet with 1 nmol/kg/day exendin-4 intraperitoneal injection for 10 weeks.
Cell Stress Chaperones
September 2014
Accumulation of excess hepatic lipids contributes to insulin resistance and liver disease associated with endoplasmic reticulum (ER) stress. Exendin-4 is an agonist of the glucagon-like peptide 1 receptor and plays a role in improving insulin resistance and liver disease by increasing silent mating type information regulation 2 homolog (SIRT) 1. However, the effects and mechanism of action of exendin-4 on responses to palmitic acid (PA)-induced ER stress in hepatocytes have not been clearly defined.
View Article and Find Full Text PDFPurpose: Obesity has been suggested to be linked to asthma. However, it is not yet known whether obesity directly leads to airway hyperreactivity (AHR) or obesity-induced airway inflammation associated with asthma. We investigated obesity- related changes in adipokines, AHR, and lung inflammation in a murine model of asthma and obesity.
View Article and Find Full Text PDFPurpose: We investigated the mRNA levels of peroxisome proliferator-activated receptor (PPAR)-α, PPAR-γ, adipokines, and cytokines in the lung tissue of lean and obese mice with and without ovalbumin (OVA) challenge, and the effect of rosiglitazone, a PPAR-γ agonist.
Methods: We developed 6 mice models: OVA-challenged lean mice with and without rosiglitazone; obese mice with and without rosiglitazone; and OVA-challenged obese mice with and without rosiglitazone. We performed real-time polymerase chain reaction for leptin, leptin receptor, adiponectin, vascular endothelial growth factor (VEGF), tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β, PPAR-α and PPAR-γ from the lung tissue and determined the cell counts and cytokine levels in the bronchoalveolar lavage fluid.
Background: There are few studies of the epidemiology and clinical outcomes of patients with in-hospital cardiac arrest (IHCA) in a general hospital ward.
Objective: To investigate the clinical outcomes of IHCA cases that occurred in the general ward of a university hospital and that were witnessed and/or monitored.
Methods: We prospectively gathered data on all IHCAs in the general ward of Asan Medical Center, Seoul, South Korea, that were recorded by the Medical Emergency Team between March 2008 and February 2010.
Non-alcoholic fatty liver disease (NAFLD), one of the most common liver diseases, is caused by the disruption of hepatic lipid homeostasis. It is associated with insulin resistance as seen in type 2 diabetes mellitus. Glucagon-like peptide-1 (GLP-1) is an incretin that increases insulin sensitivity and aids glucose metabolism.
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