Mitochondrial function contributes to oxysterol-induced osteogenic differentiation in mouse embryonic stem cells

AbstractOxysterols, oxidized derivatives of cholesterol, are biologically active molecules. Specific oxysterols have potent osteogenic properties that act on osteoprogenitor cells. However, the molecular mechanisms underlying these osteoinductive effects on embryonic stem cells (ESCs) are unknown. This study investigated the effect of an oxysterol combination of 22(S)-hydroxycholesterol and 20(S)-hydroxycholesterol (SS) on osteogenic differentiation of ESCs and the alterations to mitochondrial activity during differentiation. Osteogenic differentiation was assessed by alkaline phosphatase (ALP) activity, matrix mineralization, mRNA expression of osteogenic factors, runt-related transcription factor 2, osterix, and osteocalcin, and protein levels of collagen type IA (COLIA) and osteopontin (OPN). Treatment of cells with SS increased osteoinductive activity compared to the control group. Intracellular reactive oxygen species production, intracellular ATP content, mitochondrial membrane potential, mitochondrial mass, mitochondrial DNA copy number, and mRNA expression of peroxisome proliferator-activated receptor-γ coactivators 1α and β, transcription factors involved in mitochondrial biogenesis, were significantly increased during osteogenesis, indicating upregulation of mitochondrial activity. Oxysterol combinations also increased protein levels of mitochondrial respiratory complexes I–V. We also found that SS treatment increased hedgehog signaling target genes, Smo and Gli1 expression. Inhibition of Hh signaling by cyclopamine suppressed mitochondrial biogenesis and ESC osteogenesis. Subsequently, oxysterol-induced Wnt/β-catenin pathways were inhibited by repression of Hh signaling and mitochondrial biogenesis. Transfection of β-catenin specific siRNA decreased the protein levels of COLIA and OPN, as well as ALP activity. Collectively, these data suggest that lipid-based oxysterols enhance differentiation of ESCs toward the osteogenic lineage by regulating mitochondrial activity, canonical Hh/Gli, and Wnt/β-catenin signaling

Osteogenic Effect of Inducible Nitric Oxide Synthase (iNOS)-Loaded Mineralized Nanoparticles on Embryonic Stem Cells

Background/Aims: This study investigated the effect of inducible nitric oxide synthase-loaded mineralized nanoparticles (iNOS-MNPs) on the osteogenic differentiation of mouse embryonic stem cells (ESCs). Methods: We prepared iNOS-MNPs using an anionic block copolymer template-mediated calcium carbonate (CaCO3) mineralization process in the presence of iNOS. iNOS-MNPs were spherical and had a narrow size distribution. iNOS was stably loaded within MNPs without denaturation. In order to confirm the successful introduction of iNOS-MNPs into the cytosol of ESCs, intracellular levels of nitric oxide (NO) was determined with a fluorometric analysis. A NO effector molecule, cyclic guanosine 3’,5’ monophosphate (cGMP) was also quantified with a competitive enzyme immunoassay. Cell viability in response to iNOS-MNP treatment was determined using the cell counting kit-8 (CCK-8) assay. Alkaline phosphatase (ALP) activity assay, intracellular calcium quantification assay, and Alizarin red S staining for matrix mineralization were performed to investigate osteogenic differentiation of ESCs. The protein levels of Runt-related transcription factor 2 (RUNX2), osteocalcin (OCN), and osterix (OSX) as osteogenic-related factors were also assessed by immunofluorescence staining and Western blot analysis. The complex pathways associated with iNOS-MNP-derived osteogenic differentiation of ESCs were evaluated by network-based analysis. Results: Cells with iNOS-MNPs displayed a significant increase in NO and cGMP concentration compared with the control group. When cells were exposed to iNOS-MNPs, there were no adverse effects on cell viability. Importantly, iNOS-MNP uptake promoted the osteogenic differentiation of ESCs. Using transcriptome profiling, we obtained 1,836 differentially-induced genes and performed functional enrichment analysis with ClueGO and KEGG. These analyses identified significantly enriched and interconnected molecular pathways such as protein kinase activity, estrogen receptor activity, bone morphogenetic protein (BMP) receptor binding, ligand-gated ion channel activity, and phosphatidylinositol 3-phosphate binding. Conclusion: These findings suggest that iNOS-MNPs can induce osteogenic differentiation in ESCs by integrating complex signaling pathways

Increasing late diagnosis in HIV infection in South Korea: 2000-2007

<p>Abstract</p> <p>Background</p> <p>The number of Koreans diagnosed with human immunodeficiency virus (HIV) infections is increasing annually; however, CD4+ T-cell counts at diagnosis have decreased. The purpose of the present study was to identify clinical and epidemiologic associations with low CD4+ T-cell counts at the time of HIV diagnosis in a Korean population.</p> <p>Methods</p> <p>Data from 2,299 HIV-infected individuals with initial CD4+ T-cell counts measured within 6 months of HIV diagnosis and reason for HIV testing were recorded and measured from 2000 to 2007. Data were selected from the database of the Korea Centers for Disease Control and Prevention. Late diagnosis was defined by CD4+ T-cell counts <200 cells/mm³. Reasons for HIV testing were analyzed using logistic regression including epidemiologic variables.</p> <p>Results</p> <p>A total of 858 individuals (37.3%) were included in the late diagnosis group. Individuals with a late diagnosis were older, exposed through heterosexual contact, and demonstrated clinical manifestations of acquired immunodeficiency syndrome (AIDS). The primary reason for HIV testing was a routine health check-up (41%) followed by clinical manifestations (31%) of AIDS. The proportion of individuals with a late diagnosis was higher in individuals tested due to clinical symptoms in public health centers (adjusted odds ratio [AOR], 17.3; 95% CI, 1.7-175) and hospitals (AOR, 4.9; 95% CI, 3.4-7.2) compared to general health check-up. Late diagnosis annually increased in individuals diagnosed by voluntary testing both in public health centers (PHCs, P = 0.017) and in hospitals (P = 0.063). Routine testing due to risky behaviors resulted in earlier detection than testing secondary to health check-ups, although this difference was not statistically significant (AOR, 0.7; P = 0.187). Individuals identified as part of hospital health check-ups more frequently had a late diagnosis (P = 0.001)</p> <p>Conclusions</p> <p>HIV infection was primarily detected by voluntary testing with identification in PHCs and by testing due to clinical symptoms in hospitals. However, early detection was not influenced by either voluntary testing or general health check-up. It is important to encourage voluntary testing for early detection to decrease the prevalence of HIV infection and AIDS progression.</p

Obesity and hepatocellular carcinoma in patients receiving entecavir for chronic hepatitis B

Background/Aims This study aimed to clarify the effect of obesity on the development of hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB) patients receiving antiviral treatment. Methods This study applied a retrospective analysis to a historical cohort in Bundang Jesaeng Hospital. In total, 102 CHB patients were treated with entecavir as an initial treatment for CHB and checked for obesity using a body composition analyzer. Hepatic steatosis was measured semiquantitatively using Hamaguchi’s scoring system in ultrasonography. Risk factors for the development of HCC were analyzed, including obesity-related factors (body mass index [BMI], waist circumference [WC], waist-to-hip ratio [WHR], visceral fat area [VFA], and hepatic steatosis). Results The median follow-up duration of the patients was 45.2 months (interquartile range: 36.0-58.3 months). The cumulative incidence rates of HCC at 1 year, 3 years, and 5 years were 0%, 5.3%, and 9.0%, respectively. Univariable analysis revealed that the risk factors for HCC development were a platelet count of <120,000 /mm2 (hazard ratio [HR]=5.21, P=0.031), HBeAg negativity (HR=5.61, P=0.039), and liver cirrhosis (HR=10.26, P=0.031). Multivariable analysis showed that the significant risk factor for HCC development was liver cirrhosis (HR=9.07, P=0.042). However, none of the obesity-related risk factors were significantly associated with HCC: BMI ≥25 kg/m2 (HR=0.90, P=0.894), WC ≥90 cm (HR=1.10, P=0.912), WHR ≥0.9 (HR=1.94, P=0.386), VFA ≥100 cm2 (HR=1.69, P=0.495), and hepatic steatosis (HR=0.57, P=0.602). Conclusion HCC development is associated with liver cirrhosis but not obesity-related factors in CHB patients receiving entecavir

Effectiveness of 99mTc-tetrofosmin for assessment of heart functions in micropigs

This study examined the suitability of a nuclear imaging technique using 99mTc-tetrofosmin as an agent to assess the heart functions of healthy micropigs. The mean age of the pigs was 360 days (male), and the mean body weight was 35.3 kg ranging from 34.5-36 kg. There were no significant perfusion defects in any of the reconstructed images. Gated single-photon emission computed tomography imaging can be used to calculate the ventricular volume and ejection fraction (EF). In this case, an EF of 79% was calculated from the ventricular volume of the end-systolic image (10 ml) subtracted from that of the end-diastolic volume (49 ml). A perfusion defect (particularly the apex, lateral wall) is unlikely because of the presence of a preserved wall motion in a segment with a defect. It is concluded that quantitative cardiac scintigraphy, using 99mTc-tetrofosmin is an adequate technique for estimating the heart functions of healthy micropigs

Impact of Alcohol Consumption on Quality of Life, Depressive Mood and Metabolic Syndrome in Obstructive Lung Disease Patients: Analysis of Data from Korean National Health and Nutrition Examination Survey from 2014 and 2016

Background The objective of this study was to investigate whether alcohol consumption might affect the quality of life (QOL), depressive mood, and metabolic syndrome in patients with obstructive lung disease (OLD). Methods Data were obtained from the Korean National Health and Nutrition Examination Survey from 2014 and 2016. OLD was defined as spirometry of forced expiratory volume in 1 second/forced vital capacity <0.7 in those aged more than 40 years. QOL was evaluated using the European Quality of Life Questionnaire-5D (EQ-5D) index. Patient Health Questionnaire-9 (PHQ-9) was used to assess the severity of depressive mood. Alcohol consumption was based on a history of alcohol ingestion during the previous month. Results A total of 984 participants with OLD (695 males, 289 females, age 65.8±9.7 years) were enrolled. The EQ-5D index was significantly higher in alcohol drinkers (n=525) than in non-alcohol drinkers (n=459) (0.94±0.11 vs. 0.91±0.13, p=0.002). PHQ-9 scores were considerably lower in alcohol drinkers than in non-alcohol drinkers (2.15±3.57 vs. 2.78±4.13, p=0.013). However, multiple logistic regression analysis showed that alcohol consumption was not associated with EQ-5D index or PHQ-9 score. Body mass index ≥25 kg/m2, triglyceride ≥150 mg/dL, high-density lipoprotein <40 mg/dL in men and <50 mg/dL in women, and blood pressure ≥130/85 mm Hg were significantly more common in alcohol drinkers than in non-alcohol drinkers (all p<0.05). Conclusion Alcohol consumption did not change the QOL or depressive mood of OLD patients. However, metabolic syndrome-related factors were more common in alcohol drinkers than in non-alcohol drinkers

The presence of high level soluble herpes virus entry mediator in sera of gastric cancer patients

The development of gastric cancer (GC) is closely related to chronic inflammation caused by Helicobacter pylori infection, and herpes virus entry mediator (HVEM) is a receptor expressed on the surface of leukocytes that mediates potent inflammatory responses in animal models. However, the role of HVEM in human GC has not been studied. Previously, we showed that the interaction of HVEM on human leukocytes with its ligand LIGHT induces intracellular calcium mobilization, which results in inflammatory responses including induction of proinflammatory cytokine production and anti-bacterial activities. In this study, we report that leukocytes from GC patients express lower levels of membrane HVEM (mHVEM) and have lower LIGHT-induced bactericidal activities than those from healthy controls (HC). In contrast, levels of soluble HVEM (sHVEM) in the sera of GC patients were significantly higher than in those of HC. We found that monocyte membrane-bound HVEM is released into the medium when cells are activated by proinflammatory cytokines such as TNF-α and IL-8, which are elevated in the sera of GC patients. mHVEM level dropped in parallel with the release of sHVEM, and release was completely blocked by the metalloprotease inhibitor, GM6001. We also found that the low level of mHVEM on GC patient leukocytes was correlated with low LIGHT-induced bactericidal activities against H. pylori and S. aureus and production of reactive oxygen species. Our results indicate that mHVEM on leukocytes and sHVEM in sera may contribute to the development and/or progression of GC

A Case of Osteoclast-like Giant Cell Tumor of the Pancreas with Ductal Adenocarcinoma: Histopathological, Immunohistochemical, Ultrastructural and Molecular Biological Studies

Osteoclast-like giant cell tumor of the pancreas is a very rare neoplasm, of which the histiogenesis remains controversial. A 63-yr-old woman was hospitalized for evaluation of epigastric pain. An abdominal computerized tomography revealed the presence of a large cystic mass, arising from the tail of pancreas. A distal pancreatectomy with splenectomy was performed. Histologically, the tumor was composed of mononuclear stromal cells intermingled with osteclast-like giant cells. In addition, there was a small area of moderately to well differentiated ductal adenocarcinoma. The final pathologic diagnosis was osteoclast-like giant cell tumor of the pancreas with ductal adenocarcinoma. Here, we describe the histopathological, immunohistochemical, ultrastructural and molecular biological findings of this tumor with review of the literature pertaining to this condition

Effects of seaweed supplementation on blood glucose concentration, lipid profile, and antioxidant enzyme activities in patients with type 2 diabetes mellitus

The present study was carried out to evaluate the physiological effects of seaweed supplementation on blood glucose levels, lipid profile, and antioxidant enzyme activities in subjects with type 2 diabetes mellitus. Subjects were randomized into either a control group or a seaweed supplementation group. Pills with equal parts of dry powdered sea tangle and sea mustard were provided to the seaweed supplementation group three times a day for 4 weeks. Total daily consumption of seaweed was 48 g. We found that total dietary fiber intake was 2.5 times higher in subjects receiving seaweed supplementation than in the control group. Accordingly, fasting blood glucose levels (p<0.01) and 2-hour postprandial blood glucose measurements (p<0.05) were decreased significantly in those ingesting seaweed. Furthermore, the serum concentrations of triglycerides were decreased and high-density lipoprotein cholesterol was increased significantly in seaweed supplement group (p<0.05). However, the concentrations of total cholesterol and low-density lipoprotein cholesterol were not affected by seaweed supplementation. The level of thiobarbituric acid reactive substances in erythrocytes was significantly lower with seaweed supplementation compared to controls (p<0.05). Catalase and glutathione peroxidase activities with seaweed supplementation were higher than the controls (p<0.05), but superoxide dismutase activity was not affected. We, therefore, conclude that ingestion of seaweed influences glycemic control, lowers blood lipids, and increases antioxidant enzyme activities