Brief guide to senescence assays using cultured mammalian cells.

Cellular senescence is a crucial biological process associated with organismal aging and many chronic diseases. Here, we present a brief guide to mammalian senescence assays, including the measurement of cell cycle arrest, change in cellular morphology, senescence-associated ß-galactosidase (SA-ß-gal) staining, and the expression of senescence-associated secretory phenotype (SASP). This work will be useful for biologists with minimum expertise in cellular senescence assays.

Histopathologic Change in the Anterior Part of the Posterior Fixation Suture After a Faden Operation in an Animal Model.

PURPOSE: To observe postoperative histological changes in the anterior part of the posterior fixation suture after a Faden operation in an animal model. METHODS: A posterior fixation suture was placed at two points 6 mm posterior to the insertion of the extraocular muscle on the superior rectus muscle of the right eye in eight rabbits. The superior rectus muscle of the left eye was used as a control. The eyes were enucleated and the anterior portion of the posterior fixation suture, including the myoscleral junction, was extracted 4 weeks after surgery. Postoperative adhesion was graded from 0 to 4 based on histologic findings (hematoxylin-eosin and Masson's trichrome staining). RESULTS: Histological evaluation revealed diffuse fibrosis at the myoscleral junction and the anterior part of the posterior fixation suture after the Faden operation. The graded scores for fibrosis, acute inflammation, chronic inflammation, and foreign body reactions in the Faden operation group were significantly higher than those in the control group (P < .05). Postoperative diffuse fibrosis of the myoscleral junction and anterior-to-posterior fixation sutures were observed in an animal model. CONCLUSIONS: Histologic changes may affect ocular alignment and motility, making reoperation unpredictable after the Faden procedure. [J Pediatr Ophthalmol Strabismus. 2024;61(5):371-375.].

Association between short- and medium-term exposure to air pollutants and depressive episode using comprehensive air quality index among the population in South Korea.

BACKGROUND: Currently, air pollution is suggested as a risk factor for depressive episodes. Our study aimed to consider multiple air pollutants simultaneously, and continuously evaluate air pollutants using comprehensive air quality index (CAI) with depressive episode risk. METHODS: Using a nationally representative sample survey from South Korea between 2014 and 2020, 20,796 participants who underwent health examination and Patient Depression Questionnaire-9 were included in the study. Six air pollutants (PM10, PM2.5, O3, CO, SO2, NO2) were measured for the analysis. Every air pollutant was standardized by air quality index (AQI) and CAI was calculated for universal representation. Using logistic regression, short- and medium-term exposure by AQI and CAI with the risk of depressive episode was calculated by odds ratio and 95 % confidence interval (CI). Furthermore, consecutive measurements of CAI over 1-month time intervals were evaluated with the risk of depressive episodes. Every analysis was conducted seasonally. RESULTS: There were 950 depressive episodes occurred during the survey. An increase in AQI for short-term exposure (0-30 days) showed higher risk of depressive episode in CO, while medium-term exposure (0-120 days) showed higher risk of depressive episode in CO, SO2, PM2.5, and PM10. During the cold season, the exposure to at least one abnormal CAI within 1-month intervals over 120 days was associated with a 68 % (95 % CI 1.11-2.54) increase in the risk of depressive episode. CONCLUSIONS: Short- and medium-term exposure of air pollution may be associated with an increased risk of depressive episodes, especially for cold season.

Potential association between coronary artery disease and the inflammatory biomarker YKL-40 in asymptomatic patients with type 2 diabetes mellitus.

BACKGROUND: Inflammation plays an important role in coronary artery disease from the initiation of endothelial dysfunction to plaque formation to final rupture of the plaque. In this study, we investigated the potential pathophysiological and clinical relevance of novel cytokines secreted from various cells including adipocytes, endothelial cells, and inflammatory cells, in predicting coronary artery disease (CAD) in asymptomatic subjects with type 2 diabetes mellitus. METHODS: We enrolled a total of 70 asymptomatic type 2 diabetic patients without a documented history of cardiovascular disease, and determined serum levels of chemerin, omentin-1, YKL-40, and sCD26. We performed coronary computed tomographic angiography (cCTA) in all subjects, and defined coronary artery stenosis ≥ 50 % as significant CAD in this study. RESULTS: Subjects were classified into two groups: patients with suspected coronary artery stenosis on cCTA (group I, n = 41) and patients without any evidence of stenosis on cCTA (group II, n = 29). Group I showed significantly higher YLK-40 levels and lower HDL-C levels than group II (p = 0.038, 0.036, respectively). Levels of chemerin, omentin-1, and sCD26 were not significantly different between the two groups. Serum YKL-40 levels were positively correlated with systolic/diastolic BP, fasting/postprandial triglyceride levels, and Framingham risk score. Furthermore, YKL-40 levels showed moderate correlation with the degree of coronary artery stenosis and the coronary artery calcium score determined from cCTA. In multivariate logistic analysis, after adjusting for age, gender, smoking history, hypertension, and LDL-cholesterol, YLK-40 levels showed only borderline significance. CONCLUSIONS: YKL-40, which is secreted primarily from inflammatory cells, was associated with several CVD risk factors and was elevated in type 2 diabetic patients with suspected coronary artery stensosis on cCTA. These results suggest the possibility that the inflammatory biomarker YKL-40 might be associated with coronary artery disease in asymptomatic patients with type 2 diabetes mellitus.

The characterization of exosomes from fibrosarcoma cell and the useful usage of Dynamic Light Scattering (DLS) for their evaluation.

Exosomes are a type of extracellular vesicles containing mRNA, miRNA, and proteins of origin cells, which can control the characteristics of other cells or surroundings. Despite increasing evidence on oncogenic properties of tumor-derived exosomes, fibrosarcoma-derived exosomes remain largely unrevealed. While the proper extraction and characterization of exosomes is critical in exosomes research, there are various limitations in techniques to measure the size and homogeneity of exosomes. Here, we analyzed exosomes from a fibrosarcoma cell line WEHI-164 compared with a breast cancer cell line MDA-MD-231 as a control. Results from dot blot and western blot analysis demonstrated that GM1 ganglioside, and TSG101, HSC70 and GAPDH proteins were contained in exosomes from the WEHI-164 fibrosarcoma cell line. The existence of tetraspanins such as CD81, CD63 and CD9 was confirmed in the exosomes by ExoView analysis. The results obtained from TEM showed their sphere-like shapes of around 50 to 70 nm in radius. Through DLS, we found out that the mean radius of the exosomes derived from WEHI-164 and MDA-MB-231 cell lines was 94.4 nm and 107.8 nm, respectively, with high homogeneity. When comparing the radius measured by TEM with the radius measured by DLS, it was revealed that the difference between the two methods was about 40 nm. This study has significance in characterizing the molecular properties of exosomes from a fibrosarcoma, which has not been researched much before, and in providing clear evidence that DLS can be used as an efficient, convenient and noninvasive technique to simply check the homogeneity and size of exosomes.

A case of multiple endocrine neoplasia type 1 combined with papillary thyroid carcinoma.

This is the first report of papillary thyroid carcinoma combined with multiple endocrine neoplasia type 1 (MEN1) in Korea. MEN1 is a hereditary disease comprising neoplastic disorders such as pituitary, parathyroid and pancreatic neuroendocrine tumor, such as gastrinoma. But papillary thyroid cancer was never regarded as its component before in Korea. Herein we present a 39-year-old woman who manifested typical features of MEN1 with a coincidental papillary thyroid carcinoma. Although the family history of MEN1 was definite, her genetic analysis of DNA had revealed no germline mutation in MEN1 gene locus. Unidentified culprit gene unable us further genetic study to find LOH (loss of heterogeneity) in 11q13, the possible explanation of papillary thyroid carcinoma as a new component of MEN1. As we have first experienced a case of MEN1 combined with papillary thyroid carcinoma in Korea, we report it with the review of literature.

The level of 2-h post-challenge glucose is an independent risk factor of carotid intima-media thickness progression in Korean type 2 diabetic patients.

OBJECTIVE: To evaluate the relationship between the metabolic abnormalities commonly associated with diabetes and the changes in carotid intima-media thickness (IMT) in Korean type 2 diabetic patients who do not have clinically manifest cardiovascular disease (CVD). DESIGN: In a prospective study, a total of 152 type 2 diabetic patients were recruited from a group of outpatients at the Yonsei University Hospital. MATERIALS AND METHODS: The carotid IMTs of 152 subjects with type 2 diabetes (mean age 63.5+/-7.0 years) were determined at baseline and after a mean follow-up time of 23.7+/-3.7 months. Fasting plasma glucose, serum total cholesterol (TC), serum triglyceride, high-density lipoprotein cholesterol (HDL-C), HbA1c, oral glucose tolerance test (OGTT) results for 2-h post-challenge glucose (2hPG), and blood pressure measurements were collected every 3 months and averaged. RESULTS: The highest quartiles of baseline C-peptide and homeostatic model assessment (HOMA) index showed more IMT progression than the lowest quartiles. The change in the mean IMT correlated with average values of HbA1c (r=.219, P=.007), the 2-h post-challenge glucose (r=.239, P=.003), HDL-C (r=-.228, P=.005), LDL-C (r=.175, P=.033), and non-HDL-C (r=.194, P=.016). Multiple regression analysis demonstrated that the independent risk factor for the mean IMT change in diabetic patients was the average 2hPG level (P=.004). The change in the mean IMT of those in the lowest quartile of average 2hPG (<11.1 mmol/l) was 823+/-176 to 841+/-146 microm (P=.276). In the highest quartile (2hPG >15.3 mmol/l), however, the mean IMT increased from 794+/-127 to 882+/-153 microm (P<.001). CONCLUSION: The 2hPG parameter among the various metabolic parameters exerts the greatest influence upon the prevention of carotid IMT progression in type 2 diabetic subjects. The level of 2hPG is an independent risk factor for the progression of carotid IMT in Korean type 2 diabetic patients.

High Dielectric Performances of Flexible and Transparent Cellulose Hybrid Films Controlled by Multidimensional Metal Nanostructures.

Various wearable electronic devices have been developed for extensive outdoor activities. The key metrics for these wearable devices are high touch sensitivity and good mechanical and thermal stability of the flexible touchscreen panels (TSPs). Their dielectric constants (k) are important for high touch sensitivities. Thus, studies on flexible and transparent cover layers that have high k with outstanding mechanical and thermal reliabilities are essential. Herein, an unconventional approach for forming flexible and transparent cellulose nanofiber (CNF) films is reported. These films are used to embed ultralong metal nanofibers that serve as nanofillers to increase k significantly (above 9.2 with high transmittance of 90%). Also, by controlling the dimensions and aspect ratios of these fillers, the effects of their nanostructures and contents on the optical and dielectric properties of the films have been studied. The length of the nanofibers can be controlled using a stretching method to break the highly aligned, ultralong nanofibers. These nanofiber-embedded, high-k films are mechanically and thermally stable, and they have better Young's modulus and tensile strength with lower thermal expansion than commercial transparent plastics. The demonstration of highly sensitive TSPs using high-k CNF film for smartphones suggests that this film has significant potential for next-generation, portable electronic devices.

The relation between birth weight and insulin resistance in Korean adolescents.

Low birth weight is associated with insulin resistance and type 2 diabetes in adults. The fetal programming hypothesis has shown that insulin resistance and its associated metabolic disturbances result from a poor gestational environment, for which low birth weight is a surrogate. An at-home questionnaire survey was performed on 660 middle school students (12-15 years) in Seoul, Korea, and 152 cases were randomly selected based on their birth weight. Subjects were divided into three groups according to birth weight. We recorded their birth weight and measured their current anthropometric data, blood pressure, lipid profile, HOMA-IR, and HOMA-beta, and compared these parameters among the groups. The relation of birth weight to physiological characteristics in adolescence was examined. Systolic blood pressure, lipid profiles, and fasting plasma glucose, HOMA-beta were not significantly different among the groups, but diastolic blood pressure was lower in the third tertile. Insulin, C-peptide, and HOMA-IR were higher in the lower birth weight tertile. After adjustment for confounding factors, birth weight was inversely related to diastolic blood pressure, insulin, C-peptide, and HOMA-IR. We conclude that low birth weight may predict the risk of the insulin resistance and its progression over age, and that adequate gestational nutrition is therefore necessary to prevent low birth weight.

Metformin alleviates hepatosteatosis by restoring SIRT1-mediated autophagy induction via an AMP-activated protein kinase-independent pathway.

Metformin activates both PRKA and SIRT1. Furthermore, autophagy is induced by either the PRKA-MTOR-ULK1 or SIRT1-FOXO signaling pathways. We aimed to elucidate the mechanism by which metformin alleviates hepatosteatosis by examining the molecular interplay between SIRT1, PRKA, and autophagy. ob/ob mice were divided into 3 groups: one with ad libitum feeding of a standard chow diet, one with 300 mg/kg intraperitoneal metformin injections, and one with 3 g/d caloric restriction (CR) for a period of 4 wk. Primary hepatocytes or HepG2 cells were treated with oleic acid (OA) plus high glucose in the absence or presence of metformin. Both CR and metformin significantly improved body weight and glucose homeostasis, along with hepatic steatosis, in ob/ob mice. Furthermore, CR and metformin both upregulated SIRT1 expression and also stimulated autophagy induction and flux in vivo. Metformin also prevented OA with high glucose-induced suppression of both SIRT1 expression and SIRT1-dependent activation of autophagy machinery, thereby alleviating intracellular lipid accumulation in vitro. Interestingly, metformin treatment upregulated SIRT1 expression and activated PRKA even after siRNA-mediated knockdown of PRKAA1/2 and SIRT1, respectively. Taken together, these results suggest that metformin alleviates hepatic steatosis through PRKA-independent, SIRT1-mediated effects on the autophagy machinery.

Glycemic Effectiveness of Metformin-Based Dual-Combination Therapies with Sulphonylurea, Pioglitazone, or DPP4-Inhibitor in Drug-Naïve Korean Type 2 Diabetic Patients.

BACKGROUND: This study compared the glycemic effectiveness of three metformin-based dual therapies according to baseline hemoglobin A1c (HbA1c) to evaluate the appropriateness of the guideline enforced by the National Health Insurance Corporation of Korea for initial medication of type 2 diabetes (T2D). METHODS: This prospective observational study was conducted across 24 weeks for drug-naïve Korean T2D patients with HbA1c greater than 7.5%. Subjects were first divided into three groups based on the agent combined with metformin (group 1, gliclazide-modified release or glimepiride; group 2, pioglitazone; group 3, sitagliptin). Subjects were also classified into three categories according to baseline HbA1c (category I, 7.5%≤HbA1c<9.0%; category II, 9.0%≤HbA1c<11.0%; category III, 11.0%≤HbA1c). RESULTS: Among 116 subjects, 99 subjects completed the study, with 88 subjects maintaining the initial medication. While each of the metformin-based dual therapies showed a significant decrease in HbA1c (group 1, 8.9% to 6.4%; group 2, 9.0% to 6.6%; group 3, 9.3% to 6.3%; P<0.001 for each), there was no significant difference in the magnitude of HbA1c change among the groups. While the three HbA1c categories showed significantly different baseline HbA1c levels (8.2% vs. 9.9% vs. 11.9%; P<0.001), endpoint HbA1c was not different (6.4% vs. 6.6% vs. 6.0%; P=0.051). CONCLUSION: The three dual therapies using a combination of metformin and either sulfonylurea, pioglitazone, or sitagliptin showed similar glycemic effectiveness among drug-naïve Korean T2D patients. In addition, these regimens were similarly effective across a wide range of baseline HbA1c levels.

Glycemic Effects of Once-a-Day Rapid-Acting Insulin Analogue Addition on a Basal Insulin Analogue in Korean Subjects with Poorly Controlled Type 2 Diabetes Mellitus.

BACKGROUND: The present study investigates the efficacy in glycemic control by adding once-a-day glulisine to glargine as a basal plus regimen and factors influencing glycemic control with the basal plus regimen in Korean subjects with type 2 diabetes. METHODS: In the present retrospective study, subjects previously treated with the basal plus regimens for at least 6 months were reviewed. Changes in glycemic profiles and clinical parameters were evaluated. RESULTS: A total of 87 subjects were ultimately enrolled in this study. At baseline, mean glycated hemoglobin (A1c) and glycated albumin were 8.5% (8.0% to 9.6%) and 25.2±7.6%, respectively. After treatment with the basal plus regimen, patients had significant reductions of A1c at 6 months (0.8±0.1%, P<0.001) and their postprandial glucose levels were decreased by 48.7±10.3 mg/dL (P<0.001). Multiple logistic regression showed old age (odds ratio [OR], 1.25; 95% confidence interval [CI], 1.02 to 1.55), high initial A1c (OR, 22.21; 95% CI, 2.44 to 201.78), and lower amounts of glargine (OR, 0.85; 95% CI, 0.76 to 0.99), and glimepiride (OR, 0.23; 95% CI, 0.06 to 0.93) at baseline were independently associated with good responders whose A1c reduction was more than 0.5%. CONCLUSION: The authors suggest a basal plus regimen may be effective in reducing glucose levels of subjects with old age, high initial A1c, and patients on low doses of glimepiride and glargine. Despite the use of high doses of hypoglycemic agents, elderly patients with poorly-controlled diabetes are preferred for early initiation of the basal plus regimen.

Dimethyl sulfoxide reduces hepatocellular lipid accumulation through autophagy induction.

Induction of autophagy is known not only to regulate cellular homeostasis but also to decrease triglyceride accumulation in hepatocytes. The aim of this study is to investigate whether DMSO (dimethyl sulfoxide) has a beneficial role in free fatty acid-induced hepatic fat accumulation. In HepG2 cells, treatment with 0.5 mM palmitate for six hours significantly increased lipid and triglyceride (TG) accumulation, assessed by Oil-red O staining and TG quantification assay. Treatment with 0.01% DMSO for 16 h statistically reduced palmitate-induced TG contents. Pretreatment of 10 mM 3-methyladenine (3MA) for 2 h restored hepatocellular lipid contents, which were attenuated by treatment with DMSO. DMSO increased LC3-II conversion and decreased SQSTM1/p62 expression in a time and dose-dependent manner. In addition, the number of autophagosomes and autolysosomes, as seen under an electron microscopy, as well as the percentage of RFP-LAMP1 colocalized with GFP-LC3 dots in cells transfected with both GFP-LC3 and RFP-LAMP1, as seen under a fluorescent microscopy, also increased in DMSO-treated HepG2 cells. DMSO also suppressed p-eIF2α/p-EIF2S1, ATF4, p-AKT1, p-MTOR and p-p70s6k/p-RPS6KB2 expression as assessed by western blotting. Knockdown of ATF4 expression using siRNA suppressed ATF4 expression and phosphorylation of AKT1, MTOR and RPS6KB2, but increased LC3-II conversion. DMSO reduced not only soluble but also insoluble mtHTT (mutant huntingtin aggregates) expressions, which were masked in the presence of autophagy inhibitor. DMSO, a kind of chemical chaperone, activated autophagy by suppressing ATF4 expression and might play a protective role in the development of fatty acid-induced hepatosteatosis.

Abnormal left ventricular longitudinal functional reserve in patients with diabetes mellitus: implication for detecting subclinical myocardial dysfunction using exercise tissue Doppler echocardiography.

BACKGROUND: Subclinical myocardial dysfunction occurs in a significant number of patients with type 2 diabetes. Assessment of ventricular long-axis function by measuring mitral annular velocities using tissue Doppler echocardiography (TDE) is thought to provide a more sensitive index of systolic and diastolic function. We hypothesised that augmentation of left ventricular (LV) longitudinal contraction and relaxation during exercise would be blunted in patients with type 2 diabetes. METHODS: Mitral annular systolic (S') and early diastolic (E') velocities were measured at rest and during supine bicycle exercise (25 W, 3 min increments) in 53 patients (27 male, mean age 53+/-14 years) with type 2 diabetes and 53 subjects with age and gender-matched control. None had echocardiographic evidence of resting or inducible myocardial ischaemia. RESULTS: There were no significant differences in mitral inflow velocities at rest between the two groups. E' and S' at rest were also similar between the groups. However, S' (7.1+/-1.3 vs 8.3+/-1.8 cm/s at 25 W, p = 0.0021; 8.1+/-1.5 vs 9.1+/-2.0 cm/s at 50 W, p = 0.026) and E' (8.5+/-2.3 vs 9.9+/-3.1 cm/s at 25 W, p = 0.054; 9.1+/-2.1 vs 10.9+/-2.5 cm/s at 50 W, p = 0.0093) during exercise were significantly lower in patients with diabetes compared with controls. Longitudinal systolic and diastolic function reserve indices were significantly lower in patients with diabetes compared with that of controls (systolic index, 0.6+/-0.70 vs 1.2+/-1.5 cm/s at 25 W, p = 0.029; 1.2+/-1.2 vs 2.1+/-1.6 cm/s at 50 W, p = 0.009; diastolic index, 1.9+/-1.2 vs 2.5+/-2.2 cm/s at 25 W, p = 0.07; 2.3+/-1.3 vs 3.2+/-2.2 cm/s at 50 W, p = 0.031). CONCLUSION: In conclusion, unlike resting mitral inflow and annular velocities, changes of systolic and diastolic velocities of the mitral annulus during exercise were significantly reduced in patients with type 2 diabetes compared with the control group. The assessment of LV longitudinal functional reserve with exercise using TDE appears to be helpful in identifying early myocardial dysfunction in patients with type 2 diabetes.

Template-free magnesium oxide hollow sphere inclusion in organic-inorganic hybrid films via sol-gel reaction.

Magnesium oxide hollow spheres without a template core were conveniently prepared by stabilized bubble formation in a hybrid solution containing a magnesium acetate precursor, thus avoiding the complicated preparation process using a template. The hollow sphere could be aligned along the radial striation by spin coating, and its diameter from a micrometer to submicrometer dimension could be easily modified by the solution composition. It was also possible to control the open or closed hollow sphere by changing the solvent. Thus, the produced magnesium oxide hollow sphere is envisioned to have applications in many areas such as medicine, analysis, optics, and so on.

Comparison of body fat composition and serum adiponectin levels in diabetic obesity and non-diabetic obesity.

OBJECTIVE: Clinical aspects of diabetes and obesity are somewhat different, even at similar levels of insulin resistance. The purpose of this study was to determine differences in body fat distribution and serum adiponectin concentrations in diabetic and non-diabetic obese participants. We were also interested in identifying the characteristics of insulin resistance in these two groups, particularly from the standpoint of adiponectin. RESEARCH METHODS AND PROCEDURES: Adiponectin concentrations of 112 type 2 diabetic obese participants and 124 non-diabetic obese participants were determined. Abdominal adipose tissue areas and midthigh skeletal muscle areas were measured by computed tomography. A homeostasis model assessment of the insulin resistance score was calculated to assess insulin sensitivity. The relationships among serum adiponectin, body fat distribution, and clinical characteristics were also analyzed. RESULTS: Both abdominal subcutaneous and visceral fat areas were higher in the non-diabetic obese group, whereas midthigh low-density muscle area was higher in the diabetic obese group. The homeostasis model assessment of the insulin resistance score was similar between groups, whereas serum adiponectin was lower in the diabetic obese group. Abdominal visceral fat (beta = -0.381, p = 0.012) was a more important predictor of adiponectin concentration than low-density muscle (beta = -0.218, p = 0.026) in cases of non-diabetic obesity, whereas low-density muscle (beta = -0.413, p = 0.013) was a better predictor of adiponectin level than abdominal visceral fat (beta = - 0.228, p = 0.044) in diabetic obese patients. DISCUSSION: Therefore, factors involved in pathophysiology, including different serum adiponectin levels and body fat distributions, are believed to be responsible for differences in clinical characteristics, even at similar levels of insulin resistance in both diseases.