Cholecystectomy increases the risk of metabolic syndrome in the Korean population: a longitudinal cohort study

Background

Cholecystectomy is a common surgical procedure to treat symptomatic gallstones; however, the long-term outcomes after cholecystectomy are unknown. Therefore, we aimed to investigate whether incident metabolic syndrome (MetS) is associated with cholecystectomy through a large, population-based, longitudinal study.

Methods

Subjects aged ≥20 years who underwent cholecystectomy from 2010 to 2014 (n=76,485) and controls (n=76,485), matched for age and sex, were identified from the Korean National Health Insurance Corporation. Cox proportional hazards analyses were performed to evaluate the association between cases and incident MetS, and hazard ratios and 95% confidence intervals (CIs) were calculated.

Results

A total of 152,970 patients were included. Mean age was 52.47±12.76 years, and 50.65% of participants were male. During the follow-up period, there were 38,979 (25.48%) newly diagnosed MetS cases in the study participants. The risk of MetS in the cholecystectomy group was approximately 20% higher than that in the control group [adjusted odds ratio (OR), 1.20; 95% CI: 1.17-1.23]. In the fully adjusted models, the corresponding ORs for new-onset high waist circumference (WC), low high-density lipoprotein cholesterol (HDL-C) levels, high triglycerides (TG) levels, high blood pressure (BP), and high blood glucose levels were 1.16 (1.13-1.19), 1.19 (1.16-1.22), 1.25 (1.22-1.28), 1.27 (1.23-1.31), and 1.21 (1.18-1.24), respectively. Cholecystectomy was an independent risk factor of incident MetS, after adjusting for potential confounding factors. In the subgroup analyses, the cholecystectomy group had a higher risk of MetS than the control group in subjects without hypertension or dyslipidemia, respectively.

Conclusions

In this large, population-based study, cholecystectomy was associated with an increased risk of developing MetS, independent of other confounding factors. Therefore, careful monitoring of metabolic variables and long-term follow-up are required to evaluate MetS risk after cholecystectomy.

Association between Sleep Duration and Incident Diabetes Mellitus in Healthy Subjects: A 14-Year Longitudinal Cohort Study

BACKGROUND

This study aimed to investigate whether sleep duration and/or quality are associated with incident diabetes mellitus (DM).

METHODS

A total of 8816 of 10,030 healthy participants were enrolled in a prospective cohort study. Sleep duration and quality questionnaires were completed. Sleep quality was assessed using the Epworth Sleepiness Scale (ESS), which measures excessive daytime sleepiness in individuals.

RESULTS

During the 14-year follow-up period, 18% (1630/8816) were diagnosed with DM. A U-shaped relationship was observed between sleep duration and incident DM, with the highest risk observed when sleep duration was ≥10 h/day (hazard ratios (HR) 1.65 [1.25-2.17]). This group exhibited decreased insulin glycogenic index, a marker of insulin secretory function, during the study period. Among study participants who slept less than 10 h/day, the risk of incident DM increased when the ESS score was >10.

CONCLUSIONS

We found that the association between sleep duration and incident DM was U-shaped; both short (≤5 h) and long (≥10 h) sleep durations were associated with an increased risk for the occurrence of incident DM. When sleep duration was 10 h or longer per day, there was a tendency to develop DM due to decreased insulin secretory function.

Remnant Cholesterol Is an Independent Predictor of Type 2 Diabetes: A Nationwide Population-Based Cohort Study

OBJECTIVE

Although the atherogenic effect of remnant cholesterol (remnant-C) has been widely recognized, the relationship between remnant-C and glucose metabolism remains unclear. This retrospective, longitudinal study investigated the relationship between remnant-C and incident type 2 diabetes (T2D) in a nationwide cohort of Korean adults.

RESEARCH DESIGN AND METHODS

A total of 8,485,539 Korean adults without diabetes participated in the national health screening in 2009 and were followed up until 2019. The relationship between remnant-C quartiles and incident T2D was examined by Cox regression models. The risk of incident T2D over the continuum of remnant-C was examined with cubic spline analysis.

RESULTS

During the median follow-up period of 9.28 years, 584,649 individuals (6.8%) developed T2D. In multivariable-adjusted analyses, participants in the upper quartile of remnant-C had a higher risk of T2D, with hazard ratios of 1.25 (95% CI 1.24-1.27) in the second quartile, 1.51 (95% CI 1.50-1.53) in the third quartile, and 1.95 (95% CI 1.93-1.97) in the fourth quartile, compared with the lowest quartile. The increase in the risk of T2D owing to high remnant-C concentration was more profound in individuals with fewer traditional T2D risks, such as women, and absence of metabolic abnormalities, including impaired fasting glucose, hypertension, and atherogenic dyslipidemia. Moreover, the magnitude of the increased risk for incident T2D in individuals with higher remnant-C quartiles was higher in younger participants than older participants.

CONCLUSIONS

These findings indicate that remnant-C profiles provide additional information in predicting future progression of T2D, independent of the conventional lipid parameters.

Waist circumference and end-stage renal disease based on glycaemic status: National Health Insurance Service data 2009-2018

BACKGROUND

Obesity is associated with an increased risk of developing type 2 diabetes mellitus (T2DM) and end-stage renal disease (ESRD). This study aimed to examine the effect of waist circumference (WC) on the risk for ESRD based on glycaemic status in a Korean population-based sample.

METHODS

This cohort study with a 9.2-year follow-up period used a population-based National Health Insurance Service health checkup database with approximately 10 585 852 participants who were followed up from 2009 to the time of ESRD diagnosis. WC was categorized into seven levels in 5-cm increments, with Level 4 as the reference group. Glycaemic status was categorized into the following groups: normal fasting glucose (NFG), impaired fasting glucose (IFG), newly diagnosed T2DM, T2DM treated with ≤2 oral hypoglycaemic agents (OHAs) and diabetes treated with ≥3 OHAs or insulin. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for ESRD according to WC values and glycaemic status of the participants.

RESULTS

The study finally included 10 177 245 patients with a mean age of 47.1 (13.8) years. The study population included 5 604 446 men (55.1%) and 4 572 799 women (45.9%). In total, 8.3% (n = 877 143) of the study population had diabetes. During the mean follow-up of 9.2 (1.0) years (93 554 951 person-years of follow-up), 23 031 individuals were newly diagnosed with ESRD. The ESRD risk increased in parallel with an increase in WC in participants without T2DM, that is, the NFG and IFG groups (adjusted HRs [95% CIs] of WC Levels 4, 5 and 6: 1.17 [1.09-1.26], 1.37 [1.25-1.51] and 1.84 [1.63-2.07] in the NFG group and 1.06 [0.97-1.16], 1.23 [1.10-1.38] and 1.80 [1.57-2.06] in the IFG group, respectively). In patients with T2DM, the risk for ESRD was significantly increased in those with a low WC (adjusted HRs [95% CIs] of WC Level 1: 2.23 [1.77-2.80], 3.18 [2.70-3.74] and 10.31 [9.18-11.59] in patients with newly diagnosed diabetes, patients on ≤2 OHAs and those on ≥3 OHAs or insulin, respectively). The association between WC and ESRD thus showed a J-shaped pattern in patients with newly diagnosed T2DM and a U-shaped pattern in those on ≤2 OHAs and on ≥3 OHAs or insulin.

CONCLUSIONS

Central obesity substantially increases the risk of developing ESRD regardless of glycaemic status. The harmful effects of low WC only become significant with the progression of T2DM.

Remnant cholesterol and the risk of cardiovascular disease in type 2 diabetes: a nationwide longitudinal cohort study

BACKGROUND

Elevated remnant cholesterol (remnant-C) is considered a risk factor for cardiovascular disease (CVD); however, whether this notion applies to the East Asian population with type 2 diabetes (T2D) has not been established. This study investigated the association between remnant-C concentrations and the risk of CVD in Korean patients with T2D.

METHODS

By using the Korean National Health Insurance Service database, 1,956,452 patients with T2D and without atherosclerotic CVD who underwent regular health checks between 2009 and 2012 were included. Cox regression analyses were conducted to assess the association between remnant-C concentrations and incident CVD comprising myocardial infarction (MI) and ischemic stroke.

RESULTS

In total, 50,120 (2.56%) cases of MI and 73,231 (3.74%) cases of ischemic strokes occurred during a median follow-up of 8.1 years. The adjusted hazard ratios for MI and stroke in the highest remnant-C quartile were 1.281 (95% confidence interval [CIs], 1.249-1.314) for MI and 1.22 (1.195-1.247) for ischemic stroke, compared to those in the lowest quartiles. The results were similar, based on stratified analysis by age, sex, use of statin or fibrate, and levels of other cholesterol. The increased risk of CVD in the highest remnant-C quartile was profound in patients who had a longer T2D duration. A remnant-C concentration ≥ 30 mg/dL differentiated patients who were at a higher risk of CVD, compared to patients with a lower concentrations, regardless of whether LDL-C levels were or were not on target at ≤ 100 mg/dL.

CONCLUSION

In Korean patients with T2D, remnant-C was associated with CVD, independent of the LDL-C level or other conventional CVD risk factors. Our finding confirmed evidence of the causal role of remnant-C on CVD, as a residual risk of CVD, in East Asian patients with T2D.

Association of the atherogenic index of plasma with cardiovascular risk beyond the traditional risk factors: a nationwide population-based cohort study

Background

The atherogenic index of plasma (AIP) is composed of triglycerides and high-density lipoprotein cholesterol and is a novel marker for assessing the risk of atherogenicity and cardiometabolic health. An association between AIP and greater frequency of major adverse cardiovascular events (MACEs) in patients with type 2 diabetes mellitus and high cardiovascular (CV) disease risk has been reported. However, only few studies have examined the correlation between AIP and CV risk in general populations. We thus aimed to evaluate the relationship between AIP and CV diseases using a large-scale population dataset from the Korean National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS).

Methods

A total of 514,866 participants were enrolled from the NHIS-HEALS and classified according to the AIP quartiles. We performed univariate and multivariate Cox proportional hazards regression analyses to determine the association between AIP and MACEs, CV events, and CV mortality.

Results

During follow-up, we documented 12,133, 11,055, and 1942 cases of MACEs, CV events, and CV mortality, respectively. The multivariate-adjusted hazard ratios [HRs; 95% confidence interval (CI)] for MACEs gradually and significantly increased with the AIP quartiles [1.113 (1.054–1.175) in Q2, 1.175 (1.113–1.240) in Q3, and 1.278 (1.209–1.350) in Q4], following an adjustment for the conventional CV risk factors, including age, sex, body mass index, smoking, alcohol drinking, physical activities, household income, fasting glucose, systolic blood pressure, low-density lipoprotein cholesterol, and estimated glomerular filtration rate. In subgroup analyses, the association of AIP with MACEs and CV events was particularly outstanding in patients with diabetes.

Conclusions

AIP was significantly associated with CV risks after adjusting for the traditional risk factors. Therefore, it may be used as an effective mass screening method to identify patients at a high risk of CV events.

Supplementary information

The online version contains supplementary material available at 10.1186/s12933-022-01522-8.

Heat Shock Protein 90 Inhibitors AUY922, BIIB021 and SNX5422 Induce Bim-mediated Death of Thyroid Carcinoma Cells

BACKGROUND/AIM

Heat shock protein 90 (HSP90) controls maturation of oncogenic client proteins of cancer cells, and thus we studied the effect of HSP 90 inhibitors on cell survival and survival-related mediators in thyroid carcinoma cells.

MATERIALS AND METHODS

Human TPC-1 and SW1736 thyroid carcinoma cells were utilized. Cell viability, cytotoxic activity and apoptosis were estimated using CCK-8 assay, cytotoxicity assay and FACS analysis, respectively.

RESULTS

AUY922, BIIB021 and SNX5422 decreased cell viability, and increased cytotoxic activity and the proportion of apoptotic cells. The protein levels of cleaved PARP, cleaved caspase-3, Bax and Bim were elevated, and Bcl2 protein levels were reduced. Knockdown of Bax did not change cell viability, cytotoxic activity, the proportion of apoptotic cells and cleaved caspase-3 protein levels. Meanwhile, knockdown of Bim enhanced cell viability, and diminished cytotoxic activity, the proportion of apoptotic cells and cleaved caspase-3 protein levels. AUY922, BIIB021 and SNX5422 increased the protein levels of phospho-AMPK, and decreased those of phospho-ERK1/2, and total and phospho-AKT.

CONCLUSION

AUY922, BIIB021 and SNX5422 induce cytotoxicity by modulating Bim and ERK1/2, AKT and AMPK signaling in thyroid carcinoma cells.

Relationships between Thigh and Waist Circumference, Hemoglobin Glycation Index, and Carotid Plaque in Patients with Type 2 Diabetes

BACKGROUND

This study investigated the relationships of thigh and waist circumference with the hemoglobin glycation index (HGI) and carotid atherosclerosis in patients with type 2 diabetes.

METHODS

This observational study included 3,075 Korean patients with type 2 diabetes, in whom anthropometric measurements and carotid ultrasonography were conducted. HGI was defined as the measured hemoglobin A1c (HbA1c) level minus the predicted HbA1c level, which was calculated using the linear relationship between HbA1c and fasting plasma glucose levels. Carotid atherosclerosis was defined as a clearly isolated focal plaque or focal wall thickening >50% of the surrounding intima-media thickness.

RESULTS

The frequency of a positive HGI decreased with increasing thigh circumference in men and increased with increasing waist circumference in women after adjusting for potential confounding variables. Thigh and waist circumference had a combined augmentative effect on the likelihood of positive HGI, which was dramatically higher in patients in higher waist-to-thigh ratio quartiles (adjusted odds ratios for the highest compared to the lowest quartile: 1.595 in men and 1.570 in women). Additionally, the larger the thigh circumference, the lower the risk of carotid atherosclerosis, although in women, this relationship lacked significance after adjustment for potential confounders.

CONCLUSION

HGI was associated with thigh circumference in men and waist circumference in women. In addition, the combination of low thigh circumference and high waist circumference was strongly associated with a higher HGI in Korean patients with type 2 diabetes. In particular, thigh circumference was associated with carotid atherosclerosis in men. However, further longitudinal studies are warranted.

Underweight Increases the Risk of End-Stage Renal Diseases for Type 2 Diabetes in Korean Population: Data From the National Health Insurance Service Health Checkups 2009-2017

OBJECTIVE

There is a controversy over the association between obesity and end-stage renal disease (ESRD) in people with or without type 2 diabetes; therefore, we examined the effect of BMI on the risk of ESRD according to glycemic status in the Korean population.

RESEARCH DESIGN AND METHODS

The study monitored 9,969,848 participants who underwent a National Health Insurance Service health checkup in 2009 from baseline to the date of diagnosis of ESRD during a follow-up period of ∼8.2 years. Obesity was categorized by World Health Organization recommendations for Asian populations, and glycemic status was categorized into the following five groups: normal, impaired fasting glucose (IFG), newly diagnosed diabetes, diabetes <5 years, and diabetes ≥5 years.

RESULTS

Underweight was associated with a higher risk of ESRD in all participants after adjustment for all covariates. In the groups with IFG, newly diagnosed type 2 diabetes, diabetes duration <5 years, and diabetes ≥5 years, the hazard ratio (HR) of the underweight group increased with worsening glycemic status (HR 1.431 for IFG, 2.114 for newly diagnosed diabetes, 4.351 for diabetes <5 years, and 6.397 for diabetes ≥5 years), using normal weight with normal fasting glucose as a reference. The adjusted HRs for ESRD were also the highest in the sustained underweight group regardless of the presence of type 2 diabetes (HR 1.606 for nondiabetes and 2.14 for diabetes).

CONCLUSIONS

Underweight showed more increased HR of ESRD according to glycemic status and diabetes duration in the Korean population. These associations also persisted in the group with sustained BMI during the study period.

P5728Association of systolic blood pressure and cardiovascular outcomes at different age groups in the healthy general population: a nationwide prospective cohort study

Background

Uncertainties remain regarding the effect of blood pressure on various cardiovascular outcomes in different age groups.

Purpose

We aimed to identify 1) whether a systolic blood pressure (SBP) of 130–139 mm Hg elevates cardiovascular disease (CVD) mortality and 2) whether SBP shows a linear association with cause-specific CVD mortality in all age groups among individuals without known hypertension and CVD.

Methods

We used the Korean National Health Insurance sample data (n=429,220). Participants were categorized into three groups by age (40–59, 60–69, and 70–80 years).

Results

A positive and graded association was generally observed between SBP and overall and cause-specific CVD mortality regardless of age, except for ischemic heart disease (IHD) mortality in those aged 70–80 years. Among those aged 70–80, the hazard ratios (HRs) (95% CIs) for overall CVD mortality were 1.08 (0.92–1.28), 1.14 (0.97–1.34), and 1.34 (1.14–1.58) for SBP values of 120–129, 130–139, and 140–149 mm Hg, respectively, compared to SBP <120 mm Hg. For total stroke mortality, the corresponding HRs were 1.29 (1.02–1.64), 1.37 (1.09–1.72), and 1.52 (1.20–1.93), while for IHD mortality, the corresponding HRs were 0.90 (0.64–1.26), 0.86 (0.62–1.19), and 1.29 (0.93–1.78). Nonlinear associations were significant for IHD (Fig 1).

Figure 1

Conclusion

In the elderly Korean population, SBPs of 130–139 mm Hg elevated total stroke mortality, but not IHD mortality, compared to normal BP, and a linear association was not observed for IHD mortality in the range <140 mm Hg. Regarding an appropriate diagnostic cutoff for hypertension, an individualized approach considering each person's organ susceptibility is needed for the elderly population.

Acknowledgement/Funding

None

Evodiamine in combination with histone deacetylase inhibitors has synergistic cytotoxicity in thyroid carcinoma cells

PURPOSE

The impact of evodiamine in combination with histone deacetylase (HDAC) inhibitors on survival of thyroid carcinoma cells was identified.

METHODS

TPC-1 and SW1736 human thyroid carcinoma cells were used.

RESULTS

After treatment with evodiamine and PXD101, cell viability, the percentage of viable cells and Bcl2 protein levels decreased, whereas cytotoxic activity, the percentage of apoptotic cells, the protein levels of γH2AX, acetyl. histone H3 and cleaved PARP, and reactive oxygen species (ROS) production increased. In cells treated with both evodiamine and PXD101, compared with PXD101 alone, decrement of cell viability, the percentage of viable cells, and Bcl2 protein levels as well as increment of cytotoxic activity, the percentage of apoptotic cells, the protein levels of γH2AX and cleaved PARP, and ROS production were significant, causing decrement of Bcl2/Bax ratio. Furthermore, all of the combination index values were <1.0, suggesting synergistic cytotoxicity of two agents. Wortmannin decreased cell viability and the percentage of viable cells, whereas it increased cytotoxic activity and the percentage of apoptotic cells without alteration in ROS production. The changes in cells treated with both evodiamine and suberoylanilide hydroxamic acid or trichostatin A were similar to those in cells treated with both evodiamine and PXD101.

CONCLUSIONS

Our results demonstrate that evodiamine synergizes with HDAC inhibitors in inducing cytotoxic activities by involving survival-related proteins and ROS in thyroid carcinoma cells. Moreover, repression of PI3K/Akt signaling synergistically reinforces cytotoxicity of evodiamine combined with HDAC inhibitors in thyroid carcinoma cells.

Association between metabolic parameters and glomerular hyperfiltration in a representative Korean population without chronic kidney disease

Aims

To investigate associations of glomerular hyperfiltration with other metabolic factors in a nationally representative dataset.

Methods

We analyzed cross-sectional data from 15,918 subjects with estimated glomerular filtration rate (eGFR) >60 ml/min/1.73 m² and urine albumin creation ratio (ACR) <30 mg/g, who participated in the 5th and 6th Korea National Health and Nutrition Examination Surveys. Hyperfiltration was defined as eGFR (CKD-EPI equation) exceeding the age- and sex-specific 95th percentile for healthy control subjects.

Results

Prevalence of hyperfiltration was 5.2% and that among normal, prediabetic, and diabetic subjects was 4.9%, 5.6%, and 7.3%, respectively, after adjusting for age, sex, and body weight (p for trend = 0.008). In a multiple logistic regression analysis, hyperfiltration was associated with a body mass index ≥30 kg/m² [odds ratio (OR) = 3.461, p<0.001], waist circumference 85 cm (men) or 80 cm (women) (OR = 1.425, p = 0.015), systolic blood pressure 120–129 mmHg (OR = 1.644, p = 0.022), fasting plasma glucose 140 mg/dL (OR = 1.695, p = 0.033) and t serum triglyceride level 500 mg/dL (OR = 2.988, p = 0.001), and was independently associated with the ACR (B = 0.053, p<0.001).

Conclusions

In a general Korean population, both hyperfiltration and ACR were associated with similar metabolic parameters, and hyperfiltration correlated independently with a high ACR. Longitudinal studies are needed to further explore risks of hyperfiltration and microalbuminuria.

Enigma Plays Roles in Survival of Thyroid Carcinoma Cells through PI3K/AKT Signaling and Survivin

BACKGROUND/AIM

The aim of the present study was to assess the role of enigma protein in survival of thyroid carcinoma cells.

MATERIALS AND METHODS

BCPAP and 8505C human thyroid carcinoma cells were used. Cell viability using CCK-8 assay, the percentage of dead cells using trypan blue assay, cytotoxic activity using cytotoxicity assay, cell growth rate and cell migration using wound-healing assay were performed.

RESULTS

In enigma siRNA-transfected cells, cell viability, and the protein levels of AKT and survivin decreased. The percentage of dead cells, cytotoxic activity and cleaved poly (ADP-ribose) polymerase (PARP) protein levels increased. After transfection of p110α plasmid, the alterations in cell viability, the percentage of dead cells, cytotoxic activity, and protein levels of AKT, survivin and cleaved PARP were abrogated. Cell growth rate and cell migration were reduced with reduction of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) protein levels, as well as increased p53 and p21 protein levels.

CONCLUSION

Enigma affects cell survival through modulation of phosphatidylinositol-3 kinase/AKT signaling and survivin, and regulates cell proliferation and migration via involvement of MMP-2, MMP-9, p53 and p21 in thyroid carcinoma cells.

Synergistic cytotoxicity of the dipeptidyl peptidase-IV inhibitor gemigliptin with metformin in thyroid carcinoma cells

PURPOSE

The influence of the dipeptidyl peptidase-IV inhibitor, gemigliptin alone or in combination with metformin on survival, proliferation, and migration of thyroid carcinoma cells was investigated.

METHODS

SW1736 and TPC-1 human thyroid carcinoma cells were used.

RESULTS

Gemigliptin and metformin caused cell death in a dose-dependent manner. In cells treated with both gemigliptin and metformin, compared with metformin alone, all of the combination index values were lower than 1.0, suggesting synergistic cytotoxicity of two agents. Cell viability, the percentage of viable cells, ATP levels, and mitochondrial membrane potential decreased; however, cytotoxic activity, and the protein levels of cleaved PARP, phospho-Akt and phospho-AMP-activated protein kinase (AMPK) increased. Administration of wortmannin, but not compound C, further decreased cell viability, and further increased cytotoxic activity. Moreover, compared with control, cell proliferation and migration as well as the protein levels of p53, p21, vascular cell adhesion molecule-1 (VCAM-1), and phospho-extracellular signal-regulated kinase (ERK) 1/2 decreased. The decrement of matrix metalloproteinase-2 and matrix metalloproteinase-9 protein levels was cell specific.

CONCLUSIONS

Our results demonstrate that gemigliptin induces cytotoxic activity, and has a synergistic activity with metformin in inducing cytotoxicity via regulation of Akt and AMPK in thyroid carcinoma cells. Furthermore, gemigliptin augments the inhibitory effect of metformin on proliferation and migration through involvement of matrix metalloproteinase-2, matrix metalloproteinase-9, p53, p21, VCAM-1, and ERK in thyroid carcinoma cells.

Clinical Implications of Immunoglobulin G4 to Graves' Ophthalmopathy

BACKGROUND

This study aimed to explore the relation of immunoglobulin G4 (IgG4) to clinical and laboratory characteristics of patients newly diagnosed with Graves' disease (GD) without or with Graves' ophthalmopathy (GO) and to analyze association of IgG4 with development and grade of GO in GD patients.

METHODS

Sixty-four GD patients and 64 sex- and age-matched euthyroid subjects were enrolled. Serum levels of thyroid hormones, thyroid autoantibodies, immunoglobulin G (IgG), and IgG4 were measured, and ophthalmological and ultrasonographical evaluation was performed.

RESULTS

In GD patients compared with euthyroid subjects, levels of thyroid hormones, thyroid autoantibodies and IgG4 as well as the IgG4/IgG ratio were elevated. GD patients having GO in comparison to not having GO were characterized by a female predominance; a high incidence of smoking history; high levels of T3, free T4, TSH receptor autoantibody (TRAb) and IgG4; and a high IgG4/IgG ratio after adjusting for sex. In GD patients, the IgG4 level was the independent factor associated with GO development on multivariate analysis. When severity and activity of GO were classified using the European Group on Graves' Orbitopathy criteria in GD patients with GO, IgG4 levels and IgG4/IgG ratio were elevated in the moderate-to-severe group compared with the mild group and in the active group compared with the inactive group. IgG4 levels and IgG4/IgG ratio became elevated as clinical activity score increased. IgG4 levels were positively correlated with TRAb levels. The high IgG4 group in comparison to the normal IgG4 group had a high incidence of family history of autoimmune thyroid disease, high levels of free T4, TRAb and IgG4, a high IgG4/IgG ratio and extensive hypoechogenicity.

CONCLUSIONS

These results suggest that IgG4 levels are elevated in newly diagnosed GD patients compared with euthyroid subjects and in the presence of GO compared with the absence of GO. Moreover, our findings suggest that IgG4 levels are associated with the development and grade of GO in GD patients.

Cytotoxic effect of celastrol alone or in combination with paclitaxel on anaplastic thyroid carcinoma cells

The influence of celastrol alone or in combination with paclitaxel on survival of anaplastic thyroid carcinoma cells was investigated. In 8505C and SW1736 cells, after treatment of celastrol, cell viability decreased, and cytotoxic activity increased. The protein levels of heat shock protein (hsp) 90, hsp70, Bax, death receptor 5, cleaved caspase-3, cleaved poly (ADP-ribose) polymerase, phospho-extracellular signal-regulated kinase 1/2 (ERK1/2), and phospho-c-Jun N-terminal kinase (JNK) were elevated, and those of Bcl2, phospho-nuclear factor-kappaB (NF-κB), and total and phospho-Akt were reduced. The endoplasmic reticulum stress markers expression and reactive oxygen species production were enhanced. In celastrol-treated cells, N-acetylcysteine increased cell viability and phospho-NF-κB protein levels, and decreased reactive oxygen species production and cytotoxic activity. The protein levels of cyclooxygenase 2, phospho-ERK1/2, phospho-JNK and Bip were diminished. After treatment of both celastrol and paclitaxel, compared with paclitaxel alone, cell viability and the percentage of viable cells were reduced, and death rate and cytotoxic activity were elevated. The protein levels of phospho-ERK1/2, phospho-JNK, Bip, and cyclooxygenase 2, and reactive oxygen species production were enhanced. All of the Combination Index values calculated by Chou–Talalay equation were lower than 1.0, implying the synergism between celastrol and paclitaxel in induction of cell death. In conclusion, our results suggest that celastrol induces cytotoxicity through involvement of Bcl2 family proteins and death receptor, and modulation of phospho-NF-κB, Akt, and mitogen-activated protein kinase in association with endoplasmic reticulum stress and reactive oxygen species production in anaplastic thyroid carcinoma cells. Moreover, celastrol synergizes with paclitaxel in induction of cytotoxicity in anaplastic thyroid carcinoma cells.

Doxorubicin has a synergistic cytotoxicity with cucurbitacin B in anaplastic thyroid carcinoma cells

In this study, the combined effect of doxorubicin with cucurbitacin B on survival of anaplastic thyroid carcinoma cells was evaluated. For experiments, 8505C and CAL62 human anaplastic thyroid carcinoma cells were used. Cell viability, the percentage of viable cells, and cytotoxic activity were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, multiplexed cytotoxicity assay, and cytotoxicity assay, respectively. Reactive oxygen species production was measured. In experiments, doxorubicin and cucurbitacin B reduced cell viability in a dose- and time-dependent manner. Cotreatment of doxorubicin and cucurbitacin B, compared with treatment of doxorubicin alone, decreased the percentage of viable cells and increased cytotoxic activity. All of the combination index values were lower than 1.0, suggesting the synergism between doxorubicin and cucurbitacin B in induction of cytotoxicity. In cells treated with both doxorubicin and cucurbitacin B, compared with doxorubicin alone, the protein levels of cleaved poly(adenosine diphosphate-ribose) polymerase and cyclooxygenase 2 and reactive oxygen species production were enhanced. In contrast, the protein levels of B-cell chronic lymphocytic leukemia/lymphoma 2 and survivin and B-cell chronic lymphocytic leukemia/lymphoma 2/B-cell chronic lymphocytic leukemia/lymphoma 2-associated x protein ratio were diminished. The protein levels of Janus kinase 2 and signal transducer and activator of transcription 3 were reduced, while phospho-extracellular signal-regulated kinase 1/2 protein levels were elevated without change in total extracellular signal-regulated kinase 1/2 protein levels. These results suggest that doxorubicin synergizes with cucurbitacin B in induction of cytotoxicity in anaplastic thyroid carcinoma cells. Moreover, synergistic cytotoxicity of doxorubicin with cucurbitacin B is mediated by B-cell chronic lymphocytic leukemia/lymphoma 2 family proteins, survivin, and reactive oxygen species and modulated by Janus kinase 2/signal transducer and activator of transcription 3 and extracellular signal-regulated kinase 1/2 in anaplastic thyroid carcinoma cells.

A Potential Issue with Screening Prediabetes or Diabetes Using Serum Glucose: A Delay in Diagnosis

The aim of this study was to compare the fasting serum glucose level with the fasting plasma glucose level for diagnosing hyperglycemic states in real-life clinical situations. Additionally, we investigated a usual delay in sample processing and how such delays can impact the diagnosis of hyperglycemic states. Among 1,254 participants who had normoglycemia or impaired fasting glucose (IFG) assessed by the fasting serum glucose level, 20.9% were newly diagnosed with diabetes based on the plasma fasting glucose level. Of the participants with normoglycemia, 62.1% and 14.2% were newly diagnosed with IFG and diabetes, respectively, according to the plasma fasting glucose level. In our clinical laboratory for performing health examinations, the time delay from blood sampling to glycemic testing averaged 78±52 minutes. These findings show that the ordinary time delay for sample processing of the serum glucose for screening hyperglycemic states may be an important reason for these diagnoses to be underestimated in Korea.

Anti-cancer effect of R3V6 peptide-mediated delivery of an anti-microRNA-21 antisense-oligodeoxynucleotide in a glioblastoma animal model

MicroRNA-21 (miR-21) expression in glioblastoma inhibits the expression of pro-apoptotic genes, thereby promoting tumor growth. A previous study showed that the amphiphilic R3V6 peptide is an efficient carrier of the anti-miR-21 antisense oligodeoxynucleotide (antisense-ODN) into cells in vitro. In the current study, in vivo delivery of antisense-ODN using the R3V6 peptide was evaluated in a glioblastoma animal model. In vitro transfection showed that the R3V6 peptide delivered antisense-ODN more efficiently than polyethylenimine (25 kDa, PEI25k) in C6 glioblastoma cells. For in vivo evaluation, antisense-ODN/R3V6 complex was injected intratumorally into a C6 glioblastoma xenograft animal model. Tumor growth was suppressed by the injection of the antisense-ODN/R3V6 complex, compared with the antisense-ODN/PEI25k and scrambled-antisense-ODN (scr-antisense-ODN)/R3V6 complexes. Real-time RT-PCR showed that miR-21 levels were reduced most efficiently by the antisense-ODNR3V6 complex in tumors. Due to inhibition of miR-21, expression of the programed cell death 4 (PDCD4) gene was promoted in tumors, resulting in the induction of apoptosis of tumor cells. These results suggest that delivery of antisense-ODN using R3V6 peptides may be useful for the development of antisense-ODN therapy for glioblastoma.

Synergistic cytotoxicity of BIIB021 with triptolide through suppression of PI3K/Akt/mTOR and NF-κB signal pathways in thyroid carcinoma cells

The effec.t of BIIB021, a novel heat shock protein 90 (hsp90) inhibitor, on survival of thyroid carcinoma cells has not been evaluated. In this study, the impact of BIIB021 alone or in combination with the histone acetyltransferase inhibitor triptolide on survival of thyroid carcinoma cells was identified. In 8505C and TPC-1 thyroid carcinoma cells, BIIB021 caused cell death in conjunction with alterations in expression of hsp90 client proteins. Cotreatment of both BIIB021 and triptolide, compared with treatment of BIIB021 alone, decreased cell viability, and increased the percentage of dead cells and cytotoxic activity. All of the combination index values were lower than 1.0, suggesting synergistic activity of BIIB021 with triptolide in induction of cytotoxicity. In treatment of both BIIB021 and triptolide, compared with treatment of BIIB021 alone, the protein levels of total and phospho-p53, and cleaved caspase-3 were elevated, while those of total Akt, phospho-mTOR, phospho-4EBP1, phospho-S6K, phospho-NF-κB, survivin, X-linked inhibitor of apoptosis protein (xIAP), cellular inhibitor of apoptosis protein (cIAP) and acetyl. histone H4 were reduced. These results suggest that BIIB021 has a cytotoxic activity accompanied by regulation of hsp90 client proteins in thyroid carcinoma cells. Moreover, the synergism between BIIB021 and triptolide in induction of cytotoxicity is associated with the inhibition of PI3K/Akt/mTOR and NF-κB signal pathways, the underexpression of survivin and the activation of DNA damage response in thyroid carcinoma cells.

Comparison of the clinical characteristics of diabetes mellitus diagnosed using fasting plasma glucose and haemoglobin A1c: The 2011 Korea National Health and Nutrition Examination Survey

We compared the characteristics of a Korean adult population diagnosed with diabetes using only a fasting plasma glucose criterion or an HbA1c criterion. The single difference between these two groups was age. Further studies should be undertaken to clarify whether age-specific diagnostic criteria would be appropriate in Korean populations.

The heat shock protein 90 inhibitor SNX5422 has a synergistic activity with histone deacetylase inhibitors in induction of death of anaplastic thyroid carcinoma cells

The influence of the heat shock protein 90 (hsp90) inhibitor SNX5422 alone or in combination with the histone deacetylase (HDAC) inhibitors PXD101, suberoylanilide hydroxamic acid (SAHA), and trichostatin A (TSA) on survival of anaplastic thyroid carcinoma (ATC) cells was investigated. In 8505C and CAL62 cells, SNX5422 caused cell death with concomitant changes in the expression of hsp90 client proteins. After treatment of both SNX5422 and PXD101, SAHA and TSA, compared with treatment of SNX5422 alone, cell viability was diminished, whereas inhibition rate and cytotoxic activity were enhanced. All of the combination index values were lower than 1.0, suggesting the synergism between SNX5422 and PXD101, SAHA and TSA in induction of cell death. In cells treated with both SNX5422 and PXD101, SAHA and TSA, compared with cells treated with SNX5422 alone, the protein levels of Akt, phospho-4EBP1, phospho-S6 K, and survivin were diminished, while those of γH2AX, acetyl. histone H3, acetyl. histone H4, cleaved PARP, and cleaved caspase-3 were enhanced. In conclusion, these results demonstrate that SNX5422 has a cytotoxic activity in conjunction with alterations in the expression of hsp90 client proteins in ATC cells. Moreover, SNX5422 synergizes with HDAC inhibitors in induction of cytotoxicity accompanied by the suppression of PI3K/Akt/mTOR signaling and survivin, and the overexpression of DNA damage-related proteins in ATC cells.

Fasting plasma glucose concentrations for specified HbA1c goals in Korean populations: data from the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-2, 2011)

AIMS

To examine the correlation between the fasting plasma glucose and HbA1c levels using regression equation and to assess the average fasting plasma glucose levels for the specific HbA1c (A1C) goals in the patients with diabetes using each A1C-and fasting plasma glucose-based diagnostic criteria.

METHODS

This study included data from 4481 participants with A1C and fasting plasma glucose, but with no diabetic medications in the Korean National Health and Nutritional Examination Survey 2011. The correlation between fasting plasma glucose and A1C was examined using linear regression models.

RESULTS

The A1C levels corresponding to the fasting plasma glucose of 5.5 and 7 mmol/L were 5.75 and 6.42 %. However, in the subjects with diabetes diagnosed by the A1C criteria only, 5.5 and 7 mmol/L in the fasting plasma glucose predicted A1C of 6.49 and 7.14 % respectively. The average fasting plasma glucose levels to achieve specified A1C levels of 5.0-5.9, 6.0-6.9, 7.0-7.9, 8.0-8.9, and 9.0-9.9 % were 5.1, 6.1, 7.7, 8.8 and 11.2 mmol/L, respectively.

CONCLUSIONS

The association between A1C and fasting plasma glucose levels is in concordance with the existing criteria for diagnosis of diabetes. However, the average fasting plasma glucose concentrations to achieve targeted A1C may be lower than those in western populations.

Suppression of AKT Potentiates Synergistic Cytotoxicity of Apigenin with TRAIL in Anaplastic Thyroid Carcinoma Cells

BACKGROUND

We studied the effect of apigenin in combination with tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) on cell survival and the influence of AKT inhibition on the combined effect of apigenin with TRAIL in anaplastic thyroid carcinoma (ATC) cells.

MATERIALS AND METHODS

The human 8505C and CAL62 ATC cell lines were used.

RESULTS

Apigenin in combination with TRAIL, compared to apigenin alone, reduced cell viability and Bcl2 protein levels, elevated the percentage of dead cells, as well as the protein levels of cleaved PARP and phospho-ERK1/2. The protein levels of Bcl-xL, Bax, Bid, total ERK1/2, and total and phospho-AKT were unchanged. Administration of wortmannin further reduced cell viability, and elevated the percentage of dead cells, cytotoxic activity and cleaved PARP protein levels.

CONCLUSION

Apigenin synergizes with TRAIL through regulation of Bcl2 family proteins in inducing cytotoxicity, and suppression of AKT potentiates synergistic cytotoxicity of apigenin with TRAIL in ATC cells.

17-Allylamino-17-demethoxygeldanamycin and Herbimycin A Induce Cell Death by Modulating β-Catenin and PI3K/AKT Signaling in FRO Anaplastic Thyroid Carcinoma Cells

AIM

The aim of the present study was to evaluate the effect of heat-shock protein 90 (HSP90) inhibitors, 17-allylamino-17-demethoxygeldanamycin (17-AAG) and herbimycin A (HMA) on survival of anaplastic thyroid carcinoma (ATC) cells.

MATERIALS AND METHODS

Antitumor activities of 17-AAG and HMA were investigated in FRO ATC cells.

RESULTS

In FRO ATC cells, 17-AAG and HMA caused cell death with concomitant changes in the expression of HSP90 client proteins, increased β-catenin protein levels, and inhibited PI3K/AKT signaling. The inactivation of β-catenin by β-catenin siRNA transfection and the activation of PI3K/AKT signaling by p110α plasmid transfection abrogated cell death caused by 17-AAG and HMA.

CONCLUSION

17-AAG and HMA have cytotoxic activities accompanied by regulation of HSP90 client proteins, and cytotoxicity is associated with overexpression of β-catenin and suppression of PI3K/AKT signaling in FRO ATC cells.

The effect of 17-allylamino-17-demethoxygeldanamycin alone or in combination with paclitaxel on anaplastic thyroid carcinoma cells

The effect of 17-allylamino-17-demethoxygeldanamycin (17-AAG), an hsp90 inhibitor, alone or in combination with paclitaxel on survival of anaplastic thyroid carcinoma (ATC) was evaluated. In 8505C and CAL62 cells, after treatment of 17-AAG, cell viability decreased, and the percentage of dead cells increased. 17-AAG did not cause cleavage of caspase-3 protein, and change expression of IAPs. Pretreatment of z-VAD-fmk did not alter cell viability and the percentage of dead cells. In 17-AAG-treated cells, knockdown of p53 rescued growth inhibition, while cycloheximide attenuated cell death. When cells were treated with both 17-AAG and paclitaxel, all of the combination index values were higher than 1, indicating antagonism between 17-AAG and paclitaxel. In 17-AAG- and paclitaxel-treated cells, compared with paclitaxel alone-treated cells, the protein levels of hsp90, hsp70, and hsc70 increased. In conclusion, our results suggest that 17-AAG induces non-apoptotic cell death requiring de novo protein synthesis in ATC cells. Moreover, these results demonstrate that 17-AAG antagonizes paclitaxel with concomitant alterations in hsp90 client proteins in ATC cells.

The effects of the Korean reference value on the prevalence of osteoporosis and the prediction of fracture risk

Background

Since the reference value is the core factor of the T-score calculation, it has a significant impact on the prevalence of osteoporosis. The purpose of this study was to determine the effects of using the Korean reference value on the prevalence of osteoporosis and on the prediction of fracture risk.

Methods

We used femoral neck bone mineral density (BMD) data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2008–2011. The Korean reference was identified by the mean and standard deviation of men and women aged 20–29 years. We compared the prevalence and the fracture risk assessment tool (FRAX™) probability obtained from the Korean reference and the NHANES III reference.

Results

In men, the prevalence of osteoporosis increased when using the Korean men’s reference, and the difference increased up to 9% for those in their 80s. In women, the prevalence increased when using the NHANES III reference, and the difference increased up to 17% for those in their 80s. The reference value also affected the fracture risk probability, and the difference from changing the reference value increased in women and in subjects with more clinical fracture risk factors. In major osteoporotic fractures, the difference of the risk probability was up to 6% in women aged 70–79 years with two clinical risk factors. For femoral neck fractures, the difference was up to 7% in women aged 50–59 years with two clinical risk factors.

Conclusions

We confirmed that the reference value had significant effects on the prevalence of osteoporosis and on the fracture risk probability. The KNHANES 2008–2011 BMD data reflected the characteristics of the Korean BMD status well with regard to data size and study design; therefore, these data can be used as reference values.

Novel heat shock protein 90 inhibitor NVP-AUY922 synergizes with the histone deacetylase inhibitor PXD101 in induction of death of anaplastic thyroid carcinoma cells

CONTEXT

The influence of the novel heat shock protein 90 (hsp90) inhibitor NVP-AUY922 (AUY922) on anaplastic thyroid carcinoma (ATC) cells has not been investigated.

OBJECTIVE

The effect of AUY922 alone or in combination with the histone deacetylase inhibitor PXD101 on survival of ATC cells was evaluated.

RESULTS

In ATC cells, AUY922, compared with 17-allylamino-17-demethoxygeldanamycin, herbimycin A and radicicol, potently lead to growth inhibition and cell death with cleavage of caspase-3 and poly (ADP-ribose) polymerase (PARP) and concomitant changes in expression of hsp90 client proteins. After treatment of both AUY922 and PXD101, compared with treatment of AUY922 or PXD101 alone, the percentage of nonviable cells, annexin V-stained cells, and cytotoxic activity increased. All of the combination index values were lower than 1.0, suggesting the synergism between AUY922 and PXD101 in induction of cell death. In cells treated with both AUY922 and PXD101, compared with cells treated with AUY922 alone, the protein levels of phospho-Akt, cellular inhibitor of apoptosis protein, X-linked inhibitor of apoptosis protein, survivin, ataxia telangiectasia mutated (ATM), and ATM and Rad-3 related (ATR) decreased, whereas those of acetyl. histone H3, acetyl. histone H4, phospho-histone H2A.X, cleaved DFF45, and cleaved PARP increased.

CONCLUSION

Our results demonstrate that AUY922 potently induces cytotoxicity with concomitant modulation of hsp90 client proteins in ATC cells. Moreover, AUY922 has a synergistic activity with PXD101 in induction of cytotoxicity in conjunction with the inactivation of PI3K/Akt signaling and survivin and the activation of DNA damage response in ATC cells.

Tunicamycin induces paraptosis potentiated by inhibition of BRAFV600E in FRO anaplastic thyroid carcinoma cells

BACKGROUND/AIM

The aim of the present study was to elucidate whether tunicamycin (TM) induces paraptosis as a cell death subroutine in anaplastic thyroid carcinoma (ATC) cells.

MATERIALS AND METHODS

8505C, CAL62 and FRO cells were used. After treatment of TM, cell survival and morphology were investigated. The effect of the BRAF(V600E) inhibitor PLX4032 in combination with TM was evaluated.

RESULTS

In FRO cells, TM induced paraptosis characteristic of cytoplasmic vacuolation and endoplasmic reticulum (ER) swelling, which was not associated with caspase activation and ER stress. TM-induced paraptosis was ameliorated by pre-treatment with the translation inhibitor cycloheximide, while it was accelerated by pre-treatment with the proteasome inhibitor MG132. PLX4032 augmented TM-induced paraptosis.

CONCLUSION

TM induces paraptosis relevant to de novo protein synthesis and proteasomal activity, and inhibition of BRAF(V600E) potentiates TM-induced paraptosis in FRO cells harboring BRAF(V600E).

Hsp70 inhibition potentiates radicicol-induced cell death in anaplastic thyroid carcinoma cells

BACKGROUND/AIM

The aim of the present study was to evaluate the effect of radicicol, an inhibitor of heat shock protein (hsp) 90, alone or in combination with hsp70 inhibition on survival of anaplastic thyroid carcinoma (ATC) cells.

MATERIALS AND METHODS

Antitumor activity of radicicol-alone or in combination with the hsp70 inhibitor VER155008 was investigated in 8505C and CAL62 cells.

RESULTS

Radicicol decreased cell viability and Akt protein levels, and increased the percentage of dead cells and hsp70 protein levels. In PIK3CA plasmid-transfected cells, compared to cells treated with radicicol-alone, cell viability increased and cellular death decreased. In cells treated with both radicicol and VER155008, compared to cells treated with radicicol-alone, cell viability further decreased and the percentage of dead cells further increased, with a parallel decrease of the protein levels of heat shock cognate 70, Akt and survivin.

CONCLUSION

Our results suggest that radicicol induces cell death mediated through PI3K/Akt signaling with modulation of hsp90 client proteins and hsp70 inhibition enhances radicicol-induced cell death with suppression of survivin in ATC cells.

Unprotected daily sun exposure is differently associated with central adiposity and β-cell dysfunction by gender: the Korean National Health and Nutrition Examination Survey (KNHANES) V

BACKGROUND

Ultraviolet irradiation by sun exposure has been associated with both harms and benefits to metabolic health.

OBJECTIVE

The objective of this study was to determine whether unprotected daily sun exposure is associated with the prevalence of diabetes and explore the underlying mechanism.

METHODS

We analyzed the Korean National Health and Nutrition Survey V from 2010 to 2011. Participants 19-60 years of age were asked about the average amount of time they had been exposed to direct sunlight per day since the age of 19. We categorized participants into three groups with different levels of lifetime daily sun exposure and explored the association of sun exposure with the prevalence of diabetes.

RESULTS

The risk of diabetes was higher in subjects with more than 5h of unprotected sun exposure per day, with an odds ratio of 2.39 (95% CI 1.75-3.25), compared to those with less than 2h of sun exposure, and the association remained significant after adjusting for diabetes risk factors. Long-term sun exposure was associated with increased central obesity and the possibility of an increase in visceral adiposity, especially among women, and with decrease in beta cell function and peripheral adiposity or percent body fat in men.

CONCLUSIONS

Our study provides a cutoff for upper limit of sun exposure and suggests unprotected daily sun exposure for more than 5h should be avoided to prevent diabetes. Increased central adiposity and decreased beta cell function were observed in women and men, respectively, who had long-term unprotected daily sun exposure.

Akt inhibition enhances the cytotoxic effect of apigenin in combination with PLX4032 in anaplastic thyroid carcinoma cells harboring BRAFV600E

Aim of the present study was to evaluate the effect of apigenin in combination with BRAFV600E inhibitor PLX4032 on cell survival, and to investigate the influence of Akt inhibition on the combined effect of apigenin and PLX4032 in ATC cells harboring BRAFV600E. In 8505C and FRO cells harboring BRAFV600E, after treatment of apigenin and PLX4032, the cell viability decreased, and the percentage of dead cells increased in a time- and concentration-dependent manner, respectively. In apigenin- and PLX4032- treated cells, compared with apigenin alone-treated cells, the cell viability was lessened, and the percentage of dead cells was multiplied. In the addition of PLX4032 to apigenin, compared with the treatment of apigenin alone, the protein levels of cleaved PARP-1 and cleaved caspase-3 were elevated, and phospho-ERK protein levels were reduced, and the protein levels of total ERK, c-Myc, BRAF, phospho-Akt, phospho-p70S6K and phospho-4EBP1 were not varied. Compared with the treatment of PLX4032 alone, phosphop70S6K protein levels were reduced, and the other protein levels were not altered. Phospho-ERK protein levels were reduced only in 8505C cells. Under the co-treatment of apigenin and PLX4032, administration of the PI3K inhibitor wortmannin further decreased the cell viability, and increased the percentage of dead cells. In conclusion, our results suggest that PLX4032 augments apigenin-induced cytotoxicity in ATC cells harboring BRAFV600E. Moreover, Akt suppression potentiates the combined effect of apigenin and PLX4032 in ATC cells harboring BRAFV600E.

Enhanced gene transfer to pancreatic islets using glucagon-like peptide-1

OBJECTIVE

The efficient transfer of genes into intact islets is difficult since islets exist as clusters of differentiated cells with little replication potential. Cell proliferation in response to growth factors is known to be accompanied by loosening of cell-to-cell contacts and increasing paracellular permeability. In this study, we investigated whether gene delivery into intact islet cells was facilitated by modulating β-cell proliferation.

METHODS

Isolated rat islets were pretreated with glucagon-like peptide (GLP)-1 or human growth hormone for 24 hours, or with 300 mg/dL of glucose for 48 hours before transduction with a suboptimal dose of recombinant adenoviral vector expressing green fluorescent protein (GFP) and β-galactosidase (multiplicity of infection of 25). Transduction efficiency was assessed by measuring β-galactosidase activity and GFP expression using enzyme-linked immunosorbent assay, flow cytometry, and fluorescence microscopy. The numbers of 7-aminoactinomycin D-positive dead cells and 5-ethynyl-2-deoxyuridine (EdU)-positive proliferating cells were also monitored using flow cytometry and fluorescence microscopy.

RESULTS

The transduction efficiency of rat islet cells by a suboptimal dose of viral vector was significantly improved by GLP-1 pretreatment, accompanied by enhanced cell viability and cell proliferation. An increased GFP expression in islet cells after GLP-1 pretreatment was observed among the increased numbers of EdU-positive proliferating cells.

CONCLUSION

Pretreatment of rat islets with GLP-1 enhanced the transduction efficiency of an adenoviral vector, reducing viral dose burden while improving islet cell viability. From a therapeutic standpoint, genetic modification of pancreatic islets combined with GLP-1 pretreatment may be a promising option for ex vivo gene therapy prior to islet transplantation.

Apigenin induces c-Myc-mediated apoptosis in FRO anaplastic thyroid carcinoma cells

Apigenin promotes apoptosis in cancer cells. We studied the effect of apigenin on cell survival and c-Myc expression in FRO anaplastic thyroid carcinoma (ATC) cells. Apigenin caused apoptosis via the elevation of c-Myc levels in conjunction with the phosphorylation of p38 and p53. In the c-Myc siRNA-transfected and apigenin-treated cells, compared with the apigenin-treated control cells, apoptosis and phosphorylation of p38 and p53 were ameliorated. In the presence of apigenin, diminution of p38 and p53 did not affect cell survival although apigenin activated the phosphorylation of p38 and p53 via increased c-Myc levels. In conclusion, our results indicate that apigenin induces apoptosis mediated via c-Myc with concomitant phosphorylation of p53 and p38 in FRO ATC cells. These findings suggest that augmented c-Myc acts as a core regulator and is necessary for apigenin-induced apoptosis in FRO ATC cells.

Effect of hypoxia-inducible VEGF gene expression on revascularization and graft function in mouse islet transplantation

For gene transfer strategies to improve islet engraftment, vascular endothelial growth factor (VEGF) expression should be regulated in a way that matches the transient nature of revascularization with simultaneously avoiding undesirable effects of overexpression. The aim of this study was to investigate the effects of hypoxia-inducible VEGF gene transfer using the RTP801 promoter on islet grafts. We implanted pSV-hVEGF transfected, pRTP801-hVEGF transfected or nontransfected mouse islets under the kidney capsule of streptozotocin-induced diabetic syngeneic mice. Human VEGF immunostaining of day 3 grafts revealed that the pRTP801-hVEGF transfected group had higher hVEGF expression compared with the pSV-hVEGF transfected group. BS-1 staining of day 3 grafts from the pRTP801-hVEGF transfected group showed the highest vascular density, which was comparable with day 6 grafts from the nontransfected group. In 360 islet equivalent (IEQ)-transplantation which reverted hyperglycemia in all mice, the area under the curve of glucose levels during intraperitoneal glucose tolerance test 7 weeks post-transplant was lower in mice transplanted with pRTP801-hVEGF transfected grafts compared with mice transplanted with nontransfected grafts. In 220 IEQ-transplantations, diabetic mice transplanted with pRTP801-hVEGF islets became normoglycemic more rapidly compared with mice transplanted with pSV-hVEGF or nontransfected islets, and diabetes reversal rate after 50 days was 90%, 68%, and 50%, respectively. In conclusion, our results indicate that regulated overexpression of hVEGF in a hypoxia-inducible manner enhances islet vascular engraftment and preserves islet function overtime in transplants.

RAGE ligands induce apoptotic cell death of pancreatic β-cells via oxidative stress

Activation of the receptor for advanced glycation endproducts (RAGE) by its ligands leads to cellular damage contributing to diabetic complications. It is not clearly known whether RAGE ligands influence pancreatic β-cells. In this study, we investigated the expression of RAGE in islet cells and the effect of RAGE ligands, S100b and HMG-1, on islet cells. RAGE was expressed in INS-1 cells and isolated rat and human islets at mRNA and protein levels. RAGE and its ligand, S100b, were detected on islet cells in 28-week-old diabetic OLETF rats. Both S100b and HMG-1 induced apoptotic cell death of INS-1 and islet cells. This INS-1 cell apoptosis was accompanied by increased intracellular oxidative stress and inhibited by antioxidants or a NADPH oxidase inhibitor. Our results showing S100b/RAGE expression on islets of diabetic rat model and RAGE ligands-induced islet cell apoptosis via NADPH oxidase-mediated ROS generation suggest that RAGE ligands-RAGE interaction may contribute not only to the development of diabetic complications but also to the progressive β-cell loss in type 2 diabetes by inducing oxidative stress.

Mechanisms of adipose tissue redistribution with rosiglitazone treatment in various adipose depots

Treatment with thiazolidinediones (TZDs) improves glucose homeostasis by increasing insulin sensitivity, but it also leads to weight gain. Our hypothesis was that, in individual adipose depots, there is depot specificity for lipid storage and energy expenditure genes after TZD treatment. After 5 weeks of rosiglitazone treatment on Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an animal model of type 2 diabetes mellitus with obesity, and Long-Evans Tokushima Otsuka rats as controls, we measured changes in lipid storage and energy expenditure gene expression in various adipose depots, such as mesenteric and nonmesenteric adipose tissues (subcutaneous, epididymal, and retroperitoneal). Mesenteric fat masses did not change after TZD treatment in OLETF rats, but nonmesenteric fat masses increased. Messenger RNA expression of lipid storage genes increased in nonmesenteric fat, but energy expenditure gene expression increased in mesenteric fat after rosiglitazone treatment. In conclusion, our findings suggest that TZD treatment may be associated with the depot-specific effects of lipid storage and energy expenditure genes on fat redistribution in individual adipose tissues in OLETF rats.

Dose-related cytoprotective effect of alpha-lipoic acid on hydrogen peroxide-induced oxidative stress to pancreatic beta cells

alpha-Lipoic acid (alpha-LA), an antioxidant used for diabetic polyneuropathy, was reported to induce AMP-activated protein kinase activation and reductions in insulin secretion in pancreatic beta-cells at high concentrations (> or = 500 micromol/l). This study investigated whether alpha-LA has a protective role under oxidative stress in beta-cells and its effect is dose-related. In INS-1 cells treated with alpha-LA (150-1200 micromol/l) for 24 h, alpha-LA itself (> or = 300 micromol/l) induced apoptotic death dose-dependently. However, pre-treatment with 150 and 300 micromol/l alpha-LA reduced the hydrogen peroxide-induced apoptosis in INS-1 cells and isolated islets. alpha-LA alleviated hydrogen peroxide-induced reactive oxygen species production, mitochondrial membrane depolarization and c-JNK activation in beta-cells. alpha-LA induced phosphoinositide 3-kinase-dependent Akt phosphorylation in INS-1 cells. While alpha-LA is harmful to beta-cells at high concentrations in vitro, it has potential cytoprotective effects on beta-cells under oxidative stress as in diabetes by its antioxidant properties and possibly by Akt phosphorylation at clinically relevant concentrations.

The relationship of thyroid hormone status with myocardial function in stress cardiomyopathy

OBJECTIVE

This study aimed to investigate thyroid hormone (TH) status and its relationship with myocardial function as well as clinical and biochemical parameters in stress cardiomyopathy (CMP).

METHODS

Forty-five patients with stress CMP (the patient group), 31 patients without stress CMP (the control II group), and 58 healthy subjects (the control I group) were included. Sick euthyroid syndrome (SES) was defined as low total triiodothyronine (T(3)) with normal TSH levels.

RESULTS

In the patient group at admission, prevalence of SES was 62.2%. Compared with the control I group, the patient group had a decrease in left ventricular ejection fraction (LVEF) and systolic blood pressure (BP) and an increase in troponin-I, CK-MB, and B-type natriuretic peptide (BNP) levels. Total T(3) levels were reduced, and anti-thyroid peroxidase antibody (anti-TPO Ab) positivity, C-reactive protein (CRP) and cortisol levels were elevated. Total T(3) levels were associated with acute physiology and chronic health evaluation II (APACHE II) score, LVEF, systolic BP, and cortisol levels in multivariate analysis. In the control II group, total T(3) levels were not associated with any variables. In the SES (n=28) and myocardial dysfunction (MDys, n=27) subgroups, increased APACHE II score and BNP levels as well as decreased LVEF and systolic BP were significant. Total T(3) levels were reduced, and CRP, cortisol and catecholamines levels were elevated. In the MDys subgroup, anti-TPO Ab positivity and titer were increased.

CONCLUSION

These results suggest that total T(3) levels may be associated with myocardial contractility, clinical severity, and cortisol levels. Thyroid autoimmunity may influence myocardial contractility in stress CMP.

Effects of alpha-lipoic acid on transforming growth factor beta1-p38 mitogen-activated protein kinase-fibronectin pathway in diabetic nephropathy

In diabetic nephropathy, transforming growth factor beta1 (TGFbeta1) is related to p38 mitogen-activated protein kinase (MAPK) that induces production of fibronectin in mesangial cells. We investigated the effects of alpha-lipoic acid (ALA), a potent antioxidant, on proteinuria and TGFbeta1-p38 MAPK-fibronectin pathway in diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. After ALA treatment for 5 weeks in OLETF rats at 30 weeks of age, plasma malondialdehyde, urinary protein excretion, renal cortical TGFbeta1, and fibronectin protein levels were decreased; and urinary protein excretion was positively correlated with renal cortical TGFbeta1 and fibronectin protein levels. Phospho-form but not total-form levels as well as fold activations of each protein consisting of p38 MAPK pathway were also attenuated. These results suggest that ALA ameliorates proteinuria by attenuating expressions of TGFbeta1 and fibronectin proteins, and these favorable effects are related to inhibition of phosphorylating activation of p38 MAPK pathway in renal cortex of OLETF rats.

Prolonged insulin independence after islet allotransplants in recipients with type 1 diabetes

We sought to determine the long-term outcomes in type 1 diabetic recipients of intraportal alloislet transplants on a modified immunosuppressive protocol. Six recipients with hypoglycemia unawareness received one to two islet infusions. Induction therapy was with antithymocyte globulin (ATG) plus etanercept for tumor necrosis factor-alpha blockade. Recipients received cyclosporine and everolimus for maintenance immunosuppression for the first year posttransplant, with mycophenolic acid or mycophenolate mofetil subsequently substituted for everolimus. Recipients have been followed for 1173 +/- 270 days since their last infusion for islet graft function (insulin independence, hemoglobin A(1c) levels and C-peptide production) and for adverse events associated with the study protocol. Of the six recipients, five were insulin-independent at 1 year, and four continue to be insulin-independent at a mean of 3.4 +/- 0.4 years posttransplant. None of the six recipients experienced recurrence of severe hypoglycemia. Measured glomerular filtration rate decreased from 110.5 +/- 21.2 mL/min/1.73 m(2) pretransplant to 82.6 +/-19.1 mL/min/1.73 m(2) at 1 year posttransplant. In conclusion, islet transplants restored insulin independence for a mean of >3 years in four of six recipients treated with ATG and etanercept induction therapy and with cyclosporine and, initially, everolimus for maintenance. Our results suggest this immunosuppressive protocol may allow long-term graft survival.