We previously demonstrated that epidermal growth factor (EGF) enhances cell migration and invasion of breast cancer cells in a SMAD ubiquitination regulatory factor 1 (SMURF1)-dependent manner and that SMURF1 induces degradation of β-catenin in C2C12 cells. However, the relationship between EGF-induced SMURF1 and β-catenin expression in breast cancer cells remains unclear. So, we investigated if EGF and SMURF1 regulate β-catenin expression in MDAMB231 human breast cancer cells. When MDAMB231 cells were incubated with EGF for 24, 48, and 72 hours, EGF significantly increased expression levels of SMURF1 mRNA and protein while suppressing expression levels of β-catenin mRNA and protein. Overexpression of SMURF1 downregulated β-catenin mRNA and protein, whereas knockdown of SMURF1 increased β-catenin expression and blocked EGF-induced β-catenin downregulation. Knockdown of β-catenin enhanced cell migration and invasion of MDAMB231 cells, while β-catenin overexpression suppressed EGF-induced cell migration and invasion. Furthermore, knockdown of β-catenin enhanced vimentin expression and decreased cytokeratin expression, whereas β-catenin overexpression decreased vimentin expression and increased cytokeratin expression. These results suggest that EGF downregulates β-catenin in a SMURF1-dependent manner and that β-catenin downregulation contributes to EGF-induced cell migration and invasion in MDAMB breast cancer cells.
beta Catenin ; Breast Neoplasms ; Cell Movement ; Down-Regulation ; Epidermal Growth Factor ; Humans ; Keratins ; RNA, Messenger ; Ubiquitin ; Ubiquitination ; Vimentin

Tumor necrosis factor alpha (TNFalpha) is a multifunctional cytokine that is elevated in inflammatory diseases such as atherosclerosis, diabetes and rheumatoid arthritis. Recent evidence has suggested that beta2 adrenergic receptor (beta2AR) activation in osteoblasts suppresses osteogenic activity. In the present study, we explored whether TNFalpha modulates betaAR expression in osteoblastic cells and whether this regulation is associated with the inhibition of osteoblast differentiation by TNFalpha. In the experiments, we used C2C12 cells, MC3T3-E1 cells and primary cultured mouse bone marrow stromal cells. Among the three subtypes of betaAR, beta2 and beta3AR were found in our analysis to be upregulated by TNFalpha. Moreover, isoproterenol-induced cAMP production was observed to be significantly enhanced in TNFalpha-primed C2C12 cells, indicating that TNFalpha enhances beta2AR signaling in osteoblasts. TNFalpha was further found in C2C12 cells to suppress bone morphogenetic protein 2-induced alkaline phosphatase (ALP) activity and the expression of osteogenic marker genes including Runx2, ALP and osteocalcin. Propranolol, a beta2AR antagonist, attenuated this TNFalpha suppression of osteogenic differentiation. TNFalpha increased the expression of receptor activator of NF-kappaB ligand (RANKL), an essential osteoclastogenic factor, in C2C12 cells which was again blocked by propranolol. In summary, our data show that TNFalpha increases beta2AR expression in osteoblasts and that a blockade of beta2AR attenuates the suppression of osteogenic differentiation and stimulation of RANKL expression by TNFalpha. These findings imply that a crosstalk between TNFalpha and beta2AR signaling pathways might occur in osteoblasts to modulate their function.
Alkaline Phosphatase ; Animals ; Arthritis, Rheumatoid ; Atherosclerosis ; Bone Morphogenetic Proteins ; Durapatite ; Mesenchymal Stromal Cells ; Mice ; Osteoblasts ; Osteocalcin ; Propranolol ; Receptor Activator of Nuclear Factor-kappa B ; Receptors, Adrenergic ; Tumor Necrosis Factor-alpha

BACKGROUND: Cut-off values for visceral fat area (VFA) measured by computed tomography (CT) for identifying individuals at risk of metabolic syndrome (MetS) have not been clearly established in Korean adults, particularly for large populations. We aimed to identify optimal VFA and waist circumference (WC) cut-off values and compare the ability of VFA and WC to predict the presence of ≥2 metabolic risk factors. METHODS: We included 36,783 subjects aged 19–79 years undergoing abdominal fat CT during regular health checkups between January 2007 and February 2015 in Seoul. The risk factors for MetS except WC were based on the International Diabetes Federation criteria. Receiver operating characteristic curve analyses were used to determine the appropriate VFA and WC cut-off values for MetS. RESULTS: VFA was a more significant predictor of metabolic risk factors than WC and body mass index (BMI). The optimal cut-off values for VFA and WC were 134.6 cm2 and 88 cm for men and 91.1 cm2 and 81 cm for women, respectively. We estimated age-specific cut-off values for VFA, WC, and BMI. VFA cut-off values increased with age, particularly among women. CONCLUSION: This large population study proposed the cut-off values for VFA and WC for identifying subjects at risk of MetS among Korean adults. For more accurate diagnosis, different age-specific cut-off values for VFA and WC may be considered.
Abdominal Fat ; Adult* ; Body Mass Index ; Diagnosis ; Female ; Humans ; Intra-Abdominal Fat* ; Male ; Obesity, Abdominal ; Risk Factors ; ROC Curve ; Seoul ; Waist Circumference

The association between vitamin D levels and nonalcoholic fatty liver disease (NAFLD) has been recognized. However, few studies showed independent associations between vitamin D deficiency and NAFLD after a sex-related adjustment for metabolic factors. We aimed to study whether vitamin D deficiency is an independent risk factor of NAFLD even after controlling for metabolic syndrome and visceral fat in both sexes. In this cross-sectional study, 7,514 Korean adults (5,278 men, 2,236 women) participated in a health check-up program. They underwent blood tests, abdominal computed tomography (CT) of the visceral fat area, and ultrasonography for NAFLD screening. Multiple logistic regression analysis was used to investigate the association of vitamin D deficiency with NAFLD according to the sex differences. Vitamin D deficiency is associated with NAFLD. The adjusted odds ratio (aOR) for NAFLD increased sequentially with decreasing vitamin D level, even after adjusting for metabolic syndrome and visceral fat. The subjects in the vitamin D sufficiency group (20–30 ng/mL) had an aOR for NAFLD of 1.18 (95% CI, 1.00–1.39), whereas the deficiency group (< 20 ng/mL) had an aOR of 1.29 (95% CI, 1.10–1.52). However, we have detected a significant sex-related interaction when analyzing the results. A significant relationship between vitamin D deficiency and NAFLD was found in men (aOR, 1.33; 95% CI, 1.11–1.60) but not in women.
Adult ; Cross-Sectional Studies ; Female ; Hematologic Tests ; Humans ; Intra-Abdominal Fat ; Logistic Models ; Male ; Mass Screening ; Metabolic Syndrome X ; Non-alcoholic Fatty Liver Disease* ; Odds Ratio ; Risk Factors* ; Sex Characteristics ; Ultrasonography ; Vitamin D Deficiency ; Vitamin D* ; Vitamins*