miR-148a is a downstream effector of X-box-binding protein 1 that silences Wnt10b during adipogenesis of 3T3-L1 cells

Wnt10b, an endogenous inhibitor of adipogenesis, maintains preadipocytes in an undifferentiated state by suppressing adipogenic transcription factors. We have previously demonstrated that Wnt10b transcription during adipogenesis is negatively regulated by X-box-binding protein 1 (XBP1), an important transcription factor of the unfolded protein response. In this report, we demonstrate that XBP1s can directly induce the transcription of microRNA-148a, which in turn mediates the silencing of Wnt10b mRNA during adipogenic differentiation of 3T3-L1 cells. Stability of Wnt10b mRNA was found to be significantly increased by knockdown of XBP1s. Using computational algorithms, a set of microRNAs was predicted to bind Wnt10b mRNA, of which microRNA-148a was selected as a potential target for XBP1s. Our results revealed that microRNA-148a could bind to the 3′UTR of Wnt10b mRNA. Its ectopic expression significantly suppressed both Wnt10b expression and β-catenin activity. When we altered the expression of XBP1 in 3T3-L1 cells, microRNA-148a levels changed accordingly. A potential XBP1 response element was found in the promoter region of microRNA-148a, and XBP1s directly bound to this response element as shown by point mutation analysis and chromatin immunoprecipitation assay. In addition, a microRNA-148a mimic significantly restored adipogenic potential in XBP1-deficient 3T3-L1 cells. These findings provide the first evidence that XBP1s can regulate Wnt10b by a post-transcriptional mechanism through directly inducing microRNA-148a.

miR-148a is a downstream effector of X-box-binding protein 1 that silences Wnt10b during adipogenesis of 3T3-L1 cells

Wnt10b, an endogenous inhibitor of adipogenesis, maintains preadipocytes in an undifferentiated state by suppressing adipogenic transcription factors. We have previously demonstrated that Wnt10b transcription during adipogenesis is negatively regulated by X-box-binding protein 1 (XBP1), an important transcription factor of the unfolded protein response. In this report, we demonstrate that XBP1s can directly induce the transcription of microRNA-148a, which in turn mediates the silencing of Wnt10b mRNA during adipogenic differentiation of 3T3-L1 cells. Stability of Wnt10b mRNA was found to be significantly increased by knockdown of XBP1s. Using computational algorithms, a set of microRNAs was predicted to bind Wnt10b mRNA, of which microRNA-148a was selected as a potential target for XBP1s. Our results revealed that microRNA-148a could bind to the 3′UTR of Wnt10b mRNA. Its ectopic expression significantly suppressed both Wnt10b expression and β-catenin activity. When we altered the expression of XBP1 in 3T3-L1 cells, microRNA-148a levels changed accordingly. A potential XBP1 response element was found in the promoter region of microRNA-148a, and XBP1s directly bound to this response element as shown by point mutation analysis and chromatin immunoprecipitation assay. In addition, a microRNA-148a mimic significantly restored adipogenic potential in XBP1-deficient 3T3-L1 cells. These findings provide the first evidence that XBP1s can regulate Wnt10b by a post-transcriptional mechanism through directly inducing microRNA-148a.

Inhibition of mouse brown adipocyte differentiation by second-generation antipsychotics

Brown adipose tissue is specialized to burn lipids for thermogenesis and energy expenditure. Second-generation antipsychotics (SGA) are the most commonly used drugs for schizophrenia with several advantages over first-line drugs, however, it can cause clinically-significant weight gain. To reveal the involvement of brown adipocytes in SGA-induced weight gain, we compared the effect of clozapine, quetiapine, and ziprasidone, SGA with different propensities to induce weight gain, on the differentiation and the expression of brown fat-specific markers, lipogenic genes and adipokines in a mouse brown preadipocyte cell line. On Oil Red-O staining, the differentiation was inhibited almost completely by clozapine (40 microM) and partially by quetiapine (30 microM). Clozapine significantly down-regulated the brown adipogenesis markers PRDM16, C/EBPbeta, PPARgamma2, UCP-1, PGC-1alpha, and Cidea in dose- and time-dependent manners, whereas quetiapine suppressed PRDM16, PPARgamma2, and UCP-1 much weakly than clozapine. Clozapine also significantly inhibited the mRNA expressions of lipogenic genes ACC, SCD1, GLUT4, aP2, and CD36 as well as adipokines such as resistin, leptin, and adiponectin. In contrast, quetiapine suppressed only resistin and leptin but not those of lipogenic genes and adiponectin. Ziprasidone (10 microM) did not alter the differentiation as well as the gene expression patterns. Our results suggest for the first time that the inhibition of brown adipogenesis may be a possible mechanism to explain weight gain induced by clozapine and quetiapine.

Development and Evaluation of a Web-based Education Program on Appropriate Antibiotic Use in Korean Adolescents / 기본간호학회지

PURPOSE: This study was done to develop a web-based education program on appropriate antibiotic use and test the effects of the program on knowledge and attitudes towards antibiotic use in Korean adolescents. METHODS: The web-based education program was developed through an extensive literature review and professional advisory meetings including technical assistance from a web-based education programmer and content experts. A convenience sample of 851 students from middle and high schools participated in the assessment of effects of the program. Knowledge and attitudes of the students towards antibiotic use and satisfaction with the web-based education program were measured. Descriptive statistics and paired t-test were used to analyze the data. RESULTS: There were significant improvements in knowledge and attitudes towards antibiotic use following self-learning via the web-based education program in both middle and high school students. High school students demonstrated higher scores in knowledge and attitudes than middle school students. CONCLUSION: The results of this study indicate that this web-based education program on appropriate antibiotic use is a convenient and effective medium for self-learning in adolescents. Therefore the web-based program should be put into wide use as an effective and convenient teaching method for health education in secondary schools.

Induction of unfolded protein response during neuronal induction of rat bone marrow stromal cells and mouse embryonic stem cells

When we treated rat bone marrow stromal cells (rBMSCs) with neuronal differentiation induction media, typical unfolded protein response (UPR) was observed. BIP/GRP78 protein expression was time-dependently increased, and three branches of UPR were all activated. ATF6 increased the transcription of XBP1 which was successfully spliced by IRE1. PERK was phosphorylated and it was followed by eIF2alpha phosphorylation. Transcription of two downstream targets of eIF2alpha, ATF4 and CHOP/GADD153, were transiently up-regulated with the peak level at 24 h. Immunocytochemical study showed clear coexpression of BIP and ATF4 with NeuN and Map2, respectively. UPR was also observed during the neuronal differentiation of mouse embryonic stem (mES) cells. Finally, chemical endoplasmic reticulum (ER) stress inducers, thapsigargin, tunicamycin, and brefeldin A, dose-dependently increased both mRNA and protein expressions of NF-L, and, its expression was specific to BIP-positive rBMSCs. Our results showing the induction of UPR during neuronal differentiations of rBMSCs and mES cells as well as NF-L expression by ER stress inducers strongly suggest the potential role of UPR in neuronal differentiation.

Involvement of Endoplasmic Reticulum Stress Response in the Neuronal Differentiation

Expressions of endoplasmic reticulum stress response (ERSR) genes were examined during the neuronal differentiation of rat fetal cortical precursor cells (rCPC) and rat pheochromocytoma PC12 cells. When rCPC were differentiated into neuronal cells for 7 days, early stem cell marker, nestin, expression was decreased from day 4, and neuronal markers such as neurofilament-L, -M and Tuj1 were increased after day 4. In this condition, expressions of BIP, ATF6, and phosphorylated PERK as well as their down stream signaling molecules such as CHOP, ATF4, XBP1, GADD34, Nrf2 and p58IPK were significantly increased, suggesting the induction of ERSR during neuronal differentiation of rCPC. ERSR was also induced during the differentiation of PC12 cells for 9 days with NGF. Neurofilament-L transcript was time-dependently increased. Both mRNA and protein levels of Tuj1 were increased after the induction, and the significant increase in NeuN was observed at day 9. Similar to the expression patterns of neuronal markers, BIP/GRP78 and CHOP mRNAs were highly increased at day 9, and ATF4 mRNA was also increased from day 7. These results strongly suggest the induction and possible role of ERSR in neuronal differentiation process. Further study to identify targets responsible for neuronal induction will be necessary.

A Survey on Functional Status among Low-Income Older Adults Living at Home / 간호학회지

PURPOSE: The purpose of the study was to analyze the functional status of low income elderly living at home according to their socio-economic factors, sensory function, health status, medical service utilization, commodity and types of chronic disease. METHOD: Functional status was defined by the level of mobility, ADL and IADL categorized as independently functional, mildly impaired, moderately disabled, and severely disabled. The data was collected by home-visit interviews with 567 community dwelling adults who were 65 years of age or more with low a income status subsidized by government in ChonAn. RESULTS: 9.9% of community dwelling older adults were severely disabled, and 44.4% were moderately disabled in their functional status. There were significant differences in the functional status by age, education, religion, and types of family structure. The older adults with hearing impairment or dental problems had a significantly higher rate of severe disability. Self-rated health status and medical service utilization were also significant factors to the differences in functional status. The functional status of older adults was also significantly related to the presence of chronic health problems such as chronic back pain, stroke, and Alzheimer-dementia. CONCLUSION: The results confirmed that community dwelling older adults with low income status were more functionally disabled in comparison to general older adults at national level, while the relating factors to their functional status seemed similar to other studies on older adults. Further studies were suggested to look into functional status longitudinally and focus on the changes of functional status by managing modifiable influencing factors.