This study was performed to investigate the effects of garlic on uncoupling protein 2 (UCP2) transcriptional regulation of UCP2- luciferase transgenic mice fed on a high fat diet to induce obesity. To examine the transcriptional regulation of UCP2, we generated transgenic mice with a UCP2 promoter (-1,830/+30 bp) containing luciferase as a reporter gene. UCP2-luciferase transgenic mice were fed a 45% high-fat diet for 8 weeks to induce obesity. Subsequently, mice were maintained on either a high-fat control diet (TG-CON), or high-fat diets supplemented with 2% (TG-GL2) or 5% (TG-GL5) garlic for a further 8 weeks. Dietary garlic reduced body weight and energy efficiency ratio in the TG-GL5 group, compared to the TG-CON group. Furthermore, garlic supplementation significantly decreased white adipose tissue fat mass and plasma levels of triglycerides, total cholesterol, and leptin in the TG-GL2 and TG-GL5 groups, compared to the TG-CON group. Specifically, UCP2 promoter activity in metabolic tissues such as liver, white adipose tissue, brown adipose tissue, and skeletal muscle was increased by garlic supplementation. These results suggest that dietary garlic was partially associated with an increase of UCP2 transcriptional activity in metabolic tissues for decreasing obesity.
Interferon tau (IFNT), produced by the mononuclear trophectoderm, signals the process of maternal recognition of pregnancy in ruminants, but its expression in vivo is not well characterized. Objectives of this study were to determine IFNT gene isoforms expressed in the bovine uterus, and to identify differences in promoter sequences of IFNT genes that differ in their expression. Through the RNA-seq analysis of bovine conceptuses on days 17, 20 and 22 (day 0 = day of estrus), the expression of only two IFNT transcripts, IFNT1 and IFNTc1, were found, which were indeed classified into the IFNT gene clade. IFNT mRNAs were highest on day 17, and then decreased on days 20, and 22, which were also supported by the results of quantitative RT-PCR. Bovine ear-derived fibroblast (EF) cells were then cotransfected with luciferase reporter constructs carrying 5‘-upstream (positions -1000 to +51) regions of IFNT1 or IFNTc1 and various transcription factor expression plasmids. CDX2, either alone or with other Ap-1, ETS2 and/or CREBBP transcription factors, was found to increase luciferase activity approximately 10 and 18 fold more than twice of those cotransfected with bIFNT1, c1-Luc construct. Furthermore, The degree of transcriptional activation by a combination of the AP1, ETS2, CREBBP and/or CDX2 expression vectors was similar to that of CDX2 along plasmid. However, expression patterns of these Luc activity differented. Whereas bIFNTc1-Luc showed lowest antivity had than bIFNT1-Luc reports. Although, lowest antivity had of the bIFNTc1 –Luc report, cotransfected with the bIFNTc1-Luc construct and AP1(JUN) or/and ETS2 expression plasmid, Luc activity was enhanced approximately 2 and 4-fold more than the bIFNT1-Luc. Furthermore, along CDX2 expression factor had high effect on activity of bIFNT1-Luc reporter than the c1 gene in EF cells. These results suggest that two forms of IFNT genes are expressed in utero and their transcriptional regulations differ.
Matrix metalloproteinases (MMPs) have been known to affect to cell migration, proliferation, morphogenesis and apoptosis by degrading the extracellular matrix. In the previous studies, undifferentiated mouse embryonic stem cells (ESCs) were successfully proliferated inside the extracellular matrix (ECM) analog-conjugated three-dimensional (3D) poly ethylene glycol (PEG)-based hydrogel. However, there is no report about MMP secretion in ESCs, which makes it difficult to understand and explain how ESCs enlarge space and proliferate inside 3D PEG-based hydrogel constructed by crosslinkers containing MMP-specific cleavage peptide sequence. Therefore, we investigated what types of MMPs are released from undifferentiated ESCs and how extracellular signals derived from various niche conditions affect MMP expression of ESCs at the transcriptional level. Results showed that undifferentiated ESCs expressed specifically MMP2 and MMP3 mRNAs. Transcriptional up-regulation of MMP2 was caused by the 3D scaffold, and activation of integrin inside the 3D scaffold upregulated MMP2 mRNAs synergistically. Moreover, mouse embryonic fibroblasts (MEFs) on 2D matrix and 3D scaffold induced upregulation of MMP3 mRNAs, and activation of integrins through conjugation of extracellular matrix (ECM) analogs with 3D scaffold upregulated MMP3 mRNAs synergistically. These results suggest that successful proliferation of ESCs inside the 3D PEG-based hydrogel may be caused by increase of MMP2 and MMP3 expression resulting from 3D scaffold itself as well as activation of integrins inside the 3D PEG-based scaffold.
As one of the most severe stress conditions, drought strongly affects the plant growth and productivity. OsPIL1, a gene encoding a rice Phytochrome Interacting Factor (PIF)-Like transcription factor, was found to be down-regulated under drought stress condition. OsPIL1 shows a diurnal expression pattern and known to be involved in regulation of plant height. However, the mechanisms of down-regulation of OsPIL1 expression under stress conditions are remained unclear. In this study, the expression of PIF4 and PIF5, the most homologous genes of OsPIL1 in Arabidopsis, was analyzed and the expression of these genes were found to be oscillated in circadian manner and down-regulated in response to drought and low temperature similar to that of OsPIL1. To identify the regions involved in the responses to drought, low temperature and diurnal cycle, the promoter analysis of PIF4 was performed using transgenic Arabidopsis. Further promoter analysis is ongoing to specify regulatory regions in more detail.
As one of the most severe stress conditions, drought strongly affects the plant growth and productivity. OsPIL1, a gene encoding a rice Phytochrome Interacting Factor (PIF)-Like transcription factor, was found to be down-regulated under drought stress condition. OsPIL1 shows a diurnal expression pattern and known to be involved in regulation of plant height. However, the mechanisms of down-regulation of OsPIL1 expression under stress conditions are remained unclear. In this study, the expression of PIF4 and PIF5, the most homologous genes of OsPIL1 in Arabidopsis, was analyzed and the expression of these genes were found to be oscillated in circadian manner and down-regulated in response to drought and low temperature similar to that of OsPIL1. To identify the regions involved in the responses to drought, low temperature and diurnal cycle, the promoter analysis of PIF4 was performed using transgenic Arabidopsis. Further promoter analysis is ongoing to specify regulatory regions in more detail.
Abscisic acid (ABA) is a stress hormone that functions in abiotic stress adaptation in plants. Thus many efforts have been made to identify the molecular mechanisms of ABA signal transduction pathways. Recently there were big advances in understanding molecular mechanisms of ABA dependent expression. From the ABA receptors to the transcription factors, signaling components were discovered and the biological networks among the components were identified. In this review, we describe the ABA signaling components and the rice orthologues identified. These show that signaling network systems of ABA are highly conserved in dicot and monocot plants and we are able to manipulate the ABA signaling components to develop the abiotic stress tolerant crops.
Embryonic stem (ES) cells can self-renew maintaining the undifferentiated state. Self renewal requires many factors such as Oct4, Sox2, FoxD3, and Nanog. NF- is a transcription factor involved in many biological activities. Expression and activity of NF- increase upon differentiation of ES cells. Reportedly, Nanog protein directly binds to NF- protein and inhibits its activity in ES cells. Here, we found a potential binding site of NF- in the human Nanog promoter and postulated that NF- protein may regulate expression of the Nanog gene. We used human embryonic carcinoma (EC) cells as a model system of ES cells and confirmed decrease of Nanog and increase of NF- upon differentiation induced by retinoic acid. Although deletion analysis on the DNA fragment including NF- binding site suggested involvement of NF- in the negative regulation of the promoter, site-directed mutation of NF- binding site had no effect on the Nanog promoter activity. Furthermore, no direct association of NF- with the Nanog promoter was detected during differentiation. Therefore, we conclude that NF- protein may not be involved in transcriptional regulation of Nanog gene expression in EC cells and possibly in ES cells.
배아 줄기세포는 미분화상태에서 자가 재생을 유지할 수 있다. 자가 재생은 OCT4, SOX2와 NANOG와 같은 많은 인자들이 작용한다. 생쥐 배아 줄기세포에서 OCT4와 SOX2가 Nanog 프로모터에 결합하여 Nanog 유전자의 발현을 촉진한다는 사실은 생쥐 promoter에 관한 정밀분석으로 알려져 있다. 본 연구에서는 인간 Nanog promoter를 정밀 분석하기 위해 연속적인 결손 돌연변이를 가진 promoter-reporter constru