P-Glycoprotein/MDR1 Regulates Pokemon Gene Transcription Through p53 Expression in Human Breast Cancer Cells

P-glycoprotein (Pgp), encoded by the multidrug resistance 1 (MDR1) gene, is an efflux transporter and plays an important role in pharmacokinetics. In this study, we demonstrated that the pokemon promoter activity, the pokemon mRNA and protein expression can be significantly inhibited by Pgp. Chromatin immunoprecipitation assay showed that Pgp can bind the pokemon prompter to repress pokemon transcription activity. Furthermore, Pgp regulated pokemon transcription activity through expression of p53 as seen by use of p53 siRNA transfected MCF-7 cells or p53 mutated MDA-MB-231 cells. Moreover, p53 was detected to bind with Pgp in vivo using immunoprecipitation assay. Taken together, we conclude that Pgp can regulate the expression of pokemon through the presence of p53, suggesting that Pgp is a potent regulator and may offer an effective novel target for cancer therapy

Establishment of OPG Transgenic Mice and the Effect of OPG on Bone Microarchitecture

Osteoprotegerin (OPG) plays a determinant role in regulating bone metabolism, but the effect of OPG on bone microarchitecture needs to be further elucidated. We attempted to construct pCI-hOPGp-mOPG vector containing human OPG promoter and FLAG tag and to microinject vector into fertilized zygotes from C57BL/6J × CBA mice to prepare transgenic mice. The OPG transgenic positive mice were identified by PCR and western blotting. Twelve-week-old OPG transgenic mice (OPG-Tg mice) and wild-type mice (WT mice) were utilized in the study of bone microarchitecture. Microcomputed tomography (micro-CT) data showed that compared with WT mice, the tibia of OPG-Tg mice showed an increased volumetric BMD (vBMD), tissue BMD (tBMD), trabecular thickness (Tb.Th), and trabecular number (Tb.N), and a decreased trabecular separation (Th.Sp) (P<0.05) . The cortical bone microarchitecture parameters, such as cortical area (Ct.Ar), cortical thickness (Ct.Th), cortical BMD (Ct.BMD), cortical BMC (Ct.BMC), BMD, and BMC of femur, were increased, and the inner perimeter (In.Pm) was decreased, in OPG-Tg mice, compared to those in WT mice (P<0.05). The established OPG transgenic mouse model could be valuable for further studying the biological significance and gene regulation of OPG in vivo

SP1 enhances Zbtb7A gene expression via direct binding to GC box in HePG2 cells

<p>Abstract</p> <p>Background</p> <p>Zbtb7A is a proto-oncogenic transcriptional regulator that plays an important role in adipogenesis, osteogenesis and oncogenesis, but little is known about the regulation of Zbtb7A gene expression which is of importance in the function uncovering of this gene.</p> <p>Finding</p> <p>Here, a 5'-flanking region of the human Zbtb7A gene was cloned and characterized. It was found that the GC box within Zbtb7A promoter is necessary for the promoter activity. Furthermore, we identified that Sp1 acts as an activator in the regulation of Zbtb7A promoter activity and the physical interaction between Sp1 and GC box is responsible for the activation of Zbtb7A gene promoter.</p> <p>Conclusion</p> <p>Our results confirmed that Sp1 upregulates Zbtb7A gene expression via direct binding to GC box within the promoter.</p

Chemical Genetics of Acetyl-CoA Carboxylases

Chemical genetic studies on acetyl-CoA carboxylases (ACCs), rate-limiting enzymes in long chain fatty acid biosynthesis, have greatly advanced the understanding of their biochemistry and molecular biology and promoted the use of ACCs as targets for herbicides in agriculture and for development of drugs for diabetes, obesity and cancers. In mammals, ACCs have both biotin carboxylase (BC) and carboxyltransferase (CT) activity, catalyzing carboxylation of acetyl-CoA to malonyl-CoA. Several classes of small chemicals modulate ACC activity, including cellular metabolites, natural compounds, and chemically synthesized products. This article reviews chemical genetic studies of ACCs and the use of ACCs for targeted therapy of cancers

Mitochondrial Stress in Metabolic Inflammation: Modest Benefits and Full Losses

Energy intake and metabolic balance are the pillars of health preservation. Overnutrition causes nonspecific, persistently low inflammatory state known as metabolic inflammation. This condition contributes to the pathophysiology of various metabolic disorders, such as atherosclerosis, obesity, diabetes mellitus, and metabolic syndrome. The mitochondria maintain the balance of energy metabolism. Excessive energy stress can lead to mitochondrial dysfunction, which promotes metabolic inflammation. The inflammatory environment further impairs mitochondrial function. Accordingly, excellent organism design keeps the body metabolically healthy in the context of mitochondrial dysfunction, and moderate mitochondrial stress can have a beneficial effect. This review summarises the research progress on the multifaceted characterisation of mitochondrial dysfunction and its role in metabolic inflammation

Effect of Human S100A13 Gene Silencing on FGF-1 Transportation in Human Endothelial Cells

The S100 protein is part of a Ca2+ binding protein superfamily that contains an EF hand domain, which is involved in the onset and progression of many human diseases, especially the proliferation and metastasis of tumors. S100A13, a new member of the S100 protein family, is a requisite component of the fibroblast growth factor-1 (FGF-1) protein release complex, and is involved in human tumorigenesis by interacting with FGF-1 and interleukin-1. In this study, experiments were designed to determine the direct role of S100A13 in FGF-1 protein release and transportation. Methods: We successfully constructed the lentiviral vectors containing shRNA targeting the human S100A13 gene. Human umbilical vein endothelial cells (HUVECs) were transfected with lentiviral RNAi vectors for S100A13. Then immunofluorescence staining, real-time quantitative polymerase chain reaction and Western blotting were used to detect the inhibition efficiency of the vectors and to monitor the release and transportation of FGF-1 protein. Results: Lentiviral RNAi vectors induced suppression efficiency of S100A13 gene by 90% in HUVECs. FGF-1 protein was found to be transported from the cytoplasm to the cell membrane, and then released from cells when HUVECs were deprived of serum. The release of FGF-1 protein was blocked by the downregulation of S100A13, but the transportation was not affected, suggesting that S100A13 is a key cargo protein for FGF-1 release. Conclusion: S100A13 promotes the release of FGF-1 protein, but does not affect the transportation of FGF-1 protein in HUVECs