Project description:Given previous works showing that, in the process of adipogenic differentiation of 3T3-L1 fibroblasts, the cells need to be cultured to confluency followed by additional incubation before initiating differentiation, we hypothesized that contact inhibition of proliferation (CIP) is requisite for making the cells prone to the differentiation. We screened upregulated genes in contact-inhibited 3T3-L1 fibroblasts, as well as NIH3T3 fibroblasts that are also sensitive to contact inhibition, by a whole genome microarray analysis. We also screened the genes that undergo rapid downregulation after the initiation of adipogenic differentiation. To investigate the mechanism of contact inhibition of proliferation and adipogenic differentiation of 3T3-L1 and NIH3T3 fibroblasts, we have employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential to distinguish proliferating and contact-inhibited cells and cells that undergo adipogenic differentiation. Total RNAs from 80% confluent (3T3-L1_80%, NIH3T3_80%) and overconfluent (3T3-L1_overconfluent, NIH3T3_overconfluent) cells and cells stimulated with the adipogenic differentiation medium (ZenBio) for 2 hours (3T3-L1_adipo diff med 2 hours, NIH3T3_adipo diff med 2 hours) were harvested and subjected to the microarray analysis.
Project description:Given previous works showing that, in the process of adipogenic differentiation of 3T3-L1 fibroblasts, the cells need to be cultured to confluency followed by additional incubation before initiating differentiation, we hypothesized that contact inhibition of proliferation (CIP) is requisite for making the cells prone to the differentiation. We screened upregulated genes in contact-inhibited 3T3-L1 fibroblasts, as well as NIH3T3 fibroblasts that are also sensitive to contact inhibition, by a whole genome microarray analysis. We also screened the genes that undergo rapid downregulation after the initiation of adipogenic differentiation.
Project description:We used the 3T3-L1 preadipocyte cell line (Green and Kehinde. Cell 5:19-25, 1974; ATCC CL-173), in which adipogenic differentiation is experimentally induced when quiescent 3T3-L1 cells are incubated with serum and IDX (insulin, dexamethasone, isobutylmethylxanthine). Following IDX addition, the cells retract and re-enter the cell cycle in the so-called clonal expansion phase. Two to three days later the cells definitively exit the cell cycle, express adipocyte-specific genes, and accumulate lipids to form lipid droplets. 3T3-L1 cells were grown in DMEM/FBS 10% until they reached confluence and entred quiescence following contact inhibition. The cells were kept confluent in the same medium for 2 days. The medium was renewed and supplemented with IDX for 48 hours. The medium was supplemented with insulin and renewed every 2 days until the adipogenic differentiation was completed.
Project description:Cebpa is a critical transcription factor gene for adipocyte differentiation and adipose tissue development. However, mechanisms controlling Cebpa expression during adipogenic differentiation remain largely unknown. Here, we generated the high-resolution chromatin interaction maps of Cebpa in 3T3-L1 preadipocytes (3T3-L1) and 3T3-L1 adipocytes (3T3-L1-AD) using circularized chromosome conformation capture coupled with next-generation sequencing (4C-seq), and characterized differences in their chromatin interactomes and chromatin status of the interaction sites during adipogenic differentiation. We performed a 4C-seq experiment on inguinal white adipose tissue (iWAT) to evaluate whether chromatin interaction between Cebpa-L1-AD-En2 and Cebpa promoters in 3T3-L1 adipocytes also exists in mouse adipose tissue.
Project description:Adipose tissues are closely related to physiological functions and pathological conditions in most organs. Although differentiated 3T3-L1 preadipocytes have been used for in vitro adipose studies, the difference in cellular characteristics of adipogenic differentiation in two-dimensional (2D) culture and three-dimensional (3D) culture remain unclear. In this study, we evaluated gene expression patterns using RNA sequencing and metabolic functions using an extracellular flux analyzer in 3T3-L1 preadipocytes with and without adipogenic induction in 2D culture and 3D culture. In 2D culture, 565 up-regulated genes and 391 down-regulated genes were identified as differentially expressed genes (DEGs) by adipogenic induction of 3T3-L1 preadipocytes, whereas only 69 up-regulated genes and 59 down-regulated genes were identified as DEGs in 3D culture. Ingenuity Pathway Analysis (IPA) revealed that genes associated with lipid metabolism were identified as 2 out of the top 3 causal networks related to diseases and function in 3D spheroids, whereas only one network related to lipid metabolism was identified within the top 9 of these causal networks in the 2D planar cells, suggesting that adipogenic induction in the 3D culture condition exhibits a more adipocyte-specific gene expression pattern in 3T3-L1 preadipocytes. Real-time metabolic analysis revealed that the metabolic capacity shifted from glycolysis to mitochondrial respiration in differentiated 3T3-L1 cells in the 3D culture condition but not in those in the 2D cultured condition, suggesting that adipogenic differentiation in 3D culture induces a metabolic phenotype of well-differentiated adipocytes. Consistently, expression levels of mitochondria-encoded genes including mt-Nd6, mt-Cytb, and mt-Co1 were significantly increased by adipogenic induction of 3T3-L1 preadipocytes in 3D culture compared with those in 2D culture. Taken together, the findings suggest that induction of adipogenesis in 3D culture provides a more adipocyte-specific gene expression pattern and enhances mitochondrial respiration, resulting in more adipocyte-like cellular properties.
Project description:3T3-L1 preadipocytes were differentiated into mature adipocytes using adipogenic differentiation media. Promoter Capture Hi-C at D0 (two days post confluency) and D7 of adipocyte differentiation was performed to analyse regulatory interactions.
Project description:3T3-L1 preadipocytes were differentiated into mature adipocytes using adipogenic differentiation media. Total RNA was isolated at D0 (two days post confluency) and D7 of adipocyte differentiation. nAnT-iCAGE sequencing was performed to analyse transcriptional start sites.
