ABSTRACT: Bone marrow mesenchymal stem cells (MSC) were adipogenically differentiated followed by dedifferentiation. We are interested to know the new fat markers, adipogenic signaling pathways and dedifferentiation signaling pathways.Furthermore we are also intrested to know that how differentiated cells convert into dedifferentiated progenitor cells. To address these questions, MSC were adipogenically differentiated, followed by dedifferentiation. Finally these dedifferentiated cells were used for adipogenesis, osteogenesis and chondrogenesis. Histology, FACS, qPCR and GeneChip analyses of undifferentiated, adipogenically differentiated and dedifferentiated cells were performed. Regarding the conversion of adipogenically differentiated cells into dedifferentiated cells, gene profiling and bioinformatics demonstrated that upregulation (DHCR24, G0S2, MAP2K6, SESN3) and downregulation (DST, KAT2, MLL5, RB1, SMAD3, ZAK) of distinct genes play a curcial role in cell cycle to drive the adipogenically differentiated cells towards an arrested state to narrow down the lineage potency. However, the upregulation (CCND1, CHEK, HGF, HMGA2, SMAD3) and downregulation (CCPG1, RASSF4, RGS2) of these cell cycle genes motivates dedifferentiation of adipogenically differentiated cells to reverse the arrested state. We also found new fat markers along with signaling pathways for adipogenically differentiated and dedifferentiated cells, and also observed the influencing role of proliferation associated genes in cell cycle arrest and progression. We have differentiated bone marrow derived mesenchymal stem cells(MSC) into adipogenically differentiated cells followed by dedifferentiation. We are intrested to know new fat markers, signaling pathways for adipogenically differentiated and dedifferentiated cells, along to observe the genes associated with cell cycle arrest and progression. Results are also provide molecular insight into the process of adipogenesis and dedifferentiation. To study the adipogenic differentiation and dedifferentiation process along with "how adipogenically differentiated cells convert into dedifferentiated cells" on the molecular level, gene expression profiling with genome-wide Affymetrix HG-U133 Plus 2.0 olgonucleotide microarrays (Affymetrix, Santa Clara, CA, USA) was applied. In total, 12 GeneChips were performed for n=3 donors and 4 times (3x4=12): 3x P4 MSC (undifferentiated state), 3x adipogenically differentiated cells at day 15 (differentiated state), 3x dedifferentiated cells at day 7 (dedifferentiated state) and 3x dedifferentiated cells at day 35 (dedifferentiated state)
