Comparison of Gene Expression between stromal vascular cells (SVC) and newly identified adipose precursor (SPA)

We have identified proliferative cells in adipose tissue expressing adipocyte specific genes, which were named small proliferative adipocytes (SPA). Comparison of gene expression by microarray and real time PCR among stromal vascular cells (SVC), SPA and mature adipocyte (MA) revealed that adipocyte specific genes and several neuronal genes were increased in the order of SVC < SPA < MWA. However, proliferin 2 (PLF) was detected only in SPA. We found that SPA changed to lipid laden cells by incubation with differentiation medium containing insulin/dexamethasone/IBMX. In this study, we investigated the gene expression of differentiated SPA (D-SPA) comparing with differentiated SVC (D-SVC). Further study using microarrays and real time PCR revealed that uncoupling protein 1 (UCP1) and PLF were strongly expressed in D-SPA. These data suggested that SPA might be able to differentiate into beige cells. Epididymal fat from male C57/BL mice were digested with collagenase, and then centrifuged at 9 xg for 1 sec. The floating cells were separated from the lower phase (SVC). The floating cell fraction was centrifugazed at 226 xg for 3 min. The resultant floating cells and sediment cells were regarded as mature adipocytes (MA) and SPA, respectively. SVC and SPA were cultured in DMEM. When the cultured cells reached 90% confluency, they were harvested, and total RNA was extracted. To explore the characteristics of SPA, gene expression of SVC (S-3 2015.11.10), SPA (A-3 2015.11.10) and MA (A 2015.11.17) was compared with microarray. The number of samples was 3, the number of replication was one. The obtained results were confirmed by real time PCR and immunocytochemistry.