Apoptosis in Brown AdipocytesImplication in Obesity and Cancer

Resumen

The maintenance of tissue homeostasis is a complex balance between the rate of cell proliferation and the rate of cell death, although the balance favours apoptosis during some stages of embryogenesis or during the physiological involution of adult tissues. Apoptosis is a physiological programmed cell death that only affect individual cells and did not produce inflammatory response. Many diseases are associated with the induction or inhibition of apoptosis, that leads to cell loss (neurodegenerative disorders or ischemic injury), or cell accumulation disorders (cancer or autoinmmune disorders). In our laboratory, we have developed a model of non fibroblastic mesenchymal cell, the foetal brown adipocytes, that respond to IGF-I/insulin increasing cellular proliferation and differentiation. Our results show that serum deprivation in a brown adipocyte cell line induces apoptosis. The inhibition of caspases rescues these cells from apoptosis, decreasing the expression of Bcl-xS and increasing Bcl-2 expression. Insulin and IGF-I are survival factors in these cells through a PI 3-kinase/Akt and MAPK-dependent