Yohsuke Moriyama, Membrane Damage Repair and Cellular Senescence

Speaker:  Yohsuke Moriyama (Science and Technology Group)

Title: Membrane Damage Repair and Cellular Senescence

Abstract:

 Cellular senescence is a state of permanent cell cycle arrest characterized by its specific metabolic activity and dramatic changes in cell morphology. Originally, it was proposed to be due to the shortening of telomeres after the repeated proliferation (replicative senescence). Now that it is known that the cellular senescence is also induced by DNA damage response (DDR), oncogene expressions and several stresses.
In our study, we found that plasma membrane damage induces acute cellular senescence in human cultured cells without showing DNA damage response. During this transient membrane damage-inducing treatment, the damaged plasma membrane is continuously repaired, exposing phosphatidylserine (PS) to the outer leaflet of the plasma membrane at the damaged site. This PS exposure is also found in the naturally aged cells.
The key regulator of this membrane damage repair is extracellular calcium influx to the cytosol, and we found that this calcium influx induced mitochondrial DNA release several days after membrane damage-inducing treatment. We assume that this cytosolic mtDNA evokes innate immune pathways, and results in acute cellular senescence.

After the talk, please join for discussion with free soft drinks and pizza!