Secreted molecules as cytokines, chemokines, grow factors and the release of small extracellular vesicles (sEV) modulate the cellular microenvironment. Senescent cells main characteristics are the inhibition of the cell cycle, an increased β-galactosidase activity and a specific secretome of the previous compounds known as Senescence Associated secretory phenotype (SASP). SASP leads the microenvironment to a more pro-inflammatory state and induces senescence in the neighbouring cells through a paracrine and autocrine manner. As time goes by, the accumulation of senescent cells drives into age-related diseases. This study aimed to identify key molecular targets involved in the transmission of senescence, focusing on the role of sEV. To investigate the mechanism underlying paracrine senescence, we performed a knock-down experiment targeting RAB27A and RELA in human umbilical cord mesenchymal stem cells. These proteins are implicated in sEV biogenesis and in every paracrine senescence compound respectively. Following the knock down, cells were exposed to sEV derived from senescent cells. The effects on paracrine senescence transmission were assessed using β-galactosidase and proliferation assays. The knockdown of RAB27A and RELA significantly reduced the transmission of senescence to recipient cells, as evidenced by decreased β-galactosidase activity and maintained cellular proliferation. Next, a shotgun proteomic analysis revealed significant dysregulation of proteins associated with lysosomal function, the Golgi apparatus, and the calcium channel ORAI1, suggesting a potential involvement of the endomembrane system in the propagation of senescence signals. In conclusion, the silencing of RAB27A prevents the paracrine senescence transmission highlighting the potential of targeting the endomembrane system as a therapeutic senomorphic strategy

Poster.-- I International SENESCEL Conference, Santiago de Compostela, 7-8 October 2024

Peer reviewed