Astroglia proliferate upon the biogenesis of tunneling nanotubes via α-synuclein dependent transient nuclear translocation of focal adhesion kinase.

Astroglia play crucial neuroprotective roles by internalizing pathogenic aggregates and facilitating their degradation. Here, we show that α-SYN protofibril-induced organelle toxicities and reactive oxygen species (ROS) cause premature cellular senescence in astrocytes and astrocyte-derived cancer cells, resulting in a transient increase in the biogenesis of tunneling nanotubes (TNTs). TNT-biogenesis and TNT-mediated cell-to-cell transfer lead to clearance of α-SYN-induced organelle toxicities, reduction in cellular ROS levels, and reversal of cellular senescence. Enhanced cell proliferation is seen in the post-recovered cells after recovering from α-SYN-induced organelle toxicities. Further, we show that α-SYN-induced senescence promotes the transient localization of focal adhesion kinase (FAK) in the nucleus. FAK-mediated regulation of Rho-associated kinases plays a significant role in the biogenesis of TNTs and their subsequent proliferation. Our study emphasizes that TNT biogenesis has a potential role in the clearance of α-SYN-induced cellular toxicities, the consequences of which cause enhanced proliferation in the post-recovered astroglia cells.