Tenovin-1 Induces Senescence and Decreases Wound-Healing Activity in Cultured Rat Primary Astrocytes

Abstract

Brain aging induces neuropsychological changes, such as decreased memory capacity, language ability, and attention; and is also associated with neurodegenerative diseases. However, most of the studies on brain aging are focused on neurons, while senescence in astrocytes has received less attention. Astrocytes constitute the majority of cell types in the brain and perform various functions in the brain such as supporting brain structures, regulating blood-brain barrier permeability, transmitter uptake and regulation, and immunity modulation. Recent studies have shown that SIRT1 and SIRT2 play certain roles in cellular senescence in peripheral systems. Both SIRT1 and SIRT2 inhibitors delay tumor growth without significant general toxicity. In this study, we investigated the role of tenovin-1, an inhibitor of SIRT1 and SIRT2, on rat primary astrocytes where we observed senescence and other functional changes. Cellular senescence usually is characterized by irreversible cell cycle arrest and induces senescence-associated β-galactosidase (SA-β-gal) activity. Tenovin-1-treated astrocytes showed increased SA-β-gal-positive cell number, senescence-associated secretory phenotypes, including and , and cell cycle-related proteins like phospho-histone H3 and CDK2. Along with the molecular changes, tenovin-1 impaired the wound-healing activity of cultured primary astrocytes. These data suggest that tenovin-1 can induce cellular senescence in astrocytes possibly by inhibiting SIRT1 and SIRT2, which may play particular roles in brain aging and neurodegenerative conditions.

Etoposide Induces Mitochondrial Dysfunction and Cellular Senescence in Primary Cultured Rat Astrocytes

“…In addition to the morphological and molecular features of senescent cells, etoposide-treated astrocytes also showed a functional change manifested by their reduced wound-healing ability. The results are consistent with our previous reports showing a reduction of wound healing ability in senescence-induced astrocytes by tenovin-1 via changes in the expressions of sirt1 and 2 (Bang et al ., 2018). It has been reported that aged bone marrow-derived dendritic cells reveal impaired in vitro migration (Grolleau-Julius et al ., 2008) and old tenocytes and satellite cells also show migration defects (Chang et al ., 2012; Collins-Hooper et al ., 2012).…”

“…Western blot analysis was performed following a published protocol described previously (Bang et al ., 2018). Briefly, the cells were harvested with radioimmunoprecipitation assay (RIPA) buffer consisting of 2 mM EDTA, 0.1% (w/v) SDS, 50 mM Tris-HCl, 150 mM sodium chloride, 1% Triton X-100, and 1% (w/v) sodium deoxycholate.…”

Late Passage Cultivation Induces Aged Astrocyte Phenotypes in Rat Primary Cultured Cells

“…Our results showed that late passage cultivated astrocytes exhibited functional changes manifested by decreased wound healing capacity. These results are consistent with our previous reports showing the decreased wound healing capacity in aging-induced astrocytes through tenovin-1 or etoposide treatment ( Bang et al ., 2019a , 2019b ). Old satellite cells and tenocytes show impaired migration in vitro similar to aged bone marrow-derived dendritic cells ( Grolleau-Julius et al ., 2008 ; Chang et al ., 2012 ; Collins-Hooper et al ., 2012 ).…”

“…Sprague-Dawley (SD) rats were obtained from Samtako, Inc (Gyeonggi, Korea). Astrocytes were cultured in the brain cortex of postnatal day 2 (P2) SD rats as described previously ( Bang et al ., 2019b ). Briefly, brain cortices were isolated and mechanically triturated to make single cells.…”

“…Western blot was analyzed following a previously published protocol ( Bang et al ., 2019b ). Briefly, the cells were harvested with radioimmunoprecipitation assay (RIPA) buffer consisting of 2 mM EDTA, 0.1% (w/v) SDS, 50 mM Tris-HCl, 150 mM sodium chloride, 1% Triton X-100, and 1% (w/v) sodium deoxycholate.…”