Increased autophagic activity in senescent human dental pulp cells

Abstract

Li L, Zhu Y‐Q, Jiang L, Peng W. Increased autophagic activity in senescent human dental pulp cells. International Endodontic Journal. Abstract Aim To establish whether autophagy is involved in dental pulp cell (DPC) senescence, so as to better understand the mechanism of the ageing process within the dental pulp. Methodology Human DPCs obtained from intact molars and premolars were cultured and serially passaged. Senescence‐β‐galactosidase (SA‐β‐gal) staining was performed to assess DPC senescence, which is considered to be the senescence of cells in culture after a series of passages. Autophagic activity was analysed by Western blot for major autophagic proteins and transmission electron microscopy (TEM) for autophagic vacuoles in both young and senescent cells. Statistical analyses were performed using the Student’s t‐test. Results Senescence‐β‐galactosidase staining was higher in senescent DPC than in young cells (P = 0.011). Western blot revealed senescent DPCs had greater expression of autophagic proteins (microtubule‐associated protein light chain 3 and Beclin 1) than young cells (P = 0.04, P = 0.001). Transmission electron microscopy revealed more autophagic vacuoles in senescent DPCs compared to young cells (P = 0.029). Conclusions Expression of autophagic proteins (microtubule‐associated protein light chain 3 and Beclin 1) increased in senescent DPCs compare to young cells. More autophagic vacuoles were observed in senescent DPCs by TEM. Collectively, these data imply that autophagic activity increased in senescent DPCs.

Inhibition of autophagy alleviates the senescent state of rat mesenchymal stem cells during long-term culture

“…Sasaki et al (17) demonstrated that autophagy and senescence have been collaterally observed in the damaged bile ducts of patients with primary biliary cirrhosis. An increase in autophagic vacuoles was also evident in senescent endothelial cells (18), fibroblasts and human dental pulp cells (19,20). Recently, Goehe et al (9) reported that autophagy and senescence commonly occur in parallel following the treatment of MCF-7 breast tumor cells with chemotherapeutic drugs.…”

MTA‐induced Notch activation enhances the proliferation of human dental pulp cells by inhibiting autophagic flux

“…In adult pulp tissue, autophagy molecules are expressed at lower levels than in aged tissues (Li et al . , Lee et al . ).…”

Deferoxamine-Induced Migration and Odontoblast Differentiation via ROS-Dependent Autophagy in Dental Pulp Stem Cells

“…As a recycling system, autophagy plays a vital role in the renovation of cells and tissues [9]. Several studies have implicated the involvement of autophagy in different physiological process of DPSCs, such as tooth development [10], cellular homeostasis [11], apoptosis [12] and senescence [13]. Recently, there is emerging evidence implicating autophagy as an essential role for bone remodeling and osteoblastic differentiation [14].…”