@misc{oai:repo.qst.go.jp:00080703,
 author = {Noguchi, Miho and Ihara, Tomokazu and Suzuki, Keiji and Yokoya, Akinari and Noguchi, Miho and Ihara, Tomokazu and Yokoya, Akinari},
 month = {Oct},
 note = {Cellular senescence is induced by various stimuli including radiation, oncogenic activation, and chemotherapeutic drugs. Senescent cells are metabolically functional and present in tissue until they are removed by immune cells. Age-associated decline in immune clearance of senescent cells causes the accumulation of senescent cells, which may contribute to the manifestation of age-related pathology. We hypothesized that time-dependent demonstration of deleterious effects of ionizing radiation is attributed to the temporal change in the physiological condition of senescent cells. Therefore, we have started to investigate activity of autophagy for over 30 days in normal human diploid cells, hTERT BJ-5ta cells, exposed to 20 Gy X-rays. 
The induction of senescence was confirmed by decreased DNA synthesis and increased SA-β-gal activity. We found that the levels of LC3-II, one of the autophagy-related proteins, was increased rapidly in response to X-irradiation and formed a peak at 1 day post-irradiation, followed by a gradual decrease to the basal level at 6 days post-irradiation. After a few days, it increased again and reached to the level of the first peak at 30 days post-irradiation. 
The high autophagic activity might relate to the physiological changes caused by alterations of gene expression in senescent cells. Since gene expression profiles are thought to depend on the type of the stress that induces senescence, it is necessary to determine that whether the high autophagic activity in the late senescent cells is a preferential phenomenon in radiation induced senescence., 日本放射線影響学会第63回大会},
 title = {Temporal expression analysis of autophagy-related proteins in radiation-induced senescence},
 year = {2020}
}