integument
• dysfunctional hair follicle stem cells in doxycycline-treated mice due to blockage of proliferation
|
• noticeable after 10 days and pronounced by 6 weeks in doxycycline-treated mice
|
• bulge stem cells in doxycycline-treated mice fail to enter into the cell cycle and initiate anagen with follicles remaining in a telogen-like state unlike in control mice
• resilencing in doxycycline re-treated mice prevents hair follicle growth unlike in control mice
• however, withdrawal of doxycycline restores entry into anagen
|
• in some doxycycline-treated mice
|
• after 2 days, doxycycline-treated mice exhibit decreased proliferation and increased apoptosis of basal epidermal cells compared with control mice
• after 1 week, mice exhibit hyperproliferation of basal cells that decreases after longer induction times and increased cellular replicative senescence compared with control mice
• however, apoptosis rates are normal after 1 week of induction and removal of doxycycline prevents further increases in senescence
|
cellular
• after 1 week, doxycycline-treated mice exhibit increased cellular senescence in the epidermis compared with control mice
• however, removal of doxycycline prevents further increases in senescence and treatment with TPA does not increase senescence
|