Stability research on the construction of a mouse model for alopecia areata using two modeling methods with imiquimod
ZHENG Lingling
LI Wangting
ZHANG Lulu
DU Yang
JIN Fuxing
ZHOU Xuan
WENG Yan
WANG Jingwen
Abstract：Objective To compare the mouse models of alopecia areata(AA)constructed by two different methods of imiquimod,and explore the stable method for establishing an AA animal model.Methods A total of 48 male C57BL/6 mice aged 5-7 weeks were randomly divided into four groups.Model group 1 and Control group 1 received 0.2 g either imiquimod or Vaseline on the back of mice 1 time/day at the same time for seven consecutive days.Model group 2 and Control group 2 received 0.2 g of imiquimod or Vaseline on the same area 3 times/week at the same time for 35 d.After the completion of administration,both groups of mice were observed for a week.During the experiment,macroscopic changes in mouse hair were observed,and changes in body mass growth status of mice were continuously monitored.The depilated skin lesions were collected at the end of administration and after the observation period.The expression of IFN-γ concentration in the skin lesions was detected using ELISA,and the changes in the number of hair follicles were observed through HE staining.Additionally,immunohistochemistry was utilized to detect the infiltration of CD4+and CD8+T cells in hair follicles near the hair removal area.Results After two modeling approaches of imiquimod,the mice in Model group 1 exhibited alopecia on their dorsal and cervical regions on the third day,which progressed to complete hair loss after 7 d.Following modeling,a cyan hue appeared on the depilated area on the fifth day of observation,and micro-hair growth commenced on the seventh day.On the seventh day of modeling period,hair follicle atrophy followed by subsequent regrowth during the observation period was observed.In comparison to Control group 1,significant infiltration of CD4+and CD8+T cells along with IFN-γ expression were evident at the end of modeling(P＜0.01),but CD4+and CD8+T cell infiltration and IFN-γexpression decreased significantly during the observation period.In Model group 2,macroscopic hair loss was noted on the thirty-fifth day after modeling and microscopic examination revealed smooth skin in depilated area.Histopathological analysis demonstrated a substantial reduction in number of hair follicles compared to Control group 2.Moreover,there was an obvious increase in CD4+,CD8+T cell infiltration as well as significant elevation in IFN-γ levels(P＜0.01).The related indicators did not exhibit any noticeable changes during observation period.Conclusion The C57BL/6 AA model established by administering imiquimod three times a week for 35 d,exhibits an extended duration and greater clinical consistency with the pathogenesis observed in patients with AA.This model represents a relatively stable and ideal animal model for investigating the pathophysiology of AA.
Keywords：alopecia areatastability of animal modelsimiquimodautoimmune diseases
Publication Date：2025-04-30
Online Publishing Date：2026-08-26(First online date of this platform, not the publication date of the document)
Pages：7( 514-520 )