Objective To explore whether
aging increases severity of
colitis in
mice and its mechanism.
Methods Young (6-8 weeks)and
aged (56 weeks) C57Bl/6
mice were divided into the control and experimental group (n=5,each).
Dextran sodium sulfate(DSS) was used to induce acute
colitis mouse model in the experimental group.The
mRNA expressions of
tumor necrosis factor-α(TNF-α)and
interleukin-6(
IL-6)in
colon were measured by RT-PCR.
Tight junctions (TJs) of intestinal
epithelial cells was examined by
transmission electron microscopy (TEM).
Protein expressions of
E-cadherin and
occludin were detected by
Western blotting and
immunohistochemistry in
colon.Results Compared with the young DSS-induced
mice,the
aged DSS-induced
mice had more
weight loss(t=3.679,P=0.006),higher
disease indexes (t=2.496,P=0.037),higher histologic scores(U=0.000,P=0.008) and higher colonic
IL-6 level (U=4.000,P=0.191). The TJs of intestinal
epithelial cells were discontinuous in old healthy
rats,and the TJs were destroyed significantly in both young and
aged DSS-induced
mice. Compared with the young DSS-induced
mice,the
aged DSS-induced
mice had decreased
protein expressions of
E-cadherin (t=0.184,P=0.863)and
occludin (t=0.399,P=0.710).Conclusions
Aging leads to more severe
disease following DSS challenge. Age-related deterioration in the functions of the gastrointestinal
barrier and integrity may be one of the possible mechanisms.