Objective To compare the performance of colitis induced by dextran sulfate sodium (DSS) between Lnk-knockout mice and wild-type mice.
Methods The C57BL/6 mice with similar week age were divided into wild type group (WT), wild type mouse with colitis group (WT+DSS), Lnk-knockout group (KO) and Lnk-knockout mouse with colitis group (KO+DSS). WT and KO mice were admitted to drink water freely, WT+DSS and KO+DSS mice was allowed to drink 2.5% DSS aqueous solution freely. The experiment was carried out for 7 days to observe daily weight change, fecal texture (soft or hardness) and intestinal hemorrhage in mice, and to evaluate the disease activity index (DAI). After 7 days, the peripheral blood was collected to detect the regulatory B-cell (Breg) frequency by flow cytometry in the peripheral blood of WT mice and KO mice. The mouse was sacrificed, and the bowel was taken to observe the shape, color and measure the length of the intestine. The colonic tissue was produced by histological sections and HE staining, and histological changes were observed under the microscope.
Results The bowel movement was normal in WT group and KO group, and the mice in KO+DSS group and the WT+DSS group had manifestation of earlier diarrhea and blood-draining. In the experimental period, the weight of KO+DSS group was significantly lower than the other 3 groups, and DAI in the KO+DSS group increased significantly with time. Breg cells frequency in KO group was significantly lower than WT group. In the KO+DSS group, colon obviously shortened, microscopic examination of HE tissue section showed erosive bleeding congestion, multiple lesions shallow ulcer, inflammatory cell infiltration mucosa and submucosa with involvement of the muscle layer, which indicated increased inflammatory response.
Conclusion Lnk deficiency can aggravate the performance of DSS-induced colitis in mice, which may be related to the decrease of Breg cells frequency and negative regulation of inflammatory response in Lnk KO mice.
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