This study investigated the effect of macrophage depletion with clodronate-containing liposomes (Clo-lip) on the incidence and development of rheumatoid arthritis (RA).
The effect of macrophage depletion with Clo-lip in the spleen was assessed by HE (haematoxylin and eosin) staining and immunohistochemistry (IHC). Thirty BALB/c mice were randomly divided into three groups, which were administered PBS-lip, Clo-lip, or normal saline. RA model mice were then created and the appearance of the paws was observed. Expression of CD68 by macrophages was examined by immunofluorescence on the 49th day. Forty-five RA model mice were created and randomly divided into three groups. The experiment group was administered Clo-lip at different timepoints. The degree of arthritis score was recorded during the administration. Histological features were detected by HE staining on the 84th day.
Compared to controls, horseshoe-shaped nuclei and multi-core large cells were reduced in the experimental group (HE stain; p < 0.05). Brown tag-CD68 and tag-CD80 macrophages were fewer in the experimental group than in the control group (immunohistochemistry; p < 0.05). Furthermore, the degree of arthritis score in the experimental group was significantly decreased (p < 0.05). HE staining showed that there was no or less inflammatory cell infiltration in the articular cavity in mice in the experimental group, and that the percentage of CD68
Macrophage depletion with Clo-lip can affect the incidence and development of RA.