Our previous study suggested that suppression by cepharanthin of tumor necrosis factor-a (TNF-a)-induced matrix metalloproteinase-9 (MMP-9) could prevent destruction of the acinar structure in the salivary glands of patients with Sjögren's syndrome (SS). In this study, we observed that in vivo administration of cepharanthin prevented severe damage to acinar tissues in the murine model of human SS.
Cepharanthin was intraperitoneally administered to thymectomized female NFS/sld mice. Inflammatory lesions in the salivary and lacrimal glands were then examined histologically. Expression of phosphorylated IkB-a, MMP-9, and type IV collagen was analyzed immunohistochemically. The apoptotic cell death of acinar cells was determined.
Although extensive mononuclear cell infiltration and destruction of acinar tissue in salivary and lacrimal glands were observed in control mice, significant improvement of these lesions was evident in mice treated with cepharanthin. Immunohistochemical analysis revealed that p65, phosphorylated IkB-a, and MMP-9 were more strongly stained in the acinar cells of control mice than in cepharanthin-treated mice. Although no staining for type IV collagen was observed in the acinar tissues of control mice, continuity of staining for type IV collagen was observed in acinar tissues of cepharanthin-treated mice. Destruction of acinar tissues was attributed to the induction of apoptosis, suggesting that cepharanthin inhibits apoptosis by suppressing phosphorylation of IkB-a, followed by prevention of MMP-9 activation.
Our findings suggest that cepharanthin may be a promising agent for use in preventing destruction of acinar tissues in murine SS.