| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1925438 | Archives of Biochemistry and Biophysics | 2013 | 8 Pages |
Cystatin D encoded by Cst5 is a salivary classified type II cystatin. We investigated the dynamism of cystatin D by examining the distribution of cystatin D protein and mRNA in rats, to identify novel functions. The simultaneous expression of Cst5 and cystatin D was observed in parotid glands, however in situ hybridization showed that only acinar cells produced cystatin D. Synthesized cystatin D was localized in small vesicles and secreted from the apical side to the saliva, and from the basolateral side to the extracellular region, a second secretory pathway for cystatin D. We also identified antigen-presenting cells in the parotid glands that contained cystatin D without the expression of Cst5, indicating the uptake of cystatin D from the extracellular region. Cystatin D was detected in blood serum and renal tubular cells with megalin, indicating the circulation of cystatin D through the body and uptake by renal tubular cells. Thus, the novel dynamism of cystatin D was shown and a function for cystatin D in the regulation of antigen-presenting cell activity was proposed.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (117 K)Download as PowerPoint slideHighlights► Dynamism of salivary cystatin D, in blood, antigen presenting cells, and kidney. ► Cystatin D is produced in parotid acinar cells and localized in small vesicles. ► Cystatin D and megalin is colocalized in renal tubule cells. ► Cystatin D would affect regulation of antigen presenting cells.
