Calgranulin expression and association with the keratinocyte cytoskeleton

Area of Science:

• Dermatology
• Cell Biology
• Biochemistry

Background:

• Calgranulin A and B are intracellular calcium-binding proteins.
• These proteins are expressed by lesional keratinocytes in inflammatory dermatoses.

Purpose of the Study:

• To investigate the induction of calgranulin proteins in an in vitro system.
• To characterize the epidermal form of calgranulin.

Main Methods:

• Calgranulin-specific monoclonal antibodies were used for immunofluorescence staining.
• Indirect immunofluorescence analyzed subcellular localization.
• Western blotting and SDS-PAGE identified protein molecular weight.

Main Results:

• Calgranulin proteins were expressed in cultured skin explants within 12-24 hours.
• Cycloheximide inhibited calgranulin induction, indicating de novo synthesis.
• Calgranulins were localized to detergent-insoluble cytoskeletal preparations.
• A single 13.0 kD antigen was detected using MAC 387 antibody.

Conclusions:

• Calgranulin expression in keratinocytes is inducible in vitro.
• Calgranulins are associated with the epidermal cytoskeleton.
• Calgranulin expression may regulate cytoskeletal changes in skin diseases.