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Expression of Caspases 3, 9, and 14 in the Epidermis of Early Wounds
Author(s) -
Kuechle M.K.,
Usui M.L.,
Underwood R.A.
Publication year - 2004
Publication title -
wound repair and regeneration
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.847
H-Index - 109
eISSN - 1524-475X
pISSN - 1067-1927
DOI - 10.1111/j.1067-1927.2004.0abstractbt.x
Subject(s) - caspase , epidermis (zoology) , microbiology and biotechnology , proteases , caspase 3 , apoptosis , biology , immunohistochemistry , pathology , programmed cell death , anatomy , medicine , immunology , biochemistry , enzyme
Caspases are a family of at least 14 highly conserved aspartate proteases that are the major effector arm of apoptosis or programmed cell death. Previous immunohistochemical and biochemical studies have implicated two of the family members, caspase 3 and caspase 14, as having a role in the process of epidermal terminal differentiation. Reepithelialization of epidermal defects after wounding requires coordination between signals that initiate growth and migration as well as signals that initiate differentiation. We therefore examined the expression of caspase 3, caspase 9, and caspase 14 in the epidermis of early (up to 48 hour) human wounds. Two excisional wounds were created on the inner arm using a 3 mm biopsy punch and allowed to heal via secondary intention. Wounds were excised at 24 and 48 hours using a 6 mm biopsy punch, placed in OCT, frozen, cryosectioned and immunohistochemically labeled using affinity purified antisera for caspases 3, 9 and 14. At 24 hours, the distribution of caspase 3 and caspase 9 expression was unchanged from non‐wounded skin. Caspase 3 was found in the upper differentiating cells of the granular layer, while caspase 9 was expressed in scattered dendritic cells in the epidermis. At 48 hours, caspase 3 expression was lost in the epithelial tongue, while caspase 9 expression was found in keratinocytes at the tip of the migrating tongue. Caspase 14 expression at 24 hours was noted at the tip of the migrating epithelial tongue, while at 48 hours, the normal expression of caspase 14 in the granular layer was lost. These results suggest that in 48 hour wounds, loss of caspase 3 and 14 expression in the migrating epithelium reflects the activated state of this tissue. The onset of caspase 9 expression at 48 hours in the leading edge of the wound suggests a role for caspase 9 in wound remodeling, as caspase 9 is known to participate in tissue remodeling during development. Characterization of the caspases involved during wound healing may lead to future therapies utilizng caspases or caspase inhibitors in situations of poor or aberrant wound healing.