Gene

Cell biology

Molecular biology

Biology

Western blot

Proteolytic enzymes

Cell migration

Extracellular matrix

Biochemistry

Basement membrane

Immunology

Organic chemistry

Keratinocyte

Laminin

Toxicity

In vitro

Enzyme

Sulfur

Medicine

Chemistry

Cell

Sulfur mustard

Antibody

Immunofluorescence

Wound healing

Pathology

The Anatomical Record

ABSTRACT Laminin‐332 is a basement membrane protein composed of three genetically distinct polypeptide chains that actively promote both skin epidermal cell adhesion and migration. Proteolytic fragments of the laminin γ2 chain stimulate migration and scattering of keratinocytes and cancer cells. Sulfur mustard (SM) is a bifunctional alkylating agent that induces separation of basal keratinocytes from the dermal‐epidermal junction and invokes a strong inflammatory response leading to delayed wound repair. In the present studies, the role of laminin γ2 in SM‐induced skin injury and wound repair was investigated using the mouse ear vesicant model. We found that laminin γ2 chain mRNA was preferentially upregulated in mouse ear skin exposed to SM. In situ hybridization confirmed overexpression of laminin γ2 transcript. Western blot analysis showed increased protein expression of the full‐length proform of laminin γ2 and smaller processed fragments of laminin γ2 in skin exposed to SM. Dual immunofluorescence labeling indicated that laminin γ2 fragments are prevalent in suprabasal keratinocytes behind the leading edge in areas of hyperplasia in injured skin. In addition, co‐expression of laminin γ2 and the senescent marker, p16 −INK4a was found to overlap with the hyperplastic migratory epithelial sheet. This observation is similar to hypermotile keratinocytes reported in invasive carcinoma cells. Overall, our studies indicate that laminin γ2 is preferentially expressed in skin post SM exposure and that protein expression appears to become progressively more fragmented. The laminin γ2 fragments may play a role in regulating SM‐induced skin wound repair. Anat Rec, 2020. © 2020 American Association for Anatomy

Expression of Laminin γ2 Proteolytic Fragments in Murine Skin Following Exposure to Sulfur Mustard