Induction of keratinocyte type-I transglutaminase in epithelial cells of the rat

Abstract

Abstract. Using immunogold-silver techniques, we have demonstrated that, in rats, type-I (keratinocyte) transglutaminase is expressed primarily in stratified squamous epithelia of the integument. the upper digestive tract, and the lower female genital tract. In these epithelia, the enzyme was found to be present predominantly in the granular layer, but was evident at low levcls even in the basal layer, especially in the genital tract. N o immunoreactivity was detected in glandular, columnar, or transitional epithelia or in soft tissues. However, considerable enzyme antigenicity was observed in the endometrium and in major ducts of the pancreas and mammary glands of near-term pregnant and early postpartum females. In cultures, substantial immunoreactivity was readily identifiable not only in epidermal, vaginal, and esophageal epithelial cells (immunopositive in vivo), but also in urinary bladder, seminal vesicle, and tracheal epithelial cells (immunonegative in vivo). Primary epithelial outgrowths from bladder and seminal vesicle tissue explants were immunopositive, demonstrating rapid adaptation to the culture environment. These results reveal three distinct levels of regulation of transglutaminase exprcssion in various cell types: (1 ) during the differentiation of keratinocytes, (2) during pregnancy, being evident principally in the endometrium but detectable elsewhere as well, and (3) during the cultivation of certain epithelia which do not normally express the cnzyme in vivo. We conclude that type-I transglutaminase may be a valuable marker for elucidating the regulation of normal epithelial differentiation and squamous metaplasia.

Keratinocyte Transglutaminase Promoter Analysis:

“…Incubation of the 32 P-labeled oligomer I with nuclear extract from either rB or postconfluent SCC9, both expressing the endogenous gene (7,32), resulted in the formation of a DNA-protein complex migrating more slowly than the free oligonucleotide (Fig. 3).…”

“…To determine whether the observed DNA-nuclear protein complexes were observable in other cell types, 32 P-labeled oligomers were incubated with the same amounts of nuclear extracts of several cell types in gel electrophoretic mobility shift assays. Results using oligomer I revealed that while the DNA-binding protein was easily detected in postconfluent SCC9 and rB cells and at a reduced level in preconfluent SCC9 (Fig.…”

Apoptosis in human skin development: Morphogenesis, periderm, and stem cells

“…TGase I. B.C1 monoclonal antibody, which localizes TGase I to the spinous and granular layer, containing terminally differentiating keratinocytes in neonatal or adult skin (Parenteau et al, 1986;Michel et al, 19921, is first expressed in the periderm of human fetal skin. Whereas there is no staining in the flattened to slightly elevated periderm of the epidermis (not shown), there is sporadic staining of individual rounded periderm cells (Fig.…”

Defective stratum corneum and early neonatal death in mice lacking the gene for transglutaminase 1 (keratinocyte transglutaminase)

“…Transglutaminase 1 (TGase 1; keratinocyte TGase) has been identified as a membrane-bound TGase isozyme (12), the activation of which is coordinated with formation of cross-linked cell envelope in cultured epidermal keratinocytes (13,14). TGase 1 is expressed in the stratified squamous epithelium, predominantly in the upper spinous and granular layers beneath the stratum corneum (15,16).…”