Search Results (2)

Corneodesmosomes are specialized intercellular junctions that mediate adhesion between corneocytes in the stratum corneum (SC). The degradation of these structures is regulated by kallikrein-related peptidases (KLKs) and their inhibitors. This study aimed to elucidate the effects of Shotokuseki extract (SE), a substance rich in various trace elements, on molecules related to SC adhesion using a three-dimensional cultured human epidermis model. SE was applied to a three-dimensional epidermis model, and analyses were conducted on gene expression, protease activity, protein levels, and tissue structure. SE treatment significantly upregulated the mRNA expression of corneodesmosomal components (desmoglein1, desmocollin1, and corneodesmosin) and the major protease inhibitor serine peptidase inhibitor Kazal type 5. Concurrently, SE increased the mRNA expression of the trypsin-like protease KLK5,while significantly decreasing the mRNA expression and activity of the chymotrypsin-like protease KLK7. Although no significant changes were observed in the protein levels of corneodesmosomal components, histological analysis revealed that SE significantly increased the ratio of SC thickness to total epidermal thickness. These findings suggest that SE contributes to the homeostasis of the SC by simultaneously promoting the expression of genes encoding corneodesmosomal components, and regulating the balance of the protease/inhibitor system involved in their degradation. The selective suppression of KLK7 activity may appropriately regulate the final stage of desquamation, thereby stabilizing barrier function. Full article

The switch between keratinocyte proliferation and differentiation is regulated by extracellular calcium levels, requiring high concentrations (>1 mol/L) of extracellular calcium to induce differentiation. The Shotokuseki extract (SE) contains various ions such as calcium, but its effect on keratinocytes is unknown. This study focused on calcium-induced differentiation of keratinocytes and investigated the effects of simultaneous application of calcium and other ions on keratinocyte differentiation. The expression of differentiation markers increased when SE was added to a keratinocyte culture but not when only calcium was added at the same concentration present in SE. The calcium concentration in SE was found to be too low (0.01 mol/L) to induce differentiation of keratinocytes. In addition, the application of SE increased intracellular calcium concentration compared with calcium solution alone. Therefore, the induction of keratinocyte differentiation by SE is not calcium-dependent, or SE may alter the calcium sensitivity of keratinocytes. In our study, we found that simultaneous application of multiple ions and/or the application of trace ions may alter calcium sensitivity and the epidermal cell response. The function of ion transporters associated with these ions and the response of cells to ions depends largely on the balance among various ions and the function of trace ions. Full article