Keratin 32 inhibitors such as Alizarin and Clioquinol work by chelating metal ions in the cellular environment, which are essential for the function of various enzymes that contribute to keratinocyte differentiation and keratin assembly. Dithiothreitol (DTT) acts by disrupting the disulfide bonds that stabilize the keratin filament structure, leading to the breakdown of the filament network. Formaldehyde is known to form cross-links with keratin proteins, which interferes with the normal assembly of keratin filaments into their higher-order structures. Lithium chloride impacts signaling pathways by inhibiting GSK-3, a kinase involved in numerous cellular processes including those that regulate keratin gene expression. Methotrexate targets rapidly dividing cells and can alter the production of keratins by affecting cell proliferation.
Phorbol esters, through the activation of PKC, can modify keratin phosphorylation states, which are crucial for filament organization and stability. Retinoic acid is a well-known modulator of skin cell differentiation and can change the pattern of keratin expression in keratinocytes. Selenium sulfide indirectly influences keratinization by altering the environment of the scalp, which can have downstream effects on keratin structure and function. Staurosporine broadly targets protein kinases, which play a role in various signaling pathways, some of which may govern keratin dynamics. Tunicamycin disrupts N-linked glycosylation leading to cellular stress responses that can affect the expression levels of keratins. Urea is a denaturant that can break hydrogen bonds within keratin proteins, leading to the disassembly of the filament structure.