Epidermal Barrier Flashcards
___________________ provides the cohesivity and resiliency to the stratum corneum
gamma-glutamyl link resulting from transglutaminase activity
___________ form essential component of epidermal permeability barrier
lamellar granules and inter-corneocyte lipids
What happens within lamellar bodies when granular keratinocytes mature to the SC
Enzymes release non-polar lipids (cholesterol, FFA, ceramides) from their polar precursors (phospholipids, glucosyl ceramides, cholesterol sulfate) to form epidermal permeability barrier.
What must happen to corneodesmosomes for normal desquamation?
must be degraded by specialized proteases and glycosidases (mainly serine proteases)
Filaggrin is stored in
Keratohyalin granules
NMF is a collection of ____________ compounds derived from _____________
water-soluble
filaggrin hydrolysis
SC hydration level controls:
- Protease that hydrolyzes filaggrin
- Histidase for histidine–>urocanic acid
_________ is responsible for the water-holding capacity of SC
NMF
2 characteristics of SC responsible for protection from toxins
- highly resilient and cross-linked protein coat of corneocytes
- lipid enriched intercellular domains
What plays a regulatory role in control of desquamatory process
protease/protease inhibitors
which type of melanin is most protective to UV
eumelanin
2 factors contributing to decreased photocarcinogenesis in individuals with darker skin
- decreased DNA damage
- more efficient removal of UV-damaged cells
______________ acts as an endogenous sunscreen (in addition to melanin)
trans-urocanic acid, which is in produced in SC as a product of histidine deamination
Acidity of the outermost SC is maintained by
- formation of FFA from phospholipids
- sodium proton exchangers in SC
- conversion of histidine–>urocanic acid
Tape stripping methods can quantify
SC integrity/desquamation
efficacy of treatment with moisturizers/emollients to improve hydration and reduce scaling
