๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
Introduction
Kim B. Yancey The Biology of the Basement Membrane 28
Chapter Contents
Basal Keratinocytes: Hemidesmosome-Anchoring
Synonyms:๏ก Bullous pemphigoid antigen 1: BP230; dystonin ๏กย Bullous pemphigoid antigen 2: BP180; type XVII collagen ๏ก Laminin 311: laminin 6 ๏ก Laminin 332: laminin 5; epiligrin; kalinin; nicein; GB3 antigen; BM600 ๏ก Laminin 511: laminin 10 ๏ก Type VII collagen: the epidermolysis bullosa acquisita antigen ๏ก Nidogen: entactin
Key features
ยBasement membranes serve as: (1) a substrate for cell attachment;
(2) a template for tissue repair; (3) a matrix for cell migration; (4)ย a foundation for an infrastructure that influences differentiation, morphogenesis, and apoptosis of epithelial cell layers; and (5) a permeability barrier for cells and macromolecules
ยThe ultrastructural subregions of the epidermal basement membrane are: (1) basal keratinocytes with their cytoskeletons, hemidesmosomal plaques, and plasma membranes; (2) the lamina lucida, an electron-lucent region containing anchoring filaments; (3) the lamina densa; and (4) the sublamina densa region of the papillary dermis
ยIn the โlaminatedโ model of the epidermal basement membrane, keratin intermediate filaments within basal keratinocytes attach to hemidesmosomes at the basal plasma membranes. Anchoring filaments connect hemidesmosomes to the lamina densa. The lamina densa is tethered to the dermis by anchoring fibrils that begin and end on the underside of the lamina densa, forming ultrastructural loops that also serve as attachment sites for fibrillar proteins in the papillary dermis
ยAcquired or inherited abnormalities in structural proteins within the epidermal basement membrane often result in a disease phenotype characterized by blister formation