What is keratinocyte apoptosis?
Keratinocyte (KC) apoptosis plays a critical role in regulating epidermal development and restraining carcinogenesis. Apoptosis balances proliferation to maintain epidermal thickness, contributes to stratum corneum formation and may eliminate pre-malignant cells.
How do keratinocytes differentiate?
Keratinocytes proliferate in the basal layer of the epidermis and start differentiating on their way to the surface, undergoing gradual differentiation. During this process, they profoundly change their morphology and start to produce keratin, cytokines, growth factors, interleukins and complement factors.
Do keratinocytes undergo apoptosis?
Apoptosis of keratinocytes occurs not only during normal keratinization but also in response to various intracellular or extracellular death stimuli, such as genetic defects or UVB.
What triggers keratinocyte differentiation?
Calcium is the major regulator of keratinocyte differentiation in vivo and in vitro. A calcium gradient within the epidermis promotes the sequential differentiation of keratinocytes as they traverse the different layers of the epidermis to form the permeability barrier of the stratum corneum.
What do keratinocytes produce?
Keratinocytes are the predominant cell type of epidermis and originate in the basal layer, produce keratin, and are responsible for the formation of the epidermal water barrier by making and secreting lipids.
What happens if keratinocytes are damaged?
Upon damage the keratinocytes initiate a pro-inflammatory signaling cascade that leads to the activation of resident immune cells. Simultaneously, the tissue mediates and supports immune-suppressive functions to contain inflammation locally.
What are the keratinocytes?
Keratinocytes are the most prominent cell within the epidermis. Keratinocytes are ectodermally derived and can be distinguished from melanocytes and Langerhans cells in the epidermis by their larger size, intercellular bridges, and ample cytoplasm. Keratinocytes are present in all four layers of the epidermis.
How is keratinocytes formed?
In the basal layer of the skin, the innermost stratum, a basal keratinocyte has just divided by mitosis to form a new basal keratinocyte. This new cell starts to divide itself and produces many more keratinocytes.
What are keratinocytes?
What is the role of the keratinocytes?
As the most dominant cell type constituting the epidermis, keratinocytes play multiple roles essential for skin repair. They are the executors of the re-epithelialization process, whereby keratinocytes migrate, proliferate, and differentiate to restore the epidermal barrier.
How are keratinocytes formed?
What are keratinocytes quizlet?
Keratinocytes are the normal structural components of the epidermis. Differentiate in the stratum basale and die in the stratum granulosum.
What is the role of apoptosis in keratinocytes?
Abstract Keratinocyte (KC) apoptosis plays a critical role in regulating epidermal development and restraining carcinogenesis. Apoptosis balances proliferation to maintain epidermal thickness, contributes to stratum corneum formation and may eliminate pre-malignant cells.
How does ultraviolet B irradiation induce apoptosis of keratinocytes?
Takahashi H, Ishida-Yamamoto A, Iizuka H. Ultraviolet B irradiation induces apoptosis of keratinocytes by direct activation of Fas antigen. J Investig Dermatol Symp Proc. 2001a;6:64–68. [PubMed] [Google Scholar] Takahashi H, Honma M, Ishida-Yamamoto A, Namikawa K, Miwa A, Okado H, et al.
What are the survival (antiapoptotic) pathways in keratinocytes?
Figure 2 Survival (antiapoptotic) pathways in keratinocytes The two primary survival pathways involve activation of a mitogen-activated protein kinase (MAPK) cascade and activation of Akt.
Which keratinocytes are resistant to apoptosis in psoriatic plaques?
Wrone-Smith T, Mitra RS, Thompson CB, Jasty R, Castle VP, Nickoloff BJ. Keratinocytes derived from psoriatic plaques are resistant to apoptosis compared with normal skin. Am J Pathol. 1997;151:1321–1329.