Re-epithelialization is a key event in wound healing and any impairment in that process is associated with various pathological conditions. Epidermal keratinocyte migration and proliferation during re-epithelialization is largely regulated by the cytokines and growth factors from the provisional matrix and dermis. Extracellular matrix consists of numerous growth factors which mediate cell migra...

Insulin-like growth factor-I (IGF-I) activation of phosphoinositol 3-kinase (PI3K) is an essential pathway for keratinocyte migration that is required for epidermis wound healing. We have previously reported that activation of Galpha((q/11))-coupled-P2Y(2) purinergic receptors by extracellular nucleotides delays keratinocyte wound closure. Here, we report that activation of P2Y(2) receptors by ...

Delayed wound healing caused by inefficient re-epithelialization underlines chronic skin lesions such as those found in diabetes. The dioxin receptor (AhR) modulates cell plasticity and migration and its activation by occupational polycyclic aromatic hydrocarbons (PAHs) results in severe skin lesions such as contact hypersensitivity, dermatitis and chloracne. Using wild-type (Ahr+/+) and AhR-nu...

Apoptosis is a physiological process of programmed cell death responsible for homeostasis in the body. In skin, apoptotic process regulates keratinocyte proliferation and differentiation in that way maintaining homeostasis of epidermal compartment. The process of apoptosis is controlled by proteins of the Bcl-2 family, several proapoptotic (Bax, Bak, Bad) and antiapoptotic (Bcl-2, Bcl-x(L)) pro...

A plethora of growth factors regulate keratinocyte proliferation and differentiation that control hair morphogenesis and skin barrier formation. Wavy hair phenotypes in mice result from naturally occurring loss-of-function mutations in the genes for TGF-alpha and EGFR. Conversely, excessive activities of TGF-alpha/EGFR result in hairless phenotypes and skin cancers. Unexpectedly, we found that ...

BACKGROUND When treating extensively burned patients using cultured epidermal sheets, the main problem is the time required for its production. Conventional keratinocyte isolation is usually done using Trypsin. We used a modification of the conventional isolation method in order to improve this process and increase the number of colonies from the isolated epidermal cell population. PURPOSE To...

Maintenance of oral epithelial homeostasis requires a fine balance between cell proliferation and differentiation. However, the molecular mechanisms that couple these processes, and its deregulation in tumorigenesis are not fully understood. Cyclin D1 and its kinase partners CDK4 and CDK6 play an important role in regulating the G1-S phase of the cell cycle. Deregulation of cyclin D1 is a frequ...

Epidermal morphogenesis results from a delicate balance between keratinocyte proliferation and differentiation, and this balance is perturbed upon deletion of transcription factor Ctip2. Here we demonstrate that Ctip2, in a cell autonomous manner, controls keratinocyte proliferation and cytoskeletal organization, and regulates the onset and maintenance of differentiation in keratinocytes in cul...

Keratinocytes constitute the majority of cells in the skin's epidermis, the first line of defence against percutaneous pathogens. Schistosome larvae (cercariae) actively penetrate the epidermis to establish infection, however the response of keratinocytes to invading cercariae has not been investigated. Here we address the hypothesis that cercariae activate epidermal keratinocytes to promote th...

Received February 9, 2005; revision accepted for publication June 21, 2005. Correspondence: Misa Yamamoto, MT (Medical Technologist), CT (Cytologist), Faculty of Health Sciences, Yamaguchi University School of Medicine, MinamiKogushi 1-1-1, Ube, Yamaguchi, 755-8554, Japan. e-mail: [email protected] Fibrin Stimulates the Proliferation of Human Keratinocytes through the Autocrine Mechani...