Related Experiment Video
Updated: Jun 25, 2026
08:49
Cultivating a Three-dimensional Reconstructed Human Epidermis at a Large Scale
Published on: May 28, 2021
Les enzymes de l'espace extra-cellulaire du stratum corneum
1Université Paul Sabatier-Sciences, Bat 4R1, 118 route de Narbonne, 31062 Toulouse Cedex, France.
International Journal of Cosmetic Science
|March 11, 2009
Summary
The stratum corneum
Area of Science:
- Dermatology and biochemistry
- Skin barrier function
- Extracellular enzyme activity
Background:
- The stratum corneum, despite containing dead cells, exhibits significant extracellular metabolic activity.
- This activity is driven by enzymes secreted by Odland bodies, alongside ceramide bilayers.
- These extracellular hydrolases are similar to lysosomal enzymes.
Purpose of the Study:
- To investigate the roles of extracellular enzymes in the stratum corneum.
- To understand the transformation of lipid bilayers and corneocyte cohesion.
- To explore potential applications in cosmetology and future research directions.
Main Methods:
- Enzyme activity profiling in the stratum corneum.
- Analysis of lipid and protein components.
- Estimation of pH in the stratum corneum base.
Main Results:
- Identified key hydrolase activities including glycosidases, phospholipase, sphingomyelinase, phosphatase, esterases, sulfatases, and proteases.
- These enzymes facilitate the transformation of glucoceramide bilayers to more lipophilic ceramide bilayers.
- Enzymatic activity may reduce corneocyte cohesion and aid in foreign body removal.
Conclusions:
- Extracellular enzymes in the stratum corneum play crucial roles in skin barrier maintenance and lipid processing.
- Understanding these enzymes offers potential for cosmetic applications and future research into skin health.
- The pH at the base of the stratum corneum is estimated to be around 5.
Related Concept Videos
01:24Cells of the Epidermis
The epidermis is made of four or five layers of epithelial cells, depending on its location in the body. From deep to superficial, these layers are the stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum.
The cells in all these layers except the stratum basale are called keratinocytes, a type of cell that manufactures and stores the protein keratin. The keratinocytes in the stratum corneum are dead and regularly slough away, being replaced by cells from...
The cells in all these layers except the stratum basale are called keratinocytes, a type of cell that manufactures and stores the protein keratin. The keratinocytes in the stratum corneum are dead and regularly slough away, being replaced by cells from...
01:21Layers of the Epidermis
The epidermis, the outermost layer of the skin, is composed of several distinct layers. From deep to superficial, the layers of the epidermis are as follows:
Stratum Basale
Stratum basale, also known as the stratum germinativum, is the deepest layer of the epidermis. It is composed of a single layer of actively dividing cells called basal cells or basal keratinocytes. These cells constantly undergo cell division to replenish the upper layers of the epidermis. Additionally, melanocytes, which...
Stratum Basale
Stratum basale, also known as the stratum germinativum, is the deepest layer of the epidermis. It is composed of a single layer of actively dividing cells called basal cells or basal keratinocytes. These cells constantly undergo cell division to replenish the upper layers of the epidermis. Additionally, melanocytes, which...
01:12Renewal of Skin Epidermal Stem Cells
The skin is divided into epidermis, dermis, and hypodermis, the skin's outermost, middle, and inner layers. The human epidermal layer regularly undergoes renewal, where old, dead cells are replaced by new cells. Epidermal stem cells or EpiSCs divide and differentiate to restore the lost cells. For the renewal process, some EpiSCs continuously self-renew. In contrast, few others differentiate into transit-amplifying cells, which later form prickle or spinous cells, followed by granular cells,...
01:31Lysosomes
Lysosomes are membrane-enclosed spherical sacs derived from the Golgi apparatus. The most important function of the lysosome is degrading macromolecules and biological polymers that are released during membrane trafficking events such as the secretory, endocytic, autophagic, and phagocytic pathways. The degradation is carried out by several hydrolytic enzymes active in an acidic environment of the lysosomal lumen. These acid hydrolases are involved in cellular processes such as cell signaling,...
01:05Desmosomes
The term desmosome derives from the Greek words "desmo" and "soma" meaning "adhesion bodies." This structure was first observed during the late 1800s and described as small, dense nodules in the epidermis. Desmosomes are button-like structures that help form an interlinked network of intermediate filaments across the cells. These junctions are essential to hold cells together under mechanical stress and to maintain tissue integrity. Desmosomes are multi-protein complexes comprising desmosomal...
01:18Surface Membrane Barriers
The skin and mucous membranes serve as the primary line of defense against pathogens by providing both physical and chemical protection. These barriers are essential in preventing the entry and establishment of microbes, thereby maintaining the integrity of the host.
The outer layer of the skin, the epidermis, is a robust barrier comprising layers of closely packed keratinized cells. This dense arrangement prevents microbes from penetrating the body. The periodic shedding of epidermal cells...
The outer layer of the skin, the epidermis, is a robust barrier comprising layers of closely packed keratinized cells. This dense arrangement prevents microbes from penetrating the body. The periodic shedding of epidermal cells...