Keratohyalin
Encyclopedia
Keratohyalin is a protein structure found in granules in the stratum granulosum
of the epidermis, which may be involved in keratinization, and in Hassall corpuscles in the thymus
.
In H&E stain
ed sections, they are large deeply stained granules found in the cytoplasm
of epithelial cells in keratinized oral mucosa.
Keratohyalin is associated with eleidin
, the intermediate between keratohyalin and keratin; histological location is in the stratum lucidum, thick skin.
In the stratum granulosum
, the "grainy" third layer of the human epidermis, the protein
Keratohyalin forms dense cytoplasmic granules that promote dehydration
of the cell
as well as aggregation and cross-linking of the keratin
fibers. The nuclei
and other organelles then disintegrate, and the cells die. Further dehydration creates a tightly interlocked layer of cells that consists of keratin fibers surrounded by keratohyalin.
Stratum granulosum
The stratum granulosum is a thin layer of cells in the epidermis. Keratinocytes migrating from the underlying stratum spinosum become known as granular cells in this layer...
of the epidermis, which may be involved in keratinization, and in Hassall corpuscles in the thymus
Thymus
The thymus is a specialized organ of the immune system. The thymus produces and "educates" T-lymphocytes , which are critical cells of the adaptive immune system....
.
In H&E stain
H&E stain
H&E stain, HE stain or hematoxylin and eosin stain is a popular staining method in histology. It is the most widely used stain in medical diagnosis; for example when a pathologist looks at a biopsy of a suspected cancer, the histological section is likely to be stained with H&E and termed H&E...
ed sections, they are large deeply stained granules found in the cytoplasm
Cytoplasm
The cytoplasm is a small gel-like substance residing between the cell membrane holding all the cell's internal sub-structures , except for the nucleus. All the contents of the cells of prokaryote organisms are contained within the cytoplasm...
of epithelial cells in keratinized oral mucosa.
Keratohyalin is associated with eleidin
Eleidin
Eleidin is clear intracellular protein which is present in the stratum lucidum of the skin.Eleidin is a transformation product of the amino acid complex keratohyalin, the lifeless matter deposited in form of minute granules within the protoplasm of living cells. Eleidin is then converted to keratin...
, the intermediate between keratohyalin and keratin; histological location is in the stratum lucidum, thick skin.
In the stratum granulosum
Stratum granulosum
The stratum granulosum is a thin layer of cells in the epidermis. Keratinocytes migrating from the underlying stratum spinosum become known as granular cells in this layer...
, the "grainy" third layer of the human epidermis, the protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
Keratohyalin forms dense cytoplasmic granules that promote dehydration
Dehydration
In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...
of the cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
as well as aggregation and cross-linking of the keratin
Keratin
Keratin refers to a family of fibrous structural proteins. Keratin is the key of structural material making up the outer layer of human skin. It is also the key structural component of hair and nails...
fibers. The nuclei
Cell nucleus
In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...
and other organelles then disintegrate, and the cells die. Further dehydration creates a tightly interlocked layer of cells that consists of keratin fibers surrounded by keratohyalin.