CGRP (Calcitonine Gene Related Peptide)
Secreted with substance P, that peptid has a high vasodilatative effect ; it transmits the sensation of pain.
As protein fibers or glycoproteins, they are dermis proteins and give dermis its resistance to tractions and tensions. There are lots of types of collagens in dermis and in other parts of human body.
EDRF or Endothelium Derived Relaxing Factor
It is a subtance, nitric oxide, produced by endothelial cells and that induces vasodilatation. It is used to measure the level of inflammation.
It is a protein fibre from the extra-cell matrix. It gives elasticity to dermis.
Extra-cell matrix (of skin)
Located in the dermis, it represents all the fibers and protein gels, like proteoglycans, glycosaminoglycans, collagens and elastin, synthetized by fibroblasts, the main cells of dermis.
A protein coming from the fragmentation of a molecule, profilaggrin, which can be found in keratinocyts of the granular layer. It allows the aggregation of filaments of keratin and takes part of the creation of the cell envelope of the corneal layer. It also takes part in the function of the skin barrier. Therefore it is used to measure the keratinocyt differentiation.
Important components of conjunctive tissues, they are acids that are very strong capacities in water retention. There are many GAG, including hyaluronic acid very used for its hydrating properties.
Heat Shock Proteins
These are proteins synthetized by animal cells when they get stressed or shocked. They are a manifestation of cell suffering: the higher their expression is, the more cells suffer. HSP70 are considered as significant marker to measure an environmental pollution
Icam1 (intercellular adhesion molecule 1)
It is a gene that makes intercell relations easier or that stabilizes intercell adhesion. According to the latest studies, it would play an important part in the inflammation processes by inducing the producion of immune cells, like macrophages and granulocyts.
There are many chemicals mediators that are synthetized by animal cells. They induce inflammation phenomenae, like pain, fever, vasolidattaion, etc. In skin inflammation phenomenae, the rate of expression of cytokins is measured. Cytokins are peptide soluble factors that act at a low level of concentration, near the place where they have been synthetized ; they are communication agents.
Ex : interleukins, Tumor Necrosis Factor-alpha. Regarding PGE2, it is a lipidic mediator, derived from the phospolipids of the cell membrans. It is necessary to limit the expression of mediators in order to limit the inflammation chain, that can induce damages.
Glycoproteins made by 2 peptide chains, that are located on cell membrans and provide cell adherence.
It is an antigen, a macromolecule that is in the proliferative cells like keratinocyts in the basal layer. Its precise function is not well known yet : it might participate to the proliferative power or to the control of the cell cycle. When present, it indicates the rate of proliferative cells.
Glycoproteins that are located in the basal membran at the level of the dermo-epidermic junction and that interfere in the adherence between dermis and epidermis. These are fibers involved into the dermoepidermal anchorage.
They are the fourth cell type that can be found in epidermis (with keratinocyts, melanocyts and Merkel cells). Those dendritic cells play an important part in the skin immune system: they surround keratinocyts and control the presence of antigens, that can generate an immune response.
MDA or MalhondialdehydAn aldehyd, a product made from the lipidic peroxidation, when polyinsatured fatty acids are destructured by free radicals. It is used to measure oxidative stress in skin cells.
It is a pigment, a macromolecule, produced by melanocyts and responsible for the color of skin. Its function consists in protecting skin (the DNA of cells) against radiations of UV it absorbs by releasing them in the form of energy.
They are essential components of the extra-cell matrix. They are the result of a combination of a protein and a GAG. As they are made of long O-glycolized chains, they are like « water traps ». There are many types of proteoglycans.
It is a neuro-peptide that has functions of a neurotransmetor and aneuromodulator at the level of the peripheral nervous system, it plays also a part in the immune regulation. At the level of skin, it is an element in the process of local neuro-inflammation.
TNF-alpha (tumor necrosis factor)
It is a cytokin produced by macrophages, that works in the inflammation systemic process and the phase of acute reaction. It can be released by leucocyts, endothelial cells and other tissues as an answer to a damage.
As a chemical point of view, 3H204 (or heavy water) is a form of water where all of a few atoms of hydrogen has been replaced by tritium. 3H204 pure is very radioactiv. It is used to measure the quantity of water (H20) in the epidermis.
It is an enzyme, that catalyses the production of melanin and other pigments by oxidation from tyrosin, an amino acid, from which melanin is made.