The skin's pigment cells can be formed from completely different cells than has hitherto been thought, a new study from the Swedish medical university Karolinska Institutet shows. The results, which are published in the journal Cell, also mean the discovery of a new kind of stem cell.
The body's pigment gives essential protection against UV radiation. It is made up of a substance called melanin, which is produced by pigment cells in the skin called melanocytes. According to the established theory of body pigmentation, these melanocytes bud off from the spinal cord at an early foetal stage and then migrate to the skin where they remain for the rest of their lives.
Scientists at Karolinska Institutet in Stockholm have now shown that most melanocytes actually appear later on in foetal development from an immature cell type that exists in the skin's nerve fibres. These cells, called Schwann cell precursors (SCPs), can also be found in adults. In addition to this, the scientists have demonstrated how neuronal damage in adults can excite the maturation of melanocytes to form hyperpigmentation around the affected nerves.
"Our findings can provide new knowledge of how changes in skin pigmentation occur, not least of the links that have been observed between neurological disease and changes in pigmentation," says Professor Patrik Ernfors, who led the study.
Their results also shed new light on SCP cells, which were previously seen as an immature form of supportive cells the nervous system. The researchers describe how a change in cell signalling can make the SCP cells in the skin develop into pigment cells instead, and argue that SCP cells are really a kind of stem cell.
"This can help science to understand the development of diseases such as melanoma," says Professor Ernfors. "We ve always believed that it develops from melanocytes, but maybe it actually originates in the SCP cells."
FAQs
Pigment cells in developing vertebrates are derived from a transient and pluripotent population of cells called neural crest. The neural crest delaminates from the developing neural tube and overlying ectoderm early in development. The pigment cells are the only derivative to migrate along the dorso-lateral pathway.
What cells make skin pigment? ›
Melanin is produced by specialized cells called melanocytes. Melanocytes are scattered among other cells in the deepest layer of the outer layer of the skin (epidermis) called the basal layer. After melanin is produced, it spreads into other nearby skin cells.
What makes skin cells different from other cells? ›
Skin cells are specialized to be quickly shed and replaced, and do not have much mitochondria (which helps produce energy). Muscle cells, conversely, have lots of mitochondria because they need energy to produce movement. See the images below for more info on skin and muscle cells' shape and general appearance.
How does pigmentation form? ›
Sun Exposure. Sun exposure is a common cause of skin pigmentation. The body produces more melanin, in order to defend itself against UV rays from the sun. This may make the skin more pigmented, to shield it from the sun's rays.
How do you get pigment cells? ›
To boost melanin naturally, focus on a balanced, nutrient-rich diet. This includes antioxidant-rich foods, foods high in copper, and vitamins A and E. Besides, manage stress, guard your skin and hair against too much sun, and limit chemical treatments. This could help keep melanin levels in your hair high.
How are pigments formed? ›
Synthetic organic pigments are derived from coal tars and other petrochemicals. Inorganic pigments are made by relatively simple chemical reactions—notably oxidation—or are found naturally as earths. Inorganic pigments include white opaque pigments used to provide opacity and to lighten other colours.
How are skin cells formed? ›
The epidermis is made up of several 'sheets' of cells. The bottom sheet is where new epidermal cells are made. As old, dead skin cells are sloughed off the surface, new ones are pushed up to replace them. The epidermis also contains melanin, the pigment that gives skin its colour.
How are cells formed different from each other? ›
During meiosis, a small portion of each chromosome breaks off and reattaches to another chromosome. This process is called "crossing over" or "genetic recombination." Genetic recombination is the reason full siblings made from egg and sperm cells from the same two parents can look very different from one another.
How long does it take for skin cells to regenerate? ›
The epidermis constantly renews itself: New cells are made in the lower layers of the epidermis. These move to the surface within four weeks. This constant renewal serves to replace the cells that are lost and fall to the ground as tiny flakes of skin when the skin is rubbed.
Can you develop skin pigmentation? ›
The biggest risk factors for general hyperpigmentation are sun exposure and inflammation, as both situations can increase melanin production. The greater your exposure to the sun, the greater your risk of increased skin pigmentation.
If your body makes too much melanin, your skin gets darker. Pregnancy, Addison's disease, and sun exposure all can make your skin darker. If your body makes too little melanin, your skin gets lighter. Vitiligo is a condition that causes patches of light skin.
What is the origin of skin pigmentation? ›
Human skin pigmentation is the product of two clines produced by natural selection to adjust levels of constitutive pigmentation to levels of UV radiation (UVR). One cline was generated by high UVR near the equator and led to the evolution of dark, photoprotective, eumelanin-rich pigmentation.
What are pigment cells derived from? ›
Most vertebrate pigment cells—melanocytes in mammals and birds, supplemented by two or more other pigment cell types in other vertebrates—are derived from the neural crest.
How does pigment develop? ›
Melanin is produced by cells called melanocytes in a process called melanogenesis. Melanin is made within small membrane–bound packages called melanosomes. As they become full of melanin, they move into the slender arms of melanocytes, from where they are transferred to the keratinocytes.
How does the body produce pigment? ›
Special cells called melanocytes make melanin. Everyone has the same number of melanocytes, but some people make more melanin than others. If these cells make just a little melanin, your hair, skin, and eyes can be very light. If your cells make more, then your hair, skin, and eyes will be darker.
What is pigment produced by? ›
In general, pigments are secondary metabolites produced by microbes and are not necessarily produced by all kinds of microorganisms. Cold-adapted bacteria and fungi inhabiting cryospheric environments produce a diverse range of pigments (Table 1).
