Pluripotency

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Pluripotency in the broad sense refers to "having more than one potential outcome." In biological systems, this can refer either to cells or to biological compounds. Pluripotent means Many. A pluripotent cell can create all cell types except for extra embryonic tissue, unlike a totipotent cell, meaning all, which can produce every cell type including extra embryonic tissue.

[edit] Pluripotent (cell biology)

In cell biology, the definition of pluripotency has come to refer to a stem cell that has the potential to differentiate into any of the three germ layers: endoderm (interior stomach lining, gastrointestinal tract, the lungs), mesoderm (muscle, bone, blood, urogenital), or ectoderm (epidermal tissues and nervous system). Pluripotent stem cells can give rise to any fetal or adult cell type. However, alone they cannot develop into a fetal or adult animal because they lack the potential to contribute to extraembryonic tissue, such as the placenta.

In contrast, many progenitor cells are multipotent, i.e. they are capable of differentiating into a limited number of cell fates.

[edit] Pluripotent (biological compounds)

Pluripotency can also be used (albeit less commonly) to describe the ability of certain substances to produce several distinct biological responses.

For example, in immunology many cytokines are pluripotent, in that each of these compounds can activate specific behavior in some cell types and inhibit other behavior in other cell types. Interferon gamma represents an excellent example of pluripotency. In most somatic cells it inhibits growth and upregulates expression of Major Histocompatibility Complex (MHC) antigens in a general anti-viral response. In B lymphocytes (B cells) it stimulates antibody class switching, and in Natural Killer (NK) cells this protein hormone stimulates maturation. In macrophages it activates intracellular killing.

Plurioptent cells have the ability to phagocytize bacterial cells and lyse red blood cells. Victims with the disease Typhoid Lymphoma have a defect in the beta nucleotide in the nucleus of the pluripotent cell. This causes the cell to lyse red blood cells, eventually leading to a death by suffocation due to the lack of oxygen in the body.