Stem Cell Glossary & Terms
Pluripotent Stem Cells – Pluripotent stem cells are early stage cells that can become any type of cell in the body. They come from blastocysts leftover from infertility treatments that would otherwise be destroyed. Smaller than the point of a needle, these blastocysts are grown in a Petri dish. They are small clumps of cells, 5 to 7 days old — long before a fetus would be formed.
Cord Blood Stem Cells – Cord blood stem cells are recovered at birth from the umbilical cord.Even though they come from a newborn infant, they are still limited like adult stem cells.Unlike adult stem cells, they can grow indefinitely in culture, giving researchers a limitless supply, enough to create tissue or disease models.
Adult Stem Cells – Adult stem cells are found in some, but NOT all of the body’s mature tissues.Unlike pluripotent stem cells, they can only make the limited types of cells found in the tissue in which they reside. For example, adult stem cells from the liver can only make more liver cells. They can ONLY give rise to blood cells and a few other cell types.
iPS Cells – Induced pluripotent stem cells (iPS cells) are produced by artificially “turning back the clock” of adult cells to a more embryonic-like state. iPS cells have many characteristics of embryonic stem cells, but they are not identical. This breakthrough technology is very useful for research, such as creating disease models in a dish, but does NOT reduce the need for embryonic stem cells.
SCNT – Somatic cell nuclear transfer (SCNT) is a method for generating embryonic stem cells.Stem cells generated by SCNT are the gold standard for stem cell research
In this technique, the nucleus of an egg cell is removed and replaced with the nucleus of an adult cell, like a skin or blood cell.
Differentiation – A process that occurs during development by which cells take on their specialized functions, such as the ability of a red blood cell to carry oxygen or a nerve cell to send an electrical signal.
Blastocyst – An early stage embryo, about 5 days old. A blastocyst is a microscopic clump of about 150 cells. It is produced from an egg that has been fertilized in vitro but has not yet been implanted in the uterus. The blastocyst is about the same size as the cross section of a human hair.
Self-Renewal – The ability of a stem cell to produce more stem cells with identical characteristics as the “parent” cell.
Parthenogenesis – The activation of an unfertilized egg by chemical means. These chemical signals cause the egg to begin to divide much as it would after normal fertilization. Scientists believe that these dividing cells could also be used to derive embryonic stem cells. However, these embryonic stem cells would carry the genes from only the woman from whom the unfertilized eggs were retrieved.
Other Useful Terms
Haplotype – a group of genes or alleles usually inherited together from a single parent, reflecting the haploid genotype
HLA Haplobank – a panel or repository of iPSC lines that are homozygous for HLA types and could be used to derive immunologically-compatible tissues for therapeutic transplantation
Mitochondria – subcellular organelles that generate chemical energy to power cellular processes and also serve as sites for numerous metabolic processes and reactions
Mitochondrial replacement – a potential therapy to prevent certain mitochondrial diseases by replacing mutant maternal mitochondria in an oocyte (egg) with those from an unaffected individual prior to in vitro fertilization
Genomic modification – stable, intentional and directed change of a cell’s DNA sequence using biotechnology methods
CRISPR/Cas – a biotechnology tool, utilizing components of a prokaryotic immune system, for making highly specific genomic modifications
RNA-Seq – an analytical method that can reveal the identities and quantities of RNAs expressed from genes in a cellular sample
Disease-in-a-dish – a human disease model comprised of cultured cells displaying properties of diseased tissue. Many such models are generated using cells differentiated from iPSCs derived from individuals with a specific disease
Paracrine – influence or signaling by a cell on nearby cells or tissues through localized secretion and diffusion of small molecules or proteins
Investigational New Drug Application (IND) – a key step in development of a new drug or medical treatment in which the US Food and Drug Administration (FDA) is notified that a novel therapeutic will be used experimentally
Stem Cell Tourism – seeking or receiving stem-cell based treatments for disease or injury from clinics or practitioners that offer untested or unproven therapies