BIOL10002 Lecture Notes - Lecture 27: Mesenchymal Stem Cell, Petri Dish, Smooth Muscle Tissue
Lecture 27: Stem cells
Specialized cells in organs & tissues, can turn into different types of
cells depending on environment
Divides into daughter cells that can be two more stem cells, or one
stem cell & different type of daughter cell (specialized cell)
Potency: what types of cells can be made, the ability of a stem cell to
differentiate into different cell types
Totipotent: can become any kind of cell/whole organism: fertilized egg
(zygote)
Pluripotent: all cell types of an embryo: blastocyst
Multipotent: can become many kinds of cells: hematopoietic stem cells
from bone marrow, placenta
● umbilical cord/blood/stem cells: blood, muscle, bone,
cartilage
● somatic stem cells/adult stem cells: brain, cornea, bone
marrow, gut, skin, liver
Unipotent: oogonia, spermatogonia
Early development in mammals: after fertilization cells divide, continue
to divide, cells start to collapse on themselves to form a compaction,
becomes a blastocyst, outside layer is trophoblast which becomes
placenta, inner mass cells (ICM) contain stem cells
Mesenchymal stem cells (MSC): multipotent cells isolated from the
bone marrow (and connective tissue found in and around tissues &
organs), capable of making bone, cartilage, fat cells, characteristics
depend on where they come from and how they are isolated and
grown, being tested as treatments for many disorders, not fully
understood whether they’re actually stem cells or what types they’re
capable of generating
Difference between somatic/MSC & ES/iPS cells:
● potency: MSC multipotent, ES/iPS cells pluripotent
● somatic tissue stem cells: for most tissues occur in low
numbers, cannot be cultured very long
● ES/iPS: can be kept in culture long term, can be expanded
into large numbers
Immunocompatible designer cells:
unspecialized: can become specialized to: e.g. fat cell, neuron,
macrophage, smooth muscle cell, glial cell
capable of self-renewal
In vitro: culture dish, petri dish, flask, culture wells
cell culture conditions: nutrient rich solution (media), house in
incubator at 37 degrees with 2-20% oxygen, cells grow, divide, can be
induced to become specialized cells
culture dishes are red because phenol red indicator is added to check if
the dish remains at pH 7
Embryonic stem (ES) cells: cells from ICM of blastocyst, immortal, self-
renew, pluripotent
The nucleus of any cell is not programmed permanently/mature cells
can be reprogrammed to become pluripotent
Generating any cell type from a pluripotent cell (ES or iPS) just a matter
of finding the correct signals
Can become any specialized somatic cell spontaneously (a mixture of
cell types) or a by adding combinations of specific signals can make a
particular cell type
Reprogramming somatic cells to ES-like cells (induced pluripotent
stem cells) (iPS cells): transcription factors/genes (yamanaka factors)
added to somatic cells, creates ES stem cells
transcription factors: proteins that go into the nucleus and turn on or
turn off certain gene transcription
somatic cell: any cell of a living organism other than the reproductive
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Specialized cells in organs & tissues, can turn into different types of cells depending on environment. Divides into daughter cells that can be two more stem cells, or one stem cell & different type of daughter cell (specialized cell) Potency: what types of cells can be made, the ability of a stem cell to differentiate into different cell types. Totipotent: can become any kind of cell/whole organism: fertilized egg (zygote) Pluripotent: all cell types of an embryo: blastocyst. Multipotent: can become many kinds of cells: hematopoietic stem cells from bone marrow, placenta. Umbilical cord/blood/stem cells: blood, muscle, bone, cartilage somatic stem cells/adult stem cells: brain, cornea, bone marrow, gut, skin, liver. Embryonic stem (es) cells: cells from icm of blastocyst, immortal, self- renew, pluripotent. Potency: msc multipotent, es/ips cells pluripotent somatic tissue stem cells: for most tissues occur in low numbers, cannot be cultured very long. Es/ips: can be kept in culture long term, can be expanded into large numbers.
