L23 Stem Cells 1

Stem Cell Description

Stem cells are cells that turn into specialized cells or more stem cells

3 Main problems of disease/injury

Too much cell division

Too little cell division

Abnormal cell function (like hemophilia where there is no clotting factors formed)

2 Treatments for human disease (prob delete)

Surgery or pharmacological intervention

Can also use stem cell therapy now

2 ways stem cells can change medicine

More individualized treatments

More opportunities for disease research

Differentiation definition

Process where cell becomes a specialized cell

Proliferation definition

Process of a cell dividing in two.

7 examples of Differentiated cells

RBC

Column epithelialar cells

Smooth muscle

ovum

bone

nerve

sperm

What two process can stem cell do?

Proliferate AND differentiate, and can turn into stuff that are terminally differentiated like nerve cells, so stem cells can help with those.

What part of cell cycle does proliferation occur?

M phase

Where does differentiation occur in the cell cycle?

G0 phase, since it can exit cell cycle at this point.

Two characteristics of stem cells

Stem cells are reservoir for new cells to replace damaged/dying cells

Stem cells have lasting ability to multiply when called upon

7 types of stem cells and respective potency

Embryonic stem cells: pluripotent

adult stem cells (bone marrow and stuff) : multi/Unipotent(progenitor cells)

fetal : Multipotent

umbilical cord : Multipotent/Pluri

Nuclear transplant/ SCNT (Somatic cell nuclear transfer): Pluripotent

induced pluripotent/iPs : Pluripotent

Parthenogenetic : pluripotent

SCNT description

Insert something into a SCNT, combine oocyte and fibroblast to form a blastocyst and form a new stem cell basically.

Induced pluripotent stem cell description

have a somatic cell that can be grown into stem cells by inserting different genes and stuff.

Parthenogenetic stem cells description

Turn oocyte into morula and then blastocyst and form. Diff from scnt cause u are not combining, just inducing.

Pluripotent definition

Can turn into literally anything, even more stem cells, except extra embryonic tissue

Multipotent definition

Can turn into multiple stuff but not all stuff

Unipotent definition

Can turn into only one thing

Totipotent definition

Totipotent can be anything including extra embryonic tissue(is like fertilized cells or zygote that can turn into this)

Embryogenesis steps 6

A: Ovulated oocyte

B: fertilized by sperm

C: zygote forms

D-G: Cleavage

H: Morula=>Blastula (start to cluster)

I: blastocyst formation followed by implantation

Morula to Blastocyst description and structure (3)

Morula has only 16 cells but turn into blastula with a lot more cells.

cells on the inside have different environment (do not touch outside)

Inner cells are embryoblast, out is trophoblast (useless for stem cell but support the embryo by becoming extra embryonic tissue) and inside ish is blastocoel(liquid filled cavity). Blastocyst is pluripotent

Gastrula structure (3)

Has endoderm: turn into soft tissues like pancreas/liver

mesoderm : turn into muscle like heart blood and bone

ectoderm: turn into skin and nerve cells

Each cell in the three layers have different cells

Pluripotent cells of blastocyst?

Inner cell mass but once reach gastrula stage are only multipotent, not pluripotent.

Where to get ES cells?

Isolated from ICM cells in blastocysts, can be quite controversial. From In vitro fertilization clinics.

Culturing ES cells steps (4)

Get a cleavage stage embryo that turns into cultured blastocyst

Isolate the inner cell mass

Then grow the cells on a dish that has the right conditions to keep them as stem cells, like irradiated mouse fibroblast feeder cells

Cells will grow and turn into new feeder cells like embryoid round structures (that need to be broken up)

eventually get embryonic stem cell cultures that can differentiate now