Stem Cell Culture

• Undifferentiated cells found among specialized or differentiated cells in tissue or organ after birth • Have more restricted ability to produce different cell types an to self renew

Adult stem cells

• typically generate the cell types of the tissue in which they reside.

Adult stem cells

• Donated organs and tissues are often used to replace ailing or destroyed tissue • The need for transplantable tissues and organs far outweighs the available supply. • Stem cells, directed to differentiate into specific cell types, offer the possibility of a renewable source of replacement cells and tissues to treat diseases: • including Alzheimer's disease, spinal cord injury, stroke, burns, heart disease, diabetes, osteoarthritis, and rheumatoid arthritis.

Cell Based Therapies:

• Derived from the part of the human embryo or fetus that will ultimately produce eggs or sperms (gametes)

Embryonic germ cells

• Identify how undifferentiated stem cells become the differentiated cells. • Cancer and birth defects, are due to abnormal cell division and differentiation. • A more complete understanding of the genetic and molecular controls of these processes may yield information about how such diseases arise and suggest new strategies for therapy.

Human Development

ability to return to function to damaged cells in the living organism

Repair

• Certain adult cell types can be "reprogrammed" into other cell types in vivo using a well-controlled process of genetic modification • This strategy may offer a way to reprogram available cells into other cell types that have been lost or damaged due to disease

Reprograming:

• New medications could be tested for safety on differentiated cells generated from human pluripotent cell lines. • Other kinds of cell lines are already used in this way. • Cancer cell lines, for example, are used to screen potential anti-tumor drugs. • The availability of pluripotent stem cells would allow drug testing in a wider range of cell types.

Test New Drug Therapy

Each cell can develop into a new individual • Example: Cells from early (1-3 days) embryo

Totipotent

• Certain adult stem cell types can differentiate into cell types seen in organs or tissues other than those expected from the cells' predicted lineage • (i.e., brain stem cells that differentiate into blood cells or blood-forming cells that differentiate into cardiac muscle cells, etc). • This reported phenomenon is controversial.

Transdifferentiation:

During preimplantation stages of development, the embryo goes from a single cell zygote to a multicellular embryo called a

blastocyst

• For example, a blood-forming adult stem cell in the bone marrow = a hematopoietic stem cell • normally gives rise to the many types of ---. • cannot give rise to the cells of a very different tissue, such as nerve cells in the brain.

blood cells

feeder cells consist in a layer of cells unable to divide, which provides extracellular secretions to help another

cell to proliferate.

Under special culture conditions, the cells of the embryonic lines can be coaxed to form certain kinds of differentiated ---. In theory, these differentiated cells could be used to repair or replace defective cells or tissues.

cell types

1. How are embryonic stem cells stimulated to differentiate? (Name 3 ways) To control the differentiation of embryonic stem cells: 1. change the chemical composition of the --- 2. alter the surface of the --- 3. modify the cells by inserting specific --

culture medium culture dish genes

When unspecialized stem cells give rise to specialized cells. • While differentiating, the cell usually goes through several stages, becoming more specialized at each step. • The internal signals = genes The external signals = chemicals secreted by other cells, physical contact with neighboring cells, and certain molecules in the microenvironment

differentiation

The early stages of ---- are the point at which embryonic stem cell lines are derived

embryogenesis

The inner cell mass (the part that would form the fetus) of the embryo is isolated and disrupted to form ----. This process destroys the embryo.

embryonic cell lines

• Reprogram adult somatic cells to become like embryonic stem cells (induced pluripotent stem cells, iPSCs) through the introduction of ---

embryonic genes

The early stages of embryogenesis are the point at which embryonic stem cell lines are derived. The fertilized egg (day 1) undergoes cell division to form a 2-cell embryo, followed by 4-cell, etc. until a ball of cells is formed by the fourth day. The ball becomes hollow, forming the blastocyst. This is the stage at which pluripotent embryonic stem cell lines are generated. Following the blastocyst stage, the tissues of the embryo start to form and the cells become multipotent.

embryonic stem cells derived?

A population of connective tissue cells that are used to nourish cultured tissue cells in the laboratory.

feeder layer

. The fertilized egg (day 1) undergoes cell division to form a 2-cell embryo, followed by 4-cell, etc. until a ball of cells is formed by the

fourth day.

• This breakthrough discovery has created a powerful new way to "de-differentiate" cells whose developmental fates had been previously assumed to be determined. • Tissues derived from ---- will be a nearly identical match to the cell donor and thus probably avoid rejection by the immune system.

iPSCs

• Stem cells may remain quiescent (non-dividing) for long periods of time Until they are activated by a normal need for more cells to maintain tissues, or by disease or tissue --

injury

Following the blastocyst stage, the tissues of the embryo start to form and the cells become

multipotent.

The ball becomes hollow, forming the blastocyst. This is the stage at which ---- are generated.

pluripotent embryonic stem cell lines

• An adult stem cell = --- stem cells

somatic

• Identified in many organs and tissues • Including brain, bone marrow, peripheral blood, blood vessels, skeletal muscle, skin, teeth, heart, gut, liver, ovarian epithelium, and testis. • They are thought to reside in a specific area of each tissue (called a "---").

stem cell niche

ASC • The primary roles are to maintain and repair the --- in which they are found

tissue

• An ---, found among differentiated cells in a tissue or organ that can renew itself and can differentiate to yield some or all of the major specialized cell types of the tissue or organ.

undifferentiated cell

• Primitive (undifferentiated) cells derived from a 5-day preimplantation embryo • Capable of dividing without differentiating for a prolonged period in culture • Ability to form virtually any type of cell found in the human body

• Embryonic stem cells

Cells differentiated, but can form a number of other tissues • Example: Fetal tissue, cord blood, and adult stem cells

• Multipotent

Ability to develop into several different kinds of cells/tissues • Cells can form any (over 200) cell types • Example: Some cells of blastocyst (5 to 14 days)

• Pluripotent

a cell that has the ability to continuously divide

• Self renewable

—Cells with the ability to divide for indefinite periods in culture and to give rise to specialized cells.

• Stem cells