kapitel 3 (Tobias) - Stem Cells and regenerative medicine

Question 1

Which kind of stem cell is the cornerstone cell in skeletal stem cell research and orthopedic tissue engineering?

Answer 1

MSC

mesenchymal stem cells, marrow stromal cells, multipotent stromal cells, or, recently, medicinal supply cells

Question 2

What are the three main classes of naturally occurring stem cells?

There is a fourth kind, which is that?

Answer 2

• Embryonic stem cells (ESCs)
• Adult stem cells (ASCs)
• Fetal/perinatal stem cells (PSCs)
• 4th kind:
  Artificially created Induced Pluripotent Stem Cells (IPSCs

Question 3

What is the main distinctive characteristic between each category of stem cells?

• Embryonic stem cells (ESCs)
• Adult stem cells (ASCs)
• Fetal/perinatal stem cells (PSCs)

Answer 3

• Their potency -> their ability to differentiate into different types of cells

Question 4

Name examples of totipotent, pluripotent and multipotent cells

Answer 4

Totipotent:
- Fertilized zygote

Pluripotent:

• ESC
• IPSC
• (ASC - some with pluripotent properties have been identified)

Multipotent:

• MSC
• (ASC)
• PSC

Question 5

Where are ESCs derived from? What is the problem?

Answer 5

• Harvested from the inner cell mass of a blastocyst prior to implantation, resulting in the destruction of the embryo
• Ethical problems -> not allowed in many countries
• Strong tendency to expand and differentiate in a dysregulated manner without careful attention to culture conditions and media composition
• Tumorogenic properties: When implanted into immune compromised adult animals, embryonic stem cells undergo dysregulated cell division and differentiation resulting in the formation of teratomas, described as a mass of rapidly dividing progenitors and differentiated progeny

Question 6

Name some diseases where mesenchymal stem cells have shown promise in the treatment of

Answer 6

• Osteoarthitis
• Graft-Vs-Host disease
• Chrons Disease

Question 7

Where are perinatal stem cells typically harvested from?

Answer 7

• The umbilical cord
• Amniotic fluid
• Fetal membranes.

Question 8

PSC and ASC are both classified as multipotent. One is considered superior - which and why?

Answer 8

PSC is considered superior -> have benn reported to have superior expansion potential, increased plasticity, and may possess superior immune privilege

Question 9

Retroviral and lentiviral vectors are most commonly used to reprogram adult somatic cells into IPSC´s. What is the problem?

Answer 9

• Integrate into the host cell genome

- Risk of insertional mutagenesis or oncogenic transformation

Question 10

MSC´s can be found in many adult tissues - but in which location?

Answer 10

• Perivascular location

Question 11

Why are mesenchymal stem cells are excellent candidates for regenerative medicine?

Answer 11

• Can be isolated from adult tissues
• undergo rapid (but not limitless) proliferation to produce massive numbers of cells
• Unlikely to induce an immune response when used in an autologous manner

Question 12

In the small animal setting - where are MSC´s most commonly derived from?

Answer 12

• Bone Marrow Aspirates
• Adipose tissues

(But can be isolated from many different tissues)

Question 13

Can MSC´s be used in an autologous matter or allogenic or both?

Answer 13

Both

Question 14

What is the timeframe for creating culture-expanded mesenchymal stem cells?

Answer 14

7-14 days

Question 15

What is cytotherapy?

What is the problem?

Answer 15

Systemic administration of soluble cell suspensions (MSC´s)

• Low engraftment rate (5% - but positive results reported)

Question 16

What is tissue engineering?

Answer 16

• The combination of mesenchymal stem cells, specialized three-dimensional scaffolds, and, in some cases, additional growth factors to enhance differentiation or angiogenesis