Medical biotechnology

Question 1

What are the 4 types of physiological regeneration?

Answer 1

Adult stem cells
Proliferation of differentiated stem cells
De-differentiation
Trans-differentiation

Question 2

What are the defining characteristics of stem cells?

Answer 2

To self renew: At least one of the daughter cells keep the stem-cell ability of the mother cell

To generate differentiated cells

Question 3

What are the different type of stem cells, and which has the greatest differentiation/proliferation potential?

Answer 3

Totipotent (all): Fertilized eggs, can differentiate into all cells of the embryo and 200 tissues

Pluripotent (many): Embryonic stem cell. 5-6 days of development. Capable of unlimited proliferation and can generate cells of ALL tissues including oocytes or sperm cells

The limited cells:

• Multipotent: different cells given lineage
• Oligopotent:
• Unipotent: One cell fate “precursors”

Question 4

What are multipotent stem cells?

Answer 4

Maintained in adults, like blood cells from bone marrow, muscle cells, immune cells and neural cells

Question 5

What are the principles behind de-differentiation?

Answer 5

Generally, erasing the epigenetic markers.
Classical: Extracting the nucleus from a somatic cell and inserting it into a ocyte.
New: Insertion of transcription factor OSKM to induce differentiation of pluripotent stem cells

Question 6

What are the principles behind trans-differentiation?

Answer 6

Shifting epigenetic markers to another epigenetic annotation pattern
examples: Alpha and delta cells trans differentiating into progenitor beta cells during beta cell depletion

Question 7

What are the 4 major targets of cell therapy?

Answer 7

1. Embryonic stem cells - from embryo
2. Multipotent stem cells - from adults
3. Induced pluripotent stem cells - from somatic cell (de-differentiation)
4. Trans-differentiated cells

Question 8

What are the 3 therapies currently in use?

Answer 8

Hematopoietic stem cells
Skin cells
Pancreatic islets

Question 9

What are the main principles of gene tharapy?

Answer 9

To manipulate expression of gene by targeting the genome somehow.

• replacement of defect gene
• silencing of mutated gene by sRNA
• alleviating symptoms/pathology of gene
• editing of mutated gene by splicing

Question 10

What are the three ways to obtain pluripotent stem cells?

Answer 10

1. Embryonic stem cells
2. induced pluripotent stem cells
3. Somatic nuclear transfer

Question 11

What are the 2 types of viruses used as vector and what do they infect?

Answer 11

Retrovirus: Differentiating cells
Lentivirus: Differentiationg + quiet + differentiated

Question 12

´What are the 4 types of gene therapy

Answer 12

1. Replacing genes that are defective
2. Adding additional genes to combat a disease
   3 .Modification of gene expression
3. Editing genome

Question 13

Give an example of 1. replacing defective genes in humans

Answer 13

Using virus vectors to deliver and integrate a gene for Immunodeficient-disease types that has the transcription factor missing for proliferation of immune cells

Question 14

Give examples of therapies using differentiated cells and trans-differentiated cells

Answer 14

Differentiated: The heat have cells that keep differentiating during growth- finding inhibitor factors to inhibit the inhibitors of growth

Trans-differentiated: Neurodegenerative diseases - Astrocytes to neurons, Producing working heart cells from fibroblasts in heart

Question 15

What is the cell therapy currently in use

Answer 15

Corneal retinal stem cells

Question 16

Give an example of using 2. adding additional genes to fight against disease

Answer 16

The principle behind immune therapies: Adding RNA or DNA into the cell, make the cell produce an antigen/receptor to instigate immune reaction.

RNA/DNA vaccines: Injection of genes and creating viral proteins that can be recognized by the immune system

Question 17

What are the 2 principles to repair DNA?

Answer 17

Non homologous end joining

Homology directed DNA repair