Exam 3 - Stem cell engineering

Question 1

What are the different types of developmental capacities?

Answer 1

• Totipotency
  
  • ability of a cell to give rise to al cells of an organism including embroyonic and extra embryonic tissues
    
    • Ex : zygote
• Pluripotency
  
  • ability of a cell to give rise to all cells of the ebmryo and suvsequently adult tissues
    
    • ex: embryonic stem cells
• Mulipotency
  
  • Ability of a cell to give rise to a different cell types of a given lineage
    
    • Ex: Afult stem cells

Question 2

What are characteristics of embryonic stem cells

Answer 2

• Pluripotent
• Develop into different cell types with chracteristics appropriate for that site (even germ cells)
• capable of proliferating indefinitely in culture with unrestricted developmental potential
• ES are incapable of generating a full organism

EX: ON TEST
Embryonic stem cells are derived from the inner cell mass of a blastocyst stage of embryo

when placed back into blastocyst they integrate well

Question 3

Know Image

Question 4

What is the result of injected ES cells into an host animal?

Answer 4

• If blastocyst
  
  • leads to variety of tissues including : cartilage, bone, skin, nerves, gut, and respiratory lining
• However if injected into an embryo at laters stage or into an adult they fail to receives cues for proper differentiation leads to formation of teratmas with no axis foration or segmentation

Question 5

How could ES cells be used in drug discovery and treatment

Answer 5

• study diease mechanisms
• Through high throuput screening it could test chemical compunds
• Develope customized treatment strategies for a patients from screen libraries of compounds

Question 6

What are alternative uses to treatment with ES?

Answer 6

• DIffernt sources of Human Es Cells
  
  • Somatic cell nuclear transfer (SCeNT
• Strategies to induce ES Cell-like properties in adult somactic cells
  
  • induced pluripotent stem (iPS) cells
    *

Question 7

What is somatic cell nuclear transfer (SCeNT)

Answer 7

• Combines cloning methods with embryonic stem cell technology to produce which are custom made for patient
• Nucleus taken from somatic cell of patient and injected into oocye of donor replacing the oocyte nucleus
• blastocyst generated from this hybrid oocyte and ES cells isolated
• Ex: Type 1 diabetes
  
  • source of eggs : self, mother, relative, egg bank
  • Probelms : innefficent , avaliblity of procedure in hospitals

Question 8

How would you reprogram adult cells into ES cells ?

Answer 8

• Adults can converted into ES-like Cells by manipulating gene expression directly
• OCT4 SOX2, KiF4 and MYC
• When injected into fibrlasts they form ES like Cells that have the ability to differentate into other cell types
• however its low yield

Question 9

how would you induce pluripotent Stem celsl (iPSC)

Answer 9

• Somatic cells can be reporgammed to form iPSC
• By exposing them to defiend limited sets of transcription factors genes for stem-ness
• Picture
  
  • shows tha Kif 4 , OCT4, Sox2 are required
  • Myc is used to make process for efficent
  • Nanog is a transcription regulatory

Question 10

What are the challenges for regenerative medicine and transplantation therapy ?

Answer 10

• Challenges NEED to remember
  
  • Tissue/Immune rejection
  • Genetic and Epigentic Aberrations
• Technical Challenges
  
  • productiosn of required cell type in pure form
  • production of such cells in sufficient numbers
  • longevity / stability of cells in culture
  • delivery method
  • proper integration into tissue/organ

Question 11

How does the use of umbilican cord b?lood relate to the future orf Stem cells

Answer 11

• Undifferentiated
• No ehtical probelms
• no genetic manipulation

Question 12

How stem cells related to Skin repair?

Answer 12

• Culutred of epidermal cells taken from healthy skin regions patients used to isolate stem cells
  
  • In the mean time while the culture is growing
    
    • immediate replacement of dermis is from cadaver or artifical matrix used as barrier from preventing water
    • A matrix collagen glycosaminoglycan made of sheet lined with thin membrane silicone rubber outside
    • Fibroblasts and blood capillaries from patients tissue migrate towards the artifical skin and reform the connective tissue underneath
• Articficial skin replaced with cultured epidermal cells to reconstruct a complete skin

Other:

Fish skin can be used as wrapp too