Intro to Stem Cells

Question 1

name characteristics of stem cells

Answer 1

• self-renewal (unlimited cell division) and have active telomerase
• Differentiation
  
  • specialization to become cells with distinct structure and function

Question 2

describe the various potencies of stem cells

Answer 2

• totipotent: ability to develop into all tissues
  
  • embryonic and extra embryonic
• pluripotent: ability to develop into all cells and tissues
  
  • 210+ adult cell types, inner mass cells
• multipotent: can develop into some number of different cell types
  
  • adult stem cells
• unipotent: can develop into only one cell type
  
  • adult stem cells

Question 3

describe morula

Answer 3

• morula is totipotent
  
  • makes embryonic and extra-embryonic (placenta, amnion, chorion)

Question 4

describe blastocyst

Answer 4

• blastocyst are the inner mast cells which are pluripotent
  
  • gives rise to all derivatives of 3 primary germ layers
    
    • ecto, endo and meso

Question 5

describe hematopoietic

Answer 5

• RBC, B-cells, T-cells, NKCs, neutrophils, basophils, eosionophils, monocytes, macrophages and platelets

Question 6

describe mesenchymal cells

Answer 6

• osteocytes, chondrocytes, adipocytes and connective tissue

Question 7

describe neural stem cells

Answer 7

• neurons, astrocytes, oligodendrocytes

Question 8

describe epithelial stem cells

Answer 8

• GI lining, absorptive cells, goblet cells, paneth cells, enteroendocrine cells

Question 9

describe cell plasticity

Answer 9

• multipotent cell of one kind can be pushed to make other tissues

Question 10

describe the process of stem cell differentiation

Answer 10

• less specialized cells become more specialized –> progenitor cells –> differentiatied cells
• Transcription factors specifically bind to promoter or enhancer regions of DNA
  • control transcription downstream and trigger cascade of gene changes

Question 11

contrast allogenic ESCs and autlogous ESCs

Answer 11

• allogenic = cells taken from another body
• autologous = our stem cells extraction

Question 12

describe an embroynic stem cell culture

Answer 12

• fresh frozen embryos produced by invitro fertilization
• embryos are cultures to blastocyst stage
• inner cell mass is isolated and transferred to petridish
• cell divides and fill the dish
• pitfall: ESCs are genetically different from patients
  
  • immune response or rejection

Question 13

describe induced pluripotent stem cells (iPSCs)

Answer 13

• adult cells reprogrammed into a pluripotent state
• pitfalls: transfection of gene into adult cells requires vectors, genomic insertion has risk of mutation, tumors, reprogramming may not be complete

Question 14

define teratoma

Answer 14

• Teratoma: tumour composed to tissues normally not present at the site