Biotech 2012 spring-5_-stem_cells_1_0

INTRODUCTION OF STEM INTRODUCTION OF STEM CELL TECHNOLOGYCELL TECHNOLOGY

04/11/2304/11/23 Dr. Hariom YadavDr. Hariom Yadav

Importance of Stem Cell ResearchImportance of Stem Cell Research


1998 - Researchers first extract stem cells from human embryos

1999 - First Successful human transplant of insulin-making cells from cadavers

2001 - President Bush restricts federal funding for embryonic stem-cell research

2002 - Juvenile Diabetes Research Foundation International creates $20 million fund-raising effort to support stem-cell research

2002 - California ok stem cell research

2004 - Harvard researchers grow stem cells from embryos using private funding

2004 - Ballot measure for $3 Billion bond for stem cells

Stem Cell HistoryStem Cell History


Stem Cell – DefinitionStem Cell – Definition

• A cell that has the ability to A cell that has the ability to continuously divide and differentiate continuously divide and differentiate (develop) into various other kind(s) of (develop) into various other kind(s) of cells/tissues cells/tissues


Stem Cell CharacteristicsStem Cell Characteristics

‘‘Blank cells’ (unspecialized)Blank cells’ (unspecialized) Capable of dividing and renewing Capable of dividing and renewing

themselves for long periods of time themselves for long periods of time (proliferation and renewal)(proliferation and renewal)

Have the potential to give rise to Have the potential to give rise to specialized cell types (differentiation)specialized cell types (differentiation)



Kinds of Stem CellsKinds of Stem Cells

Stem cell Stem cell typetype DescriptionDescription ExamplesExamples

TotipotentTotipotent Each cell can develop Each cell can develop into a new individualinto a new individual

Cells from early (1-Cells from early (1-3 days) embryos3 days) embryos

PluripotentPluripotent Cells can form any (over Cells can form any (over 200) cell types200) cell types

Some cells of Some cells of blastocyst (5 to 14 blastocyst (5 to 14 days)days)

MultipotentMultipotentCells differentiated, but Cells differentiated, but can form a number of can form a number of other tissuesother tissues

Fetal tissue, cord Fetal tissue, cord blood, and adult blood, and adult stem cellsstem cells


Stem Cell DifferentiationStem Cell Differentiation

Princeton University


Kinds of Stem CellsKinds of Stem Cells

Embryonic stem cells come from a five to six-day-old embryo. They have the ability to form virtually any type of cell found in the human body.

Embryonic germ cells are derived from the part of a human embryo or foetus that will ultimately produce eggs or sperm (gametes).

Adult stem cells are undifferentiated cells found among specialised or differentiated cells in a tissue or organ after birth. Based on current research they appear to have a more restricted ability to produce different cell types and to self-renew.


Blastocyst DiagramBlastocyst Diagram

Princeton University


Sexual ReproductionSexual Reproduction

The Association of Reproductive Health Professionals


Stages of EmbryogenesisStages of Embryogenesis

Day 1Fertilized egg

Day 1Fertilized egg

Day 22-cell embryo

Day 22-cell embryo Day 3-4

Multi-cell embryoDay 3-4

Multi-cell embryo

Day 5-6BlastocystDay 5-6

BlastocystDay 11-14Tissue Differentiation

Day 11-14Tissue Differentiation


Derivation and Use of Derivation and Use of Embryonic Stem Cell LinesEmbryonic Stem Cell Lines

Isolate inner cell mass(destroys embryo)

Isolate inner cell mass(destroys embryo)

Heart muscleKidney

“Special sauce”(largely unknown)

Day 5-6BlastocystDay 5-6

Blastocyst

Inner cells(forms fetus)Inner cells

(forms fetus)

Outer cells(forms placenta)

Outer cells(forms placenta)

Heartrepaired

Culture cellsCulture cells






Embryonic stem cellsEmbryonic stem cells


Adult stem cellsAdult stem cells





ApplicationsApplications

Disease• Diabetes, Spinal

cord injury, Parkinson’s disease, heart disease

Genetic based Disease

• Cystic fibrosis, Huntington’s












Unknowns in Stem Unknowns in Stem Cell/Cloning ResearchCell/Cloning Research

• It is uncertain that human It is uncertain that human embryonic stem cells embryonic stem cells in vitroin vitro can can give rise to all the different cell give rise to all the different cell types of the adult body.types of the adult body.

• It is unknown if stem cells cultured It is unknown if stem cells cultured in vitroin vitro (apart from the embryo) (apart from the embryo) will function as the cells do when will function as the cells do when they are part of the developing they are part of the developing embryoembryo


Challenges to Stem Challenges to Stem Cell/Cloning ResearchCell/Cloning Research

• Stem cells need to be Stem cells need to be differentiated to the differentiated to the appropriate cell type(s) appropriate cell type(s) beforebefore they can be used they can be used clinically.clinically.

• Recently, abnormalities in Recently, abnormalities in chromosome number and chromosome number and structure were found in structure were found in three human ESC lines. three human ESC lines.



• Stem cell development or proliferation Stem cell development or proliferation must be controlled once placed into must be controlled once placed into patients.patients.

• Possibility of rejection of stem cell Possibility of rejection of stem cell transplants as foreign tissues is very high.transplants as foreign tissues is very high.



• Contamination by viruses, bacteria, fungi, Contamination by viruses, bacteria, fungi, and Mycoplasma possible.and Mycoplasma possible.

• The use of mouse “feeder” cells to grow The use of mouse “feeder” cells to grow ESC could result in problems due to ESC could result in problems due to xenotransplantation (complicating FDA xenotransplantation (complicating FDA requirements for clinical use).requirements for clinical use).


Stem cell and cloningStem cell and cloning

Immune rejectionImmune rejection

Somatic cell nuclear transferSomatic cell nuclear transfer











(Time 2.19.01)

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Biotech 2012 spring-5_-stem_cells_1_0