stem cells introduction
DESCRIPTION
Slide show on introduction of stem cell transplantation, harvesting, and maintenanceTRANSCRIPT
If starfish can grow a new arm,
why can’t I?
STEM CELL
• INTRODUCTION• MAINTENANCE
OF STEM CELL
SUE ®
WHERE DO I COME FROM?
GAMETES
FERTILISATION
ZYGOTE WHEN GAMETE FUSED
MORULA
BLASTOCYSTS
IMPLANTATION
EMBRYO IMPLANTED ZYGOTE TO 8TH WEEK
FETUS
HOW DOES A ONE CELL ZYGOTE
BECOME A HUMAN?Human body composed of 50-75 TRILLION cells.MORE THAN 220 TYPES OF CELL
DIFFERENTIATION GROWTH FACTORS INTRACELLULAR SIGNALLING GENETIC MATERIAL
- TO BE CONTINUED IN NEXT PART
STEM CELLAscending stalk of a treeAlso means 'to stop or to slow
down’
In this case, stop and slow down and turn into other types of cells.
DIFFERENCE OF STEM CELL AND NORMAL BODY CELLS Ability to divide throughout life
(theoretically) Ability to differentiate into many
different cell types
TYPES OF STEM CELL EMBRYONIC STEM CELL FETAL STEM CELL BERASHI CELL ADULT STEM CELL
POTENTIAL OF STEM CELLTotipotent stem cells
early embryos Each cell can form a complete organism
Pluripotent stem cells undifferentiated inner cell mass of blastocyst form any of over 200 different cell types
Multipotent stem cells ability to differentiate is more limited
TOTIPOTENT STEM CELLS Up to 8-cell stage of zygote No research work on totipotent stem
cells Our aim is NOT to create a clone human
EMBRYONIC STEM CELLS Derived from inner cell mass of
blastocysts Pluripotent
1. Ectoderm2. Mesoderm3. Endoderm
Able to replicate indefinitely
BLASTOCYSTS
ISOLATION OF EMBRYONIC STEM CELLS SOURCE
• SURPLUS EMBRYO – I.V. FERTILISATION TECHNIQUE OF ISOLATION
• MICROSURGERY• LASER-ASSISTED BLASTOCYST
DISSECTION
MAINTENANCE OF EMBRYONIC STEM CELLS STEM CELL NICHE- in vivo or in vitro stem cell microenvironment Human ES cells are often grown in - fibroblastic growth factor-2 containing, fetal bovine
serum supplemented media Grown on a feeder layer of cells- supportive in maintaining the pluripotent
characteristics of embryonic stem cells
GERM LINE STEM CELLS NICHE
HEMATOPOETIC STEM CELLS NICHE
AGING OF STEM CELLS Occurs when cultured in vitro Morphology is changed and their
proliferative capacity is decreased Causes:
1. reduction in niche signaling pathway activity
2. accumulation of Reactive Oxygen species (ROS)
BERASHI STEM CELLS Found in cord and extra embryonic
tissues and membranes Formed only by TOTIPOTENT CELLS Umbilical cord banking
FETAL STEM CELLS Taken from aborted fetal tissue Have the potential to be a greater kind
of cells that adult cells
ADULT STEM CELLS
Hematopoietic stem cells Intestinal stem cells Mesenchymal stem cells Endothelial stem cells Neural stem cells Olfactory adult stem cells Testicular cells Mammary stem cells
HISTORY OF STEM CELL RESEARCH
REGENERATIVE MEDICINE process of replacing or regenerating human
cells, tissues or organs to restore or establish normal function
grow tissues and organs in the laboratory and safely implant them when the body cannot heal itself
Advantages:1. solve the problem of the shortage of organs available
for donation2. solve the problem of organ transplant rejection
DEDIFFERENTIATION
CHALLENGES OF STEM CELL CHALLENGES OF STEM CELL RESEARCHRESEARCH If the embryo = inanimate matter
-then the resistance to embryonicstem cell research is ludicrous.
If the embryo is alive, then embryonic stem cell research is immoral.
one must differentiate between human beings and persons.