Stem Cell Biology Basics
Nozad H.Stem cell workshop
Stem cell Research center Tabriz medical university
In The Name of God
Stem Cell Characteristics
1. ‘Blank cells’ (unspecialized)
2.Capable of dividing and renewing themselves for long periods of time
(proliferation and self renewal)
3. Have the potential to give rise to specialized cell types (differentiation)
4. Plasticity and Cell based therapies
5. Very low percentage available(0.01-0.03%)
Basement membrane Extracellular matrix and
CytokinesCell-cell interactions
Niche , Selfrenew and Diffrentation relationship
Stem cell Self renew and Diffrentation pasibility
Nature 441, 1068-1074(29 June 2006)
Stem cell division regulated by factors that control the probability of self-renewing versus differentiative
From stem cell to muture cells
Three important functions of stem cells
1. Plasticity: Potential to change into other cell types
2. Homing: To travel to the site of tissue damage 2. Engraftment: To unite with other tissues
Kinds of Stem Cells
Stem cell type Description Examples
Totipotent Each cell can develop into a new individual
Cells from early (1-3 days) embryos
Pluripotent Cells can form any (over 200) cell types
Some cells of blastocyst (5 to 14 days)
MultipotentCells differentiated, but can form a number of other tissues
Fetal tissue, cord blood, and adult stem cells
This cellCan form the
Embryo and placenta
This cellCan just form the
embryo
Totipotent
Pluripotent
Multi-potent
Fully mature
http://www.stemcellresearch.org/testimony/20040929prentice.htm Reprinted with permission of Do No Harm.
Umbilical cord stem cells
1. Umbilical cord blood stem cell 2. Wharton’s Jelly
Specifity:1. Easy to reach and not expensive2. NO immune sytem reactivity(no GVHD)3. Proliferate fast4. Limited number5. The mature derived cells are not fully functional
Hematopoietic stem cell
Neural stem cell
Intestine stem cell
Mesenchymal stem cell
Inducing a "forced" expression of specific genes(Oct3/4, Sox2, Klf4 and cMyc) in somatic cells
Potential Uses of Stem Cells
1. Basic research A. understanding the complex events and molecular
basis of during development and cancer
B. Molecular mechanisms for gene control
C. Role of signals in gene expression & differentiation of the stem cell
D. Stem cell theory of cancer
2. Biotechnology(drug discovery & development)
A. Stem cells can provide specific cell types to test new drugs.
B. Safety testing of new drugs on differentiated cell lines
C. Screening of potential drugs(anti-tumor drugs)
D. Pluripotent stem cells would allow drug testing in a wider range of cell types & to reduce animal testing
Potential Uses of Stem Cells
3. Cell based therapiesA. Regenerative therapy to treat Parkinson’s, Alzheimer’sspinal cord injury, strokesevere burns, heart disease, diabetes,osteoarthritis, and rheumatoid arthritis
B. Stem cells in gene therapy
C. Stem cells in therapeutic cloning
D. Stem cells in cancer
Potential Uses of Stem Cells
Then
How we can Identify the Stemcells?