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?