Stem Cell and Its Clinical Implications

Presented by: Yogesh K. Chaudhari

Department of PharmacologyMumbai University

Mumbai

Objectives

• Define stem cell

• Outline brief history of stem cell research

• Mention the types of stem cells based on potential

Objectives (contd)

• Outline the sources of stem cell

• Explain the steps of stem cell therapy

• Discuss the health problems that might be treated by stem cells

Objectives (Contd)

• Debate for and against stem cell research

• Mention the responsibilities regarding stem cell issues

Stem Cells: Definition

- unspecialized

- self renewal- can be induced to form specific cell types

1 stem cellSelf renewal - maintains the stem cell pool

4 specialized cellsDifferentiation replaces dead or damagedcells throught the life

Why self-renew AND differentiate?1 stem cell

Clonogenic, a single ES cell gives rise to a colony of genetically identical cells, which have the same properties as the original cell

Expresses the transcription factor Oct-4Can be induced to continue proliferating or to differentiate

Lacks the G1 checkpoint in the cell cycle

ES cells spend most of their life cycle in S phase

Don’t show X inactivation

Properties of stem cell….

Stem Cell Markers

c-KitOct4 (ATGCAAAT) POU Family Protein

CD34CD38

Cd44

CD133Nestin

Cells in suspension are tagged with fluorescent markers specific for undifferentiated stem cell

Labeled cells are sent under pressure through a small nozzleand pass through an electric field 

A cell generates a negative chargeif it fluoresces and a positive charge if it does not.

Laser beam passes through one cell 

FLUROSCENT ACTIVATED CELL SORTING

Stem cell

SEPARATION OF STEM CELL

History of Stem Cell Research

• In 1998, James Thomson isolated stem cells from the inner cell mass of the early embryo.

• In 1998, John Gearhart derived human embryonic germ cells from fetal gonadal tissue (primordial germ cells).

History of Stem Cell Research

History of Stem Cell Research (Contd)

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

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

History of Stem Cell Research (Contd)

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

Asia, Japan, South Korea and Singapore is moving forwards on stem cell research.

SCAN – Stem Cell Action Network

Stem Cell Research Worldwide

Global status

• Ongoing debate regarding use of embryos

• United Nations: proposal for a global policy to ban reproductive cloning only

Debate in US• Federal funding available for research using

the Bush lines onlyES cell lines from 8/9/01

• Disadvantage of Bush stem cell lines:may have mutations or infections

• Private companies continue to pursue stem cell research therapeutic cloniing mainly

Stem cell research in other countries

• Great Britain– Therapeutic cloning , use of excess

embryos & creation of embryos allowed

• France– Reproductive and therapeutic cloning

banned

• Germany– Use of excess embryos and creation of

embryos banned

Types of Stem Cells based on potential

Types of Stem Cells based on potential

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

Pluripotent Stem Cells more potential to become any type of cell

Multipotent stem cells

• Multipotent stem cells – limited in what the cells can become

Sources of Stem Cell

Sources of Stem Cell

• Embryonic stem (ES) cells

• Tissue (Adult) stem cells

• Induced pluripotent stem cells (iPS cells)

• Somatic cell nuclear transfer (therapeutic cloning)

Sources of stem cells

embryonic stem cells

blastocyst - a very early embryo

tissue stem cellsfetus, baby and throughout life

Embryonic stem (ES) cells:

blastocyst

outer layer of cells= ‘trophectoderm’

cells inside = ‘inner cell mass’

embryonic stem cells taken fromthe inner cell mass

culture in the labto grow more cells

fluid with nutrients

Embryonic stem (ES) cells:

embryonic stem cells

PLURIPOTENT

all possible types of specialized cells

differentiation

Tissue stem cells:

muscles

skin

surface of the eye brain

breast

intestines (gut)

bone marrow

testicles

Tissue stem cells:

MULTIPOTENT

blood stem cell

found in bone marrow

differentiation

only specialized types of blood cell:red blood cells, white blood cells,

platelets

Induced pluripotent stem cell

cell from the body

‘genetic reprogramming’= add certain genes to the cell

induced pluripotent stem (iPS) cell

behaves like an embryonic stem cell

Advantage: no need for embryos! all possible types ofspecialized cells

culture iPS cells in the lab

differentiation

Induced pluripotent stem cell (Contd)

cell from the body (skin)

genetic reprogramming

pluripotent stem cell

differentiation

Somatic cell nuclear transfer

• A nucleus from an adult donor cell is inserted into a recipient egg cell from which the nucleus has been removed

• The resulting cell is then stimulated to divide as a zygote later forming embryo genetically identical to the adult donor cell

Somatic cell nuclear transfer

Goals of therapeutic cloning

– Use embryo as source for ES cells

– Use ES cells to generate an organ with genetic markers identical to the patient

– Correct genetic error in ESC in blastula stage

Pitfalls of therapeutic cloning

• Large number of eggs needed for SCNT• To harvest large number of eggs:

– excessive hormone treatment may induce high rate of ovulation

– will carry species-specific mitochondrial genes• Mixing species is reason for concern!

CloningThere are two VERY different types of cloning:

Reproductive cloning

Used to make two identical individuals

Very difficult to do

Illegal to do on humans

Molecular cloning

Used to study what a gene does

Routinely used in the biology labs

gene 1

gene 2

Reproductive cloning

remove nucleus and take the

rest of the cell

egg

take the nucleus (containing DNA)

cell from the body

Cloneidentical to the individual

that gave the nucleusDolly the sheep

Molecular cloning

gene 1

gene 2

2) Make a new piece of DNA

gene 1

gene 2

1) Take DNA out of the nucleus

cell 1 cell 2

gene 1 gene 2

3) Put new DNA into a test cell and grow copies

gene 1

cell divides

Daughter cells contain same DNA:

Genes 1 and 2 have

been cloned

gene 2

insert new DNA

Steps of Stem Cell Therapy

Steps of Stem Cell Therapy

• Defining the problem

• Finding The Right Type of Stem Cell

• Match The Stem Cell With The Recipient

• Put the stem cells in the right place

• Make The Transplanted Stem Cells Perform

Steps of Stem Cell Therapy• Define the problem

Researchers want to replace dead dopamine neurons with healthy ones

• Finding The Right Type of Stem Cell

Blastocyst stem cells?At the time, unable to differentiate into neurons

Fetal stem cells?, Excellent candidates, ethical problems

Adult stem cells?, Hard to get, too little known

Steps of Stem Cell Therapy

• Match The Stem Cell With The Recipient

Needs a good immunonlogical match.

Steps of Stem Cell Therapy (contd.)

• Put the stem cells in the right place

Surgical procedure usually required.Small holes drilled in the skull, cells injected with a needle.

Steps of Stem Cell Therapy (contd.)

• Make The Transplanted Stem Cells Perform

There was no guarantee how the transplanted cells would behave. If they did not respond to the proper signals from their environment, they might have malfunctioned or died.

Steps of Stem Cell Therapy (contd.)

Cell Culture Techniques for ESC• Isolate & transfer of inner cell mass into

plastic culture dish that contains culture medium

• Cells divide and spread

• Inner surface of culture dish is typically coated with mouse embryonic skin cells that have been treated so they will not divide

• This coating is called feeder layer:– provide ES cells with a sticky surface for

attachment and release nutrients

– There are methods for growing embryonic stem cells without mouse feeder cells

• ES cells are removed gently and plated into several different culture plates

Debate for and against stem cell

research

Pro-choice people

• “ Utilitarianism- destruction of smaller group for the sake of a larger group is justifiable.”

• …lead to significant information about the cause, new treatment possibilities, and

potential cure for many diseases.

BEFORE

AFTER

Opinions against stem cell research

Stem cells are taken from a human blastocyst, which is then destroyed. This amounts to “murder.”

There is a risk of commercial exploitation of the human participants in ESCR.

Stem cell work may bypass objections

Stem-cell work may bypass objections

Stem Cell applications

Potential Uses of Stem Cells

• Basic research – clarification of complex events such as

– Molecular mechanisms for gene control

– Role of signals in gene expression & differentiation of the stem cell

– Stem cell theory of cancer

Potential uses cont.

• Biotechnology(drug discovery & development

– Safety testing of new drugs on

differentiated cell lines

– Screening of potential drugs

Potential uses cont.• Cell based therapies:

– Regenerative therapy to treat Parkinson’s, heart disease, diabetes etc

– Stem cells in gene therapy as vehicles

– Stem cells in therapeutic cloning

– Stem cells in cancer

Stem Cell Applications

• Tissue repair- nerve, heart, muscle, organ, skin

• Cancers

• Autoimmune diseases- diabetes, rheumatoid arthritis, multiple

sclerosis.

Tissue Repair

• Regenerate spinal cord, heart tissue or any other major tissue in the body.

http://www.youtube.com/watch?feature=player_embedded&v=eXO_ApjKPaI

Replace Skin

Heart Disease

• Adult bone marrow stem cells injected into the hearts are believed to improve cardiac function in victims of heart failure or heart attack

Leukemia and Cancer

• Leukemia patients treated with stem cells emerge free of disease.

• Stem cells have also reduces pancreatic cancers in some patients.

Proliferation of white cells

Rheumatoid Arthritis

• Adult Stem Cells may be helpful in jumpstarting repair of eroded cartilage.

Type I Diabetes• Embryonic Stems Cells might be trained

to become pancreatic islets cells needed to secrete insulin.

• window to early brain development

• Identify critical genes

Down Syndrome

Diseases that are treated by stem cells are:1) Acute Leukemia• Acute Lymphoblast Leukemia (ALL)• Acute Myelogenous Leukemia (AML)• Acute Biphenotypic Leukemia • Acute Undifferentiated Leukemia2) Chronic Leukemia• Chronic Myelogenous Leukemia (CML)• Chronic Lymphocytic Leukemia (CLL)• Juvenile Chronic Myelogenous Leukemia (JCML) • Juvenile Myelomonocytic Leukemia (JMML)Syndromes• Myelodysplastic Syndromes• Amyloidosis• Chronic Myelomonocytic Leukemia (CMML)• Refractory Anemia (RA)• Refractory Anemia with Excess Blasts (RAEB)• Refractory Anemia with Excess Blasts in Transformation • (RAEB-T)• Refractory Anemia with Ringed Sideroblasts (RARS)

Disorders1) Stem Cell Disorders• Aplastic Anemia (Severe)• Fanconi Anemia • Paroxysmal Nocturnal Hemoglobinuria • Congenital Cytopenia• Dyskeratosis Congenita2) Myeloproliferative Disorders• Acute Myelofibrosis • Agnogenic Myeloid Metaplasia • Polycythemia Vera • Essential Thrombocythemia3) Lymphoproliferative Disorders• Non-Hodgkin’s Lymphoma • Hodgkin’s disease • Prolymphocytic Leukemia4) Phagocyte Disorders• Chediak-Higashi Syndrome • Chronic Granulomatous Disease • Neutrophil Actin Deficiency • Reticular Dysgenesis

5) Inherited Metabolic Disorders• Mucopolysaccharidoses (MPS) • Hurler’s Syndrome (MPS-IH) • Scheie Syndrome (MPS-IS) • Hunter’s Syndrome (MPS-II) • Sanfilippo Syndrome (MPS-III) • Morquio Syndrome (MPS-IV)• Maroteaux-Lamy Syndrome (MPS-VI)• Sly Syndrome, Beta-Glucuronidase Deficiency • Adrenoleukodystrophy • Mucolipidosis II (I-cell Disease)• Krabbe Disease • Gaucher’s Disease • Niemann-Pick Disease • Wolman Disease • Metachromatic Leukodystrophy6) Histiocytic Disorders• Familial Erythrophagocytic Lymphohistiocytosis • Histiocytosis-X • Hemophagocytosis• Langerhans’ Cell Histiocytosis

7) Inherited Immune System Disorders• Ataxia-Telangiectasia• Kostmann Syndrome• Leukocyte Adhesion Deficiency • DiGeorge Syndrome • Bare Lymphocyte Syndrome • Omenn’s Syndrome• Severe Combined Immunodeficiency • SCID with Adenosine Deaminase Deficiency• Absence of T & B Cells SCID • Absence of T Cells, Normal B Cell SCID• Common Variable Immunodeficiency • Wiskott-Aldrich Syndrome• X-Linked Lymphoproliferative DisorderOther Inherited Disorders• Lesch-Nyhan Syndrome • Cartilage-Hair Hypoplasia • Glanzmann Thrombasthenia • Osteopetrosis• Adrenoleukodystrophy• Ceroid Lipofuscinosis• Congenital Erythropoietic Porphyria• Sandhoff Disease

9) Plasma Cell Disorders• Multiple Myeloma • Plasma Cell Leukemia • Waldenstrom’s Macroglobulinemia• AmyloidosisAbnormalities1) Inherited Platelet AbnormalitiesCongenital Thrombocytopenia2) Inherited Erythrocyte Abnormalities• Beta Thalassemia Major • Sickle Cell Disease• Blackfan-Diamond Anemia• Pure Red Cell AplasiaOther Malignancies• Ewing Sarcoma • Neuroblastoma• Renal Cell Carcinoma• Retinoblastoma• Brain tumor• Ovarian Cancer• Small Cell Lung Cancer• Testicular Cancer

Responsibilities regarding stem cell

issues

Responsibilities regarding stem cell issues

Become informed

The facts about stem cell research and its curative potential.www.stemcellfunding.org

www.stemcellaction.org

Responsibilities regarding stem cell issues(contd.)

Inform others

• Contact patient and community groups and offer to give a presentation like this one. Organize a house party to help spread the word.

• Collect email addresses of supporters to be added to mailing list.

Responsibilities regarding stem cell issues (contd.)

Inform others

• Arrange to meet with your political representatives to discuss their support for stem cell research

• Find other like-minded people and work together

• Invite friends, colleagues, and caretakers of patients to become involved

Technical Challenges• Source - Cell lines may have mutations

• Delivery to target areas

• Prevention of rejection

• Suppressing tumors

Mutations can lead to leukemia

Problems with Adult Stem Cells

REFERENCES• Stem cells in class; Badran, Shahira; Bunker Hill Community

College, 2007, Boston Museum of Science Biotechnology Symposium

• Stem cells & Cloning Stem cells & Cloning; David A. Prentice, Benjamin Cummings, 2003

• http://stemcells.nih.gov/info/scireport/2001report.htm• http://www.ulb.ac.be/sciences/biodic/biodic/images/bio_animale/em

bryologie/fecondation/baefec_01_01.jpg• http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mboc4.figgrp.3748• http://www.news.wisc.edu/packages/stemcells/illustration.html• http://www.drugs.com/enc/images/images/en/17010.jpg• http://embryology.med.unsw.edu.au/Notes/placenta.htm• http://www.dnalc.org/stemcells.html• http://gslc.genetics.utah.edu/units/stemcells/

Thank you all

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