Stem Cells

STEM CELLS Khushpreet Singh | 7050014 B Tech 4th year Thapar University

STEM CELLS •  They are characterized by the ability to renew themselves  through mitotic cell division and differentiating into a diverse  range of specialized cell types.  • Research in the stem cell field grew out of findings by  Canadian scientists Ernest A. McCulloch and James E. Till in  the 1960s. • The two broad types of mammalian stem cells are: embryonic  stem cells that are isolated from the inner cell mass of  blastocysts, and adult stem cells that are found in adult tissues  EMBRYONIC CELLS This photograph shows the eye of a needle with an embryo formed only by stem cells before cellular

First use In 1998 stem cells were isolated and cultivated for the first time in the United States. Since then, numerous laboratories in the world have cultivated them. Because of ethical questions that surround work with embryonic cells, each line is monitored through official organizations.

Types of Stem Cells • Embryonic • Adult

Embryonic Stem Cells • Taken from the morula • Pluripotent (able to form many types of specialized cells)

A: Cell colonies that are not yet differentiated.

Zygote vs. Morula • Zygote— single fertilized cell (diploid and totipotent) *Totipotent cells-- cells that can form any type of human cell • Morula— ball of cells formed as zygote divides (pluripotent)

Zygote vs. Morula

Zygote (diploid cell, formed from two haploid cells)

Morula— ball of cells formed as zygote divides

Adult stem cells • Taken from adult tissues, such as blood, fat and brain tissue • Multipotent, pluripotent and unipotent types *Unipotent— cells that can develop into one type of cell only

1. Obtaining

UMBILICAL CORD There are many stem cells because

• Because the stem cells are the first that form after fertilization occurs, they are abundant in the placenta and especially in the umbilical cord. • Geneticists obtain them from the cord once the baby has been born, and it is possible to freeze the cord to harvest the stem cells later.

MITOSIS The cells multip according to th genetic program

STEM CELL

A primer on Human Embryonic Stem Cells Blastocyst from In Vitro Fertilization Clinic

Inner Cell Mass (Stem Cells)

“Blueprint” cells

A Blastocyst is a hollow ball of cells with a small clump of stem cells inside

Human Embryonic Stem Cells

Blastocyst from In Vitro Fertilization Clinic

Pipette

Stem Cells

“Blueprint” cells

A Blastocyst is a hollow ball of cells with a small clump of stem cells inside

Stem Cells

“Blueprint” cells

To remove the stem cells, the Blastocyst is opened and the stem cells removed with a pipette

2. Multiplication

Stem Cells

Once isolated, stem cells are cultivated in vitro under special conditions. It is Pipette common to resort to a substrate of irradiated cells, which serve as support without competing for space. Later, every seven days, they need to be Petri Dish separated to keep them from dying and to be able to reproduce them. 16 IS THE LIMIT FOR CULTIVATION. THIS LIMITATION GUARANTEES THE ABSENCE OF A HUMAN EMBRYO. THE EXACT

ACTIVATORS Chemical and hormonal activators guide the

3. Differentiation NEURONS have yet to be grown in the laboratory.

The stem cells are pluripotent, which is to say that they have the power to create any of the more than 200 different cells of the body. This process happens as the embryo grows. If the optimal conditions could be created in vitro, it would be possible to form in a laboratory all

WHITE BLOOD CELL Some tests have managed to produce them. RED BLOOD CELL Generating them in vit has been achieved.

Growth factors

Stem Cells

Pancreat ic

Chemical cues

Petri Dish

Muscl e

Neuro n Different chemicals / molecules are added to the stem cells to make them become specific types of cells.

4. Implantation Doctors and geneticists hope to be able to provide new pluripotent cells to damaged tissue and provoke its regeneration. Graft types 4. Autologous 5. Allogeneic

Potential uses of stem cells

Potential of embryonic stem cell • Cancer therapy: stem cells to replace organ therapy: stem cells to replace organ tissue or regrow organs • Transplants for autoimmune disorders like Lupus • Organ without risk of rejection • Grow insulin producing Beta cells to treat Type I Diabetes • Neurons to restore brain function to patients with Parkinson ’s Disease. • Rebuild an injured spine. • Create replacement skin for a burn victim. • Alzheimer ’s Disease, Lou Gehrig’s Disease,

Companies involved • • • •

RTI Biologics Cytori Therapeutics BioTime Bioheart

• LifeCell is India's first private stem cell bank based in chennai • • • • •

•

Cryo-Save AG (London ) SCCC Index Transition Therapeutics, Inc. StemCells BioMimetic Therapeutics Osteotech Neuralstem RegeneRx Biopharma Athersys Advanced Cell Technology International Stem Cell Corp Aastrom Biosciences Mesoblast

Opposition • Human embryo moral status • Opens the door to reproductive cloning implantation to difficult to enforce. • Perfecting nuclear transplantation techniques that can be used to clone humans • Destruction of innocent human life for research • Biotechnical abolition of the human family. • Degradation of human procreation, manufacturing children without normal familial

Weldon-Stupak Bill & Brownback Bill

Hurdles • After nearly ten years of research, there are no approved treatments or human trials using embryonic stem cells. • ES cells, being pluripotent cells, require specific signals for correct differentiation - if injected directly into another body, ES cells will differentiate into many different types of cells, causing a teratoma. • Differentiating ES cells into usable cells while avoiding transplant rejection are just a few of the hurdles that embryonic stem cell researchers still face. • Potential risk of cancer as stem cells can have unlimited expansion

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