Stem Cells Revised for Bio 1

8/2/2019 Stem Cells Revised for Bio 1

1/23

STEM CELLS

SD Jacinto

Bio 1

Institute of Biology

UP Diliman


2/23

Stem Cells: ScientificProgress and FutureResearch Directions


3/23

All about stem cells

Unspecialized cells

Capable ofrenewing themselves for long

periods by cell division Under special conditions can be induced to

differentiate into many types of cells withdifferent functions (e.g. myocardiocytes,

insulin producing cells) 2 types Embryonic and Adult


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Important Areas of Research

Why embryonic stem cells proliferate for a yearor more in the lab w/out differentiating but mostadult stem cells cannot

What are the factors in living organisms thatnormally regulate stem cell proliferation and selfrenewal

What are the signals in mature organism causing

stem cells to proliferate and remainunspecialized until the cells are needed for repairof a specific tissue

http://stemcells.nih.gov/info/basics/basics3.asp


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Important Areas of Research (contd)

Are signals for differentiation similar forall stem cell types

Can specific signals be identified that

promote differentiation into specific celltypes


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Embryonic stem cell (ESC) research

E stem cells are derived from ICM blastocysts ofinvitro fertilization

Tested to measure fundamental properties

E.g. morphological stability, presence of molecular surfacemarkers, chromosomal number, viability after freezing andthawing, pluripotency


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ESC and directed differentiation

By changing chemical composition of culturemedium, alter the surface of culture dish or maketransgenic cells

If directed differentiation is reliable andreproducible, ESC can be used to treat certaindiseases in the future e.g. Parkinsons disease,

traumatic spinal cord injury, Purkinje cellsdegeneration, Duchennes muscular dystrophy,heart disease and vision and hearing loss


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http://stemcells.nih.gov/info/basics/basics3.asp


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Adult Stem Cell (ASC) research

Also called somatic stem cells

Undifferentiated cells found among differentiatedcells in a tissue or organ Can renew itself

Can differentiate to yield major specialized cell types of thetissue or organ

1o role is to maintain and repair

Origin is unknown


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Adult Stem Cell (ASC) research (contd)

Research in mice showed that brain has stemcells that can differentiate into connectivetissue cells and neurons

Plasticitywas also discovered

http://stemcells.nih.gov/staticresources/info/scireport/PDFs/chapter8.pdf


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Where ASC are found

Brain, bone marrow, peripheral blood, blood vessels,skeletal muscles, skin and liver

ASC occur invery small number in each tissue; are

quiescent for many years until they are called to dutyduring injury or disease


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Potential Uses of SC

May yield information about events occurringduring human development

May yield information on how diseases arise andmay suggest new strategies for therapy

Used for drug screening

Generation of cells and tissues to be used for cellbased therapy


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Relevant alternatives

The case of the induced pluripotent stem cells

Cord blood banking


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http://www.google.com.ph/imgres?imgurl=http://www.medgadget.com/archives/img/768768ccs.jpg&imgrefurl=http://karthikkn.wordpress.com/2010/07/24/induced-pluripotent-stem-cells-ips-cells-rewindreprogram-and-

replace/&h=473&w=468&sz=58&tbnid=mxcftLsiNU8LzM:&tbnh=129&tbnw=128&prev=/images%3Fq%3Dinduced%2Bpluripotent%2Bstem%2Bcells&zoom=1&q=induced+pluripotent+stem+cells&hl=en&usg=__647dquEKjGNl5DLiHRS2f0E2Pig=&sa=X&ei=AZuhTPXkFofyvQOizNjgAw&ved=0CDcQ9QEwBA

iPSC


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Proliferate extensively and generate sufficientquantities of tissue.

Differentiate into the desired cell type(s).Survive in the recipient after transplant.Integrate into the surrounding tissue aftertransplant.

Function appropriately for the duration of therecipient's life.Avoid harming the recipient in any way.

To be useful for transplant purposes, stemcells must be reproducibly made to:


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: www.nih.gov/news/stemcell/ primer.htm
http://www.nih.gov/news/stemcell/primer.htmhttp://www.nih.gov/news/stemcell/primer.htm


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Oocytes/spermatozoa from stem cells

Possible issues for and against

In a development that could alter the ethical landscapesurrounding human embryonic stem (ES) cells, scientistshave found that mouse ES cells can develop into oocytes in

culture dishes.

It is not yet clear whether the cells can be fertilized anddevelop into embryos. But if so, and if human ES cells turnout to have similar powers, such cells might allow researchers

to get around some of the expense and ethical questions thatarise from using donated eggs for therapeutic cloningexperiments.

http://www.vetscite.org/publish/items/001224/index.html


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: easyweb.easynet.co.uk/ ~sfl/rlb_stem.htm
http://easyweb.easynet.co.uk/~sfl/rlb_stem.htmhttp://easyweb.easynet.co.uk/~sfl/rlb_stem.htm


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The Woo Suk Hwang fraud

From National University of Seoul-fakedproduction of human cloned embryo

Faked production of11 patient tailored cell lines

from embryonic clones


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Thats all fornow

Documents

Stem Cells Revised for Bio 1