anat3231: lectures overview - university of new … cell biology stem cell technology ... dong et...

ANAT3231: lectures overview

Dr Annemiek Beverdam – School of Medical Sciences, UNSW Wallace Wurth Building Room 234 – [email protected]

Stem Cell Biology

Stem Cell Technology

Resources: http://php.med.unsw.edu.au/cell biology/

Essential Cell Biology – 3rd edition Alberts

ANAT3231: lecture 1 overview


Stem Cell Biology

Tissue homeostasis and regeneration Stem cell biology Stem cell niches

Stem cell regulation Stem cells and cancer

ANAT3231: lecture 2 overview



Regenerative Medicine Stem Cell Sources

Challenges of Regenerative Medicine Homologous recombination

CRISPR/CAS9 Genome Editing

Regenerative medicine the clinical application of stem cells

"process of replacing or regenerating human cells, tissues or organs

to restore or establish normal function"

Stem Cell Sources for Regenerative Medicine

Multipotent

Stem cells derived from embryos

Stem cells derived from adults

Stem Cell Sources for Regenerative Medicine Waddington's model of epigenetic determination of development

Embryonal Carcinoma Cells are pluripotent

1964 – Pierce and Kleinsmith isolate EC cells from teratocarcinomas Source: gametes

Pluripotent In vitro culture and expansion

Genetic abnormalities

Embryonic Stem Cells are pluripotent

1981 – Martin Evans, Matthew Kaufman and Gail Martin

Pluripotent No genetic abnormalities

In vitro culture and expansion Ethical issues

Adult stem cells

“An undifferentiated cell, found among differentiated cells in a tissue or organ that can renew itself and can differentiate to yield some or all of

the major specialized cell types of the tissue or organ”

-  Bone marrow stem cells: haematopoietic stem cells -  Neural stem cells -  Intestinal stem cells -  Skin stem cells -  Umbilical cord stem cells: haematopoietic stem cells

No ethical issues Restricted plasticity Limited quantities Hard to identify

Somatic Cell Nuclear Transfer John Gurdon, 1958

The developmental potential of nuclei of differentiated cells

Somatic Cell Nuclear Transfer

“mature, differentiated cells can be reprogrammed to become pluripotent”

Pluripotent (totipotent?) Low success rate

Genetic/phenotypic abnormalities Ethical issues

Reproductive/Therapeutic Cloning

Pluripotent (totipotent?) Low success rate

Genetic/phenotypic abnormalities Ethical issues

Nuclear Reprogramming Induced pluripotency (iPS), Yamanaka, 2006


Oct4 Sox2 c-Myc Klf4

2-3 weeks

Nuclear Reprogramming Induced pluripotency (iPS), Yamanaka, 2006


Oct4 Sox2 c-Myc Klf4

Stem Cell Sources Embryonic vs Adult Stem Cells

iPS Cells

-  Can generate any cell type -  Easy to generate, maintain

and grow in lab -  Perfect genetic match to

patient

-  May retain age of parental cell

-  Inheritance of mutations: teratomas

-  No major ethical concerns

The Challenges of Regenerative Medicine

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Future Stem Cell Technologies

1- how we can induce and maintain pluripotency? 2- how we can direct differentiation? 3- how we can cure diseased cells? 4- how we can repair mutations in cells?


How can we direct differentiation? -  Uncontrolled differentiation

-  Directed differentiation

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Future Stem Cell Technologies Directed differentiation of cardiomyocytes

Mummery et al., Circ Res 2012

Future Stem Cell Technologies Directed differentiation of motor neurons

Dong et al., Nature 2014

Pluripotent stem cells

Future Stem Cell Technologies Directed differentiation of pluripotent stem cells


How can we direct differentiation?

Directed differentiation: learn from developmental biology!

Stem Cell Therapy Macular Degeneration

Masayo Takahashi (RIKEN)

iPS on skin cells of patient

Differentiate into retinal pigment epithelium cells

Grow in sheets to transplant in retina

(Surgery on 12 September 2014) keratinocytes


3- how we can cure diseased cells?


How can we cure disease?

Disease Modeling and Drug discovery

(personalized medicine)

Disease Modeling of Spinal Muscular Atrophy Mutations in SMN1

Future of Regenerative Medicine

Svensden Lab, 2009

iPS on skin fibroblasts of SMA patient

Differentiate iPS cells into neurons, astrocytes and motor neurons

Selective death of motor neurons after few weeks of culture

Response to drug to increase SMN1 levels in iSMA-motor neurons

http://www.nature.com/nature/journal/v457/n7227/full/nature07677.html


How can we repair mutations in cells?

Gene Therapy:

Knock out technology

CRISPR/CAS9 genome editing

Crossing over is a natural process that happens during meiosis

Knock out technology = directed homologous recombination in pluripotent ES cells

Homologous Recombination Technology

Mario Capecchi, Olivier Smithies, Martin Evans (2007)

Endogenous gene

ATG

neoR

= regions of homologous DNA sequence

neoR

Targeting vector

Knock out allele

Homologous recombination


Homologous Recombination Technology Engineering of targeting vectors

Repair mutations

*

Homologous Recombination Technology Engineering of targeting vectors

Expressing multiple genes from same GM locus

Gene X

Gene X


Allows us to:

Study gene function in mice

Repair mutations or produce a second protein from a GM locus in ES cells

However:

Heterozygosity in recombined ES cells

(Low rates of homologous recombination)

CRISPR/Cas9 Genome Engineering (Clustered Regularly Interspaced Short Palindromic Repeats)

Guide RNA and Cas9

http://www.youtube.com/watch?v=0dRT7slyGhs

CRISPR/Cas9 Genome engineering Repair

Homology-directed repair: Provide donor template with homology arms

Gene mutation/correction/addition (Cas9 D10A mutant)

Non-homologous end joining: Small insertion/deletion

gene disruption (and occasional errors)

CRISPR/Cas9 Genome engineering Applications in Stem Cells and Mice

ES cells iPS cells

Zygotes

CRISPR/Cas9 Genome engineering Applications in regenerative medicine

http://www.youtube.com/watch?v=0dRT7slyGhs

CRISPR/Cas9 Genome engineering Repair of Cystic Fibrosis Gene CFTR

(cystic fibrosis transmembrane conductor receptor)

Schwank et al., Cell Stem Cell 2013

Forskolin -> CFTR -> expansion

In vitro assay in intestinal organoids:

Stem Cell and Gene Therapy

The Future of Regenerative Medicine

Very hopeful and promising,

but are we there yet?

http://www.sbs.com.au/news/insight/tvepisode/stem-cells

http://iview.abc.net.au/programs/head-first/DO1333V001S00

ANAT3231: lectures overview



Regenerative Medicine Stem Cell Sources

Challenges of Regenerative Medicine Homologous Recombination

CRISPR/CAS9 Genome Editing

anat3231: lectures overview - university of new … cell biology stem cell technology ... dong et...

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