Anita Hall - Stem cells Flashcards
Link between cell signalling and stem cells?
What are the different stages in a cell’s life cycle?
What are the defining features of a stem cell?
What are the different types of stem cells?
Where are embryonic stem cells found? What potency do they have?
What are the three germ layers that a ES cell can differentiate into?
How can ES cells be stably maintained and expanded in vitro?
Ethical issues associated with working on ES cells?
What did John Gurdon discover about stem cells in (1962)?
What did Takahashi & Yamanaka (2006) discover?
When creating IPSCs, how long does reprogramming take and do different combinations of TFs introduced influence the stem cells produced?
Before you can use IPSC in academic research, what do you have to do?
IPSC test - Outline what the teratoma test is?
IPSC test - What is the embryoid body test?
IPSC test - On a genomic level how can we check whether our IPSCs resemble ES cells?
Correct genes are active - Promoters and histones of pluripotency genes expressed (demethylated -active) and pro-differentiation genes are repressed (e.g. methylated) – epigenomic modifications
IPSC test - Growth of an entire organism
What is the main safety concern when working with IPSCs?
What did Hou P. et al show with regards to pluripotent stem cell induction?
Show that pluripotent stem cells can be generated from mouse somatic cells at a frequency up to 0.2% (low) using a combination of seven small-molecule compounds that don’t integrate into the genome – one of these molecule acts via Wnt signalling
The chemically induced pluripotent stem cells resemble embryonic stem cells in terms of their…
a) Gene expression profiles
b) Epigenetic status
c) Potential for differentiation
d) Germline transmission
By using small molecules, exogenous “master genes” are dispensable for cell fate reprogramming (no need to introduce genes) –> This chemical reprogramming strategy has potential use in generating functional desirable cell types for clinical applications.
What are some examples of in-vitro assays performed on stem cells?
What are some examples of in-vivo assays performed on stem cells?
What two techniques are used for stem cell harvesting?
Stem cells harvesting
Selective adhesion - some stem cells have different adhesion molecule which can be taken advantage of
FACS sorting - method for sorting a heterogeneous mixture of biological cells into two or more containers, one cell at a time, based upon the specific light scattering and fluorescent characteristics of each cell.
What is Lineage tracing?
Lineage tracing: a powerful technique and useful to understand
Lineage tracing experiments aim to highlight the full progeny of a given cell/cell population through genetic tagging - tagging stem cells/daughter cell/trans-amplifying cell and its progeny in order to trace them
How is Lineage tracing performed using Cre-Lox as an example
Using the example 82 yr. old ALS patient - explain how Skin cells were converted to iPS cells? What did they check for - think about the intentions?
82 yr. old ALS patient - What did they do to their IPSCs in order to drive differentiation into Motor nuerons?
How did Yang et al. 2013 go about investigating motor nuerons from ALS patients?
What did Marchetto et al., 2010 find out about Rett syndrome using patient derived IPSCs?
In another more recent Rett iPSC study, what did Chin EWM et al., 2016 show?
What did Williams Syndrome patient derived IPSCs show in-vitro?
Summary - Outline how patient derived IPSCs are generated and used in modelling disease phenotypes?
In order to create a desired differentiated cell, do we always have to go back to pluripotency?
What does this figure show?
What are Tissue-specific stem cells?
How to find/identify tissue stem cells?
What are the different ‘controllable parameters’ (things that can change depending on the circumstance) from a stem cell to the fully differentiated cell?
What is the stem cell niche?
Common features of a stem cell niche?
What are transit amplifying (TA) cells?
Outline the crypt structure in the small intestine
Outline the role of Wnt and Shh signals in BMP4 (Bone morphogenetic protein 4) expression in the small intestine crypt
Small intestine - outline the role of EphB in maintaining the organisation of cells in the small intestine
What are the two types of Stem cells found in the small intestine crypt?
What did Luo and Puigserver, Nature 2016 reveal about the role of high fat diet on intestine stem cells?
What are organoids and how are they used in research?
What are skeletal Satellite Cells?
What does the attached image reveal about the Satellite stem cell niche?
How are Satellite cells activated?
How do satellite skeletal muscle stem cells remain quiescent until activated?
Outline how p38 MAPK helps to regulate satellite cell activity?
What observation was made by Cheung, TH et al with regards to miRNA-489 and the cell cycle?
What experimental setup was used to demonstrate the role of miRNA in quiescent adult stem cells? What were the results?
What experiment Rodgers JT at al., Nature, 2014 perform to show the existance of a new G0 state?
Once satellite stem cells are activated, can they divide asymmetrically or symmetrically?
What is Duchenne muscular dystrophy? What happens to satellite cells?
What is a potential future therapy for tackling Duchenne muscular dystrophy?
In what way do old stem cell niches drive disrupt muscle stem cells?
What happens when geriatric muscle stem cells switch from quiescence into senescence?
What is one way that was suggested by Brack et al., Science, 2007 to slow down the rate of satellite cell aging?
What was one signalling molecule that was indentified as having an effect on the presence of non-myogenic cells (non-muslce)?
What effect did ‘young blood’ have on the neural stem cell niche?
Definition of stem cell?
Stem cell - Stem cells are cells that have the ability to differentiate into specific cell types. The two defining characteristics of a stem cell are perpetual self-renewal and the ability to differentiate into a specialized adult cell type, the range of which is determined by the cell’s potency.
Definition of self-renewal & Potency?
Self-renewal - The cell that has the ability to divide and produce progeny that is exactly the same as the originating/parental cell – non-differentiated.
This bears a resemblance to cancer cells but stem cell division is highly regulated in contrast to the uncontrolled proliferation in cancer cells.
Potency - The number of cell types that a stem cell can differentiate into
Note - When approaching defining key words try to include…
Definition
Some molecular biology to help explain
Examples
What are two main advantages of using IPSCs over ES cells?
a) No need for embryo (ethical)
b) Contain genetic information of the patient - useful for studying disease + reduced risk of rejection upon re-introduction
Difference between neuronal and neural stem cells?
Neuronal - only produce neurons
Neural - produce neurons + other CNS cells
Outline the general steps in CNS development?
Outline the process by which the neural tube is formed?
Definition of Neural Stem cells?
Neural stem cells = stem cells of the nervous system that generate neurons and oligodendrocytes and astrocytes in the embryo and the adult CNS
They are a type of ‘tissue-specific’ stem cells (called adult stem cells when not in the embryo)
On a cellular level, explain what changes are occuring to the neural stem cells during development
On a genomic level, outline what changes occur when a neuronal cell gives rise to glial cells?
Are we able to make cerebral organoids?
YEAHHHH BUDDYYY
Can postnatal and adult mammalian brains make new neurons?
What is the brain’s ventricle system?
The ventricular system is a set of four interconnected cavities known as ventricles in the brain. Within each ventricle is a region of choroid plexus which produces the circulating cerebrospinal fluid (CSF).
Ventricular system and the central canal of the spinal cord are lined with ependyma, a specialised form of epithelium connected by tight junctions that make up the blood–cerebrospinal fluid barrier
What are the neural stem cells of the subventricular zone?
In rodents what are the progeny of the neural stem cells of the SVZ?
How does the SVZ stem cell fate differ between humans and rodents?
Is there a transcription factor programme that drives SVZ neural stem cell differentiation?
Why do rodents have the NSCs in the SVZ?
In rodents, what were the neural stem cells in subgranular zone (SGZ) responsible for?
What are the characterisitics of Neural stem cells of the subgranular zone (SGZ) and what type of cells do they produce?
Neural stem cells of the subgranular zone (SGZ) of the dentate gyrus (hc)
Neural stem cells in SGZ = a type of astrocyte/radial glia-like cell (GFAP+, nestin+ (found on immature neural cells) and Sox2+ (associated with neural/fated to be neural))
Quiescent, can self-renew & generate radial-glia like cells, neurons and astrocytes (some say subtypes have varying potency)
The neurons formed are glutamatergic dentate granule cells
What factors contribute towards the final cell fate of SGZ neural stem cells?
Is there any evidence for neurogenesis in the human adult hippocampus SGZ?
What functions do adult neurons generated from SGZ have?
What regulates Adult NSC proliferation?
Neuronal activity nearby can stop SGZ NSC proliferation
Does the vascular system help maintain the neural stem cell niche?
What are some characterisitcs of aging (and/or diseased?) brains when it comes to NSC & neurogenesis?
What is the cancer stem cell hypothesis?
What is Glioblastoma Multiforme (GBM)?
How could we use mesenchymal stem cells to target tumours?
A glioma is a type of tumor that starts in the glial cells of the brain or the spine
Has using neural stem cells (iPSC) to treat dopaminergic neuron loss in Parkinsons disease been succesful?
Where does Dopaminergic neuron development take place?
What is the role of the Isthmus in dopaminergic neuron production?
What signals do DA neurons in the Tegmentum receive during development?
What are the two major Dopaminergic neuron projections in the brain?
What happens during early DA development in the neural tube?
What key TFs are associated with driving progenitor cells to form DA neurons?
- Lmx1a
- Msx1
What are some NSC strategies to help treat and understand Parkinsons diseases? What are some key questions to take into consideration when using neural stem cells to treat Parkinson’s disease?
One strategy: Replace diseased dopaminergic neurons
- How to prevent tumours from formed after transplantation?
- What specific cell do we transplant – neuroblasts (more resilient – trouble differentiating) or DA neurons (less resilient/more fragile – already specialized)
Another NSC based strategy: neuroprotection (transplant supporting cells)
Neuroprotection - provide cell survival factors to allow them to survive for longer
Another use of NSCs in PD research
Modelling the disease in order to understand why dopaminergic neurons die in PD
