Lecture 8 PLURIPOTENT (iPSCs) Models Flashcards
What characterises neurodevelopmental disorders?
Inability to reach cognitive, emotional, and motor developmental milestones
* Associated with disruption of tightly coordinated events in brain development
Which animal model is best to recapitulate human physiology?
Mice
What are 2D cell structures best for?
Genetic manipulation, genome-wide screening, cost, ease of maintennace and duration.
Characteristics of iPSCs
- Infinite self-renewal ability (stemness)
- Pluripotency: ability to differentiate into all three embryonic germ layers
How are iPSCs generated?
From somatic cells in culture
* reprogrammed through ectopic co-expression of defined pluripotency factors
Brain organoids VS 2D models
- 2D: more reproducible and models neuroDEGENERATIVE
- Organoid: cellular interactions and models neuroDEVELOPMENTAL
How are brain organoids made?
- Skin and blood sample taken
- Make fibroblast cells from these samples
- reprogram and create induced pluripotent stem cells (iPSCs)
Assembloids: 3-part body system
- Brain organoid
- Spinal organoid
- Skeletal Muscle organoid
Rett syndrome
- Loss of function variants in MECP2 gene
- X-linked
- Autism, apnea, scoliosis, seizures
The brain of a Rett syndrome patient
Higher neuronal packing density
* smaller neurons
* fewer branches
What does MeCP2 (protein) do? (allegedly)
- Transcriptional repression/activation
- Activation of RNA polymerase complex
- Neg. regulation miRNA processing
- Modulation of higher-order Chromatin arch.
- Alt. Splicing sites
Clinical management of Rett
Regression + core features in > early childhood
* End regression, emergence of multi-systemic conditions > late childhood
* Stabilisation > adulthood
What can we see in brain organoids at different stages?
- 1 month - neuromorphology
- 3 month - synaptic function
- 6 month - synaptic phenotype
Why are orgaoids useful?
- Human relevance and personalisation
- Reduce need for animal
- modelling neuroDEVEL.
- Direct disease mechanism insights
