L15 Pregnancy Research Models Flashcards
Define 2D cell culture:
Culturing decidua, trophoblasts, myometrium, HEKs etc.
2 advantages of 2D cell culture
- Cheap
- Can isolate single cells instead of commercial cell lines
3 limitations of 2D culture
- Each passage gives chance for divergence (selective pressure within flask etc) -> very far from original phenotype commercialized in older lines
- Can be based on abnormal conditions (e.g. carcinoma for Bwo)
- Tissue harvesting: ethical approval (differences in geography)
What is a transwell system?
Using a monolayer of cells with the ability to migrate (exposing them to ex-culture medium; useful for mechanics of disease involving invasion of spiral arteries (e.g. preeclampsia))
Advantages of transwell compared to 2D cell culture vs limitations:
- Can study more cell-cell interaction
- Similar limitations
What is explant culture?
Fresh placental tissue supported in culture (typically villous placental tissue)
Give 3 advantages of explant culture:
- Lots of cell-cell interactions including on a structural level
- Multiple cell types (global response of the tissue as a unit -> even conditional responses)
- Naturally 3D as it has placental structure
Give 3 limitations of explant culture:
- Technically difficult to mimic environment (O2 etc)
- Lifespan (11 days) -> need to resupply, difficult in UK
- Are changes due to experiment or due to damage of the culture -> extremely careful controls required
What are spheroids and organoids?
Spheroids:
- ESC derived
- More simple (don’t require matrix support)
Organoid:
- Show polarity as they would in vivo, more complex
- More physiologically relevant, 3D
- Multiple cell types
Limitations of spheroids and organoids?
- Access to tissues
- Spheroid has limited viability
- Organoids are labour intensive and time consuming to set up
What is organ on chip?
- Small wells with microfluidic connections -> complex interactions carefully regulated
- Channels filled with collagen to represent basement membrane
2 advantages of organ on chip
- Useful in looking at complex interactions (as in pregnancy; very compartmentalised
- Very small amounts of cells and medium (cost saved)
2 disadvantages of organ on chip
- Expensive; either commercial or recruit an engineer specifically to make your own
- Lack of literature (does this look right?)
- Very time consuming
Applications of zebrafish:
- Useful for embryo development (transparent)
- Not useful for obstetrics or gestational disease
Advantages of mouse models:
- Mouse embryo culture
- Small animal, easy to handle
- Large litter size -> multiple outcomes at a time
- Easy to breed and maintain
- Availability of ESCs
- Short gestation time
- Good model for early pregnancy
Limitations of mouse models:
- Prominent yolk sac, altricial young, shallow trohphoblast invasion, fewer placental hormones -> lots of physiological differences to humans limit the applicability of results
- Genetic similarities have a considerable drop off by 16 weeks -> irrelevant for a lot of pregnancy disorders
Advantages of sheep models:
- Easily handled, withstand surgery well
- Fetal lamb roughly same weight as human fetus at term
- Similarity of response to IUGR as human fetus
- Precocial young (?) -> humans somewhere inbetween
- Long gestation -> long term effects of fetal exposures
- Overall: more relevant for studying obstetrics
Limitations of sheep models:
- Sheep trophoblast do not invade the uterine walls as in human pregnancy
- High maintenance cost (outdoor environment, more sophisticated training associated with labour cost)
- Less availability of Abs (specialist product)
- Not suitable for PE as sheep don’t have deep spiral arteries
Advantages of rhesus macaque models:
- Very relevant to humans (reproductive cycle with spontaneous ovulation and menstrual bleeding, similar placental structure)
Limitations of rhesus macaque models:
- Practically difficult -> extensive training
- Difficult to breed
- Ethical debates to extent of exposures and interventions
Sources of molecular materal:
- Fluid (blood, saliva, amniotic fluid)
- Biopsies
Imaging data sources:
- MRI
- X-ray (low relevancy)
- CT
- USS
- Accessible and generally widespread technology
