Molecular aspects of implantation

Question 1

Endometrium changes - proliferative stage (2)

Answer 1

Small glands with epithelial cells close together

Dense stroma

Question 2

Endometrium changes - early secretory phase (2)

Answer 2

Glands expansing

Secretory vesicles at basal side of epithelial cells

Question 3

Endometrium changes - mid secretory phase (3)

Answer 3

Further expansion of glands
Secretory vesicles at apical she of epithelial cells
Secreted material into lumen

Question 4

Endometrium changes - late secretory phase (3)

Answer 4

Long extended glands
No secretory vesicles
Oedema in stroma

Question 5

Where are steroid hormone receptors expressed?

Answer 5

Nuclei and storm of epithelial cells

Question 6

When is oestrogen receptor maximum expression?

Answer 6

Late proliferative/early secretory phase

Question 7

What is progesterone receptor maximum expression?

Answer 7

Early secretory phase

Question 8

In which cells do progesterone receptors disease in first?

Answer 8

Epithelial before stroma

Question 9

What type of leucocyte is not in the endometrial stroma?

Answer 9

B cells

Question 10

What are two abnormalities of endometrial function?

Answer 10

RIF

Recurrent miscarriage

Question 11

What is the window of implantation?

Answer 11

Endometrium receptive to embryo

Days 20-23

Question 12

Give 2 moleculs involved in the control of implantation

Answer 12

Proteases
Adhesion molecules (integrins)
Cytokines

Question 13

Give 3 types of trophoblast and their roles

Answer 13

Syncytiotrophoblast - formed inside blood vessles
Extra-villus - invasive, anchoring
Endovascular - invades blood vessels

Question 14

What is decidualisation controlled by? (2)

Answer 14

cAMP

Progesterone

Question 15

What is MMP enzyme activity controlled by? (2)

Answer 15

Expression of actual protein
Pro-MMP (trypsin and plasmin)
TIMPs inhibit

Question 16

What is the production of MMPs controlled by? (3)

Answer 16

Progesterone (decreases)
IL-1, TNFα
hCG

Question 17

What are the roles of proteases in endometrial function? (2)

Answer 17

Implantation - break down of ECM

Menstruation - break down of endometrial tissue

Question 18

Which integrins are cyclically expressed in the endometrium?

Answer 18

αvβ3
α1
α4

Question 19

Where are cytokines expressed? (2)

Answer 19

Pregnant - decidual and epithelial cells

Non-pregnant - epithelial cells

Question 20

Which Th is pregnancy bias towards?

Answer 20

Th2

Question 21

Which cytokines are important for implantation? (2)

Answer 21

IL-11

LIF

Question 22

What are 2 molecular tools/technologies?

Answer 22

Endometrial transcriptomics

Endometrial receptivity array

Question 23

Define recurrent implantation failure

Answer 23

No pregnancy after transfer of at least 3 good quality embryos

Question 24

Which intern may be involved in attachment?

Answer 24

αvβ3

Question 25

What are the roles of integrins? (3)

Answer 25

Mediate cell binding to ECM
Transduce signals from ECM into cells
Regulate gene expression

Question 26

How do we know Th2 is dominant in pregnancy?

Answer 26

Th1 diseases (RA) alleviated during pregnancy
Th2 diseases (SLE) exacerbated