Lecture 4

Question 1

Proliferative phase

Answer 1

Luminal & glandular epithelium proliferate

Stromal cell proliferation

Endothelial proliferation

Glands enlarge

Estrogen dependent

Question 2

Estrogen dependent

Answer 2

cervical mucus increases

increases progesterone receptors

Question 3

Estrogen receptors

Answer 3

estrogen is lipid soluble so can enter cell freely
receptors ERα and ERβ NHR
membrane bound ER
GPER1 (GPR30) – a G-protein coupled receptor

Question 4

Classic estrogen receptor (ER)

Answer 4

2 forms (a and b) - only ERa critical for normal cyclical uterine growth
activated by estrogen
inhibited by progesterone

Question 5

How does estrogen mediate its effects on uterine epithelium?

Answer 5

Neonatal Balb/c mice don’t have ER on uterine epithelium
CD-1 mice have (some) ER+ and ER– uterine epithelial cells

all respond to estrogen

Question 6

no ER

Answer 6

Suggests oestrogen induces epithelial proliferation through ER on neighbouring stromal cells

Question 7

ERαKO

Answer 7

Cultured on agar plates overnight
Transplanted in adult female nude mice
Ovariectomised after 1 month
Treated +/ - estrogen
Analysed proliferative response (BrdU incorporation)

Question 8

Is the ER necessary?

Answer 8

Epithelial ER are neither necessary or sufficient to mediate mitogenic response to estrogen

Stromal ER (receptor) are obligatory for oestrogen effects

Question 9

How do stromal and epithelial cells communicate?

Answer 9

Paracrine factor? 
	IGF
	EGF
	FGF
	TGF

Question 10

IGF-I – Insulin-like growth factor-I

Answer 10

produced predominantly by stroma
IGF receptor expressed in epithelium
in vitro – IGF stimulates epithelial cell proliferation

in vivo - IGF-I increases during proliferative phase of cycle
Estrogen stimulates IGF-I & receptor expression

Question 11

IGF-I – KO?

Answer 11

uterus 10% of wild-type

epithelial response to estrogen abolished

Question 12

Inhibition of IGF-I receptor prevents E-induced proliferation

Answer 12

E stimulates IGF-I expression in stroma

PPP is an IGF-I receptor inhibitor
PPP (in uterine lumen) blocks E-mediated activation of IGF-I receptor

PPP inhibits E-stimulated epithelial proliferation

Question 13

MOER mouse

Answer 13

MOER female mated with wild-type male = NO pregnancies

uteri atrophic – comparable with total ERα knock out

ovarian abnormalities – cysts & absence of corpus luteum

Question 14

What is needed for normal pregnancy

Answer 14

nuclear ERα needed for normal reproductive function

membrane ERα not sufficient

Question 15

GPER1 (GPR30) knockout mouse

Answer 15

Fertile

Reproductive organs histologically normal

uterine epithelium proliferates in response to estrogen

Question 16

Epithelial ERα is dispensable for proliferation but needed to protect against apoptosis

Answer 16

uterine epithelial-specific ERα knockout generated

E-stimulated proliferation of epithelium maintained

loss of epithelial ERα correlated with increased apoptosis (determined by TUNEL)

Question 17

Does epithelium have any role in regulating response to E?

Answer 17

GPR30 mainly located in epithelium

activated GPR30 using the specific agonist G1

activation of GPR30 prevents
phosphorylation of ERα in stroma

ERα phosphorylation important for
ERα function

Question 18

GPR30

Answer 18

Activation of GPR30 – inhibits E- induced proliferation

May provide negative balance to ERα-dependent uterine growth

Question 19

classical estrogen receptors ERα

STROMAL

Answer 19

epithelial proliferation

stromal proliferation

secretory protein production

Question 20

classical estrogen receptors ERα

EPITHELIAL

Answer 20

epithelial survival

secretory protein production

Question 21

membrane bound ER

Answer 21

insufficient for epithelial proliferation

Question 22

GPER1 (GPR30)

Answer 22

not required for stimulating proliferation may balance ERα actions