Growth Factors

Question 1

Growth factors

Answer 1

substances capable of inducing cell growth, proliferation, and/or differentiation

Question 2

Protein Growth Factors to remember

Answer 2

Nerve (NGF), Epidermal, TGF-beta family, TGF-alpha family, Fibroblast, Vascular Endothelial (VEGF), Insulin-like

Question 3

Do growth factors generally bind cell membrane receptors?

Answer 3

Yes

Question 4

Nerve Growth Factors

Answer 4

• Promotes growth, maintenance, and survival of certain target neurons
• Can also activate apoptosis (p75)

Question 5

Receptors for NGF

Answer 5

TrkA and p75NTR

Question 6

Which NGF receptor promotes apoptosis?

Answer 6

p75NTR

Question 7

Epidermal Growth Factor

Answer 7

Promotes proliferation, differentiation and survival.

Question 8

HER-2

Answer 8

growth factors; Over expression of HER-2 = breast cancer

Question 9

TGF-beta Super family

Answer 9

• Extremely broad family that regulates many different things
• TGF-beta subfamily
• Drosphilia related including bone morphogenic proteins (BMPs) and myostatin
• Regulators of sex organ development

Question 10

Genes for many growth factors or their receptors are…?

Answer 10

Proto-oncogenes

Question 11

The majority of growth factors are translated as what form and undergo what processing by members of the pro protein convertase family

Answer 11

Pro-form and they undergo proteolytic processing

Question 12

Furin

Answer 12

molecular scissors, Recognizes specific cleavage sites and cuts proteins at those cleavage sites to activate growth factors.

Question 13

Pro-form of growth factors

Answer 13

Long form that must be cleaved via furin in order to reveal portion of growth factor that can be used

Question 14

TGF-beta is very often working through…

Answer 14

Serine threonine kinases (type II receptors) and SMADs (type I receptor)

Question 15

Canonical or classical pathway for TGF-beta is dependent upon what?

Answer 15

SMADs

Question 16

Myostatin is a member of what family?

Answer 16

TGF-beta

Question 17

Growth factors and _____ affect various steps in wound healing

Answer 17

cytokines

Question 18

Phase of wound healing

Answer 18

1. Hemostasis
2. Inflammatory phase
3. Proliferative phase
4. Remodeling phase

Question 19

Growth factors are in ____ ____ parts of the tissue and expressed in ____ patterns.

Answer 19

multiple different; overlapping

Question 20

Growth factors are often ____ and ____ restricted with regard to their pattern of expression.

Answer 20

temporally; spatially