Normal tissue development - Morphogenesis

Question 1

What is angiogenesis?

Answer 1

the formation of blood vessels

Question 2

What is Morphogenesis?

Answer 2

change in shape

Question 3

function off epithelial cells?

Answer 3

Cover surfaces of sheets of tubes

Question 4

Morphology of epithelial cells?

Answer 4

cellularity → tightly packed continuous layer, barrier between interior and exterior environments
polarity → distinct apical an basolateral domains
cell-cell adhesion → held together by tight junctions, adherent junctions and desmosomes

Question 5

Morphology Mesenchymal cells

Answer 5

Motility → capable of Movement (not static)
Un polarized → if not motile, no clear polarity like epithelial cells, when migrating then display some features of polarity
interaction with extracellular matrix → able to interact with ECM and prod uce and respond to signals from matrix components, this plans aide in their differentiation and tissue formation

Question 6

what is a Z-stack?

Answer 6

serie of 2D pictures taken at different dephts with a confocal microscope, lagers can be pot en top of each other to analyse the hole structure of an sample without blur or disruption

Question 7

how does juxtacriere signaling work?

Answer 7

• Direct contact cells
• homophilic. and heterophilic binding

Question 8

What do cadherins an Catenins do?

Answer 8

are cell adhesion molecules that create boundaries between tissues

Question 9

features Cadherin s?

Answer 9

• Calcium - dependent adhesion molecules
• Cr usial for intercellular connexions
• Anchored inside cell by catenin’s

Question 10

features Catenins?

Answer 10

• keep Cadherins anchored inside the cell
• 3 types : alfa beta and gamma
• make a bridge between Cadherin and actin cytoskeleton

Question 11

Composition ECM?

Answer 11

• proteoglycans
• fibronectin
• integrins
• intracellular adaptor proteins

Question 12

features proteoglycans?

Answer 12

• Extracellular proteins with sugar attached
• Essential to presenting Paracriene factors to cell surface

Question 13

features fibronectin?

Answer 13

• Very large protein aggregate forming fibrils
• functions as intermediary adhesive molecule
• binds appropriate cell surface molecules : integrins

Question 14

features Integrins?

Answer 14

• name from ability to integrate intracellular and extracellular scaffold
• quaternary structure made of 2 Subunits a and b
• Intracellulary, bind with 2 proteins that connect with actin cytoskelet : a- actin and Talin

Question 15

features Intracellular adaptor proteins?

Answer 15

• Vinculin, Talin and a-Actin are adapter proteins which in tegrate external Signals onto the cytoskeleton
• signal might lead to cell adhesion, cell migration and formation of epithelial sheets

Question 16

what is EMT?

Answer 16

Epithelial - to- Mesenchymal Transition
- loss of epithelial cell characteristics ( polarit y, adhesion )
- start migratory features

Question 17

2 examples of EMT?

Answer 17

gastrolatien and Neurulation

Question 18

features paracriene signaling

Answer 18

• cell communication over distance
• through secreation of proteins into ECM
• proteins secreated → Signaling proteins or ligands
• proteins that bind ligands → Receptors

Question 19

what does the organizer secreate?

Answer 19

• molecules: Chordin,Noggin etc
• This prevents BMP - 4 signaling which causes a different cell fate
• BMP-4, Chordin and Noggin are Morphogens

Question 20

what does BMP-4 do?

Answer 20

induce ectoderm above to become epidermis, action blocked? ectoderm cells are allowed to their default pathway → Nervous tissue of brain and spinal

Question 21

what are Morphogens?

Answer 21

Signaling proteins Which act during development, example Paracriene Signaling

Question 22

what is the equivalence group?

Answer 22

group of cells Which have the potential to become any cells

Question 23

what is Meant whith the french flag model (morphogens)?

Answer 23

long range Indeales that act in a concentration responsive Manner to induce cellular responses

Question 24

what is Meant whith the french flag model (morphogens)?

Answer 24

long range Indeales that act in a concentration responsive Manner to induce cellular responses

Question 25

What is Sonic Hedgehog (SHH)?

Answer 25

• Secreate from embryonic limb bod Which form morphogen gradient
• gradient controls character of cells among the limb

Question 26

what is vulva development an example for?

Answer 26

organogenesis
- cell-to cell communication (juxtacriere and paracriere Signaling)

Question 27

Wnt pathway major role?

Answer 27

• cell-fate specification
• proliferation
• differentiation
• cell polarity
• mophogeresis

Question 28

what does the Wnt Signaling pathway do?

Answer 28

• induces differentiation of Pluripotent stem cells
• hematopoesis
• Neural stem cell proliferation
• induces heart formation during development
• tissue polarity

Question 29

how does the molecular Mechanism of the Wnt Signaling work?

Answer 29

• Wnt absent → Beta-catenin constantly degraded by degradation complex ( Apc)
• If Wnt binds frizzled (receptor) → Beta - catenin degration Inhibited → translocates to nucleus and activates Wnt target gene expression

Question 30

for what are Wnt target genes important?

Answer 30

• cell proliferation
• cell migration
• cell polarization

Question 31

What is APC?

Answer 31

Adenomatous polyposis coli → gene considered to be a gatekeeper in colorectal tomorigenesis
no APC = no beta- catenin degradation → to much proliferation → Wnt not controled

Question 32

Wnt signaling in cancer types?

Answer 32

• Gastrointestinal cancer → loss of APC
• leukemia → Chromosomal translocation affect Wnt Signaling
• Melanoma /
• Breast cancer → Activated Wnt in 50% linked to survival
• Metastasis → Wnt can Enhance EMT

Question 33

Wnt signaling in cancer types?

Answer 33

• Gastrointestinal cancer → loss of APC
• leukemia → Chromosomal translocation affect Wnt Signaling
• Melanoma /
• Breast cancer → Activated Wnt in 50% linked to survival
• Metastasis → Wnt can Enhance EMT