Integrating Cells into Tissues

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Integrating Cells into Tissues

• Sho Momota

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• CAM(Cell-adhesion molecules)
• ECM(Extra cellular matrix)

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ECM

• Proteoglycans
• Collagen fibers
• Multiadhesive matrix proteins

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CAM

• Cadherins
• Ig (immunoglobulin) super family
• Selectins
• Mucins
• integrins

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• Cadherins

Ca
N-teminus
Extra cellular region
cell membrane
50-60 of the sequence is identical among
different cadherins.
C-teminus
Cytoplasm
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Types of cadherin

• More than 40 different cadherins are known
• E-cadherin Preimplantation embryos,
• non-neural epethelial tissue
• P-cadherin Trophblast
• N-cadherin nervous system, lens, cardiac and
• skeletal muscle

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Character of cadherin

• Homophilic (like bind like)
• E-cadherins bind to E-cadherins
• P-cadherins bind to P-cadherins
• E-cadherins usually not bind to P-cadherins

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N-CAMs

• Group of Ca-independent cell-adhesion proteins
• Ig super family of CAMs
• Primarily Homophilic interaction
• Encoded by a single gene.

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Selectin
Blood
Sialyl Lewis-x antigen

• Extravasation of leukocytes
• require the successive formation and breakage of
  cell-cell contacts between leukocytes in the
  blood and endothelial cells lining the vessels

Sugar binding lectin domain
P-selectin

• Endothelial cell

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Integrin

• Heterodimers of ? and ? subunits
• Exhibit relatively low affinities for the ligands

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?IIb?3 integrin
platelet
Accelerates a formation of clot
Collagen or thrombin
Conformational change of ?IIb?3 integrin
Fibrinogen
platelet
Activated platelet
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Deadhesion factors

• Promote cell migration and can remodel the cell
  surface

Disintegrins
ECM
RGD sequence
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De-adhesion factors
CELL
CAM
ECM
Disintegrins
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Question?