Learning objectives:
I- Modes of migration
II- Mesenchymal cell migration
III- EMT
IV- Amoeboid cell migration
V- Plasticity
I-Modes of Migration
Guidance
• ‘’taxis’’ = cell movement according to an environment cue
• Why do cells move?
- In response to a signal
- Signal can be an attracting or repelling signal
- Today look at attracting signal
• Kinds of signals
- Random migration
Cells do not respond to a specific signal
- Chemokinesis
Similar to chemotaxis but the difference is to responds to chemical
Non-directed movement in response to chemical
- Haptotaxis
Directed movement in response to non-diffusible chemical (ECM)
- Chemotaxis
Cell moves towards soluble factor (molecule or protein, growth factor)
1. Reception of signal
2. Transduction of signal
3. Cellular response
- Cell motility towards or away from the signal
,Stroma
• (tissue), the connective, functionally supportive framework of a biological cell, tissue or organ
• In contrast, the parenchyma is the functional aspect of a tissue.
• Stroma of ovary, soft tissue is well supplied with blood, consisting of spindle-shaped (wide in the middle and tapered at
the ends) cells with a small amount of connective tissue.
Wound Healing
• Tissue:
- Epithelial cells on stroma
- Stroma = part of a tissue that has a connective and structural role. It consists of all the parts which do not carry out
the specific function of the organ i.e. connective tissue, blood vessels, nerve etc.
• GF secreted in the stroma
• Grow monolayer of cells in a medium with serum (contain GF)
• Create a wound by using a pipette tip
• bottom cells have a molecule called b1 integrin that result in cells migrating, changing shape and the wound healing
• top cells do not have integrin = cell migration reduced
Why do cell migrate and its importance
• Cell motility/migration is important for:
1. Morphogenesis
- The development of 3-D tissues
2. Defence against infections
3. Wound healing
- Repair of damaged tissues
, 4. EMT/metastasis
• 2 kinds of cell motility
1. Migration of individual cells: single cell migration
2. Coordinated tissue movement and migration: collective cell migration
Single cell migration
• There are 2 sub-types of single cell migration:
1. Mesenchymal migration
- Elongated morphology
2. Amoeboid migration
- Rounded morphology
- Round cells can also migrate
• Recently in science place cells in 3D