Mechanobiology Flashcards
What is mechanotransduction
Conversion of a physical force to a biochemical response
What is mechanosensing?
When a protein or cellular structure responds to a physical cue to initiate mechanotransduction. E.g a cell responding to surface stiffness
What is the signal cascade from mechonosensing?
- Mechanosensing with adhesion receptors
- Signal transduction
- Signal integration in the nucleus. Chromosome rearrangement
- Cellular response
How is blood pressure regulated?
Mechanoresponse to expanding/contracting blood vessels to keep blood pressure constant. When bloodflow is large, the diameter contracts to limit bloodflow to certain organs
Explain auditory mechanotransduction
Movement from sound bends cilia. Ion channels open and cause depolarisation.
How does lung on a chip imitate the gas exchange surface in lungs?
The system has a membrane flanked by endothelium and epithelium. A vacuum is introduced into the side chambers, stretching the cell layers, forming tight junctions
What are organs on chips used to study?
Inflammation, e.g adding TNFα
Neutrophils migrating from endothelial to epithelial layer to engulf bacteria
Why can nanoparticles enter through the alveoli epithelium?
Lungs can undergo mechanical stretching
What is the stiffness equation?
Stress / Strain (Pa)
What is the equation for stress?
F / A (Pa)
What is the equation for strain?
ΔL / L
What can increased tissue stiffness be an indicator of?
Chronic liver disease and cancer. The higher the stiffness in chronic liver disease, the higher the stage.
How is ECM stiffness usually altered around cancerous cells?
EMTs happen, so cell-cell adhesion is disrupted. Actomyosin contractility and cell-ECM adhesion increase
How are cellular mechanical forces measured?
Atomic force microscopy
Micropipette aspiration
Optical tweezers
Magnetic tweezers
Explain atomic force microscopy
A sensitive arm scans a sample and a laser beam is shone on it to show indentation.
