Table 1.
Summary of electrophysiological detection of ion channel mechanosensitivity.
| Measurements of Mechanosensitivity in Cation Channels | ||||
|---|---|---|---|---|
| Channel | Model Used for Electrophysiological Reading | Nature of the Intervention | Channel Specific Signal Confirmed | Type of Mechanical Stimuli |
| TRPC6 | Cell-attached patch [65,72] | Pipette applied negative pressure | No [65] Yes [72] | 25% tonic mechanical stretch; membrane stretch Osmotic swelling; membrane stretch |
| Excised patch readings of protein reconstituted in liposome [65,73] | Pipette applied negative pressure | Yes (spontaneously active but not stretch responsive) | ||
| Whole-cell patch [74] | Hypo-osmotic treatment | Yes, confirmed with inhibitor: SKF-96365 | ||
| TRPM7 | Excised inside-out patch [75] | Pipette applied negative pressure; suction; osmotic swelling; perfusion-induced mechanical stress | Yes, confirmed in TRPM7 null cells; inhibitor: 2-APB; functional KO | Osmotic swelling; membrane stretch |
| Whole-cell patch [76] | ||||
| TRPV1 | Cell-attached patch [65] | Pipette applied negative pressure (not responsive) | No response detected | Osmotic swelling; membrane stretch |
| TRPV4 | Cell-attached patch [65] | Pipette applied negative pressure (not responsive) | No response detected | Osmotic swelling; membrane stretch |
| Whole cell [77] | Cell indentation with glass rod (no loss of reading with Trpv4 KO) | Yes, confirmed in cells isolated from Trpv4 KO mice +/− | ||
| Outside-out patch [77] | High-speed pressure clamp (no loss of reading with Trpv4 KO) | Yes, confirmed in cells isolated from Trpv4 KO mice +/− TRPV4 agonist | ||
| Piezo1 | Whole cell [78] | Cell indentation with glass rod | Yes, confirmed with siRNA knockdown | Membrane stretch |
| Outside-out patch [79] | High-speed pressure clamp applied positive pressure | Yes, confirmed with siRNA knockdown | ||
| TREK-1 | Inside-out patch; outside out; cell attached [80] | Pipette applied negative pressure (No effect) | Yes (TREK-1 over expressed in COS cells) | Membrane stretch; cell swelling |
| Inside-out patch of protein reconstituted in liposomes (channel spontaneously active) [81] |
Pipette applied positive pressure (inactivates) | Yes, confirmed with TREK-1 inserted in liposome | ||
| KATP | Cell-attached; inside-out; excised-patch; perforated patch whole cell [82] | Negative pressure applied; hypotonic osmotic swelling | Yes, mechanosensitivity dependent on SUR subunit | Membrane stretch; cell swelling |