Ai-Chuan Chou's research while affiliated with National Taiwan University and other places

Publications (6)

Article
Optogenetics is an innovative technology now widely adopted by researchers in different fields of the biological sciences. However, most light-sensitive proteins adopted in optogenetics are excited by ultra-violet or visible light which has a weak tissue penetration capability. Upconversion nanoparticles (UCNPs), which absorb near-infrared (NIR) li...
Article
The concentration gradient of K⁺ across the cell membrane of a neuron determines its resting potential and cell excitability. During neurotransmission, the efflux of K⁺ from the cell via various channels will not only decrease the intracellular K⁺ content but elevate the extracellular K⁺ concentration. However, it is not clear to what extent this c...
Article
Silicon nanowire field-effect transistors modified with specific aptamers can directly detect the minute dopamine and neuropeptide Y released from cells. The binding of these molecules to the aptamers results in a conductance change of the transistor biosensor and illustrates the differential releasing mechanisms of these molecules stored in variou...
Article
Full-text available
Changes in intracellular Ca2+ concentrations ([Ca2+]i) are an important signal for various physiological activities. The Na+/Ca2+ exchangers (NCX) at the plasma membrane transport Ca2+ into or out of the cell according to the electrochemical gradients of Na+ and Ca2+ to modulate [Ca2+]i homeostasis. Calmodulin (CaM) senses [Ca2+]i changes and relay...
Article
A silicon nanowire field-effect transistor (SiNW-FET) coated with a polyvinyl chloride (PVC) membrane containing valinomycin (VAL) was employed as a biosensor (referred to as VAL-PVC/SiNW-FET) to detect the K(+)-efflux from live chromaffin cells. The detection sensitivity of K(+) with the VAL-PVC/SiNW-FET covers a broad range of concentrations from...
Article
Full-text available
Vesicle recycling is vital for maintaining membrane homeostasis and neurotransmitter release. Multiple pathways for retrieving vesicles fused to the plasma membrane have been reported in neuroendocrine cells. Dynasore, a dynamin GTPase inhibitor, has been shown to specifically inhibit endocytosis and vesicle recycling in nerve terminals. To charact...

Citations

... UCNP-assisted optogenetics enables less-invasive, deep-tissue accessible, less tissue-damaging, and physically unrestricted activation of proteins with NIR light. Previous literature reports have demonstrated the feasibility of this strategy (Hososhima et al., 2015;Shah et al., 2015;Ai et al., 2017;Lin et al., 2017;Pliss et al., 2017;Wang et al., 2017;Yadav et al., 2017;Chen et al., 2018;Lin et al., 2018;Ma et al., 2019;Miyazaki et al., 2019), most commonly using electrophysiological technique. While electrophysiology is a powerful method to test the functional response of the target protein, mechanistic details on the photocycle of the target protein when activated with NIR radiation remain an open question. ...
... Obviously, silicon nanowire field-effect transistors (SiNW-FETs) represent distinctive advantages regarding the abovementioned intrinsic sensor characteristics [37,38]. As one example, an aptamer-modified SiNW-FET has been developed to detect the K + efflux from rat primary cortical neurons [39]. According to the device configuration, the neurons were first cultured on an external coverslip and later placed on top of the SiNW-FET for the measurement. ...
... The linker chemistry for binding aptamer probes on the FET surface depends on the available functional groups on the aptamers. In the case of thiolated DNA aptamers [49,91,138], a two-molecule linker is usually used (Fig. 6a): first, an amine-terminated silane monolayer (e.g., APTMS) is formed on the gate oxide; then, MBS is reacted with the amine group to impart maleimide groups to the sensor surface. These maleimide groups, in turn, crosslink with the thiol group of the aptamers, thereby immobilizing the aptamers to the sensor surface. ...
... Another fact we have to consider when interpreting our results is that TFP is not only effective to CaM but also CaM has different roles within the cytosol and deals as a multifunctional intermediate calcium-binding messenger protein (Stevens, 1983). Also a compensatory effect through upregulation of plasma membrane Ca 2+ -dependent channels like NCX or PMCA could be an explanation for a less effective SEC62-knockout phenotype of clone1 compared to clone2 (Mohamed et al., 2010;Chou, Ju and Pan, 2015). An additional sign for a compensatory mechanism to counterbalance cellular stress induced by Ca 2+ leakage is also visible in the Ca 2+ imaging experiments. ...
... To monitor the permeability of the cell membrane and to characterize the physiological record of ions on the surface of cell membrane. A nano-sensor was constructed by Chang et al. [97], as shown in Figure 5(a). A silicon nanowire FET (SiNW-FET) was functioned with a polyvinyl chloride (PVC) membrane containing valinomycin (VAL), which was mounted on a microfluidic chip (denoted as VAL-PVC/SiNW-FET) to detect the K + efflux from living chromaffin cells. ...
... Given that Nrp1 is a single-transmembrane co-receptor, we investigated whether endocytosis is involved in LPSaccelerated Nrp1 breakdown. Dynasore is a GTPase inhibitor that can rapidly and reversibly suppress dynamin activity, culminating in the prevention of endocytosis of membrane receptors [19,23]. In a proof-of-principle study, we observed that treatment with dynasore rescued LPS-induced Nrp1 degradation in BMDMs by immunofluorescence staining (Fig. 4a). ...