Unusual effects of a nanoporous gold substrate on cell adhesion and differentiation because of independent multi-branch signaling of focal adhesions

Abstract A variety of cell behaviors, such as cell adhesion, motility, and fate, can be controlled by substrate characteristics such as surface topology and chemistry. In particular, the surface topology of substrates strongly affects cell behaviors, and the topological spacing is a critical factor in inducing cell responses. Various works have demonstrated that cell adhesion was enhanced with decreasing topological spacing although differentiation progressed slowly. However, there are exceptions, and thus, correlations between topological spacing and cell responses are still debated. We show that a nanoporous gold substrate affected cell adhesion while it neither affected osteogenic nor adipogenic differentiation. In addition, the cell adhesion was reduced with decreasing pore size. These do not agree with previous findings. A focal adhesion (FA) is an aggregate of modules comprising specific proteins such as FA kinase, talin, and vinculin. Therefore, it is suggested that because various extracellular signals can be independently branched off from the FA modules, the unusual effects of nanoporous gold substrates are related to the multi-branching of FAs. Graphical Abstrac

Sleep-Disordered Breathing Is an Independent Risk Factor of Aborted Sudden Cardiac Arrest in Patients With Coronary Artery Spasm

Background: Sleep-disordered breathing (SDB) is often associated with sudden cardiac arrest (SCA) during sleep. Coronary artery spasm (CS) also occurs during sleep and is rarely associated with SCA, but the role of SDB in the risk of SCA is unknown in CS patients. This study evaluated the breathing patterns during sleep in CS patients with a prior history of aborted SCA. Methods and Results: This study enrolled 24 patients (age 61.6±11.0 years, male/female 19/5) with CS proven by an acetylcholine provocation test. They were divided into 2 groups: prior history of aborted SCA due to fatal arrhythmia (SCA group; n=9) and no such history (no-SCA group; n=15). Patients underwent overnight polysomnography with ambulatory electrocardiography. The overall prevalence of SDB (apnea hypopnea index ≥15) was 45.8% in this cohort. SDB was more frequent in the SCA group than in the no-SCA group (88.9% vs. 20.0% P=0.001) and identified as a pivotal risk factor of aborted SCA (odds ratio: 38.9, 95% CI: 2.80–1,498.2, P=0.01). Very-low-frequency was significantly correlated with the apnea hypopnea index in patients with SCA (P=0.01, r=0.78) during sleep. Conclusions: SDB is a significant risk factor for SCA in CS patients and autonomic instability during sleep might be involved in this association.  (Circ J 2012; 76: 2204–2210