Background: Endothelial-to-mesenchymal transition (EndMT) has been identified as a critical driver of vascular inflammation and atherosclerosis, and TGF-β (transforming growth factor β) is a key mediator of EndMT. Both EndMT and atherosclerosis are promoted by disturbed flow, whereas unidirectional laminar flow limits EndMT and is atheroprotective. How EndMT and endothelial TGF-β signaling are regulated by different flow patterns is, however, still poorly understood. Methods: Flow chamber experiments in vitro and endothelium-specific knockout mice were used to study the role of tenascin-X in the regulation of EndMT and atherosclerosis as well as the underlying mechanisms. Results: In human endothelial cells as well as in human and mouse aortae, unidirectional laminar flow but not disturbed flow strongly increased endothelial expression of the extracellular matrix protein TN-X (tenascin-X) in a KLF4 (Krüppel-like factor 4) dependent manner. Mice with endothelium-specific loss of TN-X (EC-Tnxb-KO) showed increased endothelial TGF-β signaling as well as increased endothelial expression of EndMT and inflammatory marker genes. When EC-Tnxb-KO mice were subjected to partial carotid artery ligation, we observed increased vascular remodeling. EC-Tnxb-KO mice crossed to low-density lipoprotein receptor-deficient mice showed advanced atherosclerotic lesions after being fed a high-fat diet. Treatment of EC-Tnxb-KO mice with an anti-TGF-beta antibody or additional endothelial loss of TGF-beta receptors 1 and 2 normalized endothelial TGF-beta signaling and prevented EndMT. In in vitro studies, we found that TN-X through its fibrinogen-like domain directly interacts with TGF-β and thereby interferes with its binding to the TGF-β receptor. Conclusions: In summary, we show that TN-X is a central mediator of flow-induced inhibition of EndMT, endothelial inflammation and atherogenesis, which functions by binding to and by blocking the activity of TGF-β. Our data identify a novel mechanism of flow-dependent regulation of vascular TGF-β, which holds promise for generating new strategies to prevent vascular inflammation and atherosclerosis.

Idiopathic pulmonary fibrosis (IPF) is a devastating interstitial lung disease characterized by the excessive accumulation of activated myofibroblasts that deposit extracellular matrix (ECM) protein, leading to progressive scar formation and mechanical stress. However, the cellular origin and fate of myofibroblasts remain controversial, and the mechanisms by which myofibroblasts sense mechanical cues in the lung are unclear. Here, we report that periostin (Postn) is a reliable and distinctive marker for pulmonary myofibroblasts, while ablation of Postn ⁺ myofibroblasts after injury ameliorated lung fibrosis. PIEZO1 was highly expressed in Postn ⁺ myofibroblast and played a vital role in mechanoactivation of Postn ⁺ myofibroblast and development of lung fibrosis. Conditional deletion of Piezo1 in Postn ⁺ myofibroblasts significantly inhibited lung fibrosis by suppressing myofibroblast activation and proliferation. Loss of Piezo1 led to disruption of actin organization and prevention of Yap/Taz nuclear localization, thus shifting the myofibroblasts from a proliferative state into a stressed and apoptotic state. Furthermore, myofibroblast-specific Yap/Taz deletion fully recapitulated the protective phenotypes of myofibroblast- Piezo1 –KO mice. These findings show that periostin marks pulmonary myofibroblasts, and that PIEZO1-mediated mechanosensation is essential for myofibroblast activation in the lung. Targeting PIEZO1 in the periostin-expressing cells is a novel therapeutic option to interfere with fibrotic diseases such as IPF .

Timothy syndrome is a rare disorder caused by CACNA1C gene mutations and characterized by multi-organ system dysfunctions, including ventricular arrhythmias, syndactyly, dysmorphic facial features, intermittent hypoglycemia, immunodeficiency, developmental delay, and autism. Because of the low morbidity and high mortality at a young age, it remains a huge challenge to establish a diagnosis and treatment system to manage Timothy syndrome patients. Here, we aim to provide a detailed review of Timothy syndrome, discuss the mechanisms underlying dysfunctional Cav1.2 due to CACNA1C mutations, and provide some new emerging evidences in treating Timothy syndrome from cell to bedside, promoting the management of this rare disease. Impact statement: The knowledge of Timothy syndrome (TS) caused by dysfunctional Cav1.2 channel due to CACNA1C mutations is rapidly evolving as novel technologies of electrophysiology are introduced and our understanding of the mechanisms of TS develops. In this review, we focus on the TS-related dysfunctional Cav1.2 and the underlying mechanisms. We update TS-related CACNA1C mutations in a precise way over the past 20 years and summarize all reported TS patients based on their clinical presentations and molecular mechanisms, respectively. We hope this review will provide a new comprehensive way to better understand the electrophysiological mechanisms underlying TS from cell to bedside, promoting the management of TS in practice.

Rationale: Positive airway pressure (PAP) is the first-choice treatment for obstructive sleep apnea (OSA). However, its real-world effectiveness is often questioned because of usage issues. The relationship between patient sleepiness and PAP usage has been assessed in relatively small and selected populations within the research context. Objectives: To assess the impact of patient-reported sleep outcomes, particularly self-reported sleepiness and its change during therapy, on PAP usage in the real-world setting. Methods: Deidentified data for U.S.-based patients receiving PAP therapy were examined. Eligible patients were registered in the myAir app and provided self-reported sleepiness at baseline and after 7, 14, 21, and 28 days of PAP between November 2019 and April 2020. Results: A total of 95,397 registered patients met all eligibility criteria and were included in the analysis (mean age, 49.6 ± 13.0 yr; 61.6% male). Daytime sleepiness was the most common reason for PAP therapy initiation (57.1% of patients), and 42.2% of all patients had self-reported moderate to severe OSA. Self-reported sleepiness improved with PAP therapy in most patients over the assessment period, with 62.1% of patients reporting “no” or “slight” sleepiness at Day 28. There was a dose-dependent association between improvement in self-reported sleepiness at Day 28 and PAP usage, and this finding was maintained at Day 360. Self-reported sleepiness at Day 28 was associated with achieving U.S. Centers for Medicare & Medicaid Services compliance at 90 days (approximately 90% for those with no or slight sleepiness vs. <70% for those with residual very or extreme sleepiness); average daily PAP usage over 360 days was ⩾5.0 and ⩽3.7 hours, respectively, for those with no or slight versus very or extreme sleepiness. Conclusions: This study demonstrates the feasibility of capturing patient-reported outcomes via a digital platform. Patient-reported outcomes appear to be associated with PAP usage, especially self-reported sleepiness and its response to therapy. Capturing patient-reported outcomes using digital solutions during the course of treatment has the potential to enhance patient outcomes by providing actionable insights.

A new method involving a thread-based microfluidic three channel device in combination with thermal lens detection was developed for the sequential determination of Cu(ii) and Zn(ii).