Cystic fibrosis (CF) transmembrane conductance regulator (CFTR) chloride channel plays a critical role in regulating transepithelial movement of water and electrolyte in exocrine tissues. Malfunction of the channel because of mutations of the cftr gene results in CF, the most prevalent lethal genetic disease among Caucasians. Recently, the publication of atomic structures of CFTR in two distinct conformations provides, for the first time, a clear overview of the protein. However, given the highly dynamic nature of the interactions among CFTR’s various domains, better understanding of the functional significance of these structures requires an integration of these new structural insights with previously established biochemical/biophysical studies, which is the goal of this review.

Cystic fibrosis transmembrane conductance regulator (CFTR) is unique among ion channels in that after its phosphorylation by protein kinase A (PKA), its ATP-dependent gating violates microscopic reversibility caused by the intimate involvement of ATP hydrolysis in controlling channel closure. Recent studies suggest a gating model featuring an energetic coupling between opening and closing of the gate in CFTR’s transmembrane domains and association and dissociation of its two nucleotide-binding domains (NBDs). We found that permeant ions such as nitrate can increase the open probability (Po) of wild-type (WT) CFTR by increasing the opening rate and decreasing the closing rate. Nearly identical effects were seen with a construct in which activity does not require phosphorylation of the regulatory domain, indicating that nitrate primarily affects ATP-dependent gating steps rather than PKA-dependent phosphorylation. Surprisingly, the effects of nitrate on CFTR gating are remarkably similar to those of VX-770 (N-(2,4-Di-tert-butyl-5-hydroxyphenyl)-4-oxo-1,4-dihydroquinoline-3-carboxamide), a potent CFTR potentiator used in clinics. These include effects on single-channel kinetics of WT CFTR, deceleration of the nonhydrolytic closing rate, and potentiation of the Po of the disease-associated mutant G551D. In addition, both VX-770 and nitrate increased the activity of a CFTR construct lacking NBD2 (ΔNBD2), indicating that these gating effects are independent of NBD dimerization. Nonetheless, whereas VX-770 is equally effective when applied from either side of the membrane, nitrate potentiates gating mainly from the cytoplasmic side, implicating a common mechanism for gating modulation mediated through two separate sites of action.

The variability of blood pressure (BPV) has been suggested as a clinical indicator for cognitive dysfunction, yet the results from clinical studies are variable. This study investigated the relationship between BPV and the risk of cognitive decline or dementia. Bibliographic databases, including PubMed, Scopus, and Embase, were searched systematically for longitudinal cohort studies with BPV measurements and neuropsychological examinations or dementia diagnosis. A traditional meta‐analysis with subgroup analysis, and a further dose‐response meta‐analysis were conducted. Twenty cohort studies with 7 924 168 persons were included in this review. The results showed that a higher systolic BPV (SBPV), when measured with the coefficient of variation (SBP‐CV) or standard deviation (SBP‐SD), was associated with a higher risk of all‐cause dementia diagnosis but not incidence of cognitive decline on neuropsychological examinations. In subgroup analysis, the effect was more prominent when using BPV of shorter timeframes, during shorter follow‐ups, or among the elderly aged more than 65 years. No dose‐response relationship could be found. Our study suggested possible positive associations between SBPV and the risk of dementia. Further studies are required to validate these findings.

Key points: Biochemical and biophysical characterizations of three nonsense mutations of cystic fibrosis transmembrane conductance regulator (CFTR) associated with a severe form of cystic fibrosis (CF) reveal the importance and heterogenous effects of the position of the premature termination codon (PTC) on the CFTR protein function. Electrophysiological studies of W1282X‐CFTR, whose PTC is closer to the C‐terminus of CFTR, suggest the presence of both C‐terminus truncated CFTR proteins that are poorly functional and read‐through, full‐length products. For G542X‐ and E60X‐CFTR, the only mechanism capable of generating functional proteins is the read‐through, but the outcome of read‐through products is highly variable depending on the interplay between the missense mutation caused by the read‐through and the structural context of the protein. Pharmacological studies of these three PTCs with various CFTR modulators suggest position‐dependent therapeutic strategies for these disease‐inflicting mutations. About one‐third of genetic diseases and cancers are caused by the introduction of premature termination codons (PTCs). In theory, the location of the PTC in a gene determines the alternative mechanisms of translation, including premature cessation or reinitiation of translation, and read‐through, resulting in differential effects on protein integrity. In this study, we used CFTR as a model system to investigate the positional effect of the PTC because of its well‐understood structure‐function relationship and pathophysiology. The characterization of three PTC mutations, E60X‐, G542X‐ and W1282X‐CFTR revealed heterogenous effects of these PTCs on CFTR function. The W1282X mutation results in both C‐terminus truncated and read‐through proteins that are partially or fully functional. In contrast, only the read‐through protein is functional with E60X‐ and G542X‐CFTR, although abundant N‐terminus truncated proteins due to reinitiation of translation were detected in E60X‐CFTR. Single‐channel studies of the read‐through proteins of E60X‐ and G542X‐CFTR demonstrated that both mutations have a single‐channel amplitude similar to wild type (WT), and good responses to high‐affinity ATP analogues, suggesting intact ion permeation pathways and nucleotide binding domains (NBDs), albeit with reduced open probability (P_o). The comparison of the P_o of these mutations with the proposed missense mutations revealed potential identities of the read‐through products. Importantly, a majority of the functional protein studied responds to CFTR modulators like GLPG1837 and Lumacaftor. These results not only expand current understanding of the molecular (patho)physiology of CFTR, but also infer therapeutic strategies for different PTC mutations at large.

Objective: To develop evidence-based clinical practice guidelines for non-invasive neuromodulation devices in acute and preventive migraine treatment. Methods: A systematic review was conducted across six databases from 1946 to April 2025. Randomized controlled trials evaluating Food and Drug Administration-cleared or Conformité Européenne (CE)-marked non-invasive neuromodulation devices were included. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology, and recommendations were developed through consensus following GRADE Evidence-to-Decision frameworks. The working group comprised 15 senior members and six junior members. Results: From 1536 initial records, 15 studies met the inclusion criteria and were finally used to develop evidence-based recommendations. Evidence quality ranged from very low to moderate. Weak recommendations were issued for SAVI Dual, Cefaly, Relivion, and Nerivio in the treatment of acute migraine attacks, and for gammaCore Sapphire, Cefaly, and Nerivio in the preventive migraine treatment. Other cleared devices received no recommendations or have no eligible studies for the GRADE assessment. The primary limitations across studies included imprecision due to small sample sizes and various methodological concerns. Additionally, expert consensus recommendations were developed for devices and clinical scenarios not adequately covered by randomized controlled trials, including potential applications in pediatric populations, vestibular migraine, chronic migraine, menstrual migraine, and medication overuse headache. Conclusion: Non-invasive neuromodulation devices offer promising alternatives to drug treatment for migraine management. These devices are safe and generally well tolerated and devoid of drug interactions. While current evidence quality varies, ongoing research and technological advancements show encouraging potential. Future studies should adhere to International Headache Society guidelines for neuromodulation device trials, address proper sham controls and blinding assessment, and account for patient adherence challenges in device use. Expanded insurance coverage would enhance cost-effectiveness and device accessibility. These guidelines provide a framework for clinical decision-making while highlighting areas requiring further research.