Channels (Austin, Tex.)最新文献

{"title":"Biophysical and structural mechanisms of epilepsy-associated mutations in the S4-S5 Linker of KCNQ2 channels.","authors":"Inn-Chi Lee, Yen-Yu Yang, Hsueh-Kai Chang, Swee-Hee Wong, Shi-Bing Yang","doi":"10.1080/19336950.2025.2464735","DOIUrl":"10.1080/19336950.2025.2464735","url":null,"abstract":"<p><p>Mutations in <i>KCNQ2</i> are linked to various neurological disorders, including neonatal-onset epilepsy. The severity of these conditions often correlates with the mutation's location and the biochemical properties of the altered amino acid side chains. Two mutations affecting aspartate at position 212 (D212) in the S4-S5 linker of KCNQ2 have been identified. Interestingly, while the charge-conserved D212E mutation leads to severe neonatal-onset developmental and epileptic encephalopathy (DEE), the more dramatic substitution to glycine (D212G) results in self-limited familial neonatal epilepsy (SLFNE), a much milder pathology. To elucidate the underlying mechanisms, we performed electrophysiological studies and <i>in silico</i> simulations to investigate these mutations' biophysical and structural effects. Our findings reveal that the D212E mutation stabilizes the channel in the voltage sensor down-state and destabilizes the up-state, leading to a rightward shift in the voltage-dependent activation curve, slower activation kinetics, and accelerated deactivation kinetics. This disruption in KCNQ2 voltage sensitivity persists even in the more physiologically relevant KCNQ2/3 heterotetrameric channels. In contrast, the D212G mutation primarily destabilizes the up-state, but its impact on voltage sensitivity is significantly reduced in KCNQ2/3 heterotetrameric channels. These findings provide key insights into the biophysical and structural basis of <i>KCNQ2</i> D212 mutations and their contribution to epilepsy-related symptoms, offering a clearer understanding of how these mutations drive the varied clinical outcomes observed in patients.</p>","PeriodicalId":72555,"journal":{"name":"Channels (Austin, Tex.)","volume":"19 1","pages":"2464735"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11845087/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143460980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrophysiological characterization of sourced human iPSC-derived motor neurons.","authors":"Bohumila Jurkovicova-Tarabova, Robin N Stringer, Zuzana Sevcikova Tomaskova, Norbert Weiss","doi":"10.1080/19336950.2025.2480713","DOIUrl":"10.1080/19336950.2025.2480713","url":null,"abstract":"<p><p>Induced pluripotent stem cell (iPSC)-derived motor neurons provide a powerful platform for studying motor neuron diseases. These cells enable human-specific modeling of disease mechanisms and high-throughput drug screening. While commercially available iPSC-derived motor neurons offer a convenient alternative to time-intensive differentiation protocols, their electrophysiological properties and maturation require comprehensive evaluation to validate their utility for research and therapeutic applications. In this study, we characterized the electrophysiological properties of commercially available iPSC-derived motor neurons. Immunofluorescence confirmed the expression of motor neuron-specific biomarkers, indicating successful differentiation and maturation. Electrophysiological recordings revealed stable passive membrane properties, maturation-dependent improvements in action potential kinetics, and progressive increases in repetitive firing. Voltage-clamp analyses confirmed the functional expression of key ion channels, including high- and low-voltage-activated calcium channels, TTX-sensitive and TTX-insensitive sodium channels, and voltage-gated potassium channels. While the neurons exhibited hallmark features of motor neuron physiology, high input resistance, depolarized resting membrane potentials, and limited firing capacity suggest incomplete electrical maturation. Altogether, these findings underscore the potential of commercially available iPSC-derived motor neurons as a practical resource for MND research, while highlighting the need for optimized protocols to support prolonged culture and full maturation.</p>","PeriodicalId":72555,"journal":{"name":"Channels (Austin, Tex.)","volume":"19 1","pages":"2480713"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11938304/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143702178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the potential for gene therapy in Cav1.4-related retinal channelopathies.","authors":"Matthias Ganglberger, Alexandra Koschak","doi":"10.1080/19336950.2025.2480089","DOIUrl":"10.1080/19336950.2025.2480089","url":null,"abstract":"<p><p>The visual process begins with photon detection in photoreceptor outer segments within the retina, which processes light signals before transmission to the thalamus and visual cortex. Cav1.4 L-type calcium channels play a crucial role in this process, and dysfunction of these channels due to pathogenic variants in corresponding genes leads to specific manifestations in visual impairments. This review explores the journey from basic research on Cav1.4 L-type calcium channel complexes in retinal physiology and pathophysiology to their potential as gene therapy targets. Moreover, we provide a concise overview of key findings from studies using different animal models to investigate retinal diseases. It will critically examine the constraints these models present when attempting to elucidate retinal channelopathies. Additionally, the paper will explore potential strategies for addressing Cav1.4 channel dysfunction and discuss the current challenges facing gene therapy approaches in this area of research.</p>","PeriodicalId":72555,"journal":{"name":"Channels (Austin, Tex.)","volume":"19 1","pages":"2480089"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11938310/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143702190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of the C-terminal domain in modifying pH-dependent regulation of Ca_v1.4 Ca²⁺ channels.","authors":"Juan de la Rosa Vázquez, Amy Lee","doi":"10.1080/19336950.2025.2473074","DOIUrl":"10.1080/19336950.2025.2473074","url":null,"abstract":"<p><p>In the retina, Ca²⁺ influx through Ca_v1.4 Ca²⁺ channels triggers neurotransmitter release from rod and cone photoreceptors. Changes in extracellular pH modify channel opening, enabling a feedback regulation of photoreceptor output that contributes to the encoding of color and contrast. However, the mechanisms underlying pH-dependent modulation of Ca_v1.4 are poorly understood. Here, we investigated the role of the C-terminal domain (CTD) of Ca_v1.4 in pH-dependent modulation of Ba²⁺ currents (<i>I</i>_<i>Ba</i>) in HEK293T cells transfected with the full length Ca_V1.4 (FL) or variants lacking portions of the CTD due to alternative splicing (Δe47) or a disease-causing mutation (K1591X). While extracellular alkalinization caused an increase in <i>I</i>_<i>Ba</i> for each variant, the magnitude of this increase was significantly diminished (~40-50%) for both CTD variants; K1591X was unique in showing no pH-dependent increase in maximal conductance. Moreover, the auxiliary α₂δ-4 subunit augmented the pH sensitivity of <i>I</i>_<i>Ba</i>, as compared to α₂δ-1 or no α₂δ, for FL and K1591X but not Δe47. We conclude that the CTD and α₂δ-4 are critical determinants of pH-dependent modulation of Ca_v1.4 and may influence the processing of visual information in normal and diseased states of the retina.</p>","PeriodicalId":72555,"journal":{"name":"Channels (Austin, Tex.)","volume":"19 1","pages":"2473074"},"PeriodicalIF":0.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11934190/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role and mechanism of vascular wall cell ion channels in vascular fibrosis remodeling.","authors":"Xiaolin Zhang, Hai Tian, Cheng Xie, Yan Yang, Pengyun Li, Jun Cheng","doi":"10.1080/19336950.2024.2418128","DOIUrl":"10.1080/19336950.2024.2418128","url":null,"abstract":"<p><p>Fibrosis is usually the final pathological state of many chronic inflammatory diseases and may lead to organ malfunction. Excessive deposition of extracellular matrix (ECM) molecules is a characteristic of most fibrotic tissues. The blood vessel wall contains three layers of membrane structure, including the intima, which is composed of endothelial cells; the media, which is composed of smooth muscle cells; and the adventitia, which is formed by the interaction of connective tissue and fibroblasts. The occurrence and progression of vascular remodeling are closely associated with cardiovascular diseases, and vascular remodeling can alter the original structure and function of the blood vessel. Dysregulation of the composition of the extracellular matrix in blood vessels leads to the continuous advancement of vascular stiffening and fibrosis. Vascular fibrosis reaction leads to excessive deposition of the extracellular matrix in the vascular adventitia, reduces vessel compliance, and ultimately alters key aspects of vascular biomechanics. The pathogenesis of fibrosis in the vasculature and strategies for its reversal have become interesting and important challenges. Ion channels are widely expressed in the cardiovascular system; they regulate blood pressure, maintain cardiovascular function homeostasis, and play important roles in ion transport, cell differentiation, proliferation. In blood vessels, different types of ion channels in fibroblasts, smooth muscle cells and endothelial cells may be relevant mediators of the development of fibrosis in organs or tissues. This review discusses the known roles of ion channels in vascular fibrosis remodeling and discusses potential therapeutic targets for regulating remodeling and repair after vascular injury.</p>","PeriodicalId":72555,"journal":{"name":"Channels (Austin, Tex.)","volume":"18 1","pages":"2418128"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11492694/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142482288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A phenylalanine at the extracellular side of Kir1.1 facilitates potassium permeation.","authors":"Henry Sackin, Mikheil Nanazashvili","doi":"10.1080/19336950.2023.2294661","DOIUrl":"10.1080/19336950.2023.2294661","url":null,"abstract":"<p><p>The Kir1.1 (ROMK) family of weak inward rectifiers controls K secretion in the renal CCT and K recycling in the renal TALH. A single point mutant of the inward rectifier, F127V-Kir1.1b was used to investigate the K transition between the selectivity filter and the outer mouth of the channel. We hypothesize that normally an aromatic <i>Phe</i> at the external entryway of Kir1.1b facilitates outward K secretion. We tested this by replacing F127-Kir1.1b with a small aliphatic <i>Val</i>. Results indicate that removal of the <i>Phe</i> at 127 suppresses outward currents that normally contribute to K secretion. Results with the F127V mutant could be explained by increased polyamine block and/or a decrease in the avidity of Kir1.1 for K ions near the outer mouth of the channel. The latter is supported by F127V-Kir1.1b having a lower affinity (K_m = 33 mM) for K than wild-type Kir1.1b (K_m = 7 mM) during external K elevation. Conversely, chelation of K with 18-Crown-6 ether reduced K conductance faster in F127V (half-time = 6s) than in wt-Kir1.1b (half-time = 120s), implying that F127V is less hospitable to external K. In other experiments, positive membrane potentials gated the F127V mutant channel closed at physiological levels of external Ca, possibly by electrostatically depleting K adjacent to the membrane, suggesting that the <i>Phe</i> residue is critical for outward K secretion at physiological Ca. We speculate that the avidity of wt-Kir1.1b for external K could result from a cation-Pi interaction between K and the aromatic F127.</p>","PeriodicalId":72555,"journal":{"name":"Channels (Austin, Tex.)","volume":"18 1","pages":"2294661"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10773671/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139111385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A structural atlas of druggable sites on Na_v channels.","authors":"Zhangqiang Li, Qiurong Wu, Nieng Yan","doi":"10.1080/19336950.2023.2287832","DOIUrl":"10.1080/19336950.2023.2287832","url":null,"abstract":"<p><p>Voltage-gated sodium (Na_v) channels govern membrane excitability by initiating and propagating action potentials. Consistent with their physiological significance, dysfunction, or mutations in these channels are associated with various channelopathies. Na_v channels are thereby major targets for various clinical and investigational drugs. In addition, a large number of natural toxins, both small molecules and peptides, can bind to Na_v channels and modulate their functions. Technological breakthrough in cryo-electron microscopy (cryo-EM) has enabled the determination of high-resolution structures of eukaryotic and eventually human Na_v channels, alone or in complex with auxiliary subunits, toxins, and drugs. These studies have not only advanced our comprehension of channel architecture and working mechanisms but also afforded unprecedented clarity to the molecular basis for the binding and mechanism of action (MOA) of prototypical drugs and toxins. In this review, we will provide an overview of the recent advances in structural pharmacology of Na_v channels, encompassing the structural map for ligand binding on Na_v channels. These findings have established a vital groundwork for future drug development.</p>","PeriodicalId":72555,"journal":{"name":"Channels (Austin, Tex.)","volume":"18 1","pages":"2287832"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10732651/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138464760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The endocannabinoid ARA-S facilitates the activation of cardiac Kv7.1/KCNE1 channels from different species.","authors":"Irene Hiniesto-Iñigo, Veronika A Linhart, Ali S Kusay, Sara I Liin","doi":"10.1080/19336950.2024.2420651","DOIUrl":"10.1080/19336950.2024.2420651","url":null,"abstract":"<p><p>The endogenous endocannabinoid-like compound N-arachidonoyl-L-serine (ARA-S) facilitates activation of the human Kv7.1/KCNE1 channel and shortens a prolonged action potential duration and QT interval in guinea pig hearts. Hence, ARA-S is interesting to study further in cardiac models to explore the functional impact of such Kv7.1/KCNE1-mediated effects. To guide which animal models would be suitable for assessing ARA-S effects, and to aid interpretation of findings in different experimental models, it is useful to know whether Kv7.1/KCNE1 channels from relevant species respond similarly to ARA-S. To this end, we used the two-electrode voltage clamp technique to compare the effects of ARA-S on Kv7.1/KCNE1 channels from guinea pig, rabbit, and human Kv7.1/KCNE1, when expressed in <i>Xenopus laevis</i> oocytes. We found that the activation of Kv7.1/KCNE1 channels from all tested species was facilitated by ARA-S, seen as a concentration-dependent shift in the voltage-dependence of channel opening and increase in current amplitude and conductance over a broad voltage range. The rabbit channel displayed quantitatively similar effects as the human channel, whereas the guinea pig channel responded with more prominent increase in current amplitude and maximal conductance. This study suggests that rabbit and guinea pig models are both suitable for studying ARA-S effects mediated via Kv7.1/KCNE1.</p>","PeriodicalId":72555,"journal":{"name":"Channels (Austin, Tex.)","volume":"18 1","pages":"2420651"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11520554/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142514023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of four <i>KCNMA1</i> channelopathy variants on BK channel current under Ca_V1.2 activation.","authors":"Ria L Dinsdale, Andrea L Meredith","doi":"10.1080/19336950.2024.2396346","DOIUrl":"10.1080/19336950.2024.2396346","url":null,"abstract":"<p><p>Variants in <i>KCNMA1</i>, encoding the voltage- and calcium-activated K⁺ (BK) channel, are associated with human neurological disease. The effects of gain-of-function (GOF) and loss-of-function (LOF) variants have been predominantly studied on BK channel currents evoked under steady-state voltage and Ca²⁺ conditions. However, in their physiological context, BK channels exist in partnership with voltage-gated Ca²⁺ channels and respond to dynamic changes in intracellular Ca²⁺ (Ca²⁺_i). In this study, an L-type voltage-gated Ca²⁺ channel present in the brain, Ca_V1.2, was co-expressed with wild type and mutant BK channels containing GOF (D434G, N999S) and LOF (H444Q, D965V) patient-associated variants in HEK-293T cells. Whole-cell BK currents were recorded under Ca_V1.2 activation using buffering conditions that restrict Ca²⁺_i to nano- or micro-domains. Both conditions permitted wild type BK current activation in response to Ca_V1.2 Ca²⁺ influx, but differences in behavior between wild type and mutant BK channels were reduced compared to prior studies in clamped Ca²⁺_i. Only the N999S mutation produced an increase in BK current in both micro- and nano-domains using square voltage commands and was also detectable in BK current evoked by a neuronal action potential within a microdomain. These data corroborate the GOF effect of N999S on BK channel activity under dynamic voltage and Ca²⁺ stimuli, consistent with its pathogenicity in neurological disease. However, the patient-associated mutations D434G, H444Q, and D965V did not exhibit significant effects on BK current under Ca_V1.2-mediated Ca²⁺ influx, in contrast with prior steady-state protocols. These results demonstrate a differential potential for <i>KCNMA1</i> variant pathogenicity compared under diverse voltage and Ca²⁺ conditions.</p>","PeriodicalId":72555,"journal":{"name":"Channels (Austin, Tex.)","volume":"18 1","pages":"2396346"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11370921/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142115579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel benzoylurea derivative decreases TRPM7 channel function and inhibits cancer cells migration.","authors":"Xiaoding Zhang, Rui Zong, Yu Han, Xiaoming Li, Shuangyu Liu, Yixue Cao, Nan Jiang, Pingping Chen, Haixia Gao","doi":"10.1080/19336950.2024.2396339","DOIUrl":"10.1080/19336950.2024.2396339","url":null,"abstract":"<p><p>The transient receptor potential melastatin 7 channel (TRPM7) is a nonselective cation channel highly expressed in some human cancer tissues. TRPM7 is involved in the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of cancer cells. Modulation of TRPM7 could be a promising therapeutic strategy for treating cancer; however, efficient and selective pharmacological TRPM7 modulators are lacking. In this study we investigated N- [4- (4, 6-dimethyl- 2-pyrimidinyloxy) - 3- methylphenyl] -N' - [2 -(dimethylamino)] benzoylurea (SUD), a newly synthesized benzoylurea derivative, for its effects on cancer cell migration and EMT and on functional expression of TRPM7. Our previous studies showed that SUD induces cell cycle arrest and apoptosis of MCF-7 and BGC-823 cells (human breast cancer and gastric cancer cell lines, respectively). Here, we show that SUD significantly decreased the migration of both types of cancer cells. Moreover, SUD decreased vimentin expression and increased E-cadherin expression in both cell types, indicating that EMT is also decreased by SUD. Importantly, SUD potentially reduced the TRPM7-like current in a concentration-dependent manner and decreased TRPM7 expression through the PI3K/Akt signaling pathway. Finally, molecular docking simulations were used to investigate potential SUD binding sites on TRPM7. In summary, our research demonstrated that SUD is an effective TRPM7 inhibitor and a potential agent to suppress the metastasis of breast and gastric cancer by inhibiting TRPM7 expression and function.</p>","PeriodicalId":72555,"journal":{"name":"Channels (Austin, Tex.)","volume":"18 1","pages":"2396339"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11370923/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142115580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}