The actin-binding protein filamin A (FLNa) regulates neuronal migration during development, yet its roles in the mature brain remain largely obscure. Here, we probed the effects of FLNa on the regulation of ion channels that influence neuronal properties. We focused on the HCN1 channels that conduct Ih, a hyperpolarization-activated current crucial for shaping intrinsic neuronal properties. Whereas regulation of HCN1 channels by FLNa has been observed in melanoma cell lines, its physiological relevance to neuronal function and the underlying cellular pathways that govern this regulation remain unknown. Using a combination of mutational, pharmacological, and imaging approaches, we find here that FLNa facilitates a selective and reversible dynamin-dependent internalization of HCN1 channels in HEK293 cells. This internalization is accompanied by a redistribution of HCN1 channels on the cell surface, by accumulation of the channels in endosomal compartments, and by reduced Ih density. In hippocampal neurons, expression of a truncated dominant-negative FLNa enhances the expression of native HCN1. Furthermore, acute abrogation of HCN1-FLNa interaction in neurons, with the use of decoy peptides that mimic the FLNa-binding domain of HCN1, abolishes the punctate distribution of HCN1 channels in neuronal cell bodies, augments endogenous Ih, and enhances the rebound-response ("voltage-sag") of the neuronal membrane to transient hyperpolarizing events. Together, these results support a major function of FLNa in modulating ion channel abundance and membrane trafficking in neurons, thereby shaping their biophysical properties and function.
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http://dx.doi.org/10.1074/jbc.M113.522060 | DOI Listing |
Open Life Sci
December 2024
Department of Cardiology, The Third Affiliated Hospital of Zunyi Medical University (The First People's Hospital of Zunyi), Zunyi, 563000, Guizhou, People's Republic of China.
We investigated the protective effect of the NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC) on cardiomyocyte injury induced by HCN1 channel overexpression, and explored the underlying mechanisms. An HCN1 overexpression vector was constructed and transfected into H9C2 cells, followed by PDTC treatment. The experiments comprised the following groups: control, control + PDTC, overexpression negative control, HCN1 overexpression (HCN1-OE), and combined HCN1-OE + PDTC groups.
View Article and Find Full Text PDFSci Adv
January 2025
Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Cell Rep
December 2024
Department of Anesthesiology, Huashan Hospital, Fudan University, Shanghai 200040, China. Electronic address:
Dissociation, characterized by altered consciousness and perception, underlies multiple mental disorders, but the specific neuronal subtypes involved remain elusive. In mice, we find that dissociation-inducing doses of ketamine significantly inhibit retrosplenial cortex (RSC) parvalbumin interneurons (PV-INs), enhancing delta oscillations (1-3 Hz) and delta-gamma phase-amplitude coupling (δ-γ PAC) and inducing dissociation-like behaviors. Optogenetic inhibition of RSC PV-INs triggers delta oscillations, δ-γ PAC, and some dissociation-like behaviors without ketamine.
View Article and Find Full Text PDFFront Med (Lausanne)
December 2024
Division of Cardiovascular Sciences, School of Medical Sciences, University of Manchester, Manchester, United Kingdom.
Background: The sinoatrial node (SN) generates the heart rate (HR). Its spontaneous activity is regulated by a complex interplay between the modulation by the autonomic nervous system (ANS) and intrinsic factors including ion channels in SN cells. However, the systemic and intrinsic regulatory mechanisms are still poorly understood.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Rd., Wuhan,430030, China.
In vitro experiments performed on dissociated dorsal root ganglion (DRG) neurons suggest the involvement of the hyperpolarization-activated cation current (I) in enhancing neuronal excitability, potentially contributing to neuropathic pain. However, the more confirmative in vivo information about how nerve injury interacts with I is lacking. In this study, I was recorded in vivo using the dynamic single-electrode voltage clamp (dSEVC) technique on L5 DRG neurons of normal rats and those seven days after spinal nerve axotomy (SNA).
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