Voltage-gated ion channels are expressed in the Malpighian tubules and anal papillae of the yellow fever mosquito (Aedes aegypti), and may regulate ion transport during salt and water imbalance

Journal of Experimental Biology, Год журнала: 2024, Номер 227(3)

Опубликована: Янв. 10, 2024

Vectors of infectious disease include several species Aedes mosquitoes. The life cycle aegypti, the yellow fever mosquito, consists a terrestrial adult and an aquatic larval stage. Developing in coastal waters can expose larvae to fluctuating salinity, causing salt water imbalance, which is addressed by two prime osmoregulatory organs - Malpighian tubules (MTs) anal papillae (AP). Voltage-gated ion channels (VGICs) have recently been implicated regulation transport epithelia insects. In current study, we: (i) generated MT transcriptomes freshwater-acclimated brackish water-exposed Ae. (ii) detected expression voltage-gated Ca2+, K+, Na+ non-ion-selective MTs AP using transcriptomics, PCR gel electrophoresis, (iii) demonstrated that mRNA abundance many altered significantly following exposure, (iv) immunolocalized CaV1, NALCN, TRP/Painless KCNH8 custom-made antibodies. We found CaV1 be expressed apical membrane both adults, its inhibition alter potentials this epithelium. Our data demonstrate multiple VGICs are aegypti may play important role autonomous transport.

Язык: Английский

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In Silico and In Vitro Evaluation of the Molecular Mimicry of the SARS-CoV-2 Spike Protein by Common Short Constituent Sequences (cSCSs) in the Human Proteome: Toward Safer Epitope Design for Vaccine Development

Vaccines, Год журнала: 2024, Номер 12(5), С. 539 - 539

Опубликована: Май 14, 2024

Spike protein sequences in SARS-CoV-2 have been employed for vaccine epitopes, but many short constituent (SCSs) the spike are present human proteome, suggesting that some anti-spike antibodies induced by infection or vaccination may be autoantibodies against proteins. To evaluate this possibility of “molecular mimicry” silico and vitro, we exhaustively identified common SCSs (cSCSs) found both proteins bioinformatically. The commonality between two systems seemed to coincidental, only cSCSs were likely relevant potential self-epitopes based on three-dimensional information. Among three raised cSCS-containing peptides, antibody EPLDVL showed high affinity reacted with an EPLDVL-containing peptide from unc-80 homolog protein. Western blot analysis revealed also several expressed mainly small intestine, ovary, stomach. Taken together, these results most incapable inducing at least functions as a self-epitope, serious infection-induced vaccine-induced humans. High-risk cSCSs, including EPLDVL, should excluded epitopes prevent autoimmune disorders.

Язык: Английский

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Unplugging lateral fenestrations of NALCN reveals a hidden drug binding site within the pore region

Proceedings of the National Academy of Sciences, Год журнала: 2024, Номер 121(22)

Опубликована: Май 24, 2024

The sodium (Na + ) leak channel (NALCN) is a member of the four-domain voltage-gated cation family that includes prototypical and calcium channels V s Ca s, respectively). Unlike Na which have four lateral fenestrations serve as routes for lipophilic compounds to enter central cavity modulate function, NALCN has bulky residues (W311, L588, M1145, Y1436) block these openings. Structural data suggest occluded underlie pharmacological resistance NALCN, but functional evidence lacking. To test this hypothesis, we unplugged by substituting aforementioned with alanine (AAAA) compared effects , blockers on both wild-type (WT) AAAA channels. Most behaved in similar manner channels, phenytoin 2-aminoethoxydiphenyl borate (2-APB) elicited additional, distinct responses Further experiments using single mutants revealed 2-APB inner through fenestrations, implying structural specificity their modes access. Using combination computational approaches, identified amino acid critical activity, supporting existence drug binding site(s) within pore region. Intrigued activity its analogues, tested containing diphenylmethane/amine moiety WT We clinically used drugs exhibited diverse thus expanding toolbox NALCN. While low potencies active reiterate our findings lay foundation rational design develop modulators refined properties.

Язык: Английский

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Getting excited about leaks: the atypical Na⁺ channel NALCN is a key determinant of native mouse anterior pituitary endocrine cell physiology

The Journal of Physiology, Год журнала: 2025, Номер unknown

Опубликована: Янв. 2, 2025

Endocrine cells of the anterior pituitary (AP) regulate an eclectic array physiological processes, from control growth, reproduction and metabolism to coordinating responses stress. Half a century since demonstration that native AP are electrically excitable, Belal et al. (2024) have revealed atypical sodium 'leak' channel Nalcn as key regulator mouse cell resting membrane potential (RMP) this spontaneous excitability (Fig. 1). The majority endocrine secretory types in AP, including somatotrophs, corticotrophs gonadotrophs, generate calcium- dependent action potentials with typical durations 20–50 ms (Fletcher al., 2018). display richness dynamics, regulation pattern electrical varies between different types: spikes complex pseudo-plateau bursting proposed hormone secretion. However one feature common – unstable RMP (typical range −45 −55 mV) is considerably more depolarised (by >15 than equilibrium for potassium (EK). Although considerable effort has focused on ion channels spiking bursting, molecular identity remained elusive until now. In replacement external ions (e.g. NMDG+) results significant hyperpolarisation cessation (Guerineau 2021). most depolarising linear inward current, carried by Na+ ions, active at typically inhibited high Ca2+ ([Ca2+]e) but insensitive blockers voltage-gated TTX). Mathematical models require current act against background K+ maintain something, course, predicted classic work Hodgkin & Huxley published journal! These features reminiscent encoded evolutionary conserved gene NALCN (Monteil 2024). With lack specific pharmacological inhibitors used shRNA-knockdown strategy (NalcnKD) using lentiviral transduction unidentified dispersed previously clonal GH3 (Impheng agreement immunohistochemical analysis demonstrating widespread expression electrophysiological NalcnKD consistent (>90% cells) (median 15 silencing both activity intracellular calcium transients compared cells. Importantly, normal was rescued dynamic clamp inject surprisingly small conductance (0.02–0.16 nS), value similar subtracted required silence A just few picoamps large effect very (>5 GΩ) input resistance. Furthermore, NMDG-sensitive 0.05 nS) significantly reduced (>70%) suggesting indeed mediated Nalcn. While providing fundamental new insight into study also raises some intriguing questions: (i) dominant leak all types, how its functional tightly regulated RMP? Significant variability density reported across mixed population, other such TrpC been implicated 2018; Guerineau (ii) Does assemble macromolecular accessory subunits (Unc-79, Unc-80, Fam155A) 2024) properties hypothalamic hormones via their cognate GPCRs? (iii) secretion types? attenuated TRH-stimulated GH 2021), removal extracellular not equivocal Intriguingly, no phenotype modified human or animal studies mutations/deletion (iv) calcium-dependent processes beyond expression, mRNA splicing protein processing/degradation cells? (v) Finally, dynamically after period chronic stress (Duncan may be important determinant function response (patho)physiological challenges. Understanding promises reveal fountain knowledge role health disease. Please note: publisher responsible content functionality any supporting information supplied authors. Any queries (other missing content) should directed corresponding author article. Michael Shipston: I corticotroph physiology function. M.S.: Conception design work; drafting revising it critically intellectual content; final approval version published; accountable aspects work. None.

Язык: Английский

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Enhancement of Osseointegration via Endogenous Electric Field by Regulating the Charge Microenvironments around Implants

Advanced Healthcare Materials, Год журнала: 2025, Номер unknown

Опубликована: Янв. 5, 2025

The regulation of the charged microenvironment around implants is an effective way to promote osseointegration. Although homeostasis plays integral role in tissues, current research externally invasive and unsuitable for clinical applications. In this study, functional materials with different surface potential differences are prepared by changing spatial layout Ta Ag on a Ti-6Al-4V alloy (TC4). This naturally formed endogenous electric field (EEF) negatively cell membrane after vivo implantation promoted osseointegration at interface between bone implant through upregulation Ca

Язык: Английский

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Investigation regarding the physiological effects of cobalt on physiological functions in Drosophila, crayfish, and crab: Behavioral, cardiac, neural, and synaptic properties

Comparative Biochemistry and Physiology Part C Toxicology & Pharmacology, Год журнала: 2025, Номер 292, С. 110165 - 110165

Опубликована: Фев. 26, 2025

Язык: Английский

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Genotype-Phenotype Landscape of NALCN and UNC80 -Related Disorders

Neurology, Год журнала: 2025, Номер 104(7)

Опубликована: Март 6, 2025

The NALCN channelosome regulates the resting membrane potential through sodium leak currents, influencing cellular excitability. Genetic variants in and UNC80, a subunit of channelosome, cause ultra-rare severe neurodevelopmental disorders. Autosomal dominant congenital contractures limbs face, hypotonia, developmental delay (CLIFAHDD) syndrome is associated with gain-of-function (GOF) NALCN. Infantile hypotonia psychomotor retardation characteristic facies (IHPRF) 1 biallelic IHPRF 2 both resulting loss-of-function (LOF). This study aims to expand phenotypes these syndromes, exploring genotype-phenotype associations. cross-sectional including patients pathogenic or likely UNC80. Phenotypes were evaluated structured interview, questionnaires, review medical records. Associations between variants, clinical features, syndromes analyzed. Fifty-one included (34 CLIFAHDD, 9 1, 8 2; 3 months-27 years; 37.3% female). All exhibited delay, more LOF (p = 0.019). Neurodevelopmental regression was observed 29.4% CLIFAHDD syndrome, onset ataxia (70%). Patients had respiratory symptoms at birth (11.7% orotracheal intubation). Distal arthrogryposis (76.5%), episodic (41.2% ambulatory patients), paroxysmal dystonia (11.7%) exclusively diagnosed CLIFAHDD. presented frequently failure thrive (88.2%, p 0.001), central sleep apnea (CSA, 64.7%, < epilepsy (70.6%, 0.001). Epilepsy cognitive delays 0.016) refractory 58.8% patients. Earlier seizure 0.014). premature death, epilepsy, carried within pore domains. provides an in-depth characterization NALCN-related UNC80-related arthrogryposis, ataxia, while thrive, CSA, variants. We suggest associations, formulating hypotheses for validation future studies larger cohorts.

Язык: Английский

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The sodium leak channel NALCN is regulated by neuronal SNARE complex proteins

Science Advances, Год журнала: 2025, Номер 11(11)

Опубликована: Март 14, 2025

NALCN (sodium leak channel, nonselective) is vital for regulating electrical activity in neurons and other excitable cells, mutations the channel or its auxiliary proteins lead to severe neurodevelopmental disorders. Here, we show that neuronal SNARE (soluble N -ethylmaleimide–sensitive factor attachment protein receptors) complex syntaxin SNAP25 (synaptosome-associated 25), which enable synaptic transmission nervous system, inhibit of both heterologous systems primary neurons. The existence this interaction suggests neurotransmitter release machinery can regulate signaling directly therefore modulate threshold own activity. We further find reduction currents sufficient promote cell survival syntaxin-depleted cells. This disinhibited may cause puzzling phenomenon rapid death absence syntaxin. could offer opportunities future drug development against genetic diseases linked NALCN- protein–containing complexes.

Язык: Английский

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SLO2.1/NALCN Functional Complex Activity in Mouse Myometrial Smooth Muscle Cells During Pregnancy

Journal of Cellular Physiology, Год журнала: 2025, Номер 240(4)

Опубликована: Апрель 1, 2025

At the end of pregnancy, uterus transitions from a quiescent to highly contractile state. This is partly due depolarization resting membrane potential in uterine (myometrial) smooth muscle cells (MSMCs). In human MSMCs, regulated by functional complex between sodium (Na+)-activated potassium (K+) channel SLO2.1 and Na+ leak nonselective (NALCN). entering through NALCN activates SLO2.1, leading K+ efflux, hyperpolarization (cells become more negative inside), reduced contractility. Decreased SLO2.1/NALCN activity results depolarization, Ca2+ influx via voltage-dependent calcium channels, increased MSMC However, all these data are MSMCs isolated women at term, so role early pregnancy was speculative. To address this question here, we examined regulating mouse across pregnancy. We report that Slo2.1 Nalcn expressed nonpregnant pregnant mice than those late-pregnant mice. Functional studies revealed channels mediate significant portion current particularly Activation led but not later Moreover, NALCN/SLO2.1 regulates intracellular responses late Together, findings reveal conserved humans functions throughout study could open avenues for targeted pharmacological interventions pregnancy-related complications.

Язык: Английский

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Case Report: New presentation of CLIFAHDD syndrome with a novel variant in the NALCN gene and a literature review

Frontiers in Pediatrics, Год журнала: 2024, Номер 12

Опубликована: Май 30, 2024

Background Congenital contractures of the limbs and face, hypotonia, developmental delay (CLIFAHDD) syndrome (OMIM #616266) is an autosomal dominant hereditary disease that can lead to congenital contracture delay. In addition, it may result in growth retardation present various clinical symptoms, such as brain atrophy, a small pituitary gland, musculoskeletal abnormalities, abnormal breathing, abdominal hernia, facial features. Herein, we describe novel de novo missense genetic variant sodium leak channel, non-selective (NALCN) gene associated with CLIFAHDD syndrome. Case description This study describes patient varus deformities both feet, deviation ulnar side fingers, severe hypotonia. was subsequently confirmed have through testing, which also revealed NALCN (c.3553G &gt; A, p.Ala1185Thr). Conclusions Our findings further enrich known spectrum expand range options for treating NALCN-related disorders.

Язык: Английский

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