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1.
Sci Rep ; 14(1): 21615, 2024 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-39284887

RESUMO

PDZ domain mediated interactions with voltage-gated calcium (CaV) channel C-termini play important roles in localizing membrane Ca2+ signaling. The first such interaction was described between the scaffolding protein Mint-1 and CaV2.2 in mammals. In this study, we show through various in silico analyses that Mint is an animal-specific gene with a highly divergent N-terminus but a strongly conserved C-terminus comprised of a phosphotyrosine binding domain, two tandem PDZ domains (PDZ-1 and PDZ-2), and a C-terminal auto-inhibitory element that binds and inhibits PDZ-1. In addition to CaV2 chanels, most genes that interact with Mint are also deeply conserved including amyloid precursor proteins, presenilins, neurexin, and CASK and Veli which form a tripartite complex with Mint in bilaterians. Through yeast and bacterial 2-hybrid experiments, we show that Mint and CaV2 channels from cnidarians and placozoans interact in vitro, and in situ hybridization revealed co-expression in dissociated neurons from the cnidarian Nematostella vectensis. Unexpectedly, the Mint orthologue from the ctenophore Hormiphora californiensis strongly bound the divergent C-terminal ligands of cnidarian and placozoan CaV2 channels, despite neither the ctenophore Mint, nor the placozoan and cnidarian orthologues, binding the ctenophore CaV2 channel C-terminus. Altogether, our analyses suggest that the capacity of Mint to bind CaV2 channels predates bilaterian animals, and that evolutionary changes in CaV2 channel C-terminal sequences resulted in altered binding modalities with Mint.


Assuntos
Domínios PDZ , Ligação Proteica , Animais , Sequência de Aminoácidos , Placozoa/metabolismo , Placozoa/genética , Canais de Cálcio Tipo N/metabolismo , Canais de Cálcio Tipo N/genética , Humanos , Canais de Cálcio/metabolismo , Canais de Cálcio/genética
2.
J Neuroinflammation ; 21(1): 218, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39227967

RESUMO

Alzheimer's disease (AD) is the leading form of dementia, characterized by the accumulation and aggregation of amyloid in brain. Transient receptor potential vanilloid 2 (TRPV2) is an ion channel involved in diverse physiopathological processes, including microglial phagocytosis. Previous studies suggested that cannabidiol (CBD), an activator of TRPV2, improves microglial amyloid-ß (Aß) phagocytosis by TRPV2 modulation. However, the molecular mechanism of TRPV2 in microglial Aß phagocytosis remains unknown. In this study, we aimed to investigate the involvement of TRPV2 channel in microglial Aß phagocytosis and the underlying mechanisms. Utilizing human datasets, mouse primary neuron and microglia cultures, and AD model mice, to evaluate TRPV2 expression and microglial Aß phagocytosis in both in vivo and in vitro. TRPV2 was expressed in cortex, hippocampus, and microglia.Cannabidiol (CBD) could activate and sensitize TRPV2 channel. Short-term CBD (1 week) injection intraperitoneally (i.p.) reduced the expression of neuroinflammation and microglial phagocytic receptors, but long-term CBD (3 week) administration (i.p.) induced neuroinflammation and suppressed the expression of microglial phagocytic receptors in APP/PS1 mice. Furthermore, the hyper-sensitivity of TRPV2 channel was mediated by tyrosine phosphorylation at the molecular sites Tyr(338), Tyr(466), and Tyr(520) by protein tyrosine kinase JAK1, and these sites mutation reduced the microglial Aß phagocytosis partially dependence on its localization. While TRPV2 was palmitoylated at Cys 277 site and blocking TRPV2 palmitoylation improved microglial Aß phagocytosis. Moreover, it was demonstrated that TRPV2 palmitoylation was dynamically regulated by ZDHHC21. Overall, our findings elucidated the intricate interplay between TRPV2 channel regulated by tyrosine phosphorylation/dephosphorylation and cysteine palmitoylation/depalmitoylation, which had divergent effects on microglial Aß phagocytosis. These findings provide valuable insights into the underlying mechanisms linking microglial phagocytosis and TRPV2 sensitivity, and offer potential therapeutic strategies for managing AD.


Assuntos
Peptídeos beta-Amiloides , Lipoilação , Camundongos Transgênicos , Microglia , Fagocitose , Canais de Cátion TRPV , Tirosina , Animais , Camundongos , Microglia/metabolismo , Microglia/efeitos dos fármacos , Canais de Cátion TRPV/metabolismo , Peptídeos beta-Amiloides/metabolismo , Fagocitose/efeitos dos fármacos , Humanos , Fosforilação/efeitos dos fármacos , Tirosina/metabolismo , Lipoilação/efeitos dos fármacos , Células Cultivadas , Doença de Alzheimer/metabolismo , Canabidiol/farmacologia , Camundongos Endogâmicos C57BL , Canais de Cálcio
3.
Nutrients ; 16(17)2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39275318

RESUMO

Studies have demonstrated the therapeutic effects of Lindera plants. This study was undertaken to reveal the antihypertensive properties of Lindera erythrocarpa leaf ethanolic extract (LEL). Aorta segments of Sprague-Dawley rats were used to study the vasodilatory effect of LEL, and the mechanisms involved were evaluated by treating specific inhibitors or activators that affect the contractility of blood vessels. Our results revealed that LEL promotes a vasorelaxant effect through the nitric oxide/cyclic guanosine 3',5'-monophosphate pathway, blocking the Ca2+ channels, opening the K+ channels, and inhibiting the vasoconstrictive action of angiotensin II. In addition, the effects of LEL on blood pressure were investigated in spontaneously hypertensive rats by the tail-cuff method. LEL (300 or 1000 mg/kg) was orally administered to the rats, and 1000 mg/kg of LEL significantly lowered the blood pressure. Systolic blood pressure decreased by -20.06 ± 4.87%, and diastolic blood pressure also lowered by -30.58 ± 5.92% at 4 h in the 1000 mg/kg LEL group. Overall, our results suggest that LEL may be useful to treat hypertensive diseases, considering its vasorelaxing and hypotensive effects.


Assuntos
Anti-Hipertensivos , Pressão Sanguínea , GMP Cíclico , Hipertensão , Lindera , Óxido Nítrico , Extratos Vegetais , Ratos Endogâmicos SHR , Ratos Sprague-Dawley , Animais , Anti-Hipertensivos/farmacologia , Extratos Vegetais/farmacologia , Óxido Nítrico/metabolismo , Pressão Sanguínea/efeitos dos fármacos , GMP Cíclico/metabolismo , Masculino , Hipertensão/tratamento farmacológico , Ratos , Lindera/química , Canais de Potássio/metabolismo , Canais de Potássio/efeitos dos fármacos , Canais de Cálcio/metabolismo , Canais de Cálcio/efeitos dos fármacos , Folhas de Planta/química , Vasodilatação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Vasodilatadores/farmacologia
4.
Proc Natl Acad Sci U S A ; 121(35): e2402491121, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39163336

RESUMO

Activating Ca2+-sensitive enzymes of oxidative metabolism while preventing calcium overload that leads to mitochondrial and cellular injury requires dynamic control of mitochondrial Ca2+ uptake. This is ensured by the mitochondrial calcium uptake (MICU)1/2 proteins that gate the pore of the mitochondrial calcium uniporter (mtCU). MICU1 is relatively sparse in the heart, and recent studies claimed the mammalian heart lacks MICU1 gating of mtCU. However, genetic models have not been tested. We find that MICU1 is present in a complex with MCU in nonfailing human hearts. Furthermore, using murine genetic models and pharmacology, we show that MICU1 and MICU2 control cardiac mitochondrial Ca2+ influx, and that MICU1 deletion alters cardiomyocyte mitochondrial calcium signaling and energy metabolism. MICU1 loss causes substantial compensatory changes in the mtCU composition and abundance, increased turnover of essential MCU regulator (EMRE) early on and, later, of MCU, that limit mitochondrial Ca2+ uptake and allow cell survival. Thus, both the primary consequences of MICU1 loss and the ensuing robust compensation highlight MICU1's relevance in the beating heart.


Assuntos
Sinalização do Cálcio , Proteínas de Ligação ao Cálcio , Cálcio , Proteínas de Transporte de Cátions , Proteínas de Transporte da Membrana Mitocondrial , Miócitos Cardíacos , Animais , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/genética , Camundongos , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/genética , Humanos , Proteínas de Transporte de Cátions/metabolismo , Proteínas de Transporte de Cátions/genética , Miócitos Cardíacos/metabolismo , Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Mitocôndrias Cardíacas/metabolismo , Canais de Cálcio/metabolismo , Canais de Cálcio/genética , Camundongos Knockout , Miocárdio/metabolismo , Masculino
5.
Nat Cardiovasc Res ; 3(5): 500-514, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-39185387

RESUMO

The mitochondrial calcium (mCa2+) uniporter channel (mtCU) resides at the inner mitochondrial membrane and is required for Ca2+ to enter the mitochondrial matrix. The mtCU is essential for cellular function, as mCa2+ regulates metabolism, bioenergetics, signaling pathways and cell death. mCa2+ uptake is primarily regulated by the MICU family (MICU1, MICU2, MICU3), EF-hand-containing Ca2+-sensing proteins, which respond to cytosolic Ca2+ concentrations to modulate mtCU activity. Considering that mitochondrial function and Ca2+ signaling are ubiquitously disrupted in cardiovascular disease, mtCU function has been a hot area of investigation for the last decade. Here we provide an in-depth review of MICU-mediated regulation of mtCU structure and function, as well as potential mtCU-independent functions of these proteins. We detail their role in cardiac physiology and cardiovascular disease by highlighting the phenotypes of different mutant animal models, with an emphasis on therapeutic potential and targets of interest in this pathway.


Assuntos
Canais de Cálcio , Doenças Cardiovasculares , Humanos , Animais , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/patologia , Canais de Cálcio/metabolismo , Canais de Cálcio/genética , Mitocôndrias Cardíacas/metabolismo , Sinalização do Cálcio , Cálcio/metabolismo , Ativação do Canal Iônico , Relação Estrutura-Atividade
6.
Sci Adv ; 10(32): eadp6182, 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39121218

RESUMO

Endothelial cells (ECs) are highly plastic, capable of differentiating into various cell types. Endothelial-to-mesenchymal transition (EndMT) is crucial during embryonic development and contributes substantially to vascular dysfunction in many cardiovascular diseases (CVDs). While targeting EndMT holds therapeutic promise, understanding its mechanisms and modulating its pathways remain challenging. Using single-cell RNA sequencing on three in vitro EndMT models, we identified conserved gene signatures. We validated original regulators in vitro and in vivo during embryonic heart development and peripheral artery disease. EndMT induction led to global expression changes in all EC subtypes rather than in mesenchymal clusters. We identified mitochondrial calcium uptake as a key driver of EndMT; inhibiting mitochondrial calcium uniporter (MCU) prevented EndMT in vitro, and conditional Mcu deletion in ECs blocked mesenchymal activation in a hind limb ischemia model. Tissues from patients with critical limb ischemia with EndMT features exhibited significantly elevated endothelial MCU. These findings highlight MCU as a regulator of EndMT and a potential therapeutic target.


Assuntos
Sinalização do Cálcio , Células Endoteliais , Transição Epitelial-Mesenquimal , Mitocôndrias , RNA-Seq , Análise de Célula Única , Animais , Humanos , Mitocôndrias/metabolismo , RNA-Seq/métodos , Camundongos , Células Endoteliais/metabolismo , Transição Epitelial-Mesenquimal/genética , Canais de Cálcio/metabolismo , Canais de Cálcio/genética , Isquemia/metabolismo , Isquemia/patologia , Cálcio/metabolismo , Análise da Expressão Gênica de Célula Única
7.
Structure ; 32(8): 1025-1027, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39121835

RESUMO

In this issue of Structure, Chi et al.1 report structural and functional studies that reveal the inhibition mechanism of the lysosomal two-pore channel TPC2 by the antagonist SG-094, which is of interest for drug development. Antagonist binding induces the downward displacement of the voltage-sensor domain II (VSD II), which is accompanied by asymmetric conformational rearrangements of the entire channel.


Assuntos
Canais de Cálcio , Humanos , Canais de Cálcio/metabolismo , Canais de Cálcio/química , Domínios Proteicos , Bloqueadores dos Canais de Cálcio/química , Bloqueadores dos Canais de Cálcio/farmacologia
8.
Nat Neurosci ; 27(9): 1680-1694, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39160372

RESUMO

Action potentials trigger neurotransmitter release at the presynaptic active zone with spatiotemporal precision. This is supported by protein machinery that mediates synaptic vesicle priming and clustering of CaV2 Ca2+ channels nearby. One model posits that scaffolding proteins directly tether vesicles to CaV2s; however, here we find that at mouse hippocampal synapses, CaV2 clustering and vesicle priming are executed by separate machineries. CaV2 nanoclusters are positioned at variable distances from those of the priming protein Munc13. The active zone organizer RIM anchors both proteins but distinct interaction motifs independently execute these functions. In transfected cells, Liprin-α and RIM form co-assemblies that are separate from CaV2-organizing complexes. At synapses, Liprin-α1-Liprin-α4 knockout impairs vesicle priming but not CaV2 clustering. The cell adhesion protein PTPσ recruits Liprin-α, RIM and Munc13 into priming complexes without co-clustering CaV2s. We conclude that active zones consist of distinct machineries to organize CaV2s and prime vesicles, and Liprin-α and PTPσ specifically support priming site assembly.


Assuntos
Hipocampo , Sinapses , Vesículas Sinápticas , Animais , Hipocampo/metabolismo , Hipocampo/citologia , Vesículas Sinápticas/metabolismo , Camundongos , Sinapses/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Camundongos Knockout , Caveolina 2/metabolismo , Canais de Cálcio/metabolismo , Camundongos Endogâmicos C57BL
9.
Mol Brain ; 17(1): 54, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39113108

RESUMO

NVA1309 is a non-brain penetrant next-generation gabapentinoid shown to bind Cavα2δ at R243 within a triple Arginine motif forming the binding site for gabapentin and pregabalin. In this study we have compared the effects of NVA1309 with Mirogabalin, a gabapentinoid drug with higher affinity for the voltage-gated calcium channel subunit Cavα2δ-1 than pregabalin which is approved for post-herpetic neuralgia in Japan, Korea and Taiwan. Both NVA1309 and mirogabalin inhibit Cav2.2 currents in vitro and decrease Cav2.2 plasma membrane expression with higher efficacy than pregabalin. Mutagenesis of the classical binding residue arginine R243 and the newly identified binding residue lysine K615 reverse the effect of mirogabalin on Cav2.2 current, but not that of NVA1309.


Assuntos
Gabapentina , Humanos , Gabapentina/farmacologia , Animais , Ligação Proteica , Subunidades Proteicas/metabolismo , Subunidades Proteicas/química , Células HEK293 , Ácido gama-Aminobutírico/metabolismo , Membrana Celular/metabolismo , Membrana Celular/efeitos dos fármacos , Canais de Cálcio Tipo N/metabolismo , Canais de Cálcio Tipo N/genética , Pregabalina/farmacologia , Canais de Cálcio/metabolismo , Compostos Bicíclicos com Pontes
10.
Cell Calcium ; 123: 102945, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39191091

RESUMO

Orai1 is a plasma membrane Ca2+ channel involved in store operated calcium entry (SOCE). SOCE can regulate cell growth, exocytosis, gene expression and inflammation. We previously found that short palate lung and nasal epithelial clone 1's (SPLUNC1) sixth α-helix (α6) bound Orai1 to inhibit SOCE. SPLUNC1 was not proteolytically stable, so we developed ELD607, an 11 amino acid peptide based on SPLUNC1's α6 region which was more stable and more potent than SPLUNC1/α6. Here, we studied ELD607's mechanism of action. We overexpressed either Orai1-HA or Orai1-YFP in HEK293T cells to probe ELD607-Orai1 interactions by confocal microscopy. We also measured changes in Fluo-4 fluorescence in a multiplate reader as a marker of cytoplasmic Ca2+ levels. ELD607 internalized Orai1 independently of STIM1. Both 15 min and 3 h exposure to ELD607 similarly depleted Orai1 in the plasma membrane. However, 3 h exposure to ELD607 yielded greater inhibition of SOCE. ELD607 continued to colocalize with Orai1 after internalization and this process was dependent on the presence of the ubiquitin ligase NEDD4.2. Similarly, ELD607 increased the colocalization between Orai1 and ubiquitin. ELD607 also increased the colocalization between Orai1 and Rab5 and 7, but not Rab11, suggesting that Orai1 trafficked through early and late but not recycling endosomes. Finally, ELD607 caused Orai1, but not Orai2, Orai3, or STIM1 to traffic to lysosomes. We conclude that ELD607 rapidly binds to Orai1 and works in an identical fashion as full length SPLUNC1 by internalizing Orai1 and sending it to lysosomes, leading to a decrease in SOCE.


Assuntos
Cálcio , Lisossomos , Proteína ORAI1 , Humanos , Proteína ORAI1/metabolismo , Células HEK293 , Cálcio/metabolismo , Lisossomos/metabolismo , Canais de Cálcio/metabolismo , Transporte Proteico , Membrana Celular/metabolismo , Molécula 1 de Interação Estromal/metabolismo , Proteínas rab5 de Ligação ao GTP/metabolismo , Peptídeos/metabolismo , Peptídeos/farmacologia , Proteínas rab de Ligação ao GTP/metabolismo
11.
Exp Eye Res ; 247: 110029, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39127237

RESUMO

Dysregulation of calcium homeostasis can precipitate a cascade of pathological events that lead to tissue damage and cell death. Dynasore is a small molecule that inhibits endocytosis by targeting classic dynamins. In a previous study, we showed that dynasore can protect human corneal epithelial cells from damage due to tert-butyl hydroperoxide (tBHP) exposure by restoring cellular calcium (Ca2+) homeostasis. Here we report results of a follow-up study aimed at identifying the source of the damaging Ca2+. Store-operated Ca2+ entry (SOCE) is a cellular mechanism to restore intracellular calcium stores from the extracellular milieu. We found that dynasore effectively blocks SOCE in cells treated with thapsigargin (TG), a small molecule that inhibits pumping of Ca2+ into the endoplasmic reticulum (ER). Unlike dynasore however, SOCE inhibitor YM-58483 did not interfere with the cytosolic Ca2+ overload caused by tBHP exposure. We also found that dynasore effectively blocks Ca2+ release from internal sources. The inefficacy of inhibitors of ER Ca2+ channels suggested that this compartment was not the source of the Ca2+ surge caused by tBHP exposure. However, using a Ca2+-measuring organelle-entrapped protein indicator (CEPIA) reporter targeted to mitochondria, we found that dynasore can block mitochondrial Ca2+ release due to tBHP exposure. Our results suggest that dynasore exerts multiple effects on cellular Ca2+ homeostasis, with inhibition of mitochondrial Ca2+ release playing a key role in protection of corneal epithelial cells against oxidative stress due to tBHP exposure.


Assuntos
Cálcio , Epitélio Corneano , Hidrazonas , Mitocôndrias , Humanos , Epitélio Corneano/metabolismo , Epitélio Corneano/efeitos dos fármacos , Cálcio/metabolismo , Mitocôndrias/metabolismo , Hidrazonas/farmacologia , Retículo Endoplasmático/metabolismo , Tapsigargina/farmacologia , Canais de Cálcio/metabolismo , Sinalização do Cálcio/fisiologia , Células Cultivadas , terc-Butil Hidroperóxido/farmacologia , Homeostase/fisiologia
12.
PLoS Genet ; 20(8): e1011388, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39186815

RESUMO

Most neurons are not replaced after injury and thus possess robust intrinsic mechanisms for repair after damage. Axon injury triggers a calcium wave, and calcium and cAMP can augment axon regeneration. In comparison to axon regeneration, dendrite regeneration is poorly understood. To test whether calcium and cAMP might also be involved in dendrite injury signaling, we tracked the responses of Drosophila dendritic arborization neurons to laser severing of axons and dendrites. We found that calcium and subsequently cAMP accumulate in the cell body after both dendrite and axon injury. Two voltage-gated calcium channels (VGCCs), L-Type and T-Type, are required for the calcium influx in response to dendrite injury and play a role in rapid initiation of dendrite regeneration. The AC8 family adenylyl cyclase, Ac78C, is required for cAMP production after dendrite injury and timely initiation of regeneration. Injury-induced cAMP production is sensitive to VGCC reduction, placing calcium upstream of cAMP generation. We propose that two VGCCs initiate global calcium influx in response to dendrite injury followed by production of cAMP by Ac78C. This signaling pathway promotes timely initiation of dendrite regrowth several hours after dendrite damage.


Assuntos
Adenilil Ciclases , Canais de Cálcio Tipo L , Cálcio , AMP Cíclico , Dendritos , Animais , Adenilil Ciclases/metabolismo , Adenilil Ciclases/genética , Axônios/metabolismo , Axônios/fisiologia , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Canais de Cálcio/genética , Canais de Cálcio Tipo L/metabolismo , Canais de Cálcio Tipo L/genética , Canais de Cálcio Tipo T/metabolismo , Canais de Cálcio Tipo T/genética , Sinalização do Cálcio/genética , AMP Cíclico/metabolismo , Dendritos/metabolismo , Drosophila/genética , Drosophila melanogaster/genética , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Regeneração Nervosa/fisiologia , Regeneração Nervosa/genética , Neurônios/metabolismo , Regeneração/genética , Regeneração/fisiologia , Transdução de Sinais
13.
J Am Chem Soc ; 146(36): 25383-25393, 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39196894

RESUMO

The regulation of the cell membrane potential plays a crucial role in governing the transmembrane transport of various ions and cellular life processes. However, in situ and on-demand modulation of cell membrane potential for ion channel regulation is challenging. Herein, we have constructed a supramolecular assembly system based on water-soluble cationic oligo(phenylenevinylene) (OPV) and cucurbit[7]uril (CB[7]). The controllable disassembly of OPV/4CB[7] combined with the subsequent click reaction provides a step-by-step adjustable surface positive potential. These processes can be employed in situ on the plasma membrane to modulate the membrane potential on-demand for precisely controlling the activation of the transient receptor potential vanilloid 1 (TRPV1) ion channel and up-regulating exogenous calcium-responsive gene expression. Compared with typical optogenetics, electrogenetics, and mechanogenetics, our strategy provides a perspective supramolecular genetics toolbox for the regulation of membrane potential and downstream intracellular gene regulation events.


Assuntos
Imidazóis , Potenciais da Membrana , Imidazóis/química , Humanos , Hidrocarbonetos Aromáticos com Pontes/química , Polivinil/química , Membrana Celular/metabolismo , Membrana Celular/química , Canais de Cátion TRPV/metabolismo , Células HEK293 , Cálcio/metabolismo , Cálcio/química , Canais de Cálcio/metabolismo , Canais de Cálcio/química , Compostos Heterocíclicos com 2 Anéis , Compostos Macrocíclicos , Imidazolidinas
14.
Nat Commun ; 15(1): 6649, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39103356

RESUMO

Vasodilation in response to low oxygen (O2) tension (hypoxic vasodilation) is an essential homeostatic response of systemic arteries that facilitates O2 supply to tissues according to demand. However, how blood vessels react to O2 deficiency is not well understood. A common belief is that arterial myocytes are O2-sensitive. Supporting this concept, it has been shown that the activity of myocyte L-type Ca2+channels, the main ion channels responsible for vascular contractility, is reversibly inhibited by hypoxia, although the underlying molecular mechanisms have remained elusive. Here, we show that genetic or pharmacological disruption of mitochondrial electron transport selectively abolishes O2 modulation of Ca2+ channels and hypoxic vasodilation. Mitochondria function as O2 sensors and effectors that signal myocyte Ca2+ channels due to constitutive Hif1α-mediated expression of specific electron transport subunit isoforms. These findings reveal the acute O2-sensing mechanisms of vascular cells and may guide new developments in vascular pharmacology.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia , Mitocôndrias , Oxigênio , Vasodilatação , Animais , Mitocôndrias/metabolismo , Oxigênio/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Camundongos , Transdução de Sinais , Masculino , Hipóxia/metabolismo , Camundongos Endogâmicos C57BL , Artérias/metabolismo , Canais de Cálcio Tipo L/metabolismo , Canais de Cálcio Tipo L/genética , Camundongos Knockout , Transporte de Elétrons , Canais de Cálcio/metabolismo , Canais de Cálcio/genética
15.
Proc Natl Acad Sci U S A ; 121(35): e2404969121, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39172783

RESUMO

The abundance of CaV2 voltage-gated calcium channels is linked to presynaptic homeostatic plasticity (PHP), a process that recalibrates synaptic strength to maintain the stability of neural circuits. However, the molecular and cellular mechanisms governing PHP and CaV2 channels are not completely understood. Here, we uncover a previously not described form of PHP in Caenorhabditis elegans, revealing an inverse regulatory relationship between the efficiency of neurotransmitter release and the abundance of UNC-2/CaV2 channels. Gain-of-function unc-2SL(S240L) mutants, which carry a mutation analogous to the one causing familial hemiplegic migraine type 1 in humans, showed markedly reduced channel abundance despite increased channel functionality. Reducing synaptic release in these unc-2SL(S240L) mutants restored channel levels to those observed in wild-type animals. Conversely, loss-of-function unc-2DA(D726A) mutants, which harbor the D726A mutation in the channel pore, exhibited a marked increase in channel abundance. Enhancing synaptic release in unc-2DA mutants reversed this increase in channel levels. Importantly, this homeostatic regulation of UNC-2 channel levels is accompanied by the structural remodeling of the active zone (AZ); specifically, unc-2DA mutants, which exhibit increased channel abundance, showed parallel increases in select AZ proteins. Finally, our forward genetic screen revealed that WWP-1, a HECT family E3 ubiquitin ligase, is a key homeostatic mediator that removes UNC-2 from synapses. These findings highlight a self-tuning PHP regulating UNC-2/CaV2 channel abundance along with AZ reorganization, ensuring synaptic strength and stability.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Neurotransmissores , Animais , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Neurotransmissores/metabolismo , Terminações Pré-Sinápticas/metabolismo , Canais de Cálcio/metabolismo , Canais de Cálcio/genética , Transmissão Sináptica/fisiologia , Plasticidade Neuronal , Mutação , Canais de Cálcio Tipo N/metabolismo , Canais de Cálcio Tipo N/genética , Neurônios/metabolismo , Proteínas de Membrana
16.
Front Endocrinol (Lausanne) ; 15: 1450328, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39170742

RESUMO

Osteoporosis, a systemic skeletal disorder marked by diminished bone mass and compromised bone microarchitecture, is becoming increasingly prevalent due to an aging population. The underlying pathophysiology of osteoporosis is attributed to an imbalance between osteoclast-mediated bone resorption and osteoblast-mediated bone formation. Osteoclasts play a crucial role in the development of osteoporosis through various molecular pathways, including the RANK/RANKL/OPG signaling axis, cytokines, and integrins. Notably, the calcium signaling pathway is pivotal in regulating osteoclast activation and function, influencing bone resorption activity. Disruption in calcium signaling can lead to increased osteoclast-mediated bone resorption, contributing to the progression of osteoporosis. Emerging research indicates that calcium-permeable channels on the cellular membrane play a critical role in bone metabolism by modulating these intracellular calcium pathways. Here, we provide an overview of current literature on the regulation of plasma membrane calcium channels in relation to bone metabolism with particular emphasis on their dysregulation during the progression of osteoporosis. Targeting these calcium channels may represent a potential therapeutic strategy for treating osteoporosis.


Assuntos
Canais de Cálcio , Osteoporose , Humanos , Osteoporose/metabolismo , Canais de Cálcio/metabolismo , Animais , Reabsorção Óssea/metabolismo , Osteoclastos/metabolismo , Sinalização do Cálcio/fisiologia
17.
Handb Clin Neurol ; 203: 123-133, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39174244

RESUMO

The primary episodic ataxias (EAs) are a group of autosomal-dominant disorders characterized by transient recurrent incoordination and truncal instability, often triggered by physical exertion or emotional stress and variably associated with progressive baseline ataxia. There are now nine designated subtypes EA1-9 (OMIM) and late onset cerebellar ataxia with episodic features as newly designated SCA27B, based largely on genetic loci. Mutations have been identified in multiple individuals and families in 4 of the 9 EA subtypes, mostly with the onset before adulthood. This chapter focuses on the clinical assessment and management of EA, genetic diagnosis, and neurophysiologic consequences of the causative mutations in the best characterized EA syndromes: EA1 caused by mutations in KCNA1 encoding a neuronal voltage-gated potassium channel, EA2 caused by mutations in CACNA1A encoding a neuronal voltage-gated calcium channel, EA6 caused by mutations in SLC1A3 encoding a glutamate transporter that is also an anion channel, and SCA27B with late onset episodic ataxia caused by an intronic trinucleotide repeat in FGF14 encoding fibroblast growth factor 14 important in regulating the distribution of voltage-gated sodium channels in the cerebellar Purkinje and granule cells. The study of EA has illuminated previously unrecognized but important roles of ion channels and transporters in brain function with shared mechanisms underlying cerebellar ataxia, migraine, and epilepsy.


Assuntos
Ataxia , Mutação , Humanos , Ataxia/genética , Ataxia/diagnóstico , Mutação/genética , Fatores de Crescimento de Fibroblastos/genética , Canal de Potássio Kv1.1/genética , Canais de Cálcio/genética , Transportador 1 de Aminoácido Excitatório
18.
Handb Clin Neurol ; 203: 135-144, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39174245

RESUMO

Hemiplegic migraine consists of attacks of migraine with aura that includes reversible motor weakness. It is classified as familial or sporadic depending on the involvement or not of a first or second degree relative. The most described subtypes of familial hemiplegic migraine include FHM1, FHM2, and FHM3. These have been demonstrated to have a mutation in either CACNA1A, ATP1A2 or SCN1A, which encode different subunits of channels, involving P/Q-type calcium channel, Na/K pump and Na channel, respectively, located in neurons and glial cells. Mutations localized in different genes are defined as "other loci." Patients with a known mutation can have different genetic penetrance, and may present a more complex and disabling phenotype that develops earlier in life. The clinical manifestations can be similar in the three mutations, including neurologic comorbidities other than muscular weakness, such as episodes of loss of consciousness, epilepsy, gait or limb ataxia or movement disorders, among others. Treatment includes antiepileptics such as lamotrigine, valproate or topiramate, calcium blockers such as flunarizine or verapamil and acetazolamide.


Assuntos
Enxaqueca com Aura , Humanos , Enxaqueca com Aura/genética , Mutação/genética , ATPase Trocadora de Sódio-Potássio/genética , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Canais de Cálcio
19.
Curr Opin Support Palliat Care ; 18(3): 113-117, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39088823

RESUMO

PURPOSE OF REVIEW: Mirogabalin is a novel gabapentinoid medication for the treatment of neuropathic pain. The purpose of this review is to discuss current evidence for its use. Gabapentinoids are widely prescribed for neuropathic pain. Mirogabalin offers theoretical advantages over traditional gabapentinoids due to its specificity for the α2δ-1 subunit of voltage-gated calcium channels. It is theorised that this specificity may reduce adverse drug reactions by minimising binding to the α2δ-2 subunit which is responsible for many of the gabapentinoid side effects. RECENT FINDINGS: Mirogabalin's slower dissociation from the α2δ-1 compared with α2δ-2, and its higher potency may also impart an efficacy benefit over traditional gabapentinoids. These theoretical advantages of mirogabalin remain inconclusive in clinical practice, with mixed evidence regarding mirogabalin versus traditional gabapentinoids. Some studies suggest a reduced side effect profile yet, others fail to demonstrate significant differences. Regarding efficacy, mirogabalin may be superior to placebo for several neuropathic pain syndromes, but evidence of widespread benefit over traditional gabapentinoids is currently lacking. SUMMARY: Mirogabalin offers theoretical promise, but large, independent studies are required to further assess its performance versus traditional gabapentinoids.


Assuntos
Analgésicos , Compostos Bicíclicos com Pontes , Neuralgia , Humanos , Neuralgia/tratamento farmacológico , Analgésicos/uso terapêutico , Compostos Bicíclicos com Pontes/uso terapêutico , Compostos Bicíclicos com Pontes/farmacologia , Gabapentina/uso terapêutico , Canais de Cálcio/efeitos dos fármacos , Ácido gama-Aminobutírico/uso terapêutico
20.
Cell Chem Biol ; 31(8): 1394-1404, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39151406

RESUMO

Voltage-gated sodium (Nav) and calcium (Cav) channels are responsible for the initiation of electrical signals. They have long been targeted for the treatment of various diseases. The mounting number of cryoelectron microscopy (cryo-EM) structures for diverse subtypes of Nav and Cav channels from multiple organisms necessitates a generic residue numbering system to establish the structure-function relationship and to aid rational drug design or optimization. Here we suggest a structure-based residue numbering scheme, centering around the most conserved residues on each of the functional segments. We elaborate the generic numbers through illustrative examples, focusing on representative drug-binding sites of eukaryotic Nav and Cav channels. We also extend the numbering scheme to compare common disease mutations among different Nav subtypes. Application of the generic residue numbering scheme affords immediate insights into hotspots for pathogenic mutations and critical loci for drug binding and will facilitate drug discovery targeting Nav and Cav channels.


Assuntos
Canais de Cálcio , Humanos , Canais de Cálcio/metabolismo , Canais de Cálcio/química , Canais de Cálcio/genética , Canais de Sódio Disparados por Voltagem/química , Canais de Sódio Disparados por Voltagem/metabolismo , Canais de Sódio Disparados por Voltagem/genética , Animais , Sítios de Ligação , Mutação , Microscopia Crioeletrônica , Modelos Moleculares , Sequência de Aminoácidos
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