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1.
Pharmacol Res Perspect ; 8(5): e00653, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32930523

RESUMO

More than ten million patients worldwide have been diagnosed with coronavirus disease 19 (COVID-19) to date (WHO situation report, 1st July 2020). There is no vaccine to prevent infection with the causative organism, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), nor a cure. In the struggle to devise potentially useful therapeutics in record time, the repurposing of existing compounds is a key route of action. In this hypothesis paper, we argue that the bisbenzylisoquinoline and calcium channel blocker tetrandrine, originally extracted from the plant Stephania tetrandra and utilized in traditional Chinese medicine, may have potential in the treatment of COVID-19 and should be further investigated. We collate and review evidence for tetrandrine's putative mechanism of action in viral infection, specifically its recently discovered antagonism of the two-pore channel 2 (TPC2). While tetrandrine's particular history of use provides a very limited pharmacological dataset, there is a suggestion from the available evidence that it could be effective at doses used in clinical practice. We suggest that further research to investigate this possibility should be conducted.


Assuntos
Antivirais/administração & dosagem , Benzilisoquinolinas/administração & dosagem , Betacoronavirus/efeitos dos fármacos , Bloqueadores dos Canais de Cálcio/administração & dosagem , Canais de Cálcio/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Pneumonia Viral/tratamento farmacológico , Animais , Antivirais/efeitos adversos , Benzilisoquinolinas/efeitos adversos , Betacoronavirus/patogenicidade , Bloqueadores dos Canais de Cálcio/efeitos adversos , Canais de Cálcio/metabolismo , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/virologia , Interações Medicamentosas , Interações Hospedeiro-Patógeno , Humanos , Pandemias , Pneumonia Viral/diagnóstico , Pneumonia Viral/metabolismo , Pneumonia Viral/virologia , Transdução de Sinais
2.
Nat Commun ; 11(1): 4117, 2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32807785

RESUMO

Strategies for eradicating cancer stem cells (CSCs) are urgently required because CSCs are resistant to anticancer drugs and cause treatment failure, relapse and metastasis. Here, we show that photoactive functional nanocarbon complexes exhibit unique characteristics, such as homogeneous particle morphology, high water dispersibility, powerful photothermal conversion, rapid photoresponsivity and excellent photothermal stability. In addition, the present biologically permeable second near-infrared (NIR-II) light-induced nanocomplexes photo-thermally trigger calcium influx into target cells overexpressing the transient receptor potential vanilloid family type 2 (TRPV2). This combination of nanomaterial design and genetic engineering effectively eliminates cancer cells and suppresses stemness of cancer cells in vitro and in vivo. Finally, in molecular analyses of mechanisms, we show that inhibition of cancer stemness involves calcium-mediated dysregulation of the Wnt/ß-catenin signalling pathway. The present technological concept may lead to innovative therapies to address the global issue of refractory cancers.


Assuntos
Raios Infravermelhos , Nanotecnologia/métodos , Células-Tronco Neoplásicas/efeitos da radiação , Animais , Apoptose/efeitos da radiação , Western Blotting , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Linhagem Celular Tumoral , Feminino , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Microscopia de Fluorescência , Células-Tronco Neoplásicas/citologia , Células-Tronco Neoplásicas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Canais de Cátion TRPV/metabolismo , Via de Sinalização Wnt
3.
Life Sci ; 258: 118175, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32750436

RESUMO

AIMS: Human podocytes (hPC) play an important role in the pathogenesis of renal diseases. In this context, angiotensin II (Ang II) and nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) play a crucial role in podocyte injury. Recently, transmembrane protein (Tmem) 63c, a member of the Tmem-family was found to be expressed in kidney and associated with podocyte function. In this study, we analysed the expression regulation and functional impact of Tmem63c on cell viability and apoptosis in hPC in the context of Ang II activation. MATERIALS AND METHODS: Expression of Tmem63c in response to Ang II and the NFκB inhibitor Bay 11-7082 was analysed by Real-Time PCR and Western blotting. Cellular functions were determined by functional assays. KEY FINDINGS: We found Ang II to induce Tmem63c expression in hPC in a concentration-dependent manner. Inhibition of NFκB by Bay 11-7082 reduced basal as well as Ang II-induced Tmem63c expression. SiRNA-mediated down-regulation of Tmem63c diminished cell viability and protein kinase B (Akt) signaling and increased cell apoptosis of resting as well as Ang II-activated hPC. SIGNIFICANCE: These data show that Ang II induced the expression of Tmem63c in hPC, possibly via NFκB-dependent mechanisms. Moreover, down-regulation of Tmem63c was associated with reduced cell viability, indicating Tmem63c to be a potential pro-survival factor in hPC.


Assuntos
Angiotensina II/farmacologia , Canais de Cálcio/metabolismo , Podócitos/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Humanos , NF-kappa B/metabolismo , Fosforilação/efeitos dos fármacos , Podócitos/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos
4.
ACS Chem Neurosci ; 11(15): 2145-2148, 2020 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-32662982

RESUMO

Studies have shown that the calcium ion (Ca2+) plays important roles both in Alzheimer's dementia and SARS-CoV S-mediated fusion to host cell entry. An elevated level of intracellular calcium causes neuronal dysfunction, cell death, and apoptosis. Dysregulation of calcium has also been shown to increase the production of amyloid beta (Aß) protein, the hallmark of Alzheimer's dementia. Reversely, deposition of Aß is also responsible for calcium dysregulation. On the other hand, it has been well investigated that viruses can disturb host cell Ca2+ homeostasis as well as modulate signal transduction mechanisms. Viruses can also hijack the host cell calcium channels and pumps to release more intracellular Ca2+ to utilize for their life cycle. Even though evidence has not been reported on SARS-CoV-2 concerning Ca2+ regulation, however, it has been well established that Ca2+ is essential for viral entry, viral gene replication, and virion maturation and release. Recent reports suggest that SARS-CoV needs two Ca2+ ions to fuse with the host cell at the entry step. Furthermore, some calcium channel blockers (CCBs), such as nimodipine, memantine, etc., have been reported to be effective in the treatment of dementia in Alzheimer's disease (AD) as well as have shown inhibition in various virus infections.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Betacoronavirus , Bloqueadores dos Canais de Cálcio/uso terapêutico , Infecções por Coronavirus/tratamento farmacológico , Pneumonia Viral/tratamento farmacológico , Doença de Alzheimer/metabolismo , Doença de Alzheimer/psicologia , Cálcio/metabolismo , Bloqueadores dos Canais de Cálcio/química , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio/metabolismo , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/psicologia , Humanos , Pandemias , Pneumonia Viral/metabolismo , Pneumonia Viral/psicologia , Resultado do Tratamento
5.
Nat Commun ; 11(1): 3711, 2020 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-32709891

RESUMO

The skeletal muscle T-tubule is a specialized membrane domain essential for coordinated muscle contraction. However, in the absence of genetically tractable systems the mechanisms involved in T-tubule formation are unknown. Here, we use the optically transparent and genetically tractable zebrafish system to probe T-tubule development in vivo. By combining live imaging of transgenic markers with three-dimensional electron microscopy, we derive a four-dimensional quantitative model for T-tubule formation. To elucidate the mechanisms involved in T-tubule formation in vivo, we develop a quantitative screen for proteins that associate with and modulate early T-tubule formation, including an overexpression screen of the entire zebrafish Rab protein family. We propose an endocytic capture model involving firstly, formation of dynamic endocytic tubules at transient nucleation sites on the sarcolemma, secondly, stabilization by myofibrils/sarcoplasmic reticulum and finally, delivery of membrane from the recycling endosome and Golgi complex.


Assuntos
Contração Muscular/fisiologia , Proteínas Musculares/metabolismo , Músculo Esquelético/metabolismo , Músculo Esquelético/ultraestrutura , Sarcolema/fisiologia , Sarcolema/ultraestrutura , Animais , Canais de Cálcio/metabolismo , Canais de Cálcio/ultraestrutura , Canais de Cálcio Tipo L/metabolismo , Proteínas de Transporte/metabolismo , Biologia do Desenvolvimento , Complexo de Golgi/metabolismo , Masculino , Microscopia Eletrônica , Proteínas Musculares/química , Músculo Esquelético/química , Miofibrilas/metabolismo , Sarcolema/química , Retículo Sarcoplasmático/metabolismo , Peixe-Zebra
6.
Proc Natl Acad Sci U S A ; 117(28): 16383-16390, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32601238

RESUMO

Calcium uptake by the mitochondrial calcium uniporter coordinates cytosolic signaling events with mitochondrial bioenergetics. During the past decade all protein components of the mitochondrial calcium uniporter have been identified, including MCU, the pore-forming subunit. However, the specific lipid requirements, if any, for the function and formation of this channel complex are currently not known. Here we utilize yeast, which lacks the mitochondrial calcium uniporter, as a model system to address this problem. We use heterologous expression to functionally reconstitute human uniporter machinery both in wild-type yeast as well as in mutants defective in the biosynthesis of phosphatidylethanolamine, phosphatidylcholine, or cardiolipin (CL). We uncover a specific requirement of CL for in vivo reconstituted MCU stability and activity. The CL requirement of MCU is evolutionarily conserved with loss of CL triggering rapid turnover of MCU homologs and impaired calcium transport. Furthermore, we observe reduced abundance and activity of endogenous MCU in mammalian cellular models of Barth syndrome, which is characterized by a partial loss of CL. MCU abundance is also decreased in the cardiac tissue of Barth syndrome patients. Our work raises the hypothesis that impaired mitochondrial calcium transport contributes to the pathogenesis of Barth syndrome, and more generally, showcases the utility of yeast phospholipid mutants in dissecting the phospholipid requirements of ion channel complexes.


Assuntos
Canais de Cálcio/metabolismo , Cálcio/metabolismo , Mitocôndrias/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Animais , Síndrome de Barth/genética , Síndrome de Barth/metabolismo , Transporte Biológico , Canais de Cálcio/química , Canais de Cálcio/genética , Cardiolipinas/genética , Cardiolipinas/metabolismo , Humanos , Camundongos , Mitocôndrias/química , Mitocôndrias/genética , Mioblastos/metabolismo , Fosfolipídeos , Estabilidade Proteica , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética
7.
Adv Cancer Res ; 148: 233-317, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32723565

RESUMO

Ca2+ is a ubiquitous and dynamic second messenger molecule that is induced by many factors including receptor activation, environmental factors, and voltage, leading to pleiotropic effects on cell function including changes in migration, metabolism and transcription. As such, it is not surprising that aberrant regulation of Ca2+ signals can lead to pathological phenotypes, including cancer progression. However, given the highly context-specific nature of Ca2+-dependent changes in cell function, delineation of its role in cancer has been a challenge. Herein, we discuss the distinct roles of Ca2+ signaling within and between each type of cancer, including consideration of the potential of therapeutic strategies targeting these signaling pathways.


Assuntos
Antineoplásicos/uso terapêutico , Canais de Cálcio/metabolismo , Cálcio/metabolismo , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/farmacologia , Membrana Celular/metabolismo , Humanos , Terapia de Alvo Molecular , Neoplasias/metabolismo , Neoplasias/patologia
8.
Mol Cell ; 78(6): 1055-1069, 2020 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-32559424

RESUMO

Ca2+ ions are key second messengers in both excitable and non-excitable cells. Owing to the rather pleiotropic nature of Ca2+ transporters and other Ca2+-binding proteins, however, Ca2+ signaling has attracted limited attention as a potential target of anticancer therapy. Here, we discuss cancer-associated alterations of Ca2+ fluxes at specific organelles as we identify novel candidates for the development of drugs that selectively target Ca2+ signaling in malignant cells.


Assuntos
Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Neoplasias/metabolismo , Animais , Canais de Cálcio/metabolismo , Humanos , Mitocôndrias/metabolismo , Neoplasias/genética , Transdução de Sinais/fisiologia , Canais de Receptores Transientes de Potencial/metabolismo
9.
Nature ; 582(7810): 129-133, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32494073

RESUMO

Mitochondria take up Ca2+ through the mitochondrial calcium uniporter complex to regulate energy production, cytosolic Ca2+ signalling and cell death1,2. In mammals, the uniporter complex (uniplex) contains four core components: the pore-forming MCU protein, the gatekeepers MICU1 and MICU2, and an auxiliary subunit, EMRE, essential for Ca2+ transport3-8. To prevent detrimental Ca2+ overload, the activity of MCU must be tightly regulated by MICUs, which sense changes in cytosolic Ca2+ concentrations to switch MCU on and off9,10. Here we report cryo-electron microscopic structures of the human mitochondrial calcium uniporter holocomplex in inhibited and Ca2+-activated states. These structures define the architecture of this multicomponent Ca2+-uptake machinery and reveal the gating mechanism by which MICUs control uniporter activity. Our work provides a framework for understanding regulated Ca2+ uptake in mitochondria, and could suggest ways of modulating uniporter activity to treat diseases related to mitochondrial Ca2+ overload.


Assuntos
Canais de Cálcio/química , Canais de Cálcio/metabolismo , Microscopia Crioeletrônica , Sítios de Ligação/efeitos dos fármacos , Cálcio/metabolismo , Cálcio/farmacologia , Canais de Cálcio/ultraestrutura , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Modelos Moleculares , Complexos Multiproteicos/química , Complexos Multiproteicos/metabolismo , Complexos Multiproteicos/ultraestrutura
10.
Nat Commun ; 11(1): 2444, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32415068

RESUMO

The essential role of ORAI1 channels in receptor-evoked Ca2+ signaling is well understood, yet little is known about the physiological activation of the ORAI channel trio natively expressed in all cells. The roles of ORAI2 and ORAI3 have remained obscure. We show that ORAI2 and ORAI3 channels play a critical role in mediating the regenerative Ca2+ oscillations induced by physiological receptor activation, yet ORAI1 is dispensable in generation of oscillations. We reveal that ORAI2 and ORAI3 channels multimerize with ORAI1 to expand the range of sensitivity of receptor-activated Ca2+ signals, reflecting their enhanced basal STIM1-binding and heightened Ca2+-dependent inactivation. This broadened bandwidth of Ca2+ influx is translated by cells into differential activation of NFAT1 and NFAT4 isoforms. Our results uncover a long-sought role for ORAI2 and ORAI3, revealing an intricate control mechanism whereby heteromerization of ORAI channels mediates graded Ca2+ signals that extend the agonist-sensitivity to fine-tune transcriptional control.


Assuntos
Canais de Cálcio Ativados pela Liberação de Cálcio/metabolismo , Sinalização do Cálcio , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Sinalização do Cálcio/efeitos dos fármacos , Carbacol/farmacologia , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Células HEK293 , Humanos , Modelos Biológicos , Fatores de Transcrição NFATC/metabolismo , Proteína ORAI1/metabolismo , Ligação Proteica/efeitos dos fármacos , Isoformas de Proteínas/metabolismo , Multimerização Proteica/efeitos dos fármacos , Molécula 1 de Interação Estromal/metabolismo , Imagem com Lapso de Tempo
12.
PLoS One ; 15(4): e0231711, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32298357

RESUMO

Actively growing tumors are often histologically associated with Ki67 positivity, while the detection of invasiveness relies on non-quantitative pathologic evaluation of mostly advanced tumors. We recently reported that reduced expression of the Ca2+-dependent membrane-binding annexin A6 (AnxA6) is associated with increased expression of the Ca2+ activated RasGRF2 (GRF2), and that the expression status of these proteins inversely influence the growth and motility of triple negative breast cancer (TNBC) cells. Here, we establish that the reciprocal expression of AnxA6 and GRF2 is at least in part, dependent on inhibition of non-selective Ca2+ channels in AnxA6-low but not AnxA6-high TNBC cells. Immunohistochemical staining of breast cancer tissues revealed that compared to non-TNBC tumors, TNBC tumors express lower levels of AnxA6 and higher Ki67 expression. GRF2 expression levels strongly correlated with high Ki67 in pretreatment biopsies from patients with residual disease and with residual tumor size following chemotherapy. Elevated AnxA6 expression more reliably identified patients who responded to chemotherapy, while low AnxA6 levels were significantly associated with shorter distant relapse-free survival. Finally, the reciprocal expression of AnxA6 and GRF2 can delineate GRF2-low/AnxA6-high invasive from GRF2-high/AnxA6-low rapidly growing TNBCs. These data suggest that AnxA6 may be a reliable biomarker for distant relapse-free survival and response of TNBC patients to chemotherapy, and that the reciprocal expression of AnxA6 and GRF2 can reliably delineate TNBCs into rapidly growing and invasive subsets which may be more relevant for subset-specific therapeutic interventions.


Assuntos
Anexina A6/metabolismo , Canais de Cálcio/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Fatores ras de Troca de Nucleotídeo Guanina/metabolismo , Animais , Anexina A6/genética , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Feminino , Humanos , Antígeno Ki-67/metabolismo , Camundongos , Metástase Neoplásica/genética , Prognóstico , Transplante Heterólogo , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/mortalidade , Fatores ras de Troca de Nucleotídeo Guanina/genética
13.
Sci China Life Sci ; 63(5): 635-674, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32246404

RESUMO

Abiotic stresses and soil nutrient limitations are major environmental conditions that reduce plant growth, productivity and quality. Plants have evolved mechanisms to perceive these environmental challenges, transmit the stress signals within cells as well as between cells and tissues, and make appropriate adjustments in their growth and development in order to survive and reproduce. In recent years, significant progress has been made on many fronts of the stress signaling research, particularly in understanding the downstream signaling events that culminate at the activation of stress- and nutrient limitation-responsive genes, cellular ion homeostasis, and growth adjustment. However, the revelation of the early events of stress signaling, particularly the identification of primary stress sensors, still lags behind. In this review, we summarize recent work on the genetic and molecular mechanisms of plant abiotic stress and nutrient limitation sensing and signaling and discuss new directions for future studies.


Assuntos
Plantas/genética , Plantas/metabolismo , Solo/química , Estresse Fisiológico/fisiologia , Canais de Cálcio/metabolismo , Regulação da Expressão Gênica de Plantas , Metais Pesados/metabolismo , Fosforilação , Desenvolvimento Vegetal/genética , Proteínas de Plantas/metabolismo , Transdução de Sinais , Estresse Fisiológico/genética , Fatores de Transcrição/metabolismo
14.
Artigo em Inglês | MEDLINE | ID: mdl-32348177

RESUMO

Dry eye is a common sight-impairing, painful disorder characterized by disruption of the preocular tear film, whose integrity is required for ~70% of the eye's refractive power. A universal feature of clinical dry eye is hyperosmolarity of the tears resulting from their accelerated evaporation due to dysfunction of tear- and oil-producing ocular glands. A key adaptive response to dryness/hyperosmolarity is release of tear-stabilizing mucin by conjunctival goblet cells. Yet the mechanisms mediating this response to hyperosmolarity remain poorly understood. In this study of freshly excised rat conjunctiva, perforated-patch recordings revealed that during sustained hyperosmolarity, the development of a nonspecific cation (NSC) conductance depolarizes the goblet cells to a near-optimal voltage for the tonic activation of their voltage-gated calcium channels (VGCCs). In turn, as demonstrated by high-resolution membrane capacitance measurements, VGCC activation boosts the exocytotic response of conjunctival goblet cells to neural input. However, over time, VGCC activation also increases the vulnerability of these cells to the lethality of hyperosmolarity. Viability assays further revealed that hyperosmotic-induced goblet cell death is critically dependent on P2X7 receptor channels. Similar to the yin-yang impact of VGCCs on goblet cell physiology and pathobiology, P2X7 activation not only compromises goblet cell viability but also enhances exocytotic activity. Thus, the NSC/VGCC and P2X7 purinoceptor pathways are components of a previously unappreciated high-gain/high-risk adaptive strategy to combat ocular dryness. These pathways boost release of tear-stabilizing mucin at the risk of jeopardizing the viability of the conjunctival goblet cells, whose loss is a histopathological hallmark of irreversible mucin-deficient dry eye.


Assuntos
Canais de Cálcio/metabolismo , Túnica Conjuntiva/metabolismo , Síndromes do Olho Seco/metabolismo , Células Caliciformes/metabolismo , Ativação do Canal Iônico , Receptores Purinérgicos P2X7/metabolismo , Lágrimas/metabolismo , Adaptação Fisiológica , Animais , Túnica Conjuntiva/patologia , Síndromes do Olho Seco/patologia , Feminino , Células Caliciformes/patologia , Masculino , Potenciais da Membrana , Concentração Osmolar , Osmorregulação , Ratos Long-Evans , Ratos Sprague-Dawley , Transdução de Sinais
15.
J Smooth Muscle Res ; 56(0): 1-18, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32249242

RESUMO

Spontaneous rhythmic constrictions known as vasomotion are developed in several microvascular beds in vivo. Vasomotion in arterioles is considered to facilitate blood flow, while venular vasomotion would facilitate tissue metabolite drainage. Mechanisms underlying vasomotion periodically generate synchronous Ca2+ transients in vascular smooth muscle cells (VSMCs). In visceral organs, mural cells (pericytes and VSMCs) in arterioles, capillaries and venules exhibit synchronous spontaneous Ca2+ transients. Since sympathetic regulation is rather limited in the intra-organ microvessels, spontaneous activity of mural cells may play an essential role in maintaining tissue perfusion. Synchronous spontaneous Ca2+ transients in precapillary arterioles (PCAs)/capillaries appear to propagate to upstream arterioles to drive their vasomotion, while venules develop their own synchronous Ca2+ transients and associated vasomotion. Spontaneous Ca2+ transients of mural cells primarily arise from IP3 and/or ryanodine receptor-mediated Ca2+ release from sarcoendoplasmic reticulum (SR/ER) Ca2+ stores. The resultant opening of Ca2+-activated Cl- channels (CaCCs) causes a membrane depolarisation that triggers Ca2+ influx via T-type and/or L-type voltage-dependent Ca2+ channels (VDCCs). Mural cells are electrically coupled with each other via gap junctions, and thus allow the sequential spread of CaCC or VDCC-dependent depolarisations to develop the synchrony of Ca2+ transients within their network. Importantly, the synchrony of spontaneous Ca2+ transients also requires a certain range of the resting membrane potential that is maintained by the opening of Kv7 voltage-dependent K+ (Kv7) and inward rectifier K+ (Kir) channels. Thus, a depolarised membrane would evoke asynchronous, 'premature' spontaneous Ca2+ transients, while a hyperpolarised membrane prevents any spontaneous activity.


Assuntos
Cálcio/metabolismo , Microvasos/citologia , Microvasos/metabolismo , Músculo Liso Vascular/metabolismo , Arteríolas/metabolismo , Canais de Cálcio/metabolismo , Capilares/metabolismo , Canais de Cloreto/metabolismo , Retículo Endoplasmático/metabolismo , Humanos , Inositol 1,4,5-Trifosfato , Músculo Liso Vascular/citologia , Pericitos/metabolismo , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina , Vasoconstrição/fisiologia , Vasodilatação/fisiologia
16.
Neuron ; 106(5): 816-829.e6, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32229307

RESUMO

Sodium taste regulates salt intake. The amiloride-sensitive epithelial sodium channel (ENaC) is the Na+ sensor in taste cells mediating attraction to sodium salts. However, cells and intracellular signaling underlying sodium taste in taste buds remain long-standing enigmas. Here, we show that a subset of taste cells with ENaC activity fire action potentials in response to ENaC-mediated Na+ influx without changing the intracellular Ca2+ concentration and form a channel synapse with afferent neurons involving the voltage-gated neurotransmitter-release channel composed of calcium homeostasis modulator 1 (CALHM1) and CALHM3 (CALHM1/3). Genetic elimination of ENaC in CALHM1-expressing cells as well as global CALHM3 deletion abolished amiloride-sensitive neural responses and attenuated behavioral attraction to NaCl. Together, sodium taste is mediated by cells expressing ENaC and CALHM1/3, where oral Na+ entry elicits suprathreshold depolarization for action potentials driving voltage-dependent neurotransmission via the channel synapse. Thus, all steps in sodium taste signaling are voltage driven and independent of Ca2+ signals. This work also reveals ENaC-independent salt attraction.


Assuntos
Potenciais de Ação/fisiologia , Cálcio/metabolismo , Canais Epiteliais de Sódio/metabolismo , Sódio/metabolismo , Papilas Gustativas/citologia , Paladar/fisiologia , Potenciais de Ação/efeitos dos fármacos , Amilorida/farmacologia , Animais , Canais de Cálcio/metabolismo , Células Quimiorreceptoras/metabolismo , Células Quimiorreceptoras/fisiologia , Bloqueadores do Canal de Sódio Epitelial/farmacologia , Camundongos , Neurônios Aferentes/metabolismo , Técnicas de Patch-Clamp , Transdução de Sinais/efeitos dos fármacos , Transmissão Sináptica , Papilas Gustativas/metabolismo , Papilas Gustativas/fisiologia
17.
J Neurosci ; 40(19): 3707-3719, 2020 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-32269108

RESUMO

Calcineurin inhibitors, such as tacrolimus (FK506) and cyclosporine, are widely used as standard immunosuppressants in organ transplantation recipients. However, these drugs can cause severe pain in patients, commonly referred to as calcineurin inhibitor-induced pain syndrome (CIPS). Although calcineurin inhibition increases NMDAR activity in the spinal cord, the underlying mechanism remains enigmatic. Using an animal model of CIPS, we found that systemic administration of FK506 in male and female mice significantly increased the amount of α2δ-1-GluN1 complexes in the spinal cord and the level of α2δ-1-bound GluN1 proteins in spinal synaptosomes. Treatment with FK506 significantly increased the frequency of mEPSCs and the amplitudes of monosynaptic EPSCs evoked from the dorsal root and puff NMDAR currents in spinal dorsal horn neurons. Inhibiting α2δ-1 with gabapentin or disrupting the α2δ-1-NMDAR interaction with α2δ-1Tat peptide completely reversed the effects of FK506. In α2δ-1 gene KO mice, treatment with FK506 failed to increase the frequency of NMDAR-mediated mEPSCs and the amplitudes of evoked EPSCs and puff NMDAR currents in spinal dorsal horn neurons. Furthermore, systemic administration of gabapentin or intrathecal injection of α2δ-1Tat peptide reversed thermal and mechanical hypersensitivity in FK506-treated mice. In addition, genetically deleting GluN1 in dorsal root ganglion neurons or α2δ-1 genetic KO similarly attenuated FK506-induced thermal and mechanical hypersensitivity. Together, our findings indicate that α2δ-1-bound NMDARs mediate calcineurin inhibitor-induced tonic activation of presynaptic and postsynaptic NMDARs at the spinal cord level and that presynaptic NMDARs play a prominent role in the development of CIPS.SIGNIFICANCE STATEMENT Calcineurin inhibitors are immunosuppressants used to prevent rejection of transplanted organs and tissues. However, these drugs can cause severe, unexplained pain. We showed that calcineurin inhibition enhances physical interaction between α2δ-1 and NMDARs and their synaptic trafficking in the spinal cord. α2δ-1 is essential for calcineurin inhibitor-induced aberrant activation of presynaptic and postsynaptic NMDARs in the spinal cord. Furthermore, inhibiting α2δ-1 or disrupting α2δ-1-NMDAR interaction reduces calcineurin inhibitor-induced pain hypersensitivity. Eliminating NMDARs in primary sensory neurons or α2δ-1 KO also attenuates calcineurin inhibitor-induced pain hypersensitivity. This new information extends our mechanistic understanding of the role of endogenous calcineurin in regulating synaptic plasticity and nociceptive transmission and suggests new strategies for treating this painful condition.


Assuntos
Inibidores de Calcineurina/toxicidade , Canais de Cálcio/metabolismo , Hiperalgesia/induzido quimicamente , Hiperalgesia/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Animais , Feminino , Masculino , Camundongos , Plasticidade Neuronal/efeitos dos fármacos , Plasticidade Neuronal/fisiologia , Medula Espinal/efeitos dos fármacos , Medula Espinal/metabolismo
18.
Nat Commun ; 11(1): 1620, 2020 03 27.
Artigo em Inglês | MEDLINE | ID: covidwho-17830

RESUMO

Since 2002, beta coronaviruses (CoV) have caused three zoonotic outbreaks, SARS-CoV in 2002-2003, MERS-CoV in 2012, and the newly emerged SARS-CoV-2 in late 2019. However, little is currently known about the biology of SARS-CoV-2. Here, using SARS-CoV-2 S protein pseudovirus system, we confirm that human angiotensin converting enzyme 2 (hACE2) is the receptor for SARS-CoV-2, find that SARS-CoV-2 enters 293/hACE2 cells mainly through endocytosis, that PIKfyve, TPC2, and cathepsin L are critical for entry, and that SARS-CoV-2 S protein is less stable than SARS-CoV S. Polyclonal anti-SARS S1 antibodies T62 inhibit entry of SARS-CoV S but not SARS-CoV-2 S pseudovirions. Further studies using recovered SARS and COVID-19 patients' sera show limited cross-neutralization, suggesting that recovery from one infection might not protect against the other. Our results present potential targets for development of drugs and vaccines for SARS-CoV-2.


Assuntos
Anticorpos Antivirais/imunologia , Betacoronavirus/fisiologia , Anticorpos Amplamente Neutralizantes/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Internalização do Vírus , Betacoronavirus/química , Betacoronavirus/imunologia , Canais de Cálcio/metabolismo , Catepsina L/metabolismo , Catepsinas/antagonistas & inibidores , Catepsinas/metabolismo , Fusão Celular , Infecções por Coronavirus/imunologia , Reações Cruzadas , Endocitose , Células Gigantes/fisiologia , Células HEK293 , Humanos , Testes de Neutralização , Pandemias , Peptidil Dipeptidase A/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Pneumonia Viral/imunologia , Domínios Proteicos , Multimerização Proteica , Receptores Virais/metabolismo , Vírus da SARS/imunologia , Síndrome Respiratória Aguda Grave/imunologia , Glicoproteína da Espícula de Coronavírus/química , Tripsina/metabolismo
19.
J Cancer Res Clin Oncol ; 146(5): 1139-1152, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32152662

RESUMO

OBJECTIVE: Increasing evidence has revealed that mechanical stress and elevated mechanical signals promote malignant tumor transformation and metastasis. This study aimed to explore the function of the mechanically activated ion-channel Piezo1 in the colon cancer metastasis and its potential regulatory mechanism. METHODS: First, we examined the expression levels of Piezo1 and mitochondrial calcium uniporter (MCU) both in colon cancer tissues and assessed the prognostic value of Piezo1 and MCU in a colon cancer cohort (n = 110). Second, functional assays were performed to investigate the effects of Piezo1 and MCU on colon cancer cell migration, invasion, and mitochondrial membrane potential. Third, we analyzed the expression of Piezo1, MCU, and HIF-1α by overexpressing/silencing each other's expression. RESULTS: We found that Piezo1 was up-regulated and MCU was down-regulated in colon cancer tissues. Piezo1 and MCU were both correlated with poor prognosis of patients with colon cancer. Overexpressing Piezo1 and silencing MCU could promote colon cancer cell migration and metastasis, reduce mitochondrial membrane potential, and promote each other's expression. We also found that HIF-1α was up-regulated in colon cancer tissues. Additionally, silencing Piezo1 inhibited the expression of HIF-1α and VEGF, which was contrary to MCU silencing. Intriguingly, Piezo1-overexpressing cells did not regain their migration behaviors when HIF-1α expression was inhibited, which was accompanied with the re-expression of MCU and VEGF. CONCLUSION: In our study, Piezo1 is involved in colon cancer cell metastasis. Furthermore, our findings indicated a possible Piezo1-MCU-HIF-1α-VEGF axis, which still need further exploration.


Assuntos
Neoplasias do Colo/metabolismo , Canais Iônicos/metabolismo , Canais de Cálcio/metabolismo , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Estudos de Coortes , Neoplasias do Colo/patologia , Células HCT116 , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Imuno-Histoquímica , Canais Iônicos/biossíntese , Potencial da Membrana Mitocondrial , Metástase Neoplásica , Prognóstico , Transdução de Sinais , Regulação para Cima
20.
Nat Commun ; 11(1): 1620, 2020 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-32221306

RESUMO

Since 2002, beta coronaviruses (CoV) have caused three zoonotic outbreaks, SARS-CoV in 2002-2003, MERS-CoV in 2012, and the newly emerged SARS-CoV-2 in late 2019. However, little is currently known about the biology of SARS-CoV-2. Here, using SARS-CoV-2 S protein pseudovirus system, we confirm that human angiotensin converting enzyme 2 (hACE2) is the receptor for SARS-CoV-2, find that SARS-CoV-2 enters 293/hACE2 cells mainly through endocytosis, that PIKfyve, TPC2, and cathepsin L are critical for entry, and that SARS-CoV-2 S protein is less stable than SARS-CoV S. Polyclonal anti-SARS S1 antibodies T62 inhibit entry of SARS-CoV S but not SARS-CoV-2 S pseudovirions. Further studies using recovered SARS and COVID-19 patients' sera show limited cross-neutralization, suggesting that recovery from one infection might not protect against the other. Our results present potential targets for development of drugs and vaccines for SARS-CoV-2.


Assuntos
Anticorpos Antivirais/imunologia , Betacoronavirus/fisiologia , Anticorpos Amplamente Neutralizantes/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Internalização do Vírus , Betacoronavirus/química , Betacoronavirus/imunologia , Canais de Cálcio/metabolismo , Catepsina L/metabolismo , Catepsinas/antagonistas & inibidores , Catepsinas/metabolismo , Fusão Celular , Infecções por Coronavirus/imunologia , Reações Cruzadas , Endocitose , Células Gigantes/fisiologia , Células HEK293 , Humanos , Testes de Neutralização , Pandemias , Peptidil Dipeptidase A/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Pneumonia Viral/imunologia , Domínios Proteicos , Multimerização Proteica , Receptores Virais/metabolismo , Vírus da SARS/imunologia , Síndrome Respiratória Aguda Grave/imunologia , Glicoproteína da Espícula de Coronavírus/química , Tripsina/metabolismo
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