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1.
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
2.
Planta Med ; 86(10): 708-716, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32408360

RESUMO

The dietary intake of flavonoids seems to be inversely related to cardiovascular mortality. The consumption of isoflavonoids is increasing in the general population, especially due to the use of food supplements and a variety of isoflavonoid-rich foods. However, detailed studies on the vascular influence of individual pure isoflavonoids are mostly missing. For this study, 16 isoflavonoids were initially screened for their vasorelaxant properties on rat aortas. The 2 most potent of them, biochanin A and glycitein, were further tested for the mechanism of action on porcine coronary arteries. They both induced an endothelium independent vascular relaxation, with EC50 below 6 and 17 µM, respectively. Biochanin A, but not glycitein, was able to block the vasoconstriction caused by KCl, CaCl2, serotonin, and U46619 in a dose-dependent manner. Another series of experiments suggested that the major mechanism of action of biochanin A was the inhibition of L-type calcium channels. Moreover, biochanin A in relatively small concentrations (2 - 4 µM) interfered with the cGMP, but not cAMP, pathway in isolated coronary arteries. These results indicate that some isoflavonoids, in particular biochanin A, are able to have vasodilatory effects in micromolar concentrations, which is of potential clinical interest for the management of cardiovascular pathologies.


Assuntos
Canais de Cálcio , Isoflavonas , Animais , Cálcio , Vasos Coronários , Endotélio Vascular , Genisteína , Humanos , Ratos , Suínos , Vasodilatação
3.
PLoS Pathog ; 16(5): e1008605, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32453763

RESUMO

As obligate parasites, viruses highjack, modify and repurpose the cellular machinery for their own replication. Viral proteins have, therefore, evolved biological functions, such as signalling potential, that alter host cell physiology in ways that are still incompletely understood. Retroviral envelope glycoproteins interact with several host proteins, extracellularly with their cellular receptor and anti-envelope antibodies, and intracellularly with proteins of the cytoskeleton or sorting, endocytosis and recirculation pathways. Here, we examined the impact of endogenous retroviral envelope glycoprotein expression and interaction with host proteins, particularly antibodies, on the cell, independently of retroviral infection. We found that in the commonly used C57BL/6 substrains of mice, where murine leukaemia virus (MLV) envelope glycoproteins are expressed by several endogenous MLV proviruses, the highest expressed MLV envelope glycoprotein is under the control of an immune-responsive cellular promoter, thus linking MLV envelope glycoprotein expression with immune activation. We further showed that antibody ligation induces extensive internalisation from the plasma membrane into endocytic compartments of MLV envelope glycoproteins, which are not normally subject to constitutive endocytosis. Importantly, antibody binding and internalisation of MLV envelope glycoproteins initiates signalling cascades in envelope-expressing murine lymphocytic cell lines, leading to cellular activation. Similar effects were observed by MLV envelope glycoprotein ligation by its cellular receptor mCAT-1, and by overexpression in human lymphocytic cells, where it required an intact tyrosine-based YXXΦ motif in the envelope glycoprotein cytoplasmic tail. Together, these results suggest that signalling potential is a general property of retroviral envelope glycoproteins and, therefore, a target for intervention.


Assuntos
Anticorpos Antivirais/imunologia , Canais de Cálcio/imunologia , Membrana Celular/imunologia , Endocitose/imunologia , Vírus da Leucemia Murina/imunologia , Canais de Cátion TRPV/imunologia , Proteínas do Envelope Viral/imunologia , Animais , Humanos , Camundongos , Camundongos Endogâmicos BALB C
4.
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
5.
BMC Med Genet ; 21(1): 64, 2020 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-32228492

RESUMO

BACKGROUND: The calcium-selective channel TRPV6 (transient receptor potential cation channel subfamily V member 6) is crucial for maternal-fetal calcium transport across the placenta. TRPV6 mutations have recently been associated with an antenatally severe under-mineralising skeletal dysplasia accompanied by postnatal biochemical abnormalities. This is the first post-mortem report in a patient with TRPV6 skeletal dysplasia. CASE PRESENTATION: The female infant had severe antenatal and postnatal skeletal abnormalities by 20 weeks gestation and was ventilator-dependent from birth. These skeletal abnormalities were apparent at an earlier gestational age than in previous reported cases and a more severe clinical course ensued. Biochemical and skeletal abnormalities, including bone density, improved postnatally but cardiac arrest at 4 months of age led to withdrawal of intensive care. Compound heterozygous TRPV6 variants (c.1978G > C p.(Gly660Arg) and c.1528C > T p.(Arg510Ter)) were identified on exome sequencing. Post-mortem identified skeletal abnormalities but no specific abnormalities in other organ systems. No placental pathology was found, multi-organ histological features reflected prolonged intensive care only. Post-mortem macroscopic examination indicated reduced thoracic size and short, pale and pliable ribs. Histological examination identified reduced number of trabeculae in the diaphyses (away from the growth plates), whereas metaphyses showed adequate mineralisation and normal number of trabeculae, but with slightly enlarged reactive chondrocytes, indicating post-natal skeletal growth recovery. Post-mortem radiological findings demonstrated improved bone density, improved rib width, healed fractures, although ribs were still shorter than normal. Long bones (especially humerus and femur) had improved from initial poorly defined metaphyses and reduced bone density to sharply defined metaphyses, prominent growth restart lines in distal diaphyses and bone-in-bone appearance along diaphyses. CONCLUSIONS: This case provide bone histological confirmation that human skeletal development is compromised in the presence of TRPV6 pathogenic variants. Post-mortem findings were consistent with abnormal in utero skeletal mineralisation due to severe calcium deficit from compromised placental calcium transfer, followed by subsequent phenotypic improvement with adequate postnatal calcium availability. Significant skeletal recovery occurs in the early weeks of postnatal life in TRPV6 skeletal dysplasia.


Assuntos
Desenvolvimento Ósseo , Osso e Ossos/patologia , Canais de Cálcio/genética , Desenvolvimento Infantil/fisiologia , Osteocondrodisplasias/genética , Osteocondrodisplasias/patologia , Canais de Cátion TRPV/genética , Autopsia , Desenvolvimento Ósseo/genética , Osso e Ossos/anormalidades , Calcificação Fisiológica/genética , Cálcio/metabolismo , Canais de Cálcio/análise , Análise Mutacional de DNA , Feminino , Humanos , Lactente , Osteocondrodisplasias/reabilitação , Parto/fisiologia , Canais de Cátion TRPV/análise
7.
PLoS Genet ; 16(3): e1008625, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32176688

RESUMO

P/Q-type channels are the principal presynaptic calcium channels in brain functioning in neurotransmitter release. They are composed of the pore-forming CaV2.1 α1 subunit and the auxiliary α2δ-2 and ß4 subunits. ß4 is encoded by CACNB4, and its multiple splice variants serve isoform-specific functions as channel subunits and transcriptional regulators in the nucleus. In two siblings with intellectual disability, psychomotor retardation, blindness, epilepsy, movement disorder and cerebellar atrophy we identified rare homozygous variants in the genes LTBP1, EMILIN1, CACNB4, MINAR1, DHX38 and MYO15 by whole-exome sequencing. In silico tools, animal model, clinical, and genetic data suggest the p.(Leu126Pro) CACNB4 variant to be likely pathogenic. To investigate the functional consequences of the CACNB4 variant, we introduced the corresponding mutation L125P into rat ß4b cDNA. Heterologously expressed wild-type ß4b associated with GFP-CaV1.2 and accumulated in presynaptic boutons of cultured hippocampal neurons. In contrast, the ß4b-L125P mutant failed to incorporate into calcium channel complexes and to cluster presynaptically. When co-expressed with CaV2.1 in tsA201 cells, ß4b and ß4b-L125P augmented the calcium current amplitudes, however, ß4b-L125P failed to stably complex with α1 subunits. These results indicate that p.Leu125Pro disrupts the stable association of ß4b with native calcium channel complexes, whereas membrane incorporation, modulation of current density and activation properties of heterologously expressed channels remained intact. Wildtype ß4b was specifically targeted to the nuclei of quiescent excitatory cells. Importantly, the p.Leu125Pro mutation abolished nuclear targeting of ß4b in cultured myotubes and hippocampal neurons. While binding of ß4b to the known interaction partner PPP2R5D (B56δ) was not affected by the mutation, complex formation between ß4b-L125P and the neuronal TRAF2 and NCK interacting kinase (TNIK) seemed to be disturbed. In summary, our data suggest that the homozygous CACNB4 p.(Leu126Pro) variant underlies the severe neurological phenotype in the two siblings, most likely by impairing both channel and non-channel functions of ß4b.


Assuntos
Canais de Cálcio/genética , Mutação de Sentido Incorreto/genética , Transtornos do Neurodesenvolvimento/genética , Subunidades Proteicas/genética , Animais , Cálcio/metabolismo , Canais de Cálcio Tipo N/genética , Células Cultivadas , Feminino , Regulação da Expressão Gênica/genética , Células HEK293 , Hipocampo/fisiologia , Homozigoto , Humanos , Masculino , Camundongos Endogâmicos BALB C , Neurônios/metabolismo , Terminações Pré-Sinápticas/fisiologia , Isoformas de Proteínas/genética , Ratos , Transmissão Sináptica/genética
8.
PLoS One ; 15(3): e0230386, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32218573

RESUMO

Probenecid has been used for decades in the treatment of gout but recently has also been found to improve outcomes in patients with heart failure via stimulation of the transient receptor potential vanilloid 2 (TRPV2) channel in cardiomyocytes. This study tested the use of probenecid on a novel mouse model of peripartum cardiomyopathy (PPCM) as a potential treatment option. A human mutation of the human heat shock protein 20 (Hsp20-S10F) in mice has been recently shown to result in cardiomyopathy, when exposed to pregnancies. Treatment with either probenecid or control sucrose water was initiated after the first pregnancy in both wild type and Hsp20-S10F mice. Serial echocardiography was performed during subsequent pregnancies and hearts were collected after the third pregnancies for staining and molecular analysis. Hsp20-S10F mice treated with probenecid had decreased mortality, hypertrophy, TRPV2 expression and molecular parameters of heart failure. Probenecid treatment also decreased apoptosis as evidenced by an increase in the level of Bcl-2/Bax. Probenecid improved survival in a novel mouse model of PPCM and may be an appropriate therapy for humans with PPCM as it has a proven safety and tolerability in patients with heart failure.


Assuntos
Canais de Cálcio/genética , Cardiomiopatias/tratamento farmacológico , Proteínas de Choque Térmico HSP20/genética , Insuficiência Cardíaca/tratamento farmacológico , Probenecid/farmacologia , Canais de Cátion TRPV/genética , Animais , Apoptose/efeitos dos fármacos , Cardiomiopatias/diagnóstico por imagem , Cardiomiopatias/genética , Cardiomiopatias/patologia , Modelos Animais de Doenças , Ecocardiografia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/patologia , Humanos , Camundongos , Mutação/genética , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Período Periparto/efeitos dos fármacos , Gravidez , Complicações Cardiovasculares na Gravidez/tratamento farmacológico , Complicações Cardiovasculares na Gravidez/genética
9.
Proc Natl Acad Sci U S A ; 117(12): 6836-6843, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32144139

RESUMO

Visuomotor impairments characterize numerous neurological disorders and neurogenetic syndromes, such as autism spectrum disorder (ASD) and Dravet, Fragile X, Prader-Willi, Turner, and Williams syndromes. Despite recent advances in systems neuroscience, the biological basis underlying visuomotor functional impairments associated with these clinical conditions is poorly understood. In this study, we used neuroimaging connectomic approaches to map the visuomotor integration (VMI) system in the human brain and investigated the topology approximation of the VMI network to the Allen Human Brain Atlas, a whole-brain transcriptome-wide atlas of cortical genetic expression. We found the genetic expression of four genes-TBR1, SCN1A, MAGEL2, and CACNB4-to be prominently associated with visuomotor integrators in the human cortex. TBR1 gene transcripts, an ASD gene whose expression is related to neural development of the cortex and the hippocampus, showed a central spatial allocation within the VMI system. Our findings delineate gene expression traits underlying the VMI system in the human cortex, where specific genes, such as TBR1, are likely to play a central role in its neuronal organization, as well as on specific phenotypes of neurogenetic syndromes.


Assuntos
Canais de Cálcio/genética , Córtex Motor/fisiopatologia , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Transtornos do Neurodesenvolvimento/patologia , Proteínas/genética , Proteínas com Domínio T/genética , Córtex Visual/fisiopatologia , Adulto , Idoso , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/patologia , Mapeamento Encefálico , Estudos de Coortes , Epilepsias Mioclônicas/genética , Epilepsias Mioclônicas/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos do Neurodesenvolvimento/genética , Síndrome de Prader-Willi/genética , Síndrome de Prader-Willi/patologia , Desempenho Psicomotor , Percepção Visual
10.
BMC Med Genet ; 21(1): 44, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32111194

RESUMO

BACKGROUND: Abnormal calcium homeostasis related to the development of hypertension. As the key regulator of intracellular calcium concentration, voltage-dependent calcium channels (VDCCs), the variations in these genes may have important effects on the development of hypertension. Here we evaluate VDCCs variability with respect to hypertension in the Dai ethnic group of China. METHODS: A total of 1034 samples from Dai individuals were collected, of which 495 were used as cases, and 539 were used as controls. Blood pressure was measured using a standard mercury measurement method, three times with a rest for 5 min, and the average was used for analyses. Seventeen single nucleotide polymorphisms (SNPs) in the four protein-coding genes (CACNA1A, CACNA1C, CACNA1S, CACNB2) of VDCCs were identified by multiplex PCR-SNP typing technique. Chi-square tests and regression models were used to analyse the associations of SNPs with hypertension. RESULTS: The results of chi-square tests showed that the allele frequencies of 5 SNPs were significantly different between the case and the control groups (P < 0.05), but the statistical significance was lost after Bonferroni's correction. However, after adjusting for BMI, age, sex and other factors by logistic regression analyses, the results showed that 5 SNPs consistent with chi-square tests (rs2365293, rs17539088, rs16917217, rs61839222 and rs10425859) were still statistically positive. CONCLUSIONS: This finding suggested that the significant association of these SNPs with hypertension may be noteworthy in future studies.


Assuntos
Grupo com Ancestrais do Continente Asiático , Canais de Cálcio/genética , Hipertensão/etnologia , Hipertensão/genética , Polimorfismo de Nucleotídeo Único , Adulto , Idoso , Grupo com Ancestrais do Continente Asiático/etnologia , Grupo com Ancestrais do Continente Asiático/genética , Pressão Sanguínea/genética , Estudos de Casos e Controles , China/epidemiologia , Grupos Étnicos/genética , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade
11.
PLoS Comput Biol ; 16(3): e1007605, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32119665

RESUMO

Intracellular calcium ([Ca2+]i) is a basic and ubiquitous cellular signal controlling a wide variety of biological processes. A remarkable example is the steering of sea urchin spermatozoa towards the conspecific egg by a spatially and temporally orchestrated series of [Ca2+]i spikes. Although this process has been an experimental paradigm for reproduction and sperm chemotaxis studies, the composition and regulation of the signalling network underlying the cytosolic calcium fluctuations are hitherto not fully understood. Here, we used a differential equations model of the signalling network to assess which set of channels can explain the characteristic envelope and temporal organisation of the [Ca2+]i-spike trains. The signalling network comprises an initial membrane hyperpolarisation produced by an Upstream module triggered by the egg-released chemoattractant peptide, via receptor activation, cGMP synthesis and decay. Followed by downstream modules leading to intraflagellar pH (pHi), voltage and [Ca2+]i fluctuations. The Upstream module outputs were fitted to kinetic data on cGMP activity and early membrane potential changes measured in bulk cell populations. Two candidate modules featuring voltage-dependent Ca2+-channels link these outputs to the downstream dynamics and can independently explain the typical decaying envelope and the progressive spacing of the spikes. In the first module, [Ca2+]i-spike trains require the concerted action of a classical CaV-like channel and a potassium channel, BK (Slo1), whereas the second module relies on pHi-dependent CatSper dynamics articulated with voltage-dependent neutral sodium-proton exchanger (NHE). We analysed the dynamics of these two modules alone and in mixed scenarios. We show that the [Ca2+]i dynamics observed experimentally after sustained alkalinisation can be reproduced by a model featuring the CatSper and NHE module but not by those including the pH-independent CaV and BK module or proportionate mixed scenarios. We conclude in favour of the module containing CatSper and NHE and highlight experimentally testable predictions that would corroborate this conclusion.


Assuntos
Canais de Cálcio/metabolismo , Ouriços-do-Mar/metabolismo , Espermatozoides/fisiologia , Animais , Cálcio/metabolismo , Sinalização do Cálcio/fisiologia , Quimiotaxia/fisiologia , Biologia Computacional/métodos , Íons/metabolismo , Masculino , Potenciais da Membrana/fisiologia , Modelos Teóricos , Transdução de Sinais , Motilidade Espermática/fisiologia
12.
Nat Rev Neurosci ; 21(4): 213-229, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32161339

RESUMO

Chemical synapses are heterogeneous junctions formed between neurons that are specialized for the conversion of electrical impulses into the exocytotic release of neurotransmitters. Voltage-gated Ca2+ channels play a pivotal role in this process as they are the major conduits for the Ca2+ ions that trigger the fusion of neurotransmitter-containing vesicles with the presynaptic membrane. Alterations in the intrinsic function of these channels and their positioning within the active zone can profoundly alter the timing and strength of synaptic output. Advances in optical and electron microscopic imaging, structural biology and molecular techniques have facilitated recent breakthroughs in our understanding of the properties of voltage-gated Ca2+ channels that support their presynaptic functions. Here we examine the nature of these channels, how they are trafficked to and anchored within presynaptic boutons, and the mechanisms that allow them to function optimally in shaping the flow of information through neural circuits.


Assuntos
Canais de Cálcio/fisiologia , Terminações Pré-Sinápticas/fisiologia , Transmissão Sináptica/fisiologia , Vesículas Sinápticas/fisiologia , Animais , Humanos , Transporte Proteico
13.
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
14.
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
15.
Adv Neurobiol ; 24: 647-660, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32006378

RESUMO

Autism, or autism spectrum disorders (ASD), is one of the complex genetic diseases and its etiology is unknown for majority of the patients. It is characterized by deterioration in social interaction, communication, interests, imagination, and activities. As autism is a highly heterogeneous disorder, the symptoms can vary greatly in each affected individual. Oxidative stress implicates major pathogenesis of neurological disorders like ASD. Nutrients and dietary supplements play an important role in the health of an individual and there are several lines of evidence suggesting the role of dietary factors in the development or pathogenesis of ASD. The amino acids supplement has been found to reduce symptoms as they act as the precursors of neurotransmitters which in turn may extenuate mental disorders. The biosynthesis of amino acids in the brain is regulated by the concentration of amino acids in plasma. Amino acids are also considerable entities as they themselves, or peptides consisting of them, have profound antioxidant activities. Dietary constituents have an effect on the transport of amino acids across the blood-brain barrier (BBB) thus indirectly modulating the therapeutic value of amino acids. Among the other factors, voltage-gated calcium channels are directly linked to ASD as per results of genetic studies. Malfunctioning of these calcium channels causes ASD. The intricate biochemical and molecular machinery contributing to neurological disorders is still unknown. Here we discuss the preventive role of dietary amino acids against and regulation of voltage-gated calcium channels on ASD.


Assuntos
Aminoácidos/uso terapêutico , Transtorno do Espectro Autista/dietoterapia , Transtorno do Espectro Autista/metabolismo , Canais de Cálcio/metabolismo , Dieta , Aminoácidos/administração & dosagem , Aminoácidos/metabolismo , Cálcio/metabolismo , Suplementos Nutricionais , Humanos
16.
Nature ; 578(7796): 577-581, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32076270

RESUMO

Hydrogen peroxide (H2O2) is a major reactive oxygen species in unicellular and multicellular organisms, and is produced extracellularly in response to external stresses and internal cues1-4. H2O2 enters cells through aquaporin membrane proteins and covalently modifies cytoplasmic proteins to regulate signalling and cellular processes. However, whether sensors for H2O2 also exist on the cell surface remains unknown. In plant cells, H2O2 triggers an influx of Ca2+ ions, which is thought to be involved in H2O2 sensing and signalling. Here, by using forward genetic screens based on Ca2+ imaging, we isolated hydrogen-peroxide-induced Ca2+ increases (hpca) mutants in Arabidopsis, and identified HPCA1 as a leucine-rich-repeat receptor kinase belonging to a previously uncharacterized subfamily that features two extra pairs of cysteine residues in the extracellular domain. HPCA1 is localized to the plasma membrane and is activated by H2O2 via covalent modification of extracellular cysteine residues, which leads to autophosphorylation of HPCA1. HPCA1 mediates H2O2-induced activation of Ca2+ channels in guard cells and is required for stomatal closure. Our findings help to identify how the perception of extracellular H2O2 is integrated with responses to various external stresses and internal cues in plants, and have implications for the design of crops with enhanced fitness.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Peróxido de Hidrogênio/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Sinalização do Cálcio , Cisteína/química , Cisteína/metabolismo , Ativação Enzimática , Proteínas de Membrana/química , Proteínas de Membrana/genética , Mutação , Oxirredução , Células Vegetais/metabolismo , Domínios Proteicos , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética
17.
Am J Physiol Heart Circ Physiol ; 318(4): H820-H829, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32083972

RESUMO

Estrogen deficiency is considered to be an important factor leading to cardiovascular diseases (CVDs). Indeed, the prevalence of CVDs in postmenopausal women exceeds that of premenopausal women and men of the same age. Recent research findings provide evidence that estrogen plays a pivotal role in the regulation of calcium homeostasis and therefore fine-tunes normal cardiomyocyte contraction and relaxation processes. Disruption of calcium homeostasis is closely associated with the pathological mechanism of CVDs. Thus, this paper maps out and summarizes the effects and mechanisms of estrogen on calcium handling proteins in cardiac myocytes, including L-type Ca2+ channel, the sarcoplasmic reticulum Ca2+ release channel named ryanodine receptor, sarco(endo)plasmic reticulum Ca2+-ATPase, and sodium-calcium exchanger. In so doing, we provide theoretical and experimental evidence for the successful design of estrogen-based prevention and treatment therapies for CVDs.


Assuntos
Cálcio/metabolismo , Doenças Cardiovasculares/metabolismo , Estrogênios/metabolismo , Potenciais de Ação , Animais , Canais de Cálcio/metabolismo , Doenças Cardiovasculares/fisiopatologia , Humanos , Contração Miocárdica , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/fisiologia , Receptores Estrogênicos/metabolismo
18.
Metabolism ; 105: 154182, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32061660

RESUMO

The impairment of podocyte protein filtration function caused by excessive mitochondrial calcium intake is a critical feature of diabetic nephropathy (DN). Ca2+ channel transient receptor potential cation channel subfamily V member 1 (TRPV1) has been reported to protect against ischemia-reperfusion induced acute renal injury, but there is no report about its role in DN. Here, we report that dietary capsaicin potently inhibits and reverses chronic renal structural and functional damages in db/db or streptozotocin (STZ)-induced diabetic mice in a TRPV1-dependent manner. Activation of TRPV1 by capsaicin alleviated hyperglycemia-induced mitochondrial dysfunction in podocytes, accompanied by reduced mitochondria-associated membranes (MAMs) formation and fewer Ca2+ transport from endoplasmic reticulum (ER) to mitochondria. Mechanistically, TRPV1-mediated transient Ca2+ influx activated 5' AMP-activated protein kinase (AMPK) that reduced the transcription of Fundc1, a key molecule participating in MAMs formation. Inhibition of AMPK or overexpression of Fundc1 obviously blocked the inhibitory effect of capsaicin on MAMs formation and functional decline in podocytes. These findings emphasize the critical role of mitochondrial Ca2+ homeostasis in the maintenance of normal renal function and suggest an effective intervention method to counteract DN.


Assuntos
Nefropatias Diabéticas/tratamento farmacológico , Retículo Endoplasmático/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Podócitos/efeitos dos fármacos , Canais de Cátion TRPV/metabolismo , Proteínas Quinases Ativadas por AMP/antagonistas & inibidores , Proteínas Quinases Ativadas por AMP/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Canais de Cálcio/metabolismo , Capsaicina/uso terapêutico , Dieta , Inibidores Enzimáticos/farmacologia , Hiperglicemia/tratamento farmacológico , Hiperglicemia/microbiologia , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/biossíntese , Camundongos , Camundongos Endogâmicos C57BL , Membranas Mitocondriais/efeitos dos fármacos , Proteínas Mitocondriais/antagonistas & inibidores , Proteínas Mitocondriais/biossíntese
19.
Biochim Biophys Acta Mol Cell Res ; 1867(4): 118644, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31931022

RESUMO

For twenty years, ion channels have been studied in cancer progression. Several information have been collected about their involvement in cancer cellular processes like cell proliferation, motility and their participation in tumour progression using in-vivo models. Tumour microenvironment is currently the focus of many researches and the highlighting of the relationship between cancer cells and surrounding elements, is expanding. One of the major physic-chemical parameter involved in tumour progression is the hypoxia conditions observed in solid cancer. Due to their position on the cell membrane, ion channels are good candidates to transduce or to be modulated by environmental modifications. Until now, few reports have been interested in the modification of ion channel activities or expression in this context, compared to other pathological situations such as ischemia reperfusion. The aim of our review is to summarize the current knowledge about the calcium and potassium channels properties in the context of hypoxia in tumours. This review could pave the way to orientate new studies around this exciting field to obtain new potential therapeutic approaches.


Assuntos
Canais de Cálcio/metabolismo , Neoplasias/metabolismo , Oxigênio/metabolismo , Canais de Potássio/metabolismo , Microambiente Tumoral , Animais , Hipóxia Celular , Humanos
20.
Mol Cells ; 43(1): 66-75, 2020 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-31931552

RESUMO

Saturated fatty acids contribute to ß-cell dysfunction in the onset of type 2 diabetes mellitus. Cellular responses to lipotoxicity include oxidative stress, endoplasmic reticulum (ER) stress, and blockage of autophagy. Palmitate induces ER Ca2+ depletion followed by notable store-operated Ca2+ entry. Subsequent elevation of cytosolic Ca2+ can activate undesirable signaling pathways culminating in cell death. Mitochondrial Ca2+ uniporter (MCU) is the major route for Ca2+ uptake into the matrix and couples metabolism with insulin secretion. However, it has been unclear whether mitochondrial Ca2+ uptake plays a protective role or contributes to lipotoxicity. Here, we observed palmitate upregulated MCU protein expression in a mouse clonal ß-cell, MIN6, under normal glucose, but not high glucose medium. Palmitate elevated baseline cytosolic Ca2+ concentration ([Ca2+]i) and reduced depolarization-triggered Ca2+ influx likely due to the inactivation of voltage-gated Ca2+ channels (VGCCs). Targeted reduction of MCU expression using RNA interference abolished mitochondrial superoxide production but exacerbated palmitate-induced [Ca2+]i overload. Consequently, MCU knockdown aggravated blockage of autophagic degradation. In contrast, co-treatment with verapamil, a VGCC inhibitor, prevented palmitate-induced basal [Ca2+]i elevation and defective [Ca2+]i transients. Extracellular Ca2+ chelation as well as VGCC inhibitors effectively rescued autophagy defects and cytotoxicity. These observations suggest enhanced mitochondrial Ca2+ uptake via MCU upregulation is a mechanism by which pancreatic ß-cells are able to alleviate cytosolic Ca2+ overload and its detrimental consequences.


Assuntos
Citosol/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Retículo Endoplasmático/metabolismo , Células Secretoras de Insulina/fisiologia , Mitocôndrias/metabolismo , Animais , Autofagia , Cálcio/metabolismo , Canais de Cálcio/genética , Canais de Cálcio/metabolismo , Sinalização do Cálcio , Morte Celular , Linhagem Celular , Humanos , Potencial da Membrana Mitocondrial , Camundongos , Estresse Oxidativo , Palmitatos/metabolismo , RNA Interferente Pequeno/genética
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