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1.
Pan Afr Med J ; 33: 43, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31384358

RESUMO

Carpopedal spasm have various causes ranging from dsyselecrolytemia, syndromic, metabolic or endocrine causes. Any of these could cause a decrease in ionized calcium and tetany. Excessive vomiting leading to alkalosis, hypokaleamia and decreased ionised calcium should be kept in mind for early etiological diagnosis of carpopedal spasm. We report a case of 4-year-old boy presenting with a history of recurrent painful spasm and flexion of bilateral hands following excessive vomiting and electrolyte derangement.


Assuntos
Espasmo/etiologia , Vômito/complicações , Desequilíbrio Hidroeletrolítico/complicações , Cálcio/metabolismo , Pré-Escolar , Mãos , Humanos , Masculino , Desequilíbrio Hidroeletrolítico/etiologia
2.
Pestic Biochem Physiol ; 159: 144-153, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31400776

RESUMO

Ivermectin is a pesticide that has been used for over 30 years in livestock. Although there are a number of studies on the therapeutic potential of ivermectin, little is known about the effects of the drug during the early stage of pregnancy. In this study, we investigated the detrimental effects of ivermectin on porcine trophectoderm (pTr) and uterine luminal epithelial (pLE) cells. Ivermectin not only inhibited the proliferation of both cells via the regulation of cell cycle-associated genes, but also induced apoptosis in pTr and pLE cells. We also verified its effect on mitochondrial dysfunction as shown by loss of mitochondrial membrane potential, mitochondrial Ca2+ overload, and reactive oxygen species (ROS) generation in pTr and pLE cells. As a mechanistic approach, we evaluated ivermectin-mediated cell signaling interactions including PI3K, AKT and MAPK pathways. Overall, our results suggest that constant exposure to and accumulation of ivermectin may cause abnormal fetal morphogenesis and placentation during the early stages of pregnancy. Our results may further provide a comprehensive understanding of the detrimental effects of ivermectin during pregnancy and will contribute to the establishment of a complete safety profile for ivermectin and its association with environmental pollution and public health in humans and livestock.


Assuntos
Apoptose/efeitos dos fármacos , Cálcio/metabolismo , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Ivermectina/farmacologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Útero/citologia , Animais , Proliferação de Células/efeitos dos fármacos , Feminino , Suínos , Trofoblastos/citologia , Trofoblastos/efeitos dos fármacos
3.
BMC Plant Biol ; 19(1): 368, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31429706

RESUMO

BACKGROUND: We previously reported the involvement of nitric oxide (NO) and cyclic nucleotide-gated ion channel 6 (CNGC6) in the responses of plants to heat shock (HS) exposure. To elucidate their relationship with heat tolerance in Arabidopsis thaliana, we examined the effects of HS on several groups of seedlings: wild type, cngc6, and cngc6 complementation and overexpression lines. RESULTS: After HS exposure, the level of NO was lower in cngc6 seedlings than in wild-type seedlings but significantly elevated in the transgenic lines depending on CNGC6 expression level. The treatment of seeds with calcium ions (Ca2+) enhanced the NO level in Arabidopsis seedlings under HS conditions, whereas treatment with EGTA (a Ca2+ chelator) reduced it, implicating that CNGC6 stimulates the accumulation of NO depending on an increase in cytosolic Ca2+ ([Ca2+]cyt). This idea was proved by phenotypic observations and thermotolerance testing of transgenic plants overexpressing NIA2 and NOA1, respectively, in a cngc6 background. Western blotting indicated that CNGC6 stimulated the accumulation of HS proteins via NO. CONCLUSION: These data indicate that CNGC6 acts upstream of NO in the HS pathway, which improves our insufficient knowledge of the initiation of plant responses to high temerature.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Cálcio/metabolismo , Canais de Cátion Regulados por Nucleotídeos Cíclicos/metabolismo , Óxido Nítrico/metabolismo , Termotolerância , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Canais de Cálcio/metabolismo , Canais de Cátion Regulados por Nucleotídeos Cíclicos/genética , Citosol/metabolismo , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico , Mutação , Nitrato Redutase/genética , Nitrato Redutase/metabolismo , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase/metabolismo , Plântula/genética , Plântula/metabolismo
4.
J Chem Theory Comput ; 15(8): 4602-4614, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31268700

RESUMO

Many biological processes are based on molecular recognition between highly charged molecules such as nucleic acids, inorganic ions, charged amino acids, etc. For such cases, it has been demonstrated that molecular simulations with fixed partial charges often fail to achieve experimental accuracy. Although incorporation of more advanced electrostatic models (such as multipoles, mutual polarization, etc.) can significantly improve simulation accuracy, it increases computational expense by a factor of 5-20×. Indirect free energy (IFE) methods can mitigate this cost by modeling intermediate states at fixed-charge resolution. For example, an efficient "reference" model such as a pairwise Amber, CHARMM, or OPLS-AA force field can be used to derive an initial estimate, followed by thermodynamic corrections to a more advanced "target" potential such as the polarizable AMOEBA model. Unfortunately, all currently described IFE methods encounter difficulties reweighting more than ∼50 atoms between resolutions due to extensive scaling of both the magnitude of the thermodynamic corrections and their statistical uncertainty. We present an approach called "simultaneous bookending" (SB) that is fundamentally different from existing IFE methods based on a tunable sampling approximation, which permits scaling to thousands of atoms. SB is demonstrated on the relative binding affinity of Mg2+/Ca2+ to a set of metalloproteins with up to 2972 atoms, finding no statistically significant difference between direct AMOEBA results and those from correcting Amber to AMOEBA. The ability to change the resolution of thousands of atoms during reweighting suggests the approach may be applicable in the future to protein-protein binding affinities or nucleic acid thermodynamics.


Assuntos
Cálcio/metabolismo , Cátions Bivalentes/metabolismo , Magnésio/metabolismo , Metaloproteínas/metabolismo , Animais , Cálcio/química , Cátions Bivalentes/química , Bases de Dados de Proteínas , Humanos , Magnésio/química , Metaloproteínas/química , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Software , Eletricidade Estática , Termodinâmica
5.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 35(3): 209-214, 2019 May 28.
Artigo em Chinês | MEDLINE | ID: mdl-31257800

RESUMO

OBJECTIVE: To investigate the effects of apple polyphenols on pulmonary vascular remodeling in rats with pulmonary arterial hypertension and its mechanism. METHODS: Rats were randomly divided into 4 groups:control (Con) group, monocrotaline (MCT) group, apple polyphenol (APP) group,monocrotaline + apple polyphenol (MCT+APP) group. In Con group, rats received a subcutaneous injection of physical saline. In APP group, rats received intraperitoneal injection of 20 mg/kg APP, every other day. In MCT group, rats received a single subcutaneous injection of MCT(60 mg/kg). In MCT+APP group, rats received subcutaneous injection of 60 mg/kg MCT followed by an intraperitoneal injection of 20 mg/kg APP every other day. All the disposal lasted 3 weeks. Then the PAH-relevant indicators, such as mean pulmonary artery pressure(mPAP), pulmonary vascular resistance(PVR), right ventricular hypertrophy index (RVHI) ,wall thickness (WT%) and wall area (WA%) were tested. After that, the inflammatory pathway related indicators, such as interleukin1(IL-1),interleukin1(IL-6), tumor necrosis factor α(TNF-α), cyclooxygenase 2(COX-2) and myeloperoxidase(MPO) in pulmonary tissue and free intracellular Ca2+ in pulmonary smooth muscle cell(PASMC), content of eNOS and NO in endothelial cells were determined. RESULTS: Compared with the control group, the levels of mPAP, PVR, RVHI, WA%, WT%, and IL-1, IL-6, TNF-α, COX-2, MPO in tissue and the expression of Ca2 + in PASMC of MCT group were increased significantly, while the contents of eNOS and NO in endothelial cells were decreased significantly (P<0.05). Compared with the MCT group, the apple polyphenol treatment could improve the above mentioned situation, and the COX-2 and Ca2+ indicators of the apple polyphenol treatment group were decreased significantly (P<0.05). CONCLUSION: MCT can increase COX-2 expression and intracellular Ca2+ in pulmonary artery smooth muscle cells, decrease the contents of eNOS and NO in endothelial cells, while apple polyphenols can significantly inhibit these effects.


Assuntos
Malus/química , Polifenóis/farmacologia , Artéria Pulmonar/efeitos dos fármacos , Remodelação Vascular/efeitos dos fármacos , Animais , Cálcio/metabolismo , Ciclo-Oxigenase 2/metabolismo , Citocinas/metabolismo , Monocrotalina , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Artéria Pulmonar/patologia , Distribuição Aleatória , Ratos
6.
Cell Physiol Biochem ; 53(1): 215-228, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31299143

RESUMO

BACKGROUND/AIMS: With the prevalence of asthma being greater in women, detrimental effects of female sex steroids have been explored, but potential protective effects of androgens are not established. Airway smooth muscle (ASM) is a key cell type in contractility and remodelling of asthma. There are no data on expression and functionality of androgen receptor (AR) in human ASM cells. METHODS: We used primary human ASM cells from non-asthmatics vs. asthmatics to determine AR expression at baseline and with inflammation measured using Western blotting/qRT-PCR, and the role of AR in regulating intracellular Ca2+ ([Ca2+]i) measured using Fluo-3 loaded real time [Ca2+]i imaging. RESULTS: We found that compared to females, baseline AR is greater in male ASM and increases with inflammation/asthma. Androgens, via AR, blunted TNFα or IL-13-induced enhancement of ASM [Ca2+]i in both males and females, with retained efficacy in asthmatics. AR effects involve reduced Ca2+ influx via L-type channels and store-operated Ca2+ entry, the latter by downregulating STIM1 and Orai1 and increasing TMEM66. CONCLUSION: Our data show AR expression is increased in female ASM with asthma, but has retained functionality that could be used to reduce [Ca2+]i towards alleviating airway hyperresponsiveness.


Assuntos
Cálcio/metabolismo , Receptores Androgênicos/metabolismo , Asma/metabolismo , Asma/patologia , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Feminino , Humanos , Interleucina-13/farmacologia , Masculino , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Proteínas de Neoplasias/metabolismo , Proteína ORAI1/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Receptores Androgênicos/química , Receptores Androgênicos/genética , Fatores Sexuais , Molécula 1 de Interação Estromal/metabolismo , Testosterona/farmacologia , Fator de Necrose Tumoral alfa/farmacologia
7.
Cell Physiol Biochem ; 53(1): 229-241, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31302949

RESUMO

BACKGROUND/AIMS: Circulating or extracellular histones (EHs) in the bloodstream act as a damage-associated-molecular-pattern (DAMP) agent that plays a critical role in the pathogenesis of many diseases such as sepsis and sterile inflammation. To date, not much information is available to describe the mechanistic relationship between human erythrocytes and the cytotoxicity of EHs, the protein members from a highly conserved histone family across species. The present study explored this key question with a hypothesis that EHs induce eryptosis. METHODS: Freshly isolated human red blood cells (RBCs) from healthy donors were treated with EHs or agents for positive controls in a physiological buffer for 3 or 24 h. After treatments, flow cytometry was employed to quantify surface phosphatidylserine (PS) exposure from annexin-V-RFP binding, cell shrinkage from flow cytometric forward scatter (FSC) analysis, Ca2+ rise by fluo-4, reactive oxygen species (ROS) production by H2DCFDA, and caspase-3 activation by FAM-DEVD-FMK measurement. Hemolysis and membarne permeabilization were estimated respectively from hemoglobin release into supernatant and calcein leakage from RBC ghosts. RESULTS: With positive controls for validation, EHs in the pathophsyiological range were found to accumulate annexin-V binding on cell surface, decrease FSC, upregulate ROS production, elevate Ca2+ influx and increase caspase-3 activity in a 3-h incubation. Of note, no RBC hemolysis and no calcein release from ghosts were obtained after EHs treatment for 24 h. Interestingly, external Ca2+ was not a prerequisite for the EHs-mediated ROS production and PS externalization. Also, the eryptotic hallmarks in the apoptotic RBCs were partially blocked by heparin and antibody (Ab) against Toll-like receptor 2 (TLR2). CONCLUSION: EHs act as a DAMP agent in the human RBCs that induces eryptosis. The cytotoxic effect is rapid as the hallmarks of eryptosis such as cell shrinkage, surface PS exposure, [Ca2+]i rise, ROS production and caspase-3 activation can be seen 3 h after treatment in a dose-dependent manner. The EHs' cytotoxic effects could be blocked by heparin and the Ab against TLR2.


Assuntos
Eriptose/efeitos dos fármacos , Histonas/farmacologia , Anticorpos/imunologia , Anticorpos/farmacologia , Cálcio/metabolismo , Caspase 3/metabolismo , Células Cultivadas , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Heparina/farmacologia , Humanos , Espécies Reativas de Oxigênio/metabolismo , Receptor 2 Toll-Like/imunologia
8.
Arch Insect Biochem Physiol ; 102(1): e21595, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31276240

RESUMO

Honey bees Apis mellifera L. are one of the most studied insect species due to their economic importance. The interest in studying honey bees chiefly stems from the recent rapid decrease in their world population, which has become a problem of food security. Nevertheless, there are no systemic studies on the properties of the mitochondria of honey bee flight muscles. We conducted a research of the mitochondria of the flight muscles of A. mellifera L. The influence of various organic substrates on mitochondrial respiration in the presence or absence of adenosine diphosphate (ADP) was investigated. We demonstrated that pyruvate is the optimal substrate for the coupled respiration. A combination of pyruvate and glutamate is required for the maximal respiration rate. We also show that succinate oxidation does not support the oxidative phosphorylation and the generation of membrane potential. We also studied the production of reactive oxygen species by isolated mitochondria. The greatest production of H2 O2 (as a percentage of the rate of oxygen consumed) in the absence of ADP was observed during the respiration supported by α-glycerophosphate, malate, and a combination of malate with another NAD-linked substrate. We showed that honey bee flight muscle mitochondria are unable to uptake Ca2+ -ions. We also show that bee mitochondria are able to oxidize the respiration substrates effectively at the temperature of 50°Ð¡ compared to Bombus terrestris mitochondria, which were more adapted to lower temperatures.


Assuntos
Abelhas/metabolismo , Mitocôndrias Musculares/metabolismo , Animais , Cálcio/metabolismo , Respiração Celular , Feminino , Voo Animal , Peróxido de Hidrogênio/metabolismo , Masculino , Potenciais da Membrana , Camundongos , Músculos/metabolismo , Temperatura Ambiente
10.
Nat Commun ; 10(1): 2516, 2019 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-31175287

RESUMO

Store-operated Ca2+ entry, involving endoplasmic reticulum Ca2+ sensing STIM proteins and plasma membrane Orai1 channels, is a widespread and evolutionary conserved Ca2+ influx pathway. This form of Ca2+ influx occurs at discrete loci where peripheral endoplasmic reticulum juxtaposes the plasma membrane. Stimulation evokes numerous STIM1-Orai1 clusters but whether distinct signal transduction pathways require different cluster numbers is unknown. Here, we show that two Ca2+-dependent transcription factors, NFAT1 and c-fos, have different requirements for the number of STIM1-Orai1 clusters and on the Ca2+ flux through them. NFAT activation requires fewer clusters and is more robustly activated than c-fos by low concentrations of agonist. For similar cluster numbers, transcription factor recruitment occurs sequentially, arising from intrinsic differences in Ca2+ sensitivities. Variations in the number of STIM1-Orai1 clusters and Ca2+ flux through them regulate the robustness of signalling to the nucleus whilst imparting a mechanism for selective recruitment of different Ca2+-dependent transcription factors.


Assuntos
Sinalização do Cálcio , Cálcio/metabolismo , Fatores de Transcrição NFATC/metabolismo , Proteína ORAI1/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Molécula 1 de Interação Estromal/metabolismo , Animais , Linhagem Celular , Membrana Celular/metabolismo , Retículo Endoplasmático/metabolismo , Ratos , Transdução de Sinais
11.
Nat Commun ; 10(1): 2536, 2019 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-31182714

RESUMO

Optical fiber-mediated optogenetic activation and neuronal Ca2+ recording in combination with fMRI provide a multi-modal fMRI platform. Here, we developed an MRI-guided robotic arm (MgRA) as a flexible positioning system with high precision to real-time assist optical fiber brain intervention for multi-modal animal fMRI. Besides the ex vivo precision evaluation, we present the highly reliable brain activity patterns in the projected basal forebrain regions upon MgRA-driven optogenetic stimulation in the lateral hypothalamus. Also, we show the step-wise optical fiber targeting thalamic nuclei and map the region-specific functional connectivity with whole-brain fMRI accompanied by simultaneous calcium recordings to specify its circuit-specificity. The MgRA also guides the real-time microinjection to specific deep brain nuclei, which is demonstrated by an Mn-enhanced MRI method. The MgRA represents a clear advantage over the standard stereotaxic-based fiber implantation and opens a broad avenue to investigate the circuit-specific functional brain mapping with the multi-modal fMRI platform.


Assuntos
Imagem por Ressonância Magnética/instrumentação , Optogenética/instrumentação , Procedimentos Cirúrgicos Robóticos/instrumentação , Animais , Cálcio/metabolismo , Channelrhodopsins , Neuroimagem Funcional/instrumentação , Neuroimagem Funcional/métodos , Imagem por Ressonância Magnética/métodos , Masculino , Fibras Ópticas , Optogenética/métodos , Ratos Sprague-Dawley
12.
Nat Commun ; 10(1): 2533, 2019 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-31182715

RESUMO

Spatiotemporally synchronised neuronal activity is central to sensation, motion and cognition. Brain circuits consist of dynamically interconnected neuronal cell-types, thus elucidating how neuron types synergise within the network is key to understand the neuronal orchestra. Here we show that in neocortex neuron-network coupling is neuronal cell-subtype specific. Employing in vivo two-photon (2-p) Calcium (Ca) imaging and 2-p targeted whole-cell recordings, we cell-type specifically investigated the coupling profiles of genetically defined neuron populations in superficial layers (L) of mouse primary visual cortex (V1). Our data reveal novel subtlety of neuron-network coupling in inhibitory interneurons (INs). Parvalbumin (PV)- and Vasoactive intestinal peptide (VIP)-expressing INs exhibit skewed distributions towards strong network-coupling; in Somatostatin (SST)-expressing INs, however, two physiological subpopulations are identified with distinct neuron-network coupling profiles, providing direct evidence for subtype specificity. Our results thus add novel functional granularity to neuronal cell-typing, and provided insights critical to simplifying/understanding neural dynamics.


Assuntos
Interneurônios/fisiologia , Neurônios/fisiologia , Córtex Visual/citologia , Córtex Visual/fisiologia , Animais , Cálcio/metabolismo , Eletrofisiologia , Potenciais Evocados Visuais , Feminino , Masculino , Camundongos Transgênicos , Microscopia de Fluorescência por Excitação Multifotônica , Parvalbuminas/metabolismo , Estimulação Luminosa , Somatostatina/metabolismo , Peptídeo Intestinal Vasoativo/metabolismo
13.
Pestic Biochem Physiol ; 157: 1-12, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31153457

RESUMO

The use of neurotoxic chemical insecticides has led to consequences against the environment, insect resistances and side-effects on non-target organisms. In this context, we developed a novel strategy to optimize insecticide efficacy while reducing doses. It is based on nanoencapsulation of a pyrethroid insecticide, deltamethrin, used as synergistic agent, combined with a non-encapsulated oxadiazine (indoxacarb). In this case, the synergistic agent is used to increase insecticide efficacy by activation of calcium-dependant intracellular signaling pathways involved in the regulation of the membrane target of insecticides. In contrast to permethrin (pyrethroid type I), we report that deltamethrin (pyrethroid type II) produces an increase in intracellular calcium concentration in insect neurons through the reverse Na/Ca exchanger. The resulting intracellular calcium rise rendered voltage-gated sodium channels more sensitive to lower concentration of the indoxacarb metabolite DCJW. Based on these findings, in vivo studies were performed on the cockroach Periplaneta americana and mortality rates were measured at 24 h, 48 h and 72 h after treatments. Comparative studies of the toxicity between indoxacarb alone and indoxacarb combined with deltamethrin or nanoencapsulated deltamethrin (LNC-deltamethrin), indicated that LNC-deltamethrin potentiated the effect of indoxacarb. We also demonstrated that nanoencapsulation protected deltamethrin from esterase-induced enzymatic degradation and led to optimize indoxacarb efficacy while reducing doses. Moreover, our results clearly showed the benefit of using LNC-deltamethrin rather than piperonyl butoxide and deltamethrin in combination commonly used in formulation. This innovative strategy offers promise for increasing insecticide efficacy while reducing both doses and side effects on non-target organisms.


Assuntos
Cálcio/metabolismo , Inseticidas/química , Inseticidas/farmacologia , Nanocápsulas/química , Nitrilos/química , Nitrilos/farmacologia , Oxazinas/química , Oxazinas/farmacologia , Piretrinas/química , Piretrinas/farmacologia , Animais , Células Cultivadas , Baratas , Masculino , Estrutura Molecular , Periplaneta/efeitos dos fármacos , Trocador de Sódio e Cálcio/metabolismo
14.
Pestic Biochem Physiol ; 157: 152-160, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31153463

RESUMO

Malathion, one of commonly used organophosphate insecticides, has a wide range of toxic actions in different models. However, the effect of this compound on Ca2+ homeostasis and its related cytotoxicity in glial cells is elusive. This study examined whether malathion evoked intracellular Ca2+ concentration ([Ca2+]i) rises and established the relationship between Ca2+ signaling and cytotoxicity in normal human astrocytes, rat astrocytes and human glioblastoma cells. The data show that malathion induced concentration-dependent [Ca2+]i rises in Gibco® Human Astrocytes (GHA cells), but not in DI TNC1 normal rat astrocytes and DBTRG-05MG human glioblastoma cells. In GHA cells, this Ca2+ signal response was reduced by removing extracellular Ca2+. In Ca2+-free medium, pretreatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin abolished malathion-induced [Ca2+]i rises. Conversely, incubation with malathion abolished thapsigargin-induced [Ca2+]i rises. Inhibition of phospholipase C (PLC) with U73122 also blocked malathion-induced [Ca2+]i rises. In Ca2+-containing medium, malathion-induced [Ca2+]i rises was inhibited by store-operated Ca2+ channel blockers (2-APB, econazole or SKF96365) and the protein kinase C (PKC) inhibitor GF109203X. Malathion (5-25 µM) concentration-dependently caused cytotoxicity in GHA, DI TNC1 and DBTRG-05MG cells. This cytotoxic effect was partially prevented by prechelating cytosolic Ca2+ with BAPTA-AM (a selective Ca2+ chelator) only in GHA cells. Together, in GHA but not in DI TNC1 and DBTRG-05MG cells, malathion induced [Ca2+]i rises by inducing PLC-dependent Ca2+ release from the endoplasmic reticulum and Ca2+ entry via PKC-sensitive store-operated Ca2+ channels. Furthermore, malathion induced Ca2+-associated cytotoxicity, suggesting that Ca2+ chelating may have a protective effect on malathion-induced cytotoxicity in normal human astrocytes.


Assuntos
Cálcio/metabolismo , Malation/farmacologia , Animais , Sinalização do Cálcio/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Quelantes , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Humanos , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Ratos
15.
Biochemistry (Mosc) ; 84(3): 291-298, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31221067

RESUMO

Generation of patient-specific induced pluripotent stem cells (iPSCs) and their subsequent differentiation into cardiomyocytes opened new opportunities for studying pathogenesis of inherited cardiovascular diseases. One of these diseases is hypertrophic cardiomyopathy (HCM) for which no efficient therapy methods have been developed so far. In this study, the approach based on patient-specific iPSCs was applied to create a model of the disease. Genetic analysis of a hypertrophic cardiomyopathy patient revealed R326Q mutation in the MYBPC3 gene. iPSCs of the patient were generated and characterized. The cells were differentiated into cardiomyocytes together with the control iPSCs from a healthy donor. The patient's iPSC-derived cardiomyocytes exhibited early HCM features, such as abnormal calcium handling and increased intracellular calcium concentration. Therefore, cardiomyocytes obtained by directed differentiation of iPSCs from the HCM patient can be used as a model system to study HCM pathogenesis.


Assuntos
Cardiomiopatia Hipertrófica/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Modelos Biológicos , Adulto , Cálcio/metabolismo , Cardiomiopatia Hipertrófica/diagnóstico , Cardiomiopatia Hipertrófica/genética , Diferenciação Celular , Células Cultivadas , Humanos , Células-Tronco Pluripotentes Induzidas/patologia , Masculino
16.
Biochemistry (Mosc) ; 84(3): 299-309, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31221068

RESUMO

Patient-specific induced pluripotent stem cells (iPSCs) capable of differentiation into required cell type are a promising model for studying various pathological processes and development of new therapeutic approaches. However, no conventional strategies for using iPSCs in disease research have been established yet. Genetically encoded biosensors can be used for monitoring messenger molecules, metabolites, and enzyme activity in real time with the following conversion of the registered signals in quantitative data, thus allowing evaluation of the impact of certain molecules on pathology development. In this article, we describe the development of a universal cell-based platform for studying pathological processes associated with amyotrophic lateral sclerosis. For this purpose, we have created a series of plasmid constructs for monitoring endoplasmic reticulum stress, oxidative stress, apoptosis, and Ca2+-dependent hyperexcitability and generated transgenic iPSC line carrying mutation in the superoxide dismutase 1 gene (SOD1) and healthy control cell line. Both cell lines have specific transactivator sequence required for doxycycline-controlled transcriptional activation and can be used for a single-step biosensor insertion.


Assuntos
Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/patologia , Técnicas Biossensoriais/métodos , Células-Tronco Pluripotentes Induzidas/metabolismo , Apoptose , Cálcio/metabolismo , Diferenciação Celular , Células Cultivadas , Estresse do Retículo Endoplasmático , Humanos , Células-Tronco Pluripotentes Induzidas/patologia , Mutação , Estresse Oxidativo , Superóxido Dismutase-1/genética , Superóxido Dismutase-1/metabolismo
17.
Toxicol Lett ; 313: 42-49, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31154016

RESUMO

Astrocytes are the major glial cell type in the central nervous system (CNS), and the distal part of the astrocyte forms the blood-brain barrier with nearby blood vessels. They maintain the overall metabolism, growth, homeostasis of neurons, and signaling in the CNS. Ochratoxin A is considered a carcinogen and immunotoxic, nephrotoxic, and neurotoxic mycotoxin. Specifically, it exhibits neurotoxicity with high affinity for the brain. Despite some previous studies about the effects of ochratoxin A in glial cells, the intracellular working mechanism in astrocytes is not fully understood. In this study, we studied the specific working mechanism of ochratoxin A in the human astrocyte cell line, NHA-SV40LT. Ochratoxin A reduced cell proliferation with sub G0/G1 cell cycle arrest by inhibiting CCND1, CCNE1, CDK4, and MYC expression. It induced apoptosis of NHA-SV40LT cells through mitochondrial membrane potential (MMP) loss and up-regulation of BAX and TP53. In addition, ochratoxin A increased cytosolic and mitochondrial calcium levels, resulting in an increase in MMP2 and PLAUR mRNA expression in NHA-SV40LT cells. Furthermore, ochratoxin A regulated the phosphorylation of AKT, ERK1/2, and JNK signal molecules of human astrocytes. Collectively, ochratoxin A exerts neurotoxicity through anti-proliferation and mitochondria-dependent apoptosis in human astrocytes.


Assuntos
Apoptose/efeitos dos fármacos , Astrócitos/efeitos dos fármacos , Cálcio/metabolismo , Mitocôndrias/efeitos dos fármacos , Síndromes Neurotóxicas/etiologia , Ocratoxinas/toxicidade , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Astrócitos/metabolismo , Astrócitos/patologia , Sinalização do Cálcio/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação da Expressão Gênica , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Síndromes Neurotóxicas/genética , Síndromes Neurotóxicas/metabolismo , Síndromes Neurotóxicas/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo
18.
Int J Nanomedicine ; 14: 3471-3490, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31190805

RESUMO

Background: Zinc-doped hydroxyapatite has been proposed as a graft biomaterial for bone regeneration. However, the effect of zinc on osteoconductivity is still controversial, since the release and resorption of calcium, phosphorus, and zinc in graft-implanted defects have rarely been studied. Methods: Microspheres containing alginate and either non-doped carbonated hydroxyapatite (cHA) or nanocrystalline 3.2 wt% zinc-doped cHA (Zn-cHA) were implanted in critical-sized calvarial defects in Wistar rats for 1, 3, and 6 months. Histological and histomorphometric analyses were performed to evaluate the volume density of newly formed bone, residual biomaterial, and connective tissue formation. Biomaterial degradation was characterized by transmission electron microscopy (TEM) and synchrotron radiation-based X-ray microfluorescence (SR-µXRF), which enabled the elemental mapping of calcium, phosphorus, and zinc on the microsphere-implanted defects at 6 months post-implantation. Results: The bone repair was limited to regions close to the preexistent bone, whereas connective tissue occupied the major part of the defect. Moreover, no significant difference in the amount of new bone formed was found between the two microsphere groups. TEM analysis revealed the degradation of the outer microsphere surface with detachment of the nanoparticle aggregates. According to SR-µXRF, both types of microspheres released high amounts of calcium, phosphorus, and zinc, distributed throughout the defective region. The cHA microsphere surface strongly adsorbed the zinc from organic constituents of the biological fluid, and phosphorus was resorbed more quickly than calcium. In the Zn-cHA group, zinc and calcium had similar release profiles, indicating a stoichiometric dissolution of these elements and non-preferential zinc resorption. Conclusions: The nanometric size of cHA and Zn-cHA was a decisive factor in accelerating the in vivo availability of calcium and zinc. The high calcium and zinc accumulation in the defect, which was not cleared by the biological medium, played a critical role in inhibiting osteoconduction and thus impairing bone repair.


Assuntos
Alginatos/química , Regeneração Óssea , Cálcio/metabolismo , Durapatita/química , Microesferas , Nanopartículas/química , Zinco/química , Zinco/metabolismo , Animais , Materiais Biocompatíveis/química , Disponibilidade Biológica , Regeneração Óssea/efeitos dos fármacos , Carbonatos/química , Morte Celular , Linhagem Celular , Sobrevivência Celular , Feminino , Camundongos , Nanopartículas/ultraestrutura , Ratos Wistar , Crânio/fisiologia , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
19.
Eur Biophys J ; 48(6): 579-584, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31236612

RESUMO

Calcium release sites (CRSs) play a key role in excitation-contraction coupling of cardiac myocytes. Recent studies based on electron tomography and super-resolution imaging revealed that CRSs are not completely filled with ryanodine receptors (RyRs) and that the spatial arrangement of RyRs is neither uniform nor static. In this work, we studied the effect of spatial arrangement of RyRs on RyR activation using simulations based on Monte Carlo (MC) and mean-field (MF) approaches. Both approaches showed that activation of RyRs is sensitive to the arrangement of RyRs in the CRS. However, the MF simulations did not reproduce results of MC simulations for non-compact CRSs, suggesting that the approximations used in the MF approach are not suitable for simulation studies of RyRs arrangements observed experimentally. MC simulations revealed the importance of realistic spatial arrangement of RyRs for adequate modelling of calcium release in cardiac myocytes.


Assuntos
Cálcio/metabolismo , Modelos Biológicos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Método de Monte Carlo , Processos Estocásticos
20.
Nat Plants ; 5(6): 581-588, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31182842

RESUMO

Chloroplasts are integral to sensing biotic and abiotic stress in plants, but their role in transducing Ca2+-mediated stress signals remains poorly understood1,2. Here we identify cMCU, a member of the mitochondrial calcium uniporter (MCU) family, as an ion channel mediating Ca2+ flux into chloroplasts in vivo. Using a toolkit of aequorin reporters targeted to chloroplast stroma and the cytosol in cMCU wild-type and knockout lines, we provide evidence that stress-stimulus-specific Ca2+ dynamics in the chloroplast stroma correlate with expression of the channel. Fast downstream signalling events triggered by osmotic stress, involving activation of the mitogen-activated protein kinases (MAPK) MAPK3 and MAPK6, and the transcription factors MYB60 and ethylene-response factor 6 (ERF6), are influenced by cMCU activity. Relative to wild-type plants, cMCU knockouts display increased resistance to long-term water deficit and improved recovery on rewatering. Modulation of stromal Ca2+ in specific processing of stress signals identifies cMCU as a component of plant environmental sensing.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Canais de Cálcio/metabolismo , Cloroplastos/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Cálcio/metabolismo , Canais de Cálcio/genética , Cloroplastos/genética , Escherichia coli , Técnicas de Inativação de Genes , Sistema de Sinalização das MAP Quinases , Pressão Osmótica
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