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1.
Nihon Yakurigaku Zasshi ; 154(4): 171-177, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31597895

RESUMO

Recent outstanding progress in microscopic imaging technology and the advent of fluorescent probes have enabled us to visualize high spatiotemporal dynamics of intracellular molecules in living tissues. Here I introduce our research outcomes on functional fluorescence imaging of the heart especially for understanding the pathogenesis of cardiac arrhythmias. On the in situ Ca2+ imaging of perfused rat heart by rapid-scanning confocal microscopy, we found that burst emergence of intracellular Ca2+ waves evokes arrhythmogenic triggered activity and subsequent oscillatory depolarizations via the Na+-Ca2+ exchanger. Besides, impairment of Ca2+ release from the sarcoplasmic reticulum leads to emergence of Ca2+ waves and spatiotemporally inhomogeneous Ca2+ dynamics on systole, resulting in beat-to-beat Ca2+ alternans. Such alternating behaviors of Ca2+ dynamics are partly due to poor development of the transverse tubules, which are identified in murine atria and failing ventricular myocytes. In addition, impairment of the gap junctional communication via connexin 43 induced by dominant negative inhibition of neonatal rat ventricular myocyte monolayers results in generation of spiral wave reentry, suggesting the pivotal role of intercellular communications in genesis of arrhythmias. Furthermore, alterations in atrial histoanatomy, e.g., density and arrangements of myocytes and distribution of Cx43, could provide intrinsic arrhythmogenic bases of atrial fibrillation, which was revealed by combined optical imaging of the atria and precise histoanatomical examinations. In combination, fluorescence imaging of the living organisms provides indispensable information for unveiling functions and disease states.


Assuntos
Arritmias Cardíacas/fisiopatologia , Sinalização do Cálcio , Coração/diagnóstico por imagem , Imagem Óptica , Animais , Células Cultivadas , Átrios do Coração/diagnóstico por imagem , Miócitos Cardíacos/citologia , Ratos , Trocador de Sódio e Cálcio/metabolismo
2.
Chem Biol Interact ; 314: 108848, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31610156

RESUMO

Cardiomyocyte injury induced by acute myocardial infarction contributes to myocardial dysfunction. Accumulating evidence has demonstrated that pleckstrin homology domain leucine-rich repeat protein phosphatase 2 (PHLPP2) is a cytoprotective protein that protects against various adverse injuries. However, whether PHLPP2 participates in regulating myocardial-infarction-induced cardiomyocyte injury remains unknown. In the present study, we aimed to investigate the biological role and molecular mechanism of PHLPP2 in regulating hypoxia-induced cardiomyocyte injury. Cardiomyocytes were cultured in an anaerobic chamber for 24 h to induce hypoxic injury in vitro. The expression of PHLPP2 was determined by real-time quantitative PCR and Western blot analysis. Cell viability was measured by MTT assay. Cell apoptosis was assessed by TUNEL and caspase-3 activity assays. Intracellular reactive oxygen species (ROS) levels were measured by DCFH-DA probe. PHLPP2 expression was highly upregulated in hypoxia-injured cardiomyocytes. Inhibition of PHLPP2 by small interfering RNA (siRNA)-mediated gene silencing significantly improved the viability of hypoxia-injured cardiomyocytes and attenuated hypoxia-induced apoptosis and ROS production. In contrast, PHLPP2 overexpression exacerbated hypoxia-induced apoptosis and ROS production in cardiomyocytes. Mechanism research revealed that PHLPP2 silencing increased the phosphorylation of glycogen synthase kinase (GSK)-3ß and promoted the nuclear translocation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2). In addition, PHLPP2 inhibition promoted Nrf2/antioxidant response element (ARE) transcriptional activity. However, Nrf2 silencing markedly reversed PHLPP2-inhibition-mediated cardioprotection, while GSK-3ß inhibition partially blocked the PHLPP2-overexpression-induced adverse effect. Taken together, these findings demonstrate that PHLPP2 inhibition alleviates hypoxia-induced cardiomyocyte injury by reinforcing Nrf2/ARE antioxidant signaling via inactivating GSK-3ß, a pathway that highlights the importance of the PHLPP2/GSK-3ß/Nrf2/ARE signaling axis in regulation of cardiomyocyte injury. Our study suggests a potential relevance for PHLPP2 in acute myocardial infarction, and this protein may serve as a promising target for cardioprotection.


Assuntos
Elementos de Resposta Antioxidante/genética , Hipóxia Celular , Fator 2 Relacionado a NF-E2/metabolismo , Fosfoproteínas Fosfatases/metabolismo , Animais , Apoptose/efeitos dos fármacos , Sobrevivência Celular , Regulação para Baixo , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Glicogênio Sintase Quinase 3 beta/metabolismo , Camundongos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Fator 2 Relacionado a NF-E2/antagonistas & inibidores , Fator 2 Relacionado a NF-E2/genética , Fosfoproteínas Fosfatases/antagonistas & inibidores , Fosfoproteínas Fosfatases/genética , Fosforilação , Pirimidinas/farmacologia , Pirróis/farmacologia , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
3.
Life Sci ; 235: 116802, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472150

RESUMO

Substrate stiffness is essential for cell functions, but the mechanisms by which cell sense mechanical cues are still unclear. Here we show that the frequency and the amplitude of spontaneous Ca2+ oscillations were greater in chick cardiomyocytes cultured on the stiff substrates than that on the soft substrates. The spontaneous Ca2+ oscillations were increased on stiff substrates. However, an eliminated dependence of the Ca2+ oscillations on substrate stiffness was observed after applying blocker of the large-conductance Ca2+-activated K+ (BK) channels. In addition, the activity of BK channels in cardiomyocytes cultured on the stiff substrates was decreased. These results provide compelling evidences to show that BK channels are crucial in substrate stiffness-dependent regulation of the Ca2+ oscillation in cardiomyocytes.


Assuntos
Sinalização do Cálcio , Cálcio/metabolismo , Ventrículos do Coração/metabolismo , Canais de Potássio Ativados por Cálcio de Condutância Alta/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Embrião de Galinha , Galinhas , Miócitos Cardíacos/citologia , Especificidade por Substrato
4.
Adv Exp Med Biol ; 1169: 141-178, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31487023

RESUMO

Cardiac biology and heart regeneration have been intensively investigated and debated in the last 15 years. Nowadays, the well-established and old dogma that the adult heart lacks of any myocyte-regenerative capacity has been firmly overturned by the evidence of cardiomyocyte renewal throughout the mammalian life as part of normal organ cell homeostasis, which is increased in response to injury. Concurrently, reproducible evidences from independent laboratories have convincingly shown that the adult heart possesses a pool of multipotent cardiac stem/progenitor cells (CSCs or CPCs) capable of sustaining cardiomyocyte and vascular tissue refreshment after injury. CSC transplantation in animal models displays an effective regenerative potential and may be helpful to treat chronic heart failure (CHF), obviating at the poor/modest results using non-cardiac cells in clinical trials. Nevertheless, the degree/significance of cardiomyocyte turnover in the adult heart, which is insufficient to regenerate extensive damage from ischemic and non-ischemic origin, remains strongly disputed. Concurrently, different methodologies used to detect CSCs in situ have created the paradox of the adult heart harboring more than seven different cardiac progenitor populations. The latter was likely secondary to the intrinsic heterogeneity of any regenerative cell agent in an adult tissue but also to the confusion created by the heterogeneity of the cell population identified by a single cell marker used to detect the CSCs in situ. On the other hand, some recent studies using genetic fate mapping strategies claimed that CSCs are an irrelevant endogenous source of new cardiomyocytes in the adult. On the basis of these contradictory findings, here we critically reviewed the available data on adult CSC biology and their role in myocardial cell homeostasis and repair.


Assuntos
Células-Tronco Adultas , Miocárdio , Animais , Diferenciação Celular , Miocárdio/citologia , Miócitos Cardíacos/citologia
5.
Cell Physiol Biochem ; 53(2): 337-354, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31373783

RESUMO

BACKGROUND/AIMS: The availability of truly maturated cardiomyocytic subtypes is a major prerequisite for cardiovascular cell replacement therapies. Pluripotent stem cells provide a suitable source for the development of new strategies to overcome enormous hurdles such as yield, purity and safety of in vitro generated cells. METHODS: To address these issues, we have refined existing forward programming protocols by combining forced exogenous overexpression of the early cardiovascular transcription factor Nkx2.5 with a αMHC-promoter-based antibiotic selection step. Additionally, we applied small molecules such as ascorbic acid to enhance cardiomyogenic differentiation efficiency. Subsequently, we evaluated the cell fate of the resulting cardiomyocytes on the mRNA as well as protein levels. The latter was performed using high-resolution confocal microscopy. Furthermore, we examined the response of the cells` beating activities to pharmacological substance administration. RESULTS: Our results reveal an apparent influence of Nkx2.5 on the cell fate of ESC-derived cardiomyocytes. Resulting single cells exhibit characteristics of early ventricular cardiomyocytes, such as sarcomeric marker expression, spontaneous beating frequency, and distinct L-type calcium channel occurrence. CONCLUSION: Therefore, we demonstrate cardiovascular subtype forward programming of ESCs using a combination of transcription factors along with small molecule administration. However, our findings also underline current assumptions, that a terminal maturation of PSC derived cardiomyocytes in vitro is still an unsolved problem which urgently needs to be addressed in the field.


Assuntos
Reprogramação Celular , Células-Tronco Embrionárias/metabolismo , Proteína Homeobox Nkx-2.5/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Ácido Ascórbico/farmacologia , Diferenciação Celular/efeitos dos fármacos , Células-Tronco Embrionárias/citologia , Proteína Homeobox Nkx-2.5/antagonistas & inibidores , Proteína Homeobox Nkx-2.5/genética , Camundongos , Microscopia Confocal , Miócitos Cardíacos/citologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Verapamil/farmacologia
6.
Adv Exp Med Biol ; 1155: 451-462, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468422

RESUMO

Objective To determine whether taurine has protective effects on chicken myocardial apoptosis induced by hypoxic condition through inhibiting calpain-1 derived mitochondrial apoptotic pathway. Methods Chicken primary embryonic myocardial cells were isolated and cultured at 37 °C under a 5% CO2 atmosphere. Firstly the optimum concentration of taurine or PD150606 was chosen by detecting the cell viability. Chicken cardiomyocytes were cultured in 95% N2-5% CO2 atmosphere for 12 h to produce hypoxic conditions. Before hypoxic treatment, 10 mM taurine and 10 uM PD150606 (a specific calpains inhibitor) were added separately or together. The cell apoptosis was detected by acridine orange/ethidium bromide (AO/EB) double staining. Western blotting was used to determine the protein expressions of calpain-1, cytochrome c, Bcl-2, procaspase-9 and procaspase-3 in the cardiomyocytes. Results Taurine administration effectively attenuated the myocardial apoptosis under hypoxic condition, reduced the calpain-1 protein level. In addition, pre-treated taurine could up-regulate the protein expressions of Bcl-2 and procaspase-3 in hypoxic myocardial cells, down-regulate protein expression levels of cytochrome c and procaspase-9. Moreover, taurine exhibited same inhibition effect as PD150606 on the cell apoptosis and proteins express under hypoxic condition. Conclusions Taurine could attenuate the chicken cardiomyocyte apoptosis impaired by hypoxia through inhibiting calpian-1-derived mitochondrial apoptotic pathway in vitro.


Assuntos
Apoptose , Calpaína/metabolismo , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Taurina/farmacologia , Acrilatos/farmacologia , Animais , Hipóxia Celular , Células Cultivadas , Galinhas , Mitocôndrias
7.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 35(3): 273-278, 2019 May 28.
Artigo em Chinês | MEDLINE | ID: mdl-31257812

RESUMO

OBJECTIVE: To investigate the effects of myeloid differentiation-2 (MD2) gene silencing on high glucose-induced proliferation inhibition, apoptosis and inflammation in rat cardiomyocytes. METHODS: The immortalized rat cardiomyocyte cell line H9C2 were transfected with MD2 small interfering RNA (si-MD2) and negative control for 24 h, then stimulated with high glucose (HG) for 48 h. RT-qPCR was performed to detect the mRNA levels of MD2 and inflammatory factors TNF-α, IL-1ß and IL-6. MTS and flow cytometry were used to evaluate cell proliferation, cell cycle and apoptosis rate. Western blot was used to detect protein expression levels and phosphorylation levels. RESULTS: The mRNA and protein levels of MD2 in H9C2 cells were dramatically decreased after transfected with si-MD2 (P<0.01). After stimulation of high glucose, the mRNA levels of inflammatory factors, the cells in G0/G1 phase , the cell apoptosis rate and the protein level of cleaved Caspase-3 were significantly increased, while the cell proliferation ability was decreased (P<0.01). MD2 gene silencing antagonized the effects of high glucose on cell proliferation, cell cycle, cell apoptosis and the mRNA levels of TNF-α, IL-1ß , IL-6(P<0.05). Western blot analysis showed that the phosphorylation levels of extracellular signal-regulated kinase(ERK1/2), P38 mitogen-activated protein kinase(P38 MAPK) and C-Jun N-terminal kinase(JNK) protein were increased significantly in H9C2 cells treated with high glucose, which could be reversed by silencing of MD2 (P<0.01). CONCLUSION: This study demonstrates that MD2 gene silencing reverses high glucose-induced myocardial inflammation, apoptosis and proliferation inhibition via the mechanisms involving suppression of ERK, P38 MAPK, JNK signaling pathway.


Assuntos
Apoptose , Proliferação de Células , Inativação Gênica , Antígeno 96 de Linfócito/genética , Miócitos Cardíacos/citologia , Animais , Células Cultivadas , Citocinas/metabolismo , Glucose , Inflamação , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Ratos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
8.
Phytochemistry ; 166: 112065, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31362147

RESUMO

Ten undescribed neo-clerodane diterpenoids, named hispanins A-J, together with six known ones, were isolated from the aerial parts of Salvia hispanica L. Their structures were established by extensive spectroscopic analysis. The absolute configurations of the undescribed compounds were determined by the ECD data and single crystal X-ray diffraction analysis. Hispanins B and C represented the first neo-clerodane diterpenoids with a unique oxygen bridge between C-19 and C-20. All isolated compounds were evaluated for their protective effects against H2O2-induced cardiomyocyte injury. Five of these compounds showed significant cardioprotective effects.


Assuntos
Cardiotônicos/química , Cardiotônicos/farmacologia , Diterpenos Clerodânicos/química , Diterpenos Clerodânicos/farmacologia , Componentes Aéreos da Planta/química , Salvia/química , Animais , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Ratos
9.
Biomater Sci ; 7(9): 3906-3917, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31322163

RESUMO

Cardiovascular diseases represent a major socio-economic burden. In recent years, considerable effort has been invested in optimizing cell delivery strategies to advance cell transplantation therapies to restore heart function for example after an infarct. A particular issue is that the implantation of cells using a non-electroconductive matrix potentially causes arrhythmia. Here, we demonstrate that our hydrazide-functionalized nanotubes-pericardial matrix-derived electroconductive biohybrid hydrogel provides a suitable environment for maturation of human-induced pluripotent stem cell (hiPSC)-derived cardiomyocytes. hiPSC-derived cardiomyocytes exhibited an improved contraction amplitude (>500%) on conductive hydrogels compared to cells cultured on Matrigel®. This was accompanied by increased cellular alignment, enhanced connexin 43 expression, and improved sarcomere organization suggesting maturation of the hiPSC-derived cardiomyocytes. Sarcomeric length of these cells increased from 1.3 to 1.7 µm. Moreover, 3D cell-laden engineered tissues exhibited enhanced calcium handling as well as positive response to external electrical and pharmaceutical stimulation. Collectively, our data indicate that our biohybrid hydrogels consisting of solubilized nanostructured pericardial matrix and electroconductive positively charged hydrazide-conjugated carbon nanotubes provide a promising material for stem cell-based cardiac tissue engineering.


Assuntos
Materiais Biocompatíveis/química , Hidrogéis/química , Células-Tronco Pluripotentes Induzidas/citologia , Miócitos Cardíacos/citologia , Nanotubos de Carbono/química , Pericárdio/química , Tecidos Suporte/química , Biomarcadores/metabolismo , Cálcio/metabolismo , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Colágeno/química , Conexina 43/metabolismo , Combinação de Medicamentos , Condutividade Elétrica , Humanos , Laminina/química , Células-Tronco Mesenquimais/citologia , Tamanho da Partícula , Proteoglicanas/química
10.
Life Sci ; 232: 116665, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31323273

RESUMO

AIMS: Overexpression of the mechanistic target of rapamycin (mTOR), a member of the PIKK (phosphoinositide kinase-related kinase) family, protects cardiomyocytes from cell death induced by pathological stimuli such as ischemia. We previously reported that posttranslational modification of mTOR plays an important role in regulating cardiac mTOR expression. The aim of this study was to see if Tel2 (telomere maintenance 2), a protein that regulates the abundance of PIKKs, confers similar cardioprotective effects as mTOR. Tel2 is not well-characterized in cardiomyocytes, therefore we examined the effects of Tel2 on cardiomyocyte viability under ischemic stress conditions. MATERIALS AND METHODS: We overexpressed Tel2 or silenced Tel2 with siRNA in the HL-1 cardiomyocyte cell line to survey the effects of Tel2 overexpression and downregulation on cell survival during hypoxia. Adult mouse cardiomyocytes transfected with Tel2 adenoviruses were used to test whether Tel2 sufficiently prevented cardiomyocyte cell death against hydrogen peroxide (H2O2). KEY FINDINGS: Overexpressing Tel2 increased mTOR expression with a concomitant increase in mTOR Complex 1 (mTORC1) and mTORC2 activity in HL-1 cells. Tel2 deletion decreased mTOR expression, and mTORC1 and mTORC2 activity accordingly. In both HL-1 cells and adult mouse cardiomyocytes, Tel2 overexpression protected cardiomyocytes under ischemic stress. These effects were mTOR-dependent, as mTOR inhibitors blunted the effects of Tel2. While gene silencing of Tel2 did not affect cell survival under normoxia, Tel2 silencing made cardiomyocytes more vulnerable to cell death under hypoxia. SIGNIFICANCE: Upregulating Tel2 expression increases mTOR-mediated cardiomyocyte survival and targeting Tel2 could be another therapeutic strategy against ischemic heart disease.


Assuntos
Sobrevivência Celular/fisiologia , Miócitos Cardíacos/citologia , Proteínas de Ligação a Telômeros/fisiologia , Adenoviridae/genética , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular , Inativação Gênica , Peróxido de Hidrogênio/farmacologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Camundongos , Transdução de Sinais , Proteínas de Ligação a Telômeros/genética , Transfecção
11.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 35(5): 405-411, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31223109

RESUMO

Objective To investigate the effect of miR-25-3p targeting a disintegrin and metalloproteinase 10 (ADAM10) on the differentiation of P19 cells into cardiomyocytes by regulating Notch signaling pathway. Methods P19 cells were induced to differentiate into cardiomyocytes with dimethyl sulfoxide (DMSO) and collected at 0, 5, and 10 days. The mRNA levels of myocardial differentiation markers GATA4, cTnT, atrial natriuretic polypeptide (ANP) and the level of miR-25-3p were detected by real-time quantitative PCR (qRT-PCR). The protein level of ADAM10 was assessed by Western blot analysis. The miR-25-3p was over-expressed in P19 cells by infected with retrovirus, and the expression levels of miR-25-3p and ADAM10 in the infected P19 cells were detected by qRT-PCR and Western blotting. Bioinformatics were used to predict the targeted matching relationship between miR-25-3p and ADAM10 gene, which was then verified by the luciferase reporter gene system. After infection, P19 cells were induced to differentiate by DMSO for 10 days. Then the protein expression of cTnI was detected by immunofluorescence assay to calculate the differentiation rate of cardiomyocytes, and the proteins expression of myocardial differentiation markers GATA4, cTnT, ANP and Notch signaling pathway-related molecules Notch1, hes family bHLH transcription factor 1 (Hes1), Hey1, and Hey2 were detected by Western blotting. Results During the 0, 5 and 10 days of the differentiation of P19 cells into myocardial cells, the mRNA expression levels of GATA4, cTnT, ANP and the protein expression level of ADAM10 gradually increased, while the expression level of miR-25-3p gradually decreased. After retrovirus infection, the expression level of miR-25-3p in the infected P19 cells went up significantly, while the protein expression level of ADAM10 went down significantly. Subsequently, ADAM10 was confirmed as a target gene of miR-25-3p. After the 10 days of differentiation, over-expression of miR-25-3p significantly decreased the differentiation rate of cardiomyocytes, and down-regulated the levels of the markers of myocardial differentiation-related proteins GATA4, cTnT, ANP, and the Notch signaling pathway related-proteins, including Notch1, Hes1, Hey1 and Hey2. Conclusion The miR-25-3p can significantly inhibit the differentiation of P19 cells into cardiomyocytes, and the mechanism may be related to inhibite the activation of Notch signaling pathway by depressing ADAM10 expression.


Assuntos
Proteína ADAM10/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Diferenciação Celular , Proteínas de Membrana/metabolismo , MicroRNAs/metabolismo , Miócitos Cardíacos/citologia , Transdução de Sinais , Animais , Linhagem Celular Tumoral , Camundongos , Receptores Notch/metabolismo
12.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 35(2): 160-164, 2019 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-31250609

RESUMO

OBJECTIVE: To observe whether necroptosis was happened in high glucose (HG) - induced primary cardiomyocytes injury and to investigate the likely mechanism. METHODS: The primary cultured cardiomyocytes were divided into 4 groups (n=9): control group (the cardiomyocytes were incubated with 5.5 mmol/L glucose for 48 h), HG group (the cardiomyocytes were incubated with 30 mmol/L glucose for 48 h), HG + necrostatin-1 (Nec-1) group (the cardiomyocytes was co-incubated with necroptosis inhibitor Nec-1 at 100 µmol/L and HG for 48 h) and hypertonic pressure group (HPG, the cardiomyocytes was co-incubated with 5.5 mmol/L glucose and 24.5 mmol/L mannitol for 48 h). Cell viability was measured by MTT method, reactive oxygen species (ROS) generation was measured by DHE staining. The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1ß (IL-1ß) were tested by ELISA method. The mRNA and protein expressions of necroptosis related genes receptor interacting serine/threonine protein kinase 1 (RIP1), RIP3, mixed lineage kinase domain-like protein (MLKL) were tested by quantitative real-time PCR and Western blot. RESULTS: The results showed HG intervention decreased cardiomyocytes viability, increased ROS generation, up-regulated the levels of TNF-α, IL-6 and IL-1ß, increased RIP1, RIP3, MLKL expressions at mRNA and protein levels. Nec-1 treatment attenuated HG-induced increased cardiomyocytes viability, reduced ROS generation, down-regulated the levels of TNF-α, IL-6 and IL-1ß, decreased RIP1, RIP3, MLKL expressions at mRNA and protein levels. CONCLUSION: Necroptosis was happened in high glucose-induced primary cardiomyocytes injury. Inhibition of necroptosis can reduce high glucose-induced cardiomyocytes damage, may be related to inhibition of oxidative stress and depression of inflammative factors releasing.


Assuntos
Apoptose , Miócitos Cardíacos/citologia , Miócitos Cardíacos/patologia , Necrose , Células Cultivadas , Citocinas/metabolismo , Glucose/efeitos adversos , Humanos , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo
13.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 35(2): 165-168, 2019 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-31250610

RESUMO

OBJECTIVE: To investigate the effects of Notch signal on hypoxic induction factor (HIF-1α) and autophagy-associated genes Beclin1, LC3I, LC3II in oxygen-glucose deprivation (OGD) induced myocardial cell injury. METHODS: The OGD model was established using hypoxic culture box and hypoglycemic DMEM medium. The cells were divided into normal control group, OGD group, OGD + NC siRNA group, OGD + Notch1 siRNA group and OGD + HIF-1α siRNA group. Western blot was used to detect the interference effects of HIF-1α siRNA and Notch1 siRNA. The effects of Notch1 siRNA and HIF-1α siRNA on the activity of myocardial cells in OGD model were detected by the CCK-8 assay. The effects of Notch1 siRNA and HIF-1α siRNA on autophage-associated genes Beclin1, LC3I and LC3II expression were detected by Western blot. RESULTS: The results of Western blot showed that HIF-1α siRNA could effectively knock down the expression of HIF-1α in myocardial cells in OGD model, and Notch1 siRNA could effectively knock down the expression of Notch1 and HIF-1α in myocardial cells in OGD model. The result of CCK-8 assay showed that Notch1 siRNA and HIF-1α siRNA reduced the activity of myocardial cells in OGD model, and there was no statistical difference between the two groups. Western blot results showed that Notch1 siRNA and HIF-1α siRNA could reduce the expressions of the autophagy-associated genes Beclin1, LC3I and LC3II, and reduce the ratio of LC3II to LC3I at mRNA level. CONCLUSION: Notch1 plays a role in myocardial protection by regulating the expression of HIF-1α to regulate the autophagy in OGD model cells.


Assuntos
Autofagia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Miócitos Cardíacos/citologia , Receptores Notch/metabolismo , Transdução de Sinais , Proteína Beclina-1/metabolismo , Hipóxia Celular , Células Cultivadas , Glucose , Humanos , Proteínas Associadas aos Microtúbulos/metabolismo , Miócitos Cardíacos/patologia , Oxigênio
14.
Chem Biol Interact ; 309: 108723, 2019 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-31228469

RESUMO

Ischemic preconditioning and pharmacological preconditioning are common strategies to prevent lethal myocardial injury, especially nutritional preconditioning (NPC). In this study, we investigated the effects of astragaloside IV (Ast), as an NPC agent, on myocardium suffered anoxia/reoxygenation (A/R) injury. Rats received 5 mg/kg Ast daily for 3 weeks by intragastric administration. Then, hearts were harvested and underwent A/R treatment using a Langendorff apparatus. Ast- pretreatment significantly promoted functional recovery of the myocardium, reduced infarct size, and oxidative stress, and decreased the apoptotic index. Similar findings were demonstrated in H9c2 cardiomyocytes that were pretreated with Ast for 24 h. Moreover, Ast-pretreatment significantly upregulated Bcl-2 expression, especially in mitochondria. The effects of Ast treatment against A/R injury were also reflected by increased antioxidant potential, inhibited reactive oxygen species (ROS) burst, increased oxygen consumption rate, maintained mitochondrial membrane potential (MMP), inhibited mitochondrial permeability transition pore (mPTP) opening, and prevented apoptosis. Selective inhibition of Bcl-2 by ABT-737 decreased myocardial injury protection of Ast. Ast-pretreatment resulted in NPC- related effects against A/R, and mitochondria may be the target of a cascade of events elicited by upregulating Bcl-2 expression, promoting translocation of Bcl-2 into mitochondria, maintaining MMP, inhibiting ROS bursts, thereby leading to recovery of mitochondrial respiration, preventing mPTP opening, decreasing cytochrome C release, preventing apoptosis, and ultimately alleviating myocardial injury.


Assuntos
Mitocôndrias/efeitos dos fármacos , Traumatismo por Reperfusão Miocárdica/patologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Saponinas/farmacologia , Triterpenos/farmacologia , Animais , Antioxidantes/química , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Compostos de Bifenilo/farmacologia , Compostos de Bifenilo/uso terapêutico , Caspase 3/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Citocromos c/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/efeitos dos fármacos , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miocárdio/metabolismo , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Nitrofenóis/farmacologia , Nitrofenóis/uso terapêutico , Piperazinas/farmacologia , Piperazinas/uso terapêutico , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Sulfonamidas/farmacologia , Sulfonamidas/uso terapêutico , Superóxido Dismutase/metabolismo
15.
Nat Cell Biol ; 21(6): 674-686, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31160712

RESUMO

In vertebrates, multipotent progenitors located in the pharyngeal mesoderm form cardiomyocytes and branchiomeric head muscles, but the dynamic gene expression programmes and mechanisms underlying cardiopharyngeal multipotency and heart versus head muscle fate choices remain elusive. Here, we used single-cell genomics in the simple chordate model Ciona to reconstruct developmental trajectories forming first and second heart lineages and pharyngeal muscle precursors and characterize the molecular underpinnings of cardiopharyngeal fate choices. We show that FGF-MAPK signalling maintains multipotency and promotes the pharyngeal muscle fate, whereas signal termination permits the deployment of a pan-cardiac programme, shared by the first and second heart lineages, to define heart identity. In the second heart lineage, a Tbx1/10-Dach pathway actively suppresses the first heart lineage programme, conditioning later cell diversity in the beating heart. Finally, cross-species comparisons between Ciona and the mouse evoke the deep evolutionary origins of cardiopharyngeal networks in chordates.


Assuntos
Ciona intestinalis/genética , Coração/crescimento & desenvolvimento , Músculos Faríngeos/crescimento & desenvolvimento , Proteínas com Domínio T/genética , Animais , Diferenciação Celular/genética , Linhagem da Célula/genética , Ciona intestinalis/crescimento & desenvolvimento , Fatores de Crescimento de Fibroblastos/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Genômica , Mesoderma/crescimento & desenvolvimento , Camundongos , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Músculo Esquelético/crescimento & desenvolvimento , Músculo Esquelético/metabolismo , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Fatores de Transcrição/genética
16.
Cell Physiol Biochem ; 53(1): 101-120, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31215778

RESUMO

In the recent decades, cardiovascular diseases emerged as the major leading cause of human mortality. However, current clinical approaches still do not encompass a thorough therapeutic solution for improving heart function of the patients who suffered an extensive myocardial injury. Based on this status quo, stem cells could become a novel option, as a natural source of the new myocardium lineage cells, being capable of paracrine factors secretion, protection or even regeneration of the damaged heart muscle. Efficient stem cell-based therapy of the heart should lead to repair or/and replacement of the degenerated tissue with functional myocardial and endothelial cells. Hereon, various types of pluripotent and multipotent stem cells have been already studied in the pre-clinical and clinical settings, demonstrating their cardiomyogenic and regenerative potential. In this context, as a type of male adult stem/ progenitors, spermatogonial stem cells feature a remarkable ability for a formation of cardiovascular lineages, based on our own observations. Presented data supports the presumption, that spermatogonial stem cells not only have a suitable capacity to generate functional heart cells but can also potentially improve the function of an injured myocardium. In this review article, we first describe the essential molecular and pathophysiological mechanisms involved in the heart tissue injury. Afterwards, based on our ongoing study, we review the impact of the stem cell technologies on the regeneration therapy in cardiovascular and myocardial diseases. Particular emphasis is being put on the usability of spermatogonial stem cells in cardiac therapy.


Assuntos
Células-Tronco Germinativas Adultas/citologia , Traumatismos Cardíacos/terapia , Coração/fisiologia , Regeneração , Transplante de Células-Tronco , Células-Tronco/citologia , Células-Tronco Germinativas Adultas/metabolismo , Células-Tronco Germinativas Adultas/transplante , Animais , Diferenciação Celular , Coração/fisiopatologia , Traumatismos Cardíacos/patologia , Traumatismos Cardíacos/fisiopatologia , Humanos , Miocárdio/citologia , Miocárdio/patologia , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Transplante de Células-Tronco/métodos , Células-Tronco/metabolismo
17.
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
18.
Int J Mol Sci ; 20(11)2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31146354

RESUMO

Modern diagnostic strategies for early recognition of cancer therapeutics-related cardiac dysfunction involve cardiac troponins measurement. Still, the role of other markers of cardiotoxicity is still unclear. The present study was designed to investigate dynamics of response of human cardiomyocytes derived from induced pluripotent stem cells (hiPCS-CMs) to doxorubicin with the special emphasis on their morphological changes in relation to expression and organization of troponins. The hiPCS-CMs were treated with doxorubicin concentrations (1 and 0.3 µM) for 48 h and followed for next up to 6 days. Exposure of hiPCS-CMs to 1 µM doxorubicininduced suppression of both cardiac troponin T (cTnT) and cardiac troponin I (cTnI) gene expression. Conversely, lower 0.3 µM doxorubicin concentration produced no significant changes in the expression of aforementioned genes. However, the intracellular topography, arrangement, and abundance of cardiac troponin proteins markedly changed after both doxorubicin concentrations. In particular, at 48 h of treatment, both cTnT and cTnI bundles started to reorganize, with some of them forming compacted shapes extending outwards and protruding outside the cells. At later intervals (72 h and onwards), the whole troponin network collapsed and became highly disorganized following, to some degree, overall changes in the cellular shape. Moreover, membrane permeability of cardiomyocytes was increased, and intracellular mitochondrial network rearranged and hypofunctional. Together, our results demonstrate complex effects of clinically relevant doxorubicin concentrations on hiPCS-CM cells including changes in cTnT and cTnI, but also in other cellular compartments contributing to the overall cytotoxicity of this class of cytostatics.


Assuntos
Antineoplásicos/toxicidade , Doxorrubicina/toxicidade , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Troponina/metabolismo , Antineoplásicos/farmacologia , Cardiotoxicidade , Linhagem Celular , Doxorrubicina/farmacologia , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo
19.
Cell Physiol Biochem ; 53(1): 36-48, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31169990

RESUMO

BACKGROUND/AIMS: Ivabradine lowers the heart rate by inhibition of hyperpolarisation-activated cyclic nucleotide-gated (HCN) channels mediating the 'funny' pacemaker current If in the sinoatrial node. It is clinically approved for the treatment of heart failure and angina pectoris. Due to its proposed high selectivity for If administration of ivabradine is not associated with the side effects commonly observed following the application of other heart rate lowering agents. Recent evidence, however, has shown significant affinity of ivabradine towards Kv11.1 (ether-a-go-go related gene, ERG) potassium channels. Despite the inhibition of Kv11.1 channels by ivabradine, cardiac action potential (AP) duration and heart rate corrected QT interval (QTc) of the human electrocardiogram (ECG) were not prolonged. We thus surmised that compensatory mechanisms might counteract the drug's inhibitory action on Kv11.1. METHODS: The effects of ivabradine on human Kv11.1 and Kv7.1 potassium, Cav1.2 calcium, and Nav1.5 sodium channels, heterologously expressed in tsA-201 cells, were studied in the voltage-clamp mode of the whole cell patch clamp technique. In addition, changes in action potential parameters of human induced pluripotent stem cell (iPSC) derived cardiomyocytes upon application of ivabradine were studied with current-clamp experiments. RESULTS: Here we show that ivabradine exhibits significant affinity towards cardiac ion channels other than HCN. We demonstrate for the first time inhibition of human voltage-gated Nav1.5 sodium channels at therapeutically relevant concentrations. Within this study we also confirm recent findings of human Kv11.1 inhibition by low µM concentrations of ivabradine and observed no prolongation of ventricular-like APs in cardiomyocytes derived from iPSCs. CONCLUSION: Our results provide an explanation why ivabradine, despite its affinity for Kv11.1 channels, does not prolong the cardiac AP and QTc interval. Furthermore, our results suggest the inhibition of voltage-gated Nav1.5 sodium channels to underlie the recent observations of slowed atrioventricular conduction by increased atrial-His bundle intervals upon administration of ivabradine.


Assuntos
Potenciais de Ação/efeitos dos fármacos , Fármacos Cardiovasculares/farmacologia , Canais Iônicos/metabolismo , Ivabradina/farmacologia , Canais de Cálcio Tipo L/química , Canais de Cálcio Tipo L/metabolismo , Linhagem Celular , Canal de Potássio ERG1/antagonistas & inibidores , Canal de Potássio ERG1/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Canais Iônicos/antagonistas & inibidores , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.5/química , Canal de Sódio Disparado por Voltagem NAV1.5/metabolismo , Técnicas de Patch-Clamp
20.
J Nanobiotechnology ; 17(1): 72, 2019 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-31133024

RESUMO

BACKGROUND: Nano-sized vesicles, so called extracellular vesicles (EVs), from regenerative cardiac cells represent a promising new therapeutic approach to treat cardiovascular diseases. However, it is not yet sufficiently understood how cardiac-derived EVs facilitate their protective effects. Therefore, we investigated the immune modulating capabilities of EVs from human cardiac-derived adherent proliferating (CardAP) cells, which are a unique cell type with proven cardioprotective features. RESULTS: Differential centrifugation was used to isolate EVs from conditioned medium of unstimulated or cytokine-stimulated (IFNγ, TNFα, IL-1ß) CardAP cells. The derived EVs exhibited typical EV-enriched proteins, such as tetraspanins, and diameters mostly of exosomes (< 100 nm). The cytokine stimulation caused CardAP cells to release smaller EVs with a lower integrin ß1 surface expression, while the concentration between both CardAP-EV variants was unaffected. An exposure of either CardAP-EV variant to unstimulated human peripheral blood mononuclear cells (PBMCs) did not induce any T cell proliferation, which indicates a general low immunogenicity. In order to evaluate immune modulating properties, PBMC cultures were stimulated with either Phytohemagglutin or anti-CD3. The treatment of those PBMC cultures with either CardAP-EV variant led to a significant reduction of T cell proliferation, pro-inflammatory cytokine release (IFNγ, TNFα) and increased levels of active TGFß. Further investigations identified CD14+ cells as major recipient cell subset of CardAP-EVs. This interaction caused a significant lower surface expression of HLA-DR, CD86, and increased expression levels of CD206 and PD-L1. Additionally, EV-primed CD14+ cells released significantly more IL-1RA. Notably, CardAP-EVs failed to modulate anti-CD3 triggered T cell proliferation and pro-inflammatory cytokine release in monocultures of purified CD3+ T cells. Subsequently, the immunosuppressive feature of CardAP-EVs was restored when anti-CD3 stimulated purified CD3+ T cells were co-cultured with EV-primed CD14+ cells. Beside attenuated T cell proliferation, those cultures also exhibited a significant increased proportion of regulatory T cells. CONCLUSIONS: CardAP-EVs have useful characteristics that could contribute to enhanced regeneration in damaged cardiac tissue by limiting unwanted inflammatory processes. It was shown that the priming of CD14+ immune cells by CardAP-EVs towards a regulatory type is an essential step to attenuate significantly T cell proliferation and pro-inflammatory cytokine release in vitro.


Assuntos
Doenças Cardiovasculares/terapia , Vesículas Extracelulares/imunologia , Monócitos/imunologia , Miócitos Cardíacos/imunologia , Doenças Cardiovasculares/imunologia , Linhagem Celular , Proliferação de Células , Técnicas de Cocultura , Citocinas/metabolismo , Vesículas Extracelulares/metabolismo , Humanos , Imunomodulação , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/imunologia , Monócitos/citologia , Miócitos Cardíacos/citologia , Regeneração , Linfócitos T/citologia , Linfócitos T/imunologia
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