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1.
Proc Natl Acad Sci U S A ; 117(31): 18810-18821, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32690710

RESUMO

In the central nervous system, glycogen-derived bioenergetic resources in astrocytes help promote tissue survival in response to focal neuronal stress. However, our understanding of the extent to which these resources are mobilized and utilized during neurodegeneration, especially in nearby regions that are not actively degenerating, remains incomplete. Here we modeled neurodegeneration in glaucoma, the world's leading cause of irreversible blindness, and measured how metabolites mobilize through astrocyte gap junctions composed of connexin 43 (Cx43). We elevated intraocular pressure in one eye and determined how astrocyte-derived metabolites in the contralateral optic projection responded. Remarkably, astrocyte networks expand and redistribute metabolites along distances even 10 mm in length, donating resources from the unstressed to the stressed projection in response to intraocular pressure elevation. While resource donation improves axon function and visual acuity in the directly stressed region, it renders the donating tissue susceptible to bioenergetic, structural, and physiological degradation. Intriguingly, when both projections are stressed in a WT animal, axon function and visual acuity equilibrate between the two projections even when each projection is stressed for a different length of time. This equilibration does not occur when Cx43 is not present. Thus, Cx43-mediated astrocyte metabolic networks serve as an endogenous mechanism used to mitigate bioenergetic stress and distribute the impact of neurodegenerative disease processes. Redistribution ultimately renders the donating optic nerve vulnerable to further metabolic stress, which could explain why local neurodegeneration does not remain confined, but eventually impacts healthy regions of the brain more broadly.


Assuntos
Astrócitos , Glaucoma/metabolismo , Doenças Neurodegenerativas/metabolismo , Animais , Astrócitos/metabolismo , Astrócitos/fisiologia , Conexina 43/genética , Conexina 43/metabolismo , Feminino , Junções Comunicantes/metabolismo , Pressão Intraocular/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
2.
Anticancer Res ; 40(8): 4537-4545, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32727784

RESUMO

BACKGROUND/AIM: Altered connexin expression has been associated with cancer development and progression. This study evaluated connexin 26, 32, and 43 expression in association with the long-term outcomes of gastric cancer after gastrectomy. PATIENTS AND METHODS: Pathological specimens were collected from 113 patients who underwent gastrectomy for gastric cancer, of whom 104 were included in the study. The expression levels of the connexins were assessed by immunohistochemistry. The patients were classified into low and high groups according to the median histoscore of connexin. RESULTS: Cancer-specific survival (CSS) was significantly longer in the high than low connexin 43 group (p=0.030), particularly in patients >65 years old (p=0.030). A multivariate analysis identified pathological stage, differentiation type, and connexin 43 expression as possible predictors of CSS in patients (difference in the area under the curve=0.232, 0.090, and 0.094). CONCLUSION: Low connexin 43 expression predicted a poor CSS in gastric cancer patients after gastrectomy.


Assuntos
Conexina 43/metabolismo , Conexinas/metabolismo , Neoplasias Gástricas/cirurgia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Regulação para Baixo , Feminino , Gastrectomia , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Análise de Sobrevida , Resultado do Tratamento
3.
PLoS One ; 15(6): e0235220, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32584885

RESUMO

BACKGROUND: Approximately 30,000 patients with blunt cardiac trauma are recorded each year in the United States. Blunt cardiac injuries after trauma are associated with a longer hospital stay and a poor overall outcome. Organ damage after trauma is linked to increased systemic release of pro-inflammatory cytokines and damage-associated molecular patterns. However, the interplay between polytrauma and local cardiac injury is unclear. Additionally, the impact of surgical intervention on this process is currently unknown. This study aimed to determine local cardiac immunological and structural alterations after multiple trauma. Furthermore, the impact of the chosen fracture stabilization strategy (reamed versus non-reamed femoral nailing) on cardiac alterations was studied. EXPERIMENTAL APPROACH: 15 male pigs were either exposed to multiple trauma (blunt chest trauma, laparotomy, liver laceration, femur fracture and haemorrhagic shock) or sham conditions. Blood samples as well as cardiac tissue were analysed 4 h and 6 h after trauma. Additionally, murine HL-1 cells were exposed to a defined polytrauma-cocktail, mimicking the pro-inflammatory conditions after multiple trauma in vitro. RESULTS: After multiple trauma, cardiac structural changes were observed in the left ventricle. More specifically, alterations in the alpha-actinin and desmin protein expression were found. Cardiac structural alterations were accompanied by enhanced local nitrosative stress, increased local inflammation and elevated systemic levels of the high-mobility group box 1 protein. Furthermore, cardiac alterations were observed predominantly in pigs that were treated by non-reamed intramedullary reaming. The polytrauma-cocktail impaired the viability of HL-1 cells in vitro, which was accompanied by a release of troponin I and HFABP. DISCUSSION: Multiple trauma induced cardiac structural alterations in vivo, which might contribute to the development of early myocardial damage (EMD). This study also revealed that reamed femoral nailing (reamed) is associated with more prominent immunological cardiac alterations compared to nailing without reaming (non-reamed). This suggests that the choice of the initial fracture treatment strategy might be crucial for the overall outcome as well as for any post-traumatic cardiac consequences.


Assuntos
Pinos Ortopédicos/efeitos adversos , Fraturas do Fêmur/cirurgia , Traumatismo Múltiplo/patologia , Miocárdio/patologia , Actinina/metabolismo , Animais , Cálcio/metabolismo , Linhagem Celular , Sobrevivência Celular , Conexina 43/metabolismo , Citocinas/análise , Citocinas/metabolismo , Desmina/metabolismo , Fraturas do Fêmur/patologia , Proteína HMGB1/análise , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Inflamação , Masculino , Camundongos , Traumatismo Múltiplo/metabolismo , Traumatismo Múltiplo/veterinária , Miocárdio/metabolismo , Estresse Nitrosativo , Suínos , Troponina I/análise
4.
Life Sci ; 254: 117759, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32389830

RESUMO

OBJECTIVE: Metformin, introduced in 1957, is widely used as an anti-diabetic drug and has considerable benefits in cardiovascular disease reportedly, dependent or independent on its glucose-lowering effects. Aim of this study was to investigate the effect of metformin on gap junction and the inducibility of AF. METHODS: Beagle dogs were subjected to acute or chronic pacing at right atrial appendage by a pacemaker to develop an AF model and electrophysiological parameters were measured. In vitro study, a cell fast pacing model was developed by CardioExcyte 96. We performed Western blot, histology immunohistochemical staining and electron microscopy to detect the effect of metformin. RESULTS: In chronic AF model, the inducibility and duration of AF increased obviously after pacing for 6 weeks compared with sham-operated group (Inducibility, 3.33 ±â€¯5.77 vs. 85.33 ±â€¯7.89%, P<0.0001; Duration, 0.8 ±â€¯0.84 vs. 11 ±â€¯2.67 ms, P<0.0001). Effective refractory periods (ERP) decreased at left and right left atrium and atrial appendages compared with sham-operated group (123.95 ±â€¯6.57 vs. 89.96 ±â€¯7.39 ms P<0.0001). Metformin attenuated the pacing-induced increase in EPR (89.96 ±â€¯7.39 vs. 105.83 ±â€¯7.45 ms, P<0.05), AF inducibility and AF duration (Inducibility, 85.33 ±â€¯7.89 vs. 64.17 ±â€¯7.36%, Duration, 11 ±â€¯2.67 vs. 8.62 ±â€¯1.15 ms, P<0.05). The expression of Cx43 shows a significant downregulation(about 38%, P<0.001) after chronic pacing and treating with metformin could alleviate this decrease(P<0.01). However, the effect of metformin in acute pacing model is limited. The immunohistochemical staining of cardiac tissue also shown that there is more lateralized Cx43 under pacing condition (87.67 ±â€¯2.52 vs. 60.8 ±â€¯9.13%, P<0.005). These pacing-induced lateralize Cx43 could be alleviated by the metformin (48.4 ±â€¯8.62 vs. 60.8 ±â€¯9.13%, P<0.05). Additionally, metformin could affect the interactions of ZO-1 with p-Src/Cx43 via decrease the abnormal cAMP level after pacing (84.04 ±â€¯4.58 vs. 69.34 ±â€¯4.5 nmol/L, P<0.001). CONCLUSIONS: Metformin could alleviate the vulnerability of AF and attenuate the downregulation of gap junction under pacing condition via AMPK pathway and decreasing the P-Src level.


Assuntos
Fibrilação Atrial/tratamento farmacológico , Cardiotônicos/metabolismo , Metformina/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Estimulação Cardíaca Artificial/métodos , Cardiotônicos/farmacologia , Conexina 43/metabolismo , Modelos Animais de Doenças , Cães , Junções Comunicantes/efeitos dos fármacos , Átrios do Coração/metabolismo , Masculino , Taquicardia/fisiopatologia
5.
Am J Physiol Regul Integr Comp Physiol ; 318(6): R1078-R1090, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32348681

RESUMO

Cx30.2 protein content and localization were assessed during development. An account of Cx30.2, Cx43, Cx46, and Cx50, and insulin receptor (IR) responses to Cx30.2, Cx46, or Cx50 deficiency in mouse interstitial tissue (ITf)- and seminiferous tubule-enriched fractions (STf) is given. The impact of high glucose/insulin on Cx30.2 was investigated in spontaneously diabetic and obese db/db and ob/ob mouse testis and anterior pituitary (AP). Cx30.2 labeled contacts in vascular endothelial and Leydig cells and Sertoli cell junctions in stage V-VII. Cx30.2 expression is regulated differently in the interstitium and tubules. Cx30.2 at 30-kDa levels peaked by 28 days in ITf and by 14 days in STf. In STf, deleting Cx30.2 decreased Cx43 and Cx50, whereas deleting Cx50 downregulated Cx30.2. The opposite occurred in ITf. In STf, deleting Cx30.2 upregulated Cx46 except the full-length reciprocally, deleting Cx46 upregulated Cx30.2. In ITf, Cx30.2 deficiency upregulated full-length and phosphorylated Cx46, whereas deleting Cx46 downregulated 48- to 50-kDa Cx30.2. The db/db and ob/ob mouse ITf, STf, and AP showed imbalanced Cx30.2 levels. IRα levels at 135 kDa declined in Cx30.2-/- and Cx50-/- mouse ITf and Cx46-/- and Cx50-/- STf. IRß at 98 to 110 kDa dropped in Cx30.2-/- and Cx46-/- mice STf suggesting that Cx30.2 deficiency decreases active IR sites. The results show the connexins interdependence and interaction and that altering a single connexin changes the remaining connexins expression, which can modify gap junction-mediated glucose exchanges in contacting cells. Data suggest that glucose/insulin influences Cx30.2 turnover in testis and AP and, reciprocally, that connexins modulate testis glucose uptake and response to insulin.


Assuntos
Conexina 43/genética , Conexinas/genética , Diabetes Mellitus Experimental/genética , Obesidade/genética , Receptor de Insulina/genética , Testículo/metabolismo , Animais , Conexina 43/metabolismo , Conexinas/metabolismo , Diabetes Mellitus Experimental/metabolismo , Regulação da Expressão Gênica , Masculino , Camundongos , Camundongos Knockout , Obesidade/metabolismo , Receptor de Insulina/metabolismo
6.
Nat Commun ; 11(1): 1860, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32312952

RESUMO

Ependymal cells (ECs) are multiciliated neuroepithelial cells that line the ventricles of the brain and the central canal of the spinal cord (SC). How ependymal motile cilia are maintained remains largely unexplored. Here we show that zebrafish embryos deficient in Wnt signaling have defective motile cilia, yet harbor intact basal bodies. With respect to maintenance of ependymal motile cilia, plcδ3a is a target gene of Wnt signaling. Lack of Connexin43 (Cx43), especially its channel function, decreases motile cilia and intercellular Ca2+ wave (ICW) propagation. Genetic ablation of cx43 in zebrafish and mice diminished motile cilia. Finally, Cx43 is also expressed in ECs of the human SC. Taken together, our findings indicate that gap junction mediated ICWs play an important role in the maintenance of ependymal motile cilia, and suggest that the enhancement of functional gap junctions by pharmacological or genetic manipulations may be adopted to ameliorate motile ciliopathy.


Assuntos
Cílios/metabolismo , Conexina 43/metabolismo , Conexinas/metabolismo , Epêndima/metabolismo , Medula Espinal/metabolismo , Peixe-Zebra/embriologia , Animais , Diferenciação Celular , Cílios/genética , Conexina 43/genética , Epêndima/patologia , Junções Comunicantes , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Inativação de Genes , Humanos , Masculino , Camundongos , Camundongos Knockout , Transdução de Sinais/genética , Via de Sinalização Wnt/genética , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
7.
PLoS One ; 15(4): e0231272, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32271805

RESUMO

Connexin 43 (Cx43) may be important in cell death and survival due to cell-to-cell communication-independent mechanisms. In our previous study, we found that small G protein signaling modulator 3 (SGSM3), a partner of Cx43, contributes to myocardial infarction (MI) in rat hearts. Based on these previous results, we hypothesized that SGSM3 could also play a role in bone marrow-derived rat mesenchymal stem cells (MSCs), which differentiate into cardiomyocytes and/or cells with comparable phenotypes under low oxygen conditions. Cx43 and Cx43-related factor expression profiles were compared between normoxic and hypoxic conditions according to exposure time, and Sgsm3 gene knockdown (KD) using siRNA transfection was performed to validate the interaction between SGSM3 and Cx43 and to determine the roles of SGSM3 in rat MSCs. We identified that SGSM3 interacts with Cx43 in MSCs under different oxygen conditions and that Sgsm3 knockdown inhibits apoptosis and cardiomyocyte differentiation under hypoxic stress. SGSM3/Sgsm3 probably has an effect on MSC survival and thus therapeutic potential in diseased hearts, but SGSM3 may worsen the development of MSC-based therapeutic approaches in regenerative medicine. This study was performed to help us better understand the mechanisms involved in the therapeutic efficacy of MSCs, as well as provide data that could be used pharmacologically.


Assuntos
Apoptose/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Biomarcadores/metabolismo , Hipóxia Celular/efeitos dos fármacos , Conexina 43/metabolismo , Junções Comunicantes/efeitos dos fármacos , Junções Comunicantes/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Células-Tronco Mesenquimais/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Oxigênio/farmacologia , Ratos Sprague-Dawley , Estresse Fisiológico/efeitos dos fármacos , Fatores de Tempo , Via de Sinalização Wnt/efeitos dos fármacos
8.
Invest Ophthalmol Vis Sci ; 61(3): 14, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-32176265

RESUMO

Purpose: We used a human corneal epithelial cell (HCE) line to determine the involvement of the advanced glycation end products (AGEs) / receptor for AGEs (RAGE) couple in corneal epithelium wound healing. Methods: After wounding, HCE cells were exposed to two major RAGE ligands (HMGB1 and AGEs), and wound healing was evaluated using the in vitro scratch assay. Following wound healing, the HCE cells were used to study the influence of the RAGE ligands on HCE proliferation, invasion, and migration. Activation of the nuclear factor (NF)-κB signaling pathway by the AGEs/RAGE couple was tested using a luciferase reporter assay. Functional transcriptional regulation by this pathway was confirmed by quantification of expression of the connexin 43 target gene. For each experiment, specific RAGE involvement was confirmed by small interfering RNA treatments. Results: AGEs treatment at a dose of 100 µg/mL significantly improved the wound healing process in a RAGE-dependent manner by promoting cell migration, whereas HMGB1 had no effect. No significant influence of the AGEs/RAGE couple was observed on cell proliferation and invasion. However, this treatment induced an early activation of the NF-κB pathway and positively regulated the expression of the target gene, connexin 43, at both the mRNA and protein levels. Conclusions: Our results demonstrate that the RAGE pathway is activated by AGEs treatment and is involved in the promotion of corneal epithelial wound healing. This positive action is observed only during the early stages of wound healing, as illustrated by the quick activation of the NF-κB pathway and induction of connexin 43 expression.


Assuntos
Lesões da Córnea/fisiopatologia , Epitélio Anterior/efeitos dos fármacos , Produtos Finais de Glicação Avançada/farmacologia , Receptor para Produtos Finais de Glicação Avançada/fisiologia , Cicatrização/efeitos dos fármacos , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Células Cultivadas , Conexina 43/genética , Conexina 43/metabolismo , Lesões da Córnea/patologia , Relação Dose-Resposta a Droga , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Epitélio Anterior/citologia , Epitélio Anterior/lesões , Epitélio Anterior/fisiologia , Produtos Finais de Glicação Avançada/administração & dosagem , Produtos Finais de Glicação Avançada/fisiologia , Proteína HMGB1/administração & dosagem , Proteína HMGB1/farmacologia , Humanos , NF-kappa B/metabolismo , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Receptor para Produtos Finais de Glicação Avançada/genética , Transdução de Sinais/fisiologia , Cicatrização/fisiologia
9.
Zool Res ; 41(2): 203-207, 2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32150793

RESUMO

Gap junctions regulate intercellular communication between Sertoli cells and germ cells in male testes and play vital functions in spermatogenesis. Many factors in animal breeding and husbandry can induce oxidative stress, which can impair the testis microenvironment and male animal fertility. However, the underlying mechanisms are largely unknown. Recently, we identified that androgen signals promote the expression of connexin-43 (Cx43), a key component of gap junctions, to regulate spermatogenesis. Thus, we asked whether hyperactive reactive oxygen species (ROS) can impair gap junctions by interfering with Cx43 in porcine testes. Using a porcine Sertoli cell in vitro system, we found that hyperactive ROS caused extensive apoptosis in Sertoli cells, remarkable decrease in Cx43 expression, and failed maintenance of co-cultured spermatogonial stem cells (SSCs), indicating that ROS impaired the function of Sertoli cells and promoted loss of SSCs. This observation provides a possible mechanism for the impact of ROS on fertility of male animals.


Assuntos
Conexina 43/metabolismo , Integrina beta1/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Células de Sertoli/metabolismo , Suínos/metabolismo , Animais , Masculino
10.
J Pharmacol Exp Ther ; 373(3): 429-437, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32217769

RESUMO

Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) have become a promising cell source for cardiovascular research. The electrophysiological characteristic of hESC-CMs has been generally studied, but little is known about electrophysiological response to adrenergic receptor (AR) activation. This study aims to characterize electrophysiological response of hESC-CMs to adrenergic stimulation in terms of the conduction velocity (CV) and action potential (AP) shape. The H9 hESC-CMs were acquired by a classic differentiation protocol and cultured to achieve confluent cell monolayers. The AP shape and CV among the monolayers were recorded using optical mapping during electrophysiological and pharmacological stimulation experiments. Quantitative real-time polymerase chain reaction and Western blot were adopted to determine the expression levels of Connexin and ion channel gene and protein. Chronic ß-AR stimulation by isoproterenol for 24 hours in hESC-CM monolayers increased CV by approximately 50%, whereas α-AR or acute ß-AR stimulation had no significant effect; chronic ß-AR stimulation resulted in a significant Connexin (Cx) 43 and Nav1.5 upregulation at both protein and mRNA level. Isoproterenol-induced CV accelerating and Cx43 and Nav1.5 upregulation in hESC-CMs, which was attenuated by selective ß1-adrenoceptor antagonist CGP 20712A but not selective ß2-antagonist ICI 118551. Moreover, pretreatment with protein kinase A (PKA) inhibitor H89, mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (MEK) inhibitor SB203580, and MAPK inhibitor PD98059 suppressed the isoproterenol-induced CV accelerating and Cx43 upregulation, whereas it had no significant effect on Nav1.5 upregulation. The AP shape in hESC-CM monolayers was less susceptible by either ß-AR or α-AR stimulation. It was ß1-AR not ß2-AR contributing to the modification of conduction velocity among hESC-CM monolayers. Chronic ß1-AR stimulation accelerates CV by upregulating Cx43 via PKA/MEK/MAPK pathway. SIGNIFICANCE STATEMENT: These data provide new insight into the electrophysiological characteristics of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) and depict a concise signaling pathway in the adrenergic receptor (AR) regulation of action potential shape and electrical propagation across hESC-CM monolayer. It is ß1-AR not ß2-AR contributing to the modification of conduction velocity in hESC-CMs and accelerating conduction velocity by upregulating Connexin 43 via protein kinase A/ mitogen-activated protein kinase (MAPK)-extracellular signal-regulated kinase/MAPK pathway.


Assuntos
Fenômenos Eletrofisiológicos/fisiologia , Células-Tronco Embrionárias Humanas/metabolismo , Miócitos Cardíacos/metabolismo , Receptores Adrenérgicos beta 1/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Potenciais de Ação/fisiologia , Diferenciação Celular/fisiologia , Células Cultivadas , Conexina 43/metabolismo , Humanos , Transdução de Sinais/fisiologia , Regulação para Cima/fisiologia
11.
Arch Med Res ; 51(3): 215-223, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32111501

RESUMO

OBJECTIVE: Vascular calcification is commonly observed in atherosclerosis and diabetes. The renin-angiotensin II system is associated with the regulation of arterial stiffening. The aim of this study was to examine whether the angiotensin-converting enzyme inhibitors captopril attenuates artery calcification. METHODS: The rat model of arterial calcification was established by a combination of warfarin and vitamin K1. Two weeks after the induction of arterial calcification, captopril treatment was initiated. One week after captopril treatment, aortic arteries were examined to determine the calcification morphology and the connexin 43 expression. Matrix Gla protein (MGP), receptor activator of nuclear factor-κB ligand (RANKL) and extracellular regulated protein kinase (ERK) pathways were examined. RESULTS: The morphology of the calcified arteries was significantly attenuated after captopril treatment. Consistently, captopril inhibited the increased connexin 43 expression and enhanced the decreased MGP expression in calcification arteries. Furthermore, captopril enhanced the decreased SM22 expression in calcified arteries by fluorescence assay. Finally, the calcification arteries increased the p38, p-ERK and RANKL expression, which were downregulated by captopril treatment. CONCLUSIONS: We concluded that captopril attenuated the increased connexin 43 expression and enhanced the MGP and SM22 expression levels, which are associated with the inactivation of p-ERK, p38 and RANKL pathways in rat aortic arteries.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Captopril/farmacologia , Conexina 43/metabolismo , Calcificação Vascular/tratamento farmacológico , Rigidez Vascular/efeitos dos fármacos , Animais , Artérias/patologia , Aterosclerose/patologia , Proteínas de Ligação ao Cálcio/metabolismo , Regulação para Baixo , Proteínas da Matriz Extracelular/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Masculino , Proteínas dos Microfilamentos/metabolismo , Proteínas Musculares/metabolismo , Ligante RANK/metabolismo , Ratos , Ratos Sprague-Dawley , Sistema Renina-Angiotensina , Regulação para Cima , Vitamina K 1/toxicidade , Varfarina/toxicidade
12.
BMC Cardiovasc Disord ; 20(1): 85, 2020 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-32066388

RESUMO

BACKGROUND: Coronary microembolization (CME) has a poor prognosis, with ventricular arrhythmia being the most serious consequence. Understanding the underlying mechanisms could improve its management. We investigated the effects of granulocyte colony-stimulating factor (G-CSF) on connexin-43 (Cx43) expression and ventricular arrhythmia susceptibility after CME. METHODS: Forty male rabbits were randomized into four groups (n = 10 each): Sham, CME, G-CSF, and AG490 (a JAK2 selective inhibitor). Rabbits in the CME, G-CSF, and AG490 groups underwent left anterior descending (LAD) artery catheterization and CME. Animals in the G-CSF and AG490 groups received intraperitoneal injection of G-CSF and G-CSF + AG490, respectively. The ventricular structure was assessed by echocardiography. Ventricular electrical properties were analyzed using cardiac electrophysiology. The myocardial interstitial collagen content and morphologic characteristics were evaluated using Masson and hematoxylin-eosin staining, respectively. RESULTS: Western blot and immunohistochemistry were employed to analyze the expressions of Cx43, G-CSF receptor (G-CSFR), JAK2, and STAT3. The ventricular effective refractory period (VERP), VERP dispersion, and inducibility and lethality of ventricular tachycardia/fibrillation were lower in the G-CSF than in the CME group (P < 0.01), indicating less severe myocardial damage and arrhythmias. The G-CSF group showed higher phosphorylated-Cx43 expression (P < 0.01 vs. CME). Those G-CSF-induced changes were reversed by A490, indicating the involvement of JAK2. G-CSFR, phosphorylated-JAK2, and phosphorylated-STAT3 protein levels were higher in the G-CSF group than in the AG490 (P < 0.01) and Sham (P < 0.05) groups. CONCLUSION: G-CSF might attenuate myocardial remodeling via JAK2-STAT3 signaling and thereby reduce ventricular arrhythmia susceptibility after CME.


Assuntos
Arritmias Cardíacas/prevenção & controle , Doença da Artéria Coronariana/tratamento farmacológico , Fator Estimulador de Colônias de Granulócitos/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Janus Quinase 2/metabolismo , Infarto do Miocárdio/prevenção & controle , Miocárdio/enzimologia , Função Ventricular Esquerda/efeitos dos fármacos , Remodelação Ventricular/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Animais , Arritmias Cardíacas/enzimologia , Arritmias Cardíacas/patologia , Arritmias Cardíacas/fisiopatologia , Conexina 43/metabolismo , Doença da Artéria Coronariana/enzimologia , Doença da Artéria Coronariana/patologia , Doença da Artéria Coronariana/fisiopatologia , Modelos Animais de Doenças , Fibrose , Masculino , Infarto do Miocárdio/enzimologia , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Miocárdio/patologia , Fosforilação , Coelhos , Receptores de Fator Estimulador de Colônias de Granulócitos/metabolismo , Período Refratário Eletrofisiológico/efeitos dos fármacos , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais
13.
Nat Commun ; 11(1): 1073, 2020 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-32103010

RESUMO

Denervation of skeletal muscles induces severe muscle atrophy, which is preceded by cellular alterations such as increased plasma membrane permeability, reduced resting membrane potential and accelerated protein catabolism. The factors that induce these changes remain unknown. Conversely, functional recovery following denervation depends on successful reinnervation. Here, we show that activation of nicotinic acetylcholine receptors (nAChRs) by quantal release of acetylcholine (ACh) from motoneurons is sufficient to prevent changes induced by denervation. Using in vitro assays, ACh and non-hydrolysable ACh analogs repressed the expression of connexin43 and connexin45 hemichannels, which promote muscle atrophy. In co-culture studies, connexin43/45 hemichannel knockout or knockdown increased innervation of muscle fibers by dorsal root ganglion neurons. Our results show that ACh released by motoneurons exerts a hitherto unknown function independent of myofiber contraction. nAChRs and connexin hemichannels are potential molecular targets for therapeutic intervention in a variety of pathological conditions with reduced synaptic neuromuscular transmission.


Assuntos
Acetilcolina/metabolismo , Gânglios Espinais/crescimento & desenvolvimento , Músculo Esquelético/inervação , Atrofia Muscular/patologia , Receptores Nicotínicos/metabolismo , Acetilcolina/análogos & derivados , Acetilcolina/farmacologia , Animais , Permeabilidade da Membrana Celular/fisiologia , Células Cultivadas , Conexina 43/metabolismo , Conexinas/metabolismo , Masculino , Potenciais da Membrana/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Músculo Esquelético/metabolismo
14.
Chem Biol Interact ; 319: 108979, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32045570

RESUMO

Heart rhythm disturbances have been widely recognized as major triggers of cardiovascular (CV) mortality in chronic kidney disease (CKD) patients. Connexin 43 (Cx43)-composed gap junctions are essential in cardiomyocyte synchronization and may be involved in the pathological response to uremic toxins. Indoxyl sulfate (IS) is one of the most dominant uremic toxins that contribute to CKD-related cardiovascular diseases. In primary cultures of rat neonatal cardiomyocytes, we demonstrated that IS treatment decreased spontaneous contraction without impairing viability. In addition, there was disruption of gap junction intercellular communication (GJIC) between cardiomyocytes after 30 min of IS stimulation. IS caused time- and dose-dependent Cx43 redistribution, and the patterns of Cx43 immunostaining returned to baseline while IS stimulation was removed. Furthermore, IS exposure downregulated Cx43 protein and mRNA levels. Elevated JNK1 and JNK2 phosphorylation was further identified after IS exposure in both rat cardiomyocytes and H9c2 cells. The above changes as well as GJIC and Cx43 suppression were reversed by pretreatment with a JNK inhibitor (SP600125). Inhibition of p-JNK attenuated IS-mediated downward trends in Cx43 transcription and translation. In cardiac muscle from nephrectomy-induced CKD mice, an alteration in Cx43 level was identified at intercalated discs. Our findings disclosed that JNK activation might participate in the remodeling of gap junction and Cx43 expression by uremic toxin-IS both in vitro and in vivo.


Assuntos
Conexina 43/metabolismo , Indicã/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Antracenos/farmacologia , Comunicação Celular/efeitos dos fármacos , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Junções Comunicantes/efeitos dos fármacos , Junções Comunicantes/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
15.
Int J Mol Sci ; 21(2)2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31947691

RESUMO

The arrhythmogenic potential of ß1-adrenoceptor autoantibodies (ß1-AA), as well as antiarrhythmic properties of omega-3 in heart diseases, have been reported while underlying mechanisms are poorly understood. We aimed to test our hypothesis that omega-3 (eicosapentaenoic acid-EPA, docosahexaenoic acid-DHA) may inhibit matrix metalloproteinase (MMP-2) activity to prevent cleavage of ß1-AR and formation of ß1-AA resulting in attenuation of pro-arrhythmic connexin-43 (Cx43) and protein kinase C (PKC) signaling in the diseased heart. We have demonstrated that the appearance and increase of ß1-AA in blood serum of male and female 12-month-old spontaneously hypertensive rats (SHR) was associated with an increase of inducible ventricular fibrillation (VF) comparing to normotensive controls. In contrast, supplementation of hypertensive rats with omega-3 for two months suppressed ß1-AA levels and reduced incidence of VF. Suppression of ß1-AA was accompanied by a decrease of elevated myocardial MMP-2 activity, preservation of cardiac cell membrane integrity and Cx43 topology. Moreover, omega-3 abrogated decline in expression of total Cx43 as well as its phosphorylated forms at serine 368 along with PKC-ε, while decreased pro-fibrotic PKC-δ levels in hypertensive rat heart regardless the sex. The implication of MMP-2 in the action of omega-3 was also demonstrated in cultured cardiomyocytes in which desensitization of ß1-AR due to permanent activation of ß1-AR with isoproterenol was prevented by MMP-2 inhibitor or EPA. Collectively, these data support the notion that omega-3 via suppression of ß1-AA mechanistically controlled by MMP-2 may attenuate abnormal of Cx43 and PKC-ε signaling; thus, abolish arrhythmia substrate and protect rats with an advanced stage of hypertension from malignant arrhythmias.


Assuntos
Antiarrítmicos/farmacologia , Arritmias Cardíacas/etiologia , Autoanticorpos/imunologia , Autoantígenos/imunologia , Ácidos Graxos Ômega-3/farmacologia , Hipertensão/complicações , Receptores Adrenérgicos beta 1/imunologia , Animais , Arritmias Cardíacas/tratamento farmacológico , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/fisiopatologia , Biomarcadores , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Membrana Celular/ultraestrutura , Conexina 43/metabolismo , Modelos Animais de Doenças , Suscetibilidade a Doenças , Ácidos Graxos Ômega-3/metabolismo , Feminino , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/ultraestrutura , Proteína Quinase C-épsilon/metabolismo , Ratos , Ratos Endogâmicos SHR , Sarcolema/metabolismo , Sarcolema/ultraestrutura , Fibrilação Ventricular/tratamento farmacológico , Fibrilação Ventricular/etiologia , Fibrilação Ventricular/fisiopatologia
16.
Cell Mol Life Sci ; 77(4): 573-591, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31501970

RESUMO

Gap junctions consist of arrays of intercellular channels that enable adjacent cells to communicate both electrically and metabolically. Gap junctions have a wide diversity of physiological functions, playing critical roles in both excitable and non-excitable tissues. Gap junction channels are formed by integral membrane proteins called connexins. Inherited or acquired alterations in connexins are associated with numerous diseases, including heart failure, neuropathologies, deafness, skin disorders, cataracts and cancer. Gap junctions are highly dynamic structures and by modulating the turnover rate of connexins, cells can rapidly alter the number of gap junction channels at the plasma membrane in response to extracellular or intracellular cues. Increasing evidence suggests that ubiquitination has important roles in the regulation of endoplasmic reticulum-associated degradation of connexins as well as in the modulation of gap junction endocytosis and post-endocytic sorting of connexins to lysosomes. In recent years, researchers have also started to provide insights into the physiological roles of connexin ubiquitination in specific tissue types. This review provides an overview of the advances made in understanding the roles of connexin ubiquitination in the regulation of gap junction intercellular communication and discusses the emerging physiological and pathophysiological implications of these processes.


Assuntos
Conexinas/metabolismo , Junções Comunicantes/metabolismo , Ubiquitinação , Animais , Catarata/metabolismo , Catarata/patologia , Comunicação Celular , Conexina 43/metabolismo , Junções Comunicantes/patologia , Cardiopatias/metabolismo , Cardiopatias/patologia , Humanos , Neoplasias/metabolismo , Neoplasias/patologia , Processamento de Proteína Pós-Traducional
17.
J Cardiovasc Pharmacol ; 75(3): 259-267, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31868825

RESUMO

ur preclinical findings replicated women's hypersensitivity to type-2 diabetes mellitus (T2DM)-evoked cardiac dysfunction along with demonstrating estrogen (E2)-dependent disruption of the cardiac adiponectin (APN)-connexin43 (Cx43) signaling. Whether the latter molecular anomaly underlies this women's cardiovascular health problem remains unknown. We hypothesized that restoration of the disrupted APN-Cx43 signaling alleviates this sex/E2-dependent cardiac dysfunction in diabetic female rats. To test this hypothesis, we administered the adiponectin receptor 1 (AdipoR1) agonist AdipoRon (30 mg/kg/d for 10 days) to female sham operated (SO) and ovariectomized (OVX) rats, which exhibited and lacked the T2DM left ventricular (LV) dysfunction, respectively, when fed high-fat diet and received low dose streptozotocin regimen; nondiabetic control SO and OVX rats received control diet and vehicle for streptozotocin. In T2DM SO rats, LV dysfunction, AdipoRon mitigated: (1) LV hypertrophy, (2) reductions in fractional shortening, LV developed pressure, dP/dtmax, dP/dtmin, and Tau. In LV tissues of the same rats, AdipoRon reversed reduction in Cx43 and elevations in TNFα, heme-oxygenase 1 (HO-1), and circulating cardiovascular risk factor asymmetric dimethylarginine. The findings also revealed ovarian hormones independent effects of AdipoRon, which included dampening of the pro-oxidant enzyme HO-1. These novel findings yield new insight into a causal role for compromised APN-Cx43 signaling in the E2-dependent hypersensitivity to T2DM-evoked cardiac inflammation and dysfunction. Equally important, the findings identify restoration of Cx43 signaling as a viable therapeutic modality for alleviating this women's cardiovascular health-related problem.


Assuntos
Adiponectina/metabolismo , Conexina 43/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Cardiomiopatias Diabéticas/prevenção & controle , Hipertrofia Ventricular Esquerda/prevenção & controle , Piperidinas/farmacologia , Disfunção Ventricular Esquerda/prevenção & controle , Função Ventricular Esquerda/efeitos dos fármacos , Animais , Arginina/análogos & derivados , Arginina/metabolismo , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Cardiomiopatias Diabéticas/etiologia , Cardiomiopatias Diabéticas/metabolismo , Cardiomiopatias Diabéticas/fisiopatologia , Estradiol/metabolismo , Receptor alfa de Estrogênio/metabolismo , Feminino , Heme Oxigenase (Desciclizante)/metabolismo , Hipertrofia Ventricular Esquerda/etiologia , Hipertrofia Ventricular Esquerda/metabolismo , Hipertrofia Ventricular Esquerda/fisiopatologia , Ovariectomia , Ratos Wistar , Receptores de Adiponectina/agonistas , Receptores de Adiponectina/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/metabolismo , Disfunção Ventricular Esquerda/fisiopatologia , Remodelação Ventricular/efeitos dos fármacos
18.
Toxicol Lett ; 318: 57-64, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31585160

RESUMO

3-Bromopyruvate (3-BrPA) is a promising agent that has been widely studied in the treatment of cancer and pulmonary hypertension. Rotenone is a pesticide commonly used on farms and was shown to have anti-cancer activity and delay fibrosis progression in chronic kidney disease in a recent study. However, there are few studies showing the toxicity of rotenone and 3-BrPA in the myocardium. To support further medical exploration, it is necessary to clarify the side effects of these compounds on the heart. This study was designed to examine the cardiotoxicity of 3-BrPA and rotenone by investigating electrical and structural cardiac remodeling in rats. Forty male rats were divided into 4 groups (n = 10 in each group) and injected intraperitoneally with 3-BrPA, rotenone or a combination of 3-BrPA and rotenone. The ventricular effective refractory period (VERP), corrected QT interval (QTc), and ventricular tachycardia/ventricular fibrillation (VT/VF) inducibility were measured. The expression of Cx43, Kir2.1, Kir6.2, DHPRα1, KCNH2, caspase3, caspase9, Bax, Bcl2, and P53 was detected. Masson's trichrome, TUNEL, HE, and PAS staining and transmission electron microscopy were used to detect pathological and ultrastructural changes. Our results showed that rotenone alone and rotenone combined with 3-BrPA significantly increased the risk of ventricular arrhythmias. Rotenone combined with 3-BrPA caused myocardial apoptosis, and rotenone alone and rotenone combined with 3-BrPA caused electrical and structural cardiac remodeling in rats.


Assuntos
Antineoplásicos/toxicidade , Ventrículos do Coração/efeitos dos fármacos , Inseticidas/toxicidade , Piruvatos/toxicidade , Rotenona/toxicidade , Taquicardia Ventricular/induzido quimicamente , Fibrilação Ventricular/induzido quimicamente , Remodelação Ventricular/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Cardiotoxicidade , Conexina 43/genética , Conexina 43/metabolismo , Frequência Cardíaca/efeitos dos fármacos , Ventrículos do Coração/metabolismo , Ventrículos do Coração/fisiopatologia , Ventrículos do Coração/ultraestrutura , Masculino , Canais de Potássio Corretores do Fluxo de Internalização/genética , Canais de Potássio Corretores do Fluxo de Internalização/metabolismo , Ratos Wistar , Período Refratário Eletrofisiológico/efeitos dos fármacos , Medição de Risco , Taquicardia Ventricular/metabolismo , Taquicardia Ventricular/patologia , Taquicardia Ventricular/fisiopatologia , Fibrilação Ventricular/metabolismo , Fibrilação Ventricular/patologia , Fibrilação Ventricular/fisiopatologia
19.
J Pharm Pharmacol ; 72(1): 76-83, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31702064

RESUMO

OBJECTIVES: Metoprolol is regarded as a first-line medicine for the treatment of myocardial infarction (MI). However, the underlying mechanisms remain largely unknown. This study aimed to investigate the involvement of miR-1 in the pharmacological function of metoprolol. METHODS: In vivo MI model was established by left anterior descending coronary artery (LAD) ligation. The effects of metoprolol on infarct size and cardiac dysfunction were determined by triphenyltetrazolium chloride staining and cardiac echocardiography, respectively. In vitro oxidative stress cardiomyocyte model was established by H2 O2 treatment. The effect of metoprolol on the expression of miR-1 and connexin43 (Cx43) was quantified by real-time PCR and western blot, respectively. The intercellular communication was evaluated by lucifer yellow dye diffusion. KEY FINDINGS: Left anterior descending ligation-induced MI injury was markedly attenuated by metoprolol as shown by reduced infarct size and better cardiac function. Metoprolol reversed the up-regulation of miR-1 and down-regulation of Cx43 in MI heart. Moreover, in H2 O2 -stimulated cardiomyocytes, overexpression of miR-1 abolished the effects of metoprolol on Cx43 up-regulation and increased intercellular communication, indicating that miR-1 may be a necessary mediator for the cardiac protective function of metoprolol. CONCLUSIONS: Metoprolol relieves MI injury via suppression miR-1, thus increasing its target protein Cx43 and improving intercellular communication.


Assuntos
Antagonistas de Receptores Adrenérgicos beta 1/farmacologia , Metoprolol/farmacologia , MicroRNAs/metabolismo , Infarto do Miocárdio/prevenção & controle , Miócitos Cardíacos/efeitos dos fármacos , Animais , Comunicação Celular/efeitos dos fármacos , Células Cultivadas , Conexina 43/metabolismo , Modelos Animais de Doenças , Regulação para Baixo , Junções Comunicantes/efeitos dos fármacos , Junções Comunicantes/metabolismo , Junções Comunicantes/patologia , Masculino , MicroRNAs/genética , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/fisiopatologia , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Ratos Wistar , Volume Sistólico/efeitos dos fármacos , Função Ventricular Esquerda/efeitos dos fármacos
20.
Carbohydr Polym ; 229: 115516, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31826493

RESUMO

Acute myocardial infarction (MI) is a common cardiovascular disease with high mortality. In this study, an injectable thermosensitive hydrogel of chitosan (CS)/dextran (DEX)/ß-glycerophosphate (ß-GP) loaded with umbilical cord mesenchymal stem cells (UCMSCs) was prepared for MI treatment. The good biocompatibility of hydrogels was confirmed by 3T3 cells and HUVECs culture study in vitro. HUVECs encapsulated in the hydrogels showed a cell delivery ability. Furthermore, the results indicated that hydrogel could encapsulate most of UCMSCs and the cells exhibited good viability in CS/ 1.0DEX/ß-GP hydrogels. The expression of cardiac markers of cTnI and Cx43 and signaling pathways of p-Akt and p-ERK1/2 were studied, and it showed that UCMSCs differentiate towards myocardium and has a great potential for therapeutic use of cardiac repair. In conclusion, the thermosensitive hydrogel of CS/1.0 DEX/ß-GP loaded UCMSCs was a promising candidate as cell delivery vehicle for cardiac repair to reconstitute damaged myocardium.


Assuntos
Quitosana/química , Dextranos/química , Glicerofosfatos/química , Hidrogéis/química , Células 3T3 , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Conexina 43/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Infarto do Miocárdio/patologia , Infarto do Miocárdio/terapia , Reologia , Transdução de Sinais/efeitos dos fármacos , Tecidos Suporte/química , Troponina I/metabolismo
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