Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 103
Filtrar
2.
Artigo em Inglês | MEDLINE | ID: mdl-38831543

RESUMO

BACKGROUND: A common psychological problem among nurses is depression, potentially affecting their well-being and job performance. It is vital to explore how to alleviate nurses' depressive symptoms. AIM: The current research explored the mediating impact of basic psychological needs satisfaction on the link of gratitude with depressive symptoms. METHODS: The nurses in this study were from mainland China. A total of 724 subjects completed an online questionnaire, which included measures of depressive symptoms, basic psychological needs satisfaction and gratitude. RESULTS: Our research found that gratitude was negatively linked to depressive symptoms. Furthermore, basic psychological needs satisfaction had a partial mediation effect on the link of gratitude with depressive symptoms after controlling for five demographic variables. These results suggest that gratitude may influence depressive symptoms via basic psychological needs satisfaction. LINKING EVIDENCE TO ACTION: Our study found that basic psychological need satisfaction partially mediates the gratitude-depression relationship in nurses. The result means that hospital administrators and nurse leaders should design gratitude interventions to alleviate nurses' depressive symptoms. They also help nurses decrease depressive symptoms by creating an environment that meets their basic psychological needs.

3.
ACS Nano ; 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38941591

RESUMO

High-performance thermal interface materials (TIMs) are highly desired for high-power electronic devices to accelerate heat dissipation. However, the inherent trade-off conflict between achieving high thermal conductivity and excellent compliance of filler-enhanced TIMs results in the unsatisfactory interfacial heat transfer efficiency of existing TIM solutions. Here, we report the graphene fiber (GF)-based elastic TIM with metal-level thermal conductivity via mechanical-electric dual-field synergistic alignment engineering. Compared with state-of-the-art carbon fiber (CF), GF features both superb high thermal conductivity of ∼1200 W m-1 K-1 and outstanding flexibility. Under dual-field synergistic alignment regulation, GFs are vertically aligned with excellent orientation (0.88) and high array density (33.5 mg cm-2), forming continuous thermally conductive pathways. Even at a low filler content of ∼17 wt %, GF-based TIM demonstrates extraordinarily high through-plane thermal conductivity of up to 82.4 W m-1 K-1, exceeding most CF-based TIMs and even comparable to commonly used soft indium foil. Benefiting from the low stiffness of GF, GF-based TIM shows a lower compressive modulus down to 0.57 MPa, an excellent resilience rate of 95% after compressive cycles, and diminished contact thermal resistance as low as 7.4 K mm2 W-1. Our results provide a superb paradigm for the directed assembly of thermally conductive and flexible GFs to achieve scalable and high-performance TIMs, overcoming the long-standing bottleneck of mechanical-thermal mismatch in TIM design.

4.
Heliyon ; 10(9): e30075, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38699027

RESUMO

College students have a high prevalence of nomophobia. However, research on the effects of emotion regulation and resilience on nomophobia in China is lacking. This research investigated how cognitive reappraisal and expressive suppression strategies directly and indirectly affect nomophobia through resilience. Therefore, from March to May 2023, 756 university student volunteers (21.4 % men) were selected from a university in northeastern China for a questionnaire survey. Our findings suggest that college students' resilience has a masking effect on the relationship between cognitive reappraisal and nomophobia and can attenuate the negative effect of the frequency of using cognitive reappraisal strategies on nomophobia. The frequency of expressive suppression strategies directly and positively affected nomophobia. Early psychological interventions targeting resilience might be potentially effective in alleviating nomophobia among college students.

5.
Int J Biol Macromol ; 268(Pt 1): 131559, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38631576

RESUMO

Expansins are important plant cell wall proteins. They can loosen and soften the cell walls and lead to wall extension and cell expansion. To investigate their role in wood formation and fiber elongation, the PagEXPA1 that highly expressed in cell differentiation and expansion tissues was cloned from 84K poplar (Populus alba × P. glandulosa). The subcellular localization showed that PagEXPA1 located in the cell wall and it was highly expressed in primary stems and young leaves. Compared with non-transgenic 84K poplar, overexpression of PagEXPA1 can promote plant-growth, lignification, and fiber cell elongation, while PagEXPA1 Cas9-editing mutant lines exhibited the opposite phenotype. Transcriptome analysis revealed that DEGs were mainly enriched in some important processes, which are associated with cell wall formation and cellulose synthesis. The protein interaction prediction and expression analysis showed that PagCDKB2:1 and PagEXPA1 might have an interaction relationship. The luciferase complementary assay and bimolecular fluorescence complementary assay validated that PagEXPA1 can combined with PagCDKB2;1. So they promoted the expansion of xylem vascular tissues and the development of poplar though participating in the regulation of cell division and differentiation by programming the cell-cycle. It provides good foundation for molecular breeding of fast-growing and high-quality poplar varieties.


Assuntos
Parede Celular , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas , Populus , Populus/genética , Populus/crescimento & desenvolvimento , Populus/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Parede Celular/metabolismo , Parede Celular/genética , Plantas Geneticamente Modificadas , Perfilação da Expressão Gênica , Xilema/metabolismo , Xilema/genética , Desenvolvimento Vegetal/genética , Madeira/genética , Madeira/crescimento & desenvolvimento
6.
Int J Mol Sci ; 25(7)2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38612736

RESUMO

The discovery of new genes with novel functions is a major driver of adaptive evolutionary innovation in plants. Especially in woody plants, due to genome expansion, new genes evolve to regulate the processes of growth and development. In this study, we characterized the unique VeA transcription factor family in Populus alba × Populus glandulosa, which is associated with secondary metabolism. Twenty VeA genes were characterized systematically on their phylogeny, genomic distribution, gene structure and conserved motif, promoter binding site, and expression profiling. Furthermore, through ChIP-qPCR, Y1H, and effector-reporter assays, it was demonstrated that PagMYB128 directly regulated PagVeA3 to influence the biosynthesis of secondary metabolites. These results provide a basis for further elucidating the function of VeAs gene in poplar and its genetic regulation mechanism.


Assuntos
Populus , Fatores de Transcrição , Fatores de Transcrição/genética , Populus/genética , Genômica , Sítios de Ligação , Bioensaio
7.
Int J Mol Sci ; 25(3)2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38338699

RESUMO

The photoperiod is a major environmental factor in flowering control. Water spinach flowering under the inductive short-day condition decreases the yield of vegetative tissues and the eating quality. To obtain an insight into the molecular mechanism of the photoperiod-dependent regulation of the flowering time in water spinach, we performed transcriptome sequencing on water spinach under long- and short-day conditions with eight time points. Our results indicated that there were 6615 circadian-rhythm-related genes under the long-day condition and 8691 under the short-day condition. The three key circadian-rhythm genes, IaCCA1, IaLHY, and IaTOC1, still maintained single copies and similar IaCCA1, IaLHY, and IaTOC1 feedback expression patterns, indicating the conservation of reverse feedback. In the photoperiod pathway, highly conserved GI genes were amplified into two copies (IaGI1 and IaGI2) in water spinach. The significant difference in the expression of the two genes indicates functional diversity. Although the photoperiod core gene FT was duplicated to three copies in water spinach, only IaFT1 was highly expressed and strongly responsive to the photoperiod and circadian rhythms, and the almost complete inhibition of IaFT1 in water spinach may be the reason why water spinach does not bloom, no matter how long it lasts under the long-day condition. Differing from other species (I. nil, I. triloba, I. trifida) of the Ipomoea genus that have three CO members, water spinach lacks one of them, and the other two CO genes (IaCO1 and IaCO2) encode only one CCT domain. In addition, through weighted correlation network analysis (WGCNA), some transcription factors closely related to the photoperiod pathway were obtained. This work provides valuable data for further in-depth analyses of the molecular regulation of the flowering time in water spinach and the Ipomoea genus.


Assuntos
Ipomoea , Fotoperíodo , Transcriptoma , Ipomoea/genética , Flores/genética , Flores/metabolismo , Ritmo Circadiano/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
8.
J Org Chem ; 89(3): 1748-1752, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38262733

RESUMO

A highly enantioselective catalytic reduction of pyrazolo[1,5-a]pyrimidine to zanubrutinib has been realized by the Ir/(R)-t-Bu-FcPhox complex. This chiral product could be obtained in up to >99% ee in the asymmetric transformation without any other additives, providing a new route for the asymmetric synthesis of zanubrutinib.

9.
J Health Psychol ; : 13591053231222167, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38279538

RESUMO

Nurses are at increased risk for developing depressive symptoms. While previous research has suggested that strength use may be inversely related to these symptoms, the longitudinal impact of strength use on nurses' depressive symptoms remains under-explored. This study sought to examine the longitudinal relationship between strength use and depressive symptoms among Chinese nurses. Using a two-wave cross-lagged design from 2020 to 2023, 321 nurses participated in an online questionnaire survey. Using structural equation modeling, our results supported the hypothesized reciprocal model, indicating that strength use can significantly predict a reduction in depressive symptoms and vice versa. Given these findings, there's an urgent need for nurse leaders to emphasize the importance of using nurses' strengths as a strategy to alleviate depressive symptoms.

10.
Front Med ; 18(1): 128-146, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37870681

RESUMO

Tumor-derived exosomes (TEXs) enriched in immune suppressive molecules predominantly drive T-cell dysfunction and impair antitumor immunity. Chimeric antigen receptor (CAR) T-cell therapy has emerged as a promising treatment for refractory and relapsed hematological malignancies, but whether lymphoma TEXs have the same impact on CAR T-cell remains unclear. Here, we demonstrated that B-cell lymphoma-derived exosomes induce the initial activation of CD19-CAR T-cells upon stimulation with exosomal CD19. However, lymphoma TEXs might subsequently induce CAR T-cell apoptosis and impair the tumor cytotoxicity of the cells because of the upregulated expression of the inhibitory receptors PD-1, TIM3, and LAG3 upon prolonged exposure. Similar results were observed in the CAR T-cells exposed to plasma exosomes from patients with lymphoma. More importantly, single-cell RNA sequencing revealed that CAR T-cells typically showed differentiated phenotypes and regulatory T-cell (Treg) phenotype conversion. By blocking transforming growth factor ß (TGF-ß)-Smad3 signaling with TGF-ß inhibitor LY2109761, the negative effects of TEXs on Treg conversion, terminal differentiation, and immune checkpoint expression were rescued. Collectively, although TEXs lead to the initial activation of CAR T-cells, the effect of TEXs suppressed CAR T-cells, which can be rescued by LY2109761. A treatment regimen combining CAR T-cell therapy and TGF-ß inhibitors might be a novel therapeutic strategy for refractory and relapsed B-cell lymphoma.

11.
Cell Tissue Res ; 395(1): 63-79, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38040999

RESUMO

To investigate the effect and mechanism of Huogu injection (HG) on steroid-induced osteonecrosis of the femoral head (SONFH), we established a SONFH model in rabbits using horse serum and dexamethasone (DEX) and applied HG locally at the hip joint. We evaluated the therapeutic efficacy at 4 weeks using scanning electron microscopy (SEM), micro-CT, and qualitative histology including H&E, Masson's trichrome, ALP, and TUNEL staining. In vitro, we induced osteogenic differentiation of bone marrow stromal cells (BMSCs) and performed analysis on days 14 and 21 of cell differentiation. The findings, in vivo, including SEM, micro-CT, and H&E staining, showed that HG significantly maintained bone quality and trabecular number. ALP staining indicated that HG promoted the proliferation of bone cells. Moreover, the results of Masson's trichrome staining demonstrated the essential role of HG in collagen synthesis. Additionally, TUNEL staining revealed that HG reduced apoptosis. ALP and ARS staining in vitro confirmed that HG enhanced osteogenic differentiation and mineralization, consistent with the WB and qRT-PCR analysis. Furthermore, Annexin V-FITC/PI staining verified that HG inhibited osteoblast apoptosis, in agreement with the WB and qRT-PCR analyses. Furthermore, combined with the UPLC analysis, we found that naringin enhanced the osteogenic differentiation and accelerated the deposition of calcium phosphate. Salvianolic acid B protected osteoblasts derived from BMSCs against GCs-mediated apoptosis. Thus, this study not only reveals the mechanism of HG in promoting osteogenesis and anti-apoptosis of osteoblasts but also identifies the active-related components in HG, by which we provide the evidence for the application of HG in SONFH.


Assuntos
Células-Tronco Mesenquimais , Osteogênese , Animais , Coelhos , Diferenciação Celular , Osteoblastos , Apoptose , Células Cultivadas
12.
Nanomicro Lett ; 16(1): 58, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38112845

RESUMO

Highly thermally conductive graphitic film (GF) materials have become a competitive solution for the thermal management of high-power electronic devices. However, their catastrophic structural failure under extreme alternating thermal/cold shock poses a significant challenge to reliability and safety. Here, we present the first investigation into the structural failure mechanism of GF during cyclic liquid nitrogen shocks (LNS), which reveals a bubbling process characterized by "permeation-diffusion-deformation" phenomenon. To overcome this long-standing structural weakness, a novel metal-nanoarmor strategy is proposed to construct a Cu-modified graphitic film (GF@Cu) with seamless heterointerface. This well-designed interface ensures superior structural stability for GF@Cu after hundreds of LNS cycles from 77 to 300 K. Moreover, GF@Cu maintains high thermal conductivity up to 1088 W m-1 K-1 with degradation of less than 5% even after 150 LNS cycles, superior to that of pure GF (50% degradation). Our work not only offers an opportunity to improve the robustness of graphitic films by the rational structural design but also facilitates the applications of thermally conductive carbon-based materials for future extreme thermal management in complex aerospace electronics.

13.
Plants (Basel) ; 12(20)2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37896005

RESUMO

Besides increasing grain yield, improving rice (Oryza sativa L.) quality has been paid more and more attention recently. Cooking and eating quality (CEQ) is an important indicator of rice quality. Since CEQs are quantitative traits and challenging for measurement, efforts have mainly focused on two major genes, Wx and SSIIa. Chalkiness and floury endosperm significantly affect the eating quality of rice, leading to noticeable changes in CEQ. Due to the easily observable phenotype of floury endosperm, cloning single gene mutations that cause floury endosperm and evaluating changes in CEQs indirectly facilitate the exploration of the minor genes controlling CEQ. In this study, eight mutants with different degrees of floury endosperm, generated through ethylmethane sulfonate (EMS) mutagenesis, were analyzed. These mutants exhibited wide variation in starch morphology and CEQs. Particularly, the z2 mutant showed spherical starch granules significantly increased rapid visco analyzer (RVA) indexes and urea swelling, while the z4 mutant displayed extremely sharp starch granules and significantly decreased RVA indexes and urea swelling compared to the wild type. Additionally, these mutants still maintained correlations with certain RVA profiles, suggesting that the genes PUL, which affect these indexes, may not undergo mutation. Cloning these mutated genes in the future, especially in z2 and z4, will enhance the genetic network of rice eating quality and hold significant importance for molecular marker-assisted breeding to improve rice quality.

14.
Opt Express ; 31(19): 30627-30638, 2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37710602

RESUMO

In this study, we theoretically and experimentally demonstrate that the convolutional neural network (CNN) in combination with the residual blocks and the regression methods can be used to precisely and quickly reconstruct the OAM spectrum of a hybrid OAM mode no matter how the consistent OAM modes have the same or different order indices in both the azimuthal and the radial direction. For cases of the simulation testing, the mean errors of all recognized parameters for hybrid OAM modes in a four-mode fiber (4MF) and a six-mode fiber (6MF) are smaller than 0.003 and 0.008, respectively. To the best of our knowledge, this is the first time that all the OAM modes, probably existing in the core of 4MFs or 6MFs, can be precisely and quickly recognized from intensity distribution of the hybrid OAM mode itself via the deep learning method.

15.
Front Med ; 17(5): 889-906, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37418076

RESUMO

Primary central nervous system lymphoma (PCNSL) is an uncommon non-Hodgkin's lymphoma with poor prognosis. This study aimed to depict the genetic landscape of Chinese PCNSLs. Whole-genome sequencing was performed on 68 newly diagnosed Chinese PCNSL samples, whose genomic characteristics and clinicopathologic features were also analyzed. Structural variations were identified in all patients with a mean of 349, which did not significantly influence prognosis. Copy loss occurred in all samples, while gains were detected in 77.9% of the samples. The high level of copy number variations was significantly associated with poor progression-free survival (PFS) and overall survival (OS). A total of 263 genes mutated in coding regions were identified, including 6 newly discovered genes (ROBO2, KMT2C, CXCR4, MYOM2, BCLAF1, and NRXN3) detected in ⩾ 10% of the cases. CD79B mutation was significantly associated with lower PFS, TMSB4X mutation and high expression of TMSB4X protein was associated with lower OS. A prognostic risk scoring system was also established for PCNSL, which included Karnofsky performance status and six mutated genes (BRD4, EBF1, BTG1, CCND3, STAG2, and TMSB4X). Collectively, this study comprehensively reveals the genomic landscape of newly diagnosed Chinese PCNSLs, thereby enriching the present understanding of the genetic mechanisms of PCNSL.


Assuntos
Neoplasias do Sistema Nervoso Central , Linfoma , Humanos , Variações do Número de Cópias de DNA , Proteínas Nucleares/genética , Neoplasias do Sistema Nervoso Central/genética , Neoplasias do Sistema Nervoso Central/patologia , Fatores de Transcrição/genética , Prognóstico , Linfoma/genética , Genômica , China , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/patologia , Proteínas que Contêm Bromodomínio , Proteínas de Ciclo Celular/genética
16.
Front Plant Sci ; 14: 1155531, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37123819

RESUMO

Water spinach (Ipomoea aquatica Forsk) is an essential green leafy vegetable in Asia. In this study, we induced autotetraploid water spinach by colchicine. Furthermore, DNA methylation and transcriptome of tetraploid and diploid were compared using Whole Genome Bisulfite Sequencing (WGBS) and RNA-sequencing techniques. Autotetraploid water spinach was created for the first time. Compared with the diploid parent, autotetraploid water spinach had wider leaves, thicker petioles and stems, thicker and shorter adventitious roots, longer stomas, and larger parenchyma cells. The whole genome methylation level of the autotetraploid was slightly higher than that of the diploid. Compared with the diploid, 12281 Differentially Methylated Regions (DMRs)were found in the autotetraploid, including 2356 hypermethylated and 1310 hypomethylated genes, mainly enriched in 'Arginine and Proline metabolism', 'beta - Alanine metabolism', 'Plant homone signal translation', 'Ribome', and 'Plant - pathgen interaction' pathways. Correlation analysis of transcriptome and DNA methylation data showed that 121 differentially expressed genes undergone differential methylation, related to four pathways 'Other types of O-glycan biosynthesis', 'Terpenoid backbone biosynthesis', 'Biosynthesis of secondary metabolites', and 'Metabolic paths'. This work obtained important autotetraploid resources of water spinach and revealed the genomic DNA methylation changes after genome doubling, being helpful for further studying the molecular mechanism of variations caused by polyploids of the Ipomoea genus.

17.
J Hazard Mater ; 454: 131468, 2023 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-37146338

RESUMO

Heavy metals (HMs), like vanadium (V), chromium (Cr), cadmium (Cd), and nickel (Ni) toxicity due to anthropogenic, impair plant growth and yield, which is a challenging issue for agricultural production. Melatonin (ME) is a stress mitigating molecule, which alleviates HM-induced phytotoxicity, but the possible underlying mechanism of ME functions under HMs' phytotoxicity is still unclear. Current study uncovered key mechanisms for ME-mediated HMs-stress tolerance in pepper. HMs toxicity greatly reduced growth by impeding leaf photosynthesis, root architecture system, and nutrient uptake. Conversely, ME supplementation markedly enhanced growth attributes, mineral nutrient uptake, photosynthetic efficiency, as measured by chlorophyll content, gas exchange elements, chlorophyll photosynthesis genes' upregulation, and reduced HMs accumulation. ME treatment showed a significant decline in the leaf/root V, Cr, Ni, and Cd concentration which was about 38.1/33.2%, 38.5/25.9%, 34.8/24.9%, and 26.6/25.1%, respectively, when compared with respective HM treatment. Furthermore, ME remarkably reduced the ROS (reactive oxygen species) accumulation, and reinstated the integrity of cellular membrane via activating antioxidant enzymes (SOD, superoxide dismutase; CAT, catalase; APX, ascorbate peroxidase; GR, glutathione reductase; POD, peroxidase; GST, glutathione S-transferase; DHAR, dehydroascorbate reductase; MDHAR, monodehydroascorbate reductase) and as well as regulating ascorbate-glutathione (AsA-GSH) cycle. Importantly, oxidative damage showed efficient alleviations through upregulating the genes related to key defense such as SOD, CAT, POD, GR, GST, APX, GPX, DHAR, and MDHAR; along with the genes related to ME biosynthesis. ME supplementation also enhanced the level of proline and secondary metabolites, and their encoding genes expression, which may control excessive H2O2 (hydrogen peroxide) production. Finally, ME supplementation enhanced the HM stress tolerance of pepper seedlings.


Assuntos
Melatonina , Metais Pesados , Melatonina/farmacologia , Cádmio/toxicidade , Cádmio/metabolismo , Peróxido de Hidrogênio/metabolismo , Antioxidantes/metabolismo , Estresse Oxidativo , Metais Pesados/toxicidade , Metais Pesados/metabolismo , Superóxido Dismutase/metabolismo , Cromo/metabolismo , Glutationa Redutase/metabolismo , Clorofila/metabolismo , Glutationa/metabolismo , Plântula/metabolismo
18.
Heliyon ; 9(3): e14362, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36967939

RESUMO

Gliomas are inherently difficult to treat by radiotherapy because glioma cells become radioresistant over time. However, combining radiotherapy with a radiosensitizer could be an effective strategy to mitigate the radioresistance of glioma cells. Gold nanoparticles (AuNPs) have emerged as a promising nanomaterial for cancer therapy, but little is known about whether AuNPs and X-ray radiation have cytotoxic synergistic effects against tumors. In this study, we found that the combination of AuNPs and X-ray irradiation significantly reduced the viabilities, as well as the migration and invasion, of glioma cells. Mechanistically, we observed that the AuNPs inhibited radiation-induced CCL2 expression by inhibiting the TRAF6/NF-κB pathway, which likely manifested the synergistic therapeutic effect between the AuNPs and X-ray radiation. The AuNPs also re-sensitized radioresistant glioma cells by inhibiting CCL2 expression. These results were also observed in another tumor cell line with a different molecular pattern, indicating that the underlying mechanism may be ubiquitous through cancer cells. Lastly, using the glioma mouse model, we observed that AuNPs significantly reduced tumor growth in the presence of X-ray radiation compared to radiotherapy alone.

19.
Phytomedicine ; 112: 154688, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36738478

RESUMO

BACKGROUND: Sophoridine (SR) has shown the potential to be an antiarrhythmic agent. However, SR's electrophysiological properties and druggability research are relatively inadequate, which limits the development of SR as an antiarrhythmic candidate. PURPOSE: To facilitate the development process of SR as an antiarrhythmic candidate, we performed integrated studies on the electrophysiological properties of SR in vitro and ex vivo to gain more comprehensive insights into the multi-ion channel blocking effects of SR, which provided the foundation for the further drugability studies in antiarrhythmic and safety studies. Firstly, SR's electrophysiological properties and antiarrhythmic potentials were recorded and assessed at the cell and tissue levels by comprehensively integrating the patch clamp with the Electrical and Optical Mapping systems. Subsequently, the antiarrhythmic effects of SR were validated by aconitine and ouabain-induced arrhythmia in vivo. Finally, the safety of SR as an antiarrhythmic candidate compound was evaluated based on the guidelines of the Comprehensive in Vitro Proarrhythmia Assay (CiPA). STUDY DESIGN: The antiarrhythmic effect of SR was evaluated at the in vitro, ex vivo, and in vivo levels. METHODS: Isolated primary cardiomyocytes and stable cell lines were prepared to explore the electrophysiologic properties of being a multiple ion-channel blocker in vitro by whole-cell patch clamp. Using electrical and optical mapping, the negative chronotropic effect of SR was determined in langendorff-perfused rat or guinea-pig hearts.The antiarrhythmic activity of SR was assessed by the ex vivo tachyarrhythmia models induced by left coronary artery ligation (LCAL) and isoproterenol (ISO). Canonical models of aconitine and ouabain-induced arrhythmia were used to verify the antiarrhythmic effects in vivo. Finally, the pro-arrhythmic risk of SR was detected in Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes (hSCCMs) using a Microelectrode array (MEA). RESULTS: Single-cell patch assay validated the multiple ion-channel blockers of SR in transient outward current potassium currents (Ito), l-type calcium currents (ICa-l), and rapid activation delayed rectifier potassium currents (IKr). SR ex vivo depressed heart rates (HR) and ventricular conduction velocity (CV) and prolonged Q-T intervals in a concentration-dependent manner. Consistent with the changes in HRs, SR extended the active time of hearts and increased the action potential duration measured at 90% repolarization (APD90). SR could also significantly lengthen the onset time and curtail the duration of spontaneous ventricular tachycardia (VT) in the ex vivo arrhythmic model induced by LCAL. Meanwhile, SR could also significantly upregulate the programmed electrical stimulation (PES) frequency after the ISO challenge in forming electrical alternans and re-entrant excitation. Furthermore, SR exerted antiarrhythmic effects in the tachyarrhythmia models induced by aconitine and ouabain in vivo. Notably, the pro-arrhythmic risk of SR was shallow for a moderate inhibition of the human ether-à-go-go-related gene (hERG) channel. Moreover, SR prolonged field potential duration (FPDc) of hSCCMs in a concentration-dependent manner without early after depolarization (EAD) and arrhythmia occurrence. CONCLUSION: Our results indicated that SR manifested as a multiple ion-channel blocker in the electrophysiological properties and exerts antiarrhythmic effects ex vivo and in vivo. Meanwhile, due to the low pro-arrhythmic risk in the hERG inhibition assay and the induction of EAD, SR has great potential as a leading candidate in the treatment of ventricular tachyarrhythmia.


Assuntos
Antiarrítmicos , Matrinas , Ratos , Humanos , Animais , Cobaias , Antiarrítmicos/efeitos adversos , Ouabaína/metabolismo , Ouabaína/farmacologia , Ouabaína/uso terapêutico , Aconitina/farmacologia , Arritmias Cardíacas/induzido quimicamente , Arritmias Cardíacas/tratamento farmacológico , Canais Iônicos/metabolismo , Canais Iônicos/farmacologia , Miócitos Cardíacos , Isoproterenol , Potássio/metabolismo , Potássio/farmacologia , Potássio/uso terapêutico , Potenciais de Ação/fisiologia
20.
Int J Oncol ; 62(3)2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36825592

RESUMO

Cardiac glycosides (CGs) are candidate anticancer agents that function by increasing [Ca2+]i to induce apoptotic cell death in several types of cancer cells. However, new findings have shown that the anti­cancer effects of CGs involve complex cell­signal transduction mechanisms. Hence, exploring the potential mechanisms of action of CGs may provide insight into their anti­cancer effects and thus aid in the selection of the appropriate CG. Periplocymarin (PPM), which is a cardiac glycoside, is an active ingredient extracted from Cortex periplocae. The role of PPM was evaluated in HepG2 cells and xenografted nude mice. Cell proliferation, real­time ATP rate assays, western blotting, cell apoptosis assays, short interfering RNA transfection, the patch clamp technique, electron microscopy, JC­1 staining, immunofluorescence staining and autophagic flux assays were performed to evaluate the function and regulatory mechanisms of PPM in vitro. The in vivo activity of the PPM was assessed using a mouse xenograft model. The present study demonstrated that PPM synchronously activated lethal apoptosis and protective autophagy in liver cancer, and the initiation of autophagy counteracted the inherent pro­apoptotic capacity and impaired the anti­cancer effects. Specifically, PPM exerted a pro­-apoptotic effect in HepG2 cells and activated macroautophagy by initiation of the AMPK/ULK1 and mTOR signaling pathways. Activation of macroautophagy counteracted the pro­apoptotic effects of PPM, but when it was combined with an autophagy inhibitor, the anti­cancer effects of PPM in mice bearing HepG2 xenografts were observed. Collectively, these results indicated that a self­limiting effect impaired the pro­apoptotic effects of PPM in liver cancer, but when combined with an autophagy inhibitor, it may serve as a novel therapeutic option for the management of liver cancer.


Assuntos
Glicosídeos Cardíacos , Neoplasias Hepáticas , Animais , Camundongos , Humanos , Camundongos Nus , Proteínas Quinases Ativadas por AMP/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , Glicosídeos Cardíacos/farmacologia , Autofagia , Apoptose , Linhagem Celular Tumoral , Proliferação de Células
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA