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1.
Article in English | MEDLINE | ID: mdl-39159016

ABSTRACT

Ensemble learning improves the capability of convolutional neural network (CNN)-based discriminators, whose performance is crucial to the quality of generated samples in generative adversarial network (GAN). However, this learning strategy results in a significant increase in the number of parameters along with computational overhead. Meanwhile, the suitable number of discriminators required to enhance GAN performance is still being investigated. To mitigate these issues, we propose an evidential discriminator for GAN (EviD-GAN)-code is available at https://github.com/Tohokantche/EviD-GAN-to learn both the model (epistemic) and data (aleatoric) uncertainties. Specifically, by analyzing three GAN models, the relation between the distribution of discriminator's output and the generator performance has been discovered yielding a general formulation of GAN framework. With the above analysis, the evidential discriminator learns the degree of aleatoric and epistemic uncertainties via imposing a higher order distribution constraint over the likelihood as expressed in the discriminator's output. This constraint can learn an ensemble of likelihood functions corresponding to an infinite set of discriminators. Thus, EviD-GAN aggregates knowledge through the ensemble learning of discriminator that allows the generator to benefit from an informative gradient flow at a negligible computational cost. Furthermore, inspired by the gradient direction in maximum mean discrepancy (MMD)-repulsive GAN, we design an asymmetric regularization scheme for EviD-GAN. Unlike MMD-repulsive GAN that performs at the distribution level, our regularization scheme is based on a pairwise loss function, performs at the sample level, and is characterized by an asymmetric behavior during the training of generator and discriminator. Experimental results show that the proposed evidential discriminator is cost-effective, consistently improves GAN in terms of Frechet inception distance (FID) and inception score (IS), and performs better than other competing models that use multiple discriminators.

2.
Fitoterapia ; 178: 106190, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39153556

ABSTRACT

Three new neo-5,10-seco-clerodane diterpenoids (1-3), four previously undescribed ethoxy/methoxy acetal analogues (4-7), one new etherified labdane diterpenoid (8), and seven known diterpenoids (9-15) were isolated from the whole plant of Schnabelia terniflora. Their structures were established on the basis of extensive spectroscopic analysis, single-crystal X-ray diffraction data, calculated electronic circular dichroism (ECD), and Mo2(OAc)4-induced circular dichroism. Compounds 2 and 3 represent the first examples of neo-5,10-seco-clerodane diterpenoids containing a 1H-pyrrole-2,5-dione and a pyrrolidine-2,5-dione moiety, respectively. A plausible biosynthetic pathway for 1-3 is proposed. All diterpenoids were evaluated for their cytotoxic activity against non-small-cell lung cancer lines (A549 and H460) and gastric cancer lines (HGC27 and AGS). Among them, 2 and 14 showed moderate cytotoxicity against four cell lines.


Subject(s)
Antineoplastic Agents, Phytogenic , Diterpenes, Clerodane , Humans , Diterpenes, Clerodane/isolation & purification , Diterpenes, Clerodane/pharmacology , Diterpenes, Clerodane/chemistry , Molecular Structure , Cell Line, Tumor , Antineoplastic Agents, Phytogenic/pharmacology , Antineoplastic Agents, Phytogenic/isolation & purification , Phytochemicals/pharmacology , Phytochemicals/isolation & purification , China
3.
J Chromatogr A ; 1730: 465105, 2024 Aug 16.
Article in English | MEDLINE | ID: mdl-38908999

ABSTRACT

Pseudobulbus Cremastrae seu Pleiones (PCsP), a traditional Chinese medicine known as ‶Shan-Ci-Gu″, possesses properties for clearing heat, counteracting toxicity, dissipating phlegm, and resolving masses. As a TCM with multiple bases, the dried pseudobulbs of Pleione bulbocodioides (PB), Pleione yunnanensis (PY) and Cremastra appendiculata (CA) are considered to be the official sources of PCsP. Additionally, several unofficial substitutes are also available in the market. To enhance the quality control of PCsP, an integrated strategy based on Q-marker was proposed. Initially, a study of integrating plant metabolomics, target isolation, structure identification, and activity testing afforded five Q-markers, including three new compounds. Furthermore, a quality evaluation method using a single standard to determine multi-components (SSDMC) based on Q-marker was established, which could effectively distinguish PB from CA and the counterfeit herbs. Finally, the transitivity of Q-markers was explored through a representative Chinese compound prescription containing PCsP. The results indicated that the identified Q-markers together with the established analysis methods could be effectively applied for quality control of PCsP and its preparations.


Subject(s)
Drugs, Chinese Herbal , Quality Control , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/analysis , Drugs, Chinese Herbal/standards , Chromatography, High Pressure Liquid/methods , Metabolomics/methods , Medicine, Chinese Traditional/standards , Cupressaceae/chemistry
4.
Org Lett ; 26(22): 4678-4683, 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38787784

ABSTRACT

The radical 1,4-functionalizations of 1,3-enynes have emerged as a powerful strategy for the synthesis of multisubstituted allenes. However, the phosphorus-centered radical-initiated transformations remain largely elusive. Herein, visible-light photoredox catalytic regioselective radical hydrophosphinylation of 1,3-enynes with diaryl phosphine oxides as phosphinoyl radical precursors has been realized. This protocol features mild conditions, a wide substrate scope, and good functional group tolerance, producing a diverse range of phosphinoyl-substituted allenes in moderate to good yields with high atom economy. Detailed mechanistic experiments revealed a radical-polar crossover process in the reaction.

5.
Phytochemistry ; 224: 114145, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38759829

ABSTRACT

Eleven previously undescribed abietane-type diterpenoids, named caryopincanoids A-K (1-11), together with five known compounds, were isolated from the EtOH extract of the aerial parts of Caryopteris incana (Thunb.) Miq. Their structures were elucidated on the basis of comprehensive spectroscopic data, NMR calculations, and ECD calculations. The inhibitory activities of all compounds against HIF-2α gene expression in 786-O cells were tested by luciferase assay. Compounds 7, 9, 15, and 16 showed significant inhibitory effects with IC50 values ranging from 12.73 to 23.80 µM. The preliminary structure-activity relationship of these compounds was also discussed.


Subject(s)
Abietanes , Basic Helix-Loop-Helix Transcription Factors , Abietanes/chemistry , Abietanes/pharmacology , Abietanes/isolation & purification , Structure-Activity Relationship , Humans , Basic Helix-Loop-Helix Transcription Factors/antagonists & inhibitors , Basic Helix-Loop-Helix Transcription Factors/metabolism , Molecular Structure , Plant Components, Aerial/chemistry , Dose-Response Relationship, Drug
6.
Aging (Albany NY) ; 16(9): 7774-7798, 2024 05 01.
Article in English | MEDLINE | ID: mdl-38696324

ABSTRACT

BACKGROUND: Dysregulation of the immune system and N6-methyladenosine (m6A) contribute to immune therapy resistance and cancer progression in urothelial carcinoma (UC). This study aims to identify immune-related molecules, that are m6A-modified, and that are associated with tumor progression, poor prognosis, and immunotherapy response. METHODS: We identified prognostic immune genes (PIGs) using Cox analysis and random survival forest variable hunting algorithm (RSF-VH) on immune genes retrieved from the Immunology Database and Analysis Portal database (ImmPort). The RM2Target database and MeRIP-seq analysis, combined with a hypergeometric test, assessed m6A methylation in these PIGs. We analyzed the correlation between the immune pattern and prognosis, as well as their association with clinical factors in multiple datasets. Moreover, we explored the interplay between immune patterns, tumor immune cell infiltration, and m6A regulators. RESULTS: 28 PIGs were identified, of which the 10 most significant were termed methylated prognostic immune genes (MPIGs). These MPIGs were used to create an immune pattern score. Kaplan-Meier and Cox analyses indicated this pattern as an independent risk factor for UC. We observed significant associations between the immune pattern, tumor progression, and immune cell infiltration. Differential expression analysis showed correlations with m6A regulators expression. This immune pattern proved effective in predicting immunotherapy response in UC in real-world settings. CONCLUSION: The study identified a m6A-modified immune pattern in UC, offering prognostic and therapeutic response predictions. This emphasizes that immune genes may influence tumor immune status and progression through m6A modifications.


Subject(s)
Adenosine , Immunotherapy , Humans , Adenosine/analogs & derivatives , Prognosis , Urinary Bladder Neoplasms/immunology , Urinary Bladder Neoplasms/genetics , Urinary Bladder Neoplasms/drug therapy , Urinary Bladder Neoplasms/mortality , Urinary Bladder Neoplasms/pathology , Urinary Bladder Neoplasms/therapy , Gene Expression Regulation, Neoplastic , Biomarkers, Tumor/genetics , Carcinoma, Transitional Cell/immunology , Carcinoma, Transitional Cell/genetics , Carcinoma, Transitional Cell/drug therapy , Carcinoma, Transitional Cell/mortality , Carcinoma, Transitional Cell/pathology , Carcinoma, Transitional Cell/therapy
7.
Org Lett ; 26(6): 1265-1270, 2024 Feb 16.
Article in English | MEDLINE | ID: mdl-38319734

ABSTRACT

The hydroarylation of alkenes has emerged as a powerful strategy for arene functionalization. However, aryl chlorides remain a large challenge in this type of reaction due to the chemical inertness of the C(sp2)-Cl bond and high negative reduction potential. Herein, we report an anti-Markovnikov radical hydroarylation of alkenes with aryl chlorides via visible-light photoredox catalysis. The key reactive aryl radicals can be efficiently achieved from aryl chlorides by consecutive photoinduced electron transfer. This transition-metal-free protocol features mild conditions, a wide substrate scope, and functional group tolerance, producing a diverse range of linear alkylarenes in moderate to good yields. The reaction is proposed to proceed through a radical-polar crossover pathway.

8.
Nat Prod Res ; : 1-10, 2023 Dec 06.
Article in English | MEDLINE | ID: mdl-38054801

ABSTRACT

Phytochemical analysis of the fruits of Cyclocodon lancifolius led to the isolation of two new phenylpropanoid-derived glycosides (1-2), two new geranyl glucosides (3-4), and nine known compounds (5-13). Their chemical structures were elucidated by extensive spectroscopic data. The absolute configuration of the sugar moiety was determined by hydrolysis and derivatization. All compounds were evaluated for their xanthine oxidase (XO) and α-glucosidase inhibitory activities, and four compounds showed weak inhibitory activity towards XO.

9.
Chin J Nat Med ; 21(12): 927-937, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38143106

ABSTRACT

Six new abietane diterpenoids (1-6) and five undescribed iridoids (7-11) have been isolated from the aerial parts of Caryopteris mongolica. The intricate structural characterization of these compounds was meticulously undertaken using an array of advanced spectroscopic techniques. This process was further enhanced by the application of DP4+ probability analyses and electronic circular dichroism (ECD) calculations. Following isolation and structural elucidation, the cytotoxicity of these compounds was evaluated. Among them, compound 3 stood out, displaying significant cytotoxic activity against HeLa cells with an IC50 value of 7.83 ± 1.28 µmol·L-1. Additionally, compounds 1, 2, 4, 9, and 10 manifested moderate cytotoxic effects on specific cell lines, with IC50 values ranging from 11.7 to 20.9 µmol·L-1.


Subject(s)
Diterpenes , Lamiaceae , Humans , Abietanes/chemistry , HeLa Cells , Lamiaceae/chemistry , Circular Dichroism , Diterpenes/chemistry , Molecular Structure
10.
Fitoterapia ; 170: 105631, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37536472

ABSTRACT

Five new polyacetylene derivatives (1-5), cyclocodonlandiynosides A-E, and eight known analogues (6-13) were isolated and identified from the fruits of Cyclocodon lancifolius. Their structures were established via spectroscopic and chemical methods, including NMR, HRESIMS, enzymatic hydrolysis, Mo2(OAc)4-induced circular dichroism and sugar derivatization. Compound 1 contains a nitrogenous fragment, which was rarely found in C14 polyacetylenes. Compounds 3 and 4 are polyacetylene glucosides possessing novel aglycones. All the isolated polyacetylenes (except 12) were screened for their xanthine oxidase (XO) inhibitory activity. All the tested compounds, at the concentration of 62.5 µg/mL, showed XO inhibiting effects. Among them, 13 and 3 showed the most potent XO inhibitory activity with IC50 values of 87.65 and 96.32 µM, compared to the positive control allopurinol with an IC50 value of 19.25 µM.


Subject(s)
Fruit , Xanthine Oxidase , Polyacetylene Polymer , Xanthine Oxidase/chemistry , Molecular Structure , Plant Extracts/chemistry , Polyynes/chemistry , Polyynes/pharmacology , Enzyme Inhibitors/pharmacology
11.
Molecules ; 28(11)2023 May 30.
Article in English | MEDLINE | ID: mdl-37298914

ABSTRACT

Traditional organic amines exhibit inferior desorption performance and high regeneration energy consumption. The implementation of solid acid catalysts presents an efficacious approach to mitigate regeneration energy consumption. Thus, investigating high-performance solid acid catalysts holds paramount importance for the advancement and implementation of carbon capture technology. This study synthesized two Lewis acid catalysts via an ultrasonic-assisted precipitation method. A comparative analysis of the catalytic desorption properties was conducted, encompassing these two Lewis acid catalysts and three precursor catalysts. The results demonstrated that the CeO2-γ-Al2O3 catalyst demonstrated superior catalytic desorption performance. Within the desorption temperature range of 90 to 110 °C, the average desorption rate of BZA-AEP catalyzed by the CeO2-γ-Al2O3 catalyst was 87 to 354% greater compared to the desorption rate in the absence of the catalyst, and the desorption temperature can be reduced by approximately 10 °C. A comprehensive analysis of the catalytic desorption mechanism of the CeO2-γ-Al2O3 catalyst was conducted, and indicated that the synergistic effect of CeO2-γ-Al2O3 conferred a potent catalytic influence throughout the entire desorption process, spanning from the rich solution to the lean solution.


Subject(s)
Aluminum Oxide , Cerium , Carbon Dioxide , Lewis Acids , Catalysis
12.
ACS Omega ; 8(16): 14830-14840, 2023 Apr 25.
Article in English | MEDLINE | ID: mdl-37125132

ABSTRACT

Nepetaefolin F (5), an abietane diterpenoid, showed significant inhibitory activity against human cancer cells in vitro with an IC50 value of 6.3 µM. The syntheses of nepetaefolin F and its analogues are presented herein. The cytotoxicity against various cancer cell lines was evaluated; notably, the cyclopropanecarboxylate ester 42 displayed significant antitumor activity against MGC 803 cells with an IC50 value of 20.9 µM. Further studies revealed that 42 could upregulate the expression of p62, microtubule-associated protein 1 light-chain 3 ß (LC3 B-I), cleaved caspase-3, and cleaved caspase-9 and downregulate the expression of Beclin-1 and LC3B-II. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that 42 could modulate multiple signaling pathways, especially for peroxisome proliferator-activated receptor (PPAR) and AMP-activated protein kinase (AMPK), which are closely related to autophagy. These results suggested that compound 42 is a promising lead by inhibiting cell proliferation and autophagy, as inducing cell apoptosis in MGC 803 cells.

13.
Molecules ; 28(6)2023 Mar 15.
Article in English | MEDLINE | ID: mdl-36985632

ABSTRACT

To find suitable absorbents for ship-based carbon capture, the absorption and desorption properties of four mixed aqueous amines based on BZA were investigated, and the results indicated that BZA-AEP had the best absorption and desorption performance. Then, the absorption and desorption properties of different mole ratios of BZA-AEP were tested. The results showed that the average CO2 absorption rate had the highest value at the mole ratio of BZA to AEP of three. The average CO2 desorption rate had the maximum value at the mole ratio of BZA to AEP of one. Three fitted models of the absorption and desorption performance of BZA-AEP based on the test data were obtained. The p-values of all three models were less than 0.0001. Considering the performance and material cost, the BZA-AEP mole ratio of 1.5 is more appropriate for ship carbon capture. Compared with MEA, the average CO2 absorption rate increased by 48%, the CO2 desorption capacity increased by 120%, and the average CO2 desorption rate increased by 161%.

14.
Nat Prod Res ; 37(7): 1074-1081, 2023 Apr.
Article in English | MEDLINE | ID: mdl-34618613

ABSTRACT

A phytochemical investigation on the petroleum ether partition of the whole plant of Pseudocaryopteris paniculata, yield seven new compounds: one phytanes diterpenoid (2Z,6E,10E) 14-keto-2,6,10-trimethyl pentadeca-2,6,10-trien-1-carboxylic acid (1), five clerodane diterpenoids: paniculatins A-E (2, 3a/3b, 4a/4b), one abietane diterpenoid: ent-uncinatone (5), together with 12 known compounds. Their structures were elucidated on the basis of 1D and 2D Nuclear Magnetic Resonance (NMR_, Infrared Radiation (IR), and mass spectroscopic data. Compound 2, 5, and 11 showed weak selective cytotoxic activity of 11 human cancer cell lines.


Subject(s)
Antineoplastic Agents, Phytogenic , Diterpenes, Clerodane , Diterpenes , Lamiaceae , Humans , Diterpenes/pharmacology , Diterpenes/chemistry , Mass Spectrometry , Molecular Structure , Cell Line, Tumor , Antineoplastic Agents, Phytogenic/pharmacology , Antineoplastic Agents, Phytogenic/chemistry
15.
Immunol Invest ; 51(5): 1222-1231, 2022 Jul.
Article in English | MEDLINE | ID: mdl-34325607

ABSTRACT

BACKGROUND: Autoimmune thyroid disease (AITD) is an inherited, complex gene- and immune-related disorder that mainly includes Graves' disease (GD) and Hashimoto's thyroiditis (HT). Psoriasis susceptibility 1 candidate 1 (PSORS1C1) is a susceptibility gene associated with many autoimmune diseases, but its role in an individual's predisposition to AITD is unknown. METHODS: This study included 1065 Chinese Han patients with AITD and 943 matched healthy individuals. The rs3130983, rs3778638, rs3815087, and rs4959053 single nucleotide polymorphisms (SNPs) in PSORS1C1 were determined using multiplex polymerase chain reaction technology. RESULTS: Of the four SNPs, only the distribution of the rs3778638 genotypes was different between the AITD (AA, 2.67%; AG, 19.15%; and GG, 78.18%) and control (AA, 1.52%; AG, 22.2%; and GG, 75.87%) groups (P = .046). An association between rs3778683 and GD was observed (p = .039) but not with HT. No linkage disequilibrium was observed for rs3130983, rs3815087, rs3778638, and rs4959053 in PSORS1C1 among the patients with AITD and controls. CONCLUSION: This study suggests the influence of PSORS1C1 rs3778638 on the susceptibility to GDs, supporting this locus as a common autoimmunity risk factor.


Subject(s)
Autoimmune Diseases , Graves Disease , Hashimoto Disease , Psoriasis , Autoimmune Diseases/genetics , Case-Control Studies , China , Genetic Predisposition to Disease , Graves Disease/genetics , Hashimoto Disease/genetics , Humans , Polymorphism, Single Nucleotide , Proteins/genetics , Psoriasis/genetics
16.
Aging (Albany NY) ; 13(5): 6957-6981, 2021 02 17.
Article in English | MEDLINE | ID: mdl-33621953

ABSTRACT

Bladder urothelial carcinoma (BLCA) is recognized to be immunogenic and tumorigenic. This study identified a novel long noncoding RNA (lncRNA) signature for predicting survival for patients with BLCA. A univariate Cox regression model and the random survival forest-variable hunting (RSF-VH) algorithm were employed to achieve variable selection. Ten lncRNAs (LOC105375787, CYTOR, URB1-AS1, C21orf91-OT1, CASC15, LOC101928433, FLJ45139, LINC00960, HOTAIR and TTTY19) with the highest prognostic values were identified to establish the prognostic model. The nomogram integrating the signature and clinical factors showed high concordance index values of 0.94, 0.7 and 0.90 in the three datasets, and the calibration curves showed concordance between the predicted and observed 3- and 5-year survival rates. The risk score based on the 10-lncRNA signature accurately distinguished high- and low-risk BLCA patients with different disease-specific survival(DSS) or overall survival(OS) outcomes, which were stratified according to clinical factors, including T stage and tumour grade. Gene set enrichment analysis identified BLCA-specific biological pathways and enriched functional categories, such as the cell cycle, DNA repair and immune system. Furthermore, the increased infiltration of immune cells in the high-risk group indicated that lncRNA-related inflammation may reduce the survival of BLCA patients.


Subject(s)
Carcinoma, Transitional Cell/genetics , Carcinoma, Transitional Cell/mortality , RNA, Long Noncoding , Urinary Bladder Neoplasms/genetics , Urinary Bladder Neoplasms/mortality , Carcinoma, Transitional Cell/pathology , Databases, Genetic , Female , Humans , Machine Learning , Male , Nomograms , Prognosis , Survival Rate , T-Lymphocytes/metabolism , Tumor Microenvironment/immunology , Urinary Bladder Neoplasms/pathology
17.
Mol Cell Biochem ; 476(1): 425-433, 2021 Jan.
Article in English | MEDLINE | ID: mdl-32997306

ABSTRACT

Skeletal muscle satellite cells (SMSCs), also known as a multipotential stem cell population, play a crucial role during muscle growth and regeneration. In recent years, numerous miRNAs have been associated with the proliferation and differentiation of SMSCs in a number of mammalian species; however, the regulatory mechanisms of miR-194-5p in rabbit SMSCs still remain scarce. In this study, miR-194-5p was first observed to be highly expressed in the rabbit leg muscle. Furthermore, both the mimics and inhibitor of miR-194-5p were used to explore its role in the proliferation and differentiation of rabbit SMSCs cultured in vitro. Results from both EdU and CCK8 assays showed that miR-194-5p inhibited the proliferation of SMSCs. Meanwhile, Mef2c was identified as a target gene of miR-194-5p based on the dual-luciferase reporter assay results. In addition, upregulation of miR-194-5p decreased the expression levels of Mef2c and MyoG during rabbit SMSCs differentiation on Days 3 and 7 of in vitro culture. Taken together, these data demonstrated that miR-194-5p negatively regulates the proliferation and differentiation of rabbit SMSCs by targeting Mef2c.


Subject(s)
Gene Expression Regulation , MicroRNAs/genetics , MicroRNAs/metabolism , Satellite Cells, Skeletal Muscle/metabolism , Animals , Cell Differentiation , Cell Proliferation , MEF2 Transcription Factors/metabolism , Muscle Development , Myogenin/metabolism , Rabbits , Signal Transduction
18.
J Nat Prod ; 83(7): 2093-2101, 2020 07 24.
Article in English | MEDLINE | ID: mdl-32659087

ABSTRACT

Seven new (1-7) and 11 known diterpenoids were isolated and identified from Caryopteris aureoglandulosa. These diterpenoids were structurally determined by HRESIMS and NMR spectroscopic analyses, single-crystal X-ray diffraction, and ECD data. Structurally, aureoglandulosin A (1) is a highly oxygenated abietane diterpenoid with an unprecedented 7/6/6/5-ring system. Aureoglandulosins B (2) and C (3) represent naturally occurring new diterpenoids with an unusual 6/6/6/5-ring system. Additionally, the configurations of two known abietane diterpenoids 11 and 12 were determined by X-ray crystallographic data analysis for the first time. A plausible biosynthetic pathway for compounds 1-3 is proposed. The cytotoxicity of all isolates was evaluated, and compounds 1 and 11 exhibited significant cytotoxic activity against some cell lines with IC50 values in the range 1.6-8.2 µM.


Subject(s)
Antineoplastic Agents, Phytogenic/isolation & purification , Diterpenes/isolation & purification , Lamiaceae/chemistry , Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Cell Line, Tumor , Crystallography, X-Ray , Diterpenes/chemistry , Diterpenes/pharmacology , Humans , Molecular Structure , Spectrum Analysis/methods
19.
Mol Med Rep ; 22(2): 783-791, 2020 08.
Article in English | MEDLINE | ID: mdl-32626987

ABSTRACT

The apoptosis of endothelial cells (ECs) induced by oxidized low­density lipoprotein (ox­LDL) is an important contributing factor in the pathogenesis of atherosclerosis. It has been reported that microRNA (miR)­106a­5p is overexpressed in atherosclerotic plaques and involved in angiogenesis. However, its role and underlying mechanisms in ox­LDL induced EC apoptosis remain to be fully understood. In the present study the expression of miR­106a­5p in human umbilical vein ECs (HUVECs) stimulated with ox­LDL was investigated using reverse transcription­quantitative PCR analysis. Cell viability and apoptosis were assessed by MTT assay and flow cytometry, respectively. Caspase­3 activity and reactive oxygen species (ROS) levels were determined by commercial kits. The interaction between miR­106a­5p and signal transducer and activator of transcription 3 (STAT3) mRNA was examined by luciferase reporter assay. It was found that ox­LDL treatment significantly increased the levels of miR­106a­5p in a dose­dependent manner in HUVECs. Moreover, these results demonstrated that ox­LDL treatment inhibited cell viability, promoted cell apoptosis, increased caspase­3 activity and ROS levels, whereas inhibition of miR­106a­5p reversed the effects of ox­LDL on HUVECs. In addition, it was shown that STAT3 is a direct target of miR­106a­5p in HUVECs, and silencing of STAT3 impaired the protective effects of miR­106a­5p inhibition on cell apoptosis and oxidative injury induced by ox­LDL. Collectively, these results indicated that miR­106a­5p participated in ox­LDL­stimulated apoptosis and oxidative injury in HUVECs by regulating STAT3. Thus, suggesting that miR­106a­5p/STAT3 may serve as a novel therapeutic target for atherosclerosis in the future.


Subject(s)
Human Umbilical Vein Endothelial Cells/metabolism , Lipoproteins, LDL/pharmacology , MicroRNAs/genetics , MicroRNAs/metabolism , STAT3 Transcription Factor/metabolism , Apoptosis/genetics , Atherosclerosis/genetics , Atherosclerosis/metabolism , Caspase 3/metabolism , Cell Survival/genetics , Cells, Cultured , Down-Regulation , Gene Knockdown Techniques , Human Umbilical Vein Endothelial Cells/cytology , Humans , MicroRNAs/drug effects , Oxidative Stress/drug effects , RNA, Small Interfering , Reactive Oxygen Species/metabolism
20.
IEEE Trans Pattern Anal Mach Intell ; 41(12): 2947-2960, 2019 12.
Article in English | MEDLINE | ID: mdl-30273144

ABSTRACT

Unsupervised learning with generative adversarial networks (GANs) has proven to be hugely successful. Regular GANs hypothesize the discriminator as a classifier with the sigmoid cross entropy loss function. However, we found that this loss function may lead to the vanishing gradients problem during the learning process. To overcome such a problem, we propose in this paper the Least Squares Generative Adversarial Networks (LSGANs) which adopt the least squares loss for both the discriminator and the generator. We show that minimizing the objective function of LSGAN yields minimizing the Pearson χ2 divergence. We also show that the derived objective function that yields minimizing the Pearson χ2 divergence performs better than the classical one of using least squares for classification. There are two benefits of LSGANs over regular GANs. First, LSGANs are able to generate higher quality images than regular GANs. Second, LSGANs perform more stably during the learning process. For evaluating the image quality, we conduct both qualitative and quantitative experiments, and the experimental results show that LSGANs can generate higher quality images than regular GANs. Furthermore, we evaluate the stability of LSGANs in two groups. One is to compare between LSGANs and regular GANs without gradient penalty. We conduct three experiments, including Gaussian mixture distribution, difficult architectures, and a newly proposed method - datasets with small variability, to illustrate the stability of LSGANs. The other one is to compare between LSGANs with gradient penalty (LSGANs-GP) and WGANs with gradient penalty (WGANs-GP). The experimental results show that LSGANs-GP succeed in training for all the difficult architectures used in WGANs-GP, including 101-layer ResNet.

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