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1.
Artigo em Inglês | MEDLINE | ID: mdl-38814574

RESUMO

Phosphorylation, the most extensive and pleiotropic form of protein post-translation modification, is central to cellular signal transduction. Throughout the extensive co-evolution of plant hosts and viruses, modifications to phosphorylation have served multiple purposes. Such modifications highlight the evolutionary trajectories of viruses and their hosts, with pivotal roles in regulation and refinement of host-virus interactions. In plant hosts, protein phosphorylation orchestrates immune responses, enhancing the activities of defense-related proteins such as kinases and transcription factors, thereby strengthening pathogen resistance in plants. Moreover, phosphorylation influences the interactions between host and viral proteins, altering viral spread and replication within host plants. In the context of plant viruses, protein phosphorylation controls key aspects of the infection cycle, including viral protein functionality and the interplay between viruses and host plant cells, leading to effects on viral accumulation and dissemination within plant tissues. Explorations of the nuances of protein phosphorylation in plant hosts and their interactions with viruses are particularly important. This review provides a systematic summary of the biological roles of the proteins of plant viruses carrying diverse genomes in regulating infection and host responses through changes in the phosphorylation status.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38600616

RESUMO

Some synthetic dyes are fraudulently added into spices to appeal visually to consumers. Food regulations in several countries, including the United States, Australia, Japan and the European Union, strictly prohibit the use of unauthorised synthetic dyes in food. Nevertheless, illegal practices persist, where spices contaminated with potentially carcinogenic dyes have been documented, posing potential health risks to consumers. In the present study, 14 synthetic dyes were investigated through liquid chromatography/tandem mass spectrometry in 252 commercially available spices in the Singapore market. In 18 out of these (7.1%) at least 1 illegal dye was detected at concentrations ranging from 0.010 to 114 mg/kg. Besides potential health risks, presence of these adulterants also reflects the economic motivations behind their fraudulent use. Findings in the present study further emphasise the need for increased public awareness, stricter enforcement, and continuous monitoring of illegal synthetic dyes in spices to ensure Singapore's food safety.

3.
Foods ; 13(4)2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38397488

RESUMO

A total diet study is often used to evaluate a population's baseline dietary exposure to chemical hazards from across the diet. In 2021-2023, Singapore carried out a TDS, and this article presents an overview of the study design and methodological selections in Singapore's TDS, as well as its relevance to ensuring food safety. A food consumption survey was conducted on Singapore citizens and permanent residents, where food consumption patterns of the Singapore population were identified. The selection of chemical hazards and foods for inclusion in Singapore's TDS, as well as principal considerations on sampling, food preparation, and analytical testing are discussed. Commonly consumed foods by the Singapore population in food categories such as grain and grain-based products, meat and meat products, fish and seafood, vegetables, fruits, milk and dairy products were included in this study, and mean concentrations of chemicals tested in each food category were reported, with food categories possessing higher levels identified. Future work will include dietary exposure assessments for the population and analysis of the contributions by food and cooking method.

4.
JDS Commun ; 5(1): 7-12, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38223384

RESUMO

Nisin, a bacteriocin produced through fermentation using bacterium Lactococcus lactis, has several commercial variants such as nisin A and nisin Z. Nisin serves as a natural preservative with antimicrobial properties in various food products, including dairy and beverages, for extending product shelf life. The efficacy and safety of nisin A as a bacteriocin has been well characterized. However, there is limited evidence regarding the efficacy, stability, and safety of nisin Z as a food preservative, as it has not undergone comprehensive regulatory reviews. In this work, we studied the stability of nisin A and Z in a selection of yogurt drinks and found nisin to be unstable, particularly in fruit-flavored yogurt drinks. Both nisin A and Z could experience significant degradation leading to the nisin parent ion peaks dropping below detectable level before the product's expiry date. Compared with nisin A, the formation of oxidized metabolite nisin Z+O appeared to be the predominant reaction for nisin Z. These findings highlight the need for further scientific research to understand the behavior of nisin Z under different application conditions, which is crucial for assessing the efficacy and safety of nisin Z under these conditions. One potential application of this knowledge is to optimize the formulation of yogurt-based drinks to stabilize nisin Z and sustain its biopreservative function throughout the product's shelf life. Additionally, the current study shows that for the testing of the presence of nisin A or nisin Z, it is imperative to cover both the parent and the main degradant(s) of nisin. This is especially true for nisin Z, for which the regulatory approval status may vary in different markets. As such, the confirmative identification of nisin Z and its key metabolites in commercial products would be essential.

5.
Artigo em Inglês | MEDLINE | ID: mdl-38295297

RESUMO

In this study, an advanced ultra-high performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method was developed for quantifying ethoxyquin (EQ). The approach employed a distinctive antioxidant added extraction step designed to prevent ethoxyquin decomposition and maintain analytical precision. This method effectively determines residue levels of EQ in eggs, processed egg products, poultry muscle, salmon, and liquid milk. The method was shown to have a limit of quantitation (LOQ) for eggs, milk, salmon, and chicken muscle of 1.5 µg/kg, 1.9 µg/kg, 2.1 µg/kg, and 1.2 µg/kg, respectively. The recoveries of EQ ranged from 79.2% to 107.6%, with a relative standard deviation (RSD) below 8.4%. A surveillance study for the presence of EQ in different types of eggs and poultry muscle available in Singapore was conducted and a total of 140 samples were tested. EQ residues in all samples were found to be below the U.S. Food and Drug Administration (FDA) MRLs of 500 µg/kg. Some samples of salted and preserved eggs from China were detected with higher concentration of EQ.


Assuntos
Etoxiquina , Espectrometria de Massas em Tandem , Animais , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Etoxiquina/análise , Cromatografia Líquida/métodos , Aves Domésticas , Singapura , Salmão
6.
Heliyon ; 9(11): e21160, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37928012

RESUMO

Non-judicious and indiscriminate use of veterinary drugs in animal husbandry may result in accumulation of residues in animal tissues, and consequently in food for human consumption. The abuse of veterinary drugs presents a potential risk to consumer health, especially if the residue level is higher than the health-based guidance value (HBGV) such as the acceptable daily intake (ADI). Contamination of drug residues in food also promotes the emergence of antimicrobial resistance (AMR) which poses a serious threat to public health globally. There has been limited information on the occurrence and dietary exposure to veterinary drug residues in Singapore to date. In this study, the occurrence of four classes of veterinary drugs, namely beta-agonists, coccidiostats, fluoroquinolones and macrolides, were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in food widely consumed by Singapore residents. The magnitude of dietary exposure was assessed based on the consumption profile of Singapore population. Out of 216 food samples, 9.72 % were detected positive with veterinary drug residues, where majority of the positive samples were poultry and its derived products, followed by eggs and egg products. 7 veterinary drugs, specifically ciprofloxacin, enrofloxacin, clopidol, diclazuril, lasalocid, nicarbazin and tilmicosin, were detected in the samples, with clopidol and enrofloxacin being the most frequently detected drugs. Dietary exposure was evaluated using the estimated daily intake (EDI) of the detected drugs and benchmarked against the corresponding acceptable daily intake (ADI). All the %ADI values were far less than 100 in both the average and high consumer scenarios, indicating that the health risk associated with dietary exposure to these drugs in Singapore is low.

7.
Exp Biol Med (Maywood) ; 248(18): 1556-1565, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37750221

RESUMO

Abnormal mitochondrial functions are a major pathophysiological basis of diabetic cardiomyopathy. 5' AMP-activated protein kinase (AMPK) is involved in mitochondrial dynamics. As an activator of AMPK, this study examined the effect of metformin on cardiomyocytes treated with high glucose. Primary cardiomyocytes isolated from neonatal rat ventricles were exposed to a high glucose concentration (33 mM) to establish a model of high-glucose injury with or without metformin (2 mM) treatment. AMPK activity was inhibited or activated by CC (20 µM) or AICAR (50 µM). CCK-8 and TUNEL assays were used to assess cell viability and apoptosis, respectively. A JC-1 assay was used to measure the mitochondrial membrane potential, and MitoSOX™ staining was used to examine mitoROS. Mito-Tracker Green-stained mitochondria were visualized by confocal microscopy to assess mitochondrial fission. Furthermore, we measured the expression levels of AMPK-mediated mitochondrial dynein and apoptotic proteins by western blotting. Our results showed that AMPK activity was significantly decreased in cardiomyocytes under the high-glucose condition, which was accompanied by increased mitochondrial fragmentation and aggravated mitochondrial dysfunction. The mitochondrial membrane potential was decreased and oxidative stress was increased, leading to apoptosis. Activation of AMPK by either metformin or AICAR reversed myocardial mitochondrial dysfunction and inhibited apoptosis under high glucose. Furthermore, inhibition of AMPK activity abrogated the protective effect of metformin against high glucose-induced mitochondrial dysfunction and apoptosis in cardiomyocytes. Our study demonstrates that metformin protects cardiomyocytes from high glucose-induced mitochondrial fragmentation and apoptosis by activating AMPK.


Assuntos
Metformina , Doenças Mitocondriais , Animais , Ratos , Proteínas Quinases Ativadas por AMP/metabolismo , Apoptose , Glucose/metabolismo , Glucose/toxicidade , Metformina/farmacologia , Doenças Mitocondriais/metabolismo , Miócitos Cardíacos/metabolismo
8.
J Agric Food Chem ; 71(37): 13654-13661, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37681756

RESUMO

Artificial grow lights, such as light-emitting diodes (LEDs) and fluorescent grow lights, are commonly used in modern day indoor farming, citing advantages in energy efficiency and a higher controlled environment. However, the use of LEDs poses a risk in mercury contaminations as a result of its production process, specifically LEDs with polyurethane encapsulates that were traditionally produced using mercury resins as a catalyst. A total of 10.0 ppm of mercury was detected in a curly kale sample harvested from an indoor hydroponic vegetable farm, exceeding Singapore Food Regulation's limit of 0.05 ppm. Vegetables, farming inputs, and surface swabs from the affected farm were analyzed using wet acid digestion followed by cold vapor atomic absorption spectroscopy analysis. The investigation found high concentrations of mercury in the LED encapsulant, and the encapsulant material was identified to be polyurethane by Fourier transform infrared spectroscopy and pyrolysis-gas chromatography-mass spectrometry analysis, indicating the source of mercury contamination to be the LED polyurethane encapsulant.


Assuntos
Mercúrio , Verduras , Fazendas , Iluminação , Poliuretanos , Agricultura , Inocuidade dos Alimentos
9.
Foods ; 12(16)2023 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-37628020

RESUMO

This study investigated the influence of 'snackification' in Singaporean diets, leading to increased dietary acrylamide exposure. Acrylamide concentrations in commonly consumed foods within and outside the main meals were measured using liquid chromatography with tandem mass spectrometry (LC-MS/MS). High acrylamide concentrations were detected in vegetables cooked at high temperatures (ranging from 0.5 to 478.4 µg/kg) and potato-based crackers and chips (ranging from 81.8 to 2095.8 µg/kg). The estimated total dietary exposure for the Singapore population was 0.165 µg/kg bw/day for general consumers and 0.392 µg/kg bw/day for high consumers (95th percentile). The acrylamide exposure from outside main meals was nearly equivalent to that from within the main meals. The calculated margins of exposure (MOE) were below 10,000, indicating potential human health concern. These findings highlight the need for industry practices and consumer advisories to reduce acrylamide exposure from foods consumed both within and outside main meals.

10.
Foods ; 12(15)2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37569240

RESUMO

Accurate methods for meat speciation and quantification are essential for ensuring the supply of safe and wholesome meat and composite products with animal origins to negate the potential associated hazards, aid classification of consignments at the import control system, and thwart food fraud committed for financial gain. To better enhance meat safety control and combat food fraud, this study developed two duplex real-time polymerase chain reaction (real-time PCR) systems specifically designed for chicken, pork, sheep, and beef, using single-copy, chromosomally encoded, species-specific gene sequences to accurately measure the content of each meat type in meat products. DNA extracted from the raw and boiled reference materials prepared in varying proportions (ranging from 1% to 75%) were used in the development of the duplex assay to derive calibration factors to determine the meat content in different meat products. The method was further validated using proficiency test samples and market monitoring samples. Our findings showed that this method exhibits high specificity and sensitivity, with a significant accuracy range of 0.14% to 24.07% in quantifying the four meat types in both raw and processed meat products. Validation results further confirmed the effectiveness of our method in accurately quantifying meat content. Thus, we have demonstrated the duplex qPCR assays as promising approaches for implementation in routine analysis to strengthen meat safety control systems and combat meat fraud, thereby safeguarding consumer health and trust in the meat industry.

11.
Microorganisms ; 11(4)2023 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-37110268

RESUMO

Rapid and robust detection assays for Salmonella Enteritidis (SE) in shell eggs are essential to enable a quick testing turnaround time (TAT) at the earliest checkpoint and to ensure effective food safety control. Real-time polymerase chain reaction (qPCR) assays provide a workaround for the protracted lead times associated with conventional Salmonella diagnostic testing. However, DNA-based analysis cannot reliably discriminate between signals from viable and dead bacteria. We developed a strategy based on an SE qPCR assay that can be integrated into system testing to accelerate the detection of viable SE in egg-enriched cultures and verify the yielded SE isolates. The specificity of the assay was evaluated against 89 Salmonella strains, and SE was accurately identified in every instance. To define the indicator for a viable bacteria readout, viable or heat-inactivated SE were spiked into shell egg contents to generate post-enriched, artificially contaminated cultures to establish the quantification cycle (Cq) for viable SE. Our study has demonstrated that this technique could potentially be applied to accurately identify viable SE during the screening stage of naturally contaminated shell eggs following enrichment to provide an early alert, and that it consistently identified the serotypes of SE isolates in a shorter time than conventional testing.

12.
Foods ; 12(23)2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38231853

RESUMO

This study investigated the prevalence and occurrence of 3-monochloropropanediol esters (3-MCPDEs) and glycidyl esters (GEs) in domestically and commercially prepared food in Singapore and assessed the total dietary exposure for the Singaporean population. Minimal impact on the formation of 3-MCPDEs and GEs was observed from the domestic cooking methods commonly practiced in Singapore such as deep frying and stir frying. The estimated total dietary exposure to 3-MCPDEs for the Singaporean population (aged 15 to 92) was 0.982 µg/kg bw/day for general consumers and 2.212 µg/kg bw/day for high consumers (95th percentile), which accounted for 49.1% and 110.6% of the tolerable dietary intake (TDI) at 2 µg/kg bw/day by the European Food Safety Authority (EFSA). The calculated margins of exposure (MOE) for GEs based on the dietary exposure for general consumers at 0.882 µg/kg bw/day and 2.209 µg/kg bw/day for high consumers were below 10,000, indicating a potential health concern. Our study showed that the occurrence of 3-MCPDEs and GEs varied among vegetable oils, and domestic cooking methods did not significantly impact the levels of 3-MCPDEs and GEs in prepared food. The critical factor influencing the prevalence and occurrence of 3-MCPDEs and GEs was the choice of oil used for cooking, which absorbed into the cooked food. It is essential to encourage the food industry to continue its innovation on mitigation measures to control and reduce 3-MCPDEs and GEs in vegetable oil production. Consumers are advised to make informed choices on food consumption and cooking oil for food preparation to reduce their exposure to 3-MCPDEs and GEs.

13.
Exp Cell Res ; 408(1): 112856, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34597680

RESUMO

Renal interstitial fibrosis (RIF) is the common irreversible pathway by which chronic kidney disease (CKD) progresses to the end stage. The transforming growth factor-ß (TGF-ß)/signal transducer and activator of transcription 3 (STAT3) signaling pathway is a common factor leading to inflammation-mediated RIF, but its downstream regulatory mechanism is still unclear. Bioinformatics analysis predicted that serum amyloid A protein 1 (SAA1) was one of the target genes for transcriptional activation of STAT3 signaling. As an acute phase reaction protein, SAA1 plays an important role in many inflammatory reactions, and research has suggested that SAA1 is significantly elevated in the serum of patients with CKD. In this research, multiple experiments were performed to investigate the role of SAA1 in the process of RIF. SAA1 was abnormally highly expressed in kidney tissue from individuals who underwent unilateral ureteral obstruction (UUO) and TGF-ß-induced HK2 cells, and the abnormal expression was directly related to the transcriptional activation of STAT3. Additionally, SAA1 can directly target and bind valosin-containing protein (VCP)-interacting membrane selenoprotein (VIMP) to inhibit the function of the Derlin-1/VCP/VIMP complex, preventing the transportation and degradation of the misfolded protein, resulting in endoplasmic reticulum (ER) stress characterized by an increase in glucose-regulated protein 78 (GRP78) levels and ultimately promoting the occurrence and development of RIF.


Assuntos
Estresse do Retículo Endoplasmático/fisiologia , Fibrose/metabolismo , Fator de Transcrição STAT3/metabolismo , Proteína Amiloide A Sérica/metabolismo , Animais , Chaperona BiP do Retículo Endoplasmático , Fibrose/patologia , Humanos , Inflamação/metabolismo , Camundongos , Insuficiência Renal Crônica/metabolismo , Transdução de Sinais/fisiologia , Obstrução Ureteral/metabolismo
14.
J Agric Food Chem ; 69(44): 13200-13216, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34709825

RESUMO

Nontarget data acquisition for target analysis (nDATA) workflows using liquid chromatography-high-resolution accurate mass (LC-HRAM) spectrometry, spectral screening software, and a compound database have generated interest because of their potential for screening of pesticides in foods. However, these procedures and particularly the instrument processing software need to be thoroughly evaluated before implementation in routine analysis. In this work, 25 laboratories participated in a collaborative study to evaluate an nDATA workflow on high moisture produce (apple, banana, broccoli, carrot, grape, lettuce, orange, potato, strawberry, and tomato). Samples were extracted in each laboratory by quick, easy, cheap, effective, rugged, and safe (QuEChERS), and data were acquired by ultrahigh-performance liquid chromatography (UHPLC) coupled to a high-resolution quadrupole Orbitrap (QOrbitrap) or quadrupole time-of-flight (QTOF) mass spectrometer operating in full-scan mass spectrometry (MS) data-independent tandem mass spectrometry (LC-FS MS/DIA MS/MS) acquisition mode. The nDATA workflow was evaluated using a restricted compound database with 51 pesticides and vendor processing software. Pesticide identifications were determined by retention time (tR, ±0.5 min relative to the reference retention times used in the compound database) and mass errors (δM) of the precursor (RTP, δM ≤ ±5 ppm) and product ions (RTPI, δM ≤ ±10 ppm). The elution profiles of all 51 pesticides were within ±0.5 min among 24 of the participating laboratories. Successful screening was determined by false positive and false negative rates of <5% in unfortified (pesticide-free) and fortified (10 and 100 µg/kg) produce matrices. Pesticide responses were dependent on the pesticide, matrix, and instrument. The false negative rates were 0.7 and 0.1% at 10 and 100 µg/kg, respectively, and the false positive rate was 1.1% from results of the participating LC-HRAM platforms. Further evaluation was achieved by providing produce samples spiked with pesticides at concentrations blinded to the laboratories. Twenty-two of the 25 laboratories were successful in identifying all fortified pesticides (0-7 pesticides ranging from 5 to 50 µg/kg) for each produce sample (99.7% detection rate). These studies provide convincing evidence that the nDATA comprehensive approach broadens the screening capabilities of pesticide analyses and provide a platform with the potential to be easily extended to a larger number of other chemical residues and contaminants in foods.


Assuntos
Resíduos de Praguicidas , Praguicidas , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Contaminação de Alimentos/análise , Frutas/química , Resíduos de Praguicidas/análise , Praguicidas/análise , Espectrometria de Massas em Tandem , Verduras , Fluxo de Trabalho
15.
Curr Opin Virol ; 47: 38-44, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33530035

RESUMO

Much is known about the molecular interactions between positive-strand RNA viruses and dicotyledon plants. However, many important viral pathogens of the monocotyledon rice crop contain negative-strand or double-strand RNA genomes. Recent studies have shown that virus-derived small-interfering RNAs (siRNAs), host microRNAs and phytohormones regulate antiviral responses in rice plants and that rice-infecting RNA viruses encode a diverse repertoire of multifunctional proteins with counter-defensive activities. Moreover, the interactions between viral virulence proteins and host susceptibility factors also shape the virus-rice arms race. This review will focus on these recent advances and discuss strategies and challenges in the translation of discoveries made on molecular virus-rice interactions into practical virus control measures.


Assuntos
Oryza/virologia , Vírus de RNA/fisiologia , Resistência à Doença , Interações Hospedeiro-Patógeno , MicroRNAs/genética , MicroRNAs/metabolismo , Reguladores de Crescimento de Plantas/genética , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Vírus de RNA/patogenicidade , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
16.
Luminescence ; 36(4): 914-922, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33458929

RESUMO

A series of SrMg2 (PO4 )2 :Eu2+ -Eu3+ ,Dy3+ phosphors was synthesized successfully using a high-temperature solid-state method in an air atmosphere. The structures were studied in detail using X-ray diffraction (XRD) and the luminescence properties of the samples. SrMg2 (PO4 )2 :Eu2+ -Eu3+ samples can emit adjustable blue-violet light by controlling the proportion of dopant concentration of europium and dysprosium under 340 nm excitation. Dy3+ exhibits typical blue and yellow emission under 350 nm excitation. The energy transferred from Eu3+ to Dy3+ in Dy and Eu co-doped system was determined by comparing the fluorescence spectra of single-doped system. In addition, the colour coordinates of the International Commission on lighting (CIE) indicated that SrMg2 (PO4 )2 :Eu2+ -Eu3+ ,Dy3+ could be considered as a potential blue-purple phosphor for white light-emitting diode applications.


Assuntos
Disprósio , Luminescência , Európio , Luz , Difração de Raios X
17.
Clin Exp Rheumatol ; 39(1): 44-51, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32242809

RESUMO

OBJECTIVES: We sought to analyse the expression characteristics of cytochrome C oxidase subunit I in mitochondrial of MRL/lpr lupus mice. METHODS: The whole blood of MRL/lpr lupus mice was detected for whole mitochondrial genome sequencing performed by Illumina HiSeq PE150 instrument, compared with house mouse (NC_005089.1) and screened for the maximum difference gene, MT-CO1. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were used to detect the mRNA and protein expression of MT-CO1 in lupus mice and control mice. The total antioxidant capacities of lupus mice and control mice were measured using the rapid 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) method. RESULTS: The mitochondrial genome sequencing showed that five mitochondrial genes had base differences and MT-CO1 was the maximum difference gene, 31 in total. Among the 31 base difference sites, 2 were missense mutations and 29 were synonymous_variant. qRT-PCR test results showed that the MT-CO1 expression in lupus mouse blood was statistically lower than that in control mice blood (t=4.333; p=0.0003). Western blot test results revealed that the expression of MT-CO1 was lower in the lupus mice compared with the control mice at the protein level. Serum total antioxidant capacity testing showed that: the serum total antioxidant capacity of lupus mice was statistically lower than that of the control mice (t=9.957; p<0.0001). CONCLUSIONS: High mutation rate and decreased expression of MT-CO1 in MRL/lpr lupus mice accompanied the decrease of antioxidant capacity, which indicated that abnormal MT-CO1 might be involved in the pathogenesis of SLE and the production of anti-dsDNA antibodies.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons , Lúpus Eritematoso Sistêmico , Animais , Western Blotting , Complexo IV da Cadeia de Transporte de Elétrons/genética , Lúpus Eritematoso Sistêmico/genética , Camundongos , Camundongos Endogâmicos MRL lpr , RNA Mensageiro/genética
18.
FASEB J ; 35(2): e21170, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33184968

RESUMO

Secretory phospholipase A2 group IB (sPLA2-IB) and M-type phospholipase A2 receptor (PLA2R) are closely associated with proteinuria in idiopathic membranous nephropathy (IMN). Podocytes constitute an important component of glomerular filtration, and high basal autophagy is indispensable for podocyte function. The current study aimed to analyze the relationship between sPLA2-IB and podocyte autophagy in IMN and determine whether sPLA2-IB mediates abnormal autophagy regulation in podocytes. The serum sPLA2-IB level and podocyte autophagy were detected, and clinical data were collected from IMN patients with different proteinuria levels. Then, the effects of sPLA2-IB on autophagy signaling pathways were evaluated in cultured human podocytes treated with sPLA2-IB, rapamycin, p38 inhibition, and PLA2R-siRNA in vitro. We found that IMN patients with nephrotic-range proteinuria have a significantly higher level of sPLA2-IB and fewer autophagosomes than those with non-nephrotic-range proteinuria. In vitro sPLA2-IB-induced insufficient autophagy in podocytes and promoted podocyte injury via activation of the mTOR/ULK1ser757 signaling pathway. Moreover, inhibition of p38 MAPK evidently abrogated sPLA2-IB-induced autophagy and the activation of mTOR/ULK1ser757 . Additionally, PLA2R silencing demonstrated that sPLA2-IB-induced abnormal autophagy was also PLA2R-dependent. In conclusion, the results revealed that sPLA2-IB downregulated autophagy and contributed to podocyte injury via PLA2R though activation of the p38MAPK/mTOR/ULK1ser757 signaling pathway.


Assuntos
Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Autofagia/genética , Glomerulonefrite Membranosa/sangue , Fosfolipases A2 do Grupo IB/sangue , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Sistema de Sinalização das MAP Quinases/genética , Podócitos/metabolismo , Receptores da Fosfolipase A2/sangue , Serina-Treonina Quinases TOR/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Adulto , Idoso , Adesão Celular/genética , Movimento Celular/genética , Células Cultivadas , Feminino , Glomerulonefrite Membranosa/genética , Glomerulonefrite Membranosa/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Proteinúria/sangue , Receptores da Fosfolipase A2/genética , Transfecção
19.
Curr Med Sci ; 40(4): 683-690, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32862379

RESUMO

Recent studies suggested that serum secretory phospholipase A2 group IB (sPLA2-IB) was increased in idiopathic membranous nephropathy (IMN). However, the interference of high lipemia on the sPLA2-IB levels was not taken into account in these studies. The present study aimed to investigate the correlation between sPLA2-IB and lipemia, and the clinical merit of sPLA2-IB in the prediction of prognosis of IMN patients. A total of 64 IMN patients, 39 immunoglobulin A nephropathy (IgAN) patients and 64 healthy controls were included in the study. The levels of serum sPLA2-IB, lipemia and proteinuria were measured. Fifty IMN patients were followed up for 6 months. Pathologic stages were made for all IgAN and IMN patients. The results showed that the levels of serum sPLA2-IB, cholesterol and low-density lipoprotein cholesterol (LDL-C) were significantly higher, and the levels of albumin and high-density lipoprotein cholesterol (HDL-C) were significantly lower in IMN patients than in healthy controls and IgAN patients. Serum sPLA2-IB levels were also found to be higher in IgAN patients than in heathy controls, but the association of serum sPLA2-IB levels with proteinuria, cholesterol and albumin was only shown in IMN patients. Antibody against M-type receptor for secretory phospholipase A2 (PLA2R1) was positive in 81.3% IMN patients. Glomerular sPLA2-IB deposition, podocyte fused processes, and density deposition on thickened basement membrane were seen in IMN patients, but not in IgAN patients. IMN patients with lower sPLA2-IB and proteinuria levels were found to have better outcome after the 6-month follow-up. In IMN patients, sPLA2-IB levels were significantly increased in both serum and renal tissue. In conclusion, serum sPLA2-IB was closely correlated with proteinuria, albumin and cholesterol, and IMN patients with lower sPLA2-IB levels were more likely to achieve a better outcome.


Assuntos
Glomerulonefrite por IGA/patologia , Glomerulonefrite Membranosa/patologia , Fosfolipases A2 do Grupo IB/metabolismo , Hiperlipidemias/metabolismo , Adulto , Estudos de Casos e Controles , LDL-Colesterol/sangue , Feminino , Glomerulonefrite por IGA/metabolismo , Glomerulonefrite Membranosa/metabolismo , Humanos , Hiperlipidemias/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Receptores da Fosfolipase A2/metabolismo , Regulação para Cima
20.
Oxid Med Cell Longev ; 2020: 4196482, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32774672

RESUMO

METHODS: Diabetic Apoe-/- mice induced by streptozotocin were treated with vehicle, the Pin1 inhibitor juglone, or the BRD4 inhibitor JQ1 for 3 weeks. VSMCs were pretreated with juglone, JQ1, or vehicle for 45 min, and then exposed to high glucose for 48 h. Hematoxylin-eosin staining was performed to assess atherosclerotic plaques of the thoracic aorta. Western blotting was used to detect expression levels of Pin1, BRD4, cyclin D1, and matrix metalloproteinase-9 (MMP-9) in the thoracic aorta and VSMCs. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and transwell assay were used to measure proliferation and migration of VSMCs. RESULTS: Juglone and JQ1 significantly improved atherosclerosis of diabetic Apoe-/- mice and reduced high glucose-induced VSMC proliferation and migration. Cyclin D1 and MMP-9 levels in the thoracic aorta were lower in diabetic Apoe-/- mice treated with juglone and JQ1 compared with vehicle-treated diabetic Apoe-/- mice. Additionally, BRD4 protein expression in high glucose-induced VSMCs was inhibited by juglone and JQ1. Upregulation of Pin1 expression by transduction of the Pin1 plasmid vector promoted BRD4 expression induced by high glucose, and stimulated proliferation and migration of VSMCs. CONCLUSIONS: Inhibition of Pin1/BRD4 pathway may improve diabetic atherosclerosis by inhibiting proliferation and migration of VSMCs.


Assuntos
Aterosclerose/terapia , Glucose/metabolismo , Músculo Liso Vascular/fisiopatologia , Animais , Proliferação de Células , Humanos , Masculino , Camundongos , Proteínas Nucleares , Fatores de Transcrição
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