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1.
Biometals ; 34(6): 1365-1379, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34599706

RESUMO

Selenium is an essential trace element that can regulate the function of immnue cells via selenoproteins. However, the effects of selenium on human dendritic cell (DCs) remain unclear. Thus, selenoprotein levels in monocytes, immature DCs (imDCs) and mature DCs (mDCs) treated with or without Na2SeO3 were evaluated using RT-PCR, and then the immune function of imDCs and mDCs was detected by flow cytometry, cell counting and the CCK8 assay. In addition, the effects of Se on cytokine and surface marker expression were investigated by RT-PCR. The results revealed different expression levels of selenoprotein in monocytes, imDCs and mDCs, and selenoproeins could be regulated by Se. Moreover, it was indicated that anti-phagocytic activity was improved by 0.1 µM Se, whereas it was suppressed by 0.2 µM Se in imDCs; The migration of imDCs and mDCs was improved by 0.1 µM Se, whereas their migration was inhibited by treatment with 0.05 or 0.2 µM Se; The mixed lymphocyte reaction of mDCs was improved by 0.1 µM Se, and it was inhibited by 0.05 and 0.2 µM Se. In addition, 0.1 µM Se improved the immune function of DCs through the regulation of CD80, CD86, IL12-p35 and IL12-p40. Wheres 0.05 and 0.2 µM Se impaired immune function of DCs by up-regulation of interleukin (IL-10) in imDCs and down-regulation of CD80, CD86, IL12-p35 and IL12-p40 in mDCs. In conclusion, 0.1 µM Se might improve the immune function of human DCs through selenoproteins.

2.
Cancer Res ; 81(22): 5678-5691, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34593522

RESUMO

Gemcitabine (GEM) resistance is a major challenge for chemotherapy of pancreatic cancer. Previous studies have reported on the role of long noncoding RNA (lncRNA) in tumorigenesis of pancreatic cancer, however, the involvement of lncRNA in the development of GEM resistance of pancreatic cancer remains unclear. In the present study, we demonstrated that the antisense RNA1 of HIF1α (HIF1A-AS1) was significantly elevated in the GEM-resistant pancreatic cancer cells. Gain- and lost-of-function experiments validated that HIF1A-AS1 promoted GEM resistance of pancreatic cancer cells both in vitro and vivo. We further revealed that HIF1A-AS1 upregulated HIF1α expression and thus promoted glycolysis to enhance GEM resistance of pancreatic cancer cells. Mechanistically, HIF1A-AS1 facilitated the interaction between serine/threonine kinase AKT and Y-box-binding protein 1 (YB1), which promoted phosphorylation of YB1 (pYB1). Meanwhile, HIF1A-AS1 recruited pYB1 to HIF1α mRNA that consequently promoted translation of HIF1α. Furthermore, HIF1α promoted HIF1A-AS1 transcription by directly binding to the HIF1α response element in the promoter area of HIF1A-AS1 to form a positive feedback. Consistently, both HIF1A-AS1 and HIF1α were upregulated in pancreatic cancer tissues and associated with poor overall survival. Together, our results underline a reciprocal loop of HIF1A-AS1 and HIF1α that contributes to GEM resistance of pancreatic cancer and indicate that HIF1A-AS1 might serve as a novel therapeutic target for GEM resistance of pancreatic cancer. SIGNIFICANCE: These findings show that a reciprocal feedback of HIF1A-AS1 and HIF1α promotes gemcitabine resistance of pancreatic cancer, which provides an applicable therapeutic target.

3.
Cell Death Dis ; 12(9): 830, 2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34480024

RESUMO

The majority of long non-coding RNAs (lncRNAs) have been discovered to be overexpressed in pancreatic cancer (PC) and served as promoters in the tumorigenesis of PC, while the inhibitory functions of lncRNAs in the development of PC have not been fully elucidated yet. LncRNA microarray was adopted to analyze the differential expression of lncRNAs in PC tissues and that in normal peritumoral (NP) tissues. Functional role of lncRNA BM466146.1 on PC was evaluated by gain- and loss-of-function experiments in vivo and in vitro. RNA pull-down, RNA immunoprecipitation, luciferase reporter, and Chromatin-immunoprecipitation assays were performed to assess the mechanism of ZNFTR, respectively. The correlation between the expression of ZNFTR and various clinicopathological characteristics was accessed in PC specimens. This study displayed lncRNA BM466146.1 was downregulated in PC tissues and functioned as a suppressor through regulating the expression of adjacent gene Zinc finger protein 24 (ZNF24), which was assigned as ZNFTR. Mechanistically, ZNFTR interacted with activating transcription factor 3 (ATF3) and sequestered ATF3 away from the ZNF24 promoter, which consequently increased the expression of ZNF24. Further, ZNF24 inhibited the proliferative, metastatic, and pro-angiogenic abilities of PC cells by suppressing transcription of vascular endothelial growth factor A (VEGFA). Therefore, the downregulation of ZNFTR in PC led to the decreased expression of ZNF24, which further resulted in the upregulation of VEGFA to facilitate the development of PC. Meanwhile, ZNFTR was transcriptionally inhibited by the HIF-1α/HDAC1 complex-mediated deacetylation. Clinical results further demonstrated that the low expression of ZNFTR was associated with poor overall survival time. Taken together, our results implicated that ZNFTR was a hypoxia-responsive lncRNA, and functioned as an inhibitor by modulating ATF3/ZNF24/VEGFA pathway in PC.

4.
Cancer Med ; 10(19): 6795-6806, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34427987

RESUMO

The incidence and mortality of hepatocellular carcinoma (HCC) are gradually increasing during the past years. Recently, some studies have reported that malic enzyme (ME) plays an important role in cancer development, while the involvement of ME2 in HCC remains still undetermined. Here, we demonstrated that ME2 played an oncogenic role in HCC. ME2 was overexpressed in HCC tissues. TCGA database showed that the ME2 transcript level was inversely associated with the survival of HCC patients. Loss-of-function and gain-of-function assays showed that ME2 promoted HCC cell growth and migration. Furthermore, the xenografted tumorigenesis of MHCC97H cells was retarded by ME2 knockdown. ME2 silencing also suppressed the cell cycle process and induced apoptosis. Mechanistically, ME2 potentiated triglyceride synthesis, inhibition of which suppressed the proliferation and migration. We propose that ME2 promotes HCC progression by increasing triglyceride production.

5.
Oncogene ; 40(36): 5505-5517, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34294845

RESUMO

Research has indicated that hypoxia profoundly contributes to chemoresistance of pancreatic cancer (PC), while the precise mechanism has not been fully elucidated. In this study, we report a hypoxic exosomal circular RNA (circRNA)-mediated mechanism of conferred chemoresistance in PC cells. Gemcitabine (GEM) resistance was enhanced in normoxic PC cells incubated with exosomes derived from hypoxic PC cells. CircRNA microarray displayed that circZNF91 was remarkably increased in hypoxic exosomes of PC cells compared with normoxic exosomes. Overexpression of circZNF91 obviously stimulated chemoresistance in PC cells, while knockdown of circZNF91 retarded the hypoxic exosome-transmitted chemoresistance. Mechanistically, the hypoxic-induced exosomal circZNF91 transmitted into normoxic PC cells could competitively bind to miR-23b-3p, which deprives the inhibition of miR-23b-3p on expression of deacetylase Sirtuin1 (SIRT1). Consequently, the upregulated SIRT1 enhanced deacetylation-dependent stability of HIF-1α protein, leading to glycolysis and GEM chemoresistance of recipient PC cells. In addition, we revealed that the increased circZNF91 in hypoxic exosome was attributed to the transcriptional regulation by HIF-1α. Coincidently, transmission of hypoxic exosomes into subcutaneous xenografts in nude mice obviously facilitated the chemoresistance of transplanted PC tumor, which could be reversed by depletion of circZNF91 or upregulation of miR-23b-3p. Furthermore, clinical data showed that circZNF91 was significantly upregulated in PC tissues and correlated with overexpression of glycolytic enzymes and short overall survival time. Collectively, exosomal circZNF91 can function as a cargo mediating the signal transmission between hypoxic and normoxic tumor cells to promote GEM chemoresistance of PC and may potentially serve as a therapeutic target.

6.
Sheng Wu Gong Cheng Xue Bao ; 37(7): 2272-2282, 2021 Jul 25.
Artigo em Chinês | MEDLINE | ID: mdl-34327894

RESUMO

Lactic acid bacteria (LAB) are generally recognized as safe food-grade microorganisms and are widely used in food production, preservation, and as probiotics to promote human health. Given the need to develop effective drug delivery strategies, LAB have become attractive live vehicles for the oral, intranasal and vaginal delivery of therapeutic molecules. Being live and safe organisms, LAB are able to directly produce and deliver target proteins for therapeutic purpose, which remarkably reduces the cost for drug production. To date, LAB have been used to deliver a variety of functional proteins to mucosal tissues for the treatment of various diseases. This review summarized the development and application of LAB as mucosal delivery vectors in the last 20 years to provide references for future clinical research.


Assuntos
Lactobacillales , Probióticos , Sistemas de Liberação de Medicamentos , Humanos , Membrana Mucosa , Proteínas
7.
Anim Nutr ; 7(2): 393-399, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34258427

RESUMO

There are appreciable does of raffinose in soybean, but the impacts of raffinose on pigs are poorly investigated. We used 2 experiments to investigate the influence of soybean raffinose on growth performance, digestibility, humoral immunity and intestinal morphology of growing pigs. In Exp. 1, a total of 30 crossbred (Duroc × Landrace × Yorkshire) barrows (21.93 ± 0.43 kg) were randomly divided into 3 groups, and were fed with the control diet, the control diets supplemented with 0.2% and 0.5% raffinose, respectively, for 21 d. Results showed that the addition of 0.2% or 0.5% raffinose reduced (P < 0.05) average daily feed intake (ADFI), average daily gain (ADG) and nutrient digestibility, and dietary 0.5% raffinose increased the ratio of feed to gain (P < 0.05). For serum indexes, dietary 0.5% raffinose decreased growth hormone and increased glucagon-like peptide-2, immunoglobulin G, tumor necrosis factor-α (TNF-α) and interleukin-6 concentration (P < 0.05). In Exp. 2, a total of 24 crossbred barrows (38.41 ± 0.45 kg) were randomly divided into 3 groups, and were fed with the control diet (ad libitum), the raffinose diet (0.5% raffinose, ad libitum), and the control diet in the same amount as the raffinose group (feed-pair group) for 14 d, respectively. Compared with the control diet, dietary 0.5% raffinose decreased ADFI (P < 0.05). Intriguingly, the raffinose group had lower ADG than the feed-pair group, lower nutrient digestibility, lower amylase activity in duodenum, lower amylase, lipase and trypsin activities in jejunum and higher TNF-α concentration in serum compared with the other 2 groups, and a higher ratio of villus height to crypt depth compared with the control group (P < 0.05). These results showed that soybean raffinose could reduce feed voluntary intake and body gain while improving intestinal morphology without a significant negative influence on immunity. Taken together, dietary raffinose could decrease growth performance by reducing both feed intake and nutrient digestibility while inducing humoral immune response of growing pigs.

8.
Artigo em Inglês | MEDLINE | ID: mdl-34266625

RESUMO

Deoxynivalenol (DON), zearalenone (ZEN), and fumonisin B1 (FB1), as the main mycotoxins contaminating rice, often coexist in food. Thus, we have measured the genotoxicity of the three rice fungal contaminants, singly and in different combinations, with a 28-day multi-endpoint (Pig-a assay + in vivo micronucleus [MN] test + comet assay) genotoxicity platform. Male Sprague-Dawley rats received the agents orally via gavage for 28 consecutive days, before performing the abovementioned tests. Results indicated that low dose of a single mycotoxin did not show significant genotoxicity. However, some of these mycotoxins in combination induced significant genotoxicity in the peripheral blood and tissues, at sacrifice. In the peripheral blood, the binary combination of DON and FB1 significantly induced MN. In the liver, ZEN might aggravate the DNA-damaging effects of DON and FB1. Therefore, the genotoxicity of sub-chronic exposure to mycotoxins in combination cannot be ignored.


Assuntos
Micotoxinas/toxicidade , Oryza/toxicidade , Animais , Ensaio Cometa/métodos , Dano ao DNA/efeitos dos fármacos , Fumonisinas/toxicidade , Masculino , Ratos , Ratos Sprague-Dawley , Tricotecenos/toxicidade , Zearalenona/toxicidade
9.
Food Funct ; 12(15): 6809-6820, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34113945

RESUMO

This study aimed to investigate the effects of probiotic Lactobacillus paracasei NL41 on inflammation and the gut microbiota of type 2 diabetic (T2D) rats induced by high-fat diet (HFD) and low-dose streptozotocin (STZ). A T2D rat model was established by inducing Sprague-Dawley rats with HFD/STZ, followed by 12-weeks L. paracasei NL41 gavage. The blood, colonic tissues, and feces samples of these rats were collected for inflammation, histology, and intestinal microbiota profiling. L. paracasei NL41 treatment induced remarkable improvement in the inflammatory status by decreasing the levels of serum lipopolysaccharides (LPS), free fatty acids (FFA), tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-8 and increasing the level of IL-10. Gut barrier function was significantly protected in NL41-treated rats. Moreover, the strain NL41 induced changes in the microbiota structure and influenced the relative abundance of the key species. Specifically, Bacteroides, Clostridia (specifically, Ruminococcus torques), and Parasutterella were significantly reduced, while some beneficial microorganisms (Bacteroidales_S24-7_group and the families Lachnospiraceae and Ruminococcaceae) were enriched by NL41. The correlational analyses indicated that L. paracasei NL41 ameliorating inflammation was closely related to the key species of the gut microbiota. The present study indicates that probiotic L. paracasei NL41 decreases LPS-induced inflammation by improving the gut microbiota and preserving intestinal integrity.

10.
Transl Lung Cancer Res ; 10(4): 1819-1828, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34012795

RESUMO

Background: Programmed death protein (ligand) 1 [PD-(L)1] inhibitors have provided new therapeutic options for advanced lung cancer. However, patients with hepatitis B virus (HBV) infection have been traditionally excluded from most registered trials of this form of treatment. Methods: We performed a retrospective analysis of patients with HBV and advanced lung cancer who received anti-PD-1 immunotherapy from September 2018 to May 2020 in our department. Treatment-related hepatotoxicity was evaluated and recorded. Overall response rate and progression free survival were also assessed in the patients using iRECIST. Results: Seventeen patients were evaluated in this analysis. Of these, six (35.3%) experienced hepatic transaminase elevation during immunotherapy. Three of these patients developed Grade 3 hepatic immune-related adverse events and received systemic corticosteroids, following which aminotransferase levels recovered to normal in all patients and no adverse events were observed in subsequent treatment. No patient experienced HBV reactivation or flare. One patient developed active pulmonary tuberculosis (TB). Other adverse events were mild, well tolerated and short term. The objective response rate (ORR) of the cohort was 62.5%, and the median progression-free survival (PFS) was 3 months. Conclusions: Lung cancer patients can be treated safely with anti-PD-1 inhibitors in the context of HBV infection. Close monitoring for hepatotoxicity and prophylactic antiviral therapy is advised. Further studies on the use of anti-PD-1 inhibitors in HBV-infected patients are needed.

11.
ACS Omega ; 6(14): 9680-9691, 2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33869948

RESUMO

Hematoporphyrin (HP) and protoporphyrin IX (PPIX) are useful porphyrin photosensitizers with significant application values in photodynamic therapy. Currently, many strategies have been developed to improve their clinical performance, such as incorporating them with nanoparticle (NP) carriers. In this work, we studied the possibility of using ß-lactoglobulin (BLG) as a potential NP carrier due to their hydrophobic affinity, pH sensitivity, and low cost of extraction and preservation. The interaction mechanisms of BLG with HP and PPIX were investigated using spectroscopic techniques and molecular docking methods. The molecular docking results agree well with the experimental results, which demonstrate that the formations of HP-BLG and PPIX-BLG complexes are endothermic processes and the main acting force is hydrophobic force. Furthermore, the opening-closure states of EF loop have a great influence on the HP-BLG complex formation, where the central hydrophobic cavity of ß-barrel is available for HP binding at pH 7.4 but not available at pH 6.2. However, the formation of the PPIX-BLG complex is less dependent on the states of the EF loop, and the binding sites of PPIX are both located on the external surface of BLG under both pH 7.4 and 6.2 conditions. All of our results would provide new insight into the mechanisms of noncovalent interactions between BLG and HP/PPIX. It is believed that this work indicated the potential application values of BLG in designing pH-sensitive carriers for the delivery of HP and PPIX, as well as other poorly soluble drugs.

12.
Front Oncol ; 11: 650481, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33777812

RESUMO

Immunotherapy, represented by immune checkpoint inhibitors (mainly referring to programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) blockades), derives durable remission and survival benefits for multiple tumor types including digestive system tumors [gastric cancer (GC), colorectal cancer (CRC), and hepatocellular carcinoma (HCC)], particularly those with metastatic or recurrent lesions. Even so, not all patients would respond well to anti-programmed death-1/programmed death-ligand 1 agents (anti-PD-1/PD-L1) in gastrointestinal malignancies, suggesting the need for biomarkers to identify the responders and non-responders, as well as to predict the clinical outcomes. PD-L1expression has increasingly emerged as a potential biomarker when predicting the immunotherapy-based efficacy; but regrettably, PD-L1 alone is not sufficient to differentiate patients. Other molecules, such as tumor mutational burden (TMB), microsatellite instability (MSI), and circulating tumor DNA (ctDNA) as well, are involved in further explorations. Overall, there are not still no perfect or well-established biomarkers in immunotherapy for digestive system tumors at present as a result of the inherent limitations, especially for HCC. Standardizing and harmonizing the assessments of existing biomarkers, and meanwhile, switching to other novel biomarkers are presumably wise and feasible.

13.
Med Sci Monit ; 27: e929004, 2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33684094

RESUMO

BACKGROUND Selenium and peroxynitrite are known to support the growth and activity of immune cells, including T cells, B cells and macrophages. However, the role of these factors in the immune function of human immature dendritic cells (imDCs) is not clear. MATERIAL AND METHODS Monocytes from a mixture of blood samples were isolated using Ficoll density gradient centrifugation and purified with immunomagnetic beads before being induced into imDCs. Cells then either received no treatment (control group), or treatment with sodium selenite (Na2SeO3, Se), 3-morpholinosydnonimine (SIN1, which decomposes into peroxynitrite), or Se+SIN1. Cell viability, migration, and antiphagocytic abilities, oxidative stress, and protein expression of extracellular signal-regulated kinases (ERK) and MMP2 were assessed using a CCK8 assay, cell counter and flow cytometry, microplate spectrophotometer, and Western blot analysis, respectively. RESULTS Viability of imDCs was unaffected by 0.1 µmol/L of Na2SeO3, although 1 mmol/L of SIN1 decreased it significantly (P<0.05). Chemotactic migration and antiphagocytic abilities were inhibited and enhanced, respectively, by treatment with Na2SeO3 and SIN1 (P<0.05). Activities of superoxide dismutase and glutathione peroxidase were increased by Na2SeO3 and Se+SIN1 (P<0.001). Glutathione content decreased with exposure to Na2SeO3 and SIN1 (P<0.05), but increased after treatment with Se+SIN1 (P<0.05). Levels of reactive oxygen species only increased with SIN1 treatment (P<0.05). Treatment with Na2SeO3, SIN1 and Se+SIN1 increased ERK phosphorylation and decreased MMP2 protein expression (P<0.05). CONCLUSIONS Selenium and peroxynitrite can influence immune function in imDCs by regulating levels of reactive oxygen species or glutathione to activate ERK and promote antigen phagocytosis, as well as by decreasing MMP2 expression to inhibit chemotactic migration.


Assuntos
Células Dendríticas/efeitos dos fármacos , Ácido Peroxinitroso/farmacologia , Selênio/farmacologia , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Dendríticas/metabolismo , Glutationa Peroxidase/metabolismo , Humanos , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ácido Peroxinitroso/imunologia , Fagocitose/efeitos dos fármacos , Fosforilação , Espécies Reativas de Oxigênio/metabolismo , Selênio/imunologia , Superóxido Dismutase/metabolismo
14.
Food Funct ; 12(6): 2726-2740, 2021 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33681875

RESUMO

Obesity is an increasingly concerning global health issue, which is accompanied by disruption of glucose and lipid metabolisms. The aim of this study was to uncover the potential and molecular actions of puerarin, a phytochemical, for alleviating metabolic dysfunctions of glucose and lipid metabolisms. A rat model fed a high fat and high fructose diet and a HepG2 cell model challenged with fructose combined with free fatty acid were utilized to identify the effects of puerarin on obesity-associated insulin resistance and hepatic steatosis. The molecular mechanisms underlying puerarin treatment effects were further investigated using qRT-PCR and western blotting. Results show that puerarin significantly ameliorated features of obesity in rats, including bodyweight, hyperlipidemia, hyperglycemia, glucose/insulin intolerance, insulin resistance, hepatic steatosis, and oxidative stress, which are related to the activation of AMPK and PI3K/Akt pathways in the liver. Puerarin reduced lipid accumulation and caused a reduction of the mRNA expression of lipogenic genes such as SREBP-1c, FAS, SCD-1, and HMGCR, and an increment in the phosphorylation of AMPK and ACC in HepG2 cells. Moreover, puerarin ameliorated insulin resistance by increasing GLUT4 mRNA expression and activating the PI3K/Akt pathway. Treatment with the AMPK inhibitor compound C partially abolished the beneficial effects of puerarin on lipid accumulation and insulin resistance in HepG2 cells, which indicated that the protective effects of puerarin partially depend on the AMPK pathway. The present study indicates that puerarin shows potential as a functional food therapeutic for the treatment of obesity.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Glicemia , Isoflavonas/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Dieta Hiperlipídica , Fígado Gorduroso/metabolismo , Células Hep G2 , Humanos , Hiperlipidemias/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Obesidade , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
15.
J Ethnopharmacol ; 271: 113895, 2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-33524512

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Ginkgo biloba L. fruit, also known as Bai Guo, Ya Jiao Zi (in pinyin Chinese), and ginkgo nut (in English), has been used for many years as an important material in Chinese traditional medicine to treat coughs and asthma and as a disinfectant, as described in the Compendium of Materia Medica (Ben Cao Gang Mu, pinyin in Chinese), an old herbal book. Ginkgo nuts are used to treat phlegm-associated asthma, astringent gasp, frequent urination, gonorrhoea and turgidity; consumed raw to reduce phlegm and treat hangovers; and used as a disinfectant and insecticide. A similar record was also found in Sheng Nong's herbal classic (Shen Nong Ben Cao Jing, pinyin in Chinese). Recent research has shown that Ginkgo biloba L. exocarp extract (GBEE) can unblock blood vessels and improve brain function and exhibits antitumour and antibacterial activities. AIM OF STUDY: To investigate the inhibitory effect of Ginkgo biloba L. exocarp extract (GBEE) on methicillin-resistant S. aureus (MRSA) biofilms and assess its associated molecular mechanism. MATERIALS AND METHODS: The antibacterial effects of GBEE on S. aureus and MRSA were determined using the broth microdilution method. The growth curves of bacteria treated with or without GBEE were generated by measuring the CFU (colony forming unit) of cultures at different time points. The effects of GBEE on bacterial biofilm formation and mature biofilm disruption were determined by crystal violet staining. Quantitative polymerase chain reaction (qPCR) was used to measure the effects of GBEE on the gene expression profiles of MRSA biofilm-related factors at 6, 8, 12, 16 and 24 h. RESULTS: The minimum inhibitory concentration (MIC) of GBEE on S. aureus and MRSA was 4 µg/mL, and the minimum bactericidal concentration (MBC) was 8 µg/ml. Moreover, GBEE (4-12 µg/mL) inhibited S. aureus and MRSA biofilm formation in a dose-dependent manner. Interestingly, GBEE also destroyed mature biofilms of S. aureus and MRSA at 12 µg/ml. The expression of the MRSA biofilm-associated factor icaA and sarA were downregulated after 6 h of treatment with GBEE, while sigB was downregulated after 12 h. MeanwhileMeanwhile, icaR was upregulated at 12 h. In addition, GBEE also downregulated the virulence gene hld and inhibited the synthesis of staphyloxanthin. CONCLUSIONS: GBEE has excellent antibacterial effects against S. aureus and MRSA and inhibits their biofilm-forming ability by altering related gene expression.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Ginkgo biloba/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Extratos Vegetais/farmacologia , Staphylococcus aureus/fisiologia , Proteínas de Bactérias/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Virulência/efeitos dos fármacos
16.
Future Oncol ; 17(12): 1553-1569, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33397136

RESUMO

Gastric cancer, a digestive malignancy, is the sixth most frequent cancer and the second leading cause of tumor-related deaths worldwide. The emergence and advancement of immunotherapeutic agents has brought significant survival benefits for patients with gastric cancer and increasingly challenged the conventional therapy pattern involving chemotherapy and target drugs. Furthermore, these breakthroughs have paved the way for immunotherapy, especially with immune checkpoint inhibitors, which act by blocking specific signaling pathways, in particular the CTLA4 pathway and the PD-1/PD-L1 pathway. In this review, we summarize the current trials of immune checkpoint inhibitors in GC and their predictive biomarkers, and discuss their present limitations.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Inibidores de Checkpoint Imunológico/uso terapêutico , Imunoterapia/tendências , Neoplasias Gástricas/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/metabolismo , Antígeno CTLA-4/antagonistas & inibidores , Antígeno CTLA-4/metabolismo , Ensaios Clínicos como Assunto , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Imunoterapia/métodos , Estadiamento de Neoplasias , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/metabolismo , Intervalo Livre de Progressão , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/imunologia , Neoplasias Gástricas/mortalidade , Evasão Tumoral/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologia
17.
J Appl Toxicol ; 41(4): 595-606, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33067908

RESUMO

The micronucleus test (MNT) is the most widely applied short-term assay to detect clastogens or spindle disruptors. The use of flow cytometry (FCM) has been reported for micronucleated erythrocytes scoring in peripheral blood. The aim of this study was to develop a novel and practical protocol for MNT in rat peripheral blood by FCM, with the method validation. CD71-fluorescein isothiocyanate and DRAQ5 were adopted for the fluorescent staining of proteins and DNA, respectively, to detect micronuclei. To validate the method, groups of male Sprague-Dawley rats (five per group) received two oral gavage doses at 0 and 24 h of six chemicals (four positive mutagens: ethyl methanesulphonate [EMS], cyclophosphamide [CP], colchicine [COL], and ethyl nitrosourea [ENU]; two nongenotoxic chemicals: sodium saccharin and eugenol). Blood samples were collected from the tail vein before and on the five continuous days after treatments; all of which were analyzed for micronuclei presence by both the manual (Giemsa staining) and FCM methods. The FCM-based method consistently demonstrated highly sensitive responses for micronucleus detection at all concentrations and all time points for EMS, CP, COL, and ENU. Sodium saccharin and eugenol could be identified as negative in this protocol. Results obtained with the FCM-based method correlated well with the micronucleus frequencies (r = 0.659-0.952), and the proportion of immature erythrocytes (r = 0.915-0.981) tested by Giemsa staining. The method reported here, with easy operation, low background, and requirement for a regular FCM, could be an efficient system for micronucleus scoring.

18.
Biol Trace Elem Res ; 199(9): 3360-3370, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33107016

RESUMO

Selenium levels can regulate the function of T cells, macrophages, B cells, natural killer cells and other immune cells. However, the effect of selenium on the immune function of dendritic cells (DCs) isolated from selenium-supplemented mice is unknown. In this study, C57BL/6J mice were randomly divided into three groups and fed diets containing low (0.08 ppm), medium (0.25 ppm) or high (1 ppm) selenium levels for 8 weeks. Immature (imDCs) and mature (mDCs) dendritic cells were then isolated from the bone marrow. Next, the migration, phagocytic capacity and mixed lymphocyte reaction (MLR) for imDCs and mDCs were detected by transwell and flow cytometry. The levels of C-C chemokine receptor type 7 (CCR7), major histocompatibility complex II (MHCII) and reactive oxygen species (ROS) were assayed by flow cytometry. F-actin and superoxide dismutase (SOD) activity was detected by fluorescence microscopy and SOD assay kit, respectively. In addition, the extracellular signal-regulated kinase (ERK), Akt, Ras homolog gene family member A/Rho-associated protein kinase (RhoA/ROCK) signalling, selenoprotein K (SELENOK) and glutathione peroxidase 1 (GPX1) levels were measured by western blot analysis. The results indicated that selenium deficiency enhanced the migration of imDCs by ROS and SELENOK-mediated ERK, Akt and RhoA/ROCK pathways but impaired the antigen uptake of imDCs. Although a high selenium level inhibited the migration of imDCs, it had no effect on phagocytic capacity. For mDCs, low selenium levels impaired free migration, and high levels inhibited the chemotactic migration involved in F-actin and CCR7, respectively. Low and high selenium levels impaired the MLR by inhibiting MHCII surface localisation, which might be related to ROS- and SELENOK-mediated ERK, Akt and RhoA/ROCK signalling pathways. In summary, selenium may regulate the immune function of mouse DCs through the ROS- and SELENOK-mediated ERK, Akt and RhoA/ROCK signalling.


Assuntos
Selênio , Animais , Células Dendríticas , MAP Quinases Reguladas por Sinal Extracelular , Imunidade , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Proto-Oncogênicas c-akt , Selênio/farmacologia
19.
Inflammation ; 44(2): 737-745, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33130921

RESUMO

Dendritic cells (DCs) are the most powerful antigen-presenting cells known to date and play an important role in initiating and amplifying both innate and adaptive immune responses. Extracellular acidosis is an important hallmark of a variety of inflammatory processes and solid tumors. However, few studies have focused on the effect of extracellular acidosis on DCs and their functions. Cellular mechanical properties reflect the relationship between cell structure and function, including cytoskeleton (especially F-actin organization), membrane negative charges, membrane fluidity, and osmotic fragility. The study investigated the effects of extracellular acidosis on the DCs functions from the perspective of cellular migration and mechanical properties. The results showed that migration ability, F-actin contents, and membrane negative charges of DCs were reduced by extracellular acidosis no matter whether LPS stimulated its maturation or not. And these functions could not return to normal after removing acidic microenvironment, which revealed that the function impairment induced by extracellular acidosis might be irreversible. In addition, the proliferation capacity of stimulated allogeneic T cells was impaired by extracellular acidosis. Our results suggest extracellular acidosis may play an immunosuppressive role in DCs-mediated immune process.

20.
Cell Cycle ; 19(24): 3639-3649, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33323026

RESUMO

The present study aimed to assess the role of miR-1275 in cardiac ischemia reperfusion injury. H9 human embryonic stem cell (hESC)-derived cardiomyocytes stimulated by oxygen-glucose deprivation/reoxygenation (OGD/R) were used to simulate myocardial injury in vitro. miR-1275 expression levels in cells were measured by RT-qPCR. The release of lactate dehydrogenase (LDH) and creatine kinase (CK) was examined through LDH and CK ELISA kits. Cell apoptosis was detected through flow cytometry. A Fura-2 Calcium Flux Assay Kit and a Fluo-4 assay kit were used to determine the Ca2+ concentration. Expression levels of proteins were tested by Western blotting. The binding effect of miR-1275 and neuromedin U type 1 receptor (NMUR1) was detected by dual-luciferase activity assay. The results showed that miR-1275 was upregulated in OGD/R-stimulated cardiomyocytes. Inhibition of miR-1275 suppressed the increased activity of LDH and CK, cell apoptosis, reactive oxygen species (ROS) production, intracellular Ca2+ concentration and sarcoplasmic reticulum (SR) Ca2+ leak induced by OGD/R treatment in cardiomyocytes. miR-1275 directly targets 3'UTR of NMUR1 and negatively regulates NMUR1 expression. Silence of NMUR1 abolished the protecting effect of the miR-1275 antagomir on myocardial OGD/R injury. Our study indicated that the miR-1275 antagomir protects cardiomyocytes from OGD/R injury through the promotion of NMUR1.

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