Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 290
Filtrar
1.
Environ Sci Technol ; 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31961660

RESUMO

Although the fate of nanoplastics (<100 nm) in freshwater systems is increasingly well studied, much less is known about its potential threats to cyanobacterial blooms, the ultimate phenomenon of eutrophication occurrence worldwide. Previous studies have evaluated the consequences of nanoplastics increasing the membrane permeability of microbes, however, there is no direct evidence for interactions between nanoplastics and microcystin; intracellular hepatotoxins are produced by some genera of cyanobacteria. Here, we show that the amino-modified polystyrene nanoplastics (PS-NH2) promote microcystin synthesis and release from Microcystis aeruginosa, a dominant species causing cyanobacterial blooms, even without the change of coloration. We demonstrate that PS-NH2 inhibits photosystem II efficiency, reduces organic substance synthesis, and induces oxidative stress, enhancing the synthesis of microcystin. Furthermore, PS-NH2 promotes the extracellular release of microcystin from M. aeruginosa via transporter protein upregulation and impaired cell membrane integrity. Our findings propose that the presence of nanoplastics in freshwater ecosystems might enhance the threat of eutrophication to aquatic ecology and human health.

2.
FEBS Open Bio ; 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31898405

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive solid tumors in the digestive system. A greater understanding of the pathogenesis of PDAC may facilitate the search for new therapeutic targets. Guanine nucleotide-binding protein subunit gamma-12 (GNG12) belongs to the G protein family and participates in the modulation of the inflammatory signaling cascade. However, the cancer-related function and clinical relevance of GNG12 in PDAC have not previously been reported. Here, we investigated the clinical significance of GNG12 in PDAC using the Oncomine web tool, the gene expression profiling interactive analysis tool and tissue microarray (TMA). GNG12 expression was observed to be higher in PDAC patient specimens than in nontumor pancreatic tissues, and high expression of GNG12 was associated with poor prognosis. We subsequently show that GNG12 promotes pancreatic cancer cell growth in vivo and in vitro, as evaluated using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt assays, colony formation assays and a xenograft mouse model. Furthermore, our results suggest that GNG12 activates nuclear factor-κB signaling and modulates the immune response. Collectively, our findings suggest that GNG12 may be suitable as a new prognosis-related biomarker and a promising target for treatment of pancreatic cancer.

3.
J Cell Mol Med ; 24(1): 189-201, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31578820

RESUMO

SARI (suppressor of AP-1, regulated by IFN) impaired tumour growth by promoting apoptosis and inhibiting cell proliferation and tumour angiogenesis in various cancers. However, the role of SARI in regulating tumour-associated inflammation microenvironment is still elusive. In our study, the colitis-dependent and -independent primary model were established in SARI deficiency mice and immuno-reconstructive mice to investigate the functional role of SARI in regulating tumour-associated inflammation microenvironment and primary colon cancer formation. The results have shown that SARI deficiency promotes colitis-associated cancer (CAC) development only in the presence of colon inflammation. SARI inhibited tumour-associated macrophages (TAM) infiltration in colon tissues, and SARI deficiency in bone marrow cells has no observed role in the promotion of intestinal tumorigenesis. Mechanism investigations indicated that SARI down-regulates p-STAT1 and STAT1 expression in colon cancer cells, following inhibition of MCP-1/CCR2 axis activation during CAC development. Inverse correlations between SARI expression and macrophage infiltration, MCP-1 expression and p-STAT1 expression were also demonstrated in colon malignant tissues. Collectively, our results prove the inhibition role of SARI in colon cancer formation through regulating TAM infiltration.

4.
Int Immunopharmacol ; 79: 106067, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31881377

RESUMO

BACKGROUND: There is growing evidence of the ability of microRNAs (miRs) in rheumatoid arthritis (RA), thus our objective was to discuss the impact of miR-365 on the apoptosis and proliferation of synoviocytes in mice with RA by targeting IGF1 and mediating the PI3K/AKT/mTOR pathway. METHODS: RA model mice was induced by type II collagen and freund's adjuvant. The successfully modeled mice were injected with normal saline, miR-365 mimics, miR-365 inhibitors or their controls. TUNEL assay was adopted to detect apoptosis in synovial tissues, and expression of IL-1ß and IL-6 in serum and synovial tissues was measured by ELISA and RT-qPCR. Mouse synoviocytes were isolated and cultured in vitro and identified by experiments. Cells were transfected with miR-365 mimics, IGF1 siRNA, or their controls to verify the role of miR-365 and IGF1 in cell vitality, proliferation and apoptosis of synoviocytes. RESULTS: Upregulation of miR-365 increased the number of TUNEL positive cells, depressed arthritis index, X-ray imaging score, and the expression of IL-1ß and IL-6. High expression of miR-365 and low expression of IGF1 restrained the proliferation and facilitated apoptosis of synoviocytes. MiR-365 inhibited the expression of IGF1 and inhibited the activation of the PI3K/AKT/mTOR pathway. CONCLUSION: Our study presents that up-regulation of miR-365 drives on apoptosis and restrains proliferation of synoviocytes in RA through downregulation of IGF1 and the inhibition of the PI3K/AKT/mTOR pathway. Thus, miR-365 may be a potential candidate for treatment of RA.

5.
Cancer Drug Resist ; 2: 198-209, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31815253

RESUMO

The translational research strategy of targeting estrogen receptor α (ERα) positive breast cancer and then using long term anti-hormone adjuvant therapy (5-10 years) has reduced recurrences and mortality. However, resistance continues to occur and improvements are required to build on the success of tamoxifen and aromatase inhibitors (AIs) established over the past 40 years. Further translational research has described the evolution of acquired resistance of breast cancer cell lines to long term estrogen deprivation that parallels clinical experience over years. Additionally, recent reports have identified mutations in the ERα obtained from the recurrences of AI treated patients. These mutations allow the ERα to activate without ligands and auto stimulate metastatic tumor growth. Furthermore, the new biology of estrogen-induced apoptosis in acquired resistant models in vitro and in vivo has been interrogated and applied to clinical trials. Inflammation and stress are emerging concepts occurring in the process of acquired resistance and estrogen-induced apoptosis with different mechanisms. In this review, we will present progress in the understanding of acquired resistance, focus on stress and inflammatory responses in the development of acquired resistance, and consider approaches to create new treatments to improve the treatment of breast cancer with endocrine resistance.

6.
J Exp Clin Cancer Res ; 38(1): 485, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31818309

RESUMO

BACKGROUND: Recent studies have reported that Integrin alpha 2 (ITGA2) plays an essential role in tumor cell proliferation, invasion, metastasis, and angiogenesis. An abnormally expressed ITGA2 correlates with unfavorable prognoses in multiple types of cancer. However, the specific mechanism of how ITGA2 contributes to tumorigenesis remains unclear. METHODS: The GEPIA web tool was used to find the clinical relevance of ITGA2 in cancer, and this significance was verified using Western blotting analysis of paired patient tissues and immunohistochemistry of the pancreatic cancer tissue. Functional assays, such as the MTS assay, colony formation assay, and transwell assay, were used to determine the biological role of ITGA2 in human cancer. The relationship between ITGA2 and programmed death-ligand 1 (PD-L1) was examined using Western blot analysis, RT-qPCR assay, and immunohistochemistry. The protein-protein interaction between ITGA2 and STAT3 was detected via co-immunoprecipitation. RESULTS: Our study showed that ITGA2 was markedly overexpressed in several malignant tumor cells and clinical tissues. Blocking ITGA2 inhibited the proliferation and invasion ability of cancer cells significantly, whereas overexpressed ITGA2 increased the degree of those processes considerably. Additionally, the RNA-seq assay indicated that ITGA2 transcriptionally regulated the expression of PD-L1 in pancreatic cancer. We also demonstrated that ITGA2 interacted with STAT3 and up-regulated the phosphorylation of STAT3; this interaction might involve the mechanism of ITGA2 inducing PD-L1 expression in cancer cells. Our results suggest that ITGA2 plays a critical role in cancer cell progression and the regulation of PD-L1 by activating the STAT3 pathway. CONCLUSIONS: We identified a novel mechanism by which ITGA2 plays a critical role in modulating cancer immune response by transcriptionally increasing the expression of PD-L1 in cancer cells. Thus, targeting ITGA2 is an effective method to enhance the efficacy of checkpoint immunotherapy against cancer.

7.
Nanomaterials (Basel) ; 9(12)2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31835756

RESUMO

Lead-free double perovskites have been considered as a potential environmentally friendly photovoltaic material for substituting the hybrid lead halide perovskites due to their high stability and nontoxicity. Here, lead-free double perovskite Cs2AgBiBr6 films are initially fabricated by single-source evaporation deposition under high vacuum condition. X-ray diffraction and scanning electron microscopy characterization show that the high crystallinity, flat, and pinhole-free double perovskite Cs2AgBiBr6 films were obtained after post-annealing at 300 °C for 15 min. By changing the annealing temperature, annealing time, and film thickness, perovskite Cs2AgBiBr6 solar cells with planar heterojunction structure of FTO/TiO2/Cs2AgBiBr6/Spiro-OMeTAD/Ag achieve an encouraging power conversion efficiency of 0.70%. Our preliminary work opens a feasible approach for preparing high-quality double perovskite Cs2AgBiBr6 films wielding considerable potential for photovoltaic application.

8.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 50(6): 867-871, 2019 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-31880119

RESUMO

OBJECTIVE: To explore the effect of smoking on the histological subtype and prognosis of patients with lung adenocarcinoma (LAC) in China. METHODS: According to the new International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society(IASLC/ATS/ERS)classification, 266 donors with primary LAC were reclassified. The correlation between clinicopathological factors including smoking status and the histological subtype was analyzed, and survival analysis was used to analyze the prognosis of primary LAC. RESULTS: There were four main histological subtypes including acinar predominant adenocarcinoma (APA) 30.1%, papillary predominant adenocarcinoma (PPA) 26.7%, solid predominant adenocarcinoma (SPA) 25.9%, and lepidic predominant adenocarcinoma (LPA) 11.7%.Smoking was associated with the histological subtype.The proportion of smokers was significantly higher than non-smokers in the SPA group, and the proportion of non-smokers was higher in other subtypes group. Cox regression model showed that the histological subtype and TNM stage were the independent predictors of prognostic in all patients.TNM stage was the predictor of postoperative survival in both smokers and non-smokers, and histological subtypes was the predictor only in smokers (ß=0.898, RR=2.455). Compared with the non-SPA group, the prognosis of the SPA group was significantly worse. CONCLUSION: Smoking is associated with SPA subtype, which affect the prognosis of primary LAC.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Fumar , China , Humanos , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos
9.
Artigo em Inglês | MEDLINE | ID: mdl-31781040

RESUMO

Background: Oxidative stress plays an important role in the pathogenesis of polycystic ovary syndrome (PCOS). Glutathione peroxidase 1 (GPx1) and catalase (CAT) are the major intracellular antioxidant enzymes that can detoxify hydrogen peroxide into water, preventing cellular injury from reactive oxygen species. The aim of the present study was to investigate the association of GPx1 P198L (Pro198Leu, C559T, rs1050450) and CAT C-262T (rs1001179) genetic polymorphisms with the risk of PCOS and evaluate the effects of the genotypes on clinical, hormonal, metabolic and oxidative stress parameters in Chinese women. Methods: This is a case-control study of 654 patients with PCOS and 535 controls. The GPx1 P198L, CAT C-262T, and superoxide dismutase 2 (SOD2) A16V genotypes were determined by polymerase chain reaction amplification and restriction analysis. Clinical, hormonal, metabolic and oxidative stress parameters were also analyzed. Results: The frequencies of the PL + LL genotype (14.1 vs. 8.4%) and L allele (7.3 vs. 4.4%) of GPx1 P198L polymorphism were significantly higher in patients with PCOS than in control subjects. Genotype (PL + LL) remained a significant predictor for PCOS in prognostic models including age, body mass index (BMI), insulin resistance index, total cholesterol, triglycerides, high-density lipoprotein-cholesterol, and low-density lipoprotein-cholesterol as covariates (OR = 2.105, 95%CI: 1.330-3.331, P = 0.001). Patients carrying the L allele had relatively high average ovarian volume, waist circumference, and malondialdehyde levels (P < 0.07) compared with patients with the PP genotype. We also demonstrated that the subjects with both GPx1 L and SOD2 A alleles further increase the risk of PCOS compared with the individuals carrying the PP/VV genotype after adjusting for age and BMI (OR = 5.774, 95%CI: 2.243-14.863, P < 0.001). However, no significant differences were observed in the frequencies of the CAT C-262T genotypes and alleles between PCOS and control groups. Conclusions: The GPx1 P198L, but not CAT C-262T, genetic polymorphism is associated with the risk of PCOS in Chinese women.

10.
Sci Rep ; 9(1): 17422, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31758007

RESUMO

Hybrid two-dimensional (2D) halide perovskites has been widely studied due to its potential application for high performance perovskite solar cells. Understanding the relationship between microstructural and opto-electronic properties is very important for fabricating high-performance 2D perovskite solar cell. In this work, the effect of solvent annealing on grain growth was investigated to enhance the efficiency of photovoltaic devices with 2D perovskite films based on (BA)2(MA)3Pb4I13 prepared by single-source thermal evaporation. Results show that solvent annealing with the introduction of solvent vapor can effectively enhance the crystallization of the (BA)2(MA)3Pb4I13 thin films and produce denser, larger-crystal grains. The thin films also display a favorable band gap of 1.896 eV, which benefits for increasing the charge-diffusion lengths. The solvent-annealed (BA)2(MA)3Pb4I13 thin-film solar cell prepared by single-source thermal evaporation shows an efficiency range of 2.54-4.67%. Thus, the proposed method can be used to prepare efficient large-area 2D perovskite solar cells.

11.
J Exp Clin Cancer Res ; 38(1): 463, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31718704

RESUMO

BACKGROUND: Overexpressed PES1 promotes carcinogenesis in various types of malignant tumors. However, the biological role and clinical significance of PES1 in pancreatic cancer are still unexplored. METHODS: The expression level of PES1 in pancreatic cancer cell lines and pancreatic cancer patient samples was determined using Western Blotting analysis, RT-qPCR analysis, immunohistochemical (IHC) analysis of tissue microarray, and the GEPIA web tool. MTS assay, colony formation assay, and xenograft tumor assay were used to evaluate the tumor growth ability of pancreatic cancer cells. RESULTS: We established that the expression of PES1 was abnormally increased in pancreatic cancer tissues and led to poor prognosis of pancreatic cancer patients. We also found that PES1 was responsible for promoting cell growth and contributed to bromodomain and cancer cell resistance to extra-terminal (BET) inhibitors in pancreatic cancer. Furthermore, we showed that PES1 interacted with BRD4 to enhance c-Myc expression, which is the primary cause of cancer cell resistance to BET inhibitors in pancreatic cancer. Finally, CDK5 inhibitors were proven to destabilize PES1 and overcome cancer cell resistance to BET inhibitors in pancreatic cancer cells. CONCLUSIONS: We have shown that PES1 could be one of the promoting factors of tumor growth and a prognosis-related protein of pancreatic cancer. Targeting PES1 with CDK5 inhibitors might help overcome cancer cell resistance to BET inhibitors in pancreatic cancer cells.

12.
ACS Appl Mater Interfaces ; 11(49): 45737-45745, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31738510

RESUMO

The influence of Pb/Ag dual doping on the thermoelectric performance of BiCuSeO was investigated. It reveals that the electrical conductivity can be obviously improved owing to the increased carrier concentration mostly caused by the divalent Pb2+ doping at trivalent Bi3+. The electrical conductivity improves from 7.29 S/cm for BiCuSeO to 397.40 S/cm for Pb0.06Bi0.94Cu0.94Ag0.06SeO and Pb0.06Bi0.94CuSeO at 327 K. Combined with the moderate Seebeck coefficient (>120 µV/K) due to the large effective mass, a large power factor with 834 µW/mK2 is achieved. Meanwhile, the lattice thermal conductivity is visibly decreased, mainly benefiting from the substitution of Ag+ at the Cu+ site since the phonon scattering can be enhanced by mass fluctuation and strain fluctuation between the two elements. Thus, the total thermal conductivity is suppressed effectively compared with the Ag-free sample Pb0.06Bi0.94CuSeO. Finally, a maximum ZT value with nearly 1.0 has been obtained for Pb0.06Bi0.94Cu0.94Ag0.06SeO at 873 K, which is ∼64% and ∼47% larger than those of the pristine sample BiCuSeO and Ag-free sample Pb0.06Bi0.94CuSeO. Additionally, the ZT is also larger than the maximum value for the reported Pb-free samples BiCu0.94Ag0.06SeO and Bi0.92Ag0.08CuSeO, suggesting Pb and Ag are effective codopants of BiCuSeO to synergetically tune its electrical and thermal transport properties.

13.
Cancer Manag Res ; 11: 8893-8903, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632149

RESUMO

Objectives: The aim was to define the role of chemotherapy in stage II nasopharyngeal carcinoma (NPC) and to identify the toxicity of chemotherapy for these patients in the era of intensity-modulated radiotherapy (IMRT). Methods: Between January 2002 and December 2013, 169 patients with stage II NPC were analyzed. Of these patients, 149 patients treated with chemotherapy were divided into three groups as follows: neoadjuvant chemotherapy followed by IMRT (NCT) group, concurrent chemotherapy with IMRT (CCRT) group, and neoadjuvant chemotherapy followed by CCRT (NC+CCRT) group. In addition, 20 patients received IMRT alone. We retrospectively assessed the 10-year survival and acute adverse effects in the patients using SPSS software. Results: The median follow-up time was 93 months (2-160 months). The 10-year OS of the NCT, CCRT, NC+CCRT groups vs the IMRT alone group was 69.8%, 63.4%, 69.7% vs 72.4%, respectively (P=0.664, 0.940, and 0.998, respectively). Both univariable and multivariable analyses showed that the addition of chemotherapy to IMRT did not significantly improve the 10-year survival outcomes. The hematotoxicity and mucous reaction of patients with chemotherapy were more serious than those with IMRT alone (P=0.007 and 0.049). Distant metastasis for stage II NPC patients mostly occurred within 3 years, which is very different from patients with advanced NPC. Conclusion: Patients with stage II NPC who are treated with IMRT may obtain satisfactory long-term survival outcomes. The additional chemotherapy cannot significantly increase survival; however, it may remarkably increase treatment-associated acute toxic reactions.

14.
Mol Cancer Ther ; 18(10): 1684-1695, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31511352

RESUMO

Our clinically relevant finding is that glucocorticoids block estrogen (E2)-induced apoptosis in long-term E2-deprived (LTED) breast cancer cells. However, the mechanism remains unclear. Here, we demonstrated that E2 widely activated adipose inflammatory factors such as fatty acid desaturase 1 (FADS1), IL6, and TNFα in LTED breast cancer cells. Activation of glucocorticoid receptor (GR) by the synthetic glucocorticoid dexamethasone upregulated FADS1 and IL6, but downregulated TNFα expression. Furthermore, dexamethasone was synergistic or additive with E2 in upregulating FADS1 and IL6 expression, whereas it selectively and constantly suppressed TNFα expression induced by E2 in LTED breast cancer cells. Regarding regulation of endoplasmic reticulum stress, dexamethasone effectively blocked activation of protein kinase RNA-like endoplasmic reticulum kinase (PERK) by E2, but it had no inhibitory effects on inositol-requiring protein 1 alpha (IRE1α) expression increased by E2 Consistently, results from reverse-phase protein array (RPPA) analysis demonstrated that dexamethasone could not reverse IRE1α-mediated degradation of PI3K/Akt-associated signal pathways activated by E2 Unexpectedly, activated GR preferentially repressed nuclear factor-κB (NF-κB) DNA-binding activity and expression of NF-κB-dependent gene TNFα induced by E2, leading to the blockade of E2-induced apoptosis. Together, these data suggest that trans-suppression of NF-κB by GR in the nucleus is a fundamental mechanism thereby blocking E2-induced apoptosis in LTED breast cancer cells. This study provided an important rationale for restricting the clinical use of glucocorticoids, which will undermine the beneficial effects of E2-induced apoptosis in patients with aromatase inhibitor-resistant breast cancer.

15.
Materials (Basel) ; 12(18)2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31527498

RESUMO

Tin telluride (SnTe), with the same rock salt structure and similar band structure of PbTe alloys, was developed as a good thermoelectric material. In this work, SnTe quasi crystal was grown by vertical Bridgman method, with texturing degree achieved at 0.98. Two sets of samples, perpendicular and parallel to the growth direction, were cut to investigate thermoelectric properties. As a result, a carrier concentration (pH) of ~9.5 × 1020 cm-3 was obtained, which may have originated from fully generated Sn vacancies during the long term crystal growth. The relatively high Seebeck coefficient of ~30 µVK-1 and ~40 µVK-1 along the two directions was higher than most pristine SnTe reported in the literature, which leads to the room temperature (PF) for SnTe_IP and SnTe_OP achieved at ~14.0 µWcm-1K-2 and ~7.0 µWcm-1K-2, respectively. Finally, the maximum dimensionless figure of merit (ZT) values were around 0.55 at 873 K.

16.
Am J Cancer Res ; 9(8): 1722-1733, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31497353

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is considered to be the deadliest cancer type in the world. Chemotherapy resistance, including gemcitabine, is the main reason for poor prognosis in PDAC patients. Increased aerobic glycolysis is involved in chemotherapy resistance in PDAC. Fructose-1,6-bisphosphatase (FBP1) is one of the key enzymes in the process of gluconeogenesis and negatively regulates aerobic glycolysis. FBP1 loss is common in PDAC patient specimens and is associated with gemcitabine resistance by activating the MAPK pathway. While the regulatory mechanism of FBP1 in pancreatic cancer remains un-elucidated. Here, we found that ubiquitin-specific protease 44 (USP44) was down-regulated in PDAC patients, and USP44 might be a prognostic marker for PDAC patients. USP44 inhibit tumor cells progression and regulated gemcitabine resistance in PDAC. Importantly, we revealed USP44 promoted FBP1 deubiquitination to increase FBP1 protein expression in pancreatic cancer, which might be one of the underlying mechanisms of USP44 impeding the progression of pancreatic cancer. Collectively, the recognition of USP44 in the stabilization of FBP1 indicates USP44 might be considered as a new prognostic marker for pancreatic cancer therapy.

17.
J Mater Chem B ; 7(38): 5762-5774, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31465075

RESUMO

The development of smart materials and surfaces with multiple antibacterial actions is of great importance for both fundamental research and practical applications, but this has proved to be extremely challenging. In this work, we proposed to integrate salt-responsive polyDVBAPS (poly(3-(dimethyl(4-vinylbenzyl) ammonio)propyl sulfonate)), antifouling polyHEAA (poly(N-hydroxyethyl acrylamide)), and bactericidal TCS (triclosan) into single surfaces by polymerizing and grafting polyDVBAPS and polyHEAA onto the substrate in a different way to form two types of polyDVBAPS/poly(HEAA-g-TCS) and poly(DVBAPS-b-HEAA-g-TCS) brushes with different hierarchical structures, as confirmed by X-ray photoelectron spectroscopy (XPS), atom force microscopy (AFM), and ellipsometry. Both types of polymer brushes demonstrated their tri-functional antibacterial activity to resist bacterial attachment by polyHEAA, to release ∼90% of dead bacteria from the surface by polyDVBAPS, and to kill ∼90% of bacteria on the surface by TCS. Comparative studies also showed that removal of any component from polyDVBAPS/poly(HEAA-g-TCS) and poly(DVBAPS-b-HEAA-g-TCS) compromised the overall antibacterial performance, further supporting a synergistic effect of the three compatible components. More importantly, the presence of salt-responsive polyDVBAPS allowed both brushes to regenerate with almost unaffected antibacterial capacity for reuse in multiple kill-and-release cycles. The tri-functional antibacterial surfaces present a promising design strategy for further developing next-generation antibacterial materials and coatings for antibacterial applications.

18.
Endocr J ; 66(10): 923-936, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31292308

RESUMO

Promoting brown adipose tissue (BAT) formation and function reduces obesity. Ellagic Acid (EA), located abundantly in plant extracts and fruits, has been shown to modulate formation and differentiation of adipocytes, although its role in the process of browning of white adipose tissue (WAT) has not been elucidated. In this study, fifty-six five-week old SD rats were randomly assigned to receive normal diet (ND, 10% lipids) or high-fat diet (HFD, 60% lipid) with or without various dosages of EA for 24 weeks. Our results showed that high fat diet intake triggered overweight, glucose intolerance and white adipocyte hypertrophy, the effects of which were mitigated by EA treatment. Meanwhile, EA supplementation reduced serum resistin levels, improved hepatic steatosis and serum lipid profile in DIO (high fat diet induced obesity) rats. Moreover, EA supplementation significantly decreased mRNA expression of Zfp423 and Aldh1a1, the key determinants of WAT plasticity. EA also increased mRNA expression of brown adipocyte markers including UCP1, PRDM16, Cidea, PGC1α, Ppar-α; beige markers including CD137and TMEM26; mitochondrial biogenesis markers including TFAM in inguinal WAT (iWAT) when compared to their counterparts. EA treatment significantly improved mitochondrial function, as measured by citrate synthase activity. More importantly, EA markedly elevated the expression of UCP1 in iWAT, which is a specific protein of brown adipocyte. In conclusion, our results provided evidence that EA improved obesity-induced dyslipidemia and hepatic steatosis in DIO rats via browning of iWAT through suppressing white adipocyte maintaining genes and promoting expression of key thermogenic genes. These findings suggest that EA could be a promising therapeutic avenue to treat metabolic diseases.

19.
Langmuir ; 35(25): 8285-8293, 2019 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-31194566

RESUMO

Polyzwitterionic brushes with strong antipolyelectrolyte effects have shown great potential as versatile platforms for the development of switchable friction/lubrication and bacterial absorption/desorption surfaces. However, the surface property switches of these brushes are usually triggered by high salt concentrations (>0.53 M), thereby greatly limiting their applications in biological fields where the salt concentration for mammals is ?0.15 M. To solve this problem, an electric field was used to assist the salt-responsive process of the polyzwitterionic brushes to achieve bacterial release at low concentrations of the salt solution. Briefly, poly(3-(dimethyl (4-vinylbenzyl) ammonium) propyl sulfonate) (polyDVBAPS) brushes grafted on ITO surfaces were prepared by surface initiated atom transfer radical polymerization. The bacterial release of this surface was conducted under an electric field, where anions were migrated and enriched around the brush-grafted ITO surface as anode. The local high concentration ion led to the conformation change of the brush and release of the attached bacteria. The effect of salt type, salt concentration, electric field strength, and conducting time on the bacterial release properties were investigated. The results indicated that under an electrical field of 3 V/mm, polyDVBAPS showed release capacities of ?93% for E. coli and ?81% for S. aureus in 0.12 M NaCl electrolyte solution. Furthermore, by the introduction of a bactericidal agent, i.e., Triclosan (TCS), an antibacterial surface with dual functions of killing and release was fabricated. This surface could kill ?90% and release 95% of attached E. coli in a 0.12 M NaCl solution by the application of a 3 V/mm electric field. This work demonstrated the feasibility of triggering a salt-responsive behavior of polyzwitterionic at low salt concentration by assistance of electric field, which would greatly extend the applications of polyzwitterionic, in particular in biological applications.

20.
Mucosal Immunol ; 12(5): 1130-1140, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31182817

RESUMO

SARI functions as a suppressor of colon cancer and predicts survival of colon cancer patients, but its role in regulating colitis has not been characterized. Here we show that SARI-/- mice were highly susceptible to colitis, which was associated with enhanced macrophage infiltration and inflammatory cytokine production. Bone marrow reconstitution experiments demonstrated that disease susceptibility was not dependent on the deficiency of SARI in the immune compartment but on the protective role of SARI in the intestinal epithelial cells (IECs). Furthermore, SARI deficiency enhanced Chemokine (C-C motif) Ligand 2 (CCL2) production and knockout of CCR2 blocks the promoting role of SARI deficiency on colitis. Mechanistically, SARI directly targets and promotes signal transducer and activator of transcription 1 (STAT1) degradation in IECs, followed by persistent inactivation of the STAT1/CCL2 transcription complex. In summary, SARI attenuated colitis in mice by impairing colitis-dependent STAT1/CCL2 transcriptional activation in IECs and macrophages recruitment in colon tissue.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA