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1.
Nat Commun ; 11(1): 4977, 2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33020483

RESUMO

Although thousands of breast cancer cells disseminate and home to bone marrow until primary surgery, usually less than a handful will succeed in establishing manifest metastases months to years later. To identify signals that support survival or outgrowth in patients, we profile rare bone marrow-derived disseminated cancer cells (DCCs) long before manifestation of metastasis and identify IL6/PI3K-signaling as candidate pathway for DCC activation. Surprisingly, and similar to mammary epithelial cells, DCCs lack membranous IL6 receptor expression and mechanistic dissection reveals IL6 trans-signaling to regulate a stem-like state of mammary epithelial cells via gp130. Responsiveness to IL6 trans-signals is found to be niche-dependent as bone marrow stromal and endosteal cells down-regulate gp130 in premalignant mammary epithelial cells as opposed to vascular niche cells. PIK3CA activation renders cells independent from IL6 trans-signaling. Consistent with a bottleneck function of microenvironmental DCC control, we find PIK3CA mutations highly associated with late-stage metastatic cells while being extremely rare in early DCCs. Our data suggest that the initial steps of metastasis formation are often not cancer cell-autonomous, but also depend on microenvironmental signals.

2.
Prostate ; 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33022763

RESUMO

BACKGROUND: Recent genomic profiling has identified a subtype of prostate cancer (PCa) characterized by two key genetic alterations: missense mutation of speckle-type POZ protein (SPOP) and homozygous deletion of chromodomain helicase DNA-binding protein 1 (CHD1). Mutually exclusive with E26 transformation-specific (ETS) rearrangements, this subtype displays high genomic instability. Previous studies indicate that deficient SPOP or CHD1 alone leads to feeble prostate abnormalities and each protein is involved in DNA damage response (DDR). It remains to be determined whether CHD1 and SPOP cooperate to suppress prostate tumorigenesis and DDR. METHODS: Prostate-specific single or double knockout of Spop and Chd1 was generated with the Cre/loxP system in mice. Wild-type or mutant SPOP (F102C, F133V) overexpression and CHD1 knockdown with short hairpin RNA were created in human benign prostatic hyperplasia cell line BPH1. The levels of DNA damage and homologous recombination repair were measured by immunofluorescence staining of γH2AX and RAD51, respectively. RESULTS: Spop/Chd1 double-knockout mice displayed prostatic intraepithelial neoplasia at both young (3 months) and old (12 months) ages and failed to generate prostate adenocarcinoma. Compared with wild-type or single-knockout mice, the double-knockout prostate harbored moderately higher proliferating cells and dramatically augmented the level of γH2AX staining, although androgen receptor-positive cells and apoptotic cells remained at a similar level. In BPH1 cell line, SPOP mutant overexpression and CHD1 silencing synergistically sensitized the cells to DNA damage by camptothecin, an inducer of double-strand breaks. CONCLUSIONS: Our results indicate that SPOP and CHD1 can synergistically promote repair of naturally occurring or chemically induced DNA damages in prostate epithelial cells. Regarding the progression of the SPOP/CHD1 subtype of PCa, other functionally complementary drivers warrant further identification. The clinical implication is that this subtype of PCa may be particularly sensitive to poly(ADP-ribose) polymerase inhibitors or DNA-damaging agents.

3.
Biomaterials ; 265: 120416, 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-33007612

RESUMO

Hepatocellular carcinoma (HCC) is one of the most lethal tumors worldwide. This study aims to address the lack of faithful and available in vitro models for patient-specific drug screening for HCC. We recently established a novel modeling system using three-dimensional (3D) bioprinting technology and constructed hepatorganoids with HepaRG cells, which retain the liver function and prolong the survival of mice with liver failure after abdominal transplantation. Here we extend this modeling system to establish individualized model for hepatocellular carcinoma. HCC specimens were obtained from six patients after surgery. Primary HCC cells were isolated and mixed with gelatin and sodium alginate to form the bioink for printing. Patient-derived three-dimensional bio-printed HCC (3DP-HCC) models were successfully established afterward and grew well during long-term culture. These models retained the features of parental HCCs, including stable expression of the biomarker, stable maintenances of the genetic alterations and expression profiles. 3DP-HCC models are capable of displaying the results of drug screening intuitively and quantitatively. In conclusion, 3DP-HCC models are faithful in vitro models that are reliable in long-term culture and able to predict patient-specific drugs for personalized treatment.

4.
BMC Cancer ; 20(1): 980, 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33036576

RESUMO

BACKGROUND: Serum lipids were reported to be the prognostic factors of various cancers, but their prognostic value in malignant biliary tumor (MBT) patients remains unclear. Thus we aim to assess and compare prognosis values of different serum lipids, and construct a novel prognostic nomogram based on serum lipids. METHODS: Patients with a confirmed diagnosis of MBT at our institute from 2003 to 2017 were retrospectively reviewed. Prognosis-related factors were identified via univariate and multivariate Cox regression analyses. Then the novel prognostic nomogram and a 3-tier staging system were constructed based on these factors and further compared to the TNM staging system. RESULTS: A total of 368 patients were included in this study. Seven optimal survival-related factors-TC/HDL >  10.08, apolipoprotein B >  0.9 g/L, lipoprotein> 72 mg/L, lymph node metastasis, radical cure, CA199 > 37 U/mL, and tumor differentiation -were included to construct the prognostic nomogram. The C-indexes in training and validation sets were 0.738 and 0.721, respectively. Besides, ROC curves, calibration plots, and decision curve analysis all suggested favorable discrimination and predictive ability. The nomogram also performed better predictive ability than the TNM system and nomogram without lipid parameters. And the staging system based on nomogram also presented better discriminative ability than TNM system (P < 0.001). CONCLUSIONS: The promising prognostic nomogram based on lipid parameters provided an intuitive method for performing survival prediction and facilitating individualized treatment and was a great complement to the TNM staging system in predicting overall survival.

5.
Arch Gynecol Obstet ; 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32888090

RESUMO

PURPOSE: To evaluate the therapeutic role of lymphadenectomy on patients with malignant ovarian germ cell tumor (MOGCT) and to investigate the risk factors of lymph node metastasis. METHODS: Patients of MOGCT between 1988 and 2013 with definite lymph node information were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Survival curves were estimated using the Kaplan-Meier method, and Cox regression analyses were performed to evaluate the effects of clinical and pathologic variables on survival. RESULTS: 2424 MOGCT patients with information on lymph nodes were included. Of the entire cohort, 46.2% patients received lymphadenectomy. The most common (42.2%) histologic type was teratoma, and 70.6% patients had FIGO stage I disease. Cox proportional model verified that age, grade, and log odds of positive lymph nodes (LODDS) were independent prognostic factors. Subgroup analysis showed that the association between the lymph node resection and better survival in the different age cohort. CONCLUSIONS: Lymphadenectomy is not recommended for children (0-14 years). For patients 40 years of age and older, and for those who have the dysgerminoma type or endodermal sinus type, lymphadenectomy had an outstanding therapeutic role. As a parameter to assess lymph node status, LODDS could be used to classify MOGCTs.

6.
J Surg Oncol ; 2020 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-32885449

RESUMO

BACKGROUND: Stromal and immune cells play important roles in hepatocellular carcinoma (HCC) development and progression. However, tools for predicting the prognosis of patients with HCC based on stromal and immune scores are not well established. We aimed to develop nomograms that predicted the disease-free survival (DFS) and overall survival (OS) of patients after radical surgery. METHODS: Basic information of 251 patients were retrieved from The Cancer Genome Atlas. Multivariate Cox analyses identified variables predicting the prognosis of patients. DFS and OS nomograms were constructed based on the stromal and immune scores of the training group and verified in the well-matched test group. RESULTS: An intermediate stromal score (hazards ratio [HR] = 3.177; P < .001] was an independent risk factor for DFS. An intermediate immune score independently predicted a longer DFS (HR = 0.323; P = .002) and OS (HR = 0.305; P = .021); a high immune score predicted a longer DFS (HR = 0.289; P = .002). The concordance index (C-index) of nomograms was 0.729 for DFS and 0.696 for OS in the test group. CONCLUSION: Nomograms based on the stromal and immune scores favorably predicted the DFS and OS of patients with HCC after radical surgery.

7.
Crit Rev Food Sci Nutr ; : 1-17, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32885986

RESUMO

Foodborne diseases caused by pathogens and toxins are a serious threat to food safety and human health; thus, they are major concern to society. Existing conventional foodborne pathogen or toxin detection methods, including microbiological assay, nucleic acid-based assays, immunological assays, and instrumental analytical method, are time-consuming, labor-intensive and expensive. Because of the fast response and high sensitivity, cell-based biosensors are promising novel tools for food safety risk assessment and monitoring. This review focuses on the properties of mammalian cell-based biosensors and applications in the detection of foodborne pathogens (bacteria and viruses) and toxins (bacterial toxins, mycotoxins and marine toxins). We discuss mammalian cell adhesion and how it is involved in the establishment of 3D cell culture models for mammalian cell-based biosensors, as well as evaluate their limitations for commercialization and further development prospects.

8.
Artigo em Inglês | MEDLINE | ID: mdl-32876735

RESUMO

Neoantigens are T-cell antigens derived from protein-coding mutations in tumor cells. Although neoantigens have recently been linked to anti-tumor immunity in long-term survivors of cancers such as melanoma, their prognostic and immune-modulatory role in many cancer types remain unexplored. We investigate neoantigens in hepatocellular carcinoma (HCC) through a combination of whole exome sequencing (WES), RNA sequencing (RNA-seq), computational bioinformation, and immunohistochemistry. Our analysis reveals that patients carried with TP53 neoantigen have a longer overall survival than others (p = 0.0371) and they showed higher Immune score (p = 0.0441), higher cytotoxic lymphocytes infiltration (p = 0.0428), and higher CYT score (p = 0.0388). In contrast, the prognosis is not associated with TMB and neoantigen load. Our study draws a preliminary conclusion that it is not TMB or neoantigen load but the TP53 specific neoantigen is related to overall survival of HCC patients. We suggest that the TP53 neoantigen may affect prognosis by regulating anti-tumor immunity and that the TP53 neoantigen may be harnessed as potential targets for immunotherapies of HCC.

9.
Zool Res ; : 1-7, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32918406

RESUMO

Recent studies have shown that the closely related cinereous tit (Parus cinereus) and green-backed tit (P. monticolus) in China display strong egg recognition ability in contrast to tit species in Europe, which lack such ability. However, egg recognition in other populations of cinereous and green-backed tits and additional Paridae species still requires further research. Here, we compared the egg recognition abilities of cinereous tits across China, green-backed tits (P. m. insperatus) in Taiwan, China, and five other species from the Paridae family, including the marsh tit (Poecile palustris), varied tit (Sittiparus varius), willow tit (Poecile montanus), coal tit (Periparus ater), and ground tit (Pseudopodoces humilis). Results showed that the Hebei (58.8% egg rejection, n=17) and Liaoning populations (53.3%, n=15) of cinereous tits, and the Guizhou (100%, n=12) and Taiwan populations (75%, n=12) of green-backed tits all exhibited high egg recognition ability. The egg recognition ability of these tits was significantly greater than that of the other five species in the Paridae family. The varied tit (5.4%, n=37), marsh tit (8.3%, n=12), willow tit (Hebei: 25%, n=20; Beijing: 9.5%, n=21), coal tit (16.7%, n=18), and ground tit (0, n=5) species all showed low egg recognition abilities, with no significant differences found among them. Egg recognition was not associated with a single phylogenetic group but occurred in several groups of tits. In particular, those species widely distributed in the Indomalayan realm, thus overlapping with small cuckoo species, displayed strong egg recognition ability, whereas tit species in the Palearctic realm exhibited low or no egg recognition ability.

10.
Artigo em Inglês | MEDLINE | ID: mdl-32957886

RESUMO

BACKGROUND: Neoantigens are newly formed antigens that have not been previously recognized by the immune system. They may arise from altered tumor proteins that form as a result of mutations. Although neoantigens have recently been linked to antitumor immunity in long-term survivors of cancers, such as melanoma and colorectal cancer, their prognostic and immune-modulatory role in many cancer types remains undefined. OBJECTIVE: The purpose of this study is to identify prognostic markers for long-term extrahepatic cholangiocarcinoma (EHCC) survival. METHODS: We investigated neoantigens in EHCC, a rare aggressive cancer with a 5-year overall survival rate lower than 10%, using a combination of whole exome sequencing (WES), RNA sequencing (RNA-seq), computational biophysics, and immunohistochemistry. RESULTS: Our analysis revealed a decreased neutrophil infiltration-related trend of high-quality neoantigen load with IC50 <500 nM (r=0.445, P=0.043). Among 24 EHCC patients examined, we identified four long term survivors with WDFY3 neoantigens, and none with WDFY3 neoantigens in the short-term survivors. The WDFY3 neoantigens are associated with a lower infiltration of neutrophils (p=0.013), lower expression of CCL5 (p=0.025), CXCL9 (p=0.036) and TIGIT (p=0.016), and less favorable prognosis (p=0.030). In contrast, the prognosis was not significantly associated with tumor mutation burden, neoantigen load, or immune cell infiltration. CONCLUSION: We suggest that the WDFY3 neoantigens may affect prognosis by regulating antitumor immunity and that the WDFY3 neoantigens may be harnessed as potential targets for immunotherapy of EHCC.

11.
Bioorg Chem ; 104: 104246, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32911197

RESUMO

Cryptotanshinone (1), a major bioactive constituent in the traditional Chinese medicinal herb Dan-Shen Salvia miltiorrhiza Bunge, has been reported to possess remarkable pharmacological activities. To improve its bioactivities and physicochemical properties, in the present study, cryptotanshinone (1) was biotransformed with the fungus Cunninghamella elegans AS3.2028. Three oxygenated products (2-4) at C-3 of cryptotanshinone (1) were obtained, among them 2 was a new compound. Their structures were elucidated by comprehensive spectroscopic analysis including HRESIMS, NMR and ECD data. All of the biotransformation products (2-4) were found to inhibit significantly lipopolysaccharide-induced nitric oxide production in BV2 microglia cells with the IC50 values of 0.16-1.16 µM, approximately 2-20 folds stronger than the substrate (1). These biotransformation products also displayed remarkably improved inhibitory effects on the production of inflammatory cytokines (IL-1ß, IL-6, TNF-α, COX-2 and iNOS) in BV-2 cells via targeting TLR4 compared to substrate (1). The underlying mechanism of 2 was elucidated by comparative transcriptome analysis, which suggested that it reduced neuroinflammatory mainly through mitogen-activated protein kinase (MAPK) signaling pathway. Western blotting results revealed that 2 downregulated LPS-induced phosphorylation of JNK, ERK, and p38 in MAPK signaling pathway. These findings provide a basal material for the discovery of candidates in treating Alzheimer's disease.

12.
Artigo em Inglês | MEDLINE | ID: mdl-32920480

RESUMO

Gas chromatography-mass spectrometry (GC-MS) is an ideal tool for analyzing the intermediates of tricarboxylic acid cycle and glycolysis, sugars, organic acids and amino acids, etc. High-throughput metabolomics methods are required by large-scale clinical researches, and time of flight mass spectrometry (TOF MS) having fast scanning rate is preferable for rapid GC. Quadrupole MS (qMS) instruments have 95% market share, and their potential in rapid metabolomics is worth being studied. In this work, a within 15-min GC program was established and matched by qMS scanning for plasma metabolome analysis after N-methyl-N-(trimethylsilyl)-trifluoroacetamide derivatization. Compared to the longer-time program GC-qMS method, the rapid GC-qMS method had nearly no metabolome information loss, and it had excellent profile performance in repeatability, intra-day and inter-day precision, sampling range, linearity and extraction recovery. Compared to TOF MS, qMS achieved similar results in investigating lung cancer serum metabolic disruptions. Partial least squares-discriminant analysis revealed that the two datasets acquired by qMS and TOF MS had very similar model parameters, and most of top ranked differential metabolites were the same. This study provides a rapid and economical GC-qMS metabolomics method for researchers. Still, MS having faster scanning rate and higher sensitivity are recommended, if possible, to detect more small peaks and some co-eluted peaks.

13.
J Ovarian Res ; 13(1): 113, 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32958014

RESUMO

OBJECTIVE: To assess the anti-tumor activity and side effects of different dosages of paclitaxel (albumin binding type) (hereinafter referred to as nab-P) combined with Apatinib (hereinafter referred to as AP) in platinum-resistant ovarian cancer cell line and xenograft models. METHODS: SKOV-3/DDP cell line was selected as the research object in cytology experiment. Firstly, we divided it into three groups for experiments to explore the individual effects of nab-P and AP. a): Control group, blank control, no drug intervention; b): nab-P group, nab-P 40 µmol/l; c): AP group, AP 50 µmol/l (Drug doses were IC-50 values that detected by MTT assay). Apoptosis related protein (Bax, bcl-2), vascular related protein(p-VEGFR-2), invasion related protein (MMP-2) expression were detected by Western blot and Cellular immunofluorescence, the invasion ability of tumor cells were detected by Transwell and Cell scratch test. Based on these dates, secondly, establishing different doses of nab-P combined with Ap to explore the curative effect of combination therapy. a): Control group, blank control, no drug intervention; b): Group-1, nab-P 5 µmol/l + AP 10 µmol/l, c): Group-2, nab-P 4.5 µmol/l + AP 10 µmol/l, d): Group-3, nab-P 4 µmol/l + AP 10 µmol/l, e): nab-P group, nab-P 5 µmol/l, f): AP group, AP 10 µmol/l (MTT assay). The combination index was analyzed by Compusyn software, Western blot, Immunofluescence, Transwell and Cell scratch test also were also chose to observe of inhibition effect. Thirdly, we used xenograft models to verify the results of cytological experiments. Tumor-forming BALB/c female nude mice were randomly divided into 4 groups, a): Control group, no drug intervention, only saline injection, b): nab-P 20 mg/kg + AP 150 mg/kg, c): nab-P 18 mg/kg + AP 150 mg/kg, d): nab-P 16 mg/kg + AP 150 mg/kg (The doses were guided by the pharmaceutical manufacturers). The tumor growth curve was analyzed during the experiment. And the apoptosis related protein (Bax, bcl-2), angiogenesis related protein (CD31, p-VEGFR-2) and invasion related protein (MMP-2) were observed by Western blot, Immunofluescence and Immunohistochemistry to analysis the ant-tumor effects. The quality of life in nude mice were observed to analysed the drug-induced side effects. RESULT: In the separate medication section, (1) The IC-50 value of nab-P was 45.53 ± 4.06 µmol/l, while the AP was 50.66 ± 4.96 umol/L (48 h). (2) The expressions of bcl-2 (nab-P group, AP group), p-VEGFR-2 (AP group), MMP-2(nab-P group, AP group) were higher than Control group, while Bax (nab-P group, AP group) lower (P < 0.01). (3) The cell invasive ability was decreased after the nab-P and AP intervation (P < 0.01). In the combination medication section, (1) Compusyn showed the Combination index (Cl) were all below 1 (Cl < 1), that means nab-P and AP are synergism. (2) The combination IC-50 value was nab-P 5.28 µmol/l + AP 10.56 µmol/l (48 h). (3) In the detection of related protein expression, the combination of drugs can improve the anti-tumor effect, otherwise, after combined with AP, when nab-P were reduced dose in proper quantity, there were no obvious different in drug effect. (4) After reducing the doses of nab-P, the average food intake of nude mice increased from 4.50 g ± 0.17 to 5.55 g ± 0.13, and the one-hour activity increased from 6.11 min ±0.16 to 6.34 min ±0.13. CONCLUSION: nab-P, a chemotherapeutic agent, can play an anti-tumor role in platinum-resistant ovarian cancer, but it can cause adverse effects that increase with dose. When combined with AP, the two drugs have synergistic effect, which can improve the anti-tumor effects of single drug. In addition, when combined with AP, the doses of nab-P can be appropriately reduced under the standard of recommended to reduce the toxicity of chemotherapy drugs, without affecting the anti-tumor effect.

14.
Sci Rep ; 10(1): 15021, 2020 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-32929120

RESUMO

Ubiquinol-cytochrome c reductase hinge protein (UQCRH) is the hinge protein for the multi-subunit complex III of the mitochondrial electron transport chain and is involved in the electron transfer reaction between cytochrome c1 and c. Recent genome-wide transcriptomic and epigenomic profiling of clear cell renal cell carcinoma (ccRCC) by The Cancer Genome Atlas (TCGA) identified UQCRH as the top-ranked gene showing inverse correlation between DNA hypermethylation and mRNA downregulation. The function and underlying mechanism of UQCRH in the Warburg effect metabolism of ccRCC have not been characterized. Here, we verified the clinical association of low UQCRH expression and shorter survival of ccRCC patients through in silico analysis and identified KMRC2 as a highly relevant ccRCC cell line that displays hypermethylation-induced UQCRH extinction. Ectopic overexpression of UQCRH in KMRC2 restored mitochondrial membrane potential, increased oxygen consumption, and attenuated the Warburg effect at the cellular level. UQCRH overexpression in KMRC2 induced higher apoptosis and slowed down in vitro and in vivo tumor growth. UQCRH knockout by CRISPR/Cas9 had little impact on the metabolism and proliferation of 786O ccRCC cell line, suggesting the dispensable role of UQCRH in cells that have entered a Warburg-like state through other mechanisms. Together, our study suggests that loss of UQCRH expression by hypermethylation may promote kidney carcinogenesis through exacerbating the functional decline of mitochondria thus reinforcing the Warburg effect.

15.
BMC Genomics ; 21(1): 556, 2020 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-32791963

RESUMO

BACKGROUND: Tea plant is one of the most important non-alcoholic beverage crops worldwide. While potassium (K+) is an essential macronutrient and greatly affects the growth and development of plants, the molecular mechanism underlying K+ uptake and transport in tea plant root, especially under limited-K+ conditions, is still poorly understood. In plants, HAK/KUP/KT family members play a crucial role in K+ acquisition and translocation, growth and development, and response to stresses. Nevertheless, the biological functions of these genes in tea plant are still in mystery, especially their roles in K+ uptake and stress responses. RESULTS: In this study, a total of 21 non-redundant HAK/KUP/KT genes (designated as CsHAKs) were identified in tea plant. Phylogenetic and structural analysis classified the CsHAKs into four clusters (I, II, III, IV), containing 4, 8, 4 and 5 genes, respectively. Three major categories of cis-acting elements were found in the promoter regions of CsHAKs. Tissue-specific expression analysis indicated extremely low expression levels in various tissues of cluster I CsHAKs with the exception of a high root expression of CsHAK4 and CsHAK5, a constitutive expression of clusters II and III CsHAKs, and a moderate cluster IV CsHAKs expression. Remarkably, the transcript levels of CsHAKs in roots were significantly induced or suppressed after exposure to K+ deficiency, salt and drought stresses, and phytohormones treatments. Also notably, CsHAK7 was highly expressed in all tissues and was further induced under various stress conditions. Therefore, functional characterization of CsHAK7 was performed, and the results demostrated that CsHAK7 locates on plasma membrane and plays a key role in K+ transport in yeast. Taken together, the results provide promising candidate CsHAKs for further functional studies and contribute to the molecular breeding for new tea plants varieties with highly efficient utilization of K+. CONCLUSION: This study demonstrated the first genome-wide analysis of CsHAK family genes of tea plant and provides a foundation for understanding the classification and functions of the CsHAKs in tea plants.

16.
Sci Rep ; 10(1): 13294, 2020 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-32764704

RESUMO

Seed deterioration due to ageing strongly affects both germplasm preservation and agricultural production. Decelerating seed deterioration and boosting seed viability become increasingly urgent. The loss of seed viability is inevitable even under cold storage. For species with short-lived seed or for regions with poor preservation infrastructure where cold storage is not readily available, seed enhancement is more reliable to increase seed viability and longevity. Antioxidant priming as a way of seed enhancement usually improves seed germination. As for post-priming survival, however, significant uncertainty exists. The controversy lies particularly on seeds of high germination percentage (GP > 95%) whose viability is hardly improvable and the benefits of priming depend on prolonging seed longevity. Therefore, this study timed antioxidant priming to prolong the longevity of high-viability seeds under artificially accelerated ageing (AAA). Rice (Nipponbare) seeds (GP > 97%) under room-temperature-storage (RTS) for 6 months. were resistant to AAA first with little viability loss for a certain period, the resistant stage. This resistance gradually vanished without GP change, during a prolonged RTS period which was named the vulnerable stage. According to the results, although antioxidant priming severely curtailed the resistant stage for seeds with a long plateau in the survival curve, it decelerated viability loss for seeds in the vulnerable stage. In complement to seed storage, priming potentially retains high seed GP which would decrease without seed enhancement. To maximize the benefits of priming for high-GP seeds, two time points are advised as the start of a time window for priming: (1) just at the end of the resistant stage without notable viability loss, which is hard to grasp by GP monitoring; (2) slight but identifiable GP decline.

17.
Mediators Inflamm ; 2020: 6243019, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32774147

RESUMO

Objective: To investigate the role of soluble interleukin-2R (sIL-2R) in idiopathic inflammatory myopathies (IIM). Methods: Serum sIL-2R levels were measured in 74 dermatomyositis (DM), 16 immune-mediated necrotizing myopathy (IMNM), 24 rheumatoid arthritis (RA), 20 systemic lupus erythematosus (SLE), and 20 healthy controls (HCs) by chemiluminescent immunometric assay. Clinical features and laboratory data were collected from electronic medical record. Disease activity was evaluated by using physician global disease activity and myositis disease activity assessment visual analog scale (MYOACT) on admission. 20 DM patients were followed. Serum sIL-2R levels were analyzed and compared with clinical features, laboratory data, and measures of disease activity. Results: Serum sIL-2R levels were significantly higher in DM patients than in IMNM patients and HCs (648.8 ± 433.1 U/ml vs. 352.3 ± 126.0 U/ml and 648.8 ± 433.1 U/ml vs. 285.8 ± 101.9 U/ml, respectively; all P < 0.001), while there was no significant difference between IMNM and HCs. There were also no significant differences of sIL-2R levels in DM, SLE, and RA. Importantly, serum sIL-2R levels were significantly higher in treatment-naïve or active DM patients than those that are not (1100.9 ± 550.4 U/ml vs. 615.6 ± 330.4 U/ml, P = 0.006; 808.8 ± 421.6 U/ml vs. 339.8 ± 103.4 U/ml, P < 0.001). DM patients with skin ulcers had significantly higher sIL-2R levels than those without (889.3 ± 509.9 U/ml vs. 640.0 ± 368.7 U/ml, P = 0.023). Cross-sectional analysis in DM showed that sIL-2R levels positively correlated with CK, ESR, CRP, ferritin, physician VAS, and MYOACT scores (rho = 0.278, rho = 0.474, rho = 0.469, rho = 0.454, r = 0.646, and r = 0.600, respectively; all P < 0.05), negatively correlated with T cell counts and MMT8 scores (r = -0.380, P = 0.002; rho = -0.394, P = 0.001). Follow-up study showed that changes in sIL-2R levels after treatment correlated with changes in physician VAS and MYOACT scores (r = 0.823 and r = 0.695, respectively; all P < 0.01). Conclusion: Serum sIL-2R levels were elevated in DM but not in IMNM. Serum sIL-2R could act as a disease activity marker and be associated with ulcerative skin lesions in DM.

18.
Int J Biol Macromol ; 2020 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-32791267

RESUMO

Bacteriocins are a subclass of antibacterial peptides considered to be the most promising alternative to antibiotics. A large number of unknown bacteriocins are hidden in lactic acid bacteria. In this study, by combining the genome with LC-MS/MS, 14 novel bacteriocins produced by Lactobacillus rhamnosus LS-8 were detected. Moreover, these bacteriocins were successfully cloned via plasmid pET-28a(+) and pET-30a(+) and heterologously expressed in Escherichia coli BL21. Escherichia coli ATCC25922 and Staphylococcus aureus ATCC25923 were used to confirm their antibacterial activity. Subsequently, the four bacteriocins (pH 25, S68, S81, and S137) with the strongest antibacterial ability were selected, and their expression conditions were optimized. Purification was performed by cation exchange chromatography and high performance liquid chromatography, and the active parts were collected and analyzed by mass spectrometry. The mass spectrometry analysis revealed that peptide coverage was >71.39%. The MICs of the four bacteriocins against four pathogenic bacteria ranged from 5.38 to 19.84 µg/ml. In addition, these bacteriocins significantly inhibited the growth of four standard pathogenic bacteria. They also exhibited broad-spectrum bacteriostasis on Gram-positive and Gram-negative bacteria. Therefore, these new bacteriocins have great potential in the study of alternative antibiotics.

19.
IUBMB Life ; 2020 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-32827356

RESUMO

Protein glutaminase (PG) is an enzyme that specifically catalyzes the deamidation of glutamine residues on proteins or peptides, remarkably improving the solubility, emulsification and foaming properties of food proteins and, thereby, conferring great potential in food industry applications. PG is primarily produced from wild strains of Chryseobacterium proteolyticum and the low enzyme production yield restricts large-scale industrial applications. In this context, by evaluating different cleavage site insertions between the pro-region and mature domain of PG as well as different linkers flanking the cleavage site, an E. coli expression and purification protocol has been developed to produce active recombinant PG. To simplify the production workflow, we developed a sequential dual expression system. More than 15 mg of pure and active PG was obtained from 1 L of shaking-flask bacteria culture by one-step nickel affinity chromatography purification. The enzymatic characteristics of the recombinant PG protein were similar to those of native PG. For the deamidation effect of recombinant PG, the deamidation degree (DD) of gliadin reached up to 67% and the solubility increased 84-fold. Thus, this study provides a practical approach to mass producing active PG proteins and investigates its potential applications on food proteins.

20.
Anal Chem ; 92(18): 12481-12488, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32786433

RESUMO

Complex mixtures of hydrocarbons are ubiquitous as petroleum fuels and, consequently, environmental contaminants. Because they contain thousands of individual components with similar molecular structures, detailed chemical characterization of hydrocarbon mixtures relies on advanced analytical techniques that are not accessible to many researchers. Many analyses of hydrocarbon mixtures instead characterize them as "unresolved complex mixtures", with quantification limited to a small number of resolvable components and/or total observed mass within specified volatility ranges. This work develops a new analytical approach to characterize the hydrocarbon component of petroleum and environmental mixtures by "hydrocarbon group" (defined by carbon number, degree of unsaturation and, in certain cases, degree of branching) using gas chromatography coupled to a unit-mass-resolution electron ionization quadrupole mass spectrometer (GC/EI-MS), a standard and widely available instrument. Average mass spectra of hydrocarbons from a widely used spectral library are combined with chromatographic signal representing the molecular ion of each hydrocarbon group to recreate the magnitude and mass spectra of the chromatogram. Characterization of hydrocarbons in diesel fuel by this approach is in good agreement with state-of-the-art techniques relying on high-resolution and fast-response mass spectrometers. Application of this approach to subsurface soil gas samples from remediated sites of underground storage tank spills demonstrates that composition of hydrocarbons in environmental samples varies significantly and that the total signal of samples from contaminated sites may contain a substantial fraction of oxygenated components.

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