Publications by authors named "Hailong Yang"

88 Publications

EGCG Induces Pro-inflammatory Response in Macrophages to Prevent Bacterial Infection through the 67LR/p38/JNK Signaling Pathway.

J Agric Food Chem 2021 May 17;69(20):5638-5651. Epub 2021 May 17.

Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu, China.

Extensive studies focused on the therapeutic efficacy of epigallocatechin-3-gallate (EGCG) against bacterial infection. However, little is known about its prophylactic efficacy against bacterial infection. Herein, we found that EGCG showed an effective prophylactic efficacy against bacterial infection with a broad spectrum, including Gram-negative, Gram-positive, and drug-resistant bacteria. Pretreatment with EGCG through intraperitoneal injection, intravenous injection, or intragastric administration significantly reduced the bacterial load, inflammatory response, and mortality in mouse abdominal infection models induced by bacterial inoculation or cecal ligation and puncture. Pretreatment with EGCG by intraperitoneal injection significantly increased the numbers of neutrophils and monocytes/macrophages in the abdominal cavity and peripheral blood of mice, and depletion of neutrophils and monocytes/macrophages by specific antibodies or chemical drugs obviously increased the bacterial load in mice. Of note, EGCG did not directly induce neutrophil and macrophage migration, and it just induced phagocyte migration in the presence of macrophages in a co-cultured system, implying that EGCG-induced phagocyte migration relies on its immunoregulatory effects on macrophages. EGCG markedly induced the production of cytokines and chemokines in macrophages and mouse peritoneal lavage, including tumor necrosis factor-α (TNF-α), interleukin-1 β (IL-1β), IL-6, CXC chemokine ligands 1 and 2 (CXCL1 and 2), and monocyte chemotactic protein-1 (MCP-1). EGCG significantly induced the phosphorylation of p38 and JNK mitogen-activated protein kinases (MAPKs) in macrophages, and inhibition of p38 and JNK MAPKs markedly reduced EGCG-induced chemokine and cytokine production. Anti-67-kDa laminin receptor (67LR) antibody treatment significantly reduced EGCG-induced chemokine production and p38 and JNK phosphorylation in macrophages. Together, EGCG showed an obvious prophylactic efficacy against bacterial infection by inducing a pro-inflammatory response in macrophages through the 67LR/p38/JNK signaling pathway, supporting the further development of EGCG as a potent prophylaxis for bacterial infection and providing new clues to understand the healthcare function of green tea.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.jafc.1c01353DOI Listing
May 2021

Generation of coherent multicolor noise-like pulse complex in Yb-doped fiber laser mode-locked by GIMF-SA.

Opt Express 2021 May;29(10):14336-14344

We have demonstrated the generation of multicolor noise-like pulse complex in a passively Yb-doped mode-locked fiber laser based on a single mode-graded index multimode-single mode fiber (SMF-GIMF-SMF) device as the saturable absorber (SA). The stimulated Raman scattering (SRS) effect leads to the cascaded generation of the main noise-like pulse (NLP) at 1028.8 nm together with the noise like Raman pulse (RP) at 1076.1 nm. The generated dual wavelength pulses demonstrate the unique properties of mutually synchronization and coherence. The autocorrelation traces show that each of the synchronously mode-locked pulses exhibits a double-scale structure with a narrow peak which consists of a train of quasi-periodic beat pulses with a 35.7 fs pulse width and a pulse separation of about 77.2 fs. The total output power reaches 102.5 mW with 34% of it belonging to the RP. And furthermore, by separating the two pulses with spectral filters, the modulation fringes cannot be observed anymore. These results indicate that the Raman component participates in the mode-locking operation as a 'signal' instead of 'noise'. Such a coherent Raman pulse source provides a novel platform for numerous applications, such as frequency comb spectroscopy and so on.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.425326DOI Listing
May 2021

A Photoresponsive Nanozyme for Synergistic Catalytic Therapy and Dual Phototherapy.

Small 2021 Mar 19;17(10):e2007090. Epub 2021 Jan 19.

Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, Bionanomaterials & Translational Engineering Laboratory, Beijing Key Laboratory of Bioprocess, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing, 100029, China.

Dual phototherapy, including photodynamic therapy (PDT) and photothermal therapy (PTT), has shown a great prospect in cancer treatment. However, its therapeutic effect is restricted by the depth of light penetration in tissue and tumor hypoxia environment. Herein, inspired by the specific response of nanozymes to the tumor microenvironment (TME), a simple and versatile nanozyme-mediated synergistic dual phototherapy nanoplatform (denoted as FePc/HNCSs) is constructed using hollow nitrogen-doped carbon nanospheres (HNCSs) and iron phthalocyanine (FePc). FePc/HNCSs simultaneously exhibit peroxidase (POD)- and catalase (CAT)-like activities, which not only can convert endogenous hydrogen peroxide (H O ) into highly toxic hydroxyl radicals (•OH) for catalytic therapy, but also decompose H O to oxygen (O ) to enhance O -dependent PDT. In addition, their enzyme-like activities are significantly enhanced under light irradiation. Combining with the excellent photothermal effect, FePc/HNCSs realize a high tumor inhibition rate of 96.3%. This strategy opens a new horizon for exploring a more powerful tumor treatment nanoplatform.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/smll.202007090DOI Listing
March 2021

Anti-infective Effects of a Fish-Derived Antimicrobial Peptide Against Drug-Resistant Bacteria and Its Synergistic Effects With Antibiotic.

Front Microbiol 2020 23;11:602412. Epub 2020 Nov 23.

Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China.

Antimicrobial peptides (AMPs) play pivotal roles in protecting against microbial infection in fish. However, AMPs from topmouth culter () are rarely known. In our study, we isolated an AMP from the head kidney of topmouth culter, which belonged to liver-expressed antimicrobial peptide 2 (LEAP-2) family. Topmouth culter LEAP-2 showed inhibitory effects on aquatic bacterial growth, including antibiotic-resistant bacteria, with minimal inhibitory concentration values ranging from 18.75 to 150 μg/ml. It was lethal for (resistant to ampicillin), and took less than 60 min to kill at a concentration of 5 × MIC. Scanning electron microscope (SEM) and SYTOX Green uptake assay indicated that it impaired the integrity of bacterial membrane by eliciting pore formation, thereby increasing the permeabilization of bacterial membrane. In addition, it showed none inducible drug resistance to aquatic bacteria. Interestingly, it efficiently delayed ampicillin-induced drug resistance in (sensitive to ampicillin) and sensitized ampicillin-resistant bacteria to ampicillin. The chequerboard assay indicated that topmouth culter LEAP-2 generated synergistic effects with ampicillin, indicating the combinational usage potential of topmouth culter LEAP-2 with antibiotics. As expected, topmouth culter LEAP-2 significantly alleviated ampicillin-resistant infection , and enhanced the therapeutic efficacy of ampicillin against . Our findings provide a fish innate immune system-derived peptide candidate for the substitute of antibiotics and highlight its potential for application in antibiotic-resistant bacterial infection in aquaculture industry.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2020.602412DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7719739PMC
November 2020

Thermoelectric Properties of Sb-S System Compounds from DFT Calculations.

Materials (Basel) 2020 Oct 22;13(21). Epub 2020 Oct 22.

Aix-Marseille University, University of Toulon, CNRS, IM2NP, Campus St Jérôme, 13013 Marseille, France.

By combining density functional theory, quantum theory of atoms in molecules and transport properties calculations, we evaluated the thermoelectric properties of Sb-S system compounds and shed light on their relationships with electronic structures. The results show that, for SbS, the large density of states (DOS) variation induces a large Seebeck coefficient. Taking into account the long-range weak bonds distribution, SbS should exhibit low lattice thermal conductivity. Therefore, SbS is promising for thermoelectric applications. The insertion of Be atoms into the SbS interstitial sites demonstrates the electrical properties and Seebeck coefficient anisotropy and sheds light on the understanding of the role of quasi-one-dimensional structure in the electron transport. The large interstitial sites existing in SbS are at the origin of phonons anharmonicity which counteracts the thermal transport. The introduction of Zn and Ga atoms into these interstitial sites could result in an enhancement of all the thermoelectric properties.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ma13214707DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7684470PMC
October 2020

Fluoxetine regulates glucose and lipid metabolism via the PI3K‑AKT signaling pathway in diabetic rats.

Mol Med Rep 2020 Oct 4;22(4):3073-3080. Epub 2020 Aug 4.

Department of Clinical Psychology, Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu 210000, P.R. China.

Diabetes mellitus poses a major threat towards global heath due to a lack of effective treatment. Fluoxetine hydrochloride, a selective 5‑hydroxytryptamine reuptake inhibitor, is the most commonly used antidepressant in clinical therapy; however, the potential molecular mechanisms of fluoxetine in diabetes remain unknown. In the present study, reduced glucose, total cholesterol and triglyceride levels and lipid metabolism, as well as upregulated proliferator‑activated receptor γ, fatty acid synthase and lipoprotein lipase, and downregulated sterol regulatory element‑binding protein 1‑c were detected in rats with streptozotocin (STZ)‑induced diabetes following treatment with fluoxetine. Furthermore, fluoxetine significantly inhibited the expression levels of glucose metabolism‑associated proteins in liver tissues, including glycogen synthase kinase 3β (GSK‑3β), glucose‑6 phosphatase catalytic subunit (G6PC), phosphoenolpyruvate carboxykinase (PEPCK) and forkhead box protein O1 (FOXO1). In addition, fluoxetine treatment notably attenuated morphological liver damage in rats with STZ‑induced diabetes. Additionally, fluoxetine could inhibit the phosphatidylinositol 3‑kinase‑protein kinase B (PI3K‑AKT) signaling pathway, whereas LY294002, a specific inhibitor of PI3K, suppressed the function of PI3K‑AKT signaling and suppressed the expression levels of glucose metabolism‑associated proteins, including GSK‑3β, G6PC, PEPCK and FOXO1 in BRL‑3A cells. The results of the present study revealed that fluoxetine may regulate glucose and lipid metabolism via the PI3K‑AKT signaling pathway in diabetic rats.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/mmr.2020.11416DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7453494PMC
October 2020

High SARS-CoV-2 antibody prevalence among healthcare workers exposed to COVID-19 patients.

J Infect 2020 09 4;81(3):420-426. Epub 2020 Jun 4.

Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China. Electronic address:

The seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was examined among 105 healthcare workers (HCWs) exposed to four patients who were laboratory confirmed with coronavirus disease 2019 (COVID-19), the disease caused by SARS-CoV-2 infection. These HCWs were immediately under quarantine for 14 days as soon as they were identified as close contacts. The nasopharyngeal swab samples were collected on the first and 14 day of the quarantine, while the serum samples were obtained on the 14 day of the quarantine. With the assay of enzyme immunoassay (EIA) and microneutralization assay, 17.14% (18/105) of HCWs were seropositive, while their swab samples were found to be SARS-CoV-2 RNA negative. Risk analysis revealed that wearing face mask could reduce the infection risk (odds ratio [OR], 0.127, 95% confidence interval [CI] 0.017, 0.968), while when exposed to COVID-19 patients, doctors might have higher risk of seroconversion (OR, 346.837, 95% CI 8.924, 13479.434), compared with HCWs exposed to colleagues as well as nurses and general service assistants who exposed to patients. Our study revealed that the serological testing is useful for the identification of asymptomatic or subclinical infection of SARS-CoV-2 among close contacts with COVID-19 patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jinf.2020.05.067DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7270786PMC
September 2020

Comparative Studies on Bioactive Compounds, Ganoderic Acid Biosynthesis, and Antioxidant Activity of Pileus and Stipes of Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes) Fruiting Body at Different Growth Stages.

Int J Med Mushrooms 2020 ;22(2):133-144

School of Life & Environmental Sciences, Wenzhou University, Wenzhou, China.

Total phenolics, flavonoids, and polysaccharides, and individual ganoderic acid (GA) contents, antioxidant capacity, and transcription levels of key enzyme genes involved in GA biosynthesis in pileus and stipes of Ganoderma lucidum fruiting body at different growth stages were investigated in this study. Results showed that the highest total phenolics and total flavonoids contents were determined in stipes at spore maturity stage, resulting in high antioxidant activity, while the highest total polysaccharide content was found in pileus at the same stage. The pileus contained more GA than the stipes, and higher contents of ganoderic acid A and D were found at fruiting body mature stage while that of ganoderic acid B, C2, and G were found at bud elongation stage. Results from quantitative real-time PCR indicated that higher gene transcription levels of hydroxyl methylglutaryl-CoA reductase (hmgr), farnesyl pyrophosphate synthase (fps), squalene synthase (sqs), and oxidosqualene cyclase (osc) were found in pileus at bud elongation stage. Our findings will be helpful for understanding the biosynthesis of bioactive components and determining the harvest time for the desired G. lucidum fruiting bodies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1615/IntJMedMushrooms.2020033683DOI Listing
December 2020

A Frog-Derived Immunomodulatory Peptide Promotes Cutaneous Wound Healing by Regulating Cellular Response.

Front Immunol 2019 17;10:2421. Epub 2019 Oct 17.

Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, China.

Wound healing-promoting peptides exhibit excellent therapeutic potential in regenerative medicine. However, amphibian-derived wound healing-promoting peptides and their mechanism of action remain to be further elucidated. We hereby characterized a wound healing-promoting peptide, Ot-WHP, derived from Chinese concave-eared frog . It efficiently promoted wound healing in a mouse model of full-thickness wounds. Ot-WHP significantly increased the number of neutrophils in wounds, and modestly promoted neutrophil phagocytosis and phorbol myristate acetate (PMA)-induced neutrophil extracellular trap formation. Ot-WHP also significantly increased the number of macrophages in wound sites, and directly induced chemokine, cytokine and growth factor production in macrophages by activating mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB) signaling pathways. Of note, Ot-WHP did not act as a chemoattractant for neutrophils and macrophages, suggesting its chemotactic activity depends on inducing chemoattractant production in macrophages. Besides, Ot-WHP directly promoted keratinocyte migration by enhancing integrin expression and cell adhesion. In addition, Ot-WHP significantly enhanced the cross-talk between macrophages and keratinocytes/fibroblasts by promoting keratinocyte/fibroblast proliferation, and fibroblast-to-myofibroblast transition despite having no direct effects on keratinocyte/fibroblast proliferation, and fibroblast differentiation. Collectively, Ot-WHP directly elicited the production of regulatory factors in macrophages, consequently initiated and accelerated the inflammatory phase by recruiting neutrophils and macrophages to wounds, and in turn enhanced the cross-talk between macrophages and keratinocytes/fibroblasts, additionally promoted keratinocyte migration, and finally promoted cutaneous wound healing. Our findings provide a promising immunomodulator for acute wound management and new clues for understanding the mechanism of action of amphibian-derived wound healing-promoting peptides.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2019.02421DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6812695PMC
November 2020

High Oxygen Treatments Enhance the Contents of Phenolic Compound and Ganoderic Acid, and the Antioxidant and DNA Damage Protective Activities of Fruiting Body.

Front Microbiol 2019 18;10:2363. Epub 2019 Oct 18.

School of Life and Environmental Sciences, Wenzhou University, Wenzhou, China.

is a famous medicinal mushroom used as Chinese medicine or functional food and has been accepted across the globe. It is important to enhance the contents of bioactive compounds, which in turn improves the quality and biological activity of fruiting body. In this work, freshly harvested fruiting bodies were treated continuously with air or with 60 and 80% oxygen for 6 days. Samples were collected and determined initially and at 1 day interval during treatment. A high total ganoderic acid content of 29.44 g kg was obtained in samples treated with 60% oxygen at day 3. Quantitative reverse transcriptase (qRT)-PCR and high-performance liquid chromatography (HPLC) analysis showed that the expression levels of hydroxymethylglutaryl-CoA synthase, squalene synthase, and oxidosqualene cyclase genes were substantially increased, resulting in the increase of ganoderic acids A, B, and C2 and ganoderenic acid B. The scavenging activities with 1,1-diphenyl-2-picrylhydrazyl radical, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical, hydroxyl radical, and superoxide radical and the DNA damage protective activity were also enhanced by high oxygen treatment. The results of this work provided a potential method to enhance the active metabolite synthesis in the fruiting body of .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2019.02363DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6813255PMC
October 2019

A Nanozyme with Photo-Enhanced Dual Enzyme-Like Activities for Deep Pancreatic Cancer Therapy.

Angew Chem Int Ed Engl 2019 09 2;58(36):12624-12631. Epub 2019 Aug 2.

Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, Bionanomaterials & Translational Engineering Laboratory, Beijing Key Laboratory of bioprocess, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.

Nanozymes have attracted extensive interest owing to their high stability, low cost and easy preparation, especially in the field of cancer therapy. However, the relatively low catalytic activity of nanozymes in the tumor microenvironment (TME) has limited their applications. Herein, we report a novel nanozyme ([email protected] O ) with dual enzyme-like activities for highly efficient tumor catalytic therapy. [email protected] O shows the intrinsic photothermal effect as well as photo-enhanced peroxidase-like and catalase-like activities in the acidic TME, thereby effectively killing tumor cells and overcoming the tumor hypoxia. Importantly, a possible photo-enhanced synergistic catalytic mechanism of [email protected] O was first disclosed. We believe that this work will advance the development of nanozymes in tumor catalytic therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/anie.201904751DOI Listing
September 2019

An atypical case of serotonin syndrome with normal dose of selective serotonin inhibitors: A case report.

Medicine (Baltimore) 2019 May;98(19):e15554

Department of Emergency.

Rationale: As increasing frequency of serotonergic drug use, SS (serotonin syndrome) occurred more than ever. But clinicians have not enough knowledge and experience about SS as a potentially life-threatening condition. SS is usually caused by the increased serotonin activity in the central nervous system which may due to a serotonergic agent overdose or the concomitant use of 2 or more serotonergic antidepressants. We report a case of SS due to a normal dose of selective serotonin inhibitors (SSRIs) thus to remind clinicians to pay attention to such patients and make an early diagnosis and initiation of therapy in the clinical practice.

Patient Concerns: We report here a 49-year-old man presented with lethargic, less communicative, and insomnia for 20 days while a diagnosis of depression was considered and he was treated with SSRIs.

Diagnosis: The patient in our case fulfilled the 3 criteria existed now for diagnosing SS, including the Sternbach criteria, Radomski revised diagnostic criteria, and the Hunter serotonin toxicity criteria.

Interventions: All the antidepressants were stopped and cyproheptadine with an initial dose of 12 mg a day was started along with supportive care. The patient was also admitted to emergency intensive care unit for further treatment. He was sedated and paralyzed by intravenous Midazolam and Clonazepam along with physical cooling and supportive care.

Outcomes: All of the patient's symptoms abated gradually and he soon could get off the bed and be communicative. Finally, the patient made a full recovery and he was discharged from the hospital.

Lessons: Our case suggests an atypical clinical course while the medicine the patient takes was not in so much dose. We assumed that there may have been some variation in metabolism of these agents, resulting in increased possibility that led to the subsequent syndrome. Thus, it is essential for clinicians to keep in mind when patients taking serotonergic agents who demonstrate acute change in their mental status. Besides, clinicians should be aware of such patients who seem to be sensitive to SSRIs, who may require a genetic testing before the initiation of SSRI therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/MD.0000000000015554DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6531198PMC
May 2019

A small mycobacteriophage-derived peptide and its improved isomer restrict mycobacterial infection via dual mycobactericidal-immunoregulatory activities.

J Biol Chem 2019 05 20;294(19):7615-7631. Epub 2019 Mar 20.

From the Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou 215123, Jiangsu,

Mycobacteriophages express various peptides/proteins to infect (). Particular attention has been paid to mycobacteriophage-derived endolysin proteins. We herein characterized a small mycobacteriophage-derived peptide designated AK15 with potent anti- activity. AK15 adopted cationic amphiphilic α-helical structure, and on the basis of this structure, we designed six isomers with increased hydrophobic moment by rearranging amino acid residues of the helix. We found that one of these isomers, AK15-6, exhibits enhanced anti-mycobacterial efficiency. Both AK15 and AK15-6 directly inhibited by trehalose 6,6'-dimycolate (TDM) binding and membrane disruption. They both exhibited bactericidal activity, cell selectivity, and synergistic effects with rifampicin, and neither induced drug resistance to They efficiently attenuated mycobacterial load in the lungs of -infected mice. We observed that lysine, arginine, tryptophan, and an α-helix are key structural requirements for their direct anti-mycobacterial action. Of note, they also exhibited immunomodulatory effects, including inhibition of proinflammatory response in TDM-stimulated or -infected murine bone marrow-derived macrophages (BMDMs) and -infected mice and induction of only a modest level of cytokine (tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6)) production in murine BMDMs and a T-cell cytokine (interferin-γ (IFN-γ) and TNF-α) response in murine lung and spleen. In summary, characterization of a small mycobacteriophage-derived peptide and its improved isomer revealed that both efficiently restrain infection via dual mycobactericidal-immunoregulatory activities. Our work provides clues for identifying small mycobacteriophage-derived anti-mycobacterial peptides and improving those that have cationic amphiphilic α-helices.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1074/jbc.RA118.006968DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6514635PMC
May 2019

A Single-Atom Nanozyme for Wound Disinfection Applications.

Angew Chem Int Ed Engl 2019 04 5;58(15):4911-4916. Epub 2019 Mar 5.

Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, Bionanomaterials & Translational Engineering Laboratory, Beijing Key Laboratory of Bioprocess, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing, 100029, China.

Single-atom catalysts (SACs), as homogeneous catalysts, have been widely explored for chemical catalysis. However, few studies focus on the applications of SACs in enzymatic catalysis. Herein, we report that a zinc-based zeolitic-imidazolate-framework (ZIF-8)-derived carbon nanomaterial containing atomically dispersed zinc atoms can serve as a highly efficient single-atom peroxidase mimic. To reveal its structure-activity relationship, the structural evolution of the single-atom nanozyme (SAzyme) was systematically investigated. Furthermore, the coordinatively unsaturated active zinc sites and catalytic mechanism of the SAzyme are disclosed using density functional theory (DFT) calculations. The SAzyme, with high therapeutic effect and biosafety, shows great promises for wound antibacterial applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/anie.201813994DOI Listing
April 2019

Work-family conflict and job burn-out among Chinese doctors: the mediating role of coping styles.

Gen Psychiatr 2018 21;31(1):e000004. Epub 2018 Aug 21.

Department of Clinical Psychology, Nanjing Brain Hospital Affiliated to Nanjing Medical University, Nanjing, China.

Background: Burn-out among doctors threatens their own health, and that of their patients. To identify risk factors of the doctor burn-out is vital to improving their health and increasing the quality of healthcare services. This study aims to explore the relationship between work-family conflict (WFC) and burn-out among Chinese doctors and the mediating role of coping styles in this relationship.

Methods: A cross-sectional survey was conducted in China, with a questionnaire packet which consisted of the Chinese Maslach Burnout Inventory (CMBI), WFC Scale and the Simplified Coping Style Questionnaire (SCSQ). A total of 2530 doctors participated in the survey. Correlation analysis was performed to explore the relationship between CMBI, WFC and SCSQ scores. A linear regression model was set to determine the mediating role of coping styles on the relationship between WFC and burn-out.

Results: Doctors who had higher scores on work interfering with family conflict, reported more emotional exhaustion (r=0.514, P<0.001) and had a sense of accomplishment (r=-0.149, P<0.001). Simultaneously, family interfering with work (FIW) was positively associated with all dimensions of burn-out (r=0.213, 0.504, 0.088, respectively, P<0.001). Coping styles had partial, complete and even mediating effects on the relationship between WFC and burn-out among Chinese doctors.

Conclusions: WFC was correlated with burn-out, and coping style was a mediator in this relationship among Chinese doctors. Coping style was a positive resource against burn-out.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/gpsych-2018-000004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6211271PMC
August 2018

Anti-inflammatory activities of Aedes aegypti cecropins and their protection against murine endotoxin shock.

Parasit Vectors 2018 Aug 14;11(1):470. Epub 2018 Aug 14.

Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences, Soochow University, Suzhou, 215123, Jiangsu, China.

Background: Mosquitoes are armed with physiologically active compounds to suppress the host immunity including host inflammatory reaction. However, the specific anti-inflammatory components in mosquitoes remain unknown.

Results: By searching for the immunomodulatory molecules from the mosquito Aedes aegypti (Diptera: Culicidae) at NCBI for anti-inflammatory function, five cecropins (for short in this study: AeaeCec1, 2, 3, 4 and 5) were selected. AeaeCec1-5 efficiently inhibited the expression of inducible nitric oxide synthase (iNOS), nitrite, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in lipopolysaccharide (LPS)-stimulated mouse peritoneal macrophages and human peripheral blood mononuclear cells (PBMCs) with low toxicity to mammalian cells. Among the five analogues, AeaeCec5 had the strongest anti-inflammatory activity, and generated an additive effect with other AeaeCec peptides. In a mouse model of endotoxin shock, AeaeCec1-5 effectively reduced TNF-α, IL-1β and IL-6 expression in lungs, serum and peritoneal lavage and correspondingly reduced lung damage and edema, with AeaeCec5 showing the best protection. In mice infected with Escherichia coli or Pseudomonas aeruginosa, administration of AeaeCec5 reduced the production of TNF-α, IL-1β and IL-6 and correspondingly reduced lung tissue damage. These effects of Ae. aegypti AeaeCec1-5 were attributed to an efficient inhibition of the activation of mitogen-activated protein kinases (MAPKs) and transcriptional nuclear factor-κB (NF-κB) signaling pathways, as well as partial neutralization of LPS.

Conclusions: The current work characterized the specific anti-inflammatory agents in Ae. aegypti and provided AeaeCec5 as a potent anti-endotoxin peptide that could serve as the basis for the development of anti-inflammatory therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13071-018-3000-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6092832PMC
August 2018

A frog cathelicidin peptide effectively promotes cutaneous wound healing in mice.

Biochem J 2018 09 11;475(17):2785-2799. Epub 2018 Sep 11.

School of Basic Medical Sciences, Kunming Medical University, Kunming, Yunnan, China

Although cathelicidins in mammals have been well characterized, little is known about the function of cathelicidin in amphibians. In the present study, a novel 24-residue peptide (cathelicidin-NV, ARGKKECKDDRCRLLMKRGSFSYV) belonging to the cathelicidin family was identified from the skin of the plateau frog Cathelicidin-NV showed strong wound healing-promoting activity in a murine model with a full-thickness dermal wound. It directly enhanced the proliferation of keratinocyte cells, resulting in accelerated re-epithelialization of the wound site. Cathelicidin-NV also promoted the proliferation of fibroblasts, the differentiation of fibroblasts to myofibroblasts and collagen production in fibroblasts, which are implicated in wound contraction and repair processes. Furthermore, cathelicidin-NV promoted the release of monocyte chemoattractant protein-1, tumor necrosis factor-α, vascular endothelial growth factor and transforming growth factor-β1 and , which are essential in the wound-healing processes such as migration, proliferation and differentiation. The MAPK (ERK, JNK and p38) signaling pathways were involved in the wound healing-promoting effect. Additionally, unlike other cathelicidins, cathelicidin-NV did not have any direct effect on microbes and showed no cytotoxicity and hemolytic activity toward mammalian cells at concentrations up to 200 µg/ml. This current study may facilitate the understanding of the cellular and molecular events that underlie quick wound healing in In addition, the combination of these properties makes cathelicidin-NV an excellent candidate for skin wound therapeutics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1042/BCJ20180286DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6134359PMC
September 2018

In Situ Growth of Pd Nanosheets on g-C N Nanosheets with Well-Contacted Interface and Enhanced Catalytic Performance for 4-Nitrophenol Reduction.

Small 2018 Jul 19:e1801812. Epub 2018 Jul 19.

Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing Key Laboratory of Bioprocess, Bionanomaterials and Translational Engineering Laboratory, State Key Laboratory of Organic-Inorganic Composites, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.

Loading novel metal nanosheets onto nanosheet support can improve their catalytic performance, but the morphological incompatibility makes it difficult to construct a well-contacted interface, which is of particular interest in supported catalysts. Herein, Pd nanosheets (Pd NSs) are supported onto graphitic carbon nitride nanosheets (CNNSs) with intimate face-to-face contact through an in situ growth method. This method overcomes the limitations of the morphological incompatibility and ensures the intimate interfacial contact between Pd NSs and CNNSs. The nitrogen-rich nature of CNNSs endows Pd NSs with abundant anchoring sites, which optimizes the electronic structure and improves the chemical and morphological stability of Pd NSs. The supported Pd NSs demonstrate high dispersion and exhibit largely enhanced activity toward the reduction of 4-nitrophenol. The concentration-normalized rate constant is up to 3052 min g L, which is 5.4 times higher than that obtained by unsupported Pd NSs. No obvious deactivation is observed after six runs of the recycling experiments. It is believed that the supported novel metal nanosheets with the intimately contacted interface may show promising applications in catalysis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/smll.201801812DOI Listing
July 2018

MiR-183 promotes preadipocyte differentiation by suppressing Smad4 in goats.

Gene 2018 Aug 8;666:158-164. Epub 2018 May 8.

Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China. Electronic address:

As a well-conserved microRNA, miR-183 is ubiquitously expressed in many tissues and cells including backfat and the 3T3-L1 adipocytes; however, the mechanisms regulating miR-183 in adipogenesis remain poorly understood. Here, we explored the expression pattern and role of miR-183 in adipogenesis using hircine preadipocytes. The results showed that miR-183 was up-regulated during preadipocyte differentiation, and overexpression of miR-183 enhanced lipid accumulation and dramatically increased the mRNA expression of the adipogenic genes PPARγ, C/EBPα, SREBP-1c, FAS, and ACC. Using bioinformatics tools, we predicted Smad4 to be a target of miR-183. This was subsequently validated with a luciferase reporter assay. Overexpression of miR-183 suppressed the mRNA and protein levels of Smad4 significantly, whereas inhibiting miR-183 had the opposite effect. However, inhibition of Smad4 greatly accelerated lipid deposition and increased the expression of adipogenic genes which consists with the results of miR-183 overexpression. In conclusion, these results indicate that miR-183 promotes hircine preadipocyte differentiation by targeting Smad4.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.gene.2018.05.022DOI Listing
August 2018

A Co-Precursor Approach Coupled with a Supercritical Modification Method for Constructing Highly Transparent and Superhydrophobic Polymethylsilsesquioxane Aerogels.

Molecules 2018 Mar 30;23(4). Epub 2018 Mar 30.

School of Materials Science and Engineering, Beihang University, Xueyuan Road 37, Beijing 100191, China.

Polymethylsilsesquioxane (PMSQ) aerogels obtained from methyltrimethoxysilane (MTMS) are well-known high-performance porous materials. Highly transparent and hydrophobic PMSQ aerogel would play an important role in transparent vacuum insulation panels. Herein, the co-precursor approach and supercritical modification method were developed to prepare the PMSQ aerogels with high transparency and superhydrophobicity. Firstly, benefiting from the introduction of tetramethoxysilane (TMOS) in the precursor, the pore structure became more uniform and the particle size was decreased. As the TMOS content increased, the light transmittance increased gradually from 54.0% to 81.2%, whereas the contact angle of water droplet decreased from 141° to 99.9°, ascribed to the increase of hydroxyl groups on the skeleton surface. Hence, the supercritical modification method utilizing hexamethyldisilazane was also introduced to enhance the hydrophobic methyl groups on the aerogel's surface. As a result, the obtained aerogels revealed superhydrophobicity with a contact angle of 155°. Meanwhile, the developed surface modification method did not lead to any significant changes in the pore structure resulting in the superhydrophobic aerogel with a high transparency of 77.2%. The proposed co-precursor approach and supercritical modification method provide a new horizon in the fabrication of highly transparent and superhydrophobic PMSQ aerogels.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/molecules23040797DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6017923PMC
March 2018

Evaluating architecture impact on system energy efficiency.

PLoS One 2017 21;12(11):e0188428. Epub 2017 Nov 21.

Sino-German Joint Software Institute, School of Computer Science and Engineering, Beihang University, Beijing, China.

As the energy consumption has been surging in an unsustainable way, it is important to understand the impact of existing architecture designs from energy efficiency perspective, which is especially valuable for High Performance Computing (HPC) and datacenter environment hosting tens of thousands of servers. One obstacle hindering the advance of comprehensive evaluation on energy efficiency is the deficient power measuring approach. Most of the energy study relies on either external power meters or power models, both of these two methods contain intrinsic drawbacks in their practical adoption and measuring accuracy. Fortunately, the advent of Intel Running Average Power Limit (RAPL) interfaces has promoted the power measurement ability into next level, with higher accuracy and finer time resolution. Therefore, we argue it is the exact time to conduct an in-depth evaluation of the existing architecture designs to understand their impact on system energy efficiency. In this paper, we leverage representative benchmark suites including serial and parallel workloads from diverse domains to evaluate the architecture features such as Non Uniform Memory Access (NUMA), Simultaneous Multithreading (SMT) and Turbo Boost. The energy is tracked at subcomponent level such as Central Processing Unit (CPU) cores, uncore components and Dynamic Random-Access Memory (DRAM) through exploiting the power measurement ability exposed by RAPL. The experiments reveal non-intuitive results: 1) the mismatch between local compute and remote memory node caused by NUMA effect not only generates dramatic power and energy surge but also deteriorates the energy efficiency significantly; 2) for multithreaded application such as the Princeton Application Repository for Shared-Memory Computers (PARSEC), most of the workloads benefit a notable increase of energy efficiency using SMT, with more than 40% decline in average power consumption; 3) Turbo Boost is effective to accelerate the workload execution and further preserve the energy, however it may not be applicable on system with tight power budget.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0188428PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5697812PMC
December 2017

Do all leaf photosynthesis parameters of rice acclimate to elevated CO , elevated temperature, and their combination, in FACE environments?

Glob Chang Biol 2018 04 27;24(4):1685-1707. Epub 2017 Nov 27.

State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.

Leaf photosynthesis of crops acclimates to elevated CO and temperature, but studies quantifying responses of leaf photosynthetic parameters to combined CO and temperature increases under field conditions are scarce. We measured leaf photosynthesis of rice cultivars Changyou 5 and Nanjing 9108 grown in two free-air CO enrichment (FACE) systems, respectively, installed in paddy fields. Each FACE system had four combinations of two levels of CO (ambient and enriched) and two levels of canopy temperature (no warming and warmed by 1.0-2.0°C). Parameters of the C photosynthesis model of Farquhar, von Caemmerer and Berry (the FvCB model), and of a stomatal conductance (g ) model were estimated for the four conditions. Most photosynthetic parameters acclimated to elevated CO , elevated temperature, and their combination. The combination of elevated CO and temperature changed the functional relationships between biochemical parameters and leaf nitrogen content for Changyou 5. The g model significantly underestimated g under the combination of elevated CO and temperature by 19% for Changyou 5 and by 10% for Nanjing 9108 if no acclimation was assumed. However, our further analysis applying the coupled g -FvCB model to an independent, previously published FACE experiment showed that including such an acclimation response of g hardly improved prediction of leaf photosynthesis under the four combinations of CO and temperature. Therefore, the typical procedure that crop models using the FvCB and g models are parameterized from plants grown under current ambient conditions may not result in critical errors in projecting productivity of paddy rice under future global change.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/gcb.13961DOI Listing
April 2018

Pyridine-Directed Asymmetric Hydrogenation of 1,1-Diarylalkenes.

Org Lett 2017 10 8;19(19):5062-5065. Epub 2017 Sep 8.

Department of Chemistry, Southern University of Science and Technology , Shenzhen, Guangdong 518055, China.

Highly enantioselective pyridine-directed rhodium-catalyzed asymmetric hydrogenation of challenging 1,1-diarylalkenes is achieved by using [Rh(NBD)DuanPhos]BF as a precatalyst. Various types of 2-pyridine substituted 1,1-diarylalkenes could be hydrogenated with good to excellent enantioselectivities, which provide an efficient route to the synthesis of pharmaceutically and biologically active compounds containing a 2-pyridyl ethane unit.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.orglett.7b02262DOI Listing
October 2017

The first identified cathelicidin from tree frogs possesses anti-inflammatory and partial LPS neutralization activities.

Amino Acids 2017 09 7;49(9):1571-1585. Epub 2017 Jun 7.

School of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Yuhua Avenue, Chenggong District, Kunming, 650500, Yunnan, China.

As of February 2017, approximately 7639 amphibian species have been described in the AmphibiaWeb database. However, only 20 cathelicidin-like antimicrobial peptides have been identified to date from 10 amphibian species. Half of these peptides were identified from genome sequences and have not yet been functionally characterized. In this study, a novel cathelicidin-like peptide designated cathelicidin-PP was purified from the skin of tree frog Polypedates puerensis. Cathelicidin-PP is a 32 residue peptide of sequence ASENGKCNLLCLVKKKLRAVGNVIKTVVGKIA. Circular dichroism spectroscopy indicated that cathelicidin-PP mainly adopts a β-sheet structure in membrane-mimetic solutions. Cathelicidin-PP exhibits potent antimicrobial activity against bacteria and fungi, especially Gram-negative bacteria. Meanwhile, it shows low cytotoxicity toward mammalian cells. Scanning electron microscopy analysis indicated that cathelicidin-PP kills bacteria through the disruption of the bacterial cell membrane integrity. Furthermore, cathelicidin-PP exerts significant anti-inflammatory functions by inhibiting the lipopolysaccharide (LPS)-mediated generation of nitric oxide and pro-inflammatory cytokines, tumor necrosis factor-α, interleukin-1β, and interleukin-6. The MAPKs (ERK, JNK, and p38) and NF-κB signaling pathways are involved in the anti-inflammatory effect. Cathelicidin-PP caused partial neutralization of LPS in a dose-dependent manner. Quantitative PCR indicated that infection of tree frogs with bacteria causes increased expression of cathelicidin-PP in immune-related tissues. Taken together, cathelicidin-PP is the first identified cathelicidin-like peptide from tree frogs. Our findings demonstrate that in addition to direct bactericidal capacity, cathelicidin-PP also possesses immunomodulatory properties, including partial neutralization of LPS, and inhibiting the production of inflammatory cytokines.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00726-017-2449-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5561178PMC
September 2017

Speeding up profiling program's runtime characteristics for workload consolidation.

PLoS One 2017 27;12(4):e0175861. Epub 2017 Apr 27.

Sino-German Joint Software Institute, Beihang University, Beijing, China.

Workload consolidation is a common method to increase resource utilization of the clusters or data centers while still trying to ensure the performance of the workloads. In order to get the maximum benefit from workload consolidation, the task scheduler has to understand the runtime characteristics of the individual program and schedule the programs with less resource conflict onto the same server. We propose a set of metrics to comprehensively depict the runtime characteristics of programs. The metrics set consists of two types of metrics: resource usage and resource sensitivity. The resource sensitivity refers to the performance degradation caused by insufficient resources. The resource usage of a program is easy to get by common performance analysis tools, but the resource sensitivity can not be obtained directly. The simplest and the most intuitive way to obtain the resource sensitivity of a program is to run the program in an environment with controllable resources and record the performance achieved under all possible resource conditions. However, such a process is very much time consuming when multiple resources are involved and each resource is controlled in fine granularity. In order to obtain the resource sensitivity of a program quickly, we propose a method to speed up the resource sensitivity profiling process. Our method is realized based on two level profiling acceleration strategies. First, taking advantage of the resource usage information, we set up the maximum resource usage of the program as the upper bound of the controlled resource. In this way, the range of controlling resource levels can be narrowed, and the number of experiments can be significantly reduced. Secondly, using a prediction model achieved by interpolation, we can reduce the time spent on profiling even further because the resource sensitivity in most of the resource conditions is obtained by interpolation instead of real program execution. These two profiling acceleration strategies have been implemented and applied in profiling program runtime characteristics. Our experiment results show that the proposed two-level profiling acceleration strategy not only shortens the process of profiling, but also guarantees the accuracy of the resource sensitivity. With the fast profiling method, the average absolute error of the resource sensitivity can be controlled within 0.05.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0175861PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5407827PMC
September 2017

Performance Optimization of Marine Science and Numerical Modeling on HPC Cluster.

PLoS One 2017 3;12(1):e0169130. Epub 2017 Jan 3.

School of Computer Science and Engineering, Beihang University, Beijing, China.

Marine science and numerical modeling (MASNUM) is widely used in forecasting ocean wave movement, through simulating the variation tendency of the ocean wave. Although efforts have been devoted to improve the performance of MASNUM from various aspects by existing work, there is still large space unexplored for further performance improvement. In this paper, we aim at improving the performance of propagation solver and data access during the simulation, in addition to the efficiency of output I/O and load balance. Our optimizations include several effective techniques such as the algorithm redesign, load distribution optimization, parallel I/O and data access optimization. The experimental results demonstrate that our approach achieves higher performance compared to the state-of-the-art work, about 3.5x speedup without degrading the prediction accuracy. In addition, the parameter sensitivity analysis shows our optimizations are effective under various topography resolutions and output frequencies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0169130PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5207787PMC
September 2017

Improved Production and Antitumor Properties of Triterpene Acids from Submerged Culture of Ganoderma lingzhi.

Molecules 2016 Oct 20;21(10). Epub 2016 Oct 20.

Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China.

Triterpene acids (TAs) are the major bioactive constituents in the medicinal fungus . However, fermentative production of TAs has not been optimized for commercial use, and whether the TAs isolated from submerged culture mycelia possess antitumor activity needs to be further proven. In this study, enhanced TA yield and productivity were attained with using response surface methodology. The interactions of three variables were studied using a Box-Benhnken design, namely initial pH, dissolved oxygen (DO) and fermentation temperature. The optimum conditions were an initial pH of 5.9, 20.0% DO and 28.6 °C. These conditions resulted in a TA yield of 308.1 mg/L in a 5-L stirred bioreactor. Furthermore, the optimized conditions were then successfully scaled up to a production scale of 200 L, and maximum TA production and productivity of 295.3 mg/L and 49.2 mg/L/day were achieved, which represented 80.9% and 111.5% increases, respectively, compared with the non-optimized conditions. Additionally, the triterpene acid extract (TAE) from mycelia was found to be cytotoxic to the SMMC-7721 and SW620 cell lines in vitro, and the TAE exhibited dose-dependent antitumor activity against the solid tumor sarcoma 180 in vivo. Chemical analysis revealed that the key active triterpene compounds, ganoderic acid T and ganoderic acid Me, predominated in the extract.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/molecules21101395DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6273529PMC
October 2016

Phage display-derived oligopeptide-functionalized probes for in vivo specific photoacoustic imaging of osteosarcoma.

Nanomedicine 2017 01 10;13(1):111-121. Epub 2016 Sep 10.

MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China. Electronic address:

Specific detection of various tumor types remains crucial for designing effective treatment strategies. We demonstrate photoacoustic imaging (PAI) using high-affinity and high-specificity peptide-based probes for accurate and specific diagnosis of osteosarcoma. Herein, two new tumor-specific oligopeptides, termed PT6 and PT7, were identified using phage display-based screening on an osteosarcoma cell line (UMR-106). The identified oligopeptides were able to detect clinical osteosarcoma samples on tissue microarrays. Oligopeptide-conjugated PEGylated gold nanorods (PGNR) were designed to specifically target UMR-106 cells. More importantly, PAI revealed that both PGNR-PT6 and PGNR-PT7 could bind selectively to subcutaneous UMR-106 xenografts after systemic administration and enhance the contrast of osteosarcoma images by 170% and 230%, respectively, compared to tumor-bearing mice injected with PGNRs conjugated to scrambled oligopeptides. PAI employing PGNRs conjugated to specifically designed nanoprobes may provide a new method for tumor type-specific diagnosis of osteosarcoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.nano.2016.09.002DOI Listing
January 2017

Identification and functional characterization of the AGO1 ortholog in maize.

J Integr Plant Biol 2016 Aug 7;58(8):749-58. Epub 2016 Apr 7.

Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.

Eukaryotic Argonaute proteins play primary roles in miRNA and siRNA pathways that are essential for numerous developmental and biological processes. However, the functional roles of the four ZmAGO1 genes have not yet been characterized in maize (Zea mays L.). In the present study, ZmAGO1a was identified from four putative ZmAGO1 genes for further characterization. Complementation of the Arabidopsis ago1-27 mutant with ZmAGO1a indicated that constitutive overexpression of ZmAGO1a could restore the smaller rosette, serrated leaves, later flowering and maturation, lower seed set, and darker green leaves at late stages of the mutant to the wild-type phenotype. The expression profiles of ZmAGO1a under five different abiotic stresses indicated that ZmAGO1a shares expression patterns similar to those of Argonaute genes in rice, Arabidopsis, and wheat. Further, variation in ZmAGO1a alleles among diverse maize germplasm that resulted in several amino acid changes revealed genetic diversity at this locus. The present data suggest that ZmAGO1a might be an important AGO1 ortholog in maize. The results presented provide further insight into the function of ZmAGO1a.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jipb.12467DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5071735PMC
August 2016

A cecropin-like antimicrobial peptide with anti-inflammatory activity from the black fly salivary glands.

Parasit Vectors 2015 Oct 24;8:561. Epub 2015 Oct 24.

Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University, Suzhou, Jiangsu, China.

Background: Several antimicrobial peptides (AMPs) belonging to the cecropin family have been identified from the salivary glands of different black fly species, however, the immunological functions for these molecules were poorly understood.

Methods: A novel cecropin-like antimicrobial peptide (SibaCec) was purified using reverse phase high-performance liquid chromatography (RP-HPLC) from the salivary glands of the black fly Simulium bannaense. The amino acid sequence of SibaCec was determined by a combination method of automated Edman degradation and cDNA sequencing. The morphologic changes of Gram-negative bacteria Escherichia coli treated with SibaCec were assessed by scanning electron microscopy (SEM). Quantitative PCR (qPCR) was performed to analyze the mRNA expression of the inducible NO synthase (iNOS) and pro-inflammatory cytokines. Nitric oxide (NO) generation was examined using a Griess assay and the secretion of pro-inflammatory cytokines was determined by an enzyme-linked immunosorbent assay (ELISA). The activation of extracellular signal-regulated kinase (ERK), p38, and the nuclear translocation of nuclear factor-kappaB (NF-κB) were assessed by Western blotting analysis. Circular dichroism (CD) spectroscopy was performed to evaluate the secondary structure of SibaCec in solvent environment. Interaction of SibaCec with lipopolysaccharide (LPS) was studied using fluorescein isothiocyanate (FITC)- conjugated LPS aggregates. Neutralization of LPS by SibaCec was assayed with the chromogenic limulus amebocyte lysate (LAL) test. qPCR was also used to analyze the expression of SibaCec mRNA in the salivary glands of insects after oral infection with the bacteria E.coli.

Results: SibaCec possessed potent antimicrobial activity against Gram-negative bacteria, and showed low cytotoxicity toward mammalian cells. SEM analysis indicated that SibaCec killed bacteria through the disruption of cell membrane integrity. Furthermore, SibaCec significantly inhibited lipopolysaccharide (LPS)-induced production of NO and pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interferon-1β (IL-1β) and interferon-6 (IL-6) by blocking the activation of MAPKs and NF-κB signaling pathways. It mainly adopted an α-helix conformation in membrane-mimetic environments. SibaCec could interact and neutralize LPS. Infection of black flies with bacteria caused an upregulation of the expression of SibaCec.

Conclusions: These results demonstrated that in addition to the bactericidal capacity, SibaCec can function as immune regulator, inhibiting host secretion of inflammatory factors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13071-015-1176-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4620007PMC
October 2015