Publications by authors named "Mei Zhou"

346 Publications

Plasma metabolomic profiling of patients recovered from COVID-19 with pulmonary sequelae 3 months after discharge.

Clin Infect Dis 2021 Feb 17. Epub 2021 Feb 17.

Department of Respiratory and Critical Care Medicine, NHC Key Laboratory of Pulmonary Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.

Background: Elucidation of the molecular mechanisms involved in the pathogenesis of coronavirus disease (COVID-19) may help to discover therapeutic targets.

Methods: To determine the metabolomic profile of circulating plasma from COVID-19 survivors with pulmonary sequelae 3 months after discharge, a random, outcome-stratified case-control sample was analyzed. We enrolled 103 recovered COVID-19 patients as well as 27 healthy donors, and performed pulmonary function tests, computerized tomography (CT) scans, laboratory examinations, and liquid chromatography-mass spectrometry.

Results: Plasma metabolite profiles of COVID-19 survivors with abnormal pulmonary function were evidently different from those of healthy donors or subjects with normal pulmonary function. These alterations were associated with disease severity and mainly involved amino acid, and glycerophospholipid metabolic pathways. Furthermore, increased levels of triacylglycerols, phosphatidylcholines, prostaglandin E2, arginine, and decreased levels of betain and adenosine were associated with pulmonary CO diffusing capacity and total lung capacity. The global plasma metabolomic profile differed between subjects with abnormal and normal pulmonary function.

Conclusions: Further metabolite-based analysis may help to identify the mechanisms underlying pulmonary dysfunction in COVID-19 survivors, and provide potential therapeutic targets in the future.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/cid/ciab147DOI Listing
February 2021

In vitro activities of a novel antimicrobial peptide isolated from phyllomedusa tomopterna.

Microb Pathog 2021 Feb 11;153:104795. Epub 2021 Feb 11.

Beijing University of Chinese Medicine, School of Chinese Materia Medica, Beijing, 100029, China. Electronic address:

Because of the abuse of antibiotics, clinical strains began to become more drug-resistant. Their evolution has long surpassed the speed of us looking for a new generation of antibacterial drugs. Therefore, it is urgent to discover a new antimicrobial substance to alleviate the pressure on conventional antibiotics. Antimicrobial peptides (AMP) are known for their significant activity towards a broad spectrum of bacteria, protozoa, yeasts, filamentous fungi. Here, we report a novel AMP named Dermaseptin-TO. Results demonstrate that Dermaseptin-TO can quickly exhibit antimicrobial activity to bacteria and yeast in a dose-related way. The highest minimum inhibit concentration (MIC) was observed in the E.faecalis group (128 μM). Also, haemolytic outcomes showed no more than 10.65% of red blood cells were affected when in the same concentrations or below. Besides, Dermaseptin-TO also showed anticancer activity at a higher concentration. From the above, evidence proved that Phyllomedusine frog skin secretion is still a rich source that contains novel AMP and Dermaseptin-TO is competent to become an antimicrobial agent, its anticancer activity may broaden the way in basic cancer research. Also, following the same templates in molecular cloning may acquire new AMP classes with potent antimicrobial effects that could widen drug design in new anti-infective drugs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.micpath.2021.104795DOI Listing
February 2021

Gender differences in health insurance coverage in China.

Int J Equity Health 2021 Feb 1;20(1):52. Epub 2021 Feb 1.

School of Economics, Sichuan University, Chengdu, China.

Background: China initiated a reform of the health insurance system in the late 1990s. The new insurance, Urban Employee Basic Medical Insurance (UEBMI), is employment-based, which makes it more difficult than it used to be for those unemployed or informal employed (most of whom are women) to be covered by health insurance.

Methods: Based on three large sample of micro datasets, we first use statistical methods to identify gender differences in health insurance. Next, we construct a logistic regression model to capture the differences in insurance coverage across age groups using the parameter of interaction terms for gender and age groups.

Results: Based on data from a demographic survey that covers a large sample, we find that in the below 50 (in 2005) or 60 (in 2015) years age group, the coverage gap of UEBMI between men and women was relatively smaller, while a larger disparity existed in the above 50 (in 2005) or 60 (in 2015) group. Moreover, gender differences in health insurance were more significant in the low-education group, while no gender differences were found in the high-education group.

Conclusions: This paper explains the gender gap in health insurance and the reason for the wider gap among older people. Our study indicates that because the UEBMI in China mainly covers people with formal jobs, a lower labor participation rate (even much lower in formal jobs) of women has led to their greater difficulty in obtaining health insurance. Since the older women's greater difficulty in obtaining jobs or susceptibility to lay-offs during the period of the UEBMI's implementation, the possibility of being covered was even much lower. In fact, it was because of the combined effects of the UEBMI system and the labor market condition at that time that older women had a lower proportion of being covered under the UEBMI.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12939-021-01383-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7852118PMC
February 2021

Resveratrol attenuates methamphetamine-induced memory impairment via inhibition of oxidative stress and apoptosis in mice.

J Food Biochem 2021 Feb 27;45(2):e13622. Epub 2021 Jan 27.

Wuhan Institutes of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan, China.

Methamphetamine (METH) abuse produces serious neurotoxicity to the central nervous system along with long-term cognitive dysfunction. Resveratrol, a natural polyphenol, has broad application prospects in the treatment of neurodegenerative diseases. Therefore, this study was conducted to investigate whether resveratrol might alleviate METH-induced memory deficits in vivo. We found that multiple exposures to METH significantly impaired cognitive functions and caused long-lasting memory deficits (p < .05). Pretreatment of resveratrol (10 or 100 mg/kg) remarkably attenuated METH-induced memory impairment in mice (p < .05). Bioinformatics analysis results showed that resveratrol might alleviate memory deficits by inhibiting METH-induced oxidative damage and apoptosis. Molecular docking showed that resveratrol had hydrogen bonding interactions with Kelch-like ECH associated protein 1 (Keap1), a repressor protein of the classic antioxidant Keap1-Nrf2 pathway. Further results validated oxidative stress parameters, apoptosis, and expression of Keap1 were significantly increased, while the translocation and activation of nuclear factor erythroid 2-related factor 2 (Nrf2) into the nucleus and expression of its downstream proteins were greatly decreased in the hippocampus after METH exposure (p < .05). These changes caused by METH could be prevented by resveratrol (p < .05). Therefore, these findings suggested that the prevention of resveratrol on memory dysfunction induced by METH was possibly related to the activation of the Keap1-Nrf2 pathway and reduction of apoptosis. Supplementation of resveratrol could be a potential treatment for preventing the neurotoxicity of METH in the future. PRACTICAL APPLICATIONS: As one of the worst commonly abused psychostimulants, methamphetamine (METH) addiction produces serious complications including cognitive impairment and memory deficits. Resveratrol is a natural polyphenol that has important nutritional supplements and protective effects in the treatment of many neurodegenerative diseases. In this study, the results of bioinformatics prediction and experimental validation showed that resveratrol might effectively prevent memory impairment via the interaction with Keap1, activation of the Keap1-Nrf2 pathway, and inhibition of DNA damage and apoptotic responses post METH exposure. Therefore, these findings provide new ideas and insights into the application of resveratrol in the treatment of nervous system damage caused by METH.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jfbc.13622DOI Listing
February 2021

Activation of estrogen receptor beta signaling reduces stemness of glioma stem cells.

Stem Cells 2021 Jan 20. Epub 2021 Jan 20.

Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, Texas, USA.

Glioblastoma (GBM) is the most common and deadliest tumor of the central nervous system. GBM has poor prognosis and glioma stem cells (GSCs) are implicated in tumor initiation and therapy resistance. Estrogen receptor β (ERβ) is expressed in GBM and exhibit tumor suppressive function. However, the role of ERβ in GSCs and the therapeutic potential of ERβ agonists on GSCs remain largely unknown. Here, we examined whether ERβ modulates GSCs stemness and tested the utility of two ERβ selective agonists (LY500307 and Liquiritigenin) to reduce the stemness of GSCs. The efficacy of ERβ agonists was examined on GSCs isolated from established and patient derived GBMs. Our results suggested that knockout of ERβ increased the proportion of CD133+ and SSEA+ positive GSCs and overexpression of ERβ reduced the proportion of GSCs in GBM cells. Overexpression of ERβ or treatment with ERβ agonists significantly inhibited the GSCs cell viability, neurosphere formation, self-renewal ability, induced the apoptosis and reduced expression of stemness markers in GSCs. RNA sequencing analysis revealed that ERβ agonist modulate pathways related to stemness, differentiation and apoptosis. Mechanistic studies showed that ERβ overexpression or agonist treatment reduced glutamate receptor signaling pathway and induced apoptotic pathways. In orthotopic models, ERβ overexpression or ERβ agonists treatment significantly reduced the GSCs mediated tumor growth and improved the mice overall survival. Immunohistochemical studies demonstrated that ERβ overexpression decreased SOX2 and GRM3 expression and increased expression of GFAP in tumors. These results suggest that ERβ activation could be a promising therapeutic strategy to eradicate GSCs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/stem.3337DOI Listing
January 2021

Circulating Monocytic Myeloid-Derived Suppressor Cells Are Elevated and Associated with Poor Prognosis in Acute Myeloid Leukemia.

J Immunol Res 2020 21;2020:7363084. Epub 2020 Dec 21.

Department of Hematology, The Second Hospital of Anhui Medical University, and Hematology Research Center, Anhui Medical University, Hefei, Anhui, China.

Background: Monocytic myeloid-derived suppressor cells (M-MDSCs) characterized with the phenotype of CD14HLA-DR have attracted a lot of attention in the field of human tumor immunology. However, little is known about the roles of M-MDSCs in acute myeloid leukemia (AML) as opposed to their multiple roles in solid tumors.

Methods: We examined the frequencies of M-MDSCs identified for CD14HLA-DR by flow cytometry in the peripheral circulating blood of 109 newly diagnosed adult patients with AML and 30 healthy controls (HC). Then, we, respectively, validated the clinic significance of circulating M-MDSCs on the relevance of spectral features for diagnostic stratification, induction therapy response, treatment effect maintenance, and long-term survival in AML.

Results: Circulating M-MDSC frequencies of AML were significantly higher than those of HC both in CD14 monocytes (46.22% ± 2.95% vs. 1.07% ± 0.17%, < 0.01) and peripheral blood mononuclear cells (PBMCs) (4.21% ± 0.80% vs. 0.17% ± 0.03%, < 0.01). Elevated circulating M-MDSCs in patients with AML were significantly associated with low complete remission (CR) rate, high relapse/refractory rate, and poor long-term survival, but had no correlation with common clinic risks and cytogenetic molecular risk categories.

Conclusions: It was demonstrated that circulating M-MDSCs are elevated and associated with poor prognosis in AML, suggesting M-MDSCs might be a prognostic indicator for AML.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2020/7363084DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7769680PMC
December 2020

Bionic Silk Fibroin Film Induces Morphological Changes and Differentiation of Tendon Stem/Progenitor Cells.

Appl Bionics Biomech 2020 1;2020:8865841. Epub 2020 Dec 1.

Department of Orthopedics/Sports Medicine Center, State Key Laboratory of Trauma, Burn and Combined Injury, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing 400038, China.

Purpose: Tendon injuries are common musculoskeletal system disorders, but the ability for tendon regeneration is limited. Silk fibroin (SF) film may be suitable for tendon regeneration due to its excellent biocompatibility and physical properties. This study is aimed at evaluating the application value of bionic SF film in tendon regeneration.

Methods: Tendon stem/progenitor cells (TSPCs) were isolated from rat Achilles tendon and characterized based on their surface marker expression and multilineage differentiation potential. SF films with smooth or bionic microstructure surfaces (5, 10, 15, 20 m) were prepared. The morphology and mechanical properties of natural tendons and SF films were characterized. TSPCs were used as the seed cells, and the cell viability and cell adhesion morphology were analyzed. The tendongenesis-related gene expression of TSPCs was also evaluated using quantitative polymerase chain reaction.

Results: Compared to the native tendon, only the 10, 15, and 20 m SF film groups had comparable maximum loading and ultimate stress, with the exception of the breaking elongation rate. The 10 m SF film group had the highest percentage of oriented cells and the most significant changes in cell morphology. The most significant upregulations in the expression of , , and were also observed in the 10 m SF film group.

Conclusion: SF film with a bionic microstructure can serve as a tissue engineering scaffold and provide biophysical cues for the use of TSPCs to achieve proper cellular adherence arrangement and morphology as well as promote the tenogenic differentiation of TSPCs, making it a valuable customizable biomaterial for future applications in tendon repair.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2020/8865841DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7725557PMC
December 2020

Comparison of clinical characteristics among younger and elderly deceased patients with COVID-19: a retrospective study.

Aging (Albany NY) 2020 12 11;13(1):16-26. Epub 2020 Dec 11.

Department of Respiratory and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.

We aimed to compare the age-related clinical characteristics between younger and elderly deceased COVID-19 patients. This single-center retrospective study included 163 adult deceased COVID-19 patients who were admitted to Wuhan Union Hospital West Campus from January 12, 2020, to March 30, 2020. Demographic and clinical features were collected by reviewing the medical records. The median age of the 163 deceased patients was 69 (interquartile range [IQR], 62-78) years. They were classified as younger (age 18-69 years; 86/163, 52.8%) and elderly (≥70 years; 77/163, 47.2%) subjects. Younger deceased patients were more likely to develop fever (72/86 vs 54/77, P=0.039) than elderly deceased patients were while anorexia was (29/77 vs 19/86, P=0.029) more common in elderly deceased patients than in younger deceased patients. In multivariate analyses, age was a protective factor for acute cardiac injury of deceased COVID-19 patients (odds ratio [OR] 0.968, [95% confidence interval (CI), 0.940-0.997]; P=0.033) while chronic cardiac disease was a risk factor for acute cardiac injury of deceased COVID-19 patients (OR 2.660 [95%CI, 1.034-6.843]; P=0.042). Our study described the clinical characteristics of younger and elderly deceased COVID-19 patients and demonstrated that younger deceased patients were more likely to develop an acute cardiac injury.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.18632/aging.202139DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7835042PMC
December 2020

Identification of a new myotropic decapeptide from the skin secretion of the red-eyed leaf frog, Agalychnis callidryas.

PLoS One 2020 3;15(12):e0243326. Epub 2020 Dec 3.

Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China.

Bradykinin-related peptides (BRPs) family is one of the most significant myotropic peptide families derived from frog skin secretions. Here, a novel BRP callitide was isolated and identified from the red-eyed leaf frog, Agalychnis callidryas, with atypical primary structure FRPAILVRPK-NH2. The mature peptide was cleaved N-terminally at a classic propeptide convertase cleavage site (-KR-) and at the C-terminus an unusual -GKGKGK sequence was removed using the first G residue as an amide donor for the C-terminally-located K residue. Thereafter, the synthetic replicates of callitide were assessed the myotropic activity and showed a significant contraction of balder, with the 0.63 nM EC50 value, more potent than most discovered myotropic peptides. The binding mode was further speculated by molecular docking and stimulation. The result indicated that the C-terminal of callitide might selectively bind to bradykinin receptor B2 (BKRB2). Further investigation of the callitide needs to be done in the future to be exploited as potential future drug leads.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0243326PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7714090PMC
January 2021

Bionic Silk Fibroin Film Promotes Tenogenic Differentiation of Tendon Stem/Progenitor Cells by Activating Focal Adhesion Kinase.

Stem Cells Int 2020 4;2020:8857380. Epub 2020 Nov 4.

Department of Orthopedics/Sports Medicine Center, State Key Laboratory of Trauma, Burn and Combined Injury, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing 400038, China.

Background: Tendon injuries are common musculoskeletal disorders in clinic. Due to the limited regeneration ability of tendons, tissue engineering technology is often used as an effective approach to treat tendon injuries. Silk fibroin (SF) films have excellent biological activities and physical properties, which is suitable for tendon regeneration. The present study is aimed at preparing a SF film with a bionic microstructure and investigating its biological effects.

Methods: A SF film with a smooth surface or bionic microstructure was prepared. After seeding tendon stem/progenitor cells (TSPCs) on the surface, the cell morphology, the expression level of tenogenic genes and proteins, and the focal adhesion kinase (FAK) activation were measured to evaluate the biological effect of SF films.

Results: The TSPCs on SF films with a bionic microstructure exhibited a slender cell morphology, promoted the expression of tenogenic genes and proteins, such as SCX, TNC, TNMD, and COLIA1, and activated FAK. FAK inhibitors blocked the enhanced expression of tenogenic genes and proteins.

Conclusion: SF films with a bionic microstructure may serve as a scaffold, provide biophysical cues to alter the cellular adherence arrangement and cell morphology, and enhance the tenogenic gene and protein expression in TSPCs. FAK activation plays a key role during this biological response process.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2020/8857380DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7657703PMC
November 2020

PKCβ increases ROS levels leading to vascular endothelial injury in diabetic foot ulcers.

Am J Transl Res 2020 15;12(10):6409-6421. Epub 2020 Oct 15.

Department of Orthopedics, The Second Affiliated Hospital, Chongqing Medical University Chongqing 400010, China.

Objective: To explore the role and mechanism of oxidative stress injury in the diabetic foot.

Methods: Immunohistochemistry and staining were used to detect changes in diabetic foot tissue, and the CCK-8 method was used to measure high glucose effect on cell viability. The DCFH-DA assay was used to detect the intracellular ROS content, and colorimetric methods were used to detect the activities of the CAT and SOD enzymes and the NO and MDA content in tissues and cells. In addition, the protein expression levels of PKCβ, p66shc, eNOS, ICAM-1 and NF-κB in tissues and cells were detected by Western blotting, and the distribution of p66shc and eNOS was observed by immunofluorescence.

Results: The results of clinical specimens experiments showed that the DFU group exhibited disordered morphology and increased glucose metabolism, decreased activities of the enzymes CAT and SOD in tissues, and increased MDA and NO contents compared to those in the CON group. Furthermore, protein levels of the p-PKCβ, p-p66shc, ICAM-1, and p-NF-κB were increased, and eNOS protein level was decreased; these results were consistent in clinical specimens and in vitro experiments.

Conclusions: High glucose levels may induce oxidative stress injury in cells and tissues by activating the PKCβ-p66shc signaling pathway.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7653566PMC
October 2020

A Novel Amphibian Antimicrobial Peptide, Phylloseptin-PV1, Exhibits Effective Anti- Activity Without Inducing Either Hepatic or Renal Toxicity in Mice.

Front Microbiol 2020 26;11:565158. Epub 2020 Oct 26.

Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, United Kingdom.

In order to part address the problem of drug-resistant pathogens, antimicrobial peptides (AMPs) have been proposed as alternatives to traditional antibiotics. Herein, a novel phylloseptin peptide, named phylloseptin-PV1 (PPV1), is described from the defensive skin secretion of the Neotropical white-lined leaf frog, . The peptide was synthesized by solid phase peptide synthesis (SPPS) and purified by RP-HPLC, prior to assessment of its biological activities. PPV1 not only demonstrated potent antimicrobial activity against planktonic ESKAPE microorganisms and the yeast, , but also inhibited and eradicated and MRSA biofilms. The antimicrobial mechanism was shown to include permeabilization of target cell membranes. The antimicrobial activity of the peptide was then evaluated using mice. PPV1 also exhibited antiproliferative activity against the cancer cell lines, H157, MCF-7, and U251MG, but had a lower potency against the normal cell line, HMEC-1. Although, the peptide possessed a moderate hemolytic action on mammalian red blood cells , it did not induce significant hepatic or renal toxicity in injected infected mice. These studies have thus found PPV1 to be a potent phylloseptin group AMP, which can effectively inhibit staphylococci, both and , without eliciting toxicity. These data thus provide support for further evaluation of PPV1 as a novel antimicrobial agent with therapeutic potential.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2020.565158DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7649123PMC
October 2020

Identification of Signatures of Selection by Whole-Genome Resequencing of a Chinese Native Pig.

Front Genet 2020 17;11:566255. Epub 2020 Sep 17.

Key Laboratory of Pig Molecular Quantitative Genetics of Anhui Academy of Agricultural Sciences, Anhui Provincial Key Laboratory of Livestock and Poultry Product Safety Engineering, Institute of Animal Husbandry and Veterinary Medicine, Anhui Academy of Agricultural Sciences, Hefei, China.

Identification of genomic signatures of selection that help reveal genetic mechanisms underlying traits in domesticated pigs is of importance. Anqing six-end-white pig (ASP), a representative of the native breeds in China, has many distinguishing phenotypic characteristics. To identify the genomic signatures of selection of the ASP, whole-genome sequencing of 20 ASPs produced 469.01 Gb of sequence data and more than 26 million single-nucleotide polymorphisms. Combining these data with the available whole genomes of 13 Chinese wild boars, 157 selected regions harboring 48 protein-coding genes were identified by applying the polymorphism levels (θπ) and genetic differentiation ( ) based cross approaches. The genes found to be positively selected in ASP are involved in crucial biological processes such as coat color ( ), salivary secretion ( ), reproduction ( , , , , and ), olfactory transduction ( ), and growth ( , , and ). Our research increased the knowledge of ASP phenotype-related genes and help to improve our understanding of the underlying biological mechanisms and provide valuable genetic resources that enable effective use of pigs in agricultural production.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fgene.2020.566255DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7527633PMC
September 2020

KDM1A inhibition is effective in reducing stemness and treating triple negative breast cancer.

Breast Cancer Res Treat 2021 Jan 14;185(2):343-357. Epub 2020 Oct 14.

Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA.

Purpose: Cancer stem cells (CSCs) are highly tumorigenic, spared by chemotherapy, sustain tumor growth, and are implicated in tumor recurrence after conventional therapies in triple negative breast cancer (TNBC). Lysine-specific histone demethylase 1A (KDM1A) is highly expressed in several human malignancies and CSCs including TNBC. However, the precise mechanistic role of KDM1A in CSC functions and therapeutic utility of KDM1A inhibitor for treating TNBC is poorly understood.

Methods: The effect of KDM1A inhibition on cell viability, apoptosis, and invasion were examined by Cell Titer Glo, Caspase 3/7 Glo, and matrigel invasion assays, respectively. Stemness and self-renewal of CSCs were examined using mammosphere formation and extreme limiting dilution assays. Mechanistic studies were conducted using RNA-sequencing, RT-qPCR, Western blotting and reporter gene assays. Mouse xenograft and patient derived xenograft models were used for preclinical evaluation of KDM1A inhibitor.

Results: TCGA data sets indicated that KDM1A is highly expressed in TNBC. CSCs express high levels of KDM1A and inhibition of KDM1A reduced the CSCs enrichment in TNBC cells. KDM1A inhibition reduced cell viability, mammosphere formation, self-renewal and promoted apoptosis of CSCs. Mechanistic studies suggested that IL6-JAK-STAT3 and EMT pathways were downregulated in KDM1A knockdown and KDM1A inhibitor treated cells. Importantly, doxycycline inducible knockout of KDM1A reduced tumor progression in orthotopic xenograft models and KDM1A inhibitor NCD38 treatment significantly reduced tumor growth in patient derived xenograft (PDX) models.

Conclusions: Our results establish that KDM1A inhibition mitigates CSCs functions via inhibition of STAT3 and EMT signaling, and KDM1A inhibitor NCD38 may represent a novel class of drug for treating TNBC.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10549-020-05963-1DOI Listing
January 2021

Stress-induced premature senescence activated by the SENEX gene mediates apoptosis resistance of diffuse large B-cell lymphoma via promoting immunosuppressive cells and cytokines.

Immun Inflamm Dis 2020 12 4;8(4):672-683. Epub 2020 Oct 4.

Department of Hematology, The Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.

Background: The underlying cause of relapsed and refractory (r/r) diffuse large B-cell lymphoma (DLBCL) is usually related to apoptosis resistance to antitumor drugs. The recent years have provided lots of evidence that tumor cells may undergo stress-induced premature senescence (SIPS) in response to chemotherapy, but how SIPS affects lymphoma cells remains inconclusive.

Methods: Fifty-two DLBCL patients, including 6 newly diagnosed (ND), 17 complete remissions (CR), and 29 (r/r), were enrolled in this study. We used a senescence-associated-β-galactosidase (SA-β-Gal) staining kit for senescence staining. Suppressive immune cells including regulatory T cells (Treg) and myeloid-derived suppressor cells (MDSC) were detected by flow cytometry (FCM). Secreted cytokines were measured by ELISA Kit and SENEX gene expression was detected by a quantitative real-time polymerase chain reaction. We used 40 nM doxorubicin to induce the SIPS model of DLBCL in vitro. Apoptosis and proliferation activity of senescent LY8 cells were respectively detected by FCM and CCK8. SENEX gene was silenced by RNA interference.

Results: The proportion of senescent lymphoma cells was significantly increased in r/r DLBCL patients, concomitant with increased Treg, MDSC, and various secreted cytokines with proinflammatory and immunosuppressive effects. The SENEX gene was significantly elevated in the SIPS model. Senescent DLBCL cells had good antiapoptotic ability and proliferative activity accompanied by increased immunosuppressive cytokines. Interestingly, when we silenced the SENEX gene in the DLBCL cell line, the results were the opposite to the above.

Conclusion: SIPS activated by the SENEX gene mediates apoptosis resistance of r/r DLBCL via promoting immunosuppressive cells and cytokines.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/iid3.356DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7654415PMC
December 2020

Immunoregulatory Roles of Extracellular Vesicles and Associated Therapeutic Applications in Lung Cancer.

Front Immunol 2020 28;11:2024. Epub 2020 Aug 28.

NHC Key Laboratory of Pulmonary Diseases, Department of Respiratory and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.

Lung cancer represents a fatal condition that has the highest morbidity and mortality among malignancies. The currently available treatments fall short of improving the survival and quality of life of late-stage lung cancer patients. Extracellular vesicles (EVs) secreted by tumors or immune cells transport proteins, lipids, and nucleic acids to other cells, thereby mediating immune regulation in the tumor microenvironment. The cargo carried by EVs vary by cellular state or extracellular milieu. So far, multiple studies have suggested that EVs from lung tumor cells (TEVs) or immune cells promote tumor progression mainly through suppressing antitumor immunity. However, modified or engineered EVs can be used as vaccines to elicit antitumor immunity. In addition, blocking the function of immunosuppressive EVs and using EVs carrying immunogenic medicine or EVs from certain immune cells also shows great potential in lung cancer treatment. To provide information for future studies on the role of EVs in lung cancer immunity, this review focus on the immunoregulatory role of EVs and associated treatment applications in lung cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2020.02024DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7483575PMC
August 2020

Broad-Spectrum Antimicrobial Activity and Improved Stability of a D-Amino Acid Enantiomer of DMPC-10A, the Designed Derivative of Dermaseptin Truncates.

Antibiotics (Basel) 2020 Sep 21;9(9). Epub 2020 Sep 21.

School of Pharmacy, Queen's University Belfast, Belfast BT9 7BL, UK.

DMPC-10A (ALWKKLLKK-Cha-NH) is a 10-mer peptide derivative from the N-terminal domain of Dermaseptin-PC which has shown broad-spectrum antimicrobial activity as well as a considerable hemolytic effect. In order to reduce hemolytic activity and improve stability to endogenous enzymes, a D-amino acid enantiomer (DMPC-10B) was designed by substituting all L-Lys and L-Leu with their respective D-form amino acid residues, while the Ala and Trp remained unchanged. The D-amino acid enantiomer exhibited similar antimicrobial potency to the parent peptide but exerted lower cytotoxicity and hemolytic activity. Meanwhile, DMPC-10B exhibited remarkable resistance to hydrolysis by trypsin and chymotrypsin. In addition to these advantages, DMPC-10B exhibited an outstanding antibacterial effect against Methicillin-resistant (MRSA) and using the larva model and displayed synergistic activities with gentamicin against carbapenem-resistant strains. This indicates that DMPC-10B would be a promising alternative for treating antibiotic-resistant pathogens.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/antibiotics9090627DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7557582PMC
September 2020

Identification of Melanoma From Hyperspectral Pathology Image Using 3D Convolutional Networks.

IEEE Trans Med Imaging 2021 Jan 29;40(1):218-227. Epub 2020 Dec 29.

Skin biopsy histopathological analysis is one of the primary methods used for pathologists to assess the presence and deterioration of melanoma in clinical. A comprehensive and reliable pathological analysis is the result of correctly segmented melanoma and its interaction with benign tissues, and therefore providing accurate therapy. In this study, we applied the deep convolution network on the hyperspectral pathology images to perform the segmentation of melanoma. To make the best use of spectral properties of three dimensional hyperspectral data, we proposed a 3D fully convolutional network named Hyper-net to segment melanoma from hyperspectral pathology images. In order to enhance the sensitivity of the model, we made a specific modification to the loss function with caution of false negative in diagnosis. The performance of Hyper-net surpassed the 2D model with the accuracy over 92%. The false negative rate decreased by nearly 66% using Hyper-net with the modified loss function. These findings demonstrated the ability of the Hyper-net for assisting pathologists in diagnosis of melanoma based on hyperspectral pathology images.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1109/TMI.2020.3024923DOI Listing
January 2021

apolipoprotein E-enriched corona guides dihydroartemisinin-decorating nanoparticles towards LDLr-mediated tumor-homing chemotherapy.

Asian J Pharm Sci 2020 Jul 5;15(4):482-491. Epub 2019 Jul 5.

Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang 110016, China.

The therapeutic efficiency of active targeting nanoparticulate drug delivery systems (nano-DDS) is highly compromised by the plasma proteins adsorption on nanoparticles (NPs) surface, which significantly hinders cell membrane receptors to recognize the designed ligands, and provokes the off-target toxicity and rapid clearance of NPs . Herein, we report a novel dihydroartemisinin (DHA)-decorating nano-DDS that specifically recruits endogenous apolipoprotein E (apoE) on the NPs surface. The apoE-anchored corona is able to prolong PLGA-PEG2000-DHA (PPD) NPs circulation capability in blood, facilitate NPs accumulating in tumor cells by the passive enhanced permeability and retention (EPR) effect and low-density lipoprotein receptor (LDLr)-mediated target transport, and ultimately improve the antitumor activity. Our findings demonstrate that the strategy of regulated apoE-enriched corona ensures NPs an efficient LDLr-mediated tumor-homing chemotherapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ajps.2019.05.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7486546PMC
July 2020

Metabolic characteristics of large and small extracellular vesicles from pleural effusion reveal biomarker candidates for the diagnosis of tuberculosis and malignancy.

J Extracell Vesicles 2020 Jul 14;9(1):1790158. Epub 2020 Jul 14.

Department of Respiratory and Critical Care Medicine, NHC Key Laboratory of Pulmonary Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.

Pleural effusion is a common respiratory disease worldwide; however, rapid and accurate diagnoses of tuberculosis pleural effusion (TPE) and malignancy pleural effusion (MPE) remain challenging. Although extracellular vesicles (EVs) have been confirmed as promising sources of disease biomarkers, little is known about the metabolite compositions of its subpopulations and their roles in the diagnosis of pleural effusion. Here, we performed metabolomics and lipidomics analysis to investigate the metabolite characteristics of two EV subpopulations derived from pleural effusion by differential ultracentrifugation, namely large EVs (lEVs, pelleted at 20,000 × g) and small EVs (sEVs, pelleted at 110,000 × g), and assessed their metabolite differences between tuberculosis and malignancy. A total of 579 metabolites, including amino acids, acylcarnitines, organic acids, steroids, amides and various lipid species, were detected. The results showed that the metabolic profiles of lEVs and sEVs overlapped with and difference from each other but significantly differed from those of pleural effusion. Additionally, different type of vesicles and pleural effusion showed unique metabolic enrichments. Furthermore, lEVs displayed more significant and larger metabolic alterations between the tuberculosis and malignancy groups, and their differential metabolites were more closely related to clinical parameters than those of sEV. Finally, a panel of four biomarker candidates, including phenylalanine, leucine, phosphatidylcholine 35:0, and sphingomyelin 44:3, in pleural lEVs was defined based on the comprehensive discovery and validation workflow. This panel showed high performance for distinguishing TPE and MPE, particularly in patients with delayed or missed diagnosis, such as the area under the receiver-operating characteristic curve (AUC) >0.95 in both sets. We conducted comprehensive metabolic profiling analysis of EVs, and further explored the metabolic reprogramming of tuberculosis and malignancy at the level of metabolites in lEVs and sEVs, providing insight into the mechanism of pleural effusion, and identifying novel biomarkers for diagnosing TPE and MPE.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/20013078.2020.1790158DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7480510PMC
July 2020

Lipophilic Extract and Tanshinone IIA Derived from Attenuate Uric Acid Nephropathy through Suppressing Oxidative Stress-Activated MAPK Pathways.

Am J Chin Med 2020 15;48(6):1455-1473. Epub 2020 Sep 15.

State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, P. R. China.

Uric acid nephropathy (UAN) is caused by excessive uric acid, which results in the damage of renal tissue urate crystals deposition in the kidneys. The roots and rhizomes of Bunge () have been clinically used in many prescriptions to treat uric acid-induced renal damage. This study investigates the uricosuric and nephroprotective effects of the ethyl acetate extract of (EASM) and tanshinone IIA (a major component of , Tan-IIA) on UAN and explores the underlying molecular mechanism. Both EASM and Tan-IIA significantly decreased serum uric acid (SUA), serum creatinine (SCR), urine uric acid (UUA), and increased urine creatinine (UCR), and blood urea nitrogen (BUN) levels in experimental UAN mice. In adenine and potassium oxonate-induced mice, EASM and Tan-IIA treatment alleviated renal dysfunction and downregulated the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Moreover, EASM treatment significantly prevented excessive reactive oxygen species (ROS) production in uric acid-induced HK-2 cells and suppressed the expression of nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4). EASM also suppressed ROS-activated mitogen-activated protein kinases (MAPKs) and . These results suggest that both EASM and Tan-IIA demonstrated inhibitory effects on UAN through relieving NOX4-mediated oxidative stress and suppressing MAPK pathways activation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1142/S0192415X20500718DOI Listing
October 2020

Identification and Target-Modification of SL-BBI: A Novel Bowman-Birk Type Trypsin Inhibitor from .

Biomolecules 2020 08 28;10(9). Epub 2020 Aug 28.

Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast BT9 7BL, UK.

The peptides from the ranacyclin family share similar active disulphide loop with plant-derived Bowman-Birk type inhibitors, some of which have the dual activities of trypsin inhibition and antimicrobial. Herein, a novel Bowman-Birk type trypsin inhibitor of the ranacyclin family was identified from the skin secretion of broad-folded frog () by molecular cloning method and named as SL-BBI. After chemical synthesis, it was proved to be a potent inhibitor of trypsin with a Ki value of 230.5 nM and showed weak antimicrobial activity against tested microorganisms. Modified analogue K-SL maintains the original inhibitory activity with a Ki value of 77.27 nM while enhancing the antimicrobial activity. After the substitution of active P1 site to phenylalanine and P2' site to isoleucine, F-SL regenerated its inhibitory activity on chymotrypsin with a Ki value of 309.3 nM and exhibited antiproliferative effects on PC-3, MCF-7 and a series of non-small cell lung cancer cell lines without cell membrane damage. The affinity of F-SL for the β subunits in the yeast 20S proteasome showed by molecular docking simulations enriched the understanding of the possible action mode of Bowman-Birk type inhibitors. Further mechanistic studies have shown that F-SL can activate caspase 3/7 in H157 cells and induce apoptosis, which means it has the potential to become an anticancer agent.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/biom10091254DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7565067PMC
August 2020

Characterisation of a novel peptide, Brevinin-1H, from the skin secretion of Amolops hainanensis and rational design of several analogues.

Chem Biol Drug Des 2021 Feb 7;97(2):273-282. Epub 2020 Sep 7.

Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast, UK.

As drug-resistant bacteria have become a serious health problem and have caused thousands of deaths, finding new antibiotics has become an urgent research priority. A novel antimicrobial peptide, named Brevinin-1H, was identified in the skin secretion of Amolops hainanensis through 'shotgun' cloning. It has broad-spectrum antimicrobial activity against tested micro-organisms and has anticancer cell activity. To improve its bioactivity and decrease its cytotoxicity, two structural analogues-Brevinin-1Ha and Brevinin-1HY-were designed based on the secondary structure of the natural peptide. Brevinin-1HY, in which tyrosine substituted Pro , had similar activity to the natural peptide against Gram-negative bacteria and cancer cells, but showed a dramatic increase in haemolytic activity and cytotoxicity at its minimum inhibitory concentration. Brevinin-1Ha, which transferred the Rana-box from the C-terminal to a central position, had significantly decreased haemolytic activity, but also in antimicrobial and anticancer activity. The present data suggest that increasing the proportion of α-helix structure in an AMP can increase its target micro-organism bioactivity to some extent.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/cbdd.13779DOI Listing
February 2021

Using surveillance to determine the number of individuals with sickle cell disease in California and Georgia, 2005-2016.

Pediatr Hematol Oncol 2020 Nov 12;37(8):747-751. Epub 2020 Aug 12.

Division of Blood Disorders, National Center for Birth Defects and Disabilities, CDC, Atlanta, Georgia, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/08880018.2020.1779886DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7855365PMC
November 2020

Modification and Targeted Design of N-Terminal Truncates Derived from Brevinin with Improved Therapeutic Efficacy.

Biology (Basel) 2020 Aug 6;9(8). Epub 2020 Aug 6.

Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland, UK.

Antimicrobial peptides (AMPs) are a class of molecules that play an essential role in innate immune regulation. The Brevinin-1 family are AMPs that show strong pharmacological and antimicrobial potential. A novel peptide, B1A, was designed based on the primary structure of brevinin-1PLb and brevinin-1PLc. Subsequently, a synthesised replicate was subjected to a series of bioassays and was found to display antimicrobial activity. However, it also displayed high levels of haemolysis in a horse red blood cell haemolytic assay, suggesting potential toxicity. Therefore, we rationally designed a number of B1A analogues with aim of retaining antimicrobial activity, lowering toxicity, and to explore the structure-activity relationship of its N-terminus. B1A and its analogues still retained the "Rana Box" and the FLP-motif, which is a feature of this subfamily. However, the introduction of Lys and Trp residues into the peptide sequences revealed that antimicrobial activity of these analogues remained unchanged once the hydrophobicity and the charge reached the threshold. Hence, the idea that the hydrophobicity saturation in different situations is related to antimicrobial activity can be understood via the structure-activity relationship. Meanwhile, it could also be the starting point for the generation of peptides with specific antimicrobial activity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/biology9080209DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7464788PMC
August 2020

The absence of oestrogen receptor beta disturbs collagen I type deposition during Achilles tendon healing by regulating the IRF5-CCL3 axis.

J Cell Mol Med 2020 09 10;24(17):9925-9935. Epub 2020 Aug 10.

Department of Orthopedic Surgery, Southwest Hospital, Army Medical University, Chongqing, China.

Achilles tendon healing (ATH) remains an unanswered question in the field of sports medicine because it does not produce tissue with homology to the previously uninjured tissue. Oestrogen receptor β (ERβ) is involved in the injury and repair processes of tendons. Our previous study confirmed that ERβ plays a role in the early stage of ATH by affecting adipogenesis, but its role in extracellular matrix (ECM) remodelling is unknown. We established a 4-week Achilles tendon repair model to investigate the mechanism through which ERβ affects ATH at the very beginning of ECM remodelling phase. In vitro studies were performed using tendon-derived stem cells (TDSCs) due to their promising role in tendon healing. Behavioural and biomechanical tests revealed that ERβ-deficient mice exhibit weaker mobility and inferior biomechanical properties, and immunofluorescence staining and qRT-PCR showed that these mice exhibited an erroneous ECM composition, as mainly characterized by decreased collagen type I (Col I) deposition. The changes in gene expression profiles between ERβ-knockout and WT mice at 1 week were analysed by RNA sequencing to identify factors affecting Col I deposition. The results highlighted the IRF5-CCL3 axis, and this finding was verified with CCL3-treated TDSCs. These findings revealed that ERβ regulates Col I deposition during ATH via the IRF5-CCL3 axis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jcmm.15592DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7520326PMC
September 2020

Retrograde Labeling of Different Distribution Features of DRG P2X2 and P2X3 Receptors in a Neuropathic Pain Rat Model.

Biomed Res Int 2020 22;2020:9861459. Epub 2020 Jul 22.

School of Physical Education, Jianghan University, Wuhan 430056, China.

The distributions of P2X subtypes during peripheral neuropathic pain conditions and their differential roles are not fully understood. To explore these characteristics, the lumbosacral dorsal root ganglion (DRG) in the chronic constriction injury (CCI) sciatic nerve rat model was studied. Retrograde trace labeling combined with immunofluorescence technology was applied to analyze the distribution of neuropathic nociceptive P2X1-6 receptors. Our results suggest that Fluoro-Gold (FG) retrograde trace labeling is an efficient method for studying lumbosacral DRG neurons in the CCI rat model, especially when the DRG neurons are divided into small, medium, and large subgroups. We found that neuropathic nociceptive lumbosacral DRG neurons (i.e., FG-positive cells) were significantly increased in medium DRG neurons, while they declined in the large DRG neurons in the CCI group. P2X3 receptors were markedly upregulated in medium while P2X2 receptors were significantly decreased in small FG-positive DRG neurons. There were no significant changes in other P2X receptors (including P2X1, P2X4, P2X5, and P2X6). We anticipate that P2X receptors modulate nociceptive sensitivity primarily through P2X3 subtypes that are upregulated in medium neuropathic nociceptive DRG neurons and/or via the downregulation of P2X2 cells in neuropathic nociceptive small DRG neurons.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2020/9861459DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7396081PMC
July 2020

Enhanced Antimicrobial Activity of N-Terminal Derivatives of a Novel Brevinin-1 Peptide from The Skin Secretion of .

Toxins (Basel) 2020 07 30;12(8). Epub 2020 Jul 30.

Natural Drug Discovery Group, School of Pharmacy, Queen's University, Belfast BT9 7BL, Northern Ireland, UK.

Antimicrobial peptides (AMPs) are promising therapeutic alternatives compared to conventional antibiotics for the treatment of drug-resistant bacterial infections. However, the application of the overwhelming majority of AMPs is limited because of the high toxicity and high manufacturing costs. Amphibian skin secretion has been proven to be a promising source for the discovery and development of novel AMPs. Herein, we discovered a novel AMP from the skin secretion of , and designed the analogues by altering the key factors, including conformation, net charge and amphipathicity, to generate short AMPs with enhanced therapeutic efficacy. All the peptides were chemically synthesised, followed by evaluating their biological activity, stability and cytotoxicity. OSd, OSe and OSf exhibited broad-spectrum antibacterial effects, especially OSf, which presented the highest therapeutic index for the tested bacteria. Moreover, these peptides displayed good stability. The results from scanning electron microscopy and transmission electron microscopy studies, indicated that brevinin-OS, OSd, OSe and OSf possessed rapid bactericidal ability by disturbing membrane permeability and causing the release of cytoplasmic contents. In addition, OSd, OSe and OSf dramatically decreased the mortality of waxworms acutely infected with MRSA. Taken together, these data suggested that a balance between positive charge, degrees of α-helicity and hydrophobicity, is necessary for maintaining antimicrobial activity, and these data successfully contributed to the design of short AMPs with significant bactericidal activity and cell selectivity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/toxins12080484DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7472354PMC
July 2020

Pharmacological Effects of a Novel Bradykinin-Related Peptide (RR-18) from the Skin Secretion of the Hejiang Frog () on Smooth Muscle.

Biomedicines 2020 Jul 17;8(7). Epub 2020 Jul 17.

Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Avenida da Universidade, Taipa, Macau.

Bradykinin (BK) and bradykinin-related peptides (BRPs), which were identified from a diversity of amphibian skin secretions, exerted contractile and relaxing effects on non-vascular and vascular smooth muscle, respectively. Here, we report a novel bradykinin-related peptide with a molecular mass of 1890.2 Da, RVAGPDKPARISGLSPLR, which was isolated and identified from skin secretions, followed by a C-terminal extension sequence VAPQIV. The biosynthetic precursor-encoding cDNA was cloned by the "shotgun" cloning method, and the novel RR-18 was identified and structurally confirmed by high-performance liquid chromatography (HPLC) and tandem mass spectrometry (MS/MS). Subsequently, the myotropic activity of the synthetic replicate of RR-18 was investigated on the rat bladder, uterus, tail artery and ileum smooth muscle. The peptide was named RR-18 in accordance (R = N-terminal arginine, R = C-terminal arginine, 18 = number of residues). In this study, the synthetic replicates of RR-18 showed no agonist/antagonism of BK-induced rat bladder and uterus smooth muscle contraction. However, it displayed an antagonism of bradykinin-induced rat ileum contraction and arterial smooth muscle relaxation. The EC values of BK for ileum and artery, were 214.7 nM and 18.3 nM, respectively. When the tissue was pretreated with the novel peptide, RR-18, at the maximally effective concentration of bradykinin (1 × 10 M), bradykinin-induced contraction of the ileum and relaxation of the arterial smooth muscle was reduced by 50-60% and 30-40%, respectively. In conclusion, RR-18 represents novel bradykinin antagonising peptide from amphibian skin secretions. It may provide new insight into possible treatment options for chronic pain and chronic inflammation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/biomedicines8070225DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7400415PMC
July 2020

Ranacyclin-NF, a Novel Bowman-Birk Type Protease Inhibitor from the Skin Secretion of the East Asian Frog, .

Biology (Basel) 2020 Jul 2;9(7). Epub 2020 Jul 2.

Natural Drug Discovery Group, School of Pharmacy, Queen's University Belfast, Belfast BT9 7BL, UK.

Serine protease inhibitors are found in plants, animals and microorganisms, where they play important roles in many physiological and pathological processes. Inhibitor scaffolds based on natural proteins and peptides have gradually become the focus of current research as they tend to bind to their targets with greater specificity than small molecules. In this report, a novel Bowman-Birk type inhibitor, named ranacyclin-NF (RNF), is described and was identified in the skin secretion of the East Asian frog, . A synthetic replicate of the peptide was subjected to a series of functional assays. It displayed trypsin inhibitory activity with an inhibitory constant, Ki, of 447 nM and had negligible direct cytotoxicity. No observable direct antimicrobial activity was found but RNF improved the therapeutic potency of Gentamicin against Methicillin-resistant (MRSA). RNF shared significant sequence similarity to previously reported and related inhibitors from (ORB) and (ranacyclin-T), both of which were found to be multi-functional. Two analogues of RNF, named ranacyclin-NF1 (RNF1) and ranacyclin-NF3L (RNF3L), were designed based on some features of ORB and ranacyclin-T to study structure-activity relationships. Structure-activity studies demonstrated that residues outside of the trypsin inhibitory loop (TIL) may be related to the efficacy of trypsin inhibitory activity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/biology9070149DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7407945PMC
July 2020