Expression and significance of lysyl oxidase-like 1 and fibulin-5 in the cardinal ligament tissue of patients with pelvic floor dysfunction

Pelvic organ prolapse （POP） is a disabling disorder in women characterized by a loss of pelvic floor support, leading to the herniation of the uterus into or through the vagina. POP is a complex problem that likely involves multiple mechanisms with limited therapies available, and is associated with defects in connective tissue including elastic fibers. This study was designed to investigate the expression of fibulin-5 and lysyl oxidase-like 1 （LOXL1） in the cardinal ligament in samples taken from the POP group compared to the non-POP group. Specimens were obtained during abdominal hysterectomy from the cardinal ligament of 53 women with POP and 25 age- and par- ity- matched women with non-POP among post-menopausal women with benign gynecologic pathology. Protein expression was evaluated using the immunohistochemical staining method. For statistical analyses, chi-square test and Spearman＇s correlation were used with the statistical package SPSS13.0 system. Our results showed that both fibulin-5 and LOXL1 expressions were decreased in the cardinal ligament in the POP group compared to the non- POP group （P 〈 0.05）. The expression of fibulin-5 and LOXL1 were correlated closely with the stage of POP, ac- companied by stress urinary incontinence and frequency of vaginal delivery （P 〈 0.05）, but had no relationship with post-menopausal state （P 〉 0.05）. The expression of fibulin-5 was positively associated with LOXL1 in POP （P 〈 0.05）. We conclude that changes in fibulin-5 and LOXL1 expression may play a role in the development of POP.

The role of lysyl oxidase-like 1 and fibulin-5 in the development of atherosclerosis and pelvic organ prolapse

Dear Editor： I would like to congratulate Zhou et al.[1] on their study of the correlation between expression of lysyl oxidase-like 1 （LOX-1） and fibulin-5 （F5） in the car- dinal ligament tissue and pelvic organ prolapse （POP）. In their elegant work, they evaluated the levels of LOX-1 and F5 in connective tissue of the cardinal ligament in order to demonstrate signs of elastinopa- thy in women with POP. They stress the concept that several environmental risk factors could cause qualitative and quantitative changes in the connective tissue promoting POP. The above authors conclude that the specific mechanism of LOXL1 and F5 involved in the development of POP is unclear.

Lack of association between lysyl oxidase-like 1 polymorphisms and primary open angle glaucoma: a meta-analysis

AIM:To study the associations between lysyl oxidaselike 1(LOXL1)polymorphisms and primary open angle glaucoma(POAG)remain inconsistent.In this study,we have performed a meta-analysis to investigate the association of LOXL1 polymorphisms with POAG risk.METHODS:Published literature from PubMed and other databases were retrieved.All studies evaluating the association between LOXL1 polymorphisms(rs2165241,rs1048661,rs3825942)and POAG risk were included.Pooled odds ratio(OR)and 95%confidence interval(CI)were calculated using random-or fixed-effects model.RESULTS:Twelve studies were identified as eligible articles,with thirteen(2098 cases and 16 473 controls),thirteen(1795 cases and 2916 controls)and sixteen population cohorts(2456 cases and 2846 controls)for the association of rs2165241,rs1048661 and rs3825942with POAG risk respectively.Overall analyses showed noassociation between each LOXL1 polymorphism and POAG risk,and the negative associations were remained when the subjects were stratified as Caucasian and Asian.The heterozygote of rs2165241 was associated with reduced POAG risk in hospital-based populations(TC vs CC:OR,0.79,95%CI:0.63-0.99),and rs1048661was associated with increased POAG risk in hospitalbased populations in a dominant model(TT vs CC+CT:OR,1.23,95%CI:1.01-1.50);however,these associations were not found in population-based subjects.CONCLUSION:This meta-analysis suggests that LOXL1 polymorphisms are not associated with POAG risk.Given the limited sample size,the associations of LOXL1 polymorphisms with POAG risk in hospital-based populations await further investigation.

Critical evaluation of the glucose oxidase-like activity of gold nanoparticles stabilized by different polymers

Polymer stabilizers are widely used to synthesize gold nanoparticles(Au NPs)to prevent their aggregation and improve their stability.Although stabilizers are known to greatly influence both the structure and size of Au NPs,limited efforts explore their effects on the activity of Au NPs for biocatalysis.Herein,different polymers are used as stabilizers to synthesize Au NPs.For the glucose oxidase-like activity,we find that without the spatial barrier from stabilizers,naked Au NPs show significantly high catalytic activity as well as the worst stability.Among the polymers,polyacrylic acid-stabilized Au NPs exhibit the highest activity,whose Vmax(0.74μM·s^(−1))is higher than that of the natural glucose oxidase(0.37μM·s^(−1))due to the smallest particle size(<2 nm)and the weak spatial resistance of polyacrylic acid.These variable catalytic results derive from the comprehensive effects including size,steric hindrance,and electronic effect.However,further selectivity and activity tests have exposed shortcomings.They possess universal activities for aldose oxidation,whereas cannot retain activities in typical physiological environments.Our findings highlight the role of polymer stabilizers in imposing effects on the glucose oxidase-like activity of Au NPs and provide a basis for further Au NPs engineering and applications.

Portable multi-amplified temperature sensing for tumor exosomes based on MnO_(2)/IR780 nanozyme with high photothermal effect and oxidase-like activity

Efficient determination of tumor exosomes using portable devices is crucial for the establishment of facile and convenient early cancer diagnostic methods. However, it is still challenging to effectively amplify the detection signal to achieve tumor exosomes detection with high sensitivity by portable devices. To address this issue, we developed a portable multi-amplified temperature sensing strategy for highly sensitive detecting tumor exosomes based on multifunctional manganese dioxide/IR780 nanosheets(MnO_(2)/IR780 NSs) nanozyme with high oxidase-like activity and enhanced photothermal performance.Inspiringly, MnO_(2)/IR780 NSs were synthesized via a facile one-step method with mild experimental conditions, which not only exhibited a stronger photothermal effect than that of MnO_(2) but also showed excellent oxidase-like activity that can catalyze the oxidation of 3',3',5',5'-tetramethylbenzidine(TMB) to generate TMB oxide(oxTMB) with a robust photothermal property, thus conjoining with MnO_(2)/IR780 NSs to further enhance the temperature signal. The present assay enables highly sensitive determination of tumor exosomes with the detection limit down to 5.1×10~3 particles/mL, which was comparable or superior to those of the most previously reported sensors. Furthermore, detection of tumor exosomes spiked in biological samples was successfully realized. More importantly, our method showed the recommendable portability, robust applicability, and easy manipulation. By taking advantages of these features,this high-performance photothermal sensor offered a promising alternative means for nondestructive early cancer diagnosis and treatment efficacy evaluation.

Enhanced oxidase-like activity of g-C_(3)N_(4) nanosheets supported Pd nanosheets for ratiometric fluorescence detection of acetylcholinesterase activity and its inhibitor

The undesirable enzymatic activity of nanozymes under near neutral p H condition and the traditional single signal output always restrict the analytical application of nanozyme-based biosensors.Herein,graphitic carbon nitride nanosheets supported palladium nanosheets composite (Pd/g-C_(3)N_(4)) with both oxidase-like activity and fluorescent property is synthesized.Notably,Pd/g-C_(3)N_(4)exhibits enhanced oxidase-like activity compared to Pd NSs under p H 7.4.By combining Pd/g-C_(3)N_(4)with o-phenylenediamine(OPD),a ratiometric fluorescence assay for acetylcholinesterase (ACh E) activity detection is developed.Pd/g-C_(3)N_(4)can catalyze oxidation of nonfluorescent OPD to fluorescent oxidized OPD (ox OPD,Em=565nm),which can quench fluorescence of g-C_(3)N_(4)supporter (Em=441 nm) through fluorescence resonance energy transfer (FRET).However,in presence of ACh E,acetylthiocholine can be hydrolyzed into thiocholine,which will block the oxidase-like activity of Pd/g-C_(3)N_(4)and then hamper the FRET process.This ratiometric fluorescence assay is also viable to screen ACh E inhibitor.This work will guide design of ratiometric fluorescence assay based on nanozymes with improved enzymatic activity.

Fabrication of CeO2/rGO Nanocomposites with Oxidase-like Activity and Their Application in Colorimetric Sensing of Ascorbic Acid

Nanomaterial-based artificial enzymes（nanozymes） have shown great potential for application in colori- metric sensing. In this paper, the nanocomposites of CeO2 and reduced graphene oxide（rCK）） were fabricated via a one-pot hydrothermal process, in which CeO2 nanoparticles were well anchored on the surface of rGO. The prepared CeO2/rGO nanocomposites exhibited excellent catalytic activity for the oxidation of 3,3＇,5,5＇-tetramethylbenzidine（TMB） in the presence of 02. Compared with the individual CeO2 nanoparticles, the nanocomposites had a higher affinity and adsorptivity towards the substrate TMB, which was due to the combination of rGO. In addi- tion, based on the oxidase-like activity of CeO2/rGO nanocomposites, a facile and sensitive colormetric sensor for ascorbic acid（AA） was investigated. The detection limit of AA was low（0.15μmol/L） and the linear detection range was between 0.5μmol/L and 40μmol/L. Fttrthermore, the colorimetric system was used for the detection of AA in medicine and food analysis, such as tablets, beverage and milk powder.

Pyrophosphate-Mediated On-Off-On Oxidase-Like Activity Switching of Nanosized MnFe_(2)O_(4) for Alkaline Phosphatase Sensing

Developing reliable and facile approaches for alkaline phosphatase(ALP)sensing is important due to its role as a clinical biomarker for many diseases.In this study,we proposed a new and convenient colorimetric assay based on the pyrophosphate(PPi)-mediated oxidase-mimicking activity switching of nanosized MnFe_(2)O_(4) for the detection of ALP.The synthesized MnFe_(2)O_(4) exhibited high oxidase-like activity to catalyze the oxidation of colorless 3,3′,5,5′-tetramethylbenzidine(TMB)to its blue product TMBox in the presence of dissolved O2,leading to a color reaction rapidly and remarkably;PPi could significantly inhibit the activity of the MnFe_(2)O_(4) nanozyme via the strong interaction between PPi and the Fe(III)species in MnFe_(2)O_(4),resulting in the suppression of the TMB color reaction;when ALP was added,it hydrolyzed the PPi substrate to phosphate(Pi)that had no obvious effect on the MnFe_(2)O_(4) activity,and such that the TMB color reaction catalyzed by the nanozyme could be observed again.With the above principle,linear colorimetric determination of ALP in the scope of 0.6-55 U L−1 was achieved,giving the limit of detection down to 0.27 U L−1.Besides,the developed assay could provide selective response toward ALP against other co-existing biological species.Furthermore,reliable detection of ALP in human serum samples was verified by our assay,revealing its great promise as an effective and facile tool for ALP monitoring in clinical practice.

Neural Wiskott-Aldrich syndrome protein(N-WASP)promotes distant metastasis in pancreatic ductal adenocarcinoma via activation of LOXL2

Pancreatic ductal adenocarcinoma(PDAC)is one of the most aggressive solid malignancies.A specific mechanism of its metastasis has not been established.In this study,we investigated whether Neural Wiskott-Aldrich syndrome protein(N-WASP)plays a role in distant metastasis of PDAC.We found that N-WASP is markedly expressed in clinical patients with PDAC.Clinical analysis showed a notably more distant metastatic pattern in the N-WASP-high group compared to the N-WASP-low group.N-WASP was noted to be a novel mediator of epithelialmesenchymal transition(EMT)via gene expression profile studies.Knockdown of N-WASP in pancreatic cancer cells significantly inhibited cell invasion,migration,and EMT.We also observed positive association of lysyl oxidase-like 2(LOXL2)and focal adhesion kinase(FAK)with the N-WASP-mediated response,wherein EMT and invadopodia function were modulated.Both N-WASP and LOXL2 depletion significantly reduced the incidence of liver and lung metastatic lesions in orthotopic mouse models of pancreatic cancer.These results elucidate a novel role for N-WASP signaling associated with LOXL2 in EMT and invadopodia function,with respect to regulation of intercellular communication in tumor cells for promoting pancreatic cancer metastasis.These findings may aid in the development of therapeutic strategies against pancreatic cancer.

Identification of the involvement of LOXL4 in generation of keratocystic odontogenic tumors by RNA-Seq analysis

Keratocystic odontogenic tumors （KCOT） are benign, locally aggressive intraosseous tumors of odontogenic origin. KCOT have a higher stromal microvessel density （MVD） than dentigerous cysts （DC） and normal oral mucosa. To identify genes in the stroma of KCOT involved in tumor development and progression, RNA sequencing （RNA-Seq） was performed using samples from KCOT and primary stromal fibroblasts isolated from gingival tissues. Seven candidate genes that possess a function potentially related to KCOT progression were selected and their expression levels were confirmed by quantitative PCR, immunohistochemistry and enzyme-linked immunosorbent assay. Expression of lysyl oxidase-like 4 （LOXL4）, the only candidate gene that encodes a secreted protein, was enhanced at both the mRNA and protein levels in KCOT stromal tissues and primary KCOT stromal fibroblasts compared to control tissues and primary fibroblasts （P〈0.05）. In vitro, high expression of LOXL4 could enhance proliferation and migration of the human umbilical vein endothelial cells （HUVECs）. There was a significant, positive correlation between LOXL4 protein expression and MVD in stroma of KCOT and control tissues （r=0.882）. These data suggest that abnormal expression of LOXL4 of KCOT may enhance angiogenesis in KCOT, which may help to promote the locally aggressive biological behavior of KCOT.

The association of LOXL1 polymorphisms with exfoliation syndrome/glaucoma: Meta-analysis

AIM: To investigate the association of lysyl oxidaselike 1(LOXL1) single nucleotide polymorphisms(SNPs)with exfoliation syndrome(XFS)/exfoliation glaucoma(XFG).METHODS: Published manuscripts from Pub Med and EMBASE were identified until May 2014. Summary odds ratios(ORs) and 95% confidence intervals(CIs) for LOXL1(rs1048661, rs2165241 and rs3825942) polymorphisms and the risk of XFS/XFG were estimated using random-or fixed- effect model.· RESULTS: The three LOXL1 polymorphisms(rs1048661, rs3825942, and rs2165241) were associated with an increased risk for XFS/XFG among Caucasians,with OR 2.19(1.96-2.45), 8.8(6.05-12.79) and 3.41(3.11-3.73), respectively. On the contrast, the rs1048661 and rs2165241, but not rs3825942 polymorphism, have a potential protective effect on XFS/XFG in Asians, with OR0.06(0.02-0.18), 0.15(0.09-0.25), respectively.CONCLUSION: There is strong evidence that LOXL1 polymorphisms are associated with XFS/XFG risk. The strength of risk might be ethnicity-dependent.

A revisiting of transition metal phosphide(Cu_(3)P and FeP)nanozymes for two sugar-related reactions

Transition metal phosphides(TMPs)are essential catalysts for some general catalytic reactions.However,their potentials for biological catalysis have seldom been explored.Herein,we investigated the enzyme-like properties of four TMPs(FeP,CoP,Ni_(2)P,and Cu_(3)P)towards two sugar-related reactions.Among the four TMPs,Cu_(3)P nanoparticles(NPs)efficiently catalyzed the hydrolysis of glycosidic bonds as glycoside hydrolase mimics,and FeP NPs possessed both glucose oxidase-like(GOx-like)and peroxidase-like activities,which combined into a cascade reaction for glucose’s simple and one-step colorimetric biosensor without GOx.Cu_(3)P and FeP NPs with distinctive enzyme-like activities have shown unique biological catalysis potentials for further applications with an attractive and challenging goal of developing nanomaterials to mimic natural enzymes,which encourages more efforts to reveal TMP’s capabilities towards biocatalysis.

Target-triggered inhibiting oxidase-mimicking activity of platinum nanoparticles for ultrasensitive colorimetric detection of silver ion

The development of efficient methods for the detection of hazardous and toxic elements is extremely important for environmental security and public health. In this work, we developed a facile colorimetric assaying system for Ag+ detection in aqueous solution. Chitosan-stabilized platinum nanoparticles(ChPtNPs) were synthesized and severed as an artificial oxidase to catalyze the oxidation of the substrate3,30,5,50-tetramethylbenzidine(TMB) and generate color signal. In the presence of Ag+, due to the strong metallophilic interactions between Ag+ and Pt2+ on the surface of Ch-PtNPs, Ag+ can weaken the affinity to the substrates and inactivate the catalytic activity of Ch-PtNPs, leading to decreased absorbance signal to varying degrees depending on Ag+ amount. Combing the specific binding between Ch-PtNPs and Ag+ with signal amplification procedure based on the Ch-PtNPs-catalyzed TMB oxidation, a sensitive,selective, simple, cost-effective, and rapid detection method for Ag+ can be realized. Ag+ ions in tap and lake waters have been successfully detected. We ensured that the proposed method can be a potential alternative for Ag+ determination in environmental samples.

Highly accessible aqueous synthesis of well-dispersed dendrimer type platinum nanoparticles and their catalytic applications

The application of novel methodologies to the synthesis of nanomaterials is still a challenge in many different technological and scientific fields.New efficient and reproducible synthetic methodologies,that produce fewer residues and reduce the cost of raw materials must be developed.In the present work,we have explored the attractive possibility to apply the cheap iron (Ⅱ) sulphate salt in the reduction process of the K2PtCl4 to produce colloids suspensions.The synthesis took places in water and was assisted by sodium citrate (SC) using polyvinylpyrrolidone (PVP) as a surfactant.The adjustment of this novelty process allows obtaining well-dispersed and sub-20 nm dendrimer-type platinum nanoparticles (Pt D-NPs).The nano-dendrimers produced have been characterized using dynamic light scattering (DLS),transmission electron microscopy (TEM),high-resolution TEM (HR-TEM),XRD spectroscopy,inductive couple plasma (ICP) analysis,Fourier transform infrared (FT-IR) and ultraviolet-visible (UV-vis) spectroscopy.Interesting conformational results derived from the size and shape will be discussed.Catalytic application of the Pt D-NPs has been explored in the reduction of p-nitrophenol (p-NP) to p-aminophenol (p-AP) in aqueous media at room temperature obtained TOF value of 253 min^-1.Finally,our Pt D-NPs were tested as artificial metalloenzyme showing catechol oxidase activity for oxidation of L-DOPA.

Atomically dispersed N-coordinated Fe-Fe dual-sites with enhanced enzyme-like activities

Replacement of enzymes with nanomaterials such as atomically dispersed metal catalysts is one of the most crucial steps in addressing the challenges in biocataiysis.Despite the breakthroughs of single-atom catalysts in enzyme-mimicking,a fundamental investigation on the development of an instructional strategy is still required for mimicking biatomic/multiatomic active sites in natural enzymes and constructing synergistically enhanced metal atom active sites.Herein,Fe_(2)NC catalysts with atomically dispersed Fe-Fe dual-sites supported by the metal-organic frameworks-derived nitrogen-doped carbon are employed as biomimetic catalysts to perform proof-of-concept investigation.The effect of Fe atom number toward typical oxidase(cytochrome C oxidase,NADH oxidase,and ascorbic acid oxidase)and peroxidase(NADH peroxidase and ascorbic acid peroxidase)activities is systematically evaluated by experimental and theoretical investigations.A peroxo-like O_(2) adsorption in Fe_(2)NC nanozymes could accelerate the O-O activation and thus achieve the enhanced enzyme-like activities.This work achieves the vivid simulation of the enzyme active sites and provides the theoretical basis for the design of high-performance nanozymes.As a concept application,a colorimetric biosensor for the detection of S^(2-) in tap water is established based on the inhibition of enzyme-like activity of Fe_(2)NC nanozymes.

Black phosphorus quantum dots as multifunctional nanozymes for tumor photothermal/catalytic synergistic therapy

Nanozymes are nanomaterials with enzyme-like properties that have attracted significant interest owing to their high stability,easy preparation,and tunable catalytic properties,especially in the field of cancer therapy.However,the unfavorable catalytic effects of nanozymes in the acidic tumor microenvironment have limited their applications.Herein,we developed a biomimetic erythrocyte membrane-camouflaged ultrasmall black phosphorus quantum dots(BPQDs)nanozymes that simultaneously exhibited an exceptional near-infrared(NIR)photothermal property and dramatically photothermal-enhanced glucose oxidase(GOx)-like activity in the acidic tumor microenvironment.We demonstrated the engineered BPQDs gave a photothermal conversion efficiency of 28.9%that could rapidly heat the tumor up to 50℃ while effectively localized into tumors via homing peptide iRGD leading after intravenously injection.Meanwhile,the significantly enhanced GOx-like activity of BPQDs under NIR irradiation was capable of catalytical generating massive toxic reactive oxygen species via using cellular glucose.By combining the intrinsic photothermal property and the unique photothermal-enhanced GOx-like catalytic activity,the developed BPQDs were demonstrated to be an effective therapeutic strategy for inhibiting tumor growth in vivo.We believe that this work will provide a novel perspective for the development of nanozymes in tumor catalytic therapy.

Bimetallic AuRu aerogel with enzyme-like activity for colorimetric detection of Fe^(2+) and glucose

Aerogels have become a hot topic of research due to their extremely low density and special interconnected structure as well as their enzyme-like activity.The development of new multifunctional nano-enzyme aerogels with high activity and good stability is still a considerable challenge.In this paper,AuRu aerogels with peroxidase and oxidase activities were synthesized using a simple one-step method and successfully used to construct colorimetric sensors for the detection of Fe^(2+)and glucose based on their enzyme-like activities.Furthermore,we are fortunate to find that AuRu aerogels have good photothermal properties.This suggests that AuRu aerogels can be used not only for in vitro testing but also for promising applications such as disease treatment.