Upregulation of TRIM16 mitigates doxorubicin-induced cardiotoxicity by modulating TAK1 and YAP/Nrf2 pathways in mice.

The clinic application of doxorubicin (DOX) is severely limited by its severe cardiotoxicity. Tripartite motif-containing protein 16 (TRIM16) has E3 ubiquitin ligase activity and is upregulated in cardiomyocytes under pathological stress, yet its role in DOX-induced cardiotoxicity remains elusive. This study aims to investigate the role and mechanism of TRIM16 in DOX cardiotoxicity. Following TRIM16 overexpression in hearts with AAV9-TRIM16, mice were intravenously administered DOX at a dose of 4 mg/kg/week for 4 weeks to assess the impact of TRIM16 on doxorubicin-induced cardiotoxicity. Transfection of OE-TRIM16 plasmids and siRNA-TRIM16 was performed in neonatal rat cardiomyocytes (NRCMs). Our results revealed that DOX challenge elicited a significant upregulation of TRIM16 proteins in cardiomyocytes. TRIM16 overexpression efficiently ameliorated cardiac function while suppressing inflammation, ROS generation, apoptosis and fibrosis provoked by DOX in the myocardium. TRIM16 knockdown exacerbated these alterations caused by DOX in NRCMs. Mechanistically, OE-TRIM16 augmented the ubiquitination and degradation of p-TAK1, thereby arresting JNK and p38MAPK activation evoked by DOX in cardiomyocytes. Furthermore, DOX enhanced the interaction between p-TAK1 and YAP1 proteins, resulting in a reduction in YAP and Nrf2 proteins in cardiomyocytes. OE-TRIM16 elevated YAP levels and facilitated its nuclear translocation, thereby promoting Nrf2 expression and mitigating oxidative stress and inflammation. This effect was nullified by siTRIM16 or TAK1 inhibitor Takinib. Collectively, the current study elaborates that upregulating TRIM16 mitigates DOX-induced cardiotoxicity through anti-inflammation and anti-oxidative stress by modulating TAK1-mediated p38 and JNK as well as YAP/Nrf2 pathways, and targeting TRIM16 may provide a novel strategy to treat DOX-induced cardiotoxicity.

Flt3 Activation Mitigates Mitochondrial Fragmentation and Heart Dysfunction through Rebalanced L-OPA1 Processing by Hindering the Interaction between Acetylated p53 and PHB2 in Cardiac Remodeling.

Recent studies have shown that FMS-like receptor tyrosine kinase 3 (Flt3) has a beneficial effect on cardiac maladaptive remodeling. However, the role and mechanism of Flt3 in mitochondrial dynamic imbalance under cardiac stress remains poorly understood. This study aims to investigate how Flt3 regulates p53-mediated optic atrophy 1 (OPA1) processing and mitochondrial fragmentation to improve cardiac remodeling. Mitochondrial fragmentation in cardiomyocytes was induced by isoprenaline (ISO) and H2O2 challenge, respectively, in vitro. Cardiac remodeling in mice was established by ligating the left anterior descending coronary artery or by chronic ISO challenge, respectively, in vivo. Our results demonstrated that the protein expression of acetylated-p53 (ac-p53) in mitochondria was significantly increased under cell stress conditions, facilitating the dissociation of PHB2-OPA1 complex by binding to prohibitin 2 (PHB2), a molecular chaperone that stabilizes OPA1 in mitochondria. This led to the degradation of the long isoform of OPA1 (L-OPA1) that facilitates mitochondrial fusion and resultant mitochondrial network fragmentation. This effect was abolished by a p53 K371R mutant that failed to bind to PHB2 and impeded the formation of the ac-p53-PHB2 complex. The activation of Flt3 significantly reduced ac-p53 expression in mitochondria via SIRT1, thereby hindering the formation of the ac-p53-PHB2 complex and potentiating the stability of the PHB2-OPA1 complex. This ultimately inhibits L-OPA1 processing and leads to the balancing of mitochondrial dynamics. These findings highlight a novel mechanism by which Flt3 activation mitigates mitochondrial fragmentation and dysfunction through the reduction of L-OPA1 processing by dampening the interaction between ac-p53 and PHB2 in cardiac maladaptive remodeling.

Inhibition of the maize salt overly sensitive pathway by ZmSK3 and ZmSK4.

Soil salinity is a worldwide problem that adversely affects plant growth and crop productivity. The salt overly sensitive (SOS) pathway is evolutionarily conserved and essential for plant salt tolerance. In this study, we reveal how the maize shaggy/glycogen synthase kinase 3-like kinases ZmSK3 and ZmSK4, orthologs of brassinosteroid insensitive 2 in Arabidopsis thaliana, regulate the maize SOS pathway. ZmSK3 and ZmSK4 interact with and phosphorylate ZmSOS2, a core member of the maize SOS pathway. The mutants defective in ZmSK3 or ZmSK4 are hyposensitive to salt stress, with higher salt-induced activity of ZmSOS2 than that in the wild type. Furthermore, the Ca2+ sensors ZmSOS3 and ZmSOS3-like calcium binding protein 8 (ZmSCaBP8) activate ZmSOS2 to maintain Na+/K+ homeostasis under salt stress and may participate in the regulation of ZmSOS2 by ZmSK3 and ZmSK4. These findings discover the regulation of the maize SOS pathway and provide important gene targets for breeding salt-tolerant maize.

Activation of FMS-like tyrosine kinase 3 protects against isoprenaline-induced cardiac hypertrophy by improving autophagy and mitochondrial dynamics.

FMS-like receptor tyrosine kinase 3 (Flt3) expression was reported to increase in the heart in response to pathological stress, but the role of Flt3 activation and its underlying mechanisms remain poorly elucidated. This study was designed to investigate the role of Flt3 activation in sympathetic hyperactivity-induced cardiac hypertrophy and its mechanisms through autophagy and mitochondrial dynamics. In vivo, cardiac hypertrophy was established by subcutaneous injection of isoprenaline (6 mg/kg·day) in C57BL/6 mice for 7 consecutive days. The Flt3-ligand intervention was launched 2 h prior to isoprenaline each day. In vitro, experiments of cardiomyocyte hypertrophy, autophagy, and mitochondrial dynamics were performed in neonatal rat cardiomyocytes (NRCMs). Our results revealed that the expression level of Flt3 protein was significantly increased in the hypertrophic myocardium provoked by isoprenaline administration. Flt3-ligand intervention alleviated isoprenaline-induced cardiac oxidative stress, hypertrophy, fibrosis, and contractile dysfunction. Isoprenaline stimulation impaired autophagic flux in hypertrophic mouse hearts, supported by the accumulation of LC3II and P62 proteins, while Flt3-ligand restored the impairment of autophagic flux. Flt3 activation normalized the imbalance of mitochondrial fission and fusion in the hearts of mice evoked by isoprenaline as evidenced by the neutralization of elevated mitochondrial fission markers and reduced mitochondrial fusion markers. In NRCMs, Flt3-ligand treatment attenuated isoprenaline-stimulated hypertrophy, which was abolished by a Flt3-specific blocker AC220. Activating Flt3 reversed isoprenaline-induced autophagosome accumulation and impairment of autophagic flux probably by enhancing SIRT1 expression and consequently TFEB nuclear translocation. Flt3 activation improved the imbalance of mitochondrial dynamics induced by isoprenaline in NRCMs through the SIRT1/P53 pathway. Activation of Flt3 mitigated ISO-stimulated hypertrophy probably involves the restoration of autophagic flux and balance of mitochondrial dynamics. Therefore, activation of Flt3 attenuates isoprenaline-induced cardiac hypertrophy in vivo and in vitro, the potential mechanism probably attributes to SIRT1/TFEB-mediated autophagy promotion and SIRT1/P53-mediated mitochondrial dynamics balance. These findings suggest that activation of Flt3 may be a novel target for protection against cardiac remodeling and heart failure during sympathetic hyperactivity.

Impaired autophagy and mitochondrial dynamics are involved in Sorafenib-induced cardiomyocyte apoptosis.

Sorafenib (Sor), a novel multi-target anticancer drug also induces severe toxicity in heart, while the mechanism of its cardiotoxicity remains to be fully elucidated. Dysregulation of autophagy and mitochondrial dynamics imbalance have been implicated in cardiomyocyte death. The aim of this study is to test the hypothesis that Sor disrupts autophagy and mitochondrial dynamics, thereby aggravating Sor-induced oxidative stress damage to cardiomyocytes. Our results revealed that Sor (≥ 5 µM) concentration- and time-dependently reduced cell viability and induced apoptosis in H9c2 myoblasts. Sor treatment promoted intracellular reactive oxygen species (ROS) generation, and subsequent Ca2+ overload as well as apoptosis, which were abolished by the ROS scavenger MPG. Sor inhibited the basal autophagy activity of cells, as supported by the fact that ERK1/2 inhibition-dependent decreases of autophagosomes and autolysosomes, and p62 accumulation in a concentration- and time-dependent manner. Improving autophagy with rapamycin abrogated Sor-induced ROS and Ca2+ overloads, and cell apoptosis. Furthermore, Sor compromised mitochondrial morphology and caused excessive mitochondrial fragmentation in cells. The imbalance of mitochondrial dynamics was attributed to ROS-mediated CaMKII overactivity, and increased phosphorylation of dynamin-related protein 1 (phosph-Drp1). Suppression of CaMKII with KN-93 or mitochondrial fission with mitochondrial division inhibitor-1 (Mdivi-1) attenuated Sor-induced ROS and Ca2+ overloads as well as apoptosis. In conclusion, these results provide the first evidence that impairments in autophagy and mitochondrial dynamics are involved in Sor-induced cardiomyocyte apoptosis. The present study may provide a potential strategy for preventing or reducing cardiotoxicity of Sor.

Development of dual-enhancer biocatalyst with photothermal property for the degradation of cephalosporin.

The abuse of cephalosporins poses a serious threat to human health and the ecological environment. In this work, cephalosporinase (AmpC enzyme) and Prussian blue (PB) crystals were encapsulated into ZIF-8 metal-organic frameworks (MOFs), and a photothermal AmpC/PB@ZIF-8 MOFs (APZ) nanocatalyst was prepared for the catalytic degradation of cephalosporin. The temperature of the APZ catalytic degradation system can be regulated by irradiation with near infrared light due to the photothermal effect of PB, and then, the activity of the APZ biocatalyst is significantly enhanced. Thereby, the degradation efficiency of cefuroxime can reach to 96%, and the degradation kinetic rate of cefuroxime augmented 4.5-fold comparing with that catalyzed by free enzyme. Moreover, encapsulation of the enzyme and PB can increase the affinity and charge transfer efficiency between APZ and substrate molecules, which can also improve the degradation efficiency of cephalosporins. Catalytic degradation pathways for three generations of cephalosporins were proposed based on their degradation products. The dual-enhancer biocatalyst based on the photothermal effect and immobilization of the PB and enzyme can significantly enhance the activity and stability of the enzyme, and it can also be recycled. Therefore, the biocatalyst has potential applications for the effective degradation of cephalosporins in the environment.

Development of dual-ligand titanium (IV) hydrophilic network sorbent for highly selective enrichment of phosphopeptides.

A hydrophilic metal-organic network based on Ti4+ and dual natural ligand, tannic acid (TA) and phytic acid (PA), has been developed to enrich phosphopeptides from complex bio-samples prior to liquid chromatography-mass spectrometric analysis. Due to the strong chelation ability of TA and PA, abundant Ti4+ can be immobilized in the material, forming hydrophilic network by one-step coordination-driven self-assembly approach. The sorbent, TA-Ti-PA@Fe3O4, exhibited satisfactory selectivity for the phosphopeptides in the tryptic digest of ß-casein, and can eliminate the interference components in 1000-fold excess of bovine serum albumin. The adsorption capacity of the sorbents for phosphopeptides was up to 35.2 mg g-1 and the adsorbing equilibrium can be reached in 5 min. The adsorbing mechanism has been investigated and the results indicated that the Ti4+ in forms of [Ti(f-TA)(H2O)4]2+, [Ti(f-PA)(H2O)4]2+ and Ti(f-PA)2(H2O)2 may play an important role in the adsorption process. The sorbent of the TA-Ti-PA@Fe3O4 has been applied to enrichment of the phosphopeptides in tryptic digest of rat liver lysate, and 3408 phosphopeptides have been identified, while the numbers of the identified phosphopeptides were 2730 and 1217 when the sample was enriched by the commercial TiO2 and Fe3+-IMAC kit, respectively. This work provides a strategy to enrich phosphopeptides from complex samples and shows great potential application in phosphoproteome research.

Downregulation of miR-128 Ameliorates Ang II-Induced Cardiac Remodeling via SIRT1/PIK3R1 Multiple Targets.

Recent studies reported that miR-128 was differentially expressed in cardiomyocytes in response to pathologic stress. However, its function and mechanism remain to be fully elucidated. The aim of the present study was to investigate the role of miR-128 in chronic angiotensin II (Ang II) infusion-induced cardiac remodeling and its underlying mechanism. The cardiac remodeling and heart failure in vivo were established in C57BL/6 mice by chronic subcutaneous Ang II delivery. Knocking down miR-128 was conducted in the hearts of the mice by intravenous injection of HBAAV2/9-miR-128-GFP sponge (miR-128 inhibitor). In vitro experiments of cardiac hypertrophy, apoptosis, and aberrant autophagy were performed in cultured cells after Ang II treatment or transfection of miR-128 antagomir. Our results showed that chronic Ang II delivery for 28 days induced cardiac dysfunction, hypertrophy, fibrosis, apoptosis, and oxidative stress in the mice, while the miR-128 expression was notably enhanced in the left ventricle. Silencing miR-128 in the hearts of mice ameliorated Ang II-induced cardiac dysfunction, hypertrophy, fibrosis apoptosis, and oxidative stress injury. Moreover, Ang II induced excessive autophagy in the mouse hearts, which was suppressed by miR-128 knockdown. In cultured cells, Ang II treatment induced a marked elevation in the miR-128 expression. Downregulation of miR-128 in the cells by transfection with miR-128 antagomir attenuated Ang II-induced apoptosis and oxidative injury probably via directly targeting on the SIRT1/p53 pathway. Intriguingly, we found that miR-128 inhibition activated PIK3R1/Akt/mTOR pathway and thereby significantly damped Ang II-stimulated pathological autophagy in cardiomyocytes, which consequently mitigated cell oxidative stress and apoptosis. In conclusion, downregulation of miR-128 ameliorates Ang II-provoked cardiac oxidative stress, hypertrophy, fibrosis, apoptosis, and dysfunction in mice, likely through targeting on PIK3R1/Akt/mTORC1 and/or SIRT1/p53 pathways. These results indicate that miR-128 inhibition might be a potent therapeutic strategy for maladaptive cardiac remodeling and heart failure.

QKI-Regulated Alternative Splicing Events in Cervical Cancer: Pivotal Mechanism and Potential Therapeutic Strategy.

QKI is a vital regulator in RNA splicing and maturation, but its role in cervical cancer (CC) is little known. In this study, we found that QKI is decreased in human CC, and overexpression of QKI inhibits HeLa cell proliferation and promotes the apoptosis of cancer cells. We identified hundreds of endogenous QKI-regulated alternative splicing events (ASEs) and differentially expressed genes (DEGs) in QKI-overexpressed HeLa cells by RNA-seq and selectively validated their expression by quantitative reverse-transcription polymerase chain reaction. The gene ontology and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that QKI-regulated ASEs and DEGs were closely related to cancer, apoptosis, and transcriptional regulatory functions. In short, QKI may affect the occurrence and development of CC by regulating gene expression through AS.

Inhibition of the Ras/ERK1/2 pathway contributes to the protective effect of ginsenoside Re against intimal hyperplasia.

Neointimal hyperplasia is the major cause of carotid stenosis after vascular injury, which restricts the long-term efficacy of endovascular treatment and endarterectomy in preventing stenosis. Ginsenoside Re (Re) is a major active ingredient of ginseng having multifaceted pharmacological effects on the cardiovascular system, and is a potential treatment for restenosis. In this study, we demonstrated that Re treatment significantly inhibited vascular injury-induced neointimal thickening, reduced the intimal area and intima/media (I/M) ratio, increased the lumen area, and inhibited pro-inflammatory cytokines. In cultured A7R5 cells, Re inhibited LPS-induced proliferation and migration as evidenced by suppressed colony formation and shortened migration distance, accompanied by the downregulated expression of pro-inflammatory cytokines. Re promoted VSMC apoptosis induced by balloon injury in vivo and LPS challenge in vitro. Moreover, Re inhibited autophagy in VSMCs evoked by balloon injury and LPS as supported by reduced LC3II and increased p62 expressions. Suppression of autophagy with the specific autophagy inhibitor spautin-1 efficiently inhibited LPS-induced cell proliferation and inflammation and promoted caspase-3/7 activities. Mechanistically, we found that Re attenuated Ras/ERK1/2 expression in VSMCs in vivo and in vitro. The MEK1/2 inhibitor PD98059 showed similar effects to Re on cell proliferation, migration, apoptosis, and the levels of autophagy and cytokines. In conclusion, we provided significant evidence that Re inhibited vascular injury-induced neointimal thickening probably by promoting VSMC apoptosis and inhibiting autophagy via suppression of the Ras/MEK/ERK1/2 signaling pathway.

Activated FMS-like tyrosine kinase 3 ameliorates angiotensin II-induced cardiac remodelling.

AIM: FMS-like receptor tyrosine kinase 3 (Flt3) has been reported to be increased in cardiomyocytes responding to ischaemic stress. This study was to determine whether Flt3 activation could ameliorate pressure overload-induced heart hypertrophy and fibrosis, and to elucidate the mechanisms of action. METHODS: In vivo cardiac hypertrophy and remodelling experiments were conducted by infusing angiotensin II (Ang II) chronically in male C57BL/6 mice. Flt3-specific ligand (FL) was administered intraperitoneally every two days (5 µg/mouse). In vitro experiments on hypertrophy, apoptosis and autophagy mechanism were performed in neonatal rat cardiomyocytes (NRCMs) and H9c2 cells with adenovirus vector-mediated overexpression of Flt3. RESULTS: Our results demonstrated that following chronic Ang II infusion for 4 weeks, the mice exhibited heart hypertrophy, fibrosis, apoptosis and contractile dysfunction. Meanwhile, Ang II induced autophagic responses in mouse hearts, as evidenced by increased LC3 II and decreased P62 expression. These pathological alterations in Ang II-treated mice were significantly ameliorated by Flt3 activation with FL administration. In NRCMs and Flt3-overexpressed H9c2 cells, FL attenuated Ang II-induced pathological autophagy and inactivated AMPK/mTORC1/FoxO3a signalling, thereby efficiently mitigating cell hypertrophy and apoptosis. Conversely, the AMPK activator metformin or the mTORC1 inhibitor rapamycin reversed the effects of FL on the alterations of autophagy, hypertrophy and apoptosis in cardiomyocytes induced by Ang II. CONCLUSION: Flt3 activation ameliorates cardiac hypertrophy, fibrosis and contractile dysfunction in the mouse model of chronic pressure overload, most likely via suppressing AMPK/mTORC1/FoxO3a-mediated autophagy. These results provide new evidence supporting Flt3 as a novel therapeutic target in maladaptive cardiac remodelling.

[Short-term and long-term efficacy of PGLA thread-embedding therapy in treatment of stage â post-stroke shoulder-hand syndrome].

OBJECTIVE: To investigate short-term and long-term efficacy of PGLA thread-embedding therapy in the treatment of stage Ⅰ post-stroke shoulder-hand syndrome. METHODS: A total of 60 patients with stage Ⅰ post-stroke shoulder-hand syndrome were randomly divided into control group and treatment group, with 30 patients in each group. The patients in the control group were given acupuncture combined with rehabilitation training, and those in the treatment group were given PGLA thread-embedding therapy combined with rehabilitation training. Conventional acupuncture was performed once a day, and thread-embedding therapy was performed once every 5 days. Both groups were treated for 30 days. Clinical outcome, Visual Analogue Scale (VAS) score, hand edema score, and Fugl-Meyer Assessment (FMA) score were compared within and between groups immediately and at 1 month after treatment. RESULTS: The treatment group had a significantly higher overall response rate than the control group immediately and at 1 month after treatment (93.33%/86.67% vs 73.33%/56.67%, P<0.05). Both groups had significant reductions in VAS score and hand edema score and a significant increase in FMA score immediately and at 1 month after treatment (P<0.05), and the treatment group had significantly greater improvements than the control group (P<0.05). CONCLUSION: PGLA thread-embedding therapy has a better clinical effect than conventional acupuncture in the treatment of stage Ⅰ post-stroke shoulder-hand syndrome.

Fluorescence Resonance Energy Transfer-Mediated Immunosensor Based on Design and Synthesis of the Substrate of Amp Cephalosporinase for Biosensing.

The traditional enzyme-linked immunosorbent assay (ELISA) has some disadvantages, such as insufficient sensitivity and low stability of the labeled enzyme, which limit its further applications. In this study, a more stable enzyme, Amp cephalosporinase (AmpC), was selected as the labeled enzyme, and its substrate was designed and synthesized. This substrate contained the cephalosporin ring core as the enzymatic recognition section and the structural motif of the 3-hydroxyflavone (3-HF) as the reporter molecule. AmpC can specifically catalyze the substrate and release 3-HF, which can enter the cavity of ß-cyclodextrin (ß-CD) on the surface of ZnS quantum dots and form a fluorescence resonance energy transfer (FRET) signal amplification system. An AmpC-catalyzed, FRET-mediated ultrasensitive immunosensor (ACF immunosensor) for procalcitonin (PCT) was developed by combining the signal amplification system of the polystyrene microspheres and effective immune-based magnetic separation. The ACF immunosensor has high sensitivity and specificity for the detection of PCT: its linear range is from 0.1 ng mL-1 to 70 ng mL-1, and the limit of detection can reach 0.03 ng mL-1. The spiking recoveries of PCT in human serum samples range from 98.3% to 107%, with relative standard deviations ranging from 2.14% to 12.0%. This approach was applied to detect PCT in real patient serum samples, and the results are consistent with those obtained with a commercial ELISA kit.

Phytic acid functionalized Fe3O4 nanoparticles loaded with Ti(IV) ions for phosphopeptide enrichment in mass spectrometric analysis.

A novel magnetic nanomaterial for use in metal ion based affinity chromatography is described. It is based on the chelation between the phosphate groups of phytic acid (PA) and Ti(IV) ions. Due to the large number (6) of phosphate groups of PA, it has a large capacity for Ti(IV) ions. PA was first immobilized on magnetite nanoparticles (PA-MNPs) and then loaded with Ti(IV) ions to obtain the sorbent (Ti-PA-MNPs). The fraction of Ti(IV) ions on the surface of PA-MNPs that is exposed to the solution binds the phosphate groups of phosphopeptides. The bound phosphopeptides can then be magnetically separated. The method was applied to the enrichment of the phosphopeptides in a ß-casein tryptic digest. A tryptic digest of bovine serum albumin (BSA) was added at a molar ratio (ß-casein to BSA) of 1:2000 to study selectivity. The phosphopeptides were quantified by mass spectrometry. The limit of detection can be as low as 8 × 10-10 mol L-1. This sorbent has a high absorption capacity (53.5 µg mg-1) and shows good recoveries (90%). As many as 2145 phosphopeptides were isolated from 500 µg tryptic digest of a rat liver lysate after enrichment by Ti-PA-MNPs. This is superior to that (1568 phosphopeptides) of commercial TiO2 kit. Graphical abstract Schematic presentation of fabrication for a novel modified magnetic nanomaterial (Ti-PA-MNPs) based on the chelation of phytic acid (PA) with Ti(IV) ions. Ti-PA-MNPs were successfully applied to enriching low abundance phosphopeptides from biosamples in mass spectrometric analysis.

Characterization, source, and retention of microplastic in sandy beaches and mangrove wetlands of the Qinzhou Bay, China.

Severe microplastic pollution from anthropogenic activities in coastal zones presents an imminent risk to marine ecosystems. In this study, abundant microplastics (15-12,852 items kg-1) with sizes ranging between 0.16 and 5.0 mm were extracted from 17 sediment samples collected in sandy beaches and mangrove wetlands of the Qinzhou Bay, Guangxi Province, Southwest China. Three types of microplastics (i.e. polystyrene, polypropylene, and polyethylene) were identified with Fourier transform infrared (FTIR) spectroscopy analysis. These detected microplastics were characterized by different colors (white, transparent, yellow, green, red, and blue) and shapes (fragment, fiber, and sphere). Microplastics were concentrated on supratidal beaches and wetlands outside of mangrove, and less abundant on intertidal beaches and inside of mangrove wetlands. Meanwhile, high microplastic concentrations were observed near mollusk farms. The spatial distribution and chemical speciation indicated that microplastics were derived from disintegration of large plastic debris (e.g., Styrofoam buoys used to support mollusk rafts) abandoned by aquaculture industry. Further, coastal vegetation (e.g. mangrove) could trap microplastic particles.

Phosphate-imprinted magnetic nanoparticles using phenylphosphonic acid as a template for excellent recognition of tyrosine phosphopeptides.

The tyrosine phosphorylation of proteins and peptides plays a vital role in cell signal transduction pathways, and it is very important to assay them for understanding their action mechanism. Due to the low levels of the tyrosine phosphopeptides (pTyr) in cells, it is a challenge to enrich them with traditional sorbents, therefore, development of specific and selective sorbents is urgent and necessary. In this work, the phosphate-imprinted magnetic nanoparticles (PMNPs) to enrich the pTyr with high efficiency and selectivity have been fabricated using the phenylphosphonic acid as a template for the "epitope" of pTyr. The magnetic nanoparticles have been functionalized with TiO2 and then the imprinting silica shells have been coated on the surface of the functional core to obtain the PMNPs sorbents. The PMNPs can obviously shorten the enrichment time and improve the adsorption efficiency for pTyr, and the epitope imprinting films provide an excellent selective recognition ability to target. The recognition capability of PMNPs for pTyr is 90.3 µg/mg and the imprinting factor of the sorbents can reach 24.4. The results indicate that the PMNPs can enrich the pTyr from the tryptic digest of ß-casein samples with high specificity, and the spiking recoveries of the pTyr range from 85.1% to 93.8% with the RSD from 0.04 to 3.73. With the high adsorption capacity, rapid separation, excellent specificity and recyclability, the PMNPs sorbents show great potential for analysis of the phosphorylation of peptides in biological and medical fields.

Adsorption of antibiotics on microplastics.

Microplastics and antibiotics are two classes of emerging contaminants with proposed negative impacts to aqueous ecosystems. Adsorption of antibiotics on microplastics may result in their long-range transport and may cause compound combination effects. In this study, we investigated the adsorption of 5 antibiotics [sulfadiazine (SDZ), amoxicillin (AMX), tetracycline (TC), ciprofloxacin (CIP), and trimethoprim (TMP)] on 5 types of microplastics [polyethylene (PE), polystyrene (PS), polypropylene (PP), polyamide (PA), and polyvinyl chloride (PVC)] in the freshwater and seawater systems. Scanning Electron Microscope (SEM) and X-ray diffractometer (XRD) analysis revealed that microplastics have different surface characterizes and various degrees of crystalline. Adsorption isotherms demonstrated that PA had the strongest adsorption capacity for antibiotics with distribution coefficient (Kd) values ranged from 7.36 ±â€¯0.257 to 756 ±â€¯48.0 L kg-1 in the freshwater system, which can be attributed to its porous structure and hydrogen bonding. Relatively low adsorption capacity was observed on other four microplastics. The adsorption amounts of 5 antibiotics on PS, PE, PP, and PVC decreased in the order of CIP > AMX > TMP > SDZ > TC with Kf correlated positively with octanol-water partition coefficients (Log Kow). Comparing to freshwater system, adsorption capacity in seawater decreased significantly and no adsorption was observed for CIP and AMX. Our results indicated that commonly observed polyamide particles can serve as a carrier of antibiotics in the aquatic environment.

Determination of protein kinase A activity and inhibition by using hydroxyapatite nanoparticles as a fluorescent probe.

The authors describe a fluorometric method for the determination of the activity and inhibition of protein kinase A (PKA). In the presence of ATP, PKA catalyzes the transfer of phosphate groups from ATP to a peptide, and the generated phosphorylated peptide quenches the fluorescence (measured at excitation/emission peaks of 340/440 nm) of the hydroxyapatite nanoparticles (HAP-NPs). A linear logarithmic relationship of PKA concentrations with fluorescence intensity in the range from 1 to 50 U·L-1 was obtained, and the lower limit of detection (LOD) is 0.5 U·L-1. This is much lower than LODs reported in the literature. The PKA inhibitor H-89 was studied, and the inhibition plot has a sigmoidal shape with a half-maximal inhibitory concentration of around 750 nM of H-89. At a 4.5 nM level of H-89, fluorescence of HAP-NPs fell to levels of no PKA controls, demonstrating that the assay is a viable tool to screen for kinase inhibitors. An assay with Hela cell lysates in combination with forskolin (an activator of adenylyl cyclase) and IBMX (a phosphodiesterase inhibitor used to activate the cellular activity of PKA) resulted in decreased fluorescence of HAP-NPs. This suggests that the assay can be applied for testing in vitro cell kinase activity. In our perception, this method will enable high-throughput screening for kinase-related drugs and fluorometric enzymatic detection in various areas. Graphical abstract Fluorescence assay based on hydroxyapatite nanoparticles (HAP) fluorescence quenching was developed for analysis of the activity and inhibition of protein kinase A (PKA).

NID1, a new regulator of EMT required for metastasis and chemoresistance of ovarian cancer cells.

Nidogen-1 (NID1) has been identified as a novel candidate diagnostic biomarker of ovarian cancer in our previous study. Nevertheless, the role of NID1 in the pathogenesis of ovarian cancer is unclear. In the present study, we demonstrated that NID1 was a mesenchymal associated gene and its high expression was significantly correlated with shorter overall survival of ovarian cancer patients. The ectopic expression of NID1 in OVCAR-3 cells revealed a epithelial-mesenchymal transition (EMT) phenotype accompanied by enhancement of motility, invasiveness and cisplatin resistance, whereas the knockdown of NID1 was sufficient to convert HEY cells into epithelial phenotype with decreased capability of motility, invasiveness and cisplatin resistance. Mechanistic studies disclosed that NID1 activated ERK/MAPK signaling pathway to promote EMT. Collectively, our findings have uncovered the molecular mechanisms of NID1 in promoting ovarian cancer metastasis and chemoresistance, and provide a rationale for the therapeutic potential of NID1 suppression in ovarian cancer.

A single electrochemical biosensor for detecting the activity and inhibition of both protein kinase and alkaline phosphatase based on phosphate ions induced deposition of redox precipitates.

Protein kinase (PKA) and alkaline phosphatase (ALP) are clinically relevant enzymes for a number of diseases. In this work, we developed a new simple electrochemical biosensor for the detection of the activity and inhibition of both PKA and ALP. One common feature of the PKA and ALP catalyzing process is that PKA can hydrolysis adenosine-5'-triphosphate (ATP) and ALP can hydrolysis pyrophosphate, both reactions produce phosphate ions, and the amount of phosphate ion produced is proportional to enzyme activity. Our assay is based on the principle that phosphate ions react with molybdate to form redox molybdophosphate precipitates on the electrode surface, thus generating electrochemical current. The detection limit for PKA and ALP were much lower than existing assays. The biosensor has good specificity and was used to measure drug-stimulated PKA from lysates of HeLa cells. We also evaluated the use of the biosensor as a screening tool for enzyme inhibitors. To the best of our knowledge, this is the first report of a biosensor capable of detecting the activity of both PKA and ALP. This tool has the potential to simplify PKA and ALP clinical measurement, thereby improving diagnostics of relevant diseases. It also may serve as the basis for a simple screening method for new enzyme inhibitors for disease treatment.