PCSK9 induces endothelial cell autophagy by regulating the PI3K/ATK pathway in atherosclerotic coronary heart disease.

OBJECTIVE: Atherosclerosis is a chronic inflammatory disease of the arteries, and its pathogenesis is related to endothelial dysfunction. It has been found that the protein convertase subtilin/kexin9 type (PCSK9) plays an important role in AS, but its specific mechanism is still unclear. METHODS: In this study, we first cultured human umbilical vein endothelial cells (HUVECs) with 50 or 100µg/ml oxidized low-density lipoprotein (ox-LDL) for 24 hours to establish a coronary atherosclerosis cell model. RESULTS: The results showed that ox-LDL induced HUVEC injury and autophagy and upregulated PCSK9 protein expression in HUVECs in a concentration-dependent manner. Silencing PCSK9 expression with siRNA inhibited ox-LDL-induced HUVEC endothelial dysfunction, inhibited the release of inflammatory factors, promoted HUVEC proliferation and inhibited apoptosis. In addition, ox-LDL increased the expression of LC3B-I and LC3B-II and decreased the expression of p62. However, these processes are reversed by sh-PCSK9. In addition, sh-PCSK9 can inhibit PI3K, AKT and mTOR phosphorylation and promote autophagy. CONCLUSION: Taken together, our research shows that silencing PCSK9 inhibits the PI3K/ATK/mTOR pathway to activate ox-LDL-induced autophagy in vascular endothelial cells, alleviating endothelial cell injury and inflammation.

The perilous consequences of bowel preparation: a case study with literature review of Boerhaave syndrome.

Colonoscopy is widely acknowledged as a prevalent and efficacious approach for the diagnosis and treatment of gastrointestinal disorders. In order to guarantee an effective colonoscopy, it is imperative for patients to undergo an optimal bowel preparation regimen. This entails the consumption of a substantial volume of a non-absorbable solution to comprehensively purge the colon of any fecal residue. Nevertheless, it is noteworthy to acknowledge that the bowel preparation procedure may occasionally elicit adverse symptoms such as nausea and vomiting. In exceptional instances, the occurrence of excessive vomiting may lead to the rupture of the distal esophagus, a grave medical condition referred to as Boerhaave syndrome (BS). Timely identification and efficient intervention are imperative for the management of this infrequent yet potentially perilous ailment. This investigation presents a case study of a patient who developed BS subsequent to the ingestion of mannitol during bowel preparation. Furthermore, an exhaustive examination of extant case reports and pertinent literature on esophageal perforation linked to colonoscopy has been conducted. This analysis provides valuable insights into the prevention, reduction, and treatment of such serious complications.

Machine-learning-assisted SERS nanosensor platform toward chemical fingerprinting of Baijiu flavors.

A novel fingerprinting platform for multiplex detection of flavor molecules in Baijiu was developed by using a surface-enhanced Raman scattering (SERS) nanosensor array in combination with machine learning. The SERS sensors were constructed by core-shell Fe3O4@Ag nanoparticles modified with molecules carrying end-groups of hydroxyl, pyridyl, methyl, and amino, respectively, which interacted with flavors and led to changes in the sensors' spectra. All the Raman spectra acquired from the nanosensor array contacting with the sample were concatenated into a single SERS super-spectrum, representing the flavor fingerprint which was recognized through machine learning. Principal component analysis, support vector machine, and partial least squares were utilized to build classification and quantitation models for predictive analyses. The SERS nanosensor array was successfully used for fingerprinting ten typical flavors in Baijiu including four esters, three alcohols, and three acids, with an accuracy of 100%, linear detection ranges over two orders of magnitude, and limits of detection ranging from 3.45 × 10-3 mg/L of phenylethyl acetate to 1.21 × 10-2 mg/L of ethyl hexanoate. It was also demonstrated that satisfactory accuracies (recoveries) ranging from 96.2 to 104% and relative standard deviations ranging from 0.65 to 2.78% were obtained for the simultaneous quantification of 3-methylbutyl acetate and phenylethyl acetate in eighteen Baijiu samples of three flavor types including sauce flavor, strong flavor, and light flavor. Compared with the existing detection techniques, this chemical fingerprinting platform is easy to use, highly sensitive, and can perform multiplex detection, which has great potential for practical applications.

An all-in-one magnetic SERS nanosensor for ratiometric detection of Escherichia coli in foods.

An all-in-one nanosensor was developed for the magnetic enrichment and ratiometric surface-enhanced Raman scattering (SERS) detection of Escherichia coli (E. coli). The all-in-one nanosensor was constructed through the chemical integration of four components into a single nanoparticle, which include a manganese ferrite nanoparticle serving as the magnetic core, a thin silver shell as the SERS substrate, a self-assembled layer of 4-mercaptobenzoic acid (MBA) molecules as the SERS internal standard, and a MBA-conjugated layer of aptamer sequences as the capture probe of E. coli. In the detection of E. coli in food, the target cells were first captured by the nanosensors and magnetically enriched in a short time of 15 min, and then the ratiometric SERS was performed through the Raman intensity ratio between two specific SERS peaks produced by the captured E. coli and the internal MBA. The pre-concentration and ratiometry enabled the nanosensor to detect E. coli with a detection limit down to 10 CFU/mL. The all-in-one nanosensor was successfully applied for the detection of E. coli in various liquid foods including milk, juice, tea, and coffee, with recoveries ranging from 89 to 110% and relative standard deviation lower than 1.7%. In comparison with the previous sandwich strategy adopted by most SERS sensors, this nanosensor endowed with an easier use and a lower cost is more sensitive and reproducible, leading to a great potential in practical applications.

Higher quantum efficiency and moisture resistance of all-inorganic halide perovskite nanocrystal films in situ fabricated with cyclodextrin.

Supermolecule ß-cyclodextrin was used to assist CsPbBr3 film fabrication. In situ growth of nanocrystals was effectively confined through strong interactions between perovskite Pb2+ ions and ß-CD hydroxyl groups, producing a compact and smooth film. The quantum efficiency achieved was 85.3% with a moisture resistance over months, exceeding the record of perovskite films.

Curcumin Acetate Nanocrystals for sustained Pulmonary Delivery: Preparation, Characterization and In Vivo Evaluation.

The main objective of this study was to test the hypothesis that inhaled nanocrystals of a highly lipophilic drug could be used as a novel approach for producing sustained pulmonary delivery. Curcumin acetate, an ester prodrug of curcumin, was utilized as a highly lipophilic model drug. Curcumin acetate was subjected to wet ball milling to produce different particle sizes of nanocrystals and microparticles, and the milled curcumin acetate was spray-dried to yield similar inhalable microparticles. Following intrapulmonary administration in rats, pharmacokinetic experiments indicated that curcumin acetate significantly extended the pulmonary absorption time by 7.2-fold compared to curcumin, possibly due to the high lipophilicity of the former. The biodistribution data showed that aerosolized curcumin acetate nanocrystals 123.7 nm in size not only prolonged pulmonary retention, with the AUC value of curcumin acetate being 7.62-fold higher than that of the microparticles 1120 nm in size, but also increased the local in vivo release rate by 3.3-fold and the local availability of converted curcumin by 25.1-fold. In addition, the improved local availability resulted in better pharmacological efficacy in a monocrotaline-induced rat model of pulmonary arterial hypertension. This study was the first to demonstrate that inhalable nanocrystals are a feasible means for the sustained pulmonary delivery of highly lipophilic drugs.

Electrodeposition of polyaniline onto TiO2 nanoparticles/multiwalled carbon nanotubes for visible light photoelectrocatalysis.

In this study, polyaniline (PANI) was coated onto TiO2 nanoparticles/multiwalled carbon nanotubes (TiO2/MWCNTs) hybrid by electrochemical polymerization. Modification of TiO2/MWCNTs with PANI endows the resulted hybrid with visible light activity. The PANI/TiO2/MWCNTs hybrid shows remarkable photoelectrocatalytic activity for the degradation of RhB under visible light irradiation. The enhanced photocatalytic activity of the PANI/TiO2/MWCNTs hybrid originates from the effective charge transfer properties of the heterojunctions of PANI-TiO2 and TiO2-MWCNTs. The efficient charge transportation and high photoelectrocatalytic activity towards degradation of rhodamine B make this novel hybrid material promising for photocatalysis and for the development of photoelectrical devices.

Acoustic sensing of the initial adhesion of chemokine-stimulated cancer cells.

Chemokines together with their receptors play important roles in tumor metastasis. Intracellular signals stimulated by chemokines regulate the initial adhesion of cancer cells, which controls the subsequent cell spreading and migration. Until now, the nature of initial cell adhesion has been understood very poorly, since conventional assays are static and could not provide dynamic information. In order to address this issue, we adopt an acoustic sensor, quartz crystal microbalance (QCM), to monitor the attachment of chemokine-stimulated cancer cells in real-time. As a model, the chemokine CXCL12 was used to stimulate three human breast cancer cell lines expressing different levels of its receptor CXCR4, which triggers intracellular signaling pathways that activate integrins across cell membrane. Interaction between cellular integrins and adhesion molecules (CAMs) pre-coated on sensor surfaces were in situ monitored by QCM of which the frequency was sensitive to the mechanical connection of cells to the sensor surface. The ratio of frequency shift under stimulation to that without stimulation indicated the number and strength of integrin-CAM binding stimulated by the chemokine. The cell-surface binding was found to be enhanced by CXCL12, which depends on the CAM type and levels of chemokine and receptor, and was significantly inhibited by a blocker of the chemokine pathway. The binding of integrin with intercellular adhesion molecule was also found to be strong and in good correlated with the chemotactic indexes obtained by the classical Boyden chamber assay. This research suggests that acoustic sensing of initial cell adhesion could provide a dynamic insight into cell interfacial phenomena.

Oily nanosuspension for long-acting intramuscular delivery of curcumin didecanoate prodrug: preparation, characterization and in vivo evaluation.

The objective of this study was to prepare the nanocrystals of curcumin didecanoate (CurDD) by wet ball milling and to investigate the comparative pharmacokinetics of oily nano- and micro-suspensions after intramuscular (i.m.) administration to rats. Upon optimizing the wet ball milling parameters, CurDD nanocrystals were produced with median particle size of ~500 nm and the freeze-dried nanocrystals were readily dispersed in peanut oil to form stable nanosuspensions. Although the nanosuspension appeared to exhibit slower clearance from the injection site after i.m. injection, compared to microsuspension (~5 µm), a significantly higher maximum plasma curcumin concentration (69.0 ng/ml) was observed for the former than that for the latter (18.5 ng/ml). In addition, the nanosuspension provided significant higher plasma curcumin concentrations and brain CurDD contents for at least 15 days than the microsuspension, except for the initial times. A single i.m. injection of nanosuspension appeared to achieve reversal effect on reserpine-induced hypothermia for at least 13 days. This study demonstrates that CurDD nanosuspension may act as a long-acting i.m. injectable for sustained delivery of curcumin, potentially applicable to elicit a long-lasting antidepressant effect.

Stabilization of zeylenone in rat plasma by the presence of esterase inhibitors and its LC-MS/MS assay for pharmacokinetic study.

Six esterase inhibitors, namely EDTA·2Na(+), NaF, phenylmethanesulfonyl fluoride, dichlorvos, bis-nitrophenyl phosphate (BNPP) and thenoyltrifluoroacetone, and the mixture of NaF and BNPP, were evaluated for the stabilization of labile benzoate containing zeylenone in rat plasma. The mixture appeared to exhibit the most effectively stabilizing effect with the degraded content of zeylenone decreasing from >60% (in the absence of inhibitors) to <6%. Following the stabilization by the addition of NaF (5 mM) and BNPP (5 mM), the analytes in rat plasma were acidified by formic acid and extracted into ethyl acetate at 0°C. After chromatographic separation, the detection of zeylenone was performed on a 3200 Q-Trap with positive ion electrospray mode, monitoring the ion transition m/z 383.2 → 105.0. The method was validated over the range from 2.68 to 1340 ng/mL with inter- and intra-run precision for the quality control samples being less than 6.8%. The assay accuracy was within 100 ± 7.0%. The validated method was successfully applied to a pharmacokinetic study in rats after the intratracheal administration of zeylenone in free drug or polymeric micellar solutions. The results showed that the pulmonary absorption of zeylenone loaded in micelles was significantly retarded compared with that of free drug solutions.

Disruption of HepG2 cell adhesion by gold nanoparticle and Paclitaxel disclosed by in situ QCM measurement.

Cell adhesion is a crucial issue for cytotoxicity or anticancer effectiveness for tumor cells. However, how both nanoparticles and drugs affect cell adhesion has not yet been defined. Herein, we report for the first time that gold nanoparticles and Paclitaxel can disrupt adhesion, as well as enhance apoptosis of HepG2 cell individually and synergistically, as observed by in situ measurement using quartz crystal microbalance (QCM). It was also found by MTT assay that gold nanoparticles of low cellular cytotoxicity enhance the antiproliferation and apoptosis of HepG2 cell induced by Paclitaxel. Those findings would be of great potential for biomedical application of nanoparticles.