Influence of Protonation on the Norepinephrine Inhibiting α‑Synuclein 71–82 Oligomerization

The pathogenesis of Parkinson’s disease (PD) is closely linked to the massive presence of Lewy vesicles and Lewy axons in the cytoplasm of neurons, mainly consisting of α-synuclein (αS). Norepinephrine (NE), whose secretion can be increased by exercise, has been demonstrated to prevent the fibrillation of αS and to break down the mature αS fibrils. In this work, we focus on the influence of protonation on the inhibitory ability of NE by using amyloid core fragment αS71–82 as a template. All-atom replica-exchange molecular dynamics simulations (accumulating to 33.6 μs) in explicit water were performed to explore the inhibitory effect of protonated and nonprotonated NE on αS oligomerization. Our results show that NE/NE+ can lead to a significant decrease in β-sheet content with increasing temperature, while isolated αS maintains relatively higher β-sheet conformations until 363 K, implying that both NE and NE+ can lower the critical temperature required for αS fibril decomposition. NE and NE+ also lead to the formation of less compact αS oligomers by preventing the backbone hydrogen bonds and the side-chain packing. The protonation would affect the binding affinity, interaction modes, and binding intensity of NE with αS. Interesting, NE and NE+ have a distinct binding free energy in the electrostatic and solvation terms, which mostly counter each other and produce a weak binding intensity with αS. Our work contributes to a better understanding of the inhibitory mechanism of NE and NE+ on αS oligomerization relevant to PD pathogenesis, which may provide clues for the design of antiamyloid medicine

Electrospun Nanofibers Modified with Copper Nanoparticles for Simultaneous Extraction and Detection of Three Ochratoxins in Foods

In this study, several electrospun nanofibers were prepared and characterized, and the electrospun polystyrene/poly(ether sulfone) nanofiber coated with copper nanoparticles (PS/PES-CuNP nanofibers) was selected and utilized as solid-phase extraction adsorbent. And then, the packed-fiber solid-phase extraction coupled with high-performance liquid chromatography-fluorescence detection method was established for the efficient determination of ochratoxins in foods. With the proposed method, several factors including the type and dosage of nanofibers, sample pH, extraction time, type, and volume of elution solvent were optimized. The results suggested that low limit of detection (0.102–0.126 ng/mL), limit of quantification (0.382–0.436 ng/mL), and recoveries (85.5–111.1%) for ochratoxin A, B, and C with relative standard deviations <7% were achieved. As-synthesized PS/PES-CuNP nanofibers displayed satisfactory potential practical application in the simultaneous pretreatment and determination of mycotoxins in complex matrice samples

Development of the Au@Pt-Labeled Nanobody Lateral-Flow Nanozyme Immunoassay for Visual Detection of 3‑Phenoxybenzoic Acid in Milk and Lake Water

As a major metabolite of pyrethroid pesticides, 3-phenoxybenzoic acid (3-PBA) can be an indicator of health risk and human exposure assessment. A gold–platinum (Au@Pt) nanozyme is a kind of mimic enzyme with unique properties of nanomaterials and catalytic activity. The anti-3-PBA nanobodies were labeled with Au@Pt (Au@Pt-Nbs) by electrostatic adsorption. The Au@Pt-Nbs lateral-flow nanozyme immunoassay was established for the visual and rapid detection of 3-PBA. The visualization results were quantitatively analyzed by Adobe Photoshop CC and got a cutoff value of 0.005 ng/mL. The samples of milk- and lake water-spiked 3-PBA were also analyzed, and the recoveries ranged from 102 to 108% and 95 to 112%, respectively. The results were also validated by liquid chromatography–mass spectrometry and got good correlation (R2 = 0.945). The Au@Pt-Nbs lateral-flow nanozyme immunoassay was developed by the combination of nanobodies and nanozymes, which will be a promising application in the field of safety inspection

Reformulating the Hydrolytic Enzyme Cocktail of Trichoderma reesei by Combining XYR1 Overexpression and Elimination of Four Major Cellulases to Improve Saccharification of Corn Fiber

The industrial fungus Trichoderma reesei has an outstanding capability of secreting an enzyme cocktail comprising multiple plant biomass-degrading enzymes. Herein, the overexpression of XYR1, the master transactivator controlling (hemi)­cellulase gene expression, was performed in T. reesei lacking four main cellulase-encoding genes. The resultant strain Δ4celOExyr1 was able to produce a dramatically different profile of secretory proteins on soluble glucose or lactose compared with that of the wild-type T. reesei. The Δ4celOExyr1 secretome included cellulases EGIII and BGLI as well as several hemicellulases and nonhydrolytic cellulose degradation-associated proteins that are not preferentially induced in the wild-type T. reesei strain. Δ4celOExyr1 produced a significant amount of α-arabinofuranosidase I on lactose, and the crude enzyme cocktail of Δ4celOExyr1 not only released a considerable quantity of glucose but also exhibited remarkable performance in the hydrolytic release of xylose, arabinose, and mannose from un-pretreated corn fiber. These results showed that the engineered T. reesei strain holds great potential for improving the saccharification efficiency of the hemicellulosic constituents within corn fiber

Image_1_The diagnostic value of metagenomic next-generation sequencing for identifying Pneumocystis jirovecii infection in non-HIV immunocompromised patients.jpg

BackgroundPneumocystis jirovecii pneumonia (PJP) remains an important cause of morbidity and mortality in non-HIV immunocompromised patients especially in transplant recipients. But its diagnosis remains challenging due to the insuffificient performance of conventional methods for diagnosing Pneumocystis jirovecii(P. jirovecii) infection. Therefore, the auxiliary diagnostic function of metagenomics next-generation sequencing (mNGS) in clinical practice is worth of exploring.Method34 non-HIV immunocompromised patients who were diagnosed as PJP by clinical manifestations, imaging findings, immune status of the host, and Methenamine silver staining were tested by mNGS from October 2018 to December 2020 in Sichuan Provincial People’s Hospital. The clinical performances of mNGS for P. jirovecii infection diagnosis were also evaluated with genome reads abundance and comparing with other traditional diagnostic methods.ResultsWe diagnosed a total of 34 non-HIV PJP patients by the clinical composite diagnosis. Our data shows that, compared with the clinical microbiological test, the detection rate of mNGS for P. jirovecii in non-HIV infected PJP patients is significantly higher than that of Methenamine silver staining and serum 1-3-β-D-glucan. mNGS can be used as an auxiliary diagnostic tool to help diagnosis. The number of reads mapped to the genome of P. jirovecii and the duration of patients from onset to sampling collection were statistically significant between the two groups (Reads>100 and Reads ≤ 100) (8days vs. 23days, p=0.020). In addition, univariate analysis showed that C-reactive protein (15.8mg/L vs.79.56mg/L, p=0.016), lactate dehydrogenase (696U/l vs. 494U/l, p=0.030) and procalcitonin (0.09ng/ml vs. 0.59ng/ml, p=0.028) was also statistically significant between the two groups.ConclusionsAn effective detection rate was achieved in PJP patients using mNGS testing of bronchoalveolar lavage fluid (BALF) or blood. The study also confirmed that the abundance of reads of P. jirovecii is related to the interval between the onset and sample collection. And the inflammation status during simultaneous mNGS detection might determine the abundance of pathogens. Hence, we conclude that the mNGS strategy could benefit disease diagnosis as well as treatment when complicated clinical infections appeared.</p

Multifunctional Tannic Acid (TA) and Lysozyme (Lys) Films Built Layer by Layer for Potential Application on Implant Coating

A multifunctional (TA/Lys)n film, featuring good antioxidant property, fast cell attachment at the initial stage, enhanced osteogenesis, and broad-spectrum antibacterial property, was constructed by the layer-by-layer (LBL) method. The building process was monitored by quartz crystal microbalance with dissipation (QCM-D); the physical properties, such as topography, stiffness in dry and liquid state, and conformation of Lys in the film, were thoroughly characterized. These physical properties were modulated by varying the salt concentration at which the film was constructed. The film not only allows for favorable cell attachment and proliferation of preosteoblasts Mc3t3-E1 but also provides antibacterial property against Gram-positive bacteria, S. aureus and M. lysodeikticus, and Gram-negative bacteria, E. coli. It also displays good antioxidant property, which plays a critical role on fast cell attachment at the initial stage

The effect of UQCRC1 over-expression on mitochondrial membrane potential.

<p>(A) Confocal fluorescence images of TMRE (a: Ad-GFP, b: Ad-UQCRC1); (B) Mitochondrial membrane potential of H9C2 cells assessed by TMRE (Summarized data for TMRE fluorescence intensity, <b>*</b> <i>P</i> < 0.05 <i>vs</i>. Ad-GFP, n = 5; Data are expressed as the means ± SD).</p

Determination of Estrogens in Milk Using Polypyrrole Fiber-Mediated Solid-Phase Extraction Followed by High Performance Liquid Chromatography

A solid-phase extraction (SPE) method based on conductive polypyrrole (PPy) nanofibers which were fabricated by electrospinning and in situ polymerization was developed. PPy nanofibers-mediated SPE followed by high performance liquid chromatography (HPLC) was used for the determination of three synthetic estrogens, namely diethylstilbestrol (DES), dienestrol (DIS), or hexestrol (HS) in milk sample. Extraction conditions including extraction nanofibers, donor solution pH and salt concentration were optimized. The target compounds were extracted from a 0.5 mL aqueous sample at pH 5.0 through PPy fibers, and then were eluted with 0.1 mL methanol. After extraction, the eluant was directly injected into an HPLC system for detection. Under the optimized extraction conditions, a large enrichment factor was achieved for three estrogens. The limit of detection (LOD) at a signal to noise ratio (S/N) of 3 ranged from 0.02 to 0.05 µg mL-1 for the estrogens in milk sample.</div

Table_1_Efficacy and safety of stereotactic body radiotherapy for painful bone metastases: Evidence from randomized controlled trials.docx

BackgroundPain relief is one of the main objectives of radiotherapy for cancer patients with bone metastases. Stereotactic body radiotherapy (SBRT) enables precise delivery of a higher dosage to the target area. Several trials have reported comparisons between SBRT and conventional radiotherapy (cRT) in patients with painful bone metastasis. However, the results of those investigations were inconsistent, and no systematic review or meta-analysis has been done till now.MethodsWe systematically searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and Clinicaltrials.gov up to May 1, 2022 for relevant studies. Patients with painful bone metastasis who received SBRT or cRT were included. The primary outcome was the patients’ pain response rate at three months. The secondary outcomes included the rate of pain responders at one month and six months, oral morphine equivalent dose (OMED) use, and any adverse events. STATA software 12.0 was used for the statistical analysis.ResultsWe collected 533 patients’ data from 4 randomized controlled trials (RCTs), there was a significant difference of pain response rate at 3 months between two groups (RR = 1.41, 95% CI: 1.12-1.77, I2 = 0.0%, P = 0.003). However, no significant difference was found in pain response rate at 1 month (RR = 1.19, 95% CI: 0.91-1.54, I2 = 31.5%, P = 0.201) and 6 months (RR = 1.25, 95% CI: 0.93-1.69, I2 = 0.0%, P = 0.140). OMED consumption was not significantly different in patients treated with SBRT compared with control group (WMD = -1.11, 95% CI: -17.51-15.28, I2 = 0.0%, P = 0.894). For safety outcome, no statistical difference was found between SBRT and cRT (RR = 0.72, 95% CI: 0.46-1.14, I2=20.1%, P = 0.162).ConclusionThis study shows that for painful bone metastases, patients with SBRT experienced better pain relief 3 months after radiation than patients with cRT, and SBRT did not increase the incidence of adverse events.Systematic review registrationhttps://inplasy.com/inplasy-2022-6-0099/, identifier INPLASY202260099.</p

A Facile and Universal Method to Efficiently Fabricate Diverse Protein Capsules for Multiple Potential Applications

Proteins are considered to be one of the most important highly reproducible and monodisperse building blocks with specific functions in life sciences and material science. Protein capsules and their hybrids composed of protein–polymer conjugates have been intensively explored in drug delivery, catalysis, and cell-mimicking functions. Herein, we present a facile, universal, and efficient method to fabricate the diverse protein capsules, independent of the molecular weight (Mw), isoelectric points (IEP), wettability, amino acid sequence, and functional domains of enumerated proteins. The protein capsules were well characterized by various techniques. Furthermore, their ability to store the original protein functionality was demonstrated, which was mainly embodied in their enzyme responsiveness and good biocompatibility in vitro and in vivo. We believe that these protein capsules have multiple potential applications such as in drug delivery, tissue engineering, catalysis, and other application fields