UBE3C Facilitates the ER-Associated and Peripheral Degradation of Misfolded CFTR.

The ubiquitin E3 ligase UBE3C promotes the proteasomal degradation of cytosolic proteins and endoplasmic reticulum (ER) membrane proteins. UBE3C is proposed to function downstream of the RNF185/MBRL ER-associated degradation (ERAD) branch, contributing to the ERAD of select membrane proteins. Here, we report that UBE3C facilitates the ERAD of misfolded CFTR, even in the absence of both RNF185 and its functional ortholog RNF5 (RNF5/185). Unlike RNF5/185, UBE3C had a limited impact on the ubiquitination of misfolded CFTR. UBE3C knockdown (KD) resulted in an additional increase in the functional ∆F508-CFTR channels on the plasma membrane when combined with the RNF5/185 ablation, particularly in the presence of clinically used CFTR modulators. Interestingly, although UBE3C KD failed to attenuate the ERAD of insig-1, it reduced the ERAD of misfolded ∆Y490-ABCB1 and increased cell surface expression. UBE3C KD also stabilized the mature form of ∆F508-CFTR and increased the cell surface level of T70-CFTR, a class VI CFTR mutant. These results suggest that UBE3C plays a vital role in the ERAD of misfolded CFTR and ABCB1, even within the RNF5/185-independent ERAD pathway, and it may also be involved in maintaining the peripheral quality control of CFTR.

Lactobacillus plantarum Zhang-LL Inhibits Colitis-Related Tumorigenesis by Regulating Arachidonic Acid Metabolism and CD22-Mediated B-Cell Receptor Regulation.

Colorectal cancer (CRC) is a significant health concern and is the third most commonly diagnosed and second deadliest cancer worldwide. CRC has been steadily increasing in developing countries owing to factors such as aging and epidemics. Despite extensive research, the exact pathogenesis of CRC remains unclear, and its causes are complex and variable. Numerous in vitro, animal, and clinical trials have demonstrated the efficacy of probiotics such as Lactobacillus plantarum in reversing the adverse outcomes of CRC. These findings suggest that probiotics play vital roles in the prevention, adjuvant treatment, and prognosis of CRC. In this study, we constructed a mouse model of CRC using an intraperitoneal injection of azomethane combined with dextran sodium sulfate, while administering 5-fluorouracil as well as high- and low-doses of L. plantarum Zhang-LL live or heat-killed strains. Weight changes and disease activity indices were recorded during feeding, and the number of polyps and colon length were measured after euthanasia. HE staining was used to observe the histopathological changes in the colons of mice, and ELISA was used to detect the expression levels of IL-1ß, TNF-α, and IFN-γ in serum. To investigate the specific mechanisms involved in alleviating CRC progression, gut microbial alterations were investigated using 16S rRNA amplicon sequencing and non-targeted metabolomics, and changes in genes related to CRC were assessed using eukaryotic transcriptomics. The results showed that both viable and heat-killed strains of L. plantarum Zhang-LL in high doses significantly inhibited tumorigenesis, colon shortening, adverse inflammatory reactions, intestinal tissue damage, and pro-inflammatory factor expression upregulation. Specifically, in the gut microbiota, the abundance of the dominant flora Acutalibacter muris and Lactobacillus johnsonii was regulated, PGE2 expression was significantly reduced, the arachidonic acid metabolism pathway was inhibited, and CD22-mediated B-cell receptor regulation-related gene expression was upregulated. This study showed that L. plantarum Zhang-LL live or heat-inactivated strains alleviated CRC progression by reducing the abundance of potentially pathogenic bacteria, increasing the abundance of beneficial commensal bacteria, mediating the arachidonic acid metabolism pathway, and improving host immunogenicity.

Highly stretchable, self-healing and conductive silk fibroin-based double network gels via a sonication-induced and self-emulsifying green procedure.

Regenerated silk fibroin (RSF)-based hydrogels are promising biomedical materials due to their biocompatibility and biodegradability. However, the weak mechanical properties and lack of functionality limit their practical applications. Here, we developed a tough and conductive RSF-based double network (DN) gel, consisting of a sonication-induced ß-sheet physically crosslinked RSF/S gel as the first network and a hydrophobically associated polyacrylamide/stearyl methacrylate (PAAm/C18) gel as the second network. In particular, the cross-linking points of the second network were micelles formed by emulsifying the hydrophobic monomer (C18M) with a natural SF- capryl glucoside co-surfactant. The reversible dynamic bonds in the DN provided good self-healing ability and an effective dissipative energy mechanism for the DN hydrogel, while the addition of calcium ions improved the self-healing ability and electrical conductivity of the hydrogel. Under optimal conditions, the RSF/S-PAAm/C18 DN gels exhibited large extensibility (1400%), high tensile strength (0.3 MPa), satisfactory self-healing capability (90%) and electrical conductivity (0.12 S·m-1). The full physically interacted DN hydrogels are expected to be applied in various fields such as tissue engineering, biosensors and artificial electronic skin.

Simple Preparation of a Waterborne Polyurethane Crosslinked Hydrogel Adhesive With Satisfactory Mechanical Properties and Adhesion Properties.

Waterborne polyurethane has been proven to be an ideal additive for the preparation of hydrogels with excellent mechanical properties. This work reports that a satisfactory adhesion of acrylamide hydrogels can be obtained by introducing a large amount of waterborne polyurethane into system. A series of polyurethane hydrogels was prepared by using one-pot method with acrylamide monomer and 2-hydroxymethyl methacrylate end-modified waterborne polyurethane emulsion. The hydrogels exhibit good strength (greater than 30 KPa), wide range of adjustable strain (200%-800%), and excellent compression fatigue resistance. The performance improvement is attributed to the fact that the polyurethane emulsion containing double bonds provides chemical crosslinking and forms polyurethane microregions due to hydrophilic and hydrophobic interactions. The hydrogel shows extensive and repeatable adhesion on diverse substrates. This simple preparation method through polyurethane crosslinked hydrogels is expected to become a low-cost and efficient preparation strategy for hydrogel adhesives.

Plantaricin BM-1 decreases viability of SW480 human colorectal cancer cells by inducing caspase-dependent apoptosis.

Plantaricin BM-1 is a class IIa bacteriocin produced by Lactobacillus plantarum BM-1 that has significant antimicrobial activity against food-borne bacteria. In this study, a cell proliferation assay and scanning electron microscopy were used to detect changes in the viability of SW480, Caco-2, and HCT-116 colorectal cancer cells treated with plantaricin BM-1. We found that plantaricin BM-1 significantly reduced the viability of all colorectal cancer cell lines tested, especially that of the SW480 cells. Scanning electron microscopy showed that plantaricin BM-1 treatment reduced the number of microvilli and slightly collapsed the morphology of SW480 cells. Fluorescence microscopy and flow cytometry demonstrated that plantaricin BM-1 induced apoptosis of SW480 cells in a concentration-dependent manner. Western blotting further showed that plantaricin BM-1-induced apoptosis of SW480 cells was mediated by the caspase pathway. Finally, transcriptomic analysis showed that 69 genes were differentially expressed after plantaricin BM-1 treatment (p < 0.05), of which 65 were downregulated and four were upregulated. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that expression levels of genes involved in the TNF, NF-κB, and MAPK signaling pathways, as well as functional categories such as microRNAs in cancer and transcriptional misregulation in cancer, were affected in SW480 cells following the treatment with plantaricin BM-1. In conclusion, plantaricin BM-1 induced death in SW480 cells via the caspase-dependent apoptosis pathway. Our study provides important information for further development of plantaricin BM-1 for potential applications in anti-colorectal cancer.

Effect of pH on the Conformational Transition of Silk Fibroin in Aqueous Solution Monitored by Thioflavin-T Fluorescence.

In this work, the potential application of the fluorescence dye Thioflavin-T (ThT), which can specifically bind to amyloid, as a powerful tool for monitoring secondary structural transitions of silk fibroin (SF) induced by pH in low solution concentrations was examined. Results showed that ThT emission intensities substantially increased when pH decreased from 6.8 to 4.8. This increase may be ascribed to conformational transitions from random coil to ß-sheet. The morphology and secondary structure of SF were also investigated via TEM, AFM and circular dichroism spectroscopy. The information obtained herein can be utilized not only for the development of convenient and efficient noninvasive method for monitoring the assembly behavior of SF in aqueous solution but also for in vitro fluorescence imaging.

Label-free Fluorescence Turn on Trypsin Assay Based on Gemini Surfactant/heparin/Nile Red Supramolecular Assembly.

In this research, we designed a label-free fluorometric turn-on assay for trypsin and inhibitor screening, based on a spherical cationic gemini surfactant ethylene-bis (dodecyl dimethyl ammonium bromide) (EDAB)/heparin/Nile red (NR) supramolecular assembly system. The introduction of gemini surfactant EDAB as template greatly enhanced its salt resistance and resulted in the supramolecular assemblies with diameters ranging from 20 to 100 nm. The fluorometric assay for trypsin was performed by firstly disassembling with protamine (a heparin-binding protein) and then re-assembling through hydrolysis of protamine. The disassembly and reassembly of the system resulted in a turn-off first and then a turn-on behavior of the corresponding fluorescence. The overall processes were characterized by fluorescence spectra, TEM measurements and zeta potential tests. The detection level of this assembly system for trypsin was as low as 4.2 ng mL-1. Also, the EDAB/heparin/NR assembly could be used to screen the trypsin inhibitors. The assembly system was easily-fabricated and cost-effective, but also exhibited good salt tolerance in NaCl solution at the concentration of 0-500 mM. At last, the supramolecular assembly was successfully applied to detect trypsin in human urine, demonstrating its great potential on clinical diagnosis applications.

A Facile Strategy for Fabrication Lysozyme-Loaded Mesoporous Silica Nanotubes from Electrospun Silk Fibroin Nanofiber Templates.

This paper presents a facile and low-cost strategy for fabrication lysozyme-loaded mesoporous silica nanotubes (MSNTs) by using silk fibroin (SF) nanofiber templates. The "top-down method" was adopted to dissolve degummed silk in CaCl2/ formic acid (FA) solvent, and the solution containing SF nanofibrils was used for electrospinning to prepare SF nanofiber templates. As SF contains a large number of -OH, -NH2 and -COOH groups, the silica layer could be easily formed on its surface by the Söber sol-gel method without adding any surfactant or coupling agent. After calcination, the MSNTs were obtained with inner diameters about 200 nm, the wall thickness ranges from 37 ± 2 nm to 66 ± 3 nm and the Brunauer-Emmett-Teller (BET) specific surface area was up to 200.48 m2/g, the pore volume was 1.109 cm3/g. By loading lysozyme, the MSNTs exhibited relatively high drug encapsulation efficiency up to 31.82% and an excellent long-term sustained release in 360 h (15 days). These results suggest that the MSNTs with the hierarchical structure of mesoporous and macroporous will be a promising carrier for applications in biomacromolecular drug delivery systems.

A case report of 46,XY partial gonadal dysgenesis caused by a novel mutation in the sex-determining region gene.

The sex-determining region Y (SRY) gene is a key gene involved in male sex differentiation and development. Patients with 46,XY disorders of sex development related to mutations in the high mobility group (HMG) box typically present with complete gonadal dysgenesis. In this study, we report a case of novel missense mutation c.T281G within the HMG domain of SRY in a 15-year-old patient of the female gender with 46,XY partial gonadal dysgenesis (PGD). The novel missense mutation caused the substitution of codon 94 for leucine in the HMG box of the SRY protein with an arginine codon. Leucine and arginine are aliphatic amino acids, and three-dimensional protein structure prediction revealed only slight structural changes in the SRY protein. Thus, the SRY protein had maintained some of its functions, and the patient presented with PGD. In conclusion, we identified a novel SRY mutation in a patient with 46,XY PGD. Based on the protein model, we believe that the mutation in the HMG domain helped to maintain the partial function of the SRY protein. The condition of our patient differed from the well-known 46,XY complete gonadal dysgenesis caused by mutations in the HMG region. In fact, this is the first case of 46,XY PGD caused by mutations in the HMG region to be reported, and therefore, our experience has expanded the mutation spectrum of the SRY gene. Furthermore, the present case demonstrates that mutations located in the HMG domain of SRY gene cannot be ruled out in patients with a clinical diagnosis of 46,XY PGD.

Temporal contrast reduction techniques for high dynamic-range temporal contrast measurement.

A single-shot characterization of the temporal contrast of a petawatt laser pulse with a high dynamic-range, is important not only for improving conditions of the petawatt laser facility itself, but also for various high-intensity laser physics experiments, which is still a difficult problem. In this study, a new idea for improving the dynamic-range of a single-shot temporal contrast measurement using novel temporal contrast reduction techniques is proposed. The proof-of-principle experiments applying single stage of pulse stretching, anti-saturated absorption, or optical Kerr effect successfully reduce the temporal contrast by approximately one order of magnitude. Combining with the SRSI-ETE method, its dynamic-range characterization capability is improved by approximately one order of magnitude to approximately 109. It is expected that a higher dynamic-range temporal contrast can be characterized by using cascaded temporal contrast reduction processes. The proposed techniques can also be used in the delay-scanning temporal contrast measurement to improve its dynamic range.

Visible sensing of conformational transition in model silk peptides based on a gold nanoparticles indicator.

To understand protein structural transition and ß-sheet formation is of importance in disparate areas such as silk protein processing and disease related ß-amyloid behavior. Herein, GAGSGAGAGSGAGY (GY-14), a tetradecapeptide based on the crystallizable sequence of silk fibroin, was employed as a model peptide of the crystalline regions of silk fibroin. Due to the incorporation of tyrosine (Y), GY-14 was able to reduce Au3+ to Au NPs and further stabilize them without any external reducing or capping reagents to produce GY-14 stabilized Au NPs (GY-14@Au NPs). The in situ prepared GY-14@Au NPs were utilized as a built-in colorimetric indicator. The influences of specified physiological factors including decreasing the pH, the addition of calcium ions and isopropanol treatment on the self-assembly behavior of GY-14@Au NPs in aqueous solution have been studied. On the basis of transmission electron microscopy (TEM), dynamic light scattering (DLS), atomic force microscopy (AFM), Fourier transform infrared (FT-IR) spectroscopy and circular dichroism (CD) measurements, the color changes and the UV-Vis absorption peak shift of GY-14@Au NPs were attributed to the conformational change of the GY-14 peptide. The colorimetric readout can be seen with the naked eye, providing an efficient indicator to study the conformational changes of peptides exposed to various environmental stimuli.

Aqueous-based electrospun P(NIPAAm-co-AAc)/RSF medicated fibrous mats for dual temperature- and pH-responsive drug controlled release.

This paper presents a green method for fabricating dual temperature- and pH-responsive electrospun fibrous mats from an aqueous-based blend poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAAm-co-AAc)) and regenerated silk fibroin (RSF) by employing electrospinning technique. P(NIPAAm-co-AAc) was synthesized by free radical solution polymerization and its low critical solution temperature (LCST) was in the physiological range (38.8 °C). The P(NIPAAm-co-AAc)/RSF fibers were prepared by electrospinning technology in the presence of the crosslinking agents (EDC·HCl and NHS) with water as solvent. After in situ crosslinking and water-annealing process, the water-stable composite fibrous mats were obtained. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to analyze the crosslinking process. Temperature and pH dual stimuli-responsive swelling-shrinking behavior of the fibrous mats were observed when the temperature was below and above the LCST of the copolymer at different pHs. In addition, rhodamine B-loaded the fibrous mats also showed dual temperature and pH controlled release behavior, demonstrating the potential use of the fibrous mats for "smart" controlled drug delivery applications.

A compact and alignment-free tube-type device for femtosecond pulses measurement.

A compact and alignment-free device based on transient grating self-referenced spectral interferometry is proposed to realize the temporal profile measurement of femtosecond laser pulses. The entire optical setup is composed of two lenses and two glass plates on a straight line with tubes, thereby avoiding complicated optical alignment and improving the stability and practicality of the device. Two 51.0 fs and 16.9 fs laser pulses at 800 nm and a 60.6 fs pulse at 1800 nm are all successfully measured by this device, which verifies the reliability of the device.

Aqueous-Based Coaxial Electrospinning of Genetically Engineered Silk Elastin Core-Shell Nanofibers.

A nanofabrication method for the production of flexible core-shell structured silk elastin nanofibers is presented, based on an all-aqueous coaxial electrospinning process. In this process, silk fibroin (SF) and silk-elastin-like protein polymer (SELP), both in aqueous solution, with high and low viscosity, respectively, were used as the inner (core) and outer (shell) layers of the nanofibers. The electrospinnable SF core solution served as a spinning aid for the nonelectrospinnable SELP shell solution. Uniform nanofibers with average diameter from 301 ± 108 nm to 408 ± 150 nm were obtained through adjusting the processing parameters. The core-shell structures of the nanofibers were confirmed by fluorescence and electron microscopy. In order to modulate the mechanical properties and provide stability in water, the as-spun SF-SELP nanofiber mats were treated with methanol vapor to induce ß-sheet physical crosslinks. FTIR confirmed the conversion of the secondary structure from a random coil to ß-sheets after the methanol treatment. Tensile tests of SF-SELP core-shell structured nanofibers showed good flexibility with elongation at break of 5.20% ± 0.57%, compared with SF nanofibers with an elongation at break of 1.38% ± 0.22%. The SF-SELP core-shell structured nanofibers should provide useful options to explore in the field of biomaterials due to the improved flexibility of the fibrous mats and the presence of a dynamic SELP layer on the outer surface.

[Research Progress of Silk Fibroin As a Drug Delivery Materials].

Recently, drug delivery materials have become the hotspot of medical study. Suitable delivery material plays an important role in constructing an excellent drug delivery system. Silk fibroin is a naturally occurring protein polymer with excellent biocompatibility, remarkable mechanical properties, biodegradability and outstanding processability. Due to its unique properties, silk fibroin has become a favorable carrier material for the incorporation and delivery of a range of therapeutic agents. Based on the structure and characteristics of silk fibroin, this article provides an overview of the recent research progress of silk fibroin used as drug delivery materials.

Stability and cytocompatibility of silk fibroin-capped gold nanoparticles.

Surface engineering is crucial in the colloidal stability and biocompatibility of nanoparticles (NPs). Protein silk fibroin (SF), which gained interest in biomaterial and regenerative medicine, was used in this study to stabilize gold (Au) NPs. Characterization results from UV-Vis spectroscopy revealed that SF-capped Au NPs (SF-Au NPs) possessed remarkable colloidal stabilities in the pH range of 2 to 11 and salt concentration range of 50mM to 1000 mM. In addition, dried particle samples were resuspended after lyophilization without aggregation. The results indicated that the steric hindrance rather than the electrostatic repulsion of SF-Au NPs was essential for colloidal stability. The SF-Au NPs manifested improved cytocompatibility compared with bare Au NPs, which was attributed to the inherent non-cytotoxicity of SF and the good colloidal stability of the NPs. The proposed method was simpler, more efficient, and more cost effective than the conventional modification strategies for Au NPs; thus, SF-Au NPs can be potentially used in biomedical applications.

Morphology and structure of electrospun mats from regenerated silk fibroin aqueous solutions with adjusting pH.

In this paper, regenerated silk fibroin (SF) aqueous solutions were adjusted to a pH of 6.9 by mimicing the condition in the posterior division of silkworm's gland and rheological behavior of solutions was investigated. The electrospinning technique was used to prepare fibers, and non-woven mats of regenerated B. mori silk fibroin were successfully obtained. The effects of electrospinning parameters on the morphology and diameter of regenerated silk fibers were investigated by orthogonal design. Statistical analysis showed that voltage, the concentration of regenerated SF solutions and the distance between tip and collection plate were the most dominant parameters to fiber morphology, diameter and diameter distribution, respectively. An optimal electrospinning condition was obtained in producing uniform cylindrical fibers with an average diameter of 1300nm. It was as follows: the concentration 30%, voltage 40kV, distance 20cm. The structure of electrospun mats was characterized by Raman spectroscopy (RS), wide-angle X-ray diffraction (WAXD) and modulated differential scanning calorimetry (MDSC). It was found that electrospun mats were predominantly random coil/silk I structure, and the transition to silk II (beta-sheet) rich structure should be further explored.