Synthesis via RAFT Polymerization of Tadpole-Shaped Organic/Inorganic Hybrid Poly(acrylic acid) Containing Polyhedral Oligomeric Silsesquioxane (POSS) and Their Self-assembly in Water

Tadpole-shaped inorganic/organic hybrid poly(tert-butyl acrylate) was prepared by RAFT polymerization of tert-butyl acrylate (tBA) using a POSS-containing chain transfer agent (CTA). The polymerization kinetics showed a pseudofirst-order behavior with a short induction period; the number-average molecular weights linearly increase with conversion. In conjunction with low polydispersity (PDI tBA was further hydrolyzed into amphiphilic, tadpole-shaped poly(acrylic acid) (POSS-PAA). The self-assembly behavior of POSS-PAA in aqueous solution at pH = 8.5 was investigated by transmission electron microscopy (TEM) as well as static and dynamic light scattering (SLS and DLS). The results show that POSS-PAA self-assembles in water into rather large aggregates where the POSS moieties are dispersed in the particle. The size (average radius ≈ 60 nm by DLS) is nearly independent of the chain length of PAA. The aggregates are pH-responsive, contracting when decreasing pH from 8.5 to 4

Image_1_Identification of an epicuticular wax crystal deficiency gene Brwdm1 in Chinese cabbage (Brassica campestris L. ssp. pekinensis).tiff

IntroductionThe cuticle wax covering the plant surface is a whitish hydrophobic protective barrier in Chinese cabbage, and the epicuticular wax crystal deficiency normally has higher commodity value for a tender texture and glossy appearance. Herein, two allelic epicuticular wax crystal deficiency mutants, wdm1 and wdm7, were obtained from the EMS mutagenesis population of a Chinese cabbage DH line ‘FT’.MethodsThe cuticle wax morphology was observed by Cryo-scanning electron microscopy (Cryo-SEM) and the composition of wax was determined by GC-MS. The candidate mutant gene was found by MutMap and validated by KASP. The function of candidate gene was verified by allelic variation.ResultsThe mutants had fewer wax crystals and lower leaf primary alcohol and ester content. Genetic analysis revealed that the epicuticular wax crystal deficiency phenotype was controlled by a recessive nuclear gene, named Brwdm1. MutMap and KASP analyses indicated that BraA01g004350.3C, encoding an alcohol-forming fatty acyl-CoA reductase, was the candidate gene for Brwdm1. A SNP 2,113,772 (C to T) variation in the 6th exon of Brwdm1 in wdm1 led to the 262nd amino acid substitution from threonine (T) to isoleucine (I), which existed in a rather conserved site among the amino acid sequences from Brwdm1 and its homologs. Meanwhile, the substitution changed the three-dimensional structure of Brwdm1. The SNP 2,114,994 (G to A) in the 10th exon of Brwdm1 in wdm7 resulted in the change of the 434th amino acid from valine (V) to isoleucine (I), which occurred in the STERILE domain. KASP genotyping showed that SNP 2,114,994 was co-segregated with glossy phenotype. Compared with the wild type, the relative expression of Brwdm1 was significantly decreased in the leaves, flowers, buds and siliques of wdm1.DiscussionThese results indicated that Brwdm1 was indispensable for the wax crystals formation and its mutation resulted in glossy appearance in Chinese cabbage.</p

Toward a Global Analysis of the Human Pituitary Proteome by Multiple Gel-Based Technology

We describe a comprehensive method for the analysis of complex proteomes, multiple gel-based technology (MGT), which combines in-gel IEF-LC-MS/MS and SDS-PAGE-LC-MS/MS strategies. MGT was applied to the analysis of the proteome of human pituitary tissue. A total of 1449 proteins were uniquely identified. To our knowledge, this is the most comprehensive proteomic analysis of human pituitary tissue to date. Categorization of the identified proteins revealed that MGT provides an excellent and largely unbiased access to proteins with diverse characteristics, including low-abundance proteins, membrane proteins, and proteins with extremes in pI and MW

Toward a Global Analysis of the Human Pituitary Proteome by Multiple Gel-Based Technology

We describe a comprehensive method for the analysis of complex proteomes, multiple gel-based technology (MGT), which combines in-gel IEF-LC-MS/MS and SDS-PAGE-LC-MS/MS strategies. MGT was applied to the analysis of the proteome of human pituitary tissue. A total of 1449 proteins were uniquely identified. To our knowledge, this is the most comprehensive proteomic analysis of human pituitary tissue to date. Categorization of the identified proteins revealed that MGT provides an excellent and largely unbiased access to proteins with diverse characteristics, including low-abundance proteins, membrane proteins, and proteins with extremes in pI and MW

Dasatinib Promotes Chondrogenic Differentiation of Human Mesenchymal Stem Cells via the Src/Hippo-YAP Signaling Pathway

Mesenchymal stem cells (MSCs) are progenitors of chondrocytes and could be used as a potential therapy for cartilage defects in diarthrodial joints. However, promoting chondrogenic differentiation of MSCs remains a daunting challenge. As a small molecular drug, dasatinib can promote MSC differentiation, although the exact mechanisms of chondrogenic differentiation are unclear. In this study, the differentiation of MSCs into osteoblasts, adipocytes, and chondrocytes was assessed by the protein and mRNA levels of osteoblast- and chondrocyte-related proteins using western blotting and real-time polymerase chain reaction, respectively. MSCs were induced to differentiate into chondrocytes or osteoblasts with or without dasatinib in vitro. The effects of dasatinib on cartilage regeneration were also assessed in vivo in a rabbit model of full-thickness cartilage defects using methacrylate gelatin hydrogel as scaffolds. Dasatinib promoted chondrogenic differentiation and inhibited osteogenic differentiation of MSCs. Furthermore, dasatinib significantly inhibited the expression of YAP and TAZ and the phosphorylation of Src, but it enhanced serine phosphorylation of YAP during the chondrogenic differentiation of MSCs in vitro. Inhibition of the Hippo pathway using XMU-MP-1 dramatically suppressed the serine phosphorylation of YAP and chondrogenic differentiation of MSCs. Moreover, we confirmed that the sustained release of dasatinib from the hydrogel promoted rabbit cartilage repair. The results demonstrated that dasatinib might promote chondrogenic differentiation of MSCs via the Src/Hippo-YAP signaling pathway and that hydrogel sustained-release dasatinib had a certain effect on the repair of cartilage defects

Supplementary images from The mechanobiology of actin cytoskeletal proteins during the cell–cell fusion

Supplementary images for a better understanding of the main tex

Effect of Human Milk Oligosaccharides on Learning and Memory in Mice with Alzheimer’s Disease

Alzheimer’s disease (AD) is distinguished by cognitive dysfunction and neuroinflammation in the brain. 2′-Fucosyllactose (2′-FL) is a major human milk oligosaccharide (HMO) that is abundantly present in breast milk and has been demonstrated to exhibit immunomodulatory effects. However, the role of 2′-FL and HMO in gut microbiota modulation in relation to AD remains insufficiently investigated. This study aimed to elucidate the preventive effect of the 2′-FL and HMO impact of AD and the relevant mechanism involved. Here, the behavioral results showed that 2′-FL and HMO intervention decreased the expression of Tau phosphorylation and amyloid-β (Aβ), inhibited neuroinflammation, and restored cognitive impairment in AD mice. The metagenomic analysis proved that 2′-FL and HMO intervention restored the dysbiosis of the gut microbiota in AD. Notably, 2′-FL and HMO intervention significantly enhanced the relative abundance of Clostridium and Akkermansia. The metabolomics results showed that 2′-FL and HMO enhanced the oleoyl-l-carnitine metabolism as potential drivers. More importantly, the levels of oleoyl-l-carnitine were positively correlated with the abundances of Clostridium and Akkermansia. These results indicated that 2′-FL and HMO had therapeutic potential to prevent AD-induced cognitive impairment, which is of great significance for the treatment of AD

Chiral Bifunctional Guanidine-Catalyzed Enantioselective Aza-Henry Reaction of Isatin-Derived Ketimines

An efficient asymmetric aza-Henry reaction of isatin-derived ketimines has been achieved by using a chiral guanidine–amide organocatalyst. A series of 3-substituted 3-amino-2-oxindoles was obtained with excellent results (up to 99% yield, 94% ee). Other functionalized derivatives were also conveniently transformed. This metal-free system was convenient, practical, and insensitive to air and moisture. On the basis of the crystal structure of the catalyst and NMR spectra analysis, a bifunctional catalytic model was suggested to explain the origin of the asymmetric process

Catalytic Asymmetric Henry Reaction of Nitroalkanes and Aldehydes Catalyzed by a Chiral <i>N</i>,<i>N</i>′<i>-</i>Dioxide/Cu(I) Complex

An easily available <i>N</i>,<i>N</i>′-dioxide/Cu­(I) complex has been developed for the catalytic asymmetric nitroaldol (Henry) reaction of aldehydes with nitroethane. Under mild reaction conditions, a series of substituted aromatic, heteroaromatic and α,β-unsaturated aldehydes are transformed to the corresponding <i>anti</i>-β-nitroalcohols in good to excellent yields (up to 99%) with moderate to good <i>dr</i> (up to 16.7:1 <i>anti</i>/<i>syn</i>) and high <i>ee</i> values (up to 97%). Besides nitroethane, nitromethane and 1-nitropropane were also employed as nucleophiles, and good enantioselectivities were obtained