Three-dimensional self-assembling nanofiber matrix rejuvenates aged/degenerative human tendon stem/progenitor cells

The poor healing capacity of tendons is known to worsen in the elderly. During tendon aging and degeneration, endogenous human tendon stem/progenitor cells (hTSPCs) experience profound pathological changes. Here, we explored a rejuvenation strategy for hTSPCs derived from aged/degenerated Achilles tendons (A-TSPCs) by providing three-dimensional (3D) nanofiber hydrogels and comparing them to young/healthy TSPCs (Y-TSPCs). RADA peptide hydrogel has a self-assembling ability, forms a nanofibrous 3D niche and can be further functionalized by adding RGD motifs. Cell survival, apoptosis, and proliferation assays demonstrated that RADA and RADA/RGD hydrogels support A-TSPCs in a comparable manner to Y-TSPCs. Moreover, they rejuvenated ATSPCs to a phenotype similar to that of Y-TSPCs, as evidenced by restored cell morphology and cytoskeletal architecture. Transmission electron, confocal laser scanning and atomic force microscopies demonstrated comparable ultrastructure, surface roughness and elastic modulus of A- and Y-TSPC-loaded hydrogels. Lastly, quantitative PCR revealed similar expression profiles, as well a significant upregulation of genes related to tenogenesis and multipotency. Taken together, the RADA-based hydrogels exert a rejuvenating effect by recapitulating in vitro specific features of the natural microenvironment of human TSPCs, which strongly indicates their potential to direct cell behaviour and overcome the challenge of cell aging and degeneration in tendon repair.D.D. acknowledges the EU Twinning Grant Achilles (H2020- WIDESPREAD-05-2017-Twinning Grant Nr. 810850). H.Y. thanks for the support of China Scholarship Council (CSC Grant Nr. 201606200072). S.K. and H.C-S. acknowledge the financial support for CANTER by the Bavarian State Ministry for Science and Education. The authors thank Daniela Drenkard for valuable technical assistance and Dr. Girish Pattappa for English proof-readin

Increased recruitment of endogenous stem cells and chondrogenic differentiation by a composite scaffold containing bone marrow homing peptide for cartilage regeneration

Even small cartilage defects could finally degenerate to osteoarthritis if left untreated, owing to the poor self-healing ability of articular cartilage. Stem cell transplantation has been well implemented as a common approach in cartilage tissue engineering but has technical complexity and safety concerns. The stem cell homing-based technique emerged as an alternative promising therapy for cartilage repair to overcome traditional limitations. In this study, we constructed a composite hydrogel scaffold by combining an oriented acellular cartilage matrix (ACM) with a bone marrow homing peptide (BMHP)-functionalized self-assembling peptide (SAP). We hypothesized that increased recruitment of endogenous stem cells by the composite scaffold could enhance cartilage regeneration. Methods: To test our hypothesis, in vitro proliferation, attachment and chondrogenic differentiation of rabbit mesenchymal stem cells (MSCs) were tested to confirm the bioactivities of the functionalized peptide hydrogel. The composite scaffold was then implanted into full-thickness cartilage defects on rabbit knee joints for cartilage repair, in comparison with microfracture or other sample groups. Stem cell recruitment was monitored by dual labeling with CD29 and CD90 under confocal microcopy at 1 week after implantation, followed by chondrogenic differentiation examined by qRT-PCR. Repaired tissue of the cartilage defects was evaluated by histological and immunohistochemistry staining, microcomputed tomography (micro-CT) and magnetic resonance imaging (MRI) at 3 and 6 months post-surgery. Macroscopic and histological scoring was done to evaluate the optimal in vivo repair outcomes of this composite scaffold. Results: The functionalized SAP hydrogels could stimulate rabbit MSC proliferation, attachment and chondrogenic differentiation during in vitro culture. At 7 days after implantation, increased recruitment of MSCs based on CD29(+)/CD90(+) double-positive cells was found in vivo in the composite hydrogel scaffold, as well as upregulation of cartilage-associated genes (aggrecan, Sox9 and type II collagen). After 3 and 6 months post-surgery, the articular cartilage defect in the composite scaffold-treated group was fully covered with cartilage-like tissue with a smooth surface, which was similar to the surrounding native cartilage, according to the results of histological and immunohistochemistry staining, micro-CT and MRI analysis. Macroscopic and histological scoring confirmed that the quality of cartilage repair was significantly improved with implantation of the composite scaffold at each timepoint, in comparison with microfracture or other sample groups. Conclusion: Our findings demonstrated that the composite scaffold could enhance endogenous stem cell homing and chondrogenic differentiation and significantly improve the therapeutic outcome of chondral defects. The present study provides a promising approach for in vivo cartilage repair without cell transplantation. Optimization of this strategy may offer great potential and benefits for clinical application in the future

Efficacy Comparison of Intravitreal Anti-VEGF Therapy for Three Subtypes of Neovascular Age-Related Macular Degeneration: A Systematic Review and Meta-Analysis

Purpose. Intravitreal antivascular endothelial growth factor (anti-VEGF) therapy has been widely used for the treatment of neovascularization (NV) secondary to age-related macular degeneration (AMD). This study aimed to compare the efficacy among different subtypes of neovascular age-related macular degeneration (nAMD). Methods. PubMed, Embase, and the Cochrane Library were searched for eligible studies. We performed meta-analysis using Review Manager 5.3 and Stata/SE 12.0. Results. A total of 24 studies met our inclusion criteria and were included in the systematic review. At 3 months, the mean logarithm of the minimum angle of resolution (logMAR) improvements were −0.09, −0.18, and −0.23 for type 1, 2, and 3, respectively, while the mean macular thickness (MT) changes were −104.83, −130.76, and −196.29 μm. At 12 months, the mean changes in Early Treatment of Diabetic Retinopathy Study (ETDRS) letters were 6.38, 8.12, and 9.37, while the MT decrease was 126.51, 126.52, and 139.85 μm, respectively. However, statistically significant difference was only found between type 1 and 3 in vision improvement, both in the short term (p=0.0002) and long term (p=0.01). Conclusions. The reactivity to VEGF inhibitors varied among different subtypes of nAMD. The efficacy of intravitreal anti-VEGF therapy in type 3 nAMD was statistically better than type 1 when considering vision improvement at 3 and 12 months. Thus, the lesion subtype is a predictor for the treatment outcome which can help guide prognosis

Experimental Inactivation of Microalgae in Marine Ballast Water by Microbubbles Generated through Hydrodynamic Cavitation

This paper presents a novel approach to microbubble technology for the treatment of aquatic invasive organisms in ship ballast water. The microbubbles are produced by hydrodynamic cavitation with a sudden and dramatic water pressure drop. The air and ozone microbubbles, respectively, verified the bioavailability of ship ballast water treatment using marine microalgae as an indicator. Besides the effects of an ozone injection dose, the morphological changes of cells and the effluent toxicity were investigated. Compared with the ozone microbubble treatment, the inactivation of marine microalgae by air microbubbles required a long treatment time. In the storage experiment, it was found that air microbubbles did not inhibit the growth of microalgae cells, and that the injection of active matter such as ozone was still necessary to ensure the validity of biological invasion. However, even with very low doses of ozone, the inactivation effect of ozone microbubbles was still very evident. Overall, it helps to minimize the use of active matter to reduce the toxicity of treated water, and this has the capability to develop into an environmentally acceptable and practical ballast water treatment technology

Calibrating branched GDGTs in bones to temperature and precipitation: Application to Alaska chronological sequences

Our recent study suggests that branched glycerol dialkyl glycerol tetraethers (brGDGTs) in ancient bones may have great potential for reconstructing in-situ paleoclimate conditions. However, one major problem with reconstructing past climate and environmental conditions using brGDGTs in ancient bones is the lack of calibrations specific to bones. Here we investigate the distribution of brGDGTs in 191 modern weathered bone samples in China with a broad range of mean annual air temperature (MAAT: -3.3-25.6 degrees C) and mean annual precipitation (MAP: 163-2062 mm), and present the first bone-specific brGDGT temperature and precipitation calibrations. We find that the best correlation with temperature is found in bones with a higher ratio of 6-methyl over 5-methyl brGDGT isomers, suggesting a preferential production of 6-methyl brGDGTs by bacteria inside bones. The bone-specific temperature relationship is distinct from published mineral soil calibrations (e.g., with virtually no influence from soil pH changes). We hypothesize that the lower calibration residual values result from more homogenous and semi-closed environment for bacterial growth inside the bones than soil environments. We also demonstrate that, in semi-arid and semi-humid regions (MAP: 200-710 mm), brGDGT distributions in cancellous bones with relatively high percentages of 6-methyl isomers are strongly correlated with mean annual precipitation. Application of our bone-specific brGDGT calibrations to Alaskan chronological sequences yields new insights to high latitude temperature and precipitation variations for the past 30,000 years. (C) 2020 Elsevier Ltd. All rights reserved

dockingstudyofhdacimplicationforbenzamideinhibitorsbindingmode

通过计算机模拟的对接过程研究，发现了MS-275——一种苯甲酰胺类的组蛋白去乙酰酶(HDAC)抑制剂与酶的可能的全新结合方式．这种结合方式与已经阐明的组蛋白去乙酰酶类似蛋白(HDLP)与曲古柳菌素A(trichostatin A，TSA)和suberoylanilide hydroxamic acid(SAHA)形成的复合物晶体结构中配体与酶的作用方式完全不同．从对接结果看，MS-275的作用靶点在酶活性口袋的最狭窄部位，而不是直接作用于锌离子．这似乎能够解释MS-275的低毒性特点，并且为设计和筛选全新的HDAC抑制剂提供了新思路

LC-MS/MS Analysis Unravels Deep Oxidation of Manganese Superoxide Dismutase in Kidney Cancer

Manganese superoxide dismutase (MNSOD) is one of the major scavengers of reactive oxygen species (ROS) in mitochondria with pivotal regulatory role in ischemic disorders, inflammation and cancer. Here we report oxidative modification of MNSOD in human renal cell carcinoma (RCC) by the shotgun method using data-dependent liquid chromatography tandem mass spectrometry (LC-MS/MS). While 5816 and 5571 proteins were identified in cancer and adjacent tissues, respectively, 208 proteins were found to be up- or down-regulated (p < 0.05). Ontological category, interaction network and Western blotting suggested a close correlation between RCC-mediated proteins and oxidoreductases such as MNSOD. Markedly, oxidative modifications of MNSOD were identified at histidine (H54 and H55), tyrosine (Y58), tryptophan (W147, W149, W205 and W210) and asparagine (N206 and N209) residues additional to methionine. These oxidative insults were located at three hotspots near the hydrophobic pocket of the manganese binding site, of which the oxidation of Y58, W147 and W149 was up-regulated around three folds and the oxidation of H54 and H55 was detected in the cancer tissues only (p < 0.05). When normalized to MNSOD expression levels, relative MNSOD enzymatic activity was decreased in cancer tissues, suggesting impairment of MNSOD enzymatic activity in kidney cancer due to modifications. Thus, LC-MS/MS analysis revealed multiple oxidative modifications of MNSOD at different amino acid residues that might mediate the regulation of the superoxide radicals, mitochondrial ROS scavenging and MNSOD activity in kidney cancer

Immunolocalization of Inhibin/Activin Subunit Proteins During the Breeding Season in Testes and Scented Glands of Muskrats (Ondatra zibethicus)

The objective of this study was to investigate the cellular immunolocalization of inhibin a and inhibin/activin (beta(A) and beta(B)) subunits in the muskrat testes and scented glands during the breeding season. Inhibin a and inhibin/activin (beta(A) and beta(B)) subunits were expressed in Sertoli cells and Leydig cells of testes and glandular cells of scented glands, respectively. Also, positive signals of inhibin a and inhibin/activin (beta(A) and beta(B)) subunits by Western blotting were both observed in testicular and scented glandular tissues. These results suggested that the testes and scented glands of the muskrats had the ability to synthesize inhibins and activins and that activins and inhibins might play an important role in testicular and scented glandular function in muskrats.Veterinary SciencesSCI(E)2ARTICLE91199-12057

Internet Electronic Journal of Molecular Design

Based on the topological scaffold classification approach to cluster a structural database, we propose a new criterion to evaluate the diversity of a chemical structural database. This criterion is defined as the ratio of scaffold number to total structure number in the database. Six databases have been evaluated by this criterion. To reduce the size of a database under the minimum losing structural diversity, a novel effective database compression method has been developed. The number of selected structures in each compounds group with common scaffold is determined by empirical K–4–5 rules, and the selected structures are those with the highe